question
stringlengths 13
215
| ground_truth
stringlengths 2
3.15k
| context
stringlengths 0
157k
|
|---|---|---|
What does A1C measure? | Glycated proteins, such as glycated hemoglobin (HbA1c) or glycated albumin (GA) in the blood, are essential indicators of glycemic control for diabetes mellitus. | BACKGROUND: It has been established that careful diabetes self-management is
essential in avoiding chronic complications that compromise health. Disciplined
diet control and regular exercise are the keys for the type 2 diabetes
self-management. An ability to maintain one's blood glucose at a relatively flat
level, not fluctuating wildly with meals and hypoglycemic medical intervention,
would be the goal for self-management. Hemoglobin A1c (HbA1c or simply A1c) is a
measure of a long-term blood plasma glucose average, a reliable index to reflect
one's diabetic condition. A simple regimen that could reduce the elevated A1c
levels without altering much of type 2 diabetic patients' daily routine denotes
a successful self-management strategy.
METHODS: A relatively simple model that relates the food impact on blood glucose
excursions for type 2 diabetes was studied. Meal is treated as a bolus injection
of glucose. Medical intervention of hypoglycaemic drug or injection, if any, is
lumped with secreted insulin as a damping factor. Lunch was used for test meals.
The recovery period of a blood glucose excursion returning to the pre-prandial
level, the maximal reach, and the area under the excursion curve were used to
characterize one's ability to regulate glucose metabolism. A case study is
presented here to illustrate the possibility of devising an individual-based
self-management regimen.
RESULTS: Results of the lunch study for a type 2 diabetic subject indicate that
the recovery time of the post-prandial blood glucose level can be adjusted to 4
hours, which is comparable to the typical time interval for non-diabetics: 3 to
4 hours. A moderate lifestyle adjustment of light supper coupled with morning
swimming of 20 laps in a 25 m pool for 40 minutes enabled the subject to reduce
his A1c level from 6.7 to 6.0 in six months and to maintain this level for the
subsequent six months.
CONCLUSIONS: The preliminary result of this case study is encouraging. An
individual life-style adjustment can be structured from the extracted
characteristics of the post-prandial blood glucose excursions. Additional
studies are certainly required to draw general applicable guidelines for
lifestyle adjustments of type 2 diabetic patients. BACKGROUND: The assessment of glycemic control, most commonly using glycosylated
hemoglobin (A1C), has been a major measure for care of patients with diabetes.
Historically, dichotomous thresholds have been set for intermediate outcomes
such as A1C (in this case, > 9%) on the basis of levels associated with high
risk, that is, thresholds for what would be considered poor control for all
persons.
LIMITATIONS AND POSSIBLE UNINTENDED CONSEQUENCES OF THRESHOLD MEASURES:
Dichotomous threshold measures may not accurately reflect the true impact of
care on population health because absolute risk reduction for micro- and
macrovascular complications of diabetes is not linear but rather log-linear,
with greater impact of a given improvement on patients with worse rather than
better glycemic control. Also, an "all or none" measure for all patients set at
"optimal" control may unfairly evaluate physician/health care performance.
A CONCEPTUAL MODEL FOR ASSESSING THE QUALITY OF GLYCEMIC CONTROL: A continuous
measure of A1C, as the cornerstone in quality assessment for diabetes, can
incorporate each of the Institute of Medicine's (IOM)'s quality domains:
effectiveness and equity, patient safety, patient-centered care, timeliness, and
efficiency.
CONCLUSIONS: A continuous measure of A1C can better capture than a dichotomous
measure the complexity of glycemic control at a population level. CONTEXT: Hemoglobin A1c (A1c) was recently added to the diagnostic criteria for
diabetes and prediabetes.
OBJECTIVE: Our objective was to examine performance of A1c in comparison with
fasting plasma glucose (FPG) in diagnosing dysglycemia in older adults.
DESIGN AND SETTING: We conducted a cross-sectional analysis of data from the
Health, Aging, and Body Composition study at yr 4 (2000-2001) when FPG and
standardized A1c measurements were available.
PARTICIPANTS: Of 3075 persons (aged 70-79 yr, 48% men, 42% Black) at study
entry, 1865 participants without known diabetes who had appropriate measures
were included.
MAIN OUTCOME MEASURES: Sensitivity and specificity of A1c-based diagnoses were
compared with those based on FPG and the proportion of participants identified
with dysglycemia by each measure.
RESULTS: Of all participants, 2.7 and 3.1% had undiagnosed diabetes by FPG≥126
mg/dl and A1c≥6.5%, respectively. Among the remaining participants, 21.1% had
prediabetes by impaired fasting glucose (≥100 mg/dl) and 22.2% by A1c≥5.7%.
Roughly one third of individuals with diabetes and prediabetes were identified
by either FPG or A1c alone and by both tests simultaneously. Sensitivities and
specificities of A1c compared with FPG were 56.9 and 98.4% for diabetes and 47.0
and 84.5% for prediabetes, respectively. Blacks and women were more likely to be
identified with dysglycemia by A1c than FPG.
CONCLUSIONS: In this older population, we found considerable discordance between
FPG- and A1c-based diagnosis of diabetes and prediabetes, with differences
accentuated by race and gender. Broad implementation of A1c to diagnose
dysglycemic states may substantially alter the epidemiology of these conditions
in older Americans. BACKGROUND: A1c, a surrogate measure of glycemic control, is known to have a
strong linear correlation with mean plasma glucose (MPG) when analyzed in
populations of patients. However, clinically significant intersubject
variability in this relationship exists, which suggests that A1c measurements
may not reflect actual glycemic control in some patients. In the present study
we explored the extent to which A1c accurately represents glycemic control, as
measured by MPG, for individual patients.
METHODS: Data were pooled from randomized clinical trials in which A1c and
self-monitored plasma glucose (SMPG) profiles were collected by patients with
Type 2 diabetes treated with insulin analog regimens. MPG levels were calculated
from SMPG profiles. Distributions of MPG were analyzed for patients within
similar ranges of A1c (<6.5%, 6.5%-<7.5%, 7.5%-<8.5%, 8.5%-<9.5%, and ≥9.5%) and
distributions of A1c were analyzed in patients within similar ranges of MPG
(<6.1, 6.1-<7.8, 7.8-<9.4, 9.4-<11.1, and ≥11.1 mmol/L).
RESULTS: Substantial proportions of patients had clinically significant
differences between A1c and MPG. For example, among 260 patients with A1c
between 6.5% and 7.5%, 10% had MPG levels <6.4 mmol/L, whereas 10% had MPG >9.5
mmol/L. Among the 224 patients with MPG levels ≥6.1 mmol/L and <7.8 mmol/L, 10%
had A1c <6% and 10% had A1c >8.1%.
CONCLUSIONS: In the absence of SMPG, A1c may inadequately represent glycemic
control for many diabetic patients. BACKGROUND: Diabetes mellitus is a known risk factor in the development of
peripheral vascular disease. Hemoglobin A1c (HbA1c) has been used by clinicians
as a means to measure short to intermediate term glucose control in diabetics.
Trials evaluating tight glucose control using HbA1c measurements have recently
been conducted for several medical conditions. The goal of this study is to
determine if the level of hemoglobin A1c has any effect on disease severity in
diabetic patients with limb threatening ischemia.
METHODS: A retrospective review of all patients presenting with limb threatening
ischemia between January 1 and December 31, 2007 was conducted. All patients
underwent conventional arteriography prior to intervention. Of 148 patients, 73
were diabetics with a hemoglobin A1c level performed within 3 mo of
presentation. Patients were placed into high (>7) and low (<7) hemoglobin A1c
groups and data was collected on type of presentation, comorbidities, anatomic
level of disease, tibial artery patency, need for amputation, contralateral
disease, need for an open versus an endovascular procedure, and freedom from
intervention. Fisher's exact t-test was used to compare the two groups. A P
value <0.05 was considered statistically significant.
RESULTS: Thirty-six patients had HbA1c levels above 7.0 and 37 had levels below
7.0 (mean 7.64 ± 2.04, range 5.1-14.7). There were no statistically significant
differences in the two groups in comorbities, average age, initial gangrene at
presentation, aspirin or statin use, or smoking status. Patients in the high
group were more likely to have had a previous attempt at revascularization (23
versus 11, P = 0.0049). There was no difference in the presence of contralateral
disease (7 versus 4, P = 0.3447) or in the number of patent tibial vessels.
Patients with low HbA1c levels were more likely to have the peroneal artery
affected (17 versus 8, P = 0.048). In addition, TASC II classifications of iliac
and femoral popliteal disease was similar between the two groups. Freedom from
intervention is depicted graphically by life table analysis.
CONCLUSION: Glucose control measured by hemoglobin A1c does not appear to affect
severity of disease or need for reintervention in diabetics with limb
threatening ischemia. This suggests other factors related to diabetes may play a
role in peripheral vascular disease. Larger, prospective studies are needed to
assess the affect of glucose control in limb threatening ischemia. Clinical trials to support registration of new drugs are arduous, lengthy, and
expensive. Diabetes treatment trials intended to seek indications for glycemic
control are facilitated by the regulatory acceptance of glycosylated hemoglobin
(A1C) as a validated intermediate efficacy end point. However, A1C outcomes are
not meaningful when taken outside of the context of hypoglycemia risks. Current
regulatory guidance indicates that A1C efficacy end points and hypoglycemia
safety end points be considered separately. A composite end point for diabetes
treatment trials that integrates A1C and hypoglycemia risk into a single measure
is proposed. An example would be "percentage of patients achieving A1C <7%
without unacceptable hypoglycemia." The benefits and limitations of such an
approach are discussed. BACKGROUND: Medicare payment reforms will reimburse accountable care
organizations (ACOs) for providing high-quality healthcare. Quality measures
that reliably predict health outcomes are required.
OBJECTIVES: To compare the ability of alternative wait time measures to predict
glycated hemoglobin (A1C) levels among diabetes patients.
STUDY DESIGN: This retrospective observational study relied on Veterans Health
Administration utilization data and Medicare claims data from 2005 to 2010.
METHODS: Outcomes included an average A1C level and uncontrolled A1C. Heckman
selection models simultaneously predicted the presence of an A1C value and its
level. Models were risk adjusted for prior individual health status. The main
explanatory variables of interest were facility-level primary care wait times
measured in days. Several measures were tested, including capacity measures and
retrospective and prospective time stamp measures. The time stamp measures used
either the date the appointment was created in the scheduling system (create
date) or the date the patient or provider desired the appointment (desired date)
as the start date for wait time computation. All measures were calculated
separately for new and returning patients.
RESULTS: New patient capacity and create date measures significantly predicted
outcomes, but desired date measures did not. The returning patient retrospective
create date and desired date wait time measures significantly predicted higher
and uncontrolled A1C, but capacity and prospective create date measures did not.
CONCLUSIONS: Different administrative wait times predict A1C for new and
returning patients. To properly measure quality, ACOs should use wait time
measures that demonstrate relationships with outcomes for subpopulations of
patients. Hemoglobin A1c is the measurement of glycated hemoglobin and can aid in both the
diagnosis and continued management of diabetes mellitus. Accurate glycosylated
hemoglobin A1c (A1c) measurements are an essential part of decision making in
the diagnosis and treatment of type 2 diabetes mellitus. Although national
standards exist to eliminate technical error with A1c testing, multiple patient
conditions can falsely decrease or elevate the A1c. In this review, we discuss
the methods to measure A1c and the corresponding conditions that can affect the
clinical utility of the test. Conditions that affect the A1c can be either those
that impair erythrocyte production or alter the normal process of glycation.
Some variation also has been associated with patient ethnicity and even with
normal aging. We describe alternatives to A1c testing for the above clinical
scenarios in an effort to make the practicing clinician aware of alternatives
for glucose evaluation. BACKGROUND: Monitoring of glycemic control with hemoglobin A1c (A1c) in
hemodialysis patients may be compromised by anemia and erythropoietin therapy.
Glycated albumin (GA) is an alternative measure of glycemic control but is not
commonly used because of insufficient evidence of association to clinical
outcomes. We tested whether GA measurements were associated with mortality in
hemodialysis patients with diabetes mellitus.
METHODS: The German Diabetes and Dialysis Study (4D) investigated effects of
atorvastatin on survival in 1255 patients with diabetes mellitus receiving
hemodialysis. We measured GA during months 0, 6, and 12. Cox proportional
hazards analysis was used to measure associations between GA and A1c and
all-cause mortality.
RESULTS: Patients with high baseline GA (fourth quartile) had a 42% higher
4-year mortality compared to those in the first quartile (HR 1.42; 95% CI,
1.09-1.85, P = 0.009). Repeated measurements of GA during year one also
demonstrated that individuals in the top quartile for GA (analyzed as a
time-varying covariate) had a 39% higher 4-year mortality (HR 1.39; 95% CI,
1.05-1.85, P = 0.022). The associations between high A1c and mortality using
similar analyses were less consistent; mortality in individuals with baseline
A1c values in the 3rd quartile was increased compared to 1st quartile (HR 1.36;
95% CI, 1.04-1.77, P = 0.023), but risk was not significantly increased in the
2nd or 4th quartiles, and there was a less consistent association between
time-varying A1c values and mortality.
CONCLUSIONS: High GA measurements are consistently associated with increased
mortality in patients with diabetes mellitus on hemodialysis. |
Down's syndrome occurs when an individual has an extra copy or part of a copy of chromosome 21, yes or no? | Yes, Downs syndrome is caused by a duplication or all or part of chromosome 21. | Down syndrome (DS) is a major cause of mental retardation and heart disease.
Although it is usually caused by the presence of an extra chromosome 21, a
subset of the diagnostic features may be caused by the presence of only band
21q22. We now present evidence that significantly narrows the chromosomal region
responsible for several of the phenotypic features of DS. We report a molecular
and cytogenetic analysis of a three-generation family containing four
individuals with clinical DS as manifested by the characteristic facial
appearance, endocardial cushion defect, mental retardation, and probably
dermatoglyphic changes. Autoradiograms of quantitative Southern blots of DNAs
from two affected sisters, their carrier father, and a normal control were
analyzed after hybridization with two to six unique DNA sequences regionally
mapped on chromosome 21. These include cDNA probes for the genes for
CuZn-superoxide dismutase (SOD1) mapping in 21q22.1 and for the amyloid
precursor protein (APP) mapping in 21q11.2-21.05, in addition to six probes for
single-copy sequences: D21S46 in 21q11.2-21.05, D21S47 and SF57 in 21q22.1-22.3,
and D21S39, D21S42, and D21S43 in 21q22.3. All sequences located in 21q22.3 were
present in three copies in the affected individuals, whereas those located
proximal to this region were present in only two copies. In the carrier father,
all DNA sequences were present in only two copies. Cytogenetic analysis of
affected individuals employing R and G banding of prometaphase preparations
combined with in situ hybridization revealed a translocation of the region from
very distal 21q22.1 to 21qter to chromosome 4q. Except for a possible phenotypic
contribution from the deletion of chromosome band 4q35, these data provide a
molecular definition of the minimal region of chromosome 21 which, when
duplicated, generates the facial features, heart defect, a component of the
mental retardation, and probably several of the dermatoglyphic changes of DS.
This region may include parts of bands 21q22.2 and 21q22.3, but it must exclude
the genes S0D1 and APP and most of band 21q22.1, specifically the region defined
by S0D1, SF57 and D21S47. A patient with the phenotype of trisomy 21 (Down syndrome) was found to have a
normal karyotype in blood lymphocytes and fibroblasts. Assessment of the
chromosome 21 markers SOD1, CBS, ETS2, D21S11, and BCEI showed partial trisomy
by duplication of a chromosome segment carrying the SOD1, CBS, and ETS2 loci and
flanked by the BCEI and D21S11 loci, which are not duplicated. This
submicroscopic duplication at the interface of 21q21 and 21q22.1 reduces to
about 2000-3000 kb the critical segment the trisomy of which is responsible for
the phenotype of trisomy 21. Down syndrome is usually caused by complete trisomy 21. Rarely, it is due to
partial trisomy of the segment 21q22. We report on a 33-month-old girl with
tetrasomy 21 pter-->q22.1 resulting from an extra chromosome idic(21)(q22.1).
She has craniofacial traits typical of Down syndrome, including brachycephaly,
third fontanel, upward slanting palpebral fissures, round face, and protruding
tongue. Speech development is quite delayed whereas motor development is only
mildly retarded. The molecular content of the extra isodicentric chromosome was
defined by molecular genetic investigations using 13 single copy probes unique
to chromosome 21, and SOD1 expression studies. The child was found to have 4
copies of the region defined by D21S16 (21cen) through D21S93 on 21q22.1 and two
copies of the remaining region defined by SOD1-->D21S55-->D21S123. In view of
the recent assignment of Down syndrome facial characters to the 21q22 region,
defined in part by D21S55, it is significant that this child shows a subset of
Down syndrome facial manifestations, without duplication of this region. These
results suggest that genes contributing to the facial and some of the hand
manifestations of Down syndrome also exist in the chromosomal region proximal to
D21S55 in band 21q22.1. Down's syndrome results from the production of three copies of chromosome 21
within a cell. We have devised a method termed the homologous gene quantitative
polymerase chain reaction (HGQ-PCR), which uses one pair of primers and which
can directly identify the additional copy of chromosome 21 by simultaneously
amplifying two highly homologous genes of the human liver-type
phosphofructokinase located on chromosome 21 (PFKL-CH21) and the human
muscle-type phosphofructokinase located on chromosome 1 (PFKM-CH1) for
self-detecting determination. On analysis of 34 cases of Down's syndrome,
including two cases of unbalanced translocation 46, XY, der (14; 21) (q10; q10),
+ 21, and 100 normal individuals, the relative ratio of the PFKM-CH1/PFKL-CH21
product was 1.33 +/- 0.323 (mean +/- SD) and 0.40 +/- 0.16 (mean +/- SD) for
disomy DNA and trisomy DNA, respectively. The difference between these two
groups was highly significant (P < 0.001). These results indicate that this
quantitative method is practical and may be used for the prenatal diagnosis of
Down's syndrome caused by trisomy 21. BACKGROUND: Down syndrome, characterized by an extra chromosome 21 is the most
common genetic cause for congenital malformations and learning disability. It is
well known that the extra chromosome 21 most often originates from the mother,
the incidence increases with maternal age, there may be aberrant maternal
chromosome 21 recombination and there is a higher recurrence in young women. In
spite of intensive efforts to understand the underlying reason(s) for these
characteristics, the origin still remains unknown. We hypothesize that maternal
trisomy 21 ovarian mosaicism might provide the major causative factor.
RESULTS: We used fluorescence in situ hybridization (FISH) with two chromosome
21-specific probes to determine the copy number of chromosome 21 in ovarian
cells from eight female foetuses at gestational age 14-22 weeks. All eight
phenotypically normal female foetuses were found to be mosaics, containing
ovarian cells with an extra chromosome 21. Trisomy 21 occurred with about the
same frequency in cells that had entered meiosis as in pre-meiotic and ovarian
mesenchymal stroma cells.
CONCLUSION: We suggest that most normal female foetuses are trisomy 21 ovarian
mosaics and the maternal age effect is caused by differential selection of these
cells during foetal and postnatal development until ovulation. The exceptional
occurrence of high-grade ovarian mosaicism may explain why some women have a
child with Down syndrome already at young age as well as the associated
increased incidence at subsequent conceptions. We also propose that our findings
may explain the aberrant maternal recombination patterns previously found by
family linkage analysis. Down syndrome is a genetic disorder, occurring when an individual has all or
part of an extra copy of chromosome 21. Parents of children with Down syndrome
are often confused by the term genetic disorder because they associate the term
with inheritance but have also learned that Down syndrome is not typically
inherited. These parents may have questions about the nature of chromosomes, how
Down syndrome occurs, recurrence risk and more. This article attempts to address
many of the common questions parents of children with Down syndrome express
regarding the genetics of the disorder including the mechanisms by which Down
syndrome occurs: nondisjunction, translocation and mosaicism, as well as
providing information about prenatal testing options, how the diagnosis is made
and where parents may go for further information. BACKGROUND: Down syndrome (DS), caused by an extra copy of chromosome 21,
affects 1 in 750 live births and is characterized by cognitive impairment and a
constellation of congenital defects. Currently, little is known about the
molecular pathogenesis and no direct genotype-phenotype relationship has yet
been confirmed. Since DS amniocytes are expected to have a distinct biological
behaviour compared to normal amniocytes, we hypothesize that relative
quantification of proteins produced from trisomy and euploid (chromosomally
normal) amniocytes will reveal dysregulated molecular pathways.
RESULTS: Chromosomally normal- and Trisomy 21-amniocytes were quantitatively
analyzed by using Stable Isotope Labeling of Amino acids in Cell culture and
tandem mass spectrometry. A total of 4919 unique proteins were identified from
the supernatant and cell lysate proteome. More specifically, 4548 unique
proteins were identified from the lysate, and 91% of these proteins were
quantified based on MS/MS spectra ratios of peptides containing isotope-labeled
amino acids. A total of 904 proteins showed significant differential expression
and were involved in 25 molecular pathways, each containing a minimum of 16
proteins. Sixty of these proteins consistently showed aberrant expression from
trisomy 21 affected amniocytes, indicating their potential role in DS
pathogenesis. Nine proteins were analyzed with a multiplex selected reaction
monitoring assay in an independent set of Trisomy 21-amniocyte samples and two
of them (SOD1 and NES) showed a consistent differential expression.
CONCLUSIONS: The most extensive proteome of amniocytes and amniotic fluid has
been generated and differentially expressed proteins from amniocytes with
Trisomy 21 revealed molecular pathways that seem to be most significantly
affected by the presence of an extra copy of chromosome 21. The normal human chromosome complement consists of 46 chromosomes comprising 22
morphologically different pairs of autosomes and one pair of sex chromosomes.
Variations in either chromosome number and/or structure frequently result in
significant mental impairment and/or a variety of other clinical problems, among
them, altered bone mass and strength. Chromosomal syndromes associated with
specific chromosomal abnormalities are classified as either numerical or
structural and may involve more than one chromosome. Aneuploidy refers to the
presence of an extra copy of a specific chromosome, or trisomy, as seen in
Down's syndrome (trisomy 21), or the absence of a single chromosome, or
monosomy, as seen in Turner syndrome (a single X chromosome in females: 45, X).
Aneuploidies have diverse phenotypic consequences, ranging from severe mental
retardation and developmental abnormalities to increased susceptibility to
various neoplasms and premature death. In fact, trisomy 21 is the prototypical
aneuploidy in humans, is the most common genetic abnormality associated with
longevity, and is one of the most widespread genetic causes of intellectual
disability. In this review, the impact of trisomy 21 on the bone mass,
architecture, skeletal health, and quality of life of people with Down syndrome
will be discussed. Down syndrome (DS) results from one extra copy of human chromosome 21 and leads
to several alterations including intellectual disabilities and locomotor
defects. The transchromosomic Tc1 mouse model carrying an extra
freely-segregating copy of human chromosome 21 was developed to better
characterize the relation between genotype and phenotype in DS. The Tc1 mouse
exhibits several locomotor and cognitive deficits related to DS. In this report
we analyzed the contribution of the genetic dosage of 13 conserved mouse genes
located between Abcg1 and U2af1, in the telomeric part of Hsa21. We used the
Ms2Yah model carrying a deletion of the corresponding interval in the mouse
genome to rescue gene dosage in the Tc1/Ms2Yah compound mice to determine how
the different behavioral phenotypes are affected. We detected subtle changes
with the Tc1/Ms2Yah mice performing better than the Tc1 individuals in the
reversal paradigm of the Morris water maze. We also found that Tc1/Ms2Yah
compound mutants performed better in the rotarod than the Tc1 mice. This data
support the impact of genes from the Abcg1-U2af1 region as modifiers of
Tc1-dependent memory and locomotor phenotypes. Our results emphasize the complex
interactions between triplicated genes inducing DS features. Downs syndrome (DS) occurs due to an extra copy of chromosome 21. About 3% of
cases of Downs syndrome occur due to Robertsonian translocation, most commonly t
(14; 21), other types of translocations are very rare cause of the syndrome. A
10-year-old patient with mental retardation was admitted following road traffic
accident. Patient had flabby muscles, had delayed mile stones, stunted growth
for the age, slanting of eyes, flat nasal bridge, and ineligible speech. On
cytogenetic analysis the patient had karyotype showing one normal chromosome 21
and one Robertsonian translocation t (21; 21). Parents and siblings of the
patient were phenotypically normal. Robertsonian translocation t (21; 21), can
occur by transmission from carrier parent, due to ovarian mosaicism for
Robertsonian translocation or may appear de novo. In the present case as the
parents had normal karyotype and siblings were phenotypically normal,
Robertsonian translocation probably have arisen de novo. The present case was a
case of Downs syndrome with Robertsonian translocation t (21;21) probably
arising de novo. BACKGROUND: Down syndrome comprises multiple malformations and is due to trisomy
of chromosome 21. There is epidemiologic evidence that individuals with Down
syndrome are at decreased risk for solid tumors including brain tumors. It has
been suggested that some genes expressed on the extra copy of chromosome 21 act
as tumor suppressor genes and contribute to protection against tumorigenesis.
CASE DESCRIPTION: We report the first case to our knowledge of a patient with
Down syndrome, an 8-year-old boy, with an intracranial meningioma, in which the
status of chromosome 21 was examined. The diagnosis was based on histologic
examination of the surgically resected tumor. Postoperatively, the patient's
neurologic status improved, and there was no tumor regrowth in the next 2 years.
Fluorescence in situ hybridization for chromosome 22 confirmed high allele loss
involving the neurofibromin 2 gene locus, a finding typical in meningiomas.
Fluorescence in situ hybridization also revealed chromosome 21 heterogeneity in
tumor cells; not only cells with trisomy 21 but also cells with disomy and
monosomy 21 were present. All blood cells from the patient manifested trisomy
21.
CONCLUSIONS: Deletion of the chromosome 21 allele may be associated with
tumorigenesis of meningioma in Down syndrome. This supports the hypothesis that
some genes whose expression is increased on the extra copy of chromosome 21
function as tumor suppressor genes and that they contribute to the reduced tumor
incidence in individuals with Down syndrome. Author information:
(1)Department of Neurodegenerative Disease, Institute of Neurology, University
College London, Queen Square, London WC1N 3BG, UK.
(2)Division of Psychiatry, University College London, Maple House, 149 Tottenham
Court Road, London W1T 7NF, UK.
(3)Department of Molecular Neuroscience, Institute of Neurology, University
College London, Queen Square, London WC1N 3BG, UK.
(4)Centre for Brain and Cognitive Development, Birkbeck, University of London,
Malet Street, London WC1E 7HX, UK.
(5)Lee Kong Chian School of Medicine, Nanyang Technological University, Novena
Campus, 11 Mandalay Road, Singapore 308232; and the Blizard Institute, Barts and
the London School of Medicine, Queen Mary University of London, 4 Newark Street,
London E1 2AT, UK.
(6)Francis Crick Institute, Mill Hill Laboratory, London NW7 1AA, UK. BACKGROUND: Trisomy 21 Down syndrome is the most common genetic cause for
congenital malformations and intellectual disability. It is well known that in
the outstanding majority of cases the extra chromosome 21 originates from the
mother but only in less than 10 % from the father. The mechanism underlying this
striking difference in parental origin of Trisomy 21 Down syndrome is still
unknown. However, it seems likely that the main reason is a much higher
stringency in the elimination of any trisomy 21 cells during fetal testicular
than ovarian development. We have here focussed attention on the paternal
gametic output, i.e. the incidence of disomy 21 in spermatozoa.
RESULTS: We have used fluorescence in situ hybridisation (FISH) to determine the
copy number of chromosome 21 in spermatozoa from 11 men with normal
spermiograms. Due to the well-known risk of false positive and false negative
signals using a single FISH probe, we have applied two chromosome 21q probes,
and we have added a chromosome 18-specific probe to allow differentiation
between disomy 21 and diploidy. Analysing a total number of 2000 spermatozoa per
case, we documented an average incidence of disomy 21 at 0.13 %, with a range of
0.00-0.25 % and a SD of 0.08. There was no indication of diploidy in this cohort
of 22,000 sperm.
CONCLUSION: Numerous previous studies on the incidence of disomy 21 in sperm
have been published, using FISH. As far as we are aware, none of these have
applied more than a single chromosome 21-specific probe. Accepting our mean of
0.13 % of disomy 21, and providing there is no selective fertilisation
capability of disomy 21 sperm in relation to the normal, we conclude that around
1 in 800 conceptions is expected to be trisomic for chromosome 21 of paternal
origin. Bearing in mind that the maternal origin likely is at least 10 times
more common, we tentatively propose that around 1 in 80 oocytes in the maternal
ovarian reserve may be disomy 21. One reason for this discrepancy may be a more
stringent selection against aberrant chromosome numbers during spermatogenesis
than oogenesis. Further work is required to determine the relevant stages of
spermatogenesis at which such a selection may take place. Down syndrome (DS), caused by trisomy of chromosome 21, is marked by
intellectual disability (ID) and early onset of Alzheimer's disease (AD)
neuropathology including hippocampal cholinergic projection system degeneration.
Here we determined the effects of age and maternal choline supplementation (MCS)
on hippocampal cholinergic deficits in Ts65Dn mice compared to 2N mice
sacrificed at 6-8 and 14-18 months of age. Ts65Dn mice and disomic (2N)
littermates sacrificed at ages 6-8 and 14-18 mos were used for an aging study
and Ts65Dn and 2N mice derived from Ts65Dn dams were maintained on either a
choline-supplemented or a choline-controlled diet (conception to weaning) and
examined at 14-18 mos for MCS studies. In the latter, mice were behaviorally
tested on the radial arm Morris water maze (RAWM) and hippocampal tissue was
examined for intensity of choline acetyltransferase (ChAT) immunoreactivity.
Hippocampal ChAT activity was evaluated in a separate cohort. ChAT-positive
fiber innervation was significantly higher in the hippocampus and dentate gyrus
in Ts65Dn mice compared with 2N mice, independent of age or maternal diet.
Similarly, hippocampal ChAT activity was significantly elevated in Ts65Dn mice
compared to 2N mice, independent of maternal diet. A significant increase with
age was seen in hippocampal cholinergic innervation of 2N mice, but not Ts65Dn
mice. Degree of ChAT intensity correlated negatively with spatial memory ability
in unsupplemented 2N and Ts65Dn mice, but positively in MCS 2N mice. The
increased innervation produced by MCS appears to improve hippocampal function,
making this a therapy that may be exploited for future translational approaches
in human DS. Down syndrome (DS; trisomy 21) is the most common survivable disorder due to
aneuploidy. Individuals with DS may experience multiple comorbid health problems
including congenital heart defects, endocrine abnormalities, skin and dental
problems, seizure disorders, leukemia, dementia, and obesity. These associated
conditions may necessitate pharmacotherapeutic management with various drugs.
The complex pathobiology of DS may alter drug disposition and drug response in
some individuals. For example, reports have documented increased rates of
adverse drug reactions in patients with DS treated for leukemia and dementia.
Intellectual disability resulting from DS may impact adherence to medication
regimens. In this review, we highlight literature focused on pharmacotherapy for
individuals with DS. We discuss reports of altered drug disposition or response
in patients with DS and explore social factors that may impact medication
adherence in the DS setting. Enhanced monitoring during drug therapy in
individuals with DS is justified based on reports of altered drug disposition,
drug response, and other characteristics present in this population. Down syndrome (DS), trisomy 21, is caused by increased dose of genes present on
human chromosome 21 (HSA21). The gene-dose hypothesis argues that a change in
the dose of individual genes or regulatory sequences on HSA21 is necessary for
creating DS-related phenotypes, including cognitive impairment. We focused on a
possible role for Kcnj6, the gene encoding Kir3.2 (Girk2) subunits of a
G-protein-coupled inwardly-rectifying potassium channel. This gene resides on a
segment of mouse Chromosome 16 that is present in one extra copy in the genome
of the Ts65Dn mouse, a well-studied genetic model of DS. Kir3.2
subunit-containing potassium channels serve as effectors for a number of
postsynaptic metabotropic receptors including GABAB receptors. Several studies
raise the possibility that increased Kcnj6 dose contributes to synaptic and
cognitive abnormalities in DS. To assess directly a role for Kcnj6 gene dose in
cognitive deficits in DS, we produced Ts65Dn mice that harbor only 2 copies of
Kcnj6 (Ts65Dn:Kcnj6++- mice). The reduction in Kcnj6 gene dose restored to
normal the hippocampal level of Kir3.2. Long-term memory, examined in the novel
object recognition test with the retention period of 24h, was improved to the
level observed in the normosomic littermate control mice (2N:Kcnj6++).
Significantly, both short-term and long-term potentiation (STP and LTP) was
improved to control levels in the dentate gyrus (DG) of the Ts65Dn:Kcnj6++-
mouse. In view of the ability of fluoxetine to suppress Kir3.2 channels, we
asked if fluoxetine-treated DG slices of Ts65Dn:Kcnj6+++ mice would rescue
synaptic plasticity. Fluoxetine increased STP and LTP to control levels. These
results are evidence that increased Kcnj6 gene dose is necessary for synaptic
and cognitive dysfunction in the Ts65Dn mouse model of DS. Strategies aimed at
pharmacologically reducing channel function should be explored for enhancing
cognition in DS. |
What is craniosynostosis? | Craniosynostosis is a result of premature fusion of cranial sutures, leading to alterations of the pattern of cranial growth, resulting in abnormal shape of the head and dysmorphic facial features. | Premature closure of cranial sutures (primary craniosynostosis) in children
leads to characteristic skull deformities and prevents the constricted brain
from growing normally. Although the cause remains unknown, several etiological
factors have been cited. Recently, hypovascularity has been reported as a
possible cause of craniosynostosis.
METHODS: In a prospective study regional cerebral blood flow studies were
carried out with 99mTc-HMPAO SPECT in seven children with craniosynostoses. Five
preoperative and six postoperative studies were conducted and the results
correlated with radiological and surgical findings.
RESULTS: Preoperative studies revealed regional hypovascularity in the
underlying cerebral hemisphere, corresponding to the fused sutures.
Postoperative studies revealed disappearance of these perfusion defects in most
cases, indicating normalization of perfusion following surgical decompression.
CONCLUSION: This study establishes the presence of cerebral hypovascularity in
craniosynostoses and suggests that early surgery and release of craniostenosis
is essential to achieve optimum perfusion and brain development. Craniosynostosis, premature fusion of the skull bones at the sutures, is the
second most common human birth defect in the skull. Raman microspectroscopy was
used to examine the composition, relative amounts, and locations of the mineral
and matrix produced in mouse skulls undergoing force-induced craniosynostosis.
Raman imaging revealed decreased relative mineral content in skulls undergoing
craniosynostosis compared with unloaded specimens.
INTRODUCTION: Raman microspectroscopy, a nondestructive vibrational
spectroscopic technique, was used to examine the composition, relative amounts,
and locations of the mineral and matrix produced in mouse skulls undergoing
force-induced craniosynostosis. Craniosynostosis, premature fusion of the skull
bones at the sutures, is the second most common birth defect in the face and
skull. The calvaria, or flat bones that comprise the top of the skull, are most
often affected, and craniosynostosis is a feature of over 100 human syndromes
and conditions.
MATERIALS AND METHODS: Raman images of the suture, the tips immediately adjacent
to the suture (osteogenic fronts), and mature parietal bones of loaded and
unloaded calvaria were acquired. Images were acquired at 2.6 x 2.6 microm
spatial resolution and ranged in a field of view from 180 x 210 microm to 180 x
325 microm.
RESULTS AND CONCLUSIONS: This study found that osteogenic fronts subjected to
uniaxial compression had decreased relative mineral content compared with
unloaded osteogenic fronts, presumably because of new and incomplete mineral
deposition. Increased matrix production in osteogenic fronts undergoing
craniosynostosis was observed. Understanding how force affects the composition,
relative amounts, and location of the mineral and matrix provides insight into
musculoskeletal disease in general and craniosynostosis in particular. This is
the first report in which Raman microspectroscopy was used to study
musculoskeletal disease. These data show how Raman microspectroscopy can be used
to study subtle changes that occur in disease. Craniosynostosis is a defect of the skull caused by early fusion of one or more
of the cranial sutures and affects 3 to 5 individuals per 10,000 live births.
Craniosynostosis can be divided into two main groups: syndromic and
nonsyndromic. Nonsyndromic craniosynostosis is typically an isolated finding
that is classified according to the suture(s) involved. Syndromic
craniosynostosis is associated with various dysmorphisms involving the face,
skeleton, nervous system, and other anomalies and is usually accompanied by
developmental delay. More than 180 syndromes exist that contain
craniosynostosis. Secondary effects of craniosynostosis may include vision
problems and increased intracranial pressure, among others. The molecular basis
of many types of syndromic craniosynostosis is known, and diagnostic testing
strategies will often lead to a specific diagnosis. Craniosynostosis represents a defection of the skull caused by early fusion of
one or more cranial sutures. The shape alteration of the cranial vault varies,
depending on the fused sutures, so that compensatory growth occurs in dimensions
not restricted by sutures. Craniosynostosis can be divided into two main groups:
syndromic and nonsyndromic. Nonsyndromic craniosynostosis is typically an
isolated finding that is classified according to the suture(s) involved.
Syndromic craniosynostosis is associated with various dysmorphisms involving the
face, skeleton, nervous system and is usually accompanied by developmental
delay. In the last 15 years, research on craniosynostosis has progressed from
the description of gross abnormalities to the understanding of the genetic basis
of certain cranial deformities. Mutations in the genes encoding fibroblast
growth factor receptors 1, 2 and 3 (FGFR-1, FGFR-2, FGFR-3), TWIST and MSX2
(muscle segment homebox 2) have been identified in certain syndromic
craniosynostosis. The molecular basis of many types of syndromic
craniosynostosis is known and diagnostic testing strategies will often lead to a
specific diagnosis. Although the clarification of a genetic lesion does not have
a direct impact on the management of the patient in many cases, there is a
significant benefit in providing accurate prenatal diagnosis. This review
summarizes the available knowledge on cranisynostosis and presents a graduated
strategy for the genetic diagnosis of these craniofacial defects. Craniosynostosis, the premature closure of cranial suture, is a pathologic
condition that affects 1/2000 live births. Saethre-Chotzen syndrome is a genetic
condition characterized by craniosynostosis. The Saethre-Chotzen syndrome, which
is defined by loss-of-function mutations in the TWIST gene, is the second most
prevalent craniosynostosis. Although much of the genetics and phenotypes in
craniosynostosis syndromes is understood, less is known about the underlying
ossification mechanism during suture closure. We have previously demonstrated
that physiological closure of the posterior frontal suture occurs through
endochondral ossification. Moreover, we revealed that antagonizing canonical
Wnt-signaling in the sagittal suture leads to endochondral ossification of the
suture mesenchyme and sagittal synostosis, presumably by inhibiting Twist1.
Classic Saethre-Chotzen syndrome is characterized by coronal synostosis, and the
haploinsufficient Twist1(+/-) mice represents a suitable model for studying this
syndrome. Thus, we seeked to understand the underlying ossification process in
coronal craniosynostosis in Twist1(+/-) mice. Our data indicate that coronal
suture closure in Twist1(+/-) mice occurs between postnatal day 9 and 13 by
endochondral ossification, as shown by histology, gene expression analysis, and
immunohistochemistry. In conclusion, this study reveals that coronal
craniosynostosis in Twist1(+/-) mice occurs through endochondral ossification.
Moreover, it suggests that haploinsufficiency of Twist1 gene, a target of
canonical Wnt-signaling, and inhibitor of chondrogenesis, mimics conditions of
inactive canonical Wnt-signaling leading to craniosynostosis. Craniosynostosis is the premature fusion of one or more sutures of the skull,
which can be syndromic or isolated. Mutations in FGFR1, FGFR2, or FGFR3, among
others, are often responsible for these syndromic cases. The associated of FGFR3
mutations with craniosynostosis has been restricted to three mutations, the
common p.Pro250Arg in Muenke syndrome, p.Ala391Glu in Crouzon syndrome with
acanthosis nigricans, and p.Pro250Leu identified in a family with isolated
craniosynostosis. Other FGFR3 mutations result in various skeletal dysplasias:
achondroplasia, hypochondroplasia, and thanatophoric dysplasia. Here, we report
a novel mutation in exon 8 (IIIc) of FGFR3, p.Ala334Thr, in a young boy with
mild craniosynostosis. The mutation segregated with mild craniosynostosis in the
family and was absent in 188 normal controls. Alanine 334 is evolutionarily
conserved in vertebrates and is located at the amino terminus of the βF loop in
the FGFR3c isoform. The mutation is predicted to alter the protein tertiary
structure which may impair its binding to its ligand, FGF1. The identification
of a mutation in these clinically heterogeneous disorders can aid recurrence
risk assessments. Although the implementation of a stepwise screening strategy
is useful in diagnostics, mutations in unscreened regions of genes associated
with craniosynostosis may explain a small proportion of craniosynostosis cases. Craniosynostosis is a complex condition, characterized by the premature fusion
of one of more of the cranial sutures. They can be seen individually or as part
of multisystem syndromes. This review uses computed tomography (CT) with
three-dimensional reconstructions to help describe some of the types and
classifications of craniosynostosis, as well as describing some of the
associations and the management of craniosynostosis. Craniosynostosis describes the premature fusion of one or more cranial sutures
and can lead to dramatic manifestations in terms of appearance and functional
impairment. Contemporary approaches for this condition are primarily surgical
and are associated with considerable morbidity and mortality. The additional
post-operative problems of suture refusion and bony relapse may also necessitate
repeated surgeries with their own attendant risks. Therefore, a need exists to
not only optimize current strategies but also to develop novel biological
therapies which could obviate the need for surgery and potentially treat or even
prevent premature suture fusion. Clinical studies of patients with syndromic
craniosynostosis have provided some useful insights into the important signaling
pathways and molecular events guiding suture fate. Furthermore, the highly
conserved nature of craniofacial development between humans and other species
have permitted more focused and step-wise elucidation of the molecular
underpinnings of craniosynostosis. This review will describe the clinical
manifestations of craniosynostosis, reflect on our understanding of syndromic
and non-syndromic craniosynostoses and outline the different approaches that
have been adopted in our laboratory and elsewhere to better understand the
pathogenesis of premature suture fusion. Finally, we will assess to what extent
our improved understanding of the pathogenesis of craniosynostosis, achieved
through laboratory-based and clinical studies, have made the possibility of a
non-surgical pharmacological approach both realistic and tangible. BACKGROUND: Craniosynostosis is a condition that includes the premature fusion
of one or multiple cranial sutures. Among various craniosynostosis forms,
sagittal nonsyndromic craniosynostosis is the most prevalent. Although different
gene mutations have been identified in some craniosynostosis syndromes, the
cause of sagittal nonsyndromic craniosynostosis remains largely unknown.
METHODS: To screen for candidate genes for sagittal nonsyndromic
craniosynostosis, the authors sequenced DNA of 93 sagittal nonsyndromic
craniosynostosis patients from a population-based study conducted in Iowa and
New York states. FGFR1-3 mutational hotspots and the entire TWIST1, RAB23, and
BMP2 coding regions were screened because of their known roles in human
nonsyndromic or syndromic sagittal craniosynostosis, expression patterns, and/or
animal model studies.
RESULTS: The authors identified two rare variants in their cohort. A FGFR1
insertion c.730_731insG, which led to a premature stop codon, was predicted to
abolish the entire immunoglobulin-like III domain, including the ligand-binding
region. A c.439C>G variant was observed in TWIST1 at its highly conserved loop
domain in another patient. The patient's mother harbored the same variant and
was reported with jaw abnormalities. These two variants were not detected in 116
alleles from unaffected controls or seen in the several databases; however,
TWIST1 variant was found in a low frequency of 0.000831 percent in Exome
Aggregation Consortium database.
CONCLUSIONS: The low mutation detection rate indicates that these genes account
for only a small proportion of sagittal nonsyndromic craniosynostosis patients.
The authors' results add to the perception that sagittal nonsyndromic
craniosynostosis is a complex developmental defect with considerable genetic
heterogeneity.
CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, II. Craniosynostosis is a relatively common birth defect characterized by the
premature fusion of one or more cranial sutures. Examples of craniosynostosis
syndromes include Crouzon (CS), Pfeiffer (PS), and Apert (AS) syndrome, with
clinical characteristics such as midface hypoplasia, hypertelorism, and in some
cases, limb defects. Mutations in Fibroblast Growth Factor Receptor-2 comprise
the majority of known mutations in syndromic forms of craniosynostosis. A number
of clinical reports of FGFR-associated craniosynostosis patients and mouse
mutants have been linked to gastrointestinal tract (GIT) disorders, leading to
the hypothesis of a direct link between FGFR-associated craniosynostosis
syndromes and GIT malformations. We conducted an investigation to determine GIT
symptoms in a sample of FGFR-associated craniosynostosis syndrome patients and a
mouse model of CS containing a mutation (W290R) in Fgfr2. We found that,
compared to the general population, the incidence of intestinal/bowel
malrotation (IM) was present at a higher level in our sample population of
patients with FGFR-associated craniosynostosis syndromes. We also showed that
the mouse model of CS had an increased incidence of cecal displacement,
suggestive of IM. These findings suggest a direct relationship between
FGFR-related craniosynostosis syndromes and GIT malformations. Our study may
shed further light on the potential widespread impact FGFR mutations on
different developmental systems. Based on reports of GIT malformations in
children with craniosynostosis syndromes and substantiation with our animal
model, GIT malformations should be considered in any child with an
FGFR2-associated craniosynostosis syndrome. © 2016 Wiley Periodicals, Inc. Craniosynostosis, or premature fusion of the cranial sutures, occurs in
approximately 1 in 2500 live births. The genetic causes and molecular basis of
these disorders have greatly expanded over the last 2 decades, with numerous
causative and contributory mutations having been identified. The role of
fibroblast growth factor receptor (FGFR) mutations in the etiology of certain
eponymous forms of craniosynostosis is now well elucidated; the most common
syndromes associated with craniosynostosis are Pfeifer (FGFR1, FGFR2), Apert
(FGFR2), Crouzon (FGFR2), Saethre-Chotzen (TWIST1), Jackson-Weiss (FGFR2), Greig
(GL13), and Muenke (FGFR3) syndromes. Although pathological expression of these
mutations often results in bilateral coronal craniosynostosis, single suture
fusions (typically unilateral coronal synostosis) or multiple suture
craniosynostosis are possible.The majority of patients diagnosed with
craniosynostosis lack an identifiable syndrome or genetic mutation. The
etiopathogenesis of these "nonsyndromic" forms of craniosynostosis is believed
to involve a complex interplay of genetics, epigenetics, and environmental
factors. Evaluation of genes implicated in nonsyndromic craniosynostosis has
been conflicting; some evidence demonstrates an interplay between genetic and
epigenetic influences while others do not. Certain environmental factors such as
teratogenic levels of retinoic acid, maternal metabolic and hematologic
disorders, and head growth constraint in utero may increase the likelihood of
developing craniosynostosis, but these associations are again tenuous.The
authors present 1 of 2 genetically confirmed identical twins discordant for
metopic craniosynostosis. The implications of this case are clear: epigenetic
influences, environmental influences, or both played a role in the development
of this premature suture fusion. |
Which method has been developed for assignment of enhancers to target genes? | While genomic assays can identify putative enhancers en masse, assigning target genes is a complex challenge. McEnhancer is a machine learning approach, which links target genes to putative enhancers via a semi-supervised learning algorithm that predicts gene expression patterns based on enriched sequence features. Predicted expression patterns were 73-98% accurate, predicted assignments showed strong Hi-C interaction enrichment, enhancer-associated histone modifications were evident, and known functional motifs were recovered. | |
Describe Click-PEGylation | One approach that can facilitate a targeted assessment of candidate proteins, as well as proteins that are low in abundance or proteomically challenging, is by electrophoretic mobility shift assays. Redox-modified cysteine residues are selectively tagged with a large group, such as a polyethylene glycol (PEG) polymer, and then the proteins are separated by electrophoresis followed by immunoblotting, which allows the inference of redox changes based on band shifts. However, the applicability of this method has been impaired by the difficulty of cleanly modifying protein thiols by large PEG reagents. To establish a more robust method for redox-selective PEGylation a Click chemistry approach has been developed where free thiol groups are first labelled with a reagent modified to contain an alkyne moiety, which is subsequently Click-reacted with a PEG molecule containing a complementary azide function. This strategy can be adapted to study reversibly reduced or oxidised cysteines. Separation of the thiol labelling step from the PEG conjugation greatly facilitates the fidelity and flexibility of this approach. | The redox state of cysteine thiols is critical for protein function. Whereas
cysteines play an important role in the maintece of protein structure through
the formation of internal disulfides, their nucleophilic thiol groups can become
oxidatively modified in response to diverse redox challenges and thereby
function in signalling and antioxidant defences. These oxidative modifications
occur in response to a range of agents and stimuli, and can lead to the
existence of multiple redox states for a given protein. To assess the role(s) of
a protein in redox signalling and antioxidant defence, it is thus vital to be
able to assess which of the multiple thiol redox states are present and to
investigate how these alter under different conditions. While this can be done
by a range of mass spectrometric-based methods, these are time-consuming,
costly, and best suited to study abundant proteins or to perform an unbiased
proteomic screen. One approach that can facilitate a targeted assessment of
candidate proteins, as well as proteins that are low in abundance or
proteomically challenging, is by electrophoretic mobility shift assays.
Redox-modified cysteine residues are selectively tagged with a large group, such
as a polyethylene glycol (PEG) polymer, and then the proteins are separated by
electrophoresis followed by immunoblotting, which allows the inference of redox
changes based on band shifts. However, the applicability of this method has been
impaired by the difficulty of cleanly modifying protein thiols by large PEG
reagents. To establish a more robust method for redox-selective PEGylation, we
have utilised a Click chemistry approach, where free thiol groups are first
labelled with a reagent modified to contain an alkyne moiety, which is
subsequently Click-reacted with a PEG molecule containing a complementary azide
function. This strategy can be adapted to study reversibly reduced or oxidised
cysteines. Separation of the thiol labelling step from the PEG conjugation
greatly facilitates the fidelity and flexibility of this approach. Here we show
how the Click-PEGylation technique can be used to interrogate the redox state of
proteins. |
A SLEDAI score is associated with Systemic Lupus Erythematosus. What is a SLEDAI score? | Disease activity of Systemic Lupus Erythematosis was evaluated according to the SLE Disease Activity Index (SLEDAI) score which score disease activity based on a number of parameters. | OBJECTIVE: To determine whether Systemic Lupus Erythematosus Disease Activity
Index (SLEDAI) scores correlate with the clinician's impression of level of
disease activity.
METHODS: In total, 230 patients with SLE followed at the University of Toronto
Lupus Clinic who had 5 visits 3 months apart in 1992-93 were studied. At each
visit a standard protocol was completed. A clinician who did not know the
patients or their SLEDAI scores evaluated each patient record and assigned a
clinical activity level. "Flare" was defined by new or increased therapy for
active disease, an expression of concern, or use of the term "flare" in the
physician's notes. The SLEDAI score was calculated from the database.
RESULTS: SLEDAI scores described a range of clinical activity as recognized by
the clinician. Median SLEDAI scores ranged from 2 (inactive disease) to 8
(persistently active or flare). When the clinician assessed the patient to be
improved, the median SLEDAI score decreased by 2. When the clinician assessed
that the patient was experiencing a flare, the SLEDAI score increased by a
median of 4.
CONCLUSION: Based on our data we propose the following outcomes for patients
with SLE: flare, an increase in SLEDAI > 3; improvement is a reduction in SLEDAI
of > 3; persistently active disease is change in SLEDAI +/- 3; and remission a
SLEDAI of 0. These outcomes will allow a more complete description of a
patient's response to therapeutic intervention in a responder index. OBJECTIVE: To evaluate the prevalence, disease course, and survival of patients
with systemic lupus erythematosus (SLE) in a population of over 120,000 North
American Indians (NAI), and contrast the results to those in the non-Indian
population.
METHODS: The regional arthritis center database and the medical records of all
rheumatologists, hematologists, nephrologists, and general internists with > 1
patient with SLE were searched for cases of SLE diagnosed between 1980 and 1996.
A random survey of 20% of family physicians serving this population suggested
that > 85% of all SLE cases were identified. Demographics, SLE Disease Activity
Index (SLEDAI) scores, Systemic Lupus International Collaborating
Clinics/American College of Rheumatology (SLICC/ACR) damage scores. clinical
manifestations, and therapy for NAI were contrasted with the results in
Caucasians (CAUC).
RESULTS: We identified 257 cases meeting the ACR criteria for SLE diagnosed
between 1980 and 1996. There were 49 NAI cases, resulting in a prevalence of
42.3/100,000, compared to a prevalence of 20.6/100,000 for the remainder of the
population. NAI patients were younger at diagnosis, had higher SLEDAI scores at
diagnosis, and had more frequent vasculitis, proteinuria and cellular casts.
There were no treatment differences at diagnosis or at 2 years, but NAI patients
were significantly more likely to receive treatment with prednisone or
immunosuppressives at the last clinic visit. The NAI patients had similar damage
scores at diagnosis, but significantly higher scores at 2 years and at the last
clinic visit. NAI ethnicity increased the likelihood of death more than 4-fold.
CONCLUSION: The prevalence of SLE was increased 2-fold in the NAI population.
NAI patients had higher SLEDAI scores at diagnosis and more frequent vasculitis
and renal involvement, required more treatment later in the disease course,
accumulated more damage following diagnosis, and had increased fatality. The objective of this study was to assess the incidence and risk factors of
infections in 200 SLE outpatients. All outpatients with active or inactive SLE
without infections in the previous month were included. They were assessed every
3 months. Major infections were those requiring hospitalization and parental
antibiotic therapy; minor infections required oral or topical therapy.
Sociodemographic, disease activity using the Systemic Lupus Erythematosus
Disease Activity Index (SLEDAI), therapy and laboratory variables were
evaluated. After a follow-up of 22+/-7 months, 65 (32%) patients had infections;
35% of those were major. The most common sites for infection were urinary (26%),
skin (23%), systemic (12%), and vaginal (9%). At infection onset, 50 of 65
patients (77%) had disease activity, with a mean SLEDAI score of 6.1. The
variables significantly associated with infection in the univariate analyses
were the presence of disease activity, SLEDAI score, renal activity, prednisone
dose, and IV cyclophosphamide. The only variable associated with infection in
the multivariate analyses was a SLEDAI score of 4 or higher. Most infections in
SLE outpatients were single, minor, non-life threatening, and associated with
disease activity independently of sociodemographic and therapeutic factors. Both the revised Systemic Lupus Activity Measure (SLAM-R) and the Systemic Lupus
Erythematosus Disease Activity Index (SLEDAI) are valid and reliable measures of
disease activity in systemic lupus erythematosus (SLE). However, more study of
their responsiveness is needed. The purpose of this study was to compare the
responsiveness of SLAM-R and SLEDAI to disease activity changes relevant to
physicians and patients. Patients were evaluated monthly for up to 12 months. At
each visit, the physician completed SLAM-R and SLEDAI. Patients and physicians
assessed whether relevant improvement or worsening of disease activity had
occurred since the previous visit. Based on repeated measurements, effect size
(ES), standardized response mean (SRM), and control-standardized response mean
(CSRM) were calculated for each response category, with bootstrap-based 95%
confidence intervals (CIs). Seventy-six patients contributed 471 score changes.
For physicians' responses, the CSRMs for SLAM-R and SLEDAI were -0.47 versus
-0.42 for improvement, 0.04 versus 0.003 for no change, and 0.65 versus 0.66 for
deterioration. For patients, the CSRMs for SLAM-R and SLEDAI were -0.31 versus
-0.18 for improvement, -0.08 versus 0.06 for no change, and 0.48 versus 0.05 for
deterioration. Only for SLAM-R did the 95% CIs exclude zero when improvement or
deterioration were detected. Similar results were found for ES and SRM. Both
SLAM-R and SLEDAI are responsive to changes in SLE disease activity important to
physicians. Only SLAM-R is responsive to changes important to patients. These
differences may result from the inclusion of subjective SLE manifestations in
SLAM-R. OBJECTIVE: To assess the validity, reliability, and feasibility of the Systemic
Lupus Activity Measure-Revised (SLAM-R), the Mexican version of the Systemic
Lupus Erythematosus Disease Activity Index (MEX-SLEDAI), and a Modified
SLEDAI-2000 (SLEDAI-2K) compared with the SLEDAI-2K in a multiethnic population
of patients with SLE.
METHODS: We studied 92 SLE patients from 3 US geographic areas (Alabama, Texas,
and Puerto Rico). Assessment occurred during regular outpatient, inpatient, or
study encounters. A trained physician scored the 4 instruments and also assessed
disease activity globally [physician global assessment (PGA)]. Convergent (with
SLEDAI-2K) and construct validity (with PGA) were determined by Spearman rank
(rs) correlation test. Level of agreement between the instruments was assessed
using Bland-Altman plots. Discrimit validity (distinguishing clearly active
vs mildly/nonactive disease) was assessed considering the SLEDAI-2K (and the
PGA) as the gold standard. Feasibility was explored by cost analyses.
RESULTS: The SLAM-R, the MEX-SLEDAI, and the Modified SLEDAI-2K were highly
correlated with the SLEDAI-2K (rs = 0.566, 0.755, 0.924, respectively) and with
the PGA (rs = 0.650, 0.540, 0.634, respectively). The 3 instruments showed good
agreement with the SLEDAI-2K (Bland-Altman plots). The Modified SLEDAI-2K had
better discrimit validity than the SLAM-R and the MEX-SLEDAI. The Modified
SLEDAI-2K was the least expensive instrument.
CONCLUSION: The SLAM-R, the MEX-SLEDAI, and the Modified SLEDAI-2K are adequate
options for assessment of SLE disease activity; they are also less costly than
the SLEDAI-2K. The assessment of disease activity in systemic lupus erythematosus (SLE) is a
task faced by clinicians in every day care, but it is also required for clinical
research and in randomised controlled trials. It is crucial to distinguish
disease activity from infection, chronic damage and co-morbid disease. Over the
past 20 years, many indices have been developed to objectively measure lupus
disease activity and several of these have been validated. The most widely used
indices are the British Isles Lupus Assessment Group (BILAG) index, the European
Consensus Lupus Activity Measurement (ECLAM), the Systemic Lupus Activity
Measure (SLAM), the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI)
and the Lupus Activity Index (LAI). All these indices have been validated and
have excellent reliability, validity and responsiveness to change. In addition
to the assessment of disease activity, the evaluation of damage using the
validated SLICC/ACR damage index and health-related quality of life is advised
for clinical research. BACKGROUND: Lupus band test still has no clearly defined position within either
diagnostic or disease activity measuring tools for systemic lupus erythematosus
(SLE).
OBJECTIVES: We tested the hypothesis that positive LBT correlates with global
activity of SLE measured by the SLE Disease Activity Index (SLEDAI) score.
METHODS: In total, 90 SLE patients who underwent biopsy of sunprotected
non-lesional (SPNL) skin were studied prospectively. The skin specimen was
processed for standard direct immunofluorescence. The patients were classified
into groups as negative and positive LBT, and the latter were further subdivided
on the basis of the type and morphology of the deposits. Every patient was
thoroughly examined and assigned a SLEDAI score. The relationship between LBT
findings and SLEDAI score was analysed.
RESULTS: The disease was significantly more active in patients with positive LBT
and in those with a higher number of deposited immunoreactants. Almost all
patients with renal involvement had a positive LBT.
CONCLUSIONS: LBT on SPNL skin may be a good marker of severe disease at
presentation, particularly when three immunoglobulins are found at the
dermoepidermal junction. OBJECTIVE: To determine the flare rate and the change in Safety of Estrogens in
Lupus Erythematosus: National Assessment Systemic Lupus Erythematosus Disease
Activity Index (SELENA SLEDAI) score with disease flare in pediatric systemic
lupus erythematosus (pSLE).
METHODS: A retrospective chart review of 62 patients with pSLE (ages 5-20 yrs).
A flare was defined as the start of, or increase in, the dose of corticosteroids
and/or the addition of an immunosuppressive medication. All pre-flare, flare,
and post-flare visits were recorded with a SELENA SLEDAI score calculated for
each visit. The flare rate was calculated by dividing the total number of flares
in the cohort by the total followup years.
RESULTS: Sixty-two patients were eligible. Forty-seven patients had 112 flares.
The average number of flares/patient was 1.8 +/- 2.0 and the mean inter-flare
time was 15.4 +/- 17.9 months. The flare rate in pSLE was 0.46
flares/patient-year of followup. The median time to first flare from the date of
diagnosis was 14.3 months. Patients with cytopenia, pleuritis, or pericarditis,
or a positive antibody to Smith nuclear antigen at the time of diagnosis had a
significantly higher flare rate than those who did not. The average SELENA
SLEDAI score at presentation was 12.5 +/- 5.4, at the pre-flare visit 6.3 +/-
3.5, and during a flare 7.9 +/- 5.1.
CONCLUSION: This is the first large study to report a flare rate (0.46
flares/patient-year of followup) in pSLE. The flare rate was similar to what has
been reported in pSLE previously but significantly lower than that reported in
adults with lupus. The average change in the SELENA SLEDAI score with disease
flare is 2 points. Systemic lupus erythematosus (SLE) is a connective tissue disease characterized
by the formation of autoantibodies and immune complexes. Lupus nephritis is one
of the hallmark features of SLE. CXCL10 is a chemokine secreted by IFNg-
stimulated endothelial cells and has been shown to be involved in the
pathological processes of autoimmune diseases. The objective was to measure
urinary CXCL10 in SLE patients, to compare levels between nephritis and
non-nephritis groups and to study its correlation with other variables. Sixty
lupus patients were enrolled in our trial. Thirty patients had lupus nephritis
and the other 30 were without evidence of lupus nephritis. Thirty healthy
subjects were willing to participate as a healthy control group. Renal biopsy
was performed for lupus nephritis group. Urinary CXCL10 was measured using the
ELISA technique. Serum creatinine, C3, C4 and 24 h urinary proteins were
measured. Lupus activity was assessed using systemic lupus erythematosus disease
activity index (SLEDAI) scoring system. Renal activity was measured using renal
activity scoring system. CXCL10 was significantly higher in lupus nephritis
patients than in lupus patients without nephritis. CXCL10 was significantly
correlated with renal activity score, 24 hours urinary proteins and the SLEDAI
score. It is highly valid predictor of SLE nephritis with high sensitivity and
specificity. CXCL 10 a highly sensitive and specific non-invasive diagnostic
tool for lupus nephritis patients. OBJECTIVE: Current disease activity measures for systemic lupus erythematosus
(SLE) are difficult to score or interpret and problematic for use in clinical
practice. Lupus Foundation of America (LFA)-Rapid Evaluation of Activity in
Lupus (REAL) is a pilot application composed of anchored visual analogue scores
(0-100 mm each) for each organ affected by lupus. This study evaluated the use
of LFA-REAL in capturing SLE disease activity.
METHODS: In a preliminary test of LFA-REAL, this simplified, organ-based system
was compared with the most widely used outcome measures in clinical trials, the
British Isles Lupus Assessment Group 2004 Index (BILAG), the SLE Disease
Activity Index (SLEDAI) and the Safety of Estrogens in Lupus Erythematosus
National Assessment (SELENA) SLEDAI Physician's Global Assessment (SS-PGA). The
level of agreement was analysed using Spearman rank correlations.
RESULTS: 91 patients with SLE with mild to severe disease activity were
evaluated, their median SLEDAI score was 4.0 (range 0-28) and BILAG score 8.0
(0-32). The median SS-PGA was 38 mm (4-92) versus the total REAL 50 mm (0-268),
which expands in range by additive organ scores. Thirty-three patients had
moderate to severe disease activity (≥1.5 on SS-PGA landmarks). The median
SS-PGA score of this group was 66 mm (50-92) versus median REAL score of 100 mm
(59-268), confirming ability to detect a wider distribution of scores at higher
disease activity. Total REAL correlated with SLEDAI, BILAG and SS-PGA
(correlation coefficient=0.816, 0.933 and 0.903, respectively; p<0.001 for all).
Individual LFA-REAL organ scores for musculoskeletal and mucocutaneous also
correlated with corresponding BILAG domain scores (correlation coefficient=0.925
and 0.934, p<0.001).
CONCLUSIONS: In this preliminary exercise, there were strong correlations
between LFA-REAL and validated lupus disease activity indices. Further
development may be valuable for consistent scoring in clinical trials, grading
optimal assessment of change in disease activity and reliable monitoring of
patients in practice. BACKGROUND: Systemic lupus erythematosus (SLE) is an autoimmune
connective-tissue disease involving multiple organs and systems. Some evidence
has demonstrated that disease activity could be associated with increased risk
of organ damage.
OBJECTIVES: The aim of this study was to determine the association between
systemic lupus erythematosus Disease Activity Index (SLEDAI) scores and
subclinical cardiac involvement.
METHODS: This cross-sectional study was conducted on 45 SLE patients (88%
female; mean age: 31.2 ± 8.2 years) from 2011 to 2013 in Mashhad, Iran. The
patients had no clinical signs and symptoms of cardiac problems or risk factors
for cardiovascular disease and were selected consecutively. All patients
underwent complete echocardiographic examinations (using two dimensional (2D)
tissue Doppler and 2D speckle tracking). Disease activity was evaluated by using
the SLEDAI.
RESULTS: Patients with higher SLEDAI scores had higher pulmonary artery pressure
rates (r = 0.34; P = 0.024; 95% CI (0.086 to 0.595)) and SLE durations (r =
0.43; P = 0.004; 95% CI (0.165 to 0.664). The correlation between disease
duration and left ventricular mass was also significant (r = 0.43; P = 0.009;
95% CI (0.172 to 0.681)), even after adjusting for age (r = 0.405; P = 0.016).
There was no correlation between SLEDAI scores or disease duration and the
left/right ventricle systolic function parameters. This was true while assessing
the right ventricle's diastolic function. A statistically significant
correlation was found between mitral E/E' as an index of left ventricle
diastolic impairment and the SLEDAI scores (r = 0.33; P = 0.037; 95% CI (0.074
to 0.574)) along with disease duration (r = 0.45; P = 0.004; 95% CI (0.130 to
0.662); adjusted for age: r = 0.478; P = 0.002).
CONCLUSIONS: Echocardiography is a useful noninvasive technique for screening
subclinical heart problems in SLE patients. Although disease activity in general
should suggest a closer follow-up, regular scanning would enable earlier
detection of cardiovascular involvement and should not be confined to cases with
higher SLEDAI indices or longer disease durations. We sought to evaluate a possible link between parvovirus B19 infection and the
clinical and laboratory expression of systemic lupus erythematosus (SLE). SLE
patients were examined to evaluate their clinical status and disease activity. A
complete Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score was
obtained for each patient. In addition, we determined the level of systemic
involvement throughout the course of the disease. Blood levels of IgM and IgG
antibodies to parvovirus B19, levels of anti-dsDNA, C3, and C4 were measured. A
PCR real-time assay was used to determine the presence of parvovirus B19 genetic
material. The viral genome was found in sera of 2 of 51(3.9%) patients with SLE.
There was no correlation between viral serology and the clinical and serological
parameters of the disease. More SLE patients with secondary antiphospholipid
syndrome (APS) had IgG and IgM antibodies to the virus (p < 0.029 and p < 0.018,
respectively). These patients also had a higher titer of IgG antibodies to
parvovirus B19 compared to SLE patients without APS. In this group of SLE
patients, no association was found between parvovirus infection and the presence
or activity of SLE. The results of the study suggest an association between
parvovirus infection and antibody production directed against phospholipids. To determine the expression of mTOR, Becline-1, LC3 and p62 in the peripheral
blood mononuclear cells (PBMCs) of systemic lupus erythematosus (SLE) and assess
their relationship with disease activity and immunologic features. The
expression of mTOR, Becline-1, LC3 and p62 was detected by RT-PCR in 81 SLE
subjects and 86 age- and sex-matched healthy controls. Data regarding
demographics and clinical parameters were collected. Disease activity of SLE was
evaluated according to the SLE Disease Activity Index (SLEDAI) score.
Independent sample t-test was used to analyze the expression of mTOR, Becline-1,
LC3, and p62 in the two groups. Pearson's or Spearman's correlation was
performed to analyze their relationship with disease activity and immunologic
features. The mean levels of Becline-1, LC3 and p62 mRNA were significantly
higher in SLE patients than the controls (9.96×10-4 vs 7.38×10-4 for Becline-1
with P<0.001; 4.04×10-5 vs 2.62×10-5 for LC3 with P<0.001; 9.51×10-4 vs
7.59×10-4 for p62 with P=0.008). However, the levels of mTOR mRNA in SLE
patients were not significantly different from that in controls. Correlation
analysis showed that Becline-1, LC3 and p62 mRNA levels correlated positively
with SLEDAI, IgG and ds-DNA, negatively with C3. Our results suggested that
autophagosomes formation were activated and their degradation were blocked in
SLE. Moreover, the maintece of autophagy balance can improve disease activity
and immune disorders in SLE patients. Author information:
(1)Programa de Doctorado en Farmacologia, Centro Universitario de Ciencias de la
Salud (CUCS), Universidad de Guadalajara, Sierra Mojada 950, Col. Independencia,
44340, Guadalajara, Jalisco, Mexico.
(2)Unidad de Investigación Biomédica 02 (UIEC), UMAE Hospital de Especialidades,
Centro Médico Nacional de Occidente, Instituto Mexicano del Seguro Social,
Avenida Belisario Domínguez 1000, Col. Independencia Oriente, 44340,
Guadalajara, Jalisco, Mexico.
(3)Instituto de Investigación en Ciencias Biomédicas, Centro Universitario de
Ciencias de la Salud (CUCS), Universidad de Guadalajara, Sierra Mojada 950, Col.
Independencia, 44340, Guadalajara, Jalisco, Mexico.
(4)Departamento de Fisiología, Centro Universitario de Ciencias de la Salud
(CUCS), Universidad de Guadalajara, Sierra Mojada 950, Col. Independencia,
44340, Guadalajara, Jalisco, Mexico.
(5)Laboratorio de Investigación y Desarrollo Farmacéutico, Centro Universitario
de Ciencias Exactas e Ingenierías, Universidad de Guadalajara, Blvd. Marcelino
García Barragán 421, 44430, Guadalajara, Jalisco, Mexico.
(6)Departamento de Inmunología y Reumatología, Hospital General de Occidente,
Secretaria de Salud, Av Zoquipan 1050, Seattle, 45170, Zapopan, Jalisco, Mexico.
(7)Programa Internacional de Medicina, Universidad de Autónoma de Guadalajara,
Av. Patria 1201, Col. Lomas del Valle, 45129, Zapopan, Jalisco, Mexico.
(8)Unidad Médica Familiar 4 y 8, Departamento de Epidemiologia, Instituto
Mexicano del Seguro Social (IMSS), Fidel Velázquez Sánchez 1531, Atemajac del
Valle, 44218, Guadalajara, Jalisco, Mexico.
(9)Programa de Doctorado en Farmacologia, Centro Universitario de Ciencias de la
Salud (CUCS), Universidad de Guadalajara, Sierra Mojada 950, Col. Independencia,
44340, Guadalajara, Jalisco, Mexico. [email protected].
(10)Departamento de Medicina Interna-Reumatología, Instituto Mexicano del Seguro
Social (IMSS), Hospital General Regional 110, Av Circunvalación Oblatos 2208,
Colonia Circunvalación Oblatos, 44716, Guadalajara, Jalisco, Mexico.
[email protected].
(11), Avenida Salto del Agua 2192, Colonia Jardines del Country, 44210,
Guadalajara, Mexico. [email protected]. |
What disease is the ALK tyrosine kinase associated with? | The anaplastic lymphoma kinase (ALK) gene encodes a receptor tyrosine kinase, and many kinds of ALK fusion genes have been found in a variety of carcinomas | The anaplastic lymphoma kinase (ALK) gene fuses to the nucleophosmin (NPM) gene
as a result of a (2;5) translocation associated with a subtype of human lymphoma
(initially designated anaplastic large cell lymphoma [ALCL] or
Ki-1/CD30-positive lymphoma). The immunocytochemical detection of NPM-ALK (and
proteins encoded by other ALK fusion genes) has allowed the definition of a
tumor entity, "ALK-positive lymphoma" (which shows only partial overlap with
pathologists' diagnosis of ALCL), to be defined and is invaluable in
distinguishing this disease from ALK-negative large cell lymphomas. Eight
variant ALK fusion proteins have been identified. Some are expressed only in
ALCL, some are found only in the nonhematopoietic neoplasm inflammatory
myofibroblastic tumor (IMT), and some are present in both types of maligcy.
The ALK gene is silent in adult tissues except for restricted sites within the
nervous system (consequently, patients with ALK-positive lymphoma produce
antibodies to the ALK protein) but is expressed in some neuroblastomas and
rhabdomyosarcomas. Biochemical studies suggest an anti-apoptotic function of
NPM-ALK, and this may contribute to oncogenesis. Although ALK-positive lymphomas
have a generally good prognosis, new therapeutic regimens are still needed for
patients whose disease is refractory to conventional treatment. ALK (anaplastic lymphoma kinase) is a transmembrane receptor tyrosine kinase,
initially discovered as part of the NPM-ALK fusion protein, resulting from a
chromosomal rearrangement frequently associated with anaplastic large cell
lymphomas. The native ALK protein is normally expressed in the developing and,
at a weaker level, adult nervous system. We recently demonstrated that ALK is a
novel dependence receptor. As such, in the absence of ligand, the ALK receptor
is kinase inactive and its expression results in enhanced apoptosis, whereas
kinase activation, due to a ligand or constitutive as in NPM-ALK, decreases
apoptosis. Unligated/kinase unactivated ALK receptor facilitates apoptosis via
its own cleavage by caspases, a phenomenon allowing the exposure of a
proapoptotic juxta-membrane intra-cellular domain. This review summarizes the
biological significance of the ALK receptor in cancer and development, in
perspective with its dependence receptor function. The dual function of ALK in
the physiology of development is illustrated in the visual system of Drosophila.
In this part of the nervous system, ALK in the presence of ligand appears
essential for axonal guidance, whereas in the absence of ligand, ALK expression
can lead to developmental neuronal apoptosis. ALK is also found expressed in
neural crest-derived tumors such as human neuroblastomas or glioblastomas but
its role is not fully elucidated. However, an excessive or constitutive ALK
tyrosine kinase activation can lead to deregulation of cell proliferation and
survival, therefore to human cancers such as lymphomas and inflammatory
myofibroblastic tumors. Our observations could have important implications in
the therapy of ALK-positive tumors harboring the chimeric or wild type ALK
protein. Neuroblastoma, an embryonal tumour of the peripheral sympathetic nervous system,
accounts for approximately 15% of all deaths due to childhood cancer. High-risk
neuroblastomas are rapidly progressive; even with intensive myeloablative
chemotherapy, relapse is common and almost uniformly fatal. Here we report the
detection of previously unknown mutations in the ALK gene, which encodes a
receptor tyrosine kinase, in 8% of primary neuroblastomas. Five non-synonymous
sequence variations were identified in the kinase domain of ALK, of which three
were somatic and two were germ line. The most frequent mutation, F1174L, was
also identified in three different neuroblastoma cell lines. ALK complementary
DNAs encoding the F1174L and R1275Q variants, but not the wild-type ALK cDNA,
transformed interleukin-3-dependent murine haematopoietic Ba/F3 cells to
cytokine-independent growth. Ba/F3 cells expressing these mutations were
sensitive to the small-molecule inhibitor of ALK, TAE684 (ref. 4). Furthermore,
two human neuroblastoma cell lines harbouring the F1174L mutation were also
sensitive to the inhibitor. Cytotoxicity was associated with increased amounts
of apoptosis as measured by TdT-mediated dUTP nick end labelling (TUNEL). Short
hairpin RNA (shRNA)-mediated knockdown of ALK expression in neuroblastoma cell
lines with the F1174L mutation also resulted in apoptosis and impaired cell
proliferation. Thus, activating alleles of the ALK receptor tyrosine kinase are
present in primary neuroblastoma tumours and in established neuroblastoma cell
lines, and confer sensitivity to ALK inhibition with small molecules, providing
a molecular rationale for targeted therapy of this disease. BACKGROUND: Oncogenic fusion genes consisting of EML4 and anaplastic lymphoma
kinase (ALK) are present in a subgroup of non-small-cell lung cancers,
representing 2 to 7% of such tumors. We explored the therapeutic efficacy of
inhibiting ALK in such tumors in an early-phase clinical trial of crizotinib
(PF-02341066), an orally available small-molecule inhibitor of the ALK tyrosine
kinase.
METHODS: After screening tumor samples from approximately 1500 patients with
non-small-cell lung cancer for the presence of ALK rearrangements, we identified
82 patients with advanced ALK-positive disease who were eligible for the
clinical trial. Most of the patients had received previous treatment. These
patients were enrolled in an expanded cohort study instituted after phase 1 dose
escalation had established a recommended crizotinib dose of 250 mg twice daily
in 28-day cycles. Patients were assessed for adverse events and response to
therapy.
RESULTS: Patients with ALK rearrangements tended to be younger than those
without the rearrangements, and most of the patients had little or no exposure
to tobacco and had adenocarcinomas. At a mean treatment duration of 6.4 months,
the overall response rate was 57% (47 of 82 patients, with 46 confirmed partial
responses and 1 confirmed complete response); 27 patients (33%) had stable
disease. A total of 63 of 82 patients (77%) were continuing to receive
crizotinib at the time of data cutoff, and the estimated probability of 6-month
progression-free survival was 72%, with no median for the study reached. The
drug resulted in grade 1 or 2 (mild) gastrointestinal side effects.
CONCLUSIONS: The inhibition of ALK in lung tumors with the ALK rearrangement
resulted in tumor shrinkage or stable disease in most patients. (Funded by
Pfizer and others; ClinicalTrials.gov number, NCT00585195.). Several decades of cancer research have revealed a pivotal role for tyrosine
kinases as key regulators of signaling pathways, controlling cell growth and
differentiation. Deregulation of tyrosine kinase-mediated signaling occurs
frequently in cancer and is believed to drive the initiation and progression of
disease. Chromosomal rearrangements involving the tyrosine kinase anaplastic
lymphoma kinase (ALK) occur in a variety of human maligcies including
non-small cell lung cancer (NSCLC), anaplastic large cell lymphomas, and
inflammatory myofibroblastic tumors. The aberrant activation of ALK signaling
leads to "oncogene addiction" and marked sensitivity to ALK inhibitors such as
crizotinib (PF-02341066). This review focuses on ALK rearrangements in NSCLC,
starting with the discovery of the EML4-ALK fusion oncogene, and culminating in
the recent validation of ALK as a therapeutic target in patients with
ALK-rearranged NSCLC. Current efforts seek to expand the role of ALK kinase
inhibition in lung and other cancers and to address the molecular basis for the
development of resistance. The anaplastic lymphoma kinase (ALK) is a tyrosine kinase receptor that is
involved in the pathogenesis of different types of human cancers, including
neuroblastoma (NB). In NB, ALK overexpression, or point mutations, are
associated with poor prognosis and advanced stage disease. Inhibition of ALK
kinase activity by small-molecule inhibitors in lung cancers carrying ALK
translocations has shown therapeutic potential. However, secondary mutations may
occur that, generate tumor resistance to ALK inhibitors. To overcome resistance
to ALK inhibitors in NB, we adopted an alternative RNA interference (RNAi)-based
therapeutic strategy that is able to knockdown ALK, regardless of its genetic
status [mutated, amplified, wild-type (WT)]. NB cell lines, transduced by
lentiviral short hairpin RNA (shRNA), showed reduced proliferation and increased
apoptosis when ALK was knocked down. In mice, a odelivery system for
ALK-specific small interfering RNA (siRNA), based on the conjugation of
antibodies directed against the NB-selective marker GD(2) to liposomes, showed
strong ALK knockdown in vivo in NB cells, which resulted in cell growth arrest,
apoptosis, and prolonged survival. ALK knockdown was associated with marked
reductions in vascular endothelial growth factor (VEGF) secretion, blood vessel
density, and matrix metalloproteinases (MMPs) expression in vivo, suggesting a
role for ALK in NB-induced neoangiogenesis and tumor invasion, confirming this
gene as a fundamental oncogene in NB. Tyrosine kinases have a crucial role as key regulators of signaling pathways
that influence cell differentiation and growth. Dysregulation of tyrosine
kinase-mediated signaling is understood to be an important oncogenic driver.
Genetic rearrangements involving the tyrosine kinase anaplastic lymphoma kinase
(ALK) gene occur in non-small cell lung cancer (NSCLC), anaplastic large cell
lymphomoas, inflammatory myofibroblastic tumors, and other cancers. Cells with
abnormal ALK signaling are sensitive to ALK inhibitors such as crizotinib. This
review will highlight the discovery of the fusion between echinoderm
microtubule-associated protein-like 4 (EML4) and ALK as an oncogenic driver,
recognition of other ALK gene rearrangements in NSCLC, and the confirmation that
crizotinib is an effective treatment for patients with ALK-positive NSCLC. Work
is underway to further define the role for crizotinib in the treatment of
ALK-positive lung cancer and other cancers and to investigate the molecular
mechanisms for resistance to ALK inhibition with crizotinib. PURPOSE: The aim of this study is to investigate anaplastic lymphoma kinase
(ALK) protein expression and underlying genetic aberrations in rhabdomyosarcoma
(RMS), with special attention to clinical and prognostic implications.
PATIENTS AND METHODS: A total of 189 paraffin-embedded RMS tumor specimens from
145 patients were collected on tissue microarray. ALK protein expression was
evaluated by immunohistochemistry. ALK gene (2p23) copy number and
translocations were determined by in situ hybridization. cDNA sequencing of the
receptor tyrosine kinase domain of the ALK gene was assessed in 43 samples.
RESULTS: Strong cytoplasmic ALK protein expression was more frequently observed
in alveolar RMS (ARMS) than in embryonal RMS (ERMS) (81% v 32%, respectively; P
< .001). ALK gene copy number gain was detected in the vast majority of ARMS
(88%), compared with 52% of ERMS (P < .001). ALK copy number correlated with
protein expression in primary tumors (n = 107). We identified one point mutation
(2%) and seven tumors harboring whole exon deletions (16%). In ERMS, specific
ALK gain in the primary tumor correlated with metastatic disease (100% in
metastatic disease v 29% in nonmetastatic disease; P = .004) and poor
disease-specific survival (5-year disease-specific survival: 62% v 82% for
nonspecific or no gain; P = .046).
CONCLUSION: Because ALK aberrations on genomic and protein levels are frequently
found in RMSs, in particular ARMS, and are associated with disease progression
and outcome in ERMS, ALK may play a role in tumor biology and may provide a
potential therapeutic target for these tumors. Future research should aim at the
oncogenic role of ALK and the potential effect of ALK inhibitors in RMS. BACKGROUND: Anaplastic lymphoma kinase-positive, anaplastic large cell lymphoma
(ALK+ ALCL) is a T cell lymphoma defined by the presence of chromosomal
translocations involving the ALK tyrosine kinase gene. These translocations
generate fusion proteins (e.g. NPM-ALK) with constitutive tyrosine kinase
activity, which activate numerous signalling pathways important for ALK+ ALCL
pathogenesis. The molecular chaperone heat shock protein-90 (Hsp90) plays a
critical role in allowing NPM-ALK and other signalling proteins to function in
this lymphoma. Co-chaperone proteins are important for helping Hsp90 fold
proteins and for directing Hsp90 to specific clients; however the importance of
co-chaperone proteins in ALK+ ALCL has not been investigated. Our preliminary
findings suggested that expression of the immunophilin co-chaperone, Cyclophilin
40 (Cyp40), is up-regulated in ALK+ ALCL by JunB, a transcription factor
activated by NPM-ALK signalling. In this study we examined the regulation of the
immunophilin family of co-chaperones by NPM-ALK and JunB, and investigated
whether the immunophilin co-chaperones promote the viability of ALK+ ALCL cell
lines.
METHODS: NPM-ALK and JunB were knocked-down in ALK+ ALCL cell lines with siRNA,
and the effect on the expression of the three immunophilin co-chaperones: Cyp40,
FK506-binding protein (FKBP) 51, and FKBP52 examined. Furthermore, the effect of
knock-down of the immunophilin co-chaperones, either individually or in
combination, on the viability of ALK+ ALCL cell lines and NPM-ALK levels and
activity was also examined.
RESULTS: We found that NPM-ALK promoted the transcription of Cyp40 and FKBP52,
but only Cyp40 transcription was promoted by JunB. We also observed reduced
viability of ALK+ ALCL cell lines treated with Cyp40 siRNA, but not with siRNAs
directed against FKBP52 or FKBP51. Finally, we demonstrate that the decrease in
the viability of ALK+ ALCL cell lines treated with Cyp40 siRNA does not appear
to be due to a decrease in NPM-ALK levels or the ability of this oncoprotein to
signal.
CONCLUSIONS: This is the first study demonstrating that the expression of
immunophilin family co-chaperones is promoted by an oncogenic tyrosine kinase.
Moreover, this is the first report establishing an important role for Cyp40 in
lymphoma. INTRODUCTION: Anaplastic lymphoma kinase (ALK), a tyrosine kinase receptor, has
been initially identified through its involvement in chromosomal translocations
associated with anaplastic large cell lymphoma. However, recent evidence that
aberrant ALK activity is also involved in an expanding number of tumor types,
such as other lymphomas, inflammatory myofibroblastic tumor, neuroblastomas and
some carcinomas, including non-small cell lung carcinomas, is boosting research
progress in ALK-targeted therapies.
AREAS COVERED: The first aim of this review is to describe current
understandings about the ALK tyrosine kinase and its implication in the
oncogenesis of human cancers as a fusion protein or through mutations. The
second goal is to discuss its interest as a therapeutic target and to provide a
review of the literature regarding ALK inhibitors. Mechanisms of acquired
resistance are also reviewed.
EXPERT OPINION: Several ALK inhibitors have recently been developed, offering
new treatment options in tumors driven by abnormal ALK signaling. However, as
observed with other tyrosine kinase inhibitors, resistance has emerged in
patients treated with these agents. The complexity of mechanisms of acquired
resistance recently described suggests that other therapeutic options, including
combination of ALK and other kinases targeted drugs, will be required in the
future. Neuroblastoma is a childhood extracranial solid tumour that is associated with a
number of genetic changes. Included in these genetic alterations are mutations
in the kinase domain of the anaplastic lymphoma kinase (ALK) receptor tyrosine
kinase (RTK), which have been found in both somatic and familial neuroblastoma.
In order to treat patients accordingly requires characterisation of these
mutations in terms of their response to ALK tyrosine kinase inhibitors (TKIs).
