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b2c378351d91748de08281b9769e493cd08dd9c9 | wikidoc | B3GNT1 | B3GNT1
N-acetyllactosaminide beta-1,3-N-acetylglucosaminyltransferase is an enzyme that, in humans, is encoded by the B3GNT1 gene.
# β-1,4-glucuronyltransferase
The B3GNT1 gene encodes a β-1,4-glucuronyltransferase, designated B4GAT1, that transfers glucuronic acid towards both α- and β-anomers of xylose. B4GAT1 is the priming enzyme for LARGE, a dual-activity glycosyltransferase that is capable of extending products of B4GAT1. Thus, B4GAT1 is involved in the initiation of the LARGE-dependent repeating disaccharide that is necessary for extracellular matrix protein binding to O-mannosylated α-dystroglycan that is lacking in secondary dystroglycanopathies.
# Misidentification
The B3GNT1 gene was first reported to encode a member of the beta-1,3-N-acetylglucosaminyltransferase family and thought to be responsible for the synthesis of poly-N-acetyllactosamine, a determinant for the blood group i antigen. Thus, it was also known as iGNT. | B3GNT1
N-acetyllactosaminide beta-1,3-N-acetylglucosaminyltransferase is an enzyme that, in humans, is encoded by the B3GNT1 gene.[1][2]
# β-1,4-glucuronyltransferase
The B3GNT1 gene encodes a β-1,4-glucuronyltransferase, designated B4GAT1, that transfers glucuronic acid towards both α- and β-anomers of xylose[3]. B4GAT1 is the priming enzyme for LARGE, a dual-activity glycosyltransferase that is capable of extending products of B4GAT1. Thus, B4GAT1 is involved in the initiation of the LARGE-dependent repeating disaccharide that is necessary for extracellular matrix protein binding to O-mannosylated α-dystroglycan that is lacking in secondary dystroglycanopathies.
# Misidentification
The B3GNT1 gene was first reported to encode a member of the beta-1,3-N-acetylglucosaminyltransferase family and thought to be responsible for the synthesis of poly-N-acetyllactosamine[1], a determinant for the blood group i antigen. Thus, it was also known as iGNT. | https://www.wikidoc.org/index.php/B3GNT1 | |
b2d26c9671f605a80e66ca5e1c480a7854fcb5c5 | wikidoc | BAIAP3 | BAIAP3
BAI1-associated protein 3 is a protein that in humans is encoded by the BAIAP3 gene.
BAIAP3 was identified as a protein-binding partner of BAI1. BAI1 is a p53-target gene that encodes a brain-specific angiogenesis inhibitor. The protein is a seven-span transmembrane protein and a member of the secretin receptor family. BAIAP3 interacts with the cytoplasmic region of brain-specific angiogenesis inhibitor 1. BAIAP3 also contains two C2 domains, which are often found in proteins involved in signal transduction or membrane trafficking. Its expression pattern and similarity to other proteins suggest that it may be involved in synaptic functions.
# Interactions
BAIAP3 has been shown to interact with Brain-specific angiogenesis inhibitor 1. | BAIAP3
BAI1-associated protein 3 is a protein that in humans is encoded by the BAIAP3 gene.[1][2]
BAIAP3 was identified as a protein-binding partner of BAI1. BAI1 is a p53-target gene that encodes a brain-specific angiogenesis inhibitor. The protein is a seven-span transmembrane protein and a member of the secretin receptor family. BAIAP3 interacts with the cytoplasmic region of brain-specific angiogenesis inhibitor 1. BAIAP3 also contains two C2 domains, which are often found in proteins involved in signal transduction or membrane trafficking. Its expression pattern and similarity to other proteins suggest that it may be involved in synaptic functions.[2]
# Interactions
BAIAP3 has been shown to interact with Brain-specific angiogenesis inhibitor 1.[1] | https://www.wikidoc.org/index.php/BAIAP3 | |
b324fef82214a0df79fcda4fb40a69a557641420 | wikidoc | BALB/c | BALB/c
BALB/c is an albino strain of laboratory mouse from which a number of common substrains are derived. Now over 200 generations from their origin in New York in 1920, BALB/c mice are distributed globally, and among the most widely used inbred strains used in animal experimentation.
# History
The founding animals of the strain were obtained by Halsey J. Bagg of Memorial Hospital, New York, from a mouse dealer in Ohio in 1913. From 1920, the progeny of the original colony were systematically inbred, sibling to sibling, for 26 generations over 15 years. During this time, the colony passed through the care of a number of scientists, including C.C. Little and E.C. MacDowell at the Carnegie Institution of Washington and H.J. Muller at the University of Texas. By 1935 the animals were in the possession of Muller's student, George Davis Snell, who moved them to The Jackson Laboratory. This stock provided the basis of all the BALB/c substrains that are now in use around the world.
Snell provided some animals from this stock to the National Institutes of Health (NIH) to maintain. In 1961 D. W. Bailey used some of these to generate a substrain at the University of California, San Francisco. In 1974, now 136 generations from the original breeding pair, these animals were returned to The Jackson Laboratory and were named BALB/cByJ. On 16 November, 2005, The Jackson Laboratory reported this substrain had reached its 235th generation.
Snell also provided a colleague, J. Paul Scott, with some BALB/c breeding stock in 1938 or 1939. When a fire destroyed the main Jackson Laboratory buildings in 1947, all of Snell's original breeding stock perished, but Scott's mice were in a different building and survived. Scott donated stock back, at generation 41, to repopulate the colony. The progeny of these are now termed BALB/cJ and, as of 14 December, 2006, were 221 generations from the founding stock. Other less popular substrains, such as BALB/cWt, are maintained at the Jackson Laboratory, while the BALB/cN substrain is maintained by the NIH.
# Characteristics
BALB/c mice are useful for research into both cancer and immunology. According to Michael Festing's Inbred Strains of Mice, BALB/c substrains are "particularly well known for the production of plasmacytomas on injection with mineral oil," an important process for the production of monoclonal antibodies. They are also reported as having a "low mammary tumour incidence, but do develop other types of cancers in later life, most commonly reticular neoplasms, lung tumours, and renal tumours. Most substrains have a "long reproductive life-span" , are noted for displaying high levels of anxiety and for being relatively resistant to diet-induced atherosclerosis, making them a useful model for cardiovascular research.
There are noted differences between different BALB/c substrains, though these are thought to be due to mutation rather than genetic contamination. For example, male BALB/c mice are aggressive and will fight other males if housed together. However, the BALB/Lac substrain is much more docile. The BALB/cWt is also unusual in that 3% of progeny display true hermaphroditism. | BALB/c
BALB/c is an albino strain of laboratory mouse from which a number of common substrains are derived. Now over 200 generations from their origin in New York in 1920, BALB/c mice are distributed globally, and among the most widely used inbred strains used in animal experimentation. [1]
# History
Template:Animal testing
The founding animals of the strain were obtained by Halsey J. Bagg of Memorial Hospital, New York, from a mouse dealer in Ohio in 1913. From 1920, the progeny of the original colony were systematically inbred, sibling to sibling, for 26 generations over 15 years. During this time, the colony passed through the care of a number of scientists, including C.C. Little and E.C. MacDowell at the Carnegie Institution of Washington and H.J. Muller at the University of Texas. [2] By 1935 the animals were in the possession of Muller's student, George Davis Snell, who moved them to The Jackson Laboratory. This stock provided the basis of all the BALB/c substrains that are now in use around the world. [3]
Snell provided some animals from this stock to the National Institutes of Health (NIH) to maintain. In 1961 D. W. Bailey used some of these to generate a substrain at the University of California, San Francisco. In 1974, now 136 generations from the original breeding pair, these animals were returned to The Jackson Laboratory and were named BALB/cByJ. [3] On 16 November, 2005, The Jackson Laboratory reported this substrain had reached its 235th generation. [4]
Snell also provided a colleague, J. Paul Scott, with some BALB/c breeding stock in 1938 or 1939. [2] When a fire destroyed the main Jackson Laboratory buildings in 1947, [5] all of Snell's original breeding stock perished, but Scott's mice were in a different building and survived. Scott donated stock back, at generation 41, to repopulate the colony. The progeny of these are now termed BALB/cJ and, as of 14 December, 2006, were 221 generations from the founding stock. [6] Other less popular substrains, such as BALB/cWt, are maintained at the Jackson Laboratory, while the BALB/cN substrain is maintained by the NIH. [3]
# Characteristics
BALB/c mice are useful for research into both cancer and immunology. According to Michael Festing's Inbred Strains of Mice, [1] BALB/c substrains are "particularly well known for the production of plasmacytomas on injection with mineral oil," an important process for the production of monoclonal antibodies. They are also reported as having a "low mammary tumour incidence, [1] but do develop other types of cancers in later life, most commonly reticular neoplasms, lung tumours, and renal tumours. [6] [4] Most substrains have a "long reproductive life-span" [1], are noted for displaying high levels of anxiety and for being relatively resistant to diet-induced atherosclerosis, making them a useful model for cardiovascular research. [6] [4]
There are noted differences between different BALB/c substrains, though these are thought to be due to mutation rather than genetic contamination. [7] For example, male BALB/c mice are aggressive and will fight other males if housed together. However, the BALB/Lac substrain is much more docile. [8] The BALB/cWt is also unusual in that 3% of progeny display true hermaphroditism. [9] | https://www.wikidoc.org/index.php/BALB/c | |
39baa1cbfcf0c033388c2ff72b02774343963e15 | wikidoc | BASDAI | BASDAI
# Overview
The BASDAI is important because it is a validated diagnostic test which allows a physician (usually a rheumatologist) to determine the effectiveness of a current drug therapy, or the need to institute a new drug therapy for the treatment of ankylosing spondylitis. The BASDAI consists of a one through 10 scale (one being no problem and 10 being the worst problem) in response to 6 questions pertaining to the 5 major symptoms of AS:
- Fatigue
- Spinal pain
- Joint pain / swelling
- Areas of localized tenderness (also called enthesitis, or inflammation of tendons and ligaments)
- Morning stiffness duration
- Morning stiffness severity
To give each symptom equal weighting, the average of the two scores relating to morning stiffness is taken. The resulting 0 to 50 score is divided by 5 to give a final 0 – 10 BASDAI score. Scores of 4 or greater suggest suboptimal control of disease, and patients with scores of 4 or greater are usually good candidates for either a change in their medical therapy, eligible for treatment with powerful biologic therapies such as etanercept, infliximab and adalimumab, or may be eligible for enrollment in clinical trials evaluating new drug therapies directed at Ankylosing Spondylitis.
# History
Garrett and coworkers writing in the Journal of Rheumatology in December 1994 described a self-administered 6-question measurement tool which was to become the gold standard for measuring and evaluating disease activity in Ankylosing Spondylitis (AS). This validated tool is the BASDAI, or the Bath Ankylosing Spondylitis Disease Activity Index. A research team consisting of rheumatologists, physiotherapists, and research associates with a special interest in AS developed the index in Bath, England, hence the reason for "Bath" in the name.
# Validation
BASDAI is a quick and simple index (taking between 30 secs and 2 mins to complete)
BASDAI demonstrated statistically significant (p<0.001) reliability.
BASDAI encorporates a reasonable scale. The individual symptoms and the index as a whole demonstrated good score distribution, using 95% of the scale.
BASDAI demonstrates a sensitivity to change within a short period of time. Following a 3 week physiotherapy course, the BASDAI showed a significant (p=0.009) 16.4% score improvement.
# Tools and references
- BASDAI automated calculation tool | BASDAI
# Overview
The BASDAI is important because it is a validated diagnostic test which allows a physician (usually a rheumatologist) to determine the effectiveness of a current drug therapy, or the need to institute a new drug therapy for the treatment of ankylosing spondylitis. The BASDAI consists of a one through 10 scale (one being no problem and 10 being the worst problem) in response to 6 questions pertaining to the 5 major symptoms of AS:
- Fatigue
- Spinal pain
- Joint pain / swelling
- Areas of localized tenderness (also called enthesitis, or inflammation of tendons and ligaments)
- Morning stiffness duration
- Morning stiffness severity
To give each symptom equal weighting, the average of the two scores relating to morning stiffness is taken. The resulting 0 to 50 score is divided by 5 to give a final 0 – 10 BASDAI score. Scores of 4 or greater suggest suboptimal control of disease, and patients with scores of 4 or greater are usually good candidates for either a change in their medical therapy, eligible for treatment with powerful biologic therapies such as etanercept, infliximab and adalimumab, or may be eligible for enrollment in clinical trials evaluating new drug therapies directed at Ankylosing Spondylitis.
# History
Garrett and coworkers writing in the Journal of Rheumatology in December 1994 described a self-administered 6-question measurement tool which was to become the gold standard for measuring and evaluating disease activity in Ankylosing Spondylitis (AS). This validated tool is the BASDAI, or the Bath Ankylosing Spondylitis Disease Activity Index. A research team consisting of rheumatologists, physiotherapists, and research associates with a special interest in AS developed the index in Bath, England, hence the reason for "Bath" in the name.
# Validation
BASDAI is a quick and simple index (taking between 30 secs and 2 mins to complete)
BASDAI demonstrated statistically significant (p<0.001) reliability.
BASDAI encorporates a reasonable scale. The individual symptoms and the index as a whole demonstrated good score distribution, using 95% of the scale.
BASDAI demonstrates a sensitivity to change within a short period of time. Following a 3 week physiotherapy course, the BASDAI showed a significant (p=0.009) 16.4% score improvement.
# Tools and references
- BASDAI automated calculation tool
Template:WikiDoc Sources | https://www.wikidoc.org/index.php/BASDAI | |
b22177a6598012066611eadef926e7b53e3d2446 | wikidoc | BCKDHA | BCKDHA
2-oxoisovalerate dehydrogenase subunit alpha, mitochondrial is an enzyme that in humans is encoded by the BCKDHA gene.
BCKDHA is a coding gene that is part of the BCKD complex / branched-chain alpha-keto acid dehydrogenase/.
# Discovery
BCKDHA was discovered by John Menkes in 1954. After he had seen a family with four children die after only a few months after birth, he found that their urine smelled sweet like maple syrup. While he was not the one to discover the specific gene, he did discover the maple syrup urine disease . The BCKD complex is made up of three different catalytic pieces. It was in 1960 when Dancis discovered the gene itself, but this was from Menkes discovering of the disease leading to further investigation of its origin. He found that looking at the branched-chain amino acids and their corresponding alpha-keto acids, in turn aided in the realization that they were pathogenetic compounds. Dancis was the one to specifically track down the enzymatic defect in (MSUD) by finding what gene in the pool of human chromosomes was defecting the urine. He found the gene on the level of the decarboxylation of the branched-chain amino acids.
# Gene location
Looking at BCKDHA, the cytogenetic location of this gene, on the chromosome, is located on the cytogenetic band at 19q13.2. This the long arm (q) of the chromosome 19 at 13.2. Looking at the molecular location, the base pairs 41,397,789 to 41,425,005 are on chromosome 19.
# Subcellular distribution
The cellular localization of this gene is within the mitochondrion matrix.
# Function
The second major step in the catabolism of the branched-chain amino acids, isoleucine, leucine, and valine, is catalyzed by the branched-chain alpha-keto acid dehydrogenase complex (BCKD; EC 1.2.4.4), an inner-mitochondrial enzyme complex that consists of 3 catalytic components: a heterotetrameric (alpha2, beta2) branched-chain alpha-keto acid decarboxylase (E1), a homo-24-meric dihydrolipoyl transacylase (E2; MIM 248610), and a homodimeric dihydrolipoamide dehydrogenase (E3; MIM 238331). The reaction is irreversible and constitutes the first committed step in BCAA oxidation. The complex also contains 2 regulatory enzymes, a kinase and a phosphorylase. The BCKDHA gene encodes the alpha subunit of E1, and the BCKDHB gene (MIM 248611) encodes the beta subunit of E1.
The normal function of the BCKDHA gene is to provide instructions for making the alpha subunit of the branched-chain alpha-keto dehydrogenase (BCKD) enzyme complex. The alpha subunit is one part of the BCKD enzyme complex. Two beta subunits are produced from the BCKDHB gene and connect to two alpha subunits to form the E1 (decarboxylase) component. The BCKD enzyme complex catalyzes one step in breaking down amino acids. Those amino acids being leucine, isoleucine, and valine. The BCKD enzyme complex can be found in the mitochondria, an organelle known as the powerhouse of the cell. All three amino acids can be found in protein-rich foods and when broken down, they can be used for energy. Mutations in the BCKDHA gene can lead to maple syrup urine disease .
# Clinical significance
Mutations in the BCKDHA gene occur due to single point mutations in the “alpha subunit of the BCKD enzyme complex”. Earlier cases of this disease show the mutation more frequently occurred by replacing the amino acid tyrosine. This amino acid was replaced with asparagine. The complication with mutations in the BCKDHA gene is that it disrupts the normal function of the BCKD enzyme complex; preventing the gene essentially from going about its normal functions. So, the BCKDHA gene would not be able to break down leucine, isoleucine, and valine. When these byproducts start to accumulate it produces a toxic environment for cells and tissues, specifically in the nervous system. This can lead to seizures, developmental delay, but most importantly maple syrup urine disease.
The BCKDHA has been pinpointed in people with maple syrup urine disease, due to over 80 mutations occurring in that gene. Severe symptoms arise from these mutations and cause the disease which shows soon after birth. Due to the sweet odor from the urine, the disease was termed maple syrup urine disease. The disease causes loss of appetite, nausea, lethargy, and delayed development.
## BCKDHA mutation: maple syrup urine disease
Maple syrup urine disease is an “autosomal recessive inborn error of metabolism. Meaning, as stated earlier, that there is a defect (i.e. error) in the single gene that codes for an enzyme. These enzymes promote conversions for various substrates into products. In terms of maple syrup urine disease, the enzyme defect occurs in the metabolic pathway of the “branched-chain amino acids” leucine, isoleucine, and valine. The buildup of these amino acids lead to “encephalopathy and progressive neurodegeneration” ; along with other complications.
There are five forms of maple syrup urine disease: intermediate, intermittent, thiamine-responsive and E3 deficient. The form of disease is dependent upon clinical prognosis, dietary protein tolerance, and thiamine response and level of enzyme activity. Intermediate maple syrup urine disease is a milder form of maple syrup urine disease because it persistently raises branched-chain amino acids and some keto-acid chains. Individuals with this disease have a partial BCKDHA enzyme deficiency. Meaning that it shows up sporadically or reacts to dietary thiamine therapy. | BCKDHA
2-oxoisovalerate dehydrogenase subunit alpha, mitochondrial is an enzyme that in humans is encoded by the BCKDHA gene.[1]
BCKDHA is a coding gene that is part of the BCKD complex / branched-chain alpha-keto acid dehydrogenase/.[2]
# Discovery
BCKDHA was discovered by John Menkes in 1954. After he had seen a family with four children die after only a few months after birth, he found that their urine smelled sweet like maple syrup. While he was not the one to discover the specific gene, he did discover the maple syrup urine disease [3](MSUD). The BCKD complex is made up of three different catalytic pieces. It was in 1960 when Dancis discovered the gene itself, but this was from Menkes discovering of the disease leading to further investigation of its origin. He found that looking at the branched-chain amino acids and their corresponding alpha-keto acids, in turn aided in the realization that they were pathogenetic compounds. Dancis was the one to specifically track down the enzymatic defect in (MSUD) by finding what gene in the pool of human chromosomes was defecting the urine. He found the gene on the level of the decarboxylation of the branched-chain amino acids.[4]
# Gene location
Looking at BCKDHA, the cytogenetic location of this gene, on the chromosome, is located on the cytogenetic band at 19q13.2. This the long arm (q) of the chromosome 19 at 13.2. Looking at the molecular location, the base pairs 41,397,789 to 41,425,005 are on chromosome 19.
# Subcellular distribution
The cellular localization of this gene is within the mitochondrion matrix.[5]
# Function
The second major step in the catabolism of the branched-chain amino acids, isoleucine, leucine, and valine, is catalyzed by the branched-chain alpha-keto acid dehydrogenase complex (BCKD; EC 1.2.4.4), an inner-mitochondrial enzyme complex that consists of 3 catalytic components: a heterotetrameric (alpha2, beta2) branched-chain alpha-keto acid decarboxylase (E1), a homo-24-meric dihydrolipoyl transacylase (E2; MIM 248610), and a homodimeric dihydrolipoamide dehydrogenase (E3; MIM 238331). The reaction is irreversible and constitutes the first committed step in BCAA oxidation. The complex also contains 2 regulatory enzymes, a kinase and a phosphorylase. The BCKDHA gene encodes the alpha subunit of E1, and the BCKDHB gene (MIM 248611) encodes the beta subunit of E1.[supplied by OMIM][1]
The normal function of the BCKDHA gene is to provide instructions for making the alpha subunit of the branched-chain alpha-keto dehydrogenase (BCKD) enzyme complex. The alpha subunit is one part of the BCKD enzyme complex. Two beta subunits are produced from the BCKDHB gene [6] and connect to two alpha subunits to form the E1 (decarboxylase) component. The BCKD enzyme complex catalyzes one step in breaking down amino acids. Those amino acids being leucine, isoleucine, and valine. The BCKD enzyme complex can be found in the mitochondria, an organelle known as the powerhouse of the cell. All three amino acids can be found in protein-rich foods and when broken down, they can be used for energy. Mutations in the BCKDHA gene can lead to maple syrup urine disease [7].
# Clinical significance
Mutations in the BCKDHA gene occur due to single point mutations in the “alpha subunit of the BCKD enzyme complex”[3]. Earlier cases of this disease show the mutation more frequently occurred by replacing the amino acid tyrosine. This amino acid was replaced with asparagine. The complication with mutations in the BCKDHA gene is that it disrupts the normal function of the BCKD enzyme complex; preventing the gene essentially from going about its normal functions. So, the BCKDHA gene would not be able to break down leucine, isoleucine, and valine. When these byproducts start to accumulate it produces a toxic environment for cells and tissues, specifically in the nervous system. This can lead to seizures, developmental delay, but most importantly maple syrup urine disease.
The BCKDHA has been pinpointed in people with maple syrup urine disease, due to over 80 mutations occurring in that gene. Severe symptoms arise from these mutations and cause the disease which shows soon after birth. Due to the sweet odor from the urine, the disease was termed maple syrup urine disease. The disease causes loss of appetite, nausea, lethargy, and delayed development.
## BCKDHA mutation: maple syrup urine disease
Maple syrup urine disease is an “autosomal recessive inborn error of metabolism. Meaning, as stated earlier, that there is a defect (i.e. error) in the single gene that codes for an enzyme. These enzymes promote conversions for various substrates into products. In terms of maple syrup urine disease, the enzyme defect occurs in the metabolic pathway of the “branched-chain amino acids” leucine, isoleucine, and valine[6]. The buildup of these amino acids lead to “encephalopathy and progressive neurodegeneration” [6]; along with other complications.
There are five forms of maple syrup urine disease: intermediate, intermittent, thiamine-responsive and E3 deficient. The form of disease is dependent upon clinical prognosis, dietary protein tolerance, and thiamine response and level of enzyme activity. Intermediate maple syrup urine disease is a milder form of maple syrup urine disease because it persistently raises branched-chain amino acids and some keto-acid chains. Individuals with this disease have a partial BCKDHA enzyme deficiency[3]. Meaning that it shows up sporadically or reacts to dietary thiamine therapy. | https://www.wikidoc.org/index.php/BCKDHA | |
ccaaf4909d5742f4e99d4e9d2fbc03acb263ec5c | wikidoc | BCL11A | BCL11A
B-cell lymphoma/leukemia 11A is a protein that in humans is encoded by the BCL11A gene.
# Function
The BCL11A gene encodes for a regulatory C2H2 type zinc-finger protein, that can bind to the DNA. Five alternatively spliced transcript variants of this gene, which encode distinct isoforms, have been reported. The protein associates with the SWI/SNF complex, that regulates gene expression via chromatin remodelling.
BCL11A is highly expressed in several hematopoietic lineages, and plays a role in the switch from γ- to β-globin expression during the fetal to adult erythropoiesis transition.
Furthermore, BCL11A is expressed in the brain, where it forms a protein complex with CASK to regulate axon outgrowth and branching. In the neocortex, BCL11A binds to the TBR1 regulatory region and inhibits the expression of TBR1.
# Clinical significance
The corresponding Bcl11a mouse gene is a common site of retroviral integration in myeloid leukemia, and may function as a leukemia disease gene, in part, through its interaction with BCL6. During hematopoietic cell differentiation, this gene is down-regulated. It is possibly involved in lymphoma pathogenesis since translocations associated with B-cell malignancies also deregulates its expression. In addition, BCL11A has been found to play a role in the suppression of fetal hemoglobin production. Therapeutic strategies aimed at increasing fetal globin production in diseases such as beta thalassemia and sickle cell anemia by inhibiting BCL11A are currently being explored.
Furthermore, heterozygous de novo mutations in BCL11A have been identified in an intellectual disability disorder, accompanied with global developmental delay and autism spectrum disorder. These mutations disrupt BCL11A homodimerization and transcriptional regulation.
# Interactions
BCL11A has been shown to interact with a number of proteins. BCL11A was initially discovered as a COUP-TFI interacting protein. In the nucleus, BCL11A forms paraspeckles that co-localize with NONO. In neurons, BCL11A interacts with CASK to regulate target genes. Furthermore, BCL11A interacts with the neuron-specific protein TBR1, which is also implicated in intellectual disability and autism spectrum disorder. | BCL11A
B-cell lymphoma/leukemia 11A is a protein that in humans is encoded by the BCL11A gene.[1][2][3]
# Function
The BCL11A gene encodes for a regulatory C2H2 type zinc-finger protein, that can bind to the DNA. Five alternatively spliced transcript variants of this gene, which encode distinct isoforms, have been reported.[3] The protein associates with the SWI/SNF complex, that regulates gene expression via chromatin remodelling.[4]
BCL11A is highly expressed in several hematopoietic lineages, and plays a role in the switch from γ- to β-globin expression during the fetal to adult erythropoiesis transition.[5]
Furthermore, BCL11A is expressed in the brain, where it forms a protein complex with CASK to regulate axon outgrowth and branching.[6] In the neocortex, BCL11A binds to the TBR1 regulatory region and inhibits the expression of TBR1.[7]
# Clinical significance
The corresponding Bcl11a mouse gene is a common site of retroviral integration in myeloid leukemia, and may function as a leukemia disease gene, in part, through its interaction with BCL6. During hematopoietic cell differentiation, this gene is down-regulated. It is possibly involved in lymphoma pathogenesis since translocations associated with B-cell malignancies also deregulates its expression. In addition, BCL11A has been found to play a role in the suppression of fetal hemoglobin production. Therapeutic strategies aimed at increasing fetal globin production in diseases such as beta thalassemia and sickle cell anemia by inhibiting BCL11A are currently being explored.
Furthermore, heterozygous de novo mutations in BCL11A have been identified in an intellectual disability disorder, accompanied with global developmental delay and autism spectrum disorder.[8] These mutations disrupt BCL11A homodimerization and transcriptional regulation.
# Interactions
BCL11A has been shown to interact with a number of proteins. BCL11A was initially discovered as a COUP-TFI interacting protein.[9] In the nucleus, BCL11A forms paraspeckles that co-localize with NONO.[8] In neurons, BCL11A interacts with CASK to regulate target genes.[6] Furthermore, BCL11A interacts with the neuron-specific protein TBR1, which is also implicated in intellectual disability and autism spectrum disorder.[10] | https://www.wikidoc.org/index.php/BCL11A | |
c0ea029f6633a4c25c3a4b83bfbfbc347f86e734 | wikidoc | BCL11B | BCL11B
B-cell lymphoma/leukemia 11B is a protein that in humans is encoded by the BCL11B gene.
# Function
This gene encodes a C2H2-type zinc finger protein and is closely related to BCL11A, a gene whose translocation may be associated with B-cell malignancies. The specific function of this gene has not yet been determined, but it could also be involved in some malignancies. Two alternatively spliced transcript variants, which encode distinct isoforms, have been reported.
Recent research suggests that BCL11B is crucial for ameloblasts (the cells that produce tooth enamel) to form and work properly.
# Interactions
BCL11B has been shown to interact with COUP-TFI. | BCL11B
B-cell lymphoma/leukemia 11B is a protein that in humans is encoded by the BCL11B gene.[1][2][3]
# Function
This gene encodes a C2H2-type zinc finger protein and is closely related to BCL11A, a gene whose translocation may be associated with B-cell malignancies. The specific function of this gene has not yet been determined, but it could also be involved in some malignancies. Two alternatively spliced transcript variants, which encode distinct isoforms, have been reported.[3]
Recent research suggests that BCL11B is crucial for ameloblasts (the cells that produce tooth enamel) to form and work properly.[4]
# Interactions
BCL11B has been shown to interact with COUP-TFI.[5] | https://www.wikidoc.org/index.php/BCL11B | |
9f839ee82236321677cc1f9440c71f2ae0b28ebe | wikidoc | BCL2L2 | BCL2L2
Bcl-2-like protein 2 is a protein that in humans is encoded by the BCL2L2 gene. It was originally discovered by Leonie Gibson, Suzanne Cory and colleagues at the Walter and Eliza Hall Institute of Medical Research, who called it Bcl-w.
# Function
This gene encodes a pro-survival (anti-apoptotic) member of the bcl-2 protein family. The proteins of this family form hetero- or homodimers and act as anti- and pro-apoptotic regulators. Expression of this gene in cells has been shown to contribute to reduced cell apoptosis under cytotoxic conditions. Studies of the related gene in mice indicated a role in the survival of NGF- and BDNF-dependent neurons. Mutation and knockout studies of the mouse gene demonstrated an essential role in adult spermatogenesis.
Relative to its Bcl-2 counterparts there is considerably less data on this particular protein. Located on chromosome 14q11 it appears to be redundant in most tissues apart from specific examples.
# Interactions
BCL2L2 has been shown to interact with:
- BCL2L11
- BAD, and
- PPP1CA. | BCL2L2
Bcl-2-like protein 2 is a protein that in humans is encoded by the BCL2L2 gene.[1][2] It was originally discovered by Leonie Gibson, Suzanne Cory and colleagues at the Walter and Eliza Hall Institute of Medical Research, who called it Bcl-w.[3]
# Function
This gene encodes a pro-survival (anti-apoptotic) member of the bcl-2 protein family. The proteins of this family form hetero- or homodimers and act as anti- and pro-apoptotic regulators. Expression of this gene in cells has been shown to contribute to reduced cell apoptosis under cytotoxic conditions. Studies of the related gene in mice indicated a role in the survival of NGF- and BDNF-dependent neurons. Mutation and knockout studies of the mouse gene demonstrated an essential role in adult spermatogenesis.[2]
Relative to its Bcl-2 counterparts there is considerably less data on this particular protein. Located on chromosome 14q11 it appears to be redundant in most tissues apart from specific examples.
# Interactions
BCL2L2 has been shown to interact with:
- BCL2L11[4][5]
- BAD,[6][7][8][9] and
- PPP1CA.[6] | https://www.wikidoc.org/index.php/BCL2L2 | |
420b54fc589cb5c116f5caba038fe31dade267bf | wikidoc | BLOSUM | BLOSUM
BLOSUM (BLOcks of Amino Acid SUbstitution Matrix) is a substitution matrix used for sequence alignment of proteins. BLOSUM matrices are used to score alignments between evolutionarily divergent protein sequences. Blosum is based on local alignments. Blosum was first introduced in a paper by Henikoff and Henikoff (1992; PNAS 89:10915-10919). They scanned the BLOCKS database for very conserved regions of protein families (that do not have gaps in the sequence alignment) and then counted the relative frequencies of amino acids and their substitution probabilities. Then, they calculated a log-odds score for each of the 210 possible substitutions of the 20 standard amino acids. All Blosum matrices are based on observed alignments; they are not extrapolated from comparisons or closely related proteins.
Blosum matrices with high numbers are designed for comparing closely related sequences, while Blosum matrices with low numbers are designed for comparing distant related sequences. For example, Blosum80 is used for less divergent alignments, and Blosum45 is used for more divergent alignments. Scores within a Blosum matix are log-odds scores that measure the logarithm for the ratio of the likelihood of two amino acids appearing by chance.
The matrices are based on the minimum percentage identity of the aligned protein sequence used in calculating them. Every possible identity or substitution is assigned a score based on its observed frequences in the alignment of related proteins. A positive score is given to the more likely substitutions while a negative score is given to the less likely substitutions.
BLOSUM62 is the matrix calculated by using the observed substitutions between proteins which have 62% or more sequence identity. BLOSUM has proved better at scoring distantly related sequences than the once-widely-used Point Accepted Mutation (PAM) matrices. To calculate a matrix for Blosum62, the following equation is used: B= (1/λ)log {(P i,j)/(ƒi,ƒj)} | BLOSUM
BLOSUM (BLOcks of Amino Acid SUbstitution Matrix) is a substitution matrix used for sequence alignment of proteins. BLOSUM matrices are used to score alignments between evolutionarily divergent protein sequences. Blosum is based on local alignments. Blosum was first introduced in a paper by Henikoff and Henikoff (1992; PNAS 89:10915-10919). They scanned the BLOCKS database for very conserved regions of protein families (that do not have gaps in the sequence alignment) and then counted the relative frequencies of amino acids and their substitution probabilities. Then, they calculated a log-odds score for each of the 210 possible substitutions of the 20 standard amino acids. All Blosum matrices are based on observed alignments; they are not extrapolated from comparisons or closely related proteins.
Blosum matrices with high numbers are designed for comparing closely related sequences, while Blosum matrices with low numbers are designed for comparing distant related sequences. For example, Blosum80 is used for less divergent alignments, and Blosum45 is used for more divergent alignments. Scores within a Blosum matix are log-odds scores that measure the logarithm for the ratio of the likelihood of two amino acids appearing by chance. [1]
The matrices are based on the minimum percentage identity of the aligned protein sequence used in calculating them.[2] Every possible identity or substitution is assigned a score based on its observed frequences in the alignment of related proteins.[3] A positive score is given to the more likely substitutions while a negative score is given to the less likely substitutions.
BLOSUM62 is the matrix calculated by using the observed substitutions between proteins which have 62% or more[1] sequence identity. BLOSUM has proved better at scoring distantly related sequences than the once-widely-used Point Accepted Mutation (PAM) matrices. To calculate a matrix for Blosum62, the following equation is used: B[i,j]= (1/λ)log {(P i,j)/(ƒi,ƒj)} | https://www.wikidoc.org/index.php/BLOSUM | |
75643fab0589e2f9a78c76c42b17524e038f47b6 | wikidoc | BMPR1A | BMPR1A
The bone morphogenetic protein receptor, type IA also known as BMPR1A is a protein which in humans is encoded by the BMPR1A gene. BMPR1A has also been designated as CD292 (cluster of differentiation 292).
# Function
The bone morphogenetic protein (BMP) receptors are a family of transmembrane serine/threonine kinases that include the type I receptors BMPR1A (this protein) and BMPR1B and the type II receptor BMPR2. These receptors are also closely related to the activin receptors, ACVR1 and ACVR2. The ligands of these receptors are members of the TGF beta superfamily. TGF-betas and activins transduce their signals through the formation of heteromeric complexes with 2 different types of serine (threonine) kinase receptors: type I receptors of about 50-55 kD and type II receptors of about 70-80 kD. Type II receptors bind ligands in the absence of type I receptors, but they require their respective type I receptors for signaling, whereas type I receptors require their respective type II receptors for ligand binding.
BMP's repress WNT signaling to maintain stable stem cell populations. BMPR1A null mice died at embryonic day 8.0 without mesoderm specification, demonstrating its vital role in gastrulation. It has been demonstrated in experiments using dominant negative BMPR1A chick embryos that BMPR1A plays a role in apoptosis and adipocyte development. Using constitutively active forms of BMR1A it has been shown that it plays a role in cell differentiation. Signals tranduced by the BMPR1A receptor are not essential for osteoblast formation or proliferation; however, BMPR1A is necessary for the extracellular matrix deposition by osteoblasts. In the chick embryo, BMPR1A receptors are found in low levels in limb bud mesenchyme, a differing location to BMPR1B, supporting the differing roles they play in osteogenesis.
# Ligands
- Agonists: BMP2, BMP4, BMP6, BMP7, GDF6
- Antagonists: Noggin, Chordin
# Diseases
BMPR1A, SMAD4 and PTEN are responsible for juvenile polyposis syndrome, juvenile intestinal polyposis and Cowden's disease.
# Interactions
BMPR1A has been shown to interact with:
- BMP2,
- SF3B4, and
- ZMYND11. | BMPR1A
The bone morphogenetic protein receptor, type IA also known as BMPR1A is a protein which in humans is encoded by the BMPR1A gene. BMPR1A has also been designated as CD292 (cluster of differentiation 292).[1]
# Function
The bone morphogenetic protein (BMP) receptors are a family of transmembrane serine/threonine kinases that include the type I receptors BMPR1A (this protein) and BMPR1B and the type II receptor BMPR2. These receptors are also closely related to the activin receptors, ACVR1 and ACVR2. The ligands of these receptors are members of the TGF beta superfamily. TGF-betas and activins transduce their signals through the formation of heteromeric complexes with 2 different types of serine (threonine) kinase receptors: type I receptors of about 50-55 kD and type II receptors of about 70-80 kD. Type II receptors bind ligands in the absence of type I receptors, but they require their respective type I receptors for signaling, whereas type I receptors require their respective type II receptors for ligand binding.[1]
BMP's repress WNT signaling to maintain stable stem cell populations. BMPR1A null mice died at embryonic day 8.0 without mesoderm specification, demonstrating its vital role in gastrulation.[2] It has been demonstrated in experiments using dominant negative BMPR1A chick embryos that BMPR1A plays a role in apoptosis and adipocyte development.[2] Using constitutively active forms of BMR1A it has been shown that it plays a role in cell differentiation.[2] Signals tranduced by the BMPR1A receptor are not essential for osteoblast formation or proliferation; however, BMPR1A is necessary for the extracellular matrix deposition by osteoblasts.[2] In the chick embryo, BMPR1A receptors are found in low levels in limb bud mesenchyme, a differing location to BMPR1B, supporting the differing roles they play in osteogenesis.[3]
# Ligands
- Agonists: BMP2, BMP4, BMP6, BMP7, GDF6
- Antagonists: Noggin, Chordin
# Diseases
BMPR1A, SMAD4 and PTEN are responsible for juvenile polyposis syndrome, juvenile intestinal polyposis and Cowden's disease.
# Interactions
BMPR1A has been shown to interact with:
- BMP2,[4][5][6][7]
- SF3B4,[8] and
- ZMYND11.[9] | https://www.wikidoc.org/index.php/BMPR1A | |
3dd9dcb9e9e2e8f404516a1e1c2f34fe1073d485 | wikidoc | BMPR1B | BMPR1B
Bone morphogenetic protein receptor type-1B also known as CDw293 (cluster of differentiation w293) is a protein that in humans is encoded by the BMPR1B gene.
# Function
BMPR1B is a member of the bone morphogenetic protein (BMP) receptor family of transmembrane serine/threonine kinases. The ligands of this receptor are BMPs, which are members of the TGF-beta superfamily. BMPs are involved in endochondral bone formation and embryogenesis. These proteins transduce their signals through the formation of heteromeric complexes of 2 different types of serine (threonine) kinase receptors: type I receptors of about 50-55 kD and type II receptors of about 70-80 kD. Type II receptors bind ligands in the absence of type I receptors, but they require their respective type I receptors for signaling, whereas type I receptors require their respective type II receptors for ligand binding.
The BMPR1B receptor plays a role in the formation of middle and proximal phalanges.
# Clinical significance
Mutations in this gene have been associated with primary pulmonary hypertension.
In the chick embryo, it has been shown that BMPR1B is found in precartilaginous condensations. BMPR1B is the major transducer of signals in these condensations as demonstrated in experiments using constitutively active BMPR1B receptors. BMPR1B is a more effective transducer of GDF5 than BMPR1A. Unlike BMPR1A null mice, which die at an early embryonic stage, BMPR1B null mice are viable. | BMPR1B
Bone morphogenetic protein receptor type-1B also known as CDw293 (cluster of differentiation w293) is a protein that in humans is encoded by the BMPR1B gene.[1][2]
# Function
BMPR1B is a member of the bone morphogenetic protein (BMP) receptor family of transmembrane serine/threonine kinases. The ligands of this receptor are BMPs, which are members of the TGF-beta superfamily. BMPs are involved in endochondral bone formation and embryogenesis. These proteins transduce their signals through the formation of heteromeric complexes of 2 different types of serine (threonine) kinase receptors: type I receptors of about 50-55 kD and type II receptors of about 70-80 kD. Type II receptors bind ligands in the absence of type I receptors, but they require their respective type I receptors for signaling, whereas type I receptors require their respective type II receptors for ligand binding.[3]
The BMPR1B receptor plays a role in the formation of middle and proximal phalanges.[4]
# Clinical significance
Mutations in this gene have been associated with primary pulmonary hypertension.[3]
In the chick embryo, it has been shown that BMPR1B is found in precartilaginous condensations.[5] BMPR1B is the major transducer of signals in these condensations as demonstrated in experiments using constitutively active BMPR1B receptors.[5] BMPR1B is a more effective transducer of GDF5 than BMPR1A.[5] Unlike BMPR1A null mice, which die at an early embryonic stage, BMPR1B null mice are viable.[5] | https://www.wikidoc.org/index.php/BMPR1B | |
a4e4bfc3a6c52fb5588d350708de8606208d9f6f | wikidoc | BPIFB1 | BPIFB1
BPI fold containing family B, member 1 is a protein that in humans is encoded by the BPIFB1 gene.
# Function
The protein encoded by this gene may be involved in the innate immune response to bacterial exposure in the mouth, nasal cavities, and lungs. The encoded protein is secreted and is a member of the BPI/LBP/PLUNC protein superfamily. This gene is found with other members of the superfamily in a cluster on chromosome 20. .
# Model organisms
Model organisms have been used in the study of BPIFB1 function. A conditional knockout mouse line called Bpifb1tm1e(KOMP)Wtsi was generated at the Wellcome Trust Sanger Institute. Male and female animals underwent a standardized phenotypic screen to determine the effects of deletion. Additional screens performed: - In-depth immunological phenotyping - in-depth bone and cartilage phenotyping | BPIFB1
BPI fold containing family B, member 1 is a protein that in humans is encoded by the BPIFB1 gene.[1]
# Function
The protein encoded by this gene may be involved in the innate immune response to bacterial exposure in the mouth, nasal cavities, and lungs. The encoded protein is secreted and is a member of the BPI/LBP/PLUNC protein superfamily. This gene is found with other members of the superfamily in a cluster on chromosome 20. [provided by RefSeq, Jul 2008].
# Model organisms
Model organisms have been used in the study of BPIFB1 function. A conditional knockout mouse line called Bpifb1tm1e(KOMP)Wtsi was generated at the Wellcome Trust Sanger Institute.[2] Male and female animals underwent a standardized phenotypic screen[3] to determine the effects of deletion.[4][5][6][7] Additional screens performed: - In-depth immunological phenotyping[8] - in-depth bone and cartilage phenotyping[9] | https://www.wikidoc.org/index.php/BPIFB1 | |
4316bd346f92f06da7753d8cc72370d704b2069d | wikidoc | Infant | Infant
In basic English usage, an infant is defined as a human child at the youngest stage of life, specifically before they can walk and generally before the age of one (see also child and adolescent).
The term "infant" derives from the Latin word in-fans, meaning "unable to speak." There is no exact definition for infancy. "Infant" is also a legal term with the meaning of minor; that is, any child under the age of legal adulthood.
A human infant less than a month old is a newborn infant or a neonate. The term "newborn" includes premature infants, postmature infants and full term newborns.
Upon reaching the age of one or beginning to walk, infants are subsequently referred to as "toddlers" (generally 12-36 months). Daycares with an "infant room" often call all children in it "infants" even if they are older than a year and/or walking; they sometimes use the term "walking infant".
# The newborn
## Appearance
A newborn's shoulders and hips are narrow, the abdomen protrudes slightly, and the arms and legs are relatively short. The average birth weight of a full-term newborn is approximately 7 ½ lbs.(3.2 kg), but is typically in the range of 5.5–10 pounds (2.7–4.6 kg). The average total body length is 14–20 inches (35.6–50.8 cm), although premature newborns may be much smaller. The Apgar score is a measure of a newborn's transition from the uterus during the first minutes of life.
A newborn's head is very large in proportion to the rest of the body, and the cranium is enormous relative to his or her face. While the adult human skull is about 1/8 of the total body length, the newborn's is about 1/4. At birth, many regions of the newborn's skull have not yet been converted to bone, leaving "soft spots" known as fontanels. The two largest are the diamond-shaped anterior fontanel, located at the top front portion of the head, and the smaller triangular-shaped posterior fontanel, which lies at the back of the head. Later in the child's life, these bones will fuse together in a natural process. A protein called noggin is responsible for the delay in an infant's skull fusion.
During labour and birth, the infant's skull changes shape to fit through the birth canal, sometimes causing the child to be born with a misshapen or elongated head. It will usually return to normal on its own within a few days or weeks. Special exercises sometimes advised by physicians may assist the process.
Some newborns have a fine, downy body hair called lanugo. It may be particularly noticeable on the back, shoulders, forehead, ears and face of premature infants. Lanugo disappears within a few weeks. Likewise, not all infants are born with lush heads of hair. Some may be nearly bald while others may have very fine, almost invisible hair. Some babies are even born with a full head of hair. Amongst fair-skinned parents, this fine hair may be blond, even if the parents are not. The scalp may also be temporarily bruised or swollen, especially in hairless newborns, and the area around the eyes may be puffy.
Immediately after birth, a newborn's skin is often grayish to dusky blue in color. As soon as the newborn begins to breathe, usually within a minute or two, the skin's color returns to its normal tone. Newborns are wet, covered in streaks of blood, and coated with a white substance known as vernix caseosa, which is hypothesised to act as an antibacterial barrier. The newborn may also have Mongolian spots, various other birthmarks, or peeling skin, particularly on the wrists, hands, ankles, and feet.
A newborn's genitals are enlarged and reddened, with male infants having an unusually large scrotum. The breasts may also be enlarged, even in male infants. This is caused by naturally-occurring maternal hormones and is a temporary condition. Females (and even males) may actually discharge milk from their nipples (sometimes called witch's milk), and/or a bloody or milky-like substance from the vagina. In either case, this is considered normal and will disappear in time.
The umbilical cord of a newborn is bluish-white in color. After birth, the umbilical cord is normally cut, leaving a 1–2 inch stub. The umbilical stub will dry out, shrivel, darken, and spontaneously fall off within about 3 weeks. Occasionally, hospitals may apply triple dye to the umbilical stub to prevent infection, which may temporarily color the stub and surrounding skin purple.
Newborns lose many of the above physical characteristics quickly. Thus prototypical older babies look very different. While older babies are considered "cute", newborns can be "unattractive" by the same criteria and first time parents may need to be educated in this regard.
## The newborn's senses
Newborns can feel all different sensations, but respond most enthusiastically to soft stroking, cuddling and caressing. Gentle rocking back and forth often calms a crying infant, as do massages and warm baths. Newborns may comfort themselves by sucking their thumb, or a pacifier. The need to suckle is instinctive (see suction in biology) and allows newborns to feed.
Newborn infants have unremarkable vision, being able to focus on objects only about 18 inches (45 cm) directly in front of their face. While this may not be much, it is all that is needed for the infant to look at the mother’s eyes or areola when breastfeeding. Generally, a newborn cries when wanting to feed. When a newborn is not sleeping, or feeding, or crying, he or she may spend a lot of time staring at random objects. Usually anything that is shiny, has sharp contrasting colors, or has complex patterns will catch an infant's eye. However, the newborn has a preference for looking at other human faces above all else. (see also: infant metaphysics and infant vision)
While still inside the mother, the infant could hear many internal noises, such as the mother's heartbeat, as well as many external noises including human voices, music and most other sounds. Therefore, although a newborn's ears may have some catarrh and fluid, he or she can hear sound from before birth. Newborns usually respond to a female voice over a male voice. This may explain why people will unknowingly raise the pitch of their voice when talking to newborns. The sound of other human voices, especially the mother's, can have a calming or soothing effect on the newborn. Conversely, loud or sudden noises will startle and scare a newborn.
Newborns can respond to different tastes, including sweet, sour, bitter, and salty substances, with a preference toward sweets.
A newborn has a developed sense of smell at birth, and within the first week of life can already distinguish the differences between the mother's own breast milk and the breast milk of another female.
# Infant mortality
Infant mortality is the death of an infant in the first year of life. Infant mortality can be subdivided into neonatal death, referring to deaths in the first 27 days of life, and post-neonatal death, referring to deaths after 28 days of life. Major causes of infant mortality include dehydration, infection, congenital malformation, and SIDS.
This epidemiological indicator is recognized as a very important measure of the level of health care in a country because it is directly linked with the health status of infants, children, and pregnant women as well as access to medical care, socioeconomic conditions, and public health practices.
# Care and feeding
Infants cry as a form of basic instinctive communication. A crying infant may be trying to express a variety of feelings including hunger, discomfort, overstimulation, boredom or loneliness. Many caregivers employ the use of baby monitors or babycams which enable them to hear or see an infant's cries from another room.
Feeding is typically done by breastfeeding, which is the recommended method of feeding by all major infant health organizations including the American Academy of Pediatrics. However, if breastfeeding is not possible or desired, bottle feeding may be done with expressed breast-milk or with infant formula. Infants have a sucking instinct allowing them to extract the milk from the nipples of the breasts or the nipple of the baby bottle, as well as an instinctive behavior known as rooting with which they seek out the nipple. Sometimes a wet nurse is hired to feed the infant, although this is rare, especially in developed countries.
As infants age, and their appetites grow, many parents choose from a variety of commercial, ready-made baby foods to supplement breast milk or formula for the child, while others adapt their usual meals for the dietary needs of their child.
Infants are incontinent, therefore diapers are generally used in industrialized countries, while methods similar to elimination communication are common in third world countries. Practitioners of these techniques assert that babies can control their bodily functions at the age of six months and that they are aware when they are urinating at an even earlier age. Babies can learn to signal to the parents when it is time to urinate or defecate by turning or making noises. Parents have to pay attention to the baby's actions so they can learn the signals.
Children need a relatively larger amount of sleep to function correctly (up to 18 hours for newborn babies, with a declining rate as the child ages), specially after feeding.
Babies cannot walk, although more mature infants may crawl or scoot; baby transport may be by perambulator (stroller or buggy), on the back or in front of an adult in a special carrier, cloth or cradle board, or simply by being carried in the arms. Most industrialized countries have laws requiring infants to be placed in special child safety seats when in motor vehicles.
As is the case with most other young children, infants are usually treated as special persons. Their social presence is different from that of adults, and they may be the focus of attention. Fees for transportation and entrance fees at locations such as amusement parks or museums are often waived. This special attention will wear out as the child grows older.
Common care issues for infants:
- Baby colic and/or gas.
- Childhood development.
- Hygiene:
Bathing or showering.
Cord and navel.
- Bathing or showering.
- Cord and navel.
- Day care.
- Diaper rash.
- Feeding: Breastfeeding or Infant formula (Baby bottle).
- Immunization.
- Paternal bond.
- Pacifier use.
- Sleep: bassinet and infant bed.
- Teething.
# Bibliography
- Simkin, Penny (1992 (late 1991)). Pregnancy, Childbirth and the Newborn: The Complete Guide. Meadowbook Press. ISBN 0-88166-177-5. Unknown parameter |coauthors= ignored (help); Unknown parameter |address= ignored (|location= suggested) (help); Check date values in: |year= (help).mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em} | Infant
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
In basic English usage, an infant is defined as a human child at the youngest stage of life, specifically before they can walk and generally before the age of one[1] (see also child and adolescent).
The term "infant" derives from the Latin word in-fans, meaning "unable to speak." There is no exact definition for infancy. "Infant" is also a legal term with the meaning of minor;[2] that is, any child under the age of legal adulthood.
A human infant less than a month old is a newborn infant or a neonate.[3] The term "newborn" includes premature infants, postmature infants and full term newborns.
Upon reaching the age of one or beginning to walk, infants are subsequently referred to as "toddlers" (generally 12-36 months). Daycares with an "infant room" often call all children in it "infants" even if they are older than a year and/or walking; they sometimes use the term "walking infant".
# The newborn
## Appearance
A newborn's shoulders and hips are narrow, the abdomen protrudes slightly, and the arms and legs are relatively short. The average birth weight of a full-term newborn is approximately 7 ½ lbs.(3.2 kg), but is typically in the range of 5.5–10 pounds (2.7–4.6 kg). The average total body length is 14–20 inches (35.6–50.8 cm), although premature newborns may be much smaller. The Apgar score is a measure of a newborn's transition from the uterus during the first minutes of life.
A newborn's head is very large in proportion to the rest of the body, and the cranium is enormous relative to his or her face. While the adult human skull is about 1/8 of the total body length, the newborn's is about 1/4. At birth, many regions of the newborn's skull have not yet been converted to bone, leaving "soft spots" known as fontanels. The two largest are the diamond-shaped anterior fontanel, located at the top front portion of the head, and the smaller triangular-shaped posterior fontanel, which lies at the back of the head. Later in the child's life, these bones will fuse together in a natural process. A protein called noggin is responsible for the delay in an infant's skull fusion.[4]
During labour and birth, the infant's skull changes shape to fit through the birth canal, sometimes causing the child to be born with a misshapen or elongated head. It will usually return to normal on its own within a few days or weeks. Special exercises sometimes advised by physicians may assist the process.
Some newborns have a fine, downy body hair called lanugo. It may be particularly noticeable on the back, shoulders, forehead, ears and face of premature infants. Lanugo disappears within a few weeks. Likewise, not all infants are born with lush heads of hair. Some may be nearly bald while others may have very fine, almost invisible hair. Some babies are even born with a full head of hair. Amongst fair-skinned parents, this fine hair may be blond, even if the parents are not. The scalp may also be temporarily bruised or swollen, especially in hairless newborns, and the area around the eyes may be puffy.
Immediately after birth, a newborn's skin is often grayish to dusky blue in color. As soon as the newborn begins to breathe, usually within a minute or two, the skin's color returns to its normal tone. Newborns are wet, covered in streaks of blood, and coated with a white substance known as vernix caseosa, which is hypothesised to act as an antibacterial barrier. The newborn may also have Mongolian spots, various other birthmarks, or peeling skin, particularly on the wrists, hands, ankles, and feet.
A newborn's genitals are enlarged and reddened, with male infants having an unusually large scrotum. The breasts may also be enlarged, even in male infants. This is caused by naturally-occurring maternal hormones and is a temporary condition. Females (and even males) may actually discharge milk from their nipples (sometimes called witch's milk), and/or a bloody or milky-like substance from the vagina. In either case, this is considered normal and will disappear in time.
The umbilical cord of a newborn is bluish-white in color. After birth, the umbilical cord is normally cut, leaving a 1–2 inch stub. The umbilical stub will dry out, shrivel, darken, and spontaneously fall off within about 3 weeks. Occasionally, hospitals may apply triple dye to the umbilical stub to prevent infection, which may temporarily color the stub and surrounding skin purple.
Newborns lose many of the above physical characteristics quickly. Thus prototypical older babies look very different. While older babies are considered "cute", newborns can be "unattractive" by the same criteria and first time parents may need to be educated in this regard.
## The newborn's senses
Newborns can feel all different sensations, but respond most enthusiastically to soft stroking, cuddling and caressing. Gentle rocking back and forth often calms a crying infant, as do massages and warm baths. Newborns may comfort themselves by sucking their thumb, or a pacifier. The need to suckle is instinctive (see suction in biology) and allows newborns to feed.
Newborn infants have unremarkable vision, being able to focus on objects only about 18 inches (45 cm) directly in front of their face. While this may not be much, it is all that is needed for the infant to look at the mother’s eyes or areola when breastfeeding. Generally, a newborn cries when wanting to feed. When a newborn is not sleeping, or feeding, or crying, he or she may spend a lot of time staring at random objects. Usually anything that is shiny, has sharp contrasting colors, or has complex patterns will catch an infant's eye. However, the newborn has a preference for looking at other human faces above all else. (see also: infant metaphysics and infant vision)
While still inside the mother, the infant could hear many internal noises, such as the mother's heartbeat, as well as many external noises including human voices, music and most other sounds. Therefore, although a newborn's ears may have some catarrh and fluid, he or she can hear sound from before birth. Newborns usually respond to a female voice over a male voice. This may explain why people will unknowingly raise the pitch of their voice when talking to newborns. The sound of other human voices, especially the mother's, can have a calming or soothing effect on the newborn. Conversely, loud or sudden noises will startle and scare a newborn.
Newborns can respond to different tastes, including sweet, sour, bitter, and salty substances, with a preference toward sweets.
A newborn has a developed sense of smell at birth, and within the first week of life can already distinguish the differences between the mother's own breast milk and the breast milk of another female.
# Infant mortality
Infant mortality is the death of an infant in the first year of life. Infant mortality can be subdivided into neonatal death, referring to deaths in the first 27 days of life, and post-neonatal death, referring to deaths after 28 days of life. Major causes of infant mortality include dehydration, infection, congenital malformation, and SIDS.[5]
This epidemiological indicator is recognized as a very important measure of the level of health care in a country because it is directly linked with the health status of infants, children, and pregnant women as well as access to medical care, socioeconomic conditions, and public health practices.[6]
[7]
# Care and feeding
Infants cry as a form of basic instinctive communication. A crying infant may be trying to express a variety of feelings including hunger, discomfort, overstimulation, boredom or loneliness. Many caregivers employ the use of baby monitors or babycams which enable them to hear or see an infant's cries from another room.
Feeding is typically done by breastfeeding, which is the recommended method of feeding by all major infant health organizations including the American Academy of Pediatrics.[8] However, if breastfeeding is not possible or desired, bottle feeding may be done with expressed breast-milk or with infant formula. Infants have a sucking instinct allowing them to extract the milk from the nipples of the breasts or the nipple of the baby bottle, as well as an instinctive behavior known as rooting with which they seek out the nipple. Sometimes a wet nurse is hired to feed the infant, although this is rare, especially in developed countries.
As infants age, and their appetites grow, many parents choose from a variety of commercial, ready-made baby foods to supplement breast milk or formula for the child, while others adapt their usual meals for the dietary needs of their child.
Infants are incontinent, therefore diapers are generally used in industrialized countries, while methods similar to elimination communication[9] are common in third world countries. Practitioners of these techniques assert that babies can control their bodily functions at the age of six months and that they are aware when they are urinating at an even earlier age. Babies can learn to signal to the parents when it is time to urinate or defecate by turning or making noises. Parents have to pay attention to the baby's actions so they can learn the signals.
Children need a relatively larger amount of sleep to function correctly (up to 18 hours for newborn babies, with a declining rate as the child ages), specially after feeding.
Babies cannot walk, although more mature infants may crawl or scoot; baby transport may be by perambulator (stroller or buggy), on the back or in front of an adult in a special carrier, cloth or cradle board, or simply by being carried in the arms. Most industrialized countries have laws requiring infants to be placed in special child safety seats when in motor vehicles.
As is the case with most other young children, infants are usually treated as special persons. Their social presence is different from that of adults, and they may be the focus of attention. Fees for transportation and entrance fees at locations such as amusement parks or museums are often waived. This special attention will wear out as the child grows older.
Common care issues for infants:
- Baby colic and/or gas.
- Childhood development.
- Hygiene:
Bathing or showering.
Cord and navel.
- Bathing or showering.
- Cord and navel.
- Day care.
- Diaper rash.
- Feeding: Breastfeeding or Infant formula (Baby bottle).
- Immunization.
- Paternal bond.
- Pacifier use.
- Sleep: bassinet and infant bed.
- Teething.
# Bibliography
Template:Sourcesstart
- Simkin, Penny (1992 (late 1991)). Pregnancy, Childbirth and the Newborn: The Complete Guide. Meadowbook Press. ISBN 0-88166-177-5. Unknown parameter |coauthors= ignored (help); Unknown parameter |address= ignored (|location= suggested) (help); Check date values in: |year= (help).mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}
Template:Sourcesend | https://www.wikidoc.org/index.php/Babies | |
804463a0ccc17df9a943e8c61f62d77e04cfccdc | wikidoc | Baby K | Baby K
Baby K was born in an anencephalic state on October 13, 1992, at Fairfax Hospital in Virginia. That is, she was born missing almost all of her brain. In fact, all that remained of her brain was the "brainstem", that primitive part of the brain responsible (in part) for autonomic and regulatory function, such as the control of respiration, the heartbeat and blood pressure .
# The case of Baby K.
Despite being aware of the baby's condition prior to birth,(citation needed as to accuracy of diagnosis) Ms. H., the mother of Baby K., carried the child to term, in spite of medical advice to abort. Motivated by a strong religious conviction that "all life is precious" and that God alone should decide how long the baby would live, she remained adamant that Baby K. be kept alive as long as possible. The hospital’s position was that such care would be futile.
Ms. H. wanted the hospital to continue with advanced supportive care (primarily ventilatory support), despite the generally accepted medical practice that anencephaly is not curable or treatable, and that maintained life support would be both futile and wasteful. Fairfax Hospital doctors advised a Do Not Resuscitate condition for the child. The mother refused the DNR. Baby K. was left on ventilator support for 6 weeks while Fairfax searched for another hospital to transfer her to, but all area hospitals claimed they had no room (which is believed to be not entirely true; that in actuality no other hospital wanted to take over the futile medical care expectations and legal issues surrounding the child).
After the baby came off of constant ventilator support, Ms. H. agreed to move the child to a nursing facility, but the baby returned to the hospital many times for respiratory problems.
At 6 months old, Baby K. was admitted to the hospital for severe respiratory problems. The hospital filed a legal motion to appoint a guardian for the child's care, and to declare that the hospital did not need to provide any services beyond palliative care.
At the trial , expert testimony was given to demonstrate that provision of ventilator support for anencephalic infants goes beyond the accepted standard of care. The legal team for Baby K's mother adhered to a religious sanctity of life principle as the basis for their case. In a particularly controversial decision, the U. S. District Court ruled that the hospital caring for Baby K must put her on a mechanical ventilator whenever she had trouble breathing. The court interpreted the Emergency Medical Treatment and Active Labor Act (EMTALA) to require continued ventilation for the infant. The wording of this act requires that patients who present with a medical emergency must get "such treatment as may be required to stabilize the medical condition" before the patient is transferred to another facility. The court refused to take a moral or ethical position on the issue, insisting that it was only interpreting the laws as they existed. As a result of the decision, Baby K was kept alive much longer than most anencephalic babies, living to age 2½ .
Some commentators on the decision argue that it effectively turned doctors into mere "instruments of technology", and took away a doctor's prerogative to make responsible, utilitarian medical decisions.
# Effects of Baby K. case
The case of Baby K. is of particular importance to clinical bioethics because of the rich variety of issues it raises: defining death, the nature of personhood, the notion of moral standing, medical futility, caregiver issues, resource allocation concerns and much more.
The dissenting judge in the legal case argued that the court should have used the condition anencephaly as the basis of the case, not the recurring subsidiary symptoms of respiratory distress. As the irreversibility of anencephaly is highly accepted in the medical community, he argued that the decision to continue (futile) care only resulted in irresponsible use of medical resources, and prolonged suffering. | Baby K
Baby K was born in an anencephalic state on October 13, 1992, at Fairfax Hospital in Virginia. That is, she was born missing almost all of her brain. In fact, all that remained of her brain was the "brainstem", that primitive part of the brain responsible (in part) for autonomic and regulatory function, such as the control of respiration, the heartbeat and blood pressure [1].
# The case of Baby K.
Despite being aware of the baby's condition prior to birth,(citation needed as to accuracy of diagnosis) Ms. H., the mother of Baby K., carried the child to term, in spite of medical advice to abort. Motivated by a strong religious conviction that "all life is precious" and that God alone should decide how long the baby would live,[citation needed] she remained adamant that Baby K. be kept alive as long as possible. The hospital’s position was that such care would be futile.
Ms. H. wanted the hospital to continue with advanced supportive care (primarily ventilatory support), despite the generally accepted medical practice that anencephaly is not curable or treatable, and that maintained life support would be both futile and wasteful. Fairfax Hospital doctors advised a Do Not Resuscitate condition for the child. The mother refused the DNR. Baby K. was left on ventilator support for 6 weeks while Fairfax searched for another hospital to transfer her to, but all area hospitals claimed they had no room[citation needed] (which is believed to be not entirely true; that in actuality no other hospital wanted to take over the futile medical care expectations and legal issues surrounding the child).[citation needed]
After the baby came off of constant ventilator support, Ms. H. agreed to move the child to a nursing facility, but the baby returned to the hospital many times for respiratory problems.
At 6 months old, Baby K. was admitted to the hospital for severe respiratory problems. The hospital filed a legal motion to appoint a guardian for the child's care, and to declare that the hospital did not need to provide any services beyond palliative care.
At the trial [Matter of Baby K. 16 F.3d 590 (4th Cir. 1994), n. 9 at 598.], expert testimony was given to demonstrate that provision of ventilator support for anencephalic infants goes beyond the accepted standard of care. The legal team for Baby K's mother adhered to a religious sanctity of life principle as the basis for their case. In a particularly controversial decision, the U. S. District Court ruled that the hospital caring for Baby K must put her on a mechanical ventilator whenever she had trouble breathing. The court interpreted the Emergency Medical Treatment and Active Labor Act (EMTALA) to require continued ventilation for the infant. The wording of this act requires that patients who present with a medical emergency must get "such treatment as may be required to stabilize the medical condition" before the patient is transferred to another facility. The court refused to take a moral or ethical position on the issue, insisting that it was only interpreting the laws as they existed. As a result of the decision, Baby K was kept alive much longer than most anencephalic babies, living to age 2½ .
Some commentators on the decision argue that it effectively turned doctors into mere "instruments of technology", and took away a doctor's prerogative to make responsible, utilitarian medical decisions.
# Effects of Baby K. case
The case of Baby K. is of particular importance to clinical bioethics because of the rich variety of issues it raises: defining death, the nature of personhood, the notion of moral standing, medical futility, caregiver issues, resource allocation concerns and much more.
The dissenting judge in the legal case argued that the court should have used the condition anencephaly as the basis of the case, not the recurring subsidiary symptoms of respiratory distress. As the irreversibility of anencephaly is highly accepted in the medical community, he argued that the decision to continue (futile) care only resulted in irresponsible use of medical resources, and prolonged suffering.
Template:EthicsCases
# External links
- Futile Care and the Neonate: In the Matter of Baby K at Medscape
- Anencephalic Babies page at Kennedy Institute of Ethics
- Stress and Distress in Pediatric Nurses: The Hidden Tragedy of Baby K. by Ronald M. Perkin
- FIGO
Template:WikiDoc Sources
Template:Jb1 | https://www.wikidoc.org/index.php/Baby_K | |
47a20ff7ab9e50f3003f05a0af6b99f6224060f0 | wikidoc | Banana | Banana
Banana is the common name for a fruit and also the herbaceous plants of the genus Musa which produce the commonly eaten fruit. They are native to the tropical region of Southeast Asia and Australia. Today, they are cultivated throughout the tropics.
Banana plants are of the family Musaceae. They are cultivated primarily for their fruit, and to a lesser extent for the production of fibre and as ornamental plants. As the bananas are mainly tall, upright, and fairly sturdy, they are often mistaken for trees, when the truth is the main or upright stem is called a pseudostem, literally meaning "fake stem", which for some species can obtain a height of up to 2–8 m, with leaves of up to 3.5 m in length. Each pseudostem can produce a bunch of yellow, green, or even red bananas before dying and being replaced by another pseudostem.
The banana fruit grow in hanging clusters, with up to 20 fruit to a tier (called a hand), and 3-20 tiers to a bunch. The total of the hanging clusters is known as a bunch, or commercially as a "banana stem", and can weigh from 30–50 kg. The fruit averages 125 g, of which approximately 75% is water and 25% dry matter content. Each individual fruit (known as a banana or 'finger') has a protective outer layer (a peel or skin) with a fleshy edible inner portion. Typically, the fruit has numerous strings (called 'phloem bundles') which run between the skin and the edible portion of the banana, and which are commonly removed individually after the skin is removed. Bananas are a valuable source of vitamin B6, vitamin C, and potassium.
Bananas are grown in at least 107 countries. In popular culture and commerce, "banana" usually refers to soft, sweet "dessert" bananas that are usually eaten raw. The bananas from a group of cultivars with firmer, starchier fruit are called plantains, and are generally used in cooking rather than eaten raw. Bananas may also be dried and eaten as a snack food. Dried bananas are also ground into banana flour.
Although the wild species have fruits with numerous large, hard seeds, virtually all culinary bananas have seedless fruits. Bananas are classified either as dessert bananas (meaning they are yellow and fully ripe when eaten) or as green cooking bananas. Almost all export bananas are of the dessert types; however, only about 10-15% of all production is for export, with the United States and European Union being the dominant buyers.
# Plant
The banana plant is a pseudostem that grows to 6 to 7.6 metres (20-25 feet) tall, growing from a corm. Leaves are spirally arranged and may grow 2.7 metres (9 feet) long and 60 cm (2 feet) wide. The banana plant is the largest of all herbaceous plants.
# Properties
Bananas come in a variety of sizes and colors when ripe, including yellow, purple and red. Bananas can be eaten raw though some varieties are generally cooked first. Depending upon cultivar and ripeness, the flesh can vary in taste from starchy to sweet, and texture from firm to mushy. Unripe or green bananas and plantains are used for cooking various dishes such as banana pudding and are the staple starch of many tropical populations. Banana sap is extremely sticky and can be used as a practical adhesive. Sap can be obtained from the pseudostem, from the fruit peelings, or from the fruit flesh.
Most production for local sale is of green cooking bananas and plantains, as ripe dessert bananas are easily damaged while being transported to market. Even when only transported within their country of origin, ripe bananas suffer a high rate of damage and loss.
The commercial dessert cultivars most commonly eaten in temperate countries (species Musa acuminata or the hybrid Musa × paradisiaca, a cultigen) are imported in large quantities from the tropics. They are popular in part because, being a non-seasonal crop, they are available fresh year-round. In global commerce, by far the most important of these banana cultivars is 'Cavendish', which accounts for the vast bulk of bananas exported from the tropics. The Cavendish gained popularity in the 1950s after the previously mass produced cultivar, Gros Michel, became commercially unviable due to Panama disease, a fungus which attacks the roots of the banana plant.
The most important properties making 'Cavendish' the main export banana are related to transport and shelf life rather than taste; major commercial cultivars rarely have a superior flavour compared to the less widespread cultivars. Export bananas are picked green, and then usually ripened in ripening rooms when they arrive in their country of destination. These are special rooms made air-tight and filled with ethylene gas to induce ripening. Bananas can be ordered by the retailer "ungassed", however, and may show up at the supermarket still fully green. While these bananas will ripen more slowly, the flavour will be notably richer, and the banana peel can be allowed to reach a yellow/brown speckled phase, and yet retain a firm flesh inside. Thus, shelf life is somewhat extended. The flavour and texture of bananas are affected by the temperature at which they ripen. Bananas are refrigerated to between 13.5 and 15 °C (57 and 59 °F) during transportation. At lower temperatures, the ripening of bananas permanently stalls, and the bananas will eventually turn grey.
It should be noted that Musa × paradisiaca is also the generic name for the common plantain, a coarser and starchier variant not to be confused with Musa acuminata or the Cavendish variety. Plantains have all but replaced the Cavendish in markets dominated by supply-side logistics.
In addition to the fruit, the flower of the banana plant (also known as banana blossom or banana heart) is used in Southeast Asian, Bengali and Kerala (India) cuisine, either served raw with dips or cooked in soups and curries. The tender core of the banana plant's trunk is also used, notably in the Burmese dish mohinga, Bengali and Kerala cooking. Bananas fried with batter is a popular dessert in Malaysia, Singapore and Indonesia. Banana fritters can be served with ice-cream as well. Bananas are also eaten deep fried, baked in their skin in a split bamboo, or steamed in glutinous rice wrapped in a banana leaf in Myanmar where bunches of green bananas surrounding a green coconut in a tray is an important part of traditional offerings to the Buddha and the Nats. The juice extract prepared from the tender core is used to treat kidney stones.
The leaves of the banana are large, flexible, and waterproof; they are used in many ways, including as umbrellas and to wrap food for cooking, carrying and packing cooked foods, and they are used to build houses in third world countries.. In south India, food is traditionally served on banana leaves in homes and some restaurants also follow the practice. Some farmers prefer to grow banana plants only for their leaves. Chinese zongzi (bamboo leaves are more commonly used where available) and Central American tamales are sometimes steamed in banana leaves, and the Hawaiian imu is often lined with them. Puerto Rican "pasteles" are boiled wrapped and tied inside the leaf.
Banana chips are a snack (and a healthy alternative to potato chips) produced from dehydrated or fried banana or, preferably, plantain slices, which have a dark brown colour and an intense banana taste. Bananas have also been used in the making of jam. Unlike other fruits, it is difficult to extract juice from bananas because when compressed a banana simply turns to pulp.
Seeded bananas (Musa balbisiana), considered to be one of the forerunners of the common domesticated banana, are sold in markets in Indonesia.
It is reported that in Orissa, India, juice is extracted from the corm and used as a home remedy for the treatment of jaundice. In other places honey is mixed with mashed banana fruit and used for the same purpose.
# Trade
Bananas and plantains constitute a major staple food crop for millions of people in developing countries. In most tropical countries, green (unripe) bananas used for cooking represent the main cultivars. Cooking bananas are very similar to potatoes in how they are used. Both can be fried, boiled, baked or chipped and have similar taste and texture when served. One green cooking banana has about the same calorie content as one potato.
In 2003, India led the world in banana production, representing approximately 23% of the worldwide crop, most of which was for domestic consumption. The four leading banana exporting countries were Ecuador, Costa Rica, Philippines, and Colombia, which together accounted for about two-thirds of the world's exports, each exporting more than 1 million tons. Ecuador alone provided more than 30% of global banana exports, according to FAO statistics.
The vast majority of producers are small-scale farmers growing the crop either for home consumption or for local markets. Because bananas and plantains will produce fruit year-round, they provide an extremely valuable source of food during the hunger season (that period of time when all the food from the previous harvest has been consumed, and the next harvest is still some time away). It is for these reasons that bananas and plantains are of major importance to food security.
Bananas are among the most widely consumed foods in the world. Most banana farmers receive a low unit price for their produce as supermarkets buy enormous quantities and receive a discount for that business. Competition amongst supermarkets has led to reduced margins in recent years which in turn has led to lower prices for growers. Chiquita, Del Monte, Dole and Fyffes grow their own bananas in Ecuador, Colombia, Costa Rica, Guatemala and Honduras. Banana plantations are capital intensive and demand high expertise, so the majority of independent growers are large and wealthy landowners of these countries. This has led to bananas being available as a "fair trade" item in some countries.
The banana has an extensive trade history beginning with the founding of the United Fruit Company (now Chiquita) at the end of the nineteenth century. For much of the 20th century, bananas and coffee dominated the export economies of Central America. In the 1930s, bananas and coffee made up as much as 75% of the region's exports. As late as 1960, the two crops accounted for 67% of the exports from the region. Though the two were grown in similar regions, they tended not to be distributed together. The United Fruit Company based its business almost entirely on the banana trade, as the coffee trade proved too difficult for it to control. The term "banana republic" has been broadly applied to most countries in Central America, but from a strict economic perspective only Costa Rica, Honduras, and Panama were actual "banana republics", countries with economies dominated by the banana trade.
The countries of the European Union have traditionally imported many of their bananas from the former European island colonies of the Caribbean, paying guaranteed prices above global market rates. As of 2005, these arrangements were in the process of being withdrawn under pressure from other major trading powers, principally the United States. The withdrawal of these indirect subsidies to Caribbean producers is expected to favour the banana producers of Central America, in which American companies have an economic interest.
The United States has minimal banana production. 14,000 tons of bananas were grown in Hawaii in 2001.
# History
The domestication of bananas took place in southeastern Asia. Many species of wild bananas still occur in New Guinea, Malaysia, Indonesia and the Philippines. Recent archaeological and palaeoenvironmental evidence at Kuk Swamp in the Western Highlands Province of Papua New Guinea suggests that banana cultivation there goes back to at least 5000 BCE, and possibly to 8000 BCE. This would make the New Guinean highlands the place where bananas were first domesticated. It is likely that other species of wild bananas were later also domesticated elsewhere in southeastern Asia such as the asian fighting banana known for its intense fruit taste and bright orange peels.
The banana may have been present in isolated locations of the Middle East on the eve of the rise of Islam. There is some textual evidence that the prophet Muhammad was familiar with it. The spread of Islam, was followed by the far reaching diffusion of bananas. There are numerous references to it in Islamic texts (such as poems and hadiths) beginning in the ninth century. By the tenth century the banana appears in texts from Palestine and Egypt, from it diffused into north Africa and Muslim Spain. In fact, during the medieval ages, bananas from Granada were considered amongst the best in the Arab world.
Some recent discoveries of banana phytoliths in Cameroon dating to the first millennium BCE have triggered an as yet unresolved debate about the antiquity of banana cultivation in Africa. There is linguistic evidence that bananas were already known in Madagascar around that time. The earliest evidence of banana cultivation in Africa before these recent discoveries dates to no earlier than late 6th century AD. Muslim Arabs likely brought bananas from the east coast of Africa west to the Atlantic coast and further south to Madagascar.
The banana is mentioned for the first time in written history in Buddhist texts in 600 BCE. Alexander the Great discovered the taste of the banana in the valleys of India in 327 BCE. The existence of an organized banana plantation could be found in China in 200 CE. In 650, Islamic conquerors brought the banana to Palestine. The word banana is of West African origin, and passed into English via Spanish or Portuguese.
In 15th and 16th century, Portuguese colonists started banana plantations in the Atlantic Islands, Brazil, and western Africa. As late as the Victorian Era, bananas were not widely known in Europe, although they were available via merchant trade. Jules Verne references bananas with detailed descriptions so as not to confuse readers in his book Around the World in Eighty Days (1872).
# Cultivation
While the original bananas contained rather large seeds, triploid (and thus seedless) cultivars have been selected for human consumption. These are propagated asexually from offshoots of the plant. The plant is allowed to produce 2 shoots at a time; a larger one for fruiting immediately and a smaller "sucker" or "follower" that will produce fruit in 6–8 months time. The life of a banana plantation is 25 years or longer, during which time the individual stools or planting sites may move slightly from their original positions as lateral rhizome formation dictates.
Cultivated bananas are parthenocarpic, which makes them sterile and unable to produce viable seeds. Lacking seeds, another form of propagation is required. This involves removing and transplanting part of the underground stem (called a corm). Usually this is done by carefully removing a sucker (a vertical shoot that develops from the base of the banana pseudostem) with some roots intact. However, small sympodial corms, representing not yet elongated suckers, are easier to transplant and can be left out of the ground for up to 2 weeks; they require minimal care and can be boxed together for shipment.
In some countries, bananas are commercially propagated by means of tissue culture. This method is preferred since it ensures disease-free planting material. When using vegetative parts such as suckers for propagation, there is a risk of transmitting diseases (especially the devastating Panama disease).
# Pests, diseases and natural disasters
While in no danger of outright extinction, the most common edible banana cultivar 'Cavendish' (extremely popular in Europe and the Americas) could become unviable for large-scale cultivation in the next 10-20 years. Its predecessor 'Gros Michel', discovered in the 1820s, has already suffered this fate. Like almost all bananas, it lacks genetic diversity, which makes it vulnerable to diseases, which threaten both commercial cultivation and the small-scale subsistence farming. Major diseases include:
- Panama Disease (Race 1) – fusarium wilt (a soil fungus). The fungus enters the plants through the roots and moves up with water into the trunk and leaves, producing gels and gums. These plug and cut off the flow of water and nutrients, causing the plant to wilt. Prior to 1960 almost all commercial banana production centered on the cultivar 'Gros Michel', which was highly susceptible to fusarium wilt. The cultivar 'Cavendish' was chosen as a replacement for 'Gros Michel' because out of the resistant cultivars it was viewed as producing the highest quality fruit. However, more care is required for shipping the 'Cavendish' banana, and its quality compared to 'Gros Michel' is debated.
- Tropical Race 4 - a reinvigorated strain of Panama Disease first discovered in 1993. This is a virulent form of fusarium wilt that has wiped out 'Cavendish' in several southeast Asian countries. It has yet to reach the Americas; however, soil fungi can easily be carried on boots, clothing, or tools. This is how Tropical Race 4 moves from one plantation to another and is its most likely route into Latin America. The Cavendish cultivar is highly susceptible to TR4, and over time, Cavendish is almost certain to be eliminated from commercial production by this disease. Unfortunately the only known defense to TR4 is genetic resistance.
- Black Sigatoka - a fungal leaf spot disease first observed in Fiji in 1963 or 1964. Black Sigatoka (also known as Black Leaf Streak) has spread to banana plantations throughout the tropics due to infected banana leaves being used as packing material. It affects all of the main cultivars of bananas and plantains, impeding photosynthesis by turning parts of their leaves black, and eventually killing the entire leaf. Being starved for energy, fruit production falls by 50% or more, and the bananas that do grow suffer premature ripening, making them unsuitable for export. The fungus has shown ever increasing resistance to fungicidal treatment, with the current expense for treating 1 hectare exceeding US$1000 per year. In addition to the financial expense there is the question of how long such intensive spraying can be justified environmentally. Several resistant cultivars of banana have been developed, but none has yet received wide scale commercial acceptance due to taste and texture issues.
- Banana Bunchy Top Virus (BBTV) - this virus is spread from plant to plant by aphids. It causes stunting of the leaves resulting in a "bunched" appearance. Generally, a banana plant infected with the virus will not set fruit, although mild strains exist in many areas which do allow for some fruit production. These mild strains are often mistaken for malnourishment, or a disease other than BBTV. There is no cure for BBTV, however its effect can be minimised by planting only tissue cultured plants (In-vitro propagation), controlling the aphids, and immediately removing and destroying any plant from the field that shows signs of the disease.
Even though it is no longer viable for large scale cultivation, 'Gros Michel' is not extinct and is still grown in areas where Panama Disease is not found. Likewise, 'Cavendish' is in no danger of extinction, but it may leave the shelves of the supermarkets for good if diseases make it impossible to supply the global market. It is unclear if any existing cultivar can replace 'Cavendish' on a scale needed to fill current demand, so various hybridisation and genetic engineering programs are working on creating a disease-resistant, mass-market banana.
