Unnamed: 0
int64 0
2.34M
| title
stringlengths 5
21.5M
| abst
stringlengths 1
21.5M
|
|---|---|---|
2,338,400 |
Adjusting the estimated proportion of breast cancer cases associated with BRCA1 and BRCA2 mutations: public health implications.
|
Mutations in BRCA1 or BRCA2 genes increase breast cancer risk. Assuring reliability of information about these mutations is increasingly important to the health care community; mutation testing is becoming more widespread. We describe a methodology for assessing such information.</AbstractText>Our approach integrates four interdependent epidemiologic parameters: (1) the probability of developing breast cancer, (2) the proportion of breast cancer cases with a BRCA1 or BRCA2 mutation, (3) the proportion of women that carries a mutation, and (4) the proportion of women with a mutation that develops cancer. We assess the plausibility of estimates of these parameters from published reports and commonly accessed information sources.</AbstractText>Assuming a fixed probability of developing breast cancer, the following estimates for the other three epidemiologic parameters are derived for women by age 70: 1% to 2% of all breast cancer cases are associated with a BRCA1 or BRCA2 mutation; 1 in 300 to 1 in 465 women carry a mutation; and 35 to 65% of mutation carriers develop breast cancer. Within these ranges, however, only selected combinations are plausible. The proportion of mutation-related breast cancer is lower than listed in some common information sources (1 to 2% vs 6%). Also, penetrance is somewhat lower and the carrier rate somewhat higher.</AbstractText>The four epidemiologic parameters can be integrated to test their plausibility. BRCA1 and BRCA2 mutations are associated with only one-third as many breast cancer cases in the general population as reported by commonly accessed information sources.</AbstractText>
|
2,338,401 |
Telegenetics in Maine: Successful clinical and educational service delivery model developed from a 3-year pilot project.
|
The goal of this 3-year pilot project was to increase accessibility to genetics educational and clinical services in Maine.</AbstractText>Southern Maine Genetics Services, Foundation for Blood Research in collaboration with Maine Telemedicine Services established telemedicine capacity to link with rural health care centers located in Northern, Central, and Southern Maine and public health nursing statewide for the provision of genetics clinical and educational services. Core partners included a rural family practice residency program, a rural pediatric practice in northern Maine, and public health nurses statewide. The telegenetics model created was based on development and implementation of a preventive and medical management technology solution, conducting a pilot study to collect data, and approaching insurance companies for reimbursement. Evaluation included surveys on the quality, acceptability, and usefulness of genetics services delivered via telemedicine, telephone interviews, and decision-making confidence evaluations.</AbstractText>During the project period, 24 rural clinical sites participated. In total, 93 presentations were given, and 125 patients were evaluated. Sixty-four percent of patients evaluated were pediatric. Despite site coordinator efforts to complete satisfaction surveys, the provider and patient response level was low (18% and 25%, respectively). Of those evaluations received, provider and patient response to telegenetics was positive. Decision-making confidence for genetics and neurology consultants was high. Our experience contributes to the development of telegenetics models that can be used in other rural states.</AbstractText>
|
2,338,402 |
Obstacles and opportunities in meta-analysis of genetic association studies.
|
Genetic association studies have the potential to advance our understanding of genotype-phenotype relationships, especially for common, complex diseases where other approaches, such as linkage, are less powerful. Unfortunately, many reported studies are not replicated or corroborated. This lack of reproducibility has many potential causes, relating to study design, sample size, and power issues, and from sources of true variability among populations. Genetic association studies can be considered as more similar to randomized trials than other types of observational epidemiological studies because of "Mendelian randomization" (Mendel's second law). The rationale and methodology for synthesizing randomized trials is highly relevant to the meta-analysis of genetic association studies. Nevertheless, there are a number of obstacles to overcome when performing such meta-analyses. In this review, the impacts of Type I error, lack of power, and publication and reporting biases are explored, and the role of multiple testing is discussed. A number of special features of association studies are especially pertinent, because they may lead to true variability among study results. These include population dynamics and structure, linkage disequilibrium, conformity to Hardy-Weinberg Equilibrium, bias, population stratification, statistical heterogeneity, epistatic and environmental interactions, and the choice of statistical models used in the analysis. Approaches to dealing with these issues are outlined. The supreme importance of complete and consistent study reporting and of making data readily available is also highlighted as a prerequisite for sound meta-analysis. We believe that systematic review and meta-analysis has an important role to play in understanding genetic association studies and should help us to separate the wheat from the chaff.
|
2,338,403 |
MLH1 and MSH2 promote the symmetry of double-strand break repair events at the HIS4 hotspot in Saccharomyces cerevisiae.
|
Double-strand breaks (DSBs) initiate meiotic recombination. The DSB repair model predicts that both genetic markers spanning the DSB should be included in heteroduplex DNA and be detectable as non-Mendelian segregations (NMS). In experiments testing this, a significant fraction of events do not conform to this prediction, as only one of the markers displays NMS (one-sided events). Two explanations have been proposed to account for the discrepancies between the predictions and experimental observations. One suggests that two-sided events are the norm but are "hidden" as heteroduplex repair frequently restores the parental configuration of one of the markers. Another explanation posits that one-sided events reflect events in which heteroduplex is formed predominantly on only one side of the DSB. In the absence of heteroduplex repair, the first model predicts that two-sided events would be revealed at the expense of one-sided events, while the second predicts no effect on the distribution of events when heteroduplex repair is lost. We tested these predictions by deleting the DNA mismatch repair genes MSH2 or MLH1 and analyzing the proportion of two-sided events. Unexpectedly, the results do not match the predictions of either model. In both mlh1Delta and msh2Delta, the proportion of two-sided events is significantly decreased relative to wild type. These observations can be explained in one of two ways. Either Msh2p/Mlh1p-independent mispair removal leads to restoration of one of the markers flanking the DSB site or Msh2p/Mlh1p actively promote two-sided events.
|
2,338,404 |
A model for the Neurospora circadian clock.
|
Circadian clocks are important biological oscillators that generally involve two feedback loops. Here, we propose a new model for the Neurospora crassa circadian clock. First, we model its main negative feedback loop, including only experimentally well-documented reactions, the transcriptional activation of frequency (frq) by the white-collar complex (WCC), and the post-transcriptional dimerization of FRQ with WCC. This main loop is sufficient for oscillations and a similar one lies at the core of almost all known circadian clocks. Second, the model is refined to include the less characterized enhancement of white-collar 1 (WC-1) protein synthesis by FRQ, the positive second feedback loop. Numerical testing of different hypotheses led us to propose that the synthesis of WC-1 is enhanced by FRQ monomers and repressed by FRQ dimers. We demonstrate that this second loop contributes significantly to the robustness of the oscillator period against parameter variation. A phase response curve to light pulses is also computed and agrees well with experiments. On a general level, our results show that explicit time delays are not required for sustained oscillations but that it is crucial to take into account mRNA dynamics and protein-protein interactions.
|
2,338,405 |
A family-based study of the association between the G72/G30 genes and schizophrenia in the Chinese population.
|
Studies have shown a strong positive association between schizophrenia and G72/G30, demonstrated by both individual markers and haplotypes. A further functional study also supports the role of G72 in the etiology of schizophrenia. In this study, we have replicated these results of transmission/disequilibrium testing (TDT) and haplotype analysis in the Han Chinese population, showing P values of 0.0018 and 0.00007 for individual markers and haplotypes, respectively. Hence, our data supports the hypothesis that G72/G30 are important candidate genes for explaining schizophrenia in the Han Chinese population.
|
2,338,406 |
Prodromal interventions for schizophrenia vulnerability: the risks of being "at risk".
|
Given the morbidity and difficulty of treating psychotic disorders, including schizophrenia, there has been a move toward identifying and treating adolescents and young adults who appear to be clinically at risk or "prodromal" to psychosis. The field now has greater specificity in identification, with rates of 40-50% conversion to frank psychosis within 1-2 years. There is further evidence that medications and other treatments may have some efficacy for "prodromal" patients, though with variable side effects. However, controversy remains about some of the inherent risks in prodromal research, such as medication exposure and stigma among false-positives. In this paper, we add to this discussion through an analysis of ethics in prodromal research from the more established field of predictive genetic testing. Issues are raised about the effects of information on patients, families, and institutions, as well as future insurability, the limits of confidentiality (as it relies on discretion of patients and families), the autonomy of minors with psychiatric symptoms, and even the risks for the true-positive patient.
|
2,338,407 |
Development and validation of a Breast Cancer Genetic Counseling Knowledge Questionnaire.
|
Women who undergo genetic counseling concerning their increased risk of developing breast cancer confront large quantities of complex information in a short period of time. Clinical reports have suggested that many women may not retain what they learned during counseling. A validated questionnaire to measure their knowledge, however, is lacking. In this study, we describe the development and validation of a questionnaire to assess knowledge of information typically included in genetic counseling for breast cancer. Items were empirically derived from detailed content analyses of actual genetic counseling sessions. The instrument's content validity was high, as evidenced by high levels of independent interrater agreement (0.93) on items. Subsequent data reduction and confirmatory factor analytic techniques yielded a highly reliable (alpha = 0.92) 27-item Breast Cancer Genetic Counseling Knowledge Questionnaire (BGKQ). Direct comparison of this questionnaire to a scale previously developed in the literature (BCHK; [Breast Cancer Res. Treat. 53 (1999) 69]) supported the utility of the new questionnaire for evaluation of knowledge after counseling. Compared to non-counseled groups (n = 45), women who had undergone genetic counseling (n = 28) scored significantly higher (P < 0.0001) on the BGKQ, but not on the other questionnaire, establishing the BGKQ's criterion validity. The BGKQ may, thus, provide a useful clinical and research tool for assessing knowledge of information provided during genetic counseling and exploring the potential impact of distress on knowledge, as well as the impact of knowledge on screening behaviors.
|
2,338,408 |
Differential behavioral responses to nicotine in Lewis and Fischer-344 rats.
|
Individual and strain variability in the effects of nicotine suggests the involvement of a genetic component in nicotinic cholinergic receptor (nAChR) function, which may help explain nicotine's variable behavioral and pharmacological effects in different individuals. The present study evaluated differential responses to the discriminative stimulus (DS) and rewarding properties of nicotine in Lewis (LEW) and Fischer-344 (F-344) rats. Drug discrimination (DD) data suggest that the LEW rat is more sensitive to nicotine as LEW rats acquired the nicotine discrimination at a dose of 0.4 mg/kg, whereas F-344 rats acquired the dose of 0.9 mg/kg (all nicotine doses expressed as free base). Similarly, LEW rats exhibited nicotine-conditioned place preference (CPP) at 0.6 mg/kg, whereas the F-344 rats did not. Subsequent testing with a higher dose (0.9 mg/kg) failed to maintain the nicotine-CPP in the LEW rats. Conversely, nicotine-place preference in the F-344 rats was not changed at the higher dose. Taken together, these results suggest potential differences of sensitivities in LEW and F-344 rats to the rewarding and discriminative stimulus (DS) properties of nicotine. These findings support previous research by demonstrating that the F-344 rat is less sensitive to nicotine compared to the LEW rat.
|
2,338,409 |
Protocatechuate 4,5-dioxygenase from Comamonas testosteroni T-2: biochemical and molecular properties of a new subgroup within class III of extradiol dioxygenases.
|
Comamonas testosteroni T-2 degraded at least eight aromatic compounds via protocatechuate (PCA), whose extradiol ring cleavage to 2-hydroxy-4-carboxymuconate semialdehyde (HCMS) was catalysed by PCA 4,5-dioxygenase (PmdAB). This inducible, heteromultimeric enzyme was purified. It contained two subunits, alpha (PmdA) and beta (PmdB), and the molecular masses of the denatured proteins were 18 kDa and 31 kDa, respectively. PCA was converted stoichiometrically to HCMS with an apparent K(m) of 55 muM and at a maximum velocity of 1.5 mukat. Structure-activity-relationship analysis by testing 16 related compounds as substrate for purified PmdAB revealed an absolute requirement for the vicinal diol and for the carboxylate group of PCA. Besides PCA, only 5'-hydroxy-PCA (gallate) induced oxygen uptake. The N-terminal amino acid sequence of each subunit was identical to the corresponding sequences in C. testosteroni BR6020, which facilitated sequencing of the pmdAB genes in strain T-2. Small differences in the amino acid sequence had significant effects on enzyme stability. Several homologues of pmdAB were found in sequence databases. Residues involved in substrate binding are highly conserved among the homologues. Their sequences grouped within the class III extradiol dioxygenases. Based on our biochemical and genetic analyses, we propose a new branch of the heteromultimeric enzymes within that class.
|
2,338,410 |
Application of RAPD and SCAR markers for purity testing of F1 hybrid seed in chili pepper (Capsicum annuum).
|
A simpler and better method for purity testing of hybrid pepper seed was developed. The simplest method for extracting genomic DNA, the NaOH method, was chosen. Two RAPD markers identifying male and female parents were also developed, and the PCR products of male- and female-specific RAPD markers were cloned and sequenced. From these sequences, new longer primers were constructed for conversion into SCAR markers. In blind tests the RAPD and SCAR markers were able to reliably detect contaminating exotic seeds. These PCR-based markers are therefore directly applicable for purity testing by seed companies. In addition, the PCR products of the SCAR markers could be identified by direct staining methods such as ethidium bromide and pellet painting without electrophoresis.
|
2,338,411 |
ABCA2 is a strong genetic risk factor for early-onset Alzheimer's disease.
|
Recent epidemiological, biological and genetic data indicate a relationship between cholesterol and Alzheimer's disease (AD) including the association of polymorphisms of ABCA1 (a gene that is known to participate in cholesterol and phospholipid transport) with AD prevalence. Based on these data, we postulated that genetic variation in the related and brain-specific ABCA2 gene leads to increase risk of AD. A large case-control study was conducted where the sample was randomly divided into a hypothesis-testing sample (230 cases/286 controls) and a validation sample (210 cases/233 controls). Among the 45 SNPs we tested, one synonymous SNP (rs908832) was found significantly associated with AD in both samples. Additional analyses performed on the whole sample showed a very strong association between this marker and early-onset AD (OR = 3.82, 95% C.I. = [2.00 - 7.30], P = 5 x 10(-5)). Further research is needed to understand the functional role of this polymorphism. However, together with the reported associations of AD with APOE, CYP46A1 and ABCA1, the present result adds a very significant support for the role of cholesterol and phospholipid homeostasis in AD and a rationale for testing novel cholesterol homeostasis-related therapeutic strategies in AD.
|
2,338,412 |
Reversal of a full-length mutant huntingtin neuronal cell phenotype by chemical inhibitors of polyglutamine-mediated aggregation.
|
Huntington's disease (HD) is an inherited neurodegenerative disorder triggered by an expanded polyglutamine tract in huntingtin that is thought to confer a new conformational property on this large protein. The propensity of small amino-terminal fragments with mutant, but not wild-type, glutamine tracts to self-aggregate is consistent with an altered conformation but such fragments occur relatively late in the disease process in human patients and mouse models expressing full-length mutant protein. This suggests that the altered conformational property may act within the full-length mutant huntingtin to initially trigger pathogenesis. Indeed, genotype-phenotype studies in HD have defined genetic criteria for the disease initiating mechanism, and these are all fulfilled by phenotypes associated with expression of full-length mutant huntingtin, but not amino-terminal fragment, in mouse models. As the in vitro aggregation of amino-terminal mutant huntingtin fragment offers a ready assay to identify small compounds that interfere with the conformation of the polyglutamine tract, we have identified a number of aggregation inhibitors, and tested whether these are also capable of reversing a phenotype caused by endogenous expression of mutant huntingtin in a striatal cell line from the HdhQ111/Q111 knock-in mouse.</AbstractText>We screened the NINDS Custom Collection of 1,040 FDA approved drugs and bioactive compounds for their ability to prevent in vitro aggregation of Q58-htn 1-171 amino terminal fragment. Ten compounds were identified that inhibited aggregation with IC50 < 15 microM, including gossypol, gambogic acid, juglone, celastrol, sanguinarine and anthralin. Of these, both juglone and celastrol were effective in reversing the abnormal cellular localization of full-length mutant huntingtin observed in mutant HdhQ111/Q111 striatal cells.</AbstractText>At least some compounds identified as aggregation inhibitors also prevent a neuronal cellular phenotype caused by full-length mutant huntingtin, suggesting that in vitro fragment aggregation can act as a proxy for monitoring the disease-producing conformational property in HD. Thus, identification and testing of compounds that alter in vitro aggregation is a viable approach for defining potential therapeutic compounds that may act on the deleterious conformational property of full-length mutant huntingtin.</AbstractText>
|
2,338,413 |
Atopy, asthma, and experimental approaches based on the linear model of T cell maturation.
