513 research outputs found

    Role of Tissue Factor in Venous Thrombosis

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    Venous thromboembolism (VTE) is a leading cause of morbidity and mortality worldwide. However, the mechanisms by which clots are formed in the deep veins have not been determined. Tissue factor (TF) is the primary initiator of the coagulation cascade and is essential for hemostasis. Under pathological conditions, TF is released into the circulation on small-membrane vesicles termed microparticles (MPs). Recent studies suggest that elevated levels of MPTF may trigger thrombosis. This review provides an overview of the role of TF in VTE

    Increased microparticle tissue factor activity in cancer patients with Venous Thromboembolism

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    AbstractCancer patients exhibit a high rate of thromboembolism (VTE). In this study, we analyzed levels of microparticle (MP) tissue factor (TF) activity in cancer patients with or without VTE. Blood was collected from cancer patients within 24 h of objectively diagnosed VTE (n=53) and from cancer patients without VTE (n=13). MPs were isolated from platelet poor plasma by centrifugation at 20,000g for 15 min. MP TF activity was measured using a two-stage chromogenic assay. Cancer patients with VTE had a significantly higher mean MP TF activity compared with cancer patients without VTE (1.7±3.8 pg/mL vs 0.6±0.4 pg/mL,

    Neurocognitive function in HIV infected patients on antiretroviral therapy

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    OBJECTIVE To describe factors associated with neurocognitive (NC) function in HIV-positive patients on stable combination antiretroviral therapy. DESIGN We undertook a cross-sectional analysis assessing NC data obtained at baseline in patients entering the Protease-Inhibitor-Monotherapy-Versus-Ongoing-Triple therapy (PIVOT) trial. MAIN OUTCOME MEASURE NC testing comprised of 5 domains. Raw results were z-transformed using standard and demographically adjusted normative datasets (ND). Global z-scores (NPZ-5) were derived from averaging the 5 domains and percentage of subjects with test scores >1 standard deviation (SD) below population means in at least two domains (abnormal Frascati score) calculated. Patient characteristics associated with NC results were assessed using multivariable linear regression. RESULTS Of the 587 patients in PIVOT, 557 had full NC results and were included. 77% were male, 68% Caucasian and 28% of Black ethnicity. Mean (SD) baseline and nadir CD4+ lymphocyte counts were 553(217) and 177(117) cells/µL, respectively, and HIV RNA was <50 copies/mL in all. Median (IQR) NPZ-5 score was -0.5 (-1.2/-0) overall, and -0.3 (-0.7/0.1) and -1.4 (-2/-0.8) in subjects of Caucasian and Black ethnicity, respectively. Abnormal Frascati scores using the standard-ND were observed in 51%, 38%, and 81%, respectively, of subjects overall, Caucasian and Black ethnicity (p<0.001), but in 62% and 69% of Caucasian and Black subjects using demographically adjusted-ND (p = 0.20). In the multivariate analysis, only Black ethnicity was associated with poorer NPZ-5 scores (P<0.001). CONCLUSIONS In this large group of HIV-infected subjects with viral load suppression, ethnicity but not HIV-disease factors is closely associated with NC results. The prevalence of abnormal results is highly dependent on control datasets utilised. TRIAL REGISTRY ClinicalTrials.gov, NCT01230580

    Assessing Working Memory in Mild Cognitive Impairment with Serial Order Recall.

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    BACKGROUND: Working memory (WM) is often assessed with serial order tests such as repeating digits backward. In prior dementia research using the Backward Digit Span Test (BDT), only aggregate test performance was examined. OBJECTIVE: The current research tallied primacy/recency effects, out-of-sequence transposition errors, perseverations, and omissions to assess WM deficits in patients with mild cognitive impairment (MCI). METHODS: Memory clinic patients (n = 66) were classified into three groups: single domain amnestic MCI (aMCI), combined mixed domain/dysexecutive MCI (mixed/dys MCI), and non-MCI where patients did not meet criteria for MCI. Serial order/WM ability was assessed by asking participants to repeat 7 trials of five digits backwards. Serial order position accuracy, transposition errors, perseverations, and omission errors were tallied. RESULTS: A 3 (group)×5 (serial position) repeated measures ANOVA yielded a significant group×trial interaction. Follow-up analyses found attenuation of the recency effect for mixed/dys MCI patients. Mixed/dys MCI patients scored lower than non-MCI patients for serial position 3 (p \u3c 0.003) serial position 4 (p \u3c 0.002); and lower than both group for serial position 5 (recency; p \u3c 0.002). Mixed/dys MCI patients also produced more transposition errors than both groups (p \u3c 0.010); and more omissions (p \u3c 0.020), and perseverations errors (p \u3c 0.018) than non-MCI patients. CONCLUSIONS: The attenuation of a recency effect using serial order parameters obtained from the BDT may provide a useful operational definition as well as additional diagnostic information regarding working memory deficits in MCI

