6,423 research outputs found
Imputation of variants from the 1000 Genomes Project modestly improves known associations and can identify low-frequency variant-phenotype associations undetected by HapMap based imputation
notes: PMCID: PMC3655956This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Genome-wide association (GWA) studies have been limited by the reliance on common variants present on microarrays or imputable from the HapMap Project data. More recently, the completion of the 1000 Genomes Project has provided variant and haplotype information for several million variants derived from sequencing over 1,000 individuals. To help understand the extent to which more variants (including low frequency (1% ≤ MAF <5%) and rare variants (<1%)) can enhance previously identified associations and identify novel loci, we selected 93 quantitative circulating factors where data was available from the InCHIANTI population study. These phenotypes included cytokines, binding proteins, hormones, vitamins and ions. We selected these phenotypes because many have known strong genetic associations and are potentially important to help understand disease processes. We performed a genome-wide scan for these 93 phenotypes in InCHIANTI. We identified 21 signals and 33 signals that reached P<5×10(-8) based on HapMap and 1000 Genomes imputation, respectively, and 9 and 11 that reached a stricter, likely conservative, threshold of P<5×10(-11) respectively. Imputation of 1000 Genomes genotype data modestly improved the strength of known associations. Of 20 associations detected at P<5×10(-8) in both analyses (17 of which represent well replicated signals in the NHGRI catalogue), six were captured by the same index SNP, five were nominally more strongly associated in 1000 Genomes imputed data and one was nominally more strongly associated in HapMap imputed data. We also detected an association between a low frequency variant and phenotype that was previously missed by HapMap based imputation approaches. An association between rs112635299 and alpha-1 globulin near the SERPINA gene represented the known association between rs28929474 (MAF = 0.007) and alpha1-antitrypsin that predisposes to emphysema (P = 2.5×10(-12)). Our data provide important proof of principle that 1000 Genomes imputation will detect novel, low frequency-large effect associations
New insights into the classification and nomenclature of cortical GABAergic interneurons.
A systematic classification and accepted nomenclature of neuron types is much needed but is currently lacking. This article describes a possible taxonomical solution for classifying GABAergic interneurons of the cerebral cortex based on a novel, web-based interactive system that allows experts to classify neurons with pre-determined criteria. Using Bayesian analysis and clustering algorithms on the resulting data, we investigated the suitability of several anatomical terms and neuron names for cortical GABAergic interneurons. Moreover, we show that supervised classification models could automatically categorize interneurons in agreement with experts' assignments. These results demonstrate a practical and objective approach to the naming, characterization and classification of neurons based on community consensus
A genome-wide association study identifies protein quantitative trait loci (pQTLs)
There is considerable evidence that human genetic variation influences gene expression. Genome-wide studies have revealed that mRNA levels are associated with genetic variation in or close to the gene coding for those mRNA transcripts - cis effects, and elsewhere in the genome - trans effects. The role of genetic variation in determining protein levels has not been systematically assessed. Using a genome-wide association approach we show that common genetic variation influences levels of clinically relevant proteins in human serum and plasma. We evaluated the role of 496,032 polymorphisms on levels of 42 proteins measured in 1200 fasting individuals from the population based InCHIANTI study. Proteins included insulin, several interleukins, adipokines, chemokines, and liver function markers that are implicated in many common diseases including metabolic, inflammatory, and infectious conditions. We identified eight Cis effects, including variants in or near the IL6R (p = 1.8×10 -57), CCL4L1 (p = 3.9×10-21), IL18 (p = 6.8×10-13), LPA (p = 4.4×10-10), GGT1 (p = 1.5×10-7), SHBG (p = 3.1×10-7), CRP (p = 6.4×10-6) and IL1RN (p = 7.3×10-6) genes, all associated with their respective protein products with effect sizes ranging from 0.19 to 0.69 standard