|
The linear model of maturation of IFN-gamma-producing cells from a proliferative pool of type 2 cytokine-producing T cells represents a fundamental shift in interpreting how changes in cytokine production by T cell populations are regulated. A major tenet of this model is antigen-independent, bystander proliferation of type 2 T cells and their maturation to IFN-gamma+ cells. Both clinical observations and prevailing theories of immune system development in asthma are consistent with this highly interpretative in vitro model, which allows unambiguous characterization of the modulation of the intrinsic features of T cell proliferation and differentiation by environmental and genetic factors. Hypotheses based on the linear model of T cell maturation are readily testable and should lead to a greater understanding of not only allergen-specific responses, but also the non-specific, bystander effects associated with specific responses to allergens or pathogens. Topics to be discussed in the context of the linear model of T cell maturation in this review include: (1) allergic responses to an inciting allergen that may enhance sensitivity to subsequent yet different allergens; (2) dampening the preferential accumulation of type 2 T cells during a typical immune response against viral and bacterial pathogens; (3) allergen-independent sensitization in asthmatics: (4) the 'hygiene hypothesis' for the reported increased allergy development in industrialized countries; (5) elevated IFN-gamma levels in asthmatics, in addition to the expected high levels of type 2 cytokines; (6) testing the effects of inflammatory mediators, as well as various anti-inflammation therapies on T cell maturation; and (7) testing the influence of gene variation on T cell maturation.
|
2,338,414 |
The problems with risk selection; scientific and psychosocial aspects.
|
Between 9,000 and 18,000 new cases of breast cancer per year in the United States are associated with a genetically defined predisposition. Mutations in BRCA1 and 2 account for greater than 60% of inherited breast cancer. Mutations in additional undiscovered high and low penetrance genes may account for the other 40% of inherited breast cancer cases and possibly a subset of familial breast cancer cases that lacks an autosomal-dominant pattern of inheritance. False-negative rates resulting from gene sequencing of BRCA1 and 2 may be as high as 10%-15%, making the identification of high-risk individuals a complex and often futile process for both patient and physician. As a consequence of technical limitations in BRCA1 and 2, genetic testing and the lack of comprehensive breast cancer prediction models that take into account both genetic and environmental factors, we are unable to quantify future breast cancer risk for many patients. This uncertainty often leads to the exclusion of high-risk individuals in screening and prevention trials, which is perhaps most evident in breast cancer screening trials incorporating the use of magnetic resonance imaging (MRI) to identify early cancers. These studies demonstrate that MRI increases the sensitivity of a screening protocol in mutation carriers and succeeds at detecting earlier stage cancers. Eligibility criterion for most of these trials was documented mutations in BRCA1 and 2 or future breast cancer risk predicted by family history or models, thereby possibly excluding women at significantly elevated risk that testing failed to identify or whose risk is not adequately reflected based on current models used in risk assessment. We may be turning very high-risk women away from screening trials, recommending yearly mammography and clinical breast exam, when neither will be adequate for detecting their cancers early. In addition, the impact of risk-reducing strategies including bilateral prophylactic oophorectomy (BSO) and tamoxifen has not been analyzed in these studies. For example, a 40-year-old BRCA2 carrier may only have a 10% and 50% lifetime risk of ovarian and breast cancer, respectively, and interventions including tamoxifen and breast MRI screening may significantly reduce the risk of both getting breast cancer and dying from it, thereby obviating the need for early screening or prophylactic surgeries, permitting these women to defer the quality of life struggles until they are older. A larger sample size is needed to determine the degree to which different subgroups of high-risk patients will benefit from MRI screening, with particular attention to women who have undergone BSO or who are taking tamoxifen. The challenges in risk selection are numerous and produce more questions than answers with regard to screening and management of high-risk individuals. In the future, we hope that early detection tools, risk-reduction strategies, and risk assessment preclude the need for prophylactic surgeries, inappropriate selection of patients for screening, and the associated decisions that compromise our patients' quality of life.
|
2,338,415 |
Can animal models help us select specific compounds for cancer prevention trials?
|
Animal models provide unparalleled mechanistic insights into cancer development and potential opportunity for cancer prevention. Nevertheless, species differ markedly with regard to dietary exposures, cancer development, drug effects, and toxicity thresholds; therefore, testing in a single animal system may not predict human responses. Although replication of human cancer in animal models remains inexact, more than two decades of research have clearly yielded significant gains, as is evident in agents tested--and in certain cases, approved--for the prevention of epithelial cancers. Research efficiencies achievable through preliminary testing in genetically engineered and carcinogen-induced animal models enable us to probe genetic and signaling pathways that drive normal and neoplastic processes, and thereby figure prominently in decision trees for agent development.
|
2,338,416 |
Genetics and prevention of oesophageal adenocarcinoma.
|
Gastric cancer has been declining for more than half a century, whereas the incidence of oesophageal cancer is increasing rapidly. The histopathological subtype is also changing with a predominance of oesophageal adenocarcinoma compared with squamous carcinoma. The reasons for these epidemiological changes are not clear, although population-based data have implicated gastro-oesophageal reflux disease as a risk factor. In susceptible individuals reflux of duodeno-gastric contents can lead to the development of a columnar-lined oesophagus, commonly called Barrett's oesophagus. This can then progress to adenocarcinoma via a metaplasia-dysplasia-carcinoma sequence. At the current time, the mortality from oesophageal adenocarcinoma exceeds 80% at 5 years. Therefore, endoscopic surveillance programmes have been generally recommended for patients with Barrett's oesophagus in an attempt to detect early, curable lesions. Unfortunately these programmes are cumbersome and costly and have not yet been proved to reduce population mortality. In order to improve patient outcomes we need to be able to identify patients at high risk and to understand the triggers for disease progression. There is mounting evidence that there is an underlying genetic susceptibility to Barrett's oesophagus and oesophageal adenocarcinoma. However, this is likely to be as a result of multiple low penetrance susceptibility genes which have yet to be identified. Once patients are identified as having Barrett's oesophagus their chance for developing adenocarcinoma is in the order of 0.5%-1% per year. The histological assessment of dysplasia as a predictor of cancer development is highly subjective. Therefore multiple, specific somatic mutations in the tissue have been investigated as potential biomarkers. The most promising markers to date are the presence of aneuploidy, loss of heterozygosity of p53 and cyclin D1 overexpression. However, a study of evolutionary relationships suggest that mutations occur in no obligate order. Combinatorial approaches are therefore being advocated which include genomic profiling or the use of a panel of molecular markers in order to define the common molecular signatures that can then be used to predict malignant progression. An alternative approach would be to use markers for the final common pathway following genetic instability, which is the loss of proliferative control. We have demonstrated an increase in the expression of a novel proliferation marker, Mcm2, which occurs during the malignant progression of Barrett's oesophagus. These Mcm2-expressing cells are detectable on the surface, and hence a cytological approach may be applicable. In view of the role of reflux components in the pathogenesis of Barrett's oesophagus the effect of acid and bile on the cell phenotype have been studied. These studies have demonstrated that pulsatile acid and bile exposure induce cell proliferation. The mechanism for the hyperproliferative response appears to involve p38 mitogen activated protein kinase (MAPK) pathways as well as protein kinase C (PKC) and cyclo-oxygenases. A clinical implication of the laboratory studies is that suppression of acid and bile may need to be profound in order to suppress cell proliferation and, by inference, ultimately prevent the development of dysplasia. There is some support for this concept from short-term clinical studies, and a large randomised chemoprevention trial is being instigated which will evaluate the effect of proton pump inhibitors with or without aspirin. Given the epidemic increase in oesophageal adenocarcinoma and the dismal 5-year mortality rate, a radical approach is necessary to prevent cancer development in individuals with pre-malignant lesions.
|
2,338,417 |
Application of genetics to the prevention of colorectal cancer.
|
A first-degree relative of an individual with colorectal cancer is on average at about a twofold increased risk. This could not occur without there being strong underlying risk factors that are correlated in relatives. About 90% of colorectal cases occur in people who are above median familial/genetic risk, so there is great potential to use genetics to prevent colorectal cancer. Two rare inherited syndromes have been identified: familial adenomatous polyposis (FAP) and hereditary non-polyposis colorectal cancer (HNPCC). The former appears to be mostly due to mutations in the APC gene, and the latter to mutations in mismatch repair (MMR) genes, so it would be better named as hereditary mismatch repair deficiency (HMRDS). By fully characterising a population-based series of early-onset cases, we have shown that MMR gene mutation carriers and their relatives can be more efficiently identified by characterising the tumours of early-onset cases, independently of their cancer family history, using immunohistochemistry (IHC)-not microsatellite instability (MSI) testing. This identifies the specific MMR gene likely to be involved, reducing the costs of mutation testing. Identification of genetically susceptible individuals using the tumour phenotype of affecteds, rather than family cancer history, could become the standard approach of cancer genetic services in the twenty-first century, and could lead to cancer prevention in individuals who are at a high genetic risk when young. There is an urgent need for research on the efficacy and optimisation of surveillance procedures in these high-risk individuals, and identification of the environmental, lifestyle and other genetic factors that exacerbate, or ameliorate, risk in mutation carriers.
|
2,338,418 |
Lifestyle and medical approaches to cancer prevention.
|
Cancer risk can be reduced by adopting a healthy lifestyle and by medical means. Tobacco control is central to public policies for cancer prevention. Overweight and obesity in the United States may contribute to 20% of cancer deaths in women and 14% in men. Cancer prevention strategies have progressed from a predominant lifestyle approach to a model that combines clinical investigations in a medical setting with public health interventions. This change stems from advances in identifying, developing, and testing agents with the potential either to prevent cancer initiation, or to inhibit or reverse the progression of premalignant lesions to invasive cancer. Encouraging laboratory and epidemiologic studies, along with secondary endpoints in treatment trials, have provided a strong scientific rationale for the hypothesis that a pharmacologic approach--chemoprevention--can reduce cancer risk. Numerous chemopreventive agents, including naturally occurring vitamins, minerals, phytochemicals, and synthetic compounds, have proved to be safe and effective in preclinical and clinical studies. Promising results have been reported for cancers of the prostate, breast, colon, lung, bladder, cervix, oral cavity, esophagus, skin, and liver. The use of emerging technologies, identification of biomarkers of risk, and advances in genetic research are being applied to chemoprevention research. An interdisciplinary research approach to investigate molecular and genetic markers--as well as chemoprevention and lifestyle strategies--that affect cancer risk is being applied to the most common types of cancer in the United States in women (breast) and men (prostate).
|
2,338,419 |
[Differential diagnosis of a polyhydramnion in hyperprostaglandin E syndrome: a case report].
|
A polyhydramnion is diagnosed in 0.4 to 3.3 % of all pregnancies. The most common causes of increased amniotic fluid include maternal diabetes mellitus, fetal malformations and chromosomal aberrations, twin-to-twin transfusion syndrome, rhesus incompatibility syndrome, and congenital infections. After exclusion of other etiologies for polyhydramnion, the very rare, autosomal-recessive transferred hyperprostaglandin E syndrome (HPS) has to be considered.</AbstractText>We report on a 31-year-old women who visited our obstetrical outpatient clinics at 22 + 4 weeks of gestation for prenatal ultrasound scanning and amniocentesis. This, the patient's third pregnancy had been without complications so far. She had delivered two children before, one of them bearing the HPS. The women herself suffered from epilepsy. At 26 + 0 weeks of gestation the pregnancy was complicated by a polyhydramnion requiring serial amniocentesis for reducing amniotic fluid load. Among others, her amniotic fluid was analyzed for chloride concentration and for genetic aberrations regarding HPS. Serological investigations and an oral glucose tolerance test (oGTT) were performed.</AbstractText>Amniocentesis revealed a normal chromosomal pattern. The oGTT demonstrated values in the normal range. Serological investigations regarding TORCH infections were without pathological findings. The chloride concentration was highly increased in the amniotic fluid, which is suspicious for HPS. Finally, molecular analysis proved an NKCC2-mutation responsible for HPS. A cesarean section was performed at 33 + 3 weeks of gestation.</AbstractText>If HPS is suspected to be the cause of polyhydramnions, the chloride concentrations in the amniotic fluid and molecular analysis for HPS should be performed. Interdisciplinary care, diagnostics and therapy in an experienced perinatal center are essential for an optimal outcome of the pregnancy and the newborn infant.</AbstractText>
|
2,338,420 |
Liver-specific expression of interferon gamma following adenoviral gene transfer controls hepatitis B virus replication in mice.
|
Interferons control viral replication and the growth of some malignant tumors. Since systemic application may cause severe adverse effects, tissue-specific expression is an attractive alternative. Liver-directed interferon gene therapy offers promising applications such as chronic viral hepatitis B or C or hepatocellular carcinoma and thus needs testing in vivo in suitable animal models. We therefore used the Tet-On system to regulate gene expression in adenoviral vectors, and studied the effect of liver-specific and regulated interferon gamma expression in a mouse model of chronic hepatitis B virus (HBV) infection. In a first generation adenoviral vector, genes encoding for firefly luciferase and interferons alpha, beta or gamma, respectively, were coexpressed under control of the bidirectional tetracycline-regulated promoter P(tet)bi. Liver-specific promoters driving expression of the reverse tetracycline controlled transactivator ensured local expression in the livers of HBV transgenic mice. Following gene transfer, we demonstrated low background, tight regulation and a 1000-fold induction of gene expression by doxycycline. Both genes within the bidirectional transcription unit were expressed simultaneously, and in a liver-specific fashion in cell culture and in living mice. Doxycycline-dependent interferon gamma expression effectively controlled HBV replication in mice, but did not eliminate HBV transcripts. This system will help to study the effects of local cytokine expression in mouse disease models in detail.
|
2,338,421 |
Genome-wide and Ordered-Subset linkage analyses provide support for autism loci on 17q and 19p with evidence of phenotypic and interlocus genetic correlates.
|
Autism is a neurobehavioral spectrum of phenotypes characterized by deficits in the development of language and social relationships and patterns of repetitive, rigid and compulsive behaviors. Twin and family studies point to a significant genetic etiology, and several groups have performed genomic linkage screens to identify susceptibility loci.</AbstractText>We performed a genome-wide linkage screen in 158 combined Tufts, Vanderbilt and AGRE (Autism Genetics Research Exchange) multiplex autism families using parametric and nonparametric methods with a categorical autism diagnosis to identify loci of main effect. Hypothesizing interdependence of genetic risk factors prompted us to perform exploratory studies applying the Ordered-Subset Analysis (OSA) approach using LOD scores as the trait covariate for ranking families. We employed OSA to test for interlocus correlations between loci with LOD scores > or =1.5, and empirically determined significance of linkage in optimal OSA subsets using permutation testing. Exploring phenotypic correlates as the basis for linkage increases involved comparison of mean scores for quantitative trait-based subsets of autism between optimal subsets and the remaining families.</AbstractText>A genome-wide screen for autism loci identified the best evidence for linkage to 17q11.2 and 19p13, with maximum multipoint heterogeneity LOD scores of 2.9 and 2.6, respectively. Suggestive linkage (LOD scores > or =1.5) at other loci included 3p, 6q, 7q, 12p, and 16p. OSA revealed positive correlations of linkage between the 19p locus and 17q, between 19p and 6q, and between 7q and 5p. While potential phenotypic correlates for these findings were not identified for the chromosome 7/5 combination, differences indicating more rapid achievement of "developmental milestones" was apparent in the chromosome 19 OSA-defined subsets for 17q and 6q. OSA was used to test the hypothesis that 19p linkage involved more rapid achievement of these milestones and it revealed significantly increased LOD* scores at 19p13.</AbstractText>Our results further support 19p13 as harboring an autism susceptibility locus, confirm other linkage findings at 17q11.2, and demonstrate the need to analyze more discreet trait-based subsets of complex phenotypes to improve ability to detect genetic effects.</AbstractText>
|
2,338,422 |
A genome-wide screen on the genetics of atopy in a multiethnic European population reveals a major atopy locus on chromosome 3q21.3.
|
Dissecting complex diseases in underlying distinct traits and studying these for their genetic basis might enhance the power as well as the specificity, of detection of disease genes. These phenotypes are known as intermediate phenotypes.</AbstractText>We were interested in the atopic basis of asthma, and used the sensitization to mite (Dermatophagoides pteronyssinus) allergens as a pathophysiologically important intermediate phenotype.</AbstractText>This time we performed a genome-wide scan based on the same already used multiethnic European population consisting of 82 nuclear families with at least two affected siblings. We carried out nonparametric as well as parametric MOD-score analyses based on the genotypes of 603 microsatellite markers.</AbstractText>In comparison with our first genome-wide candidate region search three novel regions additionally appeared to be significant. We obtained significant results for the region 2p12 with a MOD score of 3.35 and for the region 16q21 with a MOD score of 4.18. The most significant result was found for the region 3q21.3 with the same microsatellite marker, which showed significant linkage to atopic dermatitis (AD) in another study with a MOD score of 4.51 and an nonparametric linkage analysis (NPL) of 4.00.</AbstractText>Our findings indicate that atopy, allergic asthma, allergic rhinitis and AD on the one hand are distinct traits on both the clinical and genetic basis, but on the other hand, our results also underline that these traits are closely related diseases concerning the atopic basis of the traits.</AbstractText>
|
2,338,423 |
Clinical description and mode of inheritance of idiopathic epilepsy in English springer spaniels.