    A Search for Jet Handedness in Hadronic Z0Z^0 Decays

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    We have searched for signatures of polarization in hadronic jets from Z0qqˉZ^0 \to q \bar{q} decays using the ``jet handedness'' method. The polar angle asymmetry induced by the high SLC electron-beam polarization was used to separate quark jets from antiquark jets, expected to be left- and right-polarized, respectively. We find no evidence for jet handedness in our global sample or in a sample of light quark jets and we set upper limits at the 95% C.L. of 0.063 and 0.099 respectively on the magnitude of the analyzing power of the method proposed by Efremov {\it et al.}Comment: Revtex, 8 pages, 2 figure

    Two novel loci, COBL and SLC10A2, for Alzheimer's disease in African Americans

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    INTRODUCTION: African Americans' (AAs) late-onset Alzheimer's disease (LOAD) genetic risk profile is incompletely understood. Including clinical covariates in genetic analyses using informed conditioning might improve study power. METHODS: We conducted a genome-wide association study (GWAS) in AAs employing informed conditioning in 1825 LOAD cases and 3784 cognitively normal controls. We derived a posterior liability conditioned on age, sex, diabetes status, current smoking status, educational attainment, and affection status, with parameters informed by external prevalence information. We assessed association between the posterior liability and a genome-wide set of single-nucleotide polymorphisms (SNPs), controlling for APOE and ABCA7, identified previously in a LOAD GWAS of AAs. RESULTS: Two SNPs at novel loci, rs112404845 (P = 3.8 × 10-8), upstream of COBL, and rs16961023 (P = 4.6 × 10-8), downstream of SLC10A2, obtained genome-wide significant evidence of association with the posterior liability. DISCUSSION: An informed conditioning approach can detect LOAD genetic associations in AAs not identified by traditional GWAS

    Erratum to: Status and access to the Collaborative Cross population (Mammalian Genome (2012) 23, (706-712) DOI: 10.1007/s00335-012-9410-6)

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    The Collaborative Cross (CC) is a panel of recombinant inbred lines derived from eight genetically diverse laboratory inbred strains. Recently, the genetic architecture of the CC population was reported based on the genotype of a single male per line, and other publications reported incompletely inbred CC mice that have been used to map a variety of traits. The three breeding sites, in the US, Israel, and Australia, are actively collaborating to accelerate the inbreeding process through marker-assisted inbreeding and to expedite community access of CC lines deemed to have reached defined thresholds of inbreeding. Plans are now being developed to provide access to this novel genetic reference population through distribution centers. Here we provide a description of the distribution efforts by the University of North Carolina Systems Genetics Core, Tel Aviv University, Israel and the University of Western Australia

    Genome-level analysis of genetic regulation of liver gene expression networks

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    Liver is the primary site for metabolism of nutrients, drugs and chemical agents. While metabolic pathways are complex and tightly regulated, genetic variation among individuals, reflected in variation in gene expression levels, introduces complexity into research on liver disease. This study aimed to dissect genetic networks that control liver gene expression by combining large-scale quantitative mRNA expression analysis with genetic mapping in a reference population of BXD recombinant inbred mouse strains for which extensive SNP, haplotype and phenotypic data is publicly available. We profiled gene expression in livers of naive mice of both sexes from C57BL/6J, DBA/2J, B6D2F1, and 37 BXD strains using Agilent oligonucleotide microarrays. This data was used to map quantitative trait loci (QTLs) responsible for variation in expression of about 19,000 transcripts. We identified polymorphic cis- and trans-acting loci, including several loci that control expression of large numbers of genes in liver, by comparing the physical transcript position with the location of the controlling QTL. The data is available through a public web-based resource (www.genenetwork.org) that allows custom data mining, identification of co-regulated transcripts and correlated phenotypes, cross-tissue and –species comparisons, as well as testing of a broad array of hypotheses

    Measurement of the Charged Multiplicities in b, c and Light Quark Events from Z0 Decays