deviations per allele. Mechanisms implicated include altered rates of cleavage of bound to unbound soluble receptor (IL6R), altered secretion rates of different sized proteins (LPA), variation in gene copy number (CCL4L1) and altered transcription (GGT1). We identified one novel trans effect that was an association between ABO blood group and tumour necrosis factor alpha (TNF-alpha) levels (p = 6.8×10-40), but this finding was not present when TNF-alpha was measured using a different assay , or in a second study, suggesting an assay-specific association. Our results show that protein levels share some of the features of the genetics of gene expression. These include the presence of strong genetic effects in cis locations. The identification of protein quantitative trait loci (pQTLs) may be a powerful complementary method of improving our understanding of disease pathways. © 2008 Melzer et al
Gene transcripts associated with muscle strength: a CHARGE meta-analysis of 7,781 persons
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Background: Lower muscle strength in midlife predicts disability and mortality in later life. Bloodborne factors, including growth differentiation factor 11 (GDF11), have been linked to muscle regeneration in animal models. We aimed to identify gene transcripts associated with muscle strength in adults. Methods: Meta-analysis of whole blood gene expression (overall 17,534 unique genes measured by microarray) and hand-grip strength in four independent cohorts (n=7,781, ages: 20-104 years, weighted mean=56), adjusted for age, sex, height, weight, and leukocyte subtypes. Separate analyses were performed in subsets (older/younger than 60, male/female). Results: Expression levels of 221 genes were associated with strength after adjustment for cofactors and for multiple statistical testing, including ALAS2 (rate limiting enzyme in heme synthesis), PRF1 (perforin, a cytotoxic protein associated with inflammation), IGF1R and IGF2BP2 (both insulin like growth factor related). We identified statistical enrichment for hemoglobin biosynthesis, innate immune activation and the stress response. Ten genes were only associated in younger individuals, four in males only and one in females only. For example PIK3R2 (a negative regulator of PI3K/AKT growth pathway) was negatively associated with muscle strength in younger (=60 years). We also show that 115 genes (52%) have not previously been linked to muscle in NCBI PubMed abstracts Conclusions: This first large-scale transcriptome study of muscle strength in human adults confirmed associations with known pathways and provides new evidence for over half of the genes identified. There may be age and sex specific gene expression signatures in blood for muscle strength.Wellcome TrustFHS gene expression profiling was funded through the Division of Intramural Research
(Principal Investigator, Daniel Levy), National Heart, Lung, and Blood Institute, National
Institutes of Health, Bethesda, MD. Dr. Murabito is supported by NIH grant R01AG029451.
Dr. Kiel is supported by NIH R01 AR41398. The Framingham Heart Study is supported by
National Heart, Lung, and Blood Institute contract N01-HC-25195.The InCHIANTI study was supported in part by the Intramural Research Program, National
Institute on Aging, NIH, Baltimore MD USA. D.M. and L.W.H. were generously supported by
a Wellcome Trust Institutional Strategic Support Award (WT097835MF). W.E.H. was funded
by the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied
Health Research and Care (CLAHRC) for the South West Peninsula. The views expressed in
this publication are those of the authors and not necessarily those of the NHS, the NIHR or
the Department of Health in EnglandThe infrastructure for the NESDA study (www.nesda.nl) is funded through the Geestkracht
program of the Netherlands Organisation for Health Research and Development (Zon-Mw,
grant number 10-000-1002) and is supported by participating universities and mental health
care organizations (VU University Medical Center, GGZ inGeest, Arkin, Leiden University
Medical Center, GGZ Rivierduinen, University Medical Center Groningen, Lentis, GGZ
Friesland, GGZ Drenthe, Scientific Institute for Quality of Healthcare (IQ healthcare),
Netherlands Institute for Health Services Research (NIVEL) and Netherlands Institute of
Mental Health and Addiction (Trimbos Institute).The Rotterdam Study is funded by Erasmus Medical Center and Erasmus University,
Rotterdam, Netherlands Organization for the Health Research and Development (ZonMw),
the Netherlands Organisation of Scientific Research NWO Investments (nr.