Here, we report the identification and characterisation of two novel
neuroblastoma ALK mutations (A1099T and R1464STOP), which we have investigated
together with several previously reported but uncharacterised ALK mutations
(T1087I, D1091N, T1151M, M1166R, F1174I and A1234T). In order to understand the
potential role of these ALK mutations in neuroblastoma progression, we have
employed cell culture-based systems together with the model organism Drosophila
as a readout for ligand-independent activity. Mutation of ALK at position 1174
(F1174I) generates a gain-of-function receptor capable of activating
intracellular targets such as ERK (extracellular signal regulated kinase) and
STAT3 (signal transducer and activator of transcription 3) in a
ligand-independent manner. Analysis of these previously uncharacterised ALK
mutants and comparison with ALK(F1174) mutants suggests that ALK mutations
observed in neuroblastoma fall into three classes. These classes are: (i)
gain-of-function ligand-independent mutations such as ALK(F1174l), (ii)
kinase-dead ALK mutants, e.g. ALK(I1250T) (Schönherr et al., 2011a) and (iii)
ALK mutations that are ligand-dependent in nature. Irrespective of the nature of
the observed ALK mutants, in every case the activity of the mutant ALK receptors
could be abrogated by the ALK inhibitor crizotinib (Xalkori/PF-02341066), albeit
with differing levels of sensitivity. Phosphorylation of proteins on tyrosine residues is regulated by the activities
of protein tyrosine kinases and protein tyrosine phosphatases. Anaplastic
lymphoma kinase (ALK) is a receptor tyrosine kinase (RTK) essentially and
transiently expressed during development of the central and peripheral nervous
systems. ALK has been identified as a major neuroblastoma predisposition gene
and activating mutations have been identified in a subset of sporadic
neuroblastoma tumors. We previously established that the mutated receptors were
essentially retained in the endoplasmic reticulum/Golgi compartments due to
their constitutive activity. Intriguingly we demonstrated a stronger
phosphorylation for the minor pool of receptor addressed to the plasma membrane.
We decided to investigate the potential involvement of tyrosine phosphatase in
dephosphorylation of this intracellular pool. In this study we first showed that
general inhibition of tyrosine phosphatases resulted in a dramatic increase of
the tyrosine phosphorylation of the wild type but also of the mutated receptors.
This increase not only required the intrinsic kinase activity of the ALK
receptor but also involved the Src tyrosine kinase family. Second we provided
strong evidences that the endoplasmic reticulum associated phosphatase PTP1B is
key player in the control of ALK phosphorylation. Our data shed a new light on
the biological significance of the basal phosphorylation levels of both wild
type and mutated ALK receptors and could be essential to further understand
their roles in maligcies. Anaplastic lymphoma kinase (ALK) is an important molecular target in
neuroblastoma. Although tyrosine kinase inhibitors abrogating ALK activity are
currently in clinical use for the treatment of ALK-positive (ALK(+)) disease,
monotherapy with ALK tyrosine kinase inhibitors may not be an adequate solution
for ALK(+) neuroblastoma patients. Increased expression of the gene encoding the
transcription factor MYCN is common in neuroblastomas and correlates with poor
prognosis. We found that the kinase ERK5 [also known as big mitogen-activated
protein kinase (MAPK) 1 (BMK1)] is activated by ALK through a pathway mediated
by phosphoinositide 3-kinase (PI3K), AKT, MAPK kinase kinase 3 (MEKK3), and MAPK
kinase 5 (MEK5). ALK-induced transcription of MYCN and stimulation of cell
proliferation required ERK5. Pharmacological or RNA interference-mediated
inhibition of ERK5 suppressed the proliferation of neuroblastoma cells in
culture and enhanced the antitumor efficacy of the ALK inhibitor crizotinib in
both cells and xenograft models. Together, our results indicate that ERK5
mediates ALK-induced transcription of MYCN and proliferation of neuroblastoma,
suggesting that targeting both ERK5 and ALK may be beneficial in neuroblastoma
patients. Recent advances in the understanding of non-small cell lung cancer (NSCLC)
biology have revealed a number of 'targetable' genetic alterations that underlie
cancer growth and survival in specific patients subgroups. The anaplastic
lymphoma kinase (ALK) gene rearrangement identifies a population of NSCLCs in
whom dysregulation of ALK-tyrosine kinase (-TK) leads to uncontrolled
proliferation of cancer cells, thus providing the basis for the therapeutic use
of ALK-TK inhibitors (-TKIs) in ALK-rearranged (-positive) disease. Crizotinib
was the first ALK-TKI to undergo clinical development in ALK-positive advanced
NSCLC, in which it has been shown to greatly outperform the best available
chemotherapy regimen in either second- or first-line setting. More recently, the
novel second-generation ALK-TKI ceritinib has been shown to be highly active in
either crizotinib-pretreated or -naïve population. Nevertheless, as mechanisms
of resistance to crizotinib and ALK-TKIs in general are being progressively
elucidated, the treatment landscape of ALK-positive NSCLC is expected to evolve
rapidly. In the present review we will briefly discuss the current knowledge of
ALK-positive advanced non-small cell lung cancer. Also, we will touch upon new
developments on drugs/combination regimens aimed at inhibiting the ALK-TK, in an
attempt to delineate how treatment of ALK-positive disease may change in the
next future. Anaplastic lymphoma kinase (ALK) is a tyrosine kinase receptor involved in both
solid and hematological tumors. About 80% of ALK-positive anaplastic large-cell
lymphoma (ALCL) cases are characterized by the t(2;5)(p23;q35) translocation,
encoding for the aberrant fusion protein nucleophosmin (NPM)-ALK, whereas 5% of
non-small-cell lung cancer (NSCLC) patients carry the inv(2)(p21;p23)
rearrangement, encoding for the echinoderm microtubule-associated protein-like 4
(EML4)-ALK fusion. The ALK/c-MET/ROS inhibitor crizotinib successfully improved
the treatment of ALK-driven diseases. However, several cases of resistance
appeared in NSCLC patients, and ALK amino acid substitutions were identified as
a leading cause of resistance to crizotinib. Second-generation ALK inhibitors
have been developed in order to overcome crizotinib resistance. In this work, we
profiled in vitro the activity of crizotinib, AP26113, ASP3026, alectinib, and
ceritinib against six mutated forms of ALK associated with clinical resistance
to crizotinib (C1156Y, L1196M, L1152R, G1202R, G1269A, and S1206Y) and provide a
classification of mutants according to their level of sensitivity/resistance to
the drugs. Since the biological activity of ALK mutations extends beyond the
specific type of fusion, both NPM-ALK- and EML4-ALK-positive cellular models
were used. Our data revealed that most mutants may be targeted by using
different inhibitors. One relevant exception is represented by the G1202R
substitution, which was highly resistant to all drugs (>10-fold increased IC50
compared to wild type) and may represent the most challenging mutation to
overcome. These results provide a prediction of cross-resistance of known
crizotinib-resistant mutations against all second-generation tyrosine kinase
inhibitors (TKIs) clinically available, and therefore could be a useful tool to
help clinicians in the management of crizotinib-resistance cases. Orbital metastasis of lung cancer is rare. It often causes visual disorder. To
date, there are only a few case reports. Crizotinib is an anaplastic lymphoma
kinase (ALK) tyrosine kinase inhibitor that leads to responses in most patients
with ALK-positive non-small-cell lung cancer. Visual disorder is one of the
popular adverse events of crizotinib, but the symptom almost decreases over
time. We report a case of orbital metastasis as the disease progression of
ALK-positive lung cancer treated with crizotinib. It should be kept in mind that
orbital metastasis can be the disease progression of lung adenocarcinoma with
ALK translocation treated with crizotinib. When physicians encounter a patient
receiving crizotinib with visual disorder, we must distinguish between adverse
events and orbital metastasis. Patients with non-small cell lung cancer (NSCLC) who harbor anaplastic lymphoma
kinase (ALK) gene rearrangements can derive significant clinical benefit from
ALK tyrosine kinase inhibitor. Accurate patient identification is absolutely
crucial for successful using ALK inhibitor treatment. However, lung cancer
patients with ALK gene rearrangement after ALK inhibitor therapy eventually
develop acquired resistance to treatment. In this review, the authors summarize
the clinicopathologic features of ALK-rearranged NSCLC and the pros and cons of
current diagnostic testing. In addition, we discuss the current diagnostic flow
of ALK testing and consideration of rebiopsy sample during disease progression
in patients treated by ALK inhibitors. The anaplastic lymphoma kinase (ALK) receptor tyrosine kinase was initially
discovered as a component of the fusion protein nucleophosmin (NPM)-ALK in
anaplastic large-cell lymphoma (ALCL). Genomic alterations in ALK, including
rearrangements, point mutations, and genomic amplification, have now been
identified in several maligcies, including lymphoma, non-small cell lung
cancer (NSCLC), neuroblastoma, inflammatory myofibroblastic tumor, and others.
Importantly, ALK serves as a validated therapeutic target in these diseases.
Several ALK tyrosine kinase inhibitors (TKI), including crizotinib, ceritinib,
and alectinib, have been developed, and some of them have already been approved
for clinical use. These ALK inhibitors have all shown remarkable clinical
outcomes in ALK-rearranged NSCLC. Unfortunately, as is the case for other kinase
inhibitors in clinical use, sensitive tumors inevitably relapse due to acquired
resistance. This review focuses on the discovery, function, and therapeutic
targeting of ALK, with a particular focus on ALK-rearranged NSCLC. PURPOSE: Published data on the clinical efficacy, safety, dosage and
administration, and costs of the anaplastic lymphoma kinase (ALK) inhibitors
crizotinib and ceritinib in the treatment of non-small-cell lung cancer (NSCLC)
are reviewed and compared.
SUMMARY: The ALK protein functions as a transmembrane receptor tyrosine kinase;
rearrangements of the ALK gene are associated with the development of NSCLC with
adenocarcinoma histology. Crizotinib is an oral tyrosine kinase inhibitor
approved in 2011 as a first-line therapy for patients with metastatic ALK
mutation-driven NSCLC. Significantly improved response rates and
progression-free survival (PFS) have been reported with the use of crizotinib
therapy versus standard chemotherapy, but mutations conferring resistance to
treatment develop in most cases. The second-generation ALK inhibitor ceritinib
was approved in 2014 for the treatment of ALK-mutated NSCLC in patients who are
intolerant or develop resistance to crizotinib. In a clinical trial of ceritinib
involving 130 patients with ALK-positive NSCLC, the majority of whom had
experienced disease progression during crizotinib use, patients receiving at
least 400 mg of ceritinib daily had an overall response rate of 56% and median
PFS of seven months. Adverse effects commonly reported with the use of either
drug include visual disturbances, gastrointestinal disorders (e.g., diarrhea),
and liver enzyme abnormalities.
CONCLUSION: The tyrosine kinase inhibitors crizotinib and ceritinib provide an
effective treatment approach for patients with ALK-mutated NSCLC. Efficacy data
for both crizotinib and ceritinib indicate improved response rates and PFS with
the use of either drug as an alternative to standard chemotherapy. OBJECTIVES: Anaplastic lymphoma kinase (ALK)-positive non-small cell lung cancer
(NSCLC) is sensitive to treatment with an ALK-tyrosine kinase inhibitor (-TKI).
However, the benefit of sequential treatment with a 2nd ALK-TKI in patients who
fail a 1st ALK-TKI has been poorly addressed.
MATERIALS AND METHODS: We collected the data of 69 advanced ALK-positive NSCLCs
who were treated with one or more ALK-TKIs at three Italian institutions. The
clinical outcome of treatment with an ALK-TKI and the patterns of treatment upon
failing a 1st ALK-TKI were recorded.
RESULTS: Objective response rate (ORR) and median progression-free survival
(PFS) on a 1st ALK-TKI (mostly crizotinib) were 60.9% and 12 months,
respectively. Of the 50 patients who progressed on a 1st ALK-TKI, 22 were
further treated with a 2nd ALK-TKI (either ceritinib or alectinib), for whom an
ORR of 86.4% and median PFS of 7 months, respectively, were reported.
Conversely, 13 patients underwent rapid clinical/radiographic disease
progression leading to death shortly after discontinuation of the 1st ALK-TKI, 7
patients were managed with a 1st ALK-TKI beyond progression, and 8 patients
transitioned to other systemic treatments (mostly chemotherapy).
Post-progression survival (PPS) significantly favored the 22 patients who were
sequentially treated with a 2nd ALK-TKI over those who transitioned to other
systemic treatments (P=0.03), but not versus those who were treated with a 1st
ALK-TKI beyond progression (P=0.89).
CONCLUSION: Sequential treatment with a 2nd ALK-TKI is effective in patients who
fail a 1st ALK-TKI. Continuous ALK-inhibition upon failing a 1st ALK-TKI may be
associated with improved clinical outcome. In this era of more rational therapies, substantial efforts are being made to
identify optimal targets. The discovery of translocations involving the
anaplastic lymphoma kinase (ALK) receptor tyrosine kinase in a subset of
non-small cell lung cancers has become a paradigm for precision medicine.
Notably, ALK was initially discovered as the fusion gene in anaplastic large
cell non-Hodgkin lymphoma, a disease predomitly of childhood. The discovery
of activating kinase domain mutations of the full-length ALK receptor as the
major cause of hereditary neuroblastoma, and that somatically acquired mutations
and amplification events often drive the maligt process in a subset of
sporadic tumors, has established ALK as a tractable molecular target across
histologically diverse tumors in which ALK is a critical mediator of
oncogenesis. We are now uncovering the reexpression of this developmentally
regulated protein in a broader subset of pediatric cancers, providing
therapeutic targeting opportunities for diseases with shared molecular etiology.
This review focuses on the role of ALK in pediatric maligcies, alongside the
prospects and challenges associated with the development of effective
ALK-inhibition strategies. Anaplastic lymphoma kinase (ALK) rearrangement lung cancer responds to ALK
tyrosine kinase inhibitors. It is known that many cases ultimately acquired
resistance to crizotinib. However, a case of primary resistance is rare. We
present a case of harboring exon 19 deletion in epidermal growth factor receptor
in ALK rearranged lung adenocarcinoma, who experienced a partial tumor response
to icotinib after failure with crizotinib therapy and chemotherapy. Considering
the partial response, we conclude that it is important to find the cause of
resistance to crizotinib. We detected gene mutations with plasma by the
next-generation sequencing; the next-generation sequencing demonstrates an
attractive system to identify mutations improving the outcome of patients with a
deadly disease. Rearrangements involving the ALK gene were identified in a variety of cancers,
including paediatric tumour neuroblastoma where presence of ALK expression is
also associated with adverse prognosis. Microarrays data indicate that ALK is
expressed in another paediatric tumour - medulloblastoma. Therefore, we
investigated if the ALK gene is mutated in medulloblastoma and performed
simultaneously the molecular profiling of tumours. Tumours from sixty-four
medulloblastoma patients were studied for detection of ALK alterations in exons
23 and 25 using Sanger method. The molecular subtypes of tumours were identified
by detection of mutations in the CTNNB1 gene, monosomy 6 and by
immunohistochemistry using a panel of representative antibodies. Among three ALK
variants detected two resulted in intron variants (rs3738867, rs113866835) and
the third one was a novel heterozygous variant c.3595A>T in exon 23 identified
in the WNT type of tumour. It resulted in methionine to leucine substitution at
codon position 1199 (M1199L) of the kinase domain of ALK protein. Results of
analysis using three in silico algorithms confirmed the pathogenicity of this
single nucleotide variation. The same gene alteration was detected in both
patient and maternal peripheral blood leukocytes indicating an inherited type of
the detected variant. Presence of ALK expression in tumour tissue was confirmed
by immunohistochemistry. The tumour was diagnosed as classic medulloblastoma,
however with visible areas of focal anaplastic features. The patient has been
disease free for 6 years since diagnosis. This is the first evidence of an
inherited ALK variant in the WNT type of medulloblastoma, what altogether with
presence of ALK expression may point towards involvement of the ALK gene in this
type of tumours. Rearrangements in ALK gene and EML4 gene were first described in 2007. This
genomic aberration is found in about 2%-8% of non-small-cell lung cancer (NSCLC)
patients. Crizotinib was the first ALK tyrosine kinase inhibitor licensed for
the treatment of metastatic ALK-positive NSCLC based on a randomized Phase III
trial. Despite the initial treatment response of crizotinib, disease progression
inevitably develops after approximately 10 months of therapy. Different
resistance mechanisms have recently been described. One relevant mechanism of
resistance is the development of mutations in ALK. Novel ALK tyrosine kinase
inhibitors have been developed to overcome these mutations. Ceritinib is an oral
second-generation ALK inhibitor showing clinical activity not only in
crizotinib-resistant ALK-positive NSCLC but also in treatment-naïve ALK-positive
disease. In this paper, preclinical and clinical data of ceritinib are reviewed,
and its role in the clinical setting is put into perspective. ALK positive anaplastic large cell lymphoma is a T-cell lymphoma usually
occurring in children and young adults. It frequently involves lymph nodes and
extranodal sites and is associated with favorable prognosis. A 20-year old man
was admitted for painful mass in the left axilla with overlying skin redness.
Clinical presentation and US findings were highly suspicious for sarcoma.
Definitive diagnosis was established cytolologically and using ancillary
technologies from cytological samples. Fine needle aspiration cytology of tumor
mass (lymph node conglomerate and surrounding tissue) show predomice of
large, pleomorphic, atypical cells with large nuclei and vacuolised cytoplasm.
Atypical cells immunocytochemically were positive for LCA, CD30, CD3, EMA, and
ALK; negative for CD15 and CD56. NPM-ALK transcript was detected by reverse
transcriptase-polymerase chain reaction (RT-PCT). Molecular analysis of TCRß and
TCRγ genes demonstrated clonal TCR genes rearrangement. Complex karyotype with
multiple numerical and structural changes was found on conventional
cytogenetics. These findings excluded sarcoma and corroborated the diagnosis of
ALK positive ALCL. Cutaneous involvement in ALCL can clinically mimic sarcoma,
especially in cases with localized disease without B symptoms. In those cases,
immunostaining, PCR, and conventional cytogenetics are helpful to exclude
sarcoma. Diagn. Cytopathol. 2017;45:51-54. © 2016 Wiley Periodicals, Inc. A vast array of oncogenic variants has been identified for anaplastic lymphoma
kinase (ALK). Therefore, there is a need to better understand the role of ALK in
cancer biology in order to optimise treatment strategies. This review summarises
the latest research on the receptor tyrosine kinase ALK, and how this
information can guide the management of patients with cancer that is
ALK-positive. A variety of ALK gene alterations have been described across a
range of tumour types, including point mutations, deletions and rearrangements.
A wide variety of ALK fusions, in which the kinase domain of ALK and the
amino-terminal portion of various protein partners are fused, occur in cancer,
with echinoderm microtubule-associated protein-like 4 (EML4)-ALK being the most
prevalent in non-small-cell lung cancer (NSCLC). Different ALK fusion proteins
can mediate different signalling outputs, depending on properties such as
subcellular localisation and protein stability. The ALK fusions found in tumours
lack spatial and temporal regulation, which can also affect dimerisation and
substrate specificity. Two ALK tyrosine kinase inhibitors (TKIs), crizotinib and
ceritinib, are currently approved in Europe for use in ALK-positive NSCLC and
several others are in development. These ALK TKIs bind slightly differently
within the ATP-binding pocket of the ALK kinase domain and are associated with
the emergence of different resistance mutation patterns during therapy. This
emphasises the need to tailor the sequence of ALK TKIs according to the ALK
signature of each patient. Research into the oncogenic functions of ALK, and
fast paced development of ALK inhibitors, has substantially improved outcomes
for patients with ALK-positive NSCLC. Limited data are available surrounding the
physiological ligand-stimulated activation of ALK signalling and further
research is needed. Understanding the role of ALK in tumour biology is key to
further optimising therapeutic strategies for ALK-positive disease. BACKGROUND: Anaplastic lymphoma receptor tyrosine kinase gene (ALK) fusion is a
distinct molecular subclassification of NSCLC that is targeted by anaplastic
lymphoma kinase (ALK) inhibitors. We established a transgenic mouse model that
expresses tumors highly resembling human NSCLC harboring echinoderm microtubule
associated protein like 4 gene (EML)-ALK fusion. We aimed to test an EML4-ALK
transgenic mouse model as a platform for assessing the efficacy of ALK
inhibitors and examining mechanisms of acquired resistance to ALK inhibitors.
METHODS: Transgenic mouse lines harboring LoxP-STOP-LoxP-FLAGS-tagged human
EML4-ALK (variant 1) transgene was established by using C57BL/6N mice. The
transgenic mouse model with highly lung-specific, inducible expression of
echinoderm microtubule associated protein like 4-ALK fusion protein was
established by crossing the EML4-ALK transgenic mice with mice expressing
Cre-estrogen receptor fusion protein under the control of surfactant protein C
gene (SPC). Expression of EML4-ALK transgene was induced by intraperitoneally
injecting mice with tamoxifen. When the lung tumor of the mice treated with the
ALK inhibitor crizotinib for 2 weeks was measured, tumor shrinkage was observed.
RESULTS: EML4-ALK tumor developed after 1 week of tamoxifen treatment.
Echinoderm microtubule associated protein like 4-ALK was strongly expressed in
the lung but not in other organs. ALK and FLAGS expressions were observed by
immunohistochemistry. Treatment of EML4-ALK tumor-bearing mice with crizotinib
for 2 weeks induced dramatic shrinkage of tumors with no signs of toxicity.
Furthermore, prolonged treatment with crizotinib led to acquired resistance in
tumors, resulting in regrowth and disease progression. The resistant tumor
nodules revealed acquired ALK G1202R mutations.
CONCLUSIONS: An EML4-ALK transgenic mouse model for study of drug resistance was
successfully established with short duration of tumorigenesis. This model should
be a strong preclinical model for testing efficacy of ALK TKIs, providing a
useful tool for investigating the mechanisms of acquired resistance and pursuing
novel treatment strategies in ALK-positive lung cancer. INTRODUCTION: NSCLC with de novo anaplastic lymphoma receptor tyrosine kinase
gene (ALK) rearrangements and EGFR or KRAS mutations co-occur very rarely.
Outcomes with tyrosine kinase inhibitors (TKIs) in these patients are poorly
understood.
METHODS: Outcomes of patients with metastatic NSCLC de novo co-alterations of
ALK/EGFR or ALK/KRAS detected by fluorescence in situ hybridization (ALK) and
sequencing (EGFR/KRAS) from six Swiss centers were analyzed.
RESULTS: A total of 14 patients with adenocarcinoma were identified. Five
patients had ALK/EGFR co-alterations and nine had ALK/KRAS co-alterations. Six
of seven patients with ALK/KRAS co-alterations (86%) were primary refractory to
crizotinib. One patient has had ongoing disease stabilization for 26 months. Of
the patients with ALK/EGFR co-alterations, one immediately progressed after
receiving crizotinib for 1.3 months and two had a partial response for 5.7 and
7.3 months, respectively. Three of four patients with ALK/EGFR co-alterations
treated with an EGFR TKI achieved one or more responses in different lines of
therapy: four patients had a partial response, three with afatinib and one with
osimertinib. One patient achieved a complete remission with osimertinib, and one
patient was primary refractory to erlotinib. Median PFS during treatment with a
first EGFR TKI was 5.8 months (range 3.0-6.9 months).
CONCLUSIONS: De novo concurrent ALK/KRAS co-alterations were associated with
resistance to ALK TKI treatment in seven out of eight patients. In patients with
ALK/EGFR co-alterations, outcomes with ALK and EGFR TKIs seem inferior to what
would be expected in patients with either alteration alone, but further studies
are needed to clarify which patients with ALK/EGFR co-alterations may still
benefit from the respective TKI. |
CURB65 score is used for stratification of which disease? | CURB65 (confusion, urea, respiration, blood pressure; age>65 years) is used for assessment of pneumonia severity. | BACKGROUND: The performance of CURB65 in predicting mortality in
community-acquired pneumonia (CAP) has been tested in two large observational
studies. However, it has not been tested against generic sepsis and early
warning scores, which are increasingly being advocated for identification of
high-risk patients in acute medical wards.
METHOD: A retrospective analysis was performed of data prospectively collected
for a CAP quality improvement study. The ability to stratify mortality and
performance characteristics (sensitivity, specificity, positive predictive
value, negative predictive value and area under the receiver operating curve)
were calculated for stratifications of CURB65, CRB65, the systemic inflammatory
response syndrome (SIRS) criteria and the standardised early warning score
(SEWS).
RESULTS: 419 patients were included in the main analysis with a median age of 74
years (men = 47%). CURB65 and CRB65 stratified mortality in a more clinically
useful way and had more favourable operating characteristics than SIRS or SEWS;
for example, mortality in low-risk patients was 2% when defined by CURB65, but
9% when defined by SEWS and 11-17% when defined by variations of the SIRS
criteria. The sensitivity, specificity, positive predictive value and negative
predictive value of CURB65 was 71%, 69%, 35% and 91%, respectively, compared
with 62%, 73%, 35% and 89% for the best performing version of SIRS and 52%, 67%,
27% and 86% for SEWS. CURB65 had the greatest area under the receiver operating
curve (0.78 v 0.73 for CRB65, 0.68 for SIRS and 0.64 for SEWS).
CONCLUSIONS: CURB65 should not be supplanted by SIRS or SEWS for initial
prognostic assessment in CAP. Further research to identify better generic
prognostic tools is required. BACKGROUND AND OBJECTIVE: Hospitalization for exacerbation of COPD is associated
with a high risk of mortality. A risk-prediction model using information easily
obtained on admission could help to identify high-risk individuals. The CURB65
score was developed to predict mortality risk in community acquired pneumonia. A
retrospective study found that this score was also associated with mortality in
COPD exacerbations. We conducted a prospective study to assess the utility of
the CURB65 score in acute COPD exacerbations.
METHODS: Consecutive patients with physician diagnosed COPD exacerbations
admitted to a public hospital during a 1-year period were studied prospectively.
The CURB65 scores were calculated from information obtained at initial hospital
presentation. CURB65 = one point each for Confusion, Urea > 7 mmol/L,
Respiratory rate ≥ 30/min, low Blood pressure, age ≥ 65 years.
RESULTS: 30-day mortality data were available for 249 of 252 patients. CURB65
scores on admission significantly predicted risk of death during the hospital
admission and at 30 days. The 30-day mortality by score groups were: low risk
(scores 0-1) 2.0% (2/98), moderate risk (score 2) 6.7% (6/90) and high risk
(scores 3-5) 21.3% (13/61). CURB65 scores were not predictive of 1-year
mortality.
CONCLUSIONS: A simple 6-point score based on confusion, blood urea, respiratory
rate, blood pressure and age can be used to stratify patients with COPD
exacerbation into different management groups. The CURB65 score was as effective
in predicting early mortality in our cohort of acute COPD exacerbations as it
was in previous cohorts with community acquired pneumonia. Our findings suggest
that CURB65 scores can help clinicians to assess patients with exacerbation of
COPD. BACKGROUND: Proadrenomedullin (ProADM) confers additional prognostic information
to established clinical risk scores in lower respiratory tract infections
(LRTI). We aimed to derive a practical algorithm combining the CURB65 score with
ProADM-levels in patients with community-acquired pneumonia (CAP) and
non-CAP-LRTI.
METHODS: We used data of 1359 patients with LRTI enrolled in a multicenter
study. We chose two ProADM cut-off values by assessing the association between
ProADM levels and the risk of adverse events and mortality. A composite score
(CURB65-A) was created combining CURB65 classes with ProADM cut-offs to further
risk-stratify patients.
RESULTS: CURB65 and ProADM predicted both adverse events and mortality similarly
well in CAP and non-CAP-LRTI. The combined CURB65-A risk score provided better
prediction of death and adverse events than the CURB65 score in the entire
cohort and in CAP and non-CAP-LRTI patients. Within each CURB65 class, higher
ProADM-levels were associated with an increased risk of adverse events and
mortality. Overall, risk of adverse events (3.9%) and mortality (0.65%) was low
for patients with CURB65 score 0-1 and ProADM ≤0.75 nmol/l (CURB65-A risk class
I); intermediate (8.6% and 2.6%, respectively) for patients with CURB65 score of
2 and ProADM ≤1.5 nmol/l or CURB classes 0-1 and ProADM levels between 0.75-1.5
nmol/L (CURB65-A risk class II), and high (21.6% and 9.8%, respectively) for all
other patients (CURB65-A risk class III). If outpatient treatment was
recommended for CURB65-A risk class I and short hospitalization for CURB65-A
risk class II, 17.9% and 40.8% of 1217 hospitalized patients could have received
ambulatory treatment or a short hospitalization, respectively.
CONCLUSIONS: The new CURB65-A risk score combining CURB65 risk classes with
ProADM cut-off values accurately predicts adverse events and mortality in
patients with CAP and non-CAP-LRTI. Additional prospective cohort or
intervention studies need to validate this score and demonstrate its safety and
efficacy for the management of patients with LRTI.
TRIAL REGISTRATION: Procalcitonin-guided antibiotic therapy and hospitalisation
in patients with lower respiratory tract infections: the prohosp study;
isrctn.org Identifier: ISRCTN: ISRCTN95122877. INTRODUCTION: CD14 is one of the leukocyte differentiation antigens, and is
present in macrophages, monocytes, granulocytes and their cell membranes.
Presepsin, namely soluble CD14-subtype (sCD14-ST) is produced by circulating
plasma proteases activating cleavage of soluble CD14 (sCD14). The aim of this
study is to investigate the role of Presepsin and the CURB65 scoring system in
the evaluation of severity and outcome of CAP in an ED.
METHOD: A prospective, observational study was performed in an ED of an
university teaching hospital from November 2011 to October 2012. A total of 359
patients with CAP and 214 patients with severe CAP (SCAP) were consecutively
enrolled. Plasma Presepsin, lactate, serum PCT levels and leukocyte counts were
measured and CURB65 score were calculated at admission enrollment.
RESULT: Plasma Presepsin levels were significantly higher in SCAP patients than
in CAP patients (P < 0.0001), increasing correspondingly with the enhancement of
CURB65 score. Patients with ARDS or DIC had obviously higher plasma Presepsin
levels than those without ARDS or DIC (all P < 0.0001), and plasma Presepsin
levels were significantly higher in non-survivors than in survivors at 28-day
follow-up. In logistic regression analysis, CURB65 score was the independent
predictor of ARDS, and Presepsin was the independent predictor of DIC, and
Presepsin and CURB65 score were both the independent predictors of 28-day
mortality. The AUCs showed Presepsin in combination with CURB65 score in
predicting ARDS, SCAP and 28-day mortality was superior to Presepsin or CURB65
score alone ( all P < 0.01), Presepsin was better than CURB65 score and
leukocyte in predicting DIC ( P < 0.01).
CONCLUSION: Presepsin is a valuable biomarker in predicting severity and outcome
in CAP patients in the ED and Presepsin in combination with CURB65 score
significantly enhanced the predictive accuracy. Author information:
(1)Medical University Department, University of Basel, Kantonsspital Aarau,
Tellstrasse, Aarau 5001, Switzerland. [email protected].
(2)Medical University Department, University of Basel, Kantonsspital Aarau,
Tellstrasse, Aarau 5001, Switzerland. [email protected].
(3)Medical University Department, University of Basel, Kantonsspital Aarau,
Tellstrasse, Aarau 5001, Switzerland. [email protected].
(4)Medical University Department, University of Basel, Kantonsspital Aarau,
Tellstrasse, Aarau 5001, Switzerland. [email protected].
(5)Medical University Department, University of Basel, Kantonsspital Aarau,
Tellstrasse, Aarau 5001, Switzerland. [email protected].
(6)Medical University Department, University of Basel, Kantonsspital Aarau,
Tellstrasse, Aarau 5001, Switzerland. [email protected].
(7)Medical University Department, University of Basel, Kantonsspital Aarau,
Tellstrasse, Aarau 5001, Switzerland. [email protected].
(8)Department of Clinical Nursing Science, Kantonsspital Aarau, Tellstrasse,
Aarau 5001, Switzerland. [email protected].
(9)Department of Clinical Nursing Science, Kantonsspital Aarau, Tellstrasse,
Aarau 5001, Switzerland. [email protected].
(10)Medical University Department, University of Basel, Kantonsspital Aarau,
Tellstrasse, Aarau 5001, Switzerland. [email protected].
(11)Department of Clinical Nursing Science, Kantonsspital Aarau, Tellstrasse,
Aarau 5001, Switzerland. [email protected].
(12)Medical University Department, University of Basel, Kantonsspital Aarau,
Tellstrasse, Aarau 5001, Switzerland. [email protected].
(13)Medical University Department, University of Basel, Kantonsspital Aarau,
Tellstrasse, Aarau 5001, Switzerland. [email protected].
(14)Division of Pulmonary Medicine, Kantonsspital Aarau, Tellstrasse, Aarau
5001, Switzerland. [email protected].
(15)Department of Laboratory Medicine, Kantonsspital Aarau, Tellstrasse, Aarau
5001, Switzerland. [email protected].
(16)Department of Emergency Medicine, Kantonsspital Aarau, Tellstrasse, Aarau
5001, Switzerland. [email protected].
(17)Medical University Department, University of Basel, Kantonsspital Aarau,
Tellstrasse, Aarau 5001, Switzerland. [email protected].
(18)Division of Infectious Diseases and Hospital Hygiene, Cantonal Hospital St.
Gallen, Rorschacherstrasse 95, St. Gallen CH-9007, Switzerland.
[email protected]. Community-acquired pneumonia (CAP) is the leading cause of infectious death in
the world. Immune dysregulation during acute lung infection plays a role in lung
injury and the systemic inflammatory response. Cytokines seem to be major
players in severe lung infection cases. Here, we present a review of published
papers in the last 3 years regarding this topic. The cytokine response during
pneumonia is different in bacterial vs viral infections; some of these cytokines
correlate with clinical severity scales such as CURB65 or SOFA. Treatment
focused in the cytokine environment is an interesting area that could impact the
prognosis of CAP. Some of the agents that have been studied as co-adjuvant
therapy are corticosteroids, macrolides, and linezolid, but anyone of those have
shown a clear or proven efficacy or have been recommended as a part of the
standard of care for CAP. More studies designed to define the role of
immunomodulatory agents, such as co-adjuvant therapy in pneumonia, are needed. AIM: (i) evaluate the performance of MR-pro-ADM in reflecting the outcome and
risk for CAP patients in the emergency department, and (ii) compare the
prognostic performance of MR-pro-ADM with that of clinical scores PSI and
CURB65.
METHODS: Observational prospective, single-center study in patients with
suspected community acquired pneumonia (CAP). Eighty one patients underwent full
clinical and laboratory assessment as by protocol, and were followed up a 28
days. Primary endpoints measured were: death, death at 14 days, non-invasive
mechanical ventilation (NIMV), endotracheal intubation (EI), ICU admission,
overall hospital stay >10 days, emergency department stay >4 days. The
discriminative performance of MR-pro-ADM and clinical scores was assessed by
AUROC analysis.
RESULTS: The distribution for MR-pro-ADM followed an upward trend, increasing
with the increase of both PSI (p<0.001) and CURB65 (p<0.001) classes. However,
the difference between MRproADM values and score classes was significant only in
the case of CURB65 classes 0 and 1 (p = 0.046), 2 (p = 0.013), and 3 (p =
0.011); and with PSI classes 5, 3 (p = 0.044), and 1 (p = 0.020). As to the
differences among variables for the six end-points, MR-pro-ADM values in the two
groups selected for each considered end-point differed in a statistically
significant manner for all endpoints. Both PSI and CURB65 differed significantly
for all end-points, except for stay in the ED longer than 4 days and the
hospital stay longer than 10 days and endotracheal intubation (only PSI classes
differed with statistical significance). ROC analyses evidenced that MR-pro-ADM
values gave the greatest AUC for the prediction of death, endotracheal
intubation, hospital stay >10 days and DE stay >4 days, compared to the PSI and
CURB (though difference not statistically significant). For each endpoint
measured, the best thresholds values for Mr-pro-ADM were: 1.6 (specificity
76.5%; sensitivity 77.8%) for death; 2.5 (specificity 88.9%; sensitivity 80.0%)
for death at 14 days; 1.5 (specificity 77.0%; sensitivity 87.5%) for NIMV; 2.4
(specificity 88.7%; sensitivity 83.3%) for endotracheal intubation; 0.9
(specificity 53.5%; sensitivity 70.6%) for DE stay greater than 4 days; 1.9
(specificity 82.1%; sensitivity 55.3%) for hospital stay greater than 10 days.
The AUC for the combination of MR-pro-ADM and PSI was 81.29% [63.41%-99.17%],
but not in a statistically significant manner compared to the AUCs of the single
predictors. Conversely, the AUC for the combination of MR-pro-ADM and CURB65 was
87.58% [75.54%-99.62%], which was significantly greater than the AUC of CURB65
(p = 0.047) or PSI (p = 0.017) alone.
CONCLUSIONS: The present study confirms that assessment of MR-pro-ADM levels in
CAP patients in addition to CURB scores increases the prognostic accuracy of
CURB alone and may help rule out discrepancies arising from flawed clinical
severity classification. With particular reference to patients scoring in the
upper classes of CURB and PSI, MR-pro-ADM values provided additional information
towards a better risk stratification of those patients. In particular, our
results pointed towards two MR-pro-ADM threshold values that appear to predict
with a good degree of accuracy the patient's need for non-invasive mechanical
ventilation, endotracheal intubation, or intensive care. This aspect, however,
deserves further investigation. |
Which resource has been developed in order to study the transcriptional regulation of GABAergic cell fate? | Subpallial Enhancer Transgenic Lines is a data and tool resource to study transcriptional regulation of GABAergic cell fate. | Author information:
(1)Department of Psychiatry, Program in Neuroscience, Rock Hall, University of
California at San Francisco, San Francisco, CA 94158-2324, USA.
(2)Division of Bioinformatics, Department of Biology, Friedrich-Alexander
Universität Erlangen-Nürnberg, 91054 Erlangen, Germany.
(3)Department of Functional Genomics, MS 84-171, Lawrence Berkeley National
Laboratory, Berkeley, CA 94720, USA; U.S. Department of Energy Joint Genome
Institute, Walnut Creek, CA 94598, USA; Center for Neuroscience, University of
California Davis, Davis, CA 95618, USA.
(4)Department of Psychiatry, Program in Neuroscience, Rock Hall, University of
California at San Francisco, San Francisco, CA 94158-2324, USA; PLOS, 1160
Battery Street, San Francisco, CA 94111, USA.
(5)Department of Anatomy, Faculty of Medicine, University Murcia E-30100 and
IMIB (Instituto Murciano de Investigación Biosanitaria), 30100 Murcia, Spain.
(6)Magee-Womens Research Institute, 204 Craft Avenue, Pittsburgh, PA 15213, USA.
(7)Department of Psychiatry, Program in Neuroscience, Rock Hall, University of
California at San Francisco, San Francisco, CA 94158-2324, USA; Acetylon
Pharmaceuticals Inc., Boston, MA 02210, USA.
(8)Allen Institute for Brain Science, Seattle, WA 98103, USA.
(9)Department of Functional Genomics, MS 84-171, Lawrence Berkeley National
Laboratory, Berkeley, CA 94720, USA; U.S. Department of Energy Joint Genome
Institute, Walnut Creek, CA 94598, USA; School of Natural Sciences, University
of California, Merced, CA 95343, USA.
(10)Department of Psychiatry, Program in Neuroscience, Rock Hall, University of
California at San Francisco, San Francisco, CA 94158-2324, USA. Electronic
address: [email protected]. |
Is creatinine assessment included in the MELD score? | Yes, creatinine is included in the Model For End-Stage Liver Disease (MELD) score. Other components of the MELD score are international normalized ratio and serum billirubin. The MELD score is used for evaluation of liver cirrhosis. | BACKGROUND: The model for end-stage liver disease (MELD) score is a useful tool
to assess prognosis in critically ill cirrhotic patients. However, its
short-term prognostic superiority over the traditional Child-Turcotte-Pugh (CTP)
score has not been definitely confirmed. The creatinine serum level is an
important predictor of survival in patients with liver cirrhosis.
AIMS: To evaluate and compare the short-term prognostic accuracy of the CTP, the
creatinine-modified CTP, and the MELD scores in patients with liver cirrhosis.
METHODS: CTP, creatinine-modified CTP, and MELD scores were calculated in a
cohort of 145 cirrhotic patients. The creatinine-modified CTP was calculated as
follows: we assessed the mean creatinine serum level and standard deviation (SD)
of the 145 study patients, then assigned a score of 1 to patients with
creatinine serum levels < or = to the mean, a score of 2 to patients with
creatinine levels between the mean and the mean+1 SD, and a score of 3 to
patients with creatinine levels above the mean+1 SD. The creatinine-modified CTP
was then calculated by simply adding each patients' creatinine score to their
traditional CTP scores. We calculated and compared the accuracy (c-index) of the
three parameters in predicting 3-month survival.
RESULTS: The creatinine-modified CTP score showed better prognostic accuracy as
compared with the traditional CTP (P=0.049). However, the MELD score proved to
be better at defining patients' prognosis in the short-term as compared with
both the traditional CTP score (P=0.012) and the creatinine-modified CTP
(P=0.047). The excellent short-term prognostic accuracy of the MELD score was
confirmed even when patients with abnormal creatinine serum levels were excluded
from the analysis (c-index=0.935).
CONCLUSIONS: Adding creatinine values to the CTP slightly improves the
prognostic usefulness of the traditional CTP score alone. The MELD score has a
short-term prognostic yield that is better than what is provided by both the CTP
and CTP creatinine-modified scores, even in cirrhotic patients who are not
critically ill. The positive results obtained by using the MELD score were
confirmed even after excluding patients with impaired renal function. OBJECTIVES: This study aimed to evaluate the impact of two creatinine
measurement methods on the Model for End Stage Liver Disease (MELD) score and
glomerular filtration rate estimation (eGFR) in cirrhotic patients. We focused
on ID-MS traceable method such as compensated Jaffe (cJafCreat) and enzymatic
(EnzCreat) methods.
DESIGN AND METHODS: Potential protein-related interferences in creatinine
determination were evaluated using dialysates spiked with albumin. MELD score,
CKD-EPI formula creatinine-based eGFR and cystatin C-based eGFR were evaluated
in 100 cirrhotic patients.
RESULTS: In vitro model demonstrated that low protein levels result in an
underestimation of creatinine levels using cJafCreat. In patients, cJafCreat
created a negative bias of -6.1 μmol/L that led to higher eGFR and lower MELD
scores.
CONCLUSIONS: cJafCreat contributes to an overestimation of renal function in
cirrhotic patients and may alter cirrhosis-severity assessment. Compensated
Jaffe assays should therefore be replaced by enzymatic methods. OBJECTIVES: The model for end-stage liver disease score (MELD = 3.8*LN[total
bilirubin] + 9.6*LN[creatinine] + 11.2*[PT-INR] + 6.4) predicts mortality for
tricuspid valve surgery. However, the MELD is problematic in patients undergoing
warfarin therapy, as warfarin affects the international normalized ratio (INR).
This study aimed to determine whether a simplified MELD score that does not
require the INR for calculation could predict mortality for patients undergoing
tricuspid valve surgery. Simplified MELD score = 3.8*LN[total bilirubin] +
9.6*LN[creatinine] + 6.4.
METHODS: A total of 172 patients (male: 66, female: 106; mean age, 63.8 ± 10.3
years) who underwent tricuspid replacement (n = 18) or repair (n = 154) from
January 1991 to July 2011 at a single centre were included. Of them, 168
patients in whom the simplified MELD score could be calculated were
retrospectively analysed. The relationship between in-hospital mortality and
perioperative variables was assessed by univariate and multivariate analysis.
RESULTS: The rate of in-hospital mortality was 6.4%. The mean admission
simplified MELD score for the patients who died was significantly higher than
for those surviving beyond discharge (11.3 ± 4.1 vs 5.8 ± 4.0; P = 0.001). By
multivariate analysis, independent risk factors for in-hospital mortality
included higher simplified MELD score (P = 0.001) and tricuspid valve
replacement (P = 0.023). In-hospital mortality and morbidity increased along
with increasing simplified MELD score. Scores <0, 0-6.9, 7-13.9 and >14 were
associated with mortalities of 0, 2.0, 8.3 and 66.7%, respectively. The
incidence of serious complications (multiple organ failure, P = 0.005; prolonged
ventilation, P = 0.01; need for haemodialysis; P = 0.002) was also significantly
higher in patients with simplified MELD score ≥ 7.
CONCLUSIONS: The simplified MELD score predicts mortality in patients undergoing
tricuspid valve surgery. This model requires only total bilirubin and creatinine
and is therefore applicable in patients undergoing warfarin therapy. Amyloidosis prognosis is often related to the onset of heart failure and a
worsening that is concomitant with kidney-liver dysfunction; thus the Model for
End-stage Liver disease (MELD) may be an ideal instrument to summarize
renal-liver function. Our aim has been to test the MELD score as a prognostic
tool in amyloidosis. We evaluated 128 patients, 46 with TTR-related amyloidosis
and 82 with AL amyloidosis. All patients had a complete clinical and
echocardiography evaluation; overall biohumoral assessment included troponin I,
NT-proBNP, creatinine, total bilirubin and INR ratio. The study population was
dichotomized at the 12 cut-off level of MELD scores; those with MELD score >12
had a lower survival compared to controls in the study cohort (40.7 vs 66.3 %;
p = 0.006). Either as a continuous and dichotomized variable, MELD shows its
independent prognostic value at multivariable analysis (HR = 1.199, 95 % CI
1.082-1.329; HR = 2.707, 95 % CI 1.075-6.817, respectively). MELD shows a lower
prognostic sensitivity/specificity ratio than troponin I and NT-proBNP in the
whole study population and AL subgroup, while in TTR patients MELD has a higher
sensitivity/specificity ratio compared to troponin and NT-proBNP (ROC
analysis-AUC: 0.853 vs 0.726 vs 0.659). MELD is able to predict prognosis in
amyloidosis. A MELD score >12 selects a subgroup of patients with a higher risk
of death. The predictive accuracy seems to be more evident in TTR patients in
whom currently no effective scoring systems have been validated. AIM: To establish cut-off levels of the clinical parameters, which would predict
suboptimal 30 minutes delayed hepatobiliary phase (HBP) with high specificity.
MATERIALS AND METHODS: This retrospective study included patients with chronic
liver disease who underwent hepatocellular carcinoma screening with
Gd-EOB-DTPA-enhanced magnetic resoce imaging (MRI) between 1 January 2011 and
30 November 2014. For each case, HBP was graded as adequate or suboptimal, based
on Liver Image Reporting and Data System (LI-RADS) criteria. The following
laboratory data obtained within 3 months of the MRI date was extracted: total
bilirubin (TB), direct bilirubin (DB), serum glutamic oxaloacetic transaminase
(SGOT), serum glutamic-pyruvic transaminase (SGPT), alkaline phosphatase (ALP),
albumin, activated partial thromboplastin time (aPTT), and International
normalised ratio (INR). Model For End-Stage Liver Disease (MELD) scores were
calculated as 3.78×ln[TB] + 11.2×ln[INR] + 9.57×ln[creatinine] + 6.43. Receiver
operating characteristic (ROC) curve analysis was used to establish cut-off
values for predicting suboptimal HBP.
RESULTS: Of 284 patients, 242 (85.2%) patients (91; 57.6% male) had an adequate
HBP and 42 (14.8%) patients (13; 61.9% male) had suboptimal HBP, with mean ages
of 58.5±9.7 years and 55±12.7 years, respectively (p=0.096). Areas under the ROC
curve for predicting suboptimal HBP were 0.85 (95%CI 0.79-0.91) for the MELD
score, 0.88 (95%CI 0.82-0.93) for TB, and 0.91 (95%CI 0.86-0.95) for DB.
Accuracy, positive likelihood ratios and cut-off values for predicting
suboptimal HBP were, respectively: 86.7% and 11.2 for the MELD score ≥16.7,
88.2% and 28.7 for TB ≥4.3 mg/dl, and 91.1% and 36.4 for DB ≥1.3 mg/dl. SGOT,
SGPT, and ALP were not statistically significantly different between the groups.
CONCLUSION: Cut-off levels of MELD score, DB, and TB can predict an suboptimal
HBP with high accuracy. Prospective identification of patients with a high
likelihood of an suboptimal HBP can help to avoid administering a more costly
agent to patients who would not benefit from its unique properties. To compare the performance of eight score systems (MELD, uMELD, MELD-Na. iMELD,
UKELD, MELD-AS, CTP, and mCTP) in predicting the post-transplant mortality, we
analyzed the data of 6,014 adult cirrhotic patients who underwent liver
transplantation between January 2003 and December 2010 from the China Liver
Transplant Registry database. In hepatitis B virus (HBV) group, MELD, uMELD and
MELD-AS showed good predictive accuracies at 3-month mortality after liver
transplantation; by comparison with other five models, MELD presented the best
ability in predicting 3-month, 6-month and 1-year mortality, showing a
significantly better predictive ability than UKELD and iMELD. In hepatitis C
virus and Alcohol groups, the predictive ability did not differ significantly
between MELD and other models. Patient survivals in different MELD categories
were of statistically significant difference. Among patients with MELD score
>35, a new prognostic model based on serum creatinine, need for hemodialysis and
moderate ascites could identify the sickest one. In conclusion, MELD is superior
to other score systems in predicting short-term post-transplant survival in
patients with HBV-related liver disease. Among patients with MELD score >35, a
new prognostic model can identify the sickest patients who should be excluded
from waiting list to prevent wasteful transplantation. OBJECTIVES: To evaluate hepatic encephalopathy (HE) incidence after transjugular
intrahepatic portosystemic shunt (TIPS) and classify by gravity and frequency.
METHODS: This is a retrospective study of 75 patients with no previous episodes
of HE who underwent TIPS between 2008 and 2014 with clinical follow-up after 6
and 12 months. Patient risk factors evaluated include age, INR (international
normalized ratio), creatinine, bilirubin, and MELD score (Model for End-of-stage
Liver Disease). HE was reported using two classifications: (1) gravity divided
in moderate (West-Haven grades I-II) and severe (III-IV); (2) frequency divided
in episodic and recurrent/persistent.
RESULTS: Overall HE incidence was 36% at 6 months, with 12 month incidence
significantly decreased to 27% (p = 0.02). 13/75 (17%) patients had one episode
of moderate HE, while 3/75 (4%) patients had severe recurrent/persistent HE. Age
was the only pre-TIPS risk predictor. Post-TIPS bilirubin and INR showed
variations from basal values only in the presence of diagnosed HE. Bilirubin
significantly increased (p = 0.03) in correlation to HE severity, whereas INR
changes correlated with temporal frequency (p = 0.04). HE distribution
classified for severity is similar at 6 and 12 months, whereas when classified
for frequency shows significant differences (p = 0.04).
CONCLUSIONS: A classification by gravity and frequency attests post-TIPS HE as a
manageable risk. Monitoring of bilirubin and INR may help on clinical management
risk stratification. BACKGROUND & AIM: Patients with end-stage liver disease require valid
estimations of mortality for organ allocation and risk stratification. The model
of end-stage liver disease (MELD) score is used for this purpose in most
countries and incorporates bilirubin, International Normalized ratio, and
creatinine. The aim of this study was to evaluate the comparability of
creatinine results from different routine assays in the serum samples of
patients with liver cirrhosis.
METHODS: Residual material from 60 serum samples was available from patients in
different stages of liver cirrhosis. Four centers participated; each center
analyzed the samples with Jaffé-based and enzymatic routine assays in parallel.
In addition, an accredited calibration laboratory certified the panel of samples
by an internationally accepted reference measurement procedure (RMP) based on
isotope dilution mass spectrometry (ID-MS). This method served as the
independent reference.
RESULTS: All routine methods displayed a high correlation to the RMP (r ≥0.937,
p<0.001). Two enzymatic and two Jaffé-based methods provided results that were
all within a ±20% range of the RMP. The other methods showed deviations >20% in
up to 27% of the samples. The enzymatic methods were systematically lower,
whereas the Jaffé-based methods were systematically higher (p<0.001). The
resulting MELD scores differed from 0 to 4 points.
CONCLUSIONS: There are systematic deviations from the RMP. Jaffé-based assays
gave higher results, whereas the enzymatic-based assays gave lower results
compared to the results of the RMP. The comparability of results is limited and
could be disadvantageous to patients listed for liver transplantation. INTRODUCTION: Endovascular therapy represents a less invasive alternative to
open surgery for reconstruction of the portal vein (PV) and the
spleno-mesenteric venous confluence to treat Portal hypertension. The objective
of this study is to determine if the Model for End-Stage Liver Disease (MELD)
score is a useful method to evaluate the risk of morbidity and mortality during
endovascular approaches.
MATERIAL AND METHODS: Patients that underwent endovascular reconstruction of the
PV or spleno-mesenteric confluence were identified retrospectively. Data were
collected from November 2011 to August 2016. The MELD score was calculated using
international normalized ratio, serum billirubin and creatinine. Patients were
grouped into moderate (≤ 15) and high (> 15) MELD. Associations of the MELD
score on the postprocedural morbidity, mortality and vessels patency were
assessed by two-sided Fisher's exact test.
RESULTS: Seventeen patients were identified; MELD score distribution was: ≤ 15
in 10 patients (59%) and > 15 in 7 (41%). Even distribution of severe PV
thrombosis was treated in both groups, performing predominately jugular access
in the high MELD score group (OR 0.10; 95%; CI 0.014-0.89; p = 0.052) in
contrast to a percutaneous transhepatic access in the moderate MELD score group.
Analysis comparing moderate and high MELD scores was not able to demonstrate
differences in mortality, morbidity or patency rates.
CONCLUSION: MELD score did not prove to be a useful method to evaluate risk of
morbidity and mortality; however a high score should not contraindicate
endovascular approaches. In our experience a high technical success, good
patency rates and low complication rates were observed. Author information:
(1)University of Minnesota Medical Center, Minneapolis, MN.
(2)Emory University School of Medicine, Atlanta, GA.
(3)University of Pittsburgh Medical Center, Pittsburgh, PA.
(4)Drexel University, Philadelphia, PA.
(5)Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia.
(6)Southern California Gastrointestinal and Liver Centers, Coronado, CA.
(7)New York University Medical, New York City, NY.
(8)Piedmont Atlanta Hospital, Atlanta, GA.
(9)University of Arkansas for Medical Sciences, Little Rock, AK.
(10)Beth Israel Deaconess Medical Center, Boston, MA.
(11)Cleveland Clinic Foundation in Cleveland, OH.
(12)Baylor University Medical Center, Dallas, TX.
(13)Rush University Medical Center, Chicago, IL.
(14)Montefiore Medical Center, Bronx, NY.
(15)North Shore University Hospital, Manhasset, NY.
(16)University of Mississippi Medical Center, Jackson, MS.
(17)Royal Free Hospital, London, United Kingdom.
(18)Columbia University Medical Center, New York City, NY.
(19)University of California, San Diego Medical Center, San Diego, CA.
(20)Georgetown University, Washington, DC.
(21)Albert Einstein Medical Center, Philadelphia, PA.
(22)Rutgers University Medical Center, New Brunswick, NJ.
(23)Queen Elizabeth Hospital/University of Birmingham, Birmingham, United
Kingdom.
(24)Methodist Dallas Medical Center, Dallas, TX.
(25)University of Southern California, Los Angeles, CA.
(26)Westchester Medical Center, Valhalla, NY.
(27)Swedish Medical Center, Seattle, WA.
(28)University of Washington, Harborview, Seattle, WA.
(29)Flinders Medical Centre, Adelaide, Bedford Park, South Australia, Australia.
(30)University of Arizona Medical Center, Tucson, AZ.
(31)Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia.
(32)Cedars-Sinai Medical Center, Los Angeles, CA.
(33)Vital Therapies Inc., San Diego, CA.
(34)University of Chicago, Chicago, IL.
(35)Center for Internal Medicine, University of Rostock, Rostock, Germany. |
List the two most important synaptic markers. | postsynaptic density 95
synaptophysin | Cannabis use has been frequently associated with sex-dependent effects on brain
and behavior. We previously demonstrated that adult female rats exposed to
delta-9-tetrahydrocannabinol (THC) during adolescence develop long-term
alterations in cognitive performances and emotional reactivity, whereas
preliminary evidence suggests the presence of a different phenotype in male
rats. To thoroughly depict the behavioral phenotype induced by adolescent THC
exposure in male rats, we treated adolescent animals with increasing doses of
THC twice a day (PND 35-45) and, at adulthood, we performed a battery of
behavioral tests to measure affective- and psychotic-like symptoms as well as
cognition. Poorer memory performance and psychotic-like behaviors were present
after adolescent THC treatment in male rats, without alterations in the
emotional component. At cellular level, the expression of the NMDA receptor
subunit, GluN2B, as well as the levels of the AMPA subunits, GluA1 and GluA2,
were significantly increased in hippocampal post-synaptic fractions from
THC-exposed rats compared to controls. Furthermore, increases in the levels of
the pre-synaptic marker, synaptophysin, and the post-synaptic marker, PSD95,
were also present. Interestingly, KCl-induced [(3)H]D-ASP release from
hippocampal synaptosomes, but not gliosomes, was significantly enhanced in
THC-treated rats compared to controls. Moreover, in the same brain region,
adolescent THC treatment also resulted in a persistent neuroinflammatory state,
characterized by increased expression of the astrocyte marker, GFAP, increased
levels of the pro-inflammatory markers, TNF-α, iNOS and COX-2, as well as a
concomitant reduction of the anti-inflammatory cytokine, IL-10. Notably, none of
these alterations was observed in the prefrontal cortex (PFC). Together with our
previous findings in females, these data suggest that the sex-dependent
detrimental effects induced by adolescent THC exposure on adult behavior may
rely on its ability to trigger different region-dependent changes in glutamate
synapse and glial cells. The phenotype observed in males is mainly associated
with marked dysregulations in the hippocampus, whereas the prevalence of
alterations in the emotional sphere in females is associated with profound
changes in the PFC. Alzheimer's disease (AD) is characterized by extensive neuron loss that
accompanies profound impairments in memory and cognition. We examined the
neuronally directed effects of the retinoid X receptor agonist bexarotene in an
aggressive model of AD. We report that a two week treatment of 3.5 month old
5XFAD mice with bexarotene resulted in the clearance of intraneuronal amyloid
deposits. Importantly, neuronal loss was attenuated by 44% in the subiculum in
mice 4 months of age and 18% in layer V of the cortex in mice 8 months of age.
Moreover, bexarotene treatment improved remote memory stabilization in fear
conditioned mice and improved olfactory cross habituation. These improvements in
neuron viability and function were correlated with significant increases in the
levels of post-synaptic marker PSD95 and the pre-synaptic marker synaptophysin.
Moreover, bexarotene pretreatment improved neuron survival in primary 5XFAD
neurons in vitro in response to glutamate-induced excitotoxicity. The salutary
effects of bexarotene were accompanied by reduced plaque burden, decreased
astrogliosis, and suppression of inflammatory gene expression. Collectively,
these data provide evidence that bexarotene treatment reduced neuron loss,
elevated levels of markers of synaptic integrity that was linked to improved
cognition and in an aggressive model of AD. An improved understanding of the molecular mechanisms in synapse formation
provides insight into both learning and memory and the etiology of
neurodegenerative disorders. Coactivator-associated arginine methyltransferase 1
(CARM1) is a protein methyltransferase that negatively regulates synaptic gene
expression and inhibits neuronal differentiation. Despite its regulatory
function in neurons, little is known about the CARM1 cellular location and its
role in dendritic maturation and synapse formation. Here, we examined the
effects of CARM1 inhibition on dendritic spine and synapse morphology in the rat
hippocampus. CARM1 was localized in hippocampal post-synapses, with
immunocytochemistry and electron microscopy revealing co-localization of CARM1
with post-synaptic density (PSD)-95 protein, a post-synaptic marker. Specific
siRNA-mediated suppression of CARM1 expression resulted in precocious dendritic
maturation, with increased spine width and density at sites along dendrites and
induction of mushroom-type spines. These changes were accompanied by a striking
increase in the cluster size and number of key synaptic proteins, including
N-methyl-d-aspartate receptor subunit 2B (NR2B) and PSD-95. Similarly,
pharmacological inhibition of CARM1 activity with the CARM1-specific inhibitor
AMI-1 significantly increased spine width and mushroom-type spines and also
increased the cluster size and number of NR2B and cluster size of PSD-95. These
results suggest that CARM1 is a post-synaptic protein that plays roles in
dendritic maturation and synaptic formation and that spatiotemporal regulation
of CARM1 activity modulates neuronal connectivity and improves synaptic
dysfunction. Anesthesia and/or surgery may promote Alzheimer's disease (AD) by accelerating
its neuropathogenesis. Other studies showed different findings. However, the
potential sex difference among these studies has not been well considered, and
it is unknown whether male or female AD patients are more vulnerable to develop
postoperative cognitive dysfunction. We therefore set out to perform a proof of
concept study to determine whether anesthesia and surgery can have different
effects in male and female AD transgenic (Tg) mice, and in female AD Tg plus
Cyclophilin D knockout (CypD KO) mice. The mice received an abdominal surgery
under sevoflurane anesthesia (anesthesia/surgery). Fear Conditioning System
(FCS) was used to assess the cognitive function. Hippocampal levels of synaptic
marker postsynaptic density 95 (PSD-95) and synaptophysin (SVP) were measured
using western blot analysis. Here we showed that the anesthesia/surgery
decreased the freezing time in context test of FCS at 7 days after the
anesthesia/surgery in female, but not male, mice. The anesthesia/surgery reduced
hippocampus levels of synaptic marker PSD-95 and SVP in female, but not male,
mice. The anesthesia/surgery induced neither reduction in freezing time in FCS
nor decreased hippocampus levels of PSD-95 and SVP in the AD Tg plus CypD KO
mice. These data suggest that the anesthesia/surgery induced a sex-dependent
cognitive impairment and reduction in hippocampus levels of synaptic markers in
AD Tg mice, potentially via a mitochondria-associated mechanism. These findings
could promote clinical investigations to determine whether female AD patients
are more vulnerable to the development of postoperative cognitive dysfunction. Major cell types of the central nervous system comprise neurons, glial cells
(astrocytes, oligodendrocytes, ependymal cells, and microglia), choroid plexus
cells, cells related to blood vessels and coverings. These cells show a wide
range of reactions to various noxious agents, which can be detected in routine
stainings. Some of these reactions are nonspecific to different injuries;
however some, such as the appearance of inclusion bodies, can be highly
disease-specific. Immunohistochemical markers are widely used in neuropathologic
diagnostic practice and help to understand the pathogenesis of diseases. The
most widely used neuronal markers comprise phosphorylated and nonphosphorylated
neurofilaments, microtubule-associated protein-2, NeuN, or synaptic markers such
as synaptophysin. The best antibody for the detection of astrocytes is anti-GFAP
(glial fibrillar acidic protein); however, to support a glial origin, S100 or
vimentin is also used in the diagnostic practice. Further astroglial markers
include connexin-43, excitatory amino acid transporters, aquaporin-4, heat shock
protein Hsp27, and α-B-crystallin. Depending whether the tissue is fixed or
nonfixed, different oligodendroglial markers are available, such as myelin basic
protein, myelin oligodendrocyte glycoprotein, myelin-associated glycoprotein,
proteolipid protein, Olig2, NG2, 2' 3'-cyclic nucleotide 3-phosphodiesterase
(CNPase), and tubulin polymerization-promoting protein/p25 alpha (TPPP/p25). A
wide range of microglia functions is recognized. Apart from a role in
immune-mediated disorders, inflammation, and response to injury, microglia are
important during the development and aging of the brain. The best markers
include the clone CR3/43, Iba1, and CD68. Evaluation of cell reactions is the
first step in the diagnostic procedure. |
What is a SERM? | A SERM is a Selective Estrogen Receptor Modulator. | Selective estrogen receptor modulators (SERMs) act exclusively through estrogen
receptors and possess tissue-specific agonistic or antagonistic properties. The
effects of all referred SERMs in bone and cardiovascular system are estrogenic,
namely they inhibit postmenopausal bone loss and favorably influence plasma
lipoproteins and some coagulation factors. The aim of this paper is to review
the effects of SERMs on estrogen-dependent breast tissues and on the
endometrium. There are two types of SERMs in clinical use, based on their
chemical structure: the triphenylethylenes and the benzothiophenes. The
prototype of the SERMs with triphenylethylene structure is tamoxifen. Tamoxifen,
like all other SERMs, is an estrogen antagonist in the breast and is widely used
for adjuvant treatment of breast cancer. A recent study suggests that tamoxifen
also may prevent breast cancer in patients at risk. Because of the partial
estrogenic activity of tamoxifen in the endometrium, its clinical use is
associated with uterine hypertrophy and an increased risk of endometrial cancer.
Other triphenylethylene SERMs, droloxifene, toremifene, and idoxifene, also show
efficacy in the treatment of breast cancer, in a manner similar to tamoxifen. A
better toxicology profile and a decreased endometrial estrogen agonism may be
advantages of the new triphenylethylene SERMs. Raloxifene is a SERM with a
chemical structure different from triphenylethylenes. Raloxifene, a
benzothiophene, possesses an estrogen-antagonistic effect in the breast similar
to triphenylethylenes. Clinical studies on postmenopausal osteoporotic women on
raloxifene as compared with placebo show a significant decrease in the rate of
newly diagnosed breast cancers. In clinical studies, in contrast to tamoxifen,
no stimulatory effect in the endometrium could be observed with raloxifene. The SERMs (selective estrogen receptor modulators) are a new class of molecules
that bind to the estrogen receptor, resulting in an estradiol agonist or
antagonist response according to the target tissue. Raloxifene, a new SERM, has
been shown to prevent postmenopausal bone loss, to reduce the risk of vertebral
fractures in osteoporotic women, to decrease serum cholesterol and its LDL
fraction, and to reduce significantly the risk of breat cancer. Raloxifene is
available in France for the prevention of post-menopausal osteoporosis. Tamoxifen was approved for breast cancer prevention in October 1998. Thus, for
the first time, we as gynecologists are being asked to prescribe this drug to
healthy women. In the past each one of us has cared for women with breast cancer
who have been treated with tamoxifen by oncologists or breast surgeons for the
maligcy. Effects of tamoxifen on the uterus resulting in carcinomas,
hyperplasia, and polyps are well known. Furthermore, tamoxifen has estrogenic
properties in the venous system, increasing the incidence of deep vein
thrombosis and pulmonary emboli. A new SERM (selective estrogen receptor
modulator), raloxifene, has been approved for prevention and treatment of
osteoporosis in postmenopausal women. It does not have stimulatory effects on
the endometrium; however, it is estrogenic in the venous system. Preclinical
data, as well as the breast cancer incidence reported in studies of the
skeleton, seem to indicate that its effects in the breast are similar to those
of tamoxifen. This article reviews tamoxifen and the new SERM, raloxifene, in an
attempt to help gynecologists better understand each compound and what data are
currently known, what we hope to learn from future studies, and what currently
makes sense for clinical practice. In females, estrogens play a key role in reproduction and have beneficial
effects on the skeletal, cardiovascular, and central nervous systems. Most
estrogenic responses are mediated by estrogen receptors (ERs), either ER alpha
or ER beta, which are members of the nuclear receptor superfamily of
ligand-dependent transcription factors. Selective estrogen receptor modulators
(SERMs) are ER ligands that in some tissues act like estrogens, but block
estrogen action in others. Thus, SERMs may exhibit an agonistic or antagonistic
biocharacter depending on the context in which their activity is examined. For
example, the SERMs tamoxifen and raloxifene both exhibit ER antagonist activity
in breast and agonist activity in bone, but only tamoxifen manifests agonist
activity in the uterus. Numerous studies have examined the molecular basis for
SERM selectivity. Collectively they indicate that different ER ligands induce
distinct structural changes in the receptor that influence its ability to
interact with other proteins (e.g., coactivators or corepressors) critical for
the regulation of target gene transcription. The relative expression of
coactivators and corepressors, and the nature of the ER and of its target gene
promoter affect SERM biocharacter. Taken together, SERM selectivity reflects the
diversity of ER forms and coregulators, cell type differences in their
expression, and the diversity of ER target genes. This model provides a basis
for understanding the molecular mechanisms of SERM action, and should help
identify new SERMs with enhanced tissue or target gene selectivity. OBJECTIVE: To provide a brief review of the history of the development of
selective estrogen receptor modulators (SERMs), the current data assessing the
effect of SERMs at the organ level, and the mechanism of action of these agents.
METHODS: All the pertinent medical literature was reviewed, and the effects of
SERMs on various end-organs were summarized.
RESULTS: SERMs have been available for clinical use since the late 1960s. By the
late 1980s, several SERMs had become available that influenced clinical
practice. Multiorgan effects of these compounds include variable clinical
efficacy for treatment of menopausal symptoms involving the central nervous
system, variable effects on the genitourinary tract, and, in general, positive
effects on serum lipid levels. SERMs seem to affect bone density positively,
albeit to variable degrees, depending on the agent being used. The greatest
effect of SERMs has been on the breast, and current SERMs seem to have efficacy
for prevention of breast cancer as opposed to the controversial effect of
estrogen on the breast. Disadvantages of SERMs include exacerbation of
menopausal symptoms and, as with estrogen, an increased incidence of venous
thrombosis and pulmonary emboli. SERMs act by modifying the configuration of the
estrogen receptor. Effects at the gene transcription level seem to be tissue
specific, a factor that likely accounts for the variability of clinical action
seen.
CONCLUSION: SERMs are a viable option for treatment of various problems
associated with menopause. OBJECTIVE: Evaluation of positive properties and side effects of raloxifene
treatment with respect to its potential use as agent to improve women's health
and quality of life in postmenopausal years.
DESIGN: A review article.
SETTING: Obstetrics and Gynaecology Department, Charles University 2nd Medical
Faculty and Teaching Hospital Motol, Prague.
SUBJECT: Estrogen use may protect against osteoporosis and cardiovascular
disease, but may increase the risk of breast cancer in long-term treated women
and also may increase the risk of irregular uterine bleeding (in combination
with gestagen in non-hysterectomized women) in perimenopause and postmenopause.
Drugs with tissue-specific estrogenic effects are termed selective estrogen
receptor modulators (SERM). Tamoxifen is the first SERM successfully used in the
prevention and treatment of breast cancer. Another SERM raloxifene is widely
used in the prevention and treatment of postmenopausal osteoporosis, especially
in women without climacteric complaints. Therapy with raloxifene increases bone
mineral density, lowers serum concentrations of total and low-density
lipoprotein cholesterol, and does not stimulate endometrium and breast.
Evaluation of another potential positive effects (reducing size of uterine
leiomyomas, etc.) warrants further investigation.
CONCLUSION: Raloxifene can be used in postmenopausal women free of climacteric
symptoms for the prevention and treatment of postmenopausal osteoporosis with no
increased risk of thrombosis and with the advantage of positive side effects
during the treatment. Tibolone, selective estrogen receptor modulators (SERMs) like tamoxifen and
raloxifene, and estrogen (+/-progestogen) treatments prevent bone loss in
postmenopausal women. They exert their effects on bone via the estrogen receptor
(ER) and the increase in bone mass is due to resorption inhibition. The effect
of SERMs on bone mineral density is less than that with the other treatments,
but the SERM raloxifene still has a positive effect on vertebral fractures. In
contrast to tibolone and estrogens (+/-progestogen), SERMs do not treat
climacteric complaints, whilst estrogen plus progestogen treatments cause a high
incidence of bleeding. Estrogen plus progestogen combinations have compromising
effects on the breast. Tibolone and SERMs do not stimulate the breast or
endometrium. Unlike SERMs, tibolone does not possess antagonistic biological
effects via the ER in these tissues. Estrogenic stimulation in these tissues is
prevented by local metabolism and inhibition of steroid metabolizing enzymes by
tibolone and its metabolites. SERMs and estrogen (+/-progestogen) treatments
increase the risk of venous thromboembolism (VTE), whilst estrogen
(+/-progestogen) combinations have unwanted effects on cardiovascular events. So
far, no detrimental effects of tibolone have been observed with respect to VTE
or cardiovascular events. The clinical profile of tibolone therefore has
advantages over those of other treatment modalities. It is also clear that
tibolone is a unique compound with a specific mode of action and that it belongs
to a separate class of compounds that can best be described as selective, tissue
estrogenic activity regulators (STEARs). We studied the beneficial effects of dietary consumption of n-3 polyunsaturated
fatty acids (PUFA) and two selective estrogen receptor modulator (SERM)
derivatives (SERM-I and SERM-II) and their combined effect on serum lipids, skin
dermis and adipose layers, bone marrow adipogenesis, and cytokine secretion in
mice. Two different ovariectomized (OVX) models were studied: treatment began
immediately post-OVX in one and 3 months post-OVX in the other. Our results
showed that n-3 PUFA and both SERMs decreased triglyceride levels in the serum,
and that SERMs also decreased serum cholesterol levels while n-3 PUFA had no
similar effect. SERMs had no effect on IL-6, IL-1 beta, or IL-10 levels, but
they decreased ex vivo tumor necrosis factor (TNF-alpha). N-3 PUFA decreased
secretion of non-induced IL-6 and TNF-alpha from cultured BMC and IL-1 beta
levels in vivo (i.e., in bone marrow plasma), but its main effect was a
significant elevation in the secretion of IL-10, a known anti-inflammatory
cytokine. OVX-induced B-lymphopoiesis was not affected by LY-139481 (SERM-I)
while LY-353381 (SERM-II) exhibited an estrogen-antagonistic effect in sham and
OVX mice and elevated the amount of B-cells in bone marrow. Fish oil consumption
prevented the elevation in B-lymphopoiesis caused by OVX, but had no curative
effect on established augmented B-lymphopoiesis. This activity could be mediated
via the elevation of IL-10 which was shown to suppress B-lymphopoiesis. Both
SERMs and n-3 PUFA inhibited the increase in adipose tissue thickness caused by
OVX in mice. Our results showed that n-3 PUFA, could prevent some of the
deleterious outcomes of estrogen deficiency that were not affected by SERMs. We
observed no significant beneficial effects of the combined administration of
SERM-I, SERM-II, and PUFA on the studied parameters.The exact mechanism by which
polyunsaturated fatty acids exert their activities is still not clear, but
peroxisome proliferator-activated receptors (PPARs) might be involved in
processes which are modulated by n-3 PUFA. Selective oestrogen receptor modulators (SERMs) are compounds with a mixed
agonist/antagonist activity on oestrogen receptors. An ideal SERM is a compound
with an oestrogen antagonist effect on the breast and uterus but oestrogen
agonist effect on bone. Beside tamoxifen, a group of well-investigated SERMs is
represented by raloxifene, LY-353381 (SERM3), EM-800 and CP-336156. On an
empirical basis, tamoxifen has been used to pharmacologically treat desmoid
tumours. Recently, raloxifene, a second-generation SERM, has been used in the
treatment of familial adenomatous polyposis patients affected by desmoid tumour.
The mechanisms through which these molecules affect desmoid tumour growth appear
to be due, in part, to the fact that SERMs may act independently of oestrogen
receptors. The knowledge of the molecular basis of SERM action will make the
development of novel synthetic compounds with engineered tissue selectivity
possible. Recent advances in endocrinology open a door for clinical application of
selective estrogen receptor modulator (SERM) and selective progesterone receptor
modulator (SPRM) in the treatment of uterine leiomyoma. With regard to SERM,
treatment with raloxifene is shown to reduce leiomyoma size in postmenopausal
women. Although raloxifene causes shrinkage of leiomyomas in combination with
gonadotropin-releasing hormone agonist in premenopausal women, the effects of
monotherapy with raloxifene on leiomyoma growth in premenopausal women remain
controversial. By contrast, tamoxifen may not be suitable for long-term
treatment of leiomyomas due to an agonistic action on the endometrium. Treatment
with progesterone antagonist (RU486) or SPRM (J867) has been demonstrated to
inhibit leiomyoma growth and improve clinical symptoms in premenopausal women.
No serious adverse effects associated with SERM or SPRM have been reported. In
light of therapeutic efficacy and few adverse effects, SERM and SPRM may hold
promise as novel treatment modalities for leiomyoma. Further studies are
warranted to determine the optimal strategy for the treatment of leiomyoma with
SERM and SPRM. Most immune cells, including myeloid progenitors and terminally differentiated
dendritic cells (DC), express estrogen receptors (ER) making these cells
sensitive to estrogens. Our laboratory recently demonstrated that
17-beta-estradiol (E2) promotes the GM-CSF-mediated development of CD11c+
CD11b(int) DC from murine bone marrow precursors. We tested whether the
therapeutic selective estrogen receptor modulators (SERM), raloxifene and
tamoxifen, can perturb DC development and activation. SERM, used in treatment of
breast cancer and osteoporosis, bind to ER and mediate tissue-specific agonistic
or antagonistic effects. Raloxifene and tamoxifen inhibited the differentiation
of estrogen-dependent DC from bone marrow precursors ex vivo in competition
experiments with physiological levels of E2. DC differentiated in the presence
of SERM were assessed for their capacity to internalize fluoresceinated Ags as
well as respond to inflammatory stimuli by increasing surface expression of
molecules important for APC function. Although SERM-exposed DC exhibited
increased ability to internalize Ags, they were hyporesponsive to bacterial LPS:
relative to control DC, they less efficiently up-regulated the expression of MHC
class II, CD86, and to a lesser extent, CD80 and CD40. This phenotype indicates
that these SERM act to maintain DC in an immature state by inhibiting DC
responsiveness to inflammatory stimuli. Thus, raloxifene and tamoxifen impair
E2-promoted DC differentiation and reduce the immunostimulatory capacity of DC.
These observations suggest that SERM may depress immunity when given to healthy
individuals for the prevention of osteoporosis and breast cancer and may
interfere with immunotherapeutic strategies to improve antitumor immunity in
breast cancer patients. A selective estrogen receptor modulator (SERM) is a nonsteroidal compound with
tissue specific estrogen receptor (ER) agonist or antagonist activities. In
animals, SERMs may produce morphologic changes in hormonally-sensitive tissues
like the mammary gland. Mammary glands from female rats given the SERM LY2066948
hydrochloride (LY2066948) for 1 month at >or= 175 mg/kg had intralobular ducts
and alveoli lined by multiple layers of vacuolated, hypertrophied epithelial
cells, resembling in part the morphology of the normal male rat mammary gland.
We hypothesized that these SERM-mediated changes represented an
androgen-dependent virilism of the female rat mammary gland. To test this
hypothesis, the androgen receptor antagonist flutamide was co-administered with
LY2066948 (175 mg/kg) to female rats for 1 month. Female rats given SERM alone
had hyperandrogenemia and the duct and alveolar changes described here.
Flutamide cotreatment did not affect serum androgen levels but completely
blocked the SERM-mediated mammary gland change. In the mouse, a species that
does not have the sex-specific differences in the mammary gland observed in the
rat, SERM treatment resulted in hyperandrogenemia but did not alter mammary
gland morphology. These studies demonstrate that LY2066948 produces
species-specific, androgen-dependent mammary gland virilism in the female rat. A selective estrogen receptor modulator (SERM) for the potential treatment of
hot flushes is described.
(R)-(+)-7,9-difluoro-5-[4-(2-piperidin-1-ylethoxy)phenyl]-5H-6-oxachrysen-2-ol,
LSN2120310, potently binds ERalpha and ERbeta and is an antagonist in MCF-7
breast adenocarcinoma and Ishikawa uterine cancer cell lines. The compound is a
potent estrogen antagonist in the rat uterus. In ovariectomized rats, the
compound lowers cholesterol, maintains bone mineral density, and is efficacious
in a morphine dependent rat model of hot flush efficacy. Selective estrogen receptor modulator (SERM) is designated as synthetic ligands
for estrogen receptors (ERs), exhibiting tissue-specific
agonisitic/antagonisitic activities. Among SERM, raloxifen is a most clinically
successful as an anti-oseteoporotic agent. Such tissue-specific actions of SERM
are presumed to mediate through unusual structure alteration of liganded ERs
coupled with co-regulator recruitments. Selective estrogen receptor modulators (SERMs) bind to estrogen receptor (ER)
and develop tissue-selective actions as estrogen agonists or antagonists. As
such, SERMs have been developed to exert estrogen-like beneficial effects
against some disorders including osteoporosis, while reducing estrogen-related
risks, including breast cancer. Prevention of vertebral fractures by a SERM,
raloxifene (RLX), in osteoporotic postmenopausal women has been well
established. RLX does not increase or decrease cardiovascular events, overall
mortality, cardiovascular mortality or the overall number of strokes, but there
appears to be a small increase in stroke mortality. Both RLX and tamoxifen
similarly reduce the risk of ER-positive invasive breast cancer. At the same
time, RLX treatment is associated with 36% fewer uterine cancer incidence and
29% less thromboembolic events. Keeping these results in mind, it is our
responsibility to critically evaluate and decide timing and length of treatment,
as well as subjects with benefits or risks for the treatment of osteoporosis by
SERMs. SERM is the abbreviation of the selective estrogen receptor modulator which is
the synthetic ligands of estrogen receptor (ER) acting estrogenically or
anti-estrogenically among various tissues through modifying the ER function.
Clomifene, tamoxifen, toremifene and raloxifene are generally classified as SERM
in the clinical use. The main cause of postmenopausal osteoporosis is estrogen
deficiency and it was revealed that the continuous combined use of conjugated
estrogen and medroxyprogesterone acetate reduced the relative risk of femoral
neck fracture to 0.66, however increased the relative risk of cardiovascular
event and breast cancer to 1.29 or 1.26, respectively. From the standpoint of
safe and clinical compliance for the breast and uterine tissue, raloxifene is
recommendable for middle aged postmenopausal osteoporosis. Selective estrogen receptor modulators (SERMs) are compounds that display mixed
estrogen agonist/antagonist activity. Currently, four SERMs are licensed for
clinical use: tamoxifen, toremifene, clomifene and raloxifene. The STAR and RUTH
trials have provided useful data about the potential role of SERMs in the
primary prevention of breast cancer and cardiovascular disease in postmenopausal
women. New-generation SERMs, such as bazedoxifene, arzoxifene, lasofoxifene and
ospemifene, are currently being evaluated. The aim is to find a SERM that
conserves the skeleton and prevents breast cancer without increasing the risk of
endometrial cancer and venous thromboembolism, and without inducing hot flushes.
Technological advances in the study of estrogen receptor activation will provide
key information for drug development. Selective estrogen receptor modulators (SERMs), known previously as
"antiestrogens", are a new category of therapeutic agents used for the
prevention and treatment of diseases such as osteoporosis and breast cancer.
SERMs act as ER-agonist in some tissues while acting as ER-antagonist in others
based on conformational change of the receptors, particularly at the helix 12.
Currently, there are two classes of clinically approved SERMs; triphenylethylene
derivatives (e.g., tamoxifen) and benzothiophene derivatives (e.g., raloxifene).
Tamoxifen, raloxifene and toremifene are the most widely used SERMs. Tamoxifen,
an antagonist of the breast tissue, is the first clinically identified compound
with noticeable SERM activity. Although tamoxifen has been very successful in
breast cancer treatment, its agonistic effect on the uterus is said to be
associated with increase risk of developing endometrial cancer. Ideally, it is
presumed that SERMs should selectively act as an agonist in the bone and brain
while simultaneously acting as an antagonist in the breast and uterus.
Therefore, the therapeutic goal of SERMs is the prevention of estrogen
deficiency diseases without promoting estrogen-associated tumor growth.
Therefore, the objective of this review is to summarize various effects that
have been applied in improving the tissue-selectivity of SERMs, highlighting the
emerging understanding of their mechanism of actions in selected target tissues
and the development of the SERMs. The significance in recent discovery of
selective estrogen receptor alpha modulators, SERAMs will also be reviewed. In the elderly population, osteoporosis is a significant clinical problem
leading to disability and even death. Many patients remain untreated, despite
effective therapies, because of patients' unwillingness to take current
therapies or inability to tolerate the therapies. For this reason, ongoing
research continues to search for more effective and tolerable osteoporosis
agents. Bazedoxifene is a selective estrogen receptor modulator (SERM) currently
in development for osteoporosis prevention and treatment. A new drug application
(NDA) for postmenopausal osteoporosis prevention was recently submitted to the
FDA. Preclinical and clinical studies with bazedoxifene demonstrate more tissue
selectivity than other SERMs. In particular, bazedoxifene has minimal if any
agonist activity in the uterus and is able to antagonize effects of estrogen on
the uterus. Animal studies and early clinical studies suggest effects in the
bone similar to other SERMs with prevention of postmenopausal bone loss. Until
more data on efficacy and safety are published, however, its role in
osteoporosis is unknown. Recent clinical data on selective estrogen receptor modulators (SERMs) have
provided the basis for reassessment of the SERM concept. The molecular basis of
SERM activity involves binding of the ligand SERM to the estrogen receptor (ER),
causing conformational changes which facilitate interactions with coactivator or
corepressor proteins, and subsequently initiate or suppress transcription of
target genes. SERM activity is intrinsic to each ER ligand, which accomplishes
its unique profile by specific interactions in the target cell, leading to
tissue selective actions. We discuss the estrogenic and anti-estrogenic effects
of early SERMs, such as clomiphene citrate, used for treatment of ovulation
induction, and the triphenylethylene, tamoxifen, which has ER antagonist
activity in the breast, and is used for prevention and treatment of ER-positive
breast cancer. Since the development of tamoxifen, other triphenylethylene SERMs
have been studied for breast cancer prevention, including droloxifene,
idoxifene, toremifene, and ospemifene. Other SERMs have entered clinical
development more recently, including benzothiophenes (raloxifene and
arzoxifene), benzopyrans (ormeloxifene, levormeloxifene, and EM-800),
lasofoxifene, pipendoxifene, bazedoxifene, HMR-3339, and fulvestrant, an
anti-estrogen which is approved for breast cancer treatment. SERMs have effects
on tissues containing ER, such as the breast, bone, uterine and genitourinary
tissues, and brain, and on markers of cardiovascular risk. Current evidence
indicates that each SERM has a unique array of clinical activities. Differences
in the patterns of action of SERMs suggest that each clinical end point must be
evaluated individually, and conclusions about any particular SERM can only be
established through appropriate clinical trials. The majority of breast cancers are estrogen receptor (ER) positive and depend on
estrogen for growth. Therefore, blocking estrogen mediated actions remains the
strategy of choice for the treatment and prevention of breast cancer. The
selective estrogen receptor modulators (SERMs) are molecules that block estrogen
action in breast cancer, but can still potentially maintain the beneficial
effects of estrogen in other tissues, such as bone and cardiovascular system.
Tamoxifen, the prototypical drug of this class has been used extensively for the
past 30 years to treat and prevent breast cancer. The target of drug action, ERs
alpha and beta, are the two receptors which are responsible for the first step
in estrogen and SERM action. The SERM binds to the ERs and confers a unique
conformation to the complex. In a target site which expresses antiestrogenic
actions, the conformation of the ER is distinctly different from estrogen bound
ER. The complex recruits protein partners called corepressors to prevent the
transcription of estrogen responsive genes. In contrast, at a predomitly
estrogenic site coactivators for estrogen action are recruited. Unfortunately at
an antiestrogenic site such as breast cancer, long term SERM therapy causes the
development of acquired resistance. The breast and endometrial tumor cells
selectively become SERM stimulated. Overexpression of receptor tyrosine kinases,
HER-2, EGFR and IGFR and the signaling cascades following their activation are
frequently involved in SERM resistant breast cancers. The aberrantly activated
PI3K/AKT and MAPK pathways and their cross talk with the genomic components of
the ER action are implicated in SERM resistance. Other down stream factors of
HER-2 and EGFR signaling, such as PI3K/AKT, MAPK or mTOR pathways has also been
found to be involved in resistance mechanisms. Blocking the actions of HER-2 and
EGFR represent a rational strategy for treating SERM resistant phenotypes and
may in fact restore the sensitivity to the SERMs. Another approach exploits the
discovery that low dose estrogen will induce apoptosis in the SERM resistant
breast cancers. Numerous clinical studies are addressing these issues. Selective estrogen receptor modulators (SERMs) have the potential to treat
estrogen sensitive diseases such as uterine leiomyoma and endometriosis, which
are prevalent in reproductive age women. However, SERMs also increase the risk
of developing ovarian cysts in this population, a phenomenon that is not seen in
postmenopausal women. It is believed that current SERMs partially block
estradiol's ability to downregulate gonadotropin-releasing hormone (GnRH)
secretion from the hypothalamus thereby interfering with estradiol's negative
feedback, leading to increased ovarian stimulation by gonadotropins, and cyst
formation. It has been postulated that a SERM with poor brain exposure would
have less negative effect on the HPO axis, therefore reducing the risk of
developing ovarian cysts. In order to test this hypothesis, we identified an
early marker of SERM-dependent ovarian effects: upregulation of Cyp17a1 mRNA.