Australia is relatively free of plant diseases and therefore prohibits imports. When Cyclone Larry wiped out Australia's domestic banana crop in 2006, bananas became relatively expensive, due to both low supply domestically and the existence of laws prohibiting banana imports.
## East Africa
Most bananas grown worldwide are used for local consumption. In the tropics, bananas, especially cooking bananas, represent a major source of food, as well as a major source of income for smallholder farmers. It is in the East African highlands that bananas reach their greatest importance as a staple food crop. In countries such as Uganda, Burundi and Rwanda per capita consumption has been estimated at 450 kg per year, the highest in the world. Ugandans use the same word "matooke" to describe both banana and food.
In the past, the banana was a highly sustainable crop with a long plantation life and stable yields year round. However with the arrival of the Black Sigatoka fungus, banana production in eastern Africa has fallen by over 40%. For example, during the 1970s, Uganda produced 15 to 20 tonnes of bananas per hectare. Today, production has fallen to only 6 tonnes per hectare.
The situation has started to improve as new disease resistant cultivars have been developed by IITA and NARO such as the FHIA-17 (known in Uganda as the Kabana 3). These new cultivars taste different from the traditionally grown banana which has slowed their acceptance by local farmers. However, by adding mulch and animal manure to the soil around the base of the banana plant, these new cultivars have substantially increased yields in the areas where they have been tried.
The International Institute of Tropical Agriculture and NARO, funded by the Rockefeller Foundation and CGIAR have started trials for genetically modified banana plants that are resistant to both Black Sigatoka and banana weevils. It is developing cultivars specifically for smallholder or subsistence farmers.
# Allergic reactions
There are two forms of banana allergy. One is oral allergy syndrome which causes itching and swelling in the mouth or throat within one hour after ingestion and is related to birch tree and other pollen allergies. The other is related to latex allergies and causes urticaria and potentially serious upper gastrointestinal symptoms.
# Fibre
## Textiles
The banana plant has long been a source of fibre for high quality textiles. In Japan, the cultivation of banana for clothing and household use dates back to at least the 13th century. In the Japanese system, leaves and shoots are cut from the plant periodically to ensure softness. The harvested shoots must first be boiled in lye to prepare the fibres for the making of the yarn. These banana shoots produce fibres of varying degrees of softness, yielding yarns and textiles with differing qualities for specific uses. For example, the outermost fibres of the shoots are the coarsest, and are suitable for tablecloths, whereas the softest innermost fibres are desirable for kimono and kamishimo. This traditional Japanese banana cloth making process requires many steps, all performed by hand.
In another system employed in Nepal, the trunk of the banana plant is harvested instead, small pieces of which are subjected to a softening process, mechanical extraction of the fibres, bleaching, and drying. After that, the fibres are sent to the Kathmandu valley for the making of high end rugs with a textural quality similar to silk. These banana fibre rugs are woven by the traditional Nepalese hand-knotted methods, and are sold RugMark certified.
## Paper
Banana fibre is also used in the production of banana paper. Banana paper is used in two different senses: to refer to a paper made from the bark of the banana plant, mainly used for artistic purposes, or paper made from banana fiber, obtained from an industrialized process, from the stem and the non utilizable fruits. This paper can be either hand-made or made by industrialized machine.
# Storage and transport
In the current world marketing system, bananas are grown in the tropics where hurricanes are not common. The fruit therefore has to be transported over long distances and storage is necessary. To gain maximum life bunches are harvested before the fruit is fully mature. The fruit is carefully handled, transported quickly to the seaboard, cooled and shipped under sophisticated refrigeration. The basis of this procedure is to prevent the bananas producing ethylene which is the natural ripening agent of the fruit. This sophisticated technology allows storage and transport for 3-4 weeks at 13 degrees Celsius. On arrival at the destination the bananas are held at about 17 degrees Celsius and treated with a low concentration of ethylene. After a few days the fruit has begun to ripen and it is distributed for retail sale. It is important to note that unripe bananas can not be held in the home refrigerator as they suffer from the cold. After ripening some bananas can be held for a few days in the home refrigerator.
Australian researchers have clearly shown that the use of refrigeration is no longer essential to extend the life of bananas after harvest.
The above references report that the presence of carbon dioxide (which is produced by the fruit) extends the life and the addition of an ethylene absorbent further extends the life even at high temperatures. This simple technology involves packing the fruit in a polyethylene bag and including an ethylene absorbent, potassium permanganate, on an inert carrier. The bag is then sealed with a band or string. This low cost treatment more than doubles the life at a range of temperatures and can give a life of up to 3-4 weeks without the need of refrigeration. The method is suitable for bunches, hands and even fingers.
The technology has been successfully tested over long distances and has been confirmed by researchers in a number of countries. The longest commercial trial was from North Queensland to New Zealand by unrefrigerated rail and ship over 18 days. Importers thought that the treated bananas were harvested on the day of arrival!
Although the technology has been extensively published in recognized scientific journals and has considerable cost savings (including energy savings) it has not been widely adopted. This report is to encourage banana growers in even poor countries to try out the technology themselves. It is suggested that a freshly harvested bunch be taken and a few hands be selected and each cut in two. Half of each hand should be sealed in a polyethylene bag the other half hands should be left untreated. Even without the ethylene absorbent the beneficial effect should be obvious in a few days. Growers can then decide whether to try the full technology.
# Usage in culture
## Peels
The depiction of a person slipping on a banana peel has been a staple of physical comedy for generations. A 1906 comedy record produced by Edison Records features a popular character of the time, "Cal Stewart", claiming to describe his own such incident, saying:
I don't think much of a man what throws a bananer peelin' on the sidewalk, and I don't think much of a bananer what throws a man on the sidewalk, neither. ... my foot hit that bananer peelin' and I went up in the air, and come down ker-plunk, and fer about a minnit I seen all the stars what 'stronomy tells about, and some that hain't been discovered yit. Wall jist as I was pickin' myself up, a little boy come runnin' cross the street and he said, "Oh mister, won't you please do that agin? My mother didn't see you do it."
## Stereotypes
- Because of the stereotypical image of monkeys and apes eating bananas, they have been used for racist insults, such as throwing bananas at sports players of African descent.
## Arts
- The poet Bashō is named after the Japanese word for a banana plant. The "bashō" planted in his garden by a grateful student became a source of inspiration to his poetry, as well as a symbol of his life and home.
- The song Yes, We Have No Bananas was written by Frank Silver and Irving Cohn and originally released in 1923. Since then the song has been re-recorded several times and has been particularly popular during banana shortages.
## Symbols
Bananas are also humorously used as a phallic symbol due to similarities in size and shape. This is typified by the artwork of the debut album of The Velvet Underground, which features a banana on the front cover, yet on the original LP version, the design allowed the listener to 'peel' this banana to find a pink, phallic structure on the inside.
# Gallery
- Traditional offerings of bananas and coconut at a Nat spirit shrine in Myanmar
Traditional offerings of bananas and coconut at a Nat spirit shrine in Myanmar
- Certain banana cultivars turn red or purplish instead of yellow as they ripen.
Certain banana cultivars turn red or purplish instead of yellow as they ripen.
- Bananas are often sold in bundles, as shown above.
Bananas are often sold in bundles, as shown above. | Banana
Template:Sprotected2
Banana is the common name for a fruit and also the herbaceous plants of the genus Musa which produce the commonly eaten fruit. They are native to the tropical region of Southeast Asia and Australia. Today, they are cultivated throughout the tropics. [1]
Banana plants are of the family Musaceae. They are cultivated primarily for their fruit, and to a lesser extent for the production of fibre and as ornamental plants. As the bananas are mainly tall, upright, and fairly sturdy, they are often mistaken for trees, when the truth is the main or upright stem is called a pseudostem, literally meaning "fake stem", which for some species can obtain a height of up to 2–8 m, with leaves of up to 3.5 m in length. Each pseudostem can produce a bunch of yellow, green, or even red bananas before dying and being replaced by another pseudostem.
The banana fruit grow in hanging clusters, with up to 20 fruit to a tier (called a hand), and 3-20 tiers to a bunch. The total of the hanging clusters is known as a bunch, or commercially as a "banana stem", and can weigh from 30–50 kg. The fruit averages 125 g, of which approximately 75% is water and 25% dry matter content. Each individual fruit (known as a banana or 'finger') has a protective outer layer (a peel or skin) with a fleshy edible inner portion. Typically, the fruit has numerous strings (called 'phloem bundles') which run between the skin and the edible portion of the banana, and which are commonly removed individually after the skin is removed. Bananas are a valuable source of vitamin B6, vitamin C, and potassium.
Bananas are grown in at least 107 countries.[1] In popular culture and commerce, "banana" usually refers to soft, sweet "dessert" bananas that are usually eaten raw. The bananas from a group of cultivars with firmer, starchier fruit are called plantains, and are generally used in cooking rather than eaten raw. Bananas may also be dried and eaten as a snack food. Dried bananas are also ground into banana flour.
Although the wild species have fruits with numerous large, hard seeds, virtually all culinary bananas have seedless fruits. Bananas are classified either as dessert bananas (meaning they are yellow and fully ripe when eaten) or as green cooking bananas. Almost all export bananas are of the dessert types; however, only about 10-15% of all production is for export, with the United States and European Union being the dominant buyers.
# Plant
Template:Sect-stub
The banana plant is a pseudostem that grows to 6 to 7.6 metres (20-25 feet) tall, growing from a corm. Leaves are spirally arranged and may grow 2.7 metres (9 feet) long and 60 cm (2 feet) wide.[2] The banana plant is the largest of all herbaceous plants.[3]
# Properties
Template:Nutritionalvalue
Bananas come in a variety of sizes and colors when ripe, including yellow, purple and red. Bananas can be eaten raw though some varieties are generally cooked first. Depending upon cultivar and ripeness, the flesh can vary in taste from starchy to sweet, and texture from firm to mushy. Unripe or green bananas and plantains are used for cooking various dishes such as banana pudding and are the staple starch of many tropical populations. Banana sap is extremely sticky and can be used as a practical adhesive. Sap can be obtained from the pseudostem, from the fruit peelings, or from the fruit flesh.
Most production for local sale is of green cooking bananas and plantains, as ripe dessert bananas are easily damaged while being transported to market. Even when only transported within their country of origin, ripe bananas suffer a high rate of damage and loss.
The commercial dessert cultivars most commonly eaten in temperate countries (species Musa acuminata or the hybrid Musa × paradisiaca, a cultigen) are imported in large quantities from the tropics. They are popular in part because, being a non-seasonal crop, they are available fresh year-round. In global commerce, by far the most important of these banana cultivars is 'Cavendish', which accounts for the vast bulk of bananas exported from the tropics. The Cavendish gained popularity in the 1950s after the previously mass produced cultivar, Gros Michel, became commercially unviable due to Panama disease, a fungus which attacks the roots of the banana plant.
The most important properties making 'Cavendish' the main export banana are related to transport and shelf life rather than taste; major commercial cultivars rarely have a superior flavour compared to the less widespread cultivars. Export bananas are picked green, and then usually ripened in ripening rooms when they arrive in their country of destination. These are special rooms made air-tight and filled with ethylene gas to induce ripening. Bananas can be ordered by the retailer "ungassed", however, and may show up at the supermarket still fully green. While these bananas will ripen more slowly, the flavour will be notably richer, and the banana peel can be allowed to reach a yellow/brown speckled phase, and yet retain a firm flesh inside. Thus, shelf life is somewhat extended. The flavour and texture of bananas are affected by the temperature at which they ripen. Bananas are refrigerated to between 13.5 and 15 °C (57 and 59 °F) during transportation. At lower temperatures, the ripening of bananas permanently stalls, and the bananas will eventually turn grey.
It should be noted that Musa × paradisiaca is also the generic name for the common plantain, a coarser and starchier variant not to be confused with Musa acuminata or the Cavendish variety. Plantains have all but replaced the Cavendish in markets dominated by supply-side logistics.
In addition to the fruit, the flower of the banana plant (also known as banana blossom or banana heart) is used in Southeast Asian, Bengali and Kerala (India) cuisine, either served raw with dips or cooked in soups and curries. The tender core of the banana plant's trunk is also used, notably in the Burmese dish mohinga, Bengali and Kerala cooking. Bananas fried with batter is a popular dessert in Malaysia, Singapore and Indonesia. Banana fritters can be served with ice-cream as well. Bananas are also eaten deep fried, baked in their skin in a split bamboo, or steamed in glutinous rice wrapped in a banana leaf in Myanmar where bunches of green bananas surrounding a green coconut in a tray is an important part of traditional offerings to the Buddha and the Nats. The juice extract prepared from the tender core is used to treat kidney stones.
The leaves of the banana are large, flexible, and waterproof; they are used in many ways, including as umbrellas and to wrap food for cooking, carrying and packing cooked foods, and they are used to build houses in third world countries.. In south India, food is traditionally served on banana leaves in homes and some restaurants also follow the practice. Some farmers prefer to grow banana plants only for their leaves. Chinese zongzi (bamboo leaves are more commonly used where available) and Central American tamales are sometimes steamed in banana leaves, and the Hawaiian imu is often lined with them. Puerto Rican "pasteles" are boiled wrapped and tied inside the leaf.
Banana chips are a snack (and a healthy alternative to potato chips) produced from dehydrated or fried banana or, preferably, plantain slices, which have a dark brown colour and an intense banana taste. Bananas have also been used in the making of jam. Unlike other fruits, it is difficult to extract juice from bananas because when compressed a banana simply turns to pulp.
Seeded bananas (Musa balbisiana), considered to be one of the forerunners of the common domesticated banana, are sold in markets in Indonesia.
It is reported that in Orissa, India, juice is extracted from the corm and used as a home remedy for the treatment of jaundice. In other places honey is mixed with mashed banana fruit and used for the same purpose.
# Trade
Bananas and plantains constitute a major staple food crop for millions of people in developing countries. In most tropical countries, green (unripe) bananas used for cooking represent the main cultivars. Cooking bananas are very similar to potatoes in how they are used. Both can be fried, boiled, baked or chipped and have similar taste and texture when served. One green cooking banana has about the same calorie content as one potato.[citation needed]
In 2003, India led the world in banana production, representing approximately 23% of the worldwide crop, most of which was for domestic consumption. The four leading banana exporting countries were Ecuador, Costa Rica, Philippines, and Colombia, which together accounted for about two-thirds of the world's exports, each exporting more than 1 million tons. Ecuador alone provided more than 30% of global banana exports, according to FAO statistics.
The vast majority of producers are small-scale farmers growing the crop either for home consumption or for local markets. Because bananas and plantains will produce fruit year-round, they provide an extremely valuable source of food during the hunger season (that period of time when all the food from the previous harvest has been consumed, and the next harvest is still some time away). It is for these reasons that bananas and plantains are of major importance to food security.
Bananas are among the most widely consumed foods in the world. Most banana farmers receive a low unit price for their produce as supermarkets buy enormous quantities and receive a discount for that business. Competition amongst supermarkets has led to reduced margins in recent years which in turn has led to lower prices for growers. Chiquita, Del Monte, Dole and Fyffes grow their own bananas in Ecuador, Colombia, Costa Rica, Guatemala and Honduras. Banana plantations are capital intensive and demand high expertise, so the majority of independent growers are large and wealthy landowners of these countries. This has led to bananas being available as a "fair trade" item in some countries.
The banana has an extensive trade history beginning with the founding of the United Fruit Company (now Chiquita) at the end of the nineteenth century. For much of the 20th century, bananas and coffee dominated the export economies of Central America. In the 1930s, bananas and coffee made up as much as 75% of the region's exports. As late as 1960, the two crops accounted for 67% of the exports from the region. Though the two were grown in similar regions, they tended not to be distributed together. The United Fruit Company based its business almost entirely on the banana trade, as the coffee trade proved too difficult for it to control. The term "banana republic" has been broadly applied to most countries in Central America, but from a strict economic perspective only Costa Rica, Honduras, and Panama were actual "banana republics", countries with economies dominated by the banana trade.
The countries of the European Union have traditionally imported many of their bananas from the former European island colonies of the Caribbean, paying guaranteed prices above global market rates. As of 2005, these arrangements were in the process of being withdrawn under pressure from other major trading powers, principally the United States. The withdrawal of these indirect subsidies to Caribbean producers is expected to favour the banana producers of Central America, in which American companies have an economic interest.
The United States has minimal banana production. 14,000 tons of bananas were grown in Hawaii in 2001.[4]
# History
The domestication of bananas took place in southeastern Asia. Many species of wild bananas still occur in New Guinea, Malaysia, Indonesia and the Philippines. Recent archaeological and palaeoenvironmental evidence at Kuk Swamp in the Western Highlands Province of Papua New Guinea suggests that banana cultivation there goes back to at least 5000 BCE, and possibly to 8000 BCE. [5] This would make the New Guinean highlands the place where bananas were first domesticated. It is likely that other species of wild bananas were later also domesticated elsewhere in southeastern Asia such as the asian fighting banana known for its intense fruit taste and bright orange peels.
The banana may have been present in isolated locations of the Middle East on the eve of the rise of Islam. There is some textual evidence that the prophet Muhammad was familiar with it. The spread of Islam, was followed by the far reaching diffusion of bananas. There are numerous references to it in Islamic texts (such as poems and hadiths) beginning in the ninth century. By the tenth century the banana appears in texts from Palestine and Egypt, from it diffused into north Africa and Muslim Spain. In fact, during the medieval ages, bananas from Granada were considered amongst the best in the Arab world.[6]
Some recent discoveries of banana phytoliths in Cameroon dating to the first millennium BCE [7] have triggered an as yet unresolved debate about the antiquity of banana cultivation in Africa. There is linguistic evidence that bananas were already known in Madagascar around that time. [8] The earliest evidence of banana cultivation in Africa before these recent discoveries dates to no earlier than late 6th century AD. [9] Muslim Arabs likely brought bananas from the east coast of Africa west to the Atlantic coast and further south to Madagascar.[6]
The banana is mentioned for the first time in written history in Buddhist texts in 600 BCE.[citation needed] Alexander the Great discovered the taste of the banana in the valleys of India in 327 BCE.[citation needed] The existence of an organized banana plantation could be found in China in 200 CE.[citation needed] In 650, Islamic conquerors brought the banana to Palestine. The word banana is of West African origin, and passed into English via Spanish or Portuguese.[10]
In 15th and 16th century, Portuguese colonists started banana plantations in the Atlantic Islands, Brazil, and western Africa.[citation needed] As late as the Victorian Era, bananas were not widely known in Europe, although they were available via merchant trade.[citation needed] Jules Verne references bananas with detailed descriptions so as not to confuse readers in his book Around the World in Eighty Days (1872).
# Cultivation
While the original bananas contained rather large seeds, triploid (and thus seedless) cultivars have been selected for human consumption. These are propagated asexually from offshoots of the plant. The plant is allowed to produce 2 shoots at a time; a larger one for fruiting immediately and a smaller "sucker" or "follower" that will produce fruit in 6–8 months time. The life of a banana plantation is 25 years or longer, during which time the individual stools or planting sites may move slightly from their original positions as lateral rhizome formation dictates.
Cultivated bananas are parthenocarpic, which makes them sterile and unable to produce viable seeds. Lacking seeds, another form of propagation is required. This involves removing and transplanting part of the underground stem (called a corm). Usually this is done by carefully removing a sucker (a vertical shoot that develops from the base of the banana pseudostem) with some roots intact. However, small sympodial corms, representing not yet elongated suckers, are easier to transplant and can be left out of the ground for up to 2 weeks; they require minimal care and can be boxed together for shipment.
In some countries, bananas are commercially propagated by means of tissue culture. This method is preferred since it ensures disease-free planting material. When using vegetative parts such as suckers for propagation, there is a risk of transmitting diseases (especially the devastating Panama disease).
# Pests, diseases and natural disasters
While in no danger of outright extinction, the most common edible banana cultivar 'Cavendish' (extremely popular in Europe and the Americas) could become unviable for large-scale cultivation in the next 10-20 years. Its predecessor 'Gros Michel', discovered in the 1820s, has already suffered this fate. Like almost all bananas, it lacks genetic diversity, which makes it vulnerable to diseases, which threaten both commercial cultivation and the small-scale subsistence farming.[11][12] Major diseases include:
- Panama Disease (Race 1) – fusarium wilt (a soil fungus). The fungus enters the plants through the roots and moves up with water into the trunk and leaves, producing gels and gums. These plug and cut off the flow of water and nutrients, causing the plant to wilt. Prior to 1960 almost all commercial banana production centered on the cultivar 'Gros Michel', which was highly susceptible to fusarium wilt. The cultivar 'Cavendish' was chosen as a replacement for 'Gros Michel' because out of the resistant cultivars it was viewed as producing the highest quality fruit. However, more care is required for shipping the 'Cavendish' banana, and its quality compared to 'Gros Michel' is debated.
- Tropical Race 4 - a reinvigorated strain of Panama Disease first discovered in 1993. This is a virulent form of fusarium wilt that has wiped out 'Cavendish' in several southeast Asian countries. It has yet to reach the Americas; however, soil fungi can easily be carried on boots, clothing, or tools. This is how Tropical Race 4 moves from one plantation to another and is its most likely route into Latin America. The Cavendish cultivar is highly susceptible to TR4, and over time, Cavendish is almost certain to be eliminated from commercial production by this disease. Unfortunately the only known defense to TR4 is genetic resistance.
- Black Sigatoka - a fungal leaf spot disease first observed in Fiji in 1963 or 1964. Black Sigatoka (also known as Black Leaf Streak) has spread to banana plantations throughout the tropics due to infected banana leaves being used as packing material. It affects all of the main cultivars of bananas and plantains, impeding photosynthesis by turning parts of their leaves black, and eventually killing the entire leaf. Being starved for energy, fruit production falls by 50% or more, and the bananas that do grow suffer premature ripening, making them unsuitable for export. The fungus has shown ever increasing resistance to fungicidal treatment, with the current expense for treating 1 hectare exceeding US$1000 per year. In addition to the financial expense there is the question of how long such intensive spraying can be justified environmentally. Several resistant cultivars of banana have been developed, but none has yet received wide scale commercial acceptance due to taste and texture issues.
- Banana Bunchy Top Virus (BBTV) - this virus is spread from plant to plant by aphids. It causes stunting of the leaves resulting in a "bunched" appearance. Generally, a banana plant infected with the virus will not set fruit, although mild strains exist in many areas which do allow for some fruit production. These mild strains are often mistaken for malnourishment, or a disease other than BBTV. There is no cure for BBTV, however its effect can be minimised by planting only tissue cultured plants (In-vitro propagation), controlling the aphids, and immediately removing and destroying any plant from the field that shows signs of the disease.
Even though it is no longer viable for large scale cultivation, 'Gros Michel' is not extinct and is still grown in areas where Panama Disease is not found. Likewise, 'Cavendish' is in no danger of extinction, but it may leave the shelves of the supermarkets for good if diseases make it impossible to supply the global market. It is unclear if any existing cultivar can replace 'Cavendish' on a scale needed to fill current demand, so various hybridisation and genetic engineering programs are working on creating a disease-resistant, mass-market banana.
Australia is relatively free of plant diseases and therefore prohibits imports. When Cyclone Larry wiped out Australia's domestic banana crop in 2006, bananas became relatively expensive, due to both low supply domestically and the existence of laws prohibiting banana imports.
## East Africa
Most bananas grown worldwide are used for local consumption. In the tropics, bananas, especially cooking bananas, represent a major source of food, as well as a major source of income for smallholder farmers. It is in the East African highlands that bananas reach their greatest importance as a staple food crop. In countries such as Uganda, Burundi and Rwanda per capita consumption has been estimated at 450 kg per year, the highest in the world. Ugandans use the same word "matooke" to describe both banana and food.
In the past, the banana was a highly sustainable crop with a long plantation life and stable yields year round. However with the arrival of the Black Sigatoka fungus, banana production in eastern Africa has fallen by over 40%. For example, during the 1970s, Uganda produced 15 to 20 tonnes of bananas per hectare. Today, production has fallen to only 6 tonnes per hectare.
The situation has started to improve as new disease resistant cultivars have been developed by IITA and NARO such as the FHIA-17 (known in Uganda as the Kabana 3). These new cultivars taste different from the traditionally grown banana which has slowed their acceptance by local farmers. However, by adding mulch and animal manure to the soil around the base of the banana plant, these new cultivars have substantially increased yields in the areas where they have been tried.
The International Institute of Tropical Agriculture and NARO, funded by the Rockefeller Foundation and CGIAR have started trials for genetically modified banana plants that are resistant to both Black Sigatoka and banana weevils. It is developing cultivars specifically for smallholder or subsistence farmers.
# Allergic reactions
There are two forms of banana allergy. One is oral allergy syndrome which causes itching and swelling in the mouth or throat within one hour after ingestion and is related to birch tree and other pollen allergies. The other is related to latex allergies and causes urticaria and potentially serious upper gastrointestinal symptoms.[13]
# Fibre
## Textiles
The banana plant has long been a source of fibre for high quality textiles. In Japan, the cultivation of banana for clothing and household use dates back to at least the 13th century. In the Japanese system, leaves and shoots are cut from the plant periodically to ensure softness. The harvested shoots must first be boiled in lye to prepare the fibres for the making of the yarn. These banana shoots produce fibres of varying degrees of softness, yielding yarns and textiles with differing qualities for specific uses. For example, the outermost fibres of the shoots are the coarsest, and are suitable for tablecloths, whereas the softest innermost fibres are desirable for kimono and kamishimo. This traditional Japanese banana cloth making process requires many steps, all performed by hand.[14]
In another system employed in Nepal, the trunk of the banana plant is harvested instead, small pieces of which are subjected to a softening process, mechanical extraction of the fibres, bleaching, and drying. After that, the fibres are sent to the Kathmandu valley for the making of high end rugs with a textural quality similar to silk. These banana fibre rugs are woven by the traditional Nepalese hand-knotted methods, and are sold RugMark certified.
## Paper
Banana fibre is also used in the production of banana paper. Banana paper is used in two different senses: to refer to a paper made from the bark of the banana plant, mainly used for artistic purposes, or paper made from banana fiber, obtained from an industrialized process, from the stem and the non utilizable fruits. This paper can be either hand-made or made by industrialized machine.
# Storage and transport
In the current world marketing system, bananas are grown in the tropics where hurricanes are not common. The fruit therefore has to be transported over long distances and storage is necessary. To gain maximum life bunches are harvested before the fruit is fully mature. The fruit is carefully handled, transported quickly to the seaboard, cooled and shipped under sophisticated refrigeration. The basis of this procedure is to prevent the bananas producing ethylene which is the natural ripening agent of the fruit. This sophisticated technology allows storage and transport for 3-4 weeks at 13 degrees Celsius. On arrival at the destination the bananas are held at about 17 degrees Celsius and treated with a low concentration of ethylene. After a few days the fruit has begun to ripen and it is distributed for retail sale. It is important to note that unripe bananas can not be held in the home refrigerator as they suffer from the cold. After ripening some bananas can be held for a few days in the home refrigerator.
Australian researchers have clearly shown that the use of refrigeration is no longer essential to extend the life of bananas after harvest.[15][16][17]
The above references report that the presence of carbon dioxide (which is produced by the fruit) extends the life and the addition of an ethylene absorbent further extends the life even at high temperatures. This simple technology involves packing the fruit in a polyethylene bag and including an ethylene absorbent, potassium permanganate, on an inert carrier. The bag is then sealed with a band or string. This low cost treatment more than doubles the life at a range of temperatures and can give a life of up to 3-4 weeks without the need of refrigeration. The method is suitable for bunches, hands and even fingers.
The technology has been successfully tested over long distances and has been confirmed by researchers in a number of countries. The longest commercial trial was from North Queensland to New Zealand by unrefrigerated rail and ship over 18 days. Importers thought that the treated bananas were harvested on the day of arrival!
Although the technology has been extensively published in recognized scientific journals and has considerable cost savings (including energy savings) it has not been widely adopted. This report is to encourage banana growers in even poor countries to try out the technology themselves. It is suggested that a freshly harvested bunch be taken and a few hands be selected and each cut in two. Half of each hand should be sealed in a polyethylene bag the other half hands should be left untreated. Even without the ethylene absorbent the beneficial effect should be obvious in a few days. Growers can then decide whether to try the full technology.
# Usage in culture
## Peels
The depiction of a person slipping on a banana peel has been a staple of physical comedy for generations. A 1906 comedy record produced by Edison Records features a popular character of the time, "Cal Stewart", claiming to describe his own such incident, saying:
I don't think much of a man what throws a bananer peelin' on the sidewalk, and I don't think much of a bananer what throws a man on the sidewalk, neither. ... my foot hit that bananer peelin' and I went up in the air, and come down ker-plunk, and fer about a minnit I seen all the stars what 'stronomy tells about, and some that hain't been discovered yit. Wall jist as I was pickin' myself up, a little boy come runnin' cross the street and he said, "Oh mister, won't you please do that agin? My mother didn't see you do it."
## Stereotypes
- Because of the stereotypical image of monkeys and apes eating bananas, they have been used for racist insults, such as throwing bananas at sports players of African descent.[18]
## Arts
- The poet Bashō is named after the Japanese word for a banana plant. The "bashō" planted in his garden by a grateful student became a source of inspiration to his poetry, as well as a symbol of his life and home.[19]
- The song Yes, We Have No Bananas was written by Frank Silver and Irving Cohn and originally released in 1923. Since then the song has been re-recorded several times and has been particularly popular during banana shortages.
## Symbols
Bananas are also humorously used as a phallic symbol due to similarities in size and shape. This is typified by the artwork of the debut album of The Velvet Underground, which features a banana on the front cover, yet on the original LP version, the design allowed the listener to 'peel' this banana to find a pink, phallic structure on the inside.
# Gallery
- Traditional offerings of bananas and coconut at a Nat spirit shrine in Myanmar
Traditional offerings of bananas and coconut at a Nat spirit shrine in Myanmar
- Certain banana cultivars turn red or purplish instead of yellow as they ripen.
Certain banana cultivars turn red or purplish instead of yellow as they ripen.
- Bananas are often sold in bundles, as shown above.
Bananas are often sold in bundles, as shown above. | https://www.wikidoc.org/index.php/Banana | |
da71b9635965d1a32e70f074f1fec703c6c7d324 | wikidoc | Baryte | Baryte
Baryte (BaSO4) is a mineral consisting of barium sulfate. It is generally white or colorless, and is the main source of barium. Barite is the unofficial American spelling. The mineral is also called heavy spar or tiff. The radiating form, sometimes referred to as Bologna Stone, attained some notoriety among alchemists for the phosphorescent specimens found in the 1600s near Bologna by Vincenzo Cascariolo. Its Mohs hardness is 3, the refractive index is 1.63 and it has a specific gravity of 4.3-5. Its crystal structure is orthorhombic.
Baryte commonly occurs in lead-zinc veins in limestones, in hot spring deposits, and with hematite ore. It is often associated with the minerals anglesite and celestine.
The name baryte is derived from the Greek word βαρύς (heavy). In commerce, the mineral is sometimes referred to as "barytes." When the International Mineralogical Association formed in 1959 the American spelling "barite" was chosen as the official over the older "baryte". This decision was reversed in 1978. The term "primary baryte" refers to the first marketable product, which includes crude baryte (run of mine) and the products of simple beneficiation methods, such as washing, jigging, heavy media separation, tabling, flotation, and magnetic separation. Most crude baryte requires some upgrading to minimum purity or density. Baryte that is used as an aggregate in a "heavy" cement is crushed and screened to a uniform size. Most baryte is ground to a small, uniform size before it is used as a filler or extender, an addition to industrial products, or a weighting agent in petroleum well drilling mud.
Some 77% worldwide is used as a weighting agent for drilling fluids in oil and gas exploration. Other uses are in added-value applications which include the car, electronics, TV screen, rubber, and glass ceramics and paint industry, radiation shielding and medical applications (barium meals). Baryte is supplied in a variety of forms and the price depends on the amount of processing; filler applications commanding higher prices following intense physical processing by grinding and micronising, and there are further premiums for whiteness and brightness and colour.
Baryte is used in the manufacture of paints and paper. Although baryte contains a "heavy" metal (barium), it is not considered to be a toxic chemical by most governments because of its extreme insolubility. | Baryte
Baryte (BaSO4) is a mineral consisting of barium sulfate. It is generally white or colorless, and is the main source of barium. Barite is the unofficial American spelling. The mineral is also called heavy spar or tiff. The radiating form, sometimes referred to as Bologna Stone, attained some notoriety among alchemists for the phosphorescent specimens found in the 1600s near Bologna by Vincenzo Cascariolo. Its Mohs hardness is 3, the refractive index is 1.63 and it has a specific gravity of 4.3-5. Its crystal structure is orthorhombic.
Baryte commonly occurs in lead-zinc veins in limestones, in hot spring deposits, and with hematite ore. It is often associated with the minerals anglesite and celestine.
The name baryte is derived from the Greek word βαρύς (heavy). In commerce, the mineral is sometimes referred to as "barytes." When the International Mineralogical Association formed in 1959 the American spelling "barite" was chosen as the official over the older "baryte". This decision was reversed in 1978[1]. The term "primary baryte" refers to the first marketable product, which includes crude baryte (run of mine) and the products of simple beneficiation methods, such as washing, jigging, heavy media separation, tabling, flotation, and magnetic separation. Most crude baryte requires some upgrading to minimum purity or density. Baryte that is used as an aggregate in a "heavy" cement is crushed and screened to a uniform size. Most baryte is ground to a small, uniform size before it is used as a filler or extender, an addition to industrial products, or a weighting agent in petroleum well drilling mud.
Some 77% worldwide is used as a weighting agent for drilling fluids in oil and gas exploration. Other uses are in added-value applications which include the car, electronics, TV screen, rubber, and glass ceramics and paint industry, radiation shielding and medical applications (barium meals). Baryte is supplied in a variety of forms and the price depends on the amount of processing; filler applications commanding higher prices following intense physical processing by grinding and micronising, and there are further premiums for whiteness and brightness and colour.
Baryte is used in the manufacture of paints and paper. Although baryte contains a "heavy" metal (barium), it is not considered to be a toxic chemical by most governments because of its extreme insolubility. | https://www.wikidoc.org/index.php/Barite | |
64896a1554b705e8bf3a07c53a95eef76003468e | wikidoc | Bedbug | Bedbug
Bedbugs (or bed bugs) are small nocturnal insects of the family Cimicidae that live by hematophagy, that is by feeding on the blood of humans and other warm-blooded hosts.
# Biology
The common bedbug (Cimex lectularius) is the best adapted to human environments. It is found in temperate climates throughout the world and has been known since ancient times.
Other species include Cimex hemipterus, found in tropical regions (including Florida), which also infests poultry and bats, and Leptocimex boueti, found in the tropics of West Africa and South America, which infests bats and humans. Cimex pilosellus and C. pipistrella primarily infest bats, while Haematosiphon inodora, a species of North America, primarily infests poultry.
Oeciacus, while not strictly a bedbug, is a closely related genus primarily affecting birds.
Adult bedbugs are reddish brown, flattened, oval, and wingless, with microscopic hairs that give them a banded appearance. A common misconception is that they are not visible to the naked eye. Adults grow to 4 to 5 mm (one-eighth to three-sixteenths of an inch) in length and do not move quickly enough to escape the notice of an attentive observer. Newly hatched nymphs are translucent, lighter in color and continue to become browner and moult as they reach maturity. When it comes to size, they are often compared to lentils or appleseeds.
A recent paper by Professor Brian J. Ford and Dr Debbie Stokes gives views of a bedbug under various microscopes.
## Feeding habits
Bedbugs are generally active only at dawn, with a peak attack period about an hour before dawn, though given the opportunity, they may attempt to feed at other times of day. Attracted by warmth and the presence of carbon dioxide, the bug pierces the skin of its host with two hollow tubes. With one tube it injects its saliva, which contains anticoagulants and anesthetics, while with the other it withdraws the blood of its host. After feeding for about five minutes, the bug returns to its hiding place. The bites cannot usually be felt until some minutes or hours later, as a dermatological reaction to the injected agents. Although bedbugs can live for a year or as much as 18 months without feeding, they typically seek blood every five to ten days. While bedbugs which go dormant for lack of food often live longer than a year, well-fed specimens typically live four to six months. Low infestations may be difficult to detect, and it is not unusual for the victim not to even realize they have bedbugs early on. Patterns of bites in a row or a cluster are typical as they may be disturbed while feeding. Bites may be found in a variety of places on the body.
Bedbugs may be erroneously associated with filth in the mistaken notion that this attracts them. However, severe infestations are often associated with poor housekeeping and clutter. Bedbugs are attracted by exhaled carbon dioxide and body heat, not by dirt, and they feed on blood, not waste. In short, the cleanliness of their environments has effect on the control of bedbugs, but unlike cockroaches, does not have a direct effect on bedbugs as they feed on their hosts and not on waste. Good housekeeping in association with proper preparation and mechanical removal by vacuuming will certainly assist in control. Bed bugs are still very common and can be found in almost every household
While bedbugs have been known to harbor pathogens in their bodies, including plague and hepatitis B, they have not been linked to the transmission of any disease and are not regarded as a medical threat. Some individuals, however, can get skin infections and scars from scratching bites. While bedbugs are not regarded as a vector of transmissible diseases, they may be a significant source of alarm or distress.
Female bedbugs can lay up to five eggs in a day and 500 during a lifetime. The eggs are visible to the naked eye measuring 1 mm in length (approx. 2 grains of salt) and are a milky-white tone in color. The eggs hatch in one to two weeks. The hatchlings begin feeding immediately. They pass through five molting stages before they reach maturity. They must feed once during each of these stages. At room temperature, it takes about 5 weeks for a bedbug to pass from hatching, through the stages, to maturity. They become reproductively active only at maturity.
# Reproduction
All bedbugs mate via a process termed traumatic insemination. Instead of inserting their genitalia into the female's reproductive tract as is typical in copulation, males instead pierce females with hypodermic genitalia and ejaculate into the body cavity. This form of mating is thought to have evolved as a way for males to overcome female mating resistance. Traumatic insemination imposes a cost on females in terms of physical damage and increased risk of infection. To reduce these costs females have evolved internal and external "paragenital" structures collectively known as the “spermalege”. Within the True Bugs (Heteroptera) traumatic insemination occurs in the Prostemmatinae (Nabidae) and the Cimicoidea (Anthocoridae, Plokiophilidae, Lyctocoridae, Polyctenidae and Cimicidae), and has recently been discovered in the plant bug genus Coridromius (Miridae).
Remarkably, in the genus Afrocimex both males and females possess functional external paragenitalia, and males have been found with copulatory scars and the ejaculate of other males in their haemolymph. There is a widespread misbelief that males inseminated by other males will in turn pass the sperm of both themselves and their assailants onto females with whom they mate. While it is true that males are known to mate with and inject sperm into other males, there is however no evidence to suggest that this sperm ever fertilizes females inseminated by the victims of such acts.
# Infestations
There are several means by which dwellings can become infested with bedbugs. People can often acquire bedbugs at hotels, motels, and bed-and-breakfasts, as a result of increased domestic and international tourism, and bring them back to their homes in their luggage. They also can pick them up by inadvertently bringing infested furniture or used clothing to their household. If someone is in a place that is severely infested, bedbugs may actually crawl onto and be carried by people's clothing, although this is atypical behavior — except in the case of severe infestations, bedbugs are not usually carried from place to place by people on clothing they are currently wearing. Finally, bedbugs may travel between units in multi-unit dwellings (such as condominiums and apartment buildings), after being originally brought into the building by one of the above routes. This spread between units is dependent in part on the degree of infestation, on the material used to partition units (concrete is a more effective barrier to the spread of the infestation), and whether or not infested items are dragged through common areas while being disposed of, resulting in the shedding of bedbugs and bedbug eggs while being dragged. In some exceptional cases, the detection of bedbug hiding places can be aided by the use of dogs that have been trained to signal finding the insects by their scent much as dogs are trained to find drugs or explosives. A trained team (dog and handler) can detect and pin point a bedbug infestation within minutes. This is a fairly costly service that is not used in the majority of cases, but can be very useful in difficult cases.
## Common location of infestations
Bedbugs are very flat, which allows them to hide in tiny crevices. A crack wide enough to fit the edge of a credit card can harbor bedbugs (even in the ceiling). In the daytime, they tend to stay out of the light, preferring to remain hidden in such places as mattress seams, mattress interiors, bed frames, nearby furniture, carpeting, baseboards, inner walls, tiny wood holes, or bedroom clutter. Bedbugs can settle in the open weave of linen; this will often appear as a gray spindle a centimeter long and a thread wide, with a dark speck in the middle. Bedbugs can be found on their own, but more often congregate in groups. They are not social insects, however, and do not build or stay in nests. These groups of bedbugs are very often found in beds, usually either in the seams of a mattress (usually the seams closest to the sleeper such as those on the edging of a mattress or box spring), in the boxspring, or within the structure of the bed itself. They can also be found in a wide variety of locations in a home, such as behind baseboards, behind a picture frame, within books (near the bed), in telephones, or radios near the bed, and within the folds of curtains. When not feeding, bedbugs are likely to be found hiding in shaded areas such as the seam along which the floor and wall meet, or under the edge of the carpet. One may find a group of bugs in the seams, usually surrounded by black fecal matter and sometimes a reddish brown stain.
Bedbugs are capable of travelling as far as 100 feet to feed, but usually remain close to the host in bedrooms or on sofas where people may sleep. They feed every five to 10 days. The manner in which infestations spread throughout a home or within an apartment building is not entirely understood and differs from case to case.
It is important to inspect all adjacent rooms for infestation, as bedbugs travel easily and quickly along pipes and boards. In treatment, it is important to consider the insides of walls as potential places for bedbug infestation.
The numerical size of a bedbug infestation is to some degree variable, as it is a function of the elapsed time from the initial infestation. With regards to the elapsed time from the initial infestation, even a single female bedbug brought into a home has a potential for reproduction, with its resulting offspring then breeding, resulting in a geometric progression of population expansion if control is not undertaken. Sometimes people are not aware of the insects, and do not notice the bites. The visible bedbug infestation does not represent the infestation as a whole, as there may be infestations elsewhere in a home, however, the insects do have a tendency to stay close to their hosts (hence the name "bed" bugs).
## Detection of infestations
Confirmation of the presence of bedbugs may be through identification of the insects collected. Some individuals use the internet for insect identification, or they may take the sample to a university extension laboratory, or to a professional pest control firm. The insects may be difficult to find, but infestations are typically concentrated on or about bedding or upholstered furniture, and clusters of the insects, their eggs, and immature stages may be found on seams of mattresses, box springs and in folds of upholstered furniture.
The pattern of bites as noted earlier is another means of confirming that the infestation is indeed that of bedbugs. Though bedbug bites can occur singly, they often follow a distinctive pattern of a linear group of three bites, sometimes macabrely referred to as "breakfast, lunch and dinner". These patterns of bites are caused when a bedbug is disturbed in feeding by a person moving, and then the bedbug resumes feeding. Bedbug bites also often occur in lines marking the paths of blood vessels running close to the surface of the skin. The effect of these bites on humans varies from person to person, but often cause welts and swelling that are more itchy and longer-lasting than mosquito bites. Some people, however, have little or no reaction to bedbug bites. Those whose bodies do not initially react may subsequently develop symptoms, however, due to an allergic reaction caused by the development of antibodies. Bedbugs never crawl under one's skin and markings implying this may be signs of other skin infections or a severe allergic reaction to bedbug bites.
A technique for "catching" (detecting) bedbugs is to have a light source accessible from bed and to turn it on at about an hour before dawn, which is usually the time when bedbugs are most active. A flashlight is recommended instead of room lights, as the act of getting out of bed will cause any bedbugs present to scatter. Bedbugs can also sometimes be viewed during the day. The flashlight method is best; if you awaken during the night, leave your lights off but use your flashlight to inspect your mattress. Bedbugs are fairly fast in their movements, however, this can vary depending on how recently they have consumed a blood meal, and if treatment has been performed. Some have described their speed of travel as being about that of ants. Immature stages are quite small. A few seconds staring at a patterned sheet may be needed to notice them.
Some individuals have used glue traps placed in strategic areas around their home (sometimes used in conjunction with heating pads, or balloons filled with exhaled breath, thus offering the carbon dioxide that bedbugs look for) in order to attract and thus detect bedbug infestations. This method has varied reports of success. It likely depends on extent of infestation, and given the choice of a heating pad and low carbon dioxide, it is not unreasonable to presume that the bedbugs will go for a person preferentially -- they have had a long time to evolve in their abilities to find hosts. There are also commercial traps like "flea" traps whose effectiveness is questionable except perhaps as a means of detection, but traps will certainly not work to control an infestation.
Perhaps the easiest method for detection is to place double-sided carpet tape in long strips near or around the bed and check the strips after a day or more. This is also useful in detecting insect presence in general.
Veterinarians may mistake bedbugs' leavings on a pet's fur as "flea dirt".
Bedbugs are known for being elusive, transient and nocturnal. For many, the only way to detect and identify with certainty an infestation is to contact a pest control professional, however, this pest was largely absent as a significant part of pest control services for decades, so the pest control industry is in process of ensuring staff are well-trained.
## Controlling Infestations
With the widespread use of DDT in the 1940s and '50s, bedbugs all but disappeared from North America in the mid-twentieth century. Infestations remained common in many other parts of the world, however, and in recent years have begun to rebound in North America. Reappearance of bedbugs in North America has presented new challenges for pest control and, without DDT and similarly banned agents, no fully effective treatment is now in use. The industry is only beginning to develop procedures and techniques.
Another reason for their increase is that pest control services more often nowadays use low toxicity gel-based pesticides for control of cockroaches, the most common pest in structures, instead of residual sprays. When residual sprays meant to kill other insects were commonly being used, they resulted in a collateral insecticidal effect on potential bedbug infestations; the gel-based insecticides primarily used nowadays do not have any effect on bedbugs, as they are incapable of feeding on these baits.
The Professional Pest Management Association, a US advocacy group for pest control operators (PCOs) conducted a "proactive bed bug public relations campaign" in 2005 and 2006, resulting in increased media coverage of bedbug stories and an increase in business for PCOs, possibly distorting the scale of the increase in bedbug infestations.
If it is necessary to live with bedbugs in the short term, it is possible to create makeshift temporary barriers around a bed. Although bedbugs cannot fly or jump, they have been observed climbing a higher surface in order to then fall to a lower one, such as climbing a wall in order to fall onto a bed. That having been said, barrier strategies nevertheless often have beneficial effects: an elevated bed, for example, can be protected by applying double-sided sticky tape (carpet tape) around each leg, or by keeping each leg on a plastic furniture block in a tray of water. Bed frames can be effectively rid of adult bedbugs and eggs by use of steam or, used with caution, by spraying rubbing alcohol on any visible bugs (although this is not a permanent treatment). Small steam cleaners are available and are very effective for this local treatment. A suspect mattress can be protected by wrapping it in a painter's disposable plastic dropcloth, neatly sealing shut all the seams with packing tape, and putting it on a protected bed after a final visual inspection. Bedding can be sanitized by a 120 °F (49 °C) laundry dryer. Once sanitized, bedding should not be allowed to drape to the floor. An effective way to quarantine a protected bed is to store sanitized sleeping clothes in the bed during the day, and bathing before entering the bed.
Vermin and pets may complicate a barrier strategy. Bedbugs prefer human hosts, but will resort to other warm-blooded hosts if humans are not available, and some species can live up to eighteen months without feeding at all. A co-infestation of mice can provide an auxiliary food source to keep bedbugs established for longer. Likewise, a house cat or human guest might easily defeat a barrier by sitting on a protected bed. Such considerations should be part of any barrier strategy. | Bedbug
Bedbugs (or bed bugs) are small nocturnal insects of the family Cimicidae that live by hematophagy, that is by feeding on the blood of humans and other warm-blooded hosts.
# Biology
The common bedbug (Cimex lectularius) is the best adapted to human environments. It is found in temperate climates throughout the world and has been known since ancient times.
Other species include Cimex hemipterus, found in tropical regions (including Florida), which also infests poultry and bats, and Leptocimex boueti, found in the tropics of West Africa and South America, which infests bats and humans. Cimex pilosellus and C. pipistrella primarily infest bats, while Haematosiphon inodora, a species of North America, primarily infests poultry.
Oeciacus, while not strictly a bedbug, is a closely related genus primarily affecting birds.
Adult bedbugs are reddish brown, flattened, oval, and wingless, with microscopic hairs that give them a banded appearance. A common misconception is that they are not visible to the naked eye. Adults grow to 4 to 5 mm (one-eighth to three-sixteenths of an inch) in length and do not move quickly enough to escape the notice of an attentive observer. Newly hatched nymphs are translucent, lighter in color and continue to become browner and moult as they reach maturity. When it comes to size, they are often compared to lentils or appleseeds.
A recent paper by Professor Brian J. Ford and Dr Debbie Stokes gives views of a bedbug under various microscopes.
## Feeding habits
Bedbugs are generally active only at dawn, with a peak attack period about an hour before dawn, though given the opportunity, they may attempt to feed at other times of day. Attracted by warmth and the presence of carbon dioxide, the bug pierces the skin of its host with two hollow tubes. With one tube it injects its saliva, which contains anticoagulants and anesthetics, while with the other it withdraws the blood of its host. After feeding for about five minutes, the bug returns to its hiding place. The bites cannot usually be felt until some minutes or hours later, as a dermatological reaction to the injected agents. Although bedbugs can live for a year or as much as 18 months without feeding, they typically seek blood every five to ten days. While bedbugs which go dormant for lack of food often live longer than a year, well-fed specimens typically live four to six months. Low infestations may be difficult to detect, and it is not unusual for the victim not to even realize they have bedbugs early on. Patterns of bites in a row or a cluster are typical as they may be disturbed while feeding. Bites may be found in a variety of places on the body.
Bedbugs may be erroneously associated with filth in the mistaken notion that this attracts them. However, severe infestations are often associated with poor housekeeping and clutter. Bedbugs are attracted by exhaled carbon dioxide and body heat, not by dirt, and they feed on blood, not waste. In short, the cleanliness of their environments has effect on the control of bedbugs, but unlike cockroaches, does not have a direct effect on bedbugs as they feed on their hosts and not on waste. Good housekeeping in association with proper preparation and mechanical removal by vacuuming will certainly assist in control. Bed bugs are still very common and can be found in almost every household
While bedbugs have been known to harbor pathogens in their bodies, including plague and hepatitis B, they have not been linked to the transmission of any disease and are not regarded as a medical threat. Some individuals, however, can get skin infections and scars from scratching bites. While bedbugs are not regarded as a vector of transmissible diseases, they may be a significant source of alarm or distress.
Female bedbugs can lay up to five eggs in a day and 500 during a lifetime. The eggs are visible to the naked eye measuring 1 mm in length (approx. 2 grains of salt) and are a milky-white tone in color. The eggs hatch in one to two weeks. The hatchlings begin feeding immediately. They pass through five molting stages before they reach maturity. They must feed once during each of these stages. At room temperature, it takes about 5 weeks for a bedbug to pass from hatching, through the stages, to maturity. They become reproductively active only at maturity.
# Reproduction
All bedbugs mate via a process termed traumatic insemination.[1][2][3] Instead of inserting their genitalia into the female's reproductive tract as is typical in copulation, males instead pierce females with hypodermic genitalia and ejaculate into the body cavity. This form of mating is thought to have evolved as a way for males to overcome female mating resistance.[4][5] Traumatic insemination imposes a cost on females in terms of physical damage and increased risk of infection.[6][7] To reduce these costs females have evolved internal and external "paragenital" structures [6][7] collectively known as the “spermalege”.[1][2][3] Within the True Bugs (Heteroptera) traumatic insemination occurs in the Prostemmatinae (Nabidae) and the Cimicoidea (Anthocoridae, Plokiophilidae, Lyctocoridae, Polyctenidae and Cimicidae), and has recently been discovered in the plant bug genus Coridromius (Miridae).[8]
Remarkably, in the genus Afrocimex both males and females possess functional external paragenitalia, and males have been found with copulatory scars and the ejaculate of other males in their haemolymph. There is a widespread misbelief that males inseminated by other males will in turn pass the sperm of both themselves and their assailants onto females with whom they mate.[9] While it is true that males are known to mate with and inject sperm into other males, there is however no evidence to suggest that this sperm ever fertilizes females inseminated by the victims of such acts.[2]
# Infestations
There are several means by which dwellings can become infested with bedbugs. People can often acquire bedbugs at hotels, motels, and bed-and-breakfasts, as a result of increased domestic and international tourism, and bring them back to their homes in their luggage. They also can pick them up by inadvertently bringing infested furniture or used clothing to their household. If someone is in a place that is severely infested, bedbugs may actually crawl onto and be carried by people's clothing, although this is atypical behavior — except in the case of severe infestations, bedbugs are not usually carried from place to place by people on clothing they are currently wearing. Finally, bedbugs may travel between units in multi-unit dwellings (such as condominiums and apartment buildings), after being originally brought into the building by one of the above routes. This spread between units is dependent in part on the degree of infestation, on the material used to partition units (concrete is a more effective barrier to the spread of the infestation), and whether or not infested items are dragged through common areas while being disposed of, resulting in the shedding of bedbugs and bedbug eggs while being dragged. In some exceptional cases, the detection of bedbug hiding places can be aided by the use of dogs that have been trained to signal finding the insects by their scent much as dogs are trained to find drugs or explosives. A trained team (dog and handler) can detect and pin point a bedbug infestation within minutes. This is a fairly costly service that is not used in the majority of cases, but can be very useful in difficult cases.
## Common location of infestations
Bedbugs are very flat, which allows them to hide in tiny crevices. A crack wide enough to fit the edge of a credit card can harbor bedbugs (even in the ceiling). In the daytime, they tend to stay out of the light, preferring to remain hidden in such places as mattress seams, mattress interiors, bed frames, nearby furniture, carpeting, baseboards, inner walls, tiny wood holes, or bedroom clutter. Bedbugs can settle in the open weave of linen; this will often appear as a gray spindle a centimeter long and a thread wide, with a dark speck in the middle. Bedbugs can be found on their own, but more often congregate in groups. They are not social insects, however, and do not build or stay in nests. These groups of bedbugs are very often found in beds, usually either in the seams of a mattress (usually the seams closest to the sleeper such as those on the edging of a mattress or box spring), in the boxspring, or within the structure of the bed itself. They can also be found in a wide variety of locations in a home, such as behind baseboards, behind a picture frame, within books (near the bed), in telephones, or radios near the bed, and within the folds of curtains. When not feeding, bedbugs are likely to be found hiding in shaded areas such as the seam along which the floor and wall meet, or under the edge of the carpet. One may find a group of bugs in the seams, usually surrounded by black fecal matter and sometimes a reddish brown stain.
Bedbugs are capable of travelling as far as 100 feet to feed, but usually remain close to the host in bedrooms or on sofas where people may sleep. They feed every five to 10 days. The manner in which infestations spread throughout a home or within an apartment building is not entirely understood and differs from case to case.
It is important to inspect all adjacent rooms for infestation, as bedbugs travel easily and quickly along pipes and boards. In treatment, it is important to consider the insides of walls as potential places for bedbug infestation.
The numerical size of a bedbug infestation is to some degree variable, as it is a function of the elapsed time from the initial infestation. With regards to the elapsed time from the initial infestation, even a single female bedbug brought into a home has a potential for reproduction, with its resulting offspring then breeding, resulting in a geometric progression of population expansion if control is not undertaken. Sometimes people are not aware of the insects, and do not notice the bites. The visible bedbug infestation does not represent the infestation as a whole, as there may be infestations elsewhere in a home, however, the insects do have a tendency to stay close to their hosts (hence the name "bed" bugs).
## Detection of infestations
Confirmation of the presence of bedbugs may be through identification of the insects collected. Some individuals use the internet for insect identification, or they may take the sample to a university extension laboratory, or to a professional pest control firm. The insects may be difficult to find, but infestations are typically concentrated on or about bedding or upholstered furniture, and clusters of the insects, their eggs, and immature stages may be found on seams of mattresses, box springs and in folds of upholstered furniture.
The pattern of bites as noted earlier is another means of confirming that the infestation is indeed that of bedbugs. Though bedbug bites can occur singly, they often follow a distinctive pattern of a linear group of three bites, sometimes macabrely referred to as "breakfast, lunch and dinner". These patterns of bites are caused when a bedbug is disturbed in feeding by a person moving, and then the bedbug resumes feeding. Bedbug bites also often occur in lines marking the paths of blood vessels running close to the surface of the skin. The effect of these bites on humans varies from person to person, but often cause welts and swelling that are more itchy and longer-lasting than mosquito bites. Some people, however, have little or no reaction to bedbug bites. Those whose bodies do not initially react may subsequently develop symptoms, however, due to an allergic reaction caused by the development of antibodies. Bedbugs never crawl under one's skin and markings implying this may be signs of other skin infections or a severe allergic reaction to bedbug bites.
A technique for "catching" (detecting) bedbugs is to have a light source accessible from bed and to turn it on at about an hour before dawn, which is usually the time when bedbugs are most active. A flashlight is recommended instead of room lights, as the act of getting out of bed will cause any bedbugs present to scatter. Bedbugs can also sometimes be viewed during the day. The flashlight method is best; if you awaken during the night, leave your lights off but use your flashlight to inspect your mattress. Bedbugs are fairly fast in their movements, however, this can vary depending on how recently they have consumed a blood meal, and if treatment has been performed. Some have described their speed of travel as being about that of ants. Immature stages are quite small. A few seconds staring at a patterned sheet may be needed to notice them.
Some individuals have used glue traps placed in strategic areas around their home (sometimes used in conjunction with heating pads, or balloons filled with exhaled breath, thus offering the carbon dioxide that bedbugs look for) in order to attract and thus detect bedbug infestations. This method has varied reports of success. It likely depends on extent of infestation, and given the choice of a heating pad and low carbon dioxide, it is not unreasonable to presume that the bedbugs will go for a person preferentially -- they have had a long time to evolve in their abilities to find hosts. There are also commercial traps like "flea" traps whose effectiveness is questionable except perhaps as a means of detection, but traps will certainly not work to control an infestation.
Perhaps the easiest method for detection is to place double-sided carpet tape in long strips near or around the bed and check the strips after a day or more. This is also useful in detecting insect presence in general.
Veterinarians may mistake bedbugs' leavings on a pet's fur as "flea dirt".
Bedbugs are known for being elusive, transient and nocturnal. For many, the only way to detect and identify with certainty an infestation is to contact a pest control professional, however, this pest was largely absent as a significant part of pest control services for decades, so the pest control industry is in process of ensuring staff are well-trained.
## Controlling Infestations
With the widespread use of DDT in the 1940s and '50s, bedbugs all but disappeared from North America in the mid-twentieth century.[2] Infestations remained common in many other parts of the world, however, and in recent years have begun to rebound in North America. Reappearance of bedbugs in North America has presented new challenges for pest control and, without DDT and similarly banned agents, no fully effective treatment is now in use.[citation needed] The industry is only beginning to develop procedures and techniques.
Another reason for their increase is that pest control services more often nowadays use low toxicity gel-based pesticides for control of cockroaches, the most common pest in structures, instead of residual sprays. When residual sprays meant to kill other insects were commonly being used, they resulted in a collateral insecticidal effect on potential bedbug infestations; the gel-based insecticides primarily used nowadays do not have any effect on bedbugs, as they are incapable of feeding on these baits.
The Professional Pest Management Association, a US advocacy group for pest control operators (PCOs) conducted a "proactive bed bug public relations campaign" in 2005 and 2006, resulting in increased media coverage of bedbug stories and an increase in business for PCOs, possibly distorting the scale of the increase in bedbug infestations.[10]
If it is necessary to live with bedbugs in the short term, it is possible to create makeshift temporary barriers around a bed. Although bedbugs cannot fly or jump, they have been observed climbing a higher surface in order to then fall to a lower one, such as climbing a wall in order to fall onto a bed. That having been said, barrier strategies nevertheless often have beneficial effects: an elevated bed, for example, can be protected by applying double-sided sticky tape (carpet tape) around each leg, or by keeping each leg on a plastic furniture block in a tray of water. Bed frames can be effectively rid of adult bedbugs and eggs by use of steam or, used with caution, by spraying rubbing alcohol on any visible bugs (although this is not a permanent treatment). Small steam cleaners are available and are very effective for this local treatment. A suspect mattress can be protected by wrapping it in a painter's disposable plastic dropcloth, neatly sealing shut all the seams with packing tape, and putting it on a protected bed after a final visual inspection. Bedding can be sanitized by a 120 °F (49 °C) laundry dryer. Once sanitized, bedding should not be allowed to drape to the floor. An effective way to quarantine a protected bed is to store sanitized sleeping clothes in the bed during the day, and bathing before entering the bed.
Vermin and pets may complicate a barrier strategy. Bedbugs prefer human hosts, but will resort to other warm-blooded hosts if humans are not available, and some species can live up to eighteen months without feeding at all. A co-infestation of mice can provide an auxiliary food source to keep bedbugs established for longer. Likewise, a house cat or human guest might easily defeat a barrier by sitting on a protected bed. Such considerations should be part of any barrier strategy. | https://www.wikidoc.org/index.php/Bedbug | |
508ddb26a307d53d26e9d440d4cba6568d56733b | wikidoc | Benzyl | Benzyl
# Overview
In organic chemistry, benzyl is the term for the radical, ion or functional group C6H5CH2, which can be obtained formally by removing a hydrogen atom from toluene's methyl group. The benzyl functional group is sometimes abbreviated "Bn", not to be confused with "Bz", which is short for the benzoyl group. For example, benzyl alcohol can be abbreviated to BnOH.
In substituent nomenclature, benzyl and phenyl are commonly confused. Benzyl can be seen as a phenyl attached to a CH2 before attaching to the parent compound.
# Benzyl protective groups
Benzyl groups are frequently used in organic synthesis as protective group for alcohols and carboxylic acids.
Two common methods for benzyl ether protection:
- reaction of alcohol with benzyl bromide and a strong base such as sodium hydride as in a Williamson ether synthesis
- reaction of alcohol with benzyl trichloroacetimidate (C6H5CH2OC(CCl3)=NH) promoted by trifluoromethanesulfonic acid
The benzyl group can be removed by hydrogenation.
One study employs a benzyl pyridinium salt as a benzyl donor for alcohols.
The solvent is trifluoromethylbenzene and magnesium oxide is an acid scavenger. The reaction type for this conversion is believed to be SN1 based on the detection of trace amounts of Friedel-Crafts reaction sideproducts with toluene as a solvent. | Benzyl
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
# Overview
In organic chemistry, benzyl is the term for the radical, ion or functional group C6H5CH2, which can be obtained formally by removing a hydrogen atom from toluene's methyl group. The benzyl functional group is sometimes abbreviated "Bn", not to be confused with "Bz", which is short for the benzoyl group. For example, benzyl alcohol can be abbreviated to BnOH.
In substituent nomenclature, benzyl and phenyl are commonly confused. Benzyl can be seen as a phenyl attached to a CH2 before attaching to the parent compound.
# Benzyl protective groups
Benzyl groups are frequently used in organic synthesis as protective group for alcohols and carboxylic acids.
Two common methods for benzyl ether protection:
- reaction of alcohol with benzyl bromide and a strong base such as sodium hydride as in a Williamson ether synthesis
- reaction of alcohol with benzyl trichloroacetimidate (C6H5CH2OC(CCl3)=NH) promoted by trifluoromethanesulfonic acid
The benzyl group can be removed by hydrogenation.
One study [1] employs a benzyl pyridinium salt as a benzyl donor for alcohols.
The solvent is trifluoromethylbenzene and magnesium oxide is an acid scavenger. The reaction type for this conversion is believed to be SN1 based on the detection of trace amounts of Friedel-Crafts reaction sideproducts with toluene as a solvent. | https://www.wikidoc.org/index.php/Benzyl | |
e341f159196fe54cbb0836ce8bf84f7b9a5c9a3a | wikidoc | Bezoar | Bezoar
# Overview
A bezoar or enterolith is a sort of calculus or concretion, a stone found in the intestines of mostly ruminant animals, but occurring among others including humans. There are several varieties of bezoar, some of which have inorganic constituents and others organic. Bezoars consist of ingested foreign materials that accumulate within the gastrointestinal tract and are classified according to the materials of which they are composed. Trichobezoars (hair) and phytobezoars (fruit/vegetable) are the most frequent forms. Bezoars usually form in the stomach and can pass into the small bowel where they occasionally cause small bowel obstruction. Predisposing factors include inadequate chewing, high-fiber diets, and previous gastric surgery.
# History
Bezoars were formerly sought after because they were believed to have the power of a universal antidote against any poison. It was believed that a drinking glass which contained a bezoar set within would neutralize any poison poured into the glass. The word "bezoar" ultimately comes from the Persian pâdzahr (پادزهر), which literally means "protection from poison." In fact, some types of trichobezoar are apparently able to precipitate or bind arsenic compounds (long used as poison) from a solution.
In 1575, the surgeon Ambroise Paré described an experiment to test the properties of the Bezoar Stone. At the time, the Bezoar stone was deemed to be able to cure the effects of any poison, but Paré believed this was impossible. It happened that a cook at Paré's court was caught stealing fine silver cutlery. In his shame, the cook agreed to be poisoned. He then used the Bezoar stone to no great avail as he died in agony days after. Paré had proved that the Bezoar stone could not cure all poisons as was commonly believed at the time.
A famous case in the common law of England (Chandelor v. Lopus, 79 Eng Rep. 3, Cro. Jac. 4, Eng. Ct. Exch. 1603) announced the rule of caveat emptor, "let the buyer beware" if the goods he purchased are in fact genuine and effective. The case concerned a purchaser who sued for the return of the purchase price of an allegedly fraudulent bezoar. (How the plaintiff discovered that the bezoar did not work is not discussed in the report.) Judicial scepticism over the alleged magical powers of bezoars may well have justified this judgment in this particular case. The ruling, however, was seized on and formed an impediment to the formation of effective consumer protection remedies and the law of implied warranty well into the nineteenth century.
The Merck Manual of Diagnosis and Therapy notes that persimmons have been identified as causing epidemics of intestinal bezoars, and that up to ninety percent of food boluses that occur from eating too much of the fruit require surgery for removal.
# Bezoar pearls
In addition to bivalve pearls, there are a group of sacred natural gemstones largely considered bezoar stones, which were first documented in the Garuda Purana, one of the books of Hindu holy text Atharvaveda.
In addition to oyster pearls, also enumerated are the Conch Pearl, Cobra Pearl, Boar Pearl, Elephant Pearl, Bamboo Pearl, Whale Pearl, Fish Pearl, and Cloud Pearl. These pearls were later documented in the treatise Brihat-Samhita ("The Great Compilation") of Varahamihira, the Indian mathematician. The first documented contact with these artifacts by the Western world is described in the sole volume of 18th Century scientist Albertus Seba, entitled Cabinet of Natural Curiosities. Therein, a large collection of bezoar stones and non-oyster pearls were hand-sketched, and the collection of these items were on display in a forum which was the precursor of the modern day museum. Today, the original 446-plate volume, part of the greater work Locupletissimi Rerum Naturalium Thesauri Accurata Descriptio, is on permanent exhibit at the Koninklijke Bibliotheek in The Hague, Netherlands.
While the sacred Nine Pearls of Vedic tradition are typically considered bezoars, the Bamboo Pearl forms in the stem of the Bamboo plant, while others such as the Cloud Pearl have no known formation process.
# Types of bezoars
- Food boli (singular, bolus) imitate true bezoars and are composed of loose aggregates of food items such as seeds, fruit pith, or pits as well as other types of items such as shellac, bubble gum, and concretions of some medications.
- Pharmacobezoars (or medication bezoars) are mostly tablets or semi-liquid masses of drugs.
- Phytobezoars are composed of nondigestible food material (e.g., cellulose) and are frequently reported in patients with impaired digestion and decreased gastric motility.
- Trichobezoar is a bezoar formed from hair - an extreme form of hairball. Humans who frequently consume hair sometimes require these to be removed. This has also been called Rapunzel syndrome.
Fluoroscopic images demonstrate a bezoar in the stomach
## Miscellaneous
- Other types of bezoars are formed from items such as stone or sand, usually in young children.
- Ox bezoars are used in Chinese herbology, where they are called Niu-huang.
- In alchemy, animal bezoar is the heart and lungs of the viper, pulverized together.Template:Ref label
- In alchemy, mineral bezoar is an emetic powder of antimony, correct with spirit of nitre, and softened by repeated lotions, which were said to carry off the purgative virtue of the antimony, and substitute a diaphoretic one. It promoted sweat like the stone of the same name. Template:Ref label
# In popular culture
- A Darwin Award was awarded to someone who died from a bezoar resulting from compulsively eating her own hair .
- The first mention of the bezoar stone is by the Arabic and Persian writers. In the Arabic work attributed to Aristotle, and which was certainly written by the ninth and possibly as early as the seventh century, it is even described among the precious stones. The same is true of the oldest Persian work on medicine, namely, that of Abu Mansur Muwaffak, composed about the middle of the tenth century. A valuable monograph on the bezoar was written in 1625 by Caspar Bauhin, a learned professor and physician of Basel; this work contains all that was then known of the various qualities ascribed to this substance by the older authors.
- In the Harry Potter series, bezoars are, as noted by Professor Snape in Harry's first potions lesson, "a stone taken from the stomach of a goat, which will protect from most poisons." In Harry Potter and the Half-Blood Prince, Harry uses a bezoar to save Ron Weasley's life when he accidentally drinks poisoned mead. | Bezoar
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
# Overview
A bezoar or enterolith is a sort of calculus or concretion, a stone found in the intestines of mostly ruminant animals, but occurring among others including humans. There are several varieties of bezoar, some of which have inorganic constituents and others organic. Bezoars consist of ingested foreign materials that accumulate within the gastrointestinal tract and are classified according to the materials of which they are composed. Trichobezoars (hair) and phytobezoars (fruit/vegetable) are the most frequent forms. Bezoars usually form in the stomach and can pass into the small bowel where they occasionally cause small bowel obstruction. Predisposing factors include inadequate chewing, high-fiber diets, and previous gastric surgery.
# History
Bezoars were formerly sought after because they were believed to have the power of a universal antidote against any poison. It was believed that a drinking glass which contained a bezoar set within would neutralize any poison poured into the glass. The word "bezoar" ultimately comes from the Persian pâdzahr (پادزهر), which literally means "protection from poison." In fact, some types of trichobezoar are apparently able to precipitate or bind arsenic compounds (long used as poison) from a solution.
In 1575, the surgeon Ambroise Paré described an experiment to test the properties of the Bezoar Stone. At the time, the Bezoar stone was deemed to be able to cure the effects of any poison, but Paré believed this was impossible. It happened that a cook at Paré's court was caught stealing fine silver cutlery. In his shame, the cook agreed to be poisoned. He then used the Bezoar stone to no great avail as he died in agony days after. Paré had proved that the Bezoar stone could not cure all poisons as was commonly believed at the time.
A famous case in the common law of England (Chandelor v. Lopus, 79 Eng Rep. 3, Cro. Jac. 4, Eng. Ct. Exch. 1603) announced the rule of caveat emptor, "let the buyer beware" if the goods he purchased are in fact genuine and effective. The case concerned a purchaser who sued for the return of the purchase price of an allegedly fraudulent bezoar. (How the plaintiff discovered that the bezoar did not work is not discussed in the report.) Judicial scepticism over the alleged magical powers of bezoars may well have justified this judgment in this particular case. The ruling, however, was seized on and formed an impediment to the formation of effective consumer protection remedies and the law of implied warranty well into the nineteenth century.
The Merck Manual of Diagnosis and Therapy notes that persimmons have been identified as causing epidemics of intestinal bezoars, and that up to ninety percent of food boluses that occur from eating too much of the fruit require surgery for removal.[1]
# Bezoar pearls
In addition to bivalve pearls, there are a group of sacred natural gemstones largely considered bezoar stones, which were first documented in the Garuda Purana, one of the books of Hindu holy text Atharvaveda.
In addition to oyster pearls, also enumerated are the Conch Pearl, Cobra Pearl, Boar Pearl, Elephant Pearl, Bamboo Pearl, Whale Pearl, Fish Pearl, and Cloud Pearl. These pearls were later documented in the treatise Brihat-Samhita ("The Great Compilation") of Varahamihira, the Indian mathematician. The first documented contact with these artifacts by the Western world is described in the sole volume of 18th Century scientist Albertus Seba, entitled Cabinet of Natural Curiosities. Therein, a large collection of bezoar stones and non-oyster pearls were hand-sketched, and the collection of these items were on display in a forum which was the precursor of the modern day museum. Today, the original 446-plate volume, part of the greater work Locupletissimi Rerum Naturalium Thesauri Accurata Descriptio, is on permanent exhibit at the Koninklijke Bibliotheek in The Hague, Netherlands.
While the sacred Nine Pearls of Vedic tradition are typically considered bezoars, the Bamboo Pearl forms in the stem of the Bamboo plant, while others such as the Cloud Pearl have no known formation process.
# Types of bezoars
- Food boli (singular, bolus) imitate true bezoars and are composed of loose aggregates of food items such as seeds, fruit pith, or pits as well as other types of items such as shellac, bubble gum, and concretions of some medications.
- Pharmacobezoars (or medication bezoars) are mostly tablets or semi-liquid masses of drugs.
- Phytobezoars are composed of nondigestible food material (e.g., cellulose) and are frequently reported in patients with impaired digestion and decreased gastric motility.
- Trichobezoar is a bezoar formed from hair - an extreme form of hairball. Humans who frequently consume hair sometimes require these to be removed. This has also been called Rapunzel syndrome.
Fluoroscopic images demonstrate a bezoar in the stomach
-
-
-
## Miscellaneous
- Other types of bezoars are formed from items such as stone or sand, usually in young children.
- Ox bezoars are used in Chinese herbology, where they are called Niu-huang.
- In alchemy, animal bezoar is the heart and lungs of the viper, pulverized together.Template:Ref label
- In alchemy, mineral bezoar is an emetic powder of antimony, correct with spirit of nitre, and softened by repeated lotions, which were said to carry off the purgative virtue of the antimony, and substitute a diaphoretic one. It promoted sweat like the stone of the same name. Template:Ref label
# In popular culture
- A Darwin Award was awarded to someone who died from a bezoar resulting from compulsively eating her own hair [2].
- The first mention of the bezoar stone is by the Arabic and Persian writers. In the Arabic work attributed to Aristotle, and which was certainly written by the ninth and possibly as early as the seventh century, it is even described among the precious stones. The same is true of the oldest Persian work on medicine, namely, that of Abu Mansur Muwaffak, composed about the middle of the tenth century. A valuable monograph on the bezoar was written in 1625 by Caspar Bauhin, a learned professor and physician of Basel; this work contains all that was then known of the various qualities ascribed to this substance by the older authors.
- In the Harry Potter series, bezoars are, as noted by Professor Snape in Harry's first potions lesson, "a stone taken from the stomach of a goat, which will protect from most poisons." In Harry Potter and the Half-Blood Prince, Harry uses a bezoar to save Ron Weasley's life when he accidentally drinks poisoned mead. | https://www.wikidoc.org/index.php/Bezoar | |
d03f2daf23d76bcd12ca667b82f7a6b903bcff86 | wikidoc | Biceps | Biceps
A biceps is a muscle from either of two muscle pairs (right and left) in the body. Biceps is the Latin adjective meaning two-headed. These muscles are so-called because each has two insertions at its upper end.
- In general usage, the biceps is the biceps brachii, the prominent muscle on the inside of each upper arm, popularly associated with bodily strength because it can be flexed very visibly.
- Less commonly, the biceps is the biceps femoris, one of the hamstring muscles of the underside of each thigh.
# Usage note
Biceps is the singular. The muscle is often mistakenly called a bicep.
de:Bizeps
nl:Musculus biceps | Biceps
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
A biceps is a muscle from either of two muscle pairs (right and left) in the body. Biceps is the Latin adjective meaning two-headed. These muscles are so-called because each has two insertions at its upper end.
- In general usage, the biceps is the biceps brachii, the prominent muscle on the inside of each upper arm, popularly associated with bodily strength because it can be flexed very visibly.
- Less commonly, the biceps is the biceps femoris, one of the hamstring muscles of the underside of each thigh.
# Usage note
Biceps is the singular. The muscle is often mistakenly called a bicep.
de:Bizeps
nl:Musculus biceps
Template:WS | https://www.wikidoc.org/index.php/Biceps | |
b6a3c8c2bd963bba36d9f7e95e04ac490803df10 | wikidoc | Hallux | Hallux
# Overview
The hallux pl. halluces, also known as the big toe or "thumb toe" is the innermost toe of the foot, counted as digit I.
In humans, the hallux is longer than the second or pointer toe for a majority of people. This is an inherited trait in humans, where the dominant gene causes the normal length hallux while the homozygous recessive geneotype presents with a longer second toe. (Commonly known as "mitten foot").
# Diseases
People with the rare genetic disease fibrodysplasia ossificans progressiva characteristically have short big toes.
The big toe is the most common focus of gout and Ingrown nail attacks. | Hallux
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
# Overview
The hallux pl. halluces, also known as the big toe or "thumb toe" is the innermost toe of the foot, counted as digit I.
In humans, the hallux is longer than the second or pointer toe for a majority of people. This is an inherited trait in humans, where the dominant gene causes the normal length hallux while the homozygous recessive geneotype presents with a longer second toe. (Commonly known as "mitten foot").
# Diseases
People with the rare genetic disease fibrodysplasia ossificans progressiva characteristically have short big toes.
The big toe is the most common focus of gout and Ingrown nail attacks. | https://www.wikidoc.org/index.php/Big_toe | |
36fc6a283ba21726e6bcf6e258e594a524b37d94 | wikidoc | Biopsy | Biopsy
Synonyms and keywords: Bone biopsy, Soft tissue biopsy, Biopsy in musculoskeletal system, Biopsy of organs
# Overview
Biopsy is the gold standard test for the diagnosis of tumors. The tumor is then staged into benign and malignant tumors.
## Biopsy
- Biopsy is the gold standard test for the diagnosis of tumors.
Prerequisites for a Biopsy
- CBC, platelets and coagulation studies should be done.
- Cross-sectional imaging to evaluate local anatomy such CT scan and MRI.
- Treatment center carrying out biopsy must be capable of proper diagnosis and treatment.
- The surgeon who performs biopsy should preferably be the one who is later going to do the final excision.
Technique
- Open
- Closed
## Open Technique
- The tumor is surgically exposed and biopsy of the tumor is taken.
## Types
## Incisional biopsy
- A small surgical incision carefully placed to access tumor without contamination of critical structures.
## Excisional biopsy
- It is done for small, superficial soft tissue masses.
Incision
- Longitudinal incision in the extremities is taken.
- It should allow for extension of the incision for definitive management.
Approach
- Never expose neurovascular structures during the procedure.
- During the biopsy, all tissue exposed is considered contaminated with tumor.
- Meticulous hemostasis must be carried out.
- Post-surgery hematomas are considered contaminated with tumor.
- Always deflate the tourniquet prior to wound closure.
Biopsy
- Perform through the involved compartment of the tumor.
- For bone lesions with a soft tissue mass, perform the biopsy using the soft tissue mass.
Closure
- If drain is kept, remove the drain out of the skin in line with surgical incision.
- This helps in excising the drain site with definitive surgical extensive incision.
## Closed Technique
## Types
## Fine Needle Aspiration (FNA)
- It provides cytologic specimen.
- It is the most commonly used for carcinoma.
- It is usually not preferred for sarcoma.
## Core biopsy (Tru-cut Biopsy)
- It allows for tumor structural examination.
- It allows evaluation of both the cytologic and stromal elements of the tumor.
- It is frequently used for sarcomas.
- The various investigations must be performed in the following order:
- X-ray
MRI
- X-ray
- MRI
- Biopsy | Biopsy
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Rohan A. Bhimani, M.B.B.S., D.N.B., M.Ch.[2]
Synonyms and keywords: Bone biopsy, Soft tissue biopsy, Biopsy in musculoskeletal system, Biopsy of organs
# Overview
Biopsy is the gold standard test for the diagnosis of tumors. The tumor is then staged into benign and malignant tumors.
## Biopsy
- Biopsy is the gold standard test for the diagnosis of tumors.[1][2]
Prerequisites for a Biopsy
- CBC, platelets and coagulation studies should be done.
- Cross-sectional imaging to evaluate local anatomy such CT scan and MRI.
- Treatment center carrying out biopsy must be capable of proper diagnosis and treatment.
- The surgeon who performs biopsy should preferably be the one who is later going to do the final excision.
Technique
- Open
- Closed
## Open Technique
- The tumor is surgically exposed and biopsy of the tumor is taken.
## Types
## Incisional biopsy
- A small surgical incision carefully placed to access tumor without contamination of critical structures.
## Excisional biopsy
- It is done for small, superficial soft tissue masses.
Incision
- Longitudinal incision in the extremities is taken.
- It should allow for extension of the incision for definitive management.
Approach
- Never expose neurovascular structures during the procedure.
- During the biopsy, all tissue exposed is considered contaminated with tumor.
- Meticulous hemostasis must be carried out.
- Post-surgery hematomas are considered contaminated with tumor.
- Always deflate the tourniquet prior to wound closure.
Biopsy
- Perform through the involved compartment of the tumor.
- For bone lesions with a soft tissue mass, perform the biopsy using the soft tissue mass.
Closure
- If drain is kept, remove the drain out of the skin in line with surgical incision.
- This helps in excising the drain site with definitive surgical extensive incision.
## Closed Technique
## Types
## Fine Needle Aspiration (FNA)
- It provides cytologic specimen.
- It is the most commonly used for carcinoma.
- It is usually not preferred for sarcoma.
## Core biopsy (Tru-cut Biopsy)
- It allows for tumor structural examination.
- It allows evaluation of both the cytologic and stromal elements of the tumor.
- It is frequently used for sarcomas.
- The various investigations must be performed in the following order:
- X-ray
MRI
- X-ray
- MRI
- Biopsy | https://www.wikidoc.org/index.php/Biopsies | |
cfafe12a7388e25f6e8a5a7fb3a7e240b29c1bc5 | wikidoc | Biotin | Biotin
# Disclaimer
WikiDoc MAKES NO GUARANTEE OF VALIDITY. WikiDoc is not a professional health care provider, nor is it a suitable replacement for a licensed healthcare provider. WikiDoc is intended to be an educational tool, not a tool for any form of healthcare delivery. The educational content on WikiDoc drug pages is based upon the FDA package insert, National Library of Medicine content and practice guidelines / consensus statements. WikiDoc does not promote the administration of any medication or device that is not consistent with its labeling. Please read our full disclaimer here.
