157 research outputs found

    Principal-component-based multivariate regression for genetic association studies of metabolic syndrome components

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    <p>Abstract</p> <p>Background</p> <p>Quantitative traits often underlie risk for complex diseases. For example, weight and body mass index (BMI) underlie the human abdominal obesity-metabolic syndrome. Many attempts have been made to identify quantitative trait loci (QTL) over the past decade, including association studies. However, a single QTL is often capable of affecting multiple traits, a quality known as gene pleiotropy. Gene pleiotropy may therefore cause a loss of power in association studies focused only on a single trait, whether based on single or multiple markers.</p> <p>Results</p> <p>We propose using principal-component-based multivariate regression (PCBMR) to test for gene pleiotropy with comprehensive evaluation. This method generates one or more independent canonical variables based on the principal components of original traits and conducts a multivariate regression to test for association with these new variables. Systematic simulation studies have shown that PCBMR has great power. PCBMR-based pleiotropic association studies of abdominal obesity-metabolic syndrome and its possible linkage to chromosomal band 3q27 identified 11 susceptibility genes with significant associations. Whereas some of these genes had been previously reported to be associated with metabolic traits, others had never been identified as metabolism-associated genes.</p> <p>Conclusions</p> <p>PCBMR is a computationally efficient and powerful test for gene pleiotropy. Application of PCBMR to abdominal obesity-metabolic syndrome indicated the existence of gene pleiotropy affecting this syndrome.</p

    The closest elastic tensor of arbitrary symmetry to an elasticity tensor of lower symmetry

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    The closest tensors of higher symmetry classes are derived in explicit form for a given elasticity tensor of arbitrary symmetry. The mathematical problem is to minimize the elastic length or distance between the given tensor and the closest elasticity tensor of the specified symmetry. Solutions are presented for three distance functions, with particular attention to the Riemannian and log-Euclidean distances. These yield solutions that are invariant under inversion, i.e., the same whether elastic stiffness or compliance are considered. The Frobenius distance function, which corresponds to common notions of Euclidean length, is not invariant although it is simple to apply using projection operators. A complete description of the Euclidean projection method is presented. The three metrics are considered at a level of detail far greater than heretofore, as we develop the general framework to best fit a given set of moduli onto higher elastic symmetries. The procedures for finding the closest elasticity tensor are illustrated by application to a set of 21 moduli with no underlying symmetry.Comment: 48 pages, 1 figur

    A Community in Bloom: An affordable housing needs assessment of West Bloomington

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    Purpose of Report This report was written in response to a request from Habitat for Humanity of McLean County. The report expands upon and updates an affordable homeownership needs assessment for the Bloomington-Normal community – with an emphasis on West Bloomington – that was created in 2004. Because the housing market and economic conditions of the area have changed drastically in the last 6 years, an updated report is necessary. Data Sources and Methodology This report uses a combination of primary and, mainly, secondary data sources. Interviews were conducted with representatives of, among others, Bloomington Housing Authority, the Economic Development Council (EDC) of Bloomington-Normal Area, Mid Central Community Action, Prairie State Legal Services, and the West Bloomington Revitalization Project. A variety of data were gathered from secondary sources, such as the U.S. Department of Housing and Urban Development (HUD), the U.S. Census, the City of Bloomington, the U.S. Bureau of Labor Statistics, Mid Central Community Action, the National Association of Realtors, and the National Low Income Housing Coalition (NLIHC)

    Multi-drug resistance, inappropriate initial antibiotic therapy and mortality in Gram-negative severe sepsis and septic shock: A retrospective cohort study