SERMs known to cause ovarian cysts upregulate Cyp17a1 after only 4 days of
dosing and suppression of the HPO axis prevented this regulation, indicating
that ovarian expression of Cyp17a1 was secondary to SERM's effect on the brain.
We then characterized three SERMs with similar binding affinity and antagonist
effects on the uterus for their relative brain/plasma exposure and ovarian
effects. We found that the degree of brain exposure correlated very well with
Cyp17a1 expression. Selective estrogen receptor modulators (SERMs) have the ability to bind the
estrogen receptor (ER) and are known to confer ER agonist or antagonist effects
depending on the target tissue. A number of newer SERMs, including bazedoxifene,
lasofoxifene and ospemifene, are currently under clinical development for the
prevention and treatment of postmenopausal osteoporosis and for other
indications. Although the possibility of developing a single agent that has all
of the desired characteristics of an ideal SERM seems to be unlikely, progress
in the clinical development of SERMs targeted to the ER suggests that these
newer compounds may have attributes that represent an improvement relative to
existing SERMs. A new approach to menopausal therapy is the tissue selective
estrogen complex or the pairing of a selective estrogen receptor modulator with
estrogens. Further investigation will help to clarify relative benefits/risks of
novel SERMs in development within specific indications. Exploitation of the relationship between estrogen receptor (ER) structure and
activity has led to the development of 1) selective ER modulators (SERM),
compounds whose relative agonist/antagonist activities differ between target
tissues; 2) selective ER degraders (SERD), compounds that induce a
conformational change in the receptor that targets it for proteasomal
degradation; and 3) tissue-selective estrogen complexes (TSEC), drugs in which a
SERM and an ER agonist are combined to yield a blended activity that results in
distinct clinical profiles. In this study, we have performed a comprehensive
head-to-head analysis of the transcriptional activity of these different classes
of ERM in a cellular model of breast cancer. Not surprisingly, these studies
highlighted important functional differences and similarities among the existing
SERM, selective ER degraders, and TSEC. Of particular importance was the
identification of genes that were regulated by various TSEC combinations but not
by an estrogen or SERM alone. Cumulatively, the findings of this analysis are
informative with respect to the mechanisms by which ER is engaged by different
enhancers/promoters and highlights how promoter context influences the
pharmacological activity of ER ligands. Estrogen and selective estrogen receptor modulator (SERM) treatments for
acromegaly have received limited attention since the development of newer
pharmacologic therapies. There has been ongoing research evidence suggesting
their utility in the biochemical control of acromegaly. Therefore, the aim of
this meta-analysis was to synthesise current evidence with a view to determining
to what extent and in which acromegalic patient subsets do estrogen and SERMs
reduce IGF-1 levels. A literature search was conducted (finished December 2012),
which included all studies pertaining to estrogen or SERM treatment and IGF-1.
Seven patient subsets were identified from six published observational studies,
and were pooled using meta-analytic methods. Overall, the pooled mean loss in
IGF-1 was -29.09 nmol/L (95 % CI -37.23 to -20.95). A sensitivity analysis
indicated that women receiving estrogen had a substantially greater reduction in
IGF-1 levels compared with women receiving SERMs, with a weighted mean loss in
IGF-1 of -38.12 nmol/L (95 % CI -46.78 to -29.45) compared with -22.91 nmol/L
(95 % CI -32.73 to -13.09). There was a trend that did not reach statistical
significance for men receiving SERM treatment at -11.41 nmol/L (95 % CI -30.14
to 7.31). It was concluded that estrogen and SERMs are a low cost and effective
treatment to achieve control of IGF-1 levels in acromegalic women either as
concomitant treatment for refractory disease, or where access to conventional
therapy is restricted. Their use in men requires further study. The interaction of selective estrogen receptor modulators (SERMs) with lipid
membranes has been measured at clinically relevant serum concentrations using
the label-free technique of second harmonic generation (SHG). The SERMs
investigated in this study include raloxifene, tamoxifen, and the tamoxifen
metabolites 4-hydroxytamoxifen, N-desmethyltamoxifen, and endoxifen. Equilibrium
association constants (Ka) were measured for SERMs using varying lipid
compositions to examine how lipid phase, packing density, and cholesterol
content impact SERM-membrane interactions. Membrane-binding properties of
tamoxifen and its metabolites were compared on the basis of hydroxyl group
substitution and amine ionization to elucidate how the degree of drug ionization
impacts membrane partitioning. SERM-membrane interactions were probed under
multiple pH conditions, and drug adsorption was observed to vary with the
concentration of soluble neutral species. The agreement between Ka values
derived from SHG measurements of the interactions between SERMs and artificial
cell membranes and independent observations of the SERMs efficacy from clinical
studies suggests that quantifying membrane adsorption properties may be
important for understanding SERM action in vivo. Selective estrogen receptor modulators (SERMs) are compounds that exhibit
tissue-specific estrogen receptor (ER) agonist or antagonist activity, and are
used for various indications, including treatment of breast cancer,
osteoporosis, and menopausal symptoms. Endometrial safety has been a key
differentiator between SERMs in clinical practice. For example, tamoxifen
exhibits ER agonist activity in the uterus, resulting in an increased risk of
endometrial hyperplasia and maligcy, whereas raloxifene and bazedoxifene have
neutral effects on the uterus. Based on their efficacy and long-term safety,
SERMs are increasingly being prescribed for women who cannot tolerate other
treatment options and for younger women at an increased risk of fracture who may
remain on therapy for long periods of time. Continuing advances in the
understanding of SERM mechanisms of action and structural interactions with the
ER may lead to the development of new agents and combinations of agents to
provide optimal treatments to meet the varying needs of postmenopausal women.
One such example is the tissue selective estrogen complex, which partners a SERM
with 1 or more estrogens, with the aim of blending the desired estrogen-receptor
agonist activities of estrogens on vasomotor symptoms, vulvar-vaginal atrophy,
and loss of bone mass with the tissue selectivity of a SERM. Tamoxifen, a pioneering selective estrogen receptor modulator (SERM), has long
been a therapeutic choice for all stages of estrogen receptor (ER)-positive
breast cancer. The clinical application of long-term adjuvant antihormone
therapy for the breast cancer has significantly improved breast cancer survival.
However, acquired resistance to SERM remains a significant challenge in breast
cancer treatment. The evolution of acquired resistance to SERMs treatment was
primarily discovered using MCF-7 tumors transplanted in athymic mice to mimic
years of adjuvant treatment in patients. Acquired resistance to tamoxifen is
unique because the growth of resistant tumors is dependent on SERMs. It appears
that acquired resistance to SERM is initially able to utilize either E2 or a
SERM as the growth stimulus in the SERM-resistant breast tumors. Mechanistic
studies reveal that SERMs continuously suppress nuclear ER-target genes even
during resistance, whereas they function as agonists to activate multiple
membrane-associated molecules to promote cell growth. Laboratory observations in
vivo further show that three phases of acquired SERM-resistance exists,
depending on the length of SERMs exposure. Tumors with Phase I resistance are
stimulated by both SERMs and estrogen. Tumors with Phase II resistance are
stimulated by SERMs, but are inhibited by estrogen due to apoptosis. The
laboratory models suggest a new treatment strategy, in which limited-duration,
low-dose estrogen can be used to purge Phase II-resistant breast cancer cells.
This discovery provides an invaluable insight into the evolution of drug
resistance to SERMs, and this knowledge is now being used to justify clinical
trials of estrogen therapy following long-term antihormone therapy. All of these
results suggest that cell populations that have acquired resistance are in
constant evolution depending upon selection pressure. The limited availability
of growth stimuli in any new environment enhances population plasticity in the
trial and error search for survival. In this review, we analyze the efficacy and safety of DT56a in the treatment of
postmenopausal symptoms. Similar to all selective estrogen receptor modulators
(SERMs), DT56a demonstrates dual agonistic and antagonistic effects due to the
synergy between its components. DT56a is referred to as a plant-origin SERM
(phyto-SERM) and, for this reason, its therapeutic capacity in postmenopausal
women differs from other phytoestrogens used independently. Although interesting
data on relief of vasomotor symptoms have been reported for DT56a, further
clinical studies with a greater number of cases and a longer period of study are
required to correctly identify its indications for use as an alternative to
hormone therapy, especially in preventing osteoporosis. SERMs represent a diverse group of molecules with varying levels of estrogenic
agonist and antagonist activity in target tissues. SERMs have a long regulatory
approval history and have been studied for a variety of therapeutic indications.
The clinical effects of SERMs have been evaluated in a large number of phase 3
clinical trials. Many of the available SERMs have proved to be effective as
chemo-preventive agents and treatments for breast cancer and a number are useful
for the prevention and treatment of osteoporosis. The endometrial effect of
SERMs has been a key differentiator in clinical practice and a major hurdle for
regulatory approval. The effect of SERMs in the vagina also represents a major
distinction among different SERMs. This review summarized key clinical finding
of SERMs in different target tissues. The bone-sparing effect of estrogens is mediated primarily via estrogen receptor
(ER)α, which stimulates gene transcription through activation function (AF)-1
and AF-2. The role of ERαAF-1 for the estradiol (E2) effects is tissue specific.
The selective ER modulators (SERMs) raloxifene (Ral), lasofoxifene (Las), and
bazedoxifene (Bza) can be used to treat postmenopausal osteoporosis. They all
reduce the risk for vertebral fractures, whereas Las and partly Bza, but not
Ral, reduce the risk for nonvertebral fractures. Here, we have compared the
tissue specificity of Ral, Las, and Bza and evaluated the role of ERαAF-1 for
the effects of these SERMs, with an emphasis on bone parameters. We treated
ovariectomized (OVX) wild-type (WT) mice and OVX mice lacking ERαAF-1
(ERαAF-1(0)) with E2, Ral, Las, or Bza. All three SERMs increased trabecular
bone mass in the axial skeleton. In the appendicular skeleton, only Las
increased the trabecular bone volume/tissue volume and trabecular number,
whereas both Ral and Las increased the cortical bone thickness and strength.
However, Ral also increased cortical porosity. The three SERMs had only a minor
effect on uterine weight. Notably, all evaluated effects of these SERMs were
absent in ovx ERαAF-1(0) mice. In conclusion, all SERMs had similar effects on
axial bone mass. However, the SERMs had slightly different effects on the
appendicular skeleton since only Las increased the trabecular bone mass and only
Ral increased the cortical porosity. Importantly, all SERM effects require a
functional ERαAF-1 in female mice. These results could lead to development of
more specific treatments for osteoporosis. Although best known as a selective estrogen receptor modulator (SERM), tamoxifen
is a drug with a wide range of activities. Tamoxifen has demonstrated some
efficacy has a therapeutic for bipolar mania and is believed to exert these
effects through inhibition of protein kinase C (PKC). As the symptoms of
amphetamine treatment in rodents are believed to mimic the symptoms of a manic
episode, many of the preclinical studies for this indication have demonstrated
that tamoxifen inhibits amphetamine action. The amphetamine-induced increase in
extracellular dopamine which gives rise to the 'manic' effects is due to
interaction of amphetamine with the dopamine transporter. We and others have
demonstrated that PKC reduces amphetamine-induced reverse transport through the
dopamine transporter. In this review, we will outline the actions of tamoxifen
as a SERM and further detail another known action of tamoxifen-inhibition of
PKC. We will summarize the literature showing how tamoxifen affects amphetamine
action. Finally, we will present our hypothesis that tamoxifen, or an analog,
could be used therapeutically to reduce amphetamine abuse in addition to
treating mania. Over the past 3 decades, compounds called selective estrogen receptor modulators
(SERMs) have been developed that block the estrogen receptor in some tissues
(estrogen receptor antagonists) or stimulate the estrogen receptor in other
tissues (estrogen receptor agonists). This Practice Pearl focuses on SERMs that
clinicians can use for menopausal patients. Antiresorptive agents for treating postmenopausal osteoporosis include selective
estrogen receptor modulator (SERM), bisphosphonates and denoumab. Teriparatide
is the only Food and Drug Administration-approved anabolic agent. Synergistic
effects of combining teriparatide with an antiresorptive agent have been
proposed and studied. This article reviews the trial designs and the outcomes of
combination therapies. Results of the combination therapy for teriparatide and
bisphosphonates were mixed; while small increases of bone density were observed
in the combination therapy of teriparatide and estrogen/SERM and that of
teriparatide and denosumab. Those clinical studies were limited by small sample
sizes and lack of fracture outcomes. Selective estrogen receptor modulators (SERMs) are a class of compounds that
interact with estrogen receptors (ERs) and exert agonist or antagonist effects
on ERs in a tissue-specific manner. Tamoxifen, a first generation SERM, is used
for treatment of ER positive breast cancer. Raloxifene, a second generation
SERM, was used to prevent postmenopausal osteoporosis. The third-generation SERM
bazedoxifene (BZA) effectively prevents osteoporosis while preventing estrogenic
stimulation of breast and uterus. Notably, BZA combined with conjugated
estrogens (CE) is a new menopausal treatment. The menopausal state predisposes
to metabolic syndrome and type 2 diabetes, and therefore the effects of SERMs on
metabolic homeostasis are gaining attention. Here, we summarize knowledge of
SERMs' impacts on metabolic, homeostasis, obesity and diabetes in rodent models
and postmenopausal women. INTRODUCTION: Selective estrogen receptor modulators (SERMs) have been used
off-label in men for more than 50 years. SERMs exert their action on the
estrogen receptor agonistically or antagonistically. A fundamental knowledge of
the complex molecular action and physiology of SERMs is important in
understanding their use and future directions of study in men.
AIM: To review the basic science and mechanism of the action of estrogens, the
estrogen receptor, and SERMs, and the existing clinical publications on the use
of SERMs in men for infertility and hypogonadism with their strengths and
weaknesses and to identify the need for future studies.
METHODS: After a review of publications on the basic science of estrogen
receptors, a chronologic review of published evidence-based studies on the use
of SERMs in men for infertility and hypogonadism was undertaken.
MAIN OUTCOME MEASURES: Clinical publications were assessed for type of study,
inclusion criteria, outcome measurements, and results. Strengths and weaknesses
of the publications were assessed and discussed.
RESULTS: Few prospective rigorously controlled trials have been undertaken on
the use of SERMs in men. Most existing trials are largely retrospective
anecdotal studies with inconsistent inclusion and end-point measurements. The
SERMs are complex and at times can produce paradoxical results. Their action
likely depends on the genetics of the individual, his tissue-specific
composition of estrogen receptors, the molecular structure and pharmacodynamics
of the SERMs, and their metabolism.
CONCLUSION: Rigorously controlled trials of the use of SERMs in men are needed
to better identify their clinical benefit and long-term safety in infertile and
hypogonadal men. Recent placebo-controlled pharmaceutical industry SERM trials
have demonstrated short-term safety and efficacy in men with secondary
hypogonadism and eventually might provide an alternative to exogenous
testosterone replacement therapy in men with secondary hypogonadism. Helo S,
Wynia B, McCullough A. "Cherchez La Femme": Modulation of Estrogen Receptor
Function With Selective Modulators: Clinical Implications in the Field of
Urology. Sex Med Rev 2017;5:365-386. Selective estrogen receptor modulators (SERMs) reduce breast cancer risk.
Adoption of SERMs as prevention medication remains low. This is the first study
to quantify social, cultural, and psychologic factors driving decision making
regarding SERM use in women counseled on breast cancer prevention options. A
survey study was conducted with women counseled by a health care provider (HCP)
about SERMs. A statistical comparison of responses was performed between those
who decided to use and those who decided not to use SERMs. Independent factors
associated with the decision were determined using logistic regression. Of 1,023
participants, 726 made a decision: 324 (44.6%) decided to take a SERM and 402
(55.4%) decided not to. The most important factor for deciding on SERM use was
the HCP recommendation. Other characteristics associated with the decision
included attitudes and perceptions regarding medication intake, breast cancer
worry, trust in HCP, family members with blood clots, and others' experiences
with SERMs. The odds of SERM intake when HCP recommended were higher for
participants with a positive attitude toward taking medications than for those
with a negative attitude (Pinteraction = 0.01). This study highlights the
importance of social and cultural aspects for SERM decision making, most
importantly personal beliefs and experiences. HCPs' recommendations play a
statistically significant role in decision making and are more likely to be
followed if in line with patients' attitudes. Results indicate the need for
developing interventions for HCPs that not only focus on the presentation of
medical information but, equally as important, on addressing patients' beliefs
and experiences. Cancer Prev Res; 10(11); 625-34. ©2017 AACRSee related
editorial by Crew, p. 609. Estrogen exposure is one of the strongest risk factors for breast cancer
development. Chemoprevention with selective estrogen receptor modulators (SERM),
such as tamoxifen and raloxifene, has been shown in randomized controlled trials
to reduce breast cancer incidence by up to 50% among high-risk women. Despite
the strength of this evidence, there is significant underutilization of
chemoprevention. Given the relatively few modifiable breast cancer risk factors,
SERM use provides an important strategy for the primary prevention of this
disease. Understanding factors which influence chemoprevention decision-making
will inform efforts to implement breast cancer risk assessment and increase
chemoprevention uptake in clinical practice. Cancer Prev Res; 10(11); 609-11.
©2017 AACRSee related article by Holmberg et al., p. 625. |
Is celiac disease caused by gliadin-induced transglutaminase-2 (TG2)-dependent events ? | Celiac disease is caused by gliadin-induced transglutaminase-2 (TG2)-dependent events following ingestion of dietary gluten. | Tissue transglutaminase (TG2) modifies proteins and peptides by transamidation
or deamidation of specific glutamine residues. TG2 also has a central role in
the pathogenesis of celiac disease. The enzyme is both the target of
disease-specific autoantibodies and generates deamidated gliadin peptides
recognized by intestinal T cells from patients. Incubation of TG2 with gliadin
peptides also results in the formation of covalent TG2-peptide complexes. Here
we report the characterization of complexes between TG2 and two immunodomit
gliadin peptides. Two types of covalent complexes were found; the peptides are
either linked via a thioester bond to the active site cysteine of TG2 or via
isopeptide bonds to particular lysine residues of the enzyme. We quantified the
number of gliadin peptides bound to TG2 under different conditions. After 30 min
of incubation of TG2 at 1 microm with an equimolar ratio of peptides to TG2,
approximately equal amounts of peptides were bound by thioester and isopeptide
linkage. At higher peptide to TG2 ratios, more than one peptide was linked to
TG2, and isopeptide bond formation dominated. The lysine residues in TG2 that
act as acyl acceptors were identified by matrix assisted laser desorption
ionization and oelectrospray mass spectrometry and tandem mass spectrometry
analysis of proteolytic digests of the TG2-peptide complexes. At a high molar
excess of gliadin peptides to TG2 altogether six lysine residues of TG2 were
found to participate in isopeptide bond formation. The results are relevant to
the understanding of how antibodies to TG2 are formed in celiac disease. Transglutaminase 2 (TG2) catalyzes cross-linking or deamidation of glutamine
residues in peptides and proteins. The in vivo deamidation of gliadin peptides
plays an important role in the immunopathogenesis of celiac disease (CD).
Although deamidation is considered to be a side-reaction occurring in the
absence of suitable amines or at a low pH, a recent paper reported the selective
deamidation of the small heat shock protein 20 (Hsp20), suggesting that
deamidation could be a substrate dependent event. Here we have measured peptide
deamidation and transamidation in the same reaction to reveal factors that
affect the relative propensity for the two possible products. We report that the
propensity for deamidation by TG2 is both substrate dependent and influenced by
the reaction conditions. Direct deamidation is favored for poor substrates and
at low concentrations of active TG2, while indirect deamidation (i.e. hydrolysis
of transamidated product) can significantly contribute to the deamidation of
good peptide substrates at higher enzyme concentrations. Further, we report for
the first time that TG2 can hydrolyze iso-peptide bonds between two peptide
substrates. This was observed also for gliadin peptides introducing a novel
route for the generation of deamidated T cell epitopes in celiac disease. BACKGROUND: Celiac disease (CD) is a frequent inflammatory intestinal disease,
with a genetic background, caused by gliadin-containing food. Some gliadin
peptides are not digested by intestinal proteases and can have different
biological effects. Gliadin peptides can induce innate and adaptive T
cell-mediated immune responses. The major mediator of the stress and innate
immune response to gliadin peptides (i.e., peptides 31-43 and 31-55) is the
cytokine interleukin-15 (IL-15). Other peptides such as the 33 mer containing
the P57-68 sequence, after tissue transglutaminase deamidation, are well
presented to T cell in the intestine and can induce an adaptive immune response.
FINDINGS: In this paper, we review the recent studies on the digestion of
gliadin and the peptides released by the digestion process. We will also discuss
the mechanisms responsible for the internalization and transcytosis of
indigested gliadin peptides in the intestinal epithelium.
CONCLUSIONS: Gliadin is not completely digested by the intestinal proteases
producing bioactive peptides that have different biological effects. These
peptides are internalized in the cells by an active process of endocytosis and
can traverse the intestinal mucosa with different kinetics and immunological
effects. In vivo findings will also be discussed. Type 2 transglutaminase (TG2) has an important pathogenic role in celiac disease
(CD), an inflammatory intestinal disease that is caused by the ingestion of
gluten-containing cereals. Indeed, TG2 deamidates specific gliadin peptides,
thus enhancing their immunogenicity. Moreover, the transamidating activity seems
to provoke an autoimmune response, where TG2 is the main autoantigen. Many
studies have highlighted a possible pathogenetic role of anti-TG2 antibodies,
because they modulate TG2 enzymatic activity and they can interact with
cell-surface TG2, triggering a wide range of intracellular responses.
Autoantibodies also alter the uptake of the alpha-gliadin peptide 31-43
(p31-43), responsible of the innate immune response in CD, thus partially
protecting cells from p31-43 damaging effects in an intestinal cell line. Here,
we investigated whether anti-TG2 antibodies protect cells from p31-43-induced
damage in a CD model consisting of primary dermal fibroblasts. We found that the
antibodies specifically reduced the uptake of p31-43 by fibroblasts derived from
healthy subjects but not in those derived from CD patients. Analyses of TG2
expression and enzymatic activity did not reveal any significant difference
between fibroblasts from healthy and celiac subjects, suggesting that other
features related to TG2 may be responsible of such different behaviors, e.g.,
trafficking or subcellular distribution. Our findings are in line with the
concept that a "celiac cellular phenotype" exists and that TG2 may contribute to
this phenotype. Moreover, they suggest that the autoimmune response to TG2,
which alone may damage the celiac mucosa, also fails in its protective role in
celiac cells. |
Which resource contains accurate enhancer predictions in the developing limb? | Limb-Enhancer Genie (LEG) is a collection of highly accurate, genome-wide predictions of enhancers in the developing limb, available through a user-friendly online interface. Limb enhancers are predicted using a combination of >50 published limb-specific datasets and clusters of evolutionarily conserved transcription factor binding sites, taking advantage of the patterns observed at previously in vivo validated elements. | |
What is the first line treatment for sarcoidosis? | Sarcoidosis is a systemic granulomatous disease that affects numerous organs, commonly manifesting at the lungs and skin. Corticosteroids remain the first line of treatment. | Sarcoidosis is still a mysterious disease since we don't know exactly what is
the cause. Interestingly some patients get cured without any treatment. There is
still a controversy about the indications of treatment in sarcoidosis. This
article is an update on pharmacologic treatment in sarcoidosis. Corticosteroids
are still the first-line treatment, but alternative therapy with anti-TNF
agents, like pentoxifylline, thalidomide and anti-TNF monoclonal antibodies
become more interesting, especially in refractory sarcoidosis. The presence of granulomas in the liver raises consideration of a wide
differential diagnosis, but in most Western series, sarcoidosis accounts for a
majority of cases. This review will focus specifically on the diagnosis of and
therapy for hepatic sarcoidosis. Sarcoidosis is a systemic granulomatous disease
of unknown etiology. Hepatic involvement of sarcoidosis was described in 11.5%
of 736 patients enrolled in the ACCESS study. However, presence alone of
granulomas in an organ in sarcoidosis does not dictate treatment. The decision
to treat should be based on symptoms and severity of disease. Although hepatic
involvement usually is asymptomatic, a minority of patients progress to chronic
cholestatic disease, portal hypertension, and cirrhosis that may require liver
transplantation. Treatment of hepatic sarcoidosis should be reserved for
patients who manifest this spectrum of disease. Glucocorticoid treatment is
first-line therapy for hepatic sarcoidosis, improving symptoms and abnormal
laboratory values but generally having no effect on progression of disease. In
addition to glucocorticoids, immunomodulators such as azathioprine,
methotrexate, hydroxychloroquine, and infliximab have been used with some
positive effects on symptoms, liver enzyme abnormalities, and hepatomegaly, but
none has been shown to prevent progression of disease. Ultimately, in cases of
overt liver failure, liver transplantation is the definitive treatment. Overall,
treatment for hepatic sarcoidosis is targeted toward alleviation of symptoms but
has no curative potential at this time. Focus should be on discovering the
etiology of the disease to target therapy at prevention, not cure. BACKGROUND: Steroids remain the first-choice therapeutic in sarcoidosis;
however, long-term use is associated with toxicity. Evidence defining the best
second-line therapeutic is currently lacking. The aim of this study was to
compare the effect of methotrexate and azathioprine on prednisone tapering,
pulmonary function, and side effects in the second-line treatment of
sarcoidosis.
METHODS: An international retrospective cohort study was performed, reviewing
all patients with sarcoidosis who started methotrexate or azathioprine until 2
years after initiation or discontinuation. A linear mixed model with FEV1, vital
capacity (VC), diffusing capacity of lung for carbon monoxide (DLCO), and
prednisone dose changes over time as end points was used. Side effects were
compared with χ2 tests.
RESULTS: Two hundred patients were included, of whom 145 received methotrexate
and 55 azathioprine. Prednisone daily dose decreased a mean of 6.32 mg/y (P <
.0001) while on therapy, with a similar steroid-sparing capacity for
methotrexate and azathioprine. Of all patients completing 1 year of therapy, 70%
had a reduction in daily prednisone dose of at least 10 mg. FEV1 showed a mean
increase of 52 mL/y (P = .006) and VC of 95 mL/y (P = .001) in both treatment
groups. DLCO % predicted increased, with a mean of 1.23%/y (P = .018). There
were more patients with infections in the azathioprine group (34.6% vs 18.1%, P
= .01), but no differences regarding other side effects.
CONCLUSIONS: This retrospective study comparing the effect of second-line
therapy in sarcoidosis shows that both methotrexate and azathioprine have
significant steroid-sparing potency, a similar positive effect on lung function,
and comparable side effects, except for a higher infection rate in the
azathioprine group. PURPOSE OF REVIEW: Although glucocorticosteroids are considered the first-line
treatment in sarcoidosis, refractory cases require alternatives, such as
methotrexate (MTX). The aim of this study was to develop, on behalf of the World
Association of Sarcoidosis and Other Granulomatous Disorders (WASOG),
multinational evidence-based recommendations for the use of MTX in sarcoidosis
for routine clinical practice.
RECENT FINDINGS: A systematic literature search was conducted and combined with
the opinions of sarcoidosis experts worldwide to formulate the recommendations.
An online survey concerning 10 clinical questions was sent through the WASOG
newsletter to sarcoidosis experts. Agreement about the recommendations amongst
the world's leading sarcoidologists was evaluated. A total of 237 articles were
identified, 43 of which were included. Randomized controlled trial evidence
supporting the use of MTX in sarcoidosis was limited. Forty-five per cent (113
of 250) of the sarcoidosis experts contacted completed the survey (Europe 55%,
North America 26% and Asia 12%). Ten recommendations were formulated concerning
the indications for use, starting dose, folic acid, work-up, contraindications,
monitoring, administration options in case of adverse gastrointestinal effects,
hepatotoxicity, long-term safety and use during pregcy and breast feeding.
SUMMARY: Ten multinational evidence-based recommendations for the use of MTX in
sarcoidosis were developed, which are supported by the world's foremost
sarcoidosis experts. PURPOSE OF REVIEW: None of the medications used in clinical practice to treat
sarcoidosis have been approved by the regulatory authorities. Understanding how
to use disease-modifying antisarcoid drugs, however, is essential for physicians
treating patients with sarcoidosis. This review summarizes the recent studies of
medications used for sarcoidosis with a focus on nonsteroidal therapies. Studies
from 2006 to 2013 were considered for review to update clinicians on the most
relevant literature published over the last few years.
RECENT FINDINGS: Several recently published pieces of evidence have helped
expand our ability to more appropriately sequence second-line and third-line
therapies for sarcoidosis. For instance, methotrexate and azathioprine may be
useful and well tolerated medications as second-line treatment. Mycophenolate
mofetil might have a role in neurosarcoidosis. TNF-α blockers and other
biologics seem to be well tolerated medications for the most severely affected
patients.
SUMMARY: Corticosteroids remain the first-line therapy for sarcoidosis as many
patients never require treatment or only necessitate a short treatment duration.
Second-line and third-line therapies described in this article should be used in
patients with progressive or refractory disease or when life-threatening
complications are evident at the time of presentation. Sarcoidosis is a systemic granulomatous disease that affects numerous organs,
commonly manifesting at the lungs and skin. While corticosteroids remain the
first line of treatment, tumour necrosis factor alpha (TNF-α) inhibitors have
been investigated as one potential steroid sparing treatment for sarcoidosis.
TNF-α is one of many components involved in the formation of granulomas in
sarcoidosis. While there have been larger scale studies of biologic TNF-α
inhibition in systemic sarcoidosis, studies in cutaneous disease are limited.
Paradoxically, in some patients treated with biologic TNF-α inhibitors for other
diseases, treatment can induce the development of sarcoidosis. In the light of
this complexity, we discuss the role of TNF-α in granuloma formation, the
therapeutic role of TNF-α inhibition and immunologic abnormalities following
treatment with these TNF-α inhibitors including drug-specific alterations
involving interferon-γ, lymphotoxin-α, TNF receptor 2 (TNFR2) and T-regulatory
cells. Sarcoidosis is a rare multiorgan granulomatous disease of unknown etiology,
mostly affecting young adults, with predilection for hilar lymph nodes and the
lung. Despite clinical and histologic similarities between sarcoidosis and
tuberculosis, the role of M. tuberculosis in the etiopathogenesis of sarcoidosis
is still not clear. Over recent years numerous studies identifying peripheral
blood T-cell response to various mycobacterial antigens were published. In
parallel, there is no direct evidence for the role of alive M. tuberculosis in
the development of sarcoidosis, as evidenced by negative culture in these
patients. Exclusion of active tuberculosis as the granulomatous disease of known
cause, still remain the important step in diagnostic work-up in sarcoidosis.
Development of bronchoscopic techniques significantly reduced the number of
surgical procedures. Combination of a few biopsy techniques: transbronchial
needle aspiration, endobronchial biopsy and transbronchial lung biopsy, can
achieve the optimum diagnostic yield. Because of the large percentage of
spontaneous remission in sarcoidosis, the decision of treatment should be taken
with caution. Corticosteroids still remain first-line therapy in sarcoidosis.
Methotrexate is the most commonly used second-line drug. TNFα-antagonists are
the therapeutic option in refractory sarcoidosis. In this article we summarise
the present knowledge about the most common localization of sarcoidosis -
pulmonary sarcoidosis, with special emphasis on the current etiologic
hypothesis, possibility of diagnosis and treatment. Sarcoidosis is a systemic disease of unknown etiology characterized by the
development of non-caseating epitheloid granulomas. The lungs are the most
commonly involved organ (>90% of cases), followed by the lymph nodes, the skin,
and the eyes. Areas covered: This review summarizes current pharmacotherapy
options and future directions for the development of new therapies.
Glucocorticoids are the first-line therapy for sarcoidosis. For patients with
the most severe forms of sarcoidosis (who will need glucocorticoids for long
periods) and for those intolerant or refractory, immunosuppressive drugs are
used as sparing agents. The management of extrathoracic sarcoidosis must be
tailored to the specific organ or organs involved; however, there is limited
data from controlled trials to guide the treatment of these patients. The
emergence of biological therapies has increased the therapeutic armamentarium
available to treat sarcoidosis, with monoclonal anti-TNF agents being the most
promising, but their use is still limited by a lack of licensing and costs.
Expert commentary: The treatment of sarcoidosis is still not totally
standardized. New effective therapies are urgently needed to enable the
reduction or replacement of long-term therapy with glucocorticoids in patients
with sarcoidosis. Sarcoidosis represents a non-caseating, granulomatous disorder of unknown
aetiology whose clinical manifestation is heterogeneous and frequently
multisystemic. The portion of patients needing systemic treatment varies: though
many patients may undergo spontaneous remission, organ-threatening courses
demand systemic therapy. Corticosteroids are the first-line treatment option;
however, disease´s progression and/or major corticosteroid side effects may
require second- and third-line therapeutics. A current stepwise therapeutic
algorithm to sarcoidosis that characterizes additive and alternative therapeutic
agents is given in the following review. The prevalence of cardiac sarcoidosis has exponentially increased over the past
decade, primarily due to increased awareness and diagnostic modalities for the
disease entity. Despite an expanding patient cohort, the optimal management of
cardiac sarcoidosis remains yet to be established with a significant lack of
prospective trials to support current practice. Corticosteroids remain
first-line treatment of this disorder, and we recommend that immunosuppressive
therapy should be initiated in all patients diagnosed with cardiac sarcoidosis.
Additional pharmacotherapy may be necessary based on disease manifestations and
response to treatment. The use of nuclear imaging with 18fluorodeoxyglucose
(18FDG) positron emission tomography (PET) to guide treatment has become more
common, but lacks rigorous data from larger cohorts. Whether an improvement in
inflammatory burden as assessed by 18FDG-PET is correlated with clinical
outcomes is as yet unproven. Device therapy with implantable-cardioverter
defibrillators should be considered in all cardiac sarcoidosis patients for
either primary or secondary prevention of ventricular arrhythmias and cardiac
death. BACKGROUND: Prednisone is used as first-line therapy for pulmonary sarcoidosis.
What dosing strategy has the best balance between effect and side-effects is
largely unknown. We analyzed change in forced vital capacity (FVC) and weight
during different prednisone doses used in daily practice for treatment naïve
pulmonary sarcoidosis patients.
METHODS: Multilevel models were used to describe FVC and weight change over
time. Correlations were calculated using linear regression models.
RESULTS: Fifty-four patients were included. FVC changed over time (p < 0.001),
with an average increase of 9.6% predicted (95% CI: 7.2 to 12.1) at 12 months.
Weight changed significantly over time (p < 0.001), with an average increase of
4.3 kg (95% CI: 3.0 to 5.6) at 12 months. Although FVC and weight changed
significantly over time, there was little correlation between prednisone dose
and FVC change, while weight increase correlated significantly with cumulative
prednisone dose at 24 months. In patients treated with a high cumulative
prednisone dose, baseline FVC was on average lower (p = 0.001) compared to low
dose treated patients, while no significant differences were observed in need
for second/third-line therapy or number of exacerbations. A strategy leading to
a low cumulative dose at 12 months was defined by rapid dose tapering to
10 mg/day within 3.5 months.
CONCLUSIONS: These results suggest that prednisone therapy aimed at improving or
preserving FVC in newly- treated pulmonary sarcoidosis can often be reduced in
dose, using a treatment regimen that is characterized by early dose tapering. |
Which personality disorder is treated using dialectical behavior therapy? | Dialectical behavior therapy is an evidence-based psychosocial treatment with efficacy in reducing self-harm behaviors in borderline personality disorder. | M. Linehan developed "dialectical behavioral therapy" specifically to treat
chronically suicidal borderline patients. It rests on a biosocial model that
assumes a disorder in the regulation of emotions and in tolerance of stress. The
numerous dysfunctional patterns of behavior such as self-destructive behavior,
inability to govern impulses or severe dissociative phenomena are regarded as
attempts at problem-solving. This concept of therapy focuses on the continuing
balance between the necessity of accepting maladaptive behavior patterns in both
an intrapsychic and an interactional context while still working to change them.
A comprehensive manual outlines the clearly structured therapy and integrates a
wide choice of therapeutic strategies. Parallel to development of the therapy
itself, a method also was developed for testing therapist adherence to the
manual's guidelines, thus providing a basis for empirical evaluation. An initial
controlled, randomized study demonstrated the significant superiority of this
method to methods of unspecific psychotherapy at various levels. In the current
endeavor to develop disorder-specific approaches to the treatment of personality
disorders, "dialectical behavioral therapy" is a noteworthy model. Dialectical behavior therapy, an outpatient psychosocial treatment for
chronically suicidal women with borderline personality disorder, has been
adapted for use in a partial hospital program for women. Patients attend the
program for a minimum of five days of individual and group therapy, and full
census is 12 women. About 65 percent of participants meet at least three
criteria for borderline personality disorder, and most have suicidal and
self-injurious behavior. Their comorbid diagnoses include trauma-related
diagnoses and anxiety disorders, severe eating disorders, substance abuse, and
depression. The partial hospital program is linked to an aftercare program
offering six months of outpatient skills training based on dialectical behavior
therapy. Both programs focus on teaching patients four skills: mindfulness
(attention to one's experience), interpersonal effectiveness, emotional
regulation, and distress tolerance. Two years of operation of the women's
partial hospital program provides promising anecdotal evidence that dialectical
behavioral therapy, an outpatient approach, can be effectively modified for
partial hospital settings and a more diverse population. The aim was to investigate patients and therapists perception of receiving and
giving dialectical behavioral therapy (DBT). Ten deliberate self-harm patients
with borderline personality disorder and four DBT-therapists were interviewed.
The interviews were analyzed with qualitative content analysis. The patients
uimously regard the DBT-therapy as life saving and something that has given
them a bearable life situation. The patients and the therapists are concordant
on the effective components of the therapy: the understanding, respect, and
confirmation in combination with the cognitive and behavioral skills. The
experienced effectiveness of DBT is contrasted by the patient's pronouncedly
negative experiences from psychiatric care before entering DBT. OBJECTIVE: The authors describe the use of dialectical behavior therapy (DBT) in
treating borderline personality disorder during psychiatry residency, and assess
the status of DBT education within psychiatry residencies in the United States.
METHOD: The authors present a patient with borderline personality disorder
treated by a resident using DBT, along with perspectives from the resident's
supervisors. Additionally, self-report surveys inquiring about the attitudes and
experiences of residency directors and PGY-4 residents regarding DBT were sent
to program directors with available e-mail addresses on FREIDA online.
RESULTS: The DBT method employed by the resident had to be modified to fit the
constraints of a residency program. The patient in therapy had a tumultuous
course, ultimately resulting in the discontinuation of treatment. Survey results
suggested an underemphasis on the education and use of DBT during residency,
though the strength of this conclusion is limited by the small proportion of
surveys returned.
CONCLUSIONS: Achieving the efficacy of DBT-based treatment of borderline
personality disorder reported in the literature in the setting of a residency
program is challenging. Greater exposure to DBT during residency may increase
residents' skills in using the technique and the likelihood that they will use
it after residency. A central component of Dialectical Behavior Therapy (DBT) is the teaching of
specific behavioral skills with the aim of helping individuals with Borderline
Personality Disorder (BPD) replace maladaptive behaviors with skillful behavior.
Although existing evidence indirectly supports this proposed mechanism of
action, no study to date has directly tested it. Therefore, we examined the
skills use of 108 women with BPD participating in one of three randomized
control trials throughout one year of treatment and four months of follow-up.
Using a hierarchical linear modeling approach we found that although all
participants reported using some DBT skills before treatment started,
participants treated with DBT reported using three times more skills at the end
of treatment than participants treated with a control treatment. Significant
mediation effects also indicated that DBT skills use fully mediated the decrease
in suicide attempts and depression and the increase in control of anger over
time. DBT skills use also partially mediated the decrease of nonsuicidal
self-injury over time. Anger suppression and expression were not mediated. This
study is the first to clearly support the skills deficit model for BPD by
indicating that increasing skills use is a mechanism of change for suicidal
behavior, depression, and anger control. OBJECTIVE: At present, the most frequently investigated psychosocial
intervention for borderline personality disorder (BPD) is dialectical behavior
therapy (DBT). We conducted a meta-analysis to examine the efficacy and
long-term effectiveness of DBT.
METHOD: Systematic bibliographic research was undertaken to find relevant
literature from online databases (PubMed, PsycINFO, PsychSpider, Medline). We
excluded studies in which patients with diagnoses other than BPD were treated,
the treatment did not comprise all components specified in the DBT manual or in
the suggestions for inpatient DBT programs, patients failed to be diagnosed
according to the Diagnostic and Statistical Manual of Mental Disorders, and the
intervention group comprised fewer than 10 patients. Using a mixed-effect
hierarchical modeling approach, we calculated global effect sizes and effect
sizes for suicidal and self-injurious behaviors.
RESULTS: Calculations of postintervention global effect sizes were based on 16
studies. Of these, 8 were randomized controlled trials (RCTs), and 8 were
neither randomized nor controlled (nRCT). The dropout rate was 27.3% pre- to
posttreatment. A moderate global effect and a moderate effect size for suicidal
and self-injurious behaviors were found, when including a moderator for RCTs
with borderline-specific treatments. There was no evidence for the influence of
other moderators (e.g., quality of studies, setting, duration of intervention).
A small impairment was shown from posttreatment to follow-up, including 5 RCTs
only.
CONCLUSIONS: Future research should compare DBT with other active
borderline-specific treatments that have also demonstrated their efficacy using
several long-term follow-up assessment points. OBJECTIVE: Dialectical behavior therapy (DBT) is an empirically supported
treatment for outpatients with borderline personality disorder. However, the
utility of DBT strategies for inpatients with the disorder is unclear. This
review summarizes and synthesizes findings from trials of DBT in inpatient
settings.
METHODS: Multiple research databases were searched for articles published
through June 2011 that reported on any implementation of DBT in an inpatient
setting to address symptoms related to borderline personality disorder,
including suicidal and self-injurious behavior.
RESULTS: Eleven studies that reported pre- and posttreatment symptoms related to
borderline personality disorder were evaluated. Studies indicated that many
variations of standard DBT have been used in inpatient settings, including
approaches that do not include phone consultation, that include group therapy
only, and that vary in treatment duration (from two weeks to three months). Most
studies reported reductions in suicidal ideation, self-injurious behaviors, and
symptoms of depression and anxiety, whereas results for reducing anger and
violent behaviors were mixed. Follow-up data indicated that symptom reduction
was often maintained between one and 21 months posttreatment. On the basis of
the evidence, the authors identify essential components of an inpatient DBT
package and discuss its potential function as an "intensive orientation" to
outpatient DBT services.
CONCLUSIONS: There is considerable variation in the configuration and duration
of DBT implementation for inpatients with borderline personality disorder.
However, findings suggest that DBT may be effective in reducing symptoms related
to borderline personality disorder in inpatient settings. Future research should
standardize and systematically test inpatient DBT. (Psychiatric Services
63:881-888, 2012; doi: 10.1176/appi.ps.201100311). Neural underpinnings of emotion dysregulation in borderline personality disorder
(BPD) are characterized by limbic hyperactivity and disturbed prefrontal
activity. It is unknown whether neural correlates of emotion regulation change
after a psychotherapy which has the goal to improve emotion dysregulation in
BPD, such as dialectical behavioral therapy (DBT). We investigated distraction
as a main emotion regulation strategy before and after DBT in female patients
with BPD. Thirty-one BPD patients were instructed to either passively view or
memorize letters before being confronted with negative or neutral pictures in a
distraction task during functional magnetic resoce imaging. This paradigm was
applied before and after a 12-week residential DBT-based treatment program. We
compared the DBT group to 15 BPD control patients, who continued their usual,
non-DBT-based treatment or did not have any treatment, and 22 healthy
participants. Behaviorally, BPD groups and healthy participants did not differ
significantly with respect to alterations over time. On the neural level, BPD
patients who received DBT-based treatment showed an activity decrease in the
right inferior parietal lobe/supramarginal gyrus during distraction from
negative rather than neutral stimuli when compared to both control groups. This
decrease was correlated with improvement in self-reported borderline symptom
severity. DBT responders exhibited decreased right perigenual anterior cingulate
activity when viewing negative (rather than neutral) pictures. In conclusion,
our findings reveal changes in neural activity associated with distraction
during emotion processing after DBT in patients with BPD. These changes point to
lower emotional susceptibility during distraction after BPD symptom improvement. Objective Investigate influence and change of self-directedness (SD) in
Dialectical-Behavior Therapy (DBT) for 26 female outpatients with borderline
personality disorder (BPS). Method Variance analyses are used to evaluate
psychopathology and interpersonal problems in 2 subgroups (low vs. high SD) with
questionnaires at 3 measuring times over the period of 1 year. Results Low SD
was associated with higher psychopathology, more interpersonal problems and
lower symptomreduction. Over time of intervention the SD of all patients
improved significantly. Conclusion DBT strengthens the SD of patients with BPD.
A screening of SD before intervention, and systematic support should be
considered. OBJECTIVE: Dialectical behavior therapy (DBT) is an evidence-based psychosocial
treatment with efficacy in reducing self-harm behaviors in borderline
personality disorder (BPD). This study describes and evaluates a clinical
curriculum to teach DBT to psychiatry residents, developed at a large urban
university hospital. The curriculum objectives are to (1) have psychiatry
residents achieve basic understanding of DBT theory and clinical skill, (2)
increase residents' ability and confidence in treating self-harm behaviors (both
suicidal behavior and non-suicidal self-injury), and (3) enhance residents'
willingness to treat individuals with BPD.
METHODS: In addition to a 6-week didactic course on DBT offered to all residents
(n = 62), 25 elected to enroll in a year-long DBT clinical training curriculum
over the course of a 5-year period. The DBT clinical training consisted of 15 h
of additional didactics, ongoing conduct of individual therapy and group DBT
skills training, videotaping of individual therapy sessions, and weekly
supervision meetings utilizing videotape to provide feedback. Residents
participating in the clinical training program videotaped baseline and later
sessions, which were rated for DBT adherence. All 62 graduates of the program
were surveyed regarding the impact of the training on their practice of
psychiatry.
RESULTS: Upon graduation, a high percentage (87 % in the curriculum and 70 % in
the didactic course only) reported incorporating DBT into their psychiatry
practice, as well as willingness and confidence in treating BPD and self-harm
behaviors. Residents participating in the clinical training demonstrated
significant improvement in their ability to utilize DBT interventions,
particularly in structuring sessions, problem assessment, problem solving, and
using validation and dialectical strategies.
CONCLUSION: This DBT curriculum was effective in preparing
psychiatrists-in-training to incorporate evidence-based practices for effective
treatment of BPD and self-harm behaviors and can serve as a model for teaching
DBT during psychiatry residency training. Limitations include a small sample
size and lack of baseline survey measurement of attitudes for pre- and
post-curriculum comparison. Compliance and patience is needed when meeting patients with personality
disorder To encounter patients with personality disorders in health care
settings is often challenging. Most treatment studies published have included
only patients with borderline personality disorder. Of evaluated psychological
treatments in borderline personality disorder, dialectical behaviour therapy
(DBT) has the strongest research support, followed by mentalization based
therapy (MBT). Pharmacological treatment in personality disorders should focus
on time-limited crisis intervention and treatment of comorbidity. There are few
studies on inpatient care of persons with personality disorder. However, there
are some interesting projects on brief self-directed inpatient stays as crisis
intervention. There is a consensus to avoid long inpatient stays and coercive
measures as far as possible. Borderline Personality Disorder (BPD) is characterized by affective instability,
but self-injurious behavior appears to have an emotion-regulating effect. We
investigated whether pain-mediated affect regulation can be altered at the
neural level by residential Dialectical Behavior Therapy (DBT), providing
adaptive emotion regulation techniques. Likewise, we investigated whether pain
thresholds or the appraisal of pain change after psychotherapy. We investigated
28 patients with BPD undergoing DBT (self-referral), 15 patients with treatment
as usual and 23 healthy control subjects at two time points 12 weeks apart. We
conducted an fMRI experiment eliciting negative emotions with picture stimuli
and induced heat pain to investigate the role of pain in emotion regulation.
Additionally, we assessed heat and cold pain thresholds.At first measurement,
patients with BPD showed amygdala deactivation in response to painful
stimulation, as well as altered connectivity between left amygdala and dorsal
anterior cingulate cortex. These effects were reduced after DBT, as compared
with patients with treatment as usual. Pain thresholds did not differ between
the patient groups. We replicated the role of pain as a means of affect
regulation in BPD, indicated by increased amygdala coupling. For the first time,
we could demonstrate that pain-mediated affect regulation can be changed by DBT. |
What cellular process are okazaki fragments associated with? | Okazaki fragments are involved in DNA replication | Cytarabine is a potent anticancer drug that interferes with elongation of the
lagging strand at the replication fork during DNA synthesis. The effects of
cytarabine substitution on the structural and thermodynamic properties of a
model Okazaki fragment were investigated using UV hyperchromicity and 1H NMR
spectroscopy to determine how cytarabine alters the physicochemical properties
of Okazaki fragments that are intermediates during DNA replication. Two model
Okazaki fragments were prepared corresponding to a primary initiation site for
DNA replication in the SV40 viral genome. One model Okazaki fragment consisted
of five ribo- and seven deoxyribonucleotides on the hybrid strand, together with
its complementary (DNA) strand. The second model Okazaki fragment was identical
to the first with the exception of cytarabine substitution for deoxycytidine at
the third DNA nucleotide of the hybrid strand. Thermodynamic parameters for the
duplex to single strand transition for each model Okazaki fragment were
calculated from the concentration dependence of the T m at 260 nm. Cytarabine
significantly decreased the stability of this model Okazaki fragment, decreasing
the melting temperature from 46.8 to 42.4 degrees C at a concentration of 1.33 x
10(-5) M. The free energy for the duplex to single strand transition was 1.2
kcal/mol less favorable for the cytarabine-substituted Okazaki fragment relative
to the control at 37 degrees C. Analysis of the temperature dependence of the
imino1H resoces for the two duplexes demonstrated that cytarabine
specifically destabilized the DNA:DNA duplex portion of the model Okazaki
fragment. These results are consistent with inhibition of lagging strand DNA
synthesis by cytarabine substitution resulting from destabilization of the
DNA:DNA duplex portion of Okazaki fragments in vivo . DNA replication is one of the most important events in living cells, and it is
still a key problem how the DNA replication machinery works in its details. A
replication fork has to be a very dynamic apparatus since frequent DNA
polymerase switches from the initiating DNA polymerase alpha to the processive
elongating DNA polymerase delta occur at the leading strand (about 8 x 10(4)
fold on both strands in one replication round) as well as at the lagging strand
(about 2 x 10(7) fold on both strands in one replication round) in mammalian
cells. Lagging strand replication involves a very complex set of interacting
proteins that are able to frequently initiate, elongate and process Okazaki
fragments of 180 bp. Moreover, key proteins of this important process appear to
be controlled by S-phase check-point proteins. It became furthermore clear in
the last few years that DNA replication cannot be considered uncoupled from DNA
repair, another very important event for any living organism. The reconstitution
of nucleotide excision repair and base excision repair in vitro with purified
components clearly showed that the DNA synthesis machinery of both of these
macromolecular events are similar and do share many components of the lagging
strand DNA synthesis machinery. In this minireview we summarize our current
knowledge of the components involved in the execution and regulation of DNA
replication at the lagging strand of the replication fork. RNA primer removal from Okazaki fragments during lagging-strand replication and
the excision of damaged DNA bases requires the action of structure-specific
nucleases, such as the mammalian flap endonuclease 1 (FEN-1). This nuclease
contains two conserved motifs enriched with acidic amino acid residues that are
important for catalytic function. Similar motifs have been identified in
nucleases found in viruses, archebacteria, eubacteria, and in eukaryotes ranging
from yeast to humans. Unique among these proteins, the putative FEN-1 homologue
in Escherichia coli is contained within the N-terminal region of the DNA
polymerase I (PolN). To demonstrate that the cellular functions of FEN-1 reside
in PolN, we cloned and expressed the amino terminal domain (323 amino acid
residues) of PolI in a Saccharomyces cerevisiae strain lacking the FEN-1
homologue RAD27. Overexpression of PolN suppressed, to varying degrees,
phenotypes associated with a rad27 null strain. These include temperature
sensitivity, Okazaki fragment processing, a mutator phenotype, a G2/M cell cycle
arrest, minichromosome loss, and methyl methane sulfonate sensitivity. We
purified Rad27 and PolN proteins in order to determine whether differences in
their intrinsic nuclease activities or interaction with proliferating cell
nuclear antigen (PCNA) could explain the partial suppression of some phenotypes.
We found that the in vitro nuclease activities of Rad27 were more potent than
those of PolN and the activity of Rad27, but not PolN, was stimulated by PCNA.
We conclude that the N-terminal nuclease domain of E. coli polymerase I encodes
a functional homologue of FEN-1. Flap endonuclease 1 (FEN1) has been shown to remove 5' overhanging flap
intermediates during base excision repair and to process the 5' ends of Okazaki
fragments during lagging-strand DNA replication in vitro. To assess the in vivo
role of the mammalian enzyme in repair and replication, we used a gene-targeting
approach to generate mice lacking a functional Fen1 gene. Heterozygote animals
appear normal, whereas complete depletion of FEN1 causes early embryonic
lethality. Fen1(-/-) blastocysts fail to form inner cell mass during cellular
outgrowth, and a complete inactivation of DNA synthesis in giant cells of
blastocyst outgrowth was observed. Exposure of Fen1(-/-) blastocysts to gamma
radiation caused extensive apoptosis, implying an essential role for FEN1 in the
repair of radiation-induced DNA damage in vivo. Our data thus provide in vivo
evidence for an essential function of FEN1 in DNA repair, as well as in DNA
replication. High-fidelity DNA replication depends on both accurate incorporation of
nucleotides in the newly synthesized strand and the maturation of Okazaki
fragments. In eukaryotic cells, the latter is accomplished by a series of
coordinated actions of a set of structure-specific nucleases, which, with the
assistance of accessory proteins, recognize branched RNA/DNA configurations. In
the current model of Okazaki fragment maturation, displacement of a
27-nucleotide or longer flap is envisioned to attract replication protein A
(RPA), which inhibits flap endonuclease-1 (FEN-1) but stimulates Dna2 nuclease
for cleavage. Dna2 cleavage generates a short flap of 5-7 nucleotides, which
resists binding by RPA and further cleavage by Dna2. FEN-1 then removes the
remaining flap to produce a suitable substrate for ligation. However, FEN-1 is
not efficient in cleaving the short flap, and we therefore set out to identify
cellular factors that might regulate FEN-1 activity. Through
co-immunoprecipitation experiments, we have isolated heterogeneous nuclear
ribonucleoprotein A1 (hnRNP A1), which forms a direct complex with FEN-1 and
stimulates its enzymatic activities. The stimulation by hnRNP A1 is most
dramatic using DNA substrates with short flaps. With longer flap substrates the
hnRNP A1 effect is more modest and is suppressed by the addition of RPA. A model
is provided to explain the possible in vivo role of this interaction and
activity in Okazaki fragment maturation. An initiator RNA (iRNA) is required to prime cellular DNA synthesis. The
structure of double-stranded DNA allows the synthesis of one strand to be
continuous but the other must be generated discontinuously. Frequent priming of
the discontinuous strand results in the formation of many small segments,
designated Okazaki fragments. These short pieces need to be processed and joined
to form an intact DNA strand. Our knowledge of the mechanism of iRNA removal is
still evolving. Early reconstituted systems suggesting that the removal of iRNA
requires sequential action of RNase H and flap endonuclease 1 (FEN1) led to the
RNase H/FEN1 model. However, genetic analyses implied that Dna2p, an essential
helicase/nuclease, is required. Subsequent biochemical studies suggested
sequential action of RPA, Dna2p, and FEN1 for iRNA removal, leading to the
second model, the Dna2p/RPA/FEN1 model. Studies of strand-displacement synthesis
by polymerase delta indicated that in a reconstituted system, FEN1 could act as
soon as short flaps are created, giving rise to a third model, the FEN1-only
model. Each of the three pathways is supported by different genetic and
biochemical results. Properties of the major protein components in this process
will be discussed, and the validity of each model as a true representation of
Okazaki fragment processing will be critically evaluated in this review. DNA replication is a primary mechanism for maintaining genome integrity, but it
serves this purpose best by cooperating with other proteins involved in DNA
repair and recombination. Unlike leading strand synthesis, lagging strand
synthesis has a greater risk of faulty replication for several reasons: First, a
significant part of DNA is synthesized by polymerase alpha, which lacks a
proofreading function. Second, a great number of Okazaki fragments are
synthesized, processed and ligated per cell division. Third, the principal
mechanism of Okazaki fragment processing is via generation of flaps, which have
the potential to form a variety of structures in their sequence context.
Finally, many proteins for the lagging strand interact with factors involved in
repair and recombination. Thus, lagging strand DNA synthesis could be the best
example of a converging place of both replication and repair proteins. To
achieve the risky task with extraordinary fidelity, Okazaki fragment processing
may depend on multiple layers of redundant, but connected pathways. An essential
Dna2 endonuclease/helicase plays a pivotal role in processing common structural
intermediates that occur during diverse DNA metabolisms (e.g. lagging strand
synthesis and telomere maintece). Many roles of Dna2 suggest that the
preemptive removal of long or structured flaps ultimately contributes to genome
maintece in eukaryotes. In this review, we describe the function of Dna2 in
Okazaki fragment processing, and discuss its role in the maintece of genome
integrity with an emphasis on its functional interactions with other factors
required for genome maintece. Completion of lagging strand DNA synthesis requires processing of up to 50
million Okazaki fragments per cell cycle in mammalian cells. Even in yeast, the
Okazaki fragment maturation happens approximately a million times during a
single round of DNA replication. Therefore, efficient processing of Okazaki
fragments is vital for DNA replication and cell proliferation. During this
process, primase-synthesized RNA/DNA primers are removed, and Okazaki fragments
are joined into an intact lagging strand DNA. The processing of RNA/DNA primers
requires a group of structure-specific nucleases typified by flap endonuclease 1
(FEN1). Here, we summarize the distinct roles of these nucleases in different
pathways for removal of RNA/DNA primers. Recent findings reveal that Okazaki
fragment maturation is highly coordinated. The dynamic interactions of
polymerase δ, FEN1 and DNA ligase I with proliferating cell nuclear antigen
allow these enzymes to act sequentially during Okazaki fragment maturation. Such
protein-protein interactions may be regulated by post-translational
modifications. We also discuss studies using mutant mouse models that suggest
two distinct cancer etiological mechanisms arising from defects in different
steps of Okazaki fragment maturation. Mutations that affect the efficiency of
RNA primer removal may result in accumulation of unligated nicks and DNA
double-strand breaks. These DNA strand breaks can cause varying forms of
chromosome aberrations, contributing to development of cancer that associates
with aneuploidy and gross chromosomal rearrangement. On the other hand,
mutations that impair editing out of polymerase α incorporation errors result in
cancer displaying a strong mutator phenotype. During DNA replication, repetitive synthesis of discrete Okazaki fragments
requires mechanisms that guarantee DNA polymerase, clamp, and primase proteins
are present for every cycle. In Escherichia coli, this process proceeds through
transfer of the lagging-strand polymerase from the β sliding clamp left at a
completed Okazaki fragment to a clamp assembled on a new RNA primer. These
lagging-strand clamps are thought to be bound by the replisome from solution and
loaded a new for every fragment. Here, we discuss a surprising, alternative
lagging-strand synthesis mechanism: efficient replication in the absence of any
clamps other than those assembled with the replisome. Using single-molecule
experiments, we show that replication complexes pre-assembled on DNA support
synthesis of multiple Okazaki fragments in the absence of excess β clamps. The
processivity of these replisomes, but not the number of synthesized Okazaki
fragments, is dependent on the frequency of RNA-primer synthesis. These results
broaden our understanding of lagging-strand synthesis and emphasize the
stability of the replisome to continue synthesis without new clamps. Fifty per cent of the genome is discontinuously replicated on the lagging strand
as Okazaki fragments. Eukaryotic Okazaki fragments remain poorly characterized
and, because nucleosomes are rapidly deposited on nascent DNA, Okazaki fragment
processing and nucleosome assembly potentially affect one another. Here we show
that ligation-competent Okazaki fragments in Saccharomyces cerevisiae are sized
according to the nucleosome repeat. Using deep sequencing, we demonstrate that
ligation junctions preferentially occur near nucleosome midpoints rather than in
internucleosomal linker regions. Disrupting chromatin assembly or lagging-strand
polymerase processivity affects both the size and the distribution of Okazaki
fragments, suggesting a role for nascent chromatin, assembled immediately after
the passage of the replication fork, in the termination of Okazaki fragment
synthesis. Our studies represent the first high-resolution analysis--to our
knowledge--of eukaryotic Okazaki fragments in vivo, and reveal the
interconnection between lagging-strand synthesis and chromatin assembly. Genome-wide Okazaki fragment distribution can differentiate the discontinuous
from the semi-discontinuous DNA replication model. Here, we investigated the
genome-wide Okazaki fragment distribution in Saccharomyces cerevisiae S288C. We
improved the method based upon lambda exonuclease digestion to purify Okazaki
fragments from S288C yeast cells, followed by Illumina sequencing. The
distribution of Okazaki fragments around confirmed replication origins,
including two highly efficient replication origins, supported the discontinuous
DNA replication model. In S. cerevisiae mitochondria, Okazaki fragments were
overrepresented in the transcribed regions, indicating the interplay between
transcription and DNA replication. Lagging strand DNA replication requires the concerted actions of DNA polymerase
δ, Fen1 and DNA ligase I for the removal of the RNA/DNA primers before ligation
of Okazaki fragments. To better understand this process in human cells, we have
reconstituted Okazaki fragment processing by the short flap pathway in vitro
with purified human proteins and oligonucleotide substrates. We systematically
characterized the key events in Okazaki fragment processing: the strand
displacement, Pol δ/Fen1 combined reactions for removal of the RNA/DNA primer,
and the complete reaction with DNA ligase I. Two forms of human DNA polymerase δ
were studied: Pol δ4 and Pol δ3, which represent the heterotetramer and the
heterotrimer lacking the p12 subunit, respectively. Pol δ3 exhibits very limited
strand displacement activity in contrast to Pol δ4, and stalls on encounter with
a 5'-blocking oligonucleotide. Pol δ4 and Pol δ3 exhibit different
characteristics in the Pol δ/Fen1 reactions. While Pol δ3 produces predomitly
1 and 2 nt cleavage products irrespective of Fen1 concentrations, Pol δ4
produces cleavage fragments of 1-10 nts at low Fen1 concentrations. Pol δ3 and
Pol δ4 exhibit comparable formation of ligated products in the complete system.
While both are capable of Okazaki fragment processing in vitro, Pol δ3 exhibits
ideal characteristics for a role in Okazaki fragment processing. Pol δ3 readily
idles and in combination with Fen1 produces primarily 1 nt cleavage products, so
that nick translation predominates in the removal of the blocking strand,
avoiding the production of longer flaps that require additional processing.
These studies represent the first analysis of the two forms of human Pol δ in
Okazaki fragment processing. The findings provide evidence for the novel concept
that Pol δ3 has a role in lagging strand synthesis, and that both forms of Pol δ
may participate in DNA replication in higher eukaryotic cells. Eukaryotic chromosomal DNA is faithfully replicated in a complex series of
cell-cycle-regulated events that are incompletely understood. Here we report the
reconstitution of DNA replication free in solution with purified proteins from
the budding yeast Saccharomyces cerevisiae. The system recapitulates regulated
bidirectional origin activation; synthesis of leading and lagging strands by the
three replicative DNA polymerases Pol α, Pol δ, and Pol ε; and canonical
maturation of Okazaki fragments into continuous daughter strands. We uncover a
dual regulatory role for chromatin during DNA replication: promoting origin
dependence and determining Okazaki fragment length by restricting Pol δ
progression. This system thus provides a functional platform for the detailed
mechanistic analysis of eukaryotic chromosome replication. At DNA replication forks, the overall growth of the antiparallel two daughter
DNA chains appears to occur 5'-to-3' direction in the leading-strand and
3'-to-5' direction in the lagging-strand using enzyme system only able to
elongate 5'-to-3' direction, and I describe in this review how we have analyzed
and proved the lagging strand multistep synthesis reactions, called
Discontinuous Replication Mechanism, which involve short RNA primer synthesis,
primer-dependent short DNA chains (Okazaki fragments) synthesis, primer removal
from the Okazaki fragments and gap filling between Okazaki fragments by RNase H
and DNA polymerase I, and long lagging strand formation by joining between
Okazaki fragments with DNA ligase. |
Does wheat belongs to the genus Avena, yes or no? | oat seedlings (Avena sativa) | Gravitropism of oat (Avena sativa L.) and wheat (Triticum aestivum L.)
coleoptiles was investigated in relation to the displacement angle or to the
initially set stimulation angle (SA). We measured curvature rates at the early
phase of curvature, before it was affected by the drop in SA resulting from the
curvature response itself. The plot of the rates against the sines of initial
SAs revealed similar curves for oats and wheat, which approached saturation as
the sine increased to unity. The two species and previously analyzed rice [Iino
et al. (1996) Plant Cell Environ. 19: 1160] appeared to have similar
gravisensitivities. Initial SAs below and over 90 degrees yielded comparable
rates when the sine values were the same, indicating that the extent of
gravitropism is determined by the gravity component perpendicular to the organ's
long axis. Long-term curvature kinetics at different SAs indicated that the net
curvature rate dropped sharply before the tip reached the vertical position and
then the tip approached the vertical slowly, with clear oscillatory movements in
the case of wheat. During this late curvature phase, the coleoptile straightened
gradually, although none of its parts had yet reached the vertical. When rotated
on horizontal clinostats or displaced upwards to reduce SA in the late curvature
phase, coleoptiles bent in the opposite direction. These results demonstrated
that autotropism counteracts gravitropism to straighten coleoptiles. Fluorescent in situ hybridization (FISH) with multiple probes was used to
analyze mitotic and meiotic chromosome spreads of Avena sativa cv 'Sun II'
monosomic lines, and of A. byzantina cv 'Kanota' monosomic lines from
spontaneous haploids. The probes used were A. strigosa pAs120a (a repetitive
sequence abundant in A-genome chromatin), A. murphyi pAm1 (a repetitive sequence
abundant in C-genome chromatin), A. strigosa pITS (internal transcribed spacer
of rDNA) and the wheat rDNA probes pTa71 (nucleolus organizer region or NOR) and
pTa794 (5S). Simultaneous and sequential FISH employing pairs of these probes
allowed the identification and genome assignation of all chromosomes. FISH
mapping using mitotic and meiotic metaphases facilitated the genomic and
chromosomal identification of the monosome in each line. Of the 17 'Sun II'
lines analyzed, 13 distinct monosomic lines were found, corresponding to four
monosomes of the A-genome, five of the C-genome and four of the D-genome. In
addition, 12 distinct monosomic lines were detected among the 20 'Kanota' lines
examined, corresponding to six monosomes of the A-genome, three of the C-genome
and three of the D-genome. The results show that 19 chromosomes out of 21 of the
complement are represented by monosomes between the two genetic backgrounds. The
identity of the remaining chromosomes can be deduced either from one
intergenomic translocation detected on both 'Sun II' and 'Kanota' lines, or from
the single reciprocal, intergenomic translocation detected among the 'Sun II'
lines. These results permit a new system to be proposed for numbering the 21
chromosome pairs of the hexaploid oat complement. Accordingly, the A-genome
contains chromosomes 8A, 11A, 13A, 15A, 16A, 17A and 19A; the C-genome contains
chromosomes 1C, 2C, 3C, 4C, 5C, 6C and 7C; and the D-genome consists of
chromosomes 9D, 10D, 12D, 14D, 18D, 20D and 21D. Moreover, the FISH patterns of
16 chromosomes in 'Sun II' and 15 in 'Kanota' suggest that these chromosomes
could be involved in intergenomic translocations. By comparing the identities of
individually translocated chromosomes in the two hexaploid species with those of
other hexaploids, we detected different types of intergenomic translocations. A wild green-oats extract (Neuravena®) containing a range of potentially
bioactive components, including flavonoids and triterpene saponins, has
previously been shown to enhance animal stress responses and memory, and improve
cognitive performance in humans at a dose of 1600 mg. Methods This double-blind,
placebo-controlled, counterbalanced cross-over study assessed the effects of
single doses of the green-oat extract (GOE) across a broad range of cognitive
domains in healthy adults aged 40-65 years who self-reported that they felt that
their memory had declined with age. Participants attended on six occasions,
receiving a single dose of either placebo, 800, or 1600 mg GOE on each occasion,
with the counterbalanced order of treatments repeated twice for each
participant. Cognitive function was assessed with a range of computerized tasks
measuring attention, spatial/working/episodic memory, and executive function
pre-dose and at 1, 2.5, 4, and 6 hours post-dose. Results The results showed
that 800mg GOE increased the speed of performance across post-dose assessments
on a global measure including data from all of the timed tasks. It also improved
performance of a delayed word recall task in terms of errors and an executive
function task (Peg and Ball) in terms of decreased thinking time and overall
completion time. Working memory span (Corsi blocks) was also increased, but only
on the second occasion that this dose was taken. Discussion These results
confirm the acute cognitive effects of GOE seen in previous research, and
suggest that the optimal dose lies at or below 800 mg. Five compounds (syringic acid, tricin, acacetin, syringoside, and diosmetin)
were isolated from the aerial parts of wild oats (Avena fatua L.) using
chromatography columns of silica gel and Sephadex LH-20. Their chemical
structures were identified by means of electrospray ionization and
high-resolution mass spectrometry as well as (1)H and (13)C nuclear magnetic
resoce spectroscopic analyses. Bioassays showed that the five compounds had
significant allelopathic effects on the germination and seedling growth of wheat
(Triticum aestivum L.). The five compounds inhibited fresh wheat as well as the
shoot and root growth of wheat by approximately 50% at a concentration of 100
mg/kg, except for tricin and syringoside for shoot growth. The results of
activity testing indicated that the aerial parts of wild oats had strong
allelopathic potential and could cause different degrees of influence on
surrounding plants. Moreover, these compounds could be key allelochemicals in
wild-oat-infested wheat fields and interfere with wheat growth via allelopathy. Wide hybridization is a one of the important techniques in plant breeding. Oat
(Avena sativa L.) and pearl millet (Pennisetum glaucum L.) belong to different
subfamilies of Poaceae. In generally, such distant relative species show
uniparental chromosome elimination after successful fertilization. However, all
seven pearl millet chromosomes are retained beside the genome of oat during
embryogenesis. Hybrid seedlings develop, but show necrosis after light
irradiation. Here, a detailed protocol for wide hybridization between oat and
pearl millet is described. At present two-dimensional polyacrylamide gel electrophoresis (2-DE) is the most
widely used proteomic tool, which enables simultaneous separation of even
thousands of proteins with a high degree of resolution. The quality of 2-DE
separation depends on the type of biological material used as a protein source.
The presence of interfering compounds (e.g., phenols, as it is the fact in plant
material including oat seeds) impedes 2-DE run. With the use of this technique
it is possible to analyze the complex protein mixtures, characteristic protein
fractions, as well as individual proteins.The purpose of this chapter is to
describe the 2-DE technique (the separate stages of the first and the second
dimension) for determining the oat protein composition (oat seed proteome),
separation and preliminary identification of oat prolamin fractions.
Electrophoretically separated proteins are identified on the basis of pI markers
(identifying the location of both ends of an IPG strip) and on 2D SDS-PAGE
standards. The gel images of oat proteins are analyzed with the help of
ImageMaster 2D Platinum 6.0 program (Amersham Bioscience, part of GE Healthcare,
Uppsala, Sweden). It allows finding unique spot identifiers for the occurrence
of oat prolamin fractions in oat total proteins. The characteristic spots of
similar shape and intensity (anchoring spots) and characteristic groups of spots
can be searched for the purpose of identification. Plant growth and yield is adversely affected by soil salinity. Salt tolerant
plant growth-promoting rhizobacteria (PGPR) strain IG 3 was isolated from
rhizosphere of wheat plants. The isolate IG 3 was able to grow in presence of
NaCl ranging from 0 to 20% in Luria Bertani medium. The present study was
planned to evaluate the role of inoculation of PGPR strain IG 3 and its efficacy
in augmenting salt tolerance in oat (Avena sativa) under NaCl stress (100mM).
The physiological parameter such as shoot length, root length, shoot dry weight,
root dry weight and relative water content (RWC) were remarkably higher in IG 3
inoculated plants in comparison to un-inoculated plants under NaCl stress.
Similarly, the biochemical parameters such as proline content, electrolyte
leakage and malondialdehyde (MDA) content and activities of antioxidant enzymes
were analyzed and found to be notably lesser in IG 3 inoculated oat plants in
contrast to un-inoculated plants under salt stress. Inoculation of IG 3 strain
to oat seedlings under salt stress positively modulated the expression profile
of rbcL and WRKY1 genes. Root colonization of root surface and interior was
demonstrated using scanning electron microscopy and tetrazolium staining,
respectively. Due these outcomes, it could be implicated that inoculation of
PGPR strain IG 3 enhanced plant growth under salt stress condition. This study
demonstrates that PGPR play an imperative function in stimulating salt tolerance
in plants and can be used as biofertilizer to enhance growth of crops in saline
areas. |
Clue cells are characteristics to which causative bacteria of vaginitis? | Clue cells are characteristic to Gardnerella vaginalis vaginitis (bacterial vaginosis). Depopulation of lactobacilli from the normal vaginal flora and overgrowth of Gardnerella vaginalis and other anaerobic species are the presumed etiology. The diagnosis is confirmed when at least three of the following four findings are present (Amsel's criteria): 1) thin, homogenous discharge, 2) pH greater than 4.5, 3) positive amine test, and 4) presence of clue cell. | The purpose of this study was to determine the isolation rates of Mycoplasma
hominis and Ureaplasma urealyticum from three populations of women and also to
relate the presence of these microorganisms with some indicators of nonspecific
vaginitis. Three hundred vaginal swabs were taken from delivery, pregt and
control (not pregt) women. Cultures were done in E broth supplemented with
arginine or urea. M. hominis was isolated in 5% at delivery, 12% from pregt
and 5% from control women and U. urealyticum was isolated in 21%, 31% and 28%
respectively. There was statistical difference in the isolation rate of M.
hominis in pregt women respect to the other groups. Both microorganisms were
more frequently isolated in women with acid vaginal pH, amine-like odor in KOH
test, clue cells and leucorrhea. M. hominis was isolated in 17% and U.
urealyticum in 52% from women with nonspecific vaginitis. M. hominis was
isolated in 2% and U. urealyticum in 13% from women without nonspecific
vaginitis. Although the presence of clue cells and amine-like odor in KOH test
have relationship with Gardnerella vaginalis, these tests could also suggest the
presence of these mycoplasmas. Bacterial vaginosis is the most common cause of vaginitis, affecting over 3
million women in the United States annually. Depopulation of lactobacilli from
the normal vaginal flora and overgrowth of Gardnerella vaginalis and other
anaerobic species are the presumed etiology. To date, no scientific evidence
shows that bacterial vaginosis is a sexually transmitted disease. Malodorous
vaginal discharge is the most common symptom. Differential diagnoses include
trichomoniasis, moniliasis, and allergic or chemical dermatitis. The diagnosis
is confirmed when at least three of the following four findings are present
(Amsel's criteria): 1) thin, homogenous discharge, 2) pH greater than 4.5, 3)
positive amine test, and 4) presence of clue cells. The sensitivity and positive
predictive value are both 90%. Vaginal Gram stain is also reliable and allows
for permanent record. Cultures are nonspecific because G. vaginalis resides in
normal vaginal flora as well. Papanicolaou smears are not particularly
sensitive, but their positive predictive value is very high. The Centers for
Disease Control and Prevention recommend three treatment regimens in nonpregt
patients: oral metronidazole (500 mg twice daily for 7 days), intravaginal 2%
clindamycin cream (one applicatorful at bedtime for 7 days), or intravaginal
metronidazole gel (one to two applicatorfuls per day for 5 days). Alternative
regimens include a single 2-g oral dose of metronidazole or a 7-day course of
oral clindamycin, 300 mg twice daily. The association between bacterial
vaginosis and adverse pregcy outcomes has satisfied many criteria for a
causal inference. Treatment of bacterial vaginosis in women with previous
history of preterm labor results in fewer preterm deliveries than in untreated
women from the same population. OBJECTIVE: To define an entity of abnormal vaginal flora: aerobic vaginitis.
DESIGN: Observational study.
SETTING: University Hospital Gasthuisberg, Leuven, Belgium.
SAMPLE: 631 women attending for routine prenatal care or attending vaginitis
clinic.
METHODS: Samples were taken for fresh wet mount microscopy of vaginal fluid,
vaginal cultures and measurement of lactate, succinate and cytokine levels in
vaginal fluid. Smears deficient in lactobacilli and positive for clue cells were
considered to indicate a diagnosis of bacterial vaginosis. Aerobic vaginitis was
diagnosed if smears were deficient in lactobacilli, positive for cocci or coarse
bacilli, positive for parabasal epithelial cells, and/or positive for vaginal
leucocytes (plus their granular aspect).
RESULTS: Genital complaints include red inflammation, yellow discharge, vaginal
dyspareunia. Group B streptococci, escherichia coli, staphylococcus aureus and
trichomonas vaginalis are frequently cultured. Vaginal lactate concentration is
severely depressed in women with aerobic vaginitis, as in bacterial vaginosis,
but vaginal succinate is not produced. Also in contrast to bacterial vaginosis,
aerobic vaginitis produces a host immune response that leads to high production
of interleukin-6, interleukin-1-beta and leukaemia inhibitory factor in the
vaginal fluid.
CONCLUSION: Aerobic vaginitis is associated with aerobic micro-organisms, mainly
group B streptococci and E. coli. Its characteristics are different from those
of bacterial vaginosis and elicit an important host response. The most severe
form of aerobic vaginitis equals desquamative inflammatory vaginitis. In theory,
aerobic vaginitis may be a better candidate than bacterial vaginosis as the
cause of pregcy complications, such as ascending chorioamnionitis, preterm
rupture of the membranes and preterm delivery. OBJECTIVE: The study aimed to determine the diagnostic usefulness of the genital
Gram stain in an emergency department (ED) population.
METHODS: A linked-query of an urban, tertiary-care, university- affiliated
hospital laboratory database was conducted for all completed Chlamydia
trachomatis and Neisseria gonorrhoeae DNA probes, Trichomonas vaginalis wet
preps, and genital Gram stains performed on ED patient visits between January
and December 2004. Positive criteria for a Gram stain included greater than 10
white blood cells per high-power field, gram-negative
intracellular/extracellular diplococci (suggesting N gonorrhoeae), clue cells
(suggesting T vaginalis), or direct visualization of T vaginalis organisms. DNA
probes were used as the gold standard definition for N gonorrhoeae and C
trachomatis infection.
RESULTS: Of 1511 initially eligible ED visits, 941 were analyzed (genital Gram
stain and DNA probe results both present), with a prevalence of either C
trachomatis or N gonorrhoeae of 11.4%. A positive genital Gram stain was 75.7%
sensitive and 43.3% specific in diagnosing either C trachomatis and/or N
gonorrhoeae infection, and 80.4% sensitive and 32.2% specific when the positive
cutoff was lowered to more than 5 white blood cells/high-power field. No Gram
stains were positive for T vaginalis (with 47 positive wet mounts), and clue
cells were noted on 117 Gram stains (11.6%).
CONCLUSION: Gram stains in isolation lack sufficient diagnostic ability to
detect either C trachomatis or N gonorrhoeae infection in the ED. OBJECTIVE: To report the prevalence of Gardnerella, Trichomonas and Candida in
the cervical smears of 9 immigrant groups participating in the Dutch national
cervical screening program.
STUDY DESIGN: Cervical smears were taken from 58,904 immigrant participants and
498,405 Dutch participants. As part of the routine screening process, all smears
were screened for the overgrowth of Gardnerella (i.e. smears with an abundance
of clue cells) and for the presence of Trichomonas and Candida. The smears were
screened by 6 laboratories, all of which use the Dutch KOPAC coding system. The
odds ratio and confidence interval were calculated for the 9 immigrant groups
and compared to Dutch participants.
RESULTS: Immigrants from Suriname, Turkey and the Dutch Antilles have a 2-5
times higher prevalence of Gardnerella and Trichomonas when compared to native
Dutch women. Interestingly, the prevalence of Trichomonas in cervical smears of
Moroccan immigrants is twice as high, yet the prevalence of Gardnerella is 3
times lower than in native Dutch women.
CONCLUSIONS: Immigrants with a high prevalence of Gardnerella also have a high
prevalence of Trichomonas. In the context of the increased risk of squamous
abnormalities in smears with Gardnerella, such slides should be screened with
extra care. |
What is included in the fourth generation HIV test? | Fourth generation assays detect simultaneously antibodies for HIV and the p24 antigen. It identifies HIV infection earlier than previous generation tests. | BACKGROUND: The routine HIV screening essentially depends on the detection of
HIV specific antibodies. However, HIV p24 antigen can be detected in individuals
with recent HIV infection about 2-18 days prior to seroconversion. New fourth
generation HIV screening assays combine the detection of anti-HIV antibodies
with the simultaneous detection of HIV p24 antigen. This may result in a
reduction of the diagnostic window after primary infection.
OBJECTIVES: The performance of two novel fourth generation assays in routine
diagnostic was evaluated.
STUDY DESIGN: We compared two third generation, two fourth generation and one
antigen HIV assays in a case with acute primary HIV infection.
RESULTS: In our case, the HIV infection was detected 11 days earlier with the
fourth generation assays compared to third generation assays. Interestingly,
after the initial reactive results the fourth generation assays became negative
resulting in a second diagnostic window. During this second diagnostic window
neither third nor fourth generation HIV assays were reactive. This second
diagnostic window was caused by the absence of HIV specific antibodies and the
decline of HIV p24 antigen concentrations below the detection limits of the
fourth generation assays.
CONCLUSIONS: Fourth generation assays markedly improve the diagnosis of recent
HIV infections but the possibility of a second diagnostic window must be
considered. Universal human immunodeficiency virus (HIV) screening was recommended in 2012,
and major improvements in HIV testing have occurred in the past decade, but
identification of HIV infected individuals remains inadequate in the United
States. We report the case of a seronegative HIV-infected man who despite
clinical and laboratory findings of acquired immunodeficiency
syndrome,repeatedly tested nonreactive to third-generation HIV enzyme
immunoassays (EIAs) and Western blot testing. Serologic diagnosis in this case
required fourth-generation EIA testing due to the seronegativity of standard
testing. The fourth-generation HIV EIA was positive presumably because it
detects p24 HIV antigen as well as antibodies, unlike rapid HIV tests and
third-generation HIV EIAs.This case highlights not only the importance of
frontline providers to understand the different testing methodologies for HIV
screening and their limitations but the importance of clinical suspicion as
well. A concern during the early AIDS epidemic was the lack of a test to identify
individuals who carried the virus. The first HIV antibody test, developed in
1985, was designed to screen blood products, not to diagnose AIDS. The
first-generation assays detected IgG antibody and became positive 6 to 12 weeks
postinfection. False-positive results occurred; thus, a two-test algorithm was
developed using a Western blot or immunofluorescence test as a confirmatory
procedure. The second-generation HIV test added recombit antigens, and the
third-generation HIV tests included IgM detection, reducing the test-negative
window to approximately 3 weeks postinfection. Fourth- and fifth-generation HIV
assays added p24 antigen detection to the screening assay, reducing the
test-negative window to 11 to 14 days. A new algorithm addressed the
fourth-generation assay's ability to detect both antibody and antigen and yet
not differentiate between them. The fifth-generation HIV assay provides separate
antigen and antibody results and will require yet another algorithm. HIV
infection may now be detected approximately 2 weeks postexposure, with a reduced
number of false-positive results. OBJECTIVES: Detection of acute HIV infection is vital in preventing onward
transmission. HIV point-of-care testing (POCT) has improved uptake of HIV
testing but has been limited to third-generation assays, which only detect
chronic HIV infection. Previous evaluation of the fourth-generation Alere
Determine HIV-1/2 Ag/Ab Combo POCT showed only 50% sensitivity for HIV core
protein p24 (p24 antigen) detection, which is suboptimal for diagnosis of acute
HIV infection with limited advantage over third-generation POCT. We aimed to
assess the sensitivity of the new Alere HIV Combo POCT to detect acute HIV
infection.
METHODS: Stored samples in samples already identified as p24-positive using
standard-of-care fourth-generation assays were randomly selected alongside
groups of antibody-positive samples and HIV-negative samples. Each sample was
tested using the new Alere POCT according to manufacturer's instructions.
Sensitivity and specificity were then calculated.
RESULTS: The Alere HIV Combo POCT test demonstrated 88% sensitivity 95% CI (78%
to 98%) and 100% specificity 95% CI (99.7% to 100%) for detection of p24
antigen.
CONCLUSIONS: This new POCT shows improved sensitivity for detection of p24
antigen and may be of value for clinical use in detecting acute HIV infection.
Further evaluation of its use in a clinical setting is still required. BACKGROUND: Despite the high specificity of fourth-generation enzyme
immunoassays (4th-gen-EIA) for screening during HIV diagnosis, their positive
predictive value is low in populations with low HIV prevalence. Thus, screening
should be optimized to reduce false positive results.
OBJECTIVES: The influence of sample cutoff (S/CO) values by a 4th-gen-EIA with
the false positive rate during the routine HIV diagnosis in a low HIV prevalence
population was evaluated.
STUDY DESIGN: A total of 30,201 sera were tested for HIV diagnosis using Abbott
Architect® HIV-Ag/Ab-Combo 4th-gen-EIA at a hospital in Spain during 17 months.
Architect S/CO values were recorded, comparing the HIV-1 positive results
following Architect interpretation (S/CO≥1) with the final HIV-1 diagnosis by
confirmatory tests (line immunoassay, LIA and/or nucleic acid test, NAT). ROC
curve was also performed.
RESULTS: Among the 30,201 HIV performed tests, 256 (0.85%) were positive
according to Architect interpretation (S/CO≥1) but only 229 (0.76%) were
definitively HIV-1 positive after LIA and/or NAT. Thus, 27 (10.5%) of 256
samples with S/CO≥1 by Architect were false positive diagnose. The false
positive rate decreased when the S/CO ratio increased. All 19 samples with S/CO
≤10 were false positives and all 220 with S/CO>50 true HIV-positives. The
optimal S/CO cutoff value provided by ROC curves was 32.7. No false negative
results were found.