|
To determine clinical characteristics and mode of inheritance of idiopathic epilepsy (IE) in English Springer Spaniels.</AbstractText>Original study.</AbstractText>45 dogs with IE and 74 siblings and their respective parents.</AbstractText>IE was diagnosed on the basis of age at the time of seizure onset and results of laboratory testing and neurologic examinations. Simple segregation analysis was performed with the Davie method.</AbstractText>Median age at the onset of seizures was 3 years; however, 9 (20%) dogs were between 5 and 6 years old at the time of the onset of seizures. Twenty-one dogs (47%) had generalized seizures, and 24 (53%) had focal onset seizures. Results of segregation analysis were consistent with partially penetrant autosomal recessive or polygenic inheritance. Simulated linkage indicated that there was a 58% chance of obtaining suggestive linkage with the available pedigrees.</AbstractText>Results of the present study suggest that in English Springer Spaniels, IE segregates in a manner that is consistent with partially penetrant autosomal recessive inheritance (ie, a single major locus with modifying genes) or polygenic inheritance. Given enough families with accurate phenotypic information and available DNA, it should be possible to use genetic linkage analysis to identify chromosomal segments containing the causative gene or genes.</AbstractText>
|
2,338,424 |
[Corneal transplantation--immunological mechanisms of rejection episode].
|
Organ transplantation including cornea is often only the one method of treatment in case of their irreversible destruction. The genetic difference between donor and graft recipient makes the immunological system recognizes foreign antigens and triggers off a rejection episode. This article reviews corneal graft rejection immunology and indicates possible future options for the clinical evaluation of more specific therapeutic agents that modulate the immunological mechanisms of allograft rejection. It discusses also the role of HLA matching in the survival of corneal grafts especially in "high risk" eyes.
|
2,338,425 |
Beta-thalassaemia carrier detection by ELISA: a simple screening strategy for developing countries.
|
The frequency of beta-thalassaemia in India ranges from 3.5% to 15% in the general population and of the 100,000 children born with thalassaemia major in the world, 10,000 are in India alone. Affected children do not die immediately, but treatment by regular transfusion is costly and leads to iron overload and death. Therefore, health services in lower-economic countries can sustain patients only if the numbers can be limited. Detecting carrier couples by simple blood test can prevent thalassaemia and at-risk couples can be identified and informed of their genetic risk before having children. A prevention programme including population screening, counselling, and prenatal diagnosis will markedly reduce the birth prevalence of affected individuals. Hemoglobin A2 (HbA2) measurement in human hemolysates has great significance, since its level can indicate beta-thalassaemia carrier status in otherwise healthy individuals. We have developed a rapid, simple, and inexpensive enzyme linked immunosorbent assay (ELISA) for the quantitation of HbA2, which can be used in carrier screening programmes in developing countries like India. In a limited trial for beta-thalassaemia carrier screening, the results obtained with ELISAs were compared with those obtained with the microcolumn chromatography method (r = 0.89).
|
2,338,426 |
Rapid simulation of P values for product methods and multiple-testing adjustment in association studies.
|
A major aim of association studies is the identification of polymorphisms (usually SNPs) associated with a trait. Tests of association may be based on individual SNPs or on sets of neighboring SNPs, by use of (for example) a product P value method or Hotelling's T test. Linkage disequilibrium, the nonindependence of SNPs in physical proximity, causes problems for all these tests. First, multiple-testing correction for individual-SNP tests or for multilocus tests either leads to conservative P values (if Bonferroni correction is used) or is computationally expensive (if permutation is used). Second, calculation of product P values usually requires permutation. Here, we present the direct simulation approach (DSA), a method that accurately approximates P values obtained by permutation but is much faster. It may be used whenever tests are based on score statistics--for example, with Armitage's trend test or its multivariate analogue. The DSA can be used with binary, continuous, or count traits and allows adjustment for covariates. We demonstrate the accuracy of the DSA on real and simulated data and illustrate how it might be used in the analysis of a whole-genome association study.
|
2,338,427 |
Ferritinopathy: diagnosis by muscle or nerve biopsy, with a note on other nuclear inclusion body diseases.
|
Ferritinopathy (neuroferritinopathy) has recently been identified as an autosomal dominant, multisystem disease, mainly affecting the central nervous system. It is caused by mutations in exon 4 of the ferritin light chain gene on chromosome 19. Its fine structural hallmarks are granular nuclear inclusions in neurons, oligodendroglial and microglial cells with similar extracellular derivatives in the central nervous system, muscle, peripheral nerve, and skin. These pathognostic structures have previously been described in perivascular cells of muscle and nerve biopsy specimens in a case with an obviously identical disease, formerly described as 'granular nuclear inclusion body disease'. The nuclear inclusions, at the light microscopic level, are iron positive following histochemical iron reactions and immunoreactive for ferritin antibodies. At the electron microscopic level, in contrast to filamentous nuclear inclusions in 'neuronal intranuclear hyaline inclusion disease', dominant spinocerebellar atrophies and other trinucleotide repeat diseases, they are basically composed of granules measuring 5-15 nm. A moderate peak of iron detectable by energy dispersive microanalysis of the granular nuclear inclusions in ferritinopathy may also be significant. It is emphasized that ferritinopathy or 'granular nuclear inclusion body disease' can be diagnosed by a simple muscle or nerve biopsy without brain biopsy, autopsy, or molecular genetic testing of the considerable number of neurodegenerative diseases with possibly similar symptomatology.
|
2,338,428 |
Extremely high interleukin-6 blood levels and outcome in the critically ill are associated with tumor necrosis factor- and interleukin-1-related gene polymorphisms.
|
To determine the allelic frequencies of interleukin (IL)-6-, IL-1-, and tumor necrosis factor-alpha (TNF)-related gene polymorphisms in critically ill patients with extremely high IL-6 blood level and to examine the genetic effects on their clinical courses.</AbstractText>Population-based association study.</AbstractText>A general intensive care unit in a university teaching hospital.</AbstractText>A total of 150 consecutive critically ill patients recruited at admission to the intensive care unit, regardless of diagnosis, and 150 healthy volunteers.</AbstractText>IL-6 blood levels were measured daily with chemiluminescence immunoassay. The IL-6 peak levels were significantly correlated with simultaneously measured TNF (r = .659, p < .0001) and IL-1beta levels (r = .518, p < .0001), respectively. Single nucleotide polymorphism at position -174 and -596 sites of the IL-6 (IL6-174*G/C and IL6-596*G/A), -308 site of the TNF (TNF-308*G/A), and -511 site of the IL-1beta (IL1B-511*C/T) were identified with real-time polymerase chain reaction assay using specific fluorescence-labeled probe. Within the IL-1 receptor antagonist intron 2, a various number of tandem repeat polymorphisms (IL1RN*1-5) were identified after polymerase chain reaction with gel electrophoresis. Allelic frequencies of patients with IL-6 peak levels of > or =10,000 pg/mL (group A) were compared with those of patients with IL-6 peak levels of <10,000 pg/mL (group B). Neither IL6-174*C nor IL6-596*A were recognized in all the subjects; however, group A showed a higher frequency of TNF-308*A (p = .054), IL1B-511*T (p = .013), and non-IL1RN*1 (p = .008) allele compared with group B. TNF-308*A, IL1RN*2 or IL1RN*3 allele carriers of group A showed sustained high IL-6 levels, despite countermeasures against hypercytokinemia, and their survival rate was lower than that of the noncarriers of those high-risk alleles (p = .025).</AbstractText>TNF-308*A, IL1RN*2, and IL1RN*3 alleles were associated with the prevalence of the extremely high IL-6 blood level in the critically ill, their uncontrollable blood IL-6 kinetics, and outcome.</AbstractText>
|
2,338,429 |
A functional single-nucleotide polymorphism of the G-CSF receptor gene predisposes individuals to high-risk myelodysplastic syndrome.
|
The granulocyte colony-stimulating factor receptor (G-CSF-R) transmits signals for proliferation and differentiation of myeloid progenitor cells. Here we report on the identification of a rare single nucleotide polymorphism within its intracellular domain (G-CSF-R_Glu785Lys). Screening a cohort of 116 patients with primary myelodysplastic syndromes (MDS), de novo acute myeloid leukemia (AML) (84 patients), as well as 232 age- and sex-matched controls revealed a highly significant association of the G-CSF-R_785Lys allele with the development of high-risk MDS as defined by more than 5% bone marrow blasts (9.7% versus 0.9% in controls; P = .001; odds ratio [OR], 12.5; 95% confidence interval [CI], 2.4-58.9) or an International Prognostic Scoring System score of intermediate-2 or high (13.0% versus 0.9%; P < .001; OR, 14.0; 95% CI, 3.4-85.0). Functional analysis by retroviral transfer of G-CSF-R_785Lys into myeloid progenitor cells of G-CSF-R-deficient mice showed a significantly diminished colony-formation capacity after G-CSF stimulation as compared with cells transduced with the wild-type receptor. These results suggest that lifelong altered G-CSF response by the G-CSF-R_785Lys may render individuals susceptible to development of high-risk MDS.
|
2,338,430 |
Invasive genetic diagnosis in multiple pregnancies.
|
Chromosomal anomalies and mendelian diseases are more frequent in multiple gestations than in singletons. Prenatal diagnosis is recommended in multiple pregnancies whenever indicated. Invasive testing using amniocentesis or chorionic villus sampling can be performed safely. Chorionic villus sampling has a significant advantage over amniocentesis because it offers rapid karyotyping and biochemical and DNA studies at an early stage of pregnancy. Only experienced centers should perform these procedures because of the technical aspects and the expertise needed in handling discordant results.
|
2,338,431 |
Rational approach to genetic testing of cystic fibrosis (CF) in infertile men.
|
Male infertility as a result of isolated congenital bilateral absence of the vas deferens (CBAVD) is one primary genital form of cystic fibrosis (CF) and occurs in 1-2% of infertile men. Assisted fertilization in patients with CBAVD increases the risk of transmitting mutations in the CF gene. We developed a rational approach to genetic CF testing in infertile men. A total of 282 infertile male patients were screened for the most common CF mutations (DeltaF508, R117H, IVS8-5T). Clinical data including medical history, examination, semen analysis, sweat tests, karyotypes and hormonal values were analysed. We identified 23 patients carrying mutations in the CF gene (DeltaF508: 10 patients; R117H: six patients; IVS8-5T: 11 patients). Two patients were compound heterozygote for DeltaF508/R117H, two others for DeltaF508/IVS8-5T. Correlating these molecular analyses with the clinical data pertaining to serum follicle-stimulating hormone concentration, semen pH, sperm count and total testicular volume, we were able to develop a score with a high specificity (98.4) for the presence of a cystic fibrosis transmembrane conductance regulator (CFTR) mutation, but only with a low sensitivity (positive post-test likelihood: 62.5%; negative post-test likelihood: 6.3%). With regard to the low sensitivity and the high number of CFTR mutations found in this heterogeneous group of infertile men, we still recommend genetic CF testing before assisted fertilization.
|
2,338,432 |
Accounting for coalescent stochasticity in testing phylogeographical hypotheses: modelling Pleistocene population structure in the Idaho giant salamander Dicamptodon aterrimus.
|
Several theoretical studies have demonstrated the importance of accounting for coalescent stochasticity in phylogeographical studies, however, there are few empirical examples that do so in the context of explicit hypothesis testing. Here, we provide an example from the Idaho giant salamander (Dicamptodon aterrimus) using 118 mtDNA sequences, nearly 2 kb in length. This species is endemic to mesic forests in northern and central Idaho, and several a priori hypotheses have been erected based both on palaeoclimatic grounds and from phylogeographical studies of codistributed amphibians. Phylogenetic analysis of the D. aterrimus data suggests an expansion from a single refugium south of the Salmon River, whereas the inference from nested clade analysis is one of expansion from a single refugium in the Clearwater drainage. Explicit testing of these hypotheses, using geographically structured coalescent simulations to erect null distributions, indicates we can reject expansion from the Clearwater drainage (pCLW = 0.089), but not expansion from the South Fork of the Salmon drainage (pSAL = 0.329). Furthermore, data from codistributed amphibians suggest that there may have been two refugia, and an amova shows that most of the molecular variance partitioned between the Clearwater and the Salmon drainages (54.40%; P < 0.001) and within drainages (43.61%; P < 0.001). As a result, we also tested three a priori hypotheses which predicted that both the Clearwater and Salmon drainages functioned as refugia during the late Pleistocene; we could reject (PCORD = 0.019) divergence dates during the Cordilleran glacial maxima [c. 20 000 years before present (ybp)], during the Sangamon interglacial (c. 35 000 ybp; pSANG = 0.032), as well as pre-Pleistocene divergence (c. 1.7 Ma; ppP < 0.001). Mismatch distributions and Tajima's D within the individual drainages provide further support to recent population expansion. This work demonstrates coalescent stochasticity is an important phenomenon to consider in testing phylogeographical hypotheses, and suggests that analytical methods which fail to sufficiently quantify this uncertainty can lead to false confidence in the conclusions drawn from these methods.
|
2,338,433 |
Genetic variability in natural populations of Arabidopsis thaliana in northern Europe.
|
Ten populations of the model plant Arabidopsis thaliana were collected along a north-south gradient in Norway and screened for microsatellite polymorphisms in 25 loci and variability in quantitative traits. Overall, the average levels of genetic diversity were found to be relatively high in these populations, compared to previously published surveys of within population variability. Six of the populations were polymorphic at microsatellite loci, resulting in an overall proportion of polymorphic loci of 18%, and a relatively high gene diversity for a selfing species (HE = 0.06). Of the overall variability, 12% was found within populations. Two of six polymorphic populations contained heterozygous individuals. Both FST and phylogenetic analyses showed no correlation between geographical and genetic distances. Haplotypic diversity patterns suggested postglacial colonization of Scandinavia from a number of different sources. Heritable variation was observed for many of the studied quantitative traits, with all populations showing variability in at least some traits, even populations with no microsatellite variability. There was a positive association between variability in quantitative traits and microsatellites within populations. Several quantitative traits exhibited QST values significantly less than FST, suggesting that selection may be acting to retard differentiation for these traits.
|
2,338,434 |
Characterization of genotype-phenotype relationships and stratification by the CARD15 variant genotype for inflammatory bowel disease susceptibility loci using multiple short tandem repeat genetic markers.
|
The classification of ulcerative colitis (UC), Crohn disease (CD), and indeterminate colitis (IC) as forms of inflammatory bowel disease (IBD) is based on clinical, radiological, and histological criteria. The genetic basis of IBD is well founded, and susceptibility loci have been identified on several different chromosomes. We aimed to define genotype-phenotype relationships and interactions with the IBD susceptibility gene CARD15for various IBD susceptibility loci (IBD1, IBD2, IBD5, IBD6, IBD7, and chromosome 4) by characterizing previously described peak LOD score short tandem repeat (STR) markers. The study population consisted of 484 severely affected Caucasian patients with IBD, 144 healthy controls, and 348 nonaffected first-degree relatives of IBD patients. Associations were defined with the use of population- and family-based methodology. Correction for multiple testing was performed with a method based on an experimental false discovery rate. We provide novel evidence to show that IBD2 is involved in susceptibility to IC and terminal ileal CD in this population, with overrepresentation of IBD2 STR D12S83 (GenBank Z16592.1) allele 7 (g.49_60del[CA](6)) in IC (q = 0.038, P = 0.014) and underrepresentation of allele 8 (g.51_60del[CA](5)) in terminal ileal CD (q = 0.038, P = 0.016). The association of IBD2 with IC was confirmed by family-based testing. We also provide novel evidence to show that IBD5 is involved in susceptibility to IC and colonic/ileocolonic CD in this population, with overrepresentation of IBD5 STR D5S1984 (GenBank Z52623.1) allele 5 (g.183_186del[CA](2)) in both IC (q = 0.040, P = 0.005) and colonic/ileocolonic CD (q = 0.040, P = 0.004). Evidence is also given for potential interactions between CARD15and IBD2/IBD5. Other findings include an association of IBD2 with UC, and an association of IBD1 with terminal ileal and colonic/ileocolonic CD.
|
2,338,435 |
Spectrum of sequence variations in the FANCA gene: an International Fanconi Anemia Registry (IFAR) study.
|
Fanconi anemia (FA) is an autosomal recessive disorder that is defined by cellular hypersensitivity to DNA cross-linking agents, and is characterized clinically by developmental abnormalities, progressive bone-marrow failure, and predisposition to leukemia and solid tumors. There is extensive genetic heterogeneity, with at least 11 different FA complementation groups. FA-A is the most common group, accounting for approximately 65% of all affected individuals. The mutation spectrum of the FANCA gene, located on chromosome 16q24.3, is highly heterogeneous. Here we summarize all sequence variations (mutations and polymorphisms) in FANCA described in the literature and listed in the Fanconi Anemia Mutation Database as of March 2004, and report 61 novel FANCA mutations identified in FA patients registered in the International Fanconi Anemia Registry (IFAR). Thirty-eight novel SNPs, previously unreported in the literature or in dbSNP, were also identified. We studied the segregation of common FANCA SNPs in FA families to generate haplotypes. We found that FANCA SNP data are highly useful for carrier testing, prenatal diagnosis, and preimplantation genetic diagnosis, particularly when the disease-causing mutations are unknown. Twenty-two large genomic deletions were identified by detection of apparent homozygosity for rare SNPs. In addition, a conserved SNP haplotype block spanning at least 60 kb of the FANCA gene was identified in individuals from various ethnic groups.
|
2,338,436 |
Alphavirus replicon particles containing the gene for HER2/neu inhibit breast cancer growth and tumorigenesis.
