762 research outputs found

    Fine-mapping identifies multiple prostate cancer risk loci at 5p15, one of which associates with TERT expression

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    Associations between single nucleotide polymorphisms (SNPs) at 5p15 and multiple cancer types have been reported. We have previously shown evidence for a strong association between prostate cancer (PrCa) risk and rs2242652 at 5p15, intronic in the telomerase reverse transcriptase (TERT) gene that encodes TERT. To comprehensively evaluate the association between genetic variation across this region and PrCa, we performed a fine-mapping analysis by genotyping 134 SNPs using a custom Illumina iSelect array or Sequenom MassArray iPlex, followed by imputation of 1094 SNPs in 22 301 PrCa cases and 22 320 controls in The PRACTICAL consortium. Multiple stepwise logistic regression analysis identified four signals in the promoter or intronic regions of TERT that independently associated with PrCa risk. Gene expression analysis of normal prostate tissue showed evidence that SNPs within one of these regions also associated with TERT expression, providing a potential mechanism for predisposition to disease

    An Approximate Bayesian Estimator Suggests Strong, Recurrent Selective Sweeps in Drosophila

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    The recurrent fixation of newly arising, beneficial mutations in a species reduces levels of linked neutral variability. Models positing frequent weakly beneficial substitutions or, alternatively, rare, strongly selected substitutions predict similar average effects on linked neutral variability, if the product of the rate and strength of selection is held constant. We propose an approximate Bayesian (ABC) polymorphism-based estimator that can be used to distinguish between these models, and apply it to multi-locus data from Drosophila melanogaster. We investigate the extent to which inference about the strength of selection is sensitive to assumptions about the underlying distributions of the rates of substitution and recombination, the strength of selection, heterogeneity in mutation rate, as well as the population's demographic history. We show that assuming fixed values of selection parameters in estimation leads to overestimates of the strength of selection and underestimates of the rate. We estimate parameters for an African population of D. melanogaster (ŝ∼2E−03, ) and compare these to previous estimates. Finally, we show that surveying larger genomic regions is expected to lend much more discriminatory power to the approach. It will thus be of great interest to apply this method to emerging whole-genome polymorphism data sets in many taxa

    BRCA2 polymorphic stop codon K3326X and the risk of breast, prostate, and ovarian cancers

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    Background: The K3326X variant in BRCA2 (BRCA2*c.9976A>T; p.Lys3326*; rs11571833) has been found to be associated with small increased risks of breast cancer. However, it is not clear to what extent linkage disequilibrium with fully pathogenic mutations might account for this association. There is scant information about the effect of K3326X in other hormone-related cancers. Methods: Using weighted logistic regression, we analyzed data from the large iCOGS study including 76 637 cancer case patients and 83 796 control patients to estimate odds ratios (ORw) and 95% confidence intervals (CIs) for K3326X variant carriers in relation to breast, ovarian, and prostate cancer risks, with weights defined as probability of not having a pathogenic BRCA2 variant. Using Cox proportional hazards modeling, we also examined the associations of K3326X with breast and ovarian cancer risks among 7183 BRCA1 variant carriers. All statistical tests were two-sided. Results: The K3326X variant was associated with breast (ORw = 1.28, 95% CI = 1.17 to 1.40, P = 5.9x10- 6) and invasive ovarian cancer (ORw = 1.26, 95% CI = 1.10 to 1.43, P = 3.8x10-3). These associations were stronger for serous ovarian cancer and for estrogen receptor–negative breast cancer (ORw = 1.46, 95% CI = 1.2 to 1.70, P = 3.4x10-5 and ORw = 1.50, 95% CI = 1.28 to 1.76, P = 4.1x10-5, respectively). For BRCA1 mutation carriers, there was a statistically significant inverse association of the K3326X variant with risk of ovarian cancer (HR = 0.43, 95% CI = 0.22 to 0.84, P = .013) but no association with breast cancer. No association with prostate cancer was observed. Conclusions: Our study provides evidence that the K3326X variant is associated with risk of developing breast and ovarian cancers independent of other pathogenic variants in BRCA2. Further studies are needed to determine the biological mechanism of action responsible for these associations

    A search for charged massive long-lived particles

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    We report on a search for charged massive long-lived particles (CMLLPs), based on 5.2 fb1^{-1} of integrated luminosity collected with the D0 detector at the Fermilab Tevatron ppˉp\bar{p} collider. We search for events in which one or more particles are reconstructed as muons but have speed and ionization energy loss (dE/dx)(dE/dx) inconsistent with muons produced in beam collisions. CMLLPs are predicted in several theories of physics beyond the standard model. We exclude pair-produced long-lived gaugino-like charginos below 267 GeV and higgsino-like charginos below 217 GeV at 95% C.L., as well as long-lived scalar top quarks with mass below 285 GeV.Comment: submitted to Phys. Rev. Letter