CONCLUSIONS: We show that very low S/CO values during HIV-1 screening using
Architect can result HIV negative after confirmation by LIA and NAT. The false
positive rate is reduced when S/CO increases. BACKGROUND: Early and accurate detection of HIV is crucial when using
pre-exposure prophylaxis (PrEP) for HIV prevention to avoid PrEP initiation in
acutely infected individuals and to minimize the risk of drug resistance in
individuals with breakthrough infection.
OBJECTIVE: To determine if fourth-generation antigen/antibody (Ag/Ab) rapid
diagnostic tests (RDT) would have detected HIV infection earlier than the
third-generation RDT used in MTN-003 (VOICE).
STUDY DESIGN: 5029 VOICE participants were evaluated with third-generation Alere
Determine™ HIV-1/2, OraQuick ADVANCE® Rapid HIV-1/2, Uni-Gold™ Recombigen®
HIV-1/2 and Bio-Rad GS HIV-1/2+O EIA; and fourth-generation Alere Determine™
HIV-1/2 Ag/Ab Combo, Conformité Européene (CE)-Marked Alere™ HIV Combo and
Bio-Rad HIV Combo Ag/Ab EIA. Multispot®, GS HIV-1 Western Blot (WB) and Geenius™
(Bio-Rad) were also evaluated.
RESULTS: Of 57 antibody-negative pre-seroconversion plasma samples with HIV RNA
>20 copies/mL identified, 16 (28%) were reactive by CE-Marked Alere™ HIV Combo
(1 Ab; 9 Ag; 6 Ag/Ab reactive) and 4 (7%) by Alere Determine™ HIV-1/2 Ag/Ab
Combo (2 Ab; 2 Ag; 0 Ag/Ab reactive) (p=0.0005). Multispot® confirmed only 1 of
16 acute infections while WB and Geenius™ confirmed none. GS HIV Combo Ag/Ab EIA
identified 27 of 57 (47%) pre-seroconversion RNA-positive samples.
CONCLUSION: In VOICE, 28% of infections missed by current third-generation RDT
would have been identified with the use of CE-Marked Alere™ HIV Combo. Geenius™,
Multispot® and WB were all insensitive (<10%) in confirming infections detected
by fourth-generation assays. An improved diagnostic algorithm that includes a
fourth-generation RDT with HIV RNA testing will be essential for efficiently
identifying seroconverters on PrEP. BACKGROUND: Fourth generation assays detect simultaneously antibodies for HIV
and the p24 antigen, identifying HIV infection earlier than previous generation
tests. Previous studies have shown that the Alere Determine HIV-1/2 Combo has
lower than anticipated performance in detecting antibodies for HIV and the p24
antigen. Furthermore, there are currently very few studies evaluating the
performance of Standard Diagnostics BIOLINE HIV Ag/Ab Combo.
OBJECTIVE: To evaluate the performance of the Alere Determine HIV-1/2 Combo and
the Standard Diagnostics BIOLINE HIV Ag/Ab Combo in a panel of frozen serum
samples.
STUDY DESIGN: The testing panel included 133 previously frozen serum specimens
from the UCLA Clinical Microbiology & Immunoserology laboratory. Reference
testing included testing for HIV antibodies by a 3rd generation enzyme
immunoassay followed by HIV RNA detection. Antibody negative and RNA positive
sera were also tested by a laboratory 4th generation HIV Ab/Ag enzyme
immunoassay.
RESULTS: Reference testing yielded 97 positives for HIV infection and 36
negative samples. Sensitivity of the Alere test was 95% (88-98%), while the SD
Bioline sensitivity was 91% (83-96%). Both assays showed 100% (90-100%)
specificity. No indeterminate or invalid results were recorded. Among 13 samples
with acute infection (HIV RNA positive, HIV antibody negative), 12 were found
positive by the first assay and 8 by the second. The antigen component of the
Alere assay detected 10 acute samples, while the SD Bioline assay detected only
one.
CONCLUSIONS: Both rapid assays showed very good overall performance in detecting
HIV infection in frozen serum samples, but further improvements are required to
improve the performance in acute infection. INTRODUCTION: Rapid diagnostic testing has made HIV diagnosis and subsequent
treatment more accessible. However, multiple factors, including improper
implementation of testing strategies and clerical errors, have been reported to
lead to HIV misdiagnosis. The World Health Organization has recommended HIV
retesting prior to antiretroviral therapy (ART) initiation which has become
pertinent with scaling up of Early Access to ART for All (EAAA). In this
analysis, misdiagnosed clients are identified from a subgroup of clients
enrolled in EAAA implementation study in Swaziland.
METHODS: The subgroup to assess misdiagnosis was identified from enrolled EAAA
study clients, who had an undetectable viral load prior to ART initiation
between September 1, 2014 and May 31, 2016. One hundred and five of 2533 (4%)
clients had an undetectable viral load prior to initiation to ART (pre-ART). The
HIV status of clients was confirmed using the Determine HIV 1/2 and Uni-Gold HIV
1/2 rapid tests performed serially as recommended by the national testing
algorithm. The status of clients on ART was additionally confirmed by
fourth-generation HIV Ag/Ab combo tests, Architect and Genscreen Ultra.
RESULTS: Fourteen of the 105 (13%) clients were false positive (HIV negative) on
confirmation testing, of whom five (36%) were still in pre-ART care, while nine
(64%) were in ART care. Overall, proportion of false positive was 0.6%
(14/2533). The false-positive clients had a median CD4 of 791 cells/ml
(interquartile range (IQR): 628, 967) compared to 549 cells/ml (IQR: 387, 791)
for true positives (HIV positive) (p = 0.0081) and were nearly 20 years older
(p = 0.0008).
CONCLUSIONS: Overall 0.6% of all enrolled EAAA clients were misdiagnosed, and
64% of misdiagnosed clients were initiated on ART. With adoption of EAAA
guidelines by national governments, ART initiation regardless of immunological
criteria, strengthening of proficiency testing and adoption of retesting prior
to ART initiation would allow identification of misdiagnosed clients and further
reduce potential of initiating misdiagnosed clients on ART. INTRODUCTION: We describe the overall accuracy and performance of a serial rapid
HIV testing algorithm used in community-based HIV testing in the context of a
population-based household survey conducted in two sub-districts of
uMgungundlovu district, KwaZulu-Natal, South Africa, against reference
fourth-generation HIV-1/2 antibody and p24 antigen combination immunoassays. We
discuss implications of the findings on rapid HIV testing programmes.
METHODS: Cross-sectional design: Following enrolment into the survey,
questionnaires were administered to eligible and consenting participants in
order to obtain demographic and HIV-related data. Peripheral blood samples were
collected for HIV-related testing. Participants were offered community-based HIV
testing in the home by trained field workers using a serial algorithm with two
rapid diagnostic tests (RDTs) in series. In the laboratory, reference HIV
testing was conducted using two fourth-generation immunoassays with all
positives in the confirmatory test considered true positives. Accuracy,
sensitivity, specificity, positive predictive value, negative predictive value
and false-positive and false-negative rates were determined.
RESULTS: Of 10,236 individuals enrolled in the survey, 3740 were tested in the
home (median age 24 years (interquartile range 19-31 years), 42.1% males and HIV
positivity on RDT algorithm 8.0%). From those tested, 3729 (99.7%) had a
definitive RDT result as well as a laboratory immunoassay result. The overall
accuracy of the RDT when compared to the fourth-generation immunoassays was
98.8% (95% confidence interval (CI) 98.5-99.2). The sensitivity, specificity,
positive predictive value and negative predictive value were 91.1% (95% CI
87.5-93.7), 99.9% (95% CI 99.8-100), 99.3% (95% CI 97.4-99.8) and 99.1% (95% CI
98.8-99.4) respectively. The false-positive and false-negative rates were 0.06%
(95% CI 0.01-0.24) and 8.9% (95% CI 6.3-12.53). Compared to true positives,
false negatives were more likely to be recently infected on limited antigen
avidity assay and to report antiretroviral therapy (ART) use.
CONCLUSIONS: The overall accuracy of the RDT algorithm was high. However, there
were few false positives, and the sensitivity was lower than expected with high
false negatives, despite implementation of quality assurance measures. False
negatives were associated with recent (early) infection and ART exposure. The
RDT algorithm was able to correctly identify the majority of HIV infections in
community-based HIV testing. Messaging on the potential for false positives and
false negatives should be included in these programmes. |
Which disease is diagnosed using the Finkelstein's test? | Finkelstein's test is the classic diagnostic test for de Quervain's disease. | This short paper demonstrates that the Finkelstein's test in De Quervain's
tenosynovitis is based on an incorrect assumption. The correct basis for a
pathognomic manoeuvre in De Quervain is the provocation of tendons attrition of
the first wrist dorsal compartment against their pulley which elicits pain. The
Brunelli's test induces this friction and pain by asking the patient to hardly
adduct the thumb with the wrist in radial deviation. PURPOSE: Finkelstein's test is the classic diagnostic test for de Quervain's
disease. Finkelstein hypothesized that the entry of the muscle bellies of the
extensor pollicis brevis (EPB) and abductor pollicis longus (APL) tendons into
the first extensor compartment was responsible for the findings observed in his
now eponymous test. We agree with Finkelstein's hypothesis and further
hypothesize that this position would induce measurable bulk (muscle mass within
the retinaculum) and tethering (stretching of synovial tissue) effects within
the compartment. To test this latter hypothesis we measured the excursion and
gliding resistance of the EPB and APL tendons within the first compartment.
METHODS: Fifteen fresh-frozen cadavers were used. Gliding resistance and
excursion were measured in 4 different wrist positions, including the wrist
position of Finkelstein's test (30 degrees ulnar deviation). The bulk and
tethering effect was calculated based on the mean gliding resistance over the
tendon proximal/distal excursion cycle and the gliding resistance at the
terminal distal excursion.
RESULTS: The EPB tendon excursion was significantly more distal in 30 degrees
ulnar deviation than in 60 degrees extension. Additionally the bulk and
tethering resistance was significantly greater in 30 degrees ulnar deviation
compared with 60 degrees extension. For the APL tendon there was no significant
difference in either the tendon excursion or the bulk and tethering resistance
between 30 degrees ulnar deviation and 60 degrees extension.
CONCLUSIONS: We showed that in the position of Finkelstein's test the EPB tendon
is significantly more distal and has significantly greater bulk and tethering
effect compared with the other EPB positions. This is not the case for the APL
tendon in the position of Finkelstein's test. These results suggest that an
abnormal Finkelstein's test reflects differences of the EPB more than it does
the APL. De Quervain's stenosing tendovaginitis is an inflammation of the first dorsal
compartment. It is considered to be one of the most common forms of inflammation
of the tendon sheaths. The diagnosis is based on the case history and the
clinical examination. Finkelstein's test is pathognomonic. Should conservative
treatment not prove successful, the condition is readily amenable to surgical
treatment. Le traitement de la maladie de de Quervain (DD) est un traitement non opératoire
en première intention, néanmoins la chirurgie peut être nécessaire en cas
d’échec. Nous présentons les résultats à long terme du traitement chirurgical de
la maladie de De Quervain, de juillet 1988 à juillet 1998, 94 patients
consécutifs présentant une maladie de De Quervain ont été traités
chirurgicalement par un seul chirurgien. Il s’agissait de 80 femmes et de 14
hommes., l’âge moyen à l’intervention était de 47,4 ans (de 22 à 76). Le poignet
droit était atteint dans 43 cas et le poignet gauche dans 51 cas. Toutes les
opérations ont été conduites avec un garrot et une anesthésie locale, le
traitement ayant constitué en une incision longitudinale permettant une
résection partielle du ligament extenseur. Il y a eu 6 complications
peri-opératoires incluant une infection superficielle, un retard de
cicatrisation et 4 lésions transitoires du nerf radial. Un bon résultat a été
observé dans tous les cas avec un test de Finkelstein négatif. La simple
décompression des tendons et la résection partielle au maximum de 3 mm du
retinaculum dorsal du carpe permet d’avoir un bon résultat et peut être
recommandé dans le traitement des maladies de De Quervain avec une excellent
résultat à long terme. BACKGROUND: De Quervain's tenosynovitis is a disorder characterised by pain on
the radial (thumb) side of the wrist and functional disability of the hand. It
can be treated by corticosteroid injection, splinting and surgery.
OBJECTIVES: To summarise evidence on the efficacy and safety of corticosteroid
injections for de Quervain's tenosynovitis.
SEARCH STRATEGY: We searched the following databases: the Cochrane Central
Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, Issue 2),
MEDLINE (1966 to April 2009), EMBASE (1956 to April 2009), CINAHL (1982 to April
2009), AMED (1985 to April 2009), DARE, Dissertation Abstracts and PEDro
(physiotherapy evidence database).
SELECTION CRITERIA: Randomised and controlled clinical trials evaluating the
efficacy and safety of corticosteroid injections for de Quervain's
tenosynovitis.
DATA COLLECTION AND ANALYSIS: After screening abstracts of studies identified by
the search we obtained full text articles of studies which fulfilled the
selection criteria. We extracted data using a predefined electronic form. We
assessed the methodological quality of included trials by using the checklist
developed by Jadad and the Delphi list. We extracted data on the primary outcome
measures: treatment success; severity of pain or tenderness at the radial
styloid; functional impairment of the wrist or hand; and outcome of
Finkelstein's test, and the secondary outcome measures: proportion of patients
with side effects; type of side effects and patient satisfaction with injection
treatment.
MAIN RESULTS: We found one controlled clinical trial of 18 participants (all
pregt or lactating women) that compared one steroid injection with
methylprednisolone and bupivacaine to splinting with a thumb spica. All patients
in the steroid injection group (9/9) achieved complete relief of pain whereas
none of the patients in the thumb spica group (0/9) had complete relief of pain,
one to six days after intervention (number needed to treat to benefit (NNTB) =
1, 95% confidence interval (CI) 0.8 to 1.2). No side effects or local
complications of steroid injection were noted.
AUTHORS' CONCLUSIONS: The efficacy of corticosteroid injections for de
Quervain's tenosynovitis has been studied in only one small controlled clinical
trial, which found steroid injections to be superior to thumb spica splinting.
However, the applicability of our findings to daily clinical practice is
limited, as they are based on only one trial with a small number of included
participants, the methodological quality was poor and only pregt and
lactating women participated in the study. No adverse effects were observed. INTRODUCTION: The De Quervain's tenosynovitis is an inadequacy into the first
extensor compartment between the osteo-fibrous tunnel and the tendons. This
mechanical conflict generates a tenosynovitis of the extensor pollicis brevis
and the abductor pollicis longus tendons in first dorsal extensor compartment of
the wrist.
PATIENTS AND METHODS: The authors report a retrospective study of 20 patients
who have been treated by a longitudinal surgical approach. The mean age was 49
years old with a net female predomice. The Finkelstein's test was positive in
all cases. All patients were treated operatively by incision of the sheath,
which was sufficient to unwind the dorsal compartment tendons. The sheath palmar
flap has been sutured with skin (Le Viet plasty) to avoid a further tendons
luxation.
RESULTS: At three years follow-up, the functional results were good in all the
patients. However, non-aesthetic scars were noticed in three patients. We did
not notice neither a case of anesthesia of the radial nerve nor a tendinous
luxation in our series.
DISCUSSION: The stenosing tenosynovitis of the first dorsal extensor compartment
of the wrist is a relatively frequent pathology in the young woman. We use a
longitudinal surgical approach to avoid the radial nerve lesions. Le Viet
procedure using the palmar flap of the pulley fixed to the dermis works as a
barrier and maintains the tendons sliding on the radial styloid groove. De Quervain's disease has different clinical features. Different tests have been
described in the past, the most popular test being the Eichhoff's test, often
wrongly named as the Finkelstein's test. Over the years, a misinterpretation has
occurred between these two tests, the latter being confused with the first. To
compare the Eichhoff's test with a new test, the wrist hyperflexion and
abduction of the thumb test, we set up a prospective study over a period of
three years for a cohort of 100 patients (88 women, 12 men) presenting
spontaneous pain over the radial side of the styloid of the radius (de Quervain
tendinopathy). The purpose of the study was to compare the accuracy of the
Eichhoff's test and wrist hyperflexion and abduction of the thumb test to
diagnose correctly de Quervain's disease by comparing clinical findings using
those tests with the results on ultrasound. The wrist hyperflexion and abduction
of the thumb test revealed greater sensitivity (0.99) and an improved
specificity (0.29) together with a slightly better positive predictive value
(0.95) and an improved negative predictive value (0.67). Moreover, the study
showed us that the wrist hyperflexion and abduction of the thumb test is very
valuable in diagnosing dynamic instability after successful decompression of the
first extensor compartment. Our results support that the wrist hyperflexion and
abduction of the thumb test is a more precise tool for the diagnosis of de
Quervain's disease than the Eichhoff's test and thus could be adopted to guide
clinical diagnosis in the early stages of de Quervain's tendinopathy. The purpose of this study was to describe the technique and usefulness of
ultrasound-guided intrasheath injection of triamcinolone in the treatment of de
Quervain's disease (dQD). Our study was retrospective in design. Seventy-one
wrists of 62 patients who were treated with an ultrasound-guided triamcinolone
injection for dQD were included. A literature search was performed to compare
our results. In the literature we found supportive evidence that accurate
injection of triamcinolone in the first dorsal compartment of the wrist is
important for a good outcome. In this retrospective study we found that
treatment with ultrasound-guided injections of triamcinolone is both safe and
effective. After two injections, 91% of the patients had good long-term results,
which is a higher cure rate than found in most other studies. Furthermore, we
found that Finkelstein's test can give a false positive result. Therefore,
ultrasound should not only be considered to improve the treatment outcome, but
can also be useful as a diagnostic tool in the management of de Quervain's
disease. BACKGROUND: de Quervain's disease is an inadequacy into the first extensor
compartment of wrist between the osteofibrous tunnel and the tendons. This
mechanical conflict generates a tenosynovitis of the extensor pollicis brevis
and the abductor pollicis longus tendons in first dorsal extensor compartment of
the wrist.
AIM: (1) To compare the clinical results obtained by longitudinal and transverse
incisions and (2) the implication of clinical results in Indian population.
MATERIALS AND METHODS: This study was conducted at Kalpana Chawla Government
Medical College, Karnal, Haryana. The inclusion criteria were positive
Finkelstein's test and no response to non-surgical treatment for 6 weeks.
Forty-eight patients with de Quervain's disease who did not respond to
conservative treatment were operated with two different incisions. The patients
were followed at 6 weeks, 3 and 6 months to compare the surgical outcomes.
RESULTS: During a three-month follow-up, a significant difference was shown
between the two methods (p = 0.0001). Results of surgical treatment with
longitudinal incision were better (only one hypertrophic scar), but there were
12 postoperative complications with transverse incision. Visual analog scale
(VAS) was used to evaluate the hypertrophic scar. In transverse incision group,
out of five patients, four patients who developed hypertrophic scar have poor
score according to VAS.
CONCLUSION: Overall, longitudinal incision should be used for surgical treatment
for de Quervain's disease due to lower risk of complications. |
For which type of cancer can uc.189 be used as a potential prognostic biomarker? | ESCC | |
Does Uc.160 promote cancer? | No. Uc.160+ is a T-UCR reported to be downregulated in human cancer. In addition, Uc.160+ could possibly have a tumor suppressive role in gastric cancer. | BACKGROUND: Transcribed ultraconserved regions (T-UCRs) are a novel class of
noncoding RNAs that are highly conserved among the orthologous regions in most
vertebrates. It has been reported that T-UCRs have distinct signatures in human
cancers. We previously discovered the downregulation of T-UCR expression in
gastric cancer (GC), indicating that T-UCRs could play an important role in GC
biology. Uc.160+, a T-UCR reported to be downregulated in human cancer, has not
been examined in GC.
METHODS: We analyzed the expression pattern of Uc.160+ in nonneoplastic and
tumor tissues of the stomach by using uantitative reverse transcription
polymerase chain reaction (qRT-PCR) and in situ hybridization (ISH),
specifically focusing on the mechanism of transcriptional regulation and target
genes that are regulated by T-UCRs. We also attempted to determine the effect of
Uc.160+ expression on biological features of GC cell lines by Western blotting.
RESULTS: On the basis of the qRT-PCR and ISH results, Uc.160+ expression in
adenoma and GC tissues was clearly downregulated compared with that in
nonneoplastic mucosa tissues of the stomach. Cancer-specific DNA methylation in
the promoter region of Uc.160 was observed by bisulfite genomic DNA sequencing
analysis. The effect of DNA methylation on Uc.160+ expression was further
confirmed by reporter gene assay. We also revealed that Uc.160+ inhibited the
phosphorylation of Akt by regulating phosphatase and tensin homolog (PTEN)
expression.
CONCLUSIONS: These results indicate that Uc.160+ could possibly have a tumor
suppressive role in GC. |
What causes Black Lung? | Black lung, also known as pneumoconiosis, is caused by chronic exposure to coal dust. | Coal workers' pneumoconiosis is a preventable occupational disorder of the
respiratory system resulting from exposure to and retention of respirable coal
dust. It exists in two distinguishable forms: simple, which is seldom if ever
disabling, and complicated, also known as progressive massive fibrosis (PMF),
which is sometimes totally disabling and is associated with a high mortality
rate. The disease affects a small proportion of active U.S. miners, and only a
very small number develop PMF. In its more advanced stages, the disorder is
characterized by shortness of breath. Scientific criteria for diagnosis are well
established but are not followed in the U.S. because of Federal law and
regulation. However, an acceptable scheme for classification of chest
radiographs exists. Black lung benefits payable to miners, their survivors and
dependents are approaching $2 billion annually, and regulations concerning
eligibility for such benefits are intentionally slanted to make it possible for
claimants to receive benefits in a manner not consistent with regulations
governing similar payments to other occupationally employed persons or in
accordance with established medical criteria. It has recently been suggested that the inhalation of coal in the absence of
complicated coal workers' pneumoconiosis (CWP) or smoking can lead to disabling
airways obstruction. The cause of such obstruction has been variously attributed
to emphysema or bronchitis. The frequency of significant airways obstruction in
a group of United States coal miners seeking compensation for occupationally
induced pulmonary impairment was therefore determined. In a sample of 611 "Black
Lung" claimants there was only one subject who was a non-smoker and who in the
absence of other non-occupationally related diseases,--for example, asthma and
bronchiectasis--had sufficient airways obstruction to render it difficult for
him to carry out hard labour. An alternative explanation for his reduced
ventilatory capacity other than coal dust or smoking may be available. If the
inhalation of coal dust in the absence of smoking and complicated CWP ever
induces sufficient ventilatory impairment to preclude a miner from working, it
is indeed rare. Highlights in the history of efforts to prevent occupational lung disease among
coal miners in the United States are reviewed. The Federal Coal Mine Health and
Safety Act of 1969 is summarized, and the sources and effects of its provisions
to prevent coal workers' pneumoconiosis are examined. Descriptions follow of the
identification of coal workers' pneumoconiosis as a disease, identification of
respirable coal mine dust as its cause, and establishment and enforcement of an
exposure limit. The development of prevention efforts focusing on surveillance
of both exposure and outcome and of enforcement of dust control methods is
examined. A prospective case-control study was undertaken to assess respiratory disability
in 133 former coal miners who were claimants for "black lung" benefits.
Consecutive assignment was made to either case or control group based on their
chest radiograph having shown coal workers' pneumoconiosis or no coal workers'
pneumoconiosis. A respiratory occupational survey was completed with physical
examination that placed special emphasis on the cardiorespiratory systems.
Subjects underwent pulmonary function testing while 92 of these also received
arterial blood gases to assess respiratory disability and pulmonary
insufficiency. Arterial blood gases were superior to spirometry in assessment of
pulmonary insufficiency/disability. Smoking interacts with coal workers'
pneumoconiosis to cause pulmonary insufficiency. The most frequent spirometric
pattern was obstructive. Disability was caused by occupational injuries and
comorbidities, both of which occurred with greater frequency in miners with coal
workers' pneumoconiosis than in controls. Pulmonary insufficiency appears to be
a better discriminator than respiratory disability in coal miners, suggesting
that arterial blood gases replace spirometry in their evaluation. Greater
emphasis on smoking intervention among coal miners should be given. |
List four principles of medical ethics. | The four principles of medical ethics proposed by Beauchamp and Childress are autonomy, non-maleficence, beneficence and justice. They have been extremely influential in the field of medical ethics, and are fundamental for understanding the current approach to ethical assessment in health care. | Paid egg sharing occurs when infertile patients receive infertility treatment
free or at reduced cost in exchange for sharing some of their eggs with patients
who require donated eggs. This approach to treatment is discussed in the context
of the four principles of medical ethics, namely respect for autonomy, justice,
beneficence and non-maleficence. The implications of these ethical
considerations for responsible practice and regulation are considered. Medical ethics generally applies to individual interactions between physicians
and patients. Conversely, public health ethics typically applies to interactions
between an agency or institution and a community or population. Four main
principles underlie medical ethics: autonomy, nonmaleficence, beneficence, and
justice. By contrast, public health ethical principles address issues such as
interdependence, community trust, fundamentality, and justice. In large part
because of the significant community-level effects of public health issues,
medical ethics are suboptimal for assessing community-level public health
interventions or plans-especially in the area of emergency preparedness. To be
effective, as well as ethical, public health preparedness efforts must address
all of the core principles of public health ethics. Tom Beauchamp and James Childress have always maintained that their four
principles approach (otherwise known as principlism) is a globally applicable
framework for biomedical ethics. This claim is grounded in their belief that the
principles of respect for autonomy, non-maleficence, beneficence and justice
form part of a 'common morality', or collection of very general norms to which
everyone who is committed to morality subscribes. The difficulty, however, has
always been how to demonstrate, at least in the absence of a full-blooded
analysis of the concept of morality, whether the four principles are
foundational, and so globally applicable, in this way. In the recently published
sixth edition of Principles of Biomedical Ethics, an imaginative and
non-question-begging empirical method of determining the common morality's norms
is suggested. In this paper, I outline this method, before arguing that it is
difficult to see how it might be thought to achieve its purpose. This commentary briefly argues that the four prima facie principles of
beneficence, non-maleficence, respect for autonomy and justice enable a
clinician (and anybody else) to make ethical sense of the author's proposed
reliance on professional guidance and rules, on law, on professional integrity
and on best interests, and to subject them all to ethical analysis and criticism
based on widely acceptable basic prima facie moral obligations; and also to
confront new situations in the light of those acceptable principles. BACKGROUND: The four principles of Beauchamp and Childress--autonomy,
non-maleficence, beneficence and justice--have been extremely influential in the
field of medical ethics, and are fundamental for understanding the current
approach to ethical assessment in health care. This study tests whether these
principles can be quantitatively measured on an individual level, and then
subsequently if they are used in the decision making process when individuals
are faced with ethical dilemmas.
METHODS: The Analytic Hierarchy Process was used as a tool for the measurement
of the principles. Four scenarios, which involved conflicts between the medical
ethical principles, were presented to participants who then made judgments about
the ethicality of the action in the scenario, and their intentions to act in the
same manner if they were in the situation.
RESULTS: Individual preferences for these medical ethical principles can be
measured using the Analytic Hierarchy Process. This technique provides a useful
tool in which to highlight individual medical ethical values. On average,
individuals have a significant preference for non-maleficence over the other
principles, however, and perhaps counter-intuitively, this preference does not
seem to relate to applied ethical judgements in specific ethical dilemmas.
CONCLUSIONS: People state they value these medical ethical principles but they
do not actually seem to use them directly in the decision making process. The
reasons for this are explained through the lack of a behavioural model to
account for the relevant situational factors not captured by the principles. The
limitations of the principles in predicting ethical decision making are
discussed. Contemporary clinical ethics was founded on principlism, and the four
principles: respect for autonomy, nonmaleficence, beneficence and justice,
remain domit in medical ethics discourse and practice. These principles are
held to be expansive enough to provide the basis for the ethical practice of
medicine across cultures. Although principlism remains subject to critique and
revision, the four-principle model continues to be taught and applied across the
world. As the practice of medicine globalizes, it remains critical to examine
the extent to which both the four-principle framework, and individual principles
among the four, suffice patients and practitioners in different social and
cultural contexts. Using the four-principle model we analyze two accounts of
surrogate decision making - one from the developed and one from the developing
world - in which the clinician undertakes medical decision-making with
apparently little input from the patient and/or family. The purpose of this
analysis is to highlight challenges in assessing ethical behaviour according to
the principlist model. We next describe cultural expectations and mores that
inform both patient and clinician behaviors in these scenarios in order to argue
that the principle of respect for persons informed by culture-specific ideas of
personhood may offer an improved ethical construct for analyzing and guiding
medical practice in a globalized and plural world. This paper argues that the four prima facie principles-beneficence,
non-maleficence, respect for autonomy and justice-afford a good and widely
acceptable basis for 'doing good medical ethics'. It confronts objections that
the approach is simplistic, incompatible with a virtue-based approach to
medicine, that it requires respect for autonomy always to have priority when the
principles clash at the expense of clinical obligations to benefit patients and
global justice. It agrees that the approach does not provide universalisable
methods either for resolving such moral dilemmas arising from conflict between
the principles or their derivatives, or universalisable methods for resolving
disagreements about the scope of these principles-long acknowledged lacunae but
arguably to be found, in practice, with all other approaches to medical ethics.
The value of the approach, when properly understood, is to provide a
universalisable though prima facie set of moral commitments which all doctors
can accept, a basic moral language and a basic moral analytic framework. These
can underpin an intercultural 'moral mission statement' for the goals and
practice of medicine. There are four principles of medical ethics; Beneficence, Respect for autonomy,
Non-maleficence, and Justice. It is not easy to apply to principles of medical
ethics in the special circumstances of obstetrics and gynecology. Student
doctors must learn to be familiar with principles of medical ethics tailored to
the special circumstances while the obstetrics and gynecology practice. Respect for Autonomy (RFA) has been a mainstay of medical ethics since its
enshrinement as one of the four principles of biomedical ethics by Beauchamp and
Childress' in the late 1970s. This paper traces the development of this modern
concept from Antiquity to the present day, paying attention to its Enlightenment
origins in Kant and Rousseau. The rapid C20th developments of bioethics and RFA
are then considered in the context of the post-war period and American
socio-political thought. The validity and utility of the RFA are discussed in
light of this philosophical-historical account. It is concluded that it is not
necessary to embrace an ethic of autonomy in order to guard patients from
coercion or paternalism, and that, on the contrary, the domice of autonomy
threatens to undermine those very things which have helped doctors come to view
and respect their patients as persons. |
Which package in Bioconductor has been developed with the aim to analyze differential DNA loops from sequencing data? | Diffloop is an R/Bioconductor package that provides a suite of functions for the quality control, statistical testing, annotation, and visualization of DNA loops. | SUMMARY: The 3D architecture of DNA within the nucleus is a key determit of
interactions between genes, regulatory elements, and transcriptional machinery.
As a result, differences in DNA looping structure are associated with variation
in gene expression and cell state. To systematically assess changes in DNA
looping architecture between samples, we introduce diffloop, an R/Bioconductor
package that provides a suite of functions for the quality control, statistical
testing, annotation, and visualization of DNA loops. We demonstrate this
functionality by detecting differences between ENCODE ChIA-PET samples and
relate looping to variability in epigenetic state.
AVAILABILITY AND IMPLEMENTATION: Diffloop is implemented as an R/Bioconductor
package available at
https://bioconductor.org/packages/release/bioc/html/diffloop.html.
CONTACT: [email protected].
SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics
online. |
Which disease can be diagnosed with the "probe to bone" test? | Probe-to-bone test is used for the diagnosis of diabetic foot osteomyelitis. The test has good sensitivity and specificity. Other diagnostic tests of diabetic foot osteomyelitis are plain films and magnetic resonance imaging. | OBJECTIVE: We sought to assess the accuracy of the probe-to-bone (PTB) test in
diagnosing foot osteomyelitis in a cohort of diabetic patients with bone culture
proven disease.
RESEARCH DESIGN AND METHODS: In this 2-year longitudinal cohort study, we
enrolled 1,666 consecutive diabetic individuals who underwent an initial
standardized detailed foot assessment, followed by examinations at regular
intervals. Patients were instructed to immediately come to the foot clinic if
they developed a lower-extremity complication. For all patients with a
lower-extremity wound, we compared the results of the PTB test with those of a
culture of the affected bone. We called PTB positive if the bone or joint was
palpable and defined osteomyelitis as a positive bone culture.
RESULTS: Over a mean of 27.2 months of follow-up, 247 patients developed a foot
wound and 151 developed 199 foot infections. Osteomyelitis was found in 30
patients: 12% of those with a foot wound and 20% in those with a foot infection.
When all wounds were considered, the PTB test was highly sensitive (0.87) and
specific (0.91); the positive predictive value was only 0.57, but the negative
predictive value was 0.98.
CONCLUSIONS: The PTB test, when used in a population of diabetic patients with a
foot wound among whom the prevalence of osteomyelitis was 12%, had a relatively
low positive predictive value, but a negative test may exclude the diagnosis. CONTEXT: Osteomyelitis of the lower extremity is a commonly encountered problem
in patients with diabetes and is an important cause of amputation and admission
to the hospital. The diagnosis of lower limb osteomyelitis in patients with
diabetes remains a challenge.
OBJECTIVE: To determine the accuracy of historical features, physical
examination, and laboratory and basic radiographic testing. We searched for
systematic reviews of magnetic resoce imaging (MRI) in the diagnosis of lower
extremity osteomyelitis in patients with diabetes to compare its performance
with the reference standard.
DATA SOURCES: MEDLINE search of English-language articles published between 1966
and March 2007 related to osteomyelitis in patients with diabetes. Additional
articles were identified through a hand search of references from retrieved
articles, previous reviews, and polling experts.
STUDY SELECTION: Original studies were selected if they (1) described historical
features, physical examination, laboratory investigations, or plain radiograph
in the diagnosis of lower extremity osteomyelitis in patients with diabetes
mellitus, (2) data could be extracted to construct 2 x 2 tables or had reported
operating characteristics of the diagnostic measure, and (3) the diagnostic test
was compared with a reference standard. Of 279 articles retrieved, 21 form the
basis of this review. Data from a single high-quality meta-analysis were used to
summarize the diagnostic characteristics of MRI in osteomyelitis.
DATA EXTRACTION: Two authors independently assigned each study a quality grade
using previously published criteria and abstracted operating characteristic data
using a standardized instrument.
DATA SYNTHESIS: The gold standard for diagnosis is bone biopsy. No studies were
identified that addressed the utility of the history in the diagnosis of
osteomyelitis. An ulcer area larger than 2 cm2 (positive likelihood ratio [LR],
7.2; 95% confidence interval [CI], 1.1-49; negative LR, 0.48; 95% CI, 0.31-0.76)
and a positive "probe-to-bone" test result (summary positive LR, 6.4; 95% CI,
3.6-11; negative LR, 0.39; 95% CI, 0.20-0.76) were the best clinical findings. A
erythrocyte sedimentation rate of more than 70 mm/h increases the probability of
a diagnosis of osteomyelitis (summary LR, 11; 95% CI, 1.6-79). An abnormal plain
radiograph doubles the odds of osteomyelitis (summary LR, 2.3; 95% CI, 1.6-3.3).
A positive MRI result increases the likelihood of osteomyelitis (summary LR,
3.8; 95% CI, 2.5-5.8). However, a normal MRI result makes osteomyelitis much
less likely (summary LR, 0.14; 95% CI, 0.08-0.26). The overall accuracy (ie, the
weighted average of the sensitivity and specificity) of the MRI is 89% (95% CI,
83.0%-94.5%).
CONCLUSIONS: An ulcer area larger than 2 cm2, a positive probe-to-bone test
result, an erythrocyte sedimentation rate of more than 70 mm/h, and an abnormal
plain radiograph result are helpful in diagnosing the presence of lower
extremity osteomyelitis in patients with diabetes. A negative MRI result makes
the diagnosis much less likely when all of these findings are absent. No single
historical feature or physical examination reliably excludes osteomyelitis. The
diagnostic utility of a combination of findings is unknown. OBJECTIVE: To compare the diagnostic characteristics of tests used for a prompt
diagnosis of chronic osteomyelitis in the diabetic foot, using bone histology as
the criterion standard. The tests assessed were probe-to-bone (PTB), clinical
signs of infection, radiography signs of osteomyelitis, and ulcer specimen
culture.
RESEARCH DESIGN AND METHODS: A prospective study was performed on patients with
foot ulcers referred to our diabetic foot clinic. Ulcer infection was diagnosed
by recording clinical signs of infection and taking specimens for culture. The
presumptive diagnosis of osteomyelitis was based on these results and the
findings of a plain X-ray and PTB test. All patients with a clinical suspicion
of bone infection were subjected to surgical treatment of the affected bone.
During surgery, bone specimens were obtained for a histological diagnosis of
osteomyelitis.
RESULTS: Over 2.5 years, 210 foot lesions were consecutively examined and 132 of
these wounds with clinical suspicion of infection selected as the study sample.
Of these, 105 (79.5%) lesions were diagnosed as osteomyelitis. Among the tests
compared, the best results were yielded by the PTB test including an efficiency
of 94%, sensitivity of 98%, specificity of 78%, positive predictive value of
95%, and negative predictive value of 91% (P < 0.001, κ 0.803); the positive
likelihood ratio was 4.41, and the negative likelihood ratio was 0.02 (95% CI).
CONCLUSIONS: In our outpatient population with a high prevalence of
osteomyelitis, the PTB test was of greatest diagnostic value, especially for
neuropathic ulcers, and proved to be efficient for detecting osteomyelitis in
the diabetic foot. BACKGROUND: We investigated the validity of probe-to-bone testing in the
diagnosis of osteomyelitis in a selected subgroup of patients clinically
suspected of having diabetic foot osteomyelitis.
METHODS: Between January 1, 2007, and December 31, 2008, inpatients and
outpatients with a diabetic foot ulcer were prospectively evaluated, and those
having a clinical diagnosis of foot infection and at least one of the
osteomyelitis clinical suspicion criteria were consecutively included in this
study.
RESULTS: Sixty-five patients met the inclusion criteria and were prospectively
enrolled in the study. Forty-nine patients (75.4%) were hospitalized, and the
remaining 16 (24.6%) were followed as outpatients. Osteomyelitis was diagnosed
in 39 patients (60.0%). Probe-to-bone test results were positive in 30 patients
(46.1%). The positive predictive value for the probe-to-bone test was fairly
high (87%), but the negative predictive value was only 62%. The sensitivity and
specificity of the test were 66% and 84%, respectively. White blood cell counts
and mean C-reactive protein levels did not statistically significantly differ
between groups. However, erythrocyte sedimentation rates greater than 70 mm/h
reached statistical significance between groups. Wound area and depth were not
found to be statistically significantly different between groups.
CONCLUSIONS: Positive probe-to-bone test results and erythrocyte sedimentation
rates greater than 70 mm/h provide some support for the diagnosis of diabetic
foot osteomyelitis, but it is not strong; magnetic resoce imaging or bone
biopsy will probably be required in cases of doubt. Author information:
(1)Diabetic Foot Unit, Complutense University Clinic, Madrid, Spain; Instituto
de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Madrid,
Spain. Electronic address: [email protected].
(2)Diabetic Foot Unit, Complutense University Clinic, Madrid, Spain; Instituto
de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Madrid,
Spain.
(3)Diabetic Foot Unit, La Paloma Hospital, Las Palmas de Gran Canaria, Spain. Magnetic resoce imaging (MRI) has a higher sensitivity and specificity (90%
and 79%) than plain radiography (54% and 68%) for diagnosing diabetic foot
osteomyelitis. MRI performs somewhat better than any of several common
tests--probe to bone (PTB), erythrocyte sedimentation rate (ESR) >70 mm/hr,
C-reactive protein (CRP) >14 mg/L, procalcitonin >0.3 ng/mL, and ulcer size >2
cm²--although PTB has the highest specificity of any test and is commonly used
together with MRI. No studies have directly compared MRI with a combination of
these tests, which may assist in diagnosis. BACKGROUND: Diabetes mellitus continues to grow in global prevalence and to
consume an increasing amount of health care resources. One of the key areas of
morbidity associated with diabetes is the diabetic foot. To improve the care of
patients with diabetic foot and to provide an evidence-based multidisciplinary
management approach, the Society for Vascular Surgery in collaboration with the
American Podiatric Medical Association and the Society for Vascular Medicine
developed this clinical practice guideline.
METHODS: The committee made specific practice recommendations using the Grades
of Recommendation Assessment, Development, and Evaluation system. This was based
on five systematic reviews of the literature. Specific areas of focus included
(1) prevention of diabetic foot ulceration, (2) off-loading, (3) diagnosis of
osteomyelitis, (4) wound care, and (5) peripheral arterial disease.
RESULTS: Although we identified only limited high-quality evidence for many of
the critical questions, we used the best available evidence and considered the
patients' values and preferences and the clinical context to develop these
guidelines. We include preventive recommendations such as those for adequate
glycemic control, periodic foot inspection, and patient and family education. We
recommend using custom therapeutic footwear in high-risk diabetic patients,
including those with significant neuropathy, foot deformities, or previous
amputation. In patients with plantar diabetic foot ulcer (DFU), we recommend
off-loading with a total contact cast or irremovable fixed ankle walking boot.
In patients with a new DFU, we recommend probe to bone test and plain films to
be followed by magnetic resoce imaging if a soft tissue abscess or
osteomyelitis is suspected. We provide recommendations on comprehensive wound
care and various débridement methods. For DFUs that fail to improve (>50% wound
area reduction) after a minimum of 4 weeks of standard wound therapy, we
recommend adjunctive wound therapy options. In patients with DFU who have
peripheral arterial disease, we recommend revascularization by either surgical
bypass or endovascular therapy.
CONCLUSIONS: Whereas these guidelines have addressed five key areas in the care
of DFUs, they do not cover all the aspects of this complex condition. Going
forward as future evidence accumulates, we plan to update our recommendations
accordingly. |
Can doxycycline cause photosensitivity? | Yes, one of the most important dermatologic side effects of doxycycline is photosensitivity. Clinical symptoms vary from light sunburn-like sensation (burning, erythema) to large-area photodermatitis. | Chronic actinic dermatitis (CAD) is an uncommon, eczematous photosensitive
eruption affecting predomitly elderly men and to which drug-induced
photosensitivity may sometimes appear clinically identical. This retrospective
study compares the monochromatic irradiation results in 11 patients with CAD and
14 patients with drug-induced photosensitivity, to assess whether such testing
is useful in the differentiation of these two conditions. Thus, the action
spectra of the drug photosensitivity patients were plotted and compared with
those of 12 nonphotosensitive control patients: 10 patients were found to be
photosensitive in the UVA range; the implicated drugs included quinine,
sparfloxacin, amiodarone, doxycycline, mefenamic acid, nalidixic acid,
fenbrufen, diclofenac, enalapril, diltiazem and prochlorperazine maleate. One
patient on doxycycline was photosensitive in both the UVA and UVB ranges. The
remaining three patients were not tested until after discontinuation of their
drug and their light tests were then normal. In the CAD group, five patients
were photosensitive in the UVA, UVB and visible light ranges and six were
photosensitive in the UVA and UVB ranges. Comparison of the mean minimal
erythema dose responses then demonstrated dissociation of the drug-induced from
the CAD group in the UVB region; the result was statistically significant. This
suggests that UVA-sensitivity dissociated from UVB-sensitivity is a relative
indicator of drug-induced photosensitivity and monochromatic irradiation testing
may therefore be helpful in the differentiation of these two disorders. BACKGROUND: It has been hypothesized that certain Mycoplasma species may cause
Gulf War veterans' illnesses (GWVIs), chronic diseases characterized by pain,
fatigue, and cognitive symptoms, and that affected patients may benefit from
doxycycline treatment.
OBJECTIVE: To determine whether a 12-month course of doxycycline improves
functional status in Gulf War veterans with GWVIs.
DESIGN: A randomized, double-blind, placebo-controlled clinical trial with 12
months of treatment and 6 additional months of follow-up.
SETTING: 26 U.S. Department of Veterans Affairs and 2 U.S. Department of Defense
medical centers.
PARTICIPANTS: 491 deployed Gulf War veterans with GWVIs and detectable
Mycoplasma DNA in the blood.
INTERVENTION: Doxycycline, 200 mg, or matching placebo daily for 12 months.
MEASUREMENTS: The primary outcome was the proportion of participants who
improved more than 7 units on the Physical Component Summary score of the
Veterans Short Form-36 General Health Survey 12 months after randomization.
Secondary outcomes were measures of pain, fatigue, and cognitive function and
change in positivity for Mycoplasma species at 6, 12, and 18 months after
randomization.
RESULTS: No statistically significant differences were found between the
doxycycline and placebo groups for the primary outcome measure (43 of 238
participants [18.1%] vs. 42 of 243 participants [17.3%]; difference, 0.8
percentage point [95% CI, -6.5 to 8.0 percentage points]; P > 0.2) or for
secondary outcome measures at 1 year. In addition, possible differences in
outcomes at 3 and 6 months were not apparent at 9 or 18 months. Participants in
the doxycycline group had a higher incidence of nausea and photosensitivity.
LIMITATIONS: Adherence to treatment after 6 months was poor.
CONCLUSION: Long-term treatment with doxycycline did not improve outcomes of
GWVIs at 1 year. Approximately 13 million individuals in the United Sates suffer from rosacea, a
recurrent disease that may require long-term therapy. Topical and oral
antibiotics have been used to treat rosacea; however, high-dose antibiotics or
long-term, low-dose antibiotics commonly used for the treatment of rosacea
flares or for rosacea maintece therapy, respectively, can lead to the
development of antibiotic-resistant organisms. The first oral medication
approved by the U.S. Food and Drug Administration for the treatment of rosacea
in the United States is Oracea (CollaGenex Pharmaceuticals Inc., Newtown, PA,
USA). Oracea is a 40 mg capsule of doxycycline monohydrate, containing 30 mg
immediate-release and 10 mg delayed-release doxycycline beads
("anti-inflammatory-dose doxycycline"). Anti-inflammatory-dose doxycycline is
not an antibiotic and does not lead to the development of antibiotic-resistant
organisms. Each capsule of anti-inflammatory-dose doxycycline contains a total
of 40 mg of anhydrous doxycycline as 30 mg of immediate-release and 10 mg of
delayed-release beads. In contrast to other oral therapies,
anti-inflammatory-dose doxycycline is taken once daily, which may increase
treatment compliance. The results of two phase III trials have been encouraging,
leading to the recent release (summer 2006) of Oracea for the treatment of
rosacea in the United States. Anti-inflammatory-dose doxycycline should not be
used by individuals with known hypersensitivity to tetracyclines or increased
photosensitivity, or by pregt or nursing women (anti-inflammatory-dose
doxycycline is a pregcy category-D medication). The risk of permanent teeth
discoloration and decreased bone growth rate make anti-inflammatory-dose
doxycycline contraindicated in infants and children. However, when used
appropriately in patients with rosacea, anti-inflammatory-dose doxycycline may
help prolong the effectiveness and life span of our most precious antibiotics. OBJECTIVES: Many patients undergoing long-term doxycycline treatment do not
regularly take their treatment because of photosensitivity. Our objective was to
create an assay for determining doxycycline levels and to use hair samples for
monitoring the compliance over a longer period of time.
METHODS: We tested sera and hair samples from patients treated with doxycycline
by a suitable ultra-high performance liquid chromatography (UHPLC) based assay.
RESULTS: We estimated that the speed of hair growth is roughly 1.25 cm per month
and we were able to determine doxycycline levels over a 6-month period. We
tested 14 patients treated with doxycycline and we found similar levels of
doxycycline in the serum and the hair samples representing the last 4 months.
Linear regression analysis revealed that the level of doxycycline in the serum
remained stable over time (p = 0.7) but the level of doxycycline in the hair
decreased significantly over time (p = 0.03) indicating a degradation of this
molecule in the hair. We detected two patients who did not have antibiotic in
the hair, indicating a lack of compliance that was also confirmed by interview.
CONCLUSION: Hair samples can be used to test long-term compliance in patients to
explain failures or relapses. Onycholysis is the detachment of the nail plate from the nail bed. If
drug-induced, it can be an isolated phenomenon, but it may also accompany or
follow a cutaneous phototoxicity reaction due to drug intake and exposure to
ultraviolet irradiation. Photo-onycholysis is a rare photosensitivity reaction
due to exposure to either a natural or artificial source of light. Many drugs
are responsible for this phototoxic reaction, especially tetracyclines,
psoralens, chloramphenicol, non-steroidal anti-inflammatory drugs,
fluoroquinolones, and, rarely, doxycycline. Any patient given enough of a
therapeutic dose of an inducing drug and sufficient light irradiation can
develop phototoxic reactions. While there is no need to avoid these drugs
completely, precautions should be taken. Here we have reported the case of a
patient who developed onycholysis of his fingernails with sparing of the
toenails following administration of diclofenac therapy for lower back pain. The
onycholysis was associated with a phototoxic reaction. The swellings resolved
totally within two days, and the patient started to notice the separation of all
fingernail plates from their nail beds. The patient was treated symptomatically.
On follow-up, onycholysis had regressed slowly, and the condition recovered
totally within three months without any sequelae. |
What body process does the Dentate Gyrus Mossy Cell control? | Dentate gyrus mossy cells control spontaneous convulsive seizures and cognition | Recent experimental and modeling results demonstrated that surviving mossy cells
in the dentate gyrus play key roles in the generation of network
hyperexcitability. Here we examined if mossy cells exhibit long-term plasticity
in the posttraumatic, hyperexcitable dentate gyrus. Mossy cells 1 wk after fluid
percussion head injury did not show alterations in their current-firing
frequency (I-F) and current-membrane voltage (I-V) relationships. In spite of
the unchanged I-F and I-V curves, mossy cells showed extensive modifications in
Na(+), K(+) and h-currents, indicating the coordinated nature of these opposing
modifications. Computational experiments in a realistic large-scale model of the
dentate gyrus demonstrated that individually, these perturbations could
significantly affect network activity. Synaptic inputs also displayed
systematic, opposing modifications. Miniature excitatory postsynaptic current
(EPSC) amplitudes were decreased, whereas miniature inhibitory postsynaptic
current (IPSC) amplitudes were increased as expected from a homeostatic response
to network hyperexcitability. In addition, opposing alterations in miniature and
spontaneous synaptic event frequencies and amplitudes were observed for both
EPSCs and IPSCs. Despite extensive changes in synaptic inputs,
cannabinoid-mediated depolarization-induced suppression of inhibition was not
altered in posttraumatic mossy cells. These data demonstrate that many intrinsic
and synaptic properties of mossy cells undergo highly specific, long-term
alterations after traumatic brain injury. The systematic nature of such
extensive and opposing alterations suggests that single-cell properties are
significantly influenced by homeostatic mechanisms in hyperexcitable circuits. OBJECTIVE: Patients with temporal lobe epilepsy often display cognitive
comorbidity with recurrent seizures. However, the cellular mechanisms underlying
the impairment of neuronal information processing remain poorly understood in
temporal lobe epilepsy. Within the hippocampal formation neuronal networks
undergo major reorganization, including the sprouting of mossy fibers in the
dentate gyrus; they establish aberrant recurrent synapses between dentate
granule cells and operate via postsynaptic kainate receptors. In this report, we
tested the hypothesis that this aberrant local circuit alters information
processing of perforant path inputs constituting the major excitatory afferent
pathway from entorhinal cortex to dentate granule cells.
METHODS: Experiments were performed in dentate granule cells from control rats
and rats with temporal lobe epilepsy induced by pilocarpine hydrochloride
treatment. Neurons were recorded in patch clamp in whole cell configuration in
hippocampal slices.
RESULTS: Our present data revealed that an aberrant readout of synaptic inputs
by kainate receptors triggered a long-lasting impairment of the perforant path
input-output operation in epileptic dentate granule cells. We demonstrated that
this is due to the aberrant activity-dependent potentiation of the persistent
sodium current altering intrinsic firing properties of dentate granule cells.
INTERPRETATION: We propose that this aberrant activity-dependent intrinsic
plasticity, which lastingly impairs the information processing of cortical
inputs in dentate gyrus, may participate in hippocampal-related cognitive
deficits, such as those reported in patients with epilepsy. Author information:
(1)Department of Neuroscience, Columbia University, New York, NY 10032, USA;
Doctoral Program in Neurobiology and Behavior, Columbia University, New York, NY
10032, USA.
(2)Department of Neuroscience, Columbia University, New York, NY 10032, USA.
(3)Institute of Molecular Biology and Biotechnology (IMBB), Foundation for
Research and Technology - Hellas (FORTH), 700 13 Heraklion, Crete, Greece;
Department of Biology, School of Sciences and Engineering, University of Crete,
741 00 Heraklion, Crete, Greece, Columbia University, New York, NY 10032, USA.
(4)Institute of Molecular Biology and Biotechnology (IMBB), Foundation for
Research and Technology - Hellas (FORTH), 700 13 Heraklion, Crete, Greece.
(5)Institute of Molecular Biology and Biotechnology (IMBB), Foundation for
Research and Technology - Hellas (FORTH), 700 13 Heraklion, Crete, Greece.
Electronic address: [email protected].
(6)Department of Neuroscience, Columbia University, New York, NY 10032, USA;
Kavli Institute for Brain Science, Columbia University, New York, NY 10032, USA;
Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New
York, NY 10032, USA. Electronic address: [email protected]. Author information:
(1)Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD 21218,
USA.
(2)Institute for Cell Engineering, Johns Hopkins University School of Medicine,
Baltimore MD 21205 USA; Department of Neurology, Johns Hopkins University School
of Medicine, Baltimore MD 21205 USA.
(3)Institute for Cell Engineering, Johns Hopkins University School of Medicine,
Baltimore MD 21205 USA; Department of Neurology, Johns Hopkins University School
of Medicine, Baltimore MD 21205 USA; Solomon H. Snyder Department of
Neuroscience, Johns Hopkins University School of Medicine, Baltimore MD 21205
USA.
(4)Werner-Reichardt Centre for Integrative Neuroscience, 72076 Tübingen,
Germany.
(5)Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD 21218,
USA; Solomon H. Snyder Department of Neuroscience, Johns Hopkins University
School of Medicine, Baltimore MD 21205 USA. Electronic address:
[email protected]. Although it has been established that recurrent or prolonged clinical seizures
during infancy may cause lifelong brain damage, the underlying molecular
mechanism is still not well elucidated. The present study, to the best of our
knowledge, is the first to investigate the expression of twenty zinc (Zn)/lipid
metabolism‑associated genes in the hippocampus and cerebral cortex of rats
following recurrent neonatal seizures. In the current study, 6‑day‑old
Sprague‑Dawley rats were randomly divided into control (CONT) and recurrent
neonatal seizure (RS) groups. On postnatal day 35 (P35), mossy fiber sprouting
and gene expression were assessed by Timm staining and reverse
transcription‑quantitative polymerase chain reaction, respectively. Of the
twenty genes investigated, seven were significantly downregulated, while four
were significantly upregulated in the RS group compared with CONT rats, which
was observed in the hippocampus but not in the cerebral cortex. Meanwhile,
aberrant mossy fiber sprouting was observed in the supragranular region of the
dentate gyrus and Cornu Ammonis 3 subfield of the hippocampus in the RS group.
In addition, linear correlation analysis identified significant associations
between the expression of certain genes in the hippocampus, which accounted for
40% of the total fifty‑five gene pairs among the eleven regulated genes.
However, only eight gene pairs in the cerebral cortex exhibited significant
positive associations, which accounted for 14.5% of the total. The results of
the present study indicated the importance of hippocampal Zn/lipid
metabolism‑associated genes in recurrent neonatal seizure‑induced aberrant mossy
fiber sprouting, which may aid the identification of novel potential targets
during epileptogenesis. |
Which ligament is most commonly injured in dashboard injury? | Posterior cruciate ligament injuries have a reported incidence of between 3 and 37%, depending on the clinical setting. The most common mechanism of injury in motor vehicle accidents is a dashboard injury or direct force to the proximal anterior tibia. | The literature is divided as to the necessity of an intact posterior cruciate
ligament for functional stability. Presented here is a prospective study of
isolated posterior cruciate injuries seen in the acute stage in 13 patients, 6
males and 7 females. The diagnosis of posterior cruciate ligament tear was made
clinically and confirmed by arthroscopy. The average age at injury was 22 years.
The athletic activity at injury was varied. Hyperflexion was the most common
mechanism of injury, followed by pretibial trauma in the hyperflexed knee or in
the "dashboard" injury. There were seven complete midsubstance tears and five
partial tears. Direct visualization of the posterior cruciate ligament was not
attained in one patient. All patients were treated nonoperatively on a
physiotherapy routine. Average followup was 2.6 years. Patients were clinically
examined and subjected to KT-1000 and Cybex testing. All patients were able to
return to their previous activity and experienced no limitations with their
injured knees. Using Hughston's criteria, subjective and functional ratings were
all good. However, only 3 rated good and 10 fair when assessed objectively. We
conclude that acceptable functional stability in these patients does not
necessarily require absolute static stability. Nonoperative treatment of the
isolated posterior cruciate ligament midsubstance injury may be a viable
alternative to the difficult repair/reconstruction procedure. Posterior cruciate ligament (PCL) injuries have a reported incidence of between
3 and 37%, depending on the clinical setting. The most common mechanism of
injury in motor vehicle accidents is a dashboard injury or direct force to the
proximal anterior tibia. Sports related injuries result from hyperflexion of the
knee with the foot typically plantarflexed. The latter mechanism is the most
common cause of isolated PCL injuries, while in the trauma population as many as
95% of patients with knee injuries have combined ligamentous damage. Improved
knowledge at an anatomical, biomechanical and clinical level has provided the
orthopaedist with a more defined treatment algorithm. Isolated, partial PCL
injuries (grades I and II) can best be treated nonoperatively while complete
injuries (grade III) may require operative treatment based on clinical symptoms.
All combined ligamentous injuries usually respond best with surgical management. |
What is the normal body temperature in dogs? | According to the American Kennel Club (AKC), a temperature of 101 to 102.5 degrees Fahrenheit (38.3 to 39.2 degrees Celsius) is typical for dogs | OBJECTIVE: To assess the accuracy of obtaining body temperatures in dogs with a
noncontact infrared thermometer (NCIT) on the cornea compared with a rectal
digital thermometer (RDT).
DESIGN: Prospective single center study.
SETTING: University teaching hospital.
ANIMALS: Three hundred dogs presented with low, normal, or high body
temperatures.
INTERVENTIONS: Three body temperature readings were measured by an RDT and by an
NCIT on the cornea of the left eye by 2 investigators (experienced and
inexperienced). Results obtained by the 2 methods were compared.
MEASUREMENTS AND MAIN RESULTS: Median body temperature measured by the
experienced investigator with the RDT and the NCIT were 38.3°C (range
35.5°C-41.1°C; 95% CI: 38.2-38.4°C) and 37.7°C (35.9°C-40.1°C; 95% CI:
37.7°C-37.9°C), respectively. Measurement of RDT as well as of NCIT correlated
well between both investigators (rRDT = 0.94; rNCIT = 0.82; respectively, P <
0.001 for both methods). Mean RDT and NCIT-temperature correlated poorly (r =
0.43; P < 0.001) when taken by the experienced investigator and even less by the
nonexperienced investigator (r = 0.38; P < 0.001). Repeatability of the NCIT
revealed an unsatisfactory value (0.24°C) compared to RDT measurement (0.12°C).
Agreement between both devices in measuring low, normal, and high values,
calculated by Cohens-Kappa, was unsatisfactory (к = 0.201; P < 0.001).
Calculating the receiver operating characteristic curve to determine the best
threshold for fever (defined as RDT temperature >39.0°C) showed an area under
the curve of 0.76. Mean discomfort score was significantly lower using NCIT
compared to RDT measurement (P < 0.001).
CONCLUSIONS: There was poor agreement between body temperatures obtained by RDT
and NCIT. The corneal NCIT measurement tends to underrecognize hypothermic and
hyperthermic conditions. Although the use of the NCIT yields faster results and
is significantly more comfortable for the dog than the RDT measurement, it
cannot be recommended in dogs at this time. A 4-year-old cocker spaniel, male, of 12kg body weight was presented because of
the onset of polyuria or polydipsia. From the first months of its life, the dog
had exhibited constant serous to mucopurulent nasal discharge, productive cough,
sneezing, reverse sneezing, otitis, and recurrent episodes of fever. The
respiratory signs had been treated several times with antibiotics, without ever
achieving a complete resolution. Clinical examination revealed normal rectal
temperature (38.3°C), increased respiratory rate (40breaths/min), a copious
mucous nasal discharge and right deviation of the heart apex beat (ictus
cordis). Increased respiratory sounds with moist rales and crackles were found
on chest auscultation. An increase in serum creatinine, urea and phosphorus,
hypoalbuminemia and proteinuria were found. Lateral and ventrodorsal radiographs
of the thorax and of the abdomen showed the transposition of the heart, with the
cardiac apex pointing toward the right (dextrocardia), bronchointerstitial lung
pattern, areas of consolidation, lesions consistent with bronchiectasis caves
and a mirror-image of abdominal organs, confirming the diagnosis of complete
situs inversus (CSI). Respiratory signs, combined with CSI, suggested the
diagnosis of Kartagener syndrome (KS). Abdominal ultrasound showed an increase
in the echogenicity of the renal parenchyma, a loss of definition of the
corticomedullary line, slight bilateral pyelectasis, and decreased cortical
perfusion. The dog died 2 months later because of a further worsening of the
clinical condition. Necroscopy demonstrated the existence of CSI,
rhinosinusitis, bronchitis, and bronchiectasis, so confirming the diagnosis of
KS, and renal amyloidosis. This is the first case reported in veterinary
medicine of the presence of renal amyloidosis together with KS in a dog. |
List symptoms of Heerfordt syndrome. | Heerfordt syndrome (also known as Heerfordt-Waldenström or uveoparotid fever) is a rare presentation of sarcoidosis characterized by the presence of parotid gland enlargement, facial palsy, anterior uveitis, and fever. | Heerfordt syndrome is an unusual manifestation of systemic sarcoidosis and is
characterized by parotitis, uveitis, and facial nerve paralysis. A case is
presented and the clinical manifestations are discussed. Angiotensin converting
enzyme assays along with tissue biopsy demonstrating noncaseating granulomas
confirm the diagnosis. The Heerfordt syndrome is characterized by fever, uveitis, swelling of parotid
gland and facial nerve palsy, and 53 cases have been reported in Japan until
2000. In the present review, we mainly focused on those clinical cases reported.
Most patients were between 20 and 40 years of age, and females appeared to have
greater risk than males. The definite diagnosis of this syndrome is established
histologically according to sarcoidosis. In addition 67 gallium scan is helpful
for diagnosis, and it shows increased uptake of Ga to the ophthal lesion,
parotid glands and hilar lesions. Therapeutic trial with prednisolone is
sometimes required especially for facial palsy. Sarcoidosis is a chronic, multisystem disorder of unknown cause characterized by
noncaseating epithelioid granulomas. Infectious agents and genetic components
have been discussed. Heerfordt's syndrome with uveitis, enlargement of the
parotid glands and optional paralysis of the Nn. facialis is a form of
sarcoidosis. The diagnosis is confirmed by histology. Further analyses are
fiberoptic bronchoscopy with bronchoalveolar lavage or the gallium-67 scan in
combination with blood findings. The therapy of choice is glucocorticoids. We
present a case report of Heerfordt's syndrome and a review of the literature
covering different aspects of sarcoidosis. We report the case of a 22-year-old woman who is suspected of having primary
Sjögren s syndrome. She complaining of bilateral swelling of eyelids and the
parotid glands of three weeks duration. Physical examination revealed a
bilateral enlargement of both parotid glands, which were solid and painful.
Sjögren s syndrome was suspected at that stage, and the serologic and specific
analysis were done. All these tests didn t find any autoimmune or visceral
features typical of Sjögren s syndrome and autoantibodies were negative. During
follow-up time the right facial nerve palsy developed. Pulmonary radiography
revealed bihilar lymphadenopathy and labial salivary gland biopsy revealed
non-caseating granuloma. The patient was classified as having stage I
sarcoidosis. This case demonstrates the importance of being aware of the leading
clinical signs and symptoms in case of Heerfordt syndrome. Heerfordt's syndrome (HS) consists in its complete form of uveitis, parotid or
salivary gland enlargement and cranial nerve palsy. The objective of the present
study was to analyse if there are also links between HLA-DRB1* alleles and HS,
as it is a specific phenotype of sarcoidosis. 1,000 patients with sarcoidosis,
out of whom 83 had symptoms associated with HS, were included in the study
together with a group of 2,000 healthy individuals from the same population,
matched for sex and age. HLA-DRB1* allelic groups were determined for all
individuals, and comparisons were made between different disease subgroups and
between patients and healthy controls. We found that the HLA-DRB1*04 allele was
overrepresented in patients with symptoms associated with HS. 83 (8.3%) of all
patients had one or more of the symptoms and 46 (55%) of them were HLA-DRB1*04
positive. 44 (55%) of the patients with ocular sarcoidosis, i.e. the most common
symptom associated with HS, were HLA-DRB1*04 positive, compared with 35.9% of
healthy controls (p=0.0008), and only 26.6% of the whole group of sarcoidosis
patients (p<0.0001). HLA-DRB1*04 seems to protect against overall sarcoidosis
but appears to be a significant risk factor for ocular sarcoidosis as well as
for other manifestations associated with HS. This article reports the case of a 14-year-old boy who was presented in the case
conference with symptoms of decreased visual acuity, scintillating scotomas and
photophobia. Physical examination revealed right facial paralysis, parotid gland
swelling, high fever and poor general condition. Ophthalmoscopy revealed
anterior and posterior uveitis including macular edema and chorioretinal
infiltrates. Angiography revealed a dense pattern of hyperfluorescent lesions
and these observations resulted in the diagnosis of Heerfordt syndrome. Under
systemic prednisolone therapy, symptoms were reduced and visual acuity
recovered. We report a 39-year-old female admitted for fever. She showed physical findings
of bilateral granulomatous uveitis, swelling of the bilateral parotid glands,
and paralysis of the left second branch of the trigeminal nerve. Her chest X-ray
showed evidence of bilateral hilar lymphadenopathy. We performed biopsy of her
parotid gland, and leading to a diagnosis of noncaseating epithelioid granuloma
characterized by lymphocyte and multinucleated giant cell invasion. Therefore,
she was diagnosed with the abortive type of Heerfordt syndrome which is a
subtype of sarcoidosis. This is the only case associated with paralysis of the
trigeminal nerve without paralysis of facial nerves to be reported in Japan. As a subtype of the clinical presentations associated with sarcoidosis, the
combination of uveitis, parotid gland swelling, and facial nerve palsy is known
as Heerfordt's syndrome. This syndrome is an extremely rare disorder that has
been estimated to affect only 4.1-5.6% of patients with sarcoidosis. We present
2 cases of Heerfordt's syndrome associated with radiculopathy in the trunk. The
2 patients experienced unilateral or bilateral radiculopathy in the trunk and in
the trigeminal nerve area associated with Heerfordt's syndrome. Radiculopathy is
also a rare manifestation in patients with neurosarcoidosis. A literature review
revealed that only 51 cases of radiculopathy associated with sarcoidosis have
been documented. A diagnosis of Heerfordt's syndrome was observed in 7 out of
these 51 cases. Together with our 2 cases, 9 out of 53 patients with
radiculopathy associated with sarcoidosis have been diagnosed as having
Heerfordt's syndrome (estimated frequency, 16.9%). In conclusion, radiculopathy
is a common neurological manifestation in patients with Heerfordt's syndrome. On
the basis of our experience, we suggest that physicians consider the possibility
of Heerfordt's syndrome in cases of radiculopathy with unknown cause. We report a case of complete Heerfordt syndrome accompanied by the involvement
of small fiber neuropathy (SFN) manifesting as refracory facial pain. A
30-year-old man presented with pyrexia, a 2-week history of facial burning pain,
and difficulty of mastication. After admission to our hospital, neurological
examinations showed bilateral facial pain, trigeminal motor palsy, left facial
nerve palsy, bilateral sensory neural deafness, uveitis and swelling of the
parotid gland. Other examinations revealed bilateral hilar lymphadenopathy, high
serum titer of angiotensin coenzyme, and no response in a tuberculin-tested,
non-caseating epithelioid granuloma from lip biopsy, leading to the diagnosis of
complete Heerfordt syndrome. Mandibular skin biopsy with immunostaining for PGP
9.5 showed SFN. High-dose corticosteroids proved somewhat effective against SFN
as facial pain, but reducing the corticosteroid dose proved difficult, as
symptoms were refractory to other immunosuppressants and pain-control drugs such
as anti-epileptics and anti-depressants. The patient died of acute pancreatitis
3 years after disease onset. Autopsy showed no granuloma in hilar lymph node,
trigeminal nerve, cranial base, nerve root, and muscle. SFN in this case
probably represent a cause of refractory facial pain. Heerfordt's syndrome is a rare manifestation of sarcoidosis characterized by the
presence of facial nerve palsy, parotid gland enlargement, anterior uveitis, and
low grade fever. Two cases of Heerfordt's syndrome and a literature review are
presented. Case 1. A 53-year-old man presented with swelling of his right
eyelid, right facial nerve palsy, and swelling of his right parotid gland. A
biopsy specimen from the swollen eyelid indicated sarcoidosis and he was
diagnosed with incomplete Heerfordt's syndrome based on the absence of uveitis.
His symptoms were improved by corticosteroid therapy. Case 2. A 55-year-old
woman presented with left facial nerve palsy, bilateral hearing loss, and
swelling of her bilateral parotid glands. She had been previously diagnosed with
uveitis and bilateral hilar lymphadenopathy. Although no histological
confirmation was performed, she was diagnosed with complete Heerfordt's syndrome
on the basis of her clinical symptoms. Swelling of the bilateral parotid glands
and left facial nerve palsy were improved immediately by corticosteroid therapy.
Sarcoidosis is a relatively uncommon disease for the otolaryngologist. However,
the otolaryngologist may encounter Heerfordt's syndrome as this syndrome
presents with facial nerve palsy and swelling of the parotid gland. Therefore,
we otolaryngologists should diagnose and treat Heerfordt's syndrome
appropriately in cooperation with pneumologists and ophthalmologists. Heerfordt's syndrome is a rare manifestation of sarcoidosis and is defined as a
combination of facial palsy, parotid swelling, and uveitis, associated with a
low-grade fever. We report a case of Heerfordt's syndrome presenting with a high
fever and increased serum tumor necrosis factor alpha (TNF-α) levels. The
patient had facial palsy, parotid swelling, uveitis, and swelling of the right
supraclavicular and hilar lymph nodes. Corticosteroid therapy was initiated, and
her symptoms soon resolved completely, in tandem with a decrease in TNF-α serum
levels. Cutaneous lesions of sarcoidosis present with various manifestations including
specific and non-specific cutaneous lesions. Ichthyosiform sarcoidosis is a rare
form of cutaneous sarcoidosis, presenting with asymptomatic, adherent, polygonal
scales, mainly appearing on the lower limbs. Ichthyosiform sarcoidosis has a
predilection for dark-skinned races, and cases affecting Japanese patients have
rarely been reported in English literature. We herein describe three Japanese
cases of ichthyosiform sarcoidosis on the lower limbs. All of the patients were
female, with an age range of 57-69 years old. Histologically, sarcoidal
granulomas were located in the mid- to lower dermis. All cases had scar
sarcoidosis on the knees. Furthermore, Case 1 presented with papular
sarcoidosis on the back, and Case 3 presented with subcutaneous nodules on the
buttock as well as erythema nodosum-like lesions on the lower legs. All
patients had lung sarcoidosis, but ocular sarcoidosis was seen in only Case 2.
Case 3 showed Heerfordt syndrome with facial nerve paralysis. Histological
features showed that the granular layers were scarcely detected in the overlying
epidermis; however, filaggrin expression was not decreased. Sarcoidal
granulomas accumulated around the sweat glands in one case, whereas those
features were not detected in the other two cases. In conclusion, ichthyosiform
cutaneous sarcoidosis may be overlooked or misdiagnosed as xerotic dry skin
which is frequently found in elderly people, and ichthyosiform cutaneous lesions
may be more prevalent than previously estimated. |
In quadruped mammals, what bones make up the stifle? | In quadruped mammals, the stifle is composed of 3 bones, the femur, the tibia and the patella. | BACKGROUND: The purpose of this study was to describe the normal appearance of
the bony and soft tissue structures of the stifle joint of a Bengal tiger
(Panthera tigris) by low-field magnetic resoce imaging (MRI), and the use of
gross anatomical dissections performed as anatomical reference. A cadaver of a
mature female was imaged by MRI using specific sequences as the Spin-echo (SE)
T1-weighting and Gradient-echo (GE) STIR T2-weighting sequences in sagittal,
dorsal and transverse planes, with a magnet of 0.2 Tesla. The bony and articular
structures were identified and labelled on anatomical dissections, as well as on
the magnetic resoce (MR) images.
RESULTS: MR images showed the bone, articular cartilage, menisci and ligaments
of the normal tiger stifle. SE T1-weighted sequence provided excellent
resolution of the subchondral bones of the femur, tibia and patella compared
with the GE STIR T2-weighted MR images. Articular cartilage and synovial fluid
were visualised with high signal intensity in GE STIR T2-weighted sequence,
compared with SE T1-weighted sequence where they appeared with intermediate
intensity signal. Menisci and ligaments of the stifle joint were visible with
low signal intensity in both sequences. The infrapatellar fat pad was
hyperintense on SE T1-weighted images and showed low signal intensity on GE STIR
T2-weighted images.
CONCLUSIONS: MRI provided adequate information of the bony and soft tissues
structures of Bengal tiger stifle joints. This information can be used as
initial anatomic reference for interpretation of MR stifle images and to assist
in the diagnosis of diseases of this region. |
Are paralog genes co-regulated? | Paralog genes arise from gene duplication events during evolution, which often lead to similar proteins that cooperate in common pathways and in protein complexes. Consequently, paralogs show correlation in gene expression. | The expression of zebrafish hoxb3a and hoxb4a has been found to be mediated
through five transcripts, hoxb3a transcripts I-III and hoxb4a transcripts I-II,
driven by four promoters. A "master" promoter, located about 2 kb downstream of
hoxb5a, controls transcription of a pre-mRNA comprising exon sequences of both
genes. This unique gene structure is proposed to provide a novel mechanism to
ensure overlapping, tissue-specific expression of both genes in the posterior
hindbrain and spinal cord. Transgenic approaches were used to analyze the
functions of zebrafish hoxb3a/hoxb4a promoters and enhancer sequences containing
regions of homology that were previously identified by comparative genomics. Two
neural enhancers were shown to establish specific anterior expression borders
within the hindbrain and mediate expression in defined neuronal populations
derived from hindbrain rhombomeres (r) 5 to 8, suggesting a late role of the
genes in neuronal cell lineage specification. Species comparison showed that the
zebrafish hoxb3a r5 and r6 enhancer corresponded to a sequence within the mouse
HoxA cluster controlling activity of Hoxa3 in r5 and r6, whereas a homologous
region within the HoxB cluster activated Hoxb3 expression but limited to r5. We
conclude that the similarity of hoxb3a/Hoxa3 regulatory mechanisms reflect the
shared descent of both genes from a single ancestral paralog group 3 gene. Gene duplications have been broadly implicated in the generation of
testis-specific genes. To perform a comprehensive analysis of paralogous
testis-biased genes, we characterized the testes transcriptome of Drosophila
melanogaster by comparing gene expression in testes vs. ovaries, heads, and
gonadectomized males. A number of the identified 399 testis-biased genes code
for the known components of mature sperm. Among the detected 69 genes
downregulated in testes, a large fraction is required for viability. By
analyzing paralogs of testis-biased genes, we identified "co-regulated"
paralogous pairs in which both genes are testis biased, "anti-regulated" pairs
in which one paralog is testis biased and the other downregulated in testes, and
"neutral" pairs in which one paralog is testis biased and the other
constitutively expressed. The numbers of identified co-regulated and
anti-regulated pairs were higher than expected by chance. Testis-biased genes
included in these pairs show decreased frequency of lethal mutations, suggesting
their specific role in male reproduction. These genes also show exceptionally
high interspecific variability of expression in comparison between D.
melanogaster and the closely related D. simulans. Further, interspecific changes
in testis bias of expression are generally correlated within the co-regulated
pairs and are anti-correlated within the anti-regulated pairs, suggesting
coordinated regulation within both types of paralogous gene pairs. BACKGROUND: Genome amplification through duplication or proliferation of
transposable elements has its counterpart in genome reduction, by elimination of
DNA or by gene inactivation. Whether loss is primarily due to excision of random
length DNA fragments or the inactivation of one gene at a time is controversial.
Reduction after whole genome duplication (WGD) represents an inexorable collapse
in gene complement.
RESULTS: We compare fifteen genomes descending from six eukaryotic WGD events
20-450 Mya. We characterize the collapse over time through the distribution of
runs of reduced paralog pairs in duplicated segments. Descendant genomes of the
same WGD event behave as replicates. Choice of paralog pairs to be reduced is
random except for some resistant regions of contiguous pairs. For those paralog
pairs that are reduced, conserved copies tend to concentrate on one chromosome.
CONCLUSIONS: Both the contiguous regions of reduction-resistant pairs and the
concentration of runs of single copy genes on a single chromosome are evidence
of transcriptional co-regulation, dosage sensitivity or other functional
interaction constraining the reduction process. These constraints and their
evolution over time show a consistent pattern across evolutionary domains and a
highly reproducible pattern, as replicates, for the several descendants of a
single WGD. Cancer is among the major causes of human death and its mechanism(s) are not
fully understood. We applied a novel meta-analysis approach to multiple sets of
merged serial analysis of gene expression and microarray cancer data in order to
analyze transcriptome alterations in human cancer. Our methodology, which we
denote 'COgnate Gene Expression patterNing in tumours' (COGENT), unmasked
numerous genes that were differentially expressed in multiple cancers. COGENT
detected well-known tumor-associated (TA) genes such as TP53, EGFR and VEGF, as
well as many multi-cancer, but not-yet-tumor-associated genes. In addition, we
identified 81 co-regulated regions on the human genome (RIDGEs) by using
expression data from all cancers. Some RIDGEs (28%) consist of paralog genes
while another subset (30%) are specifically dysregulated in tumors but not in
normal tissues. Furthermore, a significant number of RIDGEs are associated with
GC-rich regions on the genome. All assembled data is freely available online
(www.oncoreveal.org) as a tool implementing COGENT analysis of multi-cancer
genes and RIDGEs. These findings engender a deeper understanding of cancer
biology by demonstrating the existence of a pool of under-studied multi-cancer
genes and by highlighting the cancer-specificity of some TA-RIDGEs. |
List 2 approved drug treatments for Inflammatory Bowel Disease (IBD). | Patients with IBD, inflammtory Bowel Disease can be treated with steroids, or 2 approved biosimilar drugs infliximab (IFX) or adalimumab (ADA) | The introduction of infliximab into clinical practice is one of the most
significant advances in the care of patients who have IBD. Infliximab has become
an important part of the medical armamentarium to treat extraintestinal
manifestations that often are refractory to other medications and are a
significant cause of morbidity in these patients. Two other TNF inhibitors
recently have demonstrated efficacy in CD: certolizumab pegol and adalimumab.
The Food and Drug Administration has approved adalimumab for use in RA. One
predicts that these agents also may have activity in the extraintestinal
manifestation for IBD. To determine whether future biologics are effective in
the EIM of IBD, one may need to look no further than the vast clinical trial
experience in primary chronic inflammatory diseases of the joints and skin: RA
and psoriasis. For example, the Food and DRug Administration recently has
approved an anti-B-cell therapy, rituximab, and a T-cell costimulation
modulator, abatacept, for use in RA. It certainly will be of interest to
determine whether these biologic agents demonstrate efficacy in the intestinal
and EIM of IBD. Biological therapies for inflammatory bowel disease (IBD) have, since their
introduction over 15 years ago, been separated from so-called 'conventional
therapies' in the therapeutic paradigm. Although the TNF inhibitor infliximab is
known to improve IBD outcomes in many different ways, several questions remain
regarding the optimal way to employ this drug in the clinic, which are the
questions not yet explored in clinical trials, in part, due to the drug's high
cost. With the introduction of biosimilar drugs, including the infliximab
biosimilar CT-P13, the therapeutic landscape in IBD will change. Access to
biological drugs will widen and patients will be treated earlier. The division
between 'conventional' and 'biological' therapy will be replaced by new
treatment paradigms. Gaps in knowledge about the best use of anti-TNF therapies
in IBD may also be filled due to the enhanced competition between manufacturers
and the expected lower costs of biosimilars. Author information:
(1)Department of Medical and Surgical Sciences, IBD Unit, University of Bologna,
Bologna, Italy. Electronic address: [email protected].
(2)Department of Medical and Surgical Sciences, IBD Unit, University of Bologna,
Bologna, Italy.
(3)AOU Gastroenterology, Careggi University Hospital, Florence, Italy.
(4)IBD Unit Complesso Integrato Columbus-Gemelli Hospital Catholic University
Foundation, Rome, Italy.
(5)University "Tor Vergata", Department of Systems Medicine, Rome, Italy.
(6)Gastroenterology Unit, Federico II University, Naples, Italy.
(7)Gastrointestinal Unit, Ospedale Central Hospital, Bolzano, Italy.
(8)Department of Medicine, Pneumology and Nutrition Clinic, V. Cervello
Hospital, Ospedali Riuniti Villa Sofia-Cervello University of Palermo, Palermo,
Italy.
(9)IBD Center, Humanitas Clinical and Research Centre, Milan, Italy.
(10)Gastroenterology Unit, A.O. Ordine Mauriziano Hospital, Turin, Italy.
(11)Department of Surgical and Gastroenterological Sciences, University of
Padua, Padua, Italy.
(12)Clinical Unit for Chronic Bowel Disorders, Department of Internal Medicine,
IBD Unit Messina, University of Messina, Messina, Italy.
(13)Department of Gastroenterology, San Camillo-Forlanini Hospital, Rome, Italy.
(14)Gastroenterology Unit, San Filippo Neri Hospital, Rome, Italy.
(15)Gastroenterology and Gastrointestinal Endoscopy Unit, IRCCS San Donato
Hospital, San Donato Milanese, Italy.
(16)Gastroenterology and Digestive Endoscopy, ASST Fatebenefratelli Sacco,
University of Milan, Milan, Italy. BACKGROUND: The incidence of inflammatory bowel disease (IBD) in childhood and
adolescence is 5-11 cases per 100 000 persons per year, corresponding to a new
diagnosis of IBD in 800-1470 patients in Germany each year.
METHODS: This review is based on pertinent publications retrieved by a selective
search in PubMed, including guidelines from Germany and abroad.
RESULTS: Children and adolescents with IBD often have extensive involvement and
an aggressive course of disease. Nonetheless, infliximab and adalimumab are the
only biological agents that have been approved for this group of patients. In
Crohn's disease, exclusive enteral nutrition is the treatment of first choice
for inducing a remission. Patients with (peri-)anal fistulae are treated
primarily with infliximab. Corticosteroids and aminosalicylates should be used
with caution. In contrast, children and adolescents with ulcerative colitis are
treated with either aminosalicylates or prednisolone to induce a remission. As a
rule, maintece pharmacotherapy with thiopurines in Crohn's disease and severe
ulcerative colitis, or with aminosalicylates in mild to moderate ulcerative
colitis, is indicated for several years, at least until the end of puberty.
Patients with refractory disease courses are treated with methylprednisolone,
anti-TNF-α-antibodies, and/or calcineurin inhibitors. The spectrum of surgical
interventions is the same as for adults. Specific aspects of the treatment of
children and adolescents with IBD include adverse drug effects, the areas of
nutrition, growth, and development, and the structured transition to adult
medicine.
CONCLUSION: Children and adolescents with IBD or suspected IBD should be cared
for by pediatric gastroenterologists in a center where such care is provided.
Individualized treatment with multidisciplinary, family-oriented longterm care
is particularly important. Drug trials in children and adolescents are needed so
that the off-label use of drugs to patients in this age group can be reduced. |
Which tool exists for microsatellite (SSR) loci detection and primer design? | Microsatellites are genomic sequences comprised of tandem repeats of short nucleotide motifs widely used as molecular markers in population genetics. FullSSR is a new bioinformatic tool for microsatellite (SSR) loci detection and primer design using genomic data from NGS assay. | |
Name curated data resources for ChIP-seq data | The MGA repository, Cistrome Data Browser and CR Cistrome are curated data resources for ChIP-seq data. | Transcription and chromatin regulators, and histone modifications play essential
roles in gene expression regulation. We have created CistromeMap as a web server
to provide a comprehensive knowledgebase of all of the publicly available
ChIP-Seq and DNase-Seq data in mouse and human. We have also manually curated
metadata to ensure annotation consistency, and developed a user-friendly display
matrix for quick navigation and retrieval of data for specific factors, cells
and papers. Finally, we provide users with summary statistics of ChIP-Seq and
DNase-Seq studies. Diversified histone modifications (HMs) are essential epigenetic features. They
play important roles in fundamental biological processes including
transcription, DNA repair and DNA replication. Chromatin regulators (CRs), which
are indispensable in epigenetics, can mediate HMs to adjust chromatin structures
and functions. With the development of ChIP-Seq technology, there is an
opportunity to study CR and HM profiles at the whole-genome scale. However, no
specific resource for the integration of CR ChIP-Seq data or CR-HM ChIP-Seq
linkage pairs is currently available. Therefore, we constructed the CR Cistrome
database, available online at http://compbio.tongji.edu.cn/cr and
http://cistrome.org/cr/, to further elucidate CR functions and CR-HM linkages.
Within this database, we collected all publicly available ChIP-Seq data on CRs
in human and mouse and categorized the data into four cohorts: the reader,
writer, eraser and remodeler cohorts, together with curated introductions and
ChIP-Seq data analysis results. For the HM readers, writers and erasers, we
provided further ChIP-Seq analysis data for the targeted HMs and schematized the
relationships between them. We believe CR Cistrome is a valuable resource for
the epigenetics community. Author information:
(1)Clinical Translational Research Center, Shanghai Pulmonary Hospital, Tongji
University, Shanghai 200433, China.
(2)Department of Bioinformatics, School of Life Sciences and Technology, Tongji
University, Shanghai 200092, China.
(3)Department of Biostatistics and Computational Biology, Dana-Farber Cancer
Institute and Harvard T.H. Chan School of Public Health, Boston, MA 02215, USA.
(4)Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute,
Boston, MA 02215, USA.
(5)MOE Key Laboratory of Bioinformatics, Bioinformatics Division and Center for
Synthetic & Systems Biology, TNLIST; Department of Automation, Tsinghua
University, Beijing 100084, China.
(6)Department of Biochemistry, University at Buffalo, Buffalo, NY 14214, USA.
(7)Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard
Medical School, Boston, MA 02215, USA.
(8)Department of Biostatistics and Computational Biology, Dana-Farber Cancer
Institute and Harvard T.H. Chan School of Public Health, Boston, MA 02215, USA
[email protected].