|
Overexpression of the HER2/neu gene in breast cancer is associated with an increased incidence of metastatic disease and with a poor prognosis. Although passive immunotherapy with the humanized monoclonal antibody trastuzumab (Herceptin) has shown some effect, a vaccine capable of inducing T-cell and humoral immunity could be more effective.</AbstractText>Virus-like replicon particles (VRP) of Venezuelan equine encephalitis virus containing the gene for HER2/neu (VRP-neu) were tested by an active immunotherapeutic approach in tumor prevention models and in a metastasis prevention model.</AbstractText>VRP-neu prevented or significantly inhibited the growth of HER2/neu-expressing murine breast cancer cells injected either into mammary tissue or intravenously. Vaccination with VRP-neu completely prevented tumor formation in and death of MMTV-c-neu transgenic mice, and resulted in high levels of neu-specific CD8+ T lymphocytes and serum IgG.</AbstractText>On the basis of these findings, clinical testing of this vaccine in patients with HER2/neu+ breast cancer is warranted.</AbstractText>
|
2,338,437 |
Rare variant of apolipoprotein E (Arg136 -->Ser) in two normolipidemic individuals.
|
Through the analysis of the common apolipoprotein (apo) E gene polymorphism in large Caucasian population study with the PCR and subsequent restriction analysis, we have identified carriers of mutant allele Arg136-->Ser. Both of them (71-years-old female and her 43-years-old son) have normal lipid parameters. We suggest that Arg136-->Ser mutation in apoE is not necessarily connected with elevated lipid levels in all cases. Furthermore, so far unidentified factors (environmental and/or genetic) are important for the development of lipid metabolism disorders in apoE Arg136-->Ser mutation carriers.
|
2,338,438 |
Under the skin: On the impartial treatment of genetic and environmental hypotheses of racial differences.
|
Environmental and genetic explanations have been given for Black-White racial differences in intelligence and other traits. In science, viable, alternative hypotheses are ideally given equal Bayesian prior weights; but this has not been true in the study of racial differences. This article advocates testing environmental and genetic hypotheses of racial differences as competing hypotheses. Two methods are described: (a) fitting means within structural equation models and (b) predicting means of interracial children. These methods have limitations that call for improved research designs of racial differences. One improvement capitalizes on biotechnology. Genetic admixture estimates--the percentage of genes of European origin that a Black individual possesses (independent of genes related to skin coloration)--can represent genetic influences. The study of interracial children can be improved by increasing sample size and by choosing family members who are most informative for a research question. Eventually, individual-admixture estimates will be replaced by molecular genetic tests of alleles of those genes that influence traits.
|
2,338,439 |
CD3 delta immunodeficiency.
|
The review describes advances in understanding the role of the CD3 delta subunit in human T-cell development as deduced from a recently described human immunodeficiency. The review also compares CD3 delta deficiency with other human CD3 subunit deficiencies and with corresponding animal models.</AbstractText>In describing CD3 delta deficiency in humans this review shows that patients with profound T-cell depletion, who present at 2-3 months with severe viral infection, lack CD3 delta as a result of a mutation in the extracellular domain of this gene. The genetic aberration was discovered by comparing patients' and normal thymocytes, using mass gene screening with the microarray technique. In humans the absence of CD3 delta results in a complete arrest in thymocyte development at the stage of double negative to double positive transition and the development of gamma delta T-cell receptor-positive T cells is also impaired.</AbstractText>Unlike patients with CD3 gamma or CD3 epsilon deficiency who have a milder condition, patients with CD3 delta deficiency present with severe lethal susceptibility to infections during early infancy. As expected, this profound immunodeficiency was cured with an allogenic bone marrow transplantation. In contrast to murine CD3 (-/) delta, which retains a normal gamma delta T-cell receptor-positive T-cell population and only partly affects the developmental transition of double positive to single positive thymocytes, CD3 delta in humans appears to be more critically required for the development of both alpha beta and gamma delta T-cell receptor-positive T-cell lineages. The studies also show for the first time that comparing relevant patients' with normal tissue using microarray technology can aid in the discovery of the genetic basis of inherited disorders.</AbstractText>
|
2,338,440 |
[The application of transgenic plant in evaluating the genotoxicity of environmental contaminants].
|
Environmental contaminants are powerful mutagenic factors for organisms. Several testing materials and methods have been used to assess the genotoxicity of environmental factors. Transgenic plants testing system can not only evaluate the level of genotoxicity, but also provide information on the genetic effects at molecular level. We introduce the use of transgenic plants in biomonitoring environmental factors.
|
2,338,441 |
[Research progress of methods of SSR primers development].
|
SSRs is one of molecular markers technology based on DNA length polymorphism and an efficient tool for population genetic studies and primary genetic linkage maps construction. Because of a special primer marker, It's necessary to know a species DNA sequence in order to design primers for PCR testing. That is to say, there is a problem of SSR primer development. For the progress of SSR marker technology, the methods of developing SSR primer could be divided into four kinds: traditional constructing and screening genome library procedure, the SSR richment procedure, avoiding screening genome library procedure and database search procedure. This paper reviewed these four methods' operation processes and their advantages and disadvantages. In addition, transferability of SSR primers in closely related species were introduced in recent years.
|
2,338,442 |
[Genetic polymorphism of 4 microsatellites DNA in 3 goat populations and relationship with heterosis].
|
Gene frequency, polymorphism information contents, number of effective alleles, heterozygosity and genetic distances were studied in Boer goat, Taihang goat and Hebei dairy goat using four microsatellite markers (OarFCB11, OarAE101, McM218, McM38). The crossing effects on Hebei dairy goat and Taihang goat with Boer goat were tested. The results indicated that there are genetic polymorphisms at four microsatellite markers in three goat breeds. Four microsatellite markers can be used for genetic diversity evaluation in goat breeds. The genetic variability of Taihang goat is the highest, and Boer goat is the lowest in three goat breeds. Genetic distances between Boer goat and Hebei dairy goat is bigger than that between Boer goat and Taihang goat. The heterosis between Boer goat and Hebei dairy goat is higher than that between Boer goat and Taihang goat. It accords with testing results on actual heterosis.
|
2,338,443 |
[Genetic polymorphisms of 6 Y-chromosome specific STR loci in the southern Chinese Han population and its application in forensic science].
|
To study the genetic polymorphisms of six Y-chromosome specific STR loci in the southern Chinese Han population and apply it in forensic science, six Y-STR loci were amplified by multiple PCR and the PCR products were detected by using ABI Prism 377 Sequencer. The haplotype frequencies at 6 Y-STR loci were determined in a total of 204 unrelated males from southern Han population of China. Ninety-three father/son pairs with demonstrated paternity and thirty-eight non-paternity father/son pairs were detected by using our Y-STR system. As a result, the number of alleles for DYS393, DYS19, DYS389 II, DYS390, DYS391 and DYS385 were 5, 6, 8, 6, 4 and 44, respectively. A total of 176 haplotypes at 6 Y-STR loci were found. Two father/son pairs with single Y-STR mutation were observed in the 93 father/son pairs with demonstrated paternity. Among the 38 non-paternity father/son pairs, one case with one Y-STR exclusion of paternity, one case with two Y-STR exclusions and 35 cases with 3 or more Y-STR exclusions were observed. Non-exclusion of paternity at 6 Y-STR loci was found only in one case. This result indicated that the six Y-STR loci were highly polymorphic and are suitable for personal identification and paternity testing.
|
2,338,444 |
Selection of twenty-four highly informative SNP markers for human identification and paternity analysis in Koreans.
|
A number of DNA marker types suitable for human identification and parentage testing have been developed, of which single nucleotide polymorphisms (SNPs) merit attention as they are abundant, genetically stable, and amenable to high-throughput automated analysis. In this regard, 24 highly informative SNP markers representing each 22 autosome and both sex chromosomes were selected, and the allele and genotype frequencies of these SNPs were determined in a group composed of 30 unrelated Koreans. Based on frequency data from this group, the estimated probability of identity (P(I)) and probability of paternity exclusion (P(E)) with 22 autosomal SNP loci were 1.905x10(-10) and 98.9%, respectively. The SNPs in this study offer a small but highly accurate database that will be an essential reference for SNP-based forensic application in the future.
|
2,338,445 |
Paternity analysis in special fatherless cases without direct testing of alleged father.
|
The ability to establish the biological father, in which the father of a person is not available, named "reverse paternity determination", is based on the determination of STR alleles in mother and her child, other children and brothers of the alleged father, and deduction of genetic constitution of the father by the basis of genetic laws. Presented herein are two cases of reverse paternity determinations. Mother and parenthood DNA was isolated from 300 microl of fresh blood collected into tubes containing the EDTA, using Wizard Genomic DNA purification kit (Promega). DNA amplification was performed using GenePrint STR System (CTT, FFv, and Silver STR III multiplex) (Promega). Amplification results were read on 0.4 mm thick sequencing size polyacrilamide gel (4% for CTT and FFv, and 6% for Silver STR III). Gels were silver stained using Silver Sequence DNA Staining Reagents (Promega). Possible alleles of the alleged father for the loci CSF1PO, TPOX, TH01, F13A01, FESFPS, vWA, D16S539, D7S820, D13S317, LPL, F13B, and HPRTB were established by the selection from alleles determined in mother and parenthood, as to as obligate alleles with which the alleged father contributes to the genetic constitution of investigated child. Probability of paternity was calculated using population data on STR allele frequencies for Romanian population established by our laboratory. These are the first cases of litigious reverse paternity determinations in Romania.
|
2,338,446 |
Genetic study of 11 Y-STRs in the populations of Reggio Calabria, Catanzaro, Cosenza (Calabria--South of Italy).
|
The ability to identify male-specific DNA renders Y-chromosomal STR systems an invaluable help in cases of rape, other sexual assault as well as in kinship testing. The "PowerPlex Y System" is a recent kit by Promega, that co-amplifies the repeat regions of 11 Y-STRs loci. In the present study, we analyzed the allelic distribution of Y-STRs loci in around 300 unrelated males belonging to the three populations of Calabria region.
|
2,338,447 |
Increased T2 signal in the middle cerebellar peduncles on MRI is not specific for fragile X premutation syndrome.
|
The fragile X premutation tremor/ataxia syndrome (FXTAS) is a recently described adult-onset neurodegenerative disorder, in which ataxia, tremor, cognitive decline, parkinsonism, neuropathy and autonomic dysfunction occur in various combinations. It is reported to display a characteristic MRI appearance, with increased T2 signal in the middle cerebellar peduncles and around the dentate nuclei. Diagnostic criteria have been proposed on the basis of these clinical and radiological features, presupposing that a CGG expansion has been demonstrated. We present three cases in which MRI and clinical findings suggested the possibility of FXTAS, although only one was confirmed on genetic testing. The phenotypic overlap with multiple system atrophy of cerebellar type (MSA-C) and the importance of genetic confirmation are emphasised.
|
2,338,448 |
Molecular and clinical description of the first US patients with congenital disorder of glycosylation Ig.
|
In this report we describe the first two US patients with congenital disorder of glycosylation type Ig (CDG-Ig). Both patients presented with symptoms indicating CDG, including developmental delay, hypotonia and failure to thrive, and tested positive for deficient glycosylation of transferrin. Labeling of the patients' lipid-linked oligosaccharides suggested mutations in the hALG12 gene, encoding a mannosyltransferase. Both patients were shown to carry previously unpublished hALG12-mutations. Patient 1 has one allele with a deletion of G29, resulting in a premature stop codon, and another allele with an 824G>A mutation yielding an S275N amino acid change. Patient 2 carries two heterozygous mutations (688T>G and 931C>T), resulting in two amino acid exchanges, Y230D and R311C. An adenoviral vector expressing wild type hALG12 corrects the abnormal lipid-linked oligosaccharide pattern of the patients' cells. In addition to common CDG symptoms, these patients also presented with low IgG and genital hypoplasia, symptoms previously described in CDG-Ig patients. We therefore conclude that a combination of developmental delay, low IgG, and genital hypoplasia should prompt CDG testing.
|
2,338,449 |
Family-based association study of the 5-HT transporter gene and schizophrenia.
|
The gene coding for the 5-HT transporter (5-HTT) is considered as a candidate gene for schizophrenia, because this transporter plays a key role in serotonin neurotransmission. Previous genetic studies focusing on this gene yielded conflicting results, presumably because of stratification biases linked to the case-control association study approach, and the potential genetic and phenotypic heterogeneity of schizophrenia. We investigated the 5-HTTLPR and 17-bp VNTR (variable number of tandem repeats) polymorphisms of this gene in 103 trios using the transmission disequilibrium test. No preferential transmission of either allele of the 17-bp VNTR was observed, but an excess of transmission of the L allele of the 5-HTTLPR polymorphism was detected (p = 0.03). As the haplotype analyses did not improve the strength of the association, our data provide convergent evidence for a significant role of the 5-HTTLPR promoter polymorphism of the 5-HTT gene in the vulnerability to schizophrenia.
|
2,338,450 |
Let them fly or light them up: matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry and fluorescence in situ hybridization (FISH).
|
This review focuses on clinical bacteriology and by and large does not cover the detection of fungi, viruses or parasites. It discusses two completely different but complementary approaches that may either supplement or replace classic culture-based bacteriology. The latter view may appear provocative in the light of the actual market penetration of molecular genetic testing in clinical bacteriology. Despite its elegance, high specificity and sensitivity, molecular genetic diagnostics has not yet reached the majority of clinical laboratories. The reasons for this are manifold: Many microbiologists and medical technologists are more familiar with classical microbiological methods than with molecular biology techniques. Culture-based methods still represent the work horse of everyday routine. The number of available FDA-approved molecular genetic tests is limited and external quality control is still under development. Finally, it appears difficult to incorporate genetic testing in the routine laboratory setting due to the limited number of samples received or the lack of appropriate resources. However, financial and time constraints, particularly in hospitals as a consequence of budget cuts and reduced length of stay, lead to a demand for significantly shorter turnaround times that cannot be met by culture-dependent diagnosis. As a consequence, smaller laboratories that do not have the technical and personal equipment required for molecular genetic amplification techniques may adopt alternative methods such as fluorescence in situ hybridization (FISH) that combines easy-to-perform molecular hybridization with microscopy, a technique familiar to every microbiologist. FISH is hence one of the technologies presented here. For large hospital or reference laboratories with a high sample volume requiring massive parallel high-throughput testing we discuss matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF) of nucleic acids, a technology that has evolved from the post-genome sequencing era, for high-throughput sequence variation analysis (1, 2).
|
2,338,451 |
Application of molecular genetic methods in macrolide, lincosamide and streptogramin resistance diagnostics and in detection of drug-resistant Mycobacterium tuberculosis.
|
Antimicrobial susceptibility testing has traditionally been based on measurements of minimal inhibitory concentrations of antimicrobials. Molecular genetic studies on antimicrobial resistance have produced a great deal of genetic information which can be used for diagnosis of antimicrobial resistance determinants. Bacteria can acquire resistance to macrolides, lincosamides and streptogramin antibiotics by modification of the target site of the drugs, by active efflux of the drugs, and by inactivation of the drugs. The genetic backgrounds of these resistance mechanisms are well known and several molecular methods for detection of resistance determinants have been developed. Outbreaks of multidrug-resistant tuberculosis have focused international attention on the emergence of Mycobacterium tuberculosis strains that are resistant to antimycobacterial agents. Knowledge of the antimycobacterial resistance genetics and progress in molecular methods has made it possible to develop rapid molecular methods for susceptibility testing. This review presents the genetic background of drug resistance and introduces some methods for genotypic susceptibility testing.
|
2,338,452 |
Genetic methods for detection of antimicrobial resistance.
|
Accurate and rapid diagnostic methods are needed to guide antimicrobial therapy and infection control interventions. Advances in real-time PCR have provided a user-friendly, rapid and reproducible testing platform catalysing an increased use of genetic assays as part of a wider strategy to minimize the development and spread of antimicrobial-resistant bacteria. In this review we outline the principal features of genetic assays in the detection of antimicrobial resistance, their advantages and limitations, and discuss specific applications in the detection of methicillin-resistant Staphylococcus aureus, glycopeptide-resistant enterococci, aminoglycoside resistance in staphylococci and enterococci, broad-spectrum resistance to beta-lactam antibiotics in gram-negative bacteria, as well as genetic elements involved in the assembly and spread of antimicrobial resistance.
|
2,338,453 |
Molecular genetic methods for diagnosis and characterisation of Chlamydia trachomatis and Neisseria gonorrhoeae: impact on epidemiological surveillance and interventions.
|
One of the mainstays in the prevention of Chlamydia trachomatis and Neisseria gonorrhoeae infections is the availability of laboratory diagnostics with high sensitivity and specificity. Assays for diagnosis of C. trachomatis include cell culture and nucleic acid amplification tests (NAATs). The major target sequences for C. trachomatis diagnosis by NAATs are located at the cryptic plasmid and the major target used for characterisation is the omp1 gene. The gold standard for diagnosis of N. gonorrhoeae is culture. However, numerous NAATs for identification of N. gonorrhoeae and a number of molecular genetic methods for characterisation of N. gonorrhoeae have been developed. Probably no routine laboratory can attain as high sensitivity by culturing C. trachomatis or N. gonorrhoeae as by using NAATs. For that reason NAATs can be recommended for diagnosing C. trachomatis, but not as the only diagnostic assay for N. gonorrhoeae, due to lack of antibiotic susceptibility testing and specificity problems, most pronounced for pharyngeal and rectal samples. Genotyping of C. trachomatis or N. gonorrhoeae provides additional information for contact tracing. It is recommended for N. gonorrhoeae, at least in low prevalence geographic areas, but cannot today be recommended for C. trachomatis. This is due to the low genetic variability and hence the limited benefits for partner notification. However, genotyping of C. trachomatis may play an important role under special circumstances.