    A super-spreading ewe infects hundreds with Q fever at a farmers' market in Germany

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    BACKGROUND: In May 2003 the Soest County Health Department was informed of an unusually large number of patients hospitalized with atypical pneumonia. METHODS: In exploratory interviews patients mentioned having visited a farmers' market where a sheep had lambed. Serologic testing confirmed the diagnosis of Q fever. We asked local health departments in Germany to identiy notified Q fever patients who had visited the farmers market. To investigate risk factors for infection we conducted a case control study (cases were Q fever patients, controls were randomly selected Soest citizens) and a cohort study among vendors at the market. The sheep exhibited at the market, the herd from which it originated as well as sheep from herds held in the vicinity of Soest were tested for Coxiella burnetii (C. burnetii). RESULTS: A total of 299 reported Q fever cases was linked to this outbreak. The mean incubation period was 21 days, with an interquartile range of 16–24 days. The case control study identified close proximity to and stopping for at least a few seconds at the sheep's pen as significant risk factors. Vendors within approximately 6 meters of the sheep's pen were at increased risk for disease compared to those located farther away. Wind played no significant role. The clinical attack rate of adults and children was estimated as 20% and 3%, respectively, 25% of cases were hospitalized. The ewe that had lambed as well as 25% of its herd tested positive for C. burnetii antibodies. CONCLUSION: Due to its size and point source nature this outbreak permitted assessment of fundamental, but seldom studied epidemiological parameters. As a consequence of this outbreak, it was recommended that pregnant sheep not be displayed in public during the 3(rd )trimester and to test animals in petting zoos regularly for C. burnetii

    Global impression of perceived difficulties in children and adolescents with attention-deficit/hyperactivity disorder: Reliability and validity of a new instrument assessing perceived difficulties from a patient, parent and physician perspective over the day

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    <p>Abstract</p> <p>Background</p> <p>The objective of this analysis was to evaluate the psychometric properties of a brief scale developed to assess the degree of difficulties in children with Attention-Deficit/Hyperactivity Disorder (ADHD). The Global Impression of Perceived Difficulties (GIPD) scale reflects overall impairment, psychosocial functioning and Quality of Life (QoL) as rated by patient, parents and physician at various times of the day.</p> <p>Methods</p> <p>In two open-label studies, ADHD-patients aged 6–17 years were treated with atomoxetine (target-dose 0.5–1.2 mg/kg/day). ADHD-related difficulties were assessed up to week 24 using the GIPD. Data from both studies were combined to validate the scale.</p> <p>Results</p> <p>Overall, 421 patients received atomoxetine. GIPD scores improved over time. All three GIPD-versions (patient, parent, physician) were internally consistent; all items showed at least moderate item-total correlation. The scale showed good test-retest reliability over a two-week period from all three perspectives. Good convergent and discriminant validity was shown.</p> <p>Conclusion</p> <p>GIPD is an internally consistent, reliable and valid measure to assess difficulties in children with ADHD at various times of the day and can be used as indicator for psychosocial impairment and QoL. The scale is sensitive to treatment-related change.</p

    Evolution of the Primate APOBEC3A Cytidine Deaminase Gene and Identification of Related Coding Regions

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    The APOBEC3 gene cluster encodes six cytidine deaminases (A3A-C, A3DE, A3F-H) with single stranded DNA (ssDNA) substrate specificity. For the moment A3A is the only enzyme that can initiate catabolism of both mitochondrial and nuclear DNA. Human A3A expression is initiated from two different methionine codons M1 or M13, both of which are in adequate but sub-optimal Kozak environments. In the present study, we have analyzed the genetic diversity among A3A genes across a wide range of 12 primates including New World monkeys, Old World monkeys and Hominids. Sequence variation was observed in exons 1–4 in all primates with up to 31% overall amino acid variation. Importantly for 3 hominids codon M1 was mutated to a threonine codon or valine codon, while for 5/12 primates strong Kozak M1 or M13 codons were found. Positive selection was apparent along a few branches which differed compared to positive selection in the carboxy-terminal of A3G that clusters with A3A among human cytidine deaminases. In the course of analyses, two novel non-functional A3A-related fragments were identified on chromosome 4 and 8 kb upstream of the A3 locus. This qualitative and quantitative variation among primate A3A genes suggest that subtle differences in function might ensue as more light is shed on this increasingly important enzyme
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