# Overview
Biotin is a vitamin that is FDA approved for the treatment of to strengthen the hair follicle and prevents hair loss as well. It is nutrient for the hair root and helps oxygenate the hair turn slowing the loss and provides resilience and resistence to hair. Common adverse reactions include gastrointestinal upset, administration of anticonvulsant medications may impair biotin absorption.
# Adult Indications and Dosage
## FDA-Labeled Indications and Dosage (Adult)
- Biotin is a major component of the formulation acts to strengthen the hair follicle and prevents hair loss as well. It is nutrient for the hair root and helps oxygenate the hair turn slowing the loss. Provides resilience and resistence to hair.
- Apply amount of the hair follicle and massage until absorbed. Use every 12 hours for the fast and sustained effect.
- Suitable for children, adolescents, adults and seniors.
## Off-Label Use and Dosage (Adult)
### Guideline-Supported Use
- BIOTINIDASE DEFICIENCY, oral: 10 to 40 milligrams daily
- BRITTLE NAILS, oral, tablet: 2.5 milligrams daily
- CARBOXYLASE DEFICIENCY, intravenous, solution: 18.4 micromoles daily
- HOLOCARBOXYLASE DEFICIENCY IN PREGNANCY, oral: 10 milligrams daily
- PARENTERAL ALIMENTATION-INDUCED DEFICIENCY, oral, solution or tablet: 0.1 to 1 milligram daily
- RECOMMENDED DIETARY ALLOWANCE (RDA), oral: 30 to 100 micrograms daily
- VAGINAL CANDIDIASIS, oral: 20 milligrams daily
### Non–Guideline-Supported Use
There is limited information regarding Off-Label Non–Guideline-Supported Use of Biotin in adult patients.
# Pediatric Indications and Dosage
## FDA-Labeled Indications and Dosage (Pediatric)
There is limited information regarding FDA-Labeled Use of Biotin in pediatric patients.
## Off-Label Use and Dosage (Pediatric)
### Guideline-Supported Use
- ALOPECIA AREATA, oral: 20 milligrams daily with oral zinc aspartate 100 milligrams and topical clobetasol propionate 0.025%
- BASAL-GANGLIA DISEASE, BIOTIN-responsive, oral or solution: 5 to 10 milligrams/kilogram daily
- BETA-METHYLCROTONYL-GLYCINURIA, solution, oral: 10 milligrams daily
- BIOTINIDASE DEFICIENCY, solution or tablet, oral: 6 to 40 milligrams daily
- PARENTERAL ALIMENTATION-INDUCED DEFICIENCY, solution or tablet, oral: 0.1 to 1 milligram daily
- PARTIAL BIOTINIDASE DEFICIENCY, solution or tablet: 5 to 10 milligrams daily or less.
- PROTEIN-ENERGY MALNUTRITION, solution or tablet, oral: BIOTIN 10 milligrams daily along with standard treatment for malnutrition
- PYRUVATE-CARBOXYLASE DEFICIENCY, solution or tablet, oral: BIOTIN 10 milligrams (mg) daily, thiamine 80 mg daily, pyridoxine 300 mg daily
- RECOMMENDED DIETARY ALLOWANCE, oral, diet or tablet: 50 micrograms daily
- UNCOMBABLE HAIR SYNDROME, solution or tablet, oral: 0.9 milligram daily in three divided doses
### Non–Guideline-Supported Use
There is limited information regarding Off-Label Non–Guideline-Supported Use of Biotin in pediatric patients.
# Contraindications
- Hypersensitivity to Biotin
# Warnings
This product is for topical application, if this product to contact with eyes rinse immediately with water and consult your doctor.
# Adverse Reactions
## Clinical Trials Experience
There is limited information regarding Clinical Trial Experience of Biotin in the drug label.
## Postmarketing Experience
- Gastrointestinal upset
- Administration of anticonvulsant medications may impair Biotin absorption
# Drug Interactions
There is limited information regarding Biotin Drug Interactions in the drug label.
# Use in Specific Populations
### Pregnancy
Pregnancy Category (FDA):
- Pregnancy Category
Pregnancy Category (AUS):
- Australian Drug Evaluation Committee (ADEC) Pregnancy Category
There is no Australian Drug Evaluation Committee (ADEC) guidance on usage of Biotin in women who are pregnant.
### Labor and Delivery
There is no FDA guidance on use of Biotin during labor and delivery.
### Nursing Mothers
There is no FDA guidance on the use of Biotin with respect to nursing mothers.
### Pediatric Use
There is no FDA guidance on the use of Biotin with respect to pediatric patients.
### Geriatic Use
There is no FDA guidance on the use of Biotin with respect to geriatric patients.
### Gender
There is no FDA guidance on the use of Biotin with respect to specific gender populations.
### Race
There is no FDA guidance on the use of Biotin with respect to specific racial populations.
### Renal Impairment
There is no FDA guidance on the use of Biotin in patients with renal impairment.
### Hepatic Impairment
There is no FDA guidance on the use of Biotin in patients with hepatic impairment.
### Females of Reproductive Potential and Males
There is no FDA guidance on the use of Biotin in women of reproductive potentials and males.
### Immunocompromised Patients
There is no FDA guidance one the use of Biotin in patients who are immunocompromised.
# Administration and Monitoring
### Administration
- Oral
### Monitoring
There is limited information regarding Monitoring of Biotin in the drug label.
# IV Compatibility
There is limited information regarding IV Compatibility of Biotin in the drug label.
# Overdosage
There is limited information regarding Chronic Overdose of Biotin in the drug label.
# Pharmacology
## Mechanism of Action
There is limited information regarding Biotin Mechanism of Action in the drug label.
## Structure
There is limited information regarding Biotin Structure in the drug label.
## Pharmacodynamics
There is limited information regarding Pharmacodynamics of Biotin in the drug label.
## Pharmacokinetics
There is limited information regarding Pharmacokinetics of Biotin in the drug label.
## Nonclinical Toxicology
There is limited information regarding Nonclinical Toxicology of Biotin in the drug label.
# Clinical Studies
There is limited information regarding Clinical Studies of Biotin in the drug label.
# How Supplied
## Storage
There is limited information regarding Biotin Storage in the drug label.
# Images
## Drug Images
## Package and Label Display Panel
# Patient Counseling Information
There is limited information regarding Patient Counseling Information of Biotin in the drug label.
# Precautions with Alcohol
- Alcohol-Biotin interaction has not been established. Talk to your doctor about the effects of taking alcohol with this medication.
# Brand Names
- BIONA-VIT ®
# Look-Alike Drug Names
There is limited information regarding Biotin Look-Alike Drug Names in the drug label.
# Drug Shortage Status
# Price | Biotin
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ammu Susheela, M.D. [2]
# Disclaimer
WikiDoc MAKES NO GUARANTEE OF VALIDITY. WikiDoc is not a professional health care provider, nor is it a suitable replacement for a licensed healthcare provider. WikiDoc is intended to be an educational tool, not a tool for any form of healthcare delivery. The educational content on WikiDoc drug pages is based upon the FDA package insert, National Library of Medicine content and practice guidelines / consensus statements. WikiDoc does not promote the administration of any medication or device that is not consistent with its labeling. Please read our full disclaimer here.
# Overview
Biotin is a vitamin that is FDA approved for the treatment of to strengthen the hair follicle and prevents hair loss as well. It is nutrient for the hair root and helps oxygenate the hair turn slowing the loss and provides resilience and resistence to hair. Common adverse reactions include gastrointestinal upset, administration of anticonvulsant medications may impair biotin absorption.
# Adult Indications and Dosage
## FDA-Labeled Indications and Dosage (Adult)
- Biotin is a major component of the formulation acts to strengthen the hair follicle and prevents hair loss as well. It is nutrient for the hair root and helps oxygenate the hair turn slowing the loss. Provides resilience and resistence to hair.
- Apply amount of the hair follicle and massage until absorbed. Use every 12 hours for the fast and sustained effect.
- Suitable for children, adolescents, adults and seniors.
## Off-Label Use and Dosage (Adult)
### Guideline-Supported Use
- BIOTINIDASE DEFICIENCY, oral: 10 to 40 milligrams daily
- BRITTLE NAILS, oral, tablet: 2.5 milligrams daily
- CARBOXYLASE DEFICIENCY, intravenous, solution: 18.4 micromoles daily
- HOLOCARBOXYLASE DEFICIENCY IN PREGNANCY, oral: 10 milligrams daily
- PARENTERAL ALIMENTATION-INDUCED DEFICIENCY, oral, solution or tablet: 0.1 to 1 milligram daily
- RECOMMENDED DIETARY ALLOWANCE (RDA), oral: 30 to 100 micrograms daily
- VAGINAL CANDIDIASIS, oral: 20 milligrams daily
### Non–Guideline-Supported Use
There is limited information regarding Off-Label Non–Guideline-Supported Use of Biotin in adult patients.
# Pediatric Indications and Dosage
## FDA-Labeled Indications and Dosage (Pediatric)
There is limited information regarding FDA-Labeled Use of Biotin in pediatric patients.
## Off-Label Use and Dosage (Pediatric)
### Guideline-Supported Use
- ALOPECIA AREATA, oral: 20 milligrams daily with oral zinc aspartate 100 milligrams and topical clobetasol propionate 0.025%
- BASAL-GANGLIA DISEASE, BIOTIN-responsive, oral or solution: 5 to 10 milligrams/kilogram daily
- BETA-METHYLCROTONYL-GLYCINURIA, solution, oral: 10 milligrams daily
- BIOTINIDASE DEFICIENCY, solution or tablet, oral: 6 to 40 milligrams daily
- PARENTERAL ALIMENTATION-INDUCED DEFICIENCY, solution or tablet, oral: 0.1 to 1 milligram daily
- PARTIAL BIOTINIDASE DEFICIENCY, solution or tablet: 5 to 10 milligrams daily or less.
- PROTEIN-ENERGY MALNUTRITION, solution or tablet, oral: BIOTIN 10 milligrams daily along with standard treatment for malnutrition
- PYRUVATE-CARBOXYLASE DEFICIENCY, solution or tablet, oral: BIOTIN 10 milligrams (mg) daily, thiamine 80 mg daily, pyridoxine 300 mg daily
- RECOMMENDED DIETARY ALLOWANCE, oral, diet or tablet: 50 micrograms daily
- UNCOMBABLE HAIR SYNDROME, solution or tablet, oral: 0.9 milligram daily in three divided doses
### Non–Guideline-Supported Use
There is limited information regarding Off-Label Non–Guideline-Supported Use of Biotin in pediatric patients.
# Contraindications
- Hypersensitivity to Biotin
# Warnings
This product is for topical application, if this product to contact with eyes rinse immediately with water and consult your doctor.
# Adverse Reactions
## Clinical Trials Experience
There is limited information regarding Clinical Trial Experience of Biotin in the drug label.
## Postmarketing Experience
- Gastrointestinal upset
- Administration of anticonvulsant medications may impair Biotin absorption
# Drug Interactions
There is limited information regarding Biotin Drug Interactions in the drug label.
# Use in Specific Populations
### Pregnancy
Pregnancy Category (FDA):
- Pregnancy Category
Pregnancy Category (AUS):
- Australian Drug Evaluation Committee (ADEC) Pregnancy Category
There is no Australian Drug Evaluation Committee (ADEC) guidance on usage of Biotin in women who are pregnant.
### Labor and Delivery
There is no FDA guidance on use of Biotin during labor and delivery.
### Nursing Mothers
There is no FDA guidance on the use of Biotin with respect to nursing mothers.
### Pediatric Use
There is no FDA guidance on the use of Biotin with respect to pediatric patients.
### Geriatic Use
There is no FDA guidance on the use of Biotin with respect to geriatric patients.
### Gender
There is no FDA guidance on the use of Biotin with respect to specific gender populations.
### Race
There is no FDA guidance on the use of Biotin with respect to specific racial populations.
### Renal Impairment
There is no FDA guidance on the use of Biotin in patients with renal impairment.
### Hepatic Impairment
There is no FDA guidance on the use of Biotin in patients with hepatic impairment.
### Females of Reproductive Potential and Males
There is no FDA guidance on the use of Biotin in women of reproductive potentials and males.
### Immunocompromised Patients
There is no FDA guidance one the use of Biotin in patients who are immunocompromised.
# Administration and Monitoring
### Administration
- Oral
### Monitoring
There is limited information regarding Monitoring of Biotin in the drug label.
# IV Compatibility
There is limited information regarding IV Compatibility of Biotin in the drug label.
# Overdosage
There is limited information regarding Chronic Overdose of Biotin in the drug label.
# Pharmacology
## Mechanism of Action
There is limited information regarding Biotin Mechanism of Action in the drug label.
## Structure
There is limited information regarding Biotin Structure in the drug label.
## Pharmacodynamics
There is limited information regarding Pharmacodynamics of Biotin in the drug label.
## Pharmacokinetics
There is limited information regarding Pharmacokinetics of Biotin in the drug label.
## Nonclinical Toxicology
There is limited information regarding Nonclinical Toxicology of Biotin in the drug label.
# Clinical Studies
There is limited information regarding Clinical Studies of Biotin in the drug label.
# How Supplied
-
## Storage
There is limited information regarding Biotin Storage in the drug label.
# Images
## Drug Images
## Package and Label Display Panel
# Patient Counseling Information
There is limited information regarding Patient Counseling Information of Biotin in the drug label.
# Precautions with Alcohol
- Alcohol-Biotin interaction has not been established. Talk to your doctor about the effects of taking alcohol with this medication.
# Brand Names
- BIONA-VIT ®[2]
# Look-Alike Drug Names
There is limited information regarding Biotin Look-Alike Drug Names in the drug label.
# Drug Shortage Status
# Price | https://www.wikidoc.org/index.php/Biotin | |
b3b02f97106adb240ce78d6489af5a1b6dec34c9 | wikidoc | Vagina | Vagina
The vagina, (from Latin, literally "sheath" or "scabbard" ) is the cylinder tubular tract leading from the uterus to the exterior of the body in female placental mammals and marsupials, or to the cloaca in female birds, monotremes, and some reptiles. Female insects and other invertebrates also have a vagina, which is the terminal part of the oviduct. The Latinate plural (rarely used in English) is vaginae.
In common speech, the term "vagina" is often used inaccurately to refer to the vulva or female genitals generally; strictly speaking, the vagina is a specific internal structure and the vulva is the exterior genitalia only.
# Human anatomy
The human vagina is an elastic muscular canal that extends from the cervix to the vulva. Although there is wide anatomical variation the average vagina is 6 to 7 inches (15 to 18 cm) in length; its elasticity allows it to stretch during sexual intercourse and during birth to offspring. The vagina connects the superficial vulva to the cervix of the deep uterus.
If the woman stands upright, the vaginal tube points in an upward-backward direction and forms an angle of slightly more than 45 degrees with the uterus. The vaginal opening is at the caudal end of the vulva, behind the opening of the urethra. Above the vagina is Mons Veneris. The vagina, along with the inside of the vulva, is reddish pink in color, as with most healthy internal mucous membranes in mammals.
Vaginal lubrication is provided by the Bartholin's glands near the vaginal opening and the cervix. The membrane of the vaginal wall also produces moisture, although it does not contain any glands. Before and during ovulation, the cervix produces cervical mucus, which provides a favorable environment for sperm to survive.
The hymen is a membrane which is situated at the opening of the vagina. As with many female animals, the hymen covers the opening of the vagina from birth until it is ruptured during activity. The hymen may rupture during sexual or non-sexual activity; the presence or absence of a hymen does not indicate prior sexual activity.
# Biological functions of the vagina
The vagina has several biological functions.
## Menstruation
The vagina provides a path for menstrual blood and tissue to leave the body. In modern societies, tampons, menstrual cups, and sanitary towels may be used to absorb or capture these fluids.
## Sexual activity
The concentration of the nerve endings that lie close to the entrance of a woman's vagina can provide pleasurable sensation during sexual activity, when stimulated in a way that the particular woman enjoys. During sexual arousal and particularly stimulation of the clitoris, the walls of the vagina self-lubricate, reducing friction during sexual activity.
An erogenous zone referred to commonly as the G-spot is located at the anterior wall of the vagina, about five centimeters in from the entrance. Some women experience intense pleasure if the G-spot is stimulated appropriately during sexual activity. A G-Spot orgasm may be responsible for female ejaculation, leading some doctors and researchers to believe that G-spot pleasure comes from the Skene's glands, a female homologue of the prostate, rather than any particular spot on the vaginal wall. Some researchers deny the existence of the G-spot.
## Childbirth
During childbirth, the vagina provides the route to deliver the baby from the uterus to its independent life outside the body of the mother. During birth, the vagina is often referred to as the birth canal. The vagina is remarkably elastic and stretches to many times its normal diameter during vaginal birth.
# Sexual health and hygiene
The vagina is self-cleansing and therefore usually needs no special treatment. Since a healthy vagina is colonized by a mutually symbiotic flora of microorganisms that protect its host from disease-causing microbes, any attempt to upset this balance may cause many undesirable outcomes, including abnormal discharge and yeast infection. The acidity of a healthy vagina due to lactic acid secreted by symbiotic microorganisms retards the growth of many strains of dangerous microbes.
The vagina is examined during gynecological exams, often using a speculum, which holds the vagina open for visual inspection of the cervix or taking of samples (see pap smear).
## Signs of Vaginal Disease
Vaginal Diseases present with lumps, discharge and sores.
- Lumps:
The presence of unusual lumps in the wall or base of the vagina is always abnormal. The most common of these is Bartholin's cyst. The cyst, which can feel like a pea, is formed by a blockage in glands which normally supply the opening of the vagina. This condition is easily treated with minor surgery or silver nitrate. Other less common causes of small lumps or vesicles are herpes simplex. They are usually multiple and very painful with a clear fluid leaving a crust. They may be associated with generalized swelling and are very tender. Lumps associated with cancer of the vaginal wall are very rare and the average age of onset is seventy years. The most common form is squamous cell carcinoma, then cancer of the glands or adenocarcinoma and finally, and even more rarely, melanoma.
- Discharge:
The great majority of vaginal discharges are normal or physiological and include blood or menses (from the uterus), the most common, and clear fluid either as a result of sexual arousal or secretions from the cervix. Other noninfective causes include dermatitis, discharge from foreign bodies such as retained tampons or foreign bodies inserted by curious children. Non-sexually transmitted discharges occur from bacterial vaginosis and thrush or candidiasis. The final group of discharges include sexually transmitted diseases, gonorrhoea, Chlamydia and Trichomonas. The discharge from thrush is slightly pungent and white, that from Trichomonas more foul and greenish and that from foreign bodies resembles the discharge of gonorrhea, greyish or yellow and purulent (like pus).
- Sores
All sores involve a break down in the walls of the fine membrane of the vaginal wall. The most common of these are abrasions and small ulcers caused by trauma. While these can be inflicted during rape most are actually caused by excessive rubbing from clothing or improper insertion of a sanitary tampon. The typical ulcer or sore caused by syphilis is painless with raised edges. These are often undetected because they occur mostly inside the vagina. The sores of herpes which occur with vesicles are extremely tender and may cause such swelling that passing urine is difficult. In the developing world a group of parasitic diseases also cause vaginal ulceration such as Leishmaniasis but these are rarely encountered in the West.
HIV/AIDS can be contracted through the vagina during intercourse but is not associated with any local vaginal or vulval disease. All the above local vulvovaginal diseases are easily treated. Often only shame prevents patients from presenting for treatment
# Additional images
- Uterus and uterine tubes.
- Organs of the female reproductive system.
- Schematic vulva anatomy.
- Uterus and right broad ligament, seen from behind.
- Sagittal section of the lower part of a female trunk, right segment.
- Posterior half of uterus and upper part of vagina.
- Layers of the vaginal wall. | Vagina
Template:Infobox Anatomy
The vagina, (from Latin, literally "sheath" or "scabbard" ) is the cylinder tubular tract leading from the uterus to the exterior of the body in female placental mammals and marsupials, or to the cloaca in female birds, monotremes, and some reptiles. Female insects and other invertebrates also have a vagina, which is the terminal part of the oviduct. The Latinate plural (rarely used in English) is vaginae.
In common speech, the term "vagina" is often used inaccurately to refer to the vulva or female genitals generally; strictly speaking, the vagina is a specific internal structure and the vulva is the exterior genitalia only.
# Human anatomy
The human vagina is an elastic muscular canal that extends from the cervix to the vulva.[1] Although there is wide anatomical variation the average vagina is 6 to 7 inches (15 to 18 cm) in length; its elasticity allows it to stretch during sexual intercourse and during birth to offspring.[2][3] The vagina connects the superficial vulva to the cervix of the deep uterus.
If the woman stands upright, the vaginal tube points in an upward-backward direction and forms an angle of slightly more than 45 degrees with the uterus. The vaginal opening is at the caudal end of the vulva, behind the opening of the urethra. Above the vagina is Mons Veneris. The vagina, along with the inside of the vulva, is reddish pink in color, as with most healthy internal mucous membranes in mammals.
Vaginal lubrication is provided by the Bartholin's glands near the vaginal opening and the cervix. The membrane of the vaginal wall also produces moisture, although it does not contain any glands. Before and during ovulation, the cervix produces cervical mucus, which provides a favorable environment for sperm to survive.
The hymen is a membrane which is situated at the opening of the vagina. As with many female animals, the hymen covers the opening of the vagina from birth until it is ruptured during activity. The hymen may rupture during sexual or non-sexual activity; the presence or absence of a hymen does not indicate prior sexual activity.
# Biological functions of the vagina
The vagina has several biological functions.
## Menstruation
The vagina provides a path for menstrual blood and tissue to leave the body. In modern societies, tampons, menstrual cups, and sanitary towels may be used to absorb or capture these fluids.
## Sexual activity
The concentration of the nerve endings that lie close to the entrance of a woman's vagina can provide pleasurable sensation during sexual activity, when stimulated in a way that the particular woman enjoys. During sexual arousal and particularly stimulation of the clitoris, the walls of the vagina self-lubricate, reducing friction during sexual activity.
An erogenous zone referred to commonly as the G-spot is located at the anterior wall of the vagina, about five centimeters in from the entrance. Some women experience intense pleasure if the G-spot is stimulated appropriately during sexual activity. A G-Spot orgasm may be responsible for female ejaculation, leading some doctors and researchers to believe that G-spot pleasure comes from the Skene's glands, a female homologue of the prostate, rather than any particular spot on the vaginal wall.[4][5][6] Some researchers deny the existence of the G-spot.[7]
## Childbirth
During childbirth, the vagina provides the route to deliver the baby from the uterus to its independent life outside the body of the mother. During birth, the vagina is often referred to as the birth canal. The vagina is remarkably elastic and stretches to many times its normal diameter during vaginal birth.
# Sexual health and hygiene
The vagina is self-cleansing and therefore usually needs no special treatment. Since a healthy vagina is colonized by a mutually symbiotic flora of microorganisms that protect its host from disease-causing microbes, any attempt to upset this balance may cause many undesirable outcomes, including abnormal discharge and yeast infection. The acidity of a healthy vagina due to lactic acid secreted by symbiotic microorganisms retards the growth of many strains of dangerous microbes.
The vagina is examined during gynecological exams, often using a speculum, which holds the vagina open for visual inspection of the cervix or taking of samples (see pap smear).
## Signs of Vaginal Disease
Vaginal Diseases present with lumps, discharge and sores.
- Lumps:[8]
The presence of unusual lumps in the wall or base of the vagina is always abnormal. The most common of these is Bartholin's cyst. The cyst, which can feel like a pea, is formed by a blockage in glands which normally supply the opening of the vagina. This condition is easily treated with minor surgery or silver nitrate. Other less common causes of small lumps or vesicles are herpes simplex. They are usually multiple and very painful with a clear fluid leaving a crust. They may be associated with generalized swelling and are very tender. Lumps associated with cancer of the vaginal wall are very rare and the average age of onset is seventy years[9]. The most common form is squamous cell carcinoma, then cancer of the glands or adenocarcinoma and finally, and even more rarely, melanoma.
- Discharge:[10]
The great majority of vaginal discharges are normal or physiological and include blood or menses (from the uterus), the most common, and clear fluid either as a result of sexual arousal or secretions from the cervix. Other noninfective causes include dermatitis, discharge from foreign bodies such as retained tampons or foreign bodies inserted by curious children. Non-sexually transmitted discharges occur from bacterial vaginosis and thrush or candidiasis. The final group of discharges include sexually transmitted diseases, gonorrhoea, Chlamydia and Trichomonas. The discharge from thrush is slightly pungent and white, that from Trichomonas more foul and greenish and that from foreign bodies resembles the discharge of gonorrhea, greyish or yellow and purulent (like pus).
- Sores[11]
All sores involve a break down in the walls of the fine membrane of the vaginal wall. The most common of these are abrasions and small ulcers caused by trauma. While these can be inflicted during rape most are actually caused by excessive rubbing from clothing or improper insertion of a sanitary tampon. The typical ulcer or sore caused by syphilis is painless with raised edges. These are often undetected because they occur mostly inside the vagina. The sores of herpes which occur with vesicles are extremely tender and may cause such swelling that passing urine is difficult. In the developing world a group of parasitic diseases also cause vaginal ulceration such as Leishmaniasis but these are rarely encountered in the West.
HIV/AIDS can be contracted through the vagina during intercourse but is not associated with any local vaginal or vulval disease[12]. All the above local vulvovaginal diseases are easily treated. Often only shame prevents patients from presenting for treatment[13]
# Additional images
- Uterus and uterine tubes.
- Organs of the female reproductive system.
- Schematic vulva anatomy.
- Uterus and right broad ligament, seen from behind.
- Sagittal section of the lower part of a female trunk, right segment.
- Posterior half of uterus and upper part of vagina.
- Layers of the vaginal wall. | https://www.wikidoc.org/index.php/Birth_canal | |
c667fb54451c42b9ceda80062b53cbf0eca75f2c | wikidoc | Bleach | Bleach
A bleach is a chemical that removes color or whitens, often via oxidation. Common chemical bleaches include "chlorine bleach", a solution of sodium hypochlorite (NaClO), and "oxygen bleach", which contains hydrogen peroxide or a peroxide-releasing compound such as sodium perborate or sodium percarbonate. To bleach something is to apply bleach, sometimes as a preliminary step in the process of dyeing. Bleaching powder is calcium hypochlorite.
# Other types of bleach
Chlorine dioxide is used for the bleaching of wood pulp, fats and oils, cellulose, flour, textiles, beeswax, and in a number of other industries.
In the food industry, some organic peroxides (benzoyl peroxide, etc.) and other agents (e.g. bromates) are used as flour bleaching and maturing agents.
Peracetic acid, ozone and hydrogen peroxide and oxygen are used in bleaching sequences in the pulp industry to produce totally chlorine free (TCF) paper.
Not all bleaches have to be of an oxidizing nature. Sodium dithionite is used as a powerful reducing agent in some bleaching formulas. It is commonly used to bleach wood pulp used to make newsprint.
# Hazards and concerns
Since bleaches are strong oxidizing agents, they can be quite hazardous, especially when reacted with other common household chemicals.
Mixing sodium hypochlorite with acids like vinegar or drain cleaners containing sodium hydrogen sulfate (sodium bisulfate), or even lemon juice can release chlorine. Hypochlorite and chlorine are in equilibrium in water, the position of the equilibrium is pH dependant and low pH (acidic) favors chlorine,
Cl2 + H2O \rightleftharpoons H+ + Cl- + HClO
Chlorine is a respiratory irritant that attacks mucous membranes and burns the skin. As little as 3.5 ppm can be detected as an odour, and 1000 ppm is likely to be fatal after a few deep breaths. Exposure to chlorine has been limited to 0.5 ppm (8-hour time-weighted average - 40 hour week) by OSHA in the US.
Sodium hypochlorite and ammonia react to form a number of products, depending on the temperature, concentration, and how they are mixed. . The main reaction is chlorination of ammonia, first giving chloramine (NH2Cl), then NHCl2 and finally nitrogen trichloride (NCl3). These materials are very irritating to eyes and lungs and are toxic above certain concentrations.
NH3 + NaOCl --> NaOH + NH2Cl
NH2Cl + NaOCl --> NaOH + NHCl2
NHCl2 + NaOCl --> NaOH + NCl3
Additional reactions produce hydrazine, in a variation of the Olin Raschig process.
NH3 + NH2Cl + NaOH --> N2H4 + NaCl + H2O
The hydrazine generated can further react with the monochloramine in an exothermic reaction:
2 NH2Cl + N2H4 --> 2 NH4Cl + N2
Industrial bleaching agents can also be sources of concern. For example, the use of elemental chlorine in the bleaching of wood pulp produces organochlorines, persistent organic pollutants, including dioxins. However, the use of chlorine dioxide in these processes has reduced the dioxin generation to under detectable levels.
# History
Chlorine was first characterized by the Swedish chemist Carl Wilhelm Scheele in 1774 (as an adherent of the Phlogiston theory, he called it "dephlogisticated marine acid"). French chemist Claude Louis Berthollet, noting the bleaching properties of chlorine, invented hypochlorite bleach in 1789. In French, bleach is known as Eau de Javel, after the village where it was manufactured.
Several alternatives to bleach have recently appeared in industrialized countries. These substances are touted as being less toxic, and the use of bleach as a stain remover has become less popular in the United States. However, due to the recent upsurge of illness due to methicillin-resistant Staphylococcus aureus (known as MRSA) and other bacterial pathogens susceptible to bleach, the bleach industry has recovered somewhat, and the use of bleach as a disinfectant is increasing in a variety of industrial and commercial, as well as household settings.
# Chemistry
The process of bleaching can be summarised in the following set of chemical reactions:
Cl2(aq) + H2O(l) \rightleftharpoons H+(aq) + Cl-(aq) + HClO(aq)
The H+ ion of the hypochlorous acid then dissolves into solution, and so the final result is effectively:
Cl2(aq) + H2O(l) \rightleftharpoons 2H+(aq) + Cl-(aq) + ClO-(aq)
# How bleaches work
Color in most dyes and pigments is produced by molecules, such as beta carotene, which contain chromophores. Chemical bleaches work in one of two ways:
- An oxidizing bleach works by breaking the chemical bonds that make up the chromophore. This changes the molecule into a different substance that either does not contain a chromophore, or contains a chromophore that does not absorb visible light.
- A reducing bleach works by converting double bonds in the chromophore into single bonds. This eliminates the ability of the chromophore to absorb visible light.
Sunlight acts as a bleach through a process leading to similar results: high energy photons of light, often in the violet or ultraviolet range, can disrupt the bonds in the chromophore, rendering the resulting substance colorless. Extended exposure often leads to massive discoloration usually reducing the colors to white light and typically very faded blue spectrums. | Bleach
Template:Two other uses
A bleach is a chemical that removes color or whitens, often via oxidation. Common chemical bleaches include "chlorine bleach", a solution of sodium hypochlorite (NaClO), and "oxygen bleach", which contains hydrogen peroxide or a peroxide-releasing compound such as sodium perborate or sodium percarbonate. To bleach something is to apply bleach, sometimes as a preliminary step in the process of dyeing. Bleaching powder is calcium hypochlorite.
# Other types of bleach
Chlorine dioxide is used for the bleaching of wood pulp, fats and oils, cellulose, flour, textiles, beeswax, and in a number of other industries.
In the food industry, some organic peroxides (benzoyl peroxide, etc.) and other agents (e.g. bromates) are used as flour bleaching and maturing agents.
Peracetic acid, ozone and hydrogen peroxide and oxygen are used in bleaching sequences in the pulp industry to produce totally chlorine free (TCF) paper.
Not all bleaches have to be of an oxidizing nature. Sodium dithionite is used as a powerful reducing agent in some bleaching formulas. It is commonly used to bleach wood pulp used to make newsprint.
# Hazards and concerns
Since bleaches are strong oxidizing agents, they can be quite hazardous, especially when reacted with other common household chemicals.
Mixing sodium hypochlorite with acids like vinegar or drain cleaners containing sodium hydrogen sulfate (sodium bisulfate), or even lemon juice can release chlorine. Hypochlorite and chlorine are in equilibrium in water, the position of the equilibrium is pH dependant and low pH (acidic) favors chlorine,[1]
Cl2 + H2O <math>\rightleftharpoons</math> H+ + Cl- + HClO
Chlorine is a respiratory irritant that attacks mucous membranes and burns the skin. As little as 3.5 ppm can be detected as an odour, and 1000 ppm is likely to be fatal after a few deep breaths. Exposure to chlorine has been limited to 0.5 ppm (8-hour time-weighted average - 40 hour week) by OSHA in the US.[2]
Sodium hypochlorite and ammonia react to form a number of products, depending on the temperature, concentration, and how they are mixed. [3]. The main reaction is chlorination of ammonia, first giving chloramine (NH2Cl), then NHCl2 and finally nitrogen trichloride (NCl3). These materials are very irritating to eyes and lungs and are toxic above certain concentrations.
NH3 + NaOCl --> NaOH + NH2Cl
NH2Cl + NaOCl --> NaOH + NHCl2
NHCl2 + NaOCl --> NaOH + NCl3
Additional reactions produce hydrazine, in a variation of the Olin Raschig process.
NH3 + NH2Cl + NaOH --> N2H4 + NaCl + H2O
The hydrazine generated can further react with the monochloramine in an exothermic reaction:[1]
2 NH2Cl + N2H4 --> 2 NH4Cl + N2
Industrial bleaching agents can also be sources of concern. For example, the use of elemental chlorine in the bleaching of wood pulp produces organochlorines, persistent organic pollutants, including dioxins. However, the use of chlorine dioxide in these processes has reduced the dioxin generation to under detectable levels.[4]
# History
Chlorine was first characterized by the Swedish chemist Carl Wilhelm Scheele in 1774 (as an adherent of the Phlogiston theory, he called it "dephlogisticated marine acid"). French chemist Claude Louis Berthollet, noting the bleaching properties of chlorine, invented hypochlorite bleach in 1789. In French, bleach is known as Eau de Javel, after the village where it was manufactured.
Several alternatives to bleach have recently appeared in industrialized countries. These substances are touted as being less toxic, and the use of bleach as a stain remover has become less popular in the United States. However, due to the recent upsurge of illness due to methicillin-resistant Staphylococcus aureus (known as MRSA) and other bacterial pathogens susceptible to bleach, the bleach industry has recovered somewhat, and the use of bleach as a disinfectant is increasing in a variety of industrial and commercial, as well as household settings.
# Chemistry
The process of bleaching can be summarised in the following set of chemical reactions:
Cl2(aq) + H2O(l) <math>\rightleftharpoons</math> H+(aq) + Cl-(aq) + HClO(aq)
The H+ ion of the hypochlorous acid then dissolves into solution, and so the final result is effectively:
Cl2(aq) + H2O(l) <math>\rightleftharpoons</math> 2H+(aq) + Cl-(aq) + ClO-(aq)
# How bleaches work
Color in most dyes and pigments is produced by molecules, such as beta carotene, which contain chromophores. Chemical bleaches work in one of two ways:
- An oxidizing bleach works by breaking the chemical bonds that make up the chromophore. This changes the molecule into a different substance that either does not contain a chromophore, or contains a chromophore that does not absorb visible light.
- A reducing bleach works by converting double bonds in the chromophore into single bonds. This eliminates the ability of the chromophore to absorb visible light.[5]
Sunlight acts as a bleach through a process leading to similar results: high energy photons of light, often in the violet or ultraviolet range, can disrupt the bonds in the chromophore, rendering the resulting substance colorless. Extended exposure often leads to massive discoloration usually reducing the colors to white light and typically very faded blue spectrums.[6] | https://www.wikidoc.org/index.php/Bleach | |
f19fc8404d1093ad00a19cf8792c994019ac3eb0 | wikidoc | Cnicus | Cnicus
Cnicus benedictus (Blessed Thistle), the sole species in the genus Cnicus, is a thistle-like plant in the family Asteraceae, native to the Mediterranean region, from Portugal north to southern France and east to Turkey. It is also sometimes called Cursed Thistle.
It is an annual plant growing to 60 cm tall, with leathery, hairy leaves up to 30 cm long and 8 cm broad, with small spines on the margins. The flowers are yellow, produced in a dense flowerhead (capitulum) 3-4 cm diameter, surrounded by numerous spiny basal bracts.
The related genus Notobasis is included in Cnicus by some botanists; it differs in slender, much spinier leaves, and purple flowers.
# Medical uses
It has sometimes been used as a herb to promote lactation. The crude drug contains about 0.2% cnicin.
It is a compontent in Bitters formulas which used to treat digestive issues.
# Edibility
These thistles are not considered edible, unlike Cirsium, Arctium and Onocordum species; the leaves are considered unpalatable if not bitter. | Cnicus
Cnicus benedictus (Blessed Thistle), the sole species in the genus Cnicus, is a thistle-like plant in the family Asteraceae, native to the Mediterranean region, from Portugal north to southern France and east to Turkey. It is also sometimes called Cursed Thistle.
It is an annual plant growing to 60 cm tall, with leathery, hairy leaves up to 30 cm long and 8 cm broad, with small spines on the margins. The flowers are yellow, produced in a dense flowerhead (capitulum) 3-4 cm diameter, surrounded by numerous spiny basal bracts.
The related genus Notobasis is included in Cnicus by some botanists; it differs in slender, much spinier leaves, and purple flowers.
# Medical uses
It has sometimes been used as a herb to promote lactation. The crude drug contains about 0.2% cnicin.
It is a compontent in Bitters formulas which used to treat digestive issues.
# Edibility
These thistles are not considered edible, unlike Cirsium, Arctium and Onocordum species; the leaves are considered unpalatable if not bitter. | https://www.wikidoc.org/index.php/Blessed_thistle | |
9511621481413c2fca1991f595f8231a5bdf69b2 | wikidoc | Osteon | Osteon
# Overview
Osteons (also called Haversian system in honor of Clopton Havers) are predominant structures found in some lamellar or compact bone. Osteons are found in many of the bones of many mammals, birds, reptiles, and amphibians running in a meandering way but generally parallel to the long axis of bones. It is this section of compact bone that is called matrix.
In the center of the osteon is a central canal, called the Haversian canal.
The central canal is surrounded by concentric layers of matrix called lamellae. These lamellae are laid down one after the other over time, each successive one inside the preceding one. Collagen fibers in a lamella run parallel to each other but the orientation of collagen fibers across separate lamellae is oblique. The fiber density is also lower at the border between adjacent lamellae, which accounts for the distinctive appearance of an osteon.
Osteocytes are found between concentric lamellae and connected to each other and the central canal by cytoplasmic processes through the canals called canaliculi. This network permits the exchange of nutrients and metabolic waste.
Osteons are separated from each other by cement lines. Collagen fibers and canaliculi do not cross cement lines.
The space between separate osteons is occupied by interstitial lamellae, which were formed by pre-existing osteons that have since been reabsorbed.
Osteons are connected to each other and the periosteum by oblique channels called Volkmann's canals.
# Use in archaeology and forensics
Osteons carry their history so that given the right conditions they can be used to "read" the sex, age, health history, motor history and apparently something of the diet of an individual's bone. Osteons and their arrangement also vary according to taxon, so that genus and sometimes species can be differentiated using a bone fragment not otherwise identifiable. This is of use in archaeology, paleontology and forensics. | Osteon
Template:Infobox Anatomy
# Overview
Osteons (also called Haversian system in honor of Clopton Havers) are predominant structures found in some lamellar or compact bone. Osteons are found in many of the bones of many mammals, birds, reptiles, and amphibians running in a meandering way but generally parallel to the long axis of bones. It is this section of compact bone that is called matrix.
In the center of the osteon is a central canal, called the Haversian canal.
The central canal is surrounded by concentric layers of matrix called lamellae. These lamellae are laid down one after the other over time, each successive one inside the preceding one. Collagen fibers in a lamella run parallel to each other but the orientation of collagen fibers across separate lamellae is oblique. The fiber density is also lower at the border between adjacent lamellae, which accounts for the distinctive appearance of an osteon.
Osteocytes are found between concentric lamellae and connected to each other and the central canal by cytoplasmic processes through the canals called canaliculi. This network permits the exchange of nutrients and metabolic waste.
Osteons are separated from each other by cement lines. Collagen fibers and canaliculi do not cross cement lines.
The space between separate osteons is occupied by interstitial lamellae, which were formed by pre-existing osteons that have since been reabsorbed.
Osteons are connected to each other and the periosteum by oblique channels called Volkmann's canals.
# Use in archaeology and forensics
Osteons carry their history so that given the right conditions they can be used to "read" the sex, age, health history, motor history and apparently something of the diet of an individual's bone. Osteons and their arrangement also vary according to taxon, so that genus and sometimes species can be differentiated using a bone fragment not otherwise identifiable. This is of use in archaeology, paleontology and forensics. | https://www.wikidoc.org/index.php/Bone_matrix | |
8fea1c9c9b33410e6f5051a2afa22e7f3acc31ae | wikidoc | Borage | Borage
Borage (Borago officinalis L.), also known as "starflower" (گل گاوزبان in Persian) is an annual herb originating in Syria, but naturalized throughout the Mediterranean region, as well as most of Europe, North Africa, and Iran. It grows to a height of 60-100 cm (2-3 feet), and is bristly-hairy all over the stems and leaves; the leaves are alternate, simple, and 5-15 cm (2-6 in) long. The flowers are small, blue or pink, with five narrow, triangular-pointed petals. It has an indeterminate growth habit allowing it to produce many seeds which may lead to it spreading prolifically beyond where it is first sown or planted. In milder climates, borage will bloom continuously for most of the year.
The leaves have been found to contain small amounts (10 ppm of dried herb) of the liver-toxic pyrrolizidine alkaloids: intermedine, lycopsamine, amabiline and supinine. They taste like fresh cucumber and are used in salads and soups especially in Germany. One of the better known recipes with borage is the Green Sauce made in Frankfurt. Frankfurter Grüne Sauce, as it is called in Germany, is made from seven herbs: parsley, chervil, chives, cress, sorrel, burnet and borage. Borage is also an ingredient in the traditional recipe for a Pimm's Cup. In the Spanish regions of Aragón and Navarra, it's also commonly eaten. One of the simplest recipes uses winter grown borage (because these have grown slowly and taste better) and before flowers appear (although not mandatory) usually cooking it in boiling water with a pair of potatoes. Once plated, the vegetables are seasoned with a little olive oil and salt, before being enjoyed.
The flower, which contains the non-toxic pyrrolizidine alkaloid thesinine, has a sweet honey-like taste and is often used to decorate desserts and dishes.
Tea made from the dried flowers is a traditional calming drink in Iran. It has a rich purple color that turns bright pink by adding a few drops of lemon juice.
Interest in borage remains high because it is the highest known plant based source of gamma-linolenic acid (18:3, cis 6,9,12-octadecatrienoic acid). The seed oil is often marketed as "starflower oil" or "borage oil."
Borage is also rich in oleic and palmitic acid, conferring a hypocholesterolemic effect. This oil, which has recently been commercialised, may regulate metabolism and the hormonal system, and is considered by many naturopathic practitioners to be a good remedy for PMS and menopause symptoms such as the hot flash. Borage is also sometimes indicated to alleviate and heal colds, bronchitis, and respiratory infections in general for its anti-inflammatory and balsamic properties. The flowers can be prepared in infusion to take advantage of its medicinal properties.
# As a companion plant
Borage is not only a pretty, flowering, edible herb, but it also improves the flavor of tomato vines when grown within a few feet of them. | Borage
Borage (Borago officinalis L.), also known as "starflower" (گل گاوزبان in Persian) is an annual herb originating in Syria, but naturalized throughout the Mediterranean region, as well as most of Europe, North Africa, and Iran. It grows to a height of 60-100 cm (2-3 feet), and is bristly-hairy all over the stems and leaves; the leaves are alternate, simple, and 5-15 cm (2-6 in) long. The flowers are small, blue or pink, with five narrow, triangular-pointed petals. It has an indeterminate growth habit allowing it to produce many seeds which may lead to it spreading prolifically beyond where it is first sown or planted. In milder climates, borage will bloom continuously for most of the year.
The leaves have been found to contain small amounts (10 ppm of dried herb) of the liver-toxic pyrrolizidine alkaloids: intermedine, lycopsamine, amabiline and supinine. They taste like fresh cucumber and are used in salads and soups especially in Germany. One of the better known recipes with borage is the Green Sauce made in Frankfurt. Frankfurter Grüne Sauce, as it is called in Germany, is made from seven herbs: parsley, chervil, chives, cress, sorrel, burnet and borage. Borage is also an ingredient in the traditional recipe for a Pimm's Cup. In the Spanish regions of Aragón and Navarra, it's also commonly eaten. One of the simplest recipes uses winter grown borage (because these have grown slowly and taste better) and before flowers appear (although not mandatory) usually cooking it in boiling water with a pair of potatoes. Once plated, the vegetables are seasoned with a little olive oil and salt, before being enjoyed.
The flower, which contains the non-toxic pyrrolizidine alkaloid thesinine, has a sweet honey-like taste and is often used to decorate desserts and dishes.
Tea made from the dried flowers is a traditional calming drink in Iran. It has a rich purple color that turns bright pink by adding a few drops of lemon juice.[citation needed]
Interest in borage remains high because it is the highest known plant based source of gamma-linolenic acid (18:3, cis 6,9,12-octadecatrienoic acid). The seed oil is often marketed as "starflower oil" or "borage oil."
Borage is also rich in oleic and palmitic acid, conferring a hypocholesterolemic effect. This oil, which has recently been commercialised, may regulate metabolism and the hormonal system, and is considered by many naturopathic practitioners to be a good remedy for PMS and menopause symptoms such as the hot flash. Borage is also sometimes indicated to alleviate and heal colds, bronchitis, and respiratory infections in general for its anti-inflammatory and balsamic properties. The flowers can be prepared in infusion to take advantage of its medicinal properties.
# As a companion plant
Borage is not only a pretty, flowering, edible herb, but it also improves the flavor of tomato vines when grown within a few feet of them.[citation needed] | https://www.wikidoc.org/index.php/Borage | |
0f2d5b4b1a53e6b428ae40140a26ce6b1a4679ce | wikidoc | Borane | Borane
In chemistry, a borane is a chemical compound of boron and hydrogen. The boranes comprise a large group of compounds with the generic formulae of BxHy. These compounds do not occur in nature. Many of the boranes readily oxidise on contact with air, some violently. The parent member BH3 is called borane, but it is known only in the gaseous state, and dimerises to form diborane, B2H6. The larger boranes all consist of boron clusters that are polyhedral, some of which exist as isomers. For example, isomers of B20H26 are based on the fusion of two 10-atom clusters.
The most important boranes are diborane B2H6, pentaborane B5H9, and decaborane B10H14.
The development of the chemistry of boron hydrides led to new experimental techniques and theoretical concepts. Boron hydrides have been studied as potential fuels, for rockets and for automotive uses.
Over the past several decades, the scope of boron hydride chemistry has grown to include cages containing atoms other than boron, such as carbon in the carboranes and metals in the metallaboranes, wherein one or more boron atoms are substituted by metal atoms.
## Generic formulae of boranes
The four series of single-cluster boranes have the following general formulae, where "n" is the number of boron atoms:-
There also exists a series of substituted neutral hypercloso-boranes that have the theoretical formulae BnHn. Examples include B12(OCH2Ph)12, which is a stable derivative of hypercloso-B12H12.
## Naming conventions
The naming of neutral boranes is illustrated by the following examples, where the Greek prefix shows the number of boron atoms and the number of hydrogen atoms is in brackets:-
- B5H9 pentaborane(9)
- B6H12 hexaborane(12)
The naming of anions is illustrated by the following, where the hydrogen count is specified first followed by the boron count, and finally the overall charge in brackets:-
- B5H8− octahydropentaborate(1−)
Optionally closo− nido− etc (see above) can be added:-
- B5H9, nido−pentaborane(9)
- B4H10, arachno−tetraborane(10)
- B6H62−, hexahydro−closo−hexaborate(2−)
Understandably many of the compounds have abbreviated common names.
## Cluster types
It was realised in the early 1970s that the geometry of boron clusters are related and that they approximate to deltahedra or to deltahedra with one or more vertices missing. The deltahedra that are found in borane chemistry are (using the names favoured by most chemists):--
One feature of these deltahedra is that boron atoms at the vertices may have different numbers of boron atoms as near neighbours. For example, in the pentagonal bipyramid, 2 borons have 3 neighbors, 3 have 4 neighbours, whereas in the octahedral cluster all vertices are the same, each boron having 4 neighbours. These differences between the boron atoms in different positions are important in determining structure, as they have different chemical shifts in the 11B NMR spectra.
- Diborane, B2H6
Diborane, B2H6
- Pentaborane-, B5H9
- Decaborane-, B10H14
- B12H122-
B12H122-
B6H10 is a typical example. Its geometry is, in essence, a 7-boron framework (pentagonal bipyramid), missing a vertex that had the highest number of near neighbours, e.g., a vertex with 5 neighbours. The extra hydrogen atoms bridge around the open face. A notable exception to this general scheme is that of B8H12, which would be expected to have a nido- geometry (based on B9H92− missing 1 vertex), but is similar in geometry to B8H14, which is based on B10H102−.
The names for the series of boranes are derived from this general scheme for the cluster geometries:-
- hypercloso- (from the Greek for "over cage") a closed complete cluster, e.g., B8Cl8 is a slightly distorted dodecahedron
- closo- (from the Greek for "cage") a closed complete cluster, e.g., icosahedral B12H122−
- nido- (from the Latin for "nest") B occupies n vertices of an n+1 deltahedron, e.g., B5H9 an octahedron missing 1 vertex
- arachno- (from the Greek for "spiders web") B occupies n vertices of an n+2 deltahedron e.g. B4H10 an octahedron missing 2 vertices
- hypho- (from the Greek for "net") B occupies n vertices of an n+3 deltahedron possibly B8H16 has this structure, an octahedron missing 3 vertices
- conjuncto- 2 or more of the above are fused together
## Bonding in boranes
Boranes are electron-deficient and pose a problem for conventional descriptions of covalent bonding that involves shared electron pairs. BH3 is a trigonal planar molecule (D3h molecular symmetry). Diborane has a hydrogen-bridged structure, see the diborane article.
The description of the bonding in the larger boranes formulated by William Lipscomb involved:
- 3 center 2 electron B-H-B hydrogen bridges
- 3-center 2-electron B-B-B bonds
- 2-center 2-electron bonds (in B-B, B-H and BH2)
The styx number was introduced to aid in electron counting where s = count of 3-center B-H-B bonds; t = count of 3-center B-B-B bonds; y = count of 2-center B-B bonds and x = count of BH2 groups.
Lipscomb's methodology has largely been superseded by a molecular orbital approach, although it still affords insights. The results of this have been summarised in a simple but powerful rule, PSEPT, often known as Wade's rules, that can be used to predict the cluster type, closo-, nido-, etc. The power of this rule is its ease of use and general applicability to many different cluster types other than boranes.
There are continuing efforts by theoretical chemists to improve the treatment of the bonding in boranes — an example is Stone's tensor surface harmonic treatment of cluster bonding. A recent development is four-center two-electron bond.
## Chemistry of boranes
### Properties and reactivity trends
Boranes are all colourless and diamagnetic. They are reactive compounds and some are pyrophoric. The majority are highly poisonous and require special handling precautions.
### Synthesis and general reactivity
- electrophilic substitution
nucleophilic substitution by Lewis bases
deprotonation by strong bases
cluster building reactions with borohydrides
reaction of a nido-borane with an alkyne to give a carborane cluster
- electrophilic substitution
- nucleophilic substitution by Lewis bases
- deprotonation by strong bases
- cluster building reactions with borohydrides
- reaction of a nido-borane with an alkyne to give a carborane cluster
Boranes can react to form hetero-boranes, e.g., carboranes or metalloboranes (clusters that contain boron and metal atoms).
# History
The development of the chemistry of boranes posed two challenges to chemists. First, new laboratory techniques had to be developed to handle these very reactive compounds; second, the structures of the compounds challenged the accepted theories of chemical bonding.
The German chemist Alfred Stock
first characterized the series of boron-hydrogen compounds. His group developed the glass vacuum line and techniques for handling the compounds. However, exposure to mercury (used in mercury diffusion pumps and float valves) caused Stock to develop mercury poisoning, which he documented in the first scientific papers on the subject. The chemical bonding of the borane clusters was investigated by Lipscomb and his co-workers. Lipscomb was awarded the Nobel prize in Chemistry in 1976 for this work. PSEPT, (Wades rules) can be used to predict the structures of boranes.
Interest in boranes increased during World War II due to the potential of uranium borohydride for enrichment of the uranium isotopes. In the US, a team led by Schlesinger developed the basic chemistry of the boron hydrides and the related aluminium hydrides. Although uranium borohydride was not utilized for isotopic separations, Schessinger’s work laid the foundation for a host of boron hydride reagents for organic synthesis, most of which were developed by his student Herbert C. Brown. Borane-based reagents are now widely used in organic synthesis. For example, sodium borohydride is the standard reagent for converting aldehydes and ketones to alcohols. Brown was awarded the Nobel prize in Chemistry in 1979 for this work.
In the 1950s and early '60s, the US and USSR invested in boron hydrides as high-energy fuels (ethylboranes, for example) for very fast aircraft such as the XB-70 Valkyrie. The development of advanced surface-to-air missiles made the fast aircraft redundant, and the fuel programs were terminated, although triethylborane (TEB) was later used to light the engines of the SR-71 Blackbird high-speed plane.
# General references
- Fox M.A., Wade K. Pure Appl. Chem. (2003),75,9, 1315
- Template:Greenwood&Earnshaw
- Template:Cotton&Wilkinson6th
# Footnotes
- ↑ Peymann T., Knobler C.B.,Khan S.I., Hawthorne M.F. Angew. Chemie Intnl Ed.(2001) 40,9,1664
- ↑ Brown, H. C. “Organic Syntheses via Boranes” John Wiley & Sons, Inc. New York: 1975. ISBN 0-471-11280-1.
cs:Borany
de:Borane
it:Borani
nl:Boranen
nds:Boran
uk:Бороводні | Borane
In chemistry, a borane is a chemical compound of boron and hydrogen. The boranes comprise a large group of compounds with the generic formulae of BxHy. These compounds do not occur in nature. Many of the boranes readily oxidise on contact with air, some violently. The parent member BH3 is called borane, but it is known only in the gaseous state, and dimerises to form diborane, B2H6. The larger boranes all consist of boron clusters that are polyhedral, some of which exist as isomers. For example, isomers of B20H26 are based on the fusion of two 10-atom clusters.
The most important boranes are diborane B2H6, pentaborane B5H9, and decaborane B10H14.
The development of the chemistry of boron hydrides led to new experimental techniques and theoretical concepts. Boron hydrides have been studied as potential fuels, for rockets and for automotive uses.
Over the past several decades, the scope of boron hydride chemistry has grown to include cages containing atoms other than boron, such as carbon in the carboranes and metals in the metallaboranes, wherein one or more boron atoms are substituted by metal atoms.
## Generic formulae of boranes
The four series of single-cluster boranes have the following general formulae, where "n" is the number of boron atoms:-
There also exists a series of substituted neutral hypercloso-boranes that have the theoretical formulae BnHn. Examples include B12(OCH2Ph)12, which is a stable derivative of hypercloso-B12H12[1].
## Naming conventions
The naming of neutral boranes is illustrated by the following examples, where the Greek prefix shows the number of boron atoms and the number of hydrogen atoms is in brackets:-
- B5H9 pentaborane(9)
- B6H12 hexaborane(12)
The naming of anions is illustrated by the following, where the hydrogen count is specified first followed by the boron count, and finally the overall charge in brackets:-
- B5H8− octahydropentaborate(1−)
Optionally closo− nido− etc (see above) can be added:-
- B5H9, nido−pentaborane(9)
- B4H10, arachno−tetraborane(10)
- B6H62−, hexahydro−closo−hexaborate(2−)
Understandably many of the compounds have abbreviated common names.
## Cluster types
It was realised in the early 1970s that the geometry of boron clusters are related and that they approximate to deltahedra or to deltahedra with one or more vertices missing. The deltahedra that are found in borane chemistry are (using the names favoured by most chemists):--
One feature of these deltahedra is that boron atoms at the vertices may have different numbers of boron atoms as near neighbours. For example, in the pentagonal bipyramid, 2 borons have 3 neighbors, 3 have 4 neighbours, whereas in the octahedral cluster all vertices are the same, each boron having 4 neighbours. These differences between the boron atoms in different positions are important in determining structure, as they have different chemical shifts in the 11B NMR spectra.
- Diborane, B2H6
Diborane, B2H6
- Pentaborane-[9], B5H9
- Decaborane-[14], B10H14
- B12H122-
B12H122-
B6H10 is a typical example. Its geometry is, in essence, a 7-boron framework (pentagonal bipyramid), missing a vertex that had the highest number of near neighbours, e.g., a vertex with 5 neighbours. The extra hydrogen atoms bridge around the open face. A notable exception to this general scheme is that of B8H12, which would be expected to have a nido- geometry (based on B9H92− missing 1 vertex), but is similar in geometry to B8H14, which is based on B10H102−.
The names for the series of boranes are derived from this general scheme for the cluster geometries:-
- hypercloso- (from the Greek for "over cage") a closed complete cluster, e.g., B8Cl8 is a slightly distorted dodecahedron
- closo- (from the Greek for "cage") a closed complete cluster, e.g., icosahedral B12H122−
- nido- (from the Latin for "nest") B occupies n vertices of an n+1 deltahedron, e.g., B5H9 an octahedron missing 1 vertex
- arachno- (from the Greek for "spiders web") B occupies n vertices of an n+2 deltahedron e.g. B4H10 an octahedron missing 2 vertices
- hypho- (from the Greek for "net") B occupies n vertices of an n+3 deltahedron possibly B8H16 has this structure, an octahedron missing 3 vertices
- conjuncto- 2 or more of the above are fused together
## Bonding in boranes
Boranes are electron-deficient and pose a problem for conventional descriptions of covalent bonding that involves shared electron pairs. BH3 is a trigonal planar molecule (D3h molecular symmetry). Diborane has a hydrogen-bridged structure, see the diborane article.
The description of the bonding in the larger boranes formulated by William Lipscomb involved:
- 3 center 2 electron B-H-B hydrogen bridges
- 3-center 2-electron B-B-B bonds
- 2-center 2-electron bonds (in B-B, B-H and BH2)
The styx number was introduced to aid in electron counting where s = count of 3-center B-H-B bonds; t = count of 3-center B-B-B bonds; y = count of 2-center B-B bonds and x = count of BH2 groups.
Lipscomb's methodology has largely been superseded by a molecular orbital approach, although it still affords insights. The results of this have been summarised in a simple but powerful rule, PSEPT, often known as Wade's rules, that can be used to predict the cluster type, closo-, nido-, etc. The power of this rule is its ease of use and general applicability to many different cluster types other than boranes.
There are continuing efforts by theoretical chemists to improve the treatment of the bonding in boranes — an example is Stone's tensor surface harmonic treatment of cluster bonding. A recent development is four-center two-electron bond.
## Chemistry of boranes
### Properties and reactivity trends
Boranes are all colourless and diamagnetic. They are reactive compounds and some are pyrophoric. The majority are highly poisonous and require special handling precautions.
### Synthesis and general reactivity
- electrophilic substitution
nucleophilic substitution by Lewis bases
deprotonation by strong bases
cluster building reactions with borohydrides
reaction of a nido-borane with an alkyne to give a carborane cluster
- electrophilic substitution
- nucleophilic substitution by Lewis bases
- deprotonation by strong bases
- cluster building reactions with borohydrides
- reaction of a nido-borane with an alkyne to give a carborane cluster
Boranes can react to form hetero-boranes, e.g., carboranes or metalloboranes (clusters that contain boron and metal atoms).
# History
The development of the chemistry of boranes posed two challenges to chemists. First, new laboratory techniques had to be developed to handle these very reactive compounds; second, the structures of the compounds challenged the accepted theories of chemical bonding.
The German chemist Alfred Stock
first characterized the series of boron-hydrogen compounds. His group developed the glass vacuum line and techniques for handling the compounds. However, exposure to mercury (used in mercury diffusion pumps and float valves) caused Stock to develop mercury poisoning, which he documented in the first scientific papers on the subject. The chemical bonding of the borane clusters was investigated by Lipscomb and his co-workers. Lipscomb was awarded the Nobel prize in Chemistry in 1976 for this work. PSEPT, (Wades rules) can be used to predict the structures of boranes.
Interest in boranes increased during World War II due to the potential of uranium borohydride for enrichment of the uranium isotopes. In the US, a team led by Schlesinger developed the basic chemistry of the boron hydrides and the related aluminium hydrides. Although uranium borohydride was not utilized for isotopic separations, Schessinger’s work laid the foundation for a host of boron hydride reagents for organic synthesis, most of which were developed by his student Herbert C. Brown. Borane-based reagents are now widely used in organic synthesis. For example, sodium borohydride is the standard reagent for converting aldehydes and ketones to alcohols. Brown was awarded the Nobel prize in Chemistry in 1979 for this work.[2]
In the 1950s and early '60s, the US and USSR invested in boron hydrides as high-energy fuels (ethylboranes, for example) for very fast aircraft such as the XB-70 Valkyrie. The development of advanced surface-to-air missiles made the fast aircraft redundant, and the fuel programs were terminated, although triethylborane (TEB) was later used to light the engines of the SR-71 Blackbird high-speed plane.[3]
# General references
- Fox M.A., Wade K. Pure Appl. Chem. (2003),75,9, 1315
- Template:Greenwood&Earnshaw
- Template:Cotton&Wilkinson6th
# Footnotes
- ↑ Peymann T., Knobler C.B.,Khan S.I., Hawthorne M.F. Angew. Chemie Intnl Ed.(2001) 40,9,1664
- ↑ Brown, H. C. “Organic Syntheses via Boranes” John Wiley & Sons, Inc. New York: 1975. ISBN 0-471-11280-1.
- ↑ http://incolor.inebraska.com/hwolfe/history/sr71.pdf
cs:Borany
de:Borane
it:Borani
nl:Boranen
nds:Boran
uk:Бороводні
Template:WS
Template:WH | https://www.wikidoc.org/index.php/Borane | |
4006e2b3641046788b789de96477278480652153 | wikidoc | Borate | Borate
Borates in chemistry are chemical compounds containing boron bonded to three oxygen atoms written as B(OR)3. In B(OR)4− anions, this number increases to four.
The borate ion is BO33−. it forms salts with metallic elements. Boron found in nature is commonly as a borate mineral. Boron is also found combined with silicate to form complex borosilicate minerals such as the tourmalines.
Borate exists in many forms. In acid and near-neutral conditions, it is boric acid, commonly written as H3BO3 but more correctly B(OH)3. The pKa of boric acid is 9.14 at 25C. Boric acid does not dissociate in aqueous solution, but is acidic due to its interaction with water molecules, forming tetrahydroxyborate:
Polyborate anions are formed at pH 7–10 if the boron concentration is higher than about 0.025 mol/L. The best known of these is the tetraborate ion, found in the mineral borax:
Even though boric acid adds hydroxide to form B(OH)4−, you may find for pKa values and other calculations, the fictitious ions are easier to use. Thus for a typical polyprotic acid, the deprotonation series dihydrogen borate , hydrogen borate and borate may be written as pH increases.
Boric acid can be used to form many polymeric ions. The tetraborate ion, B4O72−, is very common; the hydrogen tetraborate ion, HB4O7−, as well as triborate and pentaborate, are also seen. The various metaborate ions have an empirical formula of BO2−, and form metaborate compounds. Formation of these complicated, potentially infinite network structures is extensive, perhaps surpassed only by the silicates.
Common borate salts include sodium metaborate, NaBO2, and sodium tetraborate, Na2B4O7. The latter also occurs naturally as the hydrous mineral borax, Na2B4O7·10H2O. Boron, California contains large borax deposits and is used extensively for borate mining. The Atacama Desert in Chile also contains mineable borate concentrations.
Various forms of borate are used as wood preservatives or fungicides such as disodium octaborate tetrahydrate.
# Borate esters
Borate esters are organic compounds of the type B(OR)3 where R is an organic residue (for example alkyl or aryl). Borate esters include trimethyl borate, B(OCH3)3, which is used as a precursor to boronic esters for Suzuki couplings. | Borate
Borates in chemistry are chemical compounds containing boron bonded to three oxygen atoms written as B(OR)3. In B(OR)4− anions, this number increases to four.
The borate ion is BO33−. it forms salts with metallic elements. Boron found in nature is commonly as a borate mineral. Boron is also found combined with silicate to form complex borosilicate minerals such as the tourmalines.
Borate exists in many forms. In acid and near-neutral conditions, it is boric acid, commonly written as H3BO3 but more correctly B(OH)3. The pKa of boric acid is 9.14 at 25C. Boric acid does not dissociate in aqueous solution, but is acidic due to its interaction with water molecules, forming tetrahydroxyborate:
Polyborate anions are formed at pH 7–10 if the boron concentration is higher than about 0.025 mol/L. The best known of these is the tetraborate ion, found in the mineral borax:
Even though boric acid adds hydroxide to form B(OH)4−, you may find for pKa values and other calculations, the fictitious ions are easier to use. Thus for a typical polyprotic acid, the deprotonation series dihydrogen borate [H2BO3−;], hydrogen borate [HBO32−] and borate [BO33−] may be written as pH increases.
Boric acid can be used to form many polymeric ions. The tetraborate ion, B4O72−, is very common; the hydrogen tetraborate ion, HB4O7−, as well as triborate and pentaborate, are also seen. The various metaborate ions have an empirical formula of BO2−, and form metaborate compounds. Formation of these complicated, potentially infinite network structures is extensive, perhaps surpassed only by the silicates.
Common borate salts include sodium metaborate, NaBO2, and sodium tetraborate, Na2B4O7. The latter also occurs naturally as the hydrous mineral borax, Na2B4O7·10H2O. Boron, California contains large borax deposits and is used extensively for borate mining. The Atacama Desert in Chile also contains mineable borate concentrations.
Various forms of borate are used as wood preservatives or fungicides such as disodium octaborate tetrahydrate.
# Borate esters
Borate esters are organic compounds of the type B(OR)3 where R is an organic residue (for example alkyl or aryl). Borate esters include trimethyl borate, B(OCH3)3, which is used as a precursor to boronic esters for Suzuki couplings.
# External links
- Non-CCA Wood Preservatives: Guide to Selected Resources - National Pesticide Information Center
bn:বোরেট
de:Borate
nl:Boraat
Template:WikiDoc Sources | https://www.wikidoc.org/index.php/Borate | |
7a242e0a1d9e0cb8d7e24ae1599c3bbb78972f5c | wikidoc | Botany | Botany
Botany, plant science(s), phytology, or plant biology is a branch of biology and is the scientific study of plant life. Botany covers a wide range of scientific disciplines that study plants, algae, and fungi including: structure, growth, reproduction, metabolism, development, diseases, and chemical properties and evolutionary relationships between the different groups. The word is Greek (βοτάνη: botane) originally meaning pasture, grass or fodder. The study of plants and botany began with tribal lore, used to identify edible, medicinal and poisonous plants, making botany one of the oldest sciences. From this ancient interest in plants, the scope of botany has increased to include the study of over 550,000 kinds or species of living organisms.
# Scope and importance of botany
As with other life forms in biology, plant life can be studied from different perspectives, from the molecular, genetic and biochemical level through organelles, cells, tissues, organs, individuals, plant populations, and communities of plants. At each of these levels a botanist might be concerned with the classification (taxonomy), structure (anatomy and morphology), or function (physiology) of plant life.
Historically, botany covered all organisms that were not considered to be animals. Some of these organisms are no longer considered to be part of the plant kingdom – these include fungi (studied in mycology), lichens (lichenology), bacteria (bacteriology), viruses (virology) and single-celled algae, which are now grouped as part of the Protista. However, attention is still given to these groups by botanists, and fungi, lichens, bacteria and photosynthetic protists are usually covered in introductory botany courses.
The study of plants has importance for a number of reasons. Plants are a fundamental part of life on Earth. They generate the oxygen, food, fibres, fuel and medicine that allow higher life forms to exist. Plants also absorb carbon dioxide through photosynthesis, a minor greenhouse gas that in large amounts can effect global climate. It is believed that the evolution of plants has changed the global atmosphere of the earth early in the earth's history and paleobotanists study ancient plants in the fossil record. A good understanding of plants is crucial to the future of human societies as it allows us to:
- Produce food to feed an expanding population
- Understand fundamental life processes
- Produce medicine and materials to treat diseases and other ailments
- Understand environmental changes more clearly
## Human nutrition
Virtually all foods eaten come from plants, either directly from staple foods and other fruit and vegetables, or indirectly through livestock or other animals, which rely on plants for their nutrition. Plants are the fundamental base of nearly all food chains because they use the energy from the sun and nutrients from the soil and atmosphere and convert them into a form that can be consumed and utilized by animals; this is what ecologists call the first trophic level. Botanists also study how plants produce food we can eat and how to increase yields and therefore their work is important in mankind's ability to feed the world and provide food security for future generations, for example through plant breeding. Botanists also study weeds, plants which are considered to be a nuisance in a particular location. Weeds are a considerable problem in agriculture, and botany provides some of the basic science used to understand how to minimize 'weed' impact in agriculture and native ecosystems. Ethnobotany is the study of the relationships between plants and people.
## Fundamental life processes
Plants are convenient organisms in which fundamental life processes (like cell division and protein synthesis for example) can be studied, without the ethical dilemmas of studying animals or humans. The genetic laws of inheritance were discovered in this way by Gregor Mendel, who was studying the way pea shape is inherited. What Mendel learned from studying plants has had far reaching benefits outside of botany. Additionally, Barbara McClintock discovered 'jumping genes' by studying maize. These are a few examples that demonstrate how botanical research has an ongoing relevance to the understanding of fundamental biological processes.
## Medicine and materials
Many medicinal and recreational drugs, like tetrahydrocannabinol, caffeine, and nicotine come directly from the plant kingdom. Others are simple derivatives of botanical natural products; for example aspirin is based on the pain killer salicylic acid which originally came from the bark of willow trees.
There may be many novel cures for diseases provided by plants, waiting to be discovered. Popular stimulants like coffee, chocolate, tobacco, and tea also come from plants. Most alcoholic beverages come from fermenting plants such as barley and grapes.
Plants also provide us with many natural materials, such as cotton, wood, paper, linen, hemp, vegetable oils, some types of rope, and rubber. The production of silk would not be possible without the cultivation of the mulberry plant. Sugarcane, rapeseed, soy, cereal grain, biomass crops and other plant products with a high energy content have recently been put to use as sources of biofuels, which are potentially important alternatives to fossil fuels (also see biodiesel).
## Environmental changes
Plants can also help us understand changes in on our environment in many ways.
- Understanding habitat destruction and species extinction is dependent on an accurate and complete catalog of plant systematics and taxonomy.
- Plant responses to ultraviolet radiation can help us monitor problems like the ozone depletion.
- Analyzing pollen deposited by plants thousands or millions of years ago can help scientists to reconstruct past climates and predict future ones, an essential part of climate change research.
- Recording and analyzing the timing of plant life cycles are important parts of phenology used in climate-change research.
- Lichens, which are sensitive to atmospheric conditions, have been extensively used as pollution indicators.
In many different ways, plants can act a little like the 'miners canary', an early warning system alerting us to important changes in our environment. In addition to these practical and scientific reasons, plants are extremely valuable as recreation for millions of people who enjoy gardening, horticultural and culinary uses of plants every day.
# History
Early examples of plant taxonomy occur in the Rigveda, that divides plants into Vrska (tree), Osadhi (herbs useful to humans) and Virudha (creepers). which are further subdivided. The Atharvaveda divides plants into eight classes, Visakha (spreading branches), Manjari (leaves with long clusters), Sthambini (bushy plants), Prastanavati (which expands); Ekasrnga (those with monopodial growth), Pratanavati (creeping plants), Amsumati (with many stalks), and Kandini (plants with knotty joints). The Taittiriya Samhita and classifies the plant kingdom into vrksa, vana and druma (trees), visakha (shrubs with spreading branches), sasa (herbs), amsumali (a spreading or deliquescent plant), vratati (climber), stambini (bushy plant), pratanavati (creeper), and alasala (those spreading on the ground).
Manusmriti proposed a classification of plants in eight major categories. Charaka Samhitā and Sushruta Samhita and the Vaisesikas also present an elaborate taxonomy.
Parashara, the author of Vrksayurveda (the science of life of trees), classifies plants into Dvimatrka (Dicotyledons) and Ekamatrka (Monocotyledons). These are further classified into Samiganiya (Fabaceae), Puplikagalniya (Rutaceae), Svastikaganiya (Cruciferae), Tripuspaganiya (Cucurbitaceae), Mallikaganiya (Apocynaceae), and Kurcapuspaganiya (Asteraceae).
Among the earliest of botanical works in Europe, written around 300 B.C., are two large treatises by Theophrastus: On the History of Plants (Historia Plantarum) and On the Causes of Plants. Together these books constitute the most important contribution to botanical science during antiquity and on into the Middle Ages. The Roman medical writer Dioscorides provides important evidence on Greek and Roman knowledge of medicinal plants.
In ancient China, the recorded listing of different plants and herb concoctions for pharmaceutical purposes spans back to at least the Warring States (481 BC-221 BC). Many Chinese writers over the centuries contributed to the written knowledge of herbal pharmaceutics. There was the Han Dynasty (202 BC-220 AD) written work of the Huangdi Neijing and the famous pharmacologist Zhang Zhongjing of the 2nd century. There was also the 11th century scientists and statesmen Su Song and Shen Kuo, who compiled treatises on herbal medicine and included the use of mineralogy.
Important medieval works of plant physiology include the Prthviniraparyam of Udayana, Nyayavindutika of Dharmottara, Saddarsana-samuccaya of Gunaratna, and Upaskara of Sankaramisra.
In 1665, using an early microscope, Robert Hooke discovered cells in cork, and a short time later in living plant tissue. The German Leonhart Fuchs, the Swiss Conrad von Gesner, and the British authors Nicholas Culpeper and John Gerard published herbals that gave information on the medicinal uses of plants.
In 1754 Carl von Linné (Carl Linnaeus) divided the plant Kingdom into 25 classes.
## Modern botany
A considerable amount of new knowledge today is being generated from studying model plants like Arabidopsis thaliana. This weedy species in the mustard family was one of the first plants to have its genome sequenced. The sequencing of the rice (Oryza sativa) genome and a large international research community have made rice the de facto cereal/grass/monocot model. Another grass species, Brachypodium distachyon is also emerging as an experimental model for understanding the genetic, cellular and molecular biology of temperate grasses. Other commercially-important staple foods like wheat, maize, barley, rye, pearl millet and soybean are also having their genomes sequenced. Some of these are challenging to sequence because they have more than two haploid (n) sets of chromosomes, a condition known as polyploidy, common in the plant kingdom. Chlamydomonas reinhardtii (a single-celled, green alga) is another plant model organism that has been extensively studied and provided important insights into cell biology.
In 1998 the Angiosperm Phylogeny Group published a phylogeny of flowering plants based on an analysis of DNA sequences from most families of flowering plants. As a result of this work, major questions such as which families represent the earliest branches in the genealogy of angiosperms are now understood. Investigating how plant species are related to each other allows botanists to better understand the process of evolution in plants.
## Subdisciplines of Botany
- Agronomy—Application of plant science to crop production
- Bryology—Mosses, liverworts, and hornworts
- Economic botany—The place of plants in economics
- Ethnobotany—Relationship between humans and plants
- Forestry—Forest management and related studies
- Horticulture—Cultivated plants
- Paleobotany—Fossil plants
- Palynology—Pollen and spores
- Phycology - Algae
- Phytochemistry—Plant secondary chemistry and chemical processes
- Phytopathology—Plant diseases
- Plant anatomy—Cell and tissue structure
- Plant ecology—Role of plants in the environment
- Plant genetics—Genetic inheritance in plants
- Plant morphology—Structure and life cycles
- Plant physiology—Life functions of plants
- Plant systematics—Classification and naming of plants
# Notable Botanists
- Luther Burbank (1849-1926), American botanist, horticulturist, and a pioneer in agricultural science.
- Joseph Dalton Hooker (1817-1911), English botanist and explorer. Second winner of Darwin Medal.
- Thomas Henry Huxley (1825–1895), English biologist, known as "Darwin's Bulldog" for his advocacy of Charles Darwin's theory of evolution. Third winner of Darwin Medal.
- Gregor Johann Mendel (1822-1884), Augustinian priest and scientist, and is often called the father of genetics for his study of the inheritance of traits in pea plants.
- Leonardo da Vinci (1452-1519) | Botany
Botany, plant science(s), phytology, or plant biology is a branch of biology and is the scientific study of plant life. Botany covers a wide range of scientific disciplines that study plants, algae, and fungi including: structure, growth, reproduction, metabolism, development, diseases, and chemical properties and evolutionary relationships between the different groups. The word is Greek (βοτάνη: botane) originally meaning pasture, grass or fodder. The study of plants and botany began with tribal lore, used to identify edible, medicinal and poisonous plants, making botany one of the oldest sciences. From this ancient interest in plants, the scope of botany has increased to include the study of over 550,000 kinds or species of living organisms.
# Scope and importance of botany
As with other life forms in biology, plant life can be studied from different perspectives, from the molecular, genetic and biochemical level through organelles, cells, tissues, organs, individuals, plant populations, and communities of plants. At each of these levels a botanist might be concerned with the classification (taxonomy), structure (anatomy and morphology), or function (physiology) of plant life.
Historically, botany covered all organisms that were not considered to be animals. Some of these organisms are no longer considered to be part of the plant kingdom – these include fungi (studied in mycology), lichens (lichenology), bacteria (bacteriology), viruses (virology) and single-celled algae, which are now grouped as part of the Protista. However, attention is still given to these groups by botanists, and fungi, lichens, bacteria and photosynthetic protists are usually covered in introductory botany courses.
The study of plants has importance for a number of reasons. Plants are a fundamental part of life on Earth. They generate the oxygen, food, fibres, fuel and medicine that allow higher life forms to exist. Plants also absorb carbon dioxide through photosynthesis, a minor greenhouse gas that in large amounts can effect global climate. It is believed that the evolution of plants has changed the global atmosphere of the earth early in the earth's history and paleobotanists study ancient plants in the fossil record. A good understanding of plants is crucial to the future of human societies as it allows us to:
- Produce food to feed an expanding population
- Understand fundamental life processes
- Produce medicine and materials to treat diseases and other ailments
- Understand environmental changes more clearly
## Human nutrition
Virtually all foods eaten come from plants, either directly from staple foods and other fruit and vegetables, or indirectly through livestock or other animals, which rely on plants for their nutrition. Plants are the fundamental base of nearly all food chains because they use the energy from the sun and nutrients from the soil and atmosphere and convert them into a form that can be consumed and utilized by animals; this is what ecologists call the first trophic level. Botanists also study how plants produce food we can eat and how to increase yields and therefore their work is important in mankind's ability to feed the world and provide food security for future generations, for example through plant breeding. Botanists also study weeds, plants which are considered to be a nuisance in a particular location. Weeds are a considerable problem in agriculture, and botany provides some of the basic science used to understand how to minimize 'weed' impact in agriculture and native ecosystems. Ethnobotany is the study of the relationships between plants and people.
## Fundamental life processes
Plants are convenient organisms in which fundamental life processes (like cell division and protein synthesis for example) can be studied, without the ethical dilemmas of studying animals or humans. The genetic laws of inheritance were discovered in this way by Gregor Mendel, who was studying the way pea shape is inherited. What Mendel learned from studying plants has had far reaching benefits outside of botany. Additionally, Barbara McClintock discovered 'jumping genes' by studying maize. These are a few examples that demonstrate how botanical research has an ongoing relevance to the understanding of fundamental biological processes.
## Medicine and materials
Many medicinal and recreational drugs, like tetrahydrocannabinol, caffeine, and nicotine come directly from the plant kingdom. Others are simple derivatives of botanical natural products; for example aspirin is based on the pain killer salicylic acid which originally came from the bark of willow trees.[2]
There may be many novel cures for diseases provided by plants, waiting to be discovered. Popular stimulants like coffee, chocolate, tobacco, and tea also come from plants. Most alcoholic beverages come from fermenting plants such as barley and grapes.
Plants also provide us with many natural materials, such as cotton, wood, paper, linen, hemp, vegetable oils, some types of rope, and rubber. The production of silk would not be possible without the cultivation of the mulberry plant. Sugarcane, rapeseed, soy, cereal grain, biomass crops and other plant products with a high energy content have recently been put to use as sources of biofuels, which are potentially important alternatives to fossil fuels (also see biodiesel).
## Environmental changes
Plants can also help us understand changes in on our environment in many ways.
- Understanding habitat destruction and species extinction is dependent on an accurate and complete catalog of plant systematics and taxonomy.
- Plant responses to ultraviolet radiation can help us monitor problems like the ozone depletion.
- Analyzing pollen deposited by plants thousands or millions of years ago can help scientists to reconstruct past climates and predict future ones, an essential part of climate change research.
- Recording and analyzing the timing of plant life cycles are important parts of phenology used in climate-change research.
- Lichens, which are sensitive to atmospheric conditions, have been extensively used as pollution indicators.
In many different ways, plants can act a little like the 'miners canary', an early warning system alerting us to important changes in our environment. In addition to these practical and scientific reasons, plants are extremely valuable as recreation for millions of people who enjoy gardening, horticultural and culinary uses of plants every day.
# History
Early examples of plant taxonomy occur in the Rigveda, that divides plants into Vrska (tree), Osadhi (herbs useful to humans) and Virudha (creepers). which are further subdivided. The Atharvaveda divides plants into eight classes, Visakha (spreading branches), Manjari (leaves with long clusters), Sthambini (bushy plants), Prastanavati (which expands); Ekasrnga (those with monopodial growth), Pratanavati (creeping plants), Amsumati (with many stalks), and Kandini (plants with knotty joints). The Taittiriya Samhita and classifies the plant kingdom into vrksa, vana and druma (trees), visakha (shrubs with spreading branches), sasa (herbs), amsumali (a spreading or deliquescent plant), vratati (climber), stambini (bushy plant), pratanavati (creeper), and alasala (those spreading on the ground).
Manusmriti proposed a classification of plants in eight major categories. Charaka Samhitā and Sushruta Samhita and the Vaisesikas also present an elaborate taxonomy.
