307 research outputs found

    Data Management Plans: Stages, Components, and Activities

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    Data management strategies have become increasingly important as new computer technologies allow for larger and more complex data sets to be analyzed easily. As a consequence, data management has become a specialty requiring specific skills and knowledge. Many new investigators have no formal training in management of data sets. This paper describes common basic strategies critical to the management of data as applied to a data set from a longitudinal study. The stages of data management are identified. Moreover, key components and strategies, at each stage are described

    Patterns of Risk of Depressive Symptoms Among HIV-Positive Women in the Southeastern United States

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    Depressive symptoms are a common response to HIV disease, and women appear to be at particularly high risk. The authors report results from a crosssectional analysis of data collected from 280 rural women with HIV/AIDS in the Southeastern United States aimed at identifying risk factors of depressive symptoms. Stress theory provided a framework for identification of potential risk factors. Descriptive statistics, measures of association, and regression analyses were used to systematically identify patterns of risk. The final regression model included 22 factors that accounted for 69% of the variance in depressive symptoms. The majority of variance in depressive symptoms was accounted for by only six variables: the frequency of HIV symptoms, recent experiences of sadness/hopelessness, the availability of social support, and the use of three coping strategies: living positively with HIV, isolation/withdrawal, and denial/avoidance. The results suggest a number of intervention strategies for use with rural women with HIV/AIDS

    Prion protein interacts with bace1 and differentially regulates its activity towards wild type and swedish mutant amyloid precursor protein

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    In Alzheimer disease amyloid-β (Aβ) peptides derived from the amyloid precursor protein (APP) accumulate in the brain. Cleavage of APP by the β-secretase BACE1 is the rate-limiting step in the production of Aβ. We have reported previously that the cellular prion protein (PrP(C)) inhibited the action of BACE1 toward human wild type APP (APP(WT)) in cellular models and that the levels of endogenous murine Aβ were significantly increased in PrP(C)-null mouse brain. Here we investigated the molecular and cellular mechanisms underlying this observation. PrP(C) interacted directly with the prodomain of the immature Golgi-localized form of BACE1. This interaction decreased BACE1 at the cell surface and in endosomes where it preferentially cleaves APP(WT) but increased it in the Golgi where it preferentially cleaves APP with the Swedish mutation (APP(Swe)). In transgenic mice expressing human APP with the Swedish and Indiana familial mutations (APP(Swe,Ind)), PrP(C) deletion had no influence on APP proteolytic processing, Aβ plaque deposition, or levels of soluble Aβ or Aβ oligomers. In cells, although PrP(C) inhibited the action of BACE1 on APP(WT), it did not inhibit BACE1 activity toward APP(Swe). The differential subcellular location of the BACE1 cleavage of APP(Swe) relative to APP(WT) provides an explanation for the failure of PrP(C) deletion to affect Aβ accumulation in APP(Swe,Ind) mice. Thus, although PrP(C) exerts no control on cleavage of APP(Swe) by BACE1, it has a profound influence on the cleavage of APP(WT), suggesting that PrP(C) may be a key protective player against sporadic Alzheimer disease

    A pilot observational study measuring acute sarcopenia in older colorectal surgery patients

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    Abstract Objective To explore variability in acute changes in muscle mass and function in older patients undergoing elective colorectal surgery, as well as feasibility of measures, in order to refine study processes to inform the protocol for a larger study. Results Results are presented for seven participants recruited to this pilot study. It is possible to perform serial measurements of bilateral anterior thigh thickness (BATT) and handgrip strength prior to, within 24 h of surgery, and 1 week postoperatively. Gait speed can be reliably measured preoperatively and at 1 week postoperatively. In this pilot study, BATT and gait speed declined at 1 week postoperatively (median BATT 4.17 cm, 3.47 cm, p = 0.028; median gait speed 0.89 m/s, 0.83 m/s, p = 0.043). Baseline hsCRP correlated with change in BATT (τb = 0.73, p = 0.04) and baseline DHEA-S correlated with change in gait speed (τb = 0.87, p = 0.02). This pilot study has assisted to refine the protocol for our larger study, which will further characterise these changes
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