(9)Clinical Translational Research Center, Shanghai Pulmonary Hospital, Tongji
University, Shanghai 200433, China [email protected]. |
Treatment of which disease was studied in the Gore REDUCE Clinical Study? | The Gore REDUCE Clinical Study studied superiority of patent foramen ovale closure in conjunction with antiplatelet therapy over antiplatelet therapy alone in reducing the risk of recurrent clinical ischemic stroke or new silent brain infarct in patients who have had a cryptogenic stroke. | Collaborators: Volpi J, Bledsoe D, Chiu D, Guthikonda S, Imperial-Aubin D,
Kleiman N, Lin CH, Ling J, Moye S, Rizzo R, Mcintyre P, Nayre C, Wiese J,
Tenorio J, Ajike R, Tindel M, Bajwa T, Allaqaband S, Khitha J, Saxena V, Khatri
B, Bennett M, Schmidt W, Seaton D, Lobacz D, Waller D, Kavinsky C, Amin Z, Chen
M, Conners J, Cutting S, Hijazi Z, Jolly N, Kenny D, Lee V, Mohammad Y,
Prabhakaran S, Smit L, Song S, Aubry D, Dvojack S, Faza N, Glase C, Martyniuk A,
McDonald J, Sidoti F, Kar S, Lyden P, Makkar R, Nakamura M, Singh R, Dohad S,
Song S, Arabyan M, Hussaini A, Kanji R, Khanolkar P, Remba D, Senkbeil L,
Shirazi S, Villareal P, Messe S, Cucchiara B, Herrmann H, Luciano J, Mullen M,
Sansing L, Shafi N, Augelli E, DeSanto ML, Gallatti N, Kruszewski M, Mannion T,
Ventura L, Guttormsen B, Alaswad K, Hibbs S, Kokontis L, Larson G, Mattio T,
Price S, West C, Barr S, Gibbs-Buss M, Randall K, Solenski N, Gimple L, Haley EC
Jr, Lim DS, Nathan B, Worrall B, Bailes L, Brunk S, Garrison C, McKenzie R,
Sprouse N, Thaler D, Feldmann E, Kimmelstiel C, Kolychev D, de Moor M, Toma H,
Bettle M, Fariborz P, Huggins H, Joseph A, Gurley J, Lee J, Pettigrew LC,
Wallace E, Boggs P, Bowman-Connor S, Evans R, Fowler A, Hatfield M, Lacey E,
Rodgers C, Roycraft M, Taul Y, Taylor D, Vanderpool K, Yakubov S, Arce E, Eubank
G, Good A, Hicks WJ, Mejilla J, Albon A, Allardyce C, Allison L, Archer B,
Bailey A, Crabtree C, Garcia A, Gatrell R, Groezinger K, Hawkins M, Taylor M,
Jackson J, Latoche B, Metz W, Mull J, Pletcher M, Sikora L, Tanner K, MacDonald
L, Chang I, Fanale C, Pratt R, Wagner J, Derbyshire S, Giglio K, Siegel K,
Soltau M, Varner C, Wimmer R, Sethi P, Cooper M, Dohmeier C, Ganji J, Penumalli
V, Willis K, Yan Y, Earnhardt L, Fountain J, Hammonds S, Harbison W, Johnson M,
Parker G, Pineda CM, Sabir R, Willard J, Delio P, Aragon J, Chen L, Willis PS,
Bacon J, Granoff S, Isaacs L, Koches J, Khan U, Lazarine B, Miller T, Price S,
Yim S, Sommer R, Khalique O, Kitago T, Willey JZ, Adegbite E, Austin A, Borda T,
DeJesus EF, Feri A, Mendez R, Reisman A, Spencer B, Qureshi Y, Ching M, Deline
CJ, Kandal A, Leonard GT Jr, Meltser H, Mowla A, Sawyer RN Jr, Pereira L,
Shirani P, Ahmed M, Bilal M, Chichelli T, Conover C, Crumlish A, Gagnon R,
Holler D, Mehla S, Mustafa G, Parkes K, Marks D, Book D, Cinquegrani M, Helms A,
Alonge T, DeBauche C, Gosset J, Harmann L, Kadlec S, Kummer C, Mauermann S,
Vannucchi K, Wexler M, Choo J, Rorick M, Sarembock I, Schmerler M, Buscek K,
Darlington T, Francis K, Garza D, Howard W, Ibanez K, McGary E, Robertson R,
Rock D, White D, Paolillo JA Jr, Downey W, Iyengar P, Story J, Aberle S, Ahmad
S, Dellinger C, De Los Santos Y, Gettmann M, Kelly LP, Rathod J, Winkler K, Rowe
S, Jung R, Lynch J, Kuehn S, Case KM, Gilbert K, Mitchener L, Perry J, Smith M,
Weatherfield A, Prieto L, Ching EC, Gebel J Jr, Golden A, Kapadia S, Katzan I,
Khawaja Z, Krasuski R, Lu M, Morton J, Preminger T, Qureshi A, Toth G, Uchino K,
Wasielewski P, Wisco D, Bradley-Skelton S, Koepp S, Konstantinopoulos P,
Kreischer S, Lach D, Richmond A, Strozniak L, Tighe N, Turczyk J, Schneck M,
Darki A, Lewis B, Leya F, Lopez J, Morales-Vidal S, Bernier T, Del Priore J, Ray
J, Shaffer K, Shore J, Ghani M, Kipperman R, Al-Nabhan N, Norman DL, Perry BF,
Schoeffler M, Shah S, Tahirkheli N, Williams J, Wood K, Allen T, Hightower B,
Moore J, Ramsey T, Scharrer C, Mallenbaum S, Ball TC, Schmidley JW, Bidanset A,
Bucha K, Perkins J, Viers C, Mahoney PD, Evans PW, Talreja D, Zweifler R,
Bullivant M, Calayo T, Desser D, Phillips A, Rathbun J, Miller DJ, Greenbaum A,
Guerrero M, Hefzy H, Katramados A, Malik S, Mitsias P, Vivek R, Holmes T, Jones
J, Mays-Wilson K, Marzo K, Galler B, Jafir A, Khan W, Naidu S, Suri B, Wirkowski
E, Drewes W, Patel D, Feldman T, Dafer R, Levisay J, Munson R, Salinger M, Lynch
D, Syed S, Focks C, Lariosa S, Medica K, Skelskey J, Smith AJC, Anderson W,
Giurgiutin DV, Hammer M, Horev A, Jadhav A, Jovin T, Jumaa M, Linares G, Malik
A, Nanduri S, Ranawat N, Reddy V, Starr M, Totoraitis V, Wechsler L, Zaidi S,
Baxendell L, DeCesare S, Dennis L, Enlow M, Farrow C, Kane A, Kunkel M, Massaro
L, Hubbard C, Maini B, Shah J, Meise G, Moser L, Nanna C, Tanner L, Todd A,
Sanders K, Crisco LV, Gwynn M, Johnston L, Kiely J, Palmer S, Banks C, Barnes C,
Ellis-Bailey C, Loy J, McBride M, Patterson A, Skrifvars C, Wold U, Strote J,
McIntosh G, Oldemeyer B, Kaczkowski S, McIntosh K, Schmitzer P, Waller B III,
Das P, Elijovich L, Ibebuogu U, Khouzam R, Klemis J, Koshy S, Lutterman J, Wahba
M, Jones C, Cubeddu R, Cross J, Andrzejewski L, Mahmoudi H, McConnell J,
Muradova E, Silva A, Stevenson L, Younus A, McDaniel M, Morris D, Nahab F, Rab
S, Carter E, Kim D, Kim YM, Holloway B, Ro J, Sanders T, Wang K, Wilson A, Blum
M, Cohen B, Fox S, Shen R, Agar D, Aron MA, Brunetti D, Benner A, Ciprich C,
Lobur E, Martinez N, Whiset B, Call G, Hoesch R, Huan C, Meredith K, Orford
J, Allen M, Butler A, Jacketta-Dunyon C, Konery K, Siler D, Hanzel G, Abbas AS,
Fellows J, Goldstein JA, Buck S, McNally-McHugh A, Romanoski M, Honeycutt WD,
Isa A, Nieves-Quinones D, Cowden A, Honeycutt L, Olson J, Berman D, Cheatham J,
Cheatham SL, Heyer G, Holzer R, Lo W, Roach S, Chisolm J, Gimelli G, Bradbury E,
Chacon M, Jacobson K, Jensen MB, Mason P, Raval A, Sattin J, Harris A, Roginski
C, Vander Ark C, Riddick J, Jarquin-Valdivia AA, Gates S, Beesley C, Blair-Anton
B, Coman D, Hank H, Hughett G, Lineberry V, McCarthy J, Simon A, Badger R,
DeWitt D, Hannon P, Majersik J, Owan T, Smith B, Tandar A, Tkach A, Wold J,
Aitken K, Neuharth RM, Niu S, Preece LP, Tuma J, Brown D, Simmons M,
Gruetzmacher C, Jaehn N, Kelly V, McIntosh K, Schaefbauer J, Stauffacher K,
Carroll J, Kay J, Kim M, Poisson S, Jones W, Quaife R, Simpson J, Hariton J,
Harvey A, Nguyen T, Maurer H, Schmitt C, Tran BK, Wade G, Mattsson E, Jacobsen
PH, Kostulas K, Lantz M, Sahlgren B, Bazjenova T, Emmertsen K, Hastrup S,
Hougaard KD, Mortensen J, Schmitz ML, von Weitzel-Mudersbach P, Bock V, Dueholm
L, Frydendahl D, Madsen LH, Kilian AS, Lindmark K, Thomsen RB, Zachariasen M,
Back C, Berning J, Larsen VA, Simonsen S, West A, Dano M, Olesen C, Veng-Olsen
T, Waje-Andreassen U, Leirgul E, Naess H, Norgard G, Bjorgo T, Dale LS, Saetveit
M, Kaalaas AM, Thue SG, Airaksinen J, Korpela J, Roine S, Ukkonen H, Ylikotila
P, Ketola R, Kivi R, Virtamo T, Dellborg M, Eriksson P, Furenas E, Runmarker B,
Skoglund K, Hultsberg-Olsson G, Dellborg H, Lindgren A, Andsberg G, Hochbergs P,
Holm J, Petersen C, Thilen U, Wictor L, Malmgren E, Nilsson G, Paulsson K, Saha
R, Cockburn J, Keeble T, Poliacikova P, Wayne D, Bruce C, Cooter N, Mackenzie A,
Parker J, Skipper N, Christensen H, Hansen CK, Höst NB, Jeppesen LL, Krieger D,
Nielsen OW, Papina M, Rosenbaum S, Bentsen L, Pedersen A, Spence M, Kodoth V,
Lockhart C, McVerry F, Owens C, Watt M, Hunter A, Manoharan G, Smith B,
Skjelland M, Aaberge L, Brekke M, Dahl A, Hervold A, Lund C, Lunde K, Maurtveten
EH, Skaardal R, Bath P, Appleton J, Henderson R, Krish K, Sprigg N, Smith W,
Wilkins LM, Buck A, Burton J, Clarke JM, Cox P, Gilzeane N, Havard D, Richardson
C, Richardson K, Roffe J, San P, Shelton F, Willmot M, Clift P, Littleton E,
Sims D, Thorne S, Thomas A, Cunningham J, Hurley-McCormack J, Isaacs K,
McCormack J, Sondergaard L, Arlien-Soeborg P, Hoejgaard J, Christensen PR,
Jensen SL, King C, Kristensen LM, Tønder N, Mouritsen E, Petersen M, Kopecky SL,
Bell RD, Chimowitz MI, Shapiro TA, Cohen B, Kase CS, Rowley HA, Turan TN. |
Which comparisons demonstrate the applicability of StereoGene in regulatory genomics? | StereoGene rapidly estimates genome-wide correlation among pairs of genomic features. These features may represent high-throughput data mapped to reference genome or sets of genomic annotations in that reference genome. StereoGene enables correlation of continuous data directly, avoiding the data binarization and subsequent data loss. Correlations are computed among neighboring genomic positions using kernel correlation. Representing the correlation as a function of the genome position, StereoGene outputs the local correlation track as part of the analysis. StereoGene also accounts for confounders such as input DNA by partial correlation. Numerous comparisons of ChIP-Seq datasets from the Human Epigenome Atlas and FANTOM CAGE demonstrate the wide applicability of StereoGene in regulatory genomics. | MOTIVATION: Genomics features with similar genome-wide distributions are
generally hypothesized to be functionally related, for example, colocalization
of histones and transcription start sites indicate chromatin regulation of
transcription factor activity. Therefore, statistical algorithms to perform
spatial, genome-wide correlation among genomic features are required.
RESULTS: Here, we propose a method, StereoGene, that rapidly estimates
genome-wide correlation among pairs of genomic features. These features may
represent high-throughput data mapped to reference genome or sets of genomic
annotations in that reference genome. StereoGene enables correlation of
continuous data directly, avoiding the data binarization and subsequent data
loss. Correlations are computed among neighboring genomic positions using kernel
correlation. Representing the correlation as a function of the genome position,
StereoGene outputs the local correlation track as part of the analysis.
StereoGene also accounts for confounders such as input DNA by partial
correlation. We apply our method to numerous comparisons of ChIP-Seq datasets
from the Human Epigenome Atlas and FANTOM CAGE to demonstrate its wide
applicability. We observe the changes in the correlation between epigenomic
features across developmental trajectories of several tissue types consistent
with known biology and find a novel spatial correlation of CAGE clusters with
donor splice sites and with poly(A) sites. These analyses provide examples for
the broad applicability of StereoGene for regulatory genomics.
AVAILABILITY AND IMPLEMENTATION: The StereoGene C ++ source code, program
documentation, Galaxy integration scripts and examples are available from the
project homepage http://stereogene.bioinf.fbb.msu.ru/.
CONTACT: [email protected].
SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics
online. |
What is the aim of the 4D nucleome project? | The 4D Nucleome Network aims to develop and apply approaches to map the structure and dynamics of the human and mouse genomes in space and time with the goal of gaining deeper mechanistic insights into how the nucleus is organized and functions. The project will develop and benchmark experimental and computational approaches for measuring genome conformation and nuclear organization, and investigate how these contribute to gene regulation and other genome functions. | Author information:
(1)Program in Systems Biology, Department of Biochemistry and Molecular
Pharmacology, University of Massachusetts Medical School, Howard Hughes Medical
Institute, Worcester, Massachusetts 01605, USA.
(2)Department of Cell and Developmental Biology, University of Illinois,
Urbana-Champaign, Illinois 61801, USA.
(3)Division of Biology and Biological Engineering, California Institute of
Technology, Pasadena, California 91125, USA.
(4)Department of Bioengineering, University of California San Diego, La Jolla,
California 92093, USA.
(5)Department of Molecular Biology and Genetics, Cornell University, Ithaca, New
York 14853, USA.
(6)Department of Biochemistry and Molecular Biophysics, Mortimer B. Zuckerman
Mind Brain and Behavior Institute, Columbia University, New York, New York
10027, USA.
(7)Institute for Medical Engineering and Science, and Department of Physics,
Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
(8)Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies,
La Jolla, California 92037, USA.
(9)Department of Biomedical Informatics, Harvard Medical School, Boston,
Massachusetts 02115, USA.
(10)Ludwig Institute for Cancer Research, Department of Cellular and Molecular
Medicine, Institute of Genomic Medicine, Moores Cancer Center, University of
California San Diego, La Jolla California 92093, USA.
(11)Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue
North, Seattle, Washington 98109, USA.
(12)Department of Genome Sciences, University of Washington, Howard Hughes
Medical Institute, Seattle, Washington 98109, USA. |
List symptoms of the Zieve's syndrome. | Zieve's syndrome, characterized by jaundice, hyperlipidaemia and haemolytic anaemia. It usually develops in young, chronically alcoholic subjects with enlarged fatty liver. It may rarely occur with intracranial haemorrhage. | The Zieve's syndrome consists of the transient association of cholestatic
jaundice, hemolytic anemia, hyperlipemia, in a chronic alcoholic. The Authors,
after a short introduction regarding physiopathological problems, describe and
subsequently examine on the clinical ground a recent personal observation, which
had been mentioned for the rarene-s of this disease. Zieve's syndrome (ZS), which consists of transient haemolytic anaemia, jaundice,
hyperlipoproteinaemia, and alcohol-induced liver disease, was studied in male
patients during the acute (n = 20) and the remittent (n = 10) phase. Chronic
alcoholics (n = 10) without haemolysis and healthy male persons (n = 10) served
as controls. Erythrocytes were separated into old and young cells by means of
density-layer centrifugation. Those fractions which contained older red cells
disclosed a pyruvate-kinase instability which resulted in impaired metabolism.
Changes in membrane lipid composition as indicated by increased cholesterol and
polyunsaturated fatty acids (PUFA) were also detected in patients during the
acute phase of ZS. Alcohol-induced red-cell vitamin-E deficiency with a decrease
in PUFA levels may provoke an oxidation of reduced red-cell glutathione which in
turn results in the enzyme instability. This study lends further support to the
hypothesis that the putative role of the red-cell metabolic injury in the origin
of haemolysis in ZS cannot be envisaged without introducing membrane-linked and
extracellular cofactors. In 11 patients with alcohol-induced hyperlipemia, of whom 6 showed a Zieve
Syndrome increased phospholipids, triglycerides and total cholesterol were found
in the red cells stromal. The gasliquid chromatographic analysis of the
phospholipid fatty acids showed increased contents of saturated and
monounsaturated fatty acids C 16-C 18 smaller contents of longchain highly
unsaturated fatty acids. The changes in the fatty acid pattern mainly occurred
in patients with Zieve Syndrome and could be important for the mechanism of the
hemolytic anemia. Theses findings could be in connexion with vitamin E
deficiency. Reversible haemolytic anaemia associated with decreased red cell half-life and
reticulocytosis was studied in 10 patients with Zieve's syndrome. Since the
underlying cause of the red cell destruction is as yet unknown, we determined
the critical metabolic functions of the red cells in order to define the assumed
intracorpuscular defect causing haemolysis. The glucose metabolizing enzymes had
normal or raised values. - In view of the diminished ATP and raised
2,3-diphosphoglycerate (2.3 DPG) levels - a combination which suggests a
pyruvate kinase (PK) deficiency - additional procedures were carried out in
order to detect an abnormal activity of the red cell PK. Studies of biochemical
properties of PK such as thermostability, Michaelis-Menten constants, and
activation and inhibition tests brought results markedly deviating from the
norm.-Fractions containing old cells particularly disclosed PK instability. A
defective red cell matabolism resulted which was measurable through
ATP-instability, altered glucose utilization and lactate production. -
Experimental cell aging procedures led to a markedly decreased red cell
metabolism. These assays revealed that mutations of PK-control mechanisms might
be involved as factor triggering haemolytic anaemia of Zieve's syndrome. The macroscopic and microscopic findings of a case of Zieve's syndrome are
described (fatty liver, icterus, hyperlipemia and hemolytic anemia in chronic
alcoholism). The outstanding macroscopic finding is milky turbidity of the blood
in arterial and venous vascular channels as well as hepatomegaly and anaemia of
internal organs. A prominent feature of the histological picture is the
high-grade lipaemia of the large and small vessels (arteries and veins),
capillary occlusions resembling fat embolism in all organs and severe diffuse
fatty metamorphosis of the liver. Circulatory disorders and the cause of death
are discussed. Zieve's syndrome, characterized by jaundice, hyperlipaemia and haemolytic
anaemia, usually develops in young, chronically alcoholic subjects with enlarged
fatty liver. Hitherto, the course of the disease was considered favourable in
most patients, with complete regression of clinical, biological and anatomical
symptoms. However, the discovery of acute alcoholic hepatitis during repeat
needle-biopsy of the liver confirms that in some cases steatosis may mask
hyaline necrosis and neutrophil infiltration. Zieve's syndrome therefore is not
benign but precedes acute alcoholic hepatitis episodes on a normal, fibrotic or
cirrhotic liver. Zieve's syndrome consists of transient haemolytic anaemic, jaundice,
hyperlipidaemia and alcohol-induced liver disease. It is rare with less than 75
cases reported in a Medicine literature search from 1966. It can present acutely
with abdominal pain. |
What is the link between psoriatic arthritis and depression | Depression Is Associated with an Increased Risk of Psoriatic Arthritis among Patients with Psoriasis. | Psoriasis is a chronic, genetic, inflammatory skin disease affecting
approximately 2% of the population worldwide. Over the past decade, multiple
studies have shown that not only is there an association between psoriasis and
psoriatic arthritis, depression, and substance abuse, but psoriasis patients
also have a higher incidence of obesity, diabetes, heart disease and stroke. In
addition, and more concerning, young psoriatic patients particularly those with
more severe disease are at an increased mortality risk even when controlling for
these factors. The systemic inflammation in psoriasis generates elevation of
C-reactive protein, homocysteine, and inflammatory cytokines such as TNF-a,
IL-6, IL-17, IL-20, IL-22, and IL-23, which may contribute to the overall
morbidity and mortality in these patients. Within this article we will discuss
the associations between psoriasis and multiple systemic health problems. FUNDAMENTAL AND OBJECTIVE: Psychological impairment is frequent in patients with
rheumatic diseases. The aim of the study was to assess the prevalence of
symptoms of anxiety and depression in patients with psoriatic arthritis
attending rheumatology clinics.
PATIENTS AND METHOD: Multicentre cross-sectional study conducted in rheumatology
clinics. Patients with psoriatic arthritis were recruited; variables retrieved
were sociodemographic, clinical and patient centered (Hospital Anxiety and
Depression scale o HADs, EQ-5D questionnaire, etc.). Prevalence in the study
population was calculated as anxiety or depression symptoms by an HADs score ≥11
or those receiving pharmacological treatment. A logistics regression model was
used to know which variables were related to symptoms of anxiety or depression.
RESULTS: A total of 495 patients were included, 42.8% were women and median (SD)
age was 50.4 (12.7) years. Prevalence of symptoms of anxiety were 29.7% and
prevalence of symptoms of depression was 17,6%. Patients with anxiety or
depression symptoms had all EQ-5D dimensions affected (p<0.01). Higher
prevalence of anxiety was related to being a woman, a mixed onset pattern with
respect to peripheral joints and those treated with DMARD alone with respect to
DMARD+NSAID or biologic alone. A higher depression prevalence was related to
being a woman and a mixed onset pattern with respect to peripheral joints.
CONCLUSION: The prevalence of anxiety symptoms and the prevalence of depression
symptoms are high among patients suffering psoriatic arthritis in the studied
population. OBJECTIVE: Symptoms of psychological distress, including anxiety and depressive
symptoms, and illness perceptions are important in determining outcome in
patients with rheumatic disease. We aimed to compare psychological distress in
psoriatic arthritis (PsA) and rheumatoid arthritis (RA) and to test whether the
association between psychological variables and health-related quality of life
(HRQOL) was similar in the 2 forms of arthritis.
METHODS: In 83 PsA patients and 199 RA patients, we used the Patient Health
Questionnaire 9 (PHQ-9), the Symptom Checklist-90-Revised, and the Brief Illness
Perception Questionnaire to assess psychological variables and the World Health
Organization Quality of Life Instrument, Short Form to assess HRQOL. We used
hierarchical regression analysis to determine the associations between
psychological variables and HRQOL after adjusting for demographic variables and
disease parameters.
RESULTS: The prevalence of moderate to severe levels of depressive symptoms
(PHQ-9 score ≥10) was 21.7% in PsA patients, 25.1% in RA patients, and 36.7% in
those PsA patients with polyarthritis. After adjustment for severity of disease
and pain, anxiety (β = -0.28) and concern about bodily symptoms attributed to
the illness (β = -0.33) were independent correlates of physical HRQOL in PsA. In
RA, depressive symptoms (β = -0.29) and concern about the consequences of the
arthritis (β = -0.27) were independent correlates of physical HRQOL.
CONCLUSION: These findings suggest strongly that psychological factors are
important correlates of HRQOL in PsA as well as in RA. Attention to patients'
anxiety and their concern about numerous bodily symptoms attributed to the
illness may enable rheumatologists to identify and manage treatable aspects of
HRQOL in PsA. OBJECTIVE: (1) To determine the prevalence of depression and anxiety in patients
with psoriatic arthritis (PsA) and to identify associated demographic and
disease-related factors. (2) To determine whether there is a difference in the
prevalence of depression and anxiety between patients with PsA and those with
psoriasis without PsA (PsC).
METHODS: Consecutive patients attending PsA and dermatology clinics were
assessed for depression and anxiety using the Hospital Anxiety and Depression
Scale. Patients underwent a clinical assessment according to a standard protocol
and completed questionnaires assessing their health and quality of life. T
tests, ANOVA, and univariate and multivariate models were used to compare
depression and anxiety prevalence between patient cohorts and to determine
factors associated with depression and anxiety.
RESULTS: We assessed 306 patients with PsA and 135 with PsC. There were
significantly more men in the PsA group (61.4% vs 48% with PsC) and they were
more likely to be unemployed. The prevalence of both anxiety and depression was
higher in patients with PsA (36.6% and 22.2%, respectively) compared to those
with PsC (24.4% and 9.6%; p = 0.012, 0.002). Depression and/or anxiety were
associated with unemployment, female sex, and higher actively inflamed joint
count as well as disability, pain, and fatigue. In the multivariate reduced
model, employment was protective for depression (OR 0.36) and a 1-unit increase
on the fatigue severity scale was associated with an increased risk of
depression (OR 1.5).
CONCLUSION: The rate of depression and anxiety is significantly higher in
patients with PsA than in those with PsC. Depression and anxiety are associated
with disease-related factors. Psoriasis is a chronic disease that affects more than the skin. It has an impact
on every facet of an individual's life and is associated with numerous
comorbidities, such as obesity, diabetes, cardiovascular disease, psoriatic
arthritis, metabolic syndrome, squamous cell carcinoma, lymphoma, depression,
anxiety and other immune-related conditions, such as Crohn's disease. Obesity is
inextricably linked with type 2 diabetes, hypertension, hyperlipidemia, and
cardiovascular disease. Hypertension and cardiovascular disease are precursors
for myocardial infarction and stroke. Lifestyle choices, such as smoking,
alcohol consumption, inadequate nutrition and physical exercise are behaviours
that need to be addressed. With the right education from the community nurse,
patients can be informed about the decisions they make and can ultimately choose
to live a healthier life. OBJECTIVE: To estimate rates of suicidal behaviors and treated depression in
patients with psoriatic arthritis (PsA) in comparison to non-PsA patients.
METHODS: Using the Clinical Practice Research Datalink, we conducted a cohort
study of patients with PsA compared to non-PsA patients. Patients with codes for
suicidal behaviors (ideation, attempts, and suicide) and treated depression
(diagnosis plus anti-depressant prescription) recorded during follow-up were
identified as cases. We estimated incidence rates (IRs) and incidence rate
ratios (IRRs) with 95% confidence intervals (CIs) for each outcome and
stratified results in the PsA cohort by receipt of systemic PsA drugs.
RESULTS: The rates of suicide ideation, attempt, and suicide were similar for
PsA and non-PsA patients [IRR = 0.99 (95%CI: 0.67-1.47), IRR = 1.07 (95%CI:
0.86-1.34), and 0.34 (95%CI: 0.05-2.48), respectively] and rates of suicidal
behaviors were slightly higher among PsA patients who received PsA drugs
compared to those who did not. PsA patients had slightly higher rate of treated
depression compared to non-PsA patients [IRR = 1.38 (95%CI: 1.27-1.49)] and were
significantly higher in PsA patients who received drugs [IRR = 1.59 (95%CI:
1.35-1.86)].
CONCLUSIONS: Rate of depression was higher in patients with PsA compared to
non-PsA patients. The rate of suicidal behaviors was similar between the two
cohorts. Psoriasis is a systemic chronic inflammatory disease associated with
comorbidity. Many epidemiological studies have shown that psoriasis is
associated with psoriatic arthritis as well as cardiovascular and metabolic
diseases. Furthermore, obesity and psychological diseases such as depression and
anxiety disorders are linked with psoriasis and play a central role in its
management. The association of psoriasis and its comorbidity can be partly
explained by genetic and pathophysiological mechanisms. Approximately
40 psoriasis susceptibility loci have been described with the majority linked to
the innate and adaptive immune system. In some associated diseases, such as
psoriatic arthritis, an overlap of their genetic susceptibility exists.
Pathophysiologically the "psoriatic march" is a model that describes the
development of metabolic and cardiovascular diseases due to the presence of
underlying systemic inflammation. Dermatologists are the gatekeepers to
treatment for patients with psoriasis. The early detection and the management of
comorbidity is part of their responsibility. Concepts for the management of
psoriasis and tools to screen for psoriatic comorbidity have been developed in
order to support dermatologists in daily practice. Psoriasis treatments range from topical treatments and phototherapy to oral
systemic medications and injections. Despite good control of the disease when
applying appropriate treatments (according to disease severity, insurance
parameters, patient preference, and patients' ability to adhere), continued
advancements will allow even better symptomatic control, reduced adverse
effects, and patient satisfaction. This review aims to assess traditional and
new psoriasis treatments and how to apply them in clinical practice. A
literature review on psoriasis treatments and clinical applications was
performed using PubMed. Mild-to-moderate psoriasis treatments include topicals,
localized phototherapy, and newer therapies combining two types of topicals,
phototherapy with topicals, and easy-to-use foam and spray vehicles.
Moderate-to-severe psoriasis therapies include monotherapy or various
combinations of generalized phototherapy, oral treatments, and biologic agents,
with new oral and biologic agents on the horizon. Dermatologists and primary
care providers share roles in screening for associated comorbidities (including
cardiovascular disorders, chronic kidney disease, Crohn disease, dyslipidemia,
diabetes mellitus/insulin resistance, depression, metabolic syndrome, obesity,
and psoriatic arthritis), managing patients' treatments, and reevaluating
treatment needs as new therapies are approved. Continued advancements in
psoriasis treatment and improvement in coordinated care will allow better
overall care of patients with psoriasis. Conflict of interest statement: Conflict of Interest Disclosures: Dr. Takeshita
receives a research grant (to the Trusteees of the University of Pennyslvania)
from Pfizer and payment for continuing medical education work related to
psoriasis. Dr. Mehta is a full time U.S. Government employee. Dr. Ogdie receives
research grants from AbbVie (to the Group for Research and Assessment of
Psoriasis and Psoriatic Arthritis [GRAPPA]), Celgene (to GRAPPA), and Pfizer
Inc. (to the Trustees of the University of Pennsylvania and GRAPPA), and has
served as a consultant for Novartis, receiving honoraria. Dr. Van Voorhees has
served as a consultant for AbbVie, Amgen, Aqua, Astra Zeneca, Celgene, Corrona,
Dermira, Janssen, Leo, Novartis, and Pfizer, receiving honoraria; received a
research grant from AbbVie; and has other relationship with Merck. Dr. Gelfand
has served as a consultant for AbbVie, AstraZeneca, Celgene Corp, Coherus, Eli
Lilly, Janssen Biologics (formerly Centocor), Sanofi, Merck, Novartis Corp,
Endo, and Pfizer Inc., receiving honoraria; and receives research grants (to the
Trustees of the University of Pennsylvania) from AbbVie, Amgen, Eli Lilly,
Janssen, Novartis Corp, Regeneron, and Pfizer Inc.; and received payment for
continuing medical education work related to psoriasis. Dr. Gelfand is a
co-patent holder of resiquimod for treatment of cutaneous T cell lymphoma. Author information:
(1)Leaders in Medicine Program, Cumming School of Medicine, Calgary, Alberta,
Canada; Biomedical Engineering Program, Schulich School of Engineering, Calgary,
Alberta, Canada.
(2)Leaders in Medicine Program, Cumming School of Medicine, Calgary, Alberta,
Canada; Department of Community Health Sciences, Cumming School of Medicine,
Calgary, Alberta, Canada.
(3)Department of Community Health Sciences, Cumming School of Medicine, Calgary,
Alberta, Canada.
(4)Division of Dermatology, Cumming School of Medicine, Calgary, Alberta,
Canada.
(5)Department of Community Health Sciences, Cumming School of Medicine, Calgary,
Alberta, Canada; Division of Gastroenterology, Cumming School of Medicine,
Calgary, Alberta, Canada.
(6)Department of Community Health Sciences, Cumming School of Medicine, Calgary,
Alberta, Canada; Department of Psychiatry, Cumming School of Medicine, Calgary,
Alberta, Canada; Department of Physiology and Pharmacology, Cumming School of
Medicine, Calgary, Alberta, Canada.
(7)Division of Gastroenterology, Cumming School of Medicine, Calgary, Alberta,
Canada.
(8)Department of Community Health Sciences, Cumming School of Medicine, Calgary,
Alberta, Canada; Department of Psychiatry, Cumming School of Medicine, Calgary,
Alberta, Canada.
(9)Department of Community Health Sciences, Cumming School of Medicine, Calgary,
Alberta, Canada; Division of Rheumatology, Cumming School of Medicine, Calgary,
Alberta, Canada. Electronic address: [email protected]. OBJECTIVE: To investigate the predictive value of baseline depression/anxiety on
the likelihood of achieving joint remission in rheumatoid arthritis (RA) and
psoriatic arthritis (PsA) as well as the associations between baseline
depression/anxiety and the components of the remission criteria at follow-up.
METHODS: We included 1326 patients with RA and 728 patients with PsA from the
prospective observational NOR-DMARD study starting first-time tumour necrosis
factor inhibitors or methotrexate. The predictive value of depression/anxiety on
remission was explored in prespecified logistic regression models and the
associations between baseline depression/anxiety and the components of the
remission criteria in prespecified multiple linear regression models.
RESULTS: Baseline depression/anxiety according to EuroQoL-5D-3L, Short Form-36
(SF-36) Mental Health subscale ≤56 and SF-36 Mental Component Summary
≤38 negatively predicted 28-joint Disease Activity Score <2.6, Simplified
Disease Activity Index ≤3.3, Clinical Disease Activity Index ≤2.8, ACR/EULAR
Boolean and Disease Activity Index for Psoriatic Arthritis ≤4 remission after 3
and 6 months treatment in RA (p≤0.008) and partly in PsA (p from 0.001 to 0.73).
Baseline depression/anxiety was associated with increased patient's and
evaluator's global assessment, tender joint count and joint pain in RA at
follow-up, but not with swollen joint count and acute phase reactants.
CONCLUSION: Depression and anxiety may reduce likelihood of joint remission
based on composite scores in RA and PsA and should be taken into account in
individual patients when making a shared decision on a treatment target. |
Is polyadenylation a process that stabilizes a protein by adding a string of Adenosine residues to the end of the molecule? | No, polyadenylation is a process that stabilizes mRNA by adding up to 200 adenosine residues to the 3' end of the trabscript | A 104 nucleotide-long small RNA, referred to as s-poly A+ RNA, containing 30
adenosine residues on its 3' -end was found in dinoflagellates, purified and its
nucleotide sequence was determined. The sequence is: (sequence text) The
polyadenylation signal AAUAAA was not found in this RNA; this result indicates
that the 30 nucleotide-long poly A on the 3' -end is either coded for by this
gene, or the poly A chain is added on this small RNA by a mechanism different
from that for polyadenylation of messenger RNAs. Two polyadenylated small RNAs
identified previously were implicated in differentiation of chicken heart muscle
cells (Deshpande, A. K., Jakowlew, S. B., Arnold, H., Crawford, P. A. and
Siddiqui, M. A. Q. (1977) J. Biol. Chem. 252, 6521-6527), and in brain specific
mRNA transcription (Sutcliffe, J. G., Milner, R. J., Gottesfeld, J. M. and
Lerner, R. A. (1984) Nature 309, 237-241). This RNA is the first polyadenylated
small RNA to be sequenced. Formation of mRNA 3' termini involves cleavage of an mRNA precursor and
polyadenylation of the newly formed end. Cleavage of simian virus 40 late
pre-mRNA in a crude nuclear extract generated two RNAs, 5' and 3'
half-molecules. These RNAs were unmodified and linear. The 5' half-molecule
contained sequences upstream but not downstream of the poly(A) site and ended in
a 3'-terminal hydroxyl. The 3' half-molecules comprised a family of RNAs, each
of which contains only sequences downstream of the poly(A) site, and ends in a
5'-terminal phosphate. These RNAs differed only in the locations of their 5'
terminus. The 3' terminus of the 5' half-molecule was the adenosine 10
nucleotides downstream of AAUAAA, at the +1 position. The 5' terminus of the
longest 3' half-molecule was at +2. Thus, these two RNAs contain every
nucleoside and phosphate of the precursor. The existence of these half-molecules
demonstrates that endonucleolytic cleavage occurs near the poly(A) site. 5'
half-molecules generated in the presence of EDTA (which blocks polyadenylation,
but not cleavage) ended at the adenosine at position +1 of the precursor. When
incubated in the extract under suitable conditions, they became polyadenylated.
5' half-molecules formed in 3'-dATP-containing reactions contained a single
3'-deoxyadenosine (cordycepin) residue added onto the +1 adenosine and were poor
polyadenylation substrates. We infer that the +1 adenosine of the precursor
becomes the first A of the poly(A) tract and provides a 3' hydroxyl group to
which poly(A) is added posttranscriptionally. Polyadenylation of mRNA precursors by poly(A) polymerase depends on two
specificity factors and their recognition sequences. These are cleavage and
polyadenylation specificity factor (CPSF), recognizing the polyadenylation
signal AAUAAA, and poly(A) binding protein II (PAB II), interacting with the
growing poly(A) tail. Their effects are independent of ATP and an RNA 5'-cap.
Analysis of RNA-protein interactions by non-denaturing gel electrophoresis shows
that CPSF, PAB II and poly(A) polymerase form a quaternary complex with the
substrate RNA that transiently stabilizes the binding of poly(A) polymerase to
the RNA 3'-end. Only the complex formed from all three proteins is competent for
the processive synthesis of a full-length poly(A) tail. Polyadenylation of premessenger RNAs occurs posttranscriptionally in the nucleus
of eukaryotic cells by cleavage of the precursor and polymerization of adenosine
residues. In the yeast Saccharomyces cerevisiae, the mature poly(A) tail ranges
from 60 to 70 nucleotides. 3'-end processing can be reproduced in vitro with
purified factors. The cleavage reaction requires cleavage factors I and II (CF I
and CF II), whereas polyadenylation involves CF I, polyadenylation factor I
(PFI), and poly(A) polymerase (Pap1p). CF I has recently been separated into two
factors, CF IA and CF IB. We have independently purified CF IA and found that
five polypeptides cofractionate with the activity. They include Rna14p, Rna15p,
Pcf11p, a new protein called Clp1p, and remarkably, the major poly(A)-binding
protein Pab1p. Extracts from strains where the PAB1 gene is mutated or deleted
are active for cleavage but generate transcripts bearing abnormally long poly(A)
tracts. Complementation with recombit Pab1p not only restores the length of
the poly(A) tails to normal, but also triggers a poly(A) shortening activity. In
addition, a monoclonal Pab1p antibody prevents the formation of poly(A) tails in
extracts or in a reconstituted system. Our data support the notion that Pab1p is
involved in the length control of the poly(A) tails of yeast mRNAs and define a
new essential function for Pab1p in the formation of mature mRNAs. The 3'-ends of both prokaryotic and eukaryotic mRNA are polyadenylated, but the
poly(A) tracts of prokaryotic mRNA are generally shorter, ranging from 15 to 60
adenylate residues and associated with only 2-60% of the molecules of a given
mRNA species. The sites of polyadenylation of bacterial mRNA are diverse and
include the 3'-ends of primary transcripts, the sites of endonucleolytic
processing in the 3' untranslated and intercistronic regions, and sites within
the coding regions of mRNA degradation products. The diversity of
polyadenylation sites suggests that mRNA polyadenylation in prokaryotes is a
relatively indiscriminate process that can occur at all mRNA's 3'-ends and does
not require specific consensus sequences as in eukaryotes. Two poly(A)
polymerases have been identified in Escherichia coli. They are encoded by
unlinked genes, neither of which is essential for growth, suggesting significant
functional overlap. Polyadenylation promotes the degradation of a regulatory RNA
that inhibits the replication of bacterial plasmids and may play a similar role
in the degradation of mRNA. However, under certain conditions, poly(A) tracts
may lead to mRNA stabilization. Their ability to bind S1 ribosomal protein
suggests that poly(A) tracts may also play a role in mRNA translation. We have previously identified a G-rich sequence (GRS) as an auxiliary downstream
element (AUX DSE) which influences the processing efficiency of the SV40 late
polyadenylation signal. We have now determined that sequences downstream of the
core U-rich element (URE) form a fundamental part of mammalian polyadenylation
signals. These novel AUX DSEs all influenced the efficiency of 3'-end processing
in vitro by stabilizing the assembly of CstF on the core downstream URE. Three
possible mechanisms by which AUX DSEs mediate efficient in vitro 3'-end
processing have been explored. First, AUX DSEs can promote processing efficiency
by maintaining the core elements in an unstructured domain which allows the
general polyadenylation factors to efficiently assemble on the RNA substrate.
Second, AUX DSEs can enhance processing by forming a stable structure which
helps focus binding of CstF to the core downstream URE. Finally, the GRS
element, but not the binding site for the bacteriophage R17 coat protein, can
substitute for the auxiliary downstream region of the adenovirus L3
polyadenylation signal. This suggests that AUX DSE binding proteins may play an
active role in stimulating 3'-end processing by stabilizing the association of
CstF with the RNA substrate. AUX DSEs, therefore, serve as a integral part of
the polyadenylation signal and can affect signal strength and possibly
regulation. We previously demonstrated, by limited mutagenesis, that conserved sequence
elements within the 5' end of influenza virus virion RNA (vRNA) are required for
the polyadenylation of mRNA in vitro. To further characterize the nucleotide
residues at the 5' end of vRNA which might be involved in polyadenylation, a
complete set of short and long model vRNA-like templates with mutations at
nucleotides 1' to 13' (prime notation denotes numbering from the 5' end) of vRNA
were synthesized and transcribed in vitro. The products were assayed for mRNA
production with both reverse transcription-PCR and [alpha-32P]ATP incorporation
assays. Results from these independent assays showed that vRNA templates with
point mutations at positions 2', 3', 7' to 9', and 11' to 13' synthesized
polyadenylated transcripts inefficiently compared with those with mutations at
positions 1', 4' to 6', and 10'. Positions 2', 3', 7' to 9', and 11' are known
to be involved in RNA polymerase binding. Furthermore, residues at positions 11'
to 13' are known to be involved in base pairing between the 3' and 5' ends of
vRNA. These findings demonstrate that the RNA polymerase has to bind to the 5'
end of the template vRNA, which must then interact with the 3' end of the same
template for polyadenylation to occur. These results support a model in which a
cis-acting RNA polymerase is required for the polyadenylation of influenza
virus. Recently, we and others have reported that mRNAs may be polyadenylated in plant
mitochondria, and that polyadenylation accelerates the degradation rate of
mRNAs. To further characterize the molecular mechanisms involved in plant
mitochondrial mRNA degradation, we have analyzed the polyadenylation and
degradation processes of potato atp9 mRNAs. The overall majority of
polyadenylation sites of potato atp9 mRNAs is located at or in the vicinity of
their mature 3'-extremities. We show that a 3'- to 5'-exoribonuclease activity
is responsible for the preferential degradation of polyadenylated mRNAs as
compared with non-polyadenylated mRNAs, and that 20-30 adenosine residues
constitute the optimal poly(A) tail size for inducing degradation of RNA
substrates in vitro. The addition of as few as seven non-adenosine nucleotides
3' to the poly(A) tail is sufficient to almost completely inhibit the in vitro
degradation of the RNA substrate. Interestingly, the exoribonuclease activity
proceeds unimpeded by stable secondary structures present in RNA substrates.
From these results, we propose that in plant mitochondria, poly(A) tails added
at the 3' ends of mRNAs promote an efficient 3'- to 5'- degradation process. The mechanism of RNA degradation in Escherichia coli involves endonucleolytic
cleavage, polyadenylation of the cleavage product by poly(A) polymerase, and
exonucleolytic degradation by the exoribonucleases, polynucleotide phosphorylase
(PNPase) and RNase II. The poly(A) tails are homogenous, containing only
adenosines in most of the growth conditions. In the chloroplast, however, the
same enzyme, PNPase, polyadenylates and degrades the RNA molecule; there is no
equivalent for the E. coli poly(A) polymerase enzyme. Because cyanobacteria is a
prokaryote believed to be related to the evolutionary ancestor of the
chloroplast, we asked whether the molecular mechanism of RNA polyadenylation in
the Synechocystis PCC6803 cyanobacteria is similar to that in E. coli or the
chloroplast. We found that RNA polyadenylation in Synechocystis is similar to
that in the chloroplast but different from E. coli. No poly(A) polymerase enzyme
exists, and polyadenylation is performed by PNPase, resulting in heterogeneous
poly(A)-rich tails. These heterogeneous tails were found in the amino acid
coding region, the 5' and 3' untranslated regions of mRNAs, as well as in rRNA
and the single intron located at the tRNA(fmet). Furthermore, unlike E. coli,
the inactivation of PNPase or RNase II genes caused lethality. Together, our
results show that the RNA polyadenylation and degradation mechanisms in
cyanobacteria and chloroplast are very similar to each other but different from
E. coli. The addition of poly(A) tails to RNA is a phenomenon common to all organisms
examined so far. No homologues of the known polyadenylating enzymes are found in
Archaea and little is known concerning the mechanisms of messenger RNA
degradation in these organisms. Hyperthermophiles of the genus Sulfolobus
contain a protein complex with high similarity to the exosome, which is known to
degrade RNA in eukaryotes. Halophilic Archaea, however, do not encode homologues
of these eukaryotic exosome components. In this work, we analysed RNA
polyadenylation and degradation in the archaea Sulfolobus solfataricus and
Haloferax volcanii. No RNA polyadenylation was detected in the halophilic
archaeon H. volcanii. However, RNA polynucleotidylation occurred in
hyperthermophiles of the genus Sulfolobus and was mediated by the archaea
exosome complex. Together, our results identify the first organism without RNA
polyadenylation and show a polyadenylation activity of the archaea exosome. Polyadenylation is a process of endonucleolytic cleavage of the mRNA, followed
by addition of up to 250 adenosine residues to the 3' end of the mRNA.
Polyadenylation is essential for eukaryotic mRNA expression, and CstF-64 is a
subunit of the CstF polyadenylation factor that is required for accurate
polyadenylation. We discovered that there are two forms of the CstF-64 protein
in mammalian male germ cells, one of which (CstF-64) is expressed in all
tissues, the other of which (tauCstF-64) is expressed only in male germ cells
and in brain (albeit at significantly lower levels in the brain). Therefore, we
were surprised to find that, using reverse transcription-PCR, cDNA cloning, and
RNA blot analyses, tauCstF-64 mRNA was expressed at higher levels in brain than
in testis. Also, tauCstF-64 mRNA was expressed at lower but detectable levels in
all tissues tested, including epididymis, heart, kidney, liver, lung, muscle,
ovary, spleen, thymus, and uterus. These results suggest the hypothesis that
tauCstF-64 mRNA is regulated at the translational or post-translational level. The addition of poly(A)-tails to RNA is a phenomenon common to almost all
organisms. Not only homopolymeric poly(A)-tails, comprised exclusively of
adenosines, but also heteropolymeric poly(A)-rich extensions, which include the
other three nucleotides as well, have been observed in bacteria, archaea,
chloroplasts, and human cells. Polynucleotide phosphorylase (PNPase) and the
archaeal exosome, which bear strong similarities to one another, both
functionally and structurally, were found to polymerize the heteropolymeric
tails in bacteria, spinach chloroplasts, and archaea. As phosphorylases, these
enzymes use diphosphate nucleotides as substrates and can reversibly polymerize
or degrade RNA, depending on the relative concentrations of nucleotides and
inorganic phosphate. A possible scenario, illustrating the evolution of RNA
polyadenylation and its related functions, is presented, in which PNPase (or the
archaeal exosome) was the first polyadenylating enzyme to evolve and the
heteropolymeric tails that it produced, functioned in a
polyadenylation-stimulated RNA degradation pathway. Only at a later stage in
evolution, did the poly(A)-polymerases that use only ATP as a substrate, hence
producing homopolymeric adenosine extensions, arise. Following the appearance of
homopolymeric tails, a new role for polyadenylation evolved; RNA stability. This
was accomplished by utilizing stable poly(A)-tails associated with the mature 3'
ends of transcripts. Today, stable polyadenylation coexists with unstable
heteropolymeric and homopolymeric tails. Therefore, the heteropolymeric
poly(A)-rich tails, observed in bacteria, organelles, archaea, and human cells,
represent an ancestral stage in the evolution of polyadenylation. During mammalian oocyte maturation, protein synthesis is mainly controlled
through cytoplasmic polyadenylation of stored maternal mRNAs. In this study, the
role of polyadenylation modification of maternal transcripts in pig oocytes was
investigated by adding cordycepin (3'-dA), a potent polyadenylation inhibitor,
to the culture medium of porcine oocytes maturing in vitro. 3'-dA significantly
prevented cumulus expansion regardless of the concentration used, and inhibited
pig oocyte maturation in a dose-dependent manner. Further, 3'-dA 1
microg/ml-treated MII oocytes experienced significantly lower rates of cleavage
(29%) and blastocyst formation (15.35%) compared to control MII oocytes (58.6%
and 35.3%, respectively). Western blotting revealed that the activity of
mitogen-activated protein kinase (MAPK) and p34(cdc2) was significantly
decreased in oocytes and cumulus cells treated with 3'-dA at a concentration of
1 microg/ml or greater. To further explore the underlying molecular mechanisms,
expression patterns and polyadenylation states of four important genes, C-mos,
cyclin B, GDF9 and BMP15, were studied as representative maternal transcripts by
real-time PCR and the PAT assay. 3'-dA at concentrations above 1 microg/ml
significantly prevented polyadenylation and caused aberrant expression of C-mos
and GDF9 during oocyte maturation. These results suggest that polyadenylation
inhibitor blocked pig oocyte maturation in vitro by one or more of the following
actions: (1) inactivation of MAPK and MPF in oocytes, especially at the late
stages (MI and MII); (2) prevention of cumulus cell expansion through
inactivation of cellular MAPK; and (3) inhibition of the maternal mRNA
polyadenylation process, which in reverse, disrupted the maternal mRNA patterns
in pig oocytes' maturation in vitro. The majority of eukaryotic pre-mRNAs are processed by 3'-end cleavage and
polyadenylation, although in metazoa the replication-dependent histone mRNAs are
processed by 3'-end cleavage but not polyadenylation. The macromolecular complex
responsible for processing both canonical and histone pre-mRNAs contains the
approximately 1160-residue protein Symplekin. Secondary-structural prediction
algorithms identified putative HEAT domains in the 300 N-terminal residues of
all Symplekins of known sequence. The structure and dynamics of this domain were
investigated to begin elucidating the role Symplekin plays in mRNA maturation.
The crystal structure of the Drosophila melanogaster Symplekin HEAT domain was
determined to 2.4 A resolution with single-wavelength anomalous dispersion
phasing methods. The structure exhibits five canonical HEAT repeats along with
an extended 31-amino-acid loop (loop 8) between the fourth and fifth repeat that
is conserved within closely related Symplekin sequences. Molecular dynamics
simulations of this domain show that the presence of loop 8 dampens correlated
and anticorrelated motion in the HEAT domain, therefore providing a neutral
surface for potential protein-protein interactions. HEAT domains are often
employed for such macromolecular contacts. The Symplekin HEAT region not only
structurally aligns with several established scaffolding proteins, but also has
been reported to contact proteins essential for regulating 3'-end processing.
Together, these data support the conclusion that the Symplekin HEAT domain
serves as a scaffold for protein-protein interactions essential to the mRNA
maturation process. Most eukaryotic genes express mRNAs with alternative polyadenylation sites at
their 3' ends. Here we show that polyadenylated 3' termini in three yeast
species (Saccharomyces cerevisiae, Kluyveromyces lactis, and Debaryomyces
hansenii) are remarkably heterogeneous. Instead of a few discrete 3' ends, the
average yeast gene has an "end zone," a >200 bp window with >60 distinct poly(A)
sites, the most used of which represents only 20% of the mRNA molecules. The
pattern of polyadenylation within this zone varies across species, with D.
hansenii possessing a higher focus on a single domit point closer to the ORF
terminus. Some polyadenylation occurs within mRNA coding regions with a strong
bias toward the promoter. The polyadenylation pattern is determined by a highly
degenerate sequence over a broad region and by a local sequence that relies on A
residues after the cleavage point. Many domit poly(A) sites are predicted to
adopt a common secondary structure that may be recognized by the
cleavage/polyadenylation machinery. We suggest that the end zone reflects a
region permissive for polyadenylation, within which cleavage occurs
preferentially at the A-rich sequence. In S. cerevisiae strains, D. hansenii
genes adopt the S. cerevisiae polyadenylation profile, indicating that the
polyadenylation pattern is mediated primarily by species-specific factors. The addition of poly(A) tails to eukaryotic nuclear mRNAs promotes their
stability, export to the cytoplasm and translation. Subsequently, the balance
between exonucleolytic deadenylation and selective re-establishment of
translation-competent poly(A) tails by cytoplasmic poly(A) polymerases is
essential for the appropriate regulation of gene expression from oocytes to
neurons. In recent years, surprising roles for cytoplasmic poly(A)
polymerase-related enzymes that add uridylyl, rather than adenylyl, residues to
RNA 3' ends have also emerged. These terminal uridylyl transferases promote the
turnover of certain mRNAs but also modify microRNAs, their precursors and other
small RNAs to modulate their stability or biological functions. Pre-mRNA 3'-end processing, the process through which almost all eukaryotic
mRNAs acquire a poly(A) tail is generally inhibited during the cellular DNA
damage response leading to a profound impact on the level of protein expression
since unprocessed transcripts at the 3'-end will be degraded or unable to be
transported to the cytoplasm. However, a compensatory mechanism involving the
binding of the hnRNP H/F family of RNA binding proteins to an RNA G-quadruplex
(G4) structure located in the vicinity of a polyadenylation site has previously
been described to allow the transcript encoding the p53 tumour suppressor
protein to be properly processed during DNA damage and to provide the cells with
a way to react to DNA damage. Here we report that the DEAH (Asp-Glu-Ala-His) box
RNA helicase DHX36/RHAU/G4R1, which specifically binds to and resolves
parallel-stranded G4, is necessary to maintain p53 pre-mRNA 3'-end processing
following UV-induced DNA damage. DHX36 binds to the p53 RNA G4, while mutation
of the G4 impairs the ability of DHX36 to maintain pre-mRNA 3'-end processing.
Stabilization of the p53 RNA G4 with two different G4 ligands (PNADOTASQ and
PhenDC3), which is expected from previous studies to prevent DHX36 from binding
and unwinding G4s, also impairs p53 pre-mRNA 3'-end processing following UV. Our
work identifies DHX36 as a new actor in the compensatory mechanisms that are in
place to ensure that the mRNAs encoding p53 are still processed following UV. |
Which cancers compose Carney's triad? | Carney's triad is a rare pathogenic entity which consists of 3 rare soft tissue tumors: gastric leiomyosarcoma, pulmonary chondroma and extraadrenal paraganglioma. It is usually diagnosed in young women. The presence of three tumors at the same time is not required for its diagnosis (incomplete Carney's Triad). | We communicate a case with the Carney triad (gastric leiomyosarcoma, pulmonary
chondromatosis and extra-adrenal paraganglioma). It is, to our knowledge, the
first case to be communicated in the Spanish scientific literature. We discuss
some peculiar aspects of the debut and clinical evolution of this syndrome,
together with its prognosis. We conclude that in clinical practice, the
appearance in a young subject, specifically females, of multiple gastric
myogenic tumors, should elicit the performance of further noninvasive
procedures, needed to discard the diagnosis of the Carney triad. Carney's triad--gastric leiomyosarcoma, pulmonary chondroma, and extra-adrenal
paraganglioma--is a syndrome that occurs primarily in young women. To date, 28
patients with at least two of these individually unusual or rare neoplasms have
been described. This updated case report of one of the originally described
patients with Carney's triad highlights several clinically important features of
this unusual syndrome: (1) the multicentricity of both the paragangliomas and
the epithelioid leiomyosarcomas, (2) the often indolent progression of
metastatic leiomyosarcoma, (3) the potential for late recurrences, and (4) the
importance of distinguishing intra-adrenal from periadrenal
catecholamine-producing tumors (paragangliomas). Localization of paragangliomas
is facilitated by two relatively new techniques--131I-metaiodobenzylguanidine
scanning (a scintigraphic technique with high specificity for
catecholamine-producing tumors) and two-dimensional echocardiography (which can
noninvasively localize and demonstrate the anatomic relationships of
aorticopulmonary paragangliomas). In patients with this syndrome, new or
recurrent tumors frequently manifest after unusually long asymptomatic
intervals. We outline an approach for continued follow-up of patients with one
or more of the three neoplasms that constitute the syndrome. Rigorous long-term
screening of these patients should not only lead to early recognition and
resection of recurrent or new tumors but also enhance our understanding of this
intriguing syndrome. Carney's Triad comprises a triad of neoplasms: gastric stromal tumor,
extra-adrenal paraganglioma (usually functional), and pulmonary chondroma. At
least two of these are needed for the presumptive diagnosis of the Triad. This
report presents a patient who had resected a gastric tumor and nonfunctional
extra-adrenal paraganglioma. The gastric tumor resembled a gastric
leiomyosarcoma by light microscopy, but electron microscopy revealed it to be a
gastric autonomic nerve (GAN) tumor. Based on this evidence it appears that both
the gastric lesions and the paragangliomata of Carney's Triad are tumors of the
autonomic nervous system. Thus, the Triad may be a disorder of the autonomic
nervous system rather than a multiple endocrine neoplasia syndrome or multiple
hamartoma syndrome. Carney's triad is defined by the coexistence of at least two of three rare
disorders, including gastric epithelioid leiomyosarcoma (maligt
leiomyoblastoma), pulmonary chondroma, and paraganglioma, most often
extra-adrenal and functioning. We report a new case in a 10-year-old girl. The
paraganglioma, although nonfunctioning, was detected after it was searched for,
as Carney's triad was suspected. Unrelated seems the development of breast
fibroadenomas in the same patient. Whenever a patient with one component of the
triad is encountered, the possibility of this syndrome should be considered and
the other two components sought. This report encourages clinicians to consider a diagnosis of Carney's triad in
patients with multifocal gastric stromal sarcoma, extraadrenal paraganglioma
(predomitly mediastinal), or pulmonary chondroma. The authors conducted a
retrospective 20-year survey at the Hospital for Sick Children and identified
two children with Carney's triad. One child, presenting atypically with
papilledema and fundal hemorrhages from maligt hypertension and benign
intracranial hypertension from chronic iron-deficiency anemia, is the second
patient ever to date be described with the complete Carney's triad of neoplasms
at diagnosis. Another child presented more typically with gastric stromal
sarcoma and pulmonary chondroma without paraganglioma. Carney's triad is a rare
differential diagnosis for "idiopathic" hypertension or iron-deficiency anemia
from chronic gastrointestinal bleeding. If missed, patients with Carney's triad
may have the debilitating physical and mental consequences of chronic iron
deficiency and may die of untreated prolonged hypertension and metastatic
leiomyosarcoma. Carney's triad represents the association of gastric gastrointestinal stromal
tumor, pulmonary chondroma, and extraadrenal paraganglioma. Only 79 cases of
this rare condition have been described. Here, the authors describe the unusual
case of a 14-year-old boy who presented with a complete Carney's triad. This is
only the second reported case in the world literature of a patient manifesting a
complete Carney's triad at presentation. The management of each tumor is
discussed. Carney's triad is a syndrome of unknown etiology, representing a combination of
gastrointestinal stromal tumors, bronchial chondromas and vagal, adrenal or
paraadrenal paragangliomas. Two of the Carney's triad components-the
paragangliomas and the gastrointestinal stromal tumors-are potentially lethal.
Since its first description in 1977, 79 cases have been reported so far. We
report an 84-year-old male patient, who died of a hypertensive cerebral
hemorrhage. Well-differentiated clear cell carcinoma of the right kidney,
chondroma of the right bronchus and multiple jejunal stromal tumors were
detected at autopsy. To our knowledge, this is the first report of a
coincidental clear cell renal carcinoma in a patient with an atypical Carney's
triad. Gastrointestinal stromal tumours (GIST) occur mostly as sporadic solitary
lesions involving the tubular GI tract and are only rarely associated with other
benign or maligt neoplasms or occur as part of a multi-neoplastic disease as
in the setting of Carney's triad and von Recklinghausen's disease. We analysed a
total of 97 cases of surgically resected GIST looking for various types of
associated non-GIST maligcies. 18 cases (18.6 %) were identified. There were
12 women and 6 men aged 43 to 87, average age 71.7 years. 12 GISTs were located
in the stomach, four in the small intestine, and one each in the duodenum and
the vermiform appendix. Associated maligcies (mostly carcinomas) were
gastrointestinal/pancreatic (9), gynaecological (3), mammary (2), renal (1),
prostatic (1), pulmonary (2) and haematolymphoid (2) in origin. Most GISTs
(16/18) represented benign or low-risk lesions (innocent bystanders) detected
during evaluation for the known cancer, either during staging, intra-operatively
or on follow-up. Two women (43 and 72 years old) with large maligt GISTs
(10.5 and 12 cm), one of them with two simultaneous hepatic metastases resected
at the same time as the primary GIST, developed infiltrating ductal mammary
carcinoma and were alive and well 75 and 95 months postoperatively,
respectively. Furthermore, one of them developed endometrial carcinoma. We
concluded that GISTs are not uncommonly encountered in cancer-patients during
staging, intraoperatively or on follow-up and should be considered in the
differential diagnosis of newly detected focal lesions to avoid their
misinterpretation as metastasis from the known maligcy with consequently
false therapeutic decisions. Interstitial cell of Cajal (ICC) hyperplasia has been documented in conditions
associated with multiple gastrointestinal stromal tumours (GISTs) (familial GIST
syndromes, Carney's triad and von Recklinghausen's disease) and rarely in the
vicinity of sporadic GISTs. The incidence of sporadic ICC hyperplasia and the
so-called seedling leiomyoma (SLM) of the lower oesophagus has not been studied
in the KIT era. In a retrospective review of 77 consecutive, routinely processed
oesophagogastric resection specimens for distal oesophageal carcinoma, we found
foci of ICC hyperplasia in 7 of 77 (9.1%) cases and foci of SLM in 17 of 77
(22%) cases. Two types of ICC hyperplasia were recognized: a non-circumscribed
type and a nodular expansile type with peripherally compressed myenteric neural
tissues. All cases of ICC hyperplasia were vimentin+/CD34+/CD117+. SLMs were
desmin+/vimentin(-)/CD34(-)/CD117(-), similar to smooth muscles of the gut wall.
In a prospective study of 32 non-carcinomatous specimens from age-matched
patients (mostly autopsy cases), we found SLMs in only one case, but we were
unable to detect ICC hyperplasia in any of the cases. We concluded that sporadic
KIT-positive spindle-cell hyperplasia and SLMs were unexpectedly common in
distal oesophageal specimens harbouring carcinomas. The possible mechanisms
leading to the development of these putative precursor lesions will be
discussed. The case of young woman with arterial hypertension diagnosed two years before,
is here presented; she had a ferropenic anemia caused by digestive loss of
blood. Multiple gastric tumors and pararenal non functioning paraganglioma were
found. No chondromas were detected. An incomplete Carney's Triad was diagnosed.
We remark that multiple gastric tumors in a young adult suggest the possibility
of gastrointestinal stromal tumors (GIST) Endoscopic biopsy frequently is not
effective because these tumors are deep placed in the muscular gastric layers.
The importance of specific techniques for a positive diagnosis are emphasized.
Continuous follow up is needed because these tumors have uncertain prognosis.
Lung chondromas may appear years later after the GIST was removed and might be
confused with GIST metastases. We report a female teenager who presented with a gastrointestinal stromal tumor
of the stomach and a paraganglioneuroma. She later developed a pulmonary
chondroma, fulfilling the requirements of Carney's triad. This patient
demonstrates the course of the disease, which included severe emotional
symptoms. She died, at 30 years of age, 16 years after the onset of disease,
riddled with metastases. Many patients with Carney's triad survive for many
years, but we can not predict the prognosis in any patient. During her lifetime,
the patient had considerable emotional suffering, perhaps because of her
disease. A 34-year-old man, who had undergone the gastrectomy for gastrointestinal
stromal tumor (GIST) and para-aortic paraganglioma 3 years before, was found to
have a left lung tumor on a computed tomography. The tumor was revealed to be a
pulmonary hamartoma, and diagnosed as Carney's triad. This is a rare case of
complete type Carney's triad of an adult male. INTRODUCTION: Carney's triad is a rare pathogenic entity which consists of the
association in young women of multiple condromatosis in the lung, gastric
leiomyosarcoma, and extradrenal paraganglioma; although the presence of three at
the same time is not required for its diagnosis.
CASE REPORT: We present the case of a 27-year-old woman who was diagnosed of
pulmonary multiple hamartomatosis and gastric stromal tumor.
DISCUSSION: A review of the literature shows the most important prognosis
factors and therapeutic options. Surgery for gastrointestinal stromal tumors and
extradrenal paraganglioma seems to be the best treatment up to date. A curious association of three rare tumours was described by Carney in 1977.
'Carney's triad' characteristically includes multifocal pulmonary chondroma,
gastric stromal sarcoma and extra-adrenal paraganglioma. Patients may exhibit
complete or incomplete expression of the triad. Carney acknowledged that, of 79
patients, only 17 possessed all three tumours. We report here two patients with
incomplete expression of Carney's triad. Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors in
the digestive tract. In up to 90% of cases, they are characterized by activating
mutations in the KIT or the PDGFRA gene. GIST represent a paradigm for
successful targeted treatment with tyrosine kinase inhibitors (TKI). Since the
approval of the TKI imatinib in 2002 the survival of patients with metastatic
GIST has tripled. The next logical step was the concept of using imatinib in an
adjuvant approach, which was recently shown to increase overall survival
significantly. In both settings, the mutational status has high predictive
implications. In detail, GIST with KIT exon 11 mutations show the best response
rates with partial remission rates of up to 80%. In KIT exon 9 mutations, a
doubled daily dose of 800 mg imatinib is now standard. The PDGFRA exon 18
mutation D842V has been shown to lead to primary resistance. The treatment
strategy in GIST is driven by their molecular characterisation. Further research
has increased our knowledge on resistance mechanisms in solid tumors against
TKI. The number of patients with secondary resistance due to acquired KIT
mutations is increasing with treatment duration. Strategies to address this
situation are the introduction of novel pathway inhibitors targeting different
levels of signal transduction pathways, such as the mTOR/Akt pathway, the
RAS/RAF pathway, histone deacetylation, among others. Among the GIST without
mutations in the common hot spot regions of KIT and PDGFRA, the so-called
wildtype GIST, further genomic subgroups have been identified. One such subgroup
carries inactivating germline mutations in the genes encoding succinate
dehydrogenase B, C, or D. They are associated with the occurrence of
paragangliomas, so-called Carney-Stratakis syndrome. Most frequently, these GIST
are located in the stomach, showing an epithelioid phenotype and a multinodular
growth pattern. They preferentially occur in young females and often show lymph
node metastases, the latter being very unusual in sporadic GIST. In sporadic
Carney's triad additional pulmonary chondromas are observed and there are no SDH
mutations. Another small subgroup of sporadic GIST present with BRAF mutations
as an alternative genomic event. Finally, very rare kindreds with germline
mutations in either KIT or PDGFRA have been described who develop multiple GIST
and depending on the mutational subtype mastocytosis, hyperpigmentation and/or
dysphagia. In summary, the molecular characterisation of GIST has revolutionized
their treatment due to increasing knowledge about the high relevance of
predictive molecular typing in solid tumors. PURPOSE OF REVIEW: Knowledge related to gastrointestinal stromal tumor (GIST) in
the setting of nonhereditary and hereditary multiple tumor syndromes continues
to expand. This review describes associations between sporadic GIST and second
maligcies, as well as new contributions to our knowledge about hereditary
GIST multiple tumor syndromes.
RECENT FINDINGS: Sporadic GIST patients have increased risk of developing
synchronous/metachronous cancers, including nonhematologic and hematologic
maligcies. Data suggest these associations are nonrandom, more prevalent in
men and increase with age. New adrenal tumors have also been associated with
nonhereditary Carney's triad. Meanwhile, understanding of the molecular basis of
heritable GIST syndromes has improved. Several new familial GIST kindreds have
been reported, including those with germline KIT and PDGFRα mutations. Knowledge
about succinate dehydrogenase (SDH) deficiency and mutations in hereditary GIST
syndromes has expanded. It is now known that neurofibromatosis-1-associated
GISTs are SDHB-positive, whereas Carney-Stratakis syndrome-associated GISTs are
SDHB-deficient with underlying germline mutations in SDH subunits A-D.
SUMMARY: Recognition and early diagnosis of GIST syndromes allows for improved
comprehensive medical care. With additional understanding of the molecular
pathogenesis of GIST multiple tumor syndromes, we can refine our screening
programs and management of these patients and their families. |
What is the preDIVA clinical trial? | The preDIVA trial (Prevention of Dementia by Intensive Vascular Care) was an open-label, cluster-randomized controlled trial in community-dwelling individuals aged 70 to 78 years. | BACKGROUND AND PURPOSE: Cardiovascular risk factors are associated with an
increased risk of dementia. Treatment of hypertension and hypercholesterolemia
is associated with a decrease in incident dementia. Whether interventions aimed
at cardiovascular risk factors in late life also reduce dementia risk is
unknown. Here, we report the outline of a pragmatic study that will attempt to
answer this question and we describe the prevalence of cardiovascular risk
factors in the target population.
METHODS: We designed a large cluster-randomized trial with a 6-year follow-up in
3700 elderly subjects (70 to 78 y) to assess whether nurse-led intensive
vascular care in primary care decreases the incidence of dementia and reduces
disability. Secondary outcome parameters are mortality, incidence of vascular
events, and cognitive functioning. Intensive vascular care comprises treatment
of hypertension, hypercholesterolemia, diabetes and reducing overweight, smoking
cessation, and stimulating physical exercise.
RESULTS: Baseline data of 1004 subjects show that 87% of the subjects have 1 or
more cardiovascular risk factors and 44% have even 2 or more risk factors
amenable to treatment. Seventy-nine percent of the subjects receiving
antihypertensive medication still have a systolic pressure of >140 mm Hg.
CONCLUSIONS: In this older age group, the very high percentage of elderly
subjects with cardiovascular risk factors illustrates the large window of
opportunity for therapies directed to lower the cardiovascular risk and
potentially also the risk for dementia. BACKGROUND: Cardiovascular risk factors are associated with an increased risk of
dementia. We assessed whether a multidomain intervention targeting these factors
can prevent dementia in a population of community-dwelling older people.
METHODS: In this open-label, cluster-randomised controlled trial, we recruited
individuals aged 70-78 years through participating general practices in the
Netherlands. General practices within each health-care centre were randomly
assigned (1:1), via a computer-generated randomisation sequence, to either a
6-year nurse-led, multidomain cardiovascular intervention or control (usual
care). The primary outcomes were cumulative incidence of dementia and disability
score (Academic Medical Center Linear Disability Score [ALDS]) at 6 years of
follow-up. The main secondary outcomes were incident cardiovascular disease and
mortality. Outcome assessors were masked to group assignment. Analyses included
all participants with available outcome data. This trial is registered with
ISRCTN, number ISRCTN29711771.
FINDINGS: Between June 7, 2006, and March 12, 2009, 116 general practices (3526
participants) within 26 health-care centres were recruited and randomly
assigned: 63 (1890 participants) were assigned to the intervention group and 53
(1636 participants) to the control group. Primary outcome data were obtained for
3454 (98%) participants; median follow-up was 6·7 years (21 341 person-years).
Dementia developed in 121 (7%) of 1853 participants in the intervention group
and in 112 (7%) of 1601 participants in the control group (hazard ratio [HR]
0·92, 95% CI 0·71-1·19; p=0·54). Mean ALDS scores measured during follow-up did
not differ between groups (85·7 [SD 6·8] in the intervention group and 85·7
[7·1] in the control group; adjusted mean difference -0·02, 95% CI -0·38 to
0·42; p=0·93). 309 (16%) of 1885 participants died in the intervention group,
compared with 269 (16%) of 1634 participants in the control group (HR 0·98, 95%
CI 0·80-1·18; p=0·81). Incident cardiovascular disease did not differ between
groups (273 [19%] of 1469 participants in the intervention group and 228 [17%]
of 1307 participants in the control group; HR 1·06, 95% CI 0·86-1·31; p=0·57).
INTERPRETATION: A nurse-led, multidomain intervention did not result in a
reduced incidence of all-cause dementia in an unselected population of older
people. This absence of effect might have been caused by modest baseline
cardiovascular risks and high standards of usual care. Future studies should
assess the efficacy of such interventions in selected populations.
FUNDING: Dutch Ministry of Health, Welfare and Sport; Dutch Innovation Fund of
Collaborative Health Insurances; and Netherlands Organisation for Health
Research and Development. OBJECTIVES: To explore and compare sociodemographic, clinical, and
neuropsychiatric determits of dropout and nonadherence in older people
participating in an open-label cluster-randomized controlled trial-the
Prevention of Dementia by Intensive Vascular care (preDIVA) trial-over 6 years.
DESIGN: Secondary analysis.
SETTING: One hundred sixteen general practices in the Netherlands.
PARTICIPANTS: Community-dwelling individuals aged 70 to 78 (N = 2,994).
INTERVENTION: Nurse-led multidomain intervention targeting cardiovascular risk
factors to prevent dementia.
MEASUREMENTS: The associations between participant baseline sociodemographic
(age, sex, education), clinical (medical history, disability, cardiovascular
risk), neuropsychiatric (depressive symptoms (Geriatric Depression Scale-15),
and cognitive (Mini-Mental State Examination)) characteristics and dropout from
the trial and nonadherence to the trial intervention were explored using
multilevel logistic regression models.
RESULTS: Older age, poorer cognitive function, more symptoms of depression, and
greater disability were the most important determits of dropout of older
people. The presence of cardiovascular risk factors was not associated with
dropout but was associated with nonadherence. Being overweight was a risk factor
for nonadherence, whereas people with high blood pressure or a low level of
physical exercise adhered better to the intervention. The association between
poorer cognitive function and symptoms of depression and dropout was stronger in
the control group than in the intervention group, and vice versa for increased
disability.
CONCLUSION: In a large dementia prevention trial with 6-year follow-up, dropout
was associated with older age, poorer cognitive function, symptoms of
depression, and disability at baseline. These findings can help to guide the
design of future dementia prevention trials in older adults. The associations
found between cardiovascular risk factors and nonadherence need to be confirmed
in other older populations receiving cardiovascular prevention interventions. BACKGROUND AND PURPOSE: This study aimed to evaluate the effect of a nurse-led
multidomain cardiovascular intervention on white matter hyperintensity (WMH)
progression and incident lacunar infarcts in community-dwelling elderly with
hypertension.
METHODS: The preDIVA trial (Prevention of Dementia by Intensive Vascular Care)
was an open-label, cluster-randomized controlled trial in community-dwelling
individuals aged 70 to 78 years. General practices were assigned by
computer-generated randomization to 6-year nurse-led, multidomain intensive
vascular care or standard care. Of 3526 preDIVA participants, 195 nondemented
participants with a systolic blood pressure ≥140 mm Hg were consecutively
recruited to undergo magnetic resoce imaging at 2 to 3 and 5 to 6 years after
baseline. WMH volumes were measured automatically, lacunar infarcts assessed
visually, blinded to treatment allocation.
RESULTS: One hundred and twenty-six participants were available for longitudinal
analysis (64 intervention and 62 control). Annual WMH volume increase in
milliliter was similar for intervention (mean=0.73, SD=0.84) and control
(mean=0.70, SD=0.59) participants (adjusted mean difference, -0.08 mL; 95%
confidence interval, -0.30 to 0.15; P=0.50). Analyses suggested greater
intervention effects with increasing baseline WMH volumes (P for
interaction=0.03). New lacunar infarcts developed in 6 (9%) intervention and 2
(3%) control participants (odds ratio, 2.2; 95% confidence interval, 0.4-12.1;
P=0.36).
CONCLUSIONS: Nurse-led vascular care in hypertensive community-dwelling older
persons did not diminish WMH accumulation over 3 years. However, our results do
suggest this type of intervention could be effective in persons with high WMH
volumes. There was no effect on lacunar infarcts incidence but numbers were low.
CLINICAL TRIAL INFORMATION: URL: http://www.isrctn.com/ISRCTN29711771. Unique
identifier: ISRCTN29711771. |
What effect does azeliragon have on RAGE? | Azeliragon is an inhibitor of receptor for advanced glycation end products (RAGE). | Currently available drugs against Alzheimer's disease (AD) target cholinergic
and glutamatergic neurotransmissions without affecting the underlying disease
process. Putative disease-modifying drugs are in development and target
β-amyloid (Aβ) peptide and tau protein, the principal neurophatological
hallmarks of the disease. Areas covered: Phase III clinical studies of emerging
anti-Aβ drugs for the treatment of AD were searched in US and EU clinical trial
registries and in the medical literature until May 2016. Expert opinion: Drugs
in Phase III clinical development for AD include one inhibitor of the
β-secretase cleaving enzyme (BACE) (verubecestat), three anti-Aβ monoclonal
antibodies (solanezumab, gantenerumab, and aducanumab), an inhibitor of receptor
for advanced glycation end products (RAGE) (azeliragon) and the combination of
cromolyn sodium and ibuprofen (ALZT-OP1). These drugs are mainly being tested in
subjects during early phases of AD or in subjects at preclinical stage of
familial AD or even in asymptomatic subjects at high risk of developing AD. The
hope is to intervene in the disease process when it is not too late. However,
previous clinical failures with anti-Aβ drugs and the lack of fully
understanding of the pathophysiological role of Aβ in the development of AD, put
the new drugs at substantial risk of failure. |
What is the drug forxiga used for? | Dapagliflozin (Forxiga®) is the first in a novel class of glucose-lowering agents known as sodium-glucose co-transporter-2 (SGLT2) inhibitors and is used in the treatment of patients with type 2 diabetes. | In the UK, diabetes mellitus affects around 3 million people, of whom over 90%
have type 2 diabetes. Aims of treatment include minimising long-term
complications (e.g. cardiovascular disease, blindness, chronic kidney disease,
premature mortality) and avoiding unwanted effects of treatment (e.g. severe
hypoglycaemia, weight gain). Management of diabetes includes patient support and
education; addressing symptoms; lifestyle modification; targeting associated
risk factors for cardiovascular disease; and surveillance for, and management
of, complications including treatment-related hypoglycaemia. Dapagliflozin
(Forxiga) belongs to a new class of oral glucose-lowering drugs that inhibit
renal glucose reabsorption and promote glycosuria. It is licensed in the UK in
adults with type 2 diabetes as monotherapy when diet and exercise alone do not
provide adequate glycaemic control and who are unable to tolerate metformin; or,
as add-on therapy, with other glucose-lowering agents including insulin, when
these, with diet and exercise, do not provide adequate glycaemic control. The
company's advertising materials claim that dapagliflozin provides a "novel
method of controlling excess glucose" with "secondary benefit of weight loss".
Here, we review the evidence for the use of dapagliflozin in the management of
type 2 diabetes mellitus. Publisher: Résumé : La dapagliflozine, un inhibiteur spécifique des
cotransporteurs sodium-glucose de type 2 (SGLT2), inhibe la réabsorption
tubulaire rénale du glucose et accroît la gluco¬surie. Il en résulte une
diminution de la glycémie et du taux d’hémoglobine glyquée (HbA1c), avec un
risque faible d’hypo¬glycémie, une perte pondérale et une diminution de la
pression artérielle. L’efficacité sur la réduction du taux d’HbA1c est d’autant
plus importante que l’hyperglycémie est élevée, mais elle diminue en cas
d’insuffisance rénale. Les infections géni¬tales mycotiques sont plus
fréquentes, surtout chez la femme, alors que l’augmentation des infections
urinaires basses n’est que marginale. La dapagliflozine (Forxiga®),
commercialisée à la dose de 10 mg une fois par jour, est indiquée pour le
trai¬tement du diabète de type 2 et remboursée en Belgique, sous conditions, en
ajout à la metformine, un sulfamide ou le répa-glinide, une association
metformine-sulfamide/répaglinide ou une insuline basale avec au moins un
antidiabétique oral. Des données préliminaires ne démontrent pas d’augmentation
du risque cardiovasculaire par rapport au comparateur et suggèrent même une
protection cardiovasculaire et rénale, à confirmer dans l’essai DECLARE, une
grande étude prospec¬tive contrôlée actuellement en cours chez des patients
diabé¬tiques de type 2 à haut risque cardiovasculaire. |
What is the most common feature of the Doege–Potter syndrome? | Doege-Potter syndrome is a paraneoplastic syndrome characterized by hypoglycemia secondary to a solitary fibrous tumor of the pleura. | Syndrome Doege-Potter is a paraneoplastic syndrome in which hypoglycemia is the
result of tumors producing insulin growth factor-like (IGF-II) it is most often
solitary fibrous tumor of the pleura (TFSP). These are rare and may be
discovered incidentally, during non-specific respiratory symptoms or during
hypoglycemia. Hypoglycemia occurs in tumors of large volume and it disappears
after surgery, which is the treatment of choice for a permanent cure in most
cases. We present a case of Doege-Potter syndrome whose interest is to consider
the TFSP as a cause of hypoglycemia in patients with pleural tumors. Falls due to hypoglycaemia in the elderly is usually a complication of diabetic
treatment. In the absence of diabetes, hypoglycaemia may be due to insulin or
insulin-like producing tumours. The Doege-Potter syndrome is a rare
paraneoplastic syndrome, characterised by non-islet cell tumour hypoglycaemia
(NICTH) secondary to a solitary fibrous tumour that secretes insulin-like growth
factor (IGF) 2. Definitive treatment of hypoglycaemia due to NICTH is by tumour
resection. Our patient was a 78-year-old woman admitted after a fall with a
facial injury and a history of significant weight loss. Her blood sugar was
persistently low despite intravenous dextrose infusion. CT of the thorax
revealed a large heterogeneous mass measuring 11.6×16.3×15.6 cm in the right
hemithorax. A biopsy of the mass was reported as a solitary fibrous tumour.
Biochemical investigations revealed low insulin, C-peptide, IGF-1 and a high
IGF-2:IGF-1 ratio, consistent with NICTH. The patient underwent tumour resection
and the hypoglycaemia normalised completely immediately after surgery. Solitary fibrous tumour of the pleura (SFTP) is a rare primary tumour of the
pleura associated with 4% of cases with a paraneoplastic hypoglycaemia, termed
Doege-Potter syndrome (DPS). We report a case of DPS presenting with severe coma
in a 90-year-old woman. The cause was a maligt SFTP treated with surgical
resection, from which the patient made a full recovery with prevention of
recurrent hypoglycaemia. Surgical resection of the SFTP presenting with
symptomatic hypoglycaemia should be considered even in elderly patients. We describe a patient with Doege-Potter syndrome (solitary fibrous tumor of the
pleura presenting with hypoglycemia) and illustrate several important lessons
learned from the case. Seven years after the initial diagnosis, the tumor showed
significant growth and developed a high-grade undifferentiated component.
Solitary fibrous tumors do grow and cannot be deemed benign. Resection should be
considered in all patients who are candidates for operation upon diagnosis. Our
case also serves as a reminder of this rare syndrome, inasmuch as early
recognition of the association of hypoglycemia with these tumors may have
allowed for earlier diagnosis and avoidance of extensive tests in our patient. We report a rare case of metastatic maligt solitary fibrous tumor (SFT) that
presented with hypoglycemia because of insulin growth factor-2 production.
Initial workup included computed tomography imaging that revealed a large,
partially necrotic liver mass, a hypervascular pancreatic head lesion, and 2
renal lesions. Following hepatic resection, pancreatic head resection and
nephrectomy, all these lesions demonstrated pathological findings that were
consistent with SFT. The patient also had a history of an intracranial mass that
had been previously resected and treated with gamma knife therapy at an outside
institution, which was found to also be SFT. Six months after initial pancreatic
head resection, the patient developed a new lesion involving the pancreatic tail
that was found to represent recurrent metastatic SFT. This case emphasizes the
highly aggressive nature of extrapleural SFT, while rare, and the role of
imaging in follow-up for disease recurrence. AIM: Doege-Potter syndrome is a rare condition consisting of a mesenchymal
tumor, either benign or maligt, accompanied by severe hypoglycemia. The
syndrome was first described independently by two American physicians, Karl
Walter Doege (1867-1932) and Roy Pilling Potter (1879-1968), in 1930, but it was
not before 1988 that it was associated with non-islet cell tumor production of
insulin growth factor (IGF) that induces hypoglycemia as a paraneoplastic
syndrome.
CASE PRESENTATION: We present the case of a 61-year-old woman with severe
hypoglycemia that induced seizures. On the general check-up, a massive tumor
occupying the lower part of left hemi-thorax was discovered. Initially,
corticosteroids, glucose i.v. and high carbohydrate diet managed to prevent the
severe blood glucose drop. Surgery exposed a massive well-defined pleural tumor.
After surgical removal, blood glucose stabilized. Histological examination
confirmed the fibrous tumor that proved to be maligt on immunochemistry.
DISCUSSION: The authors discuss other cases reported in the literature of this
rare condition and its pathogenic mechanisms, the presented case being the first
reported in Romania.
CONCLUSIONS: The clinician should be aware of the possible existence of a
pleural tumor in a patient presenting an unexplained hypoglycemia because the
surgical removal of the tumor can solve the clinical manifestations. BACKGROUND: Solitary fibrous tumors of the pleura (SFTPs) are relatively rare
tumors that originate from mesenchymal cells of submesothelial tissue of the
pleura. Most patients with SFTPs are asymptomatic; however, pleuritic chest
pain, cough, and dyspnea can develop. If hypoglycemia is associated with a
solitary fibrous tumor, it is referred to as the Doege-Potter syndrome.
CASE PRESENTATION: A 70-year-old man had visited our hospital with a chief
complaint of dyspnea, and he was diagnosed as having a solitary fibrous tumor. A
few years later, he developed hypoglycemia, and he underwent excision of the
mass.
CONCLUSION: Occasionally, SFTPs induce several paraneoplastic events, such as
hypertrophic osteoarthropathy. We described here a patient with an SFTP with
Doege-Potter syndrome who was successfully treated with complete resection.
Although lesions can be histologically benign, they can clinically present with
maligt features. |
Milwaukee protocol was tested for treatment of which disease? | The Milwaukee protocol was tested for treatment of rabies. Therapies suggested in the Milwaukee protocol include therapeutic coma, ketamine infusion, amantadine, and the screening/prophylaxis/management of cerebral vasospasm. The Milwaukee Protocol has proved to be ineffective for rabies and should no longer be used. | On April 26, 2007, a patient from Alberta, Canada, died after 9 weeks in an
intensive care unit (ICU) from encephalitis caused by a rabies virus variant
associated with silver-haired bats. This report summarizes the clinical course
of disease in that patient, who was treated using the Milwaukee Protocol, an
experimental treatment protocol similar to one used for the rabies survivor
described in 2005. This report also describes the subsequent epidemiologic
investigations by three regional public health departments in Alberta. Rabies
continues to be a cause of human death in the developed and developing world.