Parashara, the author of Vrksayurveda (the science of life of trees), classifies plants into Dvimatrka (Dicotyledons) and Ekamatrka (Monocotyledons). These are further classified into Samiganiya (Fabaceae), Puplikagalniya (Rutaceae), Svastikaganiya (Cruciferae), Tripuspaganiya (Cucurbitaceae), Mallikaganiya (Apocynaceae), and Kurcapuspaganiya (Asteraceae). [2]
Among the earliest of botanical works in Europe, written around 300 B.C., are two large treatises by Theophrastus: On the History of Plants (Historia Plantarum) and On the Causes of Plants. Together these books constitute the most important contribution to botanical science during antiquity and on into the Middle Ages. The Roman medical writer Dioscorides provides important evidence on Greek and Roman knowledge of medicinal plants.
In ancient China, the recorded listing of different plants and herb concoctions for pharmaceutical purposes spans back to at least the Warring States (481 BC-221 BC). Many Chinese writers over the centuries contributed to the written knowledge of herbal pharmaceutics. There was the Han Dynasty (202 BC-220 AD) written work of the Huangdi Neijing and the famous pharmacologist Zhang Zhongjing of the 2nd century. There was also the 11th century scientists and statesmen Su Song and Shen Kuo, who compiled treatises on herbal medicine and included the use of mineralogy.
Important medieval works of plant physiology include the Prthviniraparyam of Udayana, Nyayavindutika of Dharmottara, Saddarsana-samuccaya of Gunaratna, and Upaskara of Sankaramisra. [3]
In 1665, using an early microscope, Robert Hooke discovered cells in cork, and a short time later in living plant tissue. The German Leonhart Fuchs, the Swiss Conrad von Gesner, and the British authors Nicholas Culpeper and John Gerard published herbals that gave information on the medicinal uses of plants.
In 1754 Carl von Linné (Carl Linnaeus) divided the plant Kingdom into 25 classes.[3]
## Modern botany
A considerable amount of new knowledge today is being generated from studying model plants like Arabidopsis thaliana. This weedy species in the mustard family was one of the first plants to have its genome sequenced. The sequencing of the rice (Oryza sativa) genome and a large international research community have made rice the de facto cereal/grass/monocot model. Another grass species, Brachypodium distachyon is also emerging as an experimental model for understanding the genetic, cellular and molecular biology of temperate grasses. Other commercially-important staple foods like wheat, maize, barley, rye, pearl millet and soybean are also having their genomes sequenced. Some of these are challenging to sequence because they have more than two haploid (n) sets of chromosomes, a condition known as polyploidy, common in the plant kingdom. Chlamydomonas reinhardtii (a single-celled, green alga) is another plant model organism that has been extensively studied and provided important insights into cell biology.
In 1998 the Angiosperm Phylogeny Group published a phylogeny of flowering plants based on an analysis of DNA sequences from most families of flowering plants. As a result of this work, major questions such as which families represent the earliest branches in the genealogy of angiosperms are now understood. Investigating how plant species are related to each other allows botanists to better understand the process of evolution in plants.
## Subdisciplines of Botany
- Agronomy—Application of plant science to crop production
- Bryology—Mosses, liverworts, and hornworts
- Economic botany—The place of plants in economics
- Ethnobotany—Relationship between humans and plants
- Forestry—Forest management and related studies
- Horticulture—Cultivated plants
- Paleobotany—Fossil plants
- Palynology—Pollen and spores
- Phycology - Algae
- Phytochemistry—Plant secondary chemistry and chemical processes
- Phytopathology—Plant diseases
- Plant anatomy—Cell and tissue structure
- Plant ecology—Role of plants in the environment
- Plant genetics—Genetic inheritance in plants
- Plant morphology—Structure and life cycles
- Plant physiology—Life functions of plants
- Plant systematics—Classification and naming of plants
# Notable Botanists
- Luther Burbank (1849-1926), American botanist, horticulturist, and a pioneer in agricultural science.
- Joseph Dalton Hooker (1817-1911), English botanist and explorer. Second winner of Darwin Medal.
- Thomas Henry Huxley (1825–1895), English biologist, known as "Darwin's Bulldog" for his advocacy of Charles Darwin's theory of evolution. Third winner of Darwin Medal.
- Gregor Johann Mendel (1822-1884), Augustinian priest and scientist, and is often called the father of genetics for his study of the inheritance of traits in pea plants.
- Leonardo da Vinci (1452-1519) | https://www.wikidoc.org/index.php/Botany | |
3ff89bb526bc82074be208c85dd50269f5956604 | wikidoc | Breast | Breast
# Overview
The term breast refers to the upper ventral region of an animal’s torso, particularly that of mammals, including human beings. The breasts of a female primate’s body contain the mammary glands, which secrete milk used to feed infants. This article deals with the human breast; for other animals, see udder and mammary gland.
Breasts are more visible on adult women, but male humans also have breasts which, although usually less prominent, are structurally identical (homologous) to the female, as they develop embryologically from the same tissues.
# Anatomy
The breasts are modified sudoriferous (sweat) glands, producing milk in females, and in some rare cases, males. Each breast has one nipple surrounded by the areola. The areola is colored from pink to dark brown and has several sebaceous glands. In females, the larger mammary glands within the breast produce the milk. They are distributed throughout the breast, with two-thirds of the tissue found within 30 mm of the base of the nipple. These are drained to the nipple by between 4 and 18 lactiferous ducts, where each duct has its own opening. The network formed by these ducts is complex, like the tangled roots of a tree. It is not always arranged radially, and branches close to the nipple. The ducts near the nipple do not act as milk reservoirs; Ramsay et al. have shown that conventionally described lactiferous sinuses do not, in fact, exist.
The remainder of the breast is composed of connective tissue (collagen and elastin), adipose tissue (fat), and Cooper's ligaments. The ratio of glands to adipose tissues rises from 1:1 in nonlactating women to 2:1 in lactating women.
The breasts sit over the pectoralis major muscle and usually extend from the level of the 2nd rib to the level of the 6th rib anteriorly. The superior lateral quadrant of the breast extends diagonally upwards towards the axillae and is known as the tail of Spence. A thin layer of mammary tissue extends from the clavicle above to the seventh or eighth ribs below and from the midline to the edge of the latissimus dorsi posteriorly. (For further explanation, see anatomical terms of location.)
The arterial blood supply to the breasts is derived from the internal thoracic artery (formerly called the internal mammary artery), lateral thoracic artery, thoracoacromial artery, and posterior intercostal arteries. The venous drainage of the breast is mainly to the axillary vein, but there is some drainage to the internal thoracic vein and the intercostal veins. Both sexes have a large concentration of blood vessels and nerves in their nipples. The nipples of both females and males can become erect in response to sexual stimuli, and also to cold.
The breast is innervated by the anterior and lateral cutaneous branches of the fourth through sixth intercostal nerves. The nipple is supplied by the T4 dermatome.
## Lymphatic drainage
About 75% of lymph from the breast travels to the ipsilateral axillary lymph nodes. The rest travels to parasternal nodes, to the other breast, or abdominal lymph nodes. The axillary nodes include the pectoral, subscapular, and humeral groups of lymph nodes. These drain to the central axillary lymph nodes, then to the apical axillary lymph nodes. The lymphatic drainage of the breasts is particularly relevant to oncology, since breast cancer is a common cancer and cancer cells can break away from a tumour and spread to other parts of the body through the lymph system by metastasis.
## Shape and support
Breasts vary in both size and shape, and their external appearance is not predictive of their internal anatomy or lactation potential. The shape of a woman’s breasts is in large part dependent on their support, which primarily comes from the Cooper's ligaments, and the underlying chest on which they rest. The breast is attached at its base to the chest wall by the deep fascia over the pectoral muscles. On its upper surface it is given some support by the covering skin where it continues on to the upper chest wall. It is this support which determines the shape of the breasts. In a small fraction of women, the frontal milk sinuses (ampulla) in the breasts are not flush with the surrounding breast tissue, which causes the sinus area to visibly bulge outward.
In discussing the support of breasts, it is helpful to draw a distinction between breasts which rest on the chest below, and those which do not. High, rounded breasts protrude almost horizontally from the chest wall. All breasts are like this in early stages of development, and such a shape is common in younger women and girls. This protruding or “high” breast is anchored to the chest at its base, and the weight is distributed evenly over the area of the base of the approximately dome- or cone-shaped breasts.
In the “low” breast, a proportion of the breasts’ weight is actually supported by the chest against which the lower breast surface comes to rest, as well as the deep anchorage at the base. The weight is thus distributed over a larger area, which has the effect of reducing the strain. In both males and females, the thoracic cavity slopes progressively outwards from the thoracic inlet (at the top of the breastbone) above to the lowest ribs which mark its lower boundary, allowing it to support the breasts.
The inframammary fold (or line, or crease) is an anatomic structure created by adherence between elements in the skin and underlying connective tissue and represents the inferior extent of breast anatomy. Some teenagers may develop breasts whose skin comes into contact with the chest below the fold at an early age, and some women may never develop such breasts; both situations are perfectly normal. The relationship of the nipple position to the fold is described as ptosis, a term also applied to other body parts and which refers in general to drooping or sagging. Due to breast weight and relaxation of support structures, the nipple-areola complex and breast tissue may eventually hang below the fold, and in some cases the breasts may extend as far as, or even beyond, the navel. The length from the nipple to the sternal notch (central, upper border) in the youthful breast averages 21 cm and is a common anthropometric figure used to assess both breast symmetry and ptosis. Lengthening of both this measurement and the distance between the nipple and the fold are both characteristic of advancing grades of ptosis.
The end of the breast, which includes the nipple, may either be flat (a 180 degree angle) or angled (angles lower than 180 degrees). Breast ends are rarely angled sharper than 60 degrees.
Angling of the end of the breast is caused in part by the ligaments that suspend it, such that the breast ends often have a more obtuse angle when a woman is lying on her back. Breasts exist in a range of ratios between length and base diameter, usually ranging from ½ to 1.
## Development
The development of a girl's breasts during puberty is triggered by sex hormones, chiefly estrogen. This hormone has been demonstrated to cause the development of woman-like, enlarged breasts in men, a condition called gynecomastia, and is sometimes used deliberately for this effect in transwomen who receive hormone replacement therapy.
In most cases, the breasts fold down over the chest wall during Tanner stage development, as shown in this diagram. It is typical for a woman’s breasts to be unequal in size particularly while the breasts are developing. Statistically it is slightly more common for the left breast to be the larger. In rare cases, the breasts may be significantly different in size, or one breast may fail to develop entirely.
A large number of medical conditions are known to cause abnormal development of the breasts during puberty. Virginal breast hypertrophy is a condition which involves excessive growth of the breasts, and in some cases the continued growth beyond the usual pubescent age. Breast hypoplasia is a condition where one or both breasts fail to develop.
In Cameroon, some girls are subjected to breast ironing to stunt breast growth in order to make them less sexually attractive in the belief that this makes them less likely to become a victim of rape.
## Changes
As breasts are mostly composed of adipose tissue, their size can change over time. This occurs for a number of reasons, most obviously when a girl grows during puberty and when a woman becomes pregnant. The breast size may also change if she gains (or loses) weight for any other reason. Any rapid increase in size of the breasts can result in the appearance of stretchmarks.
It is typical for a number of other changes to occur during pregnancy: in addition to becoming larger, the breasts generally become firmer, mainly due to hypertrophy of the mammary gland in response to the hormone prolactin. The size of the nipples may increase noticeably and their pigmentation may become darker. These changes may continue during breastfeeding. The breasts generally revert to approximately their previous size after pregnancy, although there may be some increased sagging and stretchmarks.
The size of a woman’s breasts usually fluctuates during the menstrual cycle, particularly with premenstrual water retention. An increase in breast size is a common side effect of use of the combined oral contraceptive pill.
The breasts naturally sag through aging, as the ligaments become elongated.
# Function
## Breastfeeding
The primary function of mammary glands is to nurture young by producing breast milk. The production of milk is called lactation. (While the mammary glands that produce milk are present in the male, they normally remain undeveloped.) The orb-like shape of breasts may help limit heat loss, as a fairly high temperature is required for the production of milk. Alternatively, one theory states that the shape of the human breast evolved in order to prevent infants from suffocating while feeding. Since human infants do not have a protruding jaw like human evolutionary ancestors and other primates, the infant’s nose might be blocked by a flat female chest while feeding. According to this theory, as the human jaw receded, the breasts became larger to compensate.
Milk production unrelated to pregnancy can also occur. This galactorrhea may be an adverse effect of some medicinal drugs (such as some antipsychotic medication), extreme physical stress or endocrine disorders. If it occurs in men it is called male lactation. Newborn babies are often capable of lactation because they receive the hormones prolactin and oxytocin via the mother's bloodstream, filtered through the placenta. This neonatal liquid is known colloquially as witch's milk.
## Sexual role
Breasts play an important part in human sexual behavior. They are one of most visible or obvious female secondary sex characteristics, and play an important role in sexual attraction of partners, and pleasure of the individual. On sexual arousal breast size increases, venous patterns across the breasts become more visible, and nipples harden. Breasts are sensitive to touch as they have many nerve endings, and it is common practice to press or massage breasts with hands during sexual intercourse. Oral stimulation of nipples and breasts is also common. Some women can achieve breast orgasms. In the ancient Indian work the Kama Sutra, marking breasts with nails and biting with teeth are explained as erotic.
## Other suggested functions
Zoologists point out that no female mammal other than the human has breasts of comparable size, relative to the rest of the body, when not lactating and that humans are the only primate that has permanently swollen breasts. This suggests that the external form of the breasts is connected to factors other than lactation alone.
One theory is based around the fact that, unlike nearly all other primates, human females do not display clear, physical signs of ovulation. This could have plausibly resulted in human males evolving to respond to more subtle signs of ovulation. During ovulation, the increased estrogen present in the female body results in a slight swelling of the breasts, which then males could have evolved to find attractive. In response, there would be evolutionary pressures that would favor females with more swollen breasts who would, in a manner of speaking, appear to males to be the most likely to be ovulating.
Some zoologists (notably Desmond Morris) believe that the shape of female breasts evolved as a frontal counterpart to that of the buttocks, the reason being that whilst other primates mate in the rear-entry position, humans, because of their upright posture, are more likely to successfully copulate by mating face to face, the so-called missionary position. A secondary sexual characteristic on a woman’s chest would have encouraged this in more primitive incarnations of the human race, and a face on encounter may have helped found a relationship between partners beyond merely a sexual one.
# Cultural status
## In art, religion, and legend
Historically, breasts have been regarded as fertility symbols, because they are the source of life-giving milk. Certain prehistoric female statuettes—so-called Venus figurines—often emphasised the breasts, as in the example of the Venus of Willendorf. In historic times, goddesses such as Ishtar were shown with many breasts, alluding to their role as protectors of childbirth and mothering. The legendary tribe of Amazons bared their breasts, and in some accounts removed one breast to allow better combat and archery.
Some religions afford the breast a special status, either in formal teachings or in symbolism. Islam forbids public exposure of the female breasts. In Christian iconography, some works of art depict women with their breasts in their hands or on a platter, signifying that they died as a martyr by having their breasts severed; one example of this is Saint Agatha of Sicily. In Silappatikaram, Kannagi tears off her left breast and flings it on Madurai, cursing it, causing a devastating fire.
## In practice
Breasts are secondary sex characteristics and sexually sensitive. Bare female breasts can elicit heightened sexual desires from men and women. Cultures that associate the breast primarily with sex (as opposed to with breastfeeding) tend to designate bare breasts as indecent, and they are not commonly displayed in public, in contrast to male chests. Other cultures view female toplessness as acceptable, and in some countries women have never been forbidden to bare their chests; in some African cultures, for example, the thigh is highly sexualised and never exposed in public, but the breast is not taboo. Opinion on the exposure of breasts often depends on the place and context, and in some Western societies exposure of breasts on a beach may be acceptable, although in town centres, for example, it is usually considered indecent. In some areas the prohibition against the display of a woman’s breasts only restricts exposure of the nipples.
Women in some areas and cultures are approaching the issue of breast exposure as one of sexual equality, since men (and pre-pubescent children) may bare their chests, but women and teenage girls are forbidden. In the United States, the topfree equality movement seeks to redress this imbalance. This movement won a decision in 1992 in the New York State Court of Appeals—“People v. Santorelli”, where the court ruled that the state’s indecent exposure laws do not ban women from being barebreasted. A similar movement succeeded in most parts of Canada in the 1990s. In Australia and much of Europe it is acceptable for women and teenage girls to sunbathe topless on some public beaches and swimming pools, but these are generally the only public areas where exposing breasts is acceptable.
When breastfeeding a baby in public, legal and social rules regarding indecent exposure and dress codes, as well as inhibitions of the woman, tend to be relaxed. Numerous laws around the world have made public breastfeeding legal and disallow companies from prohibiting it in the workplace. Yet the public reaction at the sight of breastfeeding can make the situation uncomfortable for those involved.
See also modesty, nudism and exhibitionism.
## Clothing
Since the breasts are flexible, their shape may be affected by clothing, and foundation garments in particular. A brassiere (bra) may be worn to give additional support and to alter the shape of the breasts. There is some debate over whether such support is desirable. A long term clinical study showed that women with large breasts can suffer shoulder pain as a result of bra straps, although a well fitting bra should support most of the breasts’ weight with proper sized cups and back band rather than on the shoulders.
## Plastic surgery
Plastic surgical procedures of the breast include those for both cosmetic and reconstructive surgery indications. Some women choose these procedures as a result of the high value placed on symmetry of the human form, and because they identify their femininity and sense of self with their breasts.
After mastectomy (the surgical removal of a breast, usually to treat breast cancer) some women undergo breast reconstruction, either with breast implants or autologous tissue transfer, using fat and tissues from the abdomen (TRAM flap) or back (latissiumus muscle flap).
Breast reduction surgery is a common procedure which involves removing excess breast tissue, fat, and skin with repositioning of the nipple-areolar complex (NAC). Cosmetic procedures include breast lifts (mastopexy), breast augmentation with implants, and procedures that combine both elements. Implants containing either silicone gel or saline are available for augmentation and reconstructive surgeries. Surgery can repair inverted nipples by releasing ductal tissues which are tethering. Breast lift with or without reduction can be part of upper body lift after massive weight loss body contouring.
Any surgery of the breast carries with it the potential for interfering with future breastfeeding, causing alterations in nipple sensation, and difficulty in interpreting mammography (xrays of the breast). A number of studies have demonstrated a similar ability to breastfeed when breast reduction patients are compared to control groups where the surgery was performed using a modern pedicle surgical technique. Plastic surgery organizations have generally discouraged elective cosmetic breast augmentation surgery for teenage girls as the volume of their breast tissue may continue to grow significantly as they mature and because of concerns about understanding long-term risks and benefits of the procedure. Breast surgery in teens for reduction of significantly enlarged breasts or surgery to correct hypoplasia and severe asymmetry is considered on a case by case basis by most surgeons.
# Health
## Pre-malignant and malignant diseases
- Carcinoma in situ, a pre-malignant condition which can progress to a malignant cancer
Malignant diseases include:
- Breast cancer
- Paget’s disease of the nipple, also known as Paget’s disease of the breast
Among women worldwide, breast cancer is the most common cause of cancer death. Breast self-examination (BSE) is an easy but unreliable method for finding possible breast cancer, which is recommended once every month.
## Infections and inflammations
These may be caused among others by trauma, secretory
stasis/milk engorgement, hormonal stimulation, infections
-r autoimmune reactions.
Repeated occurrence unrelated to lactation requires
endocrinological examination.
- Mastitis
bacterial mastitis
mastitis from milk engorgement or secretory stasis
mastitis of mumps
chronic intramammary abscess
chronic subareolar abscess
tuberculosis of the breast
syphilis of the breast
retromammary abscess
actinomycosis of the breast
Mondor’s disease
Duct ectasia syndrome
Breast engorgement
- bacterial mastitis
- mastitis from milk engorgement or secretory stasis
- mastitis of mumps
- chronic intramammary abscess
- chronic subareolar abscess
- tuberculosis of the breast
- syphilis of the breast
- retromammary abscess
- actinomycosis of the breast
- Mondor’s disease
- Duct ectasia syndrome
- Breast engorgement
## Benign conditions
Benign conditions include:
- Congenital disorders
Inverted nipple
Supernumerary nipples/supernumerary breasts (polymazia / polymastia) /duplicated nipples
- Inverted nipple
- Supernumerary nipples/supernumerary breasts (polymazia / polymastia) /duplicated nipples
- Aberrations of normal development and involution
Cyclical nodularity
Breast cysts
Fibroadenoma - benign tumor
Gynecomastia (males)
Nipple discharge, galactorrhea
Mammary fistula
- Cyclical nodularity
- Breast cysts
- Fibroadenoma - benign tumor
- Gynecomastia (males)
- Nipple discharge, galactorrhea
- Mammary fistula
- Fibrocystic disease / Fibrocystic changes
Cysts
Epithelial hyperplasia
Epithelial metaplasia
Papillomas
Adenosis
- Cysts
- Epithelial hyperplasia
- Epithelial metaplasia
- Papillomas
- Adenosis
- Pregnancy-related
Galactocoele
- Galactocoele
# Documentary film
- Breasts, directed by Meema Spadola, 1996.
# Breast: Foreign body reaction
# Breast: Epithelial hyperplasia | Breast
Template:Infobox Anatomy
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
# Overview
The term breast refers to the upper ventral region of an animal’s torso, particularly that of mammals, including human beings. The breasts of a female primate’s body contain the mammary glands, which secrete milk used to feed infants. This article deals with the human breast; for other animals, see udder and mammary gland.
Breasts are more visible on adult women, but male humans also have breasts which, although usually less prominent, are structurally identical (homologous) to the female, as they develop embryologically from the same tissues.
# Anatomy
The breasts are modified sudoriferous (sweat) glands, producing milk in females, and in some rare cases, males.[1] Each breast has one nipple surrounded by the areola. The areola is colored from pink to dark brown and has several sebaceous glands. In females, the larger mammary glands within the breast produce the milk. They are distributed throughout the breast, with two-thirds of the tissue found within 30 mm of the base of the nipple.[2] These are drained to the nipple by between 4 and 18 lactiferous ducts, where each duct has its own opening. The network formed by these ducts is complex, like the tangled roots of a tree. It is not always arranged radially, and branches close to the nipple. The ducts near the nipple do not act as milk reservoirs; Ramsay et al. have shown that conventionally described lactiferous sinuses do not, in fact, exist.
The remainder of the breast is composed of connective tissue (collagen and elastin), adipose tissue (fat), and Cooper's ligaments. The ratio of glands to adipose tissues rises from 1:1 in nonlactating women to 2:1 in lactating women.[2]
The breasts sit over the pectoralis major muscle and usually extend from the level of the 2nd rib to the level of the 6th rib anteriorly. The superior lateral quadrant of the breast extends diagonally upwards towards the axillae and is known as the tail of Spence. A thin layer of mammary tissue extends from the clavicle above to the seventh or eighth ribs below and from the midline to the edge of the latissimus dorsi posteriorly. (For further explanation, see anatomical terms of location.)
The arterial blood supply to the breasts is derived from the internal thoracic artery (formerly called the internal mammary artery), lateral thoracic artery, thoracoacromial artery, and posterior intercostal arteries. The venous drainage of the breast is mainly to the axillary vein, but there is some drainage to the internal thoracic vein and the intercostal veins. Both sexes have a large concentration of blood vessels and nerves in their nipples. The nipples of both females and males can become erect in response to sexual stimuli,[3] and also to cold.
The breast is innervated by the anterior and lateral cutaneous branches of the fourth through sixth intercostal nerves. The nipple is supplied by the T4 dermatome.
## Lymphatic drainage
About 75% of lymph from the breast travels to the ipsilateral axillary lymph nodes. The rest travels to parasternal nodes, to the other breast, or abdominal lymph nodes. The axillary nodes include the pectoral, subscapular, and humeral groups of lymph nodes. These drain to the central axillary lymph nodes, then to the apical axillary lymph nodes. The lymphatic drainage of the breasts is particularly relevant to oncology, since breast cancer is a common cancer and cancer cells can break away from a tumour and spread to other parts of the body through the lymph system by metastasis.
## Shape and support
Breasts vary in both size and shape, and their external appearance is not predictive of their internal anatomy or lactation potential. The shape of a woman’s breasts is in large part dependent on their support, which primarily comes from the Cooper's ligaments, and the underlying chest on which they rest. The breast is attached at its base to the chest wall by the deep fascia over the pectoral muscles. On its upper surface it is given some support by the covering skin where it continues on to the upper chest wall. It is this support which determines the shape of the breasts. In a small fraction of women, the frontal milk sinuses (ampulla) in the breasts are not flush with the surrounding breast tissue, which causes the sinus area to visibly bulge outward.
In discussing the support of breasts, it is helpful to draw a distinction between breasts which rest on the chest below, and those which do not. High, rounded breasts protrude almost horizontally from the chest wall. All breasts are like this in early stages of development, and such a shape is common in younger women and girls. This protruding or “high” breast is anchored to the chest at its base, and the weight is distributed evenly over the area of the base of the approximately dome- or cone-shaped breasts.
In the “low” breast, a proportion of the breasts’ weight is actually supported by the chest against which the lower breast surface comes to rest, as well as the deep anchorage at the base. The weight is thus distributed over a larger area, which has the effect of reducing the strain. In both males and females, the thoracic cavity slopes progressively outwards from the thoracic inlet (at the top of the breastbone) above to the lowest ribs which mark its lower boundary, allowing it to support the breasts.
The inframammary fold (or line, or crease) is an anatomic structure created by adherence between elements in the skin and underlying connective tissue[4] and represents the inferior extent of breast anatomy. Some teenagers may develop breasts whose skin comes into contact with the chest below the fold at an early age, and some women may never develop such breasts; both situations are perfectly normal. The relationship of the nipple position to the fold is described as ptosis, a term also applied to other body parts and which refers in general to drooping or sagging. Due to breast weight and relaxation of support structures, the nipple-areola complex and breast tissue may eventually hang below the fold, and in some cases the breasts may extend as far as, or even beyond, the navel. The length from the nipple to the sternal notch (central, upper border) in the youthful breast averages 21 cm and is a common anthropometric figure used to assess both breast symmetry and ptosis. Lengthening of both this measurement and the distance between the nipple and the fold are both characteristic of advancing grades of ptosis.
The end of the breast, which includes the nipple, may either be flat (a 180 degree angle) or angled (angles lower than 180 degrees). Breast ends are rarely angled sharper than 60 degrees.
Angling of the end of the breast is caused in part by the ligaments that suspend it, such that the breast ends often have a more obtuse angle when a woman is lying on her back. Breasts exist in a range of ratios between length and base diameter, usually ranging from ½ to 1.
## Development
The development of a girl's breasts during puberty is triggered by sex hormones, chiefly estrogen. This hormone has been demonstrated to cause the development of woman-like, enlarged breasts in men, a condition called gynecomastia, and is sometimes used deliberately for this effect in transwomen who receive hormone replacement therapy.
In most cases, the breasts fold down over the chest wall during Tanner stage development, as shown in this diagram.[5] It is typical for a woman’s breasts to be unequal in size particularly while the breasts are developing. Statistically it is slightly more common for the left breast to be the larger.[6] In rare cases, the breasts may be significantly different in size, or one breast may fail to develop entirely.
A large number of medical conditions are known to cause abnormal development of the breasts during puberty. Virginal breast hypertrophy is a condition which involves excessive growth of the breasts, and in some cases the continued growth beyond the usual pubescent age. Breast hypoplasia is a condition where one or both breasts fail to develop.
In Cameroon, some girls are subjected to breast ironing to stunt breast growth in order to make them less sexually attractive in the belief that this makes them less likely to become a victim of rape.
## Changes
As breasts are mostly composed of adipose tissue, their size can change over time. This occurs for a number of reasons, most obviously when a girl grows during puberty and when a woman becomes pregnant. The breast size may also change if she gains (or loses) weight for any other reason. Any rapid increase in size of the breasts can result in the appearance of stretchmarks.
It is typical for a number of other changes to occur during pregnancy: in addition to becoming larger, the breasts generally become firmer, mainly due to hypertrophy of the mammary gland in response to the hormone prolactin. The size of the nipples may increase noticeably and their pigmentation may become darker. These changes may continue during breastfeeding. The breasts generally revert to approximately their previous size after pregnancy, although there may be some increased sagging and stretchmarks.
The size of a woman’s breasts usually fluctuates during the menstrual cycle, particularly with premenstrual water retention. An increase in breast size is a common side effect of use of the combined oral contraceptive pill.
The breasts naturally sag through aging, as the ligaments become elongated.
# Function
## Breastfeeding
The primary function of mammary glands is to nurture young by producing breast milk. The production of milk is called lactation. (While the mammary glands that produce milk are present in the male, they normally remain undeveloped.) The orb-like shape of breasts may help limit heat loss, as a fairly high temperature is required for the production of milk. Alternatively, one theory states that the shape of the human breast evolved in order to prevent infants from suffocating while feeding.[7] Since human infants do not have a protruding jaw like human evolutionary ancestors and other primates, the infant’s nose might be blocked by a flat female chest while feeding.[7] According to this theory, as the human jaw receded, the breasts became larger to compensate.[7]
Milk production unrelated to pregnancy can also occur. This galactorrhea may be an adverse effect of some medicinal drugs (such as some antipsychotic medication), extreme physical stress or endocrine disorders. If it occurs in men it is called male lactation. Newborn babies are often capable of lactation because they receive the hormones prolactin and oxytocin via the mother's bloodstream, filtered through the placenta. This neonatal liquid is known colloquially as witch's milk.
## Sexual role
Breasts play an important part in human sexual behavior. They are one of most visible or obvious female secondary sex characteristics,[8] and play an important role in sexual attraction of partners, and pleasure of the individual. On sexual arousal breast size increases, venous patterns across the breasts become more visible, and nipples harden. Breasts are sensitive to touch as they have many nerve endings, and it is common practice to press or massage breasts with hands during sexual intercourse. [9] Oral stimulation of nipples and breasts is also common. Some women can achieve breast orgasms. In the ancient Indian work the Kama Sutra, marking breasts with nails and biting with teeth are explained as erotic.[10]
## Other suggested functions
Zoologists point out that no female mammal other than the human has breasts of comparable size, relative to the rest of the body, when not lactating and that humans are the only primate that has permanently swollen breasts. This suggests that the external form of the breasts is connected to factors other than lactation alone.
One theory is based around the fact that, unlike nearly all other primates, human females do not display clear, physical signs of ovulation. This could have plausibly resulted in human males evolving to respond to more subtle signs of ovulation. During ovulation, the increased estrogen present in the female body results in a slight swelling of the breasts, which then males could have evolved to find attractive. In response, there would be evolutionary pressures that would favor females with more swollen breasts who would, in a manner of speaking, appear to males to be the most likely to be ovulating.
Some zoologists (notably Desmond Morris) believe that the shape of female breasts evolved as a frontal counterpart to that of the buttocks, the reason being that whilst other primates mate in the rear-entry position, humans, because of their upright posture, are more likely to successfully copulate by mating face to face, the so-called missionary position. A secondary sexual characteristic on a woman’s chest would have encouraged this in more primitive incarnations of the human race, and a face on encounter may have helped found a relationship between partners beyond merely a sexual one.[11]
# Cultural status
## In art, religion, and legend
Historically, breasts have been regarded as fertility symbols, because they are the source of life-giving milk. Certain prehistoric female statuettes—so-called Venus figurines—often emphasised the breasts, as in the example of the Venus of Willendorf. In historic times, goddesses such as Ishtar were shown with many breasts, alluding to their role as protectors of childbirth and mothering. The legendary tribe of Amazons bared their breasts, and in some accounts removed one breast to allow better combat and archery.
Some religions afford the breast a special status, either in formal teachings or in symbolism. Islam forbids public exposure of the female breasts.[12] In Christian iconography, some works of art depict women with their breasts in their hands or on a platter, signifying that they died as a martyr by having their breasts severed; one example of this is Saint Agatha of Sicily. In Silappatikaram, Kannagi tears off her left breast and flings it on Madurai, cursing it, causing a devastating fire.
## In practice
Breasts are secondary sex characteristics and sexually sensitive. Bare female breasts can elicit heightened sexual desires from men and women. Cultures that associate the breast primarily with sex (as opposed to with breastfeeding) tend to designate bare breasts as indecent, and they are not commonly displayed in public, in contrast to male chests. Other cultures view female toplessness as acceptable, and in some countries women have never been forbidden to bare their chests; in some African cultures, for example, the thigh is highly sexualised and never exposed in public, but the breast is not taboo. Opinion on the exposure of breasts often depends on the place and context, and in some Western societies exposure of breasts on a beach may be acceptable, although in town centres, for example, it is usually considered indecent. In some areas the prohibition against the display of a woman’s breasts only restricts exposure of the nipples.
Women in some areas and cultures are approaching the issue of breast exposure as one of sexual equality, since men (and pre-pubescent children) may bare their chests, but women and teenage girls are forbidden. In the United States, the topfree equality movement seeks to redress this imbalance. This movement won a decision in 1992 in the New York State Court of Appeals—“People v. Santorelli”, where the court ruled that the state’s indecent exposure laws do not ban women from being barebreasted. A similar movement succeeded in most parts of Canada in the 1990s. In Australia and much of Europe it is acceptable for women and teenage girls to sunbathe topless on some public beaches and swimming pools, but these are generally the only public areas where exposing breasts is acceptable.
When breastfeeding a baby in public, legal and social rules regarding indecent exposure and dress codes, as well as inhibitions of the woman, tend to be relaxed. Numerous laws around the world have made public breastfeeding legal and disallow companies from prohibiting it in the workplace. Yet the public reaction at the sight of breastfeeding can make the situation uncomfortable for those involved.
See also modesty, nudism and exhibitionism.
## Clothing
Since the breasts are flexible, their shape may be affected by clothing, and foundation garments in particular. A brassiere (bra) may be worn to give additional support and to alter the shape of the breasts. There is some debate over whether such support is desirable. A long term clinical study showed that women with large breasts can suffer shoulder pain as a result of bra straps,[13] although a well fitting bra should support most of the breasts’ weight with proper sized cups and back band rather than on the shoulders.
## Plastic surgery
Plastic surgical procedures of the breast include those for both cosmetic and reconstructive surgery indications. Some women choose these procedures as a result of the high value placed on symmetry of the human form, and because they identify their femininity and sense of self with their breasts.
After mastectomy (the surgical removal of a breast, usually to treat breast cancer) some women undergo breast reconstruction, either with breast implants or autologous tissue transfer, using fat and tissues from the abdomen (TRAM flap) or back (latissiumus muscle flap).
Breast reduction surgery is a common procedure which involves removing excess breast tissue, fat, and skin with repositioning of the nipple-areolar complex (NAC). Cosmetic procedures include breast lifts (mastopexy), breast augmentation with implants, and procedures that combine both elements. Implants containing either silicone gel or saline are available for augmentation and reconstructive surgeries. Surgery can repair inverted nipples by releasing ductal tissues which are tethering. Breast lift with or without reduction can be part of upper body lift after massive weight loss body contouring.
Any surgery of the breast carries with it the potential for interfering with future breastfeeding,[14][15][16] causing alterations in nipple sensation, and difficulty in interpreting mammography (xrays of the breast). A number of studies have demonstrated a similar ability to breastfeed when breast reduction patients are compared to control groups where the surgery was performed using a modern pedicle surgical technique.[17][18][19][20] Plastic surgery organizations have generally discouraged elective cosmetic breast augmentation surgery for teenage girls as the volume of their breast tissue may continue to grow significantly as they mature and because of concerns about understanding long-term risks and benefits of the procedure. Breast surgery in teens for reduction of significantly enlarged breasts or surgery to correct hypoplasia and severe asymmetry is considered on a case by case basis by most surgeons.
# Health
## Pre-malignant and malignant diseases
- Carcinoma in situ, a pre-malignant condition which can progress to a malignant cancer
Malignant diseases include:
- Breast cancer
- Paget’s disease of the nipple, also known as Paget’s disease of the breast
Among women worldwide, breast cancer is the most common cause of cancer death.[21] Breast self-examination (BSE) is an easy but unreliable method for finding possible breast cancer,[22] which is recommended once every month.
## Infections and inflammations
These may be caused among others by trauma, secretory
stasis/milk engorgement, hormonal stimulation, infections
or autoimmune reactions.
Repeated occurrence unrelated to lactation requires
endocrinological examination.
- Mastitis
bacterial mastitis
mastitis from milk engorgement or secretory stasis
mastitis of mumps
chronic intramammary abscess
chronic subareolar abscess
tuberculosis of the breast
syphilis of the breast
retromammary abscess
actinomycosis of the breast
Mondor’s disease
Duct ectasia syndrome
Breast engorgement
- bacterial mastitis
- mastitis from milk engorgement or secretory stasis
- mastitis of mumps
- chronic intramammary abscess
- chronic subareolar abscess
- tuberculosis of the breast
- syphilis of the breast
- retromammary abscess
- actinomycosis of the breast
- Mondor’s disease
- Duct ectasia syndrome
- Breast engorgement
## Benign conditions
Benign conditions include:
- Congenital disorders
Inverted nipple
Supernumerary nipples/supernumerary breasts (polymazia / polymastia) /duplicated nipples
- Inverted nipple
- Supernumerary nipples/supernumerary breasts (polymazia / polymastia) /duplicated nipples
- Aberrations of normal development and involution
Cyclical nodularity
Breast cysts
Fibroadenoma - benign tumor
Gynecomastia (males)
Nipple discharge, galactorrhea
Mammary fistula
- Cyclical nodularity
- Breast cysts
- Fibroadenoma - benign tumor
- Gynecomastia (males)
- Nipple discharge, galactorrhea
- Mammary fistula
- Fibrocystic disease / Fibrocystic changes
Cysts
Epithelial hyperplasia
Epithelial metaplasia
Papillomas
Adenosis
- Cysts
- Epithelial hyperplasia
- Epithelial metaplasia
- Papillomas
- Adenosis
- Pregnancy-related
Galactocoele
- Galactocoele
# Documentary film
- Breasts, directed by Meema Spadola, 1996.
# Breast: Foreign body reaction
# Breast: Epithelial hyperplasia | https://www.wikidoc.org/index.php/Breast | |
4b4ffd069f9faa09983bb55acbcf0e568304e663 | wikidoc | Orgasm | Orgasm
# Overview
An orgasm (sexual climax) is the conclusion of the plateau phase of the sexual response cycle, and may be experienced by both males and females. Orgasm is characterized by intense physical pleasure, controlled by the involuntary, or autonomic, nervous system. It is accompanied by quick cycles of muscle contraction in the lower pelvic muscles, which surround the primary sexual organs and the anus. Orgasms are often associated with other involuntary actions, including muscular spasms in other areas of the body, a general euphoric sensation, and, frequently, vocalizations.
After orgasm, humans often feel tired and a need to rest. This is attributed to the release of prolactin. Prolactin is a typical neuroendocrine response in depressed mood and irritation.
Ongoing research at the University Medical Center of Groningen, the Netherlands, studies brain events that accompany orgasm in men and women. Techniques used involve Positron Emission Tomography (PET) and fMRI. Male and female brains act almost the same during orgasm. Brain scans showed that large parts of the cerebral cortex temporarily reduced their activity.
# From the erectile organ
Orgasm is achieved after direct stimulation of the penis or clitoris for a period of time. This stimulation can be caused by sexual intercourse, manual masturbation, anal sex, oral sex, non-penetrative sex, a sensual vibrator, or an erotic electrostimulation. Any sexual stimulation of the penis or clitoris may eventually result in an orgasm; it may also be achieved by stimulation of other erogenous zones, in the absence of physical stimulation through psychological arousal and as a nocturnal emission or "wet dream".
## Multiple orgasms
In some cases, women either do not have a refractory period or have a very short one and thus can experience a second orgasm, and perhaps further ones, soon after the first. After the first, subsequent climaxes may be stronger or more pleasurable as the stimulation accumulates. For some women, their clitoris and nipples are very sensitive after climax, making additional stimulation initially painful.
There are sensational reports of women having too many orgasms, including an unauthenticated claim that a young British woman has them constantly throughout the day, whenever she experiences the slightest vibration.
It is possible for a man to have an orgasm without ejaculation (dry orgasm) or to ejaculate without reaching orgasm. Some men have reported having multiple consecutive orgasms, particularly without ejaculation. Males who experience dry orgasms can often produce multiple orgasms, as the refractory period, is reduced. Some males are able to masturbate for hours at a time, achieving orgasm many times. In recent years, a number of books have described various techniques to achieve multiple orgasms. Most multi-orgasmic men (and their partners) report that refraining from ejaculation results in a far more energetic post-orgasm state. Additionally, some men have also reported that this can produce more powerful ejaculatory orgasms when they choose to have them.
One dangerous technique is to put pressure on the perineum, about halfway between the scrotum and the anus, just before ejaculating to prevent ejaculation. This can, however, lead to retrograde ejaculation, i.e. redirecting semen into the urinary bladder rather than through the urethra to the outside. It may also cause long term damage due to the pressure put on the nerves and blood vessels in the perineum. Men who have had prostate or bladder surgery, for whatever reason, may also experience dry orgasms because of retrograde ejaculation.
Other techniques are analogous to reports by multi-orgasmic women indicating that they must relax and "let go" to experience multiple orgasms. These techniques involve mental and physical controls over pre-ejaculatory vasocongestion and emissions, rather than ejaculatory contractions or forced retention as above. Anecdotally, successful implementation of these techniques can result in continuous or multiple "full-body" orgasms. Gentle digital stimulation of the prostate, seminal vesicles, and vas deferens provides erogenous pleasure that sustains intense emissions orgasms for some men. A dildo device (the Aneros) claims to stimulate the prostate and help men reach these kinds of orgasms.
Many men who began masturbation or other sexual activity prior to puberty report having been able to achieve multiple non-ejaculatory orgasms. Young male children are capable of having multiple orgasms due to the lack of refractory period until they reach their first ejaculation. In female children it is always possible, even after the onset of puberty. This capacity generally disappears in males with the subject's first ejaculation. Some evidence indicates that orgasms of men before puberty are qualitatively similar to the "normal" female experience of orgasm, suggesting that hormonal changes during puberty have a strong influence on the character of male orgasm.
A number of studies have pointed to the hormone prolactin as the likely cause of male refractory period. Because of this, there is currently an experimental interest in drugs which inhibit prolactin, such as cabergoline (also known as Cabeser, or Dostinex). Anecdotal reports on cabergoline suggest it may be able to eliminate the refractory period altogether, allowing men to experience multiple ejaculatory orgasms in rapid succession. At least one scientific study supports these claims. Cabergoline is a hormone-altering drug and has many potential side effects. It has not been approved for treating sexual dysfunction. Another possible reason may be an increased infusion of the hormone oxytocin. Furthermore, it is believed that the amount by which oxytocin is increased may affect the length of each refractory period.
A scientific study to successfully document natural, fully ejaculatory, multiple orgasms in an adult man was conducted at Rutgers University in 1995. During the study, six fully ejaculatory orgasms were experienced in 36 minutes, with no apparent refractory period. It can also be said that in some cases, the refractory period can be reduced or even eliminated through the course of puberty and on into adulthood. Later, P. Haake et al. observed a single male individual producing multiple orgasms without elevated prolactin response.
## Spontaneous orgasms
Orgasms can be spontaneous, seeming to occur with no direct stimulation. Occasionally, orgasms can occur during sexual dreams.
The first orgasm of this type was reported among people who had spinal cord injury (SCI). Although SCI very often leads to loss of certain sensations and altered self-perception, a person with this disturbance is not deprived of sexual feelings such as sexual arousal and erotic desires. Thus some individuals are able to initiate orgasm by mere mental stimulation. Some non-sexual activity may result in a spontaneous orgasm. The best example of such activity is a release of tension that unintentionally involves slight genital stimulation, like rubbing of the seat of the bicycle against genitals during riding, exercising, when pelvic muscles are tightened or when yawning or sneezing.
It was also discovered that some anti-depressant drugs may provoke spontaneous climax as a side effect. There is no accurate data for how many patients who were on treatment with antidepressant drugs experienced spontaneous orgasm, as most were unwilling to acknowledge the fact.
# From the prostatic structure
Some people are able to achieve orgasm through stimulation of the prostatic structure, which in men is the prostate and in women is Skene's glands; in women the location of Skenes's glands is often known as the g-spot, or Grafenberg Spot, after the physician who first identified the spot as having orgasmic potential. The stimulation can come from receptive intercourse, fingering, fisting, or penetration with a dildo.
Orgasms of this kind can cause male orgasm and ejaculation. Women do not have prostate glands, therefore can not have a prostatic orgasm. With sufficient stimulation, the prostatic structure can also be "milked." Providing that there is no simultaneous stimulation of the penis prostate milking can cause ejaculation without orgasm. When combined with penile stimulation, some men report that prostate stimulation increases the volume of their ejaculation. The prostatic structure produces a secretion that forms one of the components of ejaculate; in males sperm are transmitted up the vas deferens from the testicles, into the prostate gland as well as through the seminal vesicles to produce what we know as semen. Semen is expelled through the base of the penis out by contractions from the sphinctre and prostate, thus causing an orgasm.
Prostatic orgasms can be very pleasurable. It can cause numbness through out the entire body causing emphasis on the thighs, mid back, and head of penis. After a prostatic orgasm the body is very sensitive to touch and stimulation and may cause sleepiness.
# Other known categorizations of orgasm
Certain types and categorization of orgasm have become widely enough acknowledged to be discussed as distinctive forms of orgasm.
## Vaginal orgasm
The female body can achieve orgasm from stimulation of the clitoris and from stimulation of the G-spot. The Gräfenberg spot, or G-spot, is a small area behind the female pubic bone surrounding the urethra and accessible through the anterior wall of the vagina. Many scientists believe that only certain women possess a G-spot. The G-spot orgasm is sometimes referred to as "vaginal," because it results from stimulation inside the vagina, including during sexual intercourse. However, only stimulation of the G-spot, and not other intravaginal stimulation, results in a "vaginal orgasm." The same is true for men, who are believed to have a male G-spot, through stimulation of the prostatic structure, which in men is the prostate. This leads to a different type of male orgasm than the orgasm that results from stimulation of the penis.
The "two-orgasm theory" (the belief that in females there is a vaginal orgasm and a clitoral orgasm), has been criticized by feminists such as Ellen Ross and Rayna Rapp as a "transparently male perception of the female body". The concept of purely vaginal orgasm was first postulated by Sigmund Freud. In 1905, Freud argued that clitoral orgasm was an adolescent phenomenon, and upon reaching puberty the proper response of mature women changes to vaginal orgasms. While Freud provided no evidence for this basic assumption, the consequences of the theory were greatly elaborated, partly because many women felt inadequate when they could not achieve orgasm via vaginal intercourse that involved little or no clitoral stimulation. Freud's claims about this and many other biological subjects, were later largely proven false or based on supposition.
In 1966, Masters and Johnson published pivotal research about the phases of sexual stimulation. Their work included women and men, and unlike Alfred Kinsey earlier (in 1948 and 1953), tried to determine the physiological stages before and after orgasm. One of the results was the promotion of the idea that vaginal and clitoral orgasms follow the same stages of physical response. Masters and Johnson also argued that clitoral stimulation is the primary source of orgasms.
Recent discoveries about the size of the clitoris - it extends inside the body, around the vagina - complicate or may invalidate attempts to distinguish clitoral vs. vaginal orgasms. Recent anatomical research shows that there are nerves connecting intravaginal tissues and the clitoris. This, with the anatomical evidence that the internal part of the clitoris is a much larger organ than previously thought, could explain credible reports of orgasms in women who have undergone clitorectomy as part of female circumcision. The link between the clitoris and the vagina is evidence that the clitoris is the 'seat' of the female orgasm and is far more wide-spread than the visible part most people associate with it. But it is possible that some women have more extensive clitoral tissues and nerves than others, and so that some women can achieve orgasm only by direct stimulation of the external part of the clitoris.
## Anal orgasm
Anal orgasm is an orgasm brought on by anal stimulation, such as from anal sex, an inserted finger, or a sex toy. Some men are able to achieve an anal orgasm.
A woman may come to orgasm without stimulating the anus, by stimulation of the buttocks and anal cleft with the tongue. But typically, stimulation of the G-spot through the wall shared between the vagina and the rectum, from a sex toy, finger or a penis, may bring about an orgasm. This is often greatly facilitated through additional manual stimulation of the clitoris. Another theory on the source of anal orgasm in the female is the perineal sponge. The perineal sponge is an erectile structure located between the vagina and rectum that responds to stimulation like any other erectile tissue. Anecdotal evidence suggests that some women experience anal orgasm as qualitatively different from clitoral or vaginal orgasm, though for many others the distinction is less clear.
In both sexes pleasure can be derived from the nerve endings around the anus and the anus itself. Hence, anal-oral contact can still be pleasurable without stimulation of the clitoris. Anal orgasm has nothing to do with the prostate orgasm, although the two are often confused.
## Breast orgasm
A breast orgasm is a female orgasm that is triggered from the stimulation of a woman's breast. Not all women experience this effect when the breasts are stimulated; however, some women claim that the stimulation of the breast area during sexual intercourse and foreplay, or just the simple act of having their breasts fondled, has created mild to intense orgasms. According to one study that questioned 213 women, 29% of them had experienced a breast orgasm at one time or another, This shows that it is not common, but it is possible. An orgasm is believed to occur in part because of the hormone oxytocin, which is produced in the body during sexual excitement and arousal. It has also been shown that oxytocin is produced when an individual's nipples are stimulated and become erect.
# Other definitions of "Orgasm"
There is some debate whether certain types of sexual sensation should be accurately classified as 'orgasm', including female orgasms caused by G-spot stimulation alone, and the demonstration of extended or continuous orgasms lasting several minutes or even an hour. The question centers around clinical definition of orgasm.
Orgasm is usually defined in a clinical context strictly by the muscular contractions involved.
In these and similar cases, the sensations experienced are subjective and do not necessarily involve the involuntary contractions characteristic of orgasm. However, the sensations in both sexes are extremely pleasurable and are often felt throughout the body, causing a mental state that is often described as transcendental, and with vasocongestion and associated pleasure comparable to that of a full contractionary orgasm.
For this reason, there are views on both sides as to whether these can be accurately defined as orgasms.
# Evolutionary function of orgasms
Most male orgasms expel sperm from the body during vaginal intercourse, which can result in conception. Evolutionary biologists have several hypotheses about the role, if any, of the female orgasm in the reproductive process. In 1967, Desmond Morris first suggested in his popular-science book The Naked Ape that female orgasm evolved to encourage physical intimacy with a male partner and help reinforce the pair bond. Morris suggested that the relative difficulty in achieving female orgasm, in comparison to the male's, might be favorable in Darwinian evolution by leading the female to select mates who bear qualities like patience, care, imagination, intelligence, as opposed to qualities like size and aggression, which pertain to mate selection in other primates. Such advantageous qualities thereby become accentuated within the species, driven by the differences between male and female orgasm. If males were motivated by, and taken to the point of, orgasm in the same way as females, those advantageous qualities would not be needed, since self-interest would be enough.
Morris also proposed that orgasm might facilitate conception by exhausting the female and keeping her horizontal, thus preventing the sperm from leaking out. This possibility, sometimes called the "Poleax Hypothesis" or the "Knockout Hypothesis," is now considered highly doubtful.
Other theories are based on the idea that the female orgasm might increase fertility. For example, the 30% reduction in size of the vagina could help clench onto the penis (much like, or perhaps caused by, the pubococcygeus muscles), which would make it more stimulating for the male (thus ensuring faster or more voluminous ejaculation). The British biologists Baker and Bellis have suggested that the female orgasm may have an "upsuck" action (similar to the esophagus' ability to swallow when upside down), resulting in the retaining of favorable sperm and making conception more likely. They posited a role of female orgasm in sperm competition.
A 1997 Learning Channel documentary on sex had fiber optic cameras inside the vagina of a woman while she had sexual intercourse. During her orgasm, her pelvic muscles contracted and her cervix dipped into a pool of semen in the vagina making conception more likely. Elisabeth Lloyd has criticized the accompanying narration of this film clip which describes it as an example of "Sperm Upsuck", saying that it depicted normal orgasmic uterine contractions, which have not been shown to have any effect on fertility.
The fact that women tend to reach orgasm more easily when they are ovulating suggests that it is tied to increasing fertility.
Other biologists surmise that the orgasm simply serves to motivate sex, thus increasing the rate of reproduction, which would be selected for during evolution. Since males typically reach orgasms faster than females, it potentially encourages a female's desire to engage in intercourse more frequently, increasing the likelihood of conception.
## Female orgasm as vestigial
The clitoris is homologous to the penis; that is, they both develop from the same embryonic structure. Stephen Jay Gould and other researchers have claimed that the clitoris is vestigial in females, and that female orgasm serves no particular evolutionary function. Proponents of this hypothesis, such as Dr. Elisabeth Lloyd, point to the relative difficulty of achieving female orgasm through vaginal sex, the limited evidence for increased fertility after orgasm and the lack of statistical correlation between the capacity of a woman to orgasm and the likelihood that she will engage in intercourse.
Science writer Natalie Angier has criticized this hypothesis as understating the psychosocial value of female orgasm. Catherine Blackledge in The Story of V, citing studies that indicate a possible connection between orgasm and successful conception, has criticized the hypothesis as ignoring the ongoing evolutionary advantages that result from successful conception.
## Genetic basis of individual variation
A 2005 twin study found that one in three women reported never or seldom achieving orgasm during intercourse, and only one in ten always orgasmed. This variation in ability to orgasm, generally thought to be psychosocial, was found to be 34% to 45% genetic. The study, examining 4000 women, was published in Biology letters, a Royal Society journal. Dr. Elisabeth Lloyd has cited this as evidence for her Fantastic Bonus Theory.
# Medical aspects of orgasm
## Physiological responses
### In male humans
During orgasm, a human male experiences rapid, rhythmic contractions of the anal sphincter, the prostate, and the muscles of the penis. These contractions typically cause ejaculation -- they force stored semen to be expelled through the penis's urethral opening. The process takes from three to ten seconds, and is generally considered to be highly pleasurable
As a man ages, normally the amount of semen he ejaculates diminishes, and so does the duration of orgasms. This does not normally affect the pleasurable feeling, but merely shortens its duration.
After ejaculation, a refractory period usually occurs during which a man cannot achieve another orgasm. This can be anywhere from less than a minute to several hours, depending on age and other individual factors.
As a man nears orgasm during stimulation of the penis, he feels an intense and highly pleasurable pulsating sensation of neuromuscular euphoria. These pulses begin with a throb of the anal sphincter and travel to the tip of the penis. They eventually increase in speed and intensity as the orgasm approaches, until a final "plateau" of pleasure sustained for several seconds, the orgasm.
During orgasm, semen is ejaculated and may continue to be ejaculated for a few seconds after the euphoric sensation gradually tapers off. It is believed that the exact feeling of "orgasm" varies from one man to another, but most agree that it is highly pleasurable.
### In female humans
A human female orgasm lasts much longer than that of the male. It is preceded by erection of the clitoris and moistening of the vaginal opening. Some women exhibit a sex flush, a reddening of the skin over much of the body due to increased blood flow to the skin. As a woman nears orgasm, the clitoral glans moves inward under the clitoral hood, and the labia minora (inner lips) become darker. As orgasm becomes imminent, the outer third of the vagina tightens and narrows, while overall the vagina lengthens and dilates and also becomes congested from engorged soft tissue. The uterus then experiences muscular contractions. A woman experiences full orgasm when her uterus, vagina, anus, and pelvic muscles undergo a series of rhythmic contractions. Most women find these contractions very pleasurable. Recently, researchers from the University Medical Center of Groningen, the Netherlands, showed that it is possible to objectively recognize orgasms just by the specific frequencies of these contractions (abstract). After orgasm, the clitoris re-emerges from under the clitoral hood, and returns to its normal size, typically within ten minutes.
## Orgasm and health
Orgasm, and indeed sex as a whole, are physical activities that can require exertion of many major bodily systems. A 1997 study in the British Medical Journal based upon 918 men age 45-59 found that after a ten year follow-up, men who had fewer orgasms were twice as likely to die of any cause as those having two or more orgasms a week. A follow-up in 2001 which focused more specifically on cardiovascular health found that having sex three or more times a week was associated with a 50% reduction in the risk of heart attack or stroke. (Note that as a rule, correlation does not imply causation).
## Orgasmic dysfunction
The inability to have orgasm is called anorgasmia, ejaculatory anhedonia, or inorgasmia. If a male experiences erection and ejaculation but no orgasm, he is said to have sexual anhedonia.
For a variety of reasons, some people choose to fake an orgasm. A recent Redbook survey shows that 52% of women regularly fake orgasms. Only 17% are likely to have an orgasm during sexual intercourse, because the clitoris often is not stimulated enough by intercourse alone. 43% of women report “some kind of sexual problem,” such as inability to achieve orgasm, boredom with sex, or total lack of interest in sex.
If orgasm is desired, anorgasmia is mainly attributed to an inability to relax, or "let go." It seems to be closely associated with performance pressure and an unwillingness to pursue pleasure, as separate from the other person's satisfaction. Often, women worry so much about the pleasure of their partner that they become anxious, which manifests as impatience with the delay of orgasm for them. This delay can lead to frustration of not reaching orgasmic sexual satisfaction. Psychoanalyst Wilhelm Reich, in his 1927 book The Function of the Orgasm was the first to make orgasm central to the concept of mental health, and defined neurosis in terms of blocks to having full orgasm. Although orgasm dysfunction can have psychological components, physiological factors often play a role. For instance, delayed orgasm or the inability to achieve orgasm is a common side effect of many medications.
Specifically in relation to simultaneous orgasm and similar practices, many sexologists claim that the problem of premature ejaculation is closely related to the idea encouraged by a scientific approach in early 20th century when mutual orgasm was overly emphasized as an objective and a sign of true sexual satisfaction in intimate relationships. A focus that is brought to the subject of simultaneous orgasm raises the problem that a man becomes too concerned with delaying ejaculation, which in fact deprives the intercourse from the necessary spontaneity and thus only making simultaneous orgasm even more difficult to reach. When partners become preoccupied with controlling and synchronizing their actions instead of enjoying the process, this may lead to sexual disturbance.
## Drugs and orgasm
Certain drugs have been reported to have enhancing effects on orgasm. Nitrite inhalants are used by both men and women to enhance orgasm. Marijuana enhances both male and female orgasms, while at the same time delaying ejaculation. GHB, GBL and 1,4 Butanediol are commonly used to enhance orgasms. Both male and female users of stimulants, such as 3,4-MDMA (ecstasy), and psychedelics like LSD and psilocybin-containing mushrooms sometimes report heightened sexual pleasure. Throughout history, recreational drugs have been used to enhance orgasm but, due to lack of research (or government-mandated research restrictions), may be unreliable or have hazardous side effects. Anecdotal evidence suggests that women have enhanced orgasms with sildenafil (commercially known as Viagra).
# In tantric sex
Tantric sex is the ancient Indian spiritual tradition of sexual practices. It attributes a different value to orgasm than traditional cultural approaches to sexuality. Some practitioners of tantric sex aim to eliminate orgasm from sexual intercourse by remaining for a long time in the pre-orgasmic and non-emission state. Advocates of this, such as Rajneesh, claim that it eventually causes orgasmic feelings to spread out to all of one's conscious experience.
Some advocates of tantric and neotantric sex claim that Western culture focuses too much on the goal of climactic orgasm, which reduces our ability to have intense pleasure during other moments of the sexual experience. Eliminating this enables a richer, fuller and more intense connection.
These practices should not be confused with Buddhist tantra (Vajrayana).
# In other animals
The mechanics of male orgasm are similar in most mammals. Females of some mammal and some non-mammal species such as alligators have clitorises.
There has been ongoing research about the sexuality and orgasms of dolphins, a species which apparently engages in sexual intercourse for reasons other than procreation. Dolphin orgasms have also been witnessed during sexual intercourse with humans, a practice which some humans have indulged in with pleasure.
See Animal sexuality.
# Books
- Gabriele Froböse, Rolf Froböse, Michael Gross (Translator): Lust and Love: Is it more than Chemistry? Publisher: Royal Society of Chemistry, ISBN 0-85404-867-7, (2006).
- Komisaruk, Barry R.; Beyer-Flores, Carlos; Whipple, Beverly. The Science of Orgasm. Baltimore, MD; London: The Johns Hopkins University Press, 2006 (hardcover, ISBN 0-8018-8490-X).
# Notes
- ↑ What Every Woman Needs to Know About Sexual Satisfaction - Marriage
- ↑ Exton, MS (2001). "Coitus-induced orgasm stimulates prolactin secretion in healthy subjects". Psychoneuroendocrinology. 26 (3): 287–94. Unknown parameter |coauthors= ignored (help); Unknown parameter |month= ignored (help).mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}
- ↑ Sobrinho, LG (2003). "Prolactin, psychological stress and environment in humans: adaptation and maladaptation". Pituitary. 6 (1): 35–9.
- ↑ Georgiadis J, Kortekaas R, Kuipers R, Nieuwenburg A, Pruim J, Reinders A, Holstege G (2006). "Regional cerebral blood flow changes associated with clitorally induced orgasm in healthy women". Eur J Neurosci. 24 (11): 3305–16. PMID 17156391.CS1 maint: Multiple names: authors list (link)
- ↑ "British woman suffers from orgasms every 5 minutes". Pravda. 26.05.2006. Check date values in: |date= (help)
- ↑ Jump up to: 6.0 6.1 Janssen, D.F. (October 2002). "Volume II: The Sexual Curriculum: The Manufacture and Performance of Pre-Adult Sexualities.". Growing Up Sexually -- The Sexual Curriculum.
- ↑ "Continuous Male Orgasms". Learn to enhance and maintain indefinitely the physiological events and associated pleasure of an absolutely imminent ejaculatory orgasm.
- ↑ Byerly, Paul & Lori. "How to make sex better for him". Boys who discover masturbation before puberty can't ejaculate, but they can have orgasms. They can also have multiple orgasms like women can, but then lose this ability when puberty adds ejaculation to their orgasms.
- ↑ Krüger, Tillmann H.C. (2003). "Effects of acute prolactin manipulation on sexual drive and function in males". Journal of Endocrinology. 179 (3): 357–65. Unknown parameter |coauthors= ignored (help); Unknown parameter |month= ignored (help)
- ↑ Whipple, B. (1998). "Male Multiple Ejaculatory Orgasms: A Case Study". Journal of Sex Education and Therapy. 23 (2): 157–62. Unknown parameter |coauthors= ignored (help)
- ↑ Haake, P. (2002). "Absence of orgasm-induced prolactin secretion in a healthy multi-orgasmic male subject". International Journal of Impotence Research. 14 (2): 133–5. Unknown parameter |coauthors= ignored (help); Unknown parameter |month= ignored (help)
- ↑ "The core of female orgasm". Human Sexuality - Orgasm. Sex Terms.
- ↑ Ellen Ross, Rayna Rapp Sex and Society: A Research Note from Social History and Anthropology Comparative Studies in Society and History, Vol. 23, No. 1 (Jan., 1981), pp. 51-72
- ↑ "Masters and Johnson". The Discovery Channel.
- ↑ O'Connell HE, Sanjeevan KV, Hutson JM. Anatomy of the Clitoris J Urol. 2005 Oct;174 (4 Pt 1):1189-95; Time for rethink on the clitoris at BBC News site.
- ↑ Taormino, Tristan. "Anal sex v. vaginal sex".
- ↑ Morin, Jack (1998). Anal Pleasure and Health (3d Edition ed.). Down There Press. ISBN 0-940208-20-2.CS1 maint: Extra text (link)
- ↑ Levay, Simon (2005-11-15). Human Sexuality, Second Edition. Sinauer Associates, Inc. ISBN 9780878934652. Unknown parameter |coauthors= ignored (help)
- ↑ Otto, Herbert A. (1988) New Orgasm Options: Expanding Sexual Pleasure.
- ↑ "The Journal of Sexual Medicine".
- ↑ Schwartz, Bob (May 1992). The One Hour Orgasm: A New Approach to Achieving Maximum Sexual Pleasure. Breakthru Publishing. ISBN 0942540077.
- ↑ Baker, R. R., and Bellis, M. A. (1993). Human sperm competition: Ejaculation manipulation by females and a function for the female orgasm. Animal Behavior, 46, 887-909.
- ↑ Morris, Dr. Desmond (host) (1997). The Human Sexes (TV). The Learning Channel.
- ↑ Reviews
- ↑ Adam, David (2005-06-08). "Female orgasm all in the genes". The Guardian.
- ↑ Reviews
- ↑ "Female orgasm is 'down to genes'". BBC. 2005-06-07.
- ↑ "Genetic influences on variation in female orgasmic function: a twin study by Dr KM Dunn, Dr LF Cherkas and Prof TD Spector" (Press release). Primary Care Sciences Research Centre, Keele University. 2005-06-07.
- ↑ Reviews
- ↑ "Do all orgasms feel alike?".
- ↑ "Women fall into 'trance' during orgasm". Mark Henderson. Times Online.
- ↑ "Anatomic and physiologic changes during female sexual response". Clinical Proceedings. Association of Reproductive Health Professionals.
- ↑ Sex and Death, Are They Related?
- ↑ The International Encyclopedia of Sexuality: Italy
- ↑ Marijuana and Sex: A Classic Combination
- ↑ Marijuana and Sex
- ↑ Journal of Sex & Marital Therapy
- ↑ Rajneesh, Bhagwan Shree (1983). Tantra, Spirituality, and Sex.
- ↑ Chia, Mantak & Abrams, Douglas (1996). The Multi-Orgasmic Man. Harper San Francisco. ISBN 0-06-251336-2.CS1 maint: Multiple names: authors list (link)
- ↑ Douglas, N & Slinger, P (1979). Sexual Secrets: The Alchemy of Ecstasy. Destiny Books.CS1 maint: Multiple names: authors list (link)
- ↑ Crocodilian Captive Care FAQ (Caiman, Alligator, Crocodile)
- ↑ National Geographic's Dolphins: The wild side documentary (1999), IMDb. "Sex is as frequent as it is casual, a social tool used to strengthen and maintain bonds. But beneath the harmony lies a darker side of dolphins. Gangs of strong males pick on younger or smaller dolphins.", quote from National Geographic website | Orgasm
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Phone:617-632-7753
# Overview
An orgasm (sexual climax) is the conclusion of the plateau phase of the sexual response cycle, and may be experienced by both males and females. Orgasm is characterized by intense physical pleasure, controlled by the involuntary, or autonomic, nervous system.[1] It is accompanied by quick cycles of muscle contraction in the lower pelvic muscles, which surround the primary sexual organs and the anus. Orgasms are often associated with other involuntary actions, including muscular spasms in other areas of the body, a general euphoric sensation, and, frequently, vocalizations.
After orgasm, humans often feel tired and a need to rest. This is attributed to the release of prolactin.[2] Prolactin is a typical neuroendocrine response in depressed mood and irritation.[3]
Ongoing research at the University Medical Center of Groningen, the Netherlands, studies brain events that accompany orgasm in men and women. Techniques used involve Positron Emission Tomography (PET) and fMRI. Male and female brains act almost the same during orgasm. Brain scans showed that large parts of the cerebral cortex temporarily reduced their activity.[4]
# From the erectile organ
Orgasm is achieved after direct stimulation of the penis or clitoris for a period of time. This stimulation can be caused by sexual intercourse, manual masturbation, anal sex, oral sex, non-penetrative sex, a sensual vibrator, or an erotic electrostimulation. Any sexual stimulation of the penis or clitoris may eventually result in an orgasm; it may also be achieved by stimulation of other erogenous zones, in the absence of physical stimulation through psychological arousal and as a nocturnal emission or "wet dream".
## Multiple orgasms
In some cases, women either do not have a refractory period or have a very short one and thus can experience a second orgasm, and perhaps further ones, soon after the first. After the first, subsequent climaxes may be stronger or more pleasurable as the stimulation accumulates. For some women, their clitoris and nipples are very sensitive after climax, making additional stimulation initially painful.
There are sensational reports of women having too many orgasms, including an unauthenticated claim that a young British woman has them constantly throughout the day, whenever she experiences the slightest vibration.[5]
It is possible for a man to have an orgasm without ejaculation (dry orgasm) or to ejaculate without reaching orgasm. Some men have reported having multiple consecutive orgasms, particularly without ejaculation. Males who experience dry orgasms can often produce multiple orgasms, as the refractory period, is reduced.[6] Some males are able to masturbate for hours at a time, achieving orgasm many times.[6] In recent years, a number of books have described various techniques to achieve multiple orgasms. Most multi-orgasmic men (and their partners) report that refraining from ejaculation results in a far more energetic post-orgasm state. Additionally, some men have also reported that this can produce more powerful ejaculatory orgasms when they choose to have them.
One dangerous technique is to put pressure on the perineum, about halfway between the scrotum and the anus, just before ejaculating to prevent ejaculation. This can, however, lead to retrograde ejaculation, i.e. redirecting semen into the urinary bladder rather than through the urethra to the outside. It may also cause long term damage due to the pressure put on the nerves and blood vessels in the perineum. Men who have had prostate or bladder surgery, for whatever reason, may also experience dry orgasms because of retrograde ejaculation.
Other techniques are analogous to reports by multi-orgasmic women indicating that they must relax and "let go" to experience multiple orgasms. These techniques involve mental and physical controls over pre-ejaculatory vasocongestion and emissions, rather than ejaculatory contractions or forced retention as above. Anecdotally, successful implementation of these techniques can result in continuous or multiple "full-body" orgasms.[7] Gentle digital stimulation of the prostate, seminal vesicles, and vas deferens provides erogenous pleasure that sustains intense emissions orgasms for some men. A dildo device (the Aneros) claims to stimulate the prostate and help men reach these kinds of orgasms.
Many men who began masturbation or other sexual activity prior to puberty report having been able to achieve multiple non-ejaculatory orgasms. Young male children are capable of having multiple orgasms due to the lack of refractory period until they reach their first ejaculation. In female children it is always possible, even after the onset of puberty. This capacity generally disappears in males with the subject's first ejaculation. Some evidence indicates that orgasms of men before puberty are qualitatively similar to the "normal" female experience of orgasm, suggesting that hormonal changes during puberty have a strong influence on the character of male orgasm.[8]
A number of studies have pointed to the hormone prolactin as the likely cause of male refractory period. Because of this, there is currently an experimental interest in drugs which inhibit prolactin, such as cabergoline (also known as Cabeser, or Dostinex). Anecdotal reports on cabergoline suggest it may be able to eliminate the refractory period altogether, allowing men to experience multiple ejaculatory orgasms in rapid succession. At least one scientific study supports these claims.[9] Cabergoline is a hormone-altering drug and has many potential side effects. It has not been approved for treating sexual dysfunction. Another possible reason may be an increased infusion of the hormone oxytocin. Furthermore, it is believed that the amount by which oxytocin is increased may affect the length of each refractory period.
A scientific study to successfully document natural, fully ejaculatory, multiple orgasms in an adult man was conducted at Rutgers University in 1995. During the study, six fully ejaculatory orgasms were experienced in 36 minutes, with no apparent refractory period.[10] It can also be said that in some cases, the refractory period can be reduced or even eliminated through the course of puberty and on into adulthood. Later, P. Haake et al. observed a single male individual producing multiple orgasms without elevated prolactin response.[11]
## Spontaneous orgasms
Orgasms can be spontaneous, seeming to occur with no direct stimulation. Occasionally, orgasms can occur during sexual dreams.
The first orgasm of this type was reported among people who had spinal cord injury (SCI). Although SCI very often leads to loss of certain sensations and altered self-perception, a person with this disturbance is not deprived of sexual feelings such as sexual arousal and erotic desires. Thus some individuals are able to initiate orgasm by mere mental stimulation. Some non-sexual activity may result in a spontaneous orgasm. The best example of such activity is a release of tension that unintentionally involves slight genital stimulation, like rubbing of the seat of the bicycle against genitals during riding, exercising, when pelvic muscles are tightened or when yawning or sneezing.
It was also discovered that some anti-depressant drugs may provoke spontaneous climax as a side effect.[12] There is no accurate data for how many patients who were on treatment with antidepressant drugs experienced spontaneous orgasm, as most were unwilling to acknowledge the fact.
# From the prostatic structure
Some people are able to achieve orgasm through stimulation of the prostatic structure, which in men is the prostate and in women is Skene's glands; in women the location of Skenes's glands is often known as the g-spot, or Grafenberg Spot, after the physician who first identified the spot as having orgasmic potential. The stimulation can come from receptive intercourse, fingering, fisting, or penetration with a dildo.
Orgasms of this kind can cause male orgasm and ejaculation. Women do not have prostate glands, therefore can not have a prostatic orgasm. With sufficient stimulation, the prostatic structure can also be "milked." Providing that there is no simultaneous stimulation of the penis prostate milking can cause ejaculation without orgasm. When combined with penile stimulation, some men report that prostate stimulation increases the volume of their ejaculation. The prostatic structure produces a secretion that forms one of the components of ejaculate; in males sperm are transmitted up the vas deferens from the testicles, into the prostate gland as well as through the seminal vesicles to produce what we know as semen. Semen is expelled through the base of the penis out by contractions from the sphinctre and prostate, thus causing an orgasm.
Prostatic orgasms can be very pleasurable. It can cause numbness through out the entire body causing emphasis on the thighs, mid back, and head of penis. After a prostatic orgasm the body is very sensitive to touch and stimulation and may cause sleepiness.
# Other known categorizations of orgasm
Certain types and categorization of orgasm have become widely enough acknowledged to be discussed as distinctive forms of orgasm.
## Vaginal orgasm
The female body can achieve orgasm from stimulation of the clitoris and from stimulation of the G-spot. The Gräfenberg spot, or G-spot, is a small area behind the female pubic bone surrounding the urethra and accessible through the anterior wall of the vagina. Many scientists believe that only certain women possess a G-spot. The G-spot orgasm is sometimes referred to as "vaginal," because it results from stimulation inside the vagina, including during sexual intercourse. However, only stimulation of the G-spot, and not other intravaginal stimulation, results in a "vaginal orgasm." The same is true for men, who are believed to have a male G-spot, through stimulation of the prostatic structure, which in men is the prostate. This leads to a different type of male orgasm than the orgasm that results from stimulation of the penis.
The "two-orgasm theory" (the belief that in females there is a vaginal orgasm and a clitoral orgasm), has been criticized by feminists such as Ellen Ross and Rayna Rapp as a "transparently male perception of the female body".[13] The concept of purely vaginal orgasm was first postulated by Sigmund Freud. In 1905, Freud argued that clitoral orgasm was an adolescent phenomenon, and upon reaching puberty the proper response of mature women changes to vaginal orgasms. While Freud provided no evidence for this basic assumption, the consequences of the theory were greatly elaborated, partly because many women felt inadequate when they could not achieve orgasm via vaginal intercourse that involved little or no clitoral stimulation. Freud's claims about this and many other biological subjects, were later largely proven false or based on supposition.
In 1966, Masters and Johnson published pivotal research about the phases of sexual stimulation. Their work included women and men, and unlike Alfred Kinsey earlier (in 1948 and 1953), tried to determine the physiological stages before and after orgasm.[14] One of the results was the promotion of the idea that vaginal and clitoral orgasms follow the same stages of physical response. Masters and Johnson also argued that clitoral stimulation is the primary source of orgasms.
Recent discoveries about the size of the clitoris - it extends inside the body, around the vagina[15] - complicate or may invalidate attempts to distinguish clitoral vs. vaginal orgasms. Recent anatomical research shows that there are nerves connecting intravaginal tissues and the clitoris. This, with the anatomical evidence that the internal part of the clitoris is a much larger organ than previously thought, could explain credible reports of orgasms in women who have undergone clitorectomy as part of female circumcision. The link between the clitoris and the vagina is evidence that the clitoris is the 'seat' of the female orgasm and is far more wide-spread than the visible part most people associate with it. But it is possible that some women have more extensive clitoral tissues and nerves than others, and so that some women can achieve orgasm only by direct stimulation of the external part of the clitoris.
## Anal orgasm
Anal orgasm is an orgasm brought on by anal stimulation, such as from anal sex, an inserted finger, or a sex toy. Some men are able to achieve an anal orgasm.
A woman may come to orgasm without stimulating the anus, by stimulation of the buttocks and anal cleft with the tongue. But typically, stimulation of the G-spot through the wall shared between the vagina and the rectum, from a sex toy, finger or a penis, may bring about an orgasm. This is often greatly facilitated through additional manual stimulation of the clitoris. Another theory on the source of anal orgasm in the female is the perineal sponge. The perineal sponge is an erectile structure located between the vagina and rectum that responds to stimulation like any other erectile tissue. Anecdotal evidence suggests that some women experience anal orgasm as qualitatively different from clitoral or vaginal orgasm, though for many others the distinction is less clear.[16]
In both sexes pleasure can be derived from the nerve endings around the anus and the anus itself. Hence, anal-oral contact can still be pleasurable without stimulation of the clitoris. Anal orgasm has nothing to do with the prostate orgasm, although the two are often confused.[17]
## Breast orgasm
A breast orgasm is a female orgasm that is triggered from the stimulation of a woman's breast.[18] Not all women experience this effect when the breasts are stimulated; however, some women claim that the stimulation of the breast area during sexual intercourse and foreplay, or just the simple act of having their breasts fondled, has created mild to intense orgasms. According to one study that questioned 213 women, 29% of them had experienced a breast orgasm at one time or another,[19] This shows that it is not common, but it is possible. An orgasm is believed to occur in part because of the hormone oxytocin, which is produced in the body during sexual excitement and arousal. It has also been shown that oxytocin is produced when an individual's nipples are stimulated and become erect.[20]
# Other definitions of "Orgasm"
There is some debate whether certain types of sexual sensation should be accurately classified as 'orgasm', including female orgasms caused by G-spot stimulation alone, and the demonstration of extended or continuous orgasms lasting several minutes or even an hour.[21] The question centers around clinical definition of orgasm.
Orgasm is usually defined in a clinical context strictly by the muscular contractions involved.
In these and similar cases, the sensations experienced are subjective and do not necessarily involve the involuntary contractions characteristic of orgasm. However, the sensations in both sexes are extremely pleasurable and are often felt throughout the body, causing a mental state that is often described as transcendental, and with vasocongestion and associated pleasure comparable to that of a full contractionary orgasm.
For this reason, there are views on both sides as to whether these can be accurately defined as orgasms.
# Evolutionary function of orgasms
Most male orgasms expel sperm from the body during vaginal intercourse, which can result in conception. Evolutionary biologists have several hypotheses about the role, if any, of the female orgasm in the reproductive process. In 1967, Desmond Morris first suggested in his popular-science book The Naked Ape that female orgasm evolved to encourage physical intimacy with a male partner and help reinforce the pair bond. Morris suggested that the relative difficulty in achieving female orgasm, in comparison to the male's, might be favorable in Darwinian evolution by leading the female to select mates who bear qualities like patience, care, imagination, intelligence, as opposed to qualities like size and aggression, which pertain to mate selection in other primates. Such advantageous qualities thereby become accentuated within the species, driven by the differences between male and female orgasm. If males were motivated by, and taken to the point of, orgasm in the same way as females, those advantageous qualities would not be needed, since self-interest would be enough.
Morris also proposed that orgasm might facilitate conception by exhausting the female and keeping her horizontal, thus preventing the sperm from leaking out. This possibility, sometimes called the "Poleax Hypothesis" or the "Knockout Hypothesis," is now considered highly doubtful.
Other theories are based on the idea that the female orgasm might increase fertility. For example, the 30% reduction in size of the vagina could help clench onto the penis (much like, or perhaps caused by, the pubococcygeus muscles), which would make it more stimulating for the male (thus ensuring faster or more voluminous ejaculation). The British biologists Baker and Bellis have suggested that the female orgasm may have an "upsuck" action (similar to the esophagus' ability to swallow when upside down), resulting in the retaining of favorable sperm and making conception more likely.[22] They posited a role of female orgasm in sperm competition.
A 1997 Learning Channel documentary on sex had fiber optic cameras inside the vagina of a woman while she had sexual intercourse. During her orgasm, her pelvic muscles contracted and her cervix dipped into a pool of semen in the vagina making conception more likely.[23] Elisabeth Lloyd has criticized the accompanying narration of this film clip which describes it as an example of "Sperm Upsuck", saying that it depicted normal orgasmic uterine contractions, which have not been shown to have any effect on fertility.[24]
The fact that women tend to reach orgasm more easily when they are ovulating suggests that it is tied to increasing fertility.[25]
Other biologists surmise that the orgasm simply serves to motivate sex, thus increasing the rate of reproduction, which would be selected for during evolution. Since males typically reach orgasms faster than females, it potentially encourages a female's desire to engage in intercourse more frequently, increasing the likelihood of conception.
## Female orgasm as vestigial
The clitoris is homologous to the penis; that is, they both develop from the same embryonic structure. Stephen Jay Gould and other researchers have claimed that the clitoris is vestigial in females, and that female orgasm serves no particular evolutionary function. Proponents of this hypothesis, such as Dr. Elisabeth Lloyd, point to the relative difficulty of achieving female orgasm through vaginal sex, the limited evidence for increased fertility after orgasm and the lack of statistical correlation between the capacity of a woman to orgasm and the likelihood that she will engage in intercourse.[26]
Science writer Natalie Angier has criticized this hypothesis as understating the psychosocial value of female orgasm. Catherine Blackledge in The Story of V, citing studies that indicate a possible connection between orgasm and successful conception, has criticized the hypothesis as ignoring the ongoing evolutionary advantages that result from successful conception.
## Genetic basis of individual variation
A 2005 twin study found that one in three women reported never or seldom achieving orgasm during intercourse, and only one in ten always orgasmed. This variation in ability to orgasm, generally thought to be psychosocial, was found to be 34% to 45% genetic. The study, examining 4000 women, was published in Biology letters, a Royal Society journal.[27][28] Dr. Elisabeth Lloyd has cited this as evidence for her Fantastic Bonus Theory.[29]
# Medical aspects of orgasm
## Physiological responses
### In male humans
During orgasm, a human male experiences rapid, rhythmic contractions of the anal sphincter, the prostate, and the muscles of the penis. These contractions typically cause ejaculation -- they force stored semen to be expelled through the penis's urethral opening. The process takes from three to ten seconds, and is generally considered to be highly pleasurable
As a man ages, normally the amount of semen he ejaculates diminishes, and so does the duration of orgasms. This does not normally affect the pleasurable feeling, but merely shortens its duration.
After ejaculation, a refractory period usually occurs during which a man cannot achieve another orgasm. This can be anywhere from less than a minute to several hours, depending on age and other individual factors.
As a man nears orgasm during stimulation of the penis, he feels an intense and highly pleasurable pulsating sensation of neuromuscular euphoria. These pulses begin with a throb of the anal sphincter and travel to the tip of the penis. They eventually increase in speed and intensity as the orgasm approaches, until a final "plateau" of pleasure sustained for several seconds, the orgasm.