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    Average charged multiplicities have been measured separately in bb, cc and light quark (u,d,su,d,s) events from Z0Z^0 decays measured in the SLD experiment. Impact parameters of charged tracks were used to select enriched samples of bb and light quark events, and reconstructed charmed mesons were used to select cc quark events. We measured the charged multiplicities: nˉuds=20.21±0.10(stat.)±0.22(syst.)\bar{n}_{uds} = 20.21 \pm 0.10 (\rm{stat.})\pm 0.22(\rm{syst.}), nˉc=21.28±0.46(stat.)0.36+0.41(syst.)\bar{n}_{c} = 21.28 \pm 0.46(\rm{stat.}) ^{+0.41}_{-0.36}(\rm{syst.}) nˉb=23.14±0.10(stat.)0.37+0.38(syst.)\bar{n}_{b} = 23.14 \pm 0.10(\rm{stat.}) ^{+0.38}_{-0.37}(\rm{syst.}), from which we derived the differences between the total average charged multiplicities of cc or bb quark events and light quark events: Δnˉc=1.07±0.47(stat.)0.30+0.36(syst.)\Delta \bar{n}_c = 1.07 \pm 0.47(\rm{stat.})^{+0.36}_{-0.30}(\rm{syst.}) and Δnˉb=2.93±0.14(stat.)0.29+0.30(syst.)\Delta \bar{n}_b = 2.93 \pm 0.14(\rm{stat.})^{+0.30}_{-0.29}(\rm{syst.}). We compared these measurements with those at lower center-of-mass energies and with perturbative QCD predictions. These combined results are in agreement with the QCD expectations and disfavor the hypothesis of flavor-independent fragmentation.Comment: 19 pages LaTex, 4 EPS figures, to appear in Physics Letters

    Association of Long Runs of Homozygosity With Alzheimer Disease Among African American Individuals

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    IMPORTANCE: Mutations in known causal Alzheimer disease (AD) genes account for only 1% to 3% of patients and almost all are dominantly inherited. Recessive inheritance of complex phenotypes can be linked to long (>1-megabase [Mb]) runs of homozygosity (ROHs) detectable by single-nucleotide polymorphism (SNP) arrays. OBJECTIVE: To evaluate the association between ROHs and AD in an African American population known to have a risk for AD up to 3 times higher than white individuals. DESIGN, SETTING, AND PARTICIPANTS: Case-control study of a large African American data set previously genotyped on different genome-wide SNP arrays conducted from December 2013 to January 2015. Global and locus-based ROH measurements were analyzed using raw or imputed genotype data. We studied the raw genotypes from 2 case-control subsets grouped based on SNP array: Alzheimer's Disease Genetics Consortium data set (871 cases and 1620 control individuals) and Chicago Health and Aging Project-Indianapolis Ibadan Dementia Study data set (279 cases and 1367 control individuals). We then examined the entire data set using imputed genotypes from 1917 cases and 3858 control individuals. MAIN OUTCOMES AND MEASURES: The ROHs larger than 1 Mb, 2 Mb, or 3 Mb were investigated separately for global burden evaluation, consensus regions, and gene-based analyses. RESULTS: The African American cohort had a low degree of inbreeding (F ~ 0.006). In the Alzheimer's Disease Genetics Consortium data set, we detected a significantly higher proportion of cases with ROHs greater than 2 Mb (P = .004) or greater than 3 Mb (P = .02), as well as a significant 114-kilobase consensus region on chr4q31.3 (empirical P value 2 = .04; ROHs >2 Mb). In the Chicago Health and Aging Project-Indianapolis Ibadan Dementia Study data set, we identified a significant 202-kilobase consensus region on Chr15q24.1 (empirical P value 2 = .02; ROHs >1 Mb) and a cluster of 13 significant genes on Chr3p21.31 (empirical P value 2 = .03; ROHs >3 Mb). A total of 43 of 49 nominally significant genes common for both data sets also mapped to Chr3p21.31. Analyses of imputed SNP data from the entire data set confirmed the association of AD with global ROH measurements (12.38 ROHs >1 Mb in cases vs 12.11 in controls; 2.986 Mb average size of ROHs >2 Mb in cases vs 2.889 Mb in controls; and 22% of cases with ROHs >3 Mb vs 19% of controls) and a gene-cluster on Chr3p21.31 (empirical P value 2 = .006-.04; ROHs >3 Mb). Also, we detected a significant association between AD and CLDN17 (empirical P value 2 = .01; ROHs >1 Mb), encoding a protein from the Claudin family, members of which were previously suggested as AD biomarkers. CONCLUSIONS AND RELEVANCE: To our knowledge, we discovered the first evidence of increased burden of ROHs among patients with AD from an outbred African American population, which could reflect either the cumulative effect of multiple ROHs to AD or the contribution of specific loci harboring recessive mutations and risk haplotypes in a subset of patients. Sequencing is required to uncover AD variants in these individuals
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