|
2,338,454 |
Molecular genetic methods in the diagnosis of lower respiratory tract infections.
|
Molecular diagnostic techniques, such as PCR, have become useful tools for the rapid etiological diagnosis of lower respiratory tract infections. Nucleic acid amplification tests (NAATs) have been evaluated for detecting most respiratory pathogens, and commercial assays are available for some pathogens. However, standardized protocols are needed before these assays are introduced into routine diagnostic use. For pneumonia, NAATs offer advantages over conventional tests for the detection of Mycoplasma pneumoniae, Legionella spp. and Chlamydia pneumoniae. For pneumococcal pneumonia in adults, PCR adds little to existing diagnostic tests, and is unable to distinguish pneumococcal colonization from infection when testing respiratory samples. Although less sensitive than culture-based methods, several commercial molecular diagnostic assays have been developed for tuberculosis and are useful rapid tests for selected patients. PCR can now be considered the rapid diagnostic test of choice for pertussis and some respiratory virus infections. Further work is required to better characterize the role of molecular diagnostic tests for diagnosing lower respiratory tract infections, and to develop standard assays that can be readily adopted by routine diagnostic laboratories.
|
2,338,455 |
Genetic heterogeneity of Beta thalassemia in Lebanon reflects historic and recent population migration.
|
Beta thalassemia is an autosomal recessive disorder characterized by reduced (beta(+)) or absent (beta(0)) beta-globin chain synthesis. In Lebanon it is the most predominant genetic defect. In this study we investigated the religious and geographic distribution of the beta-thalassemia mutations identified in Lebanon, and traced their precise origins. A total of 520 beta-globin chromosomes from patients of different religious and regional backgrounds was studied. Beta thalassemia mutations were identified using Amplification Refractory Mutation System (ARMS) PCR or direct gene sequencing. Six (IVS-I-110, IVS-I-1, IVS-I-6, IVS-II-1, cd 5 and the C > T substitution at cd 29) out of 20 beta-globin defects identified accounted for more than 86% of the total beta-thalassemia chromosomes. Sunni Muslims had the highest beta-thalassemia carrier rate and presented the greatest heterogeneity, with 16 different mutations. Shiite Muslims followed closely with 13 mutations, whereas Maronites represented 11.9% of all beta-thalassemic subjects and carried 7 different mutations. RFLP haplotype analysis showed that the observed genetic diversity originated from both new mutational events and gene flow from population migration. This study provides information about the types and distribution of beta-thalassemia mutations within each religious group and geographic region, which is essential for the implementation of screening and prevention programs.
|
2,338,456 |
Comprehensive cystic fibrosis mutation epidemiology and haplotype characterization in a southern Italian population.
|
We screened the whole coding region of the cystic fibrosis transmembrane regulator (CFTR) gene in 371 unrelated cystic fibrosis (CF) patients from three regions of southern Italy. Forty-three mutations detected 91.5% of CF mutated chromosomes by denaturing gradient gel electrophoresis analysis, and three intragenic CFTR polymorphisms predicted a myriad of rare mutations in uncharacterized CF chromosomes. Twelve mutations are peculiar to CF chromosomes from southern Italy: R1158X, 4016insT, L1065P and 711 + 1G > T are present in 6.3% of CF chromosomes in Campania; G1244E and 852del22 are present in 9.6% of CF chromosomes in Basilicata and 4382delA, 1259insA, I502T, 852del22, 4016insT, D579G, R1158X, L1077P and G1349D are frequent in Puglia (19.6% of CF alleles). Several mutations frequently found in northern Italy (e.g., R1162X, 711 + 5G > T) and northern Europe (e.g., G551D, I507del and 621 + 1G > T) are absent from the studied population. The I148T-3195del6 complex allele was present in two CF chromosomes, whereas I148T was present in both alleles (as a single mutation) in another CF patient and in five CF carriers; this could result from crossover events. The haplotype analysis of three intragenic polymorphisms (IVS8CA, IVS17bTA and IVS17bCA) compared with data from other studies revealed that several mutations (3849 + 10kbC > T, 1717-1G > A, E585X, 3272-26G > A, L558S, 2184insA and R347P) originated from multiple events, whereas others (R1158X and S549R) could be associated with one or more intragenic recombinant events. Given the large population migration from southern Italy, knowledge of the CF molecular epidemiology in this area is an important contribution to diagnosis, counselling and interlaboratory quality control for molecular laboratories worldwide.
|
2,338,457 |
[Results from 10 years of preimplantation-genetic diagnostics in The Netherlands].
|
To report the data from couples who were referred for preimplantation-genetic diagnostics (PGD) and treatment due to a significantly increased risk of offspring with a serious genetic disorder.</AbstractText>Descriptive, prospective.</AbstractText>Data were collected from couples that underwent PGD in the period 1993/'03 at Maastricht University Hospital. Embryos produced by means of in-vitro fertilisation (IVF) were subjected to genetic tests several days after fertilisation. Subsequently 1 or 2 unaffected embryos were transferred to the uterus. Where there was an increased risk of a male with an X-linked genetic disorder, the gender was determined using fluorescence in-situ hybridisation (FISH). This method was also used to detect structural chromosomal abnormalities. The polymerase chain reaction (PCR) method was used for mutation detection and/or marker analysis of monogenetic disorders.</AbstractText>A total of 691 couples were referred for PGD. The most frequent indications were X-linked disorders (30%), in particular Fragile-X syndrome, Duchenne/Becker muscular dystrophy and haemophilia A/B. This was followed by autosomal dominant disorders (26%), such as Huntington's disease and myotonic dystrophy, and then structural chromosomal abnormalities (24%). A total of 120 women underwent 260 PGD cycles. An embryo transfer was possible in 158 of the cycles and this resulted in 45 successful pregnancies. The pregnancy rate was 17% per cycle initiated and 28% per cycle with embryo transfer. Up until december 2003 29 singletons, 8 sets of twins and 1 set of triplets were born. There were no misdiagnoses and none of the babies had congenital abnormalities.</AbstractText>PGD was a reliable and successful method, with pregnancy rates similar to those of IVF or intracytoplasmatic sperm injection. PGD should be stated as an alternative during the preconception counselling of couples with an increased genetic risk, especially for disorders where PGD can be routinely applied, such as Huntington's disease, myotonic dystrophy, cystic fibrosis, spinal muscular atrophy, Fragile-X syndrome and structural chromosomal abnormalities.</AbstractText>
|
2,338,458 |
[Preimplantation genetic screening for numerical chromosomal abnormalities in embryos from women of 35 years of age and older; first results in The Netherlands].
|
To assess the results of preimplantation genetic screening (PGS) for numerical chromosomal abnormalities in embryos from women of 35 years of age and older.</AbstractText>Prospective, descriptive.</AbstractText>Women who were at least 35 years received standard IVF/ICSI treatment including ovarian hyperstimulation, after which matured oocytes were recovered and inseminated. Three days after insemination, one cell was biopsied from each of the available embryos. In these cells, the copy number of 5 (first 21 patients) or 8 chromosomes was determined using fluorescence in situ hybridisation (FISH). Only embryos with a normal or unknown FISH result were implanted in the uterus. Data were collected in an electronic database.</AbstractText>PGS was done for 28 IVF- and 22 ICSI-treatments; the average age of the 50 women at the beginning of treatment was 38.5 years. There were 360 embryos generated; of the 288 biopsied embryos 156 (54%) contained an abnormal number of chromosomes. In 45 women, 1 or 2 embryos were transferred. This resulted in 8 ongoing pregnancies (8/50; 16%) and the birth of 9 children, all of whom were found to be healthy on a paediatric examination at 3 to 10 months of age. In 4 cases there was no embryo transfer because all the embryos were chromosomally abnormal.</AbstractText>In the first 50 patients in The Netherlands, PGS resulted in an ongoing pregnancy rate of 16% per woman. All children showed normal growth and development.</AbstractText>
|
2,338,459 |
Follistatin-related protein gene (FRP) is expressed in the synovial tissues of rheumatoid arthritis, but its polymorphisms are not associated with genetic susceptibility.
|
To examine the expression level and function of follistatin-related protein gene (FRP, also referred to as FSTL1) in rheumatoid arthritis (RA), and possible association of its polymorphisms with genetic susceptibility to RA.</AbstractText>FRP mRNA expression levels in the synovial tissues from 10 patients with RA and 5 patients with OA were measured using real-time RT-PCR. Effects on the growth of synovial cells were evaluated by stably introducing FRP cDNA into a rheumatoid synovial cell line, E11. Screening of genomic DNA variations was done using DNA from 12 patients with RA and 12 healthy individuals by direct sequencing. Genotypes at the detected polymorphic sites were determined in 224 patients with RA and 220 healthy individuals using PCR-single strand conformation polymorphism.</AbstractText>FRP mRNA was overexpressed in synovial tissues from RA patients by 2.3-fold as compared with those from OA. A rheumatoid synovial cell line (E11) transfected with FRP exhibited reduced proliferation, probably mediated by secreted FRP molecule. 16 genomic variations were identified, among which 4 were polymorphisms within the promoter region and exons, and the remainder were either rare variations or intronic polymorphisms. Genotyping of 4 polymorphic sites did not reveal statistically significant association with the susceptibility to RA.</AbstractText>FRP mRNA is overexpressed in RA synovium, the product of which exerts inhibitory activity on synovial cell growth. Although new polymorphic sites were identified, they were not associated with susceptibility to RA, suggesting that overexpression of FRP is secondarily caused by synovial environment of RA.</AbstractText>
|
2,338,460 |
Changing demographics of advanced maternal age (AMA) and the impact on the predicted incidence of Down syndrome in the United States: Implications for prenatal screening and genetic counseling.
|
This study documents the changes in the percentages of advanced maternal age (AMA) pregnancies in the United States and in Washington State, underlying demographic factors, the impact on the predicted incidence of Down syndrome, and its impact on Down syndrome screening. Data on births in the United States from 1933 to 2002 were obtained from publications and the website of the National Center for Health Statistics. Data for Washington State were obtained from the website of the Washington State Department of Health. Information on births at Swedish Medical Center was obtained from hospital records. The percentage of AMA pregnancies in the US was about 14% before World War II, dropped steadily to about 5% in the 1970s and rose since the 1980s to about 14% in 2002. AMA Fractions are greatest among non-Hispanic Caucasians and Asian/Pacific Islanders, women who have college education and beyond, and are married. However, since 1980, the AMA Fractions have increased across all racial/ethnic groups, educational levels, and married and unmarried women. In Washington State in 2001, the overall AMA Fraction was about 14%, but there was considerable variation in the AMA Fraction across counties. In 1980, AMA pregnancies accounted for about 25% of pregnancies with Down syndrome in the United States. In 2002, AMA pregnancies accounted for more than 50% of Down syndrome pregnancies. Given the current AMA Fraction, offering amniocentesis to women of age 35 and above would result in one in seven pregnant women undergoing amniocentesis. Based on likelihood ratios, AMA as a screening strategy for Down syndrome is significantly inferior to combined serum and sonographic screening.
|
2,338,461 |
New simple tests for age-at-onset anticipation: application to panic disorder.
|
Recently, testing for anticipation has received renewed interest. It is well known that standard statistical methods are inappropriate for this purpose due to problems of sampling bias. Few statistical tests have been proposed for comparing mean age of onset in affected parents with mean age of onset in affected children. All of them are difficult to compute and lack software to perform the tests. In this report, we formulate the problem in terms of symmetry tests. We propose a simple generalized paired t-test and a Wilcoxon signed rank test to adjust for the bias caused by the right truncation of both the parent's and child's ages at onset. We also extend the generalized paired t-test to a random effects model that enables analysis of correlated data from nuclear families, and could be further extended to larger family structures. We illustrate the approaches with an example of panic disorder.
|
2,338,462 |
Analysis of single-locus tests to detect gene/disease associations.
|
A goal of association analysis is to determine whether variation in a particular candidate region or gene is associated with liability to complex disease. To evaluate such candidates, ubiquitous Single Nucleotide Polymorphisms (SNPs) are useful. It is critical, however, to select a set of SNPs that are in substantial linkage disequilibrium (LD) with all other polymorphisms in the region. Whether there is an ideal statistical framework to test such a set of 'tag SNPs' for association is unknown. Compared to tests for association based on frequencies of haplotypes, recent evidence suggests tests for association based on linear combinations of the tag SNPs (Hotelling T(2) test) are more powerful. Following this logical progression, we wondered if single-locus tests would prove generally more powerful than the regression-based tests? We answer this question by investigating four inferential procedures: the maximum of a series of test statistics corrected for multiple testing by the Bonferroni procedure, T(B), or by permutation of case-control status, T(P); a procedure that tests the maximum of a smoothed curve fitted to the series of of test statistics, T(S); and the Hotelling T(2) procedure, which we call T(R). These procedures are evaluated by simulating data like that from human populations, including realistic levels of LD and realistic effects of alleles conferring liability to disease. We find that power depends on the correlation structure of SNPs within a gene, the density of tag SNPs, and the placement of the liability allele. The clearest pattern emerges between power and the number of SNPs selected. When a large fraction of the SNPs within a gene are tested, and multiple SNPs are highly correlated with the liability allele, T(S) has better power. Using a SNP selection scheme that optimizes power but also requires a substantial number of SNPs to be genotyped (roughly 10-20 SNPs per gene), power of T(P) is generally superior to that for the other procedures, including T(R). Finally, when a SNP selection procedure that targets a minimal number of SNPs per gene is applied, the average performances of T(P) and T(R) are indistinguishable.
|
2,338,463 |
Prevalence of the FMR1 mutation in Taiwan assessed by large-scale screening of newborn boys and analysis of DXS548-FRAXAC1 haplotype.
|
If carrier women could be identified in time and take appropriate measures, fragile X syndrome (FXS) can be prevented. Wide screening of women to be or in their early pregnancy was considered a good approach to identify carriers without misdetection. Nevertheless, we argued against the cost-effectiveness of implementing such a screening program in Taiwan, due to the lower carrier rate found in our pilot study. To reliably estimate the prevalence of mutant FMR1 gene in Taiwan, we anonymously screened 10,046 newborn boys using bloodspot polymerase chain reaction (PCR). Among them, the sample from one boy, who was most likely had FXS, failed repeatedly in PCR amplification. The estimated prevalence of premutation (55-200 CGG repeats) and intermediate alleles (45-54 CGG repeats) was 1:1,674 (n = 6) and 1:143 (n = 70), respectively. All these estimates were constantly lower than that reported in Caucasian populations, with variable statistic significance. Furthermore, when comparing analyses of the distribution of alleles at the two most often investigated microsatellite loci, DXS548 and FRAXAC1, between 100 control and 28 unrelated fragile X chromosomes, we found no apparent founder haplotype prevalent among the fragile X patients. Because a few founder haplotypes were reportedly prevalent in two thirds of fragile X alleles in Caucasians and in Chinese from Central China, we thus suggested that lack of founder fragile X chromosomes might result in a relatively low prevalence of mutant FMR1 gene in a population, as observed in Taiwan.
|
2,338,464 |
Hereditary cancer predisposition syndromes.
|
Cancer genetics is increasingly becoming integrated into the practice of modern medical oncology. The ability to distinguish a growing proportion of the 5% to 10% of all cancers that develop in individuals who have inherited a genetic mutation conferring heightened susceptibility to specific cancers may permit targeted efforts in cancer surveillance and prevention. While these individuals comprise a small proportion of the overall burden of cancer, strategies successful in reducing their remarkable cancer risks may be generalizable to the broader population. In this review, we highlight the most common hereditary cancer syndromes, most attributable to genes inherited in an autosomal dominant manner with incomplete penetrance, and a number of rare syndromes in which particular progress has been made. The prevalence, penetrance, tumor spectrum, and underlying genetic defects are discussed and summarized in a large table in which a more comprehensive enumeration of syndromes is provided.
|
2,338,465 |
Preliminary data suggest that mutations in the CgRP pathway are not involved in human sporadic cryptorchidism.
|
In testicular descent to the scrotum, a multistep process, many anatomical and hormonal factors play a role. Cryptorchidism occurs in about 1-2% of males and may cause secondary degeneration of the testes. Animal models have shown that abnormalities, in the calcitonin gene-related peptide (CgRP) activity, could be relevant in the pathogenesis of cryptorchidism. We performed a mutation screening by PCR exon amplification, single-strand conformation polymorphism (SSCP) and sequencing in four candidate genes, CgRPs (alphaCgRP, betaCgRP), their receptor (CgRPR) and the receptor component protein (CgRP-RCP), in 90 selected cases of idiopathic unilateral or bilateral cryptorchidism. Mutation screening of the coding regions and intron-exon boundaries revealed some polymorphic variants but no pathogenic sequence changes. These preliminary data suggest that these genes are not major factors for cryptorchidism in humans.