During orgasm, semen is ejaculated and may continue to be ejaculated for a few seconds after the euphoric sensation gradually tapers off. It is believed that the exact feeling of "orgasm" varies from one man to another,[30] but most agree that it is highly pleasurable.
### In female humans
A human female orgasm lasts much longer than that of the male.[31] It is preceded by erection of the clitoris and moistening of the vaginal opening. Some women exhibit a sex flush, a reddening of the skin over much of the body due to increased blood flow to the skin. As a woman nears orgasm, the clitoral glans moves inward under the clitoral hood, and the labia minora (inner lips) become darker. As orgasm becomes imminent, the outer third of the vagina tightens and narrows, while overall the vagina lengthens and dilates and also becomes congested from engorged soft tissue.[32] The uterus then experiences muscular contractions. A woman experiences full orgasm when her uterus, vagina, anus, and pelvic muscles undergo a series of rhythmic contractions. Most women find these contractions very pleasurable. Recently, researchers from the University Medical Center of Groningen, the Netherlands, showed that it is possible to objectively recognize orgasms just by the specific frequencies of these contractions (abstract). After orgasm, the clitoris re-emerges from under the clitoral hood, and returns to its normal size, typically within ten minutes.
## Orgasm and health
Orgasm, and indeed sex as a whole, are physical activities that can require exertion of many major bodily systems. A 1997 study in the British Medical Journal[33] based upon 918 men age 45-59 found that after a ten year follow-up, men who had fewer orgasms were twice as likely to die of any cause as those having two or more orgasms a week. A follow-up in 2001 which focused more specifically on cardiovascular health found that having sex three or more times a week was associated with a 50% reduction in the risk of heart attack or stroke. (Note that as a rule, correlation does not imply causation).
## Orgasmic dysfunction
The inability to have orgasm is called anorgasmia, ejaculatory anhedonia, or inorgasmia. If a male experiences erection and ejaculation but no orgasm, he is said to have sexual anhedonia.
For a variety of reasons, some people choose to fake an orgasm. A recent Redbook survey shows that 52% of women regularly fake orgasms. Only 17% are likely to have an orgasm during sexual intercourse, because the clitoris often is not stimulated enough by intercourse alone. 43% of women report “some kind of sexual problem,” such as inability to achieve orgasm, boredom with sex, or total lack of interest in sex.
If orgasm is desired, anorgasmia is mainly attributed to an inability to relax, or "let go." It seems to be closely associated with performance pressure and an unwillingness to pursue pleasure, as separate from the other person's satisfaction. Often, women worry so much about the pleasure of their partner that they become anxious, which manifests as impatience with the delay of orgasm for them. This delay can lead to frustration of not reaching orgasmic sexual satisfaction. Psychoanalyst Wilhelm Reich, in his 1927 book The Function of the Orgasm was the first to make orgasm central to the concept of mental health, and defined neurosis in terms of blocks to having full orgasm. Although orgasm dysfunction can have psychological components, physiological factors often play a role. For instance, delayed orgasm or the inability to achieve orgasm is a common side effect of many medications.
Specifically in relation to simultaneous orgasm and similar practices, many sexologists claim that the problem of premature ejaculation[34] is closely related to the idea encouraged by a scientific approach in early 20th century when mutual orgasm was overly emphasized as an objective and a sign of true sexual satisfaction in intimate relationships. A focus that is brought to the subject of simultaneous orgasm raises the problem that a man becomes too concerned with delaying ejaculation, which in fact deprives the intercourse from the necessary spontaneity and thus only making simultaneous orgasm even more difficult to reach. When partners become preoccupied with controlling and synchronizing their actions instead of enjoying the process, this may lead to sexual disturbance.
## Drugs and orgasm
Certain drugs have been reported to have enhancing effects on orgasm. Nitrite inhalants are used by both men and women to enhance orgasm. Marijuana enhances both male and female orgasms, while at the same time delaying ejaculation.[35] GHB, GBL and 1,4 Butanediol are commonly used to enhance orgasms. Both male and female users of stimulants, such as 3,4-MDMA (ecstasy), and psychedelics like LSD and psilocybin-containing mushrooms sometimes report heightened sexual pleasure. Throughout history, recreational drugs have been used to enhance orgasm but, due to lack of research (or government-mandated research restrictions), may be unreliable or have hazardous side effects.[36] Anecdotal evidence suggests that women have enhanced orgasms with sildenafil (commercially known as Viagra).[37]
# In tantric sex
Tantric sex is the ancient Indian spiritual tradition of sexual practices. It attributes a different value to orgasm than traditional cultural approaches to sexuality. Some practitioners of tantric sex aim to eliminate orgasm from sexual intercourse by remaining for a long time in the pre-orgasmic and non-emission state. Advocates of this, such as Rajneesh, claim that it eventually causes orgasmic feelings to spread out to all of one's conscious experience.[38][39]
Some advocates of tantric and neotantric sex claim that Western culture focuses too much on the goal of climactic orgasm, which reduces our ability to have intense pleasure during other moments of the sexual experience. Eliminating this enables a richer, fuller and more intense connection.[40]
These practices should not be confused with Buddhist tantra (Vajrayana).
# In other animals
The mechanics of male orgasm are similar in most mammals. Females of some mammal and some non-mammal species such as alligators[41] have clitorises.
There has been ongoing research about the sexuality and orgasms of dolphins, a species which apparently engages in sexual intercourse for reasons other than procreation.[42] Dolphin orgasms have also been witnessed during sexual intercourse with humans, a practice which some humans have indulged in with pleasure. [43]
See Animal sexuality.
# Books
- Gabriele Froböse, Rolf Froböse, Michael Gross (Translator): Lust and Love: Is it more than Chemistry? Publisher: Royal Society of Chemistry, ISBN 0-85404-867-7, (2006).
- Komisaruk, Barry R.; Beyer-Flores, Carlos; Whipple, Beverly. The Science of Orgasm. Baltimore, MD; London: The Johns Hopkins University Press, 2006 (hardcover, ISBN 0-8018-8490-X).
# Notes
- ↑ What Every Woman Needs to Know About Sexual Satisfaction - Marriage
- ↑ Exton, MS (2001). "Coitus-induced orgasm stimulates prolactin secretion in healthy subjects". Psychoneuroendocrinology. 26 (3): 287–94. Unknown parameter |coauthors= ignored (help); Unknown parameter |month= ignored (help).mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}
- ↑ Sobrinho, LG (2003). "Prolactin, psychological stress and environment in humans: adaptation and maladaptation". Pituitary. 6 (1): 35–9.
- ↑ Georgiadis J, Kortekaas R, Kuipers R, Nieuwenburg A, Pruim J, Reinders A, Holstege G (2006). "Regional cerebral blood flow changes associated with clitorally induced orgasm in healthy women". Eur J Neurosci. 24 (11): 3305–16. PMID 17156391.CS1 maint: Multiple names: authors list (link)
- ↑ "British woman suffers from orgasms every 5 minutes". Pravda. 26.05.2006. Check date values in: |date= (help)
- ↑ Jump up to: 6.0 6.1 Janssen, D.F. (October 2002). "Volume II: The Sexual Curriculum: The Manufacture and Performance of Pre-Adult Sexualities.". Growing Up Sexually -- The Sexual Curriculum.
- ↑ "Continuous Male Orgasms". Learn to enhance and maintain indefinitely the physiological events and associated pleasure of an absolutely imminent ejaculatory orgasm.
- ↑ Byerly, Paul & Lori. "How to make sex better for him". Boys who discover masturbation before puberty can't ejaculate, but they can have orgasms. They can also have multiple orgasms like women can, but then lose this ability when puberty adds ejaculation to their orgasms.
- ↑ Krüger, Tillmann H.C. (2003). "Effects of acute prolactin manipulation on sexual drive and function in males". Journal of Endocrinology. 179 (3): 357–65. Unknown parameter |coauthors= ignored (help); Unknown parameter |month= ignored (help)
- ↑ Whipple, B. (1998). "Male Multiple Ejaculatory Orgasms: A Case Study". Journal of Sex Education and Therapy. 23 (2): 157–62. Unknown parameter |coauthors= ignored (help)
- ↑ Haake, P. (2002). "Absence of orgasm-induced prolactin secretion in a healthy multi-orgasmic male subject". International Journal of Impotence Research. 14 (2): 133–5. Unknown parameter |coauthors= ignored (help); Unknown parameter |month= ignored (help)
- ↑ "The core of female orgasm". Human Sexuality - Orgasm. Sex Terms.
- ↑ Ellen Ross, Rayna Rapp Sex and Society: A Research Note from Social History and Anthropology Comparative Studies in Society and History, Vol. 23, No. 1 (Jan., 1981), pp. 51-72
- ↑ "Masters and Johnson". The Discovery Channel.
- ↑ O'Connell HE, Sanjeevan KV, Hutson JM. Anatomy of the Clitoris J Urol. 2005 Oct;174 (4 Pt 1):1189-95; Time for rethink on the clitoris at BBC News site.
- ↑ Taormino, Tristan. "Anal sex v. vaginal sex".
- ↑ Morin, Jack (1998). Anal Pleasure and Health (3d Edition ed.). Down There Press. ISBN 0-940208-20-2.CS1 maint: Extra text (link)
- ↑ Levay, Simon (2005-11-15). Human Sexuality, Second Edition. Sinauer Associates, Inc. ISBN 9780878934652. Unknown parameter |coauthors= ignored (help)
- ↑ Otto, Herbert A. (1988) New Orgasm Options: Expanding Sexual Pleasure.
- ↑ "The Journal of Sexual Medicine".
- ↑ Schwartz, Bob (May 1992). The One Hour Orgasm: A New Approach to Achieving Maximum Sexual Pleasure. Breakthru Publishing. ISBN 0942540077.
- ↑ Baker, R. R., and Bellis, M. A. (1993). Human sperm competition: Ejaculation manipulation by females and a function for the female orgasm. Animal Behavior, 46, 887-909.
- ↑ Morris, Dr. Desmond (host) (1997). The Human Sexes (TV). The Learning Channel.
- ↑ Reviews
- ↑ Adam, David (2005-06-08). "Female orgasm all in the genes". The Guardian.
- ↑ Reviews
- ↑ "Female orgasm is 'down to genes'". BBC. 2005-06-07.
- ↑ "Genetic influences on variation in female orgasmic function: a twin study by Dr KM Dunn, Dr LF Cherkas and Prof TD Spector" (Press release). Primary Care Sciences Research Centre, Keele University. 2005-06-07.
- ↑ Reviews
- ↑ "Do all orgasms feel alike?".
- ↑ "Women fall into 'trance' during orgasm". Mark Henderson. Times Online.
- ↑ "Anatomic and physiologic changes during female sexual response". Clinical Proceedings. Association of Reproductive Health Professionals.
- ↑ Sex and Death, Are They Related?
- ↑ The International Encyclopedia of Sexuality: Italy
- ↑ Marijuana and Sex: A Classic Combination
- ↑ Marijuana and Sex
- ↑ Journal of Sex & Marital Therapy
- ↑ Rajneesh, Bhagwan Shree (1983). Tantra, Spirituality, and Sex.
- ↑ Chia, Mantak & Abrams, Douglas (1996). The Multi-Orgasmic Man. Harper San Francisco. ISBN 0-06-251336-2.CS1 maint: Multiple names: authors list (link)
- ↑ Douglas, N & Slinger, P (1979). Sexual Secrets: The Alchemy of Ecstasy. Destiny Books.CS1 maint: Multiple names: authors list (link)
- ↑ Crocodilian Captive Care FAQ (Caiman, Alligator, Crocodile)
- ↑ National Geographic's Dolphins: The wild side documentary (1999), IMDb. "Sex is as frequent as it is casual, a social tool used to strengthen and maintain bonds. But beneath the harmony lies a darker side of dolphins. Gangs of strong males pick on younger or smaller dolphins.", quote from National Geographic website
- ↑ http://www.sexwork.com/family/dolphins1.html | https://www.wikidoc.org/index.php/Breast_orgasm | |
5c90b29b75599d952ee90baef86f8bcfb6c8bb56 | wikidoc | Bronze | Bronze
Bronze is any of a broad range of copper alloys, usually with tin as the main additive, but sometimes with other elements such as phosphorus, manganese, aluminium, or silicon. (See table below.) It was particularly significant in antiquity, giving its name to the Bronze Age. "Bronze," in turn, is perhaps ultimately taken from the Persian word "berenj," meaning "brass".
# History of Bronze
Bronze was significant to any culture that encountered it. It was one of the most innovative alloys of mankind. Tools, weapons, armor, and various building materials like decorative tiles made of bronze were harder and more durable than their stone and copper ("Chalcolithic") predecessors. In early use, the impurity arsenic sometimes created a superior alloy; this is termed arsenical bronze.
The earliest tin-alloy bronzes date to the late 4th millennium BC in Susa (Iran) and some ancient sites in Luristan (Iran) and Mesopotamia (Iraq).
The two ores are rarely found together (exceptions include one ancient site in Thailand and one in Iran), so serious bronze work has always involved trade. In Europe, the major source for tin was Great Britain's deposits of ore were found in Cornwall. Phoenician traders visited Great Britain to trade goods from the Mediterranean for tin.
Though bronze is stronger (harder) than wrought iron, the Bronze Age gave way to the Iron Age. Bronze was still used during the Iron Age, but for many purposes the weaker wrought iron was found to be sufficiently strong. Archaeologists suspect that a serious disruption of the tin trade precipitated the transition. The population migrations around 1200 – 1100 BC reduced the shipping of tin around the Mediterranean (and from Great Britain), limiting supplies and raising prices. As ironworking improved, iron became cheaper, and people figured out how to make steel, which is stronger than bronze and holds a sharper edge longer.
# Properties
With the exception of steel, bronze is superior to iron in nearly every application. It is considerably less brittle than iron. Bronze only oxidizes superficially; once the surface oxidizes, the thin oxide layer protects the underlying metal from further corrosion. Copper-based alloys have lower melting points than steel or iron, and are more readily produced from their constituent metals. They are generally about 10 percent heavier than steel, although alloys using aluminium or silicon may be slightly less dense. Bronzes are softer and weaker than steel, bronze springs are less stiff (and so store less energy) for the same bulk. It resists corrosion (especially seawater corrosion) and metal fatigue better than steel and also conducts heat and electricity better than most steels. The cost of copper-base alloys is generally higher than that of steels but lower than that of nickel-base alloys such as stainless steel.
Copper and its alloys have a huge variety of uses that reflect their versatile physical, mechanical, and chemical properties. Some common examples are the high electrical conductivity of pure copper, the excellent deep-drawing qualities of cartridge case brass, the low-friction properties of bearing bronze, the resonant qualities of bell bronze, and the resistance to corrosion by sea water of several bronze alloys.
In the twentieth century, silicon was introduced as the primary alloying element, creating an alloy with wide application in industry and the major form used in contemporary statuary. Aluminium is also used for the structural metal aluminium bronze.
Bronze is the most popular metal for top-quality bells and cymbals, and more recently, saxophones. It is also widely used for cast metal sculpture (see bronze sculpture). Common bronze alloys often have the unusual and very desirable property of expanding slightly just before they set, thus filling in the finest details of a mould. Bronze parts are tough and typically used for bearings, clips, electrical connectors and springs.
Bronze also has very little metal-on-metal friction, which made it invaluable for the building of cannons where iron cannonballs would otherwise stick in the barrel. It is still widely used today for springs, bearings, bushings, automobile transmission pilot bearings, and similar fittings, and is particularly common in the bearings of small electric motors. Phosphor bronze is particularly suited to precision-grade bearings and springs.
Bronze is typically 88% copper and 12% tin. Alpha bronze consists of the alpha solid solution of tin in copper. Alpha bronze alloys of 4–5% tin are used to make coins, springs, turbines and blades.
Commercial bronze (otherwise known as brass) is 90% copper and 10% zinc, and contains no tin. It is stronger than copper and it has equivalent ductility. It is used for screws and wires.
Unlike steel, bronze struck against a hard surface will not generate sparks, so it (along with beryllium copper) is used to make hammers, mallets, wrenches and other durable tools to be used in explosive atmospheres or in the presence of flammable vapours.
# Classification of copper and its alloys | Bronze
Bronze is any of a broad range of copper alloys, usually with tin as the main additive, but sometimes with other elements such as phosphorus, manganese, aluminium, or silicon. (See table below.) It was particularly significant in antiquity, giving its name to the Bronze Age. "Bronze," in turn, is perhaps ultimately taken from the Persian word "berenj," meaning "brass".[1]
# History of Bronze
Bronze was significant to any culture that encountered it. It was one of the most innovative alloys of mankind. Tools, weapons, armor, and various building materials like decorative tiles made of bronze were harder and more durable than their stone and copper ("Chalcolithic") predecessors. In early use, the impurity arsenic sometimes created a superior alloy; this is termed arsenical bronze.
The earliest tin-alloy bronzes date to the late 4th millennium BC in Susa (Iran) and some ancient sites in Luristan (Iran) and Mesopotamia (Iraq).
The two ores are rarely found together (exceptions include one ancient site in Thailand and one in Iran), so serious bronze work has always involved trade. In Europe, the major source for tin was Great Britain's deposits of ore were found in Cornwall. Phoenician traders visited Great Britain to trade goods from the Mediterranean for tin.[citation needed]
Though bronze is stronger (harder) than wrought iron,[citation needed] the Bronze Age gave way to the Iron Age. Bronze was still used during the Iron Age, but for many purposes the weaker wrought iron was found to be sufficiently strong. Archaeologists suspect that a serious disruption of the tin trade precipitated the transition. The population migrations around 1200 – 1100 BC reduced the shipping of tin around the Mediterranean (and from Great Britain), limiting supplies and raising prices.[2] As ironworking improved, iron became cheaper, and people figured out how to make steel, which is stronger than bronze and holds a sharper edge longer.[3]
# Properties
With the exception of steel, bronze is superior to iron in nearly every application. It is considerably less brittle than iron. Bronze only oxidizes superficially; once the surface oxidizes, the thin oxide layer protects the underlying metal from further corrosion. Copper-based alloys have lower melting points than steel or iron, and are more readily produced from their constituent metals. They are generally about 10 percent heavier than steel, although alloys using aluminium or silicon may be slightly less dense. Bronzes are softer and weaker than steel, bronze springs are less stiff (and so store less energy) for the same bulk. It resists corrosion (especially seawater corrosion) and metal fatigue better than steel and also conducts heat and electricity better than most steels. The cost of copper-base alloys is generally higher than that of steels but lower than that of nickel-base alloys such as stainless steel.
Copper and its alloys have a huge variety of uses that reflect their versatile physical, mechanical, and chemical properties. Some common examples are the high electrical conductivity of pure copper, the excellent deep-drawing qualities of cartridge case brass, the low-friction properties of bearing bronze, the resonant qualities of bell bronze, and the resistance to corrosion by sea water of several bronze alloys.
In the twentieth century, silicon was introduced as the primary alloying element, creating an alloy with wide application in industry and the major form used in contemporary statuary. Aluminium is also used for the structural metal aluminium bronze.
Bronze is the most popular metal for top-quality bells and cymbals, and more recently, saxophones. It is also widely used for cast metal sculpture (see bronze sculpture). Common bronze alloys often have the unusual and very desirable property of expanding slightly just before they set, thus filling in the finest details of a mould. Bronze parts are tough and typically used for bearings, clips, electrical connectors and springs.
Bronze also has very little metal-on-metal friction, which made it invaluable for the building of cannons where iron cannonballs would otherwise stick in the barrel.[citation needed] It is still widely used today for springs, bearings, bushings, automobile transmission pilot bearings, and similar fittings, and is particularly common in the bearings of small electric motors. Phosphor bronze is particularly suited to precision-grade bearings and springs.
Bronze is typically 88% copper and 12% tin.[4] Alpha bronze consists of the alpha solid solution of tin in copper. Alpha bronze alloys of 4–5% tin are used to make coins, springs, turbines and blades.
Commercial bronze (otherwise known as brass) is 90% copper and 10% zinc, and contains no tin. It is stronger than copper and it has equivalent ductility. It is used for screws and wires.
Unlike steel, bronze struck against a hard surface will not generate sparks, so it (along with beryllium copper) is used to make hammers, mallets, wrenches and other durable tools to be used in explosive atmospheres or in the presence of flammable vapours.
# Classification of copper and its alloys[5] | https://www.wikidoc.org/index.php/Bronze | |
dadd484b8bf0da3e9c4f44acce50c7d5757ebc65 | wikidoc | Bruise | Bruise
Synonyms and keywords: Contusion; ecchymosis; ecchymoma.
# Overview
A bruise is an injury to biological tissue in which the capillaries are damaged, allowing blood to seep into the surrounding tissue. It is usually caused by blunt impact. Bruises often induce pain but are not normally dangerous. Sometimes bruises can be serious, leading to other more life threatening forms of hematoma, or can be associated with serious injuries, including fractures and internal bleeding. Minor bruises may be easily recognized, in people with light skin color, by their characteristic blue or purple appearance (idiomatically described as "black and blue") in the days following the injury.
The presence of bruises may be seen in patients with platelet or coagulation disorders. Unexplained bruising may be a warning sign of child abuse or serious medical problems, such as leukemia and meningoccocal infection. Unexplained bruising could indicate internal bleeding or certain types of cancer. A deficiency in Vitamin C can also make a person more susceptible to bruises from impacts. Also long term glucocorticoid therapy can cause easy bruising.
# Classification
## Based on Severity
Bruises can be scored on a scale from 0-5 to categorize the severity and danger of the injury.
The harm score is determined by the extent and severity of the fractures to the organs and tissues causing the bruising, in turn depending on multiple factors. A contracted muscle will bruise more severely, as can the tissues being crushed against underlying bone. Capillaries vary in strength, stiffness and toughness, which can also vary by age and medical conditions.
### Causes
Drug Side Effect
- Azacitidine
- Azficel-T
- Cetrorelix
- Choline Magnesium Trisalicylate
- Dexamethasone
- Naproxen sodium
- Meprobamate
- Oxaprozin
- Penicillamine
- Prednisolone
- Prednisone
- Ruxolitinib
- Sodium phenylbutyrate
## Light Bruises
At low levels of damage producing low-level bruising, the individual will feel some pain, either initially or delayed. The skin and surrounding region show inflammation, becoming red, tender and swollen due to the release of histamines. Repeated impacts worsen bruises, increasing the harm level. As time progresses, blood may escape and seep into the surrounding tissues even when the capillaries are being repaired, causing the bruise to darken and spread. During about the next two weeks, the bruise color changes to a dark red then to purple, black, or blue, eventually fading to yellow and disappearing as healing progresses. Some of these color changes are related to the breakdown of the hemoglobin in the escaped red blood cells. Normally, light bruises heal nearly completely on average in two weeks. Some may take a shorter or longer time and this is caused by random variation in the healing process; more severe or deeper bruises may take longer. The striking colors of a bruise are caused by hemoglobin and its breakdown products, bilirubin and biliverdin.
Treatment for light bruises is minimal, including RICE, painkillers (particularly NSAIDs) and later in recovery, some light stretching exercises may be appropriate. If swelling is severe, swelling may be reduced by applying ice and / or by elevating the area. Rest and preventing re-injury is essential for faster recovery. Very gentle massage of the area may relieve pain and encourage blood flow, though pain may indicate the massage is exacerbating the injury.
## Moderate to Severe Bruises
If bruising is severe, (harm score 2-3) it may be dangerous, or it can cause serious complications. Further bleeding and excess fluid may accumulate causing a hard, fluctuating lump or swelling hematoma. This has the potential to cause compartment syndrome as the swelling cuts off blood flow to the tissues. Blunt trauma, which cause severe bruising by shock waves, may also cause other severe and fatal harm to internal organs. Impacts to the head can cause traumatic brain injury, bleeding, bruising and massive swelling of the brain with the potential to cause concussion, coma and death. Treatment may involve emergency surgery to relieve the pressure on the brain.
Bones may be broken by similar impacts, tendons can be bruised and joints can be sprained or otherwise harmed in ways that impair the functioning of the limbs. The symptoms and signs of these injuries may appear to be those of simple bruising. Severe injuries that cause difficulty in moving a limb, abdominal bruising and the feeling of liquid under the skin may indicate a life-threatening injury and requires the attention of a doctor.
If a severely bruised muscle is used too early before healing has occurred, bone tissue may form inside the muscle, causing permanent stiffness, pain and disability. Extremely severe bruises may take as long as a year to completely heal.
# Diagnosis
## Physical Examination
- Bruise caused by a handrail, typical of extreme sports
- Severe bruises caused by car accident
- Bruised caused by a bad landing while snowboarding
# Related Chapters
- Black eye
- Burn
- Gua Sha
- Subconjunctival hemorrhage
- Petechiae
- Purpura | Bruise
For patient information, click here
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Synonyms and keywords: Contusion; ecchymosis; ecchymoma.
# Overview
A bruise is an injury to biological tissue in which the capillaries are damaged, allowing blood to seep into the surrounding tissue. It is usually caused by blunt impact. Bruises often induce pain but are not normally dangerous. Sometimes bruises can be serious, leading to other more life threatening forms of hematoma, or can be associated with serious injuries, including fractures and internal bleeding. Minor bruises may be easily recognized, in people with light skin color, by their characteristic blue or purple appearance (idiomatically described as "black and blue") in the days following the injury.
The presence of bruises may be seen in patients with platelet or coagulation disorders. Unexplained bruising may be a warning sign of child abuse or serious medical problems, such as leukemia and meningoccocal infection. Unexplained bruising could indicate internal bleeding or certain types of cancer. A deficiency in Vitamin C can also make a person more susceptible to bruises from impacts. Also long term glucocorticoid therapy can cause easy bruising.
# Classification
## Based on Severity
Bruises can be scored on a scale from 0-5 to categorize the severity and danger of the injury.
The harm score is determined by the extent and severity of the fractures to the organs and tissues causing the bruising, in turn depending on multiple factors. A contracted muscle will bruise more severely, as can the tissues being crushed against underlying bone. Capillaries vary in strength, stiffness and toughness, which can also vary by age and medical conditions.
### Causes
Drug Side Effect
- Azacitidine
- Azficel-T
- Cetrorelix
- Choline Magnesium Trisalicylate
- Dexamethasone
- Naproxen sodium
- Meprobamate
- Oxaprozin
- Penicillamine
- Prednisolone
- Prednisone
- Ruxolitinib
- Sodium phenylbutyrate
## Light Bruises
At low levels of damage producing low-level bruising, the individual will feel some pain, either initially or delayed. The skin and surrounding region show inflammation, becoming red, tender and swollen due to the release of histamines. Repeated impacts worsen bruises, increasing the harm level. As time progresses, blood may escape and seep into the surrounding tissues even when the capillaries are being repaired, causing the bruise to darken and spread. During about the next two weeks, the bruise color changes to a dark red then to purple, black, or blue, eventually fading to yellow and disappearing as healing progresses. Some of these color changes are related to the breakdown of the hemoglobin in the escaped red blood cells. Normally, light bruises heal nearly completely on average in two weeks. Some may take a shorter or longer time and this is caused by random variation in the healing process;[1] more severe or deeper bruises may take longer. The striking colors of a bruise are caused by hemoglobin and its breakdown products, bilirubin and biliverdin.
Treatment for light bruises is minimal, including RICE, painkillers (particularly NSAIDs) and later in recovery, some light stretching exercises may be appropriate. If swelling is severe, swelling may be reduced by applying ice and / or by elevating the area. Rest and preventing re-injury is essential for faster recovery. Very gentle massage of the area may relieve pain and encourage blood flow, though pain may indicate the massage is exacerbating the injury.[2]
## Moderate to Severe Bruises
If bruising is severe, (harm score 2-3) it may be dangerous, or it can cause serious complications. Further bleeding and excess fluid may accumulate causing a hard, fluctuating lump or swelling hematoma. This has the potential to cause compartment syndrome as the swelling cuts off blood flow to the tissues. Blunt trauma, which cause severe bruising by shock waves, may also cause other severe and fatal harm to internal organs. Impacts to the head can cause traumatic brain injury, bleeding, bruising and massive swelling of the brain with the potential to cause concussion, coma and death. Treatment may involve emergency surgery to relieve the pressure on the brain.
Bones may be broken by similar impacts, tendons can be bruised and joints can be sprained or otherwise harmed in ways that impair the functioning of the limbs. The symptoms and signs of these injuries may appear to be those of simple bruising. Severe injuries that cause difficulty in moving a limb, abdominal bruising and the feeling of liquid under the skin may indicate a life-threatening injury and requires the attention of a doctor.
If a severely bruised muscle is used too early before healing has occurred, bone tissue may form inside the muscle, causing permanent stiffness, pain and disability. Extremely severe bruises may take as long as a year to completely heal.
# Diagnosis
## Physical Examination
- Bruise caused by a handrail, typical of extreme sports
- Severe bruises caused by car accident
- Bruised caused by a bad landing while snowboarding
# Related Chapters
- Black eye
- Burn
- Gua Sha
- Subconjunctival hemorrhage
- Petechiae
- Purpura | https://www.wikidoc.org/index.php/Bruise | |
305f6f247613e4373dec818036d83279bbd48a82 | wikidoc | Burial | Burial
# Overview
Burial, also called interment and inhumation, is the act of placing a person or object into the ground. This is accomplished by excavating a pit or trench, placing an object in it, and covering it over.
Objects are sometimes buried in order to hide them against removal or tampering. For cables and pipelines, burial provides protection.
The remainder of this article discusses human burial.
# History
Intentional burial, particularly with grave goods may be one of the earliest detectable forms of religious practice since, as Philip Lieberman suggests, it may signify a "concern for the dead that transcends daily life." Though disputed, evidence suggests that the Neanderthals were the first hominids to intentionally bury the dead, doing so in shallow graves along with stone tools and animal bones. Exemplary sites include Shanidar in Iraq, Kebara Cave in Israel and Krapina in Croatia. Some scholars, however argue that these bodies may have been disposed of for secular reasons.
The earliest undisputed human burial dates back 130,000 years. Human skeletal remains stained with red ochre were discovered in the Skhul cave at Qafzeh, Israel. A variety of grave goods were present at the site, including the mandible of a wild boar in the arms of one of the skeletons.
Prehistoric cemeteries are referred to by the more neutral term grave field. They are one of the chief sources of information on prehistoric cultures, and numerous archaeological cultures are defined by their burial customs, such as the
Urnfield culture of the European Bronze Age.
# Reasons for human burial
After death, a corpse will start to decay and emit unpleasant odors due to gases released by bacterial decomposition. Burial prevents the living from having to see and smell the decomposing corpse, but it is not necessarily a public health requirement. Contrary to conventional wisdom, the WHO advises that only corpses carrying an infectious disease strictly require burial.
Human burial practices are the manifestation of the human desire to demonstrate "respect for the dead". Among the reasons for this are:
- Respect for the physical remains is considered necessary. If left lying on top of the ground, scavengers may eat the corpse, which is considered highly disrespectful to the deceased in many (but not all) cultures.
- Burial can be seen as an attempt to bring closure to the deceased's family and friends. By interring a body away from plain view, the pain of losing a loved one can be lessened.
- Many cultures believe in an afterlife. Burial is often believed to be a necessary step for an individual to reach the afterlife.
- Many religions prescribe a "correct" way to live, which includes customs relating to disposal of the dead.
# Burial methods
In many cultures, human corpses were usually buried in soil. The act of burying corpses is thought to have begun around 200,000 years ago during the Paleolithic period by homo sapiens, before spreading out from Africa. As a result, burial grounds are found throughout the world. Mounds of earth, temples, and underground caverns were used to store the dead bodies of ancestors. In modern times, the custom of burying dead people below ground with a stone marker to mark the place is used in almost every modern culture, although other means such as cremation are becoming more popular in the west (cremation is the norm in India and mandatory in Japan).
Some burial practices are heavily ritualized; others are simply practical.
## Natural burial
A growing trend in modern burial is the concept of natural burial. Popularised in the United Kingdom in the late 1990s, natural burial is being adopted in the United States as a method for protecting and restoring the natural environment.
With a natural burial, the body is returned to nature in a biodegradable coffin or shroud. Native vegetation (often a memorial tree) is planted over or near the grave in place of a conventional cemetery monument. The resulting green space establishes a living memorial and forms a protected wildlife preserve.
The practice of natural burial dates back to the late nineteenth century, when Sir Francis Seymour Hayden proposed "earth to earth burial," in a pamphlet of the same name, as a less gruesome alternative to either cremation or the slow putrefaction of encased corpses. The earth to earth burial movement was part of the short-lived cremation controversy of the 1870s.
Muslims also practice natural burial, with the deceased's body covered in shroud and with his\her face facing Mecca.
Natural burial grounds are also known as woodland cemeteries, eco-cemeteries, memorial nature preserves, or green burial grounds.
## Prevention of decay
Embalming is the practice of preserving a body against decay, and is used in many cultures. Mummification is a more extensive method of embalming, further delaying the decay process.
Bodies are often buried wrapped in a shroud or placed in a coffin (also called a casket). A larger container may be used, such as a ship. Coffins are usually covered by a burial liner or a burial vault, which prevents the coffin from collapsing under the weight of the earth or floating away during a flood.
These containers slow the decomposition process by (partially) physically blocking decomposing bacteria and other organisms from accessing the corpse. An additional benefit of using containers to hold the body is that if the soil covering the corpse is washed away by a flood or some other natural process, the corpse will still not be exposed to open air.
In some cultures however the goal is not to preserve the body but to allow it to decompose—or return to the Earth — naturally. In Orthodox Judaism embalming is not permitted, and the coffins are constructed so that the body will be returned to the Earth as soon as possible. Such coffins are made of wood, and have no metal parts at all. Wooden pegs are used in the place of nails.
## Inclusion of clothing and personal effects
The body may be dressed in fancy and/or ceremonial clothes. Personal objects, such as a favorite piece of jewellery or photograph, of the deceased may be included with the body. This practice, also known as the inclusion of grave goods, serves several purposes:
- In funeral services, the body is often put on display. Many cultures feel that the deceased should be presented looking his/her finest.
- The inclusion of ceremonial garb and sacred objects is sometimes viewed as necessary for reaching the afterlife.
- The inclusion of personal effects may be motivated by the beliefs that in the afterlife a person will wish to have with them what was important to them on earth. Alternatively, in some cultures it is felt that when a person dies, their possessions (and sometimes people connected to them such as wives) should go with them out of loyalty or ownership.
- Though not generally a motivation for the inclusion of grave goods with a corpse, it is worth considering that future archaeologists may find the remains (compare time capsule). Artifacts such as clothing and objects provide insight into how the individual lived. This provides a form of immortality for the deceased.
## Body positioning
Burials may be placed in a number of different positions. Christian burials are made extended, i.e., lying flat with arms and legs straight, or with the arms folded upon the chest, and with the eyes and mouth closed. Extended burials may be supine (lying on the back) or prone (lying on the front). Other ritual practices place the body in a flexed position with the legs bent or crouched with the legs folded up to the chest. Warriors in some ancient societies were buried in an upright position. In Islam, the head is pointed toward and the face is turned toward Mecca, the holiest city in Islam. Many cultures treat placement of dead people in an appropriate position to be a sign of respect even when burial is impossible.
In nonstandard burial practices, such as mass burial, the body may be positioned arbitrarily. This can be a sign of disrespect to the deceased, or at least nonchalance on the part of the inhumer, or due to considerations of time and space.
### Orientation
Historically, Christian burials were made supine east-west, with the head at the western end of the grave. This mirrors the layout of Christian churches, and for much the same reason; to view the coming of Christ on Judgement day (Eschaton). In many Christian traditions, ordained clergy are traditionally buried in the opposite orientation, and their coffins carried likewise, so that at the General Resurrection they may rise facing, and ready to minister to, their people.
### Inverted burial
For humans, maintaining an upside down position, with the head vertically below the feet, is highly uncomfortable for any extended period of time, and consequently burial in that attitude (as opposed to attitudes of rest or watchfulness, as above) is highly unusual and generally symbolic. Occasionally suicides were buried upside down, as a post mortem punishment and (as with burial at cross-roads) to inhibit the activities of the resulting undead.
In Gulliver's Travels, the Lilliputians buried their dead upside down:
They bury their dead with their heads directly downward, because they hold an opinion, that in eleven thousand moons they are all to rise again; in which period the earth (which they conceive to be flat) will turn upside down, and by this means they shall, at their resurrection, be found ready standing on their feet. The learned among them confess the absurdity of this doctrine; but the practice still continues, in compliance to the vulgar.
Swift's notion of inverted burial might seem the highest flight of fancy, but it appears that among English millenarians the idea that the world would be "turned upside down" at the Apocalypse enjoyed some currency, and there is at least one attested case of a person being buried upside down by instruction; a Major Peter Labelliere of Dorking (d. June 4, 1800) lies thus upon the summit of Box Hill. Similar stories have attached themselves to other noted eccentrics, particularly in southern England, but not always with a foundation in truth.
## Burial among African-American slaves
In the African-American slave community, slaves quickly familiarized themselves with funeral procedures and the location of gravesites of family and friends. Specific slaves were assigned to prepare dead bodies, build coffins, dig graves, and construct headstones. Slave funerals were typically at night when the workday was over, with the master present to view all the ceremonial procedures. Slaves from the nearby plantations were regularly in attendance.
At death, a slave’s body was wrapped in cloth. The hands were placed across the chest, and a metal plate was placed on top of their hands. The reasoning for the plate was to hinder their return home by suppressing any spirits in the coffin. Often, personal property was buried with slaves to appease spirits. The coffins were nailed shut once the body was inside, and carried by hand or wagon, depending on the property designated for slave burial site. Slaves were buried east to west, with the head facing east and their feet to the west. This positioning represented the ability to rise without having to turn around at the call of Gabriel’s trumpet. Gabriel’s trumpet would be blown in the eastern sunrise. East-west positioning also was the direction of home, Africa.
## Burial in the Bahá'í Faith
Bahá'í burial law prescribes both the location of burial and burial practices and precludes cremation of the dead. It is forbidden to carry the body for more than one hour's journey from the place of death. Before interment the body should be wrapped in a shroud of silk or cotton, and a ring should be placed on its finger bearing the inscription "I came forth from God, and return unto Him, detached from all save Him, holding fast to His Name, the Merciful, the Compassionate". The coffin should be of crystal, stone or hard fine wood. Also, before interment, a specific Prayer for the Dead is ordained. The formal prayer and the ring are meant to be used for those who have reached fifteen years of age.
# Locations
## Where to bury
Apart from sanitary and other practical considerations, the site of burial can be determined by religious and socio-cultural considerations.
Thus in some traditions, especially with an animistic logic, the remains of the dead are "banished" for fear their spirits would harm the living if too close; others keep remains close to help surviving generations.
Religious rules may prescribe a specific zone, e.g. some Christian traditions hold that Christians must be buried in "consecrated ground," usually a cemetery; an earlier practice, burial in or very near the church (hence the word churchyard), was generally abandoned with individual exceptions as a high posthumous honour; also many existing funeral monuments and crypts remain in use.
Royalty and high nobility often have one or more "traditional" sites of burial, generally monumental, often in a palatial chapel or cathedral; see examples on Heraldica.org.
## Marking the location of the burial
Most modern cultures mark the location of the body with a headstone. This serves two purposes. First, the grave will not accidentally be exhumed. Second, headstones often contain information or tributes to deceased. This is a form of remembrance for loved ones; it can also be viewed as a form of immortality, especially in cases of famous people's graves. Such monumental inscriptions may subsequently be useful to genealogists and family historians.
In many cultures graves will be grouped, so the monuments make up a necropolis, a "city of the dead" parallelling the community of the living.
### Unmarked grave
In many cultures graves are marked with durable markers, or monuments, intended to help remind people of the buried person. An unmarked grave is a grave with no such memorial marker.
The corpse of Pope Formosus was actually disinterred, placed on trial (see Cadaver Synod), found guilty, and ultimately thrown into the River Tiber.
### Anonymous burial
Another sort of unmarked grave is a burial site with an anonymous marker, such as a simple cross; boots, rifle and helmet; a sword and shield; a cairn of stones; or even a monument. This may occur when identification of the deceased is impossible. Although many unidentified deceased are buried in potter's fields, some are memorialized, especially in smaller communities or in the case of deaths publicized by local media.
Many countries have buried an unidentified soldier (or other member of the military) in a prominent location as a form of respect for all unidentified war dead. The United Kingdom's Tomb of the Unknown Warrior is in Westminster Abbey, France's is buried underneath the Arc de Triomphe, Italy's is buried in the Monumento al Milite Ignoto in Rome, Canada's is buried at the National War Memorial in Ottawa, Australia's Tomb of the Unknown Soldier is located at the Australian War Memorial in Canberra, New Zealand's Tomb of the Unknown Warrior is in Wellington and the United States' Tomb of the Unknown Soldier is located at Arlington National Cemetery.
Many cultures practise anonymous burial as a norm, not an exception. For instance, in parts of eastern Germany, up to 43% of burials are anonymous. According to Christian Century magazine, the perspective of the Roman Catholic Church is that anonymous burials reflect a dwindling belief in God, but others claim that the practice relates more to the exorbitant cost of grave markers and the solitary nature of German life.
### Secret burial
In rare cases, a known person may be buried without identification, perhaps to avoid desecration of the corpse, grave robbing, or vandalism of the burial site. This may be particularly the case with infamous or notorious figures. In other cases, it may be to prevent the grave from becoming a tourist attractions or a destination of pilgrimage. Survivors may cause the deceased to be buried in a secret location or other unpublished place, or in a grave with a false name (or no name at all) on the marker.
When Walt Disney was cremated his ashes were buried in a secret location in Forest Lawn Memorial Park Cemetery, California. Some burial sites at Forest Lawn, such as those of Humphrey Bogart and Mary Pickford, are secluded in private gated gardens with no public access. A number of tombs are also kept from the public eye. Forest Lawn's Court of Honour indicates that some of its crypts have plots which are reserved for individuals who may be "voted in" as "Immortals"; no amount of money can purchase a place. Photographs taken at Forest Lawn are not permitted to be published, and their information office usually refuses to reveal exactly where the remains of famous people are buried. Although the cemetery's owners state that this is meant to deter gravesite tourism, some critics say that the cemetery wishes visitors to purchase memorabilia at the funeral home's numerous gift shops instead of taking photographs for free, especially in the case of grave markers notable for their beauty.
### Multiple bodies per grave
Some couples or groups of people (such as a married couple or other family members) may wish to be buried in the same plot. In some cases, the coffins (or urns) may simply be buried side by side. In others, one casket may be interred above another. If this is planned for in advance, the first casket may be buried more deeply than is the usual practice so that the second casket may be placed over it without disturbing the first. In many states in Australia all graves are designated two or three depth (depending of the water table) for multiple burials, at the discretion of the burial rights holder, with each new interment atop the previous coffin separated by a thin layer of earth. As such all graves are dug to greater depth for the initial burial than the traditional six feet to facilitate this practice.
Mass burial is the practice of burying multiple bodies in one location. Civilizations attempting genocide often employ mass burial for victims. However, mass burial may in many cases be the only practical means of dealing with an overwhelming number of human remains, such as those resulting from a natural disaster, an act of terrorism, an epidemic, or an accident. This practice has become less common in the developed world with the advent of genetic testing, but even in the 21st century remains which are unidentifiable by current methods may be buried in a mass grave.
Individuals who are buried at the expense of the local authorities and buried in potter's fields may be buried in mass graves. Wolfgang Amadeus Mozart is believed to have been buried in such a manner. In some cases, the remains of unidentified individuals may be buried in mass graves in potter's fields, making exhumation and future identification troublesome for law enforcement.
Naval ships sunk in combat are also considered mass graves by many countries. For example, U.S. Navy policy declares such wrecks a mass grave and forbids the recovery of remains. In lieu of recovery, divers or submersibles may leave a plaque dedicated to the memory of the ship or boat and its crew, and family members are invited to attend the ceremony.
Sites of large former battlefields may also contain one or more mass graves. Douaumont ossuary is one such mass grave, and it contains the remains of 130,000 soldiers from both sides of the battle of Verdun.
Catacombs also constitute a form of mass grave. Some catacombs, for example those in Rome, were designated as a communal burial place. Some, such as the catacombs of Paris, only became a mass grave when individual burials were relocated from cemeteries marked for demolition.
Judaism does not generally allow multiple bodies in a grave. An exception to this is a grave in the military cemetery in Jerusalem, where there is a "kever ah-chim" (Heb. "grave of brothers") where two soldiers were killed together in a tank and are buried in one grave. As the bodies were so fused together with the metal of the tank that they could not be separately identified, they were buried in one grave (along with parts of the tank).
## Cremation
There are several common alternatives to burial. In cremation the body of the deceased is burned in a special oven. Most of the body is burnt during the cremation process, leaving only a few pounds of bone fragments. Bodies of small children and infants often produce very little in the way of "ashes", as ashes are composed of bone, and young people have softer bones, largely cartilage. Often these fragments are processed (ground) into a fine powder, which has led to cremated remains being called ashes. In recent times, cremation has become a popular option in the western world.
There is far greater flexibility in dealing with the remains in cremation as opposed to the traditional burial. Some of the options include scattering the ashes at a place close to the heart of the deceased or keeping the ashes at home. Ashes can also be buried either underground or in a columbarium niche.
## Live burial
Live burial sometimes occurs, in which individuals are buried while still alive. Having no way of escaping interment, they die in place, typically by asphyxiation, dehydration, starvation, or (in cold climates) exposure. People may come to be buried alive in a number of different ways:
- An individual may be intentionally buried alive as a method of execution or murder. In ancient Rome, Vestal Virgins who broke their vows were punished in this way.
- A person or group of people in a cave, mine, or other underground area may be sealed underground due to an earthquake, cave in, or other natural disaster or accident. Live burial may also occur due to avalanches on mountain slopes.
- People have been unintentionally buried alive because they were pronounced dead by a coroner or other official, when they were in fact still alive.
Writer Edgar Allan Poe wrote a number of stories and poems about premature burial, including a story called "The Premature Burial." These works inspired a widespread popular fear of this appalling but unlikely event. Various expedients have been devised to prevent this event, including burying live telephones or telemetry sensors in graves.
## Burial at cross-roads
Historically, burial at cross-roads was the method of disposing of executed criminals and suicides. At the cross-roads a rude cross usually stood, and this gave rise to the belief that these spots were selected as the next best burying-places to consecrated ground. The real explanation is that the ancient Teutonic peoples often built their altars at the cross-roads, and as human sacrifices, especially of criminals, formed part of the ritual, these spots came to be regarded as execution grounds. Hence after the introduction of Christianity, criminals and suicides were buried at the cross-roads during the night, in order to assimilate as far as possible their funeral to that of the pagans. An example of a cross-road execution-ground was the famous Tyburn in London, which stood on the spot where the Roman road to Edgware and beyond met the Roman road heading west out of London.
Superstition also played a part in the selection of cross-roads in the burial of suicides. Folk belief often held such individuals could rise as some form of undead (such as a vampire) and burying them at cross-roads would inhibit their ability to find and wreak havoc on their living relations and former associates.
## Burial of animals
### By humans
In addition to burying human remains, many human cultures also regularly bury animal remains.
Pets and other animals of emotional significance are often ceremonially buried. Most families bury deceased pets on their own properties, mainly in a yard, with a shoe box or any other type of container served as a coffin. The Ancient Egyptians are known to have mummified and buried cats, which they considered deities.
### By other animals
Humans are not always the only species to bury their dead. Chimpanzees and elephants are known to throw leaves and branches over fallen members of their family groups.
# Exhumation
The digging up of a buried body is called exhumation or disinterration, and is considered sacrilege by most cultures that bury their dead. However, exhumation can occur in the following circumstances:
- If an individual dies under suspicious circumstances, a legitimate investigating agency (such as a police agency) may exhume the body to determine the cause of death.
- Deceased individuals who were either not identified or misidentified at the time of burial may be reburied if survivors so wish.
- Remains may be exhumed in order to be reinterred at a more appropriate location. For example, the remains of Nicholas II of Russia and his family were exhumed from their resting place near Yekaterinburg so that they could be reinterred in the Peter and Paul Fortress in St. Petersburg.
- The remains of the Venerable or the Blessed are sometimes exhumed to see if they are supernaturally Incorruptible and thus a Saint. This type of exhumation is generally not considered sacrilege.
- Remains may be exhumed and reburied en masse when a cemetery is relocated.
- In rare cases (such as those of Pope Formosus or Oliver Cromwell), a body may be exhumed for posthumous execution, dissection, or gibbeting.
- Notable individuals may be exhumed to answer historical questions. Tutankhamen's remains were exhumed in 2005 in order to determine his cause of death.
- Once human remains reach a certain age, some cultures consider exhumation acceptable. This serves several purposes:
Cemeteries have a limited number of plots in which to bury the dead. Once all plots are full, older remains may be moved to an ossuary to accommodate more bodies.
It enables archaeologists to search the remains to better understand human culture.
It enables construction agencies to clear the way for new constructions.
- Cemeteries have a limited number of plots in which to bury the dead. Once all plots are full, older remains may be moved to an ossuary to accommodate more bodies.
- It enables archaeologists to search the remains to better understand human culture.
- It enables construction agencies to clear the way for new constructions.
Frequently, cultures have different sets of exhumation taboos. Occasionally these differences result in conflict, especially in cases where a culture with more lenient exhumation rules wishes to operate on the territory of a stricter culture. For example, United States construction companies have run into conflict with Native American groups that wanted to preserve their ancient burial grounds from any form of modern construction.
In folklore and mythology, exhumation has also been frequently associated with the performance of rites to banish undead manifestations. An example is the Mercy Brown Vampire Incident of Rhode Island, which occurred in 1892.
# Alternatives to burial
Human bodies are not always buried. Alternatives to burial include the following:
- Ash jump: skydivers may elect to have their cremated remains released during freefall.
- Burial at sea is the practice of depositing the body in an ocean or other large body of water instead of soil. It may be disposed in a coffin, or without one.
- Funerary cannibalism is the practice of eating the remains. This may be for many reasons: for example to partake of their strength, to spiritually "close the circle" by reabsorbing their life into the family or clan, to annihilate an enemy, or due to pathological mental conditions. The Yanomami have the habit of cremating the remains and then eating the ashes with banana paste.
- Cremation is the incineration of the remains. This practice is common amongst Hindus and is becoming increasingly common in other cultures as well. If a family member wishes, the ashes can now be turned into a gem, similar to creating synthetic diamonds.
- Ecological funeral is a method of increasing the rate of decomposition in order to help fertilize the soil.
- Excarnation is the practice of removing the flesh from the corpse without interment. The Zoroastrians have traditionally left their dead on Towers of Silence, where the flesh of the corpses is left to be devoured by vultures and other carrion-eating birds. Alternatively, it can also mean butchering the corpse by hand to remove the flesh (sometimes referred to by the neologism "defleshing").
- Gibbeting was the ancient practice of publicly displaying remains of criminals.
- Hanging coffins are coffins which have been placed on cliffs. They can be found in various locations, including China and the Philippines.
- Resomation involves disposal through an accelerated process of alkaline hydrolysis.
- Sky burial involves placing the body on a mountaintop.
- Space burial is the practice of firing the coffin into space. The coffin may be placed into orbit, sent off into space, or incinerated in the sun. Space burial is still largely in the realm of science fiction as the cost of getting a body into space is prohibitively large, although several prominent figures have had a sample of their ashes launched into space after cremation.
In most cases these alternatives are still intended to maintain respect for the dead, but some are intended to prolong the display of the remains.
Cryonics is often mistakenly assumed to be an alternative interment method, but is in fact a medical procedure carried out to physically preserve the body in the hope that it will one day be technologically possible to revive the individual. See also information theoretical death; clinical death.
# Notes and references
- ↑ Uniquely Human. 1991. ISBN 0674921836..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}
- ↑ Evolving in their graves: early burials hold clues to human origins - research of burial rituals of Neanderthals
- ↑ Uniquely Human page 163
- ↑ Simpson, Jacqueline (August 2005). "The Miller's tomb: facts, gossip, and legend". Folklore.
- ↑ Simpson, Jacqueline (Jan.—Mar 1978). "The World Upside down Shall Be: A Note on the Folklore of Doomsday". The Journal of American Folklore. 91 (359): 559–567. Check date values in: |date= (help) | Burial
# Overview
Burial, also called interment and inhumation, is the act of placing a person or object into the ground. This is accomplished by excavating a pit or trench, placing an object in it, and covering it over.
Objects are sometimes buried in order to hide them against removal or tampering. For cables and pipelines, burial provides protection.
The remainder of this article discusses human burial.
# History
Intentional burial, particularly with grave goods may be one of the earliest detectable forms of religious practice since, as Philip Lieberman suggests, it may signify a "concern for the dead that transcends daily life."[1] Though disputed, evidence suggests that the Neanderthals were the first hominids to intentionally bury the dead, doing so in shallow graves along with stone tools and animal bones.[citation needed] Exemplary sites include Shanidar in Iraq, Kebara Cave in Israel and Krapina in Croatia. Some scholars, however argue that these bodies may have been disposed of for secular reasons.[2]
The earliest undisputed human burial dates back 130,000 years. Human skeletal remains stained with red ochre were discovered in the Skhul cave at Qafzeh, Israel. A variety of grave goods were present at the site, including the mandible of a wild boar in the arms of one of the skeletons.[3]
Prehistoric cemeteries are referred to by the more neutral term grave field. They are one of the chief sources of information on prehistoric cultures, and numerous archaeological cultures are defined by their burial customs, such as the
Urnfield culture of the European Bronze Age.
# Reasons for human burial
Template:Seealso
After death, a corpse will start to decay and emit unpleasant odors due to gases released by bacterial decomposition. Burial prevents the living from having to see and smell the decomposing corpse, but it is not necessarily a public health requirement. Contrary to conventional wisdom, the WHO advises that only corpses carrying an infectious disease strictly require burial.[4][5]
Human burial practices are the manifestation of the human desire to demonstrate "respect for the dead". Among the reasons for this are:
- Respect for the physical remains is considered necessary. If left lying on top of the ground, scavengers may eat the corpse, which is considered highly disrespectful to the deceased in many (but not all) cultures.
- Burial can be seen as an attempt to bring closure to the deceased's family and friends. By interring a body away from plain view, the pain of losing a loved one can be lessened.
- Many cultures believe in an afterlife. Burial is often believed to be a necessary step for an individual to reach the afterlife.
- Many religions prescribe a "correct" way to live, which includes customs relating to disposal of the dead.
# Burial methods
In many cultures, human corpses were usually buried in soil. The act of burying corpses is thought to have begun around 200,000 years ago during the Paleolithic period by homo sapiens, before spreading out from Africa. As a result, burial grounds are found throughout the world. Mounds of earth, temples, and underground caverns were used to store the dead bodies of ancestors. In modern times, the custom of burying dead people below ground with a stone marker to mark the place is used in almost every modern culture, although other means such as cremation are becoming more popular in the west (cremation is the norm in India and mandatory in Japan).
Some burial practices are heavily ritualized; others are simply practical.
## Natural burial
A growing trend in modern burial is the concept of natural burial. Popularised in the United Kingdom in the late 1990s, natural burial is being adopted in the United States as a method for protecting and restoring the natural environment.
With a natural burial, the body is returned to nature in a biodegradable coffin or shroud. Native vegetation (often a memorial tree) is planted over or near the grave in place of a conventional cemetery monument. The resulting green space establishes a living memorial and forms a protected wildlife preserve.
The practice of natural burial dates back to the late nineteenth century, when Sir Francis Seymour Hayden proposed "earth to earth burial," in a pamphlet of the same name, as a less gruesome alternative to either cremation or the slow putrefaction of encased corpses. The earth to earth burial movement was part of the short-lived cremation controversy of the 1870s.
Muslims also practice natural burial, with the deceased's body covered in shroud and with his\her face facing Mecca.
Natural burial grounds are also known as woodland cemeteries, eco-cemeteries, memorial nature preserves, or green burial grounds.
## Prevention of decay
Embalming is the practice of preserving a body against decay, and is used in many cultures. Mummification is a more extensive method of embalming, further delaying the decay process.
Bodies are often buried wrapped in a shroud or placed in a coffin (also called a casket). A larger container may be used, such as a ship. Coffins are usually covered by a burial liner or a burial vault, which prevents the coffin from collapsing under the weight of the earth or floating away during a flood.
These containers slow the decomposition process by (partially) physically blocking decomposing bacteria and other organisms from accessing the corpse. An additional benefit of using containers to hold the body is that if the soil covering the corpse is washed away by a flood or some other natural process, the corpse will still not be exposed to open air.
In some cultures however the goal is not to preserve the body but to allow it to decompose—or return to the Earth — naturally. In Orthodox Judaism embalming is not permitted, and the coffins are constructed so that the body will be returned to the Earth as soon as possible. Such coffins are made of wood, and have no metal parts at all. Wooden pegs are used in the place of nails.
## Inclusion of clothing and personal effects
The body may be dressed in fancy and/or ceremonial clothes. Personal objects, such as a favorite piece of jewellery or photograph, of the deceased may be included with the body. This practice, also known as the inclusion of grave goods, serves several purposes:
- In funeral services, the body is often put on display. Many cultures feel that the deceased should be presented looking his/her finest.
- The inclusion of ceremonial garb and sacred objects is sometimes viewed as necessary for reaching the afterlife.
- The inclusion of personal effects may be motivated by the beliefs that in the afterlife a person will wish to have with them what was important to them on earth. Alternatively, in some cultures it is felt that when a person dies, their possessions (and sometimes people connected to them such as wives) should go with them out of loyalty or ownership.
- Though not generally a motivation for the inclusion of grave goods with a corpse, it is worth considering that future archaeologists may find the remains (compare time capsule). Artifacts such as clothing and objects provide insight into how the individual lived. This provides a form of immortality for the deceased.
## Body positioning
Burials may be placed in a number of different positions. Christian burials are made extended, i.e., lying flat with arms and legs straight, or with the arms folded upon the chest, and with the eyes and mouth closed. Extended burials may be supine (lying on the back) or prone (lying on the front). Other ritual practices place the body in a flexed position with the legs bent or crouched with the legs folded up to the chest. Warriors in some ancient societies were buried in an upright position. In Islam, the head is pointed toward and the face is turned toward Mecca, the holiest city in Islam. Many cultures treat placement of dead people in an appropriate position to be a sign of respect even when burial is impossible.
In nonstandard burial practices, such as mass burial, the body may be positioned arbitrarily. This can be a sign of disrespect to the deceased, or at least nonchalance on the part of the inhumer, or due to considerations of time and space.
### Orientation
Historically, Christian burials were made supine east-west, with the head at the western end of the grave. This mirrors the layout of Christian churches, and for much the same reason; to view the coming of Christ on Judgement day (Eschaton). In many Christian traditions, ordained clergy are traditionally buried in the opposite orientation, and their coffins carried likewise, so that at the General Resurrection they may rise facing, and ready to minister to, their people.
### Inverted burial
For humans, maintaining an upside down position, with the head vertically below the feet, is highly uncomfortable for any extended period of time, and consequently burial in that attitude (as opposed to attitudes of rest or watchfulness, as above) is highly unusual and generally symbolic. Occasionally suicides were buried upside down, as a post mortem punishment and (as with burial at cross-roads) to inhibit the activities of the resulting undead.
In Gulliver's Travels, the Lilliputians buried their dead upside down:
They bury their dead with their heads directly downward, because they hold an opinion, that in eleven thousand moons they are all to rise again; in which period the earth (which they conceive to be flat) will turn upside down, and by this means they shall, at their resurrection, be found ready standing on their feet. The learned among them confess the absurdity of this doctrine; but the practice still continues, in compliance to the vulgar.
Swift's notion of inverted burial might seem the highest flight of fancy, but it appears that among English millenarians the idea that the world would be "turned upside down" at the Apocalypse enjoyed some currency, and there is at least one attested case of a person being buried upside down by instruction; a Major Peter Labelliere of Dorking (d. June 4, 1800) lies thus upon the summit of Box Hill.[6] Similar stories have attached themselves to other noted eccentrics, particularly in southern England, but not always with a foundation in truth.[7]
## Burial among African-American slaves
In the African-American slave community, slaves quickly familiarized themselves with funeral procedures and the location of gravesites of family and friends. Specific slaves were assigned to prepare dead bodies, build coffins, dig graves, and construct headstones. Slave funerals were typically at night when the workday was over, with the master present to view all the ceremonial procedures. Slaves from the nearby plantations were regularly in attendance.
At death, a slave’s body was wrapped in cloth. The hands were placed across the chest, and a metal plate was placed on top of their hands. The reasoning for the plate was to hinder their return home by suppressing any spirits in the coffin. Often, personal property was buried with slaves to appease spirits. The coffins were nailed shut once the body was inside, and carried by hand or wagon, depending on the property designated for slave burial site. Slaves were buried east to west, with the head facing east and their feet to the west. This positioning represented the ability to rise without having to turn around at the call of Gabriel’s trumpet. Gabriel’s trumpet would be blown in the eastern sunrise. East-west positioning also was the direction of home, Africa.
## Burial in the Bahá'í Faith
Bahá'í burial law prescribes both the location of burial and burial practices and precludes cremation of the dead. It is forbidden to carry the body for more than one hour's journey from the place of death. Before interment the body should be wrapped in a shroud of silk or cotton, and a ring should be placed on its finger bearing the inscription "I came forth from God, and return unto Him, detached from all save Him, holding fast to His Name, the Merciful, the Compassionate". The coffin should be of crystal, stone or hard fine wood. Also, before interment, a specific Prayer for the Dead[8] is ordained. The formal prayer and the ring are meant to be used for those who have reached fifteen years of age.[9]
# Locations
## Where to bury
Apart from sanitary and other practical considerations, the site of burial can be determined by religious and socio-cultural considerations.
Thus in some traditions, especially with an animistic logic, the remains of the dead are "banished" for fear their spirits would harm the living if too close; others keep remains close to help surviving generations.
Religious rules may prescribe a specific zone, e.g. some Christian traditions hold that Christians must be buried in "consecrated ground," usually a cemetery; an earlier practice, burial in or very near the church (hence the word churchyard), was generally abandoned with individual exceptions as a high posthumous honour; also many existing funeral monuments and crypts remain in use.
Royalty and high nobility often have one or more "traditional" sites of burial, generally monumental, often in a palatial chapel or cathedral; see examples on Heraldica.org.
## Marking the location of the burial
Most modern cultures mark the location of the body with a headstone. This serves two purposes. First, the grave will not accidentally be exhumed. Second, headstones often contain information or tributes to deceased. This is a form of remembrance for loved ones; it can also be viewed as a form of immortality, especially in cases of famous people's graves. Such monumental inscriptions may subsequently be useful to genealogists and family historians.
In many cultures graves will be grouped, so the monuments make up a necropolis, a "city of the dead" parallelling the community of the living.
### Unmarked grave
In many cultures graves are marked with durable markers, or monuments, intended to help remind people of the buried person. An unmarked grave is a grave with no such memorial marker.
The corpse of Pope Formosus was actually disinterred, placed on trial (see Cadaver Synod), found guilty, and ultimately thrown into the River Tiber.
### Anonymous burial
Another sort of unmarked grave is a burial site with an anonymous marker, such as a simple cross; boots, rifle and helmet; a sword and shield; a cairn of stones; or even a monument. This may occur when identification of the deceased is impossible. Although many unidentified deceased are buried in potter's fields, some are memorialized, especially in smaller communities or in the case of deaths publicized by local media.
Many countries have buried an unidentified soldier (or other member of the military) in a prominent location as a form of respect for all unidentified war dead. The United Kingdom's Tomb of the Unknown Warrior is in Westminster Abbey, France's is buried underneath the Arc de Triomphe, Italy's is buried in the Monumento al Milite Ignoto in Rome, Canada's is buried at the National War Memorial in Ottawa, Australia's Tomb of the Unknown Soldier is located at the Australian War Memorial in Canberra, New Zealand's Tomb of the Unknown Warrior is in Wellington and the United States' Tomb of the Unknown Soldier is located at Arlington National Cemetery.
Many cultures practise anonymous burial as a norm, not an exception. For instance, in parts of eastern Germany, up to 43% of burials are anonymous.[10] According to Christian Century magazine, the perspective of the Roman Catholic Church is that anonymous burials reflect a dwindling belief in God, but others claim that the practice relates more to the exorbitant cost of grave markers and the solitary nature of German life.[11]
### Secret burial
In rare cases, a known person may be buried without identification, perhaps to avoid desecration of the corpse, grave robbing, or vandalism of the burial site. This may be particularly the case with infamous or notorious figures. In other cases, it may be to prevent the grave from becoming a tourist attractions or a destination of pilgrimage. Survivors may cause the deceased to be buried in a secret location or other unpublished place, or in a grave with a false name (or no name at all) on the marker.
When Walt Disney was cremated his ashes were buried in a secret location in Forest Lawn Memorial Park Cemetery, California. Some burial sites at Forest Lawn, such as those of Humphrey Bogart and Mary Pickford, are secluded in private gated gardens with no public access. A number of tombs are also kept from the public eye. Forest Lawn's Court of Honour indicates that some of its crypts have plots which are reserved for individuals who may be "voted in" as "Immortals"; no amount of money can purchase a place. Photographs taken at Forest Lawn are not permitted to be published, and their information office usually refuses to reveal exactly where the remains of famous people are buried. Although the cemetery's owners state that this is meant to deter gravesite tourism, some critics say that the cemetery wishes visitors to purchase memorabilia at the funeral home's numerous gift shops instead of taking photographs for free, especially in the case of grave markers notable for their beauty.[12]
### Multiple bodies per grave
Some couples or groups of people (such as a married couple or other family members) may wish to be buried in the same plot. In some cases, the coffins (or urns) may simply be buried side by side. In others, one casket may be interred above another. If this is planned for in advance, the first casket may be buried more deeply than is the usual practice so that the second casket may be placed over it without disturbing the first. In many states in Australia all graves are designated two or three depth (depending of the water table) for multiple burials, at the discretion of the burial rights holder, with each new interment atop the previous coffin separated by a thin layer of earth. As such all graves are dug to greater depth for the initial burial than the traditional six feet to facilitate this practice.
Mass burial is the practice of burying multiple bodies in one location. Civilizations attempting genocide often employ mass burial for victims. However, mass burial may in many cases be the only practical means of dealing with an overwhelming number of human remains, such as those resulting from a natural disaster, an act of terrorism, an epidemic, or an accident. This practice has become less common in the developed world with the advent of genetic testing, but even in the 21st century remains which are unidentifiable by current methods may be buried in a mass grave.
Individuals who are buried at the expense of the local authorities and buried in potter's fields may be buried in mass graves. Wolfgang Amadeus Mozart is believed to have been buried in such a manner.[citation needed] In some cases, the remains of unidentified individuals may be buried in mass graves in potter's fields, making exhumation and future identification troublesome for law enforcement.
Naval ships sunk in combat are also considered mass graves by many countries. For example, U.S. Navy policy declares such wrecks a mass grave and forbids the recovery of remains. In lieu of recovery, divers or submersibles may leave a plaque dedicated to the memory of the ship or boat and its crew, and family members are invited to attend the ceremony.
Sites of large former battlefields may also contain one or more mass graves. Douaumont ossuary is one such mass grave, and it contains the remains of 130,000 soldiers from both sides of the battle of Verdun.
Catacombs also constitute a form of mass grave. Some catacombs, for example those in Rome, were designated as a communal burial place. Some, such as the catacombs of Paris, only became a mass grave when individual burials were relocated from cemeteries marked for demolition.
Judaism does not generally allow multiple bodies in a grave. An exception to this is a grave in the military cemetery in Jerusalem, where there is a "kever ah-chim" (Heb. "grave of brothers") where two soldiers were killed together in a tank and are buried in one grave. As the bodies were so fused together with the metal of the tank that they could not be separately identified, they were buried in one grave (along with parts of the tank).
## Cremation
There are several common alternatives to burial. In cremation the body of the deceased is burned in a special oven. Most of the body is burnt during the cremation process, leaving only a few pounds of bone fragments. Bodies of small children and infants often produce very little in the way of "ashes", as ashes are composed of bone, and young people have softer bones, largely cartilage. Often these fragments are processed (ground) into a fine powder, which has led to cremated remains being called ashes. In recent times, cremation has become a popular option in the western world.
There is far greater flexibility in dealing with the remains in cremation as opposed to the traditional burial. Some of the options include scattering the ashes at a place close to the heart of the deceased or keeping the ashes at home. Ashes can also be buried either underground or in a columbarium niche.
## Live burial
Live burial sometimes occurs, in which individuals are buried while still alive. Having no way of escaping interment, they die in place, typically by asphyxiation, dehydration, starvation, or (in cold climates) exposure. People may come to be buried alive in a number of different ways:
- An individual may be intentionally buried alive as a method of execution or murder. In ancient Rome, Vestal Virgins who broke their vows were punished in this way.
- A person or group of people in a cave, mine, or other underground area may be sealed underground due to an earthquake, cave in, or other natural disaster or accident. Live burial may also occur due to avalanches on mountain slopes.
- People have been unintentionally buried alive because they were pronounced dead by a coroner or other official, when they were in fact still alive.
Writer Edgar Allan Poe wrote a number of stories and poems about premature burial, including a story called "The Premature Burial." These works inspired a widespread popular fear of this appalling but unlikely event. Various expedients have been devised to prevent this event, including burying live telephones or telemetry sensors in graves.
## Burial at cross-roads
Historically, burial at cross-roads was the method of disposing of executed criminals and suicides. At the cross-roads a rude cross usually stood, and this gave rise to the belief that these spots were selected as the next best burying-places to consecrated ground. The real explanation is that the ancient Teutonic peoples often built their altars at the cross-roads, and as human sacrifices, especially of criminals, formed part of the ritual, these spots came to be regarded as execution grounds.[citation needed] Hence after the introduction of Christianity, criminals and suicides were buried at the cross-roads during the night, in order to assimilate as far as possible their funeral to that of the pagans. An example of a cross-road execution-ground was the famous Tyburn in London, which stood on the spot where the Roman road to Edgware and beyond met the Roman road heading west out of London.
Superstition also played a part in the selection of cross-roads in the burial of suicides. Folk belief often held such individuals could rise as some form of undead (such as a vampire) and burying them at cross-roads would inhibit their ability to find and wreak havoc on their living relations and former associates.[citation needed]
Template:1911
## Burial of animals
### By humans
In addition to burying human remains, many human cultures also regularly bury animal remains.
Pets and other animals of emotional significance are often ceremonially buried. Most families bury deceased pets on their own properties, mainly in a yard, with a shoe box or any other type of container served as a coffin. The Ancient Egyptians are known to have mummified and buried cats, which they considered deities.
### By other animals
Humans are not always the only species to bury their dead. Chimpanzees and elephants are known to throw leaves and branches over fallen members of their family groups.[citation needed]
Template:Sectstub
# Exhumation
The digging up of a buried body is called exhumation or disinterration, and is considered sacrilege by most cultures that bury their dead. However, exhumation can occur in the following circumstances:
- If an individual dies under suspicious circumstances, a legitimate investigating agency (such as a police agency) may exhume the body to determine the cause of death.
- Deceased individuals who were either not identified or misidentified at the time of burial may be reburied if survivors so wish.[13]
- Remains may be exhumed in order to be reinterred at a more appropriate location. For example, the remains of Nicholas II of Russia and his family were exhumed from their resting place near Yekaterinburg so that they could be reinterred in the Peter and Paul Fortress in St. Petersburg.
- The remains of the Venerable or the Blessed are sometimes exhumed to see if they are supernaturally Incorruptible and thus a Saint. This type of exhumation is generally not considered sacrilege.
- Remains may be exhumed and reburied en masse when a cemetery is relocated.[14]
- In rare cases (such as those of Pope Formosus or Oliver Cromwell), a body may be exhumed for posthumous execution, dissection, or gibbeting.
- Notable individuals may be exhumed to answer historical questions. Tutankhamen's remains were exhumed in 2005 in order to determine his cause of death.
- Once human remains reach a certain age, some cultures consider exhumation acceptable. This serves several purposes:
Cemeteries have a limited number of plots in which to bury the dead. Once all plots are full, older remains may be moved to an ossuary to accommodate more bodies.
It enables archaeologists to search the remains to better understand human culture.
It enables construction agencies to clear the way for new constructions.
- Cemeteries have a limited number of plots in which to bury the dead. Once all plots are full, older remains may be moved to an ossuary to accommodate more bodies.
- It enables archaeologists to search the remains to better understand human culture.
- It enables construction agencies to clear the way for new constructions.
Frequently, cultures have different sets of exhumation taboos. Occasionally these differences result in conflict, especially in cases where a culture with more lenient exhumation rules wishes to operate on the territory of a stricter culture. For example, United States construction companies have run into conflict with Native American groups that wanted to preserve their ancient burial grounds from any form of modern construction.
In folklore and mythology, exhumation has also been frequently associated with the performance of rites to banish undead manifestations. An example is the Mercy Brown Vampire Incident of Rhode Island, which occurred in 1892.
# Alternatives to burial
Human bodies are not always buried. Alternatives to burial include the following:
- Ash jump: skydivers may elect to have their cremated remains released during freefall.
-
- Burial at sea is the practice of depositing the body in an ocean or other large body of water instead of soil. It may be disposed in a coffin, or without one.
- Funerary cannibalism is the practice of eating the remains. This may be for many reasons: for example to partake of their strength, to spiritually "close the circle" by reabsorbing their life into the family or clan, to annihilate an enemy, or due to pathological mental conditions. The Yanomami have the habit of cremating the remains and then eating the ashes with banana paste.
- Cremation is the incineration of the remains. This practice is common amongst Hindus and is becoming increasingly common in other cultures as well. If a family member wishes, the ashes can now be turned into a gem, similar to creating synthetic diamonds.
- Ecological funeral is a method of increasing the rate of decomposition in order to help fertilize the soil.
- Excarnation is the practice of removing the flesh from the corpse without interment. The Zoroastrians have traditionally left their dead on Towers of Silence, where the flesh of the corpses is left to be devoured by vultures and other carrion-eating birds. Alternatively, it can also mean butchering the corpse by hand to remove the flesh (sometimes referred to by the neologism "defleshing").
- Gibbeting was the ancient practice of publicly displaying remains of criminals.
- Hanging coffins are coffins which have been placed on cliffs. They can be found in various locations, including China and the Philippines.
- Resomation involves disposal through an accelerated process of alkaline hydrolysis.
- Sky burial involves placing the body on a mountaintop.
- Space burial is the practice of firing the coffin into space. The coffin may be placed into orbit, sent off into space, or incinerated in the sun. Space burial is still largely in the realm of science fiction as the cost of getting a body into space is prohibitively large, although several prominent figures have had a sample of their ashes launched into space after cremation.
In most cases these alternatives are still intended to maintain respect for the dead, but some are intended to prolong the display of the remains.
Cryonics is often mistakenly assumed to be an alternative interment method, but is in fact a medical procedure carried out to physically preserve the body in the hope that it will one day be technologically possible to revive the individual. See also information theoretical death; clinical death.
# Notes and references
- ↑ Uniquely Human. 1991. ISBN 0674921836..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}
- ↑ Evolving in their graves: early burials hold clues to human origins - research of burial rituals of Neanderthals
- ↑ Uniquely Human page 163
- ↑ [1]
- ↑ [2]
- ↑ Simpson, Jacqueline (August 2005). "The Miller's tomb: facts, gossip, and legend". Folklore.
- ↑ Simpson, Jacqueline (Jan.—Mar 1978). "The World Upside down Shall Be: A Note on the Folklore of Doomsday". The Journal of American Folklore. 91 (359): 559–567. Check date values in: |date= (help)
- ↑ [3]
- ↑ [4]
- ↑ [5]
- ↑ [6]
- ↑ [7]
- ↑ [8]
- ↑ [9] | https://www.wikidoc.org/index.php/Burial | |
af52d26cb648adacfc530bb43278ee096fe9a7bf | wikidoc | Bushel | Bushel
A bushel is a unit of dry volume, usually subdivided into eight local gallons in the systems of Imperial units and U.S. customary units. It is used for volumes of dry commodities, not liquids, most often in agriculture. It is abbreviated as bsh. or bu.
- 1 U.S. bushel = 35.23907017 litres = 8 corn/dry gallons = 9.309177489 wine/liquid gallons
- 1 Imperial bushel = 36.36872 litres = 8 Imperial gallons
Bushels are now most often used as units of mass rather than of volume. The bushels in which grains are bought and sold on commodity markets or at local grain elevators, and for reports of grain production, are all units of mass. This is done by assigning a standard weight to each commodity that is to be measured in bushels. These bushels depend on the commodities being measured; some of the more common ones are (all exact):
- Oats
USA: 32 lb ≈ 14.515 kg
Canada: 34 lb ≈ 15.422 kg
- USA: 32 lb ≈ 14.515 kg
- Canada: 34 lb ≈ 15.422 kg
- Barley: 48 lb ≈ 21.772 kg
- Malted Barley: 34 lb ≈ 15.422 kg
- Maize (corn): 56 lb ≈ 25.401 kg
- Wheat and soybeans: 60 lb ≈ 27.215 kg
Other specific values are defined (and those definitions may vary in different jurisdictions, including from state to state in the United States) for other grains, oilseeds, fruits, vegetables, coal, hair, and many other commodities.
Government policy in the United States is to phase out units such as the bushel and replace them with the metric system as used for all purposes in the rest of the world, and for all scientific and technical purposes world wide. It is therefore important to know how the bushel relates to the metric equivalent, and whether the bushels are used as units of mass or units of volume.
The name “bushel” has also been used to translate foreign units of a similar size and sometimes shared origin, like the German “Scheffel”.
# History
The bushel was originally a measure of capacity for grain. During the Middle Ages, the bushel of wheat was supposed to weigh 64 tower pounds, but when the tower system was abolished in the 16th century, it was described as 56 avoirdupois pounds. The bushel was rarely used in Scotland, Ireland or Wales during the Middle Ages.
Until and before the 19th century there were even more gallons in use.
Examples: | Bushel
A bushel is a unit of dry volume, usually subdivided into eight local gallons in the systems of Imperial units and U.S. customary units. It is used for volumes of dry commodities, not liquids, most often in agriculture. It is abbreviated as bsh. or bu.
- 1 U.S. bushel = 35.23907017 litres = 8 corn/dry gallons = 9.309177489 wine/liquid gallons
- 1 Imperial bushel = 36.36872 litres = 8 Imperial gallons
Bushels are now most often used as units of mass rather than of volume. The bushels in which grains are bought and sold on commodity markets or at local grain elevators, and for reports of grain production, are all units of mass. This is done by assigning a standard weight to each commodity that is to be measured in bushels. These bushels depend on the commodities being measured; some of the more common ones are (all exact):
- Oats
USA: 32 lb ≈ 14.515 kg
Canada: 34 lb ≈ 15.422 kg
- USA: 32 lb ≈ 14.515 kg
- Canada: 34 lb ≈ 15.422 kg
- Barley: 48 lb ≈ 21.772 kg
- Malted Barley: 34 lb ≈ 15.422 kg
- Maize (corn): 56 lb ≈ 25.401 kg
- Wheat and soybeans: 60 lb ≈ 27.215 kg
Other specific values are defined (and those definitions may vary in different jurisdictions, including from state to state in the United States) for other grains, oilseeds, fruits, vegetables, coal, hair, and many other commodities.
Government policy in the United States is to phase out units such as the bushel and replace them with the metric system as used for all purposes in the rest of the world, and for all scientific and technical purposes world wide. It is therefore important to know how the bushel relates to the metric equivalent, and whether the bushels are used as units of mass or units of volume.
The name “bushel” has also been used to translate foreign units of a similar size and sometimes shared origin, like the German “Scheffel”.
# History
The bushel was originally a measure of capacity for grain. During the Middle Ages, the bushel of wheat was supposed to weigh 64 tower pounds, but when the tower system was abolished in the 16th century, it was described as 56 avoirdupois pounds. The bushel was rarely used in Scotland, Ireland or Wales during the Middle Ages.
Until and before the 19th century there were even more gallons in use.
Examples: | https://www.wikidoc.org/index.php/Bushel | |
af1d7de431fd43c1d9cc7d05e7438bfbc2d40f60 | wikidoc | Butane | Butane
# Overview
Butane, also called n-butane, is the unbranched alkane with four carbon atoms, CH3CH2CH2CH3. Butane is also used as a collective term for n-butane together with its only other isomer, isobutane (also called methylpropane), CH(CH3)3.
Butanes are highly flammable, colorless, easily liquefied gases. The name butane was derived by back-formation from the name of butyric acid.
# Reactions and uses
When oxygen is plentiful, butane burns to form carbon dioxide and water vapor; when oxygen is limited, carbon (soot) or carbon monoxide may also be formed.
n-Butane is the feedstock for DuPont's catalytic process for the preparation of maleic anhydride:
n-Butane, like all hydrocarbons, undergoes free radical chlorination providing both 1-chloro- and 2-chlorobutanes, as well as more highly chlorinated derivatives. The relative rates of the chlorination is partially explained by the differing bond dissociation energies, 425 and 411 kJ/mol for the two types of C-H bonds. The two central carbon atoms have the slightly weaker C-H bonds.
Butane gas is sold bottled as a fuel for cooking and camping. When blended with Propane and other hydrocarbons, it is referred to commercially as LPG. It is also used as a petrol component, as a feedstock for the production of base petrochemicals in steam cracking, as fuel for cigarette lighters and as a propellant in aerosol sprays.
Very pure forms of butane, especially isobutane, can be used as refrigerants and have largely replaced the ozone layer depleting halomethanes, for instance in household refrigerators and freezers. The flammability of butane is not a major issue because the amount of butane in an appliance is not enough to cause a combustible mix given the amount of air in a room. The system operating pressure for butane is lower than for the halomethanes, such as R-12, so direct conversion of R-12 systems to butane, such as in automotive air conditioning systems, will not function optimally.
# Effects and health issues
Inhaling butane can cause drowsiness, narcosis, asphyxia; cardiac arrhythmia and frostbite, which can result in instant death from Asphyxiation, Acute toxicity and ventricular fibrillation. Butane is the most commonly misused volatile solvent in the UK, and was the cause of 52% of solvent related deaths in 2000. By spraying butane directly into the throat, the jet of fluid can cool rapidly to –20 °C by expansion, causing prolonged laryngospasm. "Sudden sniffing death syndrome", first described by Bass in 1970, is the most common single cause of solvent related death, resulting in 55% of known fatal cases.
# Popular culture
- Butane is referred to as "a bastard gas" on the television show King of the Hill. | Butane
Template:Chembox new
# Overview
Butane, also called n-butane, is the unbranched alkane with four carbon atoms, CH3CH2CH2CH3. Butane is also used as a collective term for n-butane together with its only other isomer, isobutane (also called methylpropane), CH(CH3)3.