The findings in this report underscore the need for continued public education
that promotes rabies prevention and postexposure prophylaxis while emphasizing
the importance of bat exposure in rabies transmission. BACKGROUND: Human rabies infection continues to be a significant public health
burden globally, and is occasionally imported to high income settings where the
Milwaukee Protocol for intensive care management has recently been employed,
with limited success in improving survival. Access to molecular diagnostics,
pre- and post-mortem, and documentation of pathophysiological responses while
using the Milwaukee protocol, can add useful insights for the future of rabies
management.
CASE PRESENTATION: A 58-year-old British Asian woman was referred to a regional
general hospital in the UK with hydrophobia, anxiety and confusion nine weeks
after receiving a dog bite in North West India. Nuchal skin biopsy, saliva, and
a skin biopsy from the site of the dog bite wound, taken on the day of
admission, all demonstrated the presence of rabies virus RNA. Within 48 hours
sequence analysis of viral RNA confirmed the diagnosis and demonstrated that the
virus was a strain closely related to canine rabies viruses circulating in South
Asia. Her condition deteriorated rapidly with increased agitation and autonomic
dysfunction. She was heavily sedated and intubated on the day after admission,
treated according to a modified Milwaukee protocol, and remained stable until
she developed heart block and profound acidosis and died on the eighth day.
Analysis of autopsy samples showed a complete absence of rabies neutralizing
antibody in cerebrospinal fluid and serum, and corresponding high levels of
virus antigen and nucleic acid in brain and cerebrospinal fluid. Quantitative
PCR showed virus was also distributed widely in peripheral tissues despite mild
or undetectable histopathological changes. Vagus nerve branches in the heart
showed neuritis, a probable Negri body but no demonstrable rabies antigen.
CONCLUSION: Rapid molecular diagnosis and strain typing is helpful in the
management of human rabies infection. Post-mortem findings such as vagal
neuritis highlight clinically important effects on the cardiovascular system
which are typical for the clinical course of rabies in humans. Management guided
by the Milwaukee protocol is feasible within well-resourced intensive care
units, but its role in improving outcome for canine-derived rabies remains
theoretical. The Milwaukee protocol has been attributed to survival in rabies encephalitis
despite a lack of scientific evidence supporting its therapeutic measures. We
have reviewed the literature with reference to specific treatment
recommendations made within the protocol. Current literature fails to support an
important role for excitotoxicity and cerebral vasospasm in rabies encephalitis.
Therapies suggested in the Milwaukee protocol include therapeutic coma, ketamine
infusion, amantadine, and the screening/prophylaxis/management of cerebral
vasospasm. None of these therapies can be substantiated in rabies or other forms
of acute viral encephalitis. Serious concerns over the current protocol
recommendations are warranted. The recommendations made by the Milwaukee
protocol warrant serious reconsideration before any future use of this failed
protocol. Rabies is a zoonotic disease that is usually transmitted to humans by animal
bites. Dogs are the most important vector worldwide. There are encephalitic and
paralytic forms of the disease. There are differences in the clinical features
of the disease acquired from dogs and bats. Neuroimaging is non-specific.
Confirmatory diagnostic laboratory tests for rabies include detection of
neutralizing anti-rabies virus antibodies in serum or cerebrospinal fluid and
rabies virus antigen or RNA in tissues or fluids. Rabies is preventable after
recognized exposures with wound cleansing and administration of rabies vaccine
and rabies immune globulin. Rabies is virtually always fatal after clinical
disease develops, and there have only been rare survivors. The Milwaukee
protocol, which includes therapeutic coma, has been shown to be ineffective and
should no longer be used. The development of novel therapeutic approaches may
depend on a better understanding of basic mechanisms underlying the disease. |
Are stress granules membraneous? | Stress granules (SG) are membrane-less compartments involved in regulating mRNAs during stress. | Cells are highly organized structures. In addition to membrane delimited
organelles, proteins and RNAs can organize themselves into specific domains.
Some examples include stress granules and subnuclear bodies. This level of
organization is essential for the correct execution of multiple processes in the
cell, ranging from cell signaling to assembly of structures such as the
ribosomes. Here we will review evidence that noncoding RNAs play a critical role
in the establishment and regulation of these domains. The unique abilities of
RNA to mark the genome in a gene-specific and condition-specific manner and to
serve as tethers nominate them as ideal molecular address codes. Although the cellular interior is crowded with various biological
macromolecules, the distribution of these macromolecules is highly
inhomogeneous. Eukaryotic cells contain numerous proteinaceous membrane-less
organelles (PMLOs), which are condensed liquid droplets formed as a result of
the reversible and highly controlled liquid-liquid phase transitions. The
interior of these cellular bodies represents an overcrowded milieu, since their
protein concentrations are noticeably higher than those of the crowded cytoplasm
and nucleoplasm. PMLOs are different in size, shape, and composition, and almost
invariantly contain intrinsically disordered proteins (e.g., eIF4B and TDP43 in
stress granules, TTP in P-bodies, RDE-12 in nuage, RNG105 in RNA granules,
centrins in centrosomes, NOPP140 in nucleoli, SRSF4 in nuclear speckles, Saf-B
in nuclear stress bodies, NOLC1 in Cajal bodies, CBP in PML nuclear bodies, SOX9
in paraspeckles, KSRP in perinucleolar compartment, and hnRNPG and Sam68 in
Sam68 nuclear body, to name a few), which indicates that the formation of these
phase-separated droplets is crucially dependent on intrinsic disorder. The goal
of this review is to show the roles of intrinsic disorder in the magic behind
biological liquid-liquid phase transitions that lead to the formation of PMLOs. Stress granules (SG) are membrane-less compartments involved in regulating mRNAs
during stress. Aberrant forms of SGs have been implicated in age-related
diseases, such as amyotrophic lateral sclerosis (ALS), but the molecular events
triggering their formation are still unknown. Here, we find that misfolded
proteins, such as ALS-linked variants of SOD1, specifically accumulate and
aggregate within SGs in human cells. This decreases the dynamics of SGs, changes
SG composition, and triggers an aberrant liquid-to-solid transition of in vitro
reconstituted compartments. We show that chaperone recruitment prevents the
formation of aberrant SGs and promotes SG disassembly when the stress subsides.
Moreover, we identify a backup system for SG clearance, which involves transport
of aberrant SGs to the aggresome and their degradation by autophagy. Thus, cells
employ a system of SG quality control to prevent accumulation of misfolded
proteins and maintain the dynamic state of SGs, which may have relevance for ALS
and related diseases. |
When is 16S rRNA Gene Sequencing used? | Taxonomic characterization is performed by genotypic approaches such as 16S rRNA gene sequencing. | Soil complexity, heterogeneity and transferability make it valuable in forensic
investigations to help obtain clues as to the origin of an unknown sample, or to
compare samples from a suspect or object with samples collected at a crime
scene. In a few countries, soil analysis is used in matters from site
verification to estimates of time after death. However, up to date the
application or use of soil information in criminal investigations has been
limited. In particular, comparing bacterial communities in soil samples could be
a useful tool for forensic science. To evaluate the relevance of this approach,
a blind test was performed to determine the origin of two questioned samples
(one from the mock crime scene and the other from a 50:50 mixture of the crime
scene and the alibi site) compared to three control samples (soil samples from
the crime scene, from a context site 25m away from the crime scene and from the
alibi site which was the suspect's home). Two biological methods were used,
Ribosomal Intergenic Spacer Analysis (RISA), and 16S rRNA gene sequencing with
Illumina Miseq, to evaluate the discriminating power of soil bacterial
communities. Both techniques discriminated well between soils from a single
source, but a combination of both techniques was necessary to show that the
origin was a mixture of soils. This study illustrates the potential of applying
microbial ecology methodologies in soil as an evaluative forensic tool. BACKGROUND: Metagenomics is a rapidly emerging field aimed to analyze microbial
diversity and dynamics by studying the genomic content of the microbiota.
Metataxonomics tools analyze high-throughput sequencing data, primarily from 16S
rRNA gene sequencing and DNAseq, to identify microorganisms and viruses within a
complex mixture. With the growing demand for analysis of the functional
microbiome, metatranscriptome studies attract more interest. To make
metatranscriptomic data sufficient for metataxonomics, new analytical workflows
are needed to deal with sparse and taxonomically less informative sequencing
data.
RESULTS: We present a new protocol, IMSA+A, for accurate taxonomy classification
based on metatranscriptome data of any read length that can efficiently and
robustly identify bacteria, fungi, and viruses in the same sample. The new
protocol improves accuracy by using a conservative reference database, employing
a new counting scheme, and by assembling shotgun reads. Assembly also reduces
analysis runtime. Simulated data were utilized to evaluate the protocol by
permuting common experimental variables. When applied to the real
metatranscriptome data for mouse intestines colonized by ASF, the protocol
showed superior performance in detection of the microorganisms compared to the
existing metataxonomics tools. IMSA+A is available at
https://github.com/JeremyCoxBMI/IMSA-A .
CONCLUSIONS: The developed protocol addresses the need for taxonomy
classification from RNAseq data. Previously not utilized, i.e., unmapped to a
reference genome, RNAseq reads can now be used to gather taxonomic information
about the microbiota present in a biological sample without conducting
additional sequencing. Any metatranscriptome pipeline that includes assembly of
reads can add this analysis with minimal additional cost of compute time. The
new protocol also creates an opportunity to revisit old metatranscriptome data,
where taxonomic content may be important but was not analyzed. Lactobacilli represent a wide range of bacterial species with several
implications for the human host. They play a crucial role in maintaining the
ecological equilibrium of different biological niches and are essential for
fermented food production and probiotic formulation. Despite the consensus about
the 'health-promoting' significance of Lactobacillus genus, its genotypic and
phenotypic characterization still poses several difficulties. The aim of this
study was to assess the integration of different approaches, genotypic (16S rRNA
gene sequencing), proteomic (MALDI-TOF MS) and metabolomic (1H-NMR), for the
taxonomic and metabolic characterization of Lactobacillus species. For this
purpose we analyzed 40 strains of various origin (intestinal, vaginal, food,
probiotics), belonging to different species. The high discriminatory power of
MALDI-TOF for species identification was underlined by the excellent agreement
with the genotypic analysis. Indeed, MALDI-TOF allowed to correctly identify 39
out of 40 Lactobacillus strains at the species level, with an overall
concordance of 97.5%. In the perspective to simplify the MALDI TOF sample
preparation, especially for routine practice, we demonstrated the perfect
agreement of the colony-picking from agar plates with the protein extraction
protocol. 1H-NMR analysis, applied to both culture supernatants and bacterial
lysates, identified a panel of metabolites whose variations in concentration
were associated with the taxonomy, but also revealed a high intra-species
variability that did not allow a species-level identification. Therefore,
despite not suitable for mere taxonomic purposes, metabolomics can be useful to
correlate particular biological activities with taxonomy and to understand the
mechanisms related to the antimicrobial effect shown by some Lactobacillus
species. The different pipelines that may be used in 16S rRNA gene profiling of bacterial
communities are known to have a significant impact on alpha and beta diversity
measures and this may prevent direct comparison of results obtained in studies
using different bioinformatic approaches to analyse raw sequences. To evaluate
the feasibility of meta-studies on food bacterial communities, we compared four
analysis procedures, varying in OTU picking and taxonomy assignment strategies.
A closed reference OTU picking resulted in the most divergent results in terms
of both alpha and beta diversity, compared to open reference methods.
Nevertheless, when OTUs were collapsed at the genus level, a high correlation
was obtained among the estimated abundances of taxa for most studies.
Aggregation of samples by their nature and occurrence of food spoilage or
fermentation resulted in a very similar classification using two beta diversity
analysis methods. We conclude that comparisons of data obtained from different
studies are feasible at the genus level, when the same OTU picking strategy is
used. Finally, we provide a new version of FoodMicrobionet (Parente et al.,
2016), including data from 26 recent studies on food bacterial communities,
together with R scripts allowing both the extraction of data in formats which
can be used in several analysis tools (including the R package phyloseq and the
Cytoscape app CoNet) and the statistical and graphical analysis using common
alpha- and beta-diversity analysis methods. |
What does intepirdine target? | Intepiridine is a 5-HT6 antagonist. | Alzheimer's disease (AD) is a major neuropsychiatric disorder affecting more
than 5 million Americans over age 65. By the year 2050, AD is expected to affect
over 30 million. Characterized by neuronal cell death accompanied by the
accumulation of neurofibrillary tangles and neuritic plaques, AD results in
devastating clinical symptomatology with a lasting psychosocial and ficial
impact. Studies have shown that the current treatments for AD, cholinesterase
inhibitors (ChEI's) and NMDA receptor antagonists, have limited efficacy. The
5-HT-6 receptor antagonists Idalopirdine and Intepirdine have shown the most
progress in current clinical trials and warrant consideration as emerging
treatments for AD. Areas covered: This review discusses 5-HT6 antagonists
currently in clinical trials as potential treatments for AD symptomatology and
how 5-HT6 physiology may play a positive role in alleviating AD symptom
pathophysiology. A literature search using PubMed was conducted using the terms
Idalopirdine, Intepirdine, 5-HT-6 antagonist, and AD as keywords.
Clinicaltrials.gov and Alzforum were also used to obtain information on clinical
trials. Expert opinion: If current Phase-3 trials are positive, 5-HT6
antagonists such as Idalopirdine and Intepirdine may be considered as
supplementary treatments to ChEI's and NMDA receptor antagonists for the
symptomatic treatment of AD. |
Is the consumption of chocolate associated with an increase in cardiovascular disease? | The consumption of natural polyphenol-rich foods, and cocoa in particular, has been related to a reduced risk of CVD, including coronary heart disease and stroke. | Traditional chocolate is derived from the cocoa bean, which is one of the most
concentrated sources of flavanols, a subgroup of the natural antioxidant plant
compounds called flavonoids. Accumulating evidence from the past 10 years
demonstrates that moderate consumption of chocolate, especially dark chocolate,
may exert protective effects against the development of cardiovascular disease.
Several mechanisms have been proposed to explain this positive influence,
including metabolic, antihypertensive, anti-inflammatory, and anti-thrombotic
effects, as well as effects on insulin sensitivity and vascular endothelial
function. Should these results be confirmed in randomised, controlled,
cross-over, multi-dose trials, then the pleasure associated with chocolate
consumption might also be justified from health and psychological perspectives.
However, since dark chocolate has substantially higher levels of flavonoids than
milk chocolate, and milk proteins may inhibit absorption of flavonoids, it might
be preferable to consume dark chocolate than the white (milk) variety. BACKGROUND & AIMS: Epidemiologic studies have suggested beneficial effects of
flavonoids on cardiovascular disease. Cocoa and particularly dark chocolate are
rich in flavonoids and recent studies have demonstrated blood pressure lowering
effects of dark chocolate. However, limited data are available on the
association of chocolate consumption and the risk of coronary heart disease
(CHD). We sought to examine the association between chocolate consumption and
prevalent CHD.
METHODS: We studied in a cross-sectional design 4970 participants aged 25-93
years who participated in the National Heart, Lung, and Blood Institute (NHLBI)
Family Heart Study. Chocolate intake was assessed through a semi-quantitative
food frequency questionnaire. We used generalized estimating equations to
estimate adjusted odds ratios.
RESULTS: Compared to subjects who did not report any chocolate intake, odds
ratios (95% CI) for CHD were 1.01 (0.76-1.37), 0.74 (0.56-0.98), and 0.43
(0.28-0.67) for subjects consuming 1-3 times/month, 1-4 times/week, and 5+
times/week, respectively (p for trend <0.0001) adjusting for age, sex, family
CHD risk group, energy intake, education, non-chocolate candy intake, linolenic
acid intake, smoking, alcohol intake, exercise, and fruit and vegetables.
Consumption of non-chocolate candy was associated with a 49% higher prevalence
of CHD comparing 5+/week vs. 0/week [OR = 1.49 (0.96-2.32)].
CONCLUSIONS: These data suggest that consumption of chocolate is inversely
related with prevalent CHD in a general United States population. Since ancient times, numerous health beneficial effects have been attributed to
chocolate, closing up its consumption to a therapeutic use. The present study
reviews some relevant studies about chocolate (and its bioactive compounds) on
some cardiovascular risk factors and stresses the need of future studies. The
consumption of cocoa/ chocolate (i) increases plasma antioxidant capacity, (ii)
diminishes platelet function and inflammation, and (iii) decreases diastolic and
systolic arterial pressures. Data currently available indicate that daily
consumption of cocoa-rich chocolate (rich in polyphenols) may at least partially
lower cardiovascular disease risk. Further studies are required in order to
establish the bioavailability and mechanisms of action of bioactive compounds in
chocolate. The study of the interaction of chocolate and its components with
candidate genes will also supply necessary information regarding the individuals
best suited to benefit from a potential cardiovascular disease treatment with
chocolate. It has been shown that the consumption of cocoa has a positive influence on a
number of cardiovascular surrogate parameters such as arterial vasodilatation
and a moderate decrease in blood pressure in humans. In the blood, a decrease in
platelet aggregation and an increase in angiogenetic progenitor cells was noted.
Furthermore, anti-inflammatory effects, an amelioration of the lipid profile and
glucose metabolism was described. An increase of endothelial NO production
following the ingestion of the antioxidant cocoa flavanols catechin and
epicatechin seems to be the leading mechanism causing these effects. In animal
studies of myocardial reperfusion, a decrease in infarct size was noted. In
several prospective cohort studies from Europe and the United States, a 50 %
reduction of mortality mostly due to a reduction of myocardial infarction was
published. Consumption up to about 25 g daily of a flavanol rich dark chocolate
(ca. 85 % cocoa content) can be recommended for cardiovascular prevention. In
this moderate dosage, the potentially harmful effects due to weight gain and
cadmium intake will be minimal. However, controlled randomized trials with well
defined clinical endpoints are needed to prove the positive effects described so
far. At this point, in time based on the information described in this article,
a moderate consumption of flavanol rich cocoa products seems to be effective in
the prevention of coronary artery disease and myocardial infarction. The consumption of cocoa and dark chocolate is associated with a lower risk of
CVD, and improvements in endothelial function may mediate this relationship.
Less is known about the effects of cocoa/chocolate on the augmentation index
(AI), a measure of vascular stiffness and vascular tone in the peripheral
arterioles. We enrolled thirty middle-aged, overweight adults in a randomised,
placebo-controlled, 4-week, cross-over study. During the active treatment
(cocoa) period, the participants consumed 37 g/d of dark chocolate and a
sugar-free cocoa beverage (total cocoa = 22 g/d, total flavanols (TF) = 814
mg/d). Colour-matched controls included a low-flavanol chocolate bar and a
cocoa-free beverage with no added sugar (TF = 3 mg/d). Treatments were matched
for total fat, saturated fat, carbohydrates and protein. The cocoa treatment
significantly increased the basal diameter and peak diameter of the brachial
artery by 6% (+2 mm) and basal blood flow volume by 22%. Substantial decreases
in the AI, a measure of arterial stiffness, were observed in only women.
Flow-mediated dilation and the reactive hyperaemia index remained unchanged. The
consumption of cocoa had no effect on fasting blood measures, while the control
treatment increased fasting insulin concentration and insulin resistance (P=
0·01). Fasting blood pressure (BP) remained unchanged, although the acute
consumption of cocoa increased resting BP by 4 mmHg. In summary, the
high-flavanol cocoa and dark chocolate treatment was associated with enhanced
vasodilation in both conduit and resistance arteries and was accompanied by
significant reductions in arterial stiffness in women. OBJECTIVE: To examine whether chocolate consumption is associated with a reduced
risk of ischaemic heart disease, we used data from a prospective study of
Swedish adults and we performed a meta-analysis of available prospective data.
METHODS AND RESULTS: The Swedish prospective study included 67 640 women and men
from the Cohort of Swedish Men and the Swedish Mammography Cohort who had
completed a food-frequency questionnaire and were free of cardiovascular disease
at baseline. Myocardial infarction (MI) cases were ascertained through linkage
with the Swedish National Patient and Cause of Death Registers. PubMed and
EMBASE databases were searched from inception until 4 February 2016 to identify
prospective studies on chocolate consumption and risk of ischaemic heart
disease.
RESULTS: The results from eligible studies were combined using a random-effects
model. During follow-up (1998-2010), 4417 MI cases were ascertained in the
Swedish study. Chocolate consumption was inversely associated with MI risk.
Compared with non-consumers, the multivariable relative risk for those who
consumed ≥3-4 servings/week of chocolate was 0.87 (95% CI 0.77 to 0.98; p for
trend =0.04). Five prospective studies on chocolate consumption and ischaemic
heart disease were identified. Together with the Swedish study, the
meta-analysis included six studies with a total of 6851 ischaemic heart disease
cases. The overall relative risk for the highest versus lowest category of
chocolate consumption was 0.90 (95% CI 0.82 to 0.97), with little heterogeneity
among studies (I(2)=24.3%).
CONCLUSIONS: Chocolate consumption is associated with lower risk of MI and
ischaemic heart disease. BACKGROUND: Sleep deprivation is a risk factor for cardiovascular disease. Cocoa
flavonoids exert cardiovascular benefits and neuroprotection. Whether chocolate
consumption may mitigate detrimental effects of sleep loss on cognitive
performance and cardiovascular parameters has never been studied.
AIM: We investigated the effects of flavanol-rich chocolate consumption on
cognitive skills and cardiovascular parameters after sleep deprivation.
METHODS: Thirty-two healthy participants underwent two baseline sessions after
one night of undisturbed sleep and two experimental sessions after one night of
total sleep deprivation. Two hours before each testing session, participants
were randomly assigned to consume high or poor flavanol chocolate bars. During
the tests were evaluated, the Psychomotor Vigilance Task and a working memory
task, office SBP and DBP, flow-mediated dilation and pulse-wave velocity.
RESULTS: Sleep deprivation increased SBP/DBP. SBP/DBP and pulse pressure were
lower after flavanol-rich treatment respect to flavanol-poor treatment (SBP:
116.9 ± 1.6 vs. 120.8 ± 1.9 mmHg, respectively, P = 0.00005; DBP: 70.5 ± 1.2 vs.
72.3 ± 1.2 mmHg, respectively, P = 0.01; pulse pressure: 46.4 ± 1.3 vs.
48.4 ± 1.5 mmHg, P = 0.004). Sleep deprivation impaired flow-mediated dilation
(5.5 ± 0.5 vs. 6.5 ± 0.6%, P = 0.02), flavanol-rich, but not flavanol-poor
chocolate counteracted this alteration (flavanol-rich/flavanol-poor chocolate:
7.0 ± 0.6 vs. 5.0 ± 0.4%, P = 0.000001). Flavanol-rich chocolate mitigated the
pulse-wave velocity increase (P = 0.001). Flavanol-rich chocolate preserved
working memory accuracy in women after sleep deprivation. Flow-mediated dilation
correlated with working memory performance accuracy in the sleep condition
(P = 0.04).
CONCLUSION: Flavanol-rich chocolate counteracted vascular impairment after sleep
deprivation and restored working memory performance. Improvement in cognitive
performance could be because of the effects of cocoa flavonoids on blood
pressure and peripheral and central blood flow. OBJECTIVES: There is previous epidemiological evidence that intake of
polyphenol-rich foods has been associated with reduced cardiovascular disease
risk. We aimed to investigate the effect of increasing dietary polyphenol intake
on microvascular function in hypertensive participants.
METHODS: All participants completed a 4-week run-in phase, consuming <2 portions
of fruit and vegetables (F&V) daily and avoiding berries and dark chocolate.
Subjects were then randomised to continue with the low-polyphenol diet for
8 weeks or to consume a high-polyphenol diet of six portions F&V (including one
portion of berries/day and 50 g of dark chocolate). Endothelium-dependent
(acetylcholine, ACh) and endothelium-independent (sodium nitroprusside)
vasodilator responses were assessed by venous occlusion plethysmography.
Compliance with the intervention was measured using food diaries and biochemical
markers.
RESULTS: Final analysis of the primary endpoint was conducted on 92
participants. Between-group comparison of change in maximum % response to ACh
revealed a significant improvement in the high-polyphenol group (p=0.02). There
was a significantly larger increase in vitamin C, carotenoids and epicatechin in
the high-polyphenol group (between-group difference p<0.001; p<0.001; p=0.008,
respectively).
CONCLUSIONS: This study has shown that increasing the polyphenol content of the
diet via consumption of F&V, berries and dark chocolate results in a significant
improvement in an established marker of cardiovascular risk in hypertensive
participants.
TRIAL REGISTRATION NUMBER: NCT01319786. BACKGROUND AND AIMS: Chocolate consumption may have a beneficial effect on
cardiovascular health, but evidence from prospective cohort studies is still
limited. We aimed to examine the prospective associations between chocolate
consumption and risk of stroke among men and women in a large population-based
cohort.
METHODS: A total of 38,182 men and 46,415 women aged 44-76 years, and free of
cardiovascular disease, diabetes, and cancer at baseline in 1995 and 1998, were
followed up until the end of 2009 and 2010, respectively. We obtained data on
chocolate consumption for each participant using a self-administrated food
frequency questionnaire that included 138 food and beverage items. Cox
proportional hazards regression models were used to estimate hazard ratios (HRs)
of stroke in relation to chocolate consumption.
RESULTS: During a median follow-up of 12.9 years, we identified 3558 incident
strokes cases (2146 cerebral infarctions and 1396 hemorrhagic strokes). After
adjustment for age, body mass index, life styles, dietary intakes, and other
risk factors, chocolate consumption was associated with a significant lower risk
of stroke in women (HR = 0.84; 95% CI, 0.71-0.99). However, the association in
men was not significant (HR = 0.94; 95% CI, 0.80-1.10). In addition, the
association did not vary by stroke subtypes in either men or women.
CONCLUSIONS: Findings from this large Japanese cohort supported a significant
inverse association between chocolate consumption and risk of developing stroke
in women. However, residual confounding could not be excluded as an alternative
explanation for our findings. The chemical structure of polyphenols consisting of aromatic rings, capable of
quenching free radicals, makes them ideal candidates to protect against
oxidation. Polyphenols are present in a variety of foods including grapes,
berries, dark chocolate, coffee and tea to mention a few. A number of studies
have shown that dietary polyphenols exert a protective effect against
hypertension, dyslipidemias, inflammation, endothelial function and
atherosclerosis, conditions associated with increased risk for cardiovascular
disease. Studies indicate that by decreasing cholesterol absorption, polyphenols
alter hepatic cholesterol homeostasis resulting in decreases in plasma lipids
and reduction in atherogenic lipoproteins thus having a protective effect
against atherosclerosis; polyphenols have also been shown to decrease the
activity of enzymes involved in the renin-angiotensinaldosterone system and
improve blood pressure. Further, they have been recognized to increase nitric
oxide production and to improve endothelial function. In this review we will
present some of the evidence derived from epidemiological studies, clinical
interventions as well as animal and cell studies supporting the cardioprotective
effects of dietary polyphenols. Oxidative and inflammatory stress represents a major risk factor for
cardiovascular disease (CVD) in overweight and obese subjects. Between the
different plant foods, chocolate has been shown to decrease CVD risk due to its
antioxidant and anti-inflammatory properties. However, as we recently showed in
epidemiological studies, meta-analyses, and human trials, dietary antioxidants
resulted more effective in subjects characterized by an ongoing oxidative
stress, than in healthy people. Aim of this work was to investigate the effect
of different concentrations of chocolate phenolic extract (CPE) on in vitro free
radical production, stimulated by phorbol 12-myristate 13-acetate (PMA), in
leukocytes extracted from blood of normo-weight and overweight/obese subjects.
Neutrophils from overweight/obese group had a significantly higher free radical
production compared to the normo-weight group. In neutrophils, the lowest CPE
concentration significantly reduced free radical production in overweight/obese
group only, and higher CPE concentrations were effective in both groups. In
monocytes, the CPE concentration that was significantly effective in reducing
free radical production was lower in overweight/obese subjects than in
normo-weight subjects. Chocolate polyphenol extracts inhibit oxidative burst in
human neutrophils and monocytes with a higher efficiency in subjects
characterized by an unphysiological oxidative/inflammatory stress, such as
overweight and obese. Results of this study provide further evidence about a
differential role of dietary antioxidant strictly related to the "stress"
condition of the subjects. BACKGROUND: Accumulating evidence suggests potential preventive effects of
chocolate/cocoa on the risk of cardio vascular disease (CVD). However, cocoa
products also contain high levels of sugar and fat, which increase CVD risk
factors. Even, the identity of the substance in chocolate/cocoa that has a
favorable effect on CVD and CVD risk factors remains unclear, growing evidence
from experimental studies suggests that cocoa polyphenols might be a major
contributor to cardiovascular-protective effects. However, epidemiological
studies, which are necessary to evaluate an association between the risk of CVD
and cocoa polyphenol, remain sparse.
METHODS: We will discuss recent evidence regarding the association between cocoa
polyphenol consumption and the risks of CVD and its risk factors by reviewing
recent epidemiological studies. We shall also provide some guidance for patient
counseling and will discuss the public health implications for recommending
cocoa polyphenol consumption to prevent CVD.
RESULTS: Epidemiological studies evaluating the association between cocoa
polyphenol itself and the risk of CVD are sparse. However, evidence from limited
epidemiological studies suggests that cocoa polyphenol consumption may lower the
risk of CVD.
CONCLUSION: Given the potential adverse effects of the consumption of cocoa
products with high fat and sugar and the fact that the most appropriate dose of
cocoa polyphenol for cardio-protective effects has not yet been established,
health care providers should remain cautious about recommending cocoa/cocoa
polyphenol consumption to their patients to reduce the risk of CVD, taking the
characteristics of individual patients into careful consideration. |
What is the association of circular RNA to breast cancer? | circRNAs are differentially expressed in breast cancer and are important in carcinogenesis because they participate in cancer-related pathways and sequester miRNAs. circRNA frequency may be a marker for cell proliferation in breast cancer. | Circular RNAs (circRNAs) are highly stable forms of non-coding RNAs with diverse
biological functions. They are implicated in modulation of gene expression thus
affecting various cellular and disease processes. Based on existing
bioinformatics approaches, we developed a comprehensive workflow called Circ-Seq
to identify and report expressed circRNAs. Circ-Seq also provides informative
genomic annotation along circRNA fused junctions thus allowing prioritization of
circRNA candidates. We applied Circ-Seq first to RNA-sequence data from breast
cancer cell lines and validated one of the large circRNAs identified. Circ-Seq
was then applied to a larger cohort of breast cancer samples (n = 885) provided
by The Cancer Genome Atlas (TCGA), including tumors and normal-adjacent tissue
samples. Notably, circRNA results reveal that normal-adjacent tissues in
estrogen receptor positive (ER+) subtype have relatively higher numbers of
circRNAs than tumor samples in TCGA. Similar phenomenon of high circRNA numbers
were observed in normal breast-mammary tissues from the Genotype-Tissue
Expression (GTEx) project. Finally, we observed that number of circRNAs in
normal-adjacent samples of ER+ subtype is inversely correlated to the
risk-of-relapse proliferation (ROR-P) score for proliferating genes, suggesting
that circRNA frequency may be a marker for cell proliferation in breast cancer.
The Circ-Seq workflow will function for both single and multi-threaded compute
environments. We believe that Circ-Seq will be a valuable tool to identify
circRNAs useful in the diagnosis and treatment of other cancers and complex
diseases. Endogenous noncoding circular RNAs (circRNAs) have gained attention for their
involvement in carcinogenesis, but their expression pattern in breast cancer has
remained largely unknown. In this two-stage study, we first used an Arraystar
Human circRNA Array to construct a genome-wide circRNA profile. We then selected
candidate circRNAs for validation using a quantitative real-time polymerase
chain reaction system. CircRNA/miRNA interactions were predicted and sequence
analyses were performed. Among 1155 differentially expressed circRNAs, 715 were
upregulated and 440 were downregulated in breast cancer tissues. The validation
study demonstrated that hsa_circ_103110, hsa_circ_104689 and hsa_circ_104821
levels were elevated in breast cancer tissues, whereas hsa_circ_006054,
hsa_circ_100219 and hsa_circ_406697 were downregulated. These circRNAs targeted
complementary miRNA response elements. The area under the receiver operating
characteristic curve for distinguishing breast cancer was 0.82 (95% CI:
0.73-0.90) when hsa_circ_006054, hsa_circ_100219 and hsa_circ_406697 were used
in combination. This study provides evidence that circRNAs are differentially
expressed in breast cancer and are important in carcinogenesis because they
participate in cancer-related pathways and sequester miRNAs. |
List 3 symptoms of Wernicke encephalopathy. | Wernicke's encephalopathy (WE) is a neurological syndrome caused by thiamine deficiency, and clinically characterized by ophthalmoplegia, ataxia and acute confusion. | BACKGROUND AND PURPOSE: Wernicke encephalopathy is a severe neurologic disorder
that results from a dietary vitamin B1 deficiency. It is characterized by
changes in consciousness, ocular abnormalities, and ataxia. This study was
undertaken to analyze and compare findings on MR imaging and neurologic symptoms
at clinical presentations of patients with Wernicke encephalopathy with and
without a history of alcohol abuse.
MATERIALS AND METHODS: A multicenter study group retrospectively reviewed MR
brain imaging findings, clinical histories, and presentations of 26 patients (14
female, 12 male) diagnosed between 1999 and 2006 with Wernicke encephalopathy.
The age range was 6-81 years (mean age, 46 .6+/-19 years).
RESULTS: Fifty percent of the patients had a history of alcohol abuse, and 50%
had no history of alcohol abuse. Eighty percent showed changes in consciousness,
77% had ocular symptoms, and 54% had ataxia. Only 38% of the patients showed the
classic triad of the disease at clinical presentation. At MR examination, 85% of
the patients showed symmetric lesions in the medial thalami and the
periventricular region of the third ventricle, 65% in the periaqueductal area,
58% in the mamillary bodies, 38% in the tectal plate, and 8% in the dorsal
medulla. Contrast enhancement of the mamillary bodies was statistically
positively correlated with the alcohol abuse group.
CONCLUSIONS: Our study confirms the usefulness of MR in reaching a prompt
diagnosis of Wernicke encephalopathy to avoid irreversible damage to brain
tissue. Contrast enhancement in the mamillary bodies is a typical finding of the
disease in the alcoholic population. Wernicke's encephalopathy is an acute neurolopsychiatric syndrome caused by
thiamine deficiency, and classically presents with the triad of opthalmopathy,
ataxia and altered mentality. Both prolonged total parenteral nutrition and
reduced oral intake can induce Wernicke's encephalopathy during hematopoietic
stem cell transplantation (HSCT). Although early treatment is important for
recovery from Wernicke's encephalopathy, the vague symptoms and characteristics
hinder early diagnosis. Furthermore, Wernicke's encephalopathy is not infrequent
and can develop at any age during HSCT. Herein, we present two young patients
developing Wernicke's encephalopathy during HSCT. Introduction. Wernicke's encephalopathy is a well-described syndrome
characterized by the classic triad of confusion, ataxia, and ophthalmoplegia.
Wernicke's encephalopathy results from thiamine (vitamin B1) deficiency. Common
causes include alcoholism and gastric disorders. Wernicke's has been described
in patients with acquired immune deficiency syndrome (AIDS); however, given
these patients' immunosuppressed state, the diagnosis of Wernicke's
encephalopathy is not apparent. Case Presentation. A 31-year-old previously
healthy male presented to the ER complaining of progressive dyspnea. Workup
revealed HIV/AIDS and PCP pneumonia. He was treated and improved. On day 14 he
became confused and developed nystagmus and ataxia. Considering his
immunocompromised state, infectious and neoplastic etiologies topped the
differential diagnosis. CT head was negative. Lumbar puncture was unremarkable.
Brain MRI revealed increased T2 signal in the medial thalamus bilaterally.
Intravenous thiamine was administered resulting in resolution of symptoms.
Discussion. The classic triad of Wernicke's encephalopathy occurs in 10% of
cases. When immunosuppressed patients develop acute neurologic symptoms
infectious or neoplastic etiologies must be excluded. However, given the
relative safety of thiamine supplementation, there should be a low threshold for
initiating therapy in order to reverse the symptoms and prevent progression to
Korsakoff dementia, which is permanent. Wernicke encephalopathy is an acute neuropsychiatric disease with heterogeneous
symptoms, including changes in mental status, ataxia and ocular abnormalities;
if left untreated, these symptoms can lead to morbidity and even to mortality.
The treatment is thiamine suppletion. Because of the heterogeneity of the
symptoms and the high risk of morbidity and mortality if the symptoms are not
treated, it is vitally important that on observing a patient's early symptoms
the clinician immediately suspects that the symptoms could point to Wernicke
encephalopathy. Wernicke-Korsakoff syndrome in patients with cancer is understudied. Much of
what is known-that significant under-recognition and delays in treatment
exist-comes from studies of alcohol misuse disorders or non-alcohol-related
Wernicke-Korsakoff syndrome in patients. We investigated the frequency and
associated features of cancer-related Wernicke-Korsakoff syndrome in the
published literature. We included 90 articles reporting on 129 patients. Only 38
(30%) of 128 patients with data available exhibited the entire triad of classic
features of Wernicke-Korsakoff syndrome: confusion, ataxia, and ophthalmoplegia
or nystagmus. Diagnosis during life was missed altogether in 22 (17%) of 128
patients. The operational diagnostic criteria (at least two of the following:
nutritional deficiency, ocular signs, cerebellar signs, and either altered
mental status or mild memory impairment), which are considered more reliable
than the classical triad, were used in only nine (7%) cases, yet 120 (94%) met
the operational criteria for diagnosis at the time of presentation when applied
retroactively. Complete recovery was reported in only 47 (36%) cases. Given that
oncologists or haematologists accounted for only 17 (19%) first authors among
the articles included, it is important that oncologists are aware of the risk
factors for cancer-related Wernicke-Korsakoff syndrome, and that they are
vigilant about diagnosing and treating the disease especially in the absence of
alcohol misuse disorders. INTRODUCTION: Wernicke's encephalopathy (WE) is a neurological syndrome caused
by thiamine deficiency, and clinically characterized by ophthalmoplegia, ataxia
and acute confusion. In developed countries, most cases of WE have been seen in
alcohol misusers. Other reported causes are gastrointestinal tract surgery,
hyperemesis gravidarum, chronic malnutrition, prolonged total parenteral
nutrition without thiamine supplementation, and increased nutrient requirements
as in trauma or septic shock. WE is a well-known postoperative complication of
gastric restrictive surgery for morbid obesity, after which patients often
experience protracted nausea and vomiting, leading to malnutrition and massive
weight loss.
PRESENTATION OF CASE: This case report concerns WE occurring in a patient who
underwent Roux-en-Y subtotal gastrectomy for gastric cancer, and subsequently
experienced neurological symptoms that proved irreversible probably due to the
lengthy time elapsing between their clinical presentation and the diagnosis of
WE.
DISCUSSION: There have been some reports of WE occurring after total or subtotal
gastrectomy for gastric cancer in non-obese patients with no history of
alcoholism, but monitoring for WE has yet to be recommended in the clinical
guidelines in this setting (as it has for bariatric surgery). Because of its
rarity and variable clinical presentation, WE is often under-diagnosed and
under-treated, and confused with other neurological problems.
CONCLUSION: There is an urgent need for the specific guidelines to take into
account not only the neoplastic follow-up of such patients, but also the
possible side effects of necessary surgery, since this could help to ensure the
timely diagnosis and management of WE in this setting, and to avoid, when
possible, claims for medical malpractice that may cause enormous costs both in
economical and professional terms. |
Describe RIblast | LncRNAs play important roles in various biological processes. Although more than 58 000 human lncRNA genes have been discovered, most known lncRNAs are still poorly characterized. One approach to understanding the functions of lncRNAs is the detection of the interacting RNA target of each lncRNA. Because experimental detections of comprehensive lncRNA-RNA interactions are difficult, computational prediction of lncRNA-RNA interactions is an indispensable technique. However, the high computational costs of existing RNA-RNA interaction prediction tools prevent their application to large-scale lncRNA datasets. 'RIblast' is an ultrafast RNA-RNA interaction prediction method based on the seed-and-extension approach. RIblast discovers seed regions using suffix arrays and subsequently extends seed regions based on an RNA secondary structure energy model. Computational experiments indicate that RIblast achieves a level of prediction accuracy similar to those of existing programs, but at speeds over 64 times faster than existing programs. | MOTIVATION: LncRNAs play important roles in various biological processes.
Although more than 58 000 human lncRNA genes have been discovered, most known
lncRNAs are still poorly characterized. One approach to understanding the
functions of lncRNAs is the detection of the interacting RNA target of each
lncRNA. Because experimental detections of comprehensive lncRNA-RNA interactions
are difficult, computational prediction of lncRNA-RNA interactions is an
indispensable technique. However, the high computational costs of existing
RNA-RNA interaction prediction tools prevent their application to large-scale
lncRNA datasets.
RESULTS: Here, we present 'RIblast', an ultrafast RNA-RNA interaction prediction
method based on the seed-and-extension approach. RIblast discovers seed regions
using suffix arrays and subsequently extends seed regions based on an RNA
secondary structure energy model. Computational experiments indicate that
RIblast achieves a level of prediction accuracy similar to those of existing
programs, but at speeds over 64 times faster than existing programs.
AVAILABILITY AND IMPLEMENTATION: The source code of RIblast is freely available
at https://github.com/fukunagatsu/RIblast .
CONTACT: [email protected] or [email protected].
SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics
online. |
What is Alzheimers disease resilience? | Some 30 to 50% of older individuals who harbor AD pathology do not become symptomatic in their lifetime. It is hypothesized that such individuals exhibit cognitive resilience that protects against AD dementia. | OBJECTIVE: To define robust resilience metrics by leveraging CSF biomarkers of
Alzheimer disease (AD) pathology within a latent variable framework and to
demonstrate the ability of such metrics to predict slower rates of cognitive
decline and protection against diagnostic conversion.
METHODS: Participants with normal cognition (n = 297) and mild cognitive
impairment (n = 432) were drawn from the Alzheimer's Disease Neuroimaging
Initiative. Resilience metrics were defined at baseline by examining the
residuals when regressing brain aging outcomes (hippocampal volume and
cognition) on CSF biomarkers. A positive residual reflected better outcomes than
expected for a given level of pathology (high resilience). Residuals were
integrated into a latent variable model of resilience and validated by testing
their ability to independently predict diagnostic conversion, cognitive decline,
and the rate of ventricular dilation.
RESULTS: Latent variables of resilience predicted a decreased risk of conversion
(hazard ratio < 0.54, p < 0.0001), slower cognitive decline (β > 0.02, p <
0.001), and slower rates of ventricular dilation (β < -4.7, p < 2 × 10-15).
These results were significant even when analyses were restricted to clinically
normal individuals. Furthermore, resilience metrics interacted with biomarker
status such that biomarker-positive individuals with low resilience showed the
greatest risk of subsequent decline.
CONCLUSIONS: Robust phenotypes of resilience calculated by leveraging AD
biomarkers and baseline brain aging outcomes provide insight into which
individuals are at greatest risk of short-term decline. Such comprehensive
definitions of resilience are needed to further our understanding of the
mechanisms that protect individuals from the clinical manifestation of AD
dementia, especially among biomarker-positive individuals. OBJECTIVE: Neuroimaging and other biomarker assays suggest that the pathological
processes of Alzheimer's disease (AD) begin years prior to clinical dementia
onset. However, some 30 to 50% of older individuals who harbor AD pathology do
not become symptomatic in their lifetime. It is hypothesized that such
individuals exhibit cognitive resilience that protects against AD dementia. We
hypothesized that in cases with AD pathology, structural changes in dendritic
spines would distinguish individuals who had or did not have clinical dementia.
METHODS: We compared dendritic spines within layer II and III pyramidal neuron
dendrites in Brodmann area 46 dorsolateral prefrontal cortex using the Golgi-Cox
technique in 12 age-matched pathology-free controls, 8 controls with AD
pathology (CAD), and 21 AD cases. We used highly optimized methods to trace
impregnated dendrites from bright-field microscopy images that enabled accurate
3-dimensional digital reconstruction of dendritic structure for morphologic
analyses.
RESULTS: Spine density was similar among control and CAD cases but was reduced
significantly in AD. Thin and mushroom spines were reduced significantly in AD
compared to CAD brains, whereas stubby spine density was decreased significantly
in CAD and AD compared to controls. Increased spine extent distinguished CAD
cases from controls and AD. Linear regression analysis of all cases indicated
that spine density was not associated with neuritic plaque score but did display
negative correlation with Braak staging.
INTERPRETATION: These observations provide cellular evidence to support the
hypothesis that dendritic spine plasticity is a mechanism of cognitive
resilience that protects older individuals with AD pathology from developing
dementia. Ann Neurol 2017;82:602-614. |
Which R package has been developed for analyzing Non-invasive prenatal testing (NIPT) data? | Non-invasive prenatal testing (NIPT) of fetal aneuploidy using cell-free fetal DNA is becoming part of routine clinical practice. RAPIDR (Reliable Accurate Prenatal non-Invasive Diagnosis R package) is an easy-to-use open-source R package that implements several published NIPT analysis methods. The input to RAPIDR is a set of sequence alignment files in the BAM format, and the outputs are calls for aneuploidy, including trisomies 13, 18, 21 and monosomy X as well as fetal sex. RAPIDR has been extensively tested with a large sample set as part of the RAPID project in the UK. The package contains quality control steps to make it robust for use in the clinical setting. | Non-invasive prenatal testing (NIPT) of fetal aneuploidy using cell-free fetal
DNA is becoming part of routine clinical practice. RAPIDR (Reliable Accurate
Prenatal non-Invasive Diagnosis R package) is an easy-to-use open-source R
package that implements several published NIPT analysis methods. The input to
RAPIDR is a set of sequence alignment files in the BAM format, and the outputs
are calls for aneuploidy, including trisomies 13, 18, 21 and monosomy X as well
as fetal sex. RAPIDR has been extensively tested with a large sample set as part
of the RAPID project in the UK. The package contains quality control steps to
make it robust for use in the clinical setting.
AVAILABILITY AND IMPLEMENTATION: RAPIDR is implemented in R and can be freely
downloaded via CRAN from here:
http://cran.r-project.org/web/packages/RAPIDR/index.html.
CONTACT: [email protected]
SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics
online. |
Is the gene CDKN2A nevogenic? | Yes, CDKN2A is nevogenic | Acneform lesions strictly confined to a Becker's nevus were observed in a
18-year-old man. Histologically, a granulomatous folliculitis with partial
destruction of the epithelial root sheath and follicular cysts with focal
penetration of keratin into the surrounding dermis were present, ruling out acne
vulgaris. The concept of Becker's nevus as a complex nevogenic process,
affecting ectodermal, neuroectodermal, and mesenchymal structures, also in terms
of dysfunction of the pilary complex, is suggested. Patients with a family history of melanoma are at increased risk of this tumor.
Those family members who also have the atypical mole syndrome are commonly
targeted for screening in the belief that they are more likely to be mutant gene
carriers. We have correlated the atypical mole syndrome phenotype and gene
carrier status in five families with germline CDKN2A mutations and shown that
family members with the atypical mole syndrome were three times more likely to
be mutant gene carriers than their relatives who did not have the atypical mole
syndrome (odds ratio 3.4; confidence interval 1.0-11. 1), supporting the view
that CDKN2A is nevogenic. Individual characteristics which best predicted mutant
gene carrier status were: nevi on the buttocks (odds ratio 4.4; confidence
interval 1. 6-12.4), nevi on the feet (odds ratio 4.2; confidence interval 1.
4-12.5), total nevus number being at least 100 (nevi > or = 2 mm in diameter)
(odds ratio 3.4; confidence interval 1.0-11.1) and two or more clinically
atypical nevi (odds ratio 3.1; confidence interval 1. 1-9.0). Gene carriers were
also significantly more likely to have noticeable freckling and possibly also
Fitzpatrick skin types 1-3. The overlap between gene carriers and nongene
carriers was, however, marked: the atypical mole syndrome did not clearly
differentiate mutant gene carriers from those with a normal gene. This study is
of significance to clinicians as the clinical practice of using the atypical
mole syndrome to identify particular family members for surveillance is shown to
be inappropriate. Until formal gene testing is available, all members of
families with an excessive number of melanoma cases should be treated as
potential mutation carriers at increased risk of melanoma. Melanocytic nevi are the most potent risk factors for melanoma yet identified.
Variation in the nevus phenotype within a population is predomitly
genetically determined. Genes that determine nevus expression may therefore act
as low penetrance melanoma susceptibility genes. Rare germline mutations in
CDKN2A predispose to melanoma and appear to be nevogenic, although the
correlation between nevus phenotype and mutation status is poor. It is plausible
that more common CDKN2A variants may influence both melanoma susceptibility and
nevus susceptibility. Ala148Thr is a G to A missense polymorphism of CDKN2A,
which is found in 4%-6% of the general population. We have investigated the role
of Ala148Thr as a low penetrance melanoma or nevus susceptibility allele in two
separate groups of individuals. The first was a sample of 488 adults recruited
from 179 families of patients with the atypical nevus phenotype and/or a family
history of melanoma, and the second was a population-based sample of 599 women.
Similar prevalences of Ala148Thr (4.9% and 5.2%) were found in both samples but
significant variation in the prevalence of the polymorphism was seen across
geographic areas within England. There was no association between Ala148Thr
status and nevus number or history of melanoma, and therefore the results did
not support the hypothesis that the Ala148Thr variant is a low penetrance
melanoma or nevus susceptibility allele. A significant protective role of
Ala148Thr on the number of atypical nevi was observed in the family sample (mean
of 1 atypical nevus in those with the allele and 3.5 nevi in those without, p =
0.02). After allowing for potential confounders this was not evident in the
population-based sample. |
Are there ways of joint Bayesian inference of risk variants? | Yes. RiVIERA (Risk Variant Inference using Epigenomic Reference Annotations) is a Bayesian model for inference of driver variants from summary statistics across multiple traits using hundreds of epigenomic annotations. | Genome wide association studies (GWAS) provide a powerful approach for
uncovering disease-associated variants in human, but fine-mapping the causal
variants remains a challenge. This is partly remedied by prioritization of
disease-associated variants that overlap GWAS-enriched epigenomic annotations.
Here, we introduce a new Bayesian model RiVIERA (Risk Variant Inference using
Epigenomic Reference Annotations) for inference of driver variants from summary
statistics across multiple traits using hundreds of epigenomic annotations. In
simulation, RiVIERA promising power in detecting causal variants and causal
annotations, the multi-trait joint inference further improved the detection
power. We applied RiVIERA to model the existing GWAS summary statistics of 9
autoimmune diseases and Schizophrenia by jointly harnessing the potential causal
enrichments among 848 tissue-specific epigenomics annotations from
ENCODE/Roadmap consortium covering 127 cell/tissue types and 8 major epigenomic
marks. RiVIERA identified meaningful tissue-specific enrichments for enhancer
regions defined by H3K4me1 and H3K27ac for Blood T-Cell specifically in the nine
autoimmune diseases and Brain-specific enhancer activities exclusively in
Schizophrenia. Moreover, the variants from the 95% credible sets exhibited high
conservation and enrichments for GTEx whole-blood eQTLs located within
transcription-factor-binding-sites and DNA-hypersensitive-sites. Furthermore,
joint modeling the nine immune traits by simultaneously inferring and exploiting
the underlying epigenomic correlation between traits further improved the
functional enrichments compared to single-trait models. |
Describe Achenbach’s syndrome. | Achenbach’s syndrome is Paroxysmal finger haematoma. It is benign condition resulting in the sudden appearance of bruising on one or more fingers, either spontaneously or after minimal trauma, and resolving without treatment.It can be differentiated from other pathologies by clinical spectrum, patient demographics and in doubtful circumstances (acute limb ischemia) by Doppler sonography. | Paroxysmal haematoma of the fingers (Achenbach's syndrome) is a rarely reported
entity. It often occurs spontaneously or subsequent to minor injuries. Because
of the sudden onset of intense burning pain and the subsequent development of
haematoma, the patients are frequently alarmed. The etiology is still unknown.
We report on 3 cases of paroxysmal haematoma of the fingers. The harmless nature
of the condition is emphasized. An acute blue finger is an uncommon but potentially serious finding with a
heterogeneous etiology. A rare group of patients will present with acute,
atraumatic, nonischemic blue fingers. The clinical course of these patients
appears to be benign. We describe the presentation of an otherwise healthy
22-year-old woman with an acute idiopathic blue finger. We highlight the
differential diagnoses and evaluation of this rare condition. AIM: The aim of this study is to establish the nature (urgent vs. non-urgent),
demographics, presentation and management of Achenbach's syndrome and to
formulate an algorithmic approach for their diagnosis and management.
MATERIALS AND METHODS: A systematic review and met-aggregation of literature
from 1944 to 2015 in English language in MedLine, Embase and Cochrane database
were conducted.
RESULTS: Achenbach's syndrome is a female-domit disease with median age of
49.5 years (range 22-76) (age ≤60, n = 11/12, 91 %). It presents with unilateral
volar discoloration of a finger (100 %). It is associated with pain (n = 7/12,
58. %), edema (n = 7/12, 58 %), and paresthesia (n = 3/12, 25 %). The median
time to resolution of symptoms without any intervention was 4 days (range 2-14).
CONCLUSION: AS is self-limiting and a non-urgent surgical condition. It can be
differentiated from other pathologies by clinical spectrum, patient demographics
and in doubtful circumstances (acute limb ischemia) by Doppler sonography. An
algorithmic approach can avoid hospital admissions, partially unnecessary
investigation and assist in patient assurance. BACKGROUND: Paroxysmal finger haematoma (also known as "Achenbach syndrome") is
a benign condition resulting in the sudden appearance of bruising on one or more
fingers, either spontaneously or after minimal trauma, and resolving without
treatment. To date, less than 40 cases have been reported.
PATIENTS AND METHODS: We report two cases of women aged over 50 years presenting
for sudden onset of digital haematomas occurring spontaneously without any prior
trauma. Laboratory and radiological tests appeared to be normal for both
patients. History-taking and clinical and laboratory data pointed towards a
diagnosis of spontaneous paroxysmal finger haematoma. Each episode resolved
spontaneously but, as is generally seen, recurrences occurred during follow-up.
DISCUSSION: In the absence of known aetiologies and/or treatments for
spontaneous paroxysmal finger haematomas, a knowledge of this rare condition can
at least help doctors reassure their patients by diagnosing their condition and
pointing out the benign nature thereof. It also helps avoid costly and
unwarranted additional investigations. |
Has intepirdine been evaluated in clinical trials? (November 2017) | Yes, intepirdine was in Phase III clinical trials in November 2017. | Alzheimer's disease (AD) is a major form of senile dementia, characterized by
progressive memory and neuronal loss combined with cognitive impairment. AD is
the most common neurodegenerative disease worldwide, affecting one-fifth of
those aged over 85 years. Recent therapeutic approaches have been strongly
influenced by five neuropathological hallmarks of AD: acetylcholine deficiency,
glutamate excitotoxicity, extracellular deposition of amyloid-β (Aβ plague),
formation of intraneuronal neurofibrillary tangles (NTFs), and
neuroinflammation. The lowered concentrations of acetylcholine (ACh) in AD
result in a progressive and significant loss of cognitive and behavioral
function. Current AD medications, memantine and acetylcholinesterase inhibitors
(AChEIs) alleviate some of these symptoms by enhancing cholinergic signaling,
but they are not curative. Since 2003, no new drugs have been approved for the
treatment of AD. This article focuses on the current research in clinical trials
targeting the neuropathological findings of AD including acetylcholine response,
glutamate transmission, Aβ clearance, tau protein deposits, and
neuroinflammation. These investigations include acetylcholinesterase inhibitors,
agonists and antagonists of neurotransmitter receptors, β-secretase (BACE) or
γ-secretase inhibitors, vaccines or antibodies targeting Aβ clearance or tau
protein, as well as anti-inflammation compounds. Ongoing Phase III clinical
trials via passive immunotherapy against Aβ peptides (crenezumab, gantenerumab,
and aducanumab) seem to be promising. Using small molecules blocking 5-HT6
serotonin receptor (intepirdine), inhibiting BACE activity (E2609, AZD3293, and
verubecestat), or reducing tau aggregation (TRx0237) are also currently in Phase
III clinical trials. We here systemically review the findings from recent
clinical trials to provide a comprehensive review of novel therapeutic compounds
in the treatment and prevention of AD. |
Is subacute sclerosing panencephalitis caused by the Measles vaccine? | Subacute sclerosing panencephalitis is caused by the Measles and can be prevented by the measles vaccine. | Two hundred and ninety cases of subacute sclerosing panencephalitis (SSPE)
registered in England and Wales from 1970 to 1989 were followed at 6-monthly
intervals. Male to female ratio was 2.8:1. Age at onset increased significantly
over the period. Measles was recorded for 81% of cases; in nearly half this had
occurred under 2 years. Measles vaccine was documented in 20 cases; in 10
measles was also documented and it could not be positively excluded in the
remainder. The calculated risk of SSPE following measles was 4.0/100,000 cases
compared with the risk after vaccine of 0.14/100,000 doses. Measles under 1 year
carried a risk 16 times greater than measles over 5 years. There was an excess
of cases in third and subsequent children. The incidence was higher in the
northwest than in the southeast of the country. Survival time varied from 4
weeks to 16 years and was shorter when measles had occurred over the mean age of
2.5 years. Of the cases 9% had a history of mental retardation before the onset
of SSPE. The incidence of SSPE has fallen following the reduction in measles
resulting from vaccination. However, because of the median 8-year interval
between measles and onset of SSPE, further cases arising from measles during the
study period must still be expected, particularly in adolescents. Subacute sclerosing panencephalitis (SSPE) is a progressive neurodegenerative
disease caused by the measles (rubeola) virus and is most often seen in
children. Many affected children have a history of measles infection in the
first years of life or exposure to the live measles virus vaccine. Typically,
there is a rapid onset of neurological symptoms degenerating into a stuporous
state in the patient. Four children and their families are reviewed. Their
individual courses, medical and nursing problems and interventions, and
implications for immunizations with the measles-mumps-rubella (MMR) vaccine will
be discussed. Subacute sclerosing panencephalitis, a rare, progressive, fatal central nervous
system disease of children, is caused by measles virus. Clinical signs occur
months to several years after recovery from acute measles infection. It is not
known where the virus persists while the disease is inapparent. Involvement of
organs outside the central nervous system has rarely been documented. To search
for possible peripheral reservoirs of measles virus we used in situ
hybridization to probe for measles virus RNA and immunocytochemical studies to
localize measles virus antigens ina variety of organs taken at autopsy from
confirmed cases of subacute sclerosing panencephalitis. Seven of 9 cadavers were
found to contain measles virus RNA or antigens, or both, in at least one
location outside the central nervous system. These sites included lymphoid
organs such as thymus, spleen, lymph nodes, and tonsil, suggesting a role for
lymphocytes in disease pathogenesis. Virus was also detected in kidney, lung,
and glandular tissues such as pancreas, adrenal, and pituitary. These reservoirs
may provide the antigenic stimulus leading to the elevated response
characteristic for subacute sclerosing panencephalitis. The Japanese Committee for the National Registry of Subacute Sclerosing
Panencephalitis (SSPE) confirmed that 215 cases of SSPE occurred in the 20 years
from 1966 to 1985, as discovered in the 10-year surveillance from April 1976
through March 1986. The annual incidence in recent years has been between 10 and
23 cases. Among cases with a certain history of measles illness or measles
vaccination, 184 (90.2%) had a history of measles illness without receiving
measles vaccine. There were 11 probable measles vaccine-associated cases (5.4%),
three (1.5%) being vaccinated with a combined use of killed and live vaccine and
eight (3.9%) with further attenuated live vaccine. There were nine cases (4.4%)
without a history of either measles illness or measles vaccination. Intervals
between measles illness and the onset of SSPE varied from 1 to 16 years (mean,
7.0 years). The periods following measles vaccination with further attenuated
live vaccine were 2 to 11 years (mean, 4.6 years). Annual incidence rates of
SSPE per million cases of measles ranged between 6.1 and 40.9 (mean, 16.1) in
the 10 measles epidemic years 1968-1977, and those following vaccination with
further attenuated live vaccine were zero in most years and at the highest 3.08
(mean, 0.9) per million doses of distributed vaccine. Between the years 1968 and 1979, 87 cases of subacute sclerosing panencephalitis
(SSPE) appeared among the Israeli-born population. The incidence of SSPE dropped
sharply in 1977, 10 years (the median age at onset of SSPE) after introduction
of mass antimeasles vaccination, and remained low in 1978 and 1979. Most of the
SSPE cases reported measles at an age significantly younger than that of the
general population. This pattern did not change after introduction of
antimeasles vaccination. Incidence was significantly lower (p less than 10(-9)
in the vaccinated population than in the unvaccinated population. Occurrence of
SSPE in some children who were vaccinated against measles could be explained by
incomplete vaccine efficacy, or by older age at vaccination, which allows the
possibility of prior exposure to measles. There was no indication that measles
vaccine can induce SSPE. Measles can persist in the central nervous system and cause subacute sclerosing
panencephalitis (SSPE), a progressive disease that is almost always fatal. The
clinical findings of SSPE include behavioral changes, ataxia, seizures, and
mental-motor deterioration that begins several years after natural infection
with the virus. Measles antibody is found in the spinal fluid, and its presence
is particularly useful in establishing the diagnosis. The mechanisms of
pathogenesis of SSPE apparently involves the selection of clones of virus, which
do not replicate to become complete virus particles. These "suppressed" viruses
are able to multiply and spread from cell to cell. The immune system of the
patient is unable to clear this infection. Several hypotheses are advanced to
explain these events. Further studies are needed, however, to develop a complete
understanding of the pathogenesis of these diseases. Fortunately, SSPE is
disappearing in the United States. This apparently is related to the widespread
use of measles vaccines and to the resulting low frequency of natural measles
infections. BACKGROUND: Subacute sclerosing panencephalitis (SSPE) is a chronic central
nervous (CNS) system infection caused by measles virus. Because changing
immunization practices affect the epidemiology of measles and consequently SSPE,
we examined the epidemiological data of our SSPE registry.
MATERIALS AND METHODS: Age of onset, age at onset of measles, duration of Latent
period and immunization status were examined in cases recorded at the SSPE
Registry Center in Turkey between 1975 and 1999.
RESULTS: Age of onset diminished from 13 years before 1994 to 7.6 years after
1995; age at onset of measles declined from 29 months to 20 months and the
Latent interval from 9.9 years to 5.9 years. Age at onset of measles and
immunization status did not directly affect the duration of the Latent period.
CONCLUSION: Although its incidence has decreased in Turkey, SSPE has been seen
at younger ages in recent years. This change cannot be attributed solely to
younger age at onset of measles. Factors affecting the duration of the Latent
period should be investigated further. This investigation reports the prevalence and clinical profile of subacute
sclerosing panencephalitis in two developed cities of southern China. A
territory-wide survey was conducted to identify all subacute sclerosing
panencephalitis cases diagnosed during 1988-2002 in Hong Kong and Macau.
Altogether, 10 cases (male:female = 7:3) were identified of whom six were still
alive. The prevalence rate of subacute sclerosing panencephalitis in Hong Kong
and Macau in 2002 was 1 per million total population or 5.5 per million
children. The mean age of presentation was 9.4 years (range = 4-14 years).
Presenting features included myoclonus (60%), deterioration in school
performance (30%), and transient visual impairment (10%). The clinical course
was highly variable. Most had subacute course, but two deteriorated rapidly and
died within 6 months. Seven children had measles infection, and the majority of
infection (86%) occurred during the world measles epidemic in 1988. The mean
interval between measles infection and onset of subacute sclerosing
panencephalitis was 6.5 years (range = 3-11 years). There has been an increasing
trend of subacute sclerosing panencephalitis in southern China after the measles
outbreak in 1988. Active surveillance of subacute sclerosing panencephalitis for
those with measles infection during the 1988 outbreak is necessary to conduct
multicenter drug trials for this devastating disease. Subacute sclerosing panencephalitis (SSPE), in the majority of cases, is caused
by the wild measles virus, although there are some reports relating SSPE to
vaccination. This paper presents an inborn that was infected during pregcy by
the measles virus and developed SSPE within the first year of life after a short
incubation period. He progressed rapidly after a mild arrest with treatment.
Subacute sclerosing panencephalitis is a fatal degenerative disease and,
although it had largely disappeared because of nearly universal measles
vaccination, it still remains a serious infection among children affected by
human immunodeficiency virus (HIV). The lack of newer cases of SSPE occurring
among normal children nowadays should not wane alertness by obstetricians and
paediatricians, to recognize the risk with measles during pregcy and the need
for prevention and recognition of SSPE at an early stage. Although some
references exist which report on SSPE cases related to vaccination, new work
weakens the possible links between measles vaccine and SSPE.
CONCLUSION: This report would like to stress the importance and success of
reducing the SSPE problem with the aid of general measles vaccination with high
coverage. AIM: To assess the impact of measles/mumps/rubella (MMR) vaccine on the
epidemiology of subacute sclerosing panencephalitis (SSPE) in England and Wales.
METHODS: Cases of SSPE resident in England and Wales with onset between 1990 and
2002 were reviewed.
RESULTS: A total of 47 cases were identified, 31 male and 16 female. There was
an average annual decline of 14% in SSPE onset over the period, consistent with
the decline in notified measles over the last 20 years. A history of measles was
present in 35 (median age 1.3 years), the most recent recorded date being 1994;
the interval from measles to onset of SSPE ranged from 2.7 to 23.4 years. Four
children with a history of receipt of a measles containing vaccine were reported
not to have had measles; two of these cases had a brain biopsy, and nucleotide
sequence data confirmed wild measles infection. Brain biopsy specimens from a
further three cases with a history of measles, of whom two had also had a
history of vaccination, showed wild-type strain.
CONCLUSION: The prevention of endemic circulation of measles virus in England
and Wales through the high coverage achieved with MMR vaccine, together with the
measles/rubella vaccination campaign of 1994, has resulted in the near
elimination of SSPE. However, the recent decline in MMR vaccine coverage, with
the associated increase in localised measles outbreaks and cases in young
infants, is of concern. It underlines the importance of maintaining high vaccine
coverage in order to protect indirectly those most vulnerable to SSPE, namely
infants too young to be vaccinated. BACKGROUND: When measles vaccines were widely introduced in the 1970s, there
were concerns that they might cause subacute sclerosing panencephalitis (SSPE):
a very rare, late-onset, neurological complication of natural measles infection.
Therefore, SSPE registries and routine measles immunization were established in
many countries concurrently. We conducted a comprehensive review of the impact
of measles immunization on the epidemiology of SSPE and examined epidemiological
evidence on whether there was any vaccine-associated risk.
METHODS: Published epidemiological data on SSPE, national SSPE incidence,
measles incidence and vaccine coverage, reports of SSPE in pregcy or shortly
post partum were reviewed. Potential adverse relationships between measles
vaccines and SSPE were examined using available data.
RESULTS: Epidemiological data showed that successful measles immunization
programmes protect against SSPE and, consistent with virological data, that
measles vaccine virus does not cause SSPE. Measles vaccine does not: accelerate
the course of SSPE; trigger SSPE or cause SSPE in those with an established
benign persistent wild measles infection. Evidence points to wild virus causing
SSPE in cases which have been immunized and have had no known natural measles
infection. Perinatal measles infection may result in SSPE with a short onset
latency and fulmit course. Such cases are very rare. SSPE during pregcy
appears to be fulmit. Infants born to mothers with SSPE have not been
subsequently diagnosed with SSPE themselves.
CONCLUSIONS: Successful measles vaccination programmes directly and indirectly
protect the population against SSPE and have the potential to eliminate SSPE
through the elimination of measles. Epidemiological and virological data suggest
that measles vaccine does not cause SSPE. INTRODUCTION: subacute sclerosing panencephalitis (SSPE) is a late, rare and
usually fatal complication of measles infection. Although a very high incidence
of SSPE in Papua New Guinea (PNG) was first recognized 20 years ago, estimated
measles vaccine coverage has remained at ≤ 70% since and a large measles
epidemic occurred in 2002. We report a series of 22 SSPE cases presenting
between November 2007 and July 2009 in Madang Province, PNG, including localized
clusters with the highest ever reported annual incidence.
METHODOLOGY/PRINCIPAL FINDINGS: as part of a prospective observational study of
severe childhood illness at Modilon Hospital, the provincial referral center,
children presenting with evidence of meningo-encephalitis were assessed in
detail including lumbar puncture in most cases. A diagnosis of SSPE was based on
clinical features and presence of measles-specific IgG in cerebrospinal fluid
and/or plasma. The estimated annual SSPE incidence in Madang province was
54/million population aged <20 years, but four sub-districts had an incidence
>100/million/year. The distribution of year of birth of the 22 children with
SSPE closely matched the reported annual measles incidence in PNG, including a
peak in 2002.
CONCLUSIONS/SIGNIFICANCE: SSPE follows measles infections in very young PNG
children. Because PNG children have known low seroconversion rates to the first
measles vaccine given at 6 months of age, efforts such as supplementary measles
immunisation programs should continue in order to reduce the pool of non-immune
people surrounding the youngest and most vulnerable members of PNG communities. Subacute sclerosing panencephalitis (SSPE) is a progressive neurological
disorder of childhood and early adolescence caused by persistent defective
measles virus. Clinical manifestations appear many years after the acute measles
infection. The incidence of SSPE has substantially declined after the
introduction of an effective vaccine. We report a case of a child with SSPE that
began with atonia, dysarthria, and intellectual deterioration without the
presence of any particular EEG anomalies. We have reported this girl who was
affected by this severe affliction in the hope that, because of the rarity of
SSPE, it would not go undiagnosed. BACKGROUND: Subacute sclerosing panencephalitis (SSPE) is a fatal encephalitis
manifesting a number of years after a primary measles infection. This disease
has become very rare since the introduction of immunisation against measles in
1976.
CASE DESCRIPTION: A 17-year-old boy presented with progressive cognitive
disturbances and extrapyramidal symptoms that had developed over a few weeks. He
had not been immunised because of his parents' religious beliefs, and had
contracted measles at 4 years of age. An EEG was performed on the basis of
clinical suspicion of SSPE, and showed the SSPE-specific, characteristic pattern
of periodic complexes as described by Radermecker. The diagnosis of SSPE was
confirmed by cerebrospinal fluid examination. Our patient died 4 months after
initial diagnosis.
CONCLUSION: SSPE is still occurring in the Netherlands. The absence of effective
treatment underlines the importance of prevention by means of immunization
against measles. In 2015, the Oregon Health Authority was notified of the death of a boy with
subacute sclerosing panencephalitis (SSPE), a rare and fatal complication of
measles. The patient, aged 14 years, had reportedly been vaccinated against
measles in the Philippines at age 8 months. However, the patient contracted
measles at age 1 year while still in the Philippines. He had been well until
2012, when his neurodegenerative symptoms began. After the diagnosis of SSPE was
made, the patient remained in home hospice care until his death. Investigators
from the Oregon Health Authority and the Oregon Health and Science University
reviewed the patient's medical records and interviewed the parents. Vaccination
against measles can prevent not only acute measles and its complications, but
also SSPE. BACKGROUND: Subacute sclerosing panencephalitis (SSPE) is a potentially fatal
complication of measles. The authors report a case of recurrent myoclonic jerks
under investigation, whose ophthalmic examination pointed to the diagnosis.
CASE PRESENTATION: A 12-year-old boy with recurrent episodes of myoclonic jerks
was found to have optic disc pallor and an irregular macular scar with
pigmentation in the left eye. The retinal finding proved to be a strong
diagnostic clue for SSPE. There was a history of exanthematous fever in
childhood. Antibodies against measles were detected in both the cerebrospinal
fluid and serum. Retinitis with intraretinal and subretinal hemorrhage in the
right eye was noted 6-weeks after the initial presentation.
CONCLUSION: The authors describe the importance of ophthalmic evaluation in
cases of recurrent myoclonic jerks. Optical coherence tomographic features and
ultrawide field imaging characteristics of a case of SSPE are described. BACKGROUND: Subacute sclerosing panencephalitis (SSPE) is a fatal complication
of measles. We reviewed California cases from 1998-2015 to understand risk
factors for SPPE and estimate incidence.
METHODS: SSPE cases had clinically compatible symptoms and measles antibody
detection in cerebrospinal fluid (CSF) or medical record documentation of SSPE.
Cases were identified though a state death certificate search, Centers for
Disease Control and Prevention reports, or investigations for undiagnosed
neurologic disease. Measles detection in CSF was performed by serology at the
California Department of Public Health or at clinical laboratories.
RESULTS: Seventeen SSPE cases were identified. Males outnumbered females 2.4:1.
Twelve (71%) cases had a history of measles-like illness; all 12 had illness
prior to 15 months of age. Eight (67%) children were exposed to measles in
California. SSPE was diagnosed at a median age of 12 years (3-35 years), with a
latency period of 9.5 years (2.5-34 years). Among measles cases reported to CDPH
during 1988-1991, the incidence of SSPE was 1:1367 for children <5 years, and
1:609 for children <12 months at time of measles disease.
CONCLUSIONS: SSPE cases in California occurred at a high rate among unvaccinated
children, particularly those infected during infancy. Protection of unvaccinated
infants requires avoidance of travel to endemic areas, or early vaccination
prior to travel at age 6-11 months. Clinicians should be aware of SSPE in
patients with compatible symptoms, even in older patients with no specific
history of measles infection. SSPE demonstrates the high human cost of "natural"
measles immunity. Author information:
(1)a Department of Pediatrics , Affiliated Hospital of Guizhou Medical
University , Guiyang , China.
(2)b Department of Ophthalmology , Affiliated Hospital of Guizhou Medical
University , Guiyang , China.
(3)c Department of Neurology , Affiliated Hospital of Guizhou Medical University
, Guiyang , China. Subacute sclerosing panencephalitis (SSPE) is a rare progressive neurological
disorder of early adolescence caused by persistent infection of the measles
virus, which remains prevalent worldwide despite an effective vaccine. SSPE is a
devastating disease with a characteristic clinical course in subcortical white
matter; however, atypical presentations of brainstem involvement may be seen in
rare cases. This review summarizes reports to date on brainstem involvement in
SSPE, including the clinical course of disease, neuroimaging presentations, and
guidelines for treatment. A comprehensive literature search was performed for
English-language publications with keywords "subacute sclerosing
panencephalitis" and "brainstem" using the National Library of Medicine PubMed
database (March 1981-September 2017). Eleven articles focusing on SSPE of the
brainstem were included. Predomit brainstem involvement remains
uncharacteristic of SSPE, which may lead to misdiagnosis and poor outcome. A
number of case reports have demonstrated brainstem involvement associated with
other intracranial lesions commonly presenting in later SSPE stages (III and
IV). However, brainstem lesions can appear in all stages, independent of higher
cortical structures. The varied clinical presentations complicate diagnosis from
a neuroimaging perspective. SSPE of the brainstem is a rare but important
clinical entity. It may present like canonical SSPE or with unique clinical
features such as absence seizures and pronounced ataxia. While SSPE generally
progresses to the brainstem, it can also begin with a primary focus of infection
in the brainstem. Awareness of varied SSPE presentations can aid in early
diagnosis as well as guide management and treatment. |
What is host induced gene silencing? | Host-induced gene silencing (HIGS) is a transgenic technology used to silence fungal genes in planta during attempted infection and thereby reduces disease levels. HIGS relies on the host plant's ability to produce mobile small interfering RNA molecules, generated from long double-stranded RNA, which are complementary to targeted fungal genes. These molecules are transferred from the plant to invading fungi via an uncharacterised mechanism, to cause gene silencing. | Fusarium graminearum is a major fungal pathogen of cereals worldwide, causing
seedling, stem base and floral diseases, including Fusarium head blight (FHB).
In addition to yield and quality losses, FHB contaminates cereal grain with
mycotoxins, including deoxynivalenol, which are harmful to human, animal and
ecosystem health. Currently, FHB control is only partially effective due to
several intractable problems. RNA interference (RNAi) is a natural mechanism
that regulates gene expression. RNAi has been exploited in the development of
new genomic tools that allow the targeted silencing of genes of interest in many
eukaryotes. Host-induced gene silencing (HIGS) is a transgenic technology used
to silence fungal genes in planta during attempted infection and thereby reduces
disease levels. HIGS relies on the host plant's ability to produce mobile small
interfering RNA molecules, generated from long double-stranded RNA, which are
complementary to targeted fungal genes. These molecules are transferred from the
plant to invading fungi via an uncharacterised mechanism, to cause gene
silencing. Here, we describe recent advances in RNAi-mediated control of plant
pathogenic fungi, highlighting the key advantages and disadvantages. We then
discuss the developments and implications of combining HIGS with other methods
of disease control. © 2017 The Authors. Pest Management Science published by
John Wiley & Sons Ltd on behalf of Society of Chemical Industry. |
What is maternal spindle transfer? | Maternal spindle transfer (MST) is a cutting edge germline-altering, IVF-based embryonic technique used to prevent the maternal transmission of serious mitochondrial diseases. | In October 2015 the UK enacted legislation to permit the clinical use of two
cutting edge germline-altering, IVF-based embryonic techniques: pronuclear
transfer and maternal spindle transfer (PNT and MST). The aim is to use these
techniques to prevent the maternal transmission of serious mitochondrial
diseases. Major claims have been made about the quality of the debates that
preceded this legislation and the significance of those debates for UK
decision-making on other biotechnologies, as well as for other countries
considering similar legislation. In this article we conduct a systematic
analysis of those UK debates and suggest that claims about their quality are
over-stated. We identify, and analyse in detail, ten areas where greater
clarity, depth and nuance would have produced sharper understandings of the
contributions, limitations and wider social impacts of these mitochondrial
interventions. We explore the implications of these additional considerations
for (i) the protection of all parties involved, should the techniques transfer
to clinical applications; (ii) the legitimacy of focussing on short-term gains
for individuals over public health considerations, and (iii) the maintece and
improvement of public trust in medical biotechnologies. We conclude that a more
measured evaluation of the content and quality of the UK debates is important
and timely: such a critique provides a clearer understanding of the possible,
but specific, contributions of these interventions, both in the UK and
elsewhere; also, these additional insights can now inform the emerging processes
of implementation, regulation and practice of mitochondrial interventions. |
Does armodafinil improve fatigue of glioma patients? | No. Eight week course of armodafinil did not improve fatigue or quality of life in glioma patients undergoing radiotherapy. However, this conclusion is based on one identified clinical trial. | BACKGROUND: Fatigue is common among glioma patients undergoing radiotherapy (RT)
and impacts quality of life (QOL). We evaluated whether armodafinil, a
wakefulness-promoting medication, improves fatigue in glioma patients undergoing
RT.
METHODS: Eligibility criteria included age ≥18 years, Karnofsky performance
status ≥60, and grade 2-4 glioma undergoing RT to a total dose of 50-60 Gy.
Patients were randomized 1:1 to armodafinil or placebo for 8 weeks beginning
within 10 days of starting RT. Fatigue and QOL were assessed at baseline, day
22, day 43, and day 56 with the Functional Assessment of Chronic Illness Therapy
- Fatigue (FACIT-F), the Functional Assessment of Cancer Therapy - General
(FACT-G), the Brief Fatigue Inventory (BFI), and the Cancer Fatigue Scale (CFS).
The primary aim was to detect a difference in the 42-day change in FACIT-F
fatigue subscale between the 2 groups using a 2-sample Wilcoxon statistic.
RESULTS: We enrolled 81 patients total (42 armodafinil and 39 placebo).
Armodafinil did not significantly improve fatigue or QOL based on the 42-day
change in FACIT-F fatigue subscale, FACT-G, CFS, or BFI. Further analysis
suggests no difference between the arms even after accounting for the potential
bias of missing data. Treatment was well tolerated with few grade 3 or 4
toxicities.
CONCLUSIONS: While treatment was well-tolerated, an 8-week course of armodafinil
did not improve fatigue or QOL in glioma patients undergoing RT in this pilot
study. Further studies are needed to determine whether pharmacologic treatment
improves fatigue in glioma patients undergoing RT. |
What is the role of tankyrases in response to Double Strand Breaks (DSBs)? | Tankyrases promote homologous recombination and check point activation in response to DSBs. | |
Which molecules are inhibited by anticancer drug Dovitinib? | Dovitinib (TKI-258/CHIR-258) is a pan receptor tyrosine kinase (RTK) inhibitor that targets VEGFR, FGFR, PDGFR, and KIT. It is being widely tested for treatment of various cancers. | The multiple kinase inhibitor dovitinib is currently under clinical
investigation for hepatocellular carcinoma (HCC). Here, we investigated the
mechanistic basis for the effects of dovitinib in HCCs. Dovitinib showed
significant antitumor activity in HCC cell lines PLC5, Hep3B, Sk-Hep1, and
Huh-7. Dovitinib downregulated phospho-STAT3 (p-STAT3) at tyrosine 705 and
subsequently reduced the levels of expression of STAT3-related proteins Mcl-1,
survivin, and cyclin D1 in a time-dependent manner. Ectopic expression of STAT3
abolished the apoptotic effect of dovitinib, indicating that STAT3 is
indispensable in mediating the effect of dovitinib in HCC. SHP-1 inhibitor
reversed downregulation of p-STAT3 and apoptosis induced by dovitinib, and
silencing of SHP-1 by RNA interference abolished the effects of dovitinib on
p-STAT3, indicating that SHP-1, a protein tyrosine phosphatase, mediates the
effects of dovitinib. Notably, dovitinib increased SHP-1 activity in HCC cells.
Incubation of dovitinib with pure SHP-1 protein enhanced its phosphatase
activity, indicating that dovitinib upregulates the activity of SHP-1 via direct
interactions. In addition, dovitinib induced apoptosis in two
sorafenib-resistant cell lines through inhibition of STAT3, and
sorafenib-resistant cells showed significant activation of STAT3, suggesting
that targeting STAT3 may be a useful approach to overcome drug resistance in
HCC. Finally, in vivo, dovitinib significantly suppressed growth of both Huh-7
and PLC5 xenograft tumors and downregulated p-STAT3 by increasing SHP-1
activity. In conclusion, dovitinib induces significant apoptosis in HCC cells
and sorafenib-resistant cells via SHP-1-mediated inhibition of STAT3. We sought to identify fibroblast growth factor receptor 2 (FGFR2) kinase domain
mutations that confer resistance to the pan-FGFR inhibitor, dovitinib, and
explore the mechanism of action of the drug-resistant mutations. We cultured
BaF3 cells overexpressing FGFR2 in high concentrations of dovitinib and
identified 14 dovitinib-resistant mutations, including the N550K mutation
observed in 25% of FGFR2(mutant) endometrial cancers (ECs). Structural and
biochemical in vitro kinase analyses, together with BaF3 proliferation assays,
showed that the resistance mutations elevate the intrinsic kinase activity of
FGFR2. BaF3 lines were used to assess the ability of each mutation to confer
cross-resistance to PD173074 and ponatinib. Unlike PD173074, ponatinib
effectively inhibited all the dovitinib-resistant FGFR2 mutants except the V565I
gatekeeper mutation, suggesting ponatinib but not dovitinib targets the active
conformation of FGFR2 kinase. EC cell lines expressing wild-type FGFR2 were
relatively resistant to all inhibitors, whereas EC cell lines expressing mutated
FGFR2 showed differential sensitivity. Within the FGFR2(mutant) cell lines,
three of seven showed marked resistance to PD173074 and relative resistance to
dovitinib and ponatinib. This suggests that alternative mechanisms distinct from
kinase domain mutations are responsible for intrinsic resistance in these three
EC lines. Finally, overexpression of FGFR2(N550K) in JHUEM-2 cells
(FGFR2(C383R)) conferred resistance (about five-fold) to PD173074, providing
independent data that FGFR2(N550K) can be associated with drug resistance.
Biochemical in vitro kinase analyses also show that ponatinib is more effective
than dovitinib at inhibiting FGFR2(N550K). We propose that tumors harboring
mutationally activated FGFRs should be treated with FGFR inhibitors that
specifically bind the active kinase. INTRODUCTION: Erlotinib is a FDA approved small molecule inhibitor of epidermal
growth factor receptor and dovitinib is a novel small molecule inhibitor of
fibroblast growth factor and vascular endothelial growth factor receptor. This
phase 1 trial was conducted to characterize the safety and determine the maximum
tolerated dose of erlotinib plus dovitinib in patients with previously treated
metastatic non-small cell lung cancer.
METHODS: Escalating dose cohorts of daily erlotinib and dovitinib dosed 5 days
on/2 days off, starting after a 2-week lead-in of erlotinib alone, were planned.
A potential pharmacokinetic interaction was hypothesized as dovitinib induces
CYP1A1/1A2. Only cohort 1 (150 mg erlotinib+300 mg dovitinib) and cohort -1 (150
mg erlotinib+200mg dovitinib) enrolled. Plasma concentrations of erlotinib were
measured pre- and post-dovitinib exposure.
RESULTS: Two of three patients in cohort 1 had a DLT (grade 3 transaminitis and
grade 3 syncope). Two of 6 patients in cohort -1 had a DLT (grade 3 pulmonary
embolism and grade 3 fatigue); thus, the study was terminated. Erlotinib
exposure (average Cmax 2308±698 ng/ml and AUC 0-24 41,030±15,577 ng×h/ml)
approximated previous reports in the six patients with pharmacokinetic analysis.
However, erlotinib Cmax and AUC0-24 decreased significantly by 93% (p=0.02) and
97% (p<0.01), respectively, during dovitinib co-administration.
CONCLUSIONS: This small study demonstrated considerable toxicity and a
significant pharmacokinetic interaction with a marked decrease in erlotinib
exposure in the presence of dovitinib, likely mediated through CYP1A1/1A2
induction. Given the toxicity and the pharmacokinetic interaction, further
investigation with this drug combination will not be pursued. Dovitinib (TKI258) is a small molecule multi-kinase inhibitor currently in
clinical phase I/II/III development for the treatment of various types of
cancers. This drug has a safe and effective pharmacokinetic/pharmacodynamic
profile. Although dovitinib can bind several kinases at omolar
concentrations, there are no reports relating to osteoporosis or osteoblast
differentiation. Herein, we investigated the effect of dovitinib on human
recombit bone morphogenetic protein (BMP)-2-induced osteoblast
differentiation in a cell culture model. Dovitinib enhanced the BMP-2-induced
alkaline phosphatase (ALP) induction, which is a representative marker of
osteoblast differentiation. Dovitinib also stimulated the translocation of
phosphorylated Smad1/5/8 into the nucleus and phosphorylation of
mitogen-activated protein kinases, including ERK1/2 and p38. In addition, the
mRNA expression of BMP-4, BMP-7, ALP, and OCN increased with dovitinib
treatment. Our results suggest that dovitinib has a potent stimulating effect on
BMP-2-induced osteoblast differentiation and this existing drug has potential
for repositioning in the treatment of bone-related disorders. Angiogenesis inhibition by the vascular endothelial growth factor receptor
(VEGFR) and platelet-derived growth factor receptor (PDGFR) inhibitor sorafenib
provides survival benefit in hepatocellular carcinoma (HCC); however, angiogenic
escape from sorafenib may occur due to angiogenesis-associated fibroblast growth
factor receptor (FGFR) pathway activation. In addition to VEGFR and PDGFR,
dovitinib inhibits FGFR. Frontline oral dovitinib (500 mg/day, 5 days on, 2 days
off; n = 82) versus sorafenib (400 mg twice daily; n = 83) was evaluated in an
open-label, randomized phase 2 study of Asian-Pacific patients with advanced
HCC. The primary and key secondary endpoints were overall survival (OS) and time
to tumor progression (TTP) as determined by a local investigator, respectively.