|
2,338,466 |
No association between 12 dopaminergic genes and schizophrenia in a large Dutch sample.
|
It has been suggested that genes involved in dopamine neurotransmission contribute to the pathogenesis of schizophrenia. However, reported associations of the disorder with genetic markers in dopaminergic genes have yielded inconsistent results. Possible explanations are differences in phenotyping, genetic heterogeneity, low marker informativity, and the use of small sample sizes. Here, we present a two-stage analysis of 12 dopaminergic genes in a large sample of Dutch schizophrenic patients. To reduce genetic heterogeneity, only patients with at least three Caucasian grandparents of Dutch ancestry were ascertained. An efficient genotyping strategy was used, in which polymorphic microsatellite markers were first screened for association in DNA pools. Promising results were followed up by individual genotyping in an extended sample. The pooled samples consisted of 208 schizophrenic patients and 288 unmatched control individuals. For each of the genes, more than one microsatellite marker was selected where possible, either intragenic or close to the gene. After correcting for multiple testing, significantly different allele frequencies were detected for DRD5 marker D4S615. Subsequently, we individually genotyped this particular marker and another DRD5 marker, as well as a DRD3 marker that could not be analyzed using the pooling strategy. This was done in an extended sample of 282 schizophrenic patients and a control sample of 585 individuals. In this second stage of the study, we found no association between these three markers and schizophrenia. The results of our comprehensive analysis provide no evidence for association between schizophrenia and 12 dopaminergic genes in a large Dutch sample.
|
2,338,467 |
mtDNA/nDNA ratio in 14484 LHON mitochondrial mutation carriers.
|
Leber's hereditary optic neuropathy (LHON) is a maternally inherited disease caused by mitochondrial DNA (mtDNA) mutations. In this study, the mtDNA/nuclear DNA ratio was evaluated in 11 LHON patients with the 14484 mutation, 13 asymptomatic carriers and 18 non-carrier relatives as controls, to reveal possible relationships between the disease and mtDNA content. DNAs from peripheral blood lymphocytes were subjected to quantitative PCR. Gender differences and age-dependent changes in the mtDNA content were not observed. Significant increase in the mtDNA content was observed only in the asymptomatic carriers (P<0.05). This indicated that individuals whose mtDNA content had increased and been maintained at certain levels were free from LHON development, whereas those whose levels had not, had developed LHON. Since the asymptomatic carriers are the stock of the future LHON patients, monitoring the mtDNA content in patients and their relatives may help to predict the prognosis of the disease.
|
2,338,468 |
New insights into cystinuria: 40 new mutations, genotype-phenotype correlation, and digenic inheritance causing partial phenotype.
|
To clarify the genotype-phenotype correlation and elucidate the role of digenic inheritance in cystinuria.</AbstractText>164 probands from the International Cystinuria Consortium were screened for mutations in SLC3A1 (type A) and SLC7A9 (type B) and classified on the basis of urine excretion of cystine and dibasic amino acids by obligate heterozygotes into 37 type I (silent heterozygotes), 46 type non-I (hyperexcretor heterozygotes), 14 mixed, and 67 untyped probands.</AbstractText>Mutations were identified in 97% of the probands, representing 282 alleles (86.8%). Forty new mutations were identified: 24 in SLC3A1 and 16 in SLC7A9. Type A heterozygotes showed phenotype I, but mutation DupE5-E9 showed phenotype non-I in some heterozygotes. Type B heterozygotes showed phenotype non-I, with the exception of 10 type B mutations which showed phenotype I in some heterozygotes. Thus most type I probands carried type A mutations and all type non-I probands carried type B mutations. Types B and A mutations contributed to mixed type, BB being the most representative genotype. Two mixed cystinuria families transmitted mutations in both genes: double compound heterozygotes (type AB) had greater aminoaciduria than single heterozygotes in their family.</AbstractText>Digenic inheritance is an exception (two of 164 families), with a limited contribution to the aminoaciduria values (partial phenotype) in cystinuria. Further mutational analysis could focus on one of the two genes (SLC3A1 preferentially for type I and SLC7A9 for type non-I probands), while for mixed probands analysis of both genes might be required, with priority given to SLC7A9.</AbstractText>
|
2,338,469 |
[Complex mutations of 1311 C-->T in exon 11 and 93 T-->C in intron 11 in G6PD gene].
|
To investigate the relationship between complex 1311 mutation of C-->T in exon 11 and 93 T-->C in intron 11 of G6PD gene and the G6PD deficiency.</AbstractText>Using NBT paper strip method to screen and quantitative NBT method to confirm G6PD deficiency. PCR-SSCP technique was used to find the abnormal exon 11 and the amplification refractory mutation system (ARMS) to identify 1311 mutation, and DNA sequencing to identify the complex mutation at 1311 in exon 11 and 93 in intron 11.</AbstractText>Abnormal band in exon 11 was found in 12 cases. DNA sequencing showed that they were 1311 mutation together with 93 mutation.</AbstractText>This complex mutation may be the cause of reduced activity of G6PD enzyme.</AbstractText>
|
2,338,470 |
Aggressive periodontitis with supernumerary teeth: a retrospective study.
|
There are four key studies in the periodontology literature reporting the correlation between supernumerary teeth and aggressive periodontitis. The aim of this study is to detect such a relationship.</AbstractText>Patients with supernumerary teeth were identified retrospectively from their orthopantomographs and were invited to the periodontology department for intraoral examination. They were then evaluated for aggressive periodontitis. The number of existing teeth, age, family histories, attachment loss, probing depths, and bleeding on probing scores were recorded.</AbstractText>Of the 5,850 subjects randomly observed among 48,000 patients, only 174 exhibited supernumerary teeth. Of these 174 subjects, only three patients were diagnosed with aggressive periodontitis. One of the patients was also suffering from Fanconi's anemia.</AbstractText>Despite the similarities (aggressive periodontitis accompanied by supernumerary teeth) in the previous reports, we do not agree with the earlier results. We rather suggest that this association might be a random occurrence, rather than a biological one, although this observation should be further investigated using genetic testing.</AbstractText>
|
2,338,471 |
BRCA1/2 testing in hereditary breast and ovarian cancer families II: impact on relationships.
|
Members of hereditary breast and ovarian cancer (HBOC) families often express concern during genetic counseling about the impact of BRCA1/2 testing on close relatives. Yet whether there are likely to be adverse effects of either the decision to undergo genetic testing or the results of testing on family relationships is unknown. One purpose of this study was to assess the impact on close family relationships. Within a randomized trial of breast cancer genetic counseling methods, members of 13 HBOC families were offered BRCA1/2 testing for a known family mutation. The Family Relationship Index (FRI) of the Family Environment Scale (FES) was used to measure perceived family cohesion, conflict, and expressiveness at baseline and again 6-9 months following the receipt of test results, or at the equivalent time for those who declined testing. Participants (n = 212) completed baseline and follow-up questionnaires. Comparisons were made between testers and non-testers as well as between those who tested positive and negative for the family mutation. One hundred eighty-one participants elected to undergo genetic testing (85%) and 47 (26%) were identified to have a mutation. After adjusting for baseline family relationship scores, counseling intervention, gender and marital status, non-testers reported a greater increase in expressiveness (P = 0.006) and cohesion (P = 0.04) than testers. Individuals who tested positive reported a decrease in expressiveness (P = 0.07), although as a trend. Regardless of test decision or test result, those who were randomized to a client-centered counseling intervention reported a decrease in conflict (P = 0.006). Overall, study results suggest that undergoing genetic testing and learning ones BRCA1/2 status may affect family relationships. Those individuals who declined testing reported feeling closer to family members and more encouraged to express emotions to other family members demonstrating potential benefit from the offer of testing. Since those who tested positive reported feeling less encouraged to express their emotions within the family, we recommend helping clients to identify others with whom they feel comfortable sharing their thoughts and feelings about their positive gene status and increased cancer risk.
|
2,338,472 |
Stool screening for colorectal cancer: molecular approaches.
|
Assay of molecular markers in stool represents a promising noninvasive approach to screen colorectal cancer. Given that neoplasms exfoliate abundantly into the lumen and that DNA recovered from stool can be assayed with sensitive techniques, there is a strong biologic rationale to pursue this emerging technology. A challenge with DNA-based testing relates to the selection of markers. Because of the molecular heterogeneity of cancer, no single marker has yielded perfect sensitivity. Several combinations of markers in early stool assays have produced high detection rates of both colorectal cancer and advanced adenomas in selected patient groups, but observations from large representative populations are lacking at present. Potential expanded applications of stool DNA testing include detection of supracolonic aerodigestive cancers and of dysplasia in inflammatory bowel disease. Further marker discovery and technologic refinements should translate into improved test performance and fuel a continued evolution with this screening approach.
|
2,338,473 |
Rapid detection of intracellular SH2D1A protein in cytotoxic lymphocytes from patients with X-linked lymphoproliferative disease and their family members.
|
Mutations in the SH2D1A gene have been described in most patients with the clinical syndrome of X-linked lymphoproliferative disease (XLP). The diagnosis of XLP is still difficult given its clinical heterogeneity and the lack of a readily available rapid diagnostic laboratory test, particularly in patients without a family history of XLP. XLP should always be a consideration in males with Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH). Four-color flow cytometric analysis was used to establish normal patterns of SH2D1A protein expression in lymphocyte subsets for healthy subjects. Three of 4 patients with XLP, as confirmed by the detection of mutations in the SH2D1A gene, had minimal intracellular SH2D1A protein in all cytotoxic cell types. The remaining patient lacked intracellular SH2D1A protein in CD56+ natural killer (NK) and T lymphocytes and had an abnormal bimodal pattern in CD8+ T cells. Carriers of SH2D1A mutations had decreased SH2D1A protein staining patterns compared with healthy controls. Eleven males with clinical syndromes consistent with XLP, predominantly EBV-HLH, had patterns of SH2D1A protein expression similar to those of healthy controls. Four-color flow cytometry provides diagnostic information that may speed the identification of this fatal disease, differentiating it from other causes of EBV-HLH.
|
2,338,474 |
No association was found between a functional SNP in ZDHHC8 and schizophrenia in a Japanese case-control population.
|
ZDHHC8 is a new and attractive candidate for a schizophrenia-susceptibility factor. First, several lines of linkage studies showed that 22q11, on which ZDHHC8 is located, is a "hot" region. Second, fine linkage disequilibrium mapping revealed a significant association around ZDHHC8. Moreover, a very recent study reported that one single nucleotide polymorphism (SNP: rs175174) in ZDHHC8 might affect the splicing process, the ZDHHC8 knock-out mice showed the gender-specific phenotype, and the transmission disequilibrium test (TDT) using this SNP also showed significant association with human female schizophrenia. Thus, we attempted a replication study of this SNP using relatively large Japanese case-control samples (561 schizophrenics and 529 controls). No association was found between schizophrenia and controls even after dividing samples by gender. Because our sample size provided quite high power, ZDHHC8 may not play a major role in Japanese schizophrenia. And our results did not support the gender-specific effect of this SNP.
|
2,338,475 |
[A probability analysis for HLA matching in adult stem cell transplantation treating nervous genetic diseases].
|
The aim of this study was to investigate the clinical feasibility of adult stem cell transplantation for lethal mono-gene inherited disease, Duchenne muscular dystrophy (DMD). A total of 30 blood samples from DMD patients were genotyped with HLA-A,-B and -DR alleles by means of polymerase chain reaction-reverse sequence specific oligonucleotide (PCR-RSSO). The HLA gene types in 30 DMD patients were compared with those of 668 unrelated donors from Umbilical Cord Blood Center of Guangdong Province and 34 910 unrelated donors from Chinese Bone Marrow Bank. The results showed that HLA gene of the DMD group was inherited in normal distribution. There was no striking difference of HLA-A, -B and -DR alleles expression between the DMD patients group and control healthy group. 25% of the DMD patients got suitable donors for stem cell transplantation, in which 15 patients found donors with >or= 5/6 HLA match at the Umbilical Cord Blood Center of Guangdong Province, i.e. occupying 50% of the total. Eight patients got 6/6 HLA matching donors at the Chinese Bone Marrow Bank, i.e. occupying 26% of the total. It is concluded that stem cells transplantation therapy for DMD patients is feasible, which will benefit these patients suffered from the lethal neuromuscular disease, and create a new way to treat this tough nervous system disease.
|
2,338,476 |
[CALM-AF10 fusion transcripts in primary leukemia with t(10;11) and in vitro chemotherapy sensitivity of leukemic cells with t(10;11)].
|
In order to determine the involvement of CALM-AF10 fusion transcripted in primary leukaemias with t(10;11) and its chemotherapy sensitivity in vitro, the AF10-CALM fusion transcripts were detected by reverse transcription-polymerase chain reaction (RT-PCR), and the chemotherapy sensitivity testing in vitro was undergone by MTT assay in five t(10;11) leukemia samples from patients with ALL, AML and lymphoblastic lymphoma. The results showed that five different-sized AF10-CALM product and four different-sized CALM-AF10 products were detected. The chemotherapy sensitivity of leukemic cells with t(10;11) in vitro to drugs is lower than that of leukemic cells without t(10;11). 3 out of 5 cases of t(10;11) leukemia were sensitive to chemotherapeutic drugs, while 31 out of 36 cases of leukemia without t(10;11) were sensitive at same condition. There were significant differences (P < 0.01), consistent with clinical features of patients. Apoptosis rate of leukemic cells with t(10;11) induced by chemotherapeutic drugs was lower than that of leukemic cells without t(10;11), (16.37 +/- 2.56)%, and (33.75 +/- 5.59)%, respectively (P < 0.01). It is concluded that the CALM-AF10 fusion transcripts are a common features and are involved in the pathogenesis of haematological malignancies with t(10;11), and are associated with a poor prognosis.
|
2,338,477 |
Migraine and cerebral white matter lesions: when to suspect cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL).
|
Patients with migraine are at an increased risk for white matter lesions, typically multiple, small, punctate hyperintensities in the deep or periventricular white matter, best observed on magnetic resonance imaging utilizing T2-weighted or FLAIR sequences. The underlying pathogenesis of white matter lesions in migraineurs is unknown, and the lesions are usually nonspecific and of unclear clinical significance.</AbstractText>Often the presence of white matter lesions causes uncertainty for physicians and anxiety for patients and may lead to a variety of diagnostic tests and treatments. Occasionally, white matter lesions may represent a secondary cause for headaches such as CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy). CADASIL is underrecognized and underdiagnosed; it should be suggested by (i) 1 or more of recurrent subcortical ischemic strokes (especially before age 60 and in the absence of vascular risk factors), migraine (especially with aura, including atypical or prolonged auras) and/or early cognitive decline or subcortical dementia; (ii) bilateral, multifocal, T2/FLAIR hyperintensities in the deep white matter and periventricular white matter with lesions involving the anterior temporal pole, external capsule, basal ganglia, and/or pons; and (iii) an autosomal-dominant family history of migraine, early-onset stroke, or dementia. The clinical spectrum of CADASIL is broad, and there is a poor genotype-phenotype correlation. In certain individuals or families, migraine may be the only clinical manifestation.</AbstractText>While the prevalence of nonspecific white matter lesions in migraineurs is increased, the white matter lesions may occasionally represent a secondary cause for headache such as CADASIL. Greater awareness of the unique clinical, neuroimaging, and pathologic features, as well as the availability of diagnostic genetic testing, should enhance the recognition and diagnosis of this fascinating condition.</AbstractText>
|
2,338,478 |
Management of patients with hereditary medullary thyroid carcinoma.
|
The heredity of medullary thyroid carcinoma within MEN2 syndrome is caused by heterozygous germline mutations in the RET proto-oncogene. Since MEN2-associated mutations involve only hot spots, the molecular genetic analysis of the RET proto-oncogene constitutes the perfect tool for the diagnosis of MEN2, being thus considered the standard method. The molecular genetic screening for MEN2-associated RET germline mutations should be carried out in all patients with an apparently sporadic medullary thyroid carcinoma or pheochromocytoma. This testing needs to include exons 10, 11, and 13 to 16 of the RET proto-oncogene. Such investigations are aimed at identifying an index person of a new MEN2 family. The detection of such a RET germline mutation is the basis for predictive molecular genetic testing within an affected family, and allows the exclusion or identification of gene carriers. For these family members at risk, prophylactic total thyroidectomy is recommended as a curative procedure, according to a risk-adapted, genetically based treatment algorithm. The management of such affected families should be always complemented by oncological and genetic counselling.
|
2,338,479 |
Transcription-based prediction of response to IFNbeta using supervised computational methods.