Butanes are highly flammable, colorless, easily liquefied gases. The name butane was derived by back-formation from the name of butyric acid.
# Reactions and uses
When oxygen is plentiful, butane burns to form carbon dioxide and water vapor; when oxygen is limited, carbon (soot) or carbon monoxide may also be formed.
n-Butane is the feedstock for DuPont's catalytic process for the preparation of maleic anhydride:
n-Butane, like all hydrocarbons, undergoes free radical chlorination providing both 1-chloro- and 2-chlorobutanes, as well as more highly chlorinated derivatives. The relative rates of the chlorination is partially explained by the differing bond dissociation energies, 425 and 411 kJ/mol for the two types of C-H bonds. The two central carbon atoms have the slightly weaker C-H bonds.
Butane gas is sold bottled as a fuel for cooking and camping. When blended with Propane and other hydrocarbons, it is referred to commercially as LPG. It is also used as a petrol component, as a feedstock for the production of base petrochemicals in steam cracking, as fuel for cigarette lighters and as a propellant in aerosol sprays.
Very pure forms of butane, especially isobutane, can be used as refrigerants and have largely replaced the ozone layer depleting halomethanes, for instance in household refrigerators and freezers. The flammability of butane is not a major issue because the amount of butane in an appliance is not enough to cause a combustible mix given the amount of air in a room. The system operating pressure for butane is lower than for the halomethanes, such as R-12, so direct conversion of R-12 systems to butane, such as in automotive air conditioning systems, will not function optimally.
# Effects and health issues
Inhaling butane can cause drowsiness, narcosis, asphyxia; cardiac arrhythmia and frostbite, which can result in instant death from Asphyxiation, Acute toxicity and ventricular fibrillation. Butane is the most commonly misused volatile solvent in the UK, and was the cause of 52% of solvent related deaths in 2000.[1] By spraying butane directly into the throat, the jet of fluid can cool rapidly to –20 °C by expansion, causing prolonged laryngospasm.[2] "Sudden sniffing death syndrome", first described by Bass in 1970,[3] is the most common single cause of solvent related death, resulting in 55% of known fatal cases.[2]
# Popular culture
- Butane is referred to as "a bastard gas" on the television show King of the Hill. | https://www.wikidoc.org/index.php/Butane | |
42728c7edf14160a3d4885e510e04a72b483e8e6 | wikidoc | C32011 | C32011
Here is the page we will use to coordinate the TV events at C32011. Open time slots are indicated below in red.
# Click on Date for Detailed Schedule
Monday June 27, 2011
Tuesday June 28, 2011
Wednesday June 29, 2011
# Monday June 27, 2011
## 9:00 AM
9:00 AM - 9:30 AM
- Interviewee: Dr. Goran Olivecrona
- Trial: Hypothermia in Awake STEMI patients: Results from the RAPID MI-ICE trial and insights to the CHILL MI Trial.
- Embargo lift: TBD
## 9:30 AM
OPEN TIME SLOT
## 10:00 AM
10:00 AM - 10:30 AM
- Interviewee: Dr. Sameer Mehta
- Trial: LUMEN GLOBAL, Population based STEMI treatment
- Embargo lift: TBD
## 10:30 AM
OPEN TIME SLOT
## 11:00 AM
11:00 AM - 11:30 AM
- Interviewee: Dr. Issam Moussa
- Trial: Should Guidelines Be Changed for Left Main PCI? : Evaluating the Evidence on the Eve of the New Guidelines Publication
- Embargo lift: 8:30 AM Monday June 27, 2011
Return to top
# Tuesday June, 28 2011
## 9:00 AM
9:00 AM - 9:30 AM
- Interviewee: Dr. Michael Rinaldi
- Trial: TBA
- Embargo lift: TBD
## 9:30 AM
9:30 AM - 10:00 AM
- Interviewee: Dr. Takeshi Kimura
- Trial: Late Stent Thrombosis and Late Restenosis of DES
- Embargo lift: TBD
## 10:00 AM
10:00 AM - 10:30 AM
- Interviewee: Dr. Jeffrey Moses
- Trial: The State of TAVI - PARTNERS: From Concept to Moratlity Benefit
- Embargo lift: 2:10 PM Tuesday June 28, 2011
## 10:30 AM
OPEN TIME SLOT
## 11:00 AM
OPEN TIME SLOT
Return to top
# Wednesday June 29, 2011
## 9:00 AM
OPEN TIME SLOT
## 9:30 AM
9:30 AM - 10:00 AM
- Interviewee: Dr. John Lasala
- Trial: PROTECT DATA
- Embargo lift: TBD
## 10:00 AM
10:00 AM - 10:30 AM
- Interviewee: Dr. Mohamed Sobhy
- Trial: Stent for Life project and ACCESS registry (Primary PCI)
- Embargo lift: TBD
## 10:30 AM
OPEN TIME SLOT
Return to top | C32011
Here is the page we will use to coordinate the TV events at C32011. Open time slots are indicated below in red.
# Click on Date for Detailed Schedule
Monday June 27, 2011
Tuesday June 28, 2011
Wednesday June 29, 2011
# Monday June 27, 2011
## 9:00 AM
9:00 AM - 9:30 AM
- Interviewee: Dr. Goran Olivecrona
- Trial: Hypothermia in Awake STEMI patients: Results from the RAPID MI-ICE trial and insights to the CHILL MI Trial.
- Embargo lift: TBD
## 9:30 AM
OPEN TIME SLOT
## 10:00 AM
10:00 AM - 10:30 AM
- Interviewee: Dr. Sameer Mehta
- Trial: LUMEN GLOBAL, Population based STEMI treatment
- Embargo lift: TBD
## 10:30 AM
OPEN TIME SLOT
## 11:00 AM
11:00 AM - 11:30 AM
- Interviewee: Dr. Issam Moussa
- Trial: Should Guidelines Be Changed for Left Main PCI? : Evaluating the Evidence on the Eve of the New Guidelines Publication
- Embargo lift: 8:30 AM Monday June 27, 2011
Return to top
# Tuesday June, 28 2011
## 9:00 AM
9:00 AM - 9:30 AM
- Interviewee: Dr. Michael Rinaldi
- Trial: TBA
- Embargo lift: TBD
## 9:30 AM
9:30 AM - 10:00 AM
- Interviewee: Dr. Takeshi Kimura
- Trial: Late Stent Thrombosis and Late Restenosis of DES
- Embargo lift: TBD
## 10:00 AM
10:00 AM - 10:30 AM
- Interviewee: Dr. Jeffrey Moses
- Trial: The State of TAVI - PARTNERS: From Concept to Moratlity Benefit
- Embargo lift: 2:10 PM Tuesday June 28, 2011
## 10:30 AM
OPEN TIME SLOT
## 11:00 AM
OPEN TIME SLOT
Return to top
# Wednesday June 29, 2011
## 9:00 AM
OPEN TIME SLOT
## 9:30 AM
9:30 AM - 10:00 AM
- Interviewee: Dr. John Lasala
- Trial: PROTECT DATA
- Embargo lift: TBD
## 10:00 AM
10:00 AM - 10:30 AM
- Interviewee: Dr. Mohamed Sobhy
- Trial: Stent for Life project and ACCESS registry (Primary PCI)
- Embargo lift: TBD
## 10:30 AM
OPEN TIME SLOT
Return to top | https://www.wikidoc.org/index.php/C32011 | |
53035751a1aff15f2e190f99bca3a66daddfc9c3 | wikidoc | C5orf3 | C5orf3
C5orf3 (chromosome 5 open reading frame 3) is a gene on chromosome 5 in humans that encodes a protein FAM114A2. This protein has a function that is not well known. C5orf3 is, however, highly conserved in mammals with homologs both in fungi and plants.
# Protein
The c5orf3 protein is 505 amino acids long with a molecular weight of 55.5 kdal and an isoelectric point of 4.66. It is predicted to stay in the nucleus after translation
There is evidence that c5orf3 interacts with another protein of unknown function from chromosome 5, c5orf4
This protein is thought to include a P loop that suggests a role in ATP- and/or GTP-binding
# Gene
The c5orf3 gene is located on chromosome 5 (5q31-33). This gene has 14 exons spanning through its sequence. The coding sequence is 2886 base pairs with a 5’ UTR of 94 base pairs and a 3’ UTR of 1273 base pairs. It is expressed at high levels in most tissues of the human body. It is also highly expressed in tissues in the human brain | C5orf3
C5orf3 (chromosome 5 open reading frame 3) is a gene on chromosome 5 in humans that encodes a protein FAM114A2. This protein has a function that is not well known. C5orf3 is, however, highly conserved in mammals with homologs both in fungi and plants.
# Protein
The c5orf3 protein is 505 amino acids long[1] with a molecular weight of 55.5 kdal and an isoelectric point of 4.66.[2] It is predicted to stay in the nucleus after translation [3]
There is evidence that c5orf3 interacts with another protein of unknown function from chromosome 5, c5orf4 [4]
This protein is thought to include a P loop [5] that suggests a role in ATP- and/or GTP-binding [6]
# Gene
The c5orf3 gene is located on chromosome 5 (5q31-33).[7] This gene has 14 exons spanning through its sequence.[1] The coding sequence is 2886 base pairs with a 5’ UTR of 94 base pairs and a 3’ UTR of 1273 base pairs.[1] It is expressed at high levels in most tissues of the human body.[7] It is also highly expressed in tissues in the human brain [8] | https://www.wikidoc.org/index.php/C5orf3 | |
44a4bb5d0f578c96c88b633cecb51f2ccee8ea3b | wikidoc | C9orf3 | C9orf3
Chromosome 9 open reading frame 3 (C9ORF3) also known as aminopeptidase O (APO) is an enzyme which in humans is encoded by the C9ORF3 gene. The protein encoded by this gene is an aminopeptidase which is most closely related in sequence to leukotriene A4 hydrolase (LTA4H). APO is a member of the M1 metalloproteinase family.
# Structure
The C9ORF3 aminopeptidase enzyme contains the following domains:
- LTA4H-like N-terminal domain
- gluzincin aminopeptidase domain
- SH3-like motif
- ARM C-terminal domain
# Function
The C9ORF3 aminopeptidase cleaves the N-terminal amino acid from polypeptides and shows a strong preference for peptides in which the N-terminus is arginine and to a lesser extent asparagine. Furthermore, the activity of the enzyme is inhibited by o-phenanthroline, a metalloprotease inhibitor and by arphamenine A, a potent inhibitor of aminopeptidases such as LTA4H. Also able to cleave angiotensin III to generate angiotensin IV, a bioactive peptide of the renin–angiotensin pathway.
Due to its aminopeptidase activity this enzyme may play a role in the proteolytic processing of bioactive peptides in those tissues where it is expressed.
# Tissue distribution
C9ORF3 Messenger RNA has been detected in human pancreas, placenta, liver, testis, and heart. The expression in the heart suggests this enzyme may also play a role in the regulating the physiology of cardiac muscle. Several ApO isoforms are expressed predominantly in blood vessels suggesting that ApO plays a role in vascular cell biology.
# Clinical significance
High expression levels of C9ORF3 is positively correlated with maximal oxygen uptake (VO2 max) and the amount of "slow-twitch" type 1 muscle fibers. | C9orf3
Chromosome 9 open reading frame 3 (C9ORF3) also known as aminopeptidase O (APO) is an enzyme which in humans is encoded by the C9ORF3 gene.[1] The protein encoded by this gene is an aminopeptidase which is most closely related in sequence to leukotriene A4 hydrolase (LTA4H).[2] APO is a member of the M1 metalloproteinase family.[3][4]
# Structure
The C9ORF3 aminopeptidase enzyme contains the following domains:[2]
- LTA4H-like N-terminal domain
- gluzincin aminopeptidase domain
- SH3-like motif
- ARM C-terminal domain
# Function
The C9ORF3 aminopeptidase cleaves the N-terminal amino acid from polypeptides and shows a strong preference for peptides in which the N-terminus is arginine and to a lesser extent asparagine. Furthermore, the activity of the enzyme is inhibited by o-phenanthroline, a metalloprotease inhibitor and by arphamenine A, a potent inhibitor of aminopeptidases such as LTA4H. Also able to cleave angiotensin III to generate angiotensin IV, a bioactive peptide of the renin–angiotensin pathway.[2]
Due to its aminopeptidase activity this enzyme may play a role in the proteolytic processing of bioactive peptides in those tissues where it is expressed.
# Tissue distribution
C9ORF3 Messenger RNA has been detected in human pancreas, placenta, liver, testis, and heart. The expression in the heart suggests this enzyme may also play a role in the regulating the physiology of cardiac muscle.[2] Several ApO isoforms are expressed predominantly in blood vessels suggesting that ApO plays a role in vascular cell biology.[3]
# Clinical significance
High expression levels of C9ORF3 is positively correlated with maximal oxygen uptake (VO2 max) and the amount of "slow-twitch" type 1 muscle fibers.[5] | https://www.wikidoc.org/index.php/C9orf3 | |
040e36224686b45e8ace643b2fc9bd83318d8360 | wikidoc | CA-125 | CA-125
CA-125 (cancer antigen 125, carcinoma antigen 125, or carbohydrate antigen 125) also known as mucin 16 or MUC16 is a protein that in humans is encoded by the MUC16 gene. MUC16 is a member of the mucin family glycoproteins. CA-125 has found application as a tumor marker or biomarker that may be elevated in the blood of some patients with specific types of cancers, or other conditions that are benign.
# Structure
Mucin 16 is a membrane associated mucin that possesses a single transmembrane domain. A unique property of MUC16 is its large size. MUC16 is more than twice as long as MUC1 and MUC4 and contains about 22,000 amino acids, making it the largest membrane-associated mucin.
MUC16 is composed of three different domains:
- An N-terminal domain
- A tandem repeat domain
- A C-terminal domain
The N-terminal and tandem repeat domains are both entirely extracellular and highly O-glycosylated. All mucins contain a tandem repeat domain that has repeating amino acid sequences high in serine, threonine and proline. The C-terminal domain contains multiple extracellular SEA (sea urchin sperm protein, enterokinase, and agrin) modules, a transmembrane domain, and a cytoplasmic tail. The extracellular region of MUC16 can be released from the cell surface by undergoing proteolytic cleavage. MUC16 is thought to be cleaved at a site in the SEA modules.
# Function
MUC16 is a component of the ocular surface (including the cornea and conjunctiva), the respiratory tract and the female reproductive tract epithelia. Since MUC16 is highly glycosylated it creates a hydrophilic environment that acts as a lubricating barrier against foreign particles and infectious agents on the apical membrane of epithelial cells. Also, the cytoplasmic tail of MUC16 has been shown to interact with cytoskeleton by binding members of the ERM protein family. The expression of mucin 16 has been shown to be altered in dry eye, cystic fibrosis, and several types of cancers.
# As a biomarker
CA-125 is the most frequently used biomarker for ovarian cancer detection. Medical societies including American Congress of Obstetricians and Gynecologists recommend against women with average risk of ovarian cancer having routine CA-125 screening or other screening for this cancer. Reasons for this include evidence that ambiguous test results are more likely to lead to further invasive, harmful, and unnecessary health care than they are likely to detect ovarian cancer in women who are at average risk of developing it.
Around 90% of women with advanced ovarian cancer have elevated levels of CA-125 in their blood serum, making CA-125 a useful tool for detecting ovarian cancer after the onset of symptoms. Monitoring CA-125 blood serum levels is also useful for determining how ovarian cancer is responding to treatment (with the duration of disease-free survival correlating with the rate of fall of CA-125) and for predicting a patient’s prognosis after treatment. This is because the persistence of high levels of CA-125 during therapy is associated with poor survival rates in patients. Also, an increase in CA-125 levels within individuals in a remission is a strong predictor of the recurrence of ovarian cancer. Indeed, a rising CA-125 level may precede clinical evidence of disease relapse by an interval of 3 to 6 months.
Prognosis relates to both the initial and post-treatment CA-125 values. A preoperative value >65 U/mL suggests a poor prognosis. Persistent elevations following chemotherapy indicate a poor prognosis. The half-life of CA-125 after chemotherapy correlates with prognosis (patients with CA-125 half-life <20 days show improved survival). Time-to-normalization (rate of fall of CA-125) affects prognosis with more rapid normalization within 3 cycles of chemotherapy correlating with improved survival.
In April 2011 the UK's National Institute for Health and Clinical Excellence (NICE) recommended that women with symptoms that could be caused by ovarian cancer should be offered a CA-125 blood test. The aim of this guideline is to help diagnose the disease at an earlier stage, when treatment is more likely to be successful. Women with higher levels of the marker in their blood would then be offered an ultrasound scan to determine whether they need further tests.
In one case, elevated serum levels of CA-125 were observed in a male patient with IgE myeloma, however more cases are needed to determine the clinical significance of CA-125 in myeloma.
## Early detection of ovarian cancer
The potential role of CA-125 for the early detection of ovarian cancer is controversial and has not yet been adopted for widespread screening efforts in asymptomatic women. The major issues with using the CA-125 biomarker are its lack of sensitivity, particularly for detecting early stages of ovarian cancer, and its lack of specificity, especially in premenopausal women. These limitations mean that CA-125 testing often gives false positives for ovarian cancer and puts patients through unnecessary further screening (sometimes including surgery) and anxiety. Also, these limitations mean that many women with early stage ovarian cancer will receive a false negative from CA-125 testing and not get further treatment for their condition.
## Specificity and sensitivity
CA-125 has limited specificity for ovarian cancer because elevated CA-125 levels can be found in individuals without ovarian cancer. For example, while CA-125 is best known as a marker for ovarian cancer, it may also be elevated in other cancers, including endometrial cancer, fallopian tube cancer, lung cancer, breast cancer and gastrointestinal cancer. CA-125 may also be elevated in a number of relatively benign conditions, such as endometriosis, several diseases of the ovary, menstruation and pregnancy. It also tends to be elevated in the presence of any inflammatory condition in the abdominal area, both cancerous and benign, as well as in cirrhosis and diabetes mellitus. Thus, CA-125 testing is not perfectly specific for ovarian cancer and often results in false positives.
The specificity of CA-125 is particularly low in premenopausal women because many benign conditions that cause fluctuations in CA-125 levels, such as menstruation, pregnancy, and pelvic inflammatory disease, are seen in this population.
CA-125 testing is also not perfectly sensitive for detecting ovarian cancer because not every patient with cancer will have elevated levels of CA-125 in their blood. For example, 79% of all ovarian cancers are positive for CA-125, whereas the remainder do not express this antigen at all. Also, only about 50% of patients with early stage ovarian cancer have elevated CA-125 levels, meaning that CA-125 has particularly poor sensitivity for ovarian cancer before the onset of symptoms. Poor sensitivity means that the use of CA-125 to detect ovarian cancer (especially in early stages of disease) can frequently lead to false negatives. Patients that receive false negatives are unlikely to seek further treatment for their disease.
## Ranges in ovarian cancer
While this test is not generally regarded as useful for large scale screening by the medical community, a high value may be an indication that the woman should receive further diagnostic screening or treatment. Normal values range from 0 to 35 (U/mL). Elevated levels in post-menopausal women are usually an indication that further screening is necessary. In pre-menopausal women, the test is less reliable as values are often elevated due to a number of non-cancerous causes, and a value above 35 is not necessarily a cause for concern.
In a patient who is clinically selected for testing due to the presence of an adnexal/pelvic mass, CA-125 has great utility to differentiate benign from malignant processes. In a post-menopausal woman with a palpable adnexal mass and CA-125 level greater than 65 U/mL, the positive predictive value is >95% for ovarian malignancy. In patients who are not as carefully selected clinically, the utility of this test decreases, thus highlighting the need for careful clinical scrutiny.
# Role in cancer
MUC16 (CA-125) has been shown to play a role in advancing tumorigenesis and tumor proliferation by several different mechanisms.
## Immune system evasion
One way that MUC16 helps the growth of tumors is by suppressing the response of natural killer cells, thereby protecting cancer cells from the immune response. Further evidence that MUC16 can protect tumor cells from the immune system is the discovery that the heavily glycosylated tandem repeat domain of MUC16 can bind to galectin-1 (an immunosuppressive protein).
## Metastatic invasion
MUC16 is also thought to participate in cell-to-cell interactions that enable the metastasis of tumor cells. This is supported by evidence showing that MUC16 binds selectively to mesothelin, a glycoprotein normally expressed by the mesothelial cells of the peritoneum (the lining of the abdominal cavity). MUC16 and mesothelin interactions are thought to provide the first step in tumor cell invasion of the peritoneum.
Mesothelin has also been found to be expressed in several types of cancers including mesothelioma, ovarian cancer and squamous cell carcinoma. Since mesothelin is also expressed by tumor cells, MUC16 and mesothelial interactions may aid in the gathering of other tumor cells to the location of a metastasis, thus increasing the size of the metastasis.
## Induced motility
Evidence suggests that expression of the cytoplasmic tail of MUC16 enables tumor cells to grow, promotes cell motility and may facilitate invasion. This appears to be due to the ability of the C-terminal domain of MUC16 to facilitate signaling that leads to a decrease in the expression of E-cadherin and increase the expression of N-cadherin and vimentin, which are expression patterns consistent with epithelial-mesenchymal transition.
## Chemotherapy resistance
MUC16 may also play a role in reducing the sensitivity of cancer cells to drug therapy. For example, overexpression of MUC16 has been shown to protect cells from the effects of genotoxic drugs, such as cisplatin.
# Discovery
CA-125 was initially detected using the murine monoclonal antibody designated OC125. Robert Bast, Robert Knapp and their research team first isolated this monoclonal antibody in 1981. The protein was named “cancer antigen 125” because OC125 was the 125th antibody produced against the ovarian cancer cell line that was being studied. | CA-125
CA-125 (cancer antigen 125, carcinoma antigen 125, or carbohydrate antigen 125) also known as mucin 16 or MUC16 is a protein that in humans is encoded by the MUC16 gene.[1][2] MUC16 is a member of the mucin family glycoproteins.[3] CA-125 has found application as a tumor marker or biomarker that may be elevated in the blood of some patients with specific types of cancers,[4] or other conditions that are benign.
# Structure
Mucin 16 is a membrane associated mucin that possesses a single transmembrane domain.[5] A unique property of MUC16 is its large size. MUC16 is more than twice as long as MUC1 and MUC4 and contains about 22,000 amino acids, making it the largest membrane-associated mucin.[6]
MUC16 is composed of three different domains:[7]
- An N-terminal domain
- A tandem repeat domain
- A C-terminal domain
The N-terminal and tandem repeat domains are both entirely extracellular and highly O-glycosylated. All mucins contain a tandem repeat domain that has repeating amino acid sequences high in serine, threonine and proline.[8] The C-terminal domain contains multiple extracellular SEA (sea urchin sperm protein, enterokinase, and agrin) modules,[9] a transmembrane domain, and a cytoplasmic tail.[7] The extracellular region of MUC16 can be released from the cell surface by undergoing proteolytic cleavage.[10] MUC16 is thought to be cleaved at a site in the SEA modules.[11]
# Function
MUC16 is a component of the ocular surface (including the cornea and conjunctiva), the respiratory tract and the female reproductive tract epithelia. Since MUC16 is highly glycosylated it creates a hydrophilic environment that acts as a lubricating barrier against foreign particles and infectious agents on the apical membrane of epithelial cells.[12] Also, the cytoplasmic tail of MUC16 has been shown to interact with cytoskeleton by binding members of the ERM protein family.[13] The expression of mucin 16 has been shown to be altered in dry eye, cystic fibrosis, and several types of cancers.[14]
# As a biomarker
CA-125 is the most frequently used biomarker for ovarian cancer detection.[15] Medical societies including American Congress of Obstetricians and Gynecologists recommend against women with average risk of ovarian cancer having routine CA-125 screening or other screening for this cancer.[16] Reasons for this include evidence that ambiguous test results are more likely to lead to further invasive, harmful, and unnecessary health care than they are likely to detect ovarian cancer in women who are at average risk of developing it.[16]
Around 90% of women with advanced ovarian cancer have elevated levels of CA-125 in their blood serum, making CA-125 a useful tool for detecting ovarian cancer after the onset of symptoms.[17] Monitoring CA-125 blood serum levels is also useful for determining how ovarian cancer is responding to treatment (with the duration of disease-free survival correlating with the rate of fall of CA-125)[18] and for predicting a patient’s prognosis after treatment.[19] This is because the persistence of high levels of CA-125 during therapy is associated with poor survival rates in patients.[19] Also, an increase in CA-125 levels within individuals in a remission is a strong predictor of the recurrence of ovarian cancer.[20] Indeed, a rising CA-125 level may precede clinical evidence of disease relapse by an interval of 3 to 6 months.
Prognosis relates to both the initial and post-treatment CA-125 values. A preoperative value >65 U/mL suggests a poor prognosis. Persistent elevations following chemotherapy indicate a poor prognosis. The half-life of CA-125 after chemotherapy correlates with prognosis (patients with CA-125 half-life <20 days show improved survival). Time-to-normalization (rate of fall of CA-125) affects prognosis with more rapid normalization within 3 cycles of chemotherapy correlating with improved survival.[21]
In April 2011 the UK's National Institute for Health and Clinical Excellence (NICE) recommended that women with symptoms that could be caused by ovarian cancer should be offered a CA-125 blood test.[22] The aim of this guideline is to help diagnose the disease at an earlier stage, when treatment is more likely to be successful. Women with higher levels of the marker in their blood would then be offered an ultrasound scan to determine whether they need further tests.
In one case, elevated serum levels of CA-125 were observed in a male patient with IgE myeloma, however more cases are needed to determine the clinical significance of CA-125 in myeloma.[23]
## Early detection of ovarian cancer
The potential role of CA-125 for the early detection of ovarian cancer is controversial and has not yet been adopted for widespread screening efforts in asymptomatic women.[24][25] The major issues with using the CA-125 biomarker are its lack of sensitivity, particularly for detecting early stages of ovarian cancer, and its lack of specificity, especially in premenopausal women.[26] These limitations mean that CA-125 testing often gives false positives for ovarian cancer and puts patients through unnecessary further screening (sometimes including surgery) and anxiety.[20] Also, these limitations mean that many women with early stage ovarian cancer will receive a false negative from CA-125 testing and not get further treatment for their condition.[27]
## Specificity and sensitivity
CA-125 has limited specificity for ovarian cancer because elevated CA-125 levels can be found in individuals without ovarian cancer. For example, while CA-125 is best known as a marker for ovarian cancer,[28] it may also be elevated in other cancers, including endometrial cancer, fallopian tube cancer, lung cancer, breast cancer and gastrointestinal cancer.[4] CA-125 may also be elevated in a number of relatively benign conditions, such as endometriosis,[29] several diseases of the ovary, menstruation[26] and pregnancy.[30] It also tends to be elevated in the presence of any inflammatory condition in the abdominal area, both cancerous and benign,[31] as well as in cirrhosis and diabetes mellitus.[32] Thus, CA-125 testing is not perfectly specific for ovarian cancer and often results in false positives.[26]
The specificity of CA-125 is particularly low in premenopausal women because many benign conditions that cause fluctuations in CA-125 levels, such as menstruation, pregnancy, and pelvic inflammatory disease, are seen in this population.[25]
CA-125 testing is also not perfectly sensitive for detecting ovarian cancer because not every patient with cancer will have elevated levels of CA-125 in their blood.[33] For example, 79% of all ovarian cancers are positive for CA-125, whereas the remainder do not express this antigen at all.[34] Also, only about 50% of patients with early stage ovarian cancer have elevated CA-125 levels, meaning that CA-125 has particularly poor sensitivity for ovarian cancer before the onset of symptoms.[26][35] Poor sensitivity means that the use of CA-125 to detect ovarian cancer (especially in early stages of disease) can frequently lead to false negatives. Patients that receive false negatives are unlikely to seek further treatment for their disease.
## Ranges in ovarian cancer
While this test is not generally regarded as useful for large scale screening by the medical community, a high value may be an indication that the woman should receive further diagnostic screening or treatment. Normal values range from 0 to 35 (U/mL).[26] Elevated levels in post-menopausal women are usually an indication that further screening is necessary. In pre-menopausal women, the test is less reliable as values are often elevated due to a number of non-cancerous causes, and a value above 35 is not necessarily a cause for concern.[25]
In a patient who is clinically selected for testing due to the presence of an adnexal/pelvic mass, CA-125 has great utility to differentiate benign from malignant processes. In a post-menopausal woman with a palpable adnexal mass and CA-125 level greater than 65 U/mL, the positive predictive value is >95% for ovarian malignancy. In patients who are not as carefully selected clinically, the utility of this test decreases, thus highlighting the need for careful clinical scrutiny.
# Role in cancer
MUC16 (CA-125) has been shown to play a role in advancing tumorigenesis and tumor proliferation by several different mechanisms.
## Immune system evasion
One way that MUC16 helps the growth of tumors is by suppressing the response of natural killer cells, thereby protecting cancer cells from the immune response.[36] Further evidence that MUC16 can protect tumor cells from the immune system is the discovery that the heavily glycosylated tandem repeat domain of MUC16 can bind to galectin-1 (an immunosuppressive protein).[37]
## Metastatic invasion
MUC16 is also thought to participate in cell-to-cell interactions that enable the metastasis of tumor cells. This is supported by evidence showing that MUC16 binds selectively to mesothelin, a glycoprotein normally expressed by the mesothelial cells of the peritoneum (the lining of the abdominal cavity).[38] MUC16 and mesothelin interactions are thought to provide the first step in tumor cell invasion of the peritoneum.[39]
Mesothelin has also been found to be expressed in several types of cancers including mesothelioma, ovarian cancer and squamous cell carcinoma.[40] Since mesothelin is also expressed by tumor cells, MUC16 and mesothelial interactions may aid in the gathering of other tumor cells to the location of a metastasis, thus increasing the size of the metastasis.[39]
## Induced motility
Evidence suggests that expression of the cytoplasmic tail of MUC16 enables tumor cells to grow, promotes cell motility and may facilitate invasion. This appears to be due to the ability of the C-terminal domain of MUC16 to facilitate signaling that leads to a decrease in the expression of E-cadherin and increase the expression of N-cadherin and vimentin, which are expression patterns consistent with epithelial-mesenchymal transition.[41]
## Chemotherapy resistance
MUC16 may also play a role in reducing the sensitivity of cancer cells to drug therapy. For example, overexpression of MUC16 has been shown to protect cells from the effects of genotoxic drugs, such as cisplatin.[42]
# Discovery
CA-125 was initially detected using the murine monoclonal antibody designated OC125. Robert Bast, Robert Knapp and their research team first isolated this monoclonal antibody in 1981.[43] The protein was named “cancer antigen 125” because OC125 was the 125th antibody produced against the ovarian cancer cell line that was being studied.[44] | https://www.wikidoc.org/index.php/CA-125 | |
1807e47e965fea3e61e7ee9106d336b43eb029fc | wikidoc | Cav2.1 | Cav2.1
The Cav2.1 P/Q voltage-dependent calcium channel is encoded by the CACNA1A gene.
# Function
Voltage-dependent calcium channels mediate the entry of calcium ions into excitable cells, and are also involved in a variety of calcium-dependent processes, including muscle contraction, hormone or neurotransmitter release, and gene expression. Calcium channels are multisubunit complexes composed of alpha-1, beta, alpha-2/delta, and gamma subunits. The channel activity is directed by the pore-forming alpha-1 subunit, whereas, the others act as auxiliary subunits regulating this activity. The distinctive properties of the calcium channel types are related primarily to the expression of a variety of alpha-1 isoforms, alpha-1A, B, C, D, E, and S. This gene encodes the alpha-1A subunit, which is predominantly expressed in neuronal tissue.
# Clinical significance
Mutations in this gene are associated with neurologic disorders, including familial hemiplegic migraine and episodic ataxia 2. One particular mutation (S218L) which is associated with hemiplegic migraine, ataxia, and seizures, may also confer a vulnerability to life-threatening cerebral edema after a minor head injury.
This gene also exhibits polymorphic variation due to (CAG)n-repeats. Multiple transcript variants have been described, however, the full-length nature of not all is known. In one set of transcript variants, the (CAG)n-repeats occur in the 3' UTR, and are not associated with any disease. However, in another set of variants, an insertion extends the coding region to include the (CAG)n-repeats which encode a polyglutamine tract. Expansion of the (CAG)n-repeats from the normal 4-16 to 21-28 in the coding region is associated with spinocerebellar ataxia 6.
# Interactions
Cav2.1 has been shown to interact with CACNB4. | Cav2.1
The Cav2.1 P/Q voltage-dependent calcium channel is encoded by the CACNA1A gene.
# Function
Voltage-dependent calcium channels mediate the entry of calcium ions into excitable cells, and are also involved in a variety of calcium-dependent processes, including muscle contraction, hormone or neurotransmitter release, and gene expression. Calcium channels are multisubunit complexes composed of alpha-1, beta, alpha-2/delta, and gamma subunits. The channel activity is directed by the pore-forming alpha-1 subunit, whereas, the others act as auxiliary subunits regulating this activity. The distinctive properties of the calcium channel types are related primarily to the expression of a variety of alpha-1 isoforms, alpha-1A, B, C, D, E, and S. This gene encodes the alpha-1A subunit, which is predominantly expressed in neuronal tissue.
# Clinical significance
Mutations in this gene are associated with neurologic disorders, including familial hemiplegic migraine and episodic ataxia 2. One particular mutation (S218L) which is associated with hemiplegic migraine, ataxia, and seizures, may also confer a vulnerability to life-threatening cerebral edema after a minor head injury.[1]
This gene also exhibits polymorphic variation due to (CAG)n-repeats. Multiple transcript variants have been described, however, the full-length nature of not all is known. In one set of transcript variants, the (CAG)n-repeats occur in the 3' UTR, and are not associated with any disease. However, in another set of variants, an insertion extends the coding region to include the (CAG)n-repeats which encode a polyglutamine tract. Expansion of the (CAG)n-repeats from the normal 4-16 to 21-28 in the coding region is associated with spinocerebellar ataxia 6.[2]
# Interactions
Cav2.1 has been shown to interact with CACNB4.[3][4] | https://www.wikidoc.org/index.php/CACNA1A | |
f4511656dd736af5fbd02477dfb927b658d55fe4 | wikidoc | CACNB4 | CACNB4
Voltage-dependent L-type calcium channel subunit beta-4 is a protein that in humans is encoded by the CACNB4 gene.
# Function
This gene encodes a member of the beta subunit family, a protein in the voltage-dependent calcium channel complex. Calcium channels mediate the influx of calcium ions into the cell upon membrane polarization and consist of a complex of alpha-1, alpha-2/delta, beta, and gamma subunits in a 1:1:1:1 ratio. Various versions of each of these subunits exist, either expressed from similar genes or the result of alternative splicing. The protein described in this record plays an important role in calcium channel function by modulating G protein inhibition, increasing peak calcium current, controlling the alpha-1 subunit membrane targeting and shifting the voltage dependence of activation and inactivation. Alternate transcriptional splice variants of this gene, encoding different isoforms, have been characterized.
# Clinical significance
Certain mutations in this gene have been associated with idiopathic generalized epilepsy (IGE) and juvenile myoclonic epilepsy (JME).
# Interactions
CACNB4 has been shown to interact with Cav2.1. | CACNB4
Voltage-dependent L-type calcium channel subunit beta-4 is a protein that in humans is encoded by the CACNB4 gene.[1][2]
# Function
This gene encodes a member of the beta subunit family, a protein in the voltage-dependent calcium channel complex. Calcium channels mediate the influx of calcium ions into the cell upon membrane polarization and consist of a complex of alpha-1, alpha-2/delta, beta, and gamma subunits in a 1:1:1:1 ratio. Various versions of each of these subunits exist, either expressed from similar genes or the result of alternative splicing. The protein described in this record plays an important role in calcium channel function by modulating G protein inhibition, increasing peak calcium current, controlling the alpha-1 subunit membrane targeting and shifting the voltage dependence of activation and inactivation. Alternate transcriptional splice variants of this gene, encoding different isoforms, have been characterized.[2]
# Clinical significance
Certain mutations in this gene have been associated with idiopathic generalized epilepsy (IGE) and juvenile myoclonic epilepsy (JME).[2]
# Interactions
CACNB4 has been shown to interact with Cav2.1.[3][4] | https://www.wikidoc.org/index.php/CACNB4 | |
6e73c6418e472208b547427385bca5dfe7048d1f | wikidoc | CACNG2 | CACNG2
Calcium channel, voltage-dependent, gamma subunit 2, also known as CACNG2 or stargazin is a protein that in humans is encoded by the CACNG2 gene.
# Function
L-type calcium channels are composed of five subunits. The protein encoded by this gene represents one of these subunits, gamma, and is one of several gamma subunit proteins. It is an integral membrane protein that is thought to stabilize the calcium channel in an inactive (closed) state. This protein is similar to the mouse stargazin protein, mutations in which having been associated with absence seizures, also known as petit-mal or spike-wave seizures. This gene is a member of the neuronal calcium channel gamma subunit gene subfamily of the PMP-22/EMP/MP20 family.
Stargazin is involved in the transportation of AMPA receptors to the synaptic membrane, and the regulation of their receptor rate constants — via its extracellular domain — once it is there. As it is highly expressed throughout the cerebral cortex, it is likely to have an important role in learning within these areas, due to the importance of AMPA receptors in LTP.
# Clinical significance
Disruptions of CACNG2 have been implicated in autism.
# Interactions
CACNG2 has been shown to interact with GRIA4, DLG4, and MAGI2. | CACNG2
Calcium channel, voltage-dependent, gamma subunit 2, also known as CACNG2 or stargazin is a protein that in humans is encoded by the CACNG2 gene.[1]
# Function
L-type calcium channels are composed of five subunits. The protein encoded by this gene represents one of these subunits, gamma, and is one of several gamma subunit proteins. It is an integral membrane protein that is thought to stabilize the calcium channel in an inactive (closed) state. This protein is similar to the mouse stargazin protein, mutations in which having been associated with absence seizures, also known as petit-mal or spike-wave seizures. This gene is a member of the neuronal calcium channel gamma subunit gene subfamily of the PMP-22/EMP/MP20 family.[1]
Stargazin is involved in the transportation of AMPA receptors to the synaptic membrane, and the regulation of their receptor rate constants — via its extracellular domain — once it is there. As it is highly expressed throughout the cerebral cortex, it is likely to have an important role in learning within these areas, due to the importance of AMPA receptors in LTP.
# Clinical significance
Disruptions of CACNG2 have been implicated in autism.[2]
# Interactions
CACNG2 has been shown to interact with GRIA4,[3] DLG4,[3][4] and MAGI2.[5] | https://www.wikidoc.org/index.php/CACNG2 | |
1e0ff5468dddc9f0b3136c0500461b27ce49351c | wikidoc | CADPS2 | CADPS2
Calcium-dependent secretion activator 2 is a protein that in humans is encoded by the CADPS2 gene.
# Function
This gene encodes a member of the calcium-dependent activator of secretion (CAPS) protein family, which are calcium-binding proteins that regulate the exocytosis of synaptic and dense-core vesicles in neurons and neuroendocrine cells.
# Interactions
This gene interacts with brain-derived neurotrophic factor.
# Clinical significance
Cadps2 has been linked to autism and is in the 7q autism susceptibility locus (AUTS1). However, the finding of aberrant CADPS2 splicing was not found to be significant in another study.
A knockout mouse model was found to have autistic-like characteristics.
CADPS2 has been linked to human and mouse brain structure in two large genomic studies. | CADPS2
Calcium-dependent secretion activator 2 is a protein that in humans is encoded by the CADPS2 gene.[1]
# Function
This gene encodes a member of the calcium-dependent activator of secretion (CAPS) protein family, which are calcium-binding proteins that regulate the exocytosis of synaptic and dense-core vesicles in neurons and neuroendocrine cells.[1]
# Interactions
This gene interacts with brain-derived neurotrophic factor.
# Clinical significance
Cadps2 has been linked to autism[2] and is in the 7q autism susceptibility locus (AUTS1). However, the finding of aberrant CADPS2 splicing was not found to be significant in another study.[3]
A knockout mouse model was found to have autistic-like characteristics.[2]
CADPS2 has been linked to human and mouse brain structure in two large genomic studies.[4][5] | https://www.wikidoc.org/index.php/CADPS2 | |
9fcc37af2d22503449a50be64fdaf9c7d8da37c6 | wikidoc | CALCRL | CALCRL
Calcitonin receptor-like (CALCRL), also known as the calcitonin receptor-like receptor (CRLR), is a human protein; it is a receptor for calcitonin gene-related peptide.
# Function
The protein encoded by the CALCRL gene is a G protein-coupled receptor related to the calcitonin receptor. CALCRL is linked to one of three single transmembrane domain receptor activity-modifying proteins (RAMPs) that are essential for functional activity.
The association of CALCRL with different RAMP proteins produces different receptors:
- with RAMP1: produces a CGRP receptor
- with RAMP2: produces an adrenomedullin (AM) receptor, designated AM1
- with RAMP3: produces a dual CGRP/AM receptor designated AM2
These receptors are linked to the G protein Gs, which activates adenylate cyclase and activation results in the generation of intracellular cyclic adenosine monophosphate (cAMP).
CGRP receptors are found throughout the body, suggesting that the protein may modulate a variety of physiological functions in all major systems (e.g., respiratory, endocrine, gastrointestinal, immune, and cardiovascular).
## Wounds
In wounds, CGRP receptors found in nerve cells deactivate the immune system, to prevent collateral damage in case of a clean wound (common case). However, when a wily pathogen such as those causing necrotizing fasciitis are involved, this is the wrong response. In very preliminary research, nerve blockers like botox have been demonstrated to block CGRP cascade, thereby allowing immune system involvement and control of pathogens, resulting in complete control and recovery.
# Structure
CALCRL associated with RAMP1 produces the CGRP receptor which is a trans-membrane protein receptor that is made up of four chains. Two of the four chains contain unique sequences. It is a heterodimer protein composed of two polypeptide chains differing in composition of their amino acid residues. The sequence reveals multiple hydrophobic and hydrophilic regions throughout the four chains in the protein.
The CGRP family of receptors including CALCRL can couple to G-protein Gαs, Gαi and Gαq subunits to transduce their signals. Furthermore binding of ligands to CALCRL can bias coupling to these G-protein. Peptide agonist bind to the extracellular loops of CALCRL. This binding in turn causes TM5 (transmembrane helix 5) and TM6 to pivot around TM3 which in turn facilitates Gαs binding.
## Adrenomedullin receptor
# Expression
The RNA expression charts show a high level in fetal lung.
# Clinical significance
Calcitonin gene-related peptide receptor antagonists are under investigation for the treatment of migraine. | CALCRL
Calcitonin receptor-like (CALCRL), also known as the calcitonin receptor-like receptor (CRLR), is a human protein; it is a receptor for calcitonin gene-related peptide.[1]
# Function
The protein encoded by the CALCRL gene is a G protein-coupled receptor related to the calcitonin receptor. CALCRL is linked to one of three single transmembrane domain receptor activity-modifying proteins (RAMPs) that are essential for functional activity.
The association of CALCRL with different RAMP proteins produces different receptors:[2][3]
- with RAMP1: produces a CGRP receptor
- with RAMP2: produces an adrenomedullin (AM) receptor, designated AM1[4]
- with RAMP3: produces a dual CGRP/AM receptor designated AM2
These receptors are linked to the G protein Gs,[5] which activates adenylate cyclase and activation results in the generation of intracellular cyclic adenosine monophosphate (cAMP).
CGRP receptors are found throughout the body, suggesting that the protein may modulate a variety of physiological functions in all major systems (e.g., respiratory, endocrine, gastrointestinal, immune, and cardiovascular).[6]
## Wounds
In wounds, CGRP receptors found in nerve cells deactivate the immune system, to prevent collateral damage in case of a clean wound (common case). However, when a wily pathogen such as those causing necrotizing fasciitis are involved, this is the wrong response. In very preliminary research, nerve blockers like botox have been demonstrated to block CGRP cascade, thereby allowing immune system involvement and control of pathogens, resulting in complete control and recovery.[7]
# Structure
CALCRL associated with RAMP1 produces the CGRP receptor which is a trans-membrane protein receptor that is made up of four chains. Two of the four chains contain unique sequences. It is a heterodimer protein composed of two polypeptide chains differing in composition of their amino acid residues. The sequence reveals multiple hydrophobic and hydrophilic regions throughout the four chains in the protein.[8]
The CGRP family of receptors including CALCRL can couple to G-protein Gαs, Gαi and Gαq subunits to transduce their signals. Furthermore binding of ligands to CALCRL can bias coupling to these G-protein.[9] Peptide agonist bind to the extracellular loops of CALCRL. This binding in turn causes TM5 (transmembrane helix 5) and TM6 to pivot around TM3 which in turn facilitates Gαs binding.[10]
## Adrenomedullin receptor
# Expression
The RNA expression charts show a high level in fetal lung.
# Clinical significance
Calcitonin gene-related peptide receptor antagonists are under investigation for the treatment of migraine.[11] | https://www.wikidoc.org/index.php/CALCRL | |
960bad545fc64e367caba0bb3761e25878f786d0 | wikidoc | CALHM1 | CALHM1
Calcium homeostasis modulator 1 (CALHM1) is a pore-forming subunit of a voltage-gated ion channel that in humans is encoded by the CALHM1 gene.
# Function
## Central nervous system
CALHM1 was identified by a tissue-specific gene expression profiling approach that screened for genes located on susceptibility loci for late-onset Alzheimer's disease (AD) and that are preferentially expressed in the hippocampus, a brain region affected early in AD. CALHM1 is a plasma membrane calcium-permeable ion channel regulated by voltage and extracellular calcium levels. The exact function of CALHM1 in the brain is not completely understood, but studies have shown that CALHM1 controls neuronal intracellular calcium homeostasis and signaling, as well as calcium-dependent neuronal excitability and memory in mouse models. Recent data have also shown that CALHM1 might facilitate the proteolytic degradation of the cerebral amyloid beta peptide, a culprit in AD pathogenesis.
## Peripheral taste system
CALHM1 is expressed in taste bud cells where it controls purinergic receptor-mediated taste transduction in the gustatory system. | CALHM1
Calcium homeostasis modulator 1 (CALHM1) is a pore-forming subunit of a voltage-gated ion channel that in humans is encoded by the CALHM1 gene.[1]
# Function
## Central nervous system
CALHM1 was identified by a tissue-specific gene expression profiling approach[2] that screened for genes located on susceptibility loci for late-onset Alzheimer's disease (AD) and that are preferentially expressed in the hippocampus,[1] a brain region affected early in AD. CALHM1 is a plasma membrane calcium-permeable ion channel regulated by voltage and extracellular calcium levels.[3] The exact function of CALHM1 in the brain is not completely understood, but studies have shown that CALHM1 controls neuronal intracellular calcium homeostasis and signaling, as well as calcium-dependent neuronal excitability and memory in mouse models.[3][4][5] Recent data have also shown that CALHM1 might facilitate the proteolytic degradation of the cerebral amyloid beta peptide, a culprit in AD pathogenesis.[6]
## Peripheral taste system
CALHM1 is expressed in taste bud cells where it controls purinergic receptor-mediated taste transduction in the gustatory system.[7][8] | https://www.wikidoc.org/index.php/CALHM1 | |
cde7d43c2fdba8f6cf1b8b11a84e833c15600c3b | wikidoc | CAMKK2 | CAMKK2
Calcium/calmodulin-dependent protein kinase kinase 2 is an enzyme that in humans is encoded by the CAMKK2 gene.
# Function
The product of this gene belongs to the serine/threonine-specific protein kinase family, and to the Ca++/calmodulin-dependent protein kinase subfamily. This protein plays a role in the calcium/calmodulin-dependent (CaM) kinase cascade by phosphorylating the downstream kinases CaMK1 and CaMK4.
CaMKK2 regulates production of the appetite stimulating hormone neuropeptide Y and functions as an AMPK kinase in the hypothalamus. It also has an important role in the development of hyperalgesia and tolerance to opioid analgesic drugs, through reduction in downstream signalling pathways and mu opioid receptor downregulation. Inhibition of CaMKK2 in mice reduces appetite and promotes weight loss.
# Isoforms
Seven transcript variants encoding six distinct isoforms have been identified for this gene. Additional splice variants have been described but their full-length nature has not been determined. The identified isoforms exhibit a distinct ability to undergo autophosphorylation and to phosphorylate the downstream kinases. | CAMKK2
Calcium/calmodulin-dependent protein kinase kinase 2 is an enzyme that in humans is encoded by the CAMKK2 gene.[1][1][2]
# Function
The product of this gene belongs to the serine/threonine-specific protein kinase family, and to the Ca++/calmodulin-dependent protein kinase subfamily. This protein plays a role in the calcium/calmodulin-dependent (CaM) kinase cascade by phosphorylating the downstream kinases CaMK1 and CaMK4.[2]
CaMKK2 regulates production of the appetite stimulating hormone neuropeptide Y and functions as an AMPK kinase in the hypothalamus.[3] It also has an important role in the development of hyperalgesia and tolerance to opioid analgesic drugs, through reduction in downstream signalling pathways and mu opioid receptor downregulation.[4][5][6] Inhibition of CaMKK2 in mice reduces appetite and promotes weight loss.[3]
# Isoforms
Seven transcript variants encoding six distinct isoforms have been identified for this gene. Additional splice variants have been described but their full-length nature has not been determined. The identified isoforms exhibit a distinct ability to undergo autophosphorylation and to phosphorylate the downstream kinases.[2][7] | https://www.wikidoc.org/index.php/CAMKK2 | |
8154304f668e06ea1fc2b17751987b867c120b38 | wikidoc | CAPNS1 | CAPNS1
Calpain small subunit 1, also known as CAPN4, is a protein that in humans is encoded by the CAPNS1 gene.
# Function
Calpains are a ubiquitous, well-conserved family of calcium-dependent, cysteine proteases. Calpain families have been implicated in neurodegenerative processes, as their activation can be triggered by calcium influx and oxidative stress. Calpain I and II are heterodimeric with distinct large subunits associated with common small subunits, all of which are encoded by different genes. The small regulatory subunit consists of an N-terminal domain, containing about 30% glycine residues and a C-terminal Ca-binding domain. Two transcript variants encoding the same protein have been identified for this gene.
# Functions
## Myotonic dystrophy
This gene encodes a small subunit common to both calpain I and II and is associated with myotonic dystrophy.
## Biomarker
Elevated expression of Capn4 has been found to be associated with progression of various cancers such as hepatocellular and renal carcinoma. | CAPNS1
Calpain small subunit 1, also known as CAPN4, is a protein that in humans is encoded by the CAPNS1 gene.[1][2][3]
# Function
Calpains are a ubiquitous, well-conserved family of calcium-dependent, cysteine proteases. Calpain families have been implicated in neurodegenerative processes, as their activation can be triggered by calcium influx and oxidative stress. Calpain I and II are heterodimeric with distinct large subunits associated with common small subunits, all of which are encoded by different genes. The small regulatory subunit consists of an N-terminal domain, containing about 30% glycine residues and a C-terminal Ca-binding domain.[4] Two transcript variants encoding the same protein have been identified for this gene.[3]
# Functions
## Myotonic dystrophy
This gene encodes a small subunit common to both calpain I and II and is associated with myotonic dystrophy.[3]
## Biomarker
Elevated expression of Capn4 has been found to be associated with progression of various cancers such as hepatocellular and renal carcinoma.
[5] | https://www.wikidoc.org/index.php/CAPNS1 | |
2a9d459555b7978662a235d1ce4a60ce37b2b5f8 | wikidoc | CAPZA2 | CAPZA2
F-actin-capping protein subunit alpha-2 also known as CapZ-alpha2 is a protein that in humans is encoded by the CAPZA2 gene.
# Structure
CapZ-alpha2 is a 33.0 kDa protein composed of 286 amino acids. CAPZA2 is located on human chromosome 7, position q31.2-q31.3. The primary sequence of CapZ-alpha2 contains three C-terminal, regularly spaced leucines at positions 258, 262 and 266 found in consensus sequence of KxxxLxxE/DLxxALxxK/R that are critical for actin binding; these residues are conserved within the CapZ-beta isoform. CapZ-alpha2 is 85% identical to CapZ-alpha1, and differ by a small number of key amino acids; 21 amino acid differences perpetrate isoform specificity. CapZ-alpha2 is expressed in a variety of tissues, including cardiac muscle and skeletal muscle, where it caps sarcomeric actin at Z-discs; the ratio of CapZ-alpha2 to CapZ-alpha1 varies significantly among different tissues.
# Function
CapZ binds the barbed end of actin filaments and prevents addition or loss of actin monomers to filaments. It has also been observed that CapZ functions to organize myofilaments during myofibrillogenesis and is present at Z-discs in muscle prior to the striation of actin filaments, suggesting that CapZ may function to direct the polarity and organization of sarcomeric actin during I-band formation. The function of CapZ-alpha2 may be modulated by the calcium-binding protein S100A in skeletal and cardiac muscle tissues, as crosslinking studies have shown S100A to directly interaction with the C-terminal region of CapZ-alpha in the presence of calcium. CapZ appears to regulate intracellular signaling of contractile proteins in cardiac muscle. It has been demonstrated that the presence of CapZ at Z-discs modulates the ability of protein phosphatase 1 (PP1) to dephosphorylate cardiac myofilament proteins, including myosin binding protein C, troponin T and myosin regulatory light chain; likely because extraction of CapZ decreased the amount of myofilament-associated PP1.
# Clinical Significance
In humans undergoing exercise-induced muscle damage via 300 maximal eccentric contractions, skeletal muscle biopsies subjected to DNA microarrays showed that CapZ-alpha expression was upregulated, suggesting that CapZ-alpha may be involved in skeletal muscle growth and remodeling, and/or stress management.
# Interactions
CapZ-alpha2 has been shown to interact with:
- ACTA1
- ACTC1
- S100A1 | CAPZA2
F-actin-capping protein subunit alpha-2 also known as CapZ-alpha2 is a protein that in humans is encoded by the CAPZA2 gene.[1]
# Structure
CapZ-alpha2 is a 33.0 kDa protein composed of 286 amino acids.[2] CAPZA2 is located on human chromosome 7, position q31.2-q31.3.[3] The primary sequence of CapZ-alpha2 contains three C-terminal, regularly spaced leucines at positions 258, 262 and 266 found in consensus sequence of KxxxLxxE/DLxxALxxK/R that are critical for actin binding; these residues are conserved within the CapZ-beta isoform.[3] CapZ-alpha2 is 85% identical to CapZ-alpha1, and differ by a small number of key amino acids; 21 amino acid differences perpetrate isoform specificity.[4] CapZ-alpha2 is expressed in a variety of tissues, including cardiac muscle and skeletal muscle, where it caps sarcomeric actin at Z-discs; the ratio of CapZ-alpha2 to CapZ-alpha1 varies significantly among different tissues.[4]
# Function
CapZ binds the barbed end of actin filaments and prevents addition or loss of actin monomers to filaments. It has also been observed that CapZ functions to organize myofilaments during myofibrillogenesis and is present at Z-discs in muscle prior to the striation of actin filaments, suggesting that CapZ may function to direct the polarity and organization of sarcomeric actin during I-band formation.[5][6] The function of CapZ-alpha2 may be modulated by the calcium-binding protein S100A in skeletal and cardiac muscle tissues, as crosslinking studies have shown S100A to directly interaction with the C-terminal region of CapZ-alpha in the presence of calcium.[7] CapZ appears to regulate intracellular signaling of contractile proteins in cardiac muscle. It has been demonstrated that the presence of CapZ at Z-discs modulates the ability of protein phosphatase 1 (PP1) to dephosphorylate cardiac myofilament proteins, including myosin binding protein C, troponin T and myosin regulatory light chain; likely because extraction of CapZ decreased the amount of myofilament-associated PP1.[8]
# Clinical Significance
In humans undergoing exercise-induced muscle damage via 300 maximal eccentric contractions, skeletal muscle biopsies subjected to DNA microarrays showed that CapZ-alpha expression was upregulated, suggesting that CapZ-alpha may be involved in skeletal muscle growth and remodeling, and/or stress management.[9]
# Interactions
CapZ-alpha2 has been shown to interact with:
- ACTA1[5]
- ACTC1[5]
- S100A1[7] | https://www.wikidoc.org/index.php/CAPZA2 | |
d098f4d867df3ec9c5499b70a3da4674b27f2c9b | wikidoc | CARD14 | CARD14
Caspase recruitment domain-containing protein 14, also known as CARD-containing MAGUK protein 2 (Carma 2), is a protein that in humans is encoded by the CARD14 gene.
# Function
The protein encoded by this gene belongs to the membrane-associated guanylate kinase (MAGUK) family, a class of proteins that functions as molecular scaffolds for the assembly of multiprotein complexes at specialized regions of the plasma membrane. This protein is also a member of the CARD protein family, which is defined by carrying a characteristic caspase-associated recruitment domain (CARD). This protein shares a similar domain structure with CARD11 protein. The CARD domains of both proteins have been shown to specifically interact with BCL10, a protein known to function as a positive regulator of cell apoptosis and NF-κB activation. The homotypic interaction with BCL10 is believed to be prevented by the linker region of CARD14, when in an inactive state. CARD14 overexpression leads to an activation of the transcription factor NF-κB and phosphorylation of BCL10. CARD14 has been shown to form a CBM signalosome, similar to the signalling of CARD11, with BCL10 and MALT1.
# Link to Psoriasis
The CARD14 gene was recently identified as the first gene directly linked to the most common form of Psoriasis. It has been suggested that a mutation in the gene plus an environmental trigger were enough to elicit plaque psoriasis. These rare, but highly penetrant, mutations were found to disrupt an auto-inhibited state of CARD14, which leads to the binding of BCL10 and the activation of NF-κB. | CARD14
Caspase recruitment domain-containing protein 14, also known as CARD-containing MAGUK protein 2 (Carma 2), is a protein that in humans is encoded by the CARD14 gene.[1][2][3]
# Function
The protein encoded by this gene belongs to the membrane-associated guanylate kinase (MAGUK) family, a class of proteins that functions as molecular scaffolds for the assembly of multiprotein complexes at specialized regions of the plasma membrane. This protein is also a member of the CARD protein family, which is defined by carrying a characteristic caspase-associated recruitment domain (CARD). This protein shares a similar domain structure with CARD11 protein. The CARD domains of both proteins have been shown to specifically interact with BCL10, a protein known to function as a positive regulator of cell apoptosis and NF-κB activation. The homotypic interaction with BCL10 is believed to be prevented by the linker region of CARD14, when in an inactive state.[4] CARD14 overexpression leads to an activation of the transcription factor NF-κB and phosphorylation of BCL10. CARD14 has been shown to form a CBM signalosome, similar to the signalling of CARD11, with BCL10 and MALT1.[1][4]
# Link to Psoriasis
The CARD14 gene was recently identified as the first gene directly linked to the most common form of Psoriasis. It has been suggested that a mutation in the gene plus an environmental trigger were enough to elicit plaque psoriasis.[5][6] These rare, but highly penetrant, mutations were found to disrupt an auto-inhibited state of CARD14, which leads to the binding of BCL10 and the activation of NF-κB.[4] | https://www.wikidoc.org/index.php/CARD14 | |
7faa287b0bf9d13f6e9aa2d5353446cc1897fd45 | wikidoc | CC2D2A | CC2D2A
Coiled-coil and C2 domain-containing protein 2A that in humans is encoded by the CC2D2A gene.
# Function
This gene encodes a coiled-coil and calcium binding domain protein that appears to play a critical role in cilia formation.
# Clinical significance
Mutations in the CC2D2A gene are associated with Meckel syndrome as well as Joubert syndrome. | CC2D2A
Coiled-coil and C2 domain-containing protein 2A that in humans is encoded by the CC2D2A gene.[1][2][3]
# Function
This gene encodes a coiled-coil and calcium binding domain protein that appears to play a critical role in cilia formation.[1]
# Clinical significance
Mutations in the CC2D2A gene are associated with Meckel syndrome as well as Joubert syndrome.[1] | https://www.wikidoc.org/index.php/CC2D2A | |
114d7597a4bb1512d389509de0ec2b0f8cd97410 | wikidoc | CCDC22 | CCDC22
Coiled-coil domain containing 22 is a protein that in humans is encoded by the CCDC22 gene.
# Function
This gene encodes a protein containing a coiled-coil domain. The encoded protein functions in the regulation of NF-kB (nuclear factor kappa-light-chain-enhancer of activated B cells) by interacting with COMMD (copper metabolism Murr1 domain-containing) proteins. The mouse orthologous protein has been shown to bind copines, which are calcium-dependent, membrane-binding proteins that may function in calcium signaling. This human gene has been identified as a novel candidate gene for syndromic X-linked intellectual disability.
# Clinical significance
Mutations in CCDC22 are associated to Ritscher-Schinzel syndrome . | CCDC22
Coiled-coil domain containing 22 is a protein that in humans is encoded by the CCDC22 gene.[1]
# Function
This gene encodes a protein containing a coiled-coil domain. The encoded protein functions in the regulation of NF-kB (nuclear factor kappa-light-chain-enhancer of activated B cells) by interacting with COMMD (copper metabolism Murr1 domain-containing) proteins. The mouse orthologous protein has been shown to bind copines, which are calcium-dependent, membrane-binding proteins that may function in calcium signaling. This human gene has been identified as a novel candidate gene for syndromic X-linked intellectual disability.
# Clinical significance
Mutations in CCDC22 are associated to Ritscher-Schinzel syndrome .[2] | https://www.wikidoc.org/index.php/CCDC22 | |
d3f4abbaeb8e76cfca2f696329830a1f6aa8654c | wikidoc | CCDC47 | CCDC47
Coiled-coil domain 47 (CCDC47) is a gene located on human chromosome 17, specifically locus 17q23.3 which encodes for the protein CCDC47. The gene has several aliases including GK001 and MSTP041. The protein itself contains coiled-coil domains, the SEEEED superfamily, a domain of unknown function (DUF1682) and a transmembrane domain. The function of the protein is unknown, but it has been proposed that CCDC47 is involved in calcium ion homeostasis and the endoplasmic reticulum overload response.
# Gene
The CCDC47 gene itself is located on the minus strand of human chromosome 17 and contains 13 exon splice sites and 14 distinct introns. After removal of exons, the gene is 3445 base pairs in length. No evidence for micro RNA or pseudogenes has been found. The gene does not have various isoforms, only transcript variant 1X exists.
# Protein
## Structure
The protein encoded by CCDC47 is 483 amino acids in length and contains both a signal peptide and transmembrane domain. It is rich in negatively charged amino acids such as aspartic acid and glutamic acid giving it an acidic isoelectric point of 4.56. The protein is also rich in methionine. In total, it weighs 55.9 kDal which is conserved through various orthologs. CCDC47 also contains the SEEEED superfamily and domain of unknown function 1682 (DUF1682). The SEEEED superfamily is a short, low complexity region which is composed mainly of serine. The family routinely lies on the clathrin adaptor complex 3 beta-1 subunit proteins. The exact function of DUF 1682 is unclear but one member of the family has been described as an adipocyte-specific protein.
There are two predicted disulfide bonds in the structure of CCDC47 at cysteines 209 to 214 and cysteines 215 to 283, respectively. The C-terminal portion of the protein is highly charged and its secondary structure is predicted to be that of an alpha helix region. This region also contains coiled coil domains which are structural motifs in which 2-7 alpha helices are coiled together and are subsequently involved in biological expression. These domains typically follow the pattern HxxHCxC where H is a hydrophobic amino acid, C is a charged amino acid and x is any amino acid. Many amino acid sequences following this pattern are seen in the C-terminal region of CCDC47 where the highest conservation through orthologs is represented.
## Regulation and translation
CCDC47 is regulated by the promoter GXP43413. The promoter is 819 base pairs in length and is highly conserved in mammals. Conserved binding sites in mammals which are located on this promoter include Nuclear Respiratory Factor 1 (NFR1), cAMP-responsive element binding protein (CREB), PAR b ZIP family and Sp4 Transcription Factor. NRF1 encodes a protein which homodimerizes and activates expression of key metabolic genes. CREB binds to cAMP response elements thereby increasing or decreasing the transcription of downstream genes while PAR b ZIP family is involved in the regulation of circadian rhythms.
In regards to the mRNA, translation begins at base pair 337 and ends at 1728. There is a strong stem loop located in the 5' UTR region from bases 289-318 which likely is involved in regulation of the mRNA due to its close proximity to the start codon.
## Cellular distribution
The final protein is thought to be translated from the endoplasmic reticulum into the cytoplasm of the cell. The protein is anchored in the membrane of the ER at the transmembrane domain located from amino acid 137 to 165. The portion of the protein which extends into the cytosol is predicted to be highly phosphorylated as the protein's phosphorylation sites are conserved into the bony fish orthologs. Research has shown that CCDC47 is expressed in the response to an ER overload making this close proximity to the ER important.
## Post translational modification
In addition to the high levels of phosphorylation seen in CCDC47, three sulfination sites are predicted and conserved in mammals, reptiles and birds but not in fish, amphibians or invertebrates. Five potential sumoylation sites are also seen and conserved back to the bony fish. There is no glycosylation of the protein as it is not predicted to extend into the extracellular portion of the cell.
# Expression
Microarray tissue expression patterns from GEO were analyzed and showed that CCDC47 appears to be an ubiquitously expressed at moderate levels in many different human tissues. Although the protein is ubiquitously expressed, the highest levels of expression are seen in neuronal tissues such as the superior cervical ganglion, brain amygdala and ciliary ganglion. Elevated expression is also seen in the thyroid and CD34+ cells.
# Homology
CCDC47 has no known paralogs through text based queries, BLAST and BLAT. The gene has many orthologs extending back to invertebrates such as C. elegans and is highly conserved in mammals with a percent identity greater than 95%. CCDC47 has been sequenced in a wide taxonomy of organisms including mammals, birds, reptiles, amphibians, bony fish and invertebrates. Percent identity of human CCDC47 to a specific ortholog declines with increasing years of divergence, as expected. Homologous genes of CCDC47 are also present in mosquitos, mushrooms, arabidopsis and Asian rice. These homologs contain the same DUF1682 which is found in CCDC47. | CCDC47
Coiled-coil domain 47 (CCDC47) is a gene located on human chromosome 17, specifically locus 17q23.3 which encodes for the protein CCDC47. The gene has several aliases including GK001 and MSTP041. The protein itself contains coiled-coil domains, the SEEEED superfamily, a domain of unknown function (DUF1682) and a transmembrane domain. The function of the protein is unknown, but it has been proposed that CCDC47 is involved in calcium ion homeostasis and the endoplasmic reticulum overload response.[1]
# Gene
The CCDC47 gene itself is located on the minus strand of human chromosome 17 and contains 13 exon splice sites and 14 distinct introns. After removal of exons, the gene is 3445 base pairs in length. No evidence for micro RNA or pseudogenes has been found. The gene does not have various isoforms, only transcript variant 1X exists.
# Protein
## Structure
The protein encoded by CCDC47 is 483 amino acids in length and contains both a signal peptide and transmembrane domain. It is rich in negatively charged amino acids such as aspartic acid and glutamic acid giving it an acidic isoelectric point of 4.56.[3] The protein is also rich in methionine. In total, it weighs 55.9 kDal which is conserved through various orthologs. CCDC47 also contains the SEEEED superfamily and domain of unknown function 1682 (DUF1682). The SEEEED superfamily is a short, low complexity region which is composed mainly of serine. The family routinely lies on the clathrin adaptor complex 3 beta-1 subunit proteins.[4] The exact function of DUF 1682 is unclear but one member of the family has been described as an adipocyte-specific protein.[5]
There are two predicted disulfide bonds in the structure of CCDC47 at cysteines 209 to 214 and cysteines 215 to 283, respectively.[6] The C-terminal portion of the protein is highly charged and its secondary structure is predicted to be that of an alpha helix region.[7] This region also contains coiled coil domains which are structural motifs in which 2-7 alpha helices are coiled together and are subsequently involved in biological expression. These domains typically follow the pattern HxxHCxC where H is a hydrophobic amino acid, C is a charged amino acid and x is any amino acid.[8] Many amino acid sequences following this pattern are seen in the C-terminal region of CCDC47 where the highest conservation through orthologs is represented.
## Regulation and translation
CCDC47 is regulated by the promoter GXP43413.[9] The promoter is 819 base pairs in length and is highly conserved in mammals. Conserved binding sites in mammals which are located on this promoter include Nuclear Respiratory Factor 1 (NFR1), cAMP-responsive element binding protein (CREB), PAR b ZIP family and Sp4 Transcription Factor. NRF1 encodes a protein which homodimerizes and activates expression of key metabolic genes. CREB binds to cAMP response elements thereby increasing or decreasing the transcription of downstream genes[10] while PAR b ZIP family is involved in the regulation of circadian rhythms.[11]
In regards to the mRNA, translation begins at base pair 337 and ends at 1728. There is a strong stem loop located in the 5' UTR region from bases 289-318 which likely is involved in regulation of the mRNA due to its close proximity to the start codon.[12]
## Cellular distribution
The final protein is thought to be translated from the endoplasmic reticulum into the cytoplasm of the cell. The protein is anchored in the membrane of the ER at the transmembrane domain located from amino acid 137 to 165.[13] The portion of the protein which extends into the cytosol is predicted to be highly phosphorylated as the protein's phosphorylation sites are conserved into the bony fish orthologs.[14] Research has shown that CCDC47 is expressed in the response to an ER overload making this close proximity to the ER important.[15]
## Post translational modification
In addition to the high levels of phosphorylation seen in CCDC47, three sulfination sites are predicted and conserved in mammals, reptiles and birds but not in fish, amphibians or invertebrates.[16] Five potential sumoylation sites are also seen and conserved back to the bony fish.[17] There is no glycosylation of the protein as it is not predicted to extend into the extracellular portion of the cell.
# Expression
Microarray tissue expression patterns from GEO were analyzed and showed that CCDC47 appears to be an ubiquitously expressed at moderate levels in many different human tissues.[18] Although the protein is ubiquitously expressed, the highest levels of expression are seen in neuronal tissues such as the superior cervical ganglion, brain amygdala and ciliary ganglion. Elevated expression is also seen in the thyroid and CD34+ cells.
# Homology
CCDC47 has no known paralogs through text based queries, BLAST and BLAT. The gene has many orthologs extending back to invertebrates such as C. elegans and is highly conserved in mammals with a percent identity greater than 95%. CCDC47 has been sequenced in a wide taxonomy of organisms including mammals, birds, reptiles, amphibians, bony fish and invertebrates. Percent identity of human CCDC47 to a specific ortholog declines with increasing years of divergence, as expected. Homologous genes of CCDC47 are also present in mosquitos, mushrooms, arabidopsis and Asian rice. These homologs contain the same DUF1682 which is found in CCDC47. | https://www.wikidoc.org/index.php/CCDC47 | |
998a7fb16981baa509fdabe9f1ab56c2c3efcf2b | wikidoc | CCDC57 | CCDC57
Coiled-coil domain-containing protein 57 is a protein that in humans is encoded by the CCDC57 gene.
# Model organisms
Model organisms have been used in the study of CCDC57 function. A conditional knockout mouse line, called Ccdc57tm1a(EUCOMM)Wtsi was generated as part of the International Knockout Mouse Consortium program — a high-throughput mutagenesis project to generate and distribute animal models of disease to interested scientists.
Male and female animals underwent a standardized phenotypic screen to determine the effects of deletion. Twenty six tests were carried out on mutant mice and two significant abnormalities were observed. The animals displayed hydrocephaly and had abnormal hypodermis fat layer morphology. | CCDC57
Coiled-coil domain-containing protein 57 is a protein that in humans is encoded by the CCDC57 gene.[1]
# Model organisms
Model organisms have been used in the study of CCDC57 function. A conditional knockout mouse line, called Ccdc57tm1a(EUCOMM)Wtsi[6][7] was generated as part of the International Knockout Mouse Consortium program — a high-throughput mutagenesis project to generate and distribute animal models of disease to interested scientists.[8][9][10]
Male and female animals underwent a standardized phenotypic screen to determine the effects of deletion.[4][11] Twenty six tests were carried out on mutant mice and two significant abnormalities were observed.[4] The animals displayed hydrocephaly and had abnormal hypodermis fat layer morphology.[4] | https://www.wikidoc.org/index.php/CCDC57 | |
35269c32b9c13897a23f9e32fb0f598580ffed76 | wikidoc | CCDC82 | CCDC82
Coiled-Coil Domain Containing protein 82 (CCDC82) is a protein that in humans, is encoded for by the gene of the same name, CCDC82. The CCDC82 gene is expressed in nearly all of human tissues at somewhat low rates. As of today, there are no patents involving CCDC82 and the function remains unknown.
# Gene
CCDC82 is located on chromosome 11 at 11q21.5.
It contains two domains of unknown function, DUF4196 and DUF4211. The DNA sequence is 37,155 base pairs long and contains 7 exons.
## Homology
CCDC82 is present in many orthologs. It is conserved throughout other mammals, reptiles, birds and bony fish. It is not found in invertebrates, bacteria or fungi. There are no paralogs.
# mRNA
## Promoter
The predicted promoter for CCDC82 is located on the minus strand and spans from base pairs 96,122,963 to 96,123,587. It is 625 base pairs long.
## Transcription factors
The transcription factors listed below are for the predicted promoter sequence and are located on the minus strand.
# Protein
The protein it encodes for is 344 amino acids in length. The protein itself is very acidic and is very rich in aspartic acid and glutamic acid. It is also very deficient in alanine, containing only two alanines in the entire sequence. The alanines are located adjacent to each other, amino acid number 233 and 234. Alanine 233 is highly conserved throughout the orthologs. The molecular weight is 40.0 kdal and the isoelectric point is 4.383
## Expression
CCDC82 is found in nearly all tissues in the human body, however it is present in higher quantities in the skeletal muscles, adrenal cortex, and the trigeminal ganglion.
## Post translational modifications
CCDC82 has several predicted phosphorylation sites. There are 32 predicted serine phosphorylation sites, 5 threonine, and 3 tyrosine.
## Interactions
CCDC82 is known to interact with two proteins. It indirectly interacts with VHL, a gene that encodes for a tumor suppressor and ubiquitin protein ligase. It also interacts with EWSR1, which functions as a transcriptional repressor.
# Clinical significance
CCDC82 is a circulat-responsive gene. Circulat is a product designed to restore systemic vascular health. It is a plant based product and taken by patients who suffer from diabetes or circulatory problems.
## Possible function
Based on the information that CCDC82 is affected by the Circulat product it could be hypothesized that CCDC82 is involved in circulatory function. However, this is purely speculation. | CCDC82
Coiled-Coil Domain Containing protein 82 (CCDC82) is a protein that in humans, is encoded for by the gene of the same name, CCDC82. The CCDC82 gene is expressed in nearly all of human tissues at somewhat low rates. As of today, there are no patents involving CCDC82 and the function remains unknown.
# Gene
CCDC82 is located on chromosome 11 at 11q21.5.[1]
It contains two domains of unknown function, DUF4196 and DUF4211.[2] The DNA sequence is 37,155 base pairs long[3] and contains 7 exons.[4]
## Homology
CCDC82 is present in many orthologs. It is conserved throughout other mammals, reptiles, birds and bony fish. It is not found in invertebrates, bacteria or fungi. There are no paralogs.[5]
# mRNA
## Promoter
The predicted promoter for CCDC82 is located on the minus strand and spans from base pairs 96,122,963 to 96,123,587. It is 625 base pairs long.[6]
## Transcription factors
The transcription factors listed below are for the predicted promoter sequence and are located on the minus strand.[7]
# Protein
The protein it encodes for is 344 amino acids in length. The protein itself is very acidic and is very rich in aspartic acid and glutamic acid. It is also very deficient in alanine, containing only two alanines in the entire sequence. The alanines are located adjacent to each other, amino acid number 233 and 234. Alanine 233 is highly conserved throughout the orthologs. The molecular weight is 40.0 kdal and the isoelectric point is 4.383[8]
## Expression
CCDC82 is found in nearly all tissues in the human body, however it is present in higher quantities in the skeletal muscles, adrenal cortex, and the trigeminal ganglion.[9][10]
## Post translational modifications
CCDC82 has several predicted phosphorylation sites.[11] There are 32 predicted serine phosphorylation sites, 5 threonine, and 3 tyrosine.[12]
## Interactions
CCDC82 is known to interact with two proteins. It indirectly interacts with VHL, a gene that encodes for a tumor suppressor and ubiquitin protein ligase. It also interacts with EWSR1, which functions as a transcriptional repressor.[13]
# Clinical significance
CCDC82 is a circulat-responsive gene.[14] Circulat is a product designed to restore systemic vascular health. It is a plant based product and taken by patients who suffer from diabetes or circulatory problems.[15]
## Possible function
Based on the information that CCDC82 is affected by the Circulat product it could be hypothesized that CCDC82 is involved in circulatory function. However, this is purely speculation. | https://www.wikidoc.org/index.php/CCDC82 | |
70780c0de7a085188893b9bc815350dc52bb2556 | wikidoc | CCDC94 | CCDC94
Coiled-coil domain containing 94 (CCDC94), is a protein that in humans is encoded by the CCDC94 gene. The CCDC94 protein contains a coiled-coil domain, a domain of unknown function (DUF572), an uncharacterized conserved protein (COG5134), and lacks a transmembrane domain.
# Gene
## Overview
CCDC94 is a 21,975 basepair gene orientated on the plus strand (see Sense) of chromosome 19 from 4,247,111-4,269,085. The gene product is a 1,441 base pair mRNA with 8 predicted exons in the human gene. As predicted by Ensemble, there exists one protein-coding alternative splice form. This splice form contains 5 exons, and 4 of them are coding exons. Promoter prediction and analysis was carried out using ElDorado. The predicted promoter region spans 714 basepairs from 4,246,532 to 4,247,245 on the plus strand of chromosome 19.
## Gene neighborhood
CCDC94 is located directly adjacent to the EBI3 gene (4,229,540-4,237,525) on the positive DNA strand. The SH2 domain gene (4,278,598-4,290,720) lies upstream from CCDC94 on the positive strand.
## Gene expression
CCDC94 is expressed in low to moderate levels throughout most regions of the body. However, slightly elevated levels of CCDC94 are expressed in the thyroid, lung, dendritic cells, and lymphoblasts. Expression data is available at BioGPS. GEO expression data is available from NCBI.
# Protein
## Properties and characteristics
CCDC94 belongs to the CWC16 family and its function is not well understood. The human form as 323 amino acid residues, with an isoelectric point of 5.618 and a molecular mass of 37,086 Daltons. There are no predicted transmembrane domains. The one alternative splice form of CCDC94 encodes for a protein with 161 amino acids. A DUF572 and COG5134 domains are located at residues 1-319 and 7-108, respectively. The coiled-coil domain region is located at residues 105-206. The intracellular localization of CCDC94 has not yet been experimentally determined, but bioinformatic analysis using PSORT highly suggests CCDC94 resides in the nucleus due to the presence of nuclear localization signals.
## Protein interactions
Protein interaction analysis for CCDC94 has been carried out using computational tools. No interactions were identified through the MINT database. CCDC94 is shown to interact with CDC5L, PLRG1, and PRPF19 with the highest score based on an anti tag coimmunoprecipitation assay. 6 additional interacting proteins were found. Closer analysis shows very little potential for these interactions to be real, thus none should be considered actual protein-protein interactions. The protein interaction from the STRING analysis is shown.
### Transcription factors
CCDC94 has a promoter region that contains sites for transcription factor binding. Notable transcription factors, as generated by the ElDorado program on Genomatix:
- Myeloid zinc finger protein (MZF1)
- Forkhead box H1 (Foxh1)
- Polyomavirus enhancer A binding protein 3 (ETV4)
- E2F-myc activator/cell cycle regulator (E2F)
- SPI-1 proto-oncogene; hematopoietic transcription factor (PU1)
## Post-translational modifications
Bioinformatic analysis of CCDC94 using NetPhos predicted 7 phosphorylation sites at serine residues, 3 at threonine residues, and 3 at tyrosine residues. Two of the threonine and all of the tyrosine phosphorylated residues are highly conserved as supported by their occurrence at the same location in several analyzed orthologs. Predicted phosphorylated tyrosines with high scores occurred on the N-terminus half of CCDC94 while serine residues are phosphorylated on the C-terminus half. Sulfinator predicted only one tyrosine sulfination site at amino acid 98. Highly probably summoylation sites at residues 90, 24, and 270 were predicted by SUMOplot.
## Tertiary structure
The tertiary structure of CCDC94 was shown to have several beta sheet regions and only one highly predicted alpha helix region. The PHYRE2 analysis of 65 residues of CCDC94, 20% of the entire amino acid sequence, was modeled with 87.9% confidence.
# Homology
## Orthologs
CCDC94 is very well conserved in many species, and the entire protein is conserved throughout all of its orthologs. However, conservation does not extend as far back as bacteria. A phylogenetic tree, generated from Biology WorkBench shows the evolutionary relationships between Homo sapiens CCDC94 and its orthologs.
The table below show CCDC94 conservation among orthologs:
## Paralogs
CCDC94 has only one paralog, CCDC130 or MGC10471. CCDC130 is very similar to CCDC94, as it contains both the DUF572 and COG5134 domain. | CCDC94
Coiled-coil domain containing 94 (CCDC94), is a protein that in humans is encoded by the CCDC94 gene.[1] The CCDC94 protein contains a coiled-coil domain, a domain of unknown function (DUF572), an uncharacterized conserved protein (COG5134), and lacks a transmembrane domain.
# Gene
## Overview
CCDC94 is a 21,975 basepair gene orientated on the plus strand (see Sense) of chromosome 19 from 4,247,111-4,269,085.[1] The gene product is a 1,441 base pair mRNA with 8 predicted exons in the human gene. As predicted by Ensemble, there exists one protein-coding alternative splice form.[3] This splice form contains 5 exons, and 4 of them are coding exons. Promoter prediction and analysis was carried out using ElDorado.[4] The predicted promoter region spans 714 basepairs from 4,246,532 to 4,247,245 on the plus strand of chromosome 19.