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    INTRODUCTION: The impact of in vitro resistance on initially appropriate antibiotic therapy (IAAT) remains unclear. We elucidated the relationship between non-IAAT and mortality, and between IAAT and multi-drug resistance (MDR) in sepsis due to Gram-negative bacteremia (GNS). METHODS: We conducted a single-center retrospective cohort study of adult intensive care unit patients with bacteremia and severe sepsis/septic shock caused by a gram-negative (GN) organism. We identified the following MDR pathogens: MDR P. aeruginosa, extended spectrum beta-lactamase and carbapenemase-producing organisms. IAAT was defined as exposure within 24 hours of infection onset to antibiotics active against identified pathogens based on in vitro susceptibility testing. We derived logistic regression models to examine a) predictors of hospital mortality and b) impact of MDR on non-IAAT. Proportions are presented for categorical variables, and median values with interquartile ranges (IQR) for continuous. RESULTS: Out of 1,064 patients with GNS, 351 (29.2%) did not survive hospitalization. Non-survivors were older (66.5 (55, 73.5) versus 63 (53, 72) years, P = 0.036), sicker (Acute Physiology and Chronic Health Evaluation II (19 (15, 25) versus 16 (12, 19), P <0.001), and more likely to be on pressors (odds ratio (OR) 2.79, 95% confidence interval (CI) 2.12 to 3.68), mechanically ventilated (OR 3.06, 95% CI 2.29 to 4.10) have MDR (10.0% versus 4.0%, P <0.001) and receive non-IAAT (43.4% versus 14.6%, P <0.001). In a logistic regression model, non-IAAT was an independent predictor of hospital mortality (adjusted OR 3.87, 95% CI 2.77 to 5.41). In a separate model, MDR was strongly associated with the receipt of non-IAAT (adjusted OR 13.05, 95% CI 7.00 to 24.31). CONCLUSIONS: MDR, an important determinant of non-IAAT, is associated with a three-fold increase in the risk of hospital mortality. Given the paucity of therapies to cover GN MDRs, prevention and development of new agents are critical

    Consensus on circulatory shock and hemodynamic monitoring. Task force of the European Society of Intensive Care Medicine.

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    OBJECTIVE: Circulatory shock is a life-threatening syndrome resulting in multiorgan failure and a high mortality rate. The aim of this consensus is to provide support to the bedside clinician regarding the diagnosis, management and monitoring of shock. METHODS: The European Society of Intensive Care Medicine invited 12 experts to form a Task Force to update a previous consensus (Antonelli et al.: Intensive Care Med 33:575-590, 2007). The same five questions addressed in the earlier consensus were used as the outline for the literature search and review, with the aim of the Task Force to produce statements based on the available literature and evidence. These questions were: (1) What are the epidemiologic and pathophysiologic features of shock in the intensive care unit ? (2) Should we monitor preload and fluid responsiveness in shock ? (3) How and when should we monitor stroke volume or cardiac output in shock ? (4) What markers of the regional and microcirculation can be monitored, and how can cellular function be assessed in shock ? (5) What is the evidence for using hemodynamic monitoring to direct therapy in shock ? Four types of statements were used: definition, recommendation, best practice and statement of fact. RESULTS: Forty-four statements were made. The main new statements include: (1) statements on individualizing blood pressure targets; (2) statements on the assessment and prediction of fluid responsiveness; (3) statements on the use of echocardiography and hemodynamic monitoring. CONCLUSIONS: This consensus provides 44 statements that can be used at the bedside to diagnose, treat and monitor patients with shock

    HLA-B*14:01 and HLA-B*35:01 are associated with trimethoprim-sulfamethoxazole induced liver injury

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    Background and AimTrimethoprim‐sulfamethoxazole (TMP‐SMX) is an important cause of idiosyncratic drug induced liver injury (DILI), but its genetic risk factors are not well understood. We investigated the relationship between variants in the HLA Class I and II genes and well characterized cases of TMP‐SMX DILI.MethodsEuropean American and African American persons with TMP‐SMX DILI were compared to respective population controls. HLA sequencing was performed by Illumina MiSeq for cases. HLA genotype imputation with attribute bagging (HIBAG) program was used to impute HLA alleles for controls. Allele frequency difference between cases and controls was tested by Fisher exact tests per ethnic group. For European Americans, multivariable logistic regression with Firth penalization was used to test HLA allelic effect after adjusting for age and the top two principal components. Molecular docking was performed to assess the HLA binding with TMP and SMX.ResultsThe European American subset had 51 cases and 12,156 controls, while the African American subset had 10 cases and 5,439 controls. Four HLA alleles were significantly associated in the European American subset, with HLA‐B*14:01 ranking at the top (OR: 9.20, 95% CI: 3.16‐22.35, p=0.0003) after covariate adjustment. All HLA‐B*14:01 carriers with TMP‐SMX DILI possessed HLA‐C*08:02, another significant allele (p=0.0026). This pattern was supported by HLA‐B*14:01‐HLA‐C*08:02 haplotype association (p=1.33x10‐5). For the African Americans, HLA‐B*35:01 had 2.8‐fold higher frequency in cases than in controls, with five of 10 patients carrying this allele. Molecular docking showed Cys67 in HLA‐B*14:01 and Phe67 in HLA‐B*35:01 to be the predictive binding sites to SMX metabolites. ConclusionHLA‐B*14:01 is associated with TMP‐SMX DILI in European Americans, and HLA‐B*35:01 may be a potential genetic risk factor for African Americans
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