|
Changes in cellular functions in response to drug therapy are mediated by specific transcriptional profiles resulting from the induction or repression in the activity of a number of genes, thereby modifying the preexisting gene activity pattern of the drug-targeted cell(s). Recombinant human interferon beta (rIFNbeta) is routinely used to control exacerbations in multiple sclerosis patients with only partial success, mainly because of adverse effects and a relatively large proportion of nonresponders. We applied advanced data-mining and predictive modeling tools to a longitudinal 70-gene expression dataset generated by kinetic reverse-transcription PCR from 52 multiple sclerosis patients treated with rIFNbeta to discover higher-order predictive patterns associated with treatment outcome and to define the molecular footprint that rIFNbeta engraves on peripheral blood mononuclear cells. We identified nine sets of gene triplets whose expression, when tested before the initiation of therapy, can predict the response to interferon beta with up to 86% accuracy. In addition, time-series analysis revealed potential key players involved in a good or poor response to interferon beta. Statistical testing of a random outcome class and tolerance to noise was carried out to establish the robustness of the predictive models. Large-scale kinetic reverse-transcription PCR, coupled with advanced data-mining efforts, can effectively reveal preexisting and drug-induced gene expression signatures associated with therapeutic effects.
|
2,338,480 |
Regeneration of the pancreatic beta cell.
|
Type 1 diabetes is the result of an autoimmune attack against the insulin-producing beta cells of the endocrine pancreas. Current treatment for patients with type 1 diabetes typically involves a rigorous and invasive regimen of testing blood glucose levels many times a day along with subcutaneous injections of recombinant DNA-derived insulin. Islet transplantation, even with its substantially improved outcome in recent years, is still not indicated for pediatric patients. However, in light of the fact that some regenerative capabilities of the endocrine pancreas have been documented and recent research has shown that human ES cell lines can be derived in vitro, this review discusses whether it is practical or even possible to combine these lines of research to more effectively treat young diabetic patients.
|
2,338,481 |
Molecular diagnosis of pseudohypoparathyroidism type Ib in a family with presumed paroxysmal dyskinesia.
|
We describe 2 sisters diagnosed initially with paroxysmal kinesigenic choreoathetosis, a condition characterized by brief episodes of spasms precipitated by sudden movement. However, subsequent testing showed hypocalcemia, hyperphosphatemia, and elevated parathyroid hormone levels consistent with pseudohypoparathyroidism type Ib. This diagnosis was confirmed by genetic testing, which identified a 3-kilobase deletion on chromosome 20q13.3. Our report describes the neurologic presentation, metabolic derangement, and underlying genetic mutation in a family. It also reinforces the importance of metabolic testing in the evaluation of pediatric patients with movement disorders.
|
2,338,482 |
Loss-of-function mutation in tryptophan hydroxylase-2 identified in unipolar major depression.
|
Dysregulation of central serotonin neurotransmission has been widely suspected as an important contributor to major depression. Here, we identify a (G1463A) single nucleotide polymorphism (SNP) in the rate-limiting enzyme of neuronal serotonin synthesis, human tryptophan hydroxylase-2 (hTPH2). The functional SNP in hTPH2 replaces the highly conserved Arg441 with His, which results in approximately 80% loss of function in serotonin production when hTPH2 is expressed in PC12 cells. Strikingly, SNP analysis in a cohort of 87 patients with unipolar major depression revealed that nine patients carried the mutant (1463A) allele, while among 219 controls, three subjects carried this mutation. In addition, this functional SNP was not found in a cohort of 60 bipolar disorder patients. Identification of a loss-of-function mutation in hTPH2 suggests that defect in brain serotonin synthesis may represent an important risk factor for unipolar major depression.
|
2,338,483 |
Nasopharyngeal aerobic bacterial flora and Staphylococcus aureus nasal carriage in deaf children.
|
Effectively communicating the promise of new technologies can be challenging, particularly when the science is not yet fully developed and its application is not well defined and understood. Toxicogenomics meshes toxicology with genomic technology (study of the entire expanse of genetic information in an organism) and may hold the promise of detecting changes in the expression of a person's genes if he or she is exposed to toxicants. As defined by the National Center for Toxicogenomics, toxicogenomics is the “collection, interpretation, and storage of information about gene and protein activity in order to identify toxic substances in the environment, and to help treat people at the greatest risk of diseases caused by environmental pollutants or toxicants” (NCT 2002). As the technology develops and more data become available, it is important that scientists and the public discuss the promises and limitations of this new field. The Committee on Communicating Toxicogenomics Information to Nonexperts designed a workshop to consider strategies for communicating toxicogenomics information to the public and other nonexpert audiences, specifically addressing communication issues surrounding some key social, ethical, and legal issues related to toxicogenomics and how information related to the social implications of toxicogenomics may be perceived by nonexperts. Because research on the communication of toxicogenomics to the public is sparse, panelists who are experts in risk and biotechnology communication were asked to present research from their work. They applied their expertise in analogous areas to discuss ways to design an effective strategy to communicate toxicogenomics information. Panelists discussed communication barriers, such as poor understanding of scientific principles and emotional responses to risk and uncertainty by the public, and health disparities in communication. The panelists also discussed effective communication tools, such as audience-based communication (focusing efforts on understanding the audience and creating messages based on the informational needs of that specific audience); mental models approach (assessing systematically what kinds of information should be conveyed to the public and then creating messages that meet those needs); public participation (encouraging public input and providing public access to the decision-making process); and developing, testing, and communicating of appropriate messages. They also discussed the importance of how the message is framed for the audience. The workshop was not intended to develop consensus on the issues related to toxicogenomics communication but to provide useful background information on risk communication that may assist agencies and organizations in effectively communicating toxicogenomics information to the public.
|
2,338,484 |
Survey of HNPCC Management Analysis of Responses from 18 International Cancer Centres.
|
Eighteen international cancer centres responded to a questionnaire designed to determine clinic practices regarding the management of Hereditary Non-Polyposis Colorectal Cancer (HNPCC). Areas covered include definition, clinical intakes, pre-genetic testing for microsatellite instability (MSI) or expression of mismatch repair (MMR) genes by immunohistochemistry (IHC), mutational analysis, consent practices, counselling, surveillance planning, and surgical decision making. In the absence of a firm evidence base, some management practices were variable, with local access to funding and other resources being influential. More consistent responses were evident for management practices with a stronger evidence base from previous clinical research. This document provides important information to guide the management of HNPCC patients, allow comparisons to be made between the approaches of various clinics to HNPCC families, and define management issues that need to be addressed in clinical research.
|
2,338,485 |
Patient perspective on the value of genetic counselling for familial pancreas cancer.
|
To assess patient views regarding the value of genetic counselling for familial pancreas cancer in the absence of predictive genetic testing.</AbstractText>At-risk adults with three or more relatives with pancreas cancer received genetic counselling prior to research screening via endoscopic ultrasound. Questionnaires were mailed after the visit to assess perceived value of the counselling session.</AbstractText>Ninety-three percent of respondents felt genetic counselling for pancreas cancer was helpful despite the lack of a causative gene, while only 7% felt that it should not be offered until such a gene is discovered. Over half of respondents believed the pancreas cancer in their family was caused by a gene mutation, and 42% thought they had inherited the mutation. The average perceived lifetime risk of developing pancreas cancer was 51%, and 87% of respondents would ultimately seek predictive genetic testing. When more information is gained, 89% would be interested in another genetic counselling session, and 82% would recommend current genetic counselling for pancreas cancer to a friend or relative with a family history of the disease.</AbstractText>Despite the lack of an identified major causative gene for pancreas cancer, respondents found genetic counselling for this malignancy to be helpful. These patients perceive their personal cancer risk to be high, and would seek predictive genetic testing if it were available. Referral for genetic counselling should be offered to appropriate individuals.</AbstractText>
|
2,338,486 |
Clinical outcome of hereditary breast cancer in the lithuanian population.
|
Breast cancer family history has been known to be one of the main cancer risk factors. Members of high-risk families should be given recommendations which may improve prophylaxis, early diagnosis and treatment. Detection of high-risk families is possible by identification of mutations in cancer susceptibility genes like BRCA1 and BRCA2 as well as by family history showing breast and/or ovary cancer aggregation. In a group of 521 breast cancer patients we identified 26 patients with hereditary breast cancer who fulfilled the following criteria: one more relative with breast cancer, vertical transmission, at least one breast cancer patient affected at the age under 50 years. 8 patients of these developed second primary breast cancer. We also compared the frequency of hereditary cancers in stage I-III with the frequency of respective cancers with negative family history. Hereditary breast cancers were diagnosed less frequently in stage I and more frequently in stage II and III (RR = 0.49, RR = 1.39, RR = 1.62, respectively). Because of importance of family history as well as genetic testing for breast cancer susceptibility genes (BRCA1/2), it is necessary to create a nationwide network of hereditary cancer clinics for proper diagnosis, treatment, and prophylaxis of these patients.
|
2,338,487 |
A phase I vaccination study with tyrosinase in patients with stage II melanoma using recombinant modified vaccinia virus Ankara (MVA-hTyr).
|
A significant percentage of patients with stage II melanomas suffer a relapse after surgery and therefore need the development of adjuvant therapies. In the study reported here, safety and immunological response were analyzed after vaccination in an adjuvant setting with recombinant modified vaccinia virus Ankara carrying the cDNA for human tyrosinase (MVA-hTyr). A total of 20 patients were included and vaccinated three times at 4-week intervals with 5x10(8) IU of MVA-hTyr each time. The responses to the viral vector, to known HLA class I-restricted tyrosinase peptides, and to dendritic cells transfected with tyrosinase mRNA, were investigated by ELISpot assay on both ex vivo T cells and on T cells stimulated in vitro prior to testing. The delivery of MVA-hTyr was safe and did not cause any side effects above grade 2. A strong response to the viral vector was achieved, indicated by an increase in the frequency of MVA-specific CD4+ and CD8+ T cells and an increase in virus-specific antibody titers. However, no tyrosinase-specific T-cell or antibody response was observed with MVA-hTyr in any of the vaccinated patients. Although MVA-hTyr provides a safe and effective antigen-delivery system, it does not elicit a measurable immune response to its transgene product in patients with stage II melanoma after repeated combined intradermal and subcutaneous vaccination. We presume that modification of the antigen and/or prime-boost vaccination applying different approaches to antigen delivery may be required to induce an effective tyrosinase-specific immune response.
|
2,338,488 |
Association analysis of the dopamine D3 receptor gene ser9gly and brain-derived neurotrophic factor gene val66met polymorphisms with antipsychotic-induced persistent tardive dyskinesia and clinical expression in Chinese schizophrenic patients.
|
The association between the dopamine D3 receptor (DRD3) ser9gly genetic polymorphism and tardive dyskinesia (TD), a serious adverse motor disorder after long-term antipsychotic treatment, has been studied extensively in recent years. However, the existence of inconsistent reports makes the role of the DRD3 ser9gly polymorphism in TD development questionable. In rodent studies, the DRD3 expression could be controlled by the brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family. In this study, we examined the association between the DRD3 ser9gly and BDNF val66met genetic polymorphisms and TD occurrence in 216 schizophrenic patients (TD/non-TD = 102/114). In addition, we also studied the effects of the DRD3 ser9gly and BDNF val66met genotypes and their gene-gene interaction on the clinical expression of TD in these TD patients. We found that the TD patients who were heterozygous for the BDNF genotypes had significantly higher abnormal involuntary movement scale (AIMS) orofacial scores (corrected p = 0.021, Bonferroni correction), and a trend of higher AIMS total and limb-trunk scores than the combined homozygous analogs. The correlation between the DRD3 ser9gly genotypes and its interaction with the BDNF val66met polymorphism, and the three classes of AIMS scores were not statistically significant. Furthermore, neither the DRD3 nor the BDNF genotypes and alleles were demonstrated to be associated with TD occurrence. We concluded that the BDNF val66met genetic polymorphism may exert its effect on the clinically phenotypic variability after TD has occurred. Further replication studies with larger sample size and stringent definition for TD is necessary.
|
2,338,489 |
Analysis of oligonucleotide array experiments with repeated measures using mixed models.
|
Two or more factor mixed factorial experiments are becoming increasingly common in microarray data analysis. In this case study, the two factors are presence (Patients with Alzheimer's disease) or absence (Control) of the disease, and brain regions including olfactory bulb (OB) or cerebellum (CER). In the design considered in this manuscript, OB and CER are repeated measurements from the same subject and, hence, are correlated. It is critical to identify sources of variability in the analysis of oligonucleotide array experiments with repeated measures and correlations among data points have to be considered. In addition, multiple testing problems are more complicated in experiments with multi-level treatments or treatment combinations.</AbstractText>In this study we adopted a linear mixed model to analyze oligonucleotide array experiments with repeated measures. We first construct a generalized F test to select differentially expressed genes. The Benjamini and Hochberg (BH) procedure of controlling false discovery rate (FDR) at 5% was applied to the P values of the generalized F test. For those genes with significant generalized F test, we then categorize them based on whether the interaction terms were significant or not at the alpha-level (alphanew = 0.0033) determined by the FDR procedure. Since simple effects may be examined for the genes with significant interaction effect, we adopt the protected Fisher's least significant difference test (LSD) procedure at the level of alphanew to control the family-wise error rate (FWER) for each gene examined.</AbstractText>A linear mixed model is appropriate for analysis of oligonucleotide array experiments with repeated measures. We constructed a generalized F test to select differentially expressed genes, and then applied a specific sequence of tests to identify factorial effects. This sequence of tests applied was designed to control for gene based FWER.</AbstractText>
|
2,338,490 |
Polymorphism profile of nine short tandem repeat Loci in the Han chinese.
|
Nine short tandem repeat (STR) markers (D3S1358, VWA, FGA, THO1, TPOX, CSFIPO, D5S818, D13S317, and D7S820) and a sex-identification marker (Amelogenin locus) were amplified with multiplex PCR and were genotyped with a four-color fluorescence method in samples from 174 unrelated Han individuals in North China. The allele frequencies, genotype frequencies, heterozygosity, probability of discrimination powers, probability of paternity exclusion and Hardy-Weinberg equilibrium expectations were determined. The results demonstrated that the genotypes at all these STR loci in Han population conform to Hardy-Weinberg equilibrium expectations. The combined discrimination power (DP) was 1.05 x 10(-10) within nine STR loci analyzed and the probability of paternity exclusion (EPP) was 0.9998. The results indicate that these nine STR loci and the Amelogenin locus are useful markers for human identification, paternity and maternity testing and sex determination in forensic sciences.
|
2,338,491 |
Clinical signs, underlying cause, and outcome in cats with seizures: 17 cases (1997-2002).
|
To determine clinical signs, results of diagnostic testing, underlying cause, and outcome in cats with seizures.</AbstractText>Retrospective study.</AbstractText>17 cats with seizures.</AbstractText>Only those cats in which an underlying metabolic abnormality causing the seizures had been identified, diagnostic imaging of the brain and CSF analysis had been done, or a necropsy had been performed were included. Seizures were classified as being a result of metabolic disease, symptomatic epilepsy (ie, epilepsy resulting from a structural lesion of the brain), or probably symptomatic epilepsy (ie, epilepsy without any extracranial or identifiable intracranial disease that is not suspected to be genetic in origin).</AbstractText>3 cats had seizures associated with an underlying metabolic disease (hepatic encephalopathy), 7 had symptomatic epilepsy (3 with neoplasia and 4 with meningoencephalitis), and 7 had probably symptomatic epilepsy. Six of the 7 cats with symptomatic epilepsy died or were euthanatized within 3 months after the diagnosis was made, whereas 6 of the 7 cats with probably symptomatic epilepsy survived for at least 12 months after the diagnosis was made.</AbstractText>Results suggest that cats with probably symptomatic epilepsy may have a good long-term prognosis.</AbstractText>
|
2,338,492 |
[Analysis of the function of liver development using medaka, Oryzias latipes].<Pagination><StartPage>1454</StartPage><EndPage>1458</EndPage><MedlinePgn>1454-8</MedlinePgn></Pagination><AuthorList CompleteYN="Y"><Author ValidYN="Y"><LastName>Watanabe</LastName><ForeName>Tomomi</ForeName><Initials>T</Initials><AffiliationInfo><Affiliation>Department of Physiological Chemistry, Graduated School of Pharmaceutical Sciences, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.</Affiliation></AffiliationInfo></Author><Author ValidYN="Y"><LastName>Nishina</LastName><ForeName>Hiroshi</ForeName><Initials>H</Initials></Author></AuthorList><Language>jpn</Language><PublicationTypeList><PublicationType UI="D016428">Journal Article</PublicationType><PublicationType UI="D016454">Review</PublicationType></PublicationTypeList></Article><MedlineJournalInfo><Country>Japan</Country><MedlineTA>Seikagaku</MedlineTA><NlmUniqueID>0413564</NlmUniqueID><ISSNLinking>0037-1017</ISSNLinking></MedlineJournalInfo><ChemicalList><Chemical><RegistryNumber>0</RegistryNumber><NameOfSubstance UI="D004268">DNA-Binding Proteins</NameOfSubstance></Chemical><Chemical><RegistryNumber>0</RegistryNumber><NameOfSubstance UI="D009687">Nuclear Proteins</NameOfSubstance></Chemical><Chemical><RegistryNumber>0</RegistryNumber><NameOfSubstance UI="D014157">Transcription Factors</NameOfSubstance></Chemical><Chemical><RegistryNumber>135845-91-9</RegistryNumber><NameOfSubstance UI="D051543">Hepatocyte Nuclear Factor 3-gamma</NameOfSubstance></Chemical></ChemicalList><CitationSubset>IM</CitationSubset><MeshHeadingList><MeshHeading><DescriptorName UI="D000818" MajorTopicYN="N">Animals</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D004268" MajorTopicYN="N">DNA-Binding Proteins</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D005820" MajorTopicYN="N">Genetic Testing</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D016678" MajorTopicYN="N">Genome</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D051543" MajorTopicYN="N">Hepatocyte Nuclear Factor 3-gamma</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D008099" MajorTopicYN="N">Liver</DescriptorName><QualifierName UI="Q000196" MajorTopicYN="Y">embryology</QualifierName><QualifierName UI="Q000502" MajorTopicYN="Y">physiology</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D009154" MajorTopicYN="Y">Mutation</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D009687" MajorTopicYN="N">Nuclear Proteins</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D038081" MajorTopicYN="N">Organogenesis</DescriptorName><QualifierName UI="Q000235" MajorTopicYN="Y">genetics</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D009990" MajorTopicYN="N">Oryzias</DescriptorName><QualifierName UI="Q000196" MajorTopicYN="Y">embryology</QualifierName><QualifierName UI="Q000235" MajorTopicYN="Y">genetics</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D014157" MajorTopicYN="N">Transcription Factors</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D015027" MajorTopicYN="N">Zebrafish</DescriptorName><QualifierName UI="Q000196" MajorTopicYN="N">embryology</QualifierName></MeshHeading></MeshHeadingList><NumberOfReferences>12</NumberOfReferences></MedlineCitation><PubmedData><History><PubMedPubDate PubStatus="pubmed"><Year>2005</Year><Month>1</Month><Day>1</Day><Hour>9</Hour><Minute>0</Minute></PubMedPubDate><PubMedPubDate PubStatus="medline"><Year>2005</Year><Month>2</Month><Day>16</Day><Hour>9</Hour><Minute>0</Minute></PubMedPubDate><PubMedPubDate PubStatus="entrez"><Year>2005</Year><Month>1</Month><Day>1</Day><Hour>9</Hour><Minute>0</Minute></PubMedPubDate></History><PublicationStatus>ppublish</PublicationStatus><ArticleIdList><ArticleId IdType="pubmed">15626034</ArticleId></ArticleIdList></PubmedData></PubmedArticle><PubmedArticle><MedlineCitation Status="MEDLINE" Owner="NLM"><PMID Version="1">15625557</PMID><DateCompleted><Year>2007</Year><Month>01</Month><Day>04</Day></DateCompleted><DateRevised><Year>2013</Year><Month>05</Month><Day>20</Day></DateRevised><Article PubModel="Print"><Journal><ISSN IssnType="Print">0888-8051</ISSN><JournalIssue CitedMedium="Print"><Issue>519</Issue><PubDate><Year>2004</Year><Month>Sep</Month></PubDate></JournalIssue><Title>National Toxicology Program technical report series</Title><ISOAbbreviation>Natl Toxicol Program Tech Rep Ser</ISOAbbreviation></Journal>NTP technical report on the toxicology and carcinogenesis studies of Stoddard Solvent IIC (Cas No. 64742-88-7) in F344/N rats and B6C3F1 mice (inhalation studies).