## Gene neighborhood
CCDC94 is located directly adjacent to the EBI3 gene (4,229,540-4,237,525) on the positive DNA strand. The SH2 domain gene (4,278,598-4,290,720) lies upstream from CCDC94 on the positive strand.[5]
## Gene expression
CCDC94 is expressed in low to moderate levels throughout most regions of the body. However, slightly elevated levels of CCDC94 are expressed in the thyroid, lung, dendritic cells, and lymphoblasts. Expression data is available at BioGPS.[6] GEO expression data is available from NCBI.[7]
# Protein
## Properties and characteristics
CCDC94 belongs to the CWC16 family[8] and its function is not well understood. The human form as 323 amino acid residues, with an isoelectric point of 5.618 and a molecular mass of 37,086 Daltons. There are no predicted transmembrane domains.[9] The one alternative splice form of CCDC94 encodes for a protein with 161 amino acids.[10] A DUF572 and COG5134 domains are located at residues 1-319 and 7-108, respectively.[11] The coiled-coil domain region is located at residues 105-206.[12] The intracellular localization of CCDC94 has not yet been experimentally determined, but bioinformatic analysis using PSORT highly suggests CCDC94 resides in the nucleus due to the presence of nuclear localization signals.[13]
## Protein interactions
Protein interaction analysis for CCDC94 has been carried out using computational tools. No interactions were identified through the MINT database.[14] CCDC94 is shown to interact with CDC5L, PLRG1, and PRPF19 with the highest score based on an anti tag coimmunoprecipitation assay.[15] 6 additional interacting proteins were found. Closer analysis shows very little potential for these interactions to be real, thus none should be considered actual protein-protein interactions. The protein interaction from the STRING analysis is shown.
### Transcription factors
CCDC94 has a promoter region that contains sites for transcription factor binding. Notable transcription factors, as generated by the ElDorado program on Genomatix:[16]
- Myeloid zinc finger protein (MZF1)
- Forkhead box H1 (Foxh1)
- Polyomavirus enhancer A binding protein 3 (ETV4)
- E2F-myc activator/cell cycle regulator (E2F)
- SPI-1 proto-oncogene; hematopoietic transcription factor (PU1)
## Post-translational modifications
Bioinformatic analysis of CCDC94 using NetPhos[17] predicted 7 phosphorylation sites at serine residues, 3 at threonine residues, and 3 at tyrosine residues. Two of the threonine and all of the tyrosine phosphorylated residues are highly conserved as supported by their occurrence at the same location in several analyzed orthologs. Predicted phosphorylated tyrosines with high scores occurred on the N-terminus half of CCDC94 while serine residues are phosphorylated on the C-terminus half. Sulfinator predicted only one tyrosine sulfination site at amino acid 98.[18] Highly probably summoylation sites at residues 90, 24, and 270 were predicted by SUMOplot.[19]
## Tertiary structure
The tertiary structure of CCDC94 was shown to have several beta sheet regions and only one highly predicted alpha helix region. The PHYRE2 analysis of 65 residues of CCDC94, 20% of the entire amino acid sequence, was modeled with 87.9% confidence.[20]
# Homology
## Orthologs
CCDC94 is very well conserved in many species, and the entire protein is conserved throughout all of its orthologs.[21] However, conservation does not extend as far back as bacteria. A phylogenetic tree, generated from Biology WorkBench[22] shows the evolutionary relationships between Homo sapiens CCDC94 and its orthologs.
The table below show CCDC94 conservation among orthologs:
## Paralogs
CCDC94 has only one paralog, CCDC130 or MGC10471.[24] CCDC130 is very similar to CCDC94, as it contains both the DUF572 and COG5134 domain.[25] | https://www.wikidoc.org/index.php/CCDC94 | |
093068a8045c302c04b176431ba491221f583535 | wikidoc | CCHCR1 | CCHCR1
Coiled-coil alpha-helical rod protein 1, also known as CCHCR1, is a protein which in humans is encoded by the CCHCR1 gene.
# Gene
The Human CCHCR1 gene is located at 6p21.33. It is also known as Coiled-Coil Alphahelical Rod Protein 1, C6orf18, Putative Gene 8 Protein, SBP, HCR (A-Helix Coiled-Coil Rod Homologue), pg8, StAR-Binding Protein, and Pg8.
# Homology
Homologes for CCHCR1 are conserved through tetrapods.
## Paralogs
## Orthologs
CCHCR1 has orthologs throughout vertebrates.
## Distant Homologs
## Homologous Domains
## Phylogeny
Phylogenetic analysis with ClustalW indicated that CCHCR1
The CCHCR1 gene has
# Protein
## Structure
The structure of CCHCR1 is primarily composed of alpha-helices, coils, and a small amount of beta sheets, according to PELE.
# Expression
# Function
May be a regulator of keratinocyte proliferation or differentiation.
# Interacting Proteins
CCHCR1 has been shown to interact with POLR2C,
KRT17
, TOP3B, Steroidogenic acute regulatory protein, TRAF4, HLA-C, TCF19, SNX29, EEF1D, and EEF1B2.
# Clinical significance
In genetically engineered mice, certain CCHCR1 polymorphisms cause upregulation of the expression of cytokeratins 6 (KRT6A), 16 (KRT16) and 17 (KRT17) and change in expression in other genes associated with terminal differentiation and formation of the cornified cell envelope. These CCHCR1 polymorphisms may therefore be associated with a susceptibility to psoriasis. Defective functioning of CCHCR1 may lead to abnormal keratinocyte proliferation which is a key feature of psoriasis.
CCHCR1 polymorphisms have also been found to be associated with multiple sclerosis. | CCHCR1
Coiled-coil alpha-helical rod protein 1, also known as CCHCR1, is a protein which in humans is encoded by the CCHCR1 gene.[1][2][3]
# Gene
The Human CCHCR1 gene is located at 6p21.33. It is also known as Coiled-Coil Alphahelical Rod Protein 1, C6orf18, Putative Gene 8 Protein, SBP, HCR (A-Helix Coiled-Coil Rod Homologue), pg8, StAR-Binding Protein, and Pg8.
# Homology
Homologes for CCHCR1 are conserved through tetrapods.
## Paralogs
## Orthologs
CCHCR1 has orthologs throughout vertebrates.
## Distant Homologs
## Homologous Domains
## Phylogeny
Phylogenetic analysis with ClustalW indicated that CCHCR1
The CCHCR1 gene has
# Protein
## Structure
The structure of CCHCR1 is primarily composed of alpha-helices, coils[clarification needed], and a small amount of beta sheets, according to PELE.[4]
# Expression
# Function
May be a regulator of keratinocyte proliferation or differentiation.
# Interacting Proteins
CCHCR1 has been shown to interact with POLR2C,[5]
KRT17
,[6] TOP3B,[7] Steroidogenic acute regulatory protein,[6] TRAF4,[8] HLA-C,[9] TCF19,[9] SNX29,[10] EEF1D,[11] and EEF1B2.[11]
# Clinical significance
In genetically engineered mice, certain CCHCR1 polymorphisms cause upregulation of the expression of cytokeratins 6 (KRT6A), 16 (KRT16) and 17 (KRT17) and change in expression in other genes associated with terminal differentiation and formation of the cornified cell envelope. These CCHCR1 polymorphisms may therefore be associated with a susceptibility to psoriasis.[12] Defective functioning of CCHCR1 may lead to abnormal keratinocyte proliferation which is a key feature of psoriasis.[13]
CCHCR1 polymorphisms have also been found to be associated with multiple sclerosis.[14] | https://www.wikidoc.org/index.php/CCHCR1 | |
1944f390311d7a48fa67baa60050c9bf87436865 | wikidoc | CCL3L1 | CCL3L1
Chemokine (C-C motif) ligand 3-like 1, also known as CCL3L1, is a protein which in humans is encoded by the CCL3L1 gene.
# Function
This gene is one of several chemokine genes clustered on the q-arm of chromosome 17. Chemokines are a family of secreted proteins involved in immunoregulatory and inflammatory processes. Specifically, chemokines attract lymphocytes to sites of infection or damage. This protein binds to several chemokine receptors including chemokine binding protein 2 (CCBP2 or D6) and chemokine (C-C motif) receptor 5 (CCR5).
CCR5 is a co-receptor for HIV, and binding of CCL3L1 to CCR5 inhibits HIV entry. Furthermore, the binding causes the receptor to be taken inside the cell by endocytosis, to eventually be reprocessed and re-expressed.
# Gene organization
The human genome reference assembly contains two full copies of the gene (CCL3L1 and CCL3L3) and an additional partial duplication, which is thought to result in a pseudogene, designated CCL3L2. This record represents the more telomeric full-length gene.
# Clinical significance
The copy number of this gene varies among individuals. This is hypothesized to be due to segmental duplication of the region containing CCL3. Most individuals have 1-6 copies in the diploid genome, although rare individuals have zero or more than six copies. With increased copy number, there is more CCL3L1 expressed, and so competition for the CCR5 binding site is increased. This leads to slower advancement of disease in HIV-infected individuals, giving those with greater copy number more resistance.
# Interactions
CCL3L1 has been shown to interact with CCR5. | CCL3L1
Chemokine (C-C motif) ligand 3-like 1, also known as CCL3L1, is a protein which in humans is encoded by the CCL3L1 gene.[1][2][3]
# Function
This gene is one of several chemokine genes clustered on the q-arm of chromosome 17. Chemokines are a family of secreted proteins involved in immunoregulatory and inflammatory processes. Specifically, chemokines attract lymphocytes to sites of infection or damage. This protein binds to several chemokine receptors including chemokine binding protein 2 (CCBP2 or D6) and chemokine (C-C motif) receptor 5 (CCR5).
CCR5 is a co-receptor for HIV, and binding of CCL3L1 to CCR5 inhibits HIV entry. Furthermore, the binding causes the receptor to be taken inside the cell by endocytosis, to eventually be reprocessed and re-expressed.[1]
# Gene organization
The human genome reference assembly contains two full copies of the gene (CCL3L1 and CCL3L3) and an additional partial duplication, which is thought to result in a pseudogene, designated CCL3L2. This record represents the more telomeric full-length gene.[1]
# Clinical significance
The copy number of this gene varies among individuals. This is hypothesized to be due to segmental duplication of the region containing CCL3. Most individuals have 1-6 copies in the diploid genome, although rare individuals have zero or more than six copies. With increased copy number, there is more CCL3L1 expressed, and so competition for the CCR5 binding site is increased. This leads to slower advancement of disease in HIV-infected individuals, giving those with greater copy number more resistance.[1]
# Interactions
CCL3L1 has been shown to interact with CCR5.[4][5] | https://www.wikidoc.org/index.php/CCL3L1 | |
0522aac3fe125dc2800e84a85e2a57fc03f13946 | wikidoc | VCAM-1 | VCAM-1
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Vascular cell adhesion protein 1 also known as vascular cell adhesion molecule 1 (VCAM-1) or cluster of differentiation 106 (CD106) is a protein that in humans is encoded by the VCAM1 gene. VCAM-1 functions as a cell adhesion molecule.
# Structure
The VCAM-1 gene contains six or seven immunoglobulin domains, and is expressed on both large and small blood vessels only after the endothelial cells are stimulated by cytokines. It is alternatively spliced into two known RNA transcripts that encode different isoforms in humans. The gene product is a cell surface sialoglycoprotein, a type I membrane protein that is a member of the Ig superfamily.
# Function
The VCAM-1 protein mediates the adhesion of lymphocytes, monocytes, eosinophils, and basophils to vascular endothelium. It also functions in leukocyte-endothelial cell signal transduction, and it may play a role in the development of atherosclerosis and rheumatoid arthritis.
Upregulation of VCAM-1 in endothelial cells by cytokines occurs as a result of increased gene transcription (e.g., in response to Tumor necrosis factor-alpha (TNF-α) and Interleukin-1 (IL-1)) and through stabilization of Messenger RNA (mRNA) (e.g., Interleukin-4 (IL-4)). The promoter region of the VCAM-1 gene contains functional tandem NF-κB (nuclear factor-kappa B) sites. The sustained expression of VCAM-1 lasts over 24 hours.
Primarily, the VCAM-1 protein is an endothelial ligand for VLA-4 (Very Late Antigen-4 or integrin α4β1) of the β1 subfamily of integrins. VCAM-1 expression has also been observed in other cell types (e.g., smooth muscle cells). It has also been shown to interact with EZR and Moesin.
CD106 also exists on the surface of some subpopulations of mesenchymal stem cells(MSC).
# Pharmacology
Certain melanoma cells can use VCAM-1 to adhere to the endothelium, and VCAM-1 may participate in monocyte recruitment to atherosclerotic sites. As a result, VCAM-1 is a potential drug target. | VCAM-1
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Vascular cell adhesion protein 1 also known as vascular cell adhesion molecule 1 (VCAM-1) or cluster of differentiation 106 (CD106) is a protein that in humans is encoded by the VCAM1 gene.[1] VCAM-1 functions as a cell adhesion molecule.
# Structure
The VCAM-1 gene contains six or seven immunoglobulin domains, and is expressed on both large and small blood vessels only after the endothelial cells are stimulated by cytokines. It is alternatively spliced into two known RNA transcripts that encode different isoforms in humans.[2] The gene product is a cell surface sialoglycoprotein, a type I membrane protein that is a member of the Ig superfamily.
# Function
The VCAM-1 protein mediates the adhesion of lymphocytes, monocytes, eosinophils, and basophils to vascular endothelium. It also functions in leukocyte-endothelial cell signal transduction, and it may play a role in the development of atherosclerosis and rheumatoid arthritis.
Upregulation of VCAM-1 in endothelial cells by cytokines occurs as a result of increased gene transcription (e.g., in response to Tumor necrosis factor-alpha (TNF-α) and Interleukin-1 (IL-1)) and through stabilization of Messenger RNA (mRNA) (e.g., Interleukin-4 (IL-4)). The promoter region of the VCAM-1 gene contains functional tandem NF-κB (nuclear factor-kappa B) sites. The sustained expression of VCAM-1 lasts over 24 hours.
Primarily, the VCAM-1 protein is an endothelial ligand for VLA-4 (Very Late Antigen-4 or integrin α4β1) of the β1 subfamily of integrins. VCAM-1 expression has also been observed in other cell types (e.g., smooth muscle cells). It has also been shown to interact with EZR[3] and Moesin.[3]
CD106 also exists on the surface of some subpopulations of mesenchymal stem cells(MSC).[4]
# Pharmacology
Certain melanoma cells can use VCAM-1 to adhere to the endothelium,[5] and VCAM-1 may participate in monocyte recruitment to atherosclerotic sites. As a result, VCAM-1 is a potential drug target. | https://www.wikidoc.org/index.php/CD106 | |
b0e78b280dcb0ca0083aa2a24652696e2ad4cfd3 | wikidoc | ICAM-1 | ICAM-1
ICAM-1 (Intercellular Adhesion Molecule 1) also known as CD54 (Cluster of Differentiation 54) is a protein that in humans is encoded by the ICAM1 gene. This gene encodes a cell surface glycoprotein which is typically expressed on endothelial cells and cells of the immune system. It binds to integrins of type CD11a / CD18, or CD11b / CD18 and is also exploited by rhinovirus as a receptor for entry into respiratory epithelium.
# Structure
ICAM-1 is a member of the immunoglobulin superfamily, the superfamily of proteins including antibodies and T-cell receptors. ICAM-1 is a transmembrane protein possessing an amino-terminus extracellular domain, a single transmembrane domain, and a carboxy-terminus cytoplasmic domain. The structure of ICAM-1 is characterized by heavy glycosylation, and the protein’s extracellular domain is composed of multiple loops created by disulfide bridges within the protein. The dominant secondary structure of the protein is the beta sheet, leading researchers to hypothesize the presence of dimerization domains within ICAM-1.
# Function
The protein encoded by this gene is a type of intercellular adhesion molecule continuously present in low concentrations in the membranes of leukocytes and endothelial cells. Upon cytokine stimulation, the concentrations greatly increase. ICAM-1 can be induced by interleukin-1 (IL-1) and tumor necrosis factor (TNF) and is expressed by the vascular endothelium, macrophages, and lymphocytes. ICAM-1 is a ligand for LFA-1 (integrin), a receptor found on leukocytes. When activated, leukocytes bind to endothelial cells via ICAM-1/LFA-1 and then transmigrate into tissues. LFA-1 has also been found in a soluble form, which seems to bind and block ICAM-1.
## Role in cell signaling
ICAM-1 is an endothelial- and leukocyte-associated transmembrane protein long known for its importance in stabilizing cell-cell interactions and facilitating leukocyte endothelial transmigration. More recently, ICAM-1 has been characterized as a site for the cellular entry of human rhinovirus. Because of these associations with immune responses, it has been hypothesized that ICAM-1 could function in signal transduction. ICAM-1 ligation produces proinflammatory effects such as inflammatory leukocyte recruitment by signaling through cascades involving a number of kinases, including the kinase p56lyn.
## Other functions
ICAM-1 and soluble ICAM-1 have antagonistic effects on the tight junctions forming the blood-testis barrier, thus playing a major role in spermatogenesis.
The presence of heavy glycosylation and other structural characteristics of ICAM-1 lend the protein binding sites for numerous ligands. ICAM-1 possesses binding sites for a number of immune-associated ligands. Notably, ICAM-1 binds to macrophage adhesion ligand-1 (Mac-1; ITGB2 / ITGAM), leukocyte function associated antigen-1 (LFA-1), and fibrinogen. These three proteins are generally expressed on endothelial cells and leukocytes, and they bind to ICAM-1 to facilitate transmigration of leukocytes across vascular endothelia in processes such as extravasation and the inflammatory response. As a result of these binding characteristics, ICAM-1 has classically been assigned the function of intercellular adhesion.
Researchers began to question the role of ICAM-1 as a simple adhesion molecule upon discovering that ICAM-1 serves as the binding site for entry of the major group of human rhinovirus (HRV) into various cell types. ICAM-1 also became known for its affinity for plasmodium falciparum-infected erythrocytes (PFIE), providing more of a role for ICAM-1 in infectious disease.
With the roles of ICAM-1 in cell-cell adhesion, extravasation, and infection more fully understood, a potential role for ICAM-1 in signal transduction was hypothesized. Most of the work involving ICAM-1 in recent years has focused on this central question as well as related questions. Researchers reasoned that, should ICAM-1 signal transduction prove to occur, it would be necessary to identify the mechanism of that signaling, the conditions and environment in which the signaling would occur, and the biological endpoints of any signaling cascades involved. Beyond its classically described functions as an adhesion and viral entry molecule, ICAM-1 has now been characterized convincingly as possessing a role in signal transduction. Furthermore, the signal-transducing functions of ICAM-1 seem to be associated primarily with proinflammatory pathways. In particular, ICAM-1 signaling seems to produce a recruitment of inflammatory immune cells such as macrophages and granulocytes.
ICAM-1 may also participate in a positive feedback loop and compete with ICAM-2 to maintain a proinflammatory environment conducive to leukocyte endothelial transmigration. At both the mRNA and protein levels of expression, ICAM-1 ligation was found to upregulate ICAM-1’s own expression in a positive-feedback loop. In addition, the expression of RANTES mRNA and protein was also found to be upregulated by ICAM-1 ligation. RANTES, or Regulated upon Activation Normal T-cell Expressed and Secreted, is a cytokine that is an inflammatory mediator chemotactic for a variety of inflammatory immune cells such as granulocytes and macrophages. However, much work remains to be done in fully characterizing the signaling of ICAM-1. The relationship between ICAM-1 and ICAM-2 signaling environments has not been established beyond mere correlation; a study linking ICAM signaling to actual modulation of an inflammatory environment in vivo has yet to be conducted. The reticular nature of signaling cascades necessitates that the downstream effectors of ICAM-1 mediated signaling through various kinases including p56lyn, Raf-1, and the MAPKs are largely unknown. A more thorough study of the cross-talk between these signaling molecules may shed further light onto the biological endpoints produced by ICAM-1 ligation and signal transduction.
# Clinical significance
ICAM-1 has been implicated in subarachnoid hemorrhage (SAH). Levels of ICAM-1 are shown to be significantly elevated in patients with SAH over control subjects in many studies. While ICAM-1 has not been shown to be directly correlated with cerebral vasospasm, a secondary symptom that affects 70% of SAH patients, treatment with anti-ICAM-1 reduced the severity of vasospasm.
ICAM-1 expressed by respiratory epithelial cells is also the binding site for rhinovirus, the causative agent of most common colds.
ICAM-1 has an important role in ocular allergies recruiting pro-inflammatory lymphocytes and mast cells promoting a type I hypersensitivity reaction.
Cannabinoid CB2 receptor agonists is found to decrease the induction of ICAM-1 and VCAM-1 surface expression in human brain tissues and primary human brain endothelial cells (BMVEC) exposed to various pro-inflammatory mediators.
# Interactions
ICAM-1 has been shown to interact with CD11a, EZR and CD18. | ICAM-1
ICAM-1 (Intercellular Adhesion Molecule 1) also known as CD54 (Cluster of Differentiation 54) is a protein that in humans is encoded by the ICAM1 gene.[1][2] This gene encodes a cell surface glycoprotein which is typically expressed on endothelial cells and cells of the immune system. It binds to integrins of type CD11a / CD18, or CD11b / CD18 and is also exploited by rhinovirus as a receptor for entry into respiratory epithelium.[3]
# Structure
ICAM-1 is a member of the immunoglobulin superfamily, the superfamily of proteins including antibodies and T-cell receptors. ICAM-1 is a transmembrane protein possessing an amino-terminus extracellular domain, a single transmembrane domain, and a carboxy-terminus cytoplasmic domain. The structure of ICAM-1 is characterized by heavy glycosylation, and the protein’s extracellular domain is composed of multiple loops created by disulfide bridges within the protein. The dominant secondary structure of the protein is the beta sheet, leading researchers to hypothesize the presence of dimerization domains within ICAM-1.[4]
# Function
The protein encoded by this gene is a type of intercellular adhesion molecule continuously present in low concentrations in the membranes of leukocytes and endothelial cells. Upon cytokine stimulation, the concentrations greatly increase. ICAM-1 can be induced by interleukin-1 (IL-1) and tumor necrosis factor (TNF) and is expressed by the vascular endothelium, macrophages, and lymphocytes. ICAM-1 is a ligand for LFA-1 (integrin), a receptor found on leukocytes.[5] When activated, leukocytes bind to endothelial cells via ICAM-1/LFA-1 and then transmigrate into tissues.[6] LFA-1 has also been found in a soluble form,[7] which seems to bind and block ICAM-1.[8]
## Role in cell signaling
ICAM-1 is an endothelial- and leukocyte-associated transmembrane protein long known for its importance in stabilizing cell-cell interactions and facilitating leukocyte endothelial transmigration. More recently, ICAM-1 has been characterized as a site for the cellular entry of human rhinovirus.[9] Because of these associations with immune responses, it has been hypothesized that ICAM-1 could function in signal transduction. ICAM-1 ligation produces proinflammatory effects such as inflammatory leukocyte recruitment by signaling through cascades involving a number of kinases, including the kinase p56lyn.
## Other functions
ICAM-1 and soluble ICAM-1 have antagonistic effects on the tight junctions forming the blood-testis barrier, thus playing a major role in spermatogenesis.[10]
The presence of heavy glycosylation and other structural characteristics of ICAM-1 lend the protein binding sites for numerous ligands. ICAM-1 possesses binding sites for a number of immune-associated ligands. Notably, ICAM-1 binds to macrophage adhesion ligand-1 (Mac-1; ITGB2 / ITGAM), leukocyte function associated antigen-1 (LFA-1), and fibrinogen. These three proteins are generally expressed on endothelial cells and leukocytes, and they bind to ICAM-1 to facilitate transmigration of leukocytes across vascular endothelia in processes such as extravasation and the inflammatory response. As a result of these binding characteristics, ICAM-1 has classically been assigned the function of intercellular adhesion.
Researchers began to question the role of ICAM-1 as a simple adhesion molecule upon discovering that ICAM-1 serves as the binding site for entry of the major group of human rhinovirus (HRV) into various cell types.[4] ICAM-1 also became known for its affinity for plasmodium falciparum-infected erythrocytes (PFIE), providing more of a role for ICAM-1 in infectious disease.
With the roles of ICAM-1 in cell-cell adhesion, extravasation, and infection more fully understood, a potential role for ICAM-1 in signal transduction was hypothesized. Most of the work involving ICAM-1 in recent years has focused on this central question as well as related questions. Researchers reasoned that, should ICAM-1 signal transduction prove to occur, it would be necessary to identify the mechanism of that signaling, the conditions and environment in which the signaling would occur, and the biological endpoints of any signaling cascades involved. Beyond its classically described functions as an adhesion and viral entry molecule, ICAM-1 has now been characterized convincingly as possessing a role in signal transduction. Furthermore, the signal-transducing functions of ICAM-1 seem to be associated primarily with proinflammatory pathways. In particular, ICAM-1 signaling seems to produce a recruitment of inflammatory immune cells such as macrophages and granulocytes.[11]
ICAM-1 may also participate in a positive feedback loop and compete with ICAM-2 to maintain a proinflammatory environment conducive to leukocyte endothelial transmigration. At both the mRNA and protein levels of expression, ICAM-1 ligation was found to upregulate ICAM-1’s own expression in a positive-feedback loop. In addition, the expression of RANTES mRNA and protein was also found to be upregulated by ICAM-1 ligation. RANTES, or Regulated upon Activation Normal T-cell Expressed and Secreted, is a cytokine that is an inflammatory mediator chemotactic for a variety of inflammatory immune cells such as granulocytes and macrophages.[12] However, much work remains to be done in fully characterizing the signaling of ICAM-1. The relationship between ICAM-1 and ICAM-2 signaling environments has not been established beyond mere correlation; a study linking ICAM signaling to actual modulation of an inflammatory environment in vivo has yet to be conducted. The reticular nature of signaling cascades necessitates that the downstream effectors of ICAM-1 mediated signaling through various kinases including p56lyn, Raf-1, and the MAPKs are largely unknown. A more thorough study of the cross-talk between these signaling molecules may shed further light onto the biological endpoints produced by ICAM-1 ligation and signal transduction.
# Clinical significance
ICAM-1 has been implicated in subarachnoid hemorrhage (SAH). Levels of ICAM-1 are shown to be significantly elevated in patients with SAH over control subjects in many studies.[13][14] While ICAM-1 has not been shown to be directly correlated with cerebral vasospasm, a secondary symptom that affects 70% of SAH patients, treatment with anti-ICAM-1 reduced the severity of vasospasm.
ICAM-1 expressed by respiratory epithelial cells is also the binding site for rhinovirus, the causative agent of most common colds.
ICAM-1 has an important role in ocular allergies recruiting pro-inflammatory lymphocytes and mast cells promoting a type I hypersensitivity reaction.
Cannabinoid CB2 receptor agonists is found to decrease the induction of ICAM-1 and VCAM-1 surface expression in human brain tissues and primary human brain endothelial cells (BMVEC) exposed to various pro-inflammatory mediators.[15]
# Interactions
ICAM-1 has been shown to interact with CD11a,[16][17][18] EZR[19] and CD18.[16][20][21] | https://www.wikidoc.org/index.php/CD54 | |
b6837fd62315813a3fd6d47f2d8377fdb4fa1cad | wikidoc | CDC14B | CDC14B
Dual specificity protein phosphatase CDC14B is an enzyme that in humans is encoded by the CDC14B gene.
The protein encoded by this gene is a member of the dual specificity protein tyrosine phosphatase family. This protein is highly similar to Saccharomyces cerevisiae Cdc14, a protein tyrosine phosphatase involved in the exit of cell mitosis and initiation of DNA replication, which suggests the role in cell cycle control. Specifically, it is thought to fulfil this role by bundling and stabilising microtubules. This protein has been shown to interact with and dephosphorylates tumor suppressor protein p53, and is thought to regulate the function of p53. Alternative splicing of this gene results in 3 transcript variants encoding distinct isoforms.
# Interactions
CDC14B has been shown to interact with p53. However, this interaction has not been reported in other studies. | CDC14B
Dual specificity protein phosphatase CDC14B is an enzyme that in humans is encoded by the CDC14B gene.[1][2]
The protein encoded by this gene is a member of the dual specificity protein tyrosine phosphatase family. This protein is highly similar to Saccharomyces cerevisiae Cdc14, a protein tyrosine phosphatase involved in the exit of cell mitosis and initiation of DNA replication, which suggests the role in cell cycle control. Specifically, it is thought to fulfil this role by bundling and stabilising microtubules. This protein has been shown to interact with and dephosphorylates tumor suppressor protein p53, and is thought to regulate the function of p53. Alternative splicing of this gene results in 3 transcript variants encoding distinct isoforms.[2]
# Interactions
CDC14B has been shown to interact with p53.[3] However, this interaction has not been reported in other studies. | https://www.wikidoc.org/index.php/CDC14B | |
1664babf3e62ac230c09ac24daea0f1ddce9eace | wikidoc | CDC25A | CDC25A
M-phase inducer phosphatase 1 also known as dual specificity phosphatase Cdc25A is a protein that in humans is encoded by the cell division cycle 25 homolog A (CDC25A) gene.
# Function
CDC25A is a member of the CDC25 family of dual-specificity phosphatases.
Dual-specificity protein phosphatases remove phosphate groups from phosphorylated tyrosine and serine / threonine residues. They represent a subgroup of the tyrosine phosphatase family (as opposed to the serine/threonine phosphatase family).
All mammals examined to date have three homologues of the ancestral Cdc25 gene (found e.g. in the fungus species S. pombe , designated Cdc25A, Cdc25B, and Cdc25C. In contrast, some invertebrates harbour 2 (e.g., the Drosophila proteins String and Twine) or four (e.g., C. elegans Cdc-25.1 - Cdc-25.4) homologues.
CDC25A is required for progression from G1 to the S phase of the cell cycle, but also plays roles in later cell cycle events. In particular, it is stabilized in metaphase cells and is degraded upon metaphase exit akin to Cyclin B. It is competent to activate the G1/S cyclin-dependent kinases CDK4 and CDK2 by removing inhibitory phosphate groups from adjacent tyrosine and threonine residues; it can also activate Cdc2 (Cdk1), the principal mitotic Cdk.
# Involvement in cancer
CDC25A is specifically degraded in response to DNA damage, resulting in cell cycle arrest. Thus, this degradation represents one axis of a DNA damage checkpoint, complementing induction of p53 and p21 in the inhibition of CDKs.
CDC25A is considered an oncogene, as it can cooperate with oncogenic RAS to transform rodent fibroblasts, and it is overexpressed in tumours from a variety of tissues, including breast and head & neck tumours. It is a target of the E2F family of transcription factors. Therefore, its overexpression is a common consequence of dysregulation of the p53-p21-Cdk axis in carcinogenesis.
# Interactions
CDC25A has been shown to interact with:
- ASK1,
- C-Raf,
- CHEK1,
- CCNE1,
- EGFR,
- PIM1 and
- YWHAB. | CDC25A
M-phase inducer phosphatase 1 also known as dual specificity phosphatase Cdc25A is a protein that in humans is encoded by the cell division cycle 25 homolog A (CDC25A) gene.
# Function
CDC25A is a member of the CDC25 family of dual-specificity phosphatases.
Dual-specificity protein phosphatases remove phosphate groups from phosphorylated tyrosine and serine / threonine residues. They represent a subgroup of the tyrosine phosphatase family (as opposed to the serine/threonine phosphatase family).
All mammals examined to date have three homologues of the ancestral Cdc25 gene (found e.g. in the fungus species S. pombe , designated Cdc25A, Cdc25B, and Cdc25C. In contrast, some invertebrates harbour 2 (e.g., the Drosophila proteins String and Twine) or four (e.g., C. elegans Cdc-25.1 - Cdc-25.4) homologues.
CDC25A is required for progression from G1 to the S phase of the cell cycle, but also plays roles in later cell cycle events. In particular, it is stabilized in metaphase cells and is degraded upon metaphase exit akin to Cyclin B. It is competent to activate the G1/S cyclin-dependent kinases CDK4 and CDK2 by removing inhibitory phosphate groups from adjacent tyrosine and threonine residues; it can also activate Cdc2 (Cdk1), the principal mitotic Cdk.
# Involvement in cancer
CDC25A is specifically degraded in response to DNA damage, resulting in cell cycle arrest. Thus, this degradation represents one axis of a DNA damage checkpoint, complementing induction of p53 and p21 in the inhibition of CDKs.
CDC25A is considered an oncogene, as it can cooperate with oncogenic RAS to transform rodent fibroblasts, and it is overexpressed in tumours from a variety of tissues, including breast and head & neck tumours. It is a target of the E2F family of transcription factors. Therefore, its overexpression is a common consequence of dysregulation of the p53-p21-Cdk axis in carcinogenesis.[1]
# Interactions
CDC25A has been shown to interact with:
- ASK1,[2]
- C-Raf,[3][4]
- CHEK1,[5][6][7][8]
- CCNE1,[9][10]
- EGFR,[11]
- PIM1[12] and
- YWHAB.[13] | https://www.wikidoc.org/index.php/CDC25A | |
5f3ceccc8b26d49b19a5b4607c6804ff8863b3a3 | wikidoc | CDC25B | CDC25B
M-phase inducer phosphatase 2 is an enzyme that in humans is encoded by the CDC25B gene.
CDC25B is a member of the CDC25 family of phosphatases. CDC25B activates the cyclin dependent kinase CDC2 by removing two phosphate groups and it is required for entry into mitosis. CDC25B shuttles between the nucleus and the cytoplasm due to nuclear localization and nuclear export signals. The protein is nuclear in the M and G1 phases of the cell cycle and moves to the cytoplasm during S and G2. CDC25B has oncogenic properties, although its role in tumor formation has not been determined. Multiple transcript variants for this gene exist.
# Interactions
CDC25B has been shown to interact with MAPK14, Casein kinase 2, alpha 1, CHEK1, MELK, Estrogen receptor alpha, YWHAB, YWHAZ, YWHAH and YWHAE. | CDC25B
M-phase inducer phosphatase 2 is an enzyme that in humans is encoded by the CDC25B gene.[1]
CDC25B is a member of the CDC25 family of phosphatases. CDC25B activates the cyclin dependent kinase CDC2 by removing two phosphate groups and it is required for entry into mitosis. CDC25B shuttles between the nucleus and the cytoplasm due to nuclear localization and nuclear export signals. The protein is nuclear in the M and G1 phases of the cell cycle and moves to the cytoplasm during S and G2. CDC25B has oncogenic properties, although its role in tumor formation has not been determined. Multiple transcript variants for this gene exist.[2]
# Interactions
CDC25B has been shown to interact with MAPK14,[3] Casein kinase 2, alpha 1,[4] CHEK1,[5] MELK,[6] Estrogen receptor alpha,[7] YWHAB,[8][9] YWHAZ,[8] YWHAH[8] and YWHAE.[8][9] | https://www.wikidoc.org/index.php/CDC25B | |
28160cd4a09963656fa5c782e44936e257f29110 | wikidoc | CDC25C | CDC25C
M-phase inducer phosphatase 3 is an enzyme that in humans is encoded by the CDC25C gene.
This gene is highly conserved during evolution and it plays a key role in the regulation of cell division. The encoded protein is a tyrosine phosphatase and belongs to the Cdc25 phosphatase family. It directs dephosphorylation of cyclin B-bound CDC2 (CDK1) and triggers entry into mitosis. It is also thought to suppress p53-induced growth arrest. Multiple alternatively spliced transcript variants of this gene have been described, however, the full-length nature of many of them is not known.
# Interactions
CDC25C has been shown to interact with MAPK14, CHEK1, PCNA, PIN1, PLK3 and NEDD4. | CDC25C
M-phase inducer phosphatase 3 is an enzyme that in humans is encoded by the CDC25C gene.[1]
This gene is highly conserved during evolution and it plays a key role in the regulation of cell division. The encoded protein is a tyrosine phosphatase and belongs to the Cdc25 phosphatase family. It directs dephosphorylation of cyclin B-bound CDC2 (CDK1) and triggers entry into mitosis. It is also thought to suppress p53-induced growth arrest. Multiple alternatively spliced transcript variants of this gene have been described, however, the full-length nature of many of them is not known.[2]
# Interactions
CDC25C has been shown to interact with MAPK14,[3] CHEK1,[4] PCNA,[5] PIN1,[6][7][8] PLK3[9] and NEDD4.[8] | https://www.wikidoc.org/index.php/CDC25C | |
20236937037f1880937bc38b8e9f49feaf2757db | wikidoc | CDC2L5 | CDC2L5
Cell division cycle 2-like protein kinase 5 is an enzyme that in humans is encoded by the CDC2L5 gene.
The protein encoded by this gene is a member of the cyclin-dependent serine/threonine protein kinase family. Members of this family are well known for their essential roles as master switches in cell cycle control. Some of the cell cycle control kinases are able to phosphorylate proteins that are important for cell differentiation and apoptosis, thus provide connections between cell proliferation, differentiation, and apoptosis. Proteins of this family may also be involved in non-cell cycle-related functions, such as neurocytoskeleton dynamics. The exact function of this protein has not yet been determined. It has unusually large N- and C-termini and is ubiquitously expressed in many tissues. Two alternatively spliced variants are described.
A 2017 study of children with rare developmental disorders found 11 children in the United Kingdom who had a fault in their CDK13 gene. This fault affected the children's communication and language skills as well as causing learning difficulties. | CDC2L5
Cell division cycle 2-like protein kinase 5 is an enzyme that in humans is encoded by the CDC2L5 gene.[1][2]
The protein encoded by this gene is a member of the cyclin-dependent serine/threonine protein kinase family. Members of this family are well known for their essential roles as master switches in cell cycle control. Some of the cell cycle control kinases are able to phosphorylate proteins that are important for cell differentiation and apoptosis, thus provide connections between cell proliferation, differentiation, and apoptosis. Proteins of this family may also be involved in non-cell cycle-related functions, such as neurocytoskeleton dynamics. The exact function of this protein has not yet been determined. It has unusually large N- and C-termini and is ubiquitously expressed in many tissues. Two alternatively spliced variants are described.[2]
A 2017 study of children with rare developmental disorders[3] found 11 children in the United Kingdom who had a fault in their CDK13 gene. This fault affected the children's communication and language skills as well as causing learning difficulties.[4] | https://www.wikidoc.org/index.php/CDC2L5 | |
919da67e32dd4b1ad2a2584f02cc50ccb725ae97 | wikidoc | CDK5R1 | CDK5R1
Cyclin-dependent kinase 5 activator 1 is an enzyme that in humans is encoded by the CDK5R1 gene.
# Function
The protein encoded by this gene (p35) is a neuron-specific activator of cyclin-dependent kinase 5 (CDK5); the activation of CDK5 is required for proper development of the central nervous system. The p35 form of this protein is proteolytically cleaved by calpain, generating a p25 form. The cleavage of p35 into p25 results in relocalization of the protein from the cell periphery to nuclear and perinuclear regions. P25 deregulates CDK5 activity by prolonging its activation and changing its cellular location. The p25 form accumulates in the brain neurons of patients with Alzheimer's disease. This accumulation correlates with an increase in CDK5 kinase activity, and may lead to aberrantly phosphorylated forms of the microtubule-associated protein tau, which contributes to Alzheimer's disease.
In melanocytic cells CDK5R1 gene expression may be regulated by MITF.
# Interactions
CDK5R1 has been shown to interact with:
- Actinin, alpha 1
- Amphiphysin,
- Beta-catenin,
- CAMK2A,
- CDK5RAP2,
- Cyclin-dependent kinase 5,
- Protein SET, | CDK5R1
Cyclin-dependent kinase 5 activator 1 is an enzyme that in humans is encoded by the CDK5R1 gene.[1][2]
# Function
The protein encoded by this gene (p35) is a neuron-specific activator of cyclin-dependent kinase 5 (CDK5); the activation of CDK5 is required for proper development of the central nervous system. The p35 form of this protein is proteolytically cleaved by calpain, generating a p25 form. The cleavage of p35 into p25 results in relocalization of the protein from the cell periphery to nuclear and perinuclear regions. P25 deregulates CDK5 activity by prolonging its activation and changing its cellular location. The p25 form accumulates in the brain neurons of patients with Alzheimer's disease. This accumulation correlates with an increase in CDK5 kinase activity, and may lead to aberrantly phosphorylated forms of the microtubule-associated protein tau, which contributes to Alzheimer's disease.[2]
In melanocytic cells CDK5R1 gene expression may be regulated by MITF.[3]
# Interactions
CDK5R1 has been shown to interact with:
- Actinin, alpha 1[4]
- Amphiphysin,[5]
- Beta-catenin,[6]
- CAMK2A,[7]
- CDK5RAP2,[8]
- Cyclin-dependent kinase 5,[9][10]
- Protein SET,[11] | https://www.wikidoc.org/index.php/CDK5R1 | |
ea62e3be5ccdf2353fbf95c7fbafe0627735e7c2 | wikidoc | CDKN1B | CDKN1B
Cyclin-dependent kinase inhibitor 1B (p27Kip1) is an enzyme inhibitor that in humans is encoded by the CDKN1B gene. It encodes a protein which belongs to the Cip/Kip family of cyclin dependent kinase (Cdk) inhibitor proteins. The encoded protein binds to and prevents the activation of cyclin E-CDK2 or cyclin D-CDK4 complexes, and thus controls the cell cycle progression at G1. It is often referred to as a cell cycle inhibitor protein because its major function is to stop or slow down the cell division cycle.
# Function
The p27Kip1 gene has a DNA sequence similar to other members of the "Cip/Kip" family which include the p21Cip1/Waf1 and p57Kip2 genes. In addition to this structural similarity the "Cip/Kip" proteins share the functional characteristic of being able to bind several different classes of Cyclin and Cdk molecules. For example, p27Kip1 binds to cyclin D either alone, or when complexed to its catalytic subunit CDK4. In doing so p27Kip1 inhibits the catalytic activity of Cdk4, which means that it prevents Cdk4 from adding phosphate residues to its principal substrate, the retinoblastoma (pRb) protein. Increased levels of the p27Kip1 protein typically cause cells to arrest in the G1 phase of the cell cycle. Likewise, p27Kip1 is able to bind other Cdk proteins when complexed to cyclin subunits such as Cyclin E/Cdk2 and Cyclin A/Cdk2.
# Regulation
In general, extracellular growth factors which promote cell division reduce transcription and translation of p27Kip1. Also, increased synthesis of CDk4,6/cyclin D causes binding of p27 to this complex, sequestering it from binding to the CDk2/cyclin E complex. Furthermore, an active CDK2/cyclin E complex will phosphorylate p27 and tag p27 for ubiquitination. A mutation of this gene may lead to loss of control over the cell cycle leading to uncontrolled cellular proliferation. Loss of p27 expression has been observed in metastatic canine mammary carcinomas. Decreased TGF-beta signalling has been suggested to cause loss of p27 expression in this tumor type.
A structured cis-regulatory element has been found in the 5' UTR of the P27 mRNA where it is thought to regulate translation relative to cell cycle progression.
P27 regulation is accomplished by two different mechanisms. In the first its concentration is changed by the individual rates of transcription, translation, and proteolysis. P27 can also be regulated by changing its subcellular location Both mechanisms act to reduce levels of p27, allowing for the activation of Cdk1 and Cdk2, and for the cell to begin progressing through the cell cycle.
## Transcription
Transcription of the CDKN1B gene is activated by Forkhead box class O family (FoxO) proteins which also acts downstream to promote p27 nuclear localization and decrease levels of COP9 subunit 5(COPS5) which helps in the degradation of p27. Transcription for p27 is activated by FoxO in response to cytokines, promyelocytic leukaemia proteins, and nuclear Akt signaling. P27 transcription has also been linked to another tumor suppressor gene, MEN1, in pancreatic islet cells where it promotes CDKN1B expression.
## Translation
Translation of CDKN1B reaches its maximum during quiescence and early G1. Translation is regulated by polypyrimidine tract-binding protein(PTB), ELAVL1, ELAVL4, and microRNAs. PTB acts by binding CDKN1b IRES to increase translation and when PTB levels decrease, G1 phase is shortened. ELAVL1 and ELAVL4 also bind to CDKN1B IRES but they do so in order to decrease translation and so depletion of either results in G1 arrest.
## Proteolysis
Degradation of the p27 protein occurs as cells exit quiescence and enter G1. Protein levels continue to fall rapidly as the cell continues through G1 and enters S phase. One of the most understood mechanisms for p27 proteolysis is the polyubiquitylation of p27 by the SCFSKP2 kinase associated protein 1 (Skp1) and 2 (Skp2). SKP1 and Skp2 degrades p27 after it has been phosphorylated at threonine 187 (Thr187) by either activating cyclin E- or cyclin A-CDK2. Skp2 is mainly responsible for the degradation of p27 levels that continues through S phase. However it is rarely expressed in early G1 where p27 levels first begin to decrease. During early G1 proteolysis of p27 is regulated by KIP1 Ubiquitylation Promoting Complex (KPC) which binds to its CDK inhibitory domain. P27 also has three Cdk-inhibited tyrosines at residues 74, 88, and 89. Of these, Tyr74 is of special interest because it is specific to p27-type inhibitors.
## Nuclear export
Alternatively to the transcription, translation, and protelytic method of regulation, p27 levels can also be changed by exporting p27 to the cytoplasm. This occurs when p27 is phosphorylated on Ser(10) which allows for CRM1, a nuclear export carrier protein, to bind to and remove p27 from the nucleus. Once p27 is excluded from the nucleus it cannot inhibit the cell’s growth. In the cytoplasm it may be degraded entirely or retained. This step occurs very early when the cell is exiting the quiescent phase and thus is independent of Skp2 degradation of p27.
## MicroRNA regulation
Because p27 levels can be moderated at the translational level, it has been proposed that p27 may be regulated by miRNAs. Recent research has suggested that both miR-221 and miR-222 control p27 levels although the pathways are not well understood.
# Role in cancer
## Proliferation
P27 is considered a tumor suppressor because of its function as a regulator of the cell cycle. In cancers it is often inactivated via impaired synthesis, accelerated degradation, or mislocalization. Inactivation of p27 is generally accomplished post-transcription by the oncogenic activation of various pathways including receptor tyrosine kinases (RTK), phosphatilidylinositol 3-kinase (PI3K), SRC, or Ras-mitogen activated protein kinase(MAPK). These act to accelerate the proteolysis of the p27 protein and allow the cancer cell to undergo rapid division and uncontrolled proliferation. When p27 is phosphorylated by Src at tyrosine 74 or 88 it ceases to inhibit cyclinE-cdk2. Src was also shown to reduce the half life of p27 meaning it is degraded faster. Many epithelial cancers are known to overexpress EGFR which plays a role in the proteolysis of p27 and in Ras-driven proteolysis. Non-epithelial cancers use different pathways to inactivate p27. Many cancer cells also upregulate Skp2 which is known to play an active role in the proteolysis of p27 As a result, Skp2 is inversely related to p27 levels and directly correlates with tumor grade in many malignancies.
## Metastasis
In cancer cells, p27 can also be mislocalized to the cytoplasm in order to facilitate metastasis. The mechanisms by which it acts on motility differ between cancers. In hepatocellular carcinoma cells p27 co-localizes with actin fibers to act on GTPase Rac and induce cell migration. In breast cancer cytoplasmic p27 reduced RHOA activity which increased a cell’s propensity for motility.
This role for p27 may indicate why cancer cells rarely fully inactivate or delete p27. By retaining p27 in some capacity it can be exported to the cytoplasm during tumorgenesis and manipulated to aid in metastasis. 70% of metastatic melanomas were shown to exhibit cytoplasmic p27, while in benign melanomas p27 remained localized to the nucleus. P27 is misplaced to the cytoplasm by the MAP2K, Ras, and Akt pathways although the mechanisms are not entirely understood. Additionally, phosphorylation of p27 at T198 by RSK1 has been shown to mislocalize p27 to the cytoplasm as well as inhibit the RhoA pathway. Because inhibition of RhoA results in a decrease in both stress fibers and focal adhesion, cell motility is increased. P27 can also be exported to the cytoplasm by oncogenic activation of the P13K pathway. Thus, mislocalization of p27 to the cytoplasm in cancer cells allows them to proliferate unchecked and provides for increased motility.
In contrast to these results, p27 has also been shown to be an inhibitor of migration in sarcoma cells. In these cells, p27 bound to stathmin which prevents stathmin from binding to tubulin and thus polymerization of microtubules increased and cell motility decreased.
## MicroRNA regulation
Studies of various cell lines including glioblastoma cell lines, three prostate cancer cell lines, and a breast tumor cell line showed that suppressing miR-221 and miR-22 expression resulted in p27-dependent G1 growth arrest Then when p27 was knocked down, cell growth resumed indicating a strong role for miRNA regulated p27. Studies in patients have demonstrated an inverse correlation between miR-221&22 and p27 protein levels. Additionally nearby healthy tissue showed high expression of the p27 protein while miR-221&22 concentrations were low.
# Regulation in specific cancers
In most cancers reduced levels of nuclear p27 are correlated with increased tumor size, increased tumor grade, and a higher propensity for metastasis. However the mechanisms by which levels of p27 are regulated vary between cancers.
## Breast
In breast cancer, Src activation has been shown to correlate with low levels of p27 Breast cancers that were Estrogen receptor negative and progesterone receptor negative were more likely to display low levels of p27 and more likely to have a high tumor grade. Similarly, breast cancer patients with BRCA1/2 mutations were more likely to have low levels of p27.
## Prostate
A mutation in the CDKN1B gene has been linked to an increased risk for hereditary prostate cancer in humans.
# Clinical significance
## Prognostic value
Several studies have demonstrated that reduced p27 levels indicate a poorer patient prognosis. However, because of the dual, contrasting roles p27 plays in cancer (as an inhibitor of growth and as a mechanism for metastasis) low levels of p27 may demonstrate that a cancer is not aggressive and will remain benign.
In ovarian cancer, p27 negative tumors progressed in 23 months compared to 85 months in p27 positive tumors and thus could be used as a prognostic marker. Similar studies have correlated low levels of p27 with a worse prognosis in breast cancer. Colorectal carcinomas that lacked p27 were shown to have increased p27-specific proteolysis and a median survival of only 69 months compared to 151 months for patients with high or normal levels of p27. The authors proposed clinicians could use patient specific levels of p27 to determine who would benefit from adjuvant therapy. Similar correlations were observed in patients with non-small cell lung cancer, those with colon, and prostate cancer.
So far studies have only evaluated the prognostic value of p27 retrospectively and a standardized scoring system has not been established. However it has been proposed that clinicians should evaluate a patient’s p27 levels in order to determine if they will be responsive to certain chemotoxins which target fast growing tumors where p27 levels are low. Or in contrast, if p27 levels are found to be high in a patient’s cancer, their risk for metastasis is higher and the physician can make an informed decision about their treatment plan. Because p27 levels are controlled post-transcriptionally, proteomic surveys can be used to establish and monitor a patient’s individual levels which aids in the future of individualized medicine.
The following cancers have been demonstrated to have an inverse correlation with p27 expression and prognosis: oro-pharyngo-laryngeal, oesophageal, gastric, colon, lung, melanoma, glioma, breast cancer, prostate, lymphoma, leukemia.
## Correlation to treatment response
P27 may also allow clinicians to better select an appropriate treatment for a patient. For example, patients with non-small cell lung cancer who were treated with platinum based chemotherapy showed reduced survival if they had low levels of p27. Similarly low levels of p27 correlated with poor results from adjuvant chemotherapy in breast cancer patients.
## Value as a therapeutic target
P27 has been explored as a potential target for cancer therapy because its levels are highly correlated to patient prognosis. This is true for a wide spectrum of cancers including colon, breast, prostate, lung, liver, stomach, and bladder.
### Use of microRNAs for therapy
Because of the role miRNAs play in p27 regulation, research is underway to determine if antagomiRs that block the activity of the miR221&222 and allow for p27 cell grow inhibition to take place could act as therapeutic cancer drugs.
# Role in Regeneration
Knockdown of CDKN1B stimulates regeneration of cochlear hair cells in mice. Since CDKN1B prevents cells from entering the cell cycle, inhibition of the protein could cause re-entry and subsequent division. In mammals where regeneration of cochlear hair cells normally does not occur, this inhibition could help regrow damaged cells who are otherwise incapable of proliferation. In fact, when the CDKN1B gene is disrupted in adult mice, hair cells of the organ of Corti proliferate, while those in control mice do not. Lack of CDKN1B expression appears to release the hair cells from natural cell-cycle arrest. Because hair cell death in the human cochlea is a major cause of hearing loss, the CDKN1B protein could be an important factor in the clinical treatment of deafness.
# Interactions
CDKN1B has been shown to interact with:
- AKT1,
- CKS1B,
- Cyclin D3,
- Cyclin E1,
- Cyclin-dependent kinase 2,
- Cyclin-dependent kinase 4,
- Grb2,
- NUP50
- SKP2,
- SPDYA, and
- XPO1. | CDKN1B
Cyclin-dependent kinase inhibitor 1B (p27Kip1) is an enzyme inhibitor that in humans is encoded by the CDKN1B gene.[1] It encodes a protein which belongs to the Cip/Kip family of cyclin dependent kinase (Cdk) inhibitor proteins. The encoded protein binds to and prevents the activation of cyclin E-CDK2 or cyclin D-CDK4 complexes, and thus controls the cell cycle progression at G1. It is often referred to as a cell cycle inhibitor protein because its major function is to stop or slow down the cell division cycle.
# Function
The p27Kip1 gene has a DNA sequence similar to other members of the "Cip/Kip" family which include the p21Cip1/Waf1 and p57Kip2 genes. In addition to this structural similarity the "Cip/Kip" proteins share the functional characteristic of being able to bind several different classes of Cyclin and Cdk molecules. For example, p27Kip1 binds to cyclin D either alone, or when complexed to its catalytic subunit CDK4. In doing so p27Kip1 inhibits the catalytic activity of Cdk4, which means that it prevents Cdk4 from adding phosphate residues to its principal substrate, the retinoblastoma (pRb) protein. Increased levels of the p27Kip1 protein typically cause cells to arrest in the G1 phase of the cell cycle. Likewise, p27Kip1 is able to bind other Cdk proteins when complexed to cyclin subunits such as Cyclin E/Cdk2 and Cyclin A/Cdk2.
# Regulation
In general, extracellular growth factors which promote cell division reduce transcription and translation of p27Kip1. Also, increased synthesis of CDk4,6/cyclin D causes binding of p27 to this complex, sequestering it from binding to the CDk2/cyclin E complex. Furthermore, an active CDK2/cyclin E complex will phosphorylate p27 and tag p27 for ubiquitination.[2] A mutation of this gene may lead to loss of control over the cell cycle leading to uncontrolled cellular proliferation.[3][4][5] Loss of p27 expression has been observed in metastatic canine mammary carcinomas.[6][7][8] Decreased TGF-beta signalling has been suggested to cause loss of p27 expression in this tumor type.[9]
A structured cis-regulatory element has been found in the 5' UTR of the P27 mRNA where it is thought to regulate translation relative to cell cycle progression.[10]
P27 regulation is accomplished by two different mechanisms. In the first its concentration is changed by the individual rates of transcription, translation, and proteolysis. P27 can also be regulated by changing its subcellular location [11] Both mechanisms act to reduce levels of p27, allowing for the activation of Cdk1 and Cdk2, and for the cell to begin progressing through the cell cycle.
## Transcription
Transcription of the CDKN1B gene is activated by Forkhead box class O family (FoxO) proteins which also acts downstream to promote p27 nuclear localization and decrease levels of COP9 subunit 5(COPS5) which helps in the degradation of p27.[12] Transcription for p27 is activated by FoxO in response to cytokines, promyelocytic leukaemia proteins, and nuclear Akt signaling.[12] P27 transcription has also been linked to another tumor suppressor gene, MEN1, in pancreatic islet cells where it promotes CDKN1B expression.[12]
## Translation
Translation of CDKN1B reaches its maximum during quiescence and early G1.[12] Translation is regulated by polypyrimidine tract-binding protein(PTB), ELAVL1, ELAVL4, and microRNAs.[12] PTB acts by binding CDKN1b IRES to increase translation and when PTB levels decrease, G1 phase is shortened.[12] ELAVL1 and ELAVL4 also bind to CDKN1B IRES but they do so in order to decrease translation and so depletion of either results in G1 arrest.[12]
## Proteolysis
Degradation of the p27 protein occurs as cells exit quiescence and enter G1.[12] Protein levels continue to fall rapidly as the cell continues through G1 and enters S phase. One of the most understood mechanisms for p27 proteolysis is the polyubiquitylation of p27 by the SCFSKP2 kinase associated protein 1 (Skp1) and 2 (Skp2).[12] SKP1 and Skp2 degrades p27 after it has been phosphorylated at threonine 187 (Thr187) by either activating cyclin E- or cyclin A-CDK2. Skp2 is mainly responsible for the degradation of p27 levels that continues through S phase.[13] However it is rarely expressed in early G1 where p27 levels first begin to decrease. During early G1 proteolysis of p27 is regulated by KIP1 Ubiquitylation Promoting Complex (KPC) which binds to its CDK inhibitory domain.[14] P27 also has three Cdk-inhibited tyrosines at residues 74, 88, and 89.[12] Of these, Tyr74 is of special interest because it is specific to p27-type inhibitors.[12]
## Nuclear export
Alternatively to the transcription, translation, and protelytic method of regulation, p27 levels can also be changed by exporting p27 to the cytoplasm. This occurs when p27 is phosphorylated on Ser(10) which allows for CRM1, a nuclear export carrier protein, to bind to and remove p27 from the nucleus.[15] Once p27 is excluded from the nucleus it cannot inhibit the cell’s growth. In the cytoplasm it may be degraded entirely or retained.[11] This step occurs very early when the cell is exiting the quiescent phase and thus is independent of Skp2 degradation of p27.[15]
## MicroRNA regulation
Because p27 levels can be moderated at the translational level, it has been proposed that p27 may be regulated by miRNAs. Recent research has suggested that both miR-221 and miR-222 control p27 levels although the pathways are not well understood.[11]
# Role in cancer
## Proliferation
P27 is considered a tumor suppressor because of its function as a regulator of the cell cycle.[12] In cancers it is often inactivated via impaired synthesis, accelerated degradation, or mislocalization.[12] Inactivation of p27 is generally accomplished post-transcription by the oncogenic activation of various pathways including receptor tyrosine kinases (RTK), phosphatilidylinositol 3-kinase (PI3K), SRC, or Ras-mitogen activated protein kinase(MAPK).[12] These act to accelerate the proteolysis of the p27 protein and allow the cancer cell to undergo rapid division and uncontrolled proliferation.[12] When p27 is phosphorylated by Src at tyrosine 74 or 88 it ceases to inhibit cyclinE-cdk2.[16] Src was also shown to reduce the half life of p27 meaning it is degraded faster.[16] Many epithelial cancers are known to overexpress EGFR which plays a role in the proteolysis of p27 and in Ras-driven proteolysis.[12] Non-epithelial cancers use different pathways to inactivate p27.[12] Many cancer cells also upregulate Skp2 which is known to play an active role in the proteolysis of p27[13] As a result, Skp2 is inversely related to p27 levels and directly correlates with tumor grade in many malignancies.[13]
## Metastasis
In cancer cells, p27 can also be mislocalized to the cytoplasm in order to facilitate metastasis. The mechanisms by which it acts on motility differ between cancers. In hepatocellular carcinoma cells p27 co-localizes with actin fibers to act on GTPase Rac and induce cell migration.[17] In breast cancer cytoplasmic p27 reduced RHOA activity which increased a cell’s propensity for motility.[18]
This role for p27 may indicate why cancer cells rarely fully inactivate or delete p27. By retaining p27 in some capacity it can be exported to the cytoplasm during tumorgenesis and manipulated to aid in metastasis. 70% of metastatic melanomas were shown to exhibit cytoplasmic p27, while in benign melanomas p27 remained localized to the nucleus.[19] P27 is misplaced to the cytoplasm by the MAP2K, Ras, and Akt pathways although the mechanisms are not entirely understood.[20][21][22] Additionally, phosphorylation of p27 at T198 by RSK1 has been shown to mislocalize p27 to the cytoplasm as well as inhibit the RhoA pathway.[23] Because inhibition of RhoA results in a decrease in both stress fibers and focal adhesion, cell motility is increased.[24] P27 can also be exported to the cytoplasm by oncogenic activation of the P13K pathway.[24] Thus, mislocalization of p27 to the cytoplasm in cancer cells allows them to proliferate unchecked and provides for increased motility.
In contrast to these results, p27 has also been shown to be an inhibitor of migration in sarcoma cells.[25] In these cells, p27 bound to stathmin which prevents stathmin from binding to tubulin and thus polymerization of microtubules increased and cell motility decreased.[25]
## MicroRNA regulation
Studies of various cell lines including glioblastoma cell lines, three prostate cancer cell lines, and a breast tumor cell line showed that suppressing miR-221 and miR-22 expression resulted in p27-dependent G1 growth arrest[11] Then when p27 was knocked down, cell growth resumed indicating a strong role for miRNA regulated p27.[11] Studies in patients have demonstrated an inverse correlation between miR-221&22 and p27 protein levels. Additionally nearby healthy tissue showed high expression of the p27 protein while miR-221&22 concentrations were low.[11]
# Regulation in specific cancers
In most cancers reduced levels of nuclear p27 are correlated with increased tumor size, increased tumor grade, and a higher propensity for metastasis. However the mechanisms by which levels of p27 are regulated vary between cancers.
## Breast
In breast cancer, Src activation has been shown to correlate with low levels of p27[16] Breast cancers that were Estrogen receptor negative and progesterone receptor negative were more likely to display low levels of p27 and more likely to have a high tumor grade.[16] Similarly, breast cancer patients with BRCA1/2 mutations were more likely to have low levels of p27.[26]
## Prostate
A mutation in the CDKN1B gene has been linked to an increased risk for hereditary prostate cancer in humans.[27]
# Clinical significance
## Prognostic value
Several studies have demonstrated that reduced p27 levels indicate a poorer patient prognosis.[12] However, because of the dual, contrasting roles p27 plays in cancer (as an inhibitor of growth and as a mechanism for metastasis) low levels of p27 may demonstrate that a cancer is not aggressive and will remain benign.[12]
In ovarian cancer, p27 negative tumors progressed in 23 months compared to 85 months in p27 positive tumors and thus could be used as a prognostic marker.[28] Similar studies have correlated low levels of p27 with a worse prognosis in breast cancer.[29] Colorectal carcinomas that lacked p27 were shown to have increased p27-specific proteolysis and a median survival of only 69 months compared to 151 months for patients with high or normal levels of p27.[30] The authors proposed clinicians could use patient specific levels of p27 to determine who would benefit from adjuvant therapy.[30] Similar correlations were observed in patients with non-small cell lung cancer,[31] those with colon,[31] and prostate cancer.[32]
So far studies have only evaluated the prognostic value of p27 retrospectively and a standardized scoring system has not been established.[12] However it has been proposed that clinicians should evaluate a patient’s p27 levels in order to determine if they will be responsive to certain chemotoxins which target fast growing tumors where p27 levels are low.[12] Or in contrast, if p27 levels are found to be high in a patient’s cancer, their risk for metastasis is higher and the physician can make an informed decision about their treatment plan.[12] Because p27 levels are controlled post-transcriptionally, proteomic surveys can be used to establish and monitor a patient’s individual levels which aids in the future of individualized medicine.
The following cancers have been demonstrated to have an inverse correlation with p27 expression and prognosis: oro-pharyngo-laryngeal, oesophageal, gastric, colon, lung, melanoma, glioma, breast cancer, prostate, lymphoma, leukemia.[13]
## Correlation to treatment response
P27 may also allow clinicians to better select an appropriate treatment for a patient. For example, patients with non-small cell lung cancer who were treated with platinum based chemotherapy showed reduced survival if they had low levels of p27.[33] Similarly low levels of p27 correlated with poor results from adjuvant chemotherapy in breast cancer patients.[34]
## Value as a therapeutic target
P27 has been explored as a potential target for cancer therapy because its levels are highly correlated to patient prognosis.[35] This is true for a wide spectrum of cancers including colon, breast, prostate, lung, liver, stomach, and bladder.[35]
### Use of microRNAs for therapy
Because of the role miRNAs play in p27 regulation, research is underway to determine if antagomiRs that block the activity of the miR221&222 and allow for p27 cell grow inhibition to take place could act as therapeutic cancer drugs.[11]
# Role in Regeneration
Knockdown of CDKN1B stimulates regeneration of cochlear hair cells in mice. Since CDKN1B prevents cells from entering the cell cycle, inhibition of the protein could cause re-entry and subsequent division. In mammals where regeneration of cochlear hair cells normally does not occur, this inhibition could help regrow damaged cells who are otherwise incapable of proliferation. In fact, when the CDKN1B gene is disrupted in adult mice, hair cells of the organ of Corti proliferate, while those in control mice do not. Lack of CDKN1B expression appears to release the hair cells from natural cell-cycle arrest.[36][37] Because hair cell death in the human cochlea is a major cause of hearing loss, the CDKN1B protein could be an important factor in the clinical treatment of deafness.
# Interactions
CDKN1B has been shown to interact with:
- AKT1,[38]
- CKS1B,[39][40]
- Cyclin D3,[41][42][43]
- Cyclin E1,[44][45]
- Cyclin-dependent kinase 2,[44][46][47][48][49]
- Cyclin-dependent kinase 4,[41][50]
- Grb2,[51]
- NUP50[52]
- SKP2,[38][39][40]
- SPDYA,[46] and
- XPO1.[44][53] | https://www.wikidoc.org/index.php/CDKN1B | |
dfbaa615f4d0b8dd62eaa27449a60c90e8e19893 | wikidoc | CDKN2A | CDKN2A
CDKN2A, also known as cyclin-dependent kinase Inhibitor 2A, is a gene which in humans is located at chromosome 9, band p21.3. It is ubiquitously expressed in many tissues and cell types. The gene codes for two proteins, including the INK4 family member p16 (or p16INK4a) and p14arf. Both act as tumor suppressors by regulating the cell cycle. p16 inhibits cyclin dependent kinases 4 and 6 (CDK4 and CDK6) and thereby activates the retinoblastoma (Rb) family of proteins, which block traversal from G1 to S-phase. p14ARF (known as p19ARF in the mouse) activates the p53 tumor suppressor. Somatic mutations of CDKN2A are common in the majority of human cancers, with estimates that CDKN2A is the second most commonly inactivated gene in cancer after p53. Germline mutations of CDKN2A are associated with familial melanoma, glioblastoma and pancreatic cancer. The CDKN2A gene also contains one of 27 SNPs associated with increased risk of coronary artery disease.
# Structure
## Gene
The CDKN2A gene resides on chromosome 9 at the band 9p21 and contains 8 exons. This gene encodes two proteins, p16 and p14ARF, which are transcribed from the same second and third exons but alternative first exons: p16 from exon 1α and ARF from exon 1β. As a result, they are translated from different reading frames and therefore possess completely different amino acid sequences. In addition to p16 and ARF, this gene produces 4 other isoforms through alternative splicing.
## Protein
### p16
This protein belongs to the CDKN2 cyclin-dependent kinase inhibitor family. p16 comprises four ankyrin repeats, each spanning a length of 33 amino acid residues and, in the tertiary structure, forming a helix-turn-helix motif. One exception is the second ankyrin repeat, which contains only one helical turn. These four motifs are connected by three loops such that they are oriented perpendicular to the helical axes.
According to its solvent-accessible surface representation, p16 features clustered charged groups on its surface and a pocket located on the right side with a negatively charged left inner wall and a positively charged right inner wall.
### p14ARF
The size of this protein is 14 kDa in humans. Within the N-terminal half of ARF are highly hydrophobic domains that serve as mitochondrial import sequences.
# Function
## P14ARF
P14ARF is a central actor of the cell cycle regulation process as it participates to the ARF-MDM2-p53 pathway and the Rb-E2F-1 pathway. It is the physiological inhibitor of MDM2, an E3 ubiquitin ligase controlling the activity and stability of P53, and loss of P14ARF activity may have a similar effect as loss of P53. P14ARF induces cell cycle arrest in G2 phase and subsequent apoptosis in a P53-dependent and P53-independent manner, and thus is regarded as a tumor suppressor. In addition, P14ARF could down-regulate E2F-dependent transcription and plays a role in the control of the G1 to S phase transition as well.
## P16（INK4A）
P16 interacts with Rb and controls the G1 to S transition. It binds to CDK4/6 inhibiting its kinase activity and prevents Rb phosphorylation. Therefore, Rb remains associated with transcription factor E2F1, preventing transcription of E2F1 target genes which are crucial for the G1/S transition. During this process, a feedback loop exists between P16 and Rb, and P16 expression is controlled by Rb. P16/Rb pathway collaborates with the mitogenic signaling cascade for the induction of reactive oxygen species, which activates the protein kinase C delta, leading to an irreversible cell cycle arrest. Thus P16 participates not only in the initiation but also in the maintenance of cellular senescence, as well in tumor suppression. On the other hand, some specific tumors harbor high levels of P16, and its function in limitation of tumorigenic progression has been inactivated via the loss of Rb.
# Clinical relevance
In human cancer cell lines derived from various tumor types, a high frequency of genetic and epigenetic alterations (e.g., promoter hyper-methylation, homozygous deletion or mutation) in the CDKN2A gene has been observed. Accordingly, epigenetic/genetic modulation of changes in CDKN2A might be a promising strategy for prevention or therapy of cancer.
The CDKN2A gene is located on the chromosome 9p21 locus, which is intriguing for several reasons. First, this region is well known in cancer genetics as one of the most common sites of deletions leading to hereditary forms of cutaneous malignant melanoma. Second, genome wide association studies have reported a significant association of chromosome 9p21 with coronary artery disease and myocardial infarction as well as the progression of atherosclerosis.
Furthermore, changes in CDKN2A status are highly variable depending on the type of cancer. In addition to skin cancer such as melanoma, changes of CDKN2A have been described in a wide spectrum of cancer types such as gastric lymphoma, Burkitt’s lymphoma, head & neck squamous cell carcinoma, oral cancer, pancreatic adenocarcinoma, non-small cell lung carcinoma, esophageal squamous cell carcinoma, gastric cancer, colorectal cancer, epithelial ovarian carcinoma and prostate cancer.
## Familial melanoma
CDKN2A is made up of four sections of exons – exon 1β, exon 1α, exon 2, and exon 3. These exons are used to create two proteins named p16 and p14ARF. Protein p16, created by exon 1α and exon 2, is responsible for tumor creation of genetic melanoma. When working normally, p16 binds to the cyclic dependent kinases CDK4 to inhibit their ability to create tumors, but when inactivated the suppression no longer occurs. When a mutation occurs in protein p16, it prevents the protein kinase of CDK4, which results in the inactivation of the tumor suppressor gene. Thus, kick starting the development of melanoma.
Melanoma only occurs in a small proportion of the population. Only 10% of those who have melanoma acquired it genetically. This disease is an autosomal dominant gene. If only two family members have melanoma, there is a 5% chance somebody in the next generation will acquire the mutated gene. Also, there is a 20-40% chance of getting hereditary melanoma in a family if 3 or more people in the past generation had melanoma. For those who carry the hereditary mutated gene CDKN2A, acquiring skin cancer is a lot easier. Those who have the gene are far more likely to get melanoma a second or third time compared to those who don’t genetically have this gene. The population that is affected by this mutation has a high familial history of melanoma or atypical moles and birth marks in large numbers, a history of primary melanoma/cancers in general, immunosuppression, skin that burns easily and doesn't tan, freckling, blue eyes, red hair, or a history of blistering. People with these high risk factors are more likely to carry inherited mutations in CDKN2A. For those who have a gene mutation, the severity is also dependent on the environmental surroundings. Out of those who carry the gene, those who express the phenotype and actually developed melanoma have a history of more sun exposure, and light skin compared to those who also had the gene but never actually developed melanoma. This suggests that this gene co-works with ones surrounding environment. If two individuals are selected who carry the CDKN2A mutation, and both genetically have the same probability of acquiring skin cancer, but one is from Australia and the other is from Europe, there is a 58% the European will acquire cancer compared to a 91% chance the Australian will get it. This is because the factors mentioned earlier pertaining to those who are more susceptible to the disease and also dependent on the amount of sunscreen one wears and the UV radiation potency in their environment.
## Clinical marker
A multi-locus genetic risk score study based on a combination of 27 loci, including the CDKN2A gene, identified individuals at increased risk for both incident and recurrent coronary artery disease events, as well as an enhanced clinical benefit from statin therapy. The study was based on a community cohort study (the Malmo Diet and Cancer study) and four additional randomized controlled trials of primary prevention cohorts (JUPITER and ASCOT) and secondary prevention cohorts (CARE and PROVE IT-TIMI 22).
## Therapeutic potential of BRAF kinase inhibitors
RAS-RAF-MEK-ERK MAP kinase pathway plays an important role in melanocytes, where melanoma arises. Stimulation of membrane bound receptors including tyrosine kinases and G-proteins receptors promote activation of RAS then activates RAF kinases which in turn promotes MEK then ERK activation. All of these proteins work together to help cell survival. A BRAF mutation in this activation chain triggers malignant transformation in melanoma cells. Melanoma relies on this BRAF mutation to grow and multiply as a tumor cell.
RNA interference of BRAF stops the multiplication of melanoma tumor cells. This suggests that BRAF inhibitors such as sorafenib, PLX4720, PLX4032, GDC-0879, GSK2118436, or AZ628 may be affective in treating melanoma. These have been tested and proven to slow down the production of melanoma due to BRAF mutation but PLX4032 and GSK2118436 show the most promise because they worked the most aggressively in early stages of cell development. Although this drug helps slow down or shrink the tumors, there are many serious side effects to using these drugs that were found in the trials including arthralgia, rash, nausea, phosphosensitivity], fatigue, pruritus and palmo-plantar dysesthesia.
## Aging
Activation of the CDKN2A locus promotes the cellular senescence tumor suppressor mechanism, which is a permanent form of growth arrest. As senescent cells accumulate with aging, expression of CDKN2A increases exponentially with aging in all mammalian species tested to date, and has been argued to serve as a biomarker of physiological age. Notably, a recent survey of cellular senescence induced by multiple treatments to several cell lines does not identify CDKN2A as belonging to a "core signature" of senescence markers. | CDKN2A
CDKN2A, also known as cyclin-dependent kinase Inhibitor 2A, is a gene which in humans is located at chromosome 9, band p21.3.[1] It is ubiquitously expressed in many tissues and cell types.[2] The gene codes for two proteins, including the INK4 family member p16 (or p16INK4a) and p14arf.[3] Both act as tumor suppressors by regulating the cell cycle. p16 inhibits cyclin dependent kinases 4 and 6 (CDK4 and CDK6) and thereby activates the retinoblastoma (Rb) family of proteins, which block traversal from G1 to S-phase. p14ARF (known as p19ARF in the mouse) activates the p53 tumor suppressor. Somatic mutations of CDKN2A are common in the majority of human cancers, with estimates that CDKN2A is the second most commonly inactivated gene in cancer after p53. Germline mutations of CDKN2A are associated with familial melanoma, glioblastoma and pancreatic cancer.[4] The CDKN2A gene also contains one of 27 SNPs associated with increased risk of coronary artery disease.[5]
# Structure[6]
## Gene
The CDKN2A gene resides on chromosome 9 at the band 9p21 and contains 8 exons.[7] This gene encodes two proteins, p16 and p14ARF, which are transcribed from the same second and third exons but alternative first exons: p16 from exon 1α and ARF from exon 1β. As a result, they are translated from different reading frames and therefore possess completely different amino acid sequences.[8] In addition to p16 and ARF, this gene produces 4 other isoforms through alternative splicing.[9]
## Protein
### p16
This protein belongs to the CDKN2 cyclin-dependent kinase inhibitor family.[9] p16 comprises four ankyrin repeats, each spanning a length of 33 amino acid residues and, in the tertiary structure, forming a helix-turn-helix motif. One exception is the second ankyrin repeat, which contains only one helical turn. These four motifs are connected by three loops such that they are oriented perpendicular to the helical axes.
According to its solvent-accessible surface representation, p16 features clustered charged groups on its surface and a pocket located on the right side with a negatively charged left inner wall and a positively charged right inner wall.[10]
### p14ARF
The size of this protein is 14 kDa in humans.[11] Within the N-terminal half of ARF are highly hydrophobic domains that serve as mitochondrial import sequences.
# Function
## P14ARF
P14ARF is a central actor of the cell cycle regulation process as it participates to the ARF-MDM2-p53 pathway and the Rb-E2F-1 pathway.[12] It is the physiological inhibitor of MDM2, an E3 ubiquitin ligase controlling the activity and stability of P53, and loss of P14ARF activity may have a similar effect as loss of P53.[13] P14ARF induces cell cycle arrest in G2 phase and subsequent apoptosis in a P53-dependent and P53-independent manner, and thus is regarded as a tumor suppressor.[14][15][16][17] In addition, P14ARF could down-regulate E2F-dependent transcription and plays a role in the control of the G1 to S phase transition as well.[18]
## P16（INK4A）
P16 interacts with Rb and controls the G1 to S transition. It binds to CDK4/6 inhibiting its kinase activity and prevents Rb phosphorylation. Therefore, Rb remains associated with transcription factor E2F1, preventing transcription of E2F1 target genes which are crucial for the G1/S transition. During this process, a feedback loop exists between P16 and Rb, and P16 expression is controlled by Rb.[19][20] P16/Rb pathway collaborates with the mitogenic signaling cascade for the induction of reactive oxygen species, which activates the protein kinase C delta, leading to an irreversible cell cycle arrest. Thus P16 participates not only in the initiation but also in the maintenance of cellular senescence, as well in tumor suppression.[21][22] On the other hand, some specific tumors harbor high levels of P16, and its function in limitation of tumorigenic progression has been inactivated via the loss of Rb.[22][23]
# Clinical relevance
In human cancer cell lines derived from various tumor types, a high frequency of genetic and epigenetic alterations (e.g., promoter hyper-methylation, homozygous deletion or mutation) in the CDKN2A gene has been observed. Accordingly, epigenetic/genetic modulation of changes in CDKN2A might be a promising strategy for prevention or therapy of cancer.
The CDKN2A gene is located on the chromosome 9p21 locus, which is intriguing for several reasons. First, this region is well known in cancer genetics as one of the most common sites of deletions leading to hereditary forms of cutaneous malignant melanoma.[8][24] Second, genome wide association studies have reported a significant association of chromosome 9p21 with coronary artery disease and myocardial infarction[25] as well as the progression of atherosclerosis.[26]
Furthermore, changes in CDKN2A status are highly variable depending on the type of cancer. In addition to skin cancer such as melanoma, changes of CDKN2A have been described in a wide spectrum of cancer types such as gastric lymphoma,[27] Burkitt’s lymphoma,[28] head & neck squamous cell carcinoma,[29] oral cancer,[30] pancreatic adenocarcinoma,[31] non-small cell lung carcinoma,[32] esophageal squamous cell carcinoma,[33] gastric cancer,[34] colorectal cancer,[35] epithelial ovarian carcinoma[36] and prostate cancer.[37]
## Familial melanoma
CDKN2A is made up of four sections of exons – exon 1β, exon 1α, exon 2, and exon 3. These exons are used to create two proteins named p16 and p14ARF. Protein p16, created by exon 1α and exon 2, is responsible for tumor creation of genetic melanoma. When working normally, p16 binds to the cyclic dependent kinases CDK4 to inhibit their ability to create tumors, but when inactivated the suppression no longer occurs.[38] When a mutation occurs in protein p16, it prevents the protein kinase of CDK4, which results in the inactivation of the tumor suppressor gene.[38] Thus, kick starting the development of melanoma.
Melanoma only occurs in a small proportion of the population. Only 10% of those who have melanoma acquired it genetically.[39] This disease is an autosomal dominant gene.[38] If only two family members have melanoma, there is a 5% chance somebody in the next generation will acquire the mutated gene. Also, there is a 20-40% chance of getting hereditary melanoma in a family if 3 or more people in the past generation had melanoma. For those who carry the hereditary mutated gene CDKN2A, acquiring skin cancer is a lot easier.[39] Those who have the gene are far more likely to get melanoma a second or third time compared to those who don’t genetically have this gene.[40] The population that is affected by this mutation has a high familial history of melanoma or atypical moles and birth marks in large numbers, a history of primary melanoma/cancers in general, immunosuppression, skin that burns easily and doesn't tan, freckling, blue eyes, red hair, or a history of blistering.[39] People with these high risk factors are more likely to carry inherited mutations in CDKN2A.[40] For those who have a gene mutation, the severity is also dependent on the environmental surroundings. Out of those who carry the gene, those who express the phenotype and actually developed melanoma have a history of more sun exposure, and light skin compared to those who also had the gene but never actually developed melanoma.[40] This suggests that this gene co-works with ones surrounding environment. If two individuals are selected who carry the CDKN2A mutation, and both genetically have the same probability of acquiring skin cancer, but one is from Australia and the other is from Europe, there is a 58% the European will acquire cancer compared to a 91% chance the Australian will get it.[40] This is because the factors mentioned earlier pertaining to those who are more susceptible to the disease and also dependent on the amount of sunscreen one wears and the UV radiation potency in their environment.[39]
## Clinical marker
A multi-locus genetic risk score study based on a combination of 27 loci, including the CDKN2A gene, identified individuals at increased risk for both incident and recurrent coronary artery disease events, as well as an enhanced clinical benefit from statin therapy. The study was based on a community cohort study (the Malmo Diet and Cancer study) and four additional randomized controlled trials of primary prevention cohorts (JUPITER and ASCOT) and secondary prevention cohorts (CARE and PROVE IT-TIMI 22).[5]
## Therapeutic potential of BRAF kinase inhibitors
RAS-RAF-MEK-ERK MAP kinase pathway plays an important role in melanocytes, where melanoma arises.[41] Stimulation of membrane bound receptors including tyrosine kinases and G-proteins receptors promote activation of RAS then activates RAF kinases which in turn promotes MEK then ERK activation. All of these proteins work together to help cell survival. A BRAF mutation in this activation chain triggers malignant transformation in melanoma cells.[42] Melanoma relies on this BRAF mutation to grow and multiply as a tumor cell.
RNA interference of BRAF stops the multiplication of melanoma tumor cells.[42] This suggests that BRAF inhibitors such as sorafenib, PLX4720, PLX4032, GDC-0879, GSK2118436, or AZ628 may be affective in treating melanoma.[41] These have been tested and proven to slow down the production of melanoma due to BRAF mutation but PLX4032 and GSK2118436 show the most promise because they worked the most aggressively in early stages of cell development.[42] Although this drug helps slow down or shrink the tumors, there are many serious side effects to using these drugs that were found in the trials including arthralgia, rash, nausea, phosphosensitivity], fatigue, pruritus and palmo-plantar dysesthesia.[42]
## Aging
Activation of the CDKN2A locus promotes the cellular senescence tumor suppressor mechanism, which is a permanent form of growth arrest. As senescent cells accumulate with aging, expression of CDKN2A increases exponentially with aging in all mammalian species tested to date, and has been argued to serve as a biomarker of physiological age.[43] Notably, a recent survey of cellular senescence induced by multiple treatments to several cell lines does not identify CDKN2A as belonging to a "core signature" of senescence markers.[44] | https://www.wikidoc.org/index.php/CDKN2A | |
b1f923318dd796490dbc286c26feaf85c2997499 | wikidoc | CDKN2C | CDKN2C
Cyclin-dependent kinase 4 inhibitor C is an enzyme that in humans is encoded by the CDKN2C gene.