Patients included in the study were ineligible for surgical and/or locoregional
therapies or had disease progression after receiving these therapies. The median
OS (95% confidence interval [CI]) was 8.0 (6.6-9.1) months for dovitinib and 8.4
(5.4-11.3) months for sorafenib. The median TTP (95% CI) per investigator
assessment was 4.1 (2.8-4.2) months and 4.1 (2.8-4.3) months for dovitinib and
sorafenib, respectively. Common any-cause adverse events included diarrhea
(62%), decreased appetite (43%), nausea (41%), vomiting (41%), fatigue (35%),
rash (34%), and pyrexia (30%) for dovitinib and palmar-plantar
erythrodysesthesia syndrome (66%) and decreased appetite (31%) for sorafenib.
Subgroup analysis revealed a significantly higher median OS for patients in the
dovitinib arm who had baseline plasma soluble VEGFR1 (sVEGFR1) and hepatocyte
growth factor (HGF) below median levels versus at or above the median levels
(median OS [95% CI]: sVEGFR1, 11.2 [9.0-13.8] and 5.7 [4.3-7.0] months,
respectively [P = .0002]; HGF, 11.2 [8.9-13.8] and 5.9 [5.0-7.6] months,
respectively [P = 0.0002]).
CONCLUSION: Dovitinib was well tolerated, but activity was not greater than
sorafenib as a frontline systemic therapy for HCC. Based on these data, no
subsequent phase 3 study has been planned. (Hepatology 2016;64:774-784). Author information:
(1)Department of Hepatobiliary Surgery, Nanfang Hospital, Southern Medical
University, Guangzhou, China; Division of Gastroenterology and Hepatology, Mayo
Clinic College of Medicine and Mayo Clinic Cancer Center, Rochester, MN, USA.
(2)Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine
and Mayo Clinic Cancer Center, Rochester, MN, USA; Department of
Gastroenterology, The Affiliated Drum Tower Hospital of Nanjing University
Medical School, Nanjing, China.
(3)Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine
and Mayo Clinic Cancer Center, Rochester, MN, USA; Department of Pathology,
Qiqihar Medical University, Qiqihar, China.
(4)Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine
and Mayo Clinic Cancer Center, Rochester, MN, USA.
(5)Department of Biochemistry and Molecular Biology, Mayo Clinic College of
Medicine, Rochester, MN, USA.
(6)Department of Laboratory Medicine and Pathology, Mayo Clinic College of
Medicine, Rochester, MN, USA.
(7)Department of Hepatobiliary Surgery, Nanfang Hospital, Southern Medical
University, Guangzhou, China.
(8)Division of Hematology and Medical Oncology, Mayo Clinic College of Medicine,
Phoenix, AZ, USA.
(9)Department of Medical Oncology, Mayo Clinic College of Medicine, Rochester,
MN, USA.
(10)Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine
and Mayo Clinic Cancer Center, Rochester, MN, USA. Electronic address:
[email protected]. PURPOSE: The majority of gastric cancer patients who achieve an initial response
to trastuzumab-based regimens develop resistance within 1 year of treatment.
This study was aimed at identifying the molecular mechanisms responsible for
resistance.
EXPERIMENTAL DESIGN: A HER2+-trastuzumab sensitive NCI-N87 gastric cancer
orthotopic nude mouse model was treated with trastuzumab until resistance
emerged. Differentially expressed transcripts between trastuzumab-resistant and
sensitive gastric cancer cell lines were annotated for functional
interrelatedness by Ingenuity Pathway Analysis software. Immunohistochemical
analyses were performed in pretreatment versus posttreatment biopsies from
gastric cancer patients receiving trastuzumab-based treatments. All statistical
tests were two-sided.
RESULTS: Four NCI-N87 trastuzumab-resistant (N87-TR) cell lines were
established. Microarray analysis showed HER2 downregulation, induction of
epithelial-to-mesenchymal transition, and indicated fibroblast growth factor
receptor 3 (FGFR3) as one of the top upregulated genes in N87-TR cell lines. In
vitro, N87-TR cell lines demonstrated a higher sensitivity than did
trastuzumab-sensitive parental cells to the FGFR3 inhibitor dovitinib, which
reduced expression of pAKT, ZEB1, and cell migration. Oral dovitinib
significantly (P = 0.0006) reduced tumor burden and prolonged mice survival
duration in N87-TR mouse models. A higher expression of FGFR3, phosphorylated
AKT, and ZEB1 were observed in biopsies from patients progressing under
trastuzumab-based therapies if compared with matched pretreatment biopsies.
CONCLUSIONS: This study identified the FGFR3/AKT axis as an escape pathway
responsible for trastuzumab resistance in gastric cancer, thus indicating the
inhibition of FGFR3 as a potential strategy to modulate this resistance. Clin
Cancer Res; 22(24); 6164-75. ©2016 AACR. BACKGROUND: Fibroblast growth factor receptor 1 (FGFR1) amplification is a
potential driving oncogene in squamous cell cancer (SCC) of the lung. The
current phase 2 study evaluated the efficacy and tolerability of dovitinib, an
FGFR inhibitor, in patients with advanced SCC of the lung.
METHODS: Patients with pretreated advanced SCC of the lung whose tumors
demonstrated FGFR1 amplification of > 5 copies by fluorescence in situ
hybridization were enrolled. Dovitinib at a dose of 500 mg was administered
orally, once daily, on days 1 to 5 of every week, followed by 2 days off. The
primary endpoint was overall response. Secondary endpoints were progression-free
survival, overall survival, and toxicity.
RESULTS: All 26 patients were men with a median age of 68 years (range, 52-80
years). The majority of patients were ever-smokers. The median duration of
dovitinib administration (28 days per cycle) was 2.5 months (range, 0.7-8.6
months). The overall response rate was 11.5% (95% confidence interval [95% CI],
0.8%-23.8%) and the disease control rate was 50% (95% CI, 30.8%-69.2%), with 3
patients achieving partial responses. Response durations for the patients with
partial responses were ≥4.5 months, ≥ 5.1 months, and 6.1 months, respectively.
After a median follow-up of 15.7 months (range, 1.2-25.6 months), the median
overall survival was 5.0 months (95% CI, 3.6-6.4 months) and the median
progression-free survival was 2.9 months (95% CI, 1.5-4.3 months). The most
common grade 3 or higher adverse events were fatigue (19.2%), anorexia (11.5%),
and hyponatremia (11.5%) (event severity was graded based on National Cancer
Institute Common Terminology Criteria for Adverse Events [version 4.0]).
CONCLUSIONS: Treatment with dovitinib demonstrated modest efficacy in patients
with advanced SCC with FGFR1 amplification. Further studies to evaluate other
biomarkers correlated with the efficacy of dovitinib in patients with SCC are
warranted. Cancer 2016;122:3024-3031. © 2016 American Cancer Society. Author information:
(1)Randall Children's Hospital at Legacy Emanuel, Children's Cancer and Blood
Disorders Program, Portland, OR 97227, USA.
(2)Division of Pediatric Hematology Oncology, Oregon Health and Science
University, Portland, OR 97239, USA.
(3)Division of Oncology, Center for Applied Medical Research (CIMA), University
of Navarra, 31008 Pamplona, Spain.
(4)Division of Hematology and Medical Oncology, Oregon Health and Science
University, Portland, OR 97239, USA.
(5)Knight Cancer Institute, Oregon Health and Science University, Portland, OR
97239, USA.
(6)Department of Molecular and Medical Genetics, Oregon Health and Science
University, Portland, OR 97239, USA.
(7)Research and Development, Oncotide Pharmaceuticals, Research Triangle Park,
NC 27710, USA .
(8)Spyryx Biosciences, Durham, NC 27713, USA.
(9)Division of Bioinformatics and Computational Biology, Department of Medical
Informatics and Clinical Epidemiology, Oregon Health and Science University,
Portland, OR 97239, USA.
(10)Dana-Farber Cancer Institute, Harvard Cancer Center, Boston, MA 02215, USA.
(11)Department of Cell and Developmental Biology, Oregon Health and Science
University, Portland, OR 97239, USA.
(12)Research and Development, Oncotide Pharmaceuticals, Research Triangle Park,
NC 27710, USA.
(13)Department of Molecular and Medical Genetics, Oregon Health and Science
University, Portland, OR USA-97239.
(14)Knight Cancer Institute, Oregon Health and Science University, Portland, OR,
USA-97239.
(15)Division of Hematology and Medical Oncology, Oregon Health and Science
University, Portland, OR, USA-97239. BACKGROUND: Overexpression of fibroblast growth factor receptor 1 (FGFR1), found
in ≤8% of hormone receptor-positive (HR+), human epidermal growth factor
receptor 2-negative (HER2-) breast cancer cases, is correlated with decreased
overall survival and resistance to endocrine therapy (ET). Dovitinib, a potent
FGFR inhibitor, has demonstrated antitumor activity in heavily pretreated
patients with FGFR pathway-amplified breast cancer.
METHODS: In this randomized, placebo-controlled phase II trial, we evaluated
whether the addition of dovitinib to fulvestrant would improve outcomes in
postmenopausal patients with HR+, HER2- advanced breast cancer that had
progressed during or after prior ET. Patients were stratified by FGF pathway
amplification and presence of visceral disease, and they were randomized 1:1 to
receive fulvestrant plus dovitinib or placebo. The primary endpoint was
progression-free survival (PFS).
RESULTS: From 15 May 2012 to 26 November 2014, 97 patients from 36 centers were
enrolled. The frequency of FGF pathway amplification was lower than anticipated,
and the study was terminated early owing to slow accrual of patients with FGF
pathway amplification. The median PFS (95% CI) was 5.5 (3.8-14.0) months vs 5.5
(3.5-10.7) months in the dovitinib vs placebo arms, respectively (HR, 0.68; did
not meet predefined efficacy criteria). For the FGF pathway-amplified subgroup
(n = 31), the median PFS (95% CI) was 10.9 (3.5-16.5) months vs 5.5 (3.5-16.4)
months in the dovitinib vs placebo arms, respectively (HR, 0.64; met the
predefined superiority criteria). Frequently reported adverse events in the
dovitinib (diarrhea, nausea, vomiting, asthenia, and headache) and placebo
(diarrhea, fatigue, nausea, and asthenia) arms were mostly low grade.
CONCLUSIONS: The safety profile of dovitinib plus fulvestrant was consistent
with the known safety profile of single-agent dovitinib. Dovitinib in
combination with fulvestrant showed promising clinical activity in the FGF
pathway-amplified subgroup. However, the data reported herein should be
interpreted with caution, given that fewer PFS events occurred in the FGF
pathway-amplified patients than was expected and that an effect of dovitinib
regardless of FGR pathway amplification status cannot be excluded, because the
population was smaller than expected.
TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01528345 . Registered 31
January 2012. OBJECTIVES: Following failure of a platinum-antifolate combination regimen,
there is no standard therapy for advanced maligt pleural mesothelioma (MPM).
The fibroblast growth factor receptor (FGFR) signaling pathways may be a
relevant target in MPM. Dovitinib inhibits multiple tyrosine receptor kinases,
predomitly the vascular endothelial growth factor receptors (VEGFR), but also
FGFRs, and could be active in MPM.
METHODS: This open-label multicentre phase II trial [NCT01769547] enrolled fit,
consenting adult patients with advanced MPM who had previously received
platinum-antifolate combination chemotherapy and up to one additional line of
systemic therapy. Dovitinib was administered orally at 500mg/day for 5days on,
2days off, in 28-day cycles. Response was assessed every 2 cycles using RECIST
1.1 criteria modified for MPM. Correlative studies included FGFR-1 amplification
on archival tumour and serum samples for circulating angiogenesis factors. The
primary end-point was the proportion of patients progression-free at 3 months
(PF3) using a two-stage design.
RESULTS: 12 patients (10 males, median age 67) were enrolled. The median number
of cycles administered was 2.5 (range 1-8). One unconfirmed partial response was
observed. PF3 was 50% (95% confidence interval 28.4% to 88.0%); although the
criterion for proceeding to stage II accrual was met, the trial was halted due
to a combination of minimal activity with several early progression events and
poor tolerability in this patient population. One of 12 tumour specimens had low
amplification of FGFR-1.
CONCLUSIONS: Dovitinib has minimal activity in previously-treated MPM. The role
of the FGFR pathway in MPM remains unclear. Prostate cancer (PCa) remains the second-leading cause of cancer-related deaths
in American men with an estimated mortality of more than 26,000 in 2016 alone.
Aggressive and metastatic tumors are treated with androgen deprivation therapies
(ADT); however, the tumors acquire resistance and develop into lethal castration
resistant prostate cancer (CRPC). With the advent of better therapeutics, the
incidences of a more aggressive neuroendocrine prostate cancer (NEPC) variant
continue to emerge. Although de novo occurrences of NEPC are rare, more than 25%
of the therapy-resistant patients on highly potent new-generation anti-androgen
therapies end up with NEPC. This, along with previous observations of an
increase in the number of such NE cells in aggressive tumors, has been suggested
as a mechanism of resistance development during prostate cancer progression.
Dovitinib (TKI-258/CHIR-258) is a pan receptor tyrosine kinase (RTK) inhibitor
that targets VEGFR, FGFR, PDGFR, and KIT. It has shown efficacy in mouse-model
of PCa bone metastasis, and is presently in clinical trials for several cancers.
We observed that both androgen receptor (AR) positive and AR-negative PCa cells
differentiate into a NE phenotype upon treatment with Dovitinib. The NE
differentiation was also observed when mice harboring PC3-xenografted tumors
were systemically treated with Dovitinib. The mechanistic underpinnings of this
differentiation are unclear, but seem to be supported through MAPK-, PI3K-, and
Wnt-signaling pathways. Further elucidation of the differentiation process will
enable the identification of alternative salvage or combination therapies to
overcome the potential resistance development. Purpose: Genetic and preclinical studies have implicated FGFR signaling in the
pathogenesis of adenoid cystic carcinoma (ACC). Dovitinib, a suppressor of FGFR
activity, may be active in ACC.Experimental Design: In a two-stage phase II
study, 35 patients with progressive ACC were treated with dovitinib 500 mg
orally for 5 of 7 days continuously. The primary endpoints were objective
response rate and change in tumor growth rate. Progression-free survival,
overall survival, metabolic response, biomarker, and quality of life were
secondary endpoints.Results: Of 34 evaluable patients, 2 (6%) had a partial
response and 22 (65%) had stable disease >4 months. Median PFS was 8.2 months
and OS was 20.6 months. The slope of the overall TGR fell from 1.95 to 0.63 on
treatment (P < 0.001). Toxicity was moderate; 63% of patients developed grade
3-4 toxicity, 94% required dose modifications, and 21% stopped treatment early.
An early metabolic response based on 18FDG-PET scans was seen in 3 of 15
patients but did not correlate with RECIST response. MYB gene translocation was
observed and significantly correlated with overexpression of MYB but did not
correlate with FGFR1 phosphorylation or clinical response to
dovitinib.Conclusions: Dovitinib produced few objective responses in patients
with ACC but did suppress the TGR with a PFS that compares favorably with those
reported with other targeted agents. Future studies of more potent and selective
FGFR inhibitors in biomarker-selected patients will be required to determine
whether FGFR signaling is a valid therapeutic target in ACC. Clin Cancer Res;
23(15); 4138-45. ©2017 AACR. Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous disease
characterized by a tumor microenvironment (TME) that overexpresses vascular
endothelial growth factor receptor (VEGFR) and fibroblast growth factor receptor
(FGFR), which can lead to neovascularization, tumor growth and metastasis.
Therapeutic strategies inhibiting these signaling pathways might lead to
innovative HNSCC treatments. Five HNSCC cell lines were characterized based on
VEGFR1-3 and FGFR1-4 expression by sqRT-PCR and treated with three different
tyrosine kinase inhibitors (TKIs) (nintedanib, dovitinib and pazopanib), all of
which are effective against VEGFR and FGFR family members. Crystal violet assays
were performed to analyze the effect of the treatments on cell growth
(viability). Additionally, VEGFR1-3 and FGFR1-4 expression data were retrieved
from The Cancer Genome Atlas (TCGA), and statistical analyses were performed to
investigate the receptor expression level in the different cell lines and the
efficacy of the single-agent treatments. A correlation analysis was performed to
quantify the degree of relationship between receptor expression and drug
efficacy. With the exception of VEGFR2, the targeted receptors were expressed at
different levels in all of the cell lines. The cell lines exhibited
concentration-dependent responses with cell line-specific differences toward two
of the three TKIs (nintedanib and dovitinib). Notably, all of the cell lines
were resistant to pazopanib. TKIs have potential as therapeutic agents for
HNSCC. Cell line-specific differences were observed in our in vitro experiments.
The observed pazopanib resistance could be explained by receptor expression.
Further investigation is required to determine TKI efficacy in HNSCC. BACKGROUND: Prior work identified the fibroblast growth factor (FGF) pathway as
a mediator of resistance to anti-vascular endothelial growth factor (VEGF)
therapy. We tested dovitinib, an inhibitor of both FGF and VEGF receptors, in
patients progressing on anti-VEGF treatment.
METHODS: Patients with measurable advanced colorectal or non-small cell lung
cancer with progression despite anti-VEGF treatment within 56 days, good
performance status and adequate organ function were eligible. A research tumor
biopsy was followed by treatment with dovitinib 500 mg on a 5-day on/2-day off
schedule for 28-day cycles. The primary endpoint of tumor response was evaluated
every 2 cycles. Secondary endpoints included toxicity and 8-week disease control
rate. Intratumor mRNA expression of angiogenic mediators was analyzed using a
next generation sequencing based expression array.
RESULTS: Ten patients treated previously with bevacizumab or ziv-aflibercept
enrolled. The study closed with termination of dovitinib development. No
responses were observed in 7 evaluable patients. The best response was stable
disease in 1 patient. Common toxicities included gastrointestinal, metabolic,
and biochemical derangements. All patients experienced at least one grade ≥ 3
treatment-related adverse event, most commonly fatigue, elevated GGT, and
lymphopenia. Expression of multiple angiogenic mediators was common in tumors
progressing on anti-VEGF therapy including high levels of FGFR1 and VEGFA.
CONCLUSIONS: We found no evidence for the activity of dovitinib in patients who
had recently progressed on anti-VEGF therapy and toxicities were significant. In
tumors progressing despite anti-VEGF therapy, a multitude of pro-angiogenic
mediators are expressed, including members of the FGF pathway. PURPOSE: Dovitinib is an orally available multi tyrosine kinase inhibitor which
inhibits VEGFR 1-3, FGFR 1-3, and PDGFR. This study was performed to investigate
the potential drug-drug interaction of dovitinib with the CYP1A2 inhibitor
fluvoxamine in patients with advanced solid tumors.
METHODS: Non-smoking patients of ≥ 18 years with advanced solid tumors,
excluding breast cancer, were included. Patients were treated with a dose of
300 mg in 5 days on/2 days off schedule. Steady-state pharmacokinetic
assessments of dovitinib were performed with or without fluvoxamine.
RESULTS: Forty-five patients were enrolled; 24 were evaluable for drug-drug
interaction assessment. Median age was 60 years (range 30-85). At steady state
the geometric mean for dovitinib (coefficient of variation%) of the area under
the plasma concentration-time curve (AUC0-72h) and maximum concentration (C max)
were 2880 ng/mL h (47%) and 144 ng/mL (41%), respectively. Following
administration of dovitinib in combination with fluvoxamine the geometric mean
of dovitinib AUC0-72h and C max were 8290 ng/mL h (60%) and 259 ng/mL (45%),
respectively. The estimated geometric mean ratios for dovitinib AUC0-72h and C
max (dovitinib + fluvoxamine vs. dovitinib alone) were 2.88 [90% confidence
interval (CI) 2.58, 3.20] and 1.80 (90% CI 1.66, 1.95). This effect is
considered a moderate drug-drug interaction.
CONCLUSIONS: Fluvoxamine co-administration resulted in a 80% increase in C max
and a 188% increase in AUC0-72h of dovitinib. Given the increase in exposure to
dovitinib observed, patients are at risk of dovitinib related toxicity.
Dovitinib should, therefore, not be co-administered with moderate and strong
CYP1A2 inhibitors, without dose reduction. |
How do circRNAs relate to tumorigenesis? | Circular RNA may promote or repress tumorigenesis. | Circular RNAs (circRNAs) are a subclass of noncoding RNAs widely expressed in
mammalian cells. We report here the tumorigenic capacity of a circRNA derived
from angiomotin-like1 (circ-Amotl1). Circ-Amotl1 is highly expressed in patient
tumor samples and cancer cell lines. Single-cell inoculations using
circ-Amotl1-transfected tumor cells showed a 30-fold increase in proliferative
capacity relative to control. Agarose colony-formation assays similarly revealed
a 142-fold increase. Tumor-take rate in nude mouse xenografts using 6-day (219
cells) and 3-day (9 cells) colonies were 100%, suggesting tumor-forming
potential of every cell. Subcutaneous single-cell injections led to the
formation of palpable tumors in 41% of mice, with tumor sizes >1 cm3 in 1 month.
We further found that this potent tumorigenicity was triggered through
interactions between circ-Amotl1 and c-myc. A putative binding site was
identified in silico and tested experimentally. Ectopic expression of
circ-Amotl1 increased retention of nuclear c-myc, appearing to promote c-myc
stability and upregulate c-myc targets. Expression of circ-Amotl1 also increased
the affinity of c-myc binding to a number of promoters. Our study therefore
reveals a novel function of circRNAs in tumorigenesis, and this subclass of
noncoding RNAs may represent a potential target in cancer therapy. BACKGROUND: Circular RNAs (circRNAs) are RNA transcripts that are widespread in
the eukaryotic genome. Recent evidence indicates that circRNAs play important
roles in tissue development, gene regulation, and carcinogenesis. However,
whether circRNAs encode functional proteins remains elusive, although
translation of several circRNAs was recently reported.
METHODS: CircRNA deep sequencing was performed by using 10 pathologically
diagnosed glioblastoma samples and their paired adjacent normal brain tissues.
Northern blotting, Sanger sequencing, antibody, and liquid chromatograph Tandem
Mass Spectrometer were used to confirm the existence of circ-FBXW7 and its
encoded protein in in two cell lines. Lentivirus-transfected stable U251 and
U373 cells were used to assess the biological functions of the novel protein
invitro and invivo (five mice per group). Clinical implications of circ-FBXW7
were assessed in 38 pathologically diagnosed glioblastoma samples and their
paired periphery normal brain tissues by using quantitative polymerase chain
reaction (two-sided log-rank test).
RESULTS: Circ-FBXW7 is abundantly expressed in the normal human brain (reads per
kilobase per million mapped reads [RPKM] = 9.31). The spanning junction open
reading frame in circ-FBXW7 driven by internal ribosome entry site encodes a
novel 21-kDa protein, which we termed FBXW7-185aa. Upregulation of FBXW7-185aa
in cancer cells inhibited proliferation and cell cycle acceleration, while
knockdown of FBXW7-185aa promoted maligt phenotypes invitro and invivo.
FBXW7-185aa reduced the half-life of c-Myc by antagonizing USP28-induced c-Myc
stabilization. Moreover, circ-FBXW7 and FBXW7-185aa levels were reduced in
glioblastoma clinical samples compared with their paired tumor-adjacent tissues
(P < .001). Circ-FBXW7 expression positively associated with glioblastoma
patient overall survival (P = .03).
CONCLUSIONS: Endogenous circRNA encodes a functional protein in human cells, and
circ-FBXW7 and FBXW7-185aa have potential prognostic implications in brain
cancer. |
Which method is available for whole genome identification of pathogenic regulatory variants in mendelian disease? | Genomiser | Author information:
(1)Queen Mary University of London, London E1 4NS, UK; Genomics England Ltd.,
London EC1M 6BQ, UK.
(2)Institute for Medical and Human Genetics, Charité-Universitätsmedizin Berlin,
Augustenburger Platz 1, 13353 Berlin, Germany.
(3)Skarnes Faculty Group, Wellcome Trust Sanger Institute, Hinxton CB10 1SA, UK.
(4)Institute for Medical and Human Genetics, Charité-Universitätsmedizin Berlin,
Augustenburger Platz 1, 13353 Berlin, Germany; Institute of Bioorganic
Chemistry, Polish Academy of Sciences, 61-704 Poz, Poland.
(5)Institute for Medical and Human Genetics, Charité-Universitätsmedizin Berlin,
Augustenburger Platz 1, 13353 Berlin, Germany; Max Planck Institute for
Molecular Genetics, Ihnestr. 63-73, 14195 Berlin, Germany.
(6)Institute for Medical and Human Genetics, Charité-Universitätsmedizin Berlin,
Augustenburger Platz 1, 13353 Berlin, Germany; Berlin-Brandenburg Center for
Regenerative Therapies (BCRT), Charité-Universitätsmedizin Berlin,
Augustenburger Platz 1, 13353 Berlin, Germany.
(7)Department of Biomedical Informatics and Intelligent Systems Program,
University of Pittsburgh, Pittsburgh, PA 15206, USA.
(8)Division of Environmental Genomics and Systems Biology, Lawrence Berkeley
National Laboratory, Berkeley, CA 94720, USA.
(9)Department of Medical Informatics and Clinical Epidemiology, Oregon Health &
Science University, Portland, OR 97239, USA.
(10)Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research,
Darlinghurst, NSW 2010, Australia; St Vincent's Clinical School, Faculty of
Medicine University of New South Wales, Darlinghurst, NSW 2010, Australia.
(11)Anacleto Lab Department of Computer Science, University of Milan, Via
Comelico, 20135 Milan, Italy.
(12)Institute for Medical and Human Genetics, Charité-Universitätsmedizin
Berlin, Augustenburger Platz 1, 13353 Berlin, Germany; Max Planck Institute for
Molecular Genetics, Ihnestr. 63-73, 14195 Berlin, Germany; Berlin-Brandenburg
Center for Regenerative Therapies (BCRT), Charité-Universitätsmedizin Berlin,
Augustenburger Platz 1, 13353 Berlin, Germany; Institute for Bioinformatics,
Department of Mathematics and Computer Science, Freie Universität Berlin,
Takustrasse, 14195 Berlin, Germany. Electronic address: [email protected]. |
Is pregabalin effective for sciatica? | No. Treatment with pregabalin did not significantly reduce the intensity of leg pain associated with sciatica and did not significantly improve other outcomes, as compared with placebo, over the course of 8 weeks. The incidence of adverse events was significantly higher in the pregabalin group than in the placebo group. | Whilst pregabalin (PGB) and gabapentin (GBP) are both used to treat neuropathic
pain, their relative role in sciatica is unclear. Our aim was to extensively
review the roles of PGB and GBP in treating sciatica. The efficacy, side effects
(SE) profile and cost of PGB and GBP in neuropathic pain states were reviewed
with special reference to sciatica. Eleven articles matched the criteria: seven
systematic reviews, one retrospective cross-sectional study, one
placebo-controlled-crossover study, one randomized placebo-controlled
double-blind study and one case report. GBP and PGB appeared to demonstrate
comparable efficacy and SE. However, the amount and quality of evidence was low,
and only indirect comparisons were available. Importantly, no direct
"head-to-head" study existed. Globally, costs varied widely (by up to 31 times)
and unpredictably (PGB cheaper than GBP, or vice versa). Formulary regulator
rulings were globally disparate; however, many exclusively favoured the more
expensive drug (whether GBP or PGB). No studies assessed PGB-GBP interchange.
Weak evidence suggests that efficacy and SE with GBP and PGB are probably
similar; however, firm conclusions are precluded. Despite weak data, and having
cited minor titration, but definite cost, advantages, UK National Institute for
Health and Clinical Excellence favoured PGB over GBP. Given that no evidence
supports unhindered PGB-GBP interchange, neither drug should probably be
favoured. Prospective "head-to-head" studies are urgently required to provide
robust evidence-based knowledge for choice of GBP or PGB in sciatica. BACKGROUND: Sciatica can be disabling, and evidence regarding medical treatments
is limited. Pregabalin is effective in the treatment of some types of
neuropathic pain. This study examined whether pregabalin may reduce the
intensity of sciatica.
METHODS: We conducted a randomized, double-blind, placebo-controlled trial of
pregabalin in patients with sciatica. Patients were randomly assigned to receive
either pregabalin at a dose of 150 mg per day that was adjusted to a maximum
dose of 600 mg per day or matching placebo for up to 8 weeks. The primary
outcome was the leg-pain intensity score on a 10-point scale (with 0 indicating
no pain and 10 the worst possible pain) at week 8; the leg-pain intensity score
was also evaluated at week 52, a secondary time point for the primary outcome.
Secondary outcomes included the extent of disability, back-pain intensity, and
quality-of-life measures at prespecified time points over the course of 1 year.
RESULTS: A total of 209 patients underwent randomization, of whom 108 received
pregabalin and 101 received placebo; after randomization, 2 patients in the
pregabalin group were determined to be ineligible and were excluded from the
analyses. At week 8, the mean unadjusted leg-pain intensity score was 3.7 in the
pregabalin group and 3.1 in the placebo group (adjusted mean difference, 0.5;
95% confidence interval [CI], -0.2 to 1.2; P=0.19). At week 52, the mean
unadjusted leg-pain intensity score was 3.4 in the pregabalin group and 3.0 in
the placebo group (adjusted mean difference, 0.3; 95% CI, -0.5 to 1.0; P=0.46).
No significant between-group differences were observed with respect to any
secondary outcome at either week 8 or week 52. A total of 227 adverse events
were reported in the pregabalin group and 124 in the placebo group. Dizziness
was more common in the pregabalin group than in the placebo group.
CONCLUSIONS: Treatment with pregabalin did not significantly reduce the
intensity of leg pain associated with sciatica and did not significantly improve
other outcomes, as compared with placebo, over the course of 8 weeks. The
incidence of adverse events was significantly higher in the pregabalin group
than in the placebo group. (Funded by the National Health and Medical Research
Council of Australia; PRECISE Australian and New Zealand Clinical Trials
Registry number, ACTRN12613000530729 .). |
Can gas vesicles be detected by ultrasound? | Gas vesicles have been identified as nanoscale reporters for ultrasound. | Ultrasound is among the most widely used biomedical imaging modalities, but has
limited ability to image specific molecular targets due to the lack of suitable
oscale contrast agents. Gas vesicles-genetically encoded protein
ostructures isolated from buoyant photosynthetic microbes-have recently been
identified as oscale reporters for ultrasound. Their unique physical
properties give gas vesicles significant advantages over conventional
microbubble contrast agents, including oscale dimensions and inherent
physical stability. Furthermore, as a genetically encoded material, gas vesicles
present the possibility that the oscale mechanical, acoustic, and targeting
properties of an imaging agent can be engineered at the level of its constituent
proteins. Here, we demonstrate that genetic engineering of gas vesicles results
in ostructures with new mechanical, acoustic, surface, and functional
properties to enable harmonic, multiplexed, and multimodal ultrasound imaging as
well as cell-specific molecular targeting. These results establish a
biomolecular platform for the engineering of acoustic omaterials. |
In what phase of clinical trials is crenezumab? (November 2017) | Crenezumab is undergoing phase III clinical trials. | Alzheimer's disease (AD) is a major form of senile dementia, characterized by
progressive memory and neuronal loss combined with cognitive impairment. AD is
the most common neurodegenerative disease worldwide, affecting one-fifth of
those aged over 85 years. Recent therapeutic approaches have been strongly
influenced by five neuropathological hallmarks of AD: acetylcholine deficiency,
glutamate excitotoxicity, extracellular deposition of amyloid-β (Aβ plague),
formation of intraneuronal neurofibrillary tangles (NTFs), and
neuroinflammation. The lowered concentrations of acetylcholine (ACh) in AD
result in a progressive and significant loss of cognitive and behavioral
function. Current AD medications, memantine and acetylcholinesterase inhibitors
(AChEIs) alleviate some of these symptoms by enhancing cholinergic signaling,
but they are not curative. Since 2003, no new drugs have been approved for the
treatment of AD. This article focuses on the current research in clinical trials
targeting the neuropathological findings of AD including acetylcholine response,
glutamate transmission, Aβ clearance, tau protein deposits, and
neuroinflammation. These investigations include acetylcholinesterase inhibitors,
agonists and antagonists of neurotransmitter receptors, β-secretase (BACE) or
γ-secretase inhibitors, vaccines or antibodies targeting Aβ clearance or tau
protein, as well as anti-inflammation compounds. Ongoing Phase III clinical
trials via passive immunotherapy against Aβ peptides (crenezumab, gantenerumab,
and aducanumab) seem to be promising. Using small molecules blocking 5-HT6
serotonin receptor (intepirdine), inhibiting BACE activity (E2609, AZD3293, and
verubecestat), or reducing tau aggregation (TRx0237) are also currently in Phase
III clinical trials. We here systemically review the findings from recent
clinical trials to provide a comprehensive review of novel therapeutic compounds
in the treatment and prevention of AD. |
Which sequence-based algorithm for branch point prediction has been proposed? | BPP is a sequence-based algorithm for branch point prediction. | MOTIVATION: Although high-throughput sequencing methods have been proposed to
identify splicing branch points in the human genome, these methods can only
detect a small fraction of the branch points subject to the sequencing depth,
experimental cost and the expression level of the mRNA. An accurate
computational model for branch point prediction is therefore an ongoing
objective in human genome research.
RESULTS: We here propose a novel branch point prediction algorithm that utilizes
information on the branch point sequence and the polypyrimidine tract. Using
experimentally validated data, we demonstrate that our proposed method
outperforms existing methods. Availability and implementation:
https://github.com/zhqingit/BPP.
CONTACT: [email protected].
SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics
online. |
What organism causes scarlet fever also known as scarletina? | Scarlet fever is a disease which can occur as a result of a group A streptococcus (group A strep), group C Streptococcus and Streptococcus hemolyticus infection. | The appearance of the "streptococcal toxic shock-like syndrome" led to a growing
interest in infections caused by Streptococcus pyogenes (group-A-streptococci).
Since 1987 some 800 cases with a lethality of 20% or more were observed.
Contrary to toxic scarlet fever the site of primary infection are the lower
respiratory tract or soft tissue infections. Erythrogenic toxins and low
molecular weight mitogens, inducing cytokines (IL-2, IL-3, IL-6, TNF-alpha,
IFN-gamma) seem to be involved in the pathogenesis of these severe infections.
Morphologically and culturally the strains isolated from cases of toxic
shock-like syndrome cannot be differentiated from isolates of epidemic scarlet
fever or sporadic cases. At the same time, when in Scandinavia an epidemic by
S.pyogenes type 1 with many cases of toxic shock was observed, the same type
caused a scarlet fever epidemic without complications in eastern Germany.
Erythrogenic toxin type A or its toxoid, respectively, can be used for
successful immunizations of rabbits. Another--antibacterial-immunization can be
done with the M-protein of S.pyogenes, which is limited by its type-specificity.
Streptococcal vaccination is required especially for developing countries with a
high incidence of rheumatic fever. Infections due to Streptococcus agalactiae
(group-B streptococci) are often underestimated though they have a first
position in septicemia and meningitis of newborns. Taxonomy and nomenclature of
streptococci are often changing; a list of the presently known species is
presented in table I. Arcanobacterium hemolyticum infections are a common cause of pharyngitis and
rash in the 10- to 30-year-old age group. Despite its prevalence, many emergency
and primary care physicians may not be aware of the pathogenic potential of this
organism. We present a case that illustrates the distinctive clinical spectrum
of A. hemolyticum infections that may be confused with drug allergy, group A
streptococcal scarlet fever, diphtheria, and even toxic shock syndrome.
Recognition of this syndrome will reduce misdiagnoses and facilitate appropriate
treatment. After a young woman had scarlet fever associated with group C beta-hemolytic
streptococcal pharyngitis, we reviewed all cases of pharyngitis treated at a
student health clinic during that semester. From 541 cases of pharyngitis, 34
cultures yielded group C Streptococcus. The patients who harbored group C
organisms were similar to the patients with group A streptococcal pharyngitis in
the presence of fever, exudate, and cervical adenopathy. The severity of
symptoms and the demonstration of scarlet fever developing from infection with
this organism supports antibiotic treatment of patients with group C
streptococcal pharyngitis. In an effort to understand the molecular genetic basis of temporal variation in
frequency and severity of bacterial disease, genetic relationships among strains
of Streptococcus pyogenes that caused scarlet fever epidemics in Canada in the
early 1940s and in eastern Germany in the 1960s to 1980s were studied.
Application of multilocus enzyme electrophoresis and comparative sequencing of
the gene (speA) encoding streptococcal pyrogenic exotoxin A (scarlet fever
toxin) revealed that new waves of scarlet fever are associated with an increase
in frequency of S. pyogenes clones carrying variant speA alleles. This finding
suggests that the occurrence of new scarlet fever epidemics can be predicted by
comprehensive monitoring of the frequency of S. pyogenes clones with variant
toxin alleles. We investigated the involvement of the recently described staphylococcal
enterotoxins G and I in toxic shock syndrome. We reexamined Staphylococcus
aureus strains isolated from patients with menstrual and nonmenstrual toxic
shock syndrome (nine cases) or staphylococcal scarlet fever (three cases). These
strains were selected because they produced none of the toxins known to be
involved in these syndromes (toxic shock syndrome toxin 1 and enterotoxins A, B,
C, and D), enterotoxin E or H, or exfoliative toxin A or B, despite the fact
that superantigenic toxins were detected in a CD69-specific flow cytometry assay
measuring T-cell activation. Sets of primers specific to the enterotoxin G and I
genes (seg and sei, respectively) were designed and used for PCR amplification.
All of the strains were positive for seg and sei. Sequence analysis confirmed
that the PCR products, corresponded to the target genes. We suggest that
staphylococcal enterotoxins G and I may be capable of causing human
staphylococcal toxic shock syndrome and staphylococcal scarlet fever. Infection with group A beta-hemolytic streptococci (GABHS) is the most common
bacterial cause of acute pharyngitis and tonsillitis beyond infancy. We report
on two patients with scarlet fever associated with hepatitis. The patients (boys
aged 6 and 7 years) both presented with a scarlatiniform rash, dark urine and
light-colored stools. Laboratory studies revealed elevated liver transaminases
and negative antibody tests against hepatitis viruses A, B and C,
cytomegalovirus and Epstein-Barr virus. Both patients were treated with
antibiotics and recovered completely within a few days. Although the association
between scarlet fever and hepatitis has been known for many decades, the
pathogenesis is still unknown. Physicians treating patients with group A
beta-hemolytic streptococcal infections should be aware of possible hepatic
involvement. BACKGROUND & OBJECTIVES: Streptococcus pyogenes (group A Streptococcus - GAS) is
an important human pathogen which causes a variety of diseases, including
tonsillopharyngitis, scarlet fever and rheumatic fever. It is important to
understand the changes in epidemiology of the diseases caused by the pathogen
for improved control of such infections. Hence, the aim of the present study was
to carry out an epidemiological analysis of GAS infections in Serbia in a 9-yr
period (1991-1999) and evaluation of susceptibility of GAS isolates obtained
during the same period to penicillin and erythromycin.
METHODS: Occurrence of tonsillopharyngitis, scarlatina and rheumatic fever was
analyzed and GAS carrier status in healthy children was examined over a 9-yr
period from 1991 to 1999. Susceptibility to penicillin and erythromycin was
determined for 1657 GAS isolates obtained from patients diagnosed with
pharyngitis or scarlet fever and 512 isolates from healthy carriers. M-type
antigen was also determined in these isolates.
RESULTS: The average incidences of tonsillopharyngitis and scarlet fever were
76.2 and 30.8 per cent respectively. A total of 166 cases of rheumatic fever
were registered. Per cent of carriers varied from 5.5 to 11.4 per cent over the
study period. Predominating M serotypes among GAS isolates tested were M1, M3,
M4, M6, M11, M12 and M18, depending on the source of clinical material and
period of isolation. Antimicrobial susceptibility testing showed susceptibility
to penicillin in all isolates tested and resistance to erythromycin in 2.41 per
cent of the isolates.
INTERPRETATION & CONCLUSION: Although the fluctuations in incidence were noted
during the nine-year period, the incidence of streptococcal tonsillopharyngitis
is low but with a steady raise in Serbia. No significant changes in the
incidence of scarlet fever and rheumatic fever were noted. Susceptibility to
penicillin remained unchanged, but the number or erythromycin resistant strains
have increased. 1. Hemolytic streptococcus has been found in 100 per cent of the throats of
patients with scarlet fever during the 1st week of the disease. 2. The average
length of time that these organisms are present in the throat varies from 10 to
20 days. 3. No morphological or cultural characteristics peculiar to the
hemolytic streptococcus from scarlet fever can be demonstrated. 4. Ten immune
sera have been prepared from different strains of scarlet fever streptococci and
each of the sera agglutinated more than 80 per cent of the strains isolated from
scarlatinal throats. On the other hand, scarlatinal streptococci are not
agglutinated by immune sera prepared from hemolytic streptococci isolated from
other pathological sources. 5. Serum from patients convalescent from scarlet
fever agglutinates weakly or not at all the homologous strain of hemolytic
streptococcus. 6. The specificity of the agglutination reaction of scarlatinal
streptococci is confirmed by absorption experiments. 7. Scarlatinal
antistreptococcic serum affords some degree of protection against virulent
scarlet fever streptococci but has no protective power against hemolytic
streptococci from other diseases. 8. In a small epidemic of scarlet fever a
healthy carrier of hemolytic streptococcus was detected; the organism carried
was identical in its serological reactions with strains of hemolytic
streptococci isolated from active cases of scarlet fever. 9. In a study of a
number of contacts with a case of scarlet fever, in only one instance was a
scarlatinal type of hemolytic streptococcus recovered from the throat. A series of observations on the blood of patients acutely ill with scarlet fever
has shown that a toxic substance can be demonstrated in the serum by means of
intracutaneous injections of the serum in persons who have not had scarlet fever
and whose serums fail to blanch the rash in scarlet fever. The reaction caused
by this substance consists of a bright red local erythema, varying from 20 to 70
mm. in diameter, of 1 to 4 days duration. The severer reactions are moderately
indurated and tender, and are followed bypigmentation and desquamation. Control
injections in persons whose serums blanch the rash in scarlet fever cause no
reaction. The toxic substance is not neutralized by mixture with a human serum
which gives a negative blanching test but is readily neutralized by a human
serum which gives a positive blanching test. It is not neutralized by normal
horse serum, but is completely neutralized by Dochez's scarlatinal
antistreptococcic serum. In a limited number of observations on the urine of
patients with scarlet fever a similar toxic substance has been found in two out
of five cases studied. Since the toxic substance described appears to resemble
the toxic substance found in the filtrates of scarlatinal hemolytic
streptococcus cultures by Dick and Dick and since it is neutralized not only by
a blanching human serum but also by Dochez's scarlatinal antistreptococcic horse
serum, the experiments reported support the conception that scarlet fever is a
local infection of the throat by a particular type of Streptococcus haemolyticus
capable of producing a toxin which is absorbed and is the cause of the general
manifestations of the disease. The grampositive bacterium S. pyogenes (beta-haemolytic group A Streptococcus)
is a natural colonizer of the human oropharynx mucous membrane and one of the
most common agents of infectious diseases in humans. S. pyogenes causes the
widest range of disease in humans among all bacterial pathogens. It is
responsible for various skin infections such as impetigo contagiosa and
erysipelas, and localized mucous membrane infections of the oropharynx (e. g.
tonsillitis and pharyngitis). Betahaemolytic group A Streptococcus causes also
invasive diseases such as sepses including puerperal sepsis. Additionally, S.
pyogenes induces toxin-mediated syndromes, i. e. scarlet fever, streptococcal
toxic shock syndrome (STSS) and necrotizing fasciitis (NF). STSS and NF are
severe, frequently fatal diseases that have emerged in Europe and Northern
America during the last two decades. Finally, some immunpathological diseases
such as acute rheumatic fever and glomerulonephritis also result from S.
pyogenes infections. Most scientists recommend penicillins (benzylpenicillin,
phenoxymethylpenicllin) as drugs of first choice for treatment of Streptococcus
tonsillopharyngitis and scarlet fever. Erysipelas and some other skin infections
should be treated with benzylpenicillin. Intensive care measurements are needed
for treatment of severe toxin-mediated S. pyogenes diseases. These measurements
include the elimination of internal bacterial foci, concomitant application of
clindamycin and benzylpenicillin and suitable treatment of shock symptoms.
Management of immunpathological diseases requires antiphlogistical therapy.
Because of the wide distribution of S. pyogenes in the general population and
the lack of an effective vaccine, possibilities for prevention allowing a
suitable protection for diseases due to S. pyogenes are very limited. BACKGROUND/PURPOSE: Little information is available on the differences in
frequency of pyrogenic exotoxin genes between strains of group A streptococci
that cause scarlet fever and those that cause pharyngotonsillitis in children in
Taiwan. This study retrospectively monitored the presence of pyrogenic exotoxin
genes, the emm typing, and the susceptibility of macrolide drugs in
Streptococcus pyogenes isolated from children diagnosed with scarlet fever and
pharyngotonsillitis in northern Taiwan.
MATERIALS AND METHODS: Isolates of S. pyogenes were recovered from children with
scarlet fever (n = 21) and acute pharyngotonsillitis (n = 29) during 2000-2011.
The isolates were characterized according to the presence of spe genes and emm
typing. Antibiograms were determined by the disk diffusion method and agar
dilution test. Polymerase chain reaction was used to detect the presence of erm
genes in isolates that showed nonsusceptibility to erythromycin. All isolates
underwent additional genotyping by pulsed-field gel electrophoresis.
RESULTS: In isolates from patients with scarlet fever, the frequencies of
pyrogenic exotoxin genes were 9.5% for speA, 81.0% for speB, 4.8% for speC, and
71.4% for speF. In isolates from patients with pharyngotonsillitis, the
frequencies were 17.2% for speA, 72.4% for speB, 13.8% for speC, and 69.0% for
speF. There were no significant differences in frequencies of the exotoxin genes
between the two groups of isolates. Eight emm sequence types were identified
from all group A streptococci isolates. The most common types were emm12
followed by emm1 and emm4. The erythromycin resistant rate was 4/50 (8%). The
ermB gene was detected in only one isolate from a patient with
pharyngotonsillitis. Pulsed-field gel electrophoresis had a total of three sets
of clustered strains, which showed >80% homology and belonged to the same emm
type.
CONCLUSION: There were no significant differences in frequencies of the spe
genes between S. pyogenes isolates from patients with scarlet fever and patients
with pharyngotonsillitis. The most common emm type was emm12. Low erythromycin
resistance in S. pyogenes was observed. Scarlet fever is one of a variety of diseases caused by group A Streptococcus
(GAS). During 2011, a scarlet fever epidemic characterized by peak monthly
incidence rates 2.9-6.7 times higher than those in 2006-2010 occurred in
Beijing, China. During the epidemic, hospital-based enhanced surveillance for
scarlet fever and pharyngitis was conducted to determine characteristics of
circulating GAS strains. The surveillance identified 3,359 clinical cases of
scarlet fever or pharyngitis. GAS was isolated from 647 of the patients; 76.4%
of the strains were type emm12, and 17.1% were emm1. Almost all isolates
harbored superantigens speC and ssa. All isolates were susceptible to
penicillin, and resistance rates were 96.1% to erythromycin, 93.7% to
tetracycline, and 79.4% to clindamycin. Because emm12 type GAS is not the
predomit type in other countries, wider surveillance for the possible spread
of emm12 type GAS from China to other countries is warranted. BACKGROUND: Several outbreaks of scarlet fever caused by Streptococcus pyogenes
were recently reported. Scarlet fever is historically considered a
toxin-mediated disease, dependent on the production of the exotoxins SpeA and
SpeC, but a strict association between scarlet fever and these exotoxins is not
always detected. The aims of this study were to characterize the scarlet fever
bacterial isolates recovered from patients in a Lisbon hospital and to identify
any distinctive characteristics of such isolates.
METHODS: We characterized a collection of 303 pharyngeal S. pyogenes collected
between 2002 and 2008. One-hundred and one were isolated from scarlet fever
patients and 202 were associated to a diagnosis of tonsillo-pharyngitis.
Isolates were characterized by T and emm typing, pulsed field gel
electrophoresis profiling and superantigen gene profiling.
RESULTS: The diversity of the scarlet fever isolates was lower than that of the
pharyngitis isolates. Specific lineages of emm87, emm4 and emm3 were
overrepresented in scarlet fever isolates but only 1 pulsed field gel
electrophoresis major lineage was significantly associated with scarlet fever.
Multivariate analysis indicated associations of ssa, speA and speC with scarlet
fever.
CONCLUSIONS: In nonoutbreak conditions, scarlet fever is caused by a number of
distinct genetic lineages. The lower diversity of these isolates and the
association with specific exotoxin genes indicates that some lineages are more
prone to cause this presentation than others even in nonoutbreak conditions. The incidence rate for scarlet fever in South Korea is rising. During 2008-2015,
we collected group A Streptococcus isolates and performed emm and exotoxin
genotyping and disk-diffusion antimicrobial tests. Scarlet fever in South Korea
was most closely associated with emm types emm4, emm28, emm1, and emm3. In 2015,
tetracycline resistance started increasing. |
What is the BioArchive system? | A small-scale automated cryopreservation and storage system (Mini-BioArchive system) used in the banking of umbilical cord blood (UCB) units. | The limited number of progenitor stem cells in umbilical cord blood (UCB)
enforces the optimization and strict control of all the procedures involved in
its therapeutic use--ie, collection, processing, cryopreservation, thawing, and
transportation--to ensure graft potency at transplantation. For this reason,
international UCB standards recommend storage of a cell sample attached to the
UCB unit as a quantitative and functional control of the unit selected for
transplantation. To validate the use of the sample attached to the UCB unit as a
quality-control tool for the final product, UCB units (n = 20) stored in liquid
nitrogen with the Bioarchive system were analyzed. The UCB units and their
attached segments were thawed, and the number and viability of total nucleated
cells, mononucleated cells, CD45 + cells, and CD34+ cells were determined, as
were colony-forming cell counts. There was no significant difference between UCB
units and segments for any of the parameters assessed. Additionally, the linear
correlation coefficient (R2) in these paired samples was 0.85 and 0.78 for CD34+
cells and colony-forming cells, respectively. In conclusion, the cell sample in
the tube segment physically linked to the transplant UCB bag predicts the total
cell content and functionality of the unit and may serve as a source for final
quality control of the UCB unit before transplantation. The performance of a small-scale automated cryopreservation and storage system
(Mini-BioArchive system) used in the banking of umbilical cord blood (UCB) units
was evaluated. After thawing the units, the viability and recovery of cells, as
well as the recovery rate of hematopoietic progenitor cells (HPCs) such as CD34+
cells, colony-forming unit-granulocyte-macrophage (CFU-GM), and total CFU were
analyzed. Twenty UCB units cryopreserved using the automated system and stored
for a median of 34 days were analyzed. Mean CD34+ cell viabilities before
freezing were 99.8+/-0.5% and after thawing were 99.8+/-0.4% in the large bag
compartments and 99.7+/-0.5% in the small compartments. The mean recovery values
for total nucleated cells, CD34+ cells, CFU-GM, and total CFU were 94.8+/-16.0%,
99.3+/-18.6%, 103.9+/-20.6%, and 94.3+/-12.5%, respectively in the large
compartments, and 95.8+/-25.9%, 106.8+/-23.9%, 101.3+/-23.3%, and 93.8+/-19.2%,
respectively in the small compartments. A small-scale automated cryopreservation
and storage system did not impair the clonogenic capacity of UCB HPCs. This
cryopreservation system could provide cellular products adequate for UCB banking
and HPC transplantation. Umbilical cord blood (CB) banks usually freeze and store CB for clinical
transplantation using conventional controlled-rate freezer or the automated
BioArchive system. The aim of this study is to compare the quality of CB
cryopreserved with conventional and automated methods and to make clear the
cause of the quality difference between the two methods. The experiment used
80 CB units: 40 were conventionally cryopreserved and the remainder were
cryopreserved with a BioArchive. After thawing, the following measures of CB
quality were compared: recovery rates of cell count, cell viability of total
nucleated cells (TNCs), mononuclear cells (MNCs), and CD34+ cells, as well as
colony-forming unit-granulocyte/macrophage (CFU-GM) content. Additionally,
processing and storage records were reviewed to quantify the number of exposures
of CB units at room temperature (transient warming event, TWE), which was
analyzed in relation to CB quality. MNC and CD34+ cell viability were as
follows: MNC, 78.2% ± 6.8% (conventional), 81.7% ± 7.2% (automated); CD34+ cell,
90.6% ± 6.9% (conventional), 94.7% ± 3.5% (automated). The absolute CFU-GM
content per CB unit was 7.1 × 105 ± 5.9 × 105 with conventional cryopreservation
and 12.3 × 105 ± 12.0 × 105 with automated cryopreservation. CBs cryopreserved
with BioArchive showed significantly higher MNC and CD34+ cell viability, and
CFU-GM content than those conventionally cryopreserved. The CB quality
comparison depending on the amount of TWEs showed no significant quality
difference between groups that were more exposed to TWEs and groups that were
less exposed. CBs cryopreserved with BioArchive were of higher quality than
conventionally cryopreserved CBs, and the cause of quality difference might be
due to the difference of freezing conditions rather than the TWE effect. |
Which algorithm has been proposed for efficient storage of WGS variant calls? | Whole-genome sequencing (WGS) data are being generated at an unprecedented rate. Analysis of WGS data requires a flexible data format to store the different types of DNA variation. Variant call format (VCF) is a general text-based format developed to store variant genotypes and their annotations. However, VCF files are large and data retrieval is relatively slow. 'SeqArray' is a new WGS variant data format implemented in the R/Bioconductor package for storing variant calls in an array-oriented manner which provides the same capabilities as VCF, but with multiple high compression options and data access using high-performance parallel computing. | MOTIVATION: Whole-genome sequencing (WGS) data are being generated at an
unprecedented rate. Analysis of WGS data requires a flexible data format to
store the different types of DNA variation. Variant call format (VCF) is a
general text-based format developed to store variant genotypes and their
annotations. However, VCF files are large and data retrieval is relatively slow.
Here we introduce a new WGS variant data format implemented in the
R/Bioconductor package 'SeqArray' for storing variant calls in an array-oriented
manner which provides the same capabilities as VCF, but with multiple high
compression options and data access using high-performance parallel computing.
RESULTS: Benchmarks using 1000 Genomes Phase 3 data show file sizes are 14.0 Gb
(VCF), 12.3 Gb (BCF, binary VCF), 3.5 Gb (BGT) and 2.6 Gb (SeqArray)
respectively. Reading genotypes in the SeqArray package are two to three times
faster compared with the htslib C library using BCF files. For the allele
frequency calculation, the implementation in the SeqArray package is over 5
times faster than PLINK v1.9 with VCF and BCF files, and over 16 times faster
than vcftools. When used in conjunction with R/Bioconductor packages, the
SeqArray package provides users a flexible, feature-rich, high-performance
programming environment for analysis of WGS variant data.
AVAILABILITY AND IMPLEMENTATION: http://www.bioconductor.org/packages/SeqArray.
CONTACT: [email protected].
SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics
online. |
Is Citrobacter rodentium pathogenic? | Yes, the mouse pathogen Citrobacter rodentium, colonize the gut mucosa via attaching and effacing lesion formation and cause diarrheal diseases. | Tracking disease progression in vivo is essential for the development of
treatments against bacterial infection. Optical imaging has become a central
tool for in vivo tracking of bacterial population development and therapeutic
response. For a precise understanding of in vivo imaging results in terms of
disease mechanisms derived from detailed postmortem observations, however, a
link between the two is needed. Here, we develop a model that provides that link
for the investigation of Citrobacter rodentium infection, a mouse model for
enteropathogenic Escherichia coli (EPEC). We connect in vivo disease progression
of C57BL/6 mice infected with bioluminescent bacteria, imaged using optical
tomography and X-ray computed tomography, to postmortem measurements of colonic
immune cell infiltration. We use the model to explore changes to both the host
immune response and the bacteria and to evaluate the response to antibiotic
treatment. The developed model serves as a novel tool for the identification and
development of new therapeutic interventions. Cell death signalling pathways contribute to tissue homeostasis and provide
innate protection from infection. Adaptor proteins such as receptor-interacting
serine/threonine-protein kinase 1 (RIPK1), receptor-interacting
serine/threonine-protein kinase 3 (RIPK3), TIR-domain-containing
adapter-inducing interferon-β (TRIF) and Z-DNA-binding protein 1
(ZBP1)/DNA-dependent activator of IFN-regulatory factors (DAI) that contain
receptor-interacting protein (RIP) homotypic interaction motifs (RHIM) play a
key role in cell death and inflammatory signalling1-3. RHIM-dependent
interactions help drive a caspase-independent form of cell death termed
necroptosis4,5. Here, we report that the bacterial pathogen enteropathogenic
Escherichia coli (EPEC) uses the type III secretion system (T3SS) effector EspL
to degrade the RHIM-containing proteins RIPK1, RIPK3, TRIF and ZBP1/DAI during
infection. This requires a previously unrecognized tripartite cysteine protease
motif in EspL (Cys47, His131, Asp153) that cleaves within the RHIM of these
proteins. Bacterial infection and/or ectopic expression of EspL leads to rapid
inactivation of RIPK1, RIPK3, TRIF and ZBP1/DAI and inhibition of tumour
necrosis factor (TNF), lipopolysaccharide or polyinosinic:polycytidylic acid
(poly(I:C))-induced necroptosis and inflammatory signalling. Furthermore, EPEC
infection inhibits TNF-induced phosphorylation and plasma membrane localization
of mixed lineage kinase domain-like pseudokinase (MLKL). In vivo, EspL cysteine
protease activity contributes to persistent colonization of mice by the
EPEC-like mouse pathogen Citrobacter rodentium. The activity of EspL defines a
family of T3SS cysteine protease effectors found in a range of bacteria and
reveals a mechanism by which gastrointestinal pathogens directly target
RHIM-dependent inflammatory and necroptotic signalling pathways. |
List two human monoclonal antibodies against Clostridium difficile toxins. | Actoxumab and bezlotoxumab are human monoclonal antibodies against C. difficile toxins A and B, respectively. They were shown to decrease Clostridium difficile recurrence. Bezlotoxumab was approved by the Food and Drug Administration and the European Medicines Agency for Clostridium difficile recurrence. | Clostridium difficile infections (CDIs) are the leading cause of
hospital-acquired infectious diarrhea and primarily involve two exotoxins, TcdA
and TcdB. Actoxumab and bezlotoxumab are human monoclonal antibodies that
neutralize the cytotoxic/cytopathic effects of TcdA and TcdB, respectively. In a
phase II clinical study, the actoxumab-bezlotoxumab combination reduced the rate
of CDI recurrence in patients who were also treated with standard-of-care
antibiotics. However, it is not known whether the antibody combination will be
effective against a broad range of C. difficile strains. As a first step toward
addressing this, we tested the ability of actoxumab and bezlotoxumab to
neutralize the activities of toxins from a number of clinically relevant and
geographically diverse strains of C. difficile. Neutralization potencies, as
measured in a cell growth/survival assay with purified toxins from various C.
difficile strains, correlated well with antibody/toxin binding affinities.
Actoxumab and bezlotoxumab neutralized toxins from culture supernatants of all
clinical isolates tested, including multiple isolates of the BI/NAP1/027 and
BK/NAP7/078 strains, at antibody concentrations well below plasma levels
observed in humans. We compared the bezlotoxumab epitopes in the TcdB receptor
binding domain across known TcdB sequences and found that key substitutions
within the bezlotoxumab epitopes correlated with the relative differences in
potencies of bezlotoxumab against TcdB of some strains, including ribotypes 027
and 078. Combined with in vitro neutralization data, epitope modeling will
enhance our ability to predict the coverage of new and emerging strains by
actoxumab-bezlotoxumab in the clinic. Clostridium difficile infection (CDI) represents the most prevalent cause of
antibiotic-associated gastrointestinal infections in health care facilities in
the developed world. Disease symptoms are caused by the two homologous
exotoxins, TcdA and TcdB. Standard therapy for CDI involves administration of
antibiotics that are associated with a high rate of disease recurrence,
highlighting the need for novel treatment paradigms that target the toxins
rather than the organism itself. A combination of human monoclonal antibodies,
actoxumab and bezlotoxumab, directed against TcdA and TcdB, respectively, has
been shown to decrease the rate of recurrence in patients treated with
standard-of-care antibiotics. However, the exact mechanism of antibody-mediated
protection is poorly understood. In this study, we show that the antitoxin
antibodies are protective in multiple murine models of CDI, including systemic
and local (gut) toxin challenge models, as well as primary and recurrent models
of infection in mice. Systemically administered actoxumab-bezlotoxumab prevents
both the damage to the gut wall and the inflammatory response, which are
associated with C. difficile in these models, including in mice challenged with
a strain of the hypervirulent ribotype 027. Furthermore, mutant antibodies
(N297Q) that do not bind to Fcγ receptors provide a level of protection similar
to that of wild-type antibodies, demonstrating that the mechanism of protection
is through direct neutralization of the toxins and does not involve host
effector functions. These data provide a mechanistic basis for the prevention of
recurrent disease observed in CDI patients in clinical trials. Collaborators: Playford G, McGechie D, Iredell J, Allworth A, Cheng A, Choi NJ,
Thalhammer F, Maieron A, Wenisch C, Meyer B, Jacobs F, Delmee M, Peetermans W,
Giot JB, Munhoz AL, Kallas EG, Ladeira JP, Bernstein CN, Grimard D, McGeer A,
Poirier A, Valiquette L, Miller M, Oughton M, Trottier S, Dolce P, Smyth D,
Gambra P, Palma S, Rojas L, Northland R, Arellano MC, Perez J, Barreto MF, Gomez
JM, Ramirez I, Correa A, Onate J, Rohacova H, Stastnik M, Zjevikova A, Blazek J,
Kumpel P, Petersen AM, Gluud LL, Staugaard HM, Tvede M, Glerup H, Madsen SM,
Helms M, Naumann R, Karthaus M, Reinshagen M, Raz R, Giladi M, Chowers M,
Bishara J, Quirino T, Castelli F, Bassetti M, Rizzardini G, Vismara E, Puoti M,
Viale P, Menichetti F, Cauda R, Bonfanti P, Franzetti F, Gori A, Minoli L,
Noriega ER, Mills GD, Ritchie S, Burns A, Pithie A, dos Santos RM, Aldomiro F,
Ferdo PB, Rola J, Reis E, Van Zyl JH, Aboo N, Richards G, Herdez MJ, de
Medrano VA, Prunonosa LM, Gonzalez JL, Reinoso JC, Martinez AR, Cisneros JD,
Banos JR, Sheridan R, Minton J, Williams J, Stanley P, Guleri A, Llewelyn M,
Todd N, Barlow G, Bacon AE, Baird IM, Baxter R, Zenilman JM, Beshay M, Betts RF,
Brettholz EM, Buitrago MI, Carlson RW, Cook PP, Dupont HL, Foley C, Freilich B,
Giron JA, Golan Y, Green S, Hall MC, Johnson DJ, Jones RK, Graham DR, Kazimir M,
Keating M, Brumble LM, Kumar PN, Liappis AP, Libke R, Mehra PK, Overcash SJ,
Mullane KM, Nguyen MH, Patel MC, Powers CK, Pullman J, Keegan J, Nepal S,
English G, Ricci RL, Risi GF, Rodriguez M, Schmitt CM, Sims MD, Kamepalli R,
Tural A, Vazquez JA, Alangaden GJ, Weavind LM, Young MA, Chen ST, Liu E, Nguyen
HH, Alfonso TB, Muse DD, Orenstein R, Yacyshyn B, Gebhard RE, Dinges W, Bolton
M, Rubin M, Kuemmerle JF, Limaye AP, Friedenberg KA, Hiemenz JW, Quadri A,
Martinez JV, Barcan LA, Cordova E, Mykietiuk A, Losso M, Fedorak RN, Steiner T,
Gerson M, Weiss K, Dlouhy P, Vitous A, Benes J, Husa P, Knizek P, Anttila VJ,
Broas M, Camou F, Postil D, Launay O, Corroyer-Simovic B, Meynard JL, Schneider
S, Molina JM, Neau D, Zalcman G, Boutoille D, Ostermann H, Heinz W, Reuter S,
Oren I, Schiff E, Umemoto T, Masubuchi T, Mukawa K, Yasuda K, Imokawa S, Fukuda
K, Ohta H, Harada N, Fujii S, Tamaki S, Yasui S, Furukawa K, Takahashi M, Uraoka
T, Watanabe M, Ikehara Y, Kodaira M, Komatsu H, Higashi K, Taguchi F, Ura N,
Serizawa Y, Fukuchi T, Ashikawa T, Shabana M, Okubo M, Matsumoto M, Kurihara A,
Miyasaka E, Shimizu M, Tominaga H, Kubota T, Kashiwazaki M, Masuda Y, Terasaki
S, Okafuji H, Mieno H, Urabe T, Okamoto E, Kajimura M, Yamagishi Y, Rydzewska G,
Mach T, Ciechanowski K, Podlasin R, Tomasiewicz K, Janczewska-Kazek E,
Czarnobilski K, Halota W, Gryglewska B, Plesniak R, Dabrowiecki P, Lipowski D,
Simanenkov V, Shcheglova L, Uspenskiy Y, Cheganov A, Han DS, Kim JS, Hong SP,
Kim TI, Jang BI, Byeon JS, Kim E, Kim MJ, Lee J, Pai H, Cheong HJ, Lee S,
Loyarte JA, Gonzalez JC, Santiago EB, Lopez JR, Baranda JM, Viladomiu AS, Calbo
E, Lannergard A, Falt J, Gardlund B, Andersson LM, Fraenkel CJ, Rombo L, Widmer
A, Chen YC, Sheng WH, Wang FD, Wang NC, Lee CH, Chen YH, Chuang YC, Unal S,
Ozaras R, Esen S, Ural O, Ayaz C, Sakarya S, Celebi A, Mistik R, Bedimo R,
Bressler A, Mckinley MJ, Quirk D, Talansky AL, Agronin ME, Akhrass FA, Ali M,
Alrabaa SF, Assi MA, Calfee DP, Carson P, Mariani PG, Guerrero D, Dubberke ER,
Hardi R, Hazan-Steinberg S, Itani KM, Jauregui-Peredo EL, Kasabji A, Hameed M,
Murillo A, Odio AJ, Shah P, Braun TI, Slim J, Sloan L, Srinivasan S, Tan MJ,
Clough LA, Herr D, Miller LG, Dorfmeister J, Khan O, Melik-Abrahamian F. During the past decade, the incidence and severity of Clostridium difficile
infection (CDI) have significantly increased, leading to a rise in
CDI-associated hospitalizations, health care costs, and mortality. Although
treatment options exist for CDI, recurrence is frequent following treatment.
Furthermore, patients with at least one CDI recurrence are at an increased risk
of developing additional recurrences. A novel approach to the prevention of
recurrent CDI is the use of monoclonal antibodies directed against the toxins
responsible for CDI as an adjunct to antibiotic treatment. Bezlotoxumab, a human
monoclonal antibody that binds and neutralizes C. difficile toxin B, is the
first therapeutic agent to receive United States Food and Drug Administration
approval for the prevention of CDI recurrence. Clinical studies have
demonstrated superior efficacy of bezlotoxumab in adults receiving antibiotic
therapy for CDI compared with antibiotic therapy alone for the prevention of CDI
recurrence. Bezlotoxumab was well tolerated in clinical trials, with the most
common adverse effects being nausea, vomiting, fatigue, pyrexia, headache, and
diarrhea. The demonstrated efficacy, safety, and characteristics of bezlotoxumab
present an advance in prevention of CDI recurrence. |
List ribosomal biogenesis proteins. | FGF13
p53
TGFβ/Activin
PTEN
Nucleostemin
HEATR1 | The microRNA miR-504 targets TP53 mRNA encoding the p53 tumor suppressor.
miR-504 resides within the fibroblast growth factor 13 (FGF13) gene, which is
overexpressed in various cancers. We report that the FGF13 locus, comprising
FGF13 and miR-504, is transcriptionally repressed by p53, defining an additional
negative feedback loop in the p53 network. Furthermore, we show that FGF13 1A is
a nucleolar protein that represses ribosomal RNA transcription and attenuates
protein synthesis. Importantly, in cancer cells expressing high levels of FGF13,
the depletion of FGF13 elicits increased proteostasis stress, associated with
the accumulation of reactive oxygen species and apoptosis. Notably, stepwise
neoplastic transformation is accompanied by a gradual increase in FGF13
expression and increased dependence on FGF13 for survival ("nononcogene
addiction"). Moreover, FGF13 overexpression enables cells to cope more
effectively with the stress elicited by oncogenic Ras protein. We propose that,
in cells in which activated oncogenes drive excessive protein synthesis, FGF13
may favor survival by maintaining translation rates at a level compatible with
the protein quality-control capacity of the cell. Thus, FGF13 may serve as an
enabler, allowing cancer cells to evade proteostasis stress triggered by
oncogene activation. Signalling by TGFβ superfamily factors plays an important role in tissue growth
and cell proliferation. In Drosophila, the activity of the TGFβ/Activin
signalling branch has been linked to the regulation of cell growth and
proliferation, but the cellular and molecular basis for these functions are not
fully understood. In this study, we show that both the RII receptor Punt (Put)
and the R-Smad Smad2 are strongly required for cell and tissue growth. Knocking
down the expression of Put or Smad2 in salivary glands causes alterations in
nucleolar structure and functions. Cells with decreased TGFβ/Activin signalling
accumulate intermediate pre-rRNA transcripts containing internal transcribed
spacer 1 regions accompanied by the nucleolar retention of ribosomal proteins.
Thus, our results show that TGFβ/Activin signalling is required for ribosomal
biogenesis, a key aspect of cellular growth control. Importantly, overexpression
of Put enhanced cell growth induced by Drosophila Myc, a well-characterized
inducer of nucleolar hypertrophy and ribosome biogenesis. PTEN is a critical tumour suppressor that is frequently mutated in human cancer.
We have previously identified a CUG initiated PTEN isoform designated PTENα,
which functions in mitochondrial bioenergetics. Here we report the
identification of another N-terminal extended PTEN isoform, designated PTENβ.
PTENβ translation is initiated from an AUU codon upstream of and in-frame with
the AUG initiation sequence for canonical PTEN. We show that the Kozak context
and a downstream hairpin structure are critical for this alternative initiation.
PTENβ localizes predomitly in the nucleolus, and physically associates with
and dephosphorylates nucleolin, which is a multifunctional nucleolar
phosphoprotein. Disruption of PTENβ alters rDNA transcription and promotes
ribosomal biogenesis, and this effect can be reversed by re-introduction of
PTENβ. Our data show that PTENβ regulates pre-rRNA synthesis and cellular
proliferation. These results demonstrate the complexity of the PTEN protein
family and the diversity of its functions. Ribosome biogenesis is an energy consuming process which takes place mainly in
the nucleolus. By producing ribosomes to fuel protein synthesis, it is tightly
connected with cell growth and cell cycle control. Perturbation of ribosome
biogenesis leads to the activation of p53 tumor suppressor protein promoting
processes like cell cycle arrest, apoptosis or senescence. This ribosome
biogenesis stress pathway activates p53 through sequestration of MDM2 by a
subset of ribosomal proteins (RPs), thereby stabilizing p53. Here, we identify
human HEATR1, as a nucleolar protein which positively regulates ribosomal RNA
(rRNA) synthesis. Downregulation of HEATR1 resulted in cell cycle arrest in a
manner dependent on p53. Moreover, depletion of HEATR1 also caused disruption of
nucleolar structure and activated the ribosomal biogenesis stress pathway - RPL5
/ RPL11 dependent stabilization and activation of p53. These findings reveal an
important role for HEATR1 in ribosome biogenesis and further support the concept
that perturbation of ribosome biosynthesis results in p53-dependent cell cycle
checkpoint activation, with implications for human pathologies including cancer. |
Which protein is regulated by Tudor interacting repair regulator (TIRR)? | Tudor interacting repair regulator (TIRR) regulates P53-binding protein 1 (53BP1) by masking its histone methyl-lysine binding function. | The tumor suppressor protein p53 and the human DNA topoisomerase I (htopoI)
interact with each other, which leads to a stimulation of the catalytic activity
of htopoI. Moreover, p53 stimulates the topoisomerase I-induced recombination
repair (TIRR) reaction. However, little was known about how p53 stimulates this
topoisomerase I activity. Here we demonstrate that monomeric p53 is sufficient
for the stimulation of the topoisomerase I-catalyzed relaxation activity, but
the tetrameric form of p53 is required for the stimulation of TIRR. We also show
that p53 stimulates topoisomerase I activity by increasing the dissociation of
htopoI from DNA. Since htopoI forms a closed ring structure around the DNA, our
results suggest that p53 induces a conformational change within htopoI that
results in an opening of the clamp, and thereby releases htopoI from DNA. The 53BP1-dependent end-joining pathway plays a critical role in double strand
break repair and is uniquely responsible for cellular sensitivity to
poly(ADP-ribose) polymerase inhibitors (PARPi) in BRCA1-deficient cancers. We
and others have investigated the downstream effectors of 53BP1, including
replication timing regulatory factor 1 (RIF1) and Pax transactivation
domain-interacting protein (PTIP), in the past few years to elucidate how loss
of the 53BP1-dependent repair pathway results in PARPi resistance in BRCA1
patients. However, questions regarding the upstream regulation of the 53BP1
pathway remain uswered. In this study, we identified the Tudor-interacting
repair regulator (TIRR) that specifically associates with the ionizing
radiation-induced foci formation region of 53BP1. 53BP1 and TIRR form a stable
complex, which is required for their expression. Moreover, the 53BP1-TIRR
complex dissociates after DNA damage, and this dissociation may be ataxia
telangiectasia mutated-dependent. Similar to 53BP1, loss of TIRR restores PARPi
resistance in BRCA1-deficient cells. Collectively, our data identified a novel
53BP1-TIRR complex in DNA damage response. TIRR may play both positive and
negative roles in 53BP1 regulation. On the one hand, it stabilizes 53BP1 and
thus positively regulates 53BP1. On the other hand, its association with 53BP1
prevents 53BP1 localization to sites of DNA damage, and thus TIRR is also an
inhibitor of 53BP1. P53-binding protein 1 (53BP1) is a multi-functional double-strand break repair
protein that is essential for class switch recombination in B lymphocytes and
for sensitizing BRCA1-deficient tumours to poly-ADP-ribose polymerase-1 (PARP)
inhibitors. Central to all 53BP1 activities is its recruitment to double-strand
breaks via the interaction of the tandem Tudor domain with dimethylated lysine
20 of histone H4 (H4K20me2). Here we identify an uncharacterized protein, Tudor
interacting repair regulator (TIRR), that directly binds the tandem Tudor domain
and masks its H4K20me2 binding motif. Upon DNA damage, the protein kinase
ataxia-telangiectasia mutated (ATM) phosphorylates 53BP1 and recruits
RAP1-interacting factor 1 (RIF1) to dissociate the 53BP1-TIRR complex. However,
overexpression of TIRR impedes 53BP1 function by blocking its localization to
double-strand breaks. Depletion of TIRR destabilizes 53BP1 in the
nuclear-soluble fraction and alters the double-strand break-induced protein
complex centring 53BP1. These findings identify TIRR as a new factor that
influences double-strand break repair using a unique mechanism of masking the
histone methyl-lysine binding function of 53BP1. |
Which algorithm is used for detection of long repeat expansions? | Identifying large expansions of short tandem repeats (STRs), such as those that cause amyotrophic lateral sclerosis (ALS) and fragile X syndrome, is challenging for short-read whole-genome sequencing (WGS) data. A solution to this problem is an important step toward integrating WGS into precision medicine. For that purpose, ExpansionHunter has been developed as a software tool that, using PCR-free WGS short-read data, can genotype repeats at the locus of interest, even if the expanded repeat is larger than the read length. | Identifying large expansions of short tandem repeats (STRs), such as those that
cause amyotrophic lateral sclerosis (ALS) and fragile X syndrome, is challenging
for short-read whole-genome sequencing (WGS) data. A solution to this problem is
an important step toward integrating WGS into precision medicine. We developed a
software tool called ExpansionHunter that, using PCR-free WGS short-read data,
can genotype repeats at the locus of interest, even if the expanded repeat is
larger than the read length. We applied our algorithm to WGS data from 3001 ALS
patients who have been tested for the presence of the C9orf72 repeat expansion
with repeat-primed PCR (RP-PCR). Compared against this truth data,
ExpansionHunter correctly classified all (212/212, 95% CI [0.98, 1.00]) of the
expanded samples as either expansions (208) or potential expansions (4).
Additionally, 99.9% (2786/2789, 95% CI [0.997, 1.00]) of the wild-type samples
were correctly classified as wild type by this method with the remaining three
samples identified as possible expansions. We further applied our algorithm to a
set of 152 samples in which every sample had one of eight different pathogenic
repeat expansions, including those associated with fragile X syndrome,
Friedreich's ataxia, and Huntington's disease, and correctly flagged all but one
of the known repeat expansions. Thus, ExpansionHunter can be used to accurately
detect known pathogenic repeat expansions and provides researchers with a tool
that can be used to identify new pathogenic repeat expansions. |
Which brain tumors does neuroligin-3 promote? | Neuroligin-3 promotes the growth of high-grade gliomas. | |
Which web resource for LIR motif-containing proteins in eukaryotes has been developed? | In the past few years it has been revealed that Atg8-interacting proteins include not only receptors but also components of the core autophagic machinery, proteins associated with vesicles and their transport, and specific proteins that are selectively degraded by autophagy. Atg8-interacting proteins contain a short linear LC3-interacting region/LC3 recognition sequence/Atg8-interacting motif (LIR/LRS/AIM) motif which is responsible for their interaction with Atg8-family proteins. These proteins are referred to as LIR-containing proteins (LIRCPs). So far, many experimental efforts have been carried out to identify new LIRCPs, leading to the characterization of some of them in the past 10 years. Given the need for the identification of LIRCPs in various organisms, the iLIR database ( https://ilir.warwick.ac.uk ) has been developed as a freely available web resource, listing all the putative canonical LIRCPs identified in silico in the proteomes of 8 model organisms using the iLIR server, combined with a Gene Ontology (GO) term analysis. | Atg8-family proteins are the best-studied proteins of the core autophagic
machinery. They are essential for the elongation and closure of the phagophore
into a proper autophagosome. Moreover, Atg8-family proteins are associated with
the phagophore from the initiation of the autophagic process to, or just prior
to, the fusion between autophagosomes with lysosomes. In addition to their
implication in autophagosome biogenesis, they are crucial for selective
autophagy through their ability to interact with selective autophagy receptor
proteins necessary for the specific targeting of substrates for autophagic
degradation. In the past few years it has been revealed that Atg8-interacting
proteins include not only receptors but also components of the core autophagic
machinery, proteins associated with vesicles and their transport, and specific
proteins that are selectively degraded by autophagy. Atg8-interacting proteins
contain a short linear LC3-interacting region/LC3 recognition
sequence/Atg8-interacting motif (LIR/LRS/AIM) motif which is responsible for
their interaction with Atg8-family proteins. These proteins are referred to as
LIR-containing proteins (LIRCPs). So far, many experimental efforts have been
carried out to identify new LIRCPs, leading to the characterization of some of
them in the past 10 years. Given the need for the identification of LIRCPs in
various organisms, we developed the iLIR database ( https://ilir.warwick.ac.uk )
as a freely available web resource, listing all the putative canonical LIRCPs
identified in silico in the proteomes of 8 model organisms using the iLIR
server, combined with a Gene Ontology (GO) term analysis. Additionally, a
curated text-mining analysis of the literature permitted us to identify novel
putative LICRPs in mammals that have not previously been associated with
autophagy. |
What is liquid liquid phase transition? | The influence of membrane-free microcompartments resulting from crowding-induced liquid/liquid phase separation (LLPS) on the dynamic spatial organization of FtsZ, the main component of the bacterial division machinery, has been studied using several LLPS systems. | Author information:
(1)Department of Molecular Medicine and USF Health Byrd Alzheimer's Research
Institute, Morsani College of Medicine, University of South Florida, Tampa, FL,
USA; Institute for Biological Instrumentation, Russian Academy of Sciences,
Pushchino, Moscow Region, Russian Federation; Biology Department, Faculty of
Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia;
Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute
of Cytology, Russian Academy of Sciences, St. Petersburg, Russian Federation.
Electronic address: [email protected].
(2)Laboratory of Structural Dynamics, Stability and Folding of Proteins,
Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russian
Federation; St. Petersburg State Polytechnical University, St. Petersburg,
Russian Federation.
(3)AnalizaDx Inc., 3615 Superior Ave., Suite 4407B, Cleveland, OH 44114, USA. The influence of membrane-free microcompartments resulting from crowding-induced
liquid/liquid phase separation (LLPS) on the dynamic spatial organization of
FtsZ, the main component of the bacterial division machinery, has been studied
using several LLPS systems. The GTP-dependent assembly cycle of FtsZ is thought
to be crucial for the formation of the septal ring, which is highly regulated in
time and space. We found that FtsZ accumulates in one of the phases and/or at
the interface, depending on the system composition and on the oligomerization
state of the protein. These results were observed both in bulk LLPS and in
lipid-stabilized, phase-separated aqueous microdroplets. The visualization of
the droplets revealed that both the location and structural arrangement of FtsZ
filaments is determined by the nature of the LLPS. Relocation upon
depolymerization of the dynamic filaments suggests the protein may shift among
microenvironments in response to changes in its association state. The existence
of these dynamic compartments driven by phase transitions can alter the local
composition and reactivity of FtsZ during its life cycle acting as a nonspecific
modulating factor of cell function. Pathological developments leading to amyotrophic lateral sclerosis (ALS) and
frontotemporal lobar degeneration (FTLD) are associated with misbehavior of
several key proteins, such as SOD1 (superoxide dismutase 1), TARDBP/TDP-43, FUS,
C9orf72, and dipeptide repeat proteins generated as a result of the translation
of the intronic hexanucleotide expansions in the C9orf72 gene, PFN1 (profilin
1), GLE1 (GLE1, RNA export mediator), PURA (purine rich element binding protein
A), FLCN (folliculin), RBM45 (RNA binding motif protein 45), SS18L1/CREST,
HNRNPA1 (heterogeneous nuclear ribonucleoprotein A1), HNRNPA2B1 (heterogeneous
nuclear ribonucleoprotein A2/B1), ATXN2 (ataxin 2), MAPT (microtubule associated
protein tau), and TIA1 (TIA1 cytotoxic granule associated RNA binding protein).
Although these proteins are structurally and functionally different and have
rather different pathological functions, they all possess some levels of
intrinsic disorder and are either directly engaged in or are at least related to
the physiological liquid-liquid phase transitions (LLPTs) leading to the
formation of various proteinaceous membrane-less organelles (PMLOs), both normal
and pathological. This review describes the normal and pathological functions of
these ALS- and FTLD-related proteins, describes their major structural
properties, glances at their intrinsic disorder status, and analyzes the
involvement of these proteins in the formation of normal and pathological PMLOs,
with the ultimate goal of better understanding the roles of LLPTs and intrinsic
disorder in the "Dr. Jekyll-Mr. Hyde" behavior of those proteins. |
Can CD55 deficiency cause thrombosis? | Yes, loss of CD55 is associated with thrombosis in patients with Paroxysmal nocturnal hemoglobinuria. CD55 deficiency with hyperactivation of complement, angiopathic thrombosis, and protein-losing enteropathy (the CHAPLE syndrome) is caused by abnormal complement activation due to biallelic loss-of-function mutations in CD55 | Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal disorder
characterized by a decrease or absence of glycosylphosphatidylinositol
(GPI)-anchored molecules such as CD55 and CD59 from the surface of affected
cells, resulting in intravascular hemolysis, cytopenia, and venous thrombosis. A
PNH-like phenotype has been detected in various hematological disorders, mainly
in aplastic anemia and myelodysplastic syndromes, but also in
lymphoproliferative syndromes (LPSs). To the best of our knowledge, CD55- or
CD59-deficient red cells have not been detected in plasma cell dyscrasias
(PCDs). The aim of this study was the detection of CD55- and/or CD59-deficient
red cell populations in patients with PCD. Seventy-seven patients were
evaluated; 62 with multiple myeloma (MM), 7 with Waldenstrom macroglobulinemia
(WM), 6 with monoclonal gammopathy of undetermined significance (MGUS), and 2
with heavy chain disease (HCD). The sephacryl gel microtyping system was
applied; Ham and sucrose lysis tests were also performed on all samples with
CD55- or CD59-negative populations. Red cells deficient in both molecules were
detected in 10 (12.9%) of 77 patients with PCD: 2 (28.6%) of 7 with WM, 1
(16.6%) of 6 with MGUS, 6 (9.6%) of 62 with MM, and 1 of 2 patients with HCD.
Isolated CD55 deficiency was found in 28.5% of all PCD patients, whereas
isolated CD59 deficiency was not observed in any patients. These findings
illustrate the existence of the PNH phenotype in the red cells of patients with
PCD; further investigation is needed into the mechanisms and significance of
this phenotype. Paroxysmal nocturnal hemoglobinuria (PNH) is a rare acquired disease
characterized by a clone of blood cells lacking glycosyl phosphatidylinositol
(GPI)-anchored proteins at the cell membrane. Deficiency of the GPI-anchored
complement inhibitors CD55 and CD59 on erythrocytes leads to intravascular
hemolysis upon complement activation. Apart from hemolysis, another prominent
feature is a highly increased risk of thrombosis. Thrombosis in PNH results in
high morbidity and mortality. Often, thrombosis occurs at unusual locations,
with the Budd–Chiari syndrome being the most frequent manifestation. Primary
prophylaxis with vitamin K antagonists reduces the risk but does not completely
prevent thrombosis. Eculizumab, a mAb against complement factor C5, effectively
reduces intravascular hemolysis and also thrombotic risk. Therefore, eculizumab
treatment has dramatically improved the prognosis of PNH. The mechanism of
thrombosis in PNH is still unknown, but the highly beneficial effect of
eculizumab on thrombotic risk suggests a major role for complement activation.
Additionally, a deficiency of GPI-anchored proteins involved in hemostasis may
be implicated. Intra-abdominal thrombosis is a complication of paroxysmal nocturnal
hemoglobinuria (PNH). There is scarcity of data on cases presenting with
thrombosis in whom PNH is the predisposing factor. We assessed the role of PNH
defect in 81 patients with intra-abdominal thrombosis, 44 patients of Budd
Chiari syndrome and 37 patients of extra hepatic venous obstruction.
Flowcytometry with glycosylphosphatidyl inositol-anchored proteins
(GPI-AP)-CD55, -CD59, and -CD16 was performed on all patients and controls to
assess the prevalence of deficiencies and PNH-type phenotype clone size.