175.010.2005.011, 911-03-012), the Research Institute for Diseases in the Elderly (014-93-
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015; RIDE2), the Ministry of Education, Culture and Science, the Ministry for Health, Welfare
and Sports, the European Commission (DG XII), and the Municipality of Rotterdam. The
authors are grateful to the study participants, the staff from the Rotterdam Study and the
participating general practitioners and pharmacists. The generation and management of
RNA-expression array data for the Rotterdam Study was executed and funded by the Human
Genotyping Facility of the Genetic Laboratory of the Department of Internal Medicine,
Erasmus MC, the Netherlands. We thank Marjolein Peters, MSc, Ms. Mila Jhamai, Ms.
Jeannette M. Vergeer-Drop, Ms. Bernadette van Ast-Copier, Mr. Marijn Verkerk and Jeroen
van Rooij, BSc for their help in creating the RNA array expression databaseSHIP is part of the Community Medicine Research net of the University of Greifswald,
Germany, which is funded by the Federal Ministry of Education and Research (grants no.
01ZZ9603, 01ZZ0103, and 01ZZ0403), the Ministry of Cultural Affairs as well as the Social
Ministry of the Federal State of Mecklenburg-West Pomerania, and the network ‘Greifswald
Approach to Individualized Medicine (GANI_MED)’ funded by the Federal Ministry of
Education and Research (grant 03IS2061A). The University of Greifswald is a member of the
'Center of Knowledge Interchange' program of the Siemens AG and the Caché Campus
program of the InterSystems GmbH
Eight common genetic variants associated with serum dheas levels suggest a key role in ageing mechanisms
Dehydroepiandrosterone sulphate (DHEAS) is the most abundant circulating steroid secreted by adrenal glands-yet its function is unknown. Its serum concentration declines significantly with increasing age, which has led to speculation that a relative DHEAS deficiency may contribute to the development of common age-related diseases or diminished longevity. We conducted a meta-analysis of genome-wide association data with 14,846 individuals and identified eight independent common SNPs associated with serum DHEAS concentrations. Genes at or near the identified loci include ZKSCAN5 (rs11761528; p = 3.15×10-36), SULT2A1 (rs2637125; p = 2.61×10-19), ARPC1A (rs740160; p = 1.56×10-16), TRIM4 (rs17277546; p = 4.50×10-11), BMF (rs7181230; p = 5.44×10-11), HHEX (rs2497306; p = 4.64×10-9), BCL2L11 (rs6738028; p = 1.72×10-8), and CYP2C9 (rs2185570; p = 2.29×10-8). These genes are associated with type 2 diabetes, lymphoma, actin filament assembly, drug and xenobiotic metabolism, and zinc finger proteins. Several SNPs were associated with changes in gene expression levels, and the related genes are connected to biological pathways linking DHEAS with ageing. This study provides much needed insight into the function of DHEAS
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Clinical, microbiological characteristics and predictors of mortality in patients with carbapenemase-producing Enterobacterales bloodstream infections: a multicentre study.