# Function
The protein encoded by this gene is a member of the INK4 family of cyclin-dependent kinase inhibitors. This protein has been shown to interact with CDK4 or CDK6, and prevent the activation of the CDK kinases, thus function as a cell growth regulator that controls cell cycle G1 progression. Ectopic expression of this gene was shown to suppress the growth of human cells in a manner that appears to correlate with the presence of a wild-type RB1 function. Studies in the knockout mice suggested the roles of this gene in regulating spermatogenesis, as well as in suppressing tumorigenesis. Two alternatively spliced transcript variants of this gene, which encode an identical protein, have been reported.
# Interactions
CDKN2C has been shown to interact with Cyclin-dependent kinase 4 and Cyclin-dependent kinase 6. | CDKN2C
Cyclin-dependent kinase 4 inhibitor C is an enzyme that in humans is encoded by the CDKN2C gene.[1][2][3]
# Function
The protein encoded by this gene is a member of the INK4 family of cyclin-dependent kinase inhibitors. This protein has been shown to interact with CDK4 or CDK6, and prevent the activation of the CDK kinases, thus function as a cell growth regulator that controls cell cycle G1 progression. Ectopic expression of this gene was shown to suppress the growth of human cells in a manner that appears to correlate with the presence of a wild-type RB1 function. Studies in the knockout mice suggested the roles of this gene in regulating spermatogenesis, as well as in suppressing tumorigenesis. Two alternatively spliced transcript variants of this gene, which encode an identical protein, have been reported.[3]
# Interactions
CDKN2C has been shown to interact with Cyclin-dependent kinase 4[1][4] and Cyclin-dependent kinase 6.[1][4][5] | https://www.wikidoc.org/index.php/CDKN2C | |
e71d5e6f9fa73e950e1e9aab9309d43fe2c39ec9 | wikidoc | CDKN2D | CDKN2D
Cyclin-dependent kinase 4 inhibitor D is an enzyme that in humans is encoded by the CDKN2D gene.
The protein encoded by this gene is a member of the INK4 family of cyclin-dependent kinase inhibitors. This protein has been shown to form a stable complex with CDK4 or CDK6, and prevent the activation of the CDK kinases, thus function as a cell growth regulator that controls cell cycle G1 progression. The abundance of the transcript of this gene was found to oscillate in a cell-cycle dependent manner with the lowest expression at mid G1 and a maximal expression during S phase. The negative regulation of the cell cycle involved in this protein was shown to participate in repressing neuronal proliferation, as well as spermatogenesis. Two alternatively spliced variants of this gene, which encode an identical protein, have been reported.
Note, this protein should not be confused with p19-ARF (mouse) or the human equivalent p14ARF, which are alternative products of the CDKN2A gene. | CDKN2D
Cyclin-dependent kinase 4 inhibitor D is an enzyme that in humans is encoded by the CDKN2D gene.[1][2]
The protein encoded by this gene is a member of the INK4 family of cyclin-dependent kinase inhibitors. This protein has been shown to form a stable complex with CDK4 or CDK6, and prevent the activation of the CDK kinases, thus function as a cell growth regulator that controls cell cycle G1 progression. The abundance of the transcript of this gene was found to oscillate in a cell-cycle dependent manner with the lowest expression at mid G1 and a maximal expression during S phase. The negative regulation of the cell cycle involved in this protein was shown to participate in repressing neuronal proliferation, as well as spermatogenesis. Two alternatively spliced variants of this gene, which encode an identical protein, have been reported.[2]
Note, this protein should not be confused with p19-ARF (mouse) or the human equivalent p14ARF, which are alternative products of the CDKN2A gene. | https://www.wikidoc.org/index.php/CDKN2D | |
983202e3d29b535b2dc048923f64742037cfbb30 | wikidoc | CDP323 | CDP323
CDP323 is a small-molecule prodrug antagonist of the vascular cell adhesion molecule 1 (VCAM-1) binding to α4-integrins. It was originally developed by the British biopharmaceutical company Celltech plc. (now UCB S.A.) and is a putative new drug for oral treatment of multiple sclerosis.
In October 2006, UCB S.A. and Biogen Idec announced a collaboration to jointly develop and commercialize CDP323 for the treatment of multiple sclerosis and other potential indications.
# Mechanism of Action
The mechanism of action of CDP323 is believed to rely on preventing immune cells to migrate from blood vessels through the vessel walls to reach various inflamed tissues, including the brain. This mechanism is thought to prevent overshooting immune reactions and subsequent tissue damage as seen during uncontrolled immune cell migration as in multiple sclerosis. CDP323 has the same mechanism of action as the monoclonal antibody natalizumab.
# Results in Animal Models
CDP323 was investigated in chronic experimental autoimmune encephalomyelitis (EAE) in mice. The drug was effective when given prophylactically (i.e., before the disease was induced in mice) and when given therapeutically (i.e., after outbreak of the disease) and reduced the disease severity significantly.
# Clinical Development
The safety, tolerability, and pharmacokinetic profile of CDP323 have been evaluated in 75 female and male healthy volunteers in three separate Phase 1 studies. CDP323 was well tolerated at oral doses up to 1000 mg given twice daily for 7 consecutive days with an adverse event profile comparable to that observed with placebo. There was no gender effect. The oral administration resulted in inhibition of VCAM-1 binding which could be maintained throughout a 12 or 24 hour dose interval at well tolerated doses
A Phase 2 study commenced in June 2007 in Europe and in the US. The study intends to enroll over 200 patients with relapsing MS who have failed earlier treatment with an interferon-beta and will compare two doses of the drug to placebo over a period of six months. The results are expected by the end of 2008., | CDP323
CDP323 is a small-molecule prodrug antagonist of the vascular cell adhesion molecule 1 (VCAM-1) binding to α4-integrins. It was originally developed by the British biopharmaceutical company Celltech plc. (now UCB S.A.) and is a putative new drug for oral treatment of multiple sclerosis.[1]
In October 2006, UCB S.A. and Biogen Idec announced a collaboration to jointly develop and commercialize CDP323 for the treatment of multiple sclerosis and other potential indications.[2]
# Mechanism of Action
The mechanism of action of CDP323 is believed to rely on preventing immune cells to migrate from blood vessels through the vessel walls to reach various inflamed tissues, including the brain. This mechanism is thought to prevent overshooting immune reactions and subsequent tissue damage as seen during uncontrolled immune cell migration as in multiple sclerosis. CDP323 has the same mechanism of action as the monoclonal antibody natalizumab.
# Results in Animal Models
CDP323 was investigated in chronic experimental autoimmune encephalomyelitis (EAE) in mice. The drug was effective when given prophylactically (i.e., before the disease was induced in mice) and when given therapeutically (i.e., after outbreak of the disease) and reduced the disease severity significantly.[3]
# Clinical Development
The safety, tolerability, and pharmacokinetic profile of CDP323 have been evaluated in 75 female and male healthy volunteers in three separate Phase 1 studies. CDP323 was well tolerated at oral doses up to 1000 mg given twice daily for 7 consecutive days with an adverse event profile comparable to that observed with placebo. There was no gender effect. The oral administration resulted in inhibition of VCAM-1 binding which could be maintained throughout a 12 or 24 hour dose interval at well tolerated doses[4]
A Phase 2 study commenced in June 2007 in Europe and in the US. The study intends to enroll over 200 patients with relapsing MS who have failed earlier treatment with an interferon-beta and will compare two doses of the drug to placebo over a period of six months. The results are expected by the end of 2008.[5],[6] | https://www.wikidoc.org/index.php/CDP323 | |
f70602c104721bd67f24157b474f8a1620bcc531 | wikidoc | CELA3B | CELA3B
Chymotrypsin-like elastase family member 3B also known as elastase-3B, protease E, or fecal elastase is an enzyme that in humans is encoded by the CELA3B gene.
Clinical literature that describes human elastase 1 activity in the pancreas or fecal material is actually referring to chymotrypsin-like elastase family, member 3B (this protein).
# Function
Elastases form a subfamily of serine proteases that hydrolyze many proteins in addition to elastin. Humans have six elastase genes which encode the structurally similar proteins elastase 1, 2, 2A, 2B, 3A, and 3B. Unlike other elastases, elastase 3B has little elastolytic activity. Like most of the human elastases, elastase 3B is secreted from the pancreas as a zymogen and, like other serine proteases such as trypsin, chymotrypsin and kallikrein, it has a digestive function in the intestine. Elastase 3B preferentially cleaves proteins after alanine residues. Elastase 3B may also function in the intestinal transport and metabolism of cholesterol. Both elastase 3A and elastase 3B have been referred to as protease E and as elastase 1, and excretion of this protein in fecal material is frequently used as a measure of pancreatic function in clinical assays.
# Clinical significance
Fecal elastase is a medical test that measures how well the pancreas is functioning.
The fecal elastase test measures the concentration of the elastase-3B enzyme found in fecal matter with an enzyme-linked immunosorbent assay (ELISA). Results of this test can give a good indication of exocrine pancreatic status, and the test is less invasive and expensive than the current "gold standard", secretin-cholecystokinin test. Levels of fecal elastase lower than 200 μg / g of stool indicate an exocrine insufficiency. Correlations between low levels and chronic pancreatitis and cancer have been reported. | CELA3B
Chymotrypsin-like elastase family member 3B also known as elastase-3B, protease E, or fecal elastase is an enzyme that in humans is encoded by the CELA3B gene.[1][2][3]
Clinical literature that describes human elastase 1 activity in the pancreas or fecal material is actually referring to chymotrypsin-like elastase family, member 3B (this protein).[4]
# Function
Elastases form a subfamily of serine proteases that hydrolyze many proteins in addition to elastin. Humans have six elastase genes which encode the structurally similar proteins elastase 1, 2, 2A, 2B, 3A, and 3B. Unlike other elastases, elastase 3B has little elastolytic activity. Like most of the human elastases, elastase 3B is secreted from the pancreas as a zymogen and, like other serine proteases such as trypsin, chymotrypsin and kallikrein, it has a digestive function in the intestine. Elastase 3B preferentially cleaves proteins after alanine residues. Elastase 3B may also function in the intestinal transport and metabolism of cholesterol. Both elastase 3A and elastase 3B have been referred to as protease E and as elastase 1, and excretion of this protein in fecal material is frequently used as a measure of pancreatic function in clinical assays.[3]
# Clinical significance
Fecal elastase is a medical test that measures how well the pancreas is functioning.
The fecal elastase test measures the concentration of the elastase-3B enzyme found in fecal matter with an enzyme-linked immunosorbent assay (ELISA). Results of this test can give a good indication of exocrine pancreatic status, and the test is less invasive and expensive than the current "gold standard", secretin-cholecystokinin test.[5] Levels of fecal elastase lower than 200 μg / g of stool indicate an exocrine insufficiency. Correlations between low levels and chronic pancreatitis[6] and cancer[7] have been reported. | https://www.wikidoc.org/index.php/CELA3B | |
aa39e317ef3d34df3130b5387bdda9d838790220 | wikidoc | CENTG2 | CENTG2
Arf-GAP with GTPase, ANK repeat and PH domain-containing protein 1 is an enzyme that in humans is encoded by the AGAP1 gene.
# Function
CENTG2 belongs to an ADP-ribosylation factor GTPase-activating (ARF-GAP) protein family involved in membrane traffic and actin cytoskeleton dynamics (Nie et al., 2002).
# HACNS1
HACNS1 is located in an intron of the gene CENTG2 (also known as Human Accelerated Region 2). HACNS1 is hypothesized to be a gene enhancer "that may have contributed to the evolution of the uniquely opposable human thumb, and possibly also modifications in the ankle or foot that allow humans to walk on two legs". Evidence to date shows that of the 110,000 gene enhancer sequences identified in the human genome, HACNS1 has undergone the most change during the evolution of humans following the split with the ancestors of chimpanzees.
# Model organisms
Model organisms have been used in the study of AGAP1 function. A conditional knockout mouse line called Agap1tm1a(EUCOMM)Wtsi was generated at the Wellcome Trust Sanger Institute. Male and female animals underwent a standardized phenotypic screen to determine the effects of deletion. Additional screens performed: - In-depth immunological phenotyping - in-depth bone and cartilage phenotyping | CENTG2
Arf-GAP with GTPase, ANK repeat and PH domain-containing protein 1 is an enzyme that in humans is encoded by the AGAP1 gene.[1]
# Function
CENTG2 belongs to an ADP-ribosylation factor GTPase-activating (ARF-GAP) protein family involved in membrane traffic and actin cytoskeleton dynamics (Nie et al., 2002).[supplied by OMIM][1]
# HACNS1
HACNS1 is located in an intron of the gene CENTG2 (also known as Human Accelerated Region 2). HACNS1 is hypothesized to be a gene enhancer "that may have contributed to the evolution of the uniquely opposable human thumb, and possibly also modifications in the ankle or foot that allow humans to walk on two legs". Evidence to date shows that of the 110,000 gene enhancer sequences identified in the human genome, HACNS1 has undergone the most change during the evolution of humans following the split with the ancestors of chimpanzees.[2]
# Model organisms
Model organisms have been used in the study of AGAP1 function. A conditional knockout mouse line called Agap1tm1a(EUCOMM)Wtsi was generated at the Wellcome Trust Sanger Institute.[3] Male and female animals underwent a standardized phenotypic screen[4] to determine the effects of deletion.[5][6][7][8] Additional screens performed: - In-depth immunological phenotyping[9] - in-depth bone and cartilage phenotyping[10] | https://www.wikidoc.org/index.php/CENTG2 | |
f1c49cbc750d8743dd1657dc3a395624607c18bf | wikidoc | CEP170 | CEP170
Centrosomal protein 170kDa, also known as CEP170, is a protein that in humans is encoded by the CEP170 gene.
# Function
The product of this gene is a component of the centrosome, a non-membraneous organelle that functions as the major microtubule-organizing center in animal cells. During interphase, the encoded protein localizes to the sub-distal appendages of mature centrioles, which are microtubule-based structures thought to help organize centrosomes. During mitosis, the protein associates with spindle microtubules near the centrosomes. The protein interacts with the intraflagellar transport protein 81 (IFT81), the SH3-domain containing protein PRAX-1, and is phosphorylated by cyclin dependent kinase 1 ( Cdk1 ) and polo-like kinase 1 ( PLK1 ), and functions in maintaining Microtubule organization, cell morphology and cilium stability.
The human genome contains a putative transcribed pseudogene. Several alternatively spliced transcript variants of this gene have been found, but the full-length nature of some of these variants has not been determined. | CEP170
Centrosomal protein 170kDa, also known as CEP170, is a protein that in humans is encoded by the CEP170 gene.[1][2]
# Function
The product of this gene is a component of the centrosome, a non-membraneous organelle that functions as the major microtubule-organizing center in animal cells. During interphase, the encoded protein localizes to the sub-distal appendages of mature centrioles, which are microtubule-based structures thought to help organize centrosomes. During mitosis, the protein associates with spindle microtubules near the centrosomes. The protein interacts with the intraflagellar transport protein 81 (IFT81), the SH3-domain containing protein PRAX-1, and is phosphorylated by cyclin dependent kinase 1 ( Cdk1 ) and polo-like kinase 1 ( PLK1 ), and functions in maintaining Microtubule organization, cell morphology and cilium stability.[1]
The human genome contains a putative transcribed pseudogene. Several alternatively spliced transcript variants of this gene have been found, but the full-length nature of some of these variants has not been determined.[1] | https://www.wikidoc.org/index.php/CEP170 | |
35cdacd13e2fbab74d2e87ee1087bf344041c6be | wikidoc | CEP290 | CEP290
Centrosomal protein of 290 kDa is a protein that in humans is encoded by the CEP290 gene. CEP290 is located on the Q arm of chromosome 12.
# Function
The gene CEP290 is a centrosomal protein that plays an important role in centrosome and cilia development. This gene is vital in the formation of the primary cilium, a small antenna-like projections of the cell membrane that plays an important role in the photoreceptors at the back of the retina (which detect light and color) and in the kidney, brain, and many other organs of the body. Knocking down levels of the CEP290 gene transcript resulted in dramatic suppression of ciliogenesis in retinal pigment epithelial cells in culture, proving just how important CEP290 is to cilia formation.
On a molecular level, CEP290 has been shown to play a critical regulatory and structural role in primary cilium formation. Recent studies have implicated CEP290 as a microtubule and membrane binding protein that might serve as a structural link between the microtubule core of the cilium and the overlying ciliary membrane. Disruption of CEP290's microtubule binding domain in the rd16 mouse model of CEP290 disease has been shown to result in rapid and dramatic retinal degeneration, demonstrating the importance of CEP290 microtubule binding in disease. The role of CEP290 in promoting ciliogensis is inhibited both by auto-regulatory domains found at either end of the CEP290 protein and through CEP290's interaction with the inhibitory protein CP110.
The discovery of the CEP290 gene has led researchers to find another gene critical in retinal function, LCA5. Clinical trials involving gene replacement of these two genes have started in Philadelphia, where researchers are hopeful that Leber Congenital Amaurosis will one day be cured.
# Structure
This gene encodes a protein with 13 putative coiled-coil domains, a region with homology to SMC chromosome segregation ATPases, six KID motifs, three tropomyosin homology domains and an ATP/GTP binding site motif A. The protein is localized to the centrosome and cilia and has sites for N-glycosylation, tyrosine sulfation, phosphorylation, N-myristoylation, and amidation.
# Clinical significance
Mutations in this gene have been associated with Joubert syndrome and nephronophthisis, and recently with a frequent form of Leber's Congenital Amaurosis, called LCA10. The presence of antibodies against this protein is associated with several forms of cancer.
A mutation in this gene leads to infant and child blindness, a disease known as Leber Congenital Amaurosis. As of today, 35 different mutations in CEP290 are responsible for causing LCA. Other mutations in CEP290 have also been identified in causing Meckel Syndrome and Joubert Syndrome, a few among many syndromes. A defective CEP290 gene is usually the cause of these disorders due to abnormal cilia. It is unknown how one mutation in a gene can cause so many different types of syndromes, particularly many of which affect the Central Nervous System. | CEP290
Centrosomal protein of 290 kDa is a protein that in humans is encoded by the CEP290 gene.[1][2][3][4] CEP290 is located on the Q arm of chromosome 12.
# Function
The gene CEP290 is a centrosomal protein that plays an important role in centrosome and cilia development. This gene is vital in the formation of the primary cilium, a small antenna-like projections of the cell membrane that plays an important role in the photoreceptors at the back of the retina (which detect light and color) and in the kidney, brain, and many other organs of the body. Knocking down levels of the CEP290 gene transcript resulted in dramatic suppression of ciliogenesis in retinal pigment epithelial cells in culture, proving just how important CEP290 is to cilia formation.
On a molecular level, CEP290 has been shown to play a critical regulatory and structural role in primary cilium formation. Recent studies have implicated CEP290 as a microtubule and membrane binding protein that might serve as a structural link between the microtubule core of the cilium and the overlying ciliary membrane.[5] Disruption of CEP290's microtubule binding domain in the rd16 mouse model of CEP290 disease [3] has been shown to result in rapid and dramatic retinal degeneration, demonstrating the importance of CEP290 microtubule binding in disease. The role of CEP290 in promoting ciliogensis is inhibited both by auto-regulatory domains found at either end of the CEP290 protein [5] and through CEP290's interaction with the inhibitory protein CP110.[6]
The discovery of the CEP290 gene has led researchers to find another gene critical in retinal function, LCA5. Clinical trials involving gene replacement of these two genes have started in Philadelphia, where researchers are hopeful that Leber Congenital Amaurosis will one day be cured.[7][8][9]
# Structure
This gene encodes a protein with 13 putative coiled-coil domains, a region with homology to SMC chromosome segregation ATPases, six KID motifs, three tropomyosin homology domains and an ATP/GTP binding site motif A. The protein is localized to the centrosome and cilia and has sites for N-glycosylation, tyrosine sulfation, phosphorylation, N-myristoylation, and amidation.[4]
# Clinical significance
Mutations in this gene have been associated with Joubert syndrome and nephronophthisis, and recently with a frequent form of Leber's Congenital Amaurosis, called LCA10. The presence of antibodies against this protein is associated with several forms of cancer.[4]
A mutation in this gene leads to infant and child blindness, a disease known as Leber Congenital Amaurosis. As of today, 35 different mutations in CEP290 are responsible for causing LCA. Other mutations in CEP290 have also been identified in causing Meckel Syndrome and Joubert Syndrome, a few among many syndromes. A defective CEP290 gene is usually the cause of these disorders due to abnormal cilia. It is unknown how one mutation in a gene can cause so many different types of syndromes, particularly many of which affect the Central Nervous System. | https://www.wikidoc.org/index.php/CEP290 | |
2de16fd324e53dc66f468e1cf4a7030b27f56212 | wikidoc | CEP350 | CEP350
Centrosome-associated protein 350 is a protein that in humans is encoded by the CEP350 gene.
CEP350 is a large protein with a CAP-Gly domain typically found in cytoskeleton-associated proteins. It primarily localizes to the centrosome, a non-membraneous organelle that functions as the major microtubule-organizing center in animal cells. CEP350 is required to anchor microtubules at the centrosome. Furthermore, it increases the stability of growing centrioles.
It is also implicated in the regulation of a class of nuclear hormone receptors in the nucleus. Several alternatively spliced transcript variants have been found, but their full-length nature has not been determined. | CEP350
Centrosome-associated protein 350 is a protein that in humans is encoded by the CEP350 gene.[1][2][3]
CEP350 is a large protein with a CAP-Gly domain typically found in cytoskeleton-associated proteins. It primarily localizes to the centrosome, a non-membraneous organelle that functions as the major microtubule-organizing center in animal cells. CEP350 is required to anchor microtubules at the centrosome. Furthermore, it increases the stability of growing centrioles.[4]
It is also implicated in the regulation of a class of nuclear hormone receptors in the nucleus. Several alternatively spliced transcript variants have been found, but their full-length nature has not been determined.[3] | https://www.wikidoc.org/index.php/CEP350 | |
5ff3559620e8d70b5ff82053dde9b02f7e5088bd | wikidoc | CEP85L | CEP85L
CEP85L, for "Centrosomal Protein 85kDa-Like" is a gene which encodes a protein that has identified as a breast cancer antigen. Nothing more is known of its function at this time. Three transcript variants encoding different isoforms have been found for this gene. It has been shown to be related to the QT interval in GWAS studies.
# Sources
- ↑ Database, GeneCards Human Gene. "CEP85L Gene - GeneCards | CE85L Protein | CE85L Antibody". www.genecards.org..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}
- ↑ Chambers JC, Zhao J, Terracciano CM, et al. (2010). "Genetic variation in SCN10A influences cardiac conduction". Nature Genetics. 42 (2): 149–152. doi:10.1038/ng.516. PMID 20062061. | CEP85L
CEP85L, for "Centrosomal Protein 85kDa-Like"[1] is a gene which encodes a protein that has identified as a breast cancer antigen. Nothing more is known of its function at this time. Three transcript variants encoding different isoforms have been found for this gene. It has been shown to be related to the QT interval in GWAS studies.[2]
# Sources
- ↑ Database, GeneCards Human Gene. "CEP85L Gene - GeneCards | CE85L Protein | CE85L Antibody". www.genecards.org..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}
- ↑ Chambers JC, Zhao J, Terracciano CM, et al. (2010). "Genetic variation in SCN10A influences cardiac conduction". Nature Genetics. 42 (2): 149–152. doi:10.1038/ng.516. PMID 20062061. | https://www.wikidoc.org/index.php/CEP85L | |
9fb708305e690f6779389eb928da3dfe0ddbb5a3 | wikidoc | CFAP47 | CFAP47
CFAP47, or cilia and flagella associated protein 47, is a human gene encoded on the X chromosome. in humans. CXorf59 is located on chromosome X at locus Xp21.1 of the human genome.
# Protein
CXorf59 is most commonly known as Cilia- and flagella- associated protein 47 (CFAP47) in other species.
# Gene
CFAP47 is a 3187 amino acid protein have seven splice variants and containing 64 exons. Genecard listed aliases for CXorf59 as Cilia and Flagella Associated Protein 47 (CFAP47), Calponin Homology Domain-Containing Protein 2 (CHDC2), FLJ3660, CXorf22, and CXorf30
# Orthologs and paralogs
Orthologs have been found in mammalia, aves, reptilia, amphibia, osteichthyes; sarcopterygii and actinopterygii, ascidiacea, gastropoda, cephalopoda, insecta, and demospongiae. There are no paralogs within the human genome.
# Expression
CXorf59 is a protein coding gene that is confirmed to be expressed in 27 different tissues. The liver, testis, thyroid, brain, and endometrium were higher in reads per kilobase of transcript (RPKM). While this gene is associated with cilia and flagella, there is no current functional information available on this protein. CXorf59 is also related to Calponin, a calcium binding protein. In the 324 to 403 base pair region, there is a Calponin homology domain. Calponin homology domains are found in cytoskeletal and signal transduction proteins. They are composed of four alpha helices and are actin-binding. | CFAP47
CFAP47, or cilia and flagella associated protein 47, is a human gene encoded on the X chromosome.[1] in humans. CXorf59 is located on chromosome X at locus Xp21.1 of the human genome.
# Protein
CXorf59 is most commonly known as Cilia- and flagella- associated protein 47 (CFAP47) in other species.
# Gene
CFAP47 is a 3187 amino acid protein have seven splice variants and containing 64 exons.[1] Genecard listed aliases for CXorf59 as Cilia and Flagella Associated Protein 47 (CFAP47), Calponin Homology Domain-Containing Protein 2 (CHDC2), FLJ3660, CXorf22, and CXorf30[2]
# Orthologs and paralogs
Orthologs have been found in mammalia, aves, reptilia, amphibia, osteichthyes; sarcopterygii and actinopterygii, ascidiacea, gastropoda, cephalopoda, insecta, and demospongiae. There are no paralogs within the human genome.
# Expression
CXorf59 is a protein coding gene that is confirmed to be expressed in 27 different tissues. The liver, testis, thyroid, brain, and endometrium were higher in reads per kilobase of transcript (RPKM).[1] While this gene is associated with cilia and flagella, there is no current functional information available on this protein.[1] CXorf59 is also related to Calponin, a calcium binding protein. In the 324 to 403 base pair region, there is a Calponin homology domain.[3] Calponin homology domains are found in cytoskeletal and signal transduction proteins. They are composed of four alpha helices and are actin-binding. | https://www.wikidoc.org/index.php/CFAP47 | |
3f8a2508e11ea236d96fd17092118d365cb148ce | wikidoc | CHI3L1 | CHI3L1
Chitinase-3-like protein 1 (CHI3L1), also known as YKL-40, is a secreted glycoprotein that is approximately 40kDa in size that in humans is encoded by the CHI3L1 gene. The name YKL-40 is derived from the three N-terminal amino acids present on the secreted form and its molecular mass. YKL-40 is expressed and secreted by various cell-types including macrophages, chondrocytes, fibroblast-like synovial cells, vascular smooth muscle cells, and hepatic stellate cells. The biological function of YKL-40 is unclear. It is not known to have a specific receptor. Its pattern of expression is associated with pathogenic processes related to inflammation, extracellular tissue remodeling, fibrosis and solid carcinomas and asthma.
# Function
Chitinases catalyze the hydrolysis of chitin, which is an abundant glycopolymer found in insect exoskeletons and fungal cell walls. The glycoside hydrolase 18 family of chitinases includes eight human family members. This gene encodes a glycoprotein member of the glycosyl hydrolase 18 family. The protein lacks chitinase activity and is secreted by activated macrophages, chondrocytes, neutrophils and synovial cells. The protein is thought to play a role in the process of inflammation and tissue remodeling. YKL-40 lacks chitinase activity due to mutations within the active site (conserved sequence: DXXDXDXE ; YKL-40 sequence: DGLDLAWL).
# Regulation and mechanism
YKL-40 has been linked to activation of the AKT pro-survival (anti-apoptotic) signaling pathway. YKL-40 promotes angiogenesis through VEGF-dependent and independent pathways.
YKL-40 is a migration factor for primary astrocytes and its expression is controlled by NFI-X3, STAT3, and AP-1.
CHI3l1 is induced by a variety of cancers and in the presence of semaphorin 7A (protein) can inhibit multiple anti-tumor immune system responses. Activating an antiviral immune pathway known as the RIG-like helicase (RLH) has the ability to counter CHI3l1 induction. Cancer cells can offset RLH by stimulating NLRX1. Poly(I:C), an RNA-like molecule, can stimulate RLH activation. RLH activation can also inhibit the expression of receptor IL-13Rα2pand lmonary metastasisre. It stores NK cell accumulation and activation. It augments the expression of IFN-α/β, chemerin and its receptor ChemR23, p-cofilin, LIMK2 and PTEN and inhibiting BRAF and NLRX1 in a MAVS-dependent manner.
# Cancer
It is assumed that YKL-40 plays a role in cancer cell proliferation, survival, invasiveness and in the regulation of cell-matrix interactions. It is suggested that YKL-40 is a marker associated with a poorer clinical outcome in genetically defined subgroups of different tumors. YKL-40 was recently introduced into (restricted) clinical practice. A few techniques are available for its detection.
YKL-40 is a Th2 promoting cytokine that is present at high levels in the tumor microenvironment and in the serum of cancer patients. Elevated levels of YKL-40 correlate strongly with stage and outcome of various types of cancer, which establish YKL-40 as a biomarker of disease severity. Targeting YKL-40 with neutralizing antibodies is effective as a treatment in animal models of glioblastoma multiforme.
YKL-40 also enhances tumor survival in response to gamma-irradiation. | CHI3L1
Chitinase-3-like protein 1 (CHI3L1), also known as YKL-40, is a secreted glycoprotein that is approximately 40kDa in size that in humans is encoded by the CHI3L1 gene.[1][2][3] The name YKL-40 is derived from the three N-terminal amino acids present on the secreted form and its molecular mass. YKL-40 is expressed and secreted by various cell-types including macrophages, chondrocytes, fibroblast-like synovial cells, vascular smooth muscle cells, and hepatic stellate cells. The biological function of YKL-40 is unclear. It is not known to have a specific receptor. Its pattern of expression is associated with pathogenic processes related to inflammation, extracellular tissue remodeling, fibrosis and solid carcinomas[4] and asthma.[5]
# Function
Chitinases catalyze the hydrolysis of chitin, which is an abundant glycopolymer found in insect exoskeletons and fungal cell walls. The glycoside hydrolase 18 family of chitinases includes eight human family members. This gene encodes a glycoprotein member of the glycosyl hydrolase 18 family. The protein lacks chitinase activity and is secreted by activated macrophages, chondrocytes, neutrophils and synovial cells. The protein is thought to play a role in the process of inflammation and tissue remodeling.[3] YKL-40 lacks chitinase activity due to mutations within the active site (conserved sequence: DXXDXDXE ; YKL-40 sequence: DGLDLAWL).[4]
# Regulation and mechanism
YKL-40 has been linked to activation of the AKT pro-survival (anti-apoptotic) signaling pathway. YKL-40 promotes angiogenesis through VEGF-dependent and independent pathways.[6]
YKL-40 is a migration factor for primary astrocytes and its expression is controlled by NFI-X3, STAT3, and AP-1.[7]
CHI3l1 is induced by a variety of cancers and in the presence of semaphorin 7A (protein) can inhibit multiple anti-tumor immune system responses. Activating an antiviral immune pathway known as the RIG-like helicase (RLH) has the ability to counter CHI3l1 induction. Cancer cells can offset RLH by stimulating NLRX1. Poly(I:C), an RNA-like molecule, can stimulate RLH activation. RLH activation can also inhibit the expression of receptor IL-13Rα2pand lmonary metastasisre. It stores NK cell accumulation and activation. It augments the expression of IFN-α/β, chemerin and its receptor ChemR23, p-cofilin, LIMK2 and PTEN and inhibiting BRAF and NLRX1 in a MAVS-dependent manner.[8]
# Cancer
It is assumed that YKL-40 plays a role in cancer cell proliferation, survival, invasiveness and in the regulation of cell-matrix interactions. It is suggested that YKL-40 is a marker associated with a poorer clinical outcome in genetically defined subgroups of different tumors. YKL-40 was recently introduced into (restricted) clinical practice. A few techniques are available for its detection.[4]
YKL-40 is a Th2 promoting cytokine that is present at high levels in the tumor microenvironment and in the serum of cancer patients.[9][10] Elevated levels of YKL-40 correlate strongly with stage and outcome of various types of cancer, which establish YKL-40 as a biomarker of disease severity.[11] Targeting YKL-40 with neutralizing antibodies is effective as a treatment in animal models of glioblastoma multiforme.[12]
YKL-40 also enhances tumor survival in response to gamma-irradiation.[6] | https://www.wikidoc.org/index.php/CHI3L1 | |
ce3d07402be8592eb180f4c7d9fcbe982b3700e7 | wikidoc | CHRNA1 | CHRNA1
Neuronal acetylcholine receptor subunit alpha-1, also known as nAChRα1, is a protein that in humans is encoded by the CHRNA1 gene. The protein encoded by this gene is a subunit of certain nicotinic acetylcholine receptors (nAchR).
The muscle acetylcholine receptor consists of 5 subunits of 4 different types: 2 alpha isoforms and 1 each of beta, gamma, and delta subunits.2 This gene encodes an alpha subunit that plays a role in acetlycholine binding/channel gating. Alternatively spliced transcript variants encoding different isoforms have been identified.
# Interactions
Cholinergic receptor, nicotinic, alpha 1 has been shown to interact with CHRND. | CHRNA1
Neuronal acetylcholine receptor subunit alpha-1, also known as nAChRα1, is a protein that in humans is encoded by the CHRNA1 gene.[1] The protein encoded by this gene is a subunit of certain nicotinic acetylcholine receptors (nAchR).
The muscle acetylcholine receptor consists of 5 subunits of 4 different types: 2 alpha isoforms and 1 each of beta, gamma, and delta subunits.2 This gene encodes an alpha subunit that plays a role in acetlycholine binding/channel gating. Alternatively spliced transcript variants encoding different isoforms have been identified.[1]
# Interactions
Cholinergic receptor, nicotinic, alpha 1 has been shown to interact with CHRND.[2][3] | https://www.wikidoc.org/index.php/CHRNA1 | |
5604ce79123a6ee689913ecf534df19ff4e5ccc6 | wikidoc | CHRNA4 | CHRNA4
Neuronal acetylcholine receptor subunit alpha-4, also known as nAChRα4, is a protein that in humans is encoded by the CHRNA4 gene. The protein encoded by this gene is a subunit of certain nicotinic acetylcholine receptors (nAchR).
The nicotinic acetylcholine receptors (nAChRs) are members of a superfamily of ligand-gated ion channels that mediate fast signal transmission at synapses. After binding acetylcholine, these pentameric receptors respond by undergoing an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane. The protein encoded by this gene is an integral membrane receptor subunit that can interact with either nAChR beta-2 or nAChR beta-4 to form a functional receptor. Mutations in this gene appear to account for a small proportion of the cases of nocturnal frontal lobe epilepsy.
# Interactive pathway map
Click on genes, proteins and metabolites below to link to respective articles.
- ↑ The interactive pathway map can be edited at WikiPathways: "NicotineDopaminergic_WP1602"..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em} | CHRNA4
Neuronal acetylcholine receptor subunit alpha-4, also known as nAChRα4, is a protein that in humans is encoded by the CHRNA4 gene.[1][2] The protein encoded by this gene is a subunit of certain nicotinic acetylcholine receptors (nAchR).
The nicotinic acetylcholine receptors (nAChRs) are members of a superfamily of ligand-gated ion channels that mediate fast signal transmission at synapses. After binding acetylcholine, these pentameric receptors respond by undergoing an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane. The protein encoded by this gene is an integral membrane receptor subunit that can interact with either nAChR beta-2 or nAChR beta-4 to form a functional receptor. Mutations in this gene appear to account for a small proportion of the cases of nocturnal frontal lobe epilepsy.[2]
# Interactive pathway map
Click on genes, proteins and metabolites below to link to respective articles.[§ 1]
- ↑ The interactive pathway map can be edited at WikiPathways: "NicotineDopaminergic_WP1602"..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em} | https://www.wikidoc.org/index.php/CHRNA4 | |
93f93d502f83d9638aa9a1ef9983ec96eb83b884 | wikidoc | CHRNA5 | CHRNA5
Neuronal acetylcholine receptor subunit alpha-5, also known as nAChRα5, is a protein that in humans is encoded by the CHRNA5 gene. The protein encoded by this gene is a subunit of certain nicotinic acetylcholine receptors (nAchR).
# Function
Nicotinic acetylcholine receptors (nAChRs), such as CHRNA5, are members of a superfamily of ligand-gated ion channels that mediate fast signal transmission at synapses. The nAChRs are thought to be (hetero)pentamers composed of homologous subunits.
# Interactive pathway map
Click on genes, proteins and metabolites below to link to respective articles.
- ↑ The interactive pathway map can be edited at WikiPathways: "NicotineDopaminergic_WP1602"..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em} | CHRNA5
Neuronal acetylcholine receptor subunit alpha-5, also known as nAChRα5, is a protein that in humans is encoded by the CHRNA5 gene.[1][2] The protein encoded by this gene is a subunit of certain nicotinic acetylcholine receptors (nAchR).
# Function
Nicotinic acetylcholine receptors (nAChRs), such as CHRNA5, are members of a superfamily of ligand-gated ion channels that mediate fast signal transmission at synapses. The nAChRs are thought to be (hetero)pentamers composed of homologous subunits.[2]
# Interactive pathway map
Click on genes, proteins and metabolites below to link to respective articles.[§ 1]
- ↑ The interactive pathway map can be edited at WikiPathways: "NicotineDopaminergic_WP1602"..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em} | https://www.wikidoc.org/index.php/CHRNA5 | |
813908427054412e42d7aeda8ff86ec10fe279cc | wikidoc | CHRNA6 | CHRNA6
Cholinergic receptor, nicotinic, alpha 6, also known as nAChRα6, is a protein that in humans is encoded by the CHRNA6 gene. The CHRNA6 gene codes for the α6 nicotinic receptor subunit that is found in certain types of nicotinic acetylcholine receptors found primarily in the brain. Neural nicotinic acetylcholine receptors containing α6 subunits are expressed on dopamine-releasing neurons in the midbrain, and dopamine release following activation of these neurons is thought to be involved in the addictive properties of nicotine. Due to their selective localisation on dopaminergic neurons, α6-containing nACh receptors have also been suggested as a possible therapeutic target for the treatment of Parkinson's disease.
# Interactive pathway map
Click on genes, proteins and metabolites below to link to respective articles.
- ↑ The interactive pathway map can be edited at WikiPathways: "NicotineDopaminergic_WP1602"..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em} | CHRNA6
Cholinergic receptor, nicotinic, alpha 6, also known as nAChRα6, is a protein that in humans is encoded by the CHRNA6 gene.[1] The CHRNA6 gene codes for the α6 nicotinic receptor subunit that is found in certain types of nicotinic acetylcholine receptors found primarily in the brain. Neural nicotinic acetylcholine receptors containing α6 subunits are expressed on dopamine-releasing neurons in the midbrain,[2] and dopamine release following activation of these neurons is thought to be involved in the addictive properties of nicotine.[3][4][5] Due to their selective localisation on dopaminergic neurons, α6-containing nACh receptors have also been suggested as a possible therapeutic target for the treatment of Parkinson's disease.[6][7]
# Interactive pathway map
Click on genes, proteins and metabolites below to link to respective articles.[§ 1]
- ↑ The interactive pathway map can be edited at WikiPathways: "NicotineDopaminergic_WP1602"..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em} | https://www.wikidoc.org/index.php/CHRNA6 | |
83c68cd3740eca88f6f2980c0517e875d28b37f4 | wikidoc | CHRNA7 | CHRNA7
Neuronal acetylcholine receptor subunit alpha-7, also known as nAChRα7, is a protein that in humans is encoded by the CHRNA7 gene. The protein encoded by this gene is a subunit of certain nicotinic acetylcholine receptors (nAchR).
# Function
The nicotinic acetylcholine receptors (nAChRs) are members of a superfamily of ligand-gated ion channels that mediate fast signal transmission at synapses. The nAChRs are thought to be hetero-pentamers composed of homologous subunits. The proposed structure for each subunit is a conserved N-terminal extracellular domain followed by three conserved transmembrane domains, a variable cytoplasmic loop, a fourth conserved transmembrane domain, and a short C-terminal extracellular region. The protein encoded by this gene forms a homo-oligomeric channel, displays marked permeability to calcium ions and is a major component of brain nicotinic receptors that are blocked by, and highly sensitive to, alpha-bungarotoxin. Once this receptor binds acetylcholine, it undergoes an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane. This gene is located in a region identified as a major susceptibility locus for juvenile myoclonic epilepsy and a chromosomal location involved in the genetic transmission of schizophrenia. An evolutionarily recent partial duplication event in this region results in a hybrid containing sequence from this gene and a novel FAM7A gene.
# Interactions
CHRNA7 has been shown to interact with FYN.
# Gene expression
The CHRNA7 gene is primarily expressed in the posterior amygdalar nucleus and the field CA3 of Ammon's horn in the mouse, and in the mammillary body in humans. Gene expression patterns from the Allen Brain Atlases can be seen here. | CHRNA7
Neuronal acetylcholine receptor subunit alpha-7, also known as nAChRα7, is a protein that in humans is encoded by the CHRNA7 gene.[1] The protein encoded by this gene is a subunit of certain nicotinic acetylcholine receptors (nAchR).
# Function
The nicotinic acetylcholine receptors (nAChRs) are members of a superfamily of ligand-gated ion channels that mediate fast signal transmission at synapses. The nAChRs are thought to be hetero-pentamers composed of homologous subunits. The proposed structure for each subunit is a conserved N-terminal extracellular domain followed by three conserved transmembrane domains, a variable cytoplasmic loop, a fourth conserved transmembrane domain, and a short C-terminal extracellular region. The protein encoded by this gene forms a homo-oligomeric channel, displays marked permeability to calcium ions and is a major component of brain nicotinic receptors that are blocked by, and highly sensitive to, alpha-bungarotoxin. Once this receptor binds acetylcholine, it undergoes an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane. This gene is located in a region identified as a major susceptibility locus for juvenile myoclonic epilepsy and a chromosomal location involved in the genetic transmission of schizophrenia. An evolutionarily recent partial duplication event in this region results in a hybrid containing sequence from this gene and a novel FAM7A gene.[2]
# Interactions
CHRNA7 has been shown to interact with FYN.[3]
# Gene expression
The CHRNA7 gene is primarily expressed in the posterior amygdalar nucleus and the field CA3 of Ammon's horn in the mouse, and in the mammillary body in humans. Gene expression patterns from the Allen Brain Atlases can be seen here. | https://www.wikidoc.org/index.php/CHRNA7 | |
6a29e0e656ac38c000ad865625dd6ba2b6492fc8 | wikidoc | CHRNA9 | CHRNA9
Neuronal acetylcholine receptor subunit alpha-9, also known as nAChRα9, is a protein that in humans is encoded by the CHRNA9 gene. The protein encoded by this gene is a subunit of certain nicotinic acetylcholine receptors (nAchR).
This gene is a member of the ligand-gated ionic channel family and nicotinic acetylcholine receptor gene superfamily. It encodes a plasma membrane protein that forms homo- or hetero-oligomeric divalent cation channels. This protein is involved in cochlea hair cell function and is expressed in both the inner and outer hair cells (OHCs) of the adult cochlea, although expression levels in adult inner hair cells is low. The activation of the alpha9/10 nAChR is via olivocochlear activity, represented by cholinergic efferent synaptic terminals originating from the superior olive region of the brainstem. The protein is additionally expressed in keratinocytes, the pituitary gland, B-cells and T-cells.
Selective block of α9α10 nicotinic acetylcholine receptors by the conotoxin RgIA has been shown to be analgesic in an animal model of nerve injury pain. | CHRNA9
Neuronal acetylcholine receptor subunit alpha-9, also known as nAChRα9, is a protein that in humans is encoded by the CHRNA9 gene.[1] The protein encoded by this gene is a subunit of certain nicotinic acetylcholine receptors (nAchR).
This gene is a member of the ligand-gated ionic channel family and nicotinic acetylcholine receptor gene superfamily. It encodes a plasma membrane protein that forms homo- or hetero-oligomeric divalent cation channels. This protein is involved in cochlea hair cell function and is expressed in both the inner and outer hair cells (OHCs) of the adult cochlea, although expression levels in adult inner hair cells is low. The activation of the alpha9/10 nAChR is via olivocochlear activity, represented by cholinergic efferent synaptic terminals originating from the superior olive region of the brainstem. The protein is additionally expressed in keratinocytes, the pituitary gland, B-cells and T-cells.[1]
Selective block of α9α10 nicotinic acetylcholine receptors by the conotoxin RgIA has been shown to be analgesic in an animal model of nerve injury pain.[2] | https://www.wikidoc.org/index.php/CHRNA9 | |
8d859f7206bc6e54447d40a2ffd2d344e4282e3d | wikidoc | CHRNB2 | CHRNB2
Neuronal acetylcholine receptor subunit beta-2 is a protein that in humans is encoded by the CHRNB2 gene.
Neuronal acetylcholine receptors are homo- or heteropentameric complexes composed of homologous alpha and beta subunits. They belong to a superfamily of ligand-gated ion channels which allow the flow of sodium and potassium across the plasma membrane in response to ligands such as acetylcholine and nicotine. This gene encodes one of several beta subunits. Mutations in this gene are associated with autosomal dominant nocturnal frontal lobe epilepsy.
# Interactive pathway map
Click on genes, proteins and metabolites below to link to respective articles.
- ↑ The interactive pathway map can be edited at WikiPathways: "NicotineDopaminergic_WP1602"..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em} | CHRNB2
Neuronal acetylcholine receptor subunit beta-2 is a protein that in humans is encoded by the CHRNB2 gene.[1][2]
Neuronal acetylcholine receptors are homo- or heteropentameric complexes composed of homologous alpha and beta subunits. They belong to a superfamily of ligand-gated ion channels which allow the flow of sodium and potassium across the plasma membrane in response to ligands such as acetylcholine and nicotine. This gene encodes one of several beta subunits. Mutations in this gene are associated with autosomal dominant nocturnal frontal lobe epilepsy.[2]
# Interactive pathway map
Click on genes, proteins and metabolites below to link to respective articles.[§ 1]
- ↑ The interactive pathway map can be edited at WikiPathways: "NicotineDopaminergic_WP1602"..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em} | https://www.wikidoc.org/index.php/CHRNB2 | |
2fdd30eb36c6e2d5814de38a43846175b97fabd4 | wikidoc | CHRNB4 | CHRNB4
Neuronal acetylcholine receptor subunit beta-4 is a protein that in humans is encoded by the CHRNB4 gene.
# Interactive pathway map
Click on genes, proteins and metabolites below to link to respective Wikipedia articles.
- ↑ The interactive pathway map can be edited at WikiPathways: "NicotineActivityonChromaffinCells_WP1603"..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em} | CHRNB4
Neuronal acetylcholine receptor subunit beta-4 is a protein that in humans is encoded by the CHRNB4 gene.[1][2]
# Interactive pathway map
Click on genes, proteins and metabolites below to link to respective Wikipedia articles. [§ 1]
- ↑ The interactive pathway map can be edited at WikiPathways: "NicotineActivityonChromaffinCells_WP1603"..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("https://upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em} | https://www.wikidoc.org/index.php/CHRNB4 | |
5b83883c39cc760acb5de7b8f8658c4eac91c0b7 | wikidoc | CHST11 | CHST11
Carbohydrate sulfotransferase 11 is an enzyme that in humans is encoded by the CHST11 gene.
# Clinical relevance
Mutations in this gene have been associated to susceptibility for osteoarthritis.
# Model organisms
Model organisms have been used in the study of CHST11 function. A conditional knockout mouse line called Chst11tm1a(KOMP)Wtsi was generated at the Wellcome Trust Sanger Institute. Male and female animals underwent a standardized phenotypic screen to determine the effects of deletion. Additional screens performed: - In-depth immunological phenotyping - in-depth bone and cartilage phenotyping | CHST11
Carbohydrate sulfotransferase 11 is an enzyme that in humans is encoded by the CHST11 gene.[1][2]
# Clinical relevance
Mutations in this gene have been associated to susceptibility for osteoarthritis.[3]
# Model organisms
Model organisms have been used in the study of CHST11 function. A conditional knockout mouse line called Chst11tm1a(KOMP)Wtsi was generated at the Wellcome Trust Sanger Institute.[4] Male and female animals underwent a standardized phenotypic screen[5] to determine the effects of deletion.[6][7][8][9] Additional screens performed: - In-depth immunological phenotyping[10] - in-depth bone and cartilage phenotyping[11] | https://www.wikidoc.org/index.php/CHST11 | |
7ddc207c0b8b471ca05a137ef984debf6f0a2ffb | wikidoc | CHST14 | CHST14
Carbohydrate sulfotransferase 14 is an enzyme that in humans is encoded by the CHST14 gene.
# Gene
CHST14, a protein-coding gene, encodes for the enzyme carbohydrate sulfotransferase 14 (CHST14)/ dermatan 4-O-sulfotransferase (D4ST1).
In humans, CHST14 is positioned on the long arm (q) of chromosome 15 at position 15.1, from base pair 40,470,961 to base pair 40,474,571. The CHST14 gene is 3,611 bases long, composed of 376 amino acids, and has a molecular mass of 42997 Da.
# Ontology
CHST14 is implicated in fetal development of connective tissues throughout multiple organ systems. It is also implicated in regulation of proliferation and neurogenesis of neural precursor cells. It has been linked to inhibition of peripheral nerve regeneration in adults.
# Function
Dermatan 4-O-sulfotransferase enzymatically transfers an active sulfate to position 4 of N-acetyl-D-galactosamine residues of dermatan sulfate, stabilizing this glycosaminoglycan. Dermatan sulfate is essential to extracellular matrix formation and is found in extensively in skin, tendons, cartilage, and the aortic wall. Mutation of CHST14 results in a deficiency of dermatan sulfate, which disrupts glycosaminoglycan constituents in fibroblasts and impairs collagen fibril linkage within collagen bundles.
# Clinical significance
Mutation of CHST14 is associated with a specific type of Ehlers–Danlos syndromes, recently specified as CHST14/D4ST1 deficiency. Previously, this condition has been independently referred to as adducted thumb-clubfoot syndrome, Ehlers-Danlos syndrome, Kosho type, musculocontractural Ehlers-Danlos syndrome, and Ehlers-Danlos type VIB. Currently, 40 patients from 27 families have been diagnosed with this autosomal recessive mutation. CHST14/D4ST1 deficiency is the first identified human disease that directly impacts dermatan sulfate production." Hallmark features include congenital malformations (extensive craniofacial defects, skin elasticity, joint laxity, multiple contractures) combined with progressive fragility of affected structures, with increased incidence of bruising, recurrent joint dislocations, pneumothorax, spinal degeneration, and other deformities. | CHST14
Carbohydrate sulfotransferase 14 is an enzyme that in humans is encoded by the CHST14 gene.[1][2]
# Gene
CHST14, a protein-coding gene, encodes for the enzyme carbohydrate sulfotransferase 14 (CHST14)/ dermatan 4-O-sulfotransferase (D4ST1).[1]
In humans, CHST14 is positioned on the long arm (q) of chromosome 15 at position 15.1, from base pair 40,470,961 to base pair 40,474,571. The CHST14 gene is 3,611 bases long, composed of 376 amino acids, and has a molecular mass of 42997 Da.[1]
# Ontology
CHST14 is implicated in fetal development of connective tissues throughout multiple organ systems.[3] It is also implicated in regulation of proliferation and neurogenesis of neural precursor cells.[4] It has been linked to inhibition of peripheral nerve regeneration in adults.[5]
# Function
Dermatan 4-O-sulfotransferase enzymatically transfers an active sulfate to position 4 of N-acetyl-D-galactosamine residues of dermatan sulfate, stabilizing this glycosaminoglycan.[6] Dermatan sulfate is essential to extracellular matrix formation and is found in extensively in skin, tendons, cartilage, and the aortic wall.[7] Mutation of CHST14 results in a deficiency of dermatan sulfate, which disrupts glycosaminoglycan constituents in fibroblasts and impairs collagen fibril linkage within collagen bundles.[6]
# Clinical significance
Mutation of CHST14 is associated with a specific type of Ehlers–Danlos syndromes, recently specified as CHST14/D4ST1 deficiency.[3] Previously, this condition has been independently referred to as adducted thumb-clubfoot syndrome,[8] Ehlers-Danlos syndrome, Kosho type,[6][9] musculocontractural Ehlers-Danlos syndrome,[10] and Ehlers-Danlos type VIB.[11] Currently, 40 patients from 27 families have been diagnosed with this autosomal recessive mutation.[12] CHST14/D4ST1 deficiency is the first identified human disease that directly impacts dermatan sulfate production.[12]" Hallmark features include congenital malformations (extensive craniofacial defects, skin elasticity, joint laxity, multiple contractures) combined with progressive fragility of affected structures, with increased incidence of bruising, recurrent joint dislocations, pneumothorax, spinal degeneration, and other deformities.[3] | https://www.wikidoc.org/index.php/CHST14 | |
ecab7728cca4394a957a223147788acc55433886 | wikidoc | CKMT1A | CKMT1A
Creatine kinase U-type, mitochondrial, also called ubiquitous mitochondrial creatine kinase (uMtCK), is in humans encoded by CKMT1A gene. CKMT1A catalyzes the reversible transfer of the γ-phosphate group of ATP to the guanidino group of Cr to yield ADP and PCr. The impairment of CKMT1A has been reported in ischaemia, cardiomyopathy, and neurodegenerative disorders. Overexpression of CKMT1A has been reported related with several tumors.
# Structure
## Gene
The CKMT1A gene lies on the chromosome location of 15q15.3 and consists of 11 exons.
## Protein
CKMT1A consists of 417 amino acids and weighs 47037Da. CKMT1A is rich in amino acids with hydroxyl-containing and basic side chains.
# Function
There are four distinct types of CK subunits in the tissue of mammals, which are expressed species specifically, developmental stage specifically, and tissue specifically. Ubiquitously expressed, CKMT1A is located in the mitochondrial intermembrane space and form both homodimeric and homooctameric molecules that are readily interconvertible. Like all the other CK isoenzymes, CKMT1A catalyzes the reversible transfer of the γ-phosphate group of ATP to the guanidino group of Cr to yield ADP and PCr. According to the “transport” (“shuttle”) hypothesis for the CK system, after synthesis within the mitochondrial matrix, the γ-phosphate group of ATP is transferred by CKMT1A in the mitochondrial intermembrane space to Cr to yield ADP plus PCr.
# Clinical significance
As an enzyme central to cell energetics, CKMT1A is often impaired in pathological situations. CKMT1A is known as a primary target of oxidative and radical-induced molecular damage; and the impairment of CKMT1A has been reported in ischaemia, cardiomyopathy, and neurodegenerative disorders due to the failure in maintaining metabolic homeostasis. Overexpression of uMtCK has been reported for several tumors with poor prognosis and this may be the adaption of cancer cells to maintain the high growth rate.
# Interactions
- Leucine-rich repeat kinase
- ASB9 | CKMT1A
Creatine kinase U-type, mitochondrial, also called ubiquitous mitochondrial creatine kinase (uMtCK), is in humans encoded by CKMT1A gene. CKMT1A catalyzes the reversible transfer of the γ-phosphate group of ATP to the guanidino group of Cr to yield ADP and PCr. The impairment of CKMT1A has been reported in ischaemia, cardiomyopathy, and neurodegenerative disorders. Overexpression of CKMT1A has been reported related with several tumors.[1][2][3]
# Structure
## Gene
The CKMT1A gene lies on the chromosome location of 15q15.3 and consists of 11 exons.
## Protein
CKMT1A consists of 417 amino acids and weighs 47037Da. CKMT1A is rich in amino acids with hydroxyl-containing and basic side chains.[4]
# Function
There are four distinct types of CK subunits in the tissue of mammals, which are expressed species specifically, developmental stage specifically, and tissue specifically. Ubiquitously expressed, CKMT1A is located in the mitochondrial intermembrane space and form both homodimeric and homooctameric molecules that are readily interconvertible.[5] Like all the other CK isoenzymes, CKMT1A catalyzes the reversible transfer of the γ-phosphate group of ATP to the guanidino group of Cr to yield ADP and PCr.[6] According to the “transport” (“shuttle”) hypothesis for the CK system, after synthesis within the mitochondrial matrix, the γ-phosphate group of ATP is transferred by CKMT1A in the mitochondrial intermembrane space to Cr to yield ADP plus PCr.
# Clinical significance
As an enzyme central to cell energetics, CKMT1A is often impaired in pathological situations. CKMT1A is known as a primary target of oxidative and radical-induced molecular damage; and the impairment of CKMT1A has been reported in ischaemia, cardiomyopathy, and neurodegenerative disorders due to the failure in maintaining metabolic homeostasis.[7][8] Overexpression of uMtCK has been reported for several tumors with poor prognosis and this may be the adaption of cancer cells to maintain the high growth rate.[9][10][11][12]
# Interactions
- Leucine-rich repeat kinase [13]
- ASB9 [14] | https://www.wikidoc.org/index.php/CKMT1A | |
ee0d9bc1937c208322e058926a968150c40d8783 | wikidoc | CKMT1B | CKMT1B
Creatine kinase, mitochondrial 1B also known as CKMT1B is one of two genes which encode the ubiquitous mitochondrial creatine kinase (ubiquitous mtCK or CKMT1).
# Function
Mitochondrial creatine (MtCK) kinase is responsible for the transfer of high energy phosphate from mitochondria to the cytosolic carrier, creatine. It belongs to the creatine kinase isoenzyme family. It exists as two isoenzymes, sarcomeric MtCK (CKMT2) and ubiquitous MtCK, encoded by separate genes. Mitochondrial creatine kinase occurs in two different oligomeric forms: dimers and octamers, in contrast to the exclusively dimeric cytosolic creatine kinase isoenzymes. Ubiquitous mitochondrial creatine kinase has 80% homology with the coding exons of sarcomeric mitochondrial creatine kinase. Two genes located near each other on chromosome 15 (CKMT1A and CKMT1B (this gene)) have been identified which encode identical mitochondrial creatine kinase proteins.
# Clinical significance
Many malignant cancers with poor prognosis have shown overexpression of ubiquitous mitochondrial creatine kinase; this may be related to high energy turnover and failure to eliminate cancer cells via apoptosis. | CKMT1B
Creatine kinase, mitochondrial 1B also known as CKMT1B is one of two genes which encode the ubiquitous mitochondrial creatine kinase (ubiquitous mtCK or CKMT1).[1]
# Function
Mitochondrial creatine (MtCK) kinase is responsible for the transfer of high energy phosphate from mitochondria to the cytosolic carrier, creatine. It belongs to the creatine kinase isoenzyme family. It exists as two isoenzymes, sarcomeric MtCK (CKMT2) and ubiquitous MtCK, encoded by separate genes. Mitochondrial creatine kinase occurs in two different oligomeric forms: dimers and octamers, in contrast to the exclusively dimeric cytosolic creatine kinase isoenzymes. Ubiquitous mitochondrial creatine kinase has 80% homology with the coding exons of sarcomeric mitochondrial creatine kinase. Two genes located near each other on chromosome 15 (CKMT1A and CKMT1B (this gene)) have been identified which encode identical mitochondrial creatine kinase proteins.[1]
# Clinical significance
Many malignant cancers with poor prognosis have shown overexpression of ubiquitous mitochondrial creatine kinase; this may be related to high energy turnover and failure to eliminate cancer cells via apoptosis.[1] | https://www.wikidoc.org/index.php/CKMT1B | |
2aec7e79feb2a011cf7c5d0f18594383b8afff59 | wikidoc | CLCNKA | CLCNKA
Chloride channel protein ClC-Ka is a protein that in humans is encoded by the CLCNKA gene. Multiple transcript variants encoding different isoforms have been found for this gene.
# Function
This gene is a member of the CLC family of voltage-gated chloride channels. The encoded protein is predicted to have 12 transmembrane domains, and requires a beta subunit called barttin to form a functional channel. It is thought to function in salt reabsorption in the kidney and potassium recycling in the inner ear. The gene is highly similar to CLCNKB, which is located 10 kb downstream from this gene.
# Gene variants
CLCNKA encodes one of the two major chloride channels found in the kidney, the ClC-Ka channel (the other class being the ClC-Kb from CLCNKB). The CLCNKA gene is subject, like all genes, to variation due to single-nucleotide polymorphisms (SNPs), in which a single base (A, T, C, or G) is randomly replaced by another base. SNPs in the coding regions of CLCKNA may have consequent changes in the amino acid sequence of the ClC-Ka chloride channel leading to altered functional capacities and subsequent physiological alterations.
Four SNPs (rs848307, rs1739843, rs1010069, and rs1805152) have been associated with increased salt-sensitivity by displaying an irregularly large increase in blood pressure following modest salt (Na+) intake, despite regular heart rate, blood pressure, and plasma renin levels before the salt ingestion. Of particular interest is a common SNP leading to the amino acid Arginine at the 83rd position to be replaced by Glycine. This variant is found to exist in approximately half of all caucasians, while a quarter of caucasians are homozygous for the allele. Although mainly studied in the context of caucasians, the SNP actually exists with a greater frequency in people of African descent, where the gene frequency is 70%. This SNP (rs10927887) was originally implicated in congestive heart failure after investigations into the heat shock protein HSPB7 showed that the CLCNKA gene was in linkage disequilibrium, meaning that the two genes are often not separated during recombination. The CLCNKA variant was then shown to be the cause of the pathology.
# Pathology
The four SNPs found to be associated with salt sensitivity consequently predispose such cardiovascular problems as left ventricular hypertrophy and dysfunction of the endothelium. The Arg83Gly SNP specifically results in a large reduction in the flow of chloride ions through the ClC-Ka channel in the thin and thick ascending limb of the nephrons. Experimentally, the membrane potential at which the channels show no net movement of ions at a given chloride concentration drops significantly with the mutation, indicating altered function in situ. This manifests as a chronic salt wasting disorder similar to Bartter syndrome, as sodium reabsorption is coupled with chloride reabsorption. The salt loss results in a decreased blood volume and consequently hyperreninemia leading (via the end product angiotensin II and aldosterone) to increased vascular tone, heart rate, water reabsorption, and blood pressure, collectively referred to as cardiorenal syndrome. Being heterozygous for this Arg83Gly variant increases the risk of heart failure by 27%, while homozygosity increases the risk by 54%. The additive stress on the heart from increased blood pressure and heart rate often only manifests as a pathology with an additional cardiovascular problem such as hypertension. Treatment for the SNP associated hyperreninemia involves drugs to block the Renin-Angiotensin-Aldosterone system to relieve the aforementioned stresses on the heart. | CLCNKA
Chloride channel protein ClC-Ka is a protein that in humans is encoded by the CLCNKA gene. Multiple transcript variants encoding different isoforms have been found for this gene.[1][2]
# Function
This gene is a member of the CLC family of voltage-gated chloride channels. The encoded protein is predicted to have 12 transmembrane domains, and requires a beta subunit called barttin to form a functional channel. It is thought to function in salt reabsorption in the kidney and potassium recycling in the inner ear. The gene is highly similar to CLCNKB, which is located 10 kb downstream from this gene.[2]
# Gene variants
CLCNKA encodes one of the two major chloride channels found in the kidney, the ClC-Ka channel (the other class being the ClC-Kb from CLCNKB). The CLCNKA gene is subject, like all genes, to variation due to single-nucleotide polymorphisms (SNPs), in which a single base (A, T, C, or G) is randomly replaced by another base.[3] SNPs in the coding regions of CLCKNA may have consequent changes in the amino acid sequence of the ClC-Ka chloride channel leading to altered functional capacities and subsequent physiological alterations.[3]
Four SNPs (rs848307, rs1739843, rs1010069, and rs1805152) have been associated with increased salt-sensitivity by displaying an irregularly large increase in blood pressure following modest salt (Na+) intake, despite regular heart rate, blood pressure, and plasma renin levels before the salt ingestion.[3] Of particular interest is a common SNP leading to the amino acid Arginine at the 83rd position to be replaced by Glycine.[4] This variant is found to exist in approximately half of all caucasians, while a quarter of caucasians are homozygous for the allele.[4] Although mainly studied in the context of caucasians, the SNP actually exists with a greater frequency in people of African descent, where the gene frequency is 70%.[4] This SNP (rs10927887) was originally implicated in congestive heart failure after investigations into the heat shock protein HSPB7 showed that the CLCNKA gene was in linkage disequilibrium, meaning that the two genes are often not separated during recombination.[4] The CLCNKA variant was then shown to be the cause of the pathology.[4]
# Pathology
The four SNPs found to be associated with salt sensitivity consequently predispose such cardiovascular problems as left ventricular hypertrophy and dysfunction of the endothelium.[3] The Arg83Gly SNP specifically results in a large reduction in the flow of chloride ions through the ClC-Ka channel in the thin and thick ascending limb of the nephrons.[4] Experimentally, the membrane potential at which the channels show no net movement of ions at a given chloride concentration drops significantly with the mutation, indicating altered function in situ.[4] This manifests as a chronic salt wasting disorder similar to Bartter syndrome,[4] as sodium reabsorption is coupled with chloride reabsorption.[3] The salt loss results in a decreased blood volume and consequently hyperreninemia leading (via the end product angiotensin II and aldosterone) to increased vascular tone, heart rate, water reabsorption, and blood pressure, collectively referred to as cardiorenal syndrome.[4] Being heterozygous for this Arg83Gly variant increases the risk of heart failure by 27%, while homozygosity increases the risk by 54%.[4] The additive stress on the heart from increased blood pressure and heart rate often only manifests as a pathology with an additional cardiovascular problem such as hypertension.[4] Treatment for the SNP associated hyperreninemia involves drugs to block the Renin-Angiotensin-Aldosterone system to relieve the aforementioned stresses on the heart.[4] | https://www.wikidoc.org/index.php/CLCNKA | |
c9277ef3895254e6432528b9d87c74a49a93e803 | wikidoc | CLDN14 | CLDN14
Claudin-14 is a protein that in humans is encoded by the CLDN14 gene. It belongs to a related family of proteins called claudins.
The protein encoded by CLDN14 is an integral membrane protein and a component of tight junctions, one mode of cell-to-cell adhesion in epithelial or endothelial cell sheets. Tight junctions form continuous seals around cells and serve as a physical barrier to prevent solutes and water from passing freely through the paracellular space.
These junctions are composed of sets of continuous networking protein strands in the outer surface of the cell membrane, with complementary grooves in the inwardly facing extracytoplasmic leaflet. The CLDN14 protein also binds to particular part of a protein called Yes-associated protein, known as its WW domain.
Defects in CLDN14 are the cause of an autosomal recessive form of nonsyndromic sensorineural deafness. Two transcript variants encoding the same protein have been found for this gene.
There are also suggestions that CLDN14 plays a role in tumour angiogenesis (blood vessel formation), as deletion of a single copy of this gene leads to tight junction defects and leaky blood vessels in a mouse model. | CLDN14
Claudin-14 is a protein that in humans is encoded by the CLDN14 gene.[1][2] It belongs to a related family of proteins called claudins.
The protein encoded by CLDN14 is an integral membrane protein and a component of tight junctions, one mode of cell-to-cell adhesion in epithelial or endothelial cell sheets. Tight junctions form continuous seals around cells and serve as a physical barrier to prevent solutes and water from passing freely through the paracellular space.
These junctions are composed of sets of continuous networking protein strands in the outer surface of the cell membrane, with complementary grooves in the inwardly facing extracytoplasmic leaflet. The CLDN14 protein also binds to particular part of a protein called Yes-associated protein, known as its WW domain.
Defects in CLDN14 are the cause of an autosomal recessive form of nonsyndromic sensorineural deafness. Two transcript variants encoding the same protein have been found for this gene.[2]
There are also suggestions that CLDN14 plays a role in tumour angiogenesis (blood vessel formation),[3] as deletion of a single copy of this gene leads to tight junction defects and leaky blood vessels in a mouse model. | https://www.wikidoc.org/index.php/CLDN14 | |
18ced0002a0fecdb5a43cb395b3d5c687cf9027d | wikidoc | CLDN16 | CLDN16
Claudin-16 is a protein that in humans is encoded by the CLDN16 gene. It belongs to the group of claudins.
Tight junctions represent one mode of cell-to-cell adhesion in epithelial or endothelial cell sheets, forming continuous seals around cells and serving as a physical barrier to prevent solutes and water from passing freely through the paracellular space. These junctions are composed of sets of continuous networking strands in the outwardly facing cytoplasmic leaflet, with complementary grooves in the inwardly facing extracytoplasmic leaflet. The protein encoded by this gene, a member of the claudin family, is an integral membrane protein and a component of tight junction strands. It is found primarily in the kidneys, specifically in the thick ascending limb of Henle, where it acts as either an intercellular pore or ion concentration sensor to regulate the paracellular resorption of magnesium ions. Defects in this gene are a cause of primary hypomagnesemia, which is characterized by massive renal magnesium wasting with hypomagnesemia and hypercalciuria, resulting in nephrocalcinosis and renal failure.
# Model organisms
Model organisms have been used in the study of CLDN16 function. A conditional knockout mouse line, called Cldn16tm1a(KOMP)Wtsi was generated as part of the International Knockout Mouse Consortium program — a high-throughput mutagenesis project to generate and distribute animal models of disease to interested scientists.
Male and female animals underwent a standardized phenotypic screen to determine the effects of deletion. Twenty five tests were carried out on homozygous mutant animals and one significant abnormality was observed: the mice displayed urolithiasis. | CLDN16
Claudin-16 is a protein that in humans is encoded by the CLDN16 gene.[1][2] It belongs to the group of claudins.
Tight junctions represent one mode of cell-to-cell adhesion in epithelial or endothelial cell sheets, forming continuous seals around cells and serving as a physical barrier to prevent solutes and water from passing freely through the paracellular space. These junctions are composed of sets of continuous networking strands in the outwardly facing cytoplasmic leaflet, with complementary grooves in the inwardly facing extracytoplasmic leaflet. The protein encoded by this gene, a member of the claudin family, is an integral membrane protein and a component of tight junction strands. It is found primarily in the kidneys, specifically in the thick ascending limb of Henle, where it acts as either an intercellular pore or ion concentration sensor to regulate the paracellular resorption of magnesium ions. Defects in this gene are a cause of primary hypomagnesemia, which is characterized by massive renal magnesium wasting with hypomagnesemia and hypercalciuria, resulting in nephrocalcinosis and renal failure.[2]
# Model organisms
Model organisms have been used in the study of CLDN16 function. A conditional knockout mouse line, called Cldn16tm1a(KOMP)Wtsi[7][8] was generated as part of the International Knockout Mouse Consortium program — a high-throughput mutagenesis project to generate and distribute animal models of disease to interested scientists.[9][10][11]
Male and female animals underwent a standardized phenotypic screen to determine the effects of deletion.[5][12] Twenty five tests were carried out on homozygous mutant animals and one significant abnormality was observed: the mice displayed urolithiasis.[5] | https://www.wikidoc.org/index.php/CLDN16 | |
18e929a76eb17ac8e096a26b086a59901a1a9440 | wikidoc | CLDN18 | CLDN18
Claudin-18 is a protein that in humans is encoded by the CLDN18 gene. It belongs to the group of claudins.
CLDN18 belongs to the large claudin family of proteins, which form tight junction strands in epithelial cells .
# Clinical significance
Isoform 2 (Claudin 18.2) is abundant in gastric tumors.
Experimental antibody IMAB362 targets Claudin 18.2 to help treat gastric cancers. | CLDN18
Claudin-18 is a protein that in humans is encoded by the CLDN18 gene.[1] It belongs to the group of claudins.
CLDN18 belongs to the large claudin family of proteins, which form tight junction strands in epithelial cells .[2] [supplied by OMIM][1]
# Clinical significance
Isoform 2 (Claudin 18.2) is abundant in gastric tumors.[3]
Experimental antibody IMAB362 targets Claudin 18.2 to help treat gastric cancers.[3] | https://www.wikidoc.org/index.php/CLDN18 | |
9ab733595bfd6e5ce562182b570437f202228a5f | wikidoc | CLEC2D | CLEC2D
C-type lectin domain family 2 member D is a protein that in humans is encoded by the CLEC2D gene.
This gene encodes a member of the natural killer cell receptor C-type lectin family. The encoded protein inhibits osteoclast formation and contains a transmembrane domain near the N-terminus as well as the C-type lectin-like extracellular domain. Several alternatively spliced transcript variants have been identified, but the full-length nature of every transcript has not been defined. CLEC2D encodes the gene for the Lectin Like Transcript-1 (LLT1) protein which is a functional ligand for the human NKR-P1A receptor, encoded by the KLRB1 gene.
In mice, there are many orthologs of the CLEC2D gene, and the presumed homolog is Clr-b/Ocil (Clec2d). Clr-b has been implicated in missing-self recognition by natural killer cells through engagement of the NKR-P1B receptor. | CLEC2D
C-type lectin domain family 2 member D is a protein that in humans is encoded by the CLEC2D gene.[1]
This gene encodes a member of the natural killer cell receptor C-type lectin family. The encoded protein inhibits osteoclast formation and contains a transmembrane domain near the N-terminus as well as the C-type lectin-like extracellular domain. Several alternatively spliced transcript variants have been identified, but the full-length nature of every transcript has not been defined.[1] CLEC2D encodes the gene for the Lectin Like Transcript-1 (LLT1) protein which is a functional ligand for the human NKR-P1A receptor, encoded by the KLRB1 gene.
In mice, there are many orthologs of the CLEC2D gene, and the presumed homolog is Clr-b/Ocil (Clec2d). Clr-b has been implicated in missing-self recognition by natural killer cells through engagement of the NKR-P1B receptor. | https://www.wikidoc.org/index.php/CLEC2D | |
64d5566f9b68fdee840ac7bbfa7f77aa28f61b6e | wikidoc | CLEC7A | CLEC7A
C-type lectin domain family 7 member A or Dectin-1 is a protein that in humans is encoded by the CLEC7A gene. CLEC7A is a member of the C-type lectin/C-type lectin-like domain (CTL/CTLD) superfamily. The encoded glycoprotein is a small type II membrane receptor with an extracellular C-type lectin-like domain fold and a cytoplasmic domain with a partial immunoreceptor tyrosine-based activation motif. It functions as a pattern-recognition receptor for a variety of β-1,3-linked and β-1,6-linked glucans from fungi and plants, and in this way plays a role in innate immune response. Expression is found on myeloid dendritic cells, monocytes, macrophages and B cells. Alternate transcriptional splice variants, encoding different isoforms, have been characterized. This gene is closely linked to other CTL/CTLD superfamily members on chromosome 12p13 in the natural killer gene complex region.
# Structure
Dectin-1 is a transmembrane protein containing an immunoreceptor tyrosine-based activation (ITAM)-like motif in its intracellular tail (which is involved in cellular activation) and one C-type lectin-like domain (carbohydrate-recognition domain, CRD) in the extracellular region (which recognizes β-glucans and endogenous ligands on T cells). The CRD is separated from the membrane by a stalk region. CLEC7A contains putative N-linked sites of glycosylation in the stalk region.
CLEC7A is expressed by macrophages, neutrophils and dendritic cells. Expression has also been studied on other immune cells including eosinophils and B cells.
# Function
The C-type lectin receptors are class of signalling pattern recognition receptors which are involved in antifungal immunity, but also play important roles in immune responses to other pathogens such as bacteria, viruses and nematodes. As a member of this receptor family, dectin-1 recognizes β-glucans and carbohydrates found in fungal cell walls, some bacteria and plants, but may also recognize other unidentified molecules (endogenous ligand on T-cells and ligand on mycobacteria). Ligand binding induces intracellular signalling via the ITAM-like motif. CLEC7A can induce both Syk dependent or Syk independent pathways. Dimerization of dectin-1 upon ligand binding leads to tyrosine phosphorylation by Src family kinases and recruitment of Syk. Syk activates transcription factor NFκB. This transcription factor is responsible for the production of numerous inflammatory cytokines and chemokines such as TNF, IL-23, IL-6, IL-2. Other responses include: respiratory burst, production of arachidonic acid metabolites, dendritic cell maturation, and phagocytosis of the ligand.
## Antifungal immunity
CLEC7A has been shown to recognize species of several fungal genera, including Saccharomyces, Candida, Pneumocystis, Coccidioides, Penicillium and others. Recognition of these organisms triggers many protective pathways, such as fungal uptake by phagocytosis and killing via respiratory burst. Activation of dectin-1 also triggers expression of many protecting antifungal cytokines and chemokines (TNF, CXCL2, IL-1b, IL-1a, CCL3, GM-CSF, G-CSF and IL-6) and the development of Th17.
## Co-stimulatory molecule
Dectin-1 can also operate as a co-stimulatory molecule via recognition of an endogenous ligand on T-cells, which leads to cellular activation and proliferation. CLEC7A can bind both CD4+ and CD8+ T cells. | CLEC7A
C-type lectin domain family 7 member A or Dectin-1 is a protein that in humans is encoded by the CLEC7A gene.[1] CLEC7A is a member of the C-type lectin/C-type lectin-like domain (CTL/CTLD) superfamily. The encoded glycoprotein is a small type II membrane receptor with an extracellular C-type lectin-like domain fold and a cytoplasmic domain with a partial immunoreceptor tyrosine-based activation motif. It functions as a pattern-recognition receptor for a variety of β-1,3-linked and β-1,6-linked glucans from fungi and plants, and in this way plays a role in innate immune response. Expression is found on myeloid dendritic cells, monocytes, macrophages and B cells. Alternate transcriptional splice variants, encoding different isoforms, have been characterized. This gene is closely linked to other CTL/CTLD superfamily members on chromosome 12p13 in the natural killer gene complex region.[1]
# Structure
Dectin-1 is a transmembrane protein containing an immunoreceptor tyrosine-based activation (ITAM)-like motif in its intracellular tail (which is involved in cellular activation) and one C-type lectin-like domain (carbohydrate-recognition domain, CRD) in the extracellular region (which recognizes β-glucans and endogenous ligands on T cells). The CRD is separated from the membrane by a stalk region. CLEC7A contains putative N-linked sites of glycosylation in the stalk region.[2][3]
CLEC7A is expressed by macrophages, neutrophils and dendritic cells.[4] Expression has also been studied on other immune cells including eosinophils and B cells.[5]
# Function
The C-type lectin receptors are class of signalling pattern recognition receptors which are involved in antifungal immunity, but also play important roles in immune responses to other pathogens such as bacteria, viruses and nematodes.[2] As a member of this receptor family, dectin-1 recognizes β-glucans and carbohydrates found in fungal cell walls, some bacteria and plants, but may also recognize other unidentified molecules (endogenous ligand on T-cells and ligand on mycobacteria).[2] Ligand binding induces intracellular signalling via the ITAM-like motif. CLEC7A can induce both Syk dependent or Syk independent pathways. Dimerization of dectin-1 upon ligand binding leads to tyrosine phosphorylation by Src family kinases and recruitment of Syk. Syk activates transcription factor NFκB. This transcription factor is responsible for the production of numerous inflammatory cytokines[5] and chemokines such as TNF, IL-23, IL-6, IL-2. Other responses include: respiratory burst, production of arachidonic acid metabolites, dendritic cell maturation, and phagocytosis of the ligand.[6]
## Antifungal immunity
CLEC7A has been shown to recognize species of several fungal genera, including Saccharomyces, Candida, Pneumocystis, Coccidioides, Penicillium and others. Recognition of these organisms triggers many protective pathways, such as fungal uptake by phagocytosis and killing via respiratory burst. Activation of dectin-1 also triggers expression of many protecting antifungal cytokines and chemokines (TNF, CXCL2, IL-1b, IL-1a, CCL3, GM-CSF, G-CSF and IL-6) and the development of Th17.[6]
## Co-stimulatory molecule
Dectin-1 can also operate as a co-stimulatory molecule via recognition of an endogenous ligand on T-cells, which leads to cellular activation and proliferation. CLEC7A can bind both CD4+ and CD8+ T cells.[6] | https://www.wikidoc.org/index.php/CLEC7A | |
02dcdae8bf3939bee26b004adb1c0dc5f922908d | wikidoc | CLINT1 | CLINT1
Clathrin interactor 1 (CLINT1), also known as EPSIN4, is a protein which in humans is encoded by the CLINT1 gene.
# Function
The CLINT1 protein binds to the terminal domain of the clathrin heavy chain and stimulates clathrin cage vesicle assembly. Clathrin coated vesicles enable neurotransmitter receptors and other proteins to be endocytosed or taken up across neuronal membranes and across the membranes of other types of cells. This enables a turnover of neuroreceptors or other proteins to be maintained and thus the numbers of receptors can be fine tuned.
# Clinical significance
The CLINT1 gene has been shown to be involved in the genetic aetiology of schizophrenia in four studies It is known that the antipsychotic drugs chlorpromazine and clozapine stabilise clathrin coated vesicles and this may be one reason why antipsychotic drugs are effective in treating delusions, auditory hallucinations and many of the other symptoms of schizophrenia.
# Interactions
CLINT1 has been shown to interact with GGA2. | CLINT1
Clathrin interactor 1 (CLINT1), also known as EPSIN4, is a protein which in humans is encoded by the CLINT1 gene.[1][2][3]
# Function
The CLINT1 protein binds to the terminal domain of the clathrin heavy chain and stimulates clathrin cage vesicle assembly. Clathrin coated vesicles enable neurotransmitter receptors and other proteins to be endocytosed or taken up across neuronal membranes and across the membranes of other types of cells. This enables a turnover of neuroreceptors or other proteins to be maintained and thus the numbers of receptors can be fine tuned.[2]
# Clinical significance
The CLINT1 gene has been shown to be involved in the genetic aetiology of schizophrenia in four studies [4][5][6][7][8] It is known that the antipsychotic drugs chlorpromazine and clozapine stabilise clathrin coated vesicles[9][10] and this may be one reason why antipsychotic drugs are effective in treating delusions, auditory hallucinations and many of the other symptoms of schizophrenia.
# Interactions
CLINT1 has been shown to interact with GGA2.[2][3] | https://www.wikidoc.org/index.php/CLINT1 |
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