Deficiencies of individual GPI-AP were seen in 17.3% cases versus 3.4% controls.
This was due to CD55 deficiency on red blood cells and CD16 deficiency on the
granulocytes. Deficiency of multiple GPI-APs was less frequent (3.7% cases).
Data of this study indicate that the PNH defect as detected with CD55, CD59, and
CD16 is not an important cause of intra-abdominal thrombosis in northwestern
India. BACKGROUND AND AIM: Routine screening for paroxysmal nocturnal hemoglobinuria
(PNH) in patients with Budd-Chiari syndrome (BCS) or portal vein thrombosis
(PVT) has been recommended in Western countries. However, little is known about
whether the routine screening test should be necessary in Chinese patients with
BCS or PVT. We conducted a prospective observational study to examine the
prevalence of PNH in these patients.
METHODS: Patients with primary BCS or non-maligt PVT who were consecutively
admitted to our department or regularly followed up between September 2009 and
December 2011 were eligible for the study and detected the expression of CD55
and CD59 on erythrocytes and granulocytes. The CD55 or CD59 deficiency was
considered as the proportion of erythrocytes or granulocytes with normal
expression of CD55 or CD59 was less than 90%. PNH was diagnosed by both CD55 and
CD59 deficient clone at flow cytometry of peripheral blood cells.
RESULTS: CD55 and/or CD59 deficiencies were found in 1.6% (2/127) of patients
with primary BCS, 1.0% (1/100) of non-maligt and non-cirrhotic patients with
PVT, and 4.7% (4/85) of cirrhotic patients with PVT. Only one patient had both
CD55 and CD59 deficiencies on granulocytes. But he had been diagnosed with PNH
before BCS.
CONCLUSIONS: Paroxysmal nocturnal hemoglobinuria was very rare in Chinese
patients with BCS or PVT, suggesting that routine screening for PNH should not
be indiscriminately performed in such patients. PURPOSE: To report on isolated central retinal artery occlusion (CRAO) as an
initial presentation in two patients with undiagnosed paroxysmal nocturnal
hemoglobinuria (PNH).
METHODS: CRAO related to the aggravation of PNH was observed in 2 of 98
consecutive PNH patients for 10 years. Ocular and systemic manifestations were
evaluated before and after systemic steroid, eculizumab and anticoagulant
administration with adjuvant ocular treatments.
RESULTS: Two young patients presented with complaints of acute painless
monocular vision loss. In both cases, fundus examination revealed retinal edema
and a cherry-red spot in the macula, consistent with CRAO. On systemic
evaluation, severe anemia and thrombocytopenia were observed, and simultaneously
thrombogenic processes were suggested by increased D-dimers, fibrinogen
degradation products and/or portal vein thrombosis. PNH testing of red blood
cells revealed a CD55 and CD59 deficiency consistent with PNH in both cases. The
systemic complications typically associated with thrombosis were not observed
for the following several months with early conservative treatments including
eculizumab.
CONCLUSIONS: Acute blindness from CRAO can be a unique manifestation of
undiagnosed PNH and its subsequent aggravation. Systemic evaluations including
PNH testing, especially in young CRAO patients, are strongly recommended for
early detection of the further systemic thrombogenic processes. Paroxysmal nocturnal hemoglobinuria (PNH) is a rare bone marrow failure disorder
that manifests with hemolytic anemia, thrombosis, and peripheral blood
cytopenias. The absence of two glycosylphosphatidylinositol (GPI)-anchored
proteins, CD55 and CD59, leads to uncontrolled complement activation that
accounts for hemolysis and other PNH manifestations. GPI anchor protein
deficiency is almost always due to somatic mutations in phosphatidylinositol
glycan class A (PIGA), a gene involved in the first step of GPI anchor
biosynthesis; however, alternative mutations that cause PNH have recently been
discovered. In addition, hypomorphic germ-line PIGA mutations that do not cause
PNH have been shown to be responsible for a condition known as multiple
congenital anomalies-hypotonia-seizures syndrome 2. Eculizumab, a first-in-class
monoclonal antibody that inhibits terminal complement, is the treatment of
choice for patients with severe manifestations of PNH. Bone marrow
transplantation remains the only cure for PNH but should be reserved for
patients with suboptimal response to eculizumab. Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hemolytic anemia with
highly variable clinical symptoms making the diagnosis and prediction of its
outcome difficult. It is caused by the expansion of a hematopoietic progenitor
cell that has acquired a mutation in the X-linked phosphatidylinositol glycan
class A (PIGA) gene that results in deficiency of the
glycosylphosphatidylinositol anchor structure responsible for fixing a wide
spectrum of proteins particularly CD55 and CD59. The clinical features of this
disease arise as a result of complement-mediated hemolysis in unprotected red
cells, leukocytes, and platelets as well as the release of free hemoglobin.
Patients may present with a variety of clinical manifestations, such as anemia,
thrombosis, kidney disease, smooth muscle dystonias, abdominal pain, dyspnea,
and extreme fatigue. PNH is an outstanding example of how an increased
understanding of pathophysiology may directly improve clinical symptoms and
treat disease-associated complications when we inhibit the terminal complement
cascade. This topic will discuss PNH overview to assist specialists looking
after PNH patients. Paroxysmal nocturnal haemoglobinuria (PNH) is a clonal haematopoietic stem cell
(HSC) disease that presents with haemolytic anaemia, thrombosis and smooth
muscle dystonias, as well as bone marrow failure in some cases. PNH is caused by
somatic mutations in PIGA (which encodes phosphatidylinositol
N-acetylglucosaminyltransferase subunit A) in one or more HSC clones. The gene
product of PIGA is required for the biosynthesis of glycosylphosphatidylinositol
(GPI) anchors; thus, PIGA mutations lead to a deficiency of GPI-anchored
proteins, such as complement decay-accelerating factor (also known as CD55) and
CD59 glycoprotein (CD59), which are both complement inhibitors. Clinical
manifestations of PNH occur when a HSC clone carrying somatic PIGA mutations
acquires a growth advantage and differentiates, generating mature blood cells
that are deficient of GPI-anchored proteins. The loss of CD55 and CD59 renders
PNH erythrocytes susceptible to intravascular haemolysis, which can lead to
thrombosis and to much of the morbidity and mortality of PNH. The accumulation
of anaphylatoxins (such as C5a) from complement activation might also have a
role. The natural history of PNH is highly variable, ranging from quiescent to
life-threatening. Therapeutic strategies include terminal complement blockade
and bone marrow transplantation. Eculizumab, a monoclonal antibody complement
inhibitor, is highly effective and the only licensed therapy for PNH. Author information:
(1)From the Section of Molecular Development of the Immune System, Laboratory of
Immunology (A.O., W.A.C., A.R.M., H.F.M., M.J.L.), the Clinical Genomics Program
(A.O., W.A.C., A.R.M., Y.Z., H.F.M., H.C.S., M.J.L.), and the Human
Immunological Diseases Section, Laboratory of Host Defenses (Y.Z., H.C.S.),
National Institute of Allergy and Infectious Diseases, the Laboratory of
Pathology, National Cancer Institute (S.P.), and Radiology and Imaging Sciences,
Clinical Center (L.R.F.), National Institutes of Health, Bethesda, MD; the
Department of Pediatrics, Division of Allergy and Immunology (A.O., E.K.-A.,
S.B., A. Kiykim, I.O.), and the Department of Pediatrics, Division of Pediatric
Gastroenterology, Hepatology, and Nutrition (E.T., D.E.), Marmara University,
Jeffrey Modell Diagnostic Center for Primary Immunodeficiency Diseases (A.O.,
E.K.-A., S.B., A. Kiykim, I.O.), and the Department of Pediatrics, Division of
Pediatric Gastroenterology, Hepatology, and Nutrition, İstanbul University
Cerrahpaşa Faculty of Medicine (Ö.F.B., T.E.), Istanbul, and the Department of
Pediatrics, Division of Pediatric Gastroenterology, Hepatology, and Nutrition,
Gazi University (B.D., S.S.), the Department of Pediatric Gastroenterology,
Hepatology, and Nutrition, Faculty of Medicine, Başkent University (F.O., Z.B.,
M.G.), and the Pediatric Gastroenterology Clinic, Dr. Sami Ulus Children's
Hospital (A.U.A.), Ankara - all in Turkey; Ludwig Boltzmann Institute for Rare
and Undiagnosed Diseases and the CeMM Research Center for Molecular Medicine of
the Austrian Academy of Sciences (R.C.A., C.D.C., N.K.S., A. Krolo, K.B.),
Clinical Institute of Pathology (R.K.), the Department of Pediatrics and
Adolescent Medicine (K.B.), and St. Anna Kinderspital and Children's Cancer
Research Institute, Department of Pediatrics (K.B.), Medical University of
Vienna, Vienna; Merck Research Laboratories (J.J.M.), and the Division of
Gastroenterology, Hepatology, and Nutrition, Boston Children's Hospital, Harvard
Medical School (S.B.S.), Boston; and the Department of Pediatric
Gastroenterology, University Medical Center-Wilhelmina Children's Hospital
(R.H.J.H.), and the Department of Rheumatology and Clinical Immunology,
University Medical Center (H.L.L.), Utrecht, the Netherlands. |
What is the approximate size of gas vesicles? | The diameter of gas vesicles is approximately 100nm. | When observed in the electron microscope intact gas vesicles appeared as
transparent areas in whole cells of Microcylus aquaticus, whereas vesicles
collapsed by centrifugation were not discernible. Within 5 min of suspending
cells containing collapsed vesicles in growth medium, small transparent vesicles
were detected. By 15 min the average number of vesicles per cell was 15. This
number remained relatively constant while the size of the vesicles increased
until they attained their maximum diamtere of 100 nm. At this time the vesicles,
interpreted as biconical structures, began to elongate presumably due to the
synthesis of the cylindrical midsection. Closely correlated with the time at
which vesicles began to elongate was the initiation of smaller vesicles which
resulted in a doubling of the number of vesicles per cell by 90 min. This
evidence coupled with the isolation of a mutant which assembles only the conical
portions of the vesicle suggests that assembly occurs in two distinct stages
subject to genetic mutation. Protein and ribonucleic acid synthesis, and
presumably adenosine triphosphate formation, were required for gas vesicle
assembly. In addition, inhibition of protein or ribonucleic acid synthesis
resulted in a loss of extant gas vesicles. Over the time course of our study,
deoxyribonucleic acid synthesis was not required for gas vesicle assembly or
stability. |
Are sleep apnea and snoring associated with cardiac arrhythmias? | Evidence supports a causal association of sleep apnea with the incidence and morbidity of hypertension, coronary heart disease, arrhythmia, heart failure, and stroke. | Cardiac arrhythmias during wakefulness and sleep in 15 patients with
sleep-induced obstructive apnea, and the effect of atropine and tracheostomy on
these arrhythmias were studied by continuous overnight Holter
electrocardiographic, respiratory and electroencephalographic recordings. Sleep
was characterized by marked sinus arrhythmia in 14, extreme sinus bradycardia (
less than 30 beats/minute) in six, asystole of 2.5 to 6.3 seconds in five,
second degree atrioventricular (A-V) block in two, and ventricular
arrhythmias--complex premature ventricular beats in 10 and ventricular
tachycardia in two. Arrhythmias during wakefulness were limited to premature
ventricular beats in six. Atropine administration was partially and tracheostomy
highly effective in preventing the majority of these arrhythmias during sleep.
Marked sinus arrhythmia during sleep is characteristic of the syndrome of
obstructive sleep apnea and is frequently accompanied by potentially
life-threatening tachy- and bradyarrhythmias. Possible mechanism of production
of these arrhythmias, the mode of action of tracheostomy and atropine, and the
probable role of similar arrhythmias in the sudden infant death syndrome are
discussed. Obstructive sleep apnea (OSA) is a syndrome in which the airflow created from
breathing ceases through the upper airway although diaphragm movement continues.
Resulting complications include severe daytime sleepiness, morning headaches,
loud snoring, and disturbed nighttime sleep. Patients affected with OSA are
frequently hypertensive and can have dangerous cardiac arrhythmias. The
diagnosis of OSA requires an all-night polysomnographic recording; neither
snoring nor other subjective complaints constitute adequate criteria for
treatment. The treatment objective for OSA is to maintain airway patency. A
potential treatment discussed here is temporary advancement of the mandible or
tongue during sleep with the use of dental appliances. Sleep-related breathing disorders may contribute to the nocturnal peak in human
mortality. Nocturnal hypoxia has been associated with serious ventricular
tachyarrhythmias as well as life-threatening bradyarrhythmias. Obesity and
snoring, both of which increase with age, have been identified as risk factors
for sleep-related breathing disorders, as have hypertension and heart disease. We investigated the frequency of cardiac arrhythmias in patients suspected of
having sleep apnea, and related them to the severity of apnea, snoring, and
nocturnal hypoxemia. We prospectively studied 458 patients who had nocturnal
polysomnography which included objective measurement of snoring (quantified by
the number of snores per hour of sleep [snoring index (SI)] and maximum
nocturnal sound intensity [(dBmax)], as well as examination of the
electrocardiogram (modified lead 2). We found 58 percent prevalence of
arrhythmias in patients with sleep apnea (apnea/hypopnea index = AHI > 10), vs
42 percent in nonapneic controls (chi 2 = 16.7, p < 0.0001). Patients with
arrhythmias had more severe apnea and nocturnal hypoxemia, but not snoring, than
patients without arrhythmias. To examine separately the relationship between the
prevalence of arrhythmias and snoring, nocturnal oxygenation, and apnea--we
selected subgroups of patients "at the opposite ends of the spectrum" with
respect to the severity of snoring, hypoxemia, and apnea. We found that 38
percent of light snorers had arrhythmias vs 39 percent of heavy snorers, 82
percent of patients with mean nocturnal oxygen saturation < 90 percent had
arrhythmias vs 40 percent of patients with mean nocturnal oxygen saturation > 90
percent (chi 2 = 7.4, p = 0.006), and 70 percent of patients with AHI > or = 40
had arrhythmias vs 42 percent with AHI < or = (chi 2 = 9.2, p = 0.002). We
conclude that patients with sleep apnea as a group have higher prevalence of
cardiac arrhythmias than nonapneic patients and that snoring alone, without
concomitant sleep apnea, is not associated with increased frequency of cardiac
arrhythmias. Patients with stable cardiac failure who snore may present sleep hypopnea and
cardiac arrhythmias. Nasal continuous positive airway pressure (CPAP) may worsen
the disordered breathing. Nasal bilevel positive airway pressure (BiPAP),
however, may help alleviate the breathing problem and eliminate sleep-related
arrhythmias. Sleep-disordered breathing is very common and is associated with an increased
risk of cardiovascular disease, cardiac arrhythmia and stroke. There are two
types of sleep apnea: obstructive and central. The objective of this review is
to provide a broad perspective of the pathophysiological and clinical aspects of
the two types of apnea and to discuss their cardiovascular adverse effects. The
diagnosis of sleep apnea syndrome is based on polysomnography, and severity is
measured with an apnea-hypopnea index that counts the total number of apneas per
hour of sleep. Recent large epidemiologic studies have shown that sleep apnea
affects about 16% of men and 5% of women between 30 and 65 years of age.
Obstructive sleep apnea is characterized by abnormal collapse of the pharyngeal
airway during sleep, snoring, vigorous inspiratory efforts causing frequent
arousal, and excessive daytime drowsiness. Central sleep apnea with
Cheyne-Stokes respiration is a form of periodic breathing with frequent periods
of hyperventilation, and carries a poor prognosis in patients with heart
failure. Obstructive apnea can also have substantial health consequences.
Although the exact mechanism linking sleep apnea with cardiovascular disease is
unknown, there is evidence that obstructive apnea is associated with a group of
proinflammatory and prothrombic factors that are also important in the
development of atherosclerosis. Nocturnal and daytime sympathetic activity is
elevated after sleep apnea. Autonomic abnormalities include an increased resting
heart rate, decreased cardiac rhythm activity, and increased blood pressure
variability. Obstructive apnea is associated with endothelial dysfunction,
increased C-reactive protein and cytokine expression, elevated fibrinogen levels
and decreased fibrinolytic activity. Enhanced platelet activity and aggregation,
leukocyte adhesion and accumulation of endothelial cells are common in both
obstructive apnea and atherosclerosis. Surges in sympathetic activity, blood
pressure, ventricular wall tension and afterload adversely affect ventricular
function. Many studies have shown that patients with obstructive apnea have an
increased incidence of daytime hypertension, and this syndrome is recognized as
an independent risk factor for hypertension. Obstructive apnea is associated
with myocardial ischemia (silent or symptomatic), acute coronary events, stroke
and transient ischemic attacks, cardiac arrhythmia, pulmonary hypertension and
heart failure. Central sleep apnea is frequent in severe heart failure. Most
heart failure patients with pulmonary congestion chronically hyperventilate
because of stimulation of vagal irritant receptors and central and peripheral
chemosensitivity. When PaCO2 falls below the threshold required to stimulate
breathing, the central drive to respiratory muscles and air inflow ceases and
central apnea ensues. Apnea, hypoxia, CO2 retention and arousals provoke
elevated sympathetic activity, increased afterload and elevated left ventricular
transmural pressure, and promote the progression of heart failure. Tentative
relationships have been identified between central apnea and markers of
inflammation, oxidative stress and endothelial dysfunction. Recent mid-terms
trials showed that nocturnal use of positive airway pressure in patients with
the two types of apnea alleviates symptoms, reduces sympathetic activity,
improves ventricular function and quality of life, and reduces daytime
drowsiness. More studies are needed to understand the mechanisms underlying the
relationship between sleep apnea and cardiovascular disease, but clinicians
should be aware of this link and should attempt to identify patients with these
syndromes. Obstructive sleep apnea (OSA) is the most common form of sleep-disordered
breathing, affecting 5-15% of the population. It is characterized by
intermittent episodes of partial or complete obstruction of the upper airway
during sleep that disrupts normal ventilation and sleep architecture, and is
typically associated with excessive daytime sleepiness, snoring, and witnessed
apneas. Patients with obstructive sleep apnea present risk to the general public
safety by causing 8-fold increase in vehicle accidents, and they may themselves
also suffer from the physiologic consequences of OSA; these include
hypertension, coronary artery disease, stroke, congestive heart failure,
pulmonary hypertension, and cardiac arrhythmias. Of these possible
cardiovascular consequences, the association between OSA and hypertension has
been found to be the most convincing. Although the exact mechanism has not been
understood, there is some evidence that OSA is associated with frequent apneas
causing mechanical effects on intrathoracic pressure, cardiac function, and
intermittent hypoxemia, which may in turn cause endothelial dysfunction and
increase in sympathetic drive. Therapy with continuous positive airway pressure
has been demonstrated to improve cardiopulmonary hemodynamics in patients with
OSA and may reverse the endothelial cell dysfunction. Despite the availability
of diagnostic measures and effective treatment, many patients with
sleep-disordered breathing remain undiagnosed. Therefore, OSA continues to be a
significant health risk both for affected individuals and for the general
public. Awareness and timely initiation of an effective treatment may prevent
potential deleterious cardiovascular effects of OSA. BACKGROUND AND PURPOSE: Nocturnal cardiac arrhythmias occur in patients with
obstructive sleep apnea (OSA), reportedly as a consequence of the autonomic
effects of recurrent apnea with subsequent oxygen desaturation. We have
investigated whether different patterns of OSA are associated with specific
arrhythmia during sleep.
PATIENTS AND METHODS: Electrocardiographic (ECG) data recorded during
polysomnography (PSG) were analysed in 257 consecutive OSA patients to determine
the prevalence of cardiac rhythm disturbances, and to relate these to breathing
pattern (normal, apnea/hypopnea, recovering ventilation, snoring) and oxygen
saturation.
RESULTS: Arrhythmias were found in 18.5% of patients. Patients with nocturnal
bradyarrhythmia (BA) had higher values of ventilatory disturbance
(apnea-hypopnea index [AHI] 58.8+/-36.8 vs 37.2+/-30.3, p=0.02), mean
desaturation amplitude (8.9+/-4 vs 5.9+/-3.4%, p=0.03), and a lower SaO(2) nadir
(69% vs 77%, p=0.003) than those without arrhythmia. The prevalence of BA in
patients with AHI>or=30/h was significantly higher than that observed in those
with AHI<30/h (7.8% vs 1.5%, respectively; chi(2)=5.61, p=0.01). In contrast,
patients with tachyarrhythmia (TA) had no significant differences in AHI, mean
desaturation amplitude or SaO(2) nadir than those without arrhythmia. No
associations were found between arrhythmia and the presence of comorbidity or
concomitant medical therapy, except for an association between tachyarrhythmia
and chronic obstructive pulmonary disease (COPD) (odds ratio 2.53; 95%
confidence intervals 1.1-5.8, p=0.03).
CONCLUSIONS: We conclude that while BA during sleep is associated with OSA
severity, concomitant COPD or beta(2)-treatment may play a role in the
development of TA during sleep. Sleep-disordered breathing (SDB), which includes obstructive sleep apnea (OSA)
as its most extreme variant, is characterized by intermittent episodes of
partial or complete obstruction of the upper airway, leading to cessation of
breathing while asleep. Cardiac arrhythmias are common problems in OSA patients,
although the true prevalence and clinical relevance of cardiac arrhythmias
remains to be determined. The presence and complexity of tachyarrhythmias and
bradyarrhythmias may influence morbidity, mortality and quality of life for
patients with OSA. Although the exact mechanisms underlying the link between OSA
and cardiac arrhythmias are not well established, they could be some of the same
proposed mechanisms relating OSA to different cardiovascular diseases, such as
repetitive pharyngeal collapse during sleep, which leads to markedly reduced or
absent airflow, followed by oxyhemoglobin desaturation, persistent inspiratory
efforts against an occluded airway and termination by arousal from sleep. These
mechanisms elicit a variety of autonomic, hemodynamic, humoral and
neuroendocrine responses that evoke acute and chronic changes in cardiovascular
function. However, despite substantial research effort, the goals of determining
in advance which patients will respond most favorably to certain treatment
options (such as continuous positive airway pressure, tracheostomy or
cardioversion) and the developing alternative treatments remain largely elusive.
Therefore, this literature review aims to summarize a broad array of the
pathophysiological mechanisms underlying the relationship between OSA and
cardiac arrhythmias and the extent of this association from an epidemiological
perspective, thereby attempting to assess the effects of OSA treatment on the
presence of cardiac arrhythmias. Obstructive sleep apnea and central sleep apnea with Cheyne-Stokes respiration
are associated with an increased risk of cardiac arrhythmia. Apnea- associated
arrhythmia may contribute to sudden cardiac death and premature mortality in
those patients. Both forms of sleep apnea excert strong modulatory effects on
the autonomic system with a special autonomic profile. Profound vagal activity
is leading to bradyarrhythmias, and sypathico-excitation to tachyarrhythmias.
Atrial fibrillation and ventricular arrhythmias in obstructive and central sleep
apnea patients are mainly found in combination with cardiovascular comorbidity
(coronary heart disease, hypertensive heart disease, chronic heart failure).
Bradyarrhythmias in OSA are induced by a cardioinhibitory vagal reflex due to
obstructed airway. CPAP-therapy has been demonstrated to reduce arrhythmias. Various cardiac arrhythmias frequently occur in patients with sleep apnea, but
complex analysis of the relationship between their severity and the probable
arrhythmogenic risk factors is conflicting. The question is what cardiovascular
risk factors and how strongly they are associated with the severity of cardiac
arrhythmias in sleep apnea. Adult males (33 with and 16 without sleep apnea),
matched for cardiovascular co-morbidity were studied by polysomnography with
simultaneous ECG monitoring. Arrhythmia severity was evaluated for each subject
by a special 7-degree scoring system. Laboratory, clinical, echocardiographic,
carotid ultrasonographic, ambulatory blood pressure, and baroreflex sensitivity
values were also assessed. Moderate sleep apnea patients had benign, but more
exaggerated cardiac arrhythmias than control subjects (2.53 ± 2.49 vs. 1.13 ±
1.64 degrees of cumulative severity, p < 0.05). We confirmed strong correlations
between the arrhythmia severity and known arrhythmogenic risk factors (left
ventricular ejection fraction and dimensions, right ventricular diameter,
baroreflex sensitivity, carotid intima-media thickness, age, previous myocardial
infarction, and also apnea-hypopnea index). In multivariate modelling only the
apnea-hypopnea index indicating the sleep apnea intensity remained highly
significantly correlated with the cumulative arrhythmia severity (beta = 0.548,
p < 0.005). In conclusion, sleep apnea modifying cardiovascular risk factors and
structures or functions provoked various nocturnal arrhythmias. The proposed
scoring system allowed a complex analysis of the contribution of various
triggers to arrhythmogenesis and confirmed the apnea-hypopnea index as an
independent risk for nocturnal cardiac arrhythmia severity in sleep apnea. Background: The mechanisms associated with the cardiovascular consequences of
obstructive sleep apnea include abrupt changes in autonomic tone, which can
trigger cardiac arrhythmias. The authors hypothesized that nocturnal cardiac
arrhythmia occurs more frequently in patients with obstructive sleep apnea.
Objective: To analyze the relationship between obstructive sleep apnea and
abnormal heart rhythm during sleep in a population sample. Methods:
Cross-sectional study with 1,101 volunteers, who form a representative sample of
the city of São Paulo. The overnight polysomnography was performed using an
EMBLA® S7000 digital system during the regular sleep schedule of the individual.
The electrocardiogram channel was extracted, duplicated, and then analyzed using
a Holter (Cardio Smart®) system. Results: A total of 767 participants (461 men)
with a mean age of 42.00 ± 0.53 years, were included in the analysis. At least
one type of nocturnal cardiac rhythm disturbance (atrial/ventricular arrhythmia
or beat) was observed in 62.7% of the sample. The occurrence of nocturnal
cardiac arrhythmias was more frequent with increased disease severity. Rhythm
disturbance was observed in 53.3% of the sample without breathing sleep
disorders, whereas 92.3% of patients with severe obstructive sleep apnea showed
cardiac arrhythmia. Isolated atrial and ventricular ectopy was more frequent in
patients with moderate/severe obstructive sleep apnea when compared to controls
(p < 0.001). After controlling for potential confounding factors, age, sex and
apnea-hypopnea index were associated with nocturnal cardiac arrhythmia.
Conclusion: Nocturnal cardiac arrhythmia occurs more frequently in patients with
obstructive sleep apnea and the prevalence increases with disease severity. Age,
sex, and the Apnea-hypopnea index were predictors of arrhythmia in this sample. BACKGROUND: Atrial fibrillation (AF) constitutes the most prevalent arrhythmia,
affecting up-to 2% of the general population. Apart from well-established risk
factors that increase the odds for the development of AF, e.g. age or arterial
hypertension, recent analyses indicate that obstructive sleep apnoea (OSA) may
independently, negatively modify the arrhythmia occur-rence profile.
Concurrently, erectile dysfunction (ED) is a commonly neglected, potent marker
of cardiovascular risk, which considerably worsens men's psychological state.
Unrecognised or untreated ED results in substantial deterioration of the
patient's therapeutic programme adherence. Because AF, OSA, and ED share
multiple risk factors and clinical consequences, in 2013 the concept of their
frequent concurrence - OSAFED syndrome - was proposed.
AIM: The aim of the study was to evaluate the prevalence of OSAFED patients with
AF in primary care practice.
METHODS: Retrospective analysis was carried out of data from primary care
physician charts (NZOZ Esculap Gniewkowo, central Poland) including 1372 men
aged 40-65 years. The primary goal was to determine the diagnosis of paroxysmal
and/or perma-nent AF, which was followed by sleep apnoea screening (polygraphy)
and erectile function evaluation (IIED-5 questionnaire).
RESULTS: Twenty-one (1.5%) patients with documented AF were identified. Based on
the sleep-polygraphic studies, 14 (67%) of them had confirmation of OSA with
mean apnoea-hypopnea index (AHI) equal to 27.5 ± 17.1. Furthermore, 11 (52%)
patients met the OSAFED syndrome criteria. Patients with OSAFED syndrome had a
mean score in IIEF-5 of 11.6 ± 3.5. The OSAFED-patients who were not diagnosed
with all the of the syndrome components prior to the study-enrolment were
characterised by substantially lower fat excess compared to their counterparts
with already established OSAFED (body mass index: 30.1 ± 4.9 vs. 37.7 ± 3.9
kg/m², respectively, p = 0.03).
CONCLUSIONS: Frequently coexisting OSAFED syndrome components in all AF patients
from the primary care setting should encourage a more active search for OSA and
ED in patients with any documented form of AF. Most of the studied patients did
not have the diagnosis of OSA nor ED done prior to participation in the study. Author information:
(1)Pulmonary and Sleep Division, Bethesda North Hospital, Cincinnati, Ohio.
Electronic address: [email protected].
(2)Respiratory Department, Institut Ricerca Biomèdica de Lleida, Hospital
Universitari Arnau de Vilanova, Lleida, Spain.
(3)Respiratory Department, Hospital Universitario de Valme, Sevilla, Spain.
(4)Department of Population Health Sciences and John Rankin Laboratory of
Pulmonary Medicine, University of Wisconsin-Madison, Madison, Wisconsin.
(5)Sleep Heart Program, the Ohio State University, Columbus, Ohio.
(6)Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts.
(7)Pulmonary, Critical Care and Sleep Medicine, University of California, San
Diego, California.
(8)Respiratory Department, Hospital Universitario de Politecnico La Fe,
Valencia, Spain.
(9)Cleveland Clinic Lerner College of Medicine, Case Western Reserve University,
Cleveland, Ohio.
(10)Division of Sleep Medicine/Department of Medicine, University of
Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania.
(11)Division of Pulmonary and Critical Care Medicine, Johns Hopkins University
School of Medicine, Baltimore, Maryland.
(12)Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts;
Beth Israel Deaconess Medical Center, Boston, Massachusetts.
(13)Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota. STUDY OBJECTIVES: Obstructive sleep apnea (OSA) is associated with increased
cardiovascular morbidity and mortality. Cardiac arrhythmias are common in
patients with OSA. However, the prevalence and significance of cardiac
arrhythmias in Asian patients with OSA are not well studied. The aim of this
study is to determine the prevalence of cardiac arrhythmias in patients with OSA
in Singapore and to evaluate possible factors that may predispose patients with
OSA to arrhythmias.
METHODS: A retrospective study of 2,019 patients was carried out from January
2011 to December 2012 at a sleep center in a tertiary medical center. Of the
population, 1,457 patients were found to have OSA and 144 patients were found to
have cardiac arrhythmias. Data collected included patient demographics,
comorbidities, and polysomnogram parameters.
RESULTS: The prevalence of cardiac arrhythmias in our OSA population is 8.0%,
compared to that of primary snorers at 4.8% (P = .015). The univariate analysis
revealed that older age, higher body mass index, comorbidities, and severity of
OSA, including apnea-hypopnea index (AHI), lowest oxygen saturation (LSAT) and
hypoxic time were correlated with a higher prevalence of cardiac arrhythmias (P
< .05). However, the multivariate analysis showed that only age and body mass
index were significantly correlated with arrhythmias. AHI, LSAT, and hypoxic
time were no longer statistically significant.
CONCLUSIONS: Our study demonstrated that cardiac arrhythmias are common in
patients with OSA in Singapore. It also suggests that given the different
demographics of our population, ethnicity may play a significant role in the
development of cardiovascular disease among patients with OSA.
COMMENTARY: A commentary on this article appears in this issue on page 1229. |
Are osteoclasts specialized in bone degradation? | Bone degradation is caused by osteoclasts, the normal bone-resorbing cells. | Bone degradation by osteoclasts depends on the formation of a sealing zone,
composed of an interlinked network of podosomes, which delimits the degradation
lacuna into which osteoclasts secrete acid and proteolytic enzymes. For
resorption to occur, the sealing zone must be coherent and stable for extended
periods of time. Using titanium roughness gradients ranging from 1 to 4.5 µm
R(a) as substrates for osteoclast adhesion, we show that microtopographic
obstacles of a length scale well beyond the range of the 'footprint' of an
individual podosome can slow down sealing-zone expansion. A clear inverse
correlation was found between ring stability, structural integrity and
sealing-zone translocation rate. Direct live-cell microscopy indicated that the
expansion of the sealing zone is locally arrested by steep, three-dimensional
'ridge-like barriers', running parallel to its perimeter. It was, however, also
evident that the sealing zone can bypass such obstacles, if pulled by
neighbouring regions, extending through flanking, obstacle-free areas. We
propose that sealing-zone dynamics, while being locally regulated by surface
roughness, are globally integrated via the associated actin cytoskeleton. The
effect of substrate roughness on osteoclast behaviour is significant in relation
to osteoclast function under physiological and pathological conditions, and may
constitute an important consideration in the design of advanced bone
replacements. In osteoclasts, Src controls podosome organization and bone degradation, which
leads to an osteopetrotic phenotype in src(-/-) mice. Since this phenotype was
even more severe in src(-/-)hck(-/-) mice, we examined the individual
contribution of Hck in bone homeostasis. Compared to wt mice, hck(-/-) mice
exhibited an osteopetrotic phenotype characterized by an increased density of
trabecular bone and decreased bone degradation, although osteoclastogenesis was
not impaired. Podosome organization and matrix degradation were found to be
defective in hck(-/-) osteoclast precursors (preosteoclast) but were normal in
mature hck(-/-) osteoclasts, probably through compensation by Src, which was
specifically overexpressed in mature osteoclasts. As a consequence of podosome
defects, the 3-dimensional migration of hck(-/-) preosteoclasts was strongly
affected in vitro. In vivo, this translated by altered bone homing of
preosteoclasts in hck(-/-) mice: in metatarsals of 1-wk-old mice, when bone
formation strongly depends on the recruitment of these cells, reduced numbers of
osteoclasts and abnormal developing trabecular bone were observed. This
phenotype was still detectable in adults. In summmary, Hck is one of the very
few effectors of preosteoclast recruitment described to date and thereby plays a
critical role in bone remodeling. |
List BET proteins. | BRD2
BRD3
BRD4
Bdf1 | Obesity is characterized by excessive accumulation of white adipose tissue.
Bromodomain-containing protein 2 (Brd2), which belongs to the bromodomain and
extraterminal domain family of proteins, suppresses adipocyte differentiation.
DNA methylation is critical for several differentiation processes and possibly
in adipocyte differentiation. However, whether DNA methylation regulates the
expression of Brd2 is not clear. In our study, we demonstrated that DNA
methylation contributes to the regulation of Brd2 expression during
pre-adipocyte differentiation. Brd2 mRNA levels were low in pre-adipocytes,
increased in early adipocytes, and declined in mature adipocytes. To test
whether and how Brd2 expression is regulated by DNA methylation during the
differentiation of 3T3-L1 pre-adipocytes to adipocytes, cells were cultured in
the presence of the methylation inhibitor 5-aza-2'-deoxycytidine (5-Aza).
Pre-adipocytes and adipocytes exposed to 5-Aza exhibited a dose-dependent
increase in Brd2 transcription levels, while only mature adipocytes exhibited
increased expression of Brd2 protein. Subsequently, we tested the DNA
methylation status of the Brd2 promoter region. Bisulfite-sequencing analysis
revealed that six CpG sites in two predicted promoters of Brd2 were demethylated
in early adipocytes and highly methylated in mature adipocytes. Digestion of
bisulfite-converted PCR products of the Brd2 promoter region from 3T3-L1 cells
with BstU1 (CGGC) revealed that the demethylation rate of the Brd2 promoter was
consistent with Brd2 mRNA expression in differentiating 3T3-L1 cells. In
conclusion, DNA demethylation of the Brd2 promoter region induced Brd2
expression during differentiation of 3T3-L1 cells into adipocytes. Uncovering new therapeutic targets for renal fibrosis holds promise for the
treatment of chronic kidney diseases. Bromodomain and extra-terminal (BET)
protein inhibitors have been shown to effectively ameliorate pathological
fibrotic responses. However, the pharmacological effects and underlying
mechanisms of these inhibitors in renal fibrosis remain elusive. In this study,
we determined that the inhibition of Brd4, a BET family member, with a selective
potent chemical inhibitor, JQ1, could prevent the development of renal fibrosis
and block the progression of fibrosis in rats that have undergone unilateral
ureteral obstruction (UUO). Inhibiting Brd4 with either JQ1 or genetic knockdown
resulted in decreased expression of fibrotic genes such as α-smooth muscle
actin, collagen IV and fibronectin both in UUO-induced fibrosis and upon TGF-β1
stimulation in HK-2 cells. Brd4 inhibition also suppressed the oxidative stress
induced by UUO in vivo or by TGF-β1 in HK-2 cells. Moreover, Nox4, which is
constitutively active in renal cells and is involved in the generation of
hydrogen peroxide, was up-regulated during UUO-mediated fibrosis and induced by
TGF-β1 in HK-2 cells, and this up-regulation could be blunted by Brd4
inhibition. Consistently, Nox4-mediated ROS generation and fibrotic gene
expression were attenuated upon Brd4 inhibition. Further, the transcriptional
activity of Nox4 was suppressed by JQ1 or siRNA against Brd4. Additionally,
Smad3 and ERK1/2 phosphorylation, which are upstream signals of Nox4 expression,
were inhibited both in JQ1-administered UUO rats and Brd4-inhibited HK-2 cells.
In conclusion, these results indicated that the inhibition of Brd4 might protect
against renal fibrosis by blocking the TGF-β-Nox4-ROS-fibrosis axis, suggesting
that Brd4 could be a promising therapeutic target. Bromodomain and Extra-terminal motif (BET) proteins play a central role in
transcription regulation and chromatin signalling pathways. They are present in
unicellular eukaryotes and in this study, the role of the BET protein Bdf1 has
been explored in Saccharomyces cerevisiae. Mutation of Bdf1 bromodomains
revealed defects on both the formation of spores and the meiotic progression,
blocking cells at the exit from prophase, before the first meiotic division.
This phenotype is associated with a massive deregulation of the transcription of
meiotic genes and Bdf1 bromodomains are required for appropriate expression of
the key meiotic transcription factor NDT80 and almost all the Ndt80-inducible
genes, including APC complex components. Bdf1 notably accumulates on the
promoter of Ndt80 and its recruitment is dependent on Bdf1 bromodomains. In
addition, the ectopic expression of NDT80 during meiosis partially bypasses this
dependency. Finally, purification of Bdf1 partners identified two independent
complexes with Bdf2 or the SWR complex, neither of which was required to
complete sporulation. Taken together, our results unveil a new role for Bdf1
-working independently from its predomit protein partners Bdf2 and the SWR1
complex-as a regulator of meiosis-specific genes. Myogenic differentiation proceeds through a highly coordinated cascade of gene
activation that necessitates epigenomic changes in chromatin structure. Using a
screen of small molecule epigenetic probes we identified three compounds which
inhibited myogenic differentiation in C2C12 myoblasts; (+)-JQ1, PFI-1, and
Bromosporine. These molecules target Bromodomain and Extra Terminal domain (BET)
proteins, which are epigenetic readers of acetylated histone lysine tail
residues. BETi-mediated anti-myogenic effects were also observed in a model of
MYOD1-mediated myogenic conversion of human fibroblasts, and in primary mouse
and human myoblasts. All three BET proteins BRD2, BRD3 and BRD4 exhibited
distinct and dynamic patterns of protein expression over the course of
differentiation without concomitant changes in mRNA levels, suggesting that BET
proteins are regulated at the post-transcriptional level. Specific BET protein
knockdown by RNA interference revealed that BRD4 was required for myogenic
differentiation, whereas BRD3 down-regulation resulted in enhanced myogenic
differentiation. ChIP experiments revealed a preferential binding of BRD4 to the
Myog promoter during C2C12 myoblast differentiation, co-incident with increased
levels of H3K27 acetylation. These results have identified an essential role for
BET proteins in the regulation of skeletal myogenesis, and assign distinct
functions to BRD3 and BRD4. |
Does temsirolimus improve survival of glioblastoma patients? | No. Temsirolimus does not prolong survival of gliobalstoma patients. | PURPOSE: Loss of PTEN, which is common in glioblastoma multiforme (GBM), results
in activation of the mammalian target of rapapmycin (mTOR), thereby increasing
mRNA translation of a number of key proteins required for cell-cycle
progression. CCI-779 is an inhibitor of mTOR. The primary objectives of this
study were to determine the efficacy of CCI-779 in patients with recurrent GBM
and to further assess the toxicity of the drug.
EXPERIMENTAL DESIGN: CCI-779 was administered weekly at a dose of 250 mg
intravenously for patients on enzyme-inducing anti-epileptic drugs (EIAEDs).
Patients not on EIAEDs were initially treated at 250 mg; however, the dose was
reduced to 170 mg because of intolerable side effects. Treatment was continued
until unacceptable toxicity, tumor progression, or patient withdrawal. The
primary endpoint was 6-month progression-free survival.
RESULTS: Forty-three patients were enrolled; 29 were not on EIAEDs. The expected
toxicity profile of increased lipids, lymphopenia, and stomatitis was seen.
There were no grade IV hematological toxicities and no toxic deaths. One patient
was progression free at 6 months. Of the patients assessable for response, there
were 2 partial responses and 20 with stabilization of disease. The median time
to progression was 9 weeks.
CONCLUSIONS: CCI-779 was well tolerated at this dose schedule; however, there
was no evidence of efficacy in patients with recurrent GBM. Despite initial
disease stabilization in approximately 50% of patients, the durability of
response was short. Because of the low toxicity profile, CCI-779 may merit
exploration in combination with other modalities. PURPOSE: A phase II study of temsirolimus was conducted in children and
adolescents with high-grade glioma, neuroblastoma or rhabdomyosarcoma.
PATIENTS AND METHODS: Temsirolimus 75 mg/m(2) was administered once weekly until
disease progression or intolerance. Using the Simon 2-stage design, further
enrolment in each disease cohort required ≥ 2 objective responses within the
first 12 weeks for the first 12 evaluable patients (those who received ≥ 3
temsirolimus doses).
RESULTS: Fifty-two heavily pretreated patients with relapsed (12%) or refractory
(88%) disease, median age 8 years (range 1-21 years), were enroled and treated.
One patient with neuroblastoma achieved confirmed partial response within the
first 12 weeks; thus, none of the 3 cohorts met the criterion for continued
enrolment. Disease stabilisation at week 12 was observed in 7 of 17 patients
(41%) with high-grade glioma (5 diffuse pontine gliomas, 1 glioblastoma
multiforme and 1 anaplastic astrocytoma), 6 of 19 (32%) with neuroblastoma and 1
of 16 (6%) with rhabdomyosarcoma (partial response confirmed at week 18). In the
three cohorts, median duration of stable disease or better was 128, 663 and 75
d, respectively. The most common treatment-related adverse events were
thrombocytopaenia, hyperlipidaemia and aesthenia. Pharmacokinetic findings were
similar to those observed in adults.
CONCLUSIONS: Temsirolimus administered weekly at the dose of 75 mg/m(2) did not
meet the primary objective efficacy threshold in children with high-grade
glioma, neuroblastoma or rhabdomyosarcoma; however, meaningful prolonged stable
disease merits further evaluation in combination therapy. The activity of single-agent targeted molecular therapies in glioblastoma has
been limited to date. The North American Brain Tumor Consortium examined the
safety, pharmacokinetics, and efficacy of combination therapy with sorafenib, a
small molecule inhibitor of Raf, vascular endothelial growth factor receptor 2,
and platelet-derived growth factor receptor-β, and temsirolimus (CCI-779), an
inhibitor of mammalian target of rapamycin. This was a phase I/II study. The
phase I component used a standard 3 × 3 dose escalation scheme to determine the
safety and tolerability of this combination therapy. The phase II component used
a 2-stage design; the primary endpoint was 6-month progression-free survival
(PFS6) rate. Thirteen patients enrolled in the phase I component. The maximum
tolerated dosage (MTD) for combination therapy was sorafenib 800 mg daily and
temsirolimus 25 mg once weekly. At the MTD, grade 3 thrombocytopenia was the
dose-limiting toxicity. Eighteen patients were treated in the phase II
component. At interim analysis, the study was terminated and did not proceed to
the second stage. No patients remained progression free at 6 months. Median PFS
was 8 weeks. The toxicity of this combination therapy resulted in a maximum
tolerated dose of temsirolimus that was only one-tenth of the single-agent dose.
Minimal activity in recurrent glioblastoma multiforme was seen at the MTD of the
2 combined agents. BACKGROUND: Pre-clinical findings suggest that combination treatment with
bevacizumab and temsirolimus could be effective against maligt pediatric
central nervous system (CNS) tumors.
PATIENTS AND METHODS: Six pediatric patients were treated as part of a phase I
trial with intravenous temsirolimus 25 mg on days 1, 8, 15, and bevacizumab at
5, 10, or 15 mg/kg on day 1 of each 21-day cycle until disease progression or
patient withdrawal.
RESULTS: The median patient age was six years (range=3-14 years). The primary
diagnoses were glioblastoma multiforme (n=2), medullobalstoma (n=2), pontine
glioma (n=1) and ependymoma (n=1). All patients had disease refractory to
standard-of-care (2-3 prior systemic therapies). Grade 3 toxicities possibly
related to drugs used occurred in two patients: anorexia, nausea, and weight
loss in one, and thrombocytopenia and alanine aminotransferase elevation in
another. One patient with glioblastoma multiforme achieved a partial response
(51% regression) and two patients (with medulloblastoma and pontine glioma) had
stable disease for four months or more (20 and 47 weeks, respectively). One
other patient (with glioblastoma multiforme) showed 18% tumor regression
(duration=12 weeks).
CONCLUSION: The combination of bevacizumab with temsirolimus was well-tolerated
and resulted in stable disease of at least four months/partial response in three
out of six pediatric patients with chemorefractory CNS tumors. Author information:
(1)Neurology Clinic, University of Heidelberg, Heidelberg, Germany. Clinical
Cooperation Unit (CCU) Neurooncology, German Cancer Consortium (DKTK), German
Cancer Research Center (DKFZ), Heidelberg, Germany.
[email protected].
(2)European Organisation for Research and Treatment of Cancer (EORTC), Lausanne,
Switzerland.
(3)SIB Swiss Institute of Bioinformatics, Lausanne, Switzerland. Neuroscience
Research Center, University Hospital Lausanne (CHUV), Lausanne, Switzerland.
(4)Neurology Clinic, University of Heidelberg, Heidelberg, Germany. CCU Brain
Tumor Immunology, DKFZ, Heidelberg, Germany.
(5)Department of Neurology/Neuro-Oncology, Erasmus MC - Cancer Institute,
Rotterdam, the Netherlands.
(6)Neuro-oncology Unit, MC Haaglanden, The Hague, the Netherlands.
(7)Department of Medical Oncology, Ospedale Bellaria, Bologna, Italy.
(8)Neuroscience Research Center, University Hospital Lausanne (CHUV), Lausanne,
Switzerland. Department of Neurosurgery, CHUV, Lausanne, Switzerland.
(9)Neurology Clinic, University of Heidelberg, Heidelberg, Germany.
(10)Pfizer, Berlin, Germany.
(11)Department of Neurology, University Hospital and University of Zurich,
Switzerland.
(12)Department of Neurosurgery, CHUV, Lausanne, Switzerland.
(13)1-Institut de Cancérologie de l'OUEST, Saint Herblain-Nantes Cedex, France.
(14)AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Service de Neurologie
2-Mazarin, UMR8257 MD4 Cognac G, CNRS, Service de Santé des Armées, Université
Paris Descartes, Paris, France.
(15)General Hospital AKH, Medical University Vienna, Austria.
(16)Institut Catala d'Oncologia (ICO), Hospital Germans Trias Pujol, Badalona,
Barcelona, Spain.
(17)Department of Neurosurgery, Medical Center, University of Freiburg, Germany.
(18)University Hospitals Bristol NHS Foundation Trust - Bristol Haematology and
Oncology Centre, Bristol, United Kingdom.
(19)Department of Oncology, CHUV, Lausanne, Switzerland.
(20)Institute of Pathology, CHUV, Lausanne, Switzerland.
(21)Department of Radio-oncology, Oncology Institute of Southern Switzerland,
Bellinzona, Switzerland. BACKGROUND: glioblastomas are highly vascularized tumors and various
antiangiogenic drugs have been investigated in clinical trials showing unclear
results. We performed a systematic review and a meta-analysis to clarify and
evaluate their effectiveness in glioblastoma patients.
PATIENTS AND METHODS: we searched relevant published and unpublished randomized
clinical trials analyzing antiangiogenic drugs versus chemotherapy in
glioblastoma patients from January 2006 to January 2016 in MEDLINE, WEB of
SCIENCE, ASCO, ESMO and SNO databases.
RESULTS: fourteen randomized clinical trials were identified (7 with
bevacizumab, 2 cilengitide, 1 enzastaurin, 1 dasatinib, 1 vandetanib, 1
temsirolimus, 1 cediranib) including 4330 patients. Antiangiogenic drugs showed
no improvement in overall survival with a pooled HR of 1.00, a trend for an
inferior outcome, in terms of overall survival, was observed in the group of
patients receiving antiangiogenic drug alone compared to cytotoxic drug alone
(HR=1.24, p=0.056). Bevacizumab did not improve overall survival. Twelve trials
(4113 patients) were analyzed for progression-free survival. Among
antiangiogenic drugs, only bevacizumab demonstrated an improvement of
progression-free survival (HR=0.63, p<0.001), both alone (HR=0.60, p=0.003) or
in combination to chemotherapy (HR=0.63; p<0.001), both as first-line treatment
(HR=0.70, p<0.001) or in recurrent disease (HR=0.52, p<0.001).
CONCLUSIONS: antiangiogenic drugs did not improve overall survival in
glioblastoma patients, either as first or second-line treatment, and either as
single agent or in combination with chemotherapy. Among antiangiogenic drugs,
only bevacizumab improved progression-free survival regardless of treatment
line, both as single agent or in combination with chemotherapy. |
What is the proteoform? | Although proteomics has rapidly developed in the past decade, researchers are still in the early stage of exploring the world of complex proteoforms, which are protein products with various primary structure alterations resulting from gene mutations, alternative splicing, post-translational modifications, and other biological processes | Proteogenomics is a research area that combines areas as proteomics and genomics
in a multi-omics setup using both mass spectrometry and high-throughput
sequencing technologies. Currently, the main goals of the field are to aid
genome annotation or to unravel the proteome complexity. Mass spectrometry based
identifications of matching or homologues peptides can further refine gene
models. Also, the identification of novel proteoforms is also made possible
based on detection of novel translation initiation sites (cognate or
near-cognate), novel transcript isoforms, sequence variation or novel (small)
open reading frames in intergenic or un-translated genic regions by analyzing
high-throughput sequencing data from RNAseq or ribosome profiling experiments.
Other proteogenomics studies using a combination of proteomics and genomics
techniques focus on antibody sequencing, the identification of immunogenic
peptides or venom peptides. Over the years, a growing amount of bioinformatics
tools and databases became available to help streamlining these cross-omics
studies. Some of these solutions only help in specific steps of the
proteogenomics studies, e.g. building custom sequence databases (based on next
generation sequencing output) for mass spectrometry fragmentation spectrum
matching. Over the last few years a handful integrative tools also became
available that can execute complete proteogenomics analyses. Some of these are
presented as stand-alone solutions, whereas others are implemented in a
web-based framework such as Galaxy. In this review we aimed at sketching a
comprehensive overview of all the bioinformatics solutions that are available
for this growing research area. © 2015 Wiley Periodicals, Inc. Mass Spec Rev
36:584-599, 2017. For top-down protein database search and identification from tandem mass
spectra, our isotopic envelope fingerprinting search algorithm and ProteinGoggle
search engine have demonstrated their strength of efficiently resolving heavily
overlapping data as well separating non-ideal data with non-ideal isotopic
envelopes from ideal ones with ideal isotopic envelopes. Here we report our
updated ProteinGoggle 2.0 for intact protein database search with full-capacity.
The indispensable updates include users' optional definition of dynamic
post-translational modifications and static chemical labeling during database
creation, comprehensive dissociation methods and ion series, as well as a
Proteoform Score for each proteoform. ProteinGoggle has previously been
benchmarked with both collision-based dissociation (CID, HCD) and electron-based
dissociation (ETD) data of either intact proteins or intact proteomes. Here we
report our further benchmarking of the new version of ProteinGoggle with
publically available photon-based dissociation (UVPD) data
(http://hdl.handle.net/2022/17316) of intact E. coli ribosomal proteins.
BIOLOGICAL SIGNIFICANCE: Protein species (aka proteoforms) function at their
molecular level, and diverse structures and biological roles of every proteoform
come from often co-occurring proteolysis, amino acid variation and
post-translational modifications. Complete and high-throughput capture of this
combinatorial information of proteoforms has become possible in evolving
top-down proteomics; yet, various methods and technologies, especially database
search and bioinformatics identification tools, in the top-down pipeline are
still in their infancy stages and demand intensive research and development. MOTIVATION: Although proteomics has rapidly developed in the past decade,
researchers are still in the early stage of exploring the world of complex
proteoforms, which are protein products with various primary structure
alterations resulting from gene mutations, alternative splicing,
post-translational modifications, and other biological processes. Proteoform
identification is essential to mapping proteoforms to their biological functions
as well as discovering novel proteoforms and new protein functions. Top-down
mass spectrometry is the method of choice for identifying complex proteoforms
because it provides a 'bird's eye view' of intact proteoforms. The combinatorial
explosion of various alterations on a protein may result in billions of possible
proteoforms, making proteoform identification a challenging computational
problem.
RESULTS: We propose a new data structure, called the mass graph, for efficient
representation of proteoforms and design mass graph alignment algorithms. We
developed TopMG, a mass graph-based software tool for proteoform identification
by top-down mass spectrometry. Experiments on top-down mass spectrometry
datasets showed that TopMG outperformed existing methods in identifying complex
proteoforms.
AVAILABILITY AND IMPLEMENTATION:
http://proteomics.informatics.iupui.edu/software/topmg/.
CONTACT: [email protected].
SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics
online. |
Are there sex differences in the transcriptome of the mouse hippocampus? | There are sex differences in the transcriptome of the developing mouse hippocampus. | |
How does neuronal activity affect neuroligin-3? | Neuronal activity-induces secretion of neuroligin-3. | Author information:
(1)Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's
Hospital, Harvard Medical School, Boston, MA 02115, USA.
(2)Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's
Hospital, Harvard Medical School, Boston, MA 02115, USA. Electronic address:
[email protected]. |
What is the role of the blood-brain barrier? | The blood–brain barrier (BBB) is a highly selective semipermeable membrane barrier that separates the circulating blood from the brain and extracellular fluid in the central nervous system (CNS). The blood–brain barrier is formed by brain endothelial cells and it allows the passage of water, some gases, and lipid-soluble molecules by passive diffusion, as well as the selective transport of molecules such as glucose and amino acids that are crucial to neural function. | The physical barrier between blood and the CNS (the blood-brain barrier, the
blood-spinal cord barrier and the blood-CSF barrier) protects the CNS from both
toxic and pathogenic agents in the blood. It is now clear that disruption of the
blood-CNS barrier plays a key role in a number of CNS disorders, particularly
those associated with neurodegeneration. Such disruption is inevitably
accompanied by inflammatory change, as immune cells and immune mediators gain
access to the brain or spinal cord. The blood-CNS barrier also presents a major
obstacle for potential CNS medicines. Robust methods to assess CNS permeation
are therefore essential for CNS drug discovery, particularly when brain
pharmacokinetics are taken into account and especially when such measures are
linked to neurochemical, physiological, behavioural or neuroimaging readouts of
drug action. Drug candidates can be successfully designed to cross the blood-CNS
barrier, but for those that can't there is the possibility of entry with a
delivery system that facilitates the movement of drug candidate across the
blood-CNS barrier. Alzheimer's disease (AD) is a chronic neurodegenerative disorder characterized
by the pathological accumulation of amyloid beta (Aβ) peptides and
neurofibrillary tangles containing hyperphosphorylated neuronal tau protein. AD
pathology is also characterized by chronic brain inflammation, which promotes
disease pathogenesis. In this context, the blood-brain barrier (BBB), a highly
specialized endothelial cell membrane that lines cerebral microvessels,
represents the interface between neural cells and circulating cells of the
immune system. The BBB thus plays a key role in the generation and maintece
of chronic inflammation during AD. The BBB operates within the neurovascular
unit (NVU), which includes clusters of glial cells, neurons and pericytes. The
NVU becomes dysfunctional during AD, and each of its components may undergo
functional changes that contribute to neuronal injury and cognitive deficit. In
transgenic animals with AD-like pathology, recent studies have shown that
circulating leukocytes migrate through the activated brain endothelium when
certain adhesion molecules are expressed, penetrating into the brain parenchyma,
interacting with the NVU components and potentially affecting their structural
integrity and functionality. Therefore, migrating immune system cells in
cerebral vessels act in concert with the modified BBB and may be integrated into
the dysfunctional NVU. Notably, blocking the adhesion mechanisms controlling
leukocyte-endothelial interactions inhibits both Aβ deposition and tau
hyperphosphorylation, and reduces memory loss in AD models. The characterization
of molecular mechanisms controlling vascular inflammation and leukocyte
trafficking could therefore help to determine the basis of BBB dysfunction
during AD and may lead to the development of new therapeutic approaches. |
Sclerostin regulates what process? | Sclerostin plays a critical role in bone homeostasis and its deficiency or pharmacological neutralization increases bone formation | The identity of the cell type responsive to sclerostin, a negative regulator of
bone mass, is unknown. Since sclerostin is expressed in vivo by mineral-embedded
osteocytes, we tested the hypothesis that sclerostin would regulate the behavior
of cells actively involved in mineralization in adult bone, the preosteocyte.
Differentiating cultures of human primary osteoblasts exposed to recombit
human sclerostin (rhSCL) for 35 days displayed dose- and time-dependent
inhibition of in vitro mineralization, with late cultures being most responsive
in terms of mineralization and gene expression. Treatment of advanced (day 35)
cultures with rhSCL markedly increased the expression of the preosteocyte marker
E11 and decreased the expression of mature markers DMP1 and SOST. Concomitantly,
matrix extracellular phosphoglycoprotein (MEPE) expression was increased by
rhSCL at both the mRNA and protein levels, whereas PHEX was decreased, implying
regulation through the MEPE-ASARM axis. We confirmed that mineralization by
human osteoblasts is exquisitely sensitive to the triphosphorylated ASARM-PO4
peptide. Immunostaining revealed that rhSCL increased the endogenous levels of
MEPE-ASARM. Importantly, antibody-mediated neutralization of endogenous
MEPE-ASARM antagonized the effect of rhSCL on mineralization, as did the PHEX
synthetic peptide SPR4. Finally, we found elevated Sost mRNA expression in the
long bones of HYP mice, suggesting that sclerostin may drive the increased
MEPE-ASARM levels and mineralization defect in this genotype. Our results
suggest that sclerostin acts through regulation of the PHEX/MEPE axis at the
preosteocyte stage and serves as a master regulator of physiologic bone
mineralization, consistent with its localization in vivo and its established
role in the inhibition of bone formation. Sclerostin is a secreted inhibitor of Wnt signaling and plays an essential role
in the regulation of bone mass. The expression of sclerostin is largely
restricted to osteocytes although its mode of transcriptional regulation is not
well understood. We observed regulated expression of sclerostin mRNA and protein
that was directly correlated with the mineralization response in cultured human
Saos-2 osteosarcoma cells and rat primary calvarial cells. Sclerostin mRNA and
protein levels were increased following treatment of cells with BMP2, BMP4 and
BMP7. Analysis of deletion mutants from the -7.4 kb upstream region of the human
sclerostin promoter did not reveal any specific regions that were responsive to
BMPs, Wnt3a, PTH, TGFβ1 or Activin A in Saos-2 cells. The downstream ECR5
element did not show enhancer activity in Saos-2 cells and also was not affected
when Saos-2 cells were treated with BMPs or PTH. Genome-wide microarray analysis
of Saos-2 cells treated with BMP2 showed significant changes in expression of
several transcription factors with putative consensus DNA binding sites in the
region of the sclerostin promoter. However, whereas most factors tested showed
either a range of inhibitory activity (DLX family, MSX2, HEY1, SMAD6/7) or lack
of activity on the sclerostin promoter including SMAD9, only MEF2B showed a
positive effect on both the promoter and ECR5 element. These results suggest
that the dramatic induction of sclerostin gene expression by BMPs in Saos-2
cells occurs indirectly and is associated with late stage differentiation of
osteoblasts and the mineralization process. Sclerostin, an osteocyte-expressed negative regulator of bone formation, is one
of the inhibitors of Wnt signaling that is a critical pathway in the correct
process of osteoblast differentiation. It has been demonstrated that Wnt
signaling through the secretion of Wnt inhibitors, such as DKK1, sFRP-2, and
sFRP-3, plays a key role in the decreased osteoblast activity associated with
multiple myeloma (MM) bone disease. We provide evidence that sclerostin is
expressed by myeloma cells that are human myeloma cell lines and plasma cells
(CD138(+) cells) obtained from the bone marrow (BM) of a large number of MM
patients with bone disease. Moreover, we show that there are no differences in
sclerostin serum levels between MM patients and controls. Thus, our data
indicate that MM cells, as a sclerostin source in the BM, could create a
microenvironment with high sclerostin concentration that could contribute toward
inhibiting osteoblast differentiation. The secreted glycoprotein, sclerostin alters bone formation. To gain insights
into the mechanism of action of sclerostin, we examined the interactions of
sclerostin with bone proteins using a sclerostin affinity capture technique.
Proteins from decalcified rat bone were captured on a sclerostin-maltose binding
protein (MBP) amylose column, or on a MBP amylose column. The columns were
extensively washed with low ionic strength buffer, and bound proteins were
eluted with buffer containing 1M sodium chloride. Eluted proteins were separated
by denaturing sodium-dodecyl sulfate gel electrophoresis and were identified by
mass spectrometry. Several previously unidentified full-length
sclerostin-interacting proteins such as alkaline phosphatase, carbonic
anhydrase, gremlin-1, fetuin A, midkine, annexin A1 and A2, and collagen α1,
which have established roles in bone formation or resorption processes, were
bound to the sclerostin-MBP amylose resin but not to the MBP amylose resin.
Other full-length sclerostin-interacting proteins such as casein kinase II and
secreted frizzled related protein 4 that modulate Wnt signaling were identified.
Several peptides derived from proteins such as Phex, asporin and follistatin
that regulate bone metabolism also bound sclerostin. Sclerostin interacts with
multiple proteins that alter bone formation and resorption and is likely to
function by altering several biologically relevant pathways in bone. Sclerostin regulates bone formation by inhibiting Wnt pathway signaling. Low
circulating sclerostin levels cause high bone mass. We hypothesized that
postmenopausal women with increased sclerostin levels have a greater risk for
osteoporosis-related fractures. We examined the association between circulating
sclerostin together with bone turnover markers and osteoporosis-related fracture
risk in 707 postmenopausal women, in a population-based study with a mean
follow-up period of 5.2 ± 1.3 years. Multivariate Cox proportional hazards
regression models were used to analyze fracture risk, adjusted for age, body
mass index, and other confounding risk factors. High sclerostin levels were
strongly associated with increased fracture risk. After adjustment for age and
other confounders, the relative fracture risk was more than sevenfold among
postmenopausal women for each 1-SD increment increase in sclerostin level. Women
in the highest quartile of sclerostin levels had about a 15-fold increase in
fracture risk. Results were similar when we compared sclerostin at the 1-year
visit to an average of two to three annual measurements. Fracture risk
attributable to sclerostin levels was 56.6% in the highest quartile. Only high
levels of bone resorption markers (plasma cross-linked C-terminal telopeptide of
type 1 collagen [p-CTx], urinary CTx [u-CTx], and urinary N-telopeptide of type
1 collagen [u-NTx]) were predictive of osteoporosis-related fractures but at
much lower hazard ratio (HR) values than that of serum sclerostin. Associations
between sclerostin levels and fracture risk were independent of bone mineral
density and other confounding risk factors. High sclerostin levels are a strong
and independent risk factor for osteoporosis-related fractures among
postmenopausal women. © 2012 American Society for Bone and Mineral Research. OBJECTIVE: Sclerostin plays a major role in regulating skeletal bone mass, but
its effects in articular cartilage are not known. The purpose of this study was
to determine whether genetic loss or pharmacologic inhibition of sclerostin has
an impact on knee joint articular cartilage.
METHODS: Expression of sclerostin was determined in articular cartilage and bone
tissue obtained from mice, rats, and human subjects, including patients with
knee osteoarthritis (OA). Mice with genetic knockout (KO) of sclerostin and
pharmacologic inhibition of sclerostin with a sclerostin-neutralizing monoclonal
antibody (Scl-Ab) in aged male rats and ovariectomized (OVX) female rats were
used to study the effects of sclerostin on pathologic processes in the knee
joint. The rat medial meniscus tear (MMT) model of OA was used to investigate
the pharmacologic efficacy of systemic Scl-Ab or intraarticular (IA) delivery of
a sclerostin antibody-Fab (Scl-Fab) fragment.
RESULTS: Sclerostin expression was detected in rodent and human articular
chondrocytes. No difference was observed in the magnitude or distribution of
sclerostin expression between normal and OA cartilage or bone. Sclerostin-KO
mice showed no difference in histopathologic features of the knee joint compared
to age-matched wild-type mice. Pharmacologic treatment of intact aged male rats
or OVX female rats with Scl-Ab had no effect on morphologic characteristics of
the articular cartilage. In the rat MMT model, pharmacologic treatment of
animals with either systemic Scl-Ab or IA injection of Scl-Fab had no effect on
lesion development or severity.
CONCLUSION: Genetic absence of sclerostin does not alter the normal development
of age-dependent OA in mice, and pharmacologic inhibition of sclerostin with
Scl-Ab has no impact on articular cartilage remodeling in rats with
posttraumatic OA. The osteocyte product sclerostin is emerging as an important paracrine regulator
of bone mass. It has recently been shown that osteocyte production of receptor
activator of NF-κB ligand (RANKL) is important in osteoclastic bone resorption,
and we reported that exogenous treatment of osteocytes with sclerostin can
increase RANKL-mediated osteoclast activity. There is good evidence that
osteocytes can themselves liberate mineral from bone in a process known as
osteocytic osteolysis. In the current study, we investigated
sclerostin-stimulated mineral dissolution by human primary osteocyte-like cells
(hOCy) and mouse MLO-Y4 cells. We found that sclerostin upregulated osteocyte
expression of carbonic anhydrase 2 (CA2/Car2), cathepsin K (CTSK/Ctsk), and
tartrate-resistant acid phosphatase (ACP5/Acp5). Because acidification of the
extracellular matrix is a critical step in the release of mineral from bone, we
further examined the regulation by sclerostin of CA2. Sclerostin stimulated CA2
mRNA and protein expression in hOCy and in MLO-Y4 cells. Sclerostin induced a
decrease in intracellular pH (pHi) in both cell types as well as a decrease in
extracellular pH (pHo) and the release of calcium ions from mineralized
substrate. These effects were reversed in the co-presence of the carbonic
anhydrase inhibitor, acetozolamide. Car2-siRNA knockdown in MLO-Y4 cells
significantly inhibited the ability of sclerostin to both reduce the pHo and
release calcium from a mineralized substrate. Knockdown in MLO-Y4 cells of each
of the putative sclerostin receptors, Lrp4, Lrp5 and Lrp6, using siRNA,
inhibited the sclerostin induction of Car2, Catk and Acp5 mRNA, as well as pHo
and calcium release. Consistent with this activity of sclerostin resulting in
osteocytic osteolysis, human trabecular bone samples treated ex vivo with
recombit human sclerostin for 7 days exhibited an increased osteocyte lacunar
area, an effect that was reversed by the co-addition of acetozolamide. These
findings suggest a new role for sclerostin in the regulation of perilacunar
mineral by osteocytes. BACKGROUND AND AIM OF THE STUDY: Sclerostin is a key negative regulator of bone
formation. It was hypothesized that sclerostin might also play a potential role
in the development of aortic valve calcification (AVC). The study aim was to
evaluate serum sclerostin levels in patients with different degrees of AVC
compared to a healthy control group, and to investigate local sclerostin
expression in explanted calcified and non-calcified aortic valves.
METHODS: A prospective cross-sectional study was performed in 115 patients (mean
age 74 +/- 7 years) with echocardiographically proven AVC. Sclerostin serum
levels were measured using ELISA and compared to values obtained from a healthy
control population. For quantification of AVC, all patients of the study cohort
underwent non-contrast-enhanced dual-source computed tomography (DSCT).
Immunohistochemistry (IHC) staining for sclerostin and mRNA sclerostin
expression was analyzed in 10 calcified aortic valves and 10 non-calcified
age-matched control valves.
RESULTS: Patients with AVC showed significantly higher sclerostin serum levels
as compared to healthy controls (0.94 +/- 0.45 versus 0.58 +/- 0.26 ng/ml, p <
0.001). A significant correlation between sclerostin serum levels and Agatston
AVC scores as assessed by DSCT was observed (r = 0.62, p < 0.001) in the study
cohort. IHC revealed positive sclerostin staining in nine calcified valves, in
contrast to negative staining for sclerostin in all non-calcified valves.
Quantitative real-time PCR confirmed the increased sclerostin expression on mRNA
level, with a significant up-regulation of sclerostin mRNA (fold change 150 +/-
52, p < 0.001) expression being shown in calcified aortic valves compared to
non-calcified control valves. Co-staining experiments revealed that
sclerostin-expressing cells co-express the major osteogenic transcription factor
Runx2 and the extracellular matrix protein osteocalcin.
CONCLUSION: Patients with AVC showed increased sclerostin serum levels compared
to a healthy reference population, and it was revealed that the severity of AVC
may be linked to increased sclerostin serum levels. Moreover, the PCR and
staining data demonstrated an increased sclerostin expression in parallel to
prototypic markers of osteogenic transdifferentiation, indicating a role of
sclerostin in the valvular calcification process. Estrogen deficiency leads to rapid bone loss and skeletal fragility. Sclerostin,
encoded by the sost gene, and a product of the osteocyte, is a negative
regulator of bone formation. Blocking sclerostin increases bone mass and
strength in animals and humans. Sirtuin1 (Sirt1), a player in aging and
metabolism, regulates bone mass and inhibits sost expression by deacetylating
histone 3 at its promoter. We asked whether a Sirt1-activating compound could
rescue ovariectomy (OVX)-induced bone loss and biomechanical deterioration in
9-week-old C57BL/6 mice. OVX resulted in a substantial decrease in skeletal
Sirt1 expression accompanied by an increase in sclerostin. Oral administration
of SRT3025, a Sirt1 activator, at 50 and 100 mg/kg·d for 6 weeks starting 6
weeks after OVX fully reversed the deleterious effects of OVX on vertebral bone
mass, microarchitecture, and femoral biomechanical properties. Treatment with
SRT3025 decreased bone sclerostin expression and increased cortical periosteal
mineralizing surface and serum propeptide of type I procollagen, a bone
formation marker. In vitro, in the murine long bone osteocyte-Y4 osteocyte-like
cell line SRT3025 down-regulated sclerostin and inactive β-catenin, whereas a
reciprocal effect was observed with EX-527, a Sirt1 inhibitor. Sirt1 activation
by Sirt1-activating compounds is a potential novel pathway to down-regulate
sclerostin and design anabolic therapies for osteoporosis concurrently
ameliorating other metabolic and age-associated conditions. BACKGROUND: Sclerostin is a Wnt pathway antagonist regulating osteoblast
activity and bone turnover, and it plays a role in cardiovascular calcification
processes. Previous findings indicate that sclerostin regulation is disturbed in
chronic kidney disease (CKD). The aim of this study was to assess the
association of circulating sclerostin levels with mortality in dialysis
patients.
METHODS: From a prospective cohort study of incident dialysis patients in the
Netherlands, all patients with measured circulating sclerostin at 3 months after
the start of dialysis (baseline) were included in the present analysis: n = 673,
age 63 ± 14 years, mean serum sclerostin (ELISA) 1.24 ± 0.57 ng/mL. By Cox
regression analyses, we assessed the association of sclerostin levels with
cardiovascular and non-cardiovascular mortality both in the short (18 months)
and long term (4-year follow-up).
RESULTS: Serum sclerostin levels in the entire cohort correlated with intact
parathyroid hormone levels (r = -0.25, P < 0.001), age (r = 0.16, P < 0.001) and
serum alkaline phosphatase (r = -0.13, P = 0.001). After adjustment for various
clinical and biochemical parameters, patients in the highest sclerostin tertile
had a significantly lower risk of cardiovascular death [hazard ratio 0.29, 95%
confidence interval (CI) 0.13-0.62] and for all-cause mortality (0.39, 95% CI
0.22-0.68) within 18 months compared with patients of the lowest tertile. The
association of sclerostin levels with outcome was less pronounced for long-term
cardiovascular mortality and absent for non-cardiovascular mortality.
CONCLUSIONS: High levels of serum sclerostin are associated with lower
short-term cardiovascular mortality in dialysis patients. The exact mechanisms
of this association, e.g. how sclerostin influences or reflects uraemic vascular
calcification, need to be investigated in further studies. BACKGROUND: TGF-β1 regulates bone metabolism and mediates bone turnover during
postmenopause. Sclerostin negatively regulates Wnt signaling pathway and also
has an important role in postmenopausal bone loss. Little is known about the
relationship between serum TGF-β1 and sclerostin during menopause.
METHODS: We compared serum levels of TGF-β1 and sclerostin in pre- and
postmenopausal women and assessed the potential correlations of these levels
with each other and with serum levels of bone turnover markers and bone mineral
density.
RESULTS: A total of 176 women (58 premenopausal, 62 early postmenopausal, and 56
late postmenopausal) were included in this study. Serum TGF-β1 level was
significantly higher in early postmenopausal women compared with premenopausal
(32.0±7.19 vs. 26.55±6.67 ng/ml, p=0.01) and late postmenopausal (32.0±7.19 vs.
28.65±7.70 pg/ml, p=0.031) women, and no significant differences in serum
sclerostin levels were observed among the 3 groups. There was a significant
negative correlation between TGF-β1 and sclerostin in early postmenopausal
women, but not in other groups of women. Based on multiple regression analysis,
only TGF-β1 (β=-0.362; p=0.007) was an independent predictor of sclerostin
during early postmenopause.
CONCLUSIONS: Our findings suggest that serum TGF-β1 level increases during
postmenopause and declines in old age. Sclerostin production is inhibited by
TGF-β1 during early postmenopause. BACKGROUND: The glycoprotein sclerostin (Scl; 22 kDa), which is involved in bone
metabolism, may play a role in vascular calcification in haemodialysis (HD)
patients. In the present study, we investigated the relation between serum Scl
(sScl) and mortality. The effects of dialysis modality and the magnitude of the
convection volume in haemodiafiltration (HDF) on sScl were also investigated.
METHODS: In a subset of patients from the CONTRAST study, a randomized
controlled trial comparing HDF with HD, sScl was measured at baseline and at
intervals of 6, 12, 24 and 36 months. Patients were divided into quartiles,
according to their baseline sScl. The relation between time-varying sScl and
mortality with a 4-year follow-up period was investigated using crude and
adjusted Cox regression models. Linear mixed models were used for longitudinal
measurements of sScl.
RESULTS: The mean (±standard deviation) age of 396 test subjects was 63.6 (±13.9
years), 61.6% were male and the median follow-up was 2.9 years. Subjects with
the highest sScl had a lower mortality risk than those with the lowest
concentrations [adjusted hazard ratio 0.51 (95% confidence interval, CI,
0.31-0.86, P = 0.01)]. Stratified models showed a stable sScl in patients
treated with HD (Δ +2.9 pmol/L/year, 95% CI -0.5 to +6.3, P = 0.09) and a
decreasing concentration in those treated with HDF (Δ -4.5 pmol/L/year, 95% CI
-8.0 to -0.9, P = 0.02). The relative change in the latter group was related to
the magnitude of the convection volume.
CONCLUSIONS: (i) A high sScl is associated with a lower mortality risk in
patients with end-stage kidney disease; (ii) treatment with HDF causes sScl to
fall; and (iii) the relative decline in patients treated with HDF is dependent
on the magnitude of the convection volume. After discovering that lack of Sost/sclerostin expression is the cause of the
high bone mass human syndromes Van Buchem disease and sclerosteosis, extensive
animal experimentation and clinical studies demonstrated that sclerostin plays a
critical role in bone homeostasis and that its deficiency or pharmacological
neutralization increases bone formation. Dysregulation of sclerostin expression
also underlies the pathophysiology of skeletal disorders characterized by loss
of bone mass, as well as the damaging effects of some cancers in bone. Thus,
sclerostin has quickly become a promising molecular target for the treatment of
osteoporosis and other skeletal diseases, and beneficial skeletal outcomes are
observed in animal studies and clinical trials using neutralizing antibodies
against sclerostin. However, the anabolic effect of blocking sclerostin
decreases with time, bone mass accrual is also accompanied by anti-catabolic
effects, and there is bone loss over time after therapy discontinuation.
Further, the cellular source of sclerostin in the bone/bone marrow
microenvironment under physiological and pathological conditions, the pathways
that regulate sclerostin expression and the mechanisms by which sclerostin
modulates the activity of osteocytes, osteoblasts, and osteoclasts remain
unclear. In this review, we highlight the current knowledge on the regulation of
Sost/sclerotin expression and its mechanism(s) of action, discuss novel
observations regarding its role in signaling pathways activated by hormones and
mechanical stimuli in bone, and propose future research needed to understand the
full potential of therapeutic interventions that modulate Sost/sclerostin
expression. The Wnt/β-catenin signaling pathway plays an essential role in osteoblast
biology. Sclerostin is a soluble antagonist of Wnt/β-catenin signaling secreted
primarily by osteocytes. Current evidence indicates that sclerostin likely
functions as a local/paracrine regulator of bone metabolism rather than as an
endocrine hormone. Nonetheless, circulating sclerostin levels in humans often
reflect changes in the bone microenvironment, although there may be exceptions
to this observation. Using existing assays, circulating sclerostin levels have
been shown to be altered in response to both hormonal stimuli and across a
variety of normal physiological and pathophysiological conditions. In both
rodents and humans, parathyroid hormone provided either intermittently or
continuously suppresses sclerostin levels. Likewise, most evidence from both
human and animal studies supports a suppressive effect of estrogen on sclerostin
levels. Efforts to examine non-hormonal/systemic regulation of sclerostin have
in general shown less consistent findings or have provided associations rather
than direct interventional information, with the exception of mechanosensory
studies which have consistently demonstrated increased sclerostin levels with
skeletal unloading, and conversely decreases in sclerostin with enhanced
skeletal loading. Herein, we will review the existent literature on both
hormonal and non-hormonal/systemic factors which have been studied for their
impact on sclerostin regulation. Tooth movement is a biological process of bone remodeling induced by mechanical
force. Sclerostin secreted by osteocytes is mechanosensory and important in bone
remodeling. However, little is known regarding the role of sclerostin in tooth
movement. In this study, models of experimental tooth movement were established
in rats and mice. Sclerostin expression was investigated with
immunohistochemistry staining, and osteoclastic activity was analyzed with
tartrate-resistant acid phosphatase (TRAP) staining. MLO-Y4 osteocyte-like cells
underwent uniaxial compression and tension stress or were cultured in hypoxia
conditions. Expression of sclerostin was assessed by RT-qPCR and ELISA. MLO-Y4
cells were cultured with recombit human sclerostin (rhSCL) interference and
then co-cultured with RAW264.7 osteoclast precursor cells. Expressions of RANKL
and OPG were analyzed by RT-qPCR, and osteoclastic activity was assessed by TRAP
staining. During tooth movement, sclerostin was expressed differently in
compression and tension sites. In SOST knock-out mice, there were significantly
fewer TRAP-positive cells than in WT mice during tooth movement in compression
sites. In-vitro studies showed that the expression of sclerostin in MLO-Y4
osteocyte-like cells was not different under a uniaxial compression and tension
force, whereas hypoxia conditions significantly increased sclerostin expression
in MLO-Y4 cells. rhSCL interference increased the expression of RANKL and the
RANKL/OPG ratio in MLO-Y4 cells and the osteoclastic induction ability of MLO-Y4
cells in experimental osteocyte-osteoclast co-culture. These data suggest that
sclerostin plays an important role in the bone remodeling of tooth movement. |
What is PARP inhibitor (PARPi) resistance? | PARPi has been designed and tested for many years and became a potential supplement for the conventional chemotherapy. However, increasing evidence indicates the appearance of the resistance to this treatment. Specifically, cancer cells may acquire new mutations or events that overcome the positive effect of these drugs. | Olaparib is an FDA-approved PARP inhibitor (PARPi) that has shown promise as a
synthetic lethal treatment approach for BRCA-mutant castration-resistant
prostate cancer (CRPC) in clinical use. However, emerging data have also shown
that even BRCA-mutant cells may be resistant to PARPi. The mechanistic basis for
these drug resistances is poorly understood. Polo-like kinase 1 (Plk1), a
critical regulator of many cell-cycle events, is significantly elevated upon
castration of mice carrying xenograft prostate tumors. Herein, by combination
with Plk1 inhibitor BI2536, we show a robust sensitization of olaparib in 22RV1,
a BRCA1-deficient CRPC cell line, as well as in CRPC xenograft tumors.
Mechanistically, monotherapy with olaparib results in an override of the G1-S
checkpoint, leading to high expression of Plk1, which attenuates olaparib's
overall efficacy. In BRCA1 wild-type C4-2 cells, Plk1 inhibition also
significantly increases the efficacy of olaparib in the presence of p53
inhibitor. Collectively, our findings not only implicate the critical role of
Plk1 in PARPi resistance in BRCA-mutant CRPC cells, but also shed new light on
the treatment of non-BRCA-mutant patient subgroups who might also respond
favorably to PARPi. Mol Cancer Ther; 16(3); 469-79. ©2017 AACR. One of the DNA repair machineries is activated by Poly (ADP-ribose) Polymerase
(PARP) enzyme. Particularly, this enzyme is involved in repair of damages to
single-strand DNA, thus decreasing the chances of generating double-strand
breaks in the genome. Therefore, the concept to block PARP enzymes by PARP
inhibitor (PARPi) was appreciated in cancer treatment. PARPi has been designed
and tested for many years and became a potential supplement for the conventional
chemotherapy. However, increasing evidence indicates the appearance of the
resistance to this treatment. Specifically, cancer cells may acquire new
mutations or events that overcome the positive effect of these drugs. This paper
describes several molecular mechanisms of PARPi resistance which were reported
most recently, and summarizes some strategies to reverse this type of drug
resistance. Poly(ADP-ribose) polymerase-1 (PARP-1) plays a central role in numerous cellular
processes including DNA repair, replication, and transcription. PARP interacts
directly, indirectly or via PARylation with various oncogenic proteins and
regulates several transcription factors thereby modulating carcinogenesis.
Therapeutic inhibition of PARP is therefore perceived as a promising anticancer
strategy and a number of PARP inhibitors (PARPi) are currently under development
and clinical evaluation. PARPi inhibit the DNA repair pathway and thus form the
concept of synthetic lethality in cancer therapeutics. Preclinical and clinical
studies have shown the potential of PARPi as chemopotentiator, radiosensitizer,
or as adjuvant therapeutic agents. Recent studies have shown that PARP-1 could
be either oncogenic or tumor suppressive in different cancers. PARP inhibitor
resistance is also a growing concern in the clinical setting. Recently, changes
in the levels of PARP-1 activity or expression in cancer patients have provided
the basis for consideration of PARP-1 regulatory proteins as potential
biomarkers. This review focuses on the current developments related to the role
of PARP in cancer progression, therapeutic strategies targeting PARP-associated
oncogenic signaling, and future opportunities in use of PARPi in anticancer
therapeutics. |
What is the association of the protein RAB10 and Alzheimers disease? | The genes SEC22B, RAB10 and FLT1 may be potential biomarkers of AD. | |
Does MC1R palmitoylation reduce pigmentation? | No, MC1R palmitoylation leads to increased pigmentation. | The melanocortin-1 receptor (MC1R), a G-protein-coupled receptor, has a crucial
role in human and mouse pigmentation. Activation of MC1R in melanocytes by
α-melanocyte-stimulating hormone (α-MSH) stimulates cAMP signalling and melanin
production and enhances DNA repair after ultraviolet irradiation. Individuals
carrying MC1R variants, especially those associated with red hair colour, fair
skin and poor tanning ability (denoted as RHC variants), are associated with
higher risk of melanoma. However, how MC1R activity is modulated by ultraviolet
irradiation, why individuals with red hair are more prone to developing
melanoma, and whether the activity of RHC variants might be restored for
therapeutic benefit are unknown. Here we demonstrate a potential MC1R-targeted
intervention strategy in mice to rescue loss-of-function MC1R in MC1R RHC
variants for therapeutic benefit by activating MC1R protein palmitoylation. MC1R
palmitoylation, primarily mediated by the protein-acyl transferase ZDHHC13, is
essential for activating MC1R signalling, which triggers increased pigmentation,
ultraviolet-B-induced G1-like cell cycle arrest and control of senescence and
melanomagenesis in vitro and in vivo. Using C57BL/6J-Mc1re/eJ mice, in which
endogenous MC1R is prematurely terminated, expressing Mc1r RHC variants, we show
that pharmacological activation of palmitoylation rescues the defects of Mc1r
RHC variants and prevents melanomagenesis. The results highlight a central role
for MC1R palmitoylation in pigmentation and protection against melanoma. |
A bite from the Lone Star Tick Amblyomma americanum, can cause the victim to become allergic to red meat, yes or no? | Conditions such as Southern tick-associated rash illness and anaphylaxis to red meat following tick bites have been attributed to the lone star tick, Ambyomma ameriacanum. | Delayed hypersensitivity disorders and food allergies are often challenging for
the clinician and patient alike. A recent discovery of an IgE antibody specific
to galactose-α-1,3-galactose, which is a carbohydrate abundantly expressed on
cells and tissues of beef, pork, and lamb, adds one more tool to aid the
clinician in making the appropriate diagnosis. A link has been discovered
between the bite of the Lone Star Tick (Amblyomma americanum) and the
development of sensitivity to galactose-α-1,3-galactose. With a high prevalence
of Lone Star Tick populations inhabiting major U.S. Army Installations, and the
type of duty required by our Service members, it could potentially affect
susceptible individuals. We describe a case of an active duty soldier who went 4
years searching for this elusive diagnosis and connection and discuss why it
should remain in the differential diagnosis when treating military health care
beneficiaries. Amblyomma americanum, also known as the lone star tick, is found in much of the
eastern United States. Since the mid-20th century, the lone star tick has been
implicated in human disease. Today, A americanum remains an important vector for
tick-borne illness. In addition to others, species of Rickettsia, Ehrlichia, and
Borrelia are all transmitted by the lone star tick. Recently described
conditions such as Southern tick-associated rash illness and anaphylaxis to red
meat following tick bites have been attributed to the lone star tick. Impressive
local reactions also can result after bites from A americanum. Early treatment
of tick-borne illness is crucial to ensure good patient outcomes. Tick-control
measures also are an important part of disease management in endemic areas. We
discuss the tick's biology, human illnesses associated with A americanum, and
methods to control tick numbers and eliminate disease in local reservoirs. |
Subsets and Splits
No saved queries yet
Save your SQL queries to embed, download, and access them later. Queries will appear here once saved.