OBJECTIVES: To investigate the clinical, microbiological characteristics and outcomes of patients with bloodstream infections (BSI) due to carbapenemase-producing Enterobacterales (CPE). METHODS: A multicentre retrospective observational study of patients with BSIs due to CPE admitted to six UK hospitals was conducted between 2011 and 2021. Multivariate analysis was used to identify factors predicting 30-day case fatality rate (CFR). RESULTS: There were 84 episodes of CPE-BSIs, 37 (44%) due to OXA-48, 35 (42%) to metallo-betalactamases (MBL) and 12 (14%) to KPC. 63% of patients were male with a median age of 64 years. Common organisms included Klebsiella spp. (61%), Escherichia coli (20%) and Enterobacter spp. (13%). Urinary devices were more often involved in OXA-48 BSIs (12/37; 32%) compared to infections caused by MBL and KPC (4/35; 11% and 1/12; 8%; P = 0.046). In contrast, central venous catheters were more frequently present in KPC-BSIs (10/12; 92%) compared with OXA-48 and MBL (11/37; 30% and 20/35; 57%; P = 0.002). Effective definitive antimicrobials were received by 72/84 (86%) patients, comprising monotherapy (32/72; 44%) or combination therapy (40/72; 56%). 30-day case fatality rate (CFR) was 38%. Sepsis or septic shock was associated with death [OR 3.81 (CI 1.19-12.14), P = 0.024]. CONCLUSION: Strategies targeting high-risk patients and adherence to infection prevention bundles for urinary devices and central venous catheters can reduce OXA-48 and KPC-BSIs. Early recognition and management of severe sepsis, prompt initiation of appropriate antimicrobial therapy and development of novel antimicrobials are crucial to mitigate the high CFR associated with CPE-BSIs
The 24-h Energy Intake of Obese Adolescents Is Spontaneously Reduced after Intensive Exercise: A Randomized Controlled Trial in Calorimetric Chambers
Background: Physical exercise can modify subsequent energy intake and appetite and may thus be of particular interest in terms of obesity treatment. However, it is still unclear whether an intensive bout of exercise can affect the energy consumption of obese children and adolescents. [br/]
Objective: To compare the impact of high vs. moderate intensity exercises on subsequent 24-h energy intake, macronutrient preferences, appetite sensations, energy expenditure and balance in obese adolescent. [br/]
Design: This randomized cross-over trial involves 15 obese adolescent boys who were asked to randomly complete three 24-h sessions in a metabolic chamber, each separated by at least 7 days: (1) sedentary (SED); (2) Low-Intensity Exercise (LIE) (40% maximal oxygen uptake, VO(2)max); (3) High-Intensity Exercise (HIE) (75% VO(2)max). Results: Despite unchanged appetite sensations, 24-h total energy intake following HIE was 6-11% lower compared to LIE and SED (p<0.05), whereas no differences appeared between SED and LIE. Energy intake at lunch was 9.4% and 8.4% lower after HIE compared to SED and LIE, respectively (p<0.05). At dinner time, it was 20.5% and 19.7% lower after HIE compared to SED and LIE, respectively (p<0.01). 24-h energy expenditure was not significantly altered. Thus, the 24-h energy balance was significantly reduced during HIE compared to SED and LIE (p<0.01), whereas those of SED and LIE did not differ. [br/]
Conclusions: In obese adolescent boys, HIE has a beneficial impact on 24-h energy balance, mainly due to the spontaneous decrease in energy intake during lunch and dinner following the exercise bout. Prescribing high-intensity exercises to promote weight loss may therefore provide effective results without affecting appetite sensations and, as a result, food frustrations
Measurement of event shapes in deep inelastic scattering at HERA
Inclusive event-shape variables have been measured in the current region of
the Breit frame for neutral current deep inelastic ep scattering using an
integrated luminosity of 45.0 pb^-1 collected with the ZEUS detector at HERA.
The variables studied included thrust, jet broadening and invariant jet mass.
The kinematic range covered was 10 < Q^2 < 20,480 GeV^2 and 6.10^-4 < x < 0.6,
where Q^2 is the virtuality of the exchanged boson and x is the Bjorken
variable. The Q dependence of the shape variables has been used in conjunction
with NLO perturbative calculations and the Dokshitzer-Webber non-perturbative
corrections (`power corrections') to investigate the validity of this approach.Comment: 7+25 pages, 6 figure
Search for New Physics with Jets and Missing Transverse Momentum in pp collisions at sqrt(s) = 7 TeV
A search for new physics is presented based on an event signature of at least
three jets accompanied by large missing transverse momentum, using a data
sample corresponding to an integrated luminosity of 36 inverse picobarns
collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector
at the LHC. No excess of events is observed above the expected standard model
backgrounds, which are all estimated from the data. Exclusion limits are
presented for the constrained minimal supersymmetric extension of the standard
model. Cross section limits are also presented using simplified models with new
particles decaying to an undetected particle and one or two jets
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