|
Stoddard solvent (white spirit/mineral spirit) is the most widely used solvent in the paint industry. It is used as a dry cleaning agent; as an extraction, cleaning, and degreasing solvent; and as a solvent in aerosols, paints, wood preservatives, asphalt products, lacquers, and varnishes. Stoddard solvent IIC was nominated by the International Union, United Auto Workers, for carcinogenicity testing because of the large volume used in industrial and other settings. Male and female F344/N rats and B6C3F1 mice were exposed to Stoddard solvent IIC (greater than 99% pure) by inhalation for 2 weeks, 3 months, or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium and mouse peripheral blood erythrocytes. 2-WEEK STUDY IN RATS: Groups of five male and five female rats were exposed to Stoddard solvent IIC by inhalation at concentrations of 0, 138, 275, 550, 1,100, or 2,200 mg/m3, 6 hours per day, 5 days per week for 16 days. All rats survived to the end of the study, and mean body weights of all exposed groups were similar to those of the chamber controls. Liver weights of males exposed to 550 mg/m3 or greater and of females exposed to 275 mg/m3 or greater were increased. Minimal diffuse cytoplasmic vacuolization of hepatocytes of the liver occurred in all females exposed to 2,200 mg/m3. 2-WEEK STUDY IN MICE: Groups of five male and five female mice were exposed to Stoddard solvent IIC by inhalation at concentrations of 0, 138, 275, 550, 1,100, or 2,200 mg/m3, 6 hours per day, 5 days per week for 17 days. All mice survived to the end of the study, and mean body weights of all exposed groups were similar to those of the chamber controls. Liver weights of males and females exposed to 275 mg/m3 or greater were significantly increased. Cytomegaly of the liver occurred in all males and females exposed to 2,200 mg/m3. 3-MONTH STUDY IN RATS: Groups of 10 male and 10 female rats were exposed to Stoddard solvent IIC by inhalation at concentrations of 0, 138, 275, 550, 1,100, or 2,200 mg/m3, 6 hours per day, 5 days per week for 14 weeks. All rats survived to the end of the study, and the final mean body weight of females exposed to 275 mg/m3 was greater than that of the chamber controls. The relative kidney, liver, and testis weights of all exposed groups of males and the absolute kidney weights of males exposed to 550 mg/m3 or greater were increased. The sperm motility of 550 mg/m3 or greater males was significantly decreased. The incidences of renal tubule granular casts were significantly increased in males exposed to 550 mg/m3 or greater, and the severities of renal tubule hyaline droplet accumulation, granular casts, and regeneration increased with increasing exposure concentration in males. The incidences of goblet cell hypertrophy of the nasal respiratory epithelium in males and females exposed to 2,200 mg/m3 were significantly increased. Sperm motility was decreased in males exposed to 550 mg/m3 or greater. 3-MONTH STUDY IN MICE: Groups of 10 male and 10 female mice were exposed to Stoddard solvent IIC by inhalation at concentrations of 0, 138, 275, 550, 1,100, or 2,200 mg/m3, 6 hours per day, 5 days per week for 14 weeks. Mean body weights of exposed groups were similar to those of the chamber controls, but liver weights of males exposed to 2,200 mg/m3 were significantly increased. The sperm motility of 2,200 mg/m3 males was significantly decreased. This reduction in sperm motility, while statistically significant, is probably of modest importance as studies in mice have found that fertility is unaffected by motility decreases of less than 40%. The incidences of hematopoietic cell proliferation of the spleen in all exposed groups of females were greater than that in the chamber controls. 2-YEAR STUDY IN RATS: Groups of 50 male and 50 female rats were exposed to Stoddard solvent IIC by inhalation at concentrations of 0, 138 (males), 550, 1,100, or 2,200 (females) mg/m3, 6 hours per day, 5 days per week for 104 to 105 weeks. Additional groups of 10 males and 10 females were exposed to the same concentrations for 3 months for renal toxicity analyses. Survival in the top exposure concentration groups of males and females was significantly less than that of the chamber controls. Mean body weights of exposed males and females were similar to those of the chamber controls. Cell proliferation analyses were performed in the left kidney of males and females after 3 months of exposure. The mean numbers of labeled cells and the labeling indices in males exposed to 550 and 1,100 mg/m3 were significantly increased. The amount of alpha2u-globulin in the right kidney of males increased with increasing exposure concentration. Also, the incidences of granular casts and cortical tubule degeneration and regeneration were generally increased in exposed males, as was the severity of hyaline droplets. These effects did not occur in females. At 2 years, the incidences of benign and benign or malignant pheochromocytoma (combined) of the adrenal medulla occurred with positive trends in males, and the incidences in the 550 and 1,100 mg/m3 groups were significantly increased. Due to increased incidences of renal tubule hyperplasia in males at 2 years, extended kidney evaluations were conducted; a slightly increased incidence of renal tubule adenoma occurred in the 1,100 mg/m3 group. Nonneoplastic lesions related to Stoddard solvent IIC exposure occurred in the kidney of males. 2-YEAR STUDY IN MICE: Groups of 50 male and 50 female mice were exposed to Stoddard solvent IIC by inhalation at concentrations of 0, 550, 1,100, or 2,200 mg/m3, 6 hours per day, 5 days per week for 105 weeks. Survival of exposed mice was similar to that of the chamber controls. Mean body weights of exposed females were greater than those of the chamber controls. The incidences of hepatocellular adenoma occurred with a positive trend in females, and the incidence of multiple hepatocellular adenoma in females exposed to 2,200 mg/m3 was significantly increased. However, the incidences of hepatocellular adenoma or carcinoma (combined) and hepatocellular carcinoma alone in exposed males and females were not significantly increased.</AbstractText>Stoddard solvent IIC was tested for mutagenicity in Salmonella typhimurium strains TA97, TA98, TA100, and TA1535, with and without S9 metabolic activation enzymes; all results were negative. In vivo, the frequency of micronucleated erythrocytes was assessed in peripheral blood samples from male and female B6C3F1 mice after 3 months of inhalation exposure to Stoddard solvent IIC, and results were negative.</AbstractText>Under the conditions of these 2-year inhalation studies, there was some evidence of carcinogenic activity of Stoddard solvent IIC in male F344/N rats based on increased incidences of adrenal medulla neoplasms; the slightly increased incidences of renal tubule adenoma may have been related to Stoddard solvent IIC exposure. There was no evidence of carcinogenic activity of Stoddard solvent IIC in female F344/N rats exposed to 550, 1,100, or 2,200 mg/m3. There was no evidence of carcinogenic activity of Stoddard solvent IIC in male B6C3F1 mice exposed to 550, 1,100, or 2,200 mg/m3. There was equivocal evidence of carcinogenic activity of Stoddard solvent IIC in female B6C3F1 mice based on increased incidences of hepatocellular adenoma; this slight increase was associated with increased body weight in exposed females. Exposure of male rats to Stoddard solvent IIC resulted in nonneoplastic lesions of the kidney characteristic of alpha2u-globulin accumulation.</AbstractText>
|
2,338,493 |
Ehlers-Danlos syndrome, classical type: case management.
|
As the field of genetics expands, there will be more need for health care professionals to possess basic knowledge of genetic conditions and patterns of inheritance to assist their patients and to make the proper referrals. Ehlers-Danlos syndrome (EDS) is a group of genetic connective tissue disorders that affects approximately 1 in 5,000 live births, including males and females of all racial and ethnic groups. The main characteristics of EDS are skin hyperextensibility, tissue fragility, andjoint hypermobility. Diagnosis of EDS is often difficult due to the complexity of symptoms and lack of specific genetic tests. However, once a diagnosis is suspected or confirmed, nurses play a vital role in assisting the patient andfamily to manage the disorder. In this article, EDS symptoms and genetic basis, suggestions for management, and resources available for health care providers, families, and patients with EDS are provided.
|
2,338,494 |
HLA-B27 typing: evaluation of an allele-specific PCR melting assay and two flow cytometric antigen assays.
|
Human leukocyte antigen B27 (HLA-B27) is a major histocompatibility complex class 1 molecule that is strongly associated with the disease ankylosing spondylitis. Testing for HLA-B27 is of diagnostic value because 90% of patients with ankylosing spondylitis have the B27 antigen. Two commonly used HLA-B27 flow cytometric assays are commercially available.</AbstractText>An allele-specific polymerase chain reaction (PCR) melting assay for HLA-B27 was compared with two available antigen assays on 371 clinical samples. The accuracy of the assays was measured by receiver operating characteristic analysis using the PCR method and sequencing as the reference standard.</AbstractText>When PCR results were compared with those of the antigen assays, complete concordance was observed except for five discrepant results that were resolved by sequence analysis. Using DNA sequencing as the gold standard, the sensitivity and specificity of PCR were 99.6 and 100.0, those of the best single antigen assay were 98.2 and 97.6, and those of a reflex combination of both antigen assays were 98.8 and 97.6.</AbstractText>The allele-specific PCR melting assay for HLA-B27 genotyping is easy to perform and has better sensitivity and specificity than antigen assays. The performance of the two flow cytometric antigen assays depends on the antibody used and the positive cutoff values assigned.</AbstractText>(c) 2004 Wiley-Liss, Inc.</CopyrightInformation>
|
2,338,495 |
Community involvement in developing policies for genetic testing: assessing the interests and experiences of individuals affected by genetic conditions.
|
Because the introduction of genetic testing into clinical medicine and public health creates concerns for the welfare of individuals affected with genetic conditions, those individuals should have a role in policy decisions about testing. Mechanisms for promoting participation range from membership on advisory committees to community dialogues to surveys that provide evidence for supporting practice guidelines. Surveys can assess the attitudes and the experiences of members of an affected group and thus inform discussions about that community's concerns regarding the appropriate use of a genetic test. Results of a survey of individuals affected with inherited dwarfism show how data can be used in policy and clinical-practice contexts. Future research of affected communities' interests should be pursued so that underrepresented voices can be heard.
|
2,338,496 |
Suggestive linkage to chromosome 6q in families with bilateral vestibulopathy.
|
Of the more than 40 genetically defined dominantly inherited hearing loss syndromes, only a few are associated with bilateral vestibulopathy. No genetic mutations have been identified in families with bilateral vestibulopathy and normal hearing.</AbstractText>To perform a genome-wide scan for linkage in four families with dominantly inherited bilateral vestibulopathy.</AbstractText>Patients in four families reported brief episodes of vertigo followed by imbalance and oscillopsia. Bilateral vestibulopathy was documented with quantitative rotational testing. Most patients with bilateral vestibulopathy also had migraine. A 10 cM genome-wide screen was conducted using 423 microsatellite markers to identify linkage with vestibulopathy.</AbstractText>The authors identified a 24 cM region on chromosome 6q suggestive of linkage to vestibulopathy in these four families (maximum lod score of 2.9 at marker D6S1556). A small fifth family with a different phenotype was not linked to this region on chromosome 6q.</AbstractText>This is the first report of linkage in families with dominantly inherited vestibulopathy and normal hearing. Genetic heterogeneity is likely with inherited vestibulopathy.</AbstractText>
|
2,338,497 |
Mutational screening of the CD40 ligand (CD40L) gene in patients with X linked hyper-IgM syndrome (XHIM) and determination of carrier status in female relatives.
|
To analyse the gene encoding the CD40 ligand (CD40L) in 11 Australian patients from 10 unrelated families with the X linked hyper-IgM (XHIM) phenotype.</AbstractText>The CD40L gene was screened for mutations using direct sequencing of exon specific polymerase chain reaction (PCR) products.</AbstractText>Ten mutations were identified. Seven of these mutations have been described previously, whereas three new nonsense mutations were identified, namely: E108X (c.322G>T), G167X (c.499G>T), and C218X (c.654C>A). Ten of 15 female family members revealed both a mutated allele and a normal allele, indicating that they were XHIM carriers.</AbstractText>The 10 mutations (including the three new ones) identified in this study reflect the heterogeneity of the CD40L gene, and indicate the need for accurate and reliable molecular testing of those patients suspected of XHIM.</AbstractText>
|
2,338,498 |
Efficacy of screening the intermediate cluster region of the bcl2 gene in follicular lymphomas by PCR.
|
The t(14;18) translocation is a common finding in nodal follicular B cell lymphomas and diffuse large B cell lymphomas, and results in the overexpression of the antiapoptotic bcl2 protein. This chromosome rearrangement can be detected by the polymerase chain reaction (PCR), with most breakpoints in the bcl2 gene occurring within either the major breakpoint region (mbr) or the minor cluster region (mcr). However, recent investigations have revealed several breakpoints between these two regions, which cluster 19 kb 3' of mbr in the "intermediate cluster region" (icr).</AbstractText><AbstractText Label="AIMS/METHODS" NlmCategory="OBJECTIVE">To analyse a series of 57 B cell follicular lymphomas known to carry the t(14;18) by PCR with primers directed against all three cluster regions to determine the efficacy of screening the icr site.</AbstractText>Twenty six samples had an mbr rearrangement, four an mcr rearrangement, and three an icr rearrangement.</AbstractText>These results suggest that screening for icr is at least as efficacious as screening for mcr rearrangements.</AbstractText>
|
2,338,499 |
Allergies in immigrants.
|
We studied the influence of environmental factors on allergy disease in immigrants that came to Israel during the last 20 years from A) Ethiopia and B) former Soviet Union. Immigrants who came from Ethiopia had no allergies upon arrival; they suffered from severe parasitic infections and had extremely elevated IgE levels. They got thorough anti parasitic treatment and were gradually integrated in the old timer Israeli population. After 5-10 years from arrival, follow up assessments showed a significant drop in IgE levels while respiratory allergies with positive skin tests Respiratory allergies with positive skin tests) to aero allergens appeared at a prevalence of 11%. Israeli born newborns and children from Ethiopian descent had no stool parasites and their total IgE levels were similar to those of the indigenous population. Immigrants from former Soviet Union who had respiratory allergies upon arrival, showed skin tested hypersensitivity to pollen common in their Russian, homelands while they were not sensitive to the Mediterranean pollen common in Israel. At yearly follow up testing over the first 10 years in Israel, odds for sensitization to Russian pollen decreased while odds for sensitization to Israeli pollen increased significantly. The results of our studies plead the case for the very important role played by the environment in the dynamics of allergy diseases.
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.