306 research outputs found
At what age do patients no longer need colorectal cancer screening?
Good evidence supports fecal occult blood testing (FOBT) for patients up to age 75 (grade of recommendation: A, based on systematic review of randomized controlled trials). There is insufficient evidence to recommend for or against colorectal cancer (CRC) screening after age 75 (grade of recommendation: D, based on expert opinion). CRC screening may be discontinued between ages 75 and 80, preferably after at least 1 negative screening examination result. Unusually healthy individuals may choose to continue screening until a later age
The V<sub>H</sub> repertoire and clonal diversification of B cells in inflammatory myopathies
The contribution of antigen-driven B-cell adaptive immune responses within the inflamed muscle of inflammatory myopathies (IMs) is largely unknown. In this study, we investigated the immunoglobulin VH gene repertoire, somatic hypermutation, clonal diversification, and selection of infiltrating B cells in muscle biopsies from IM patients (dermatomyositis and polymyositis), to determine whether B cells and/or plasma cells contribute to the associated pathologies of these diseases. The data reveal that Ig V<sub>H</sub> gene repertoires of muscle-infiltrating B cells deviate from the normal VH gene repertoire in individual patients, and differ between different types of IMs. Analysis of somatic mutations revealed clonal diversification of muscle-infiltrating B cells and evidence for a chronic B-cell response within the inflamed muscle. We conclude that muscle-infiltrating B cells undergo selection, somatic hypermutation and clonal diversification in situ during antigen-driven immune responses in patients with IMs, providing insight into the contribution of B cells to the pathological mechanisms of these disorders
Identifying barriers and facilitators in Practice Based Research Network studies
Practice Based Research Networks (PBRNs) are groups of ambulatory medical practices, devoted principally to the primary care of patients, that join to conduct and disseminate research to improve the practice of primary care. PBRN studies have provided valuable information about patient health and the impact of interventions. However, PBRN research also face barriers to successful completion which may dissuade researchers from using them. We sought to identify barriers and facilitators to the successful and timely completion of such projects
Decentralized Constrained Optimization: Double Averaging and Gradient Projection
In this paper, we consider the convex, finite-sum minimization problem with
explicit convex constraints over strongly connected directed graphs. The
constraint is an intersection of several convex sets each being known to only
one node. To solve this problem, we propose a novel decentralized projected
gradient scheme based on local averaging and prove its convergence using only
local functions' smoothness
Active Inverse Learning in Stackelberg Trajectory Games
Game-theoretic inverse learning is the problem of inferring the players'
objectives from their actions. We formulate an inverse learning problem in a
Stackelberg game between a leader and a follower, where each player's action is
the trajectory of a dynamical system. We propose an active inverse learning
method for the leader to infer which hypothesis among a finite set of
candidates describes the follower's objective function. Instead of using
passively observed trajectories like existing methods, the proposed method
actively maximizes the differences in the follower's trajectories under
different hypotheses to accelerate the leader's inference. We demonstrate the
proposed method in a receding-horizon repeated trajectory game. Compared with
uniformly random inputs, the leader inputs provided by the proposed method
accelerate the convergence of the probability of different hypotheses
conditioned on the follower's trajectory by orders of magnitude
Immunoglobulin variable-region gene mutational lineage tree analysis: application to autoimmune diseases
Lineage trees have frequently been drawn to illustrate diversification, via somatic hypermutation (SHM), of immunoglobulin variable-region (IGV) genes. In order to extract more information from IGV sequences, we developed a novel mathematical method for analyzing the graphical properties of IgV gene lineage trees, allowing quantification of the differences between the dynamics of SHM and antigen-driven selection in different lymphoid tissues, species, and disease situations. Here, we investigated trees generated from published IGV sequence data from B cell clones participating in autoimmune responses in patients with Myasthenia Gravis (MG), Rheumatoid Arthritis (RA), and Sjögren's Syndrome (SS). At present, as no standards exist for cell sampling and sequence extraction methods, data obtained by different research groups from two studies of the same disease often vary considerably. Nevertheless, based on comparisons of data groups within individual studies, we show here that lineage trees from different individual patients are often similar and can be grouped together, as can trees from two different tissues in the same patient, and even from IgG- and IgA-expressing B cell clones. Additionally, lineage trees from most studies reflect the chronic character of autoimmune diseases
Activity of Daily Living Trajectories Surrounding Acute Hospitalization of Long‐Stay Nursing Home Residents
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/101804/1/jgs12511.pd
Data management for prospective research studies using SAS® software
<p>Abstract</p> <p>Background</p> <p>Maintaining data quality and integrity is important for research studies involving prospective data collection. Data must be entered, erroneous or missing data must be identified and corrected if possible, and an audit trail created.</p> <p>Methods</p> <p>Using as an example a large prospective study, the Missouri Lower Respiratory Infection (LRI) Project, we present an approach to data management predominantly using SAS software. The Missouri LRI Project was a prospective cohort study of nursing home residents who developed an LRI. Subjects were enrolled, data collected, and follow-ups occurred for over three years. Data were collected on twenty different forms. Forms were inspected visually and sent off-site for data entry. SAS software was used to read the entered data files, check for potential errors, apply corrections to data sets, and combine batches into analytic data sets. The data management procedures are described.</p> <p>Results</p> <p>Study data collection resulted in over 20,000 completed forms. Data management was successful, resulting in clean, internally consistent data sets for analysis. The amount of time required for data management was substantially underestimated.</p> <p>Conclusion</p> <p>Data management for prospective studies should be planned well in advance of data collection. An ongoing process with data entered and checked as they become available allows timely recovery of errors and missing data.</p
Self-reported depression symptoms in haemodialysis patients: Bi-factor structures of two common measures and their association with clinical factors
Copyright © 2018 Elsevier Inc. All rights reserved.Objective: To validate the factor structure of two common self-report depression tools in a large sample of haemodialysis (HD) patients and to examine their demographic and clinical correlates, including urine output, history of depression and transplantation. Methods: Factor structures of the Beck Depression Inventory (BDI-II) and Patient Health Questionnaire (PHQ-9) were evaluated using confirmatory factor analysis (CFA). Data was utilised from the screening phase (n = 709) of a placebo-controlled feasibility randomised control trial (RCT) of sertraline in HD patients with mild to moderate Major Depressive Disorder. Alternative factor models including bi-factor models for the BDI-II and PHQ-9 were evaluated. Coefficient omega and omega-hierarchical were calculated. Results: For both measures, bi-factor measurement models had the overall best fit to the data, with dominant general depression factors. Omega-hierarchical for the general BDI-II and PHQ-9 factors was 0.94 and 0.88 respectively. Both general factors had high reliability (coefficient omega = 0.97 and 0.94 respectively) and explained over 85% of the explained common variance within their respective models. BDI-II and PHQ-9 general depression factors were negatively associated with age and urine output and positively with a history of depression, antidepressant use within the last 3 months and a history of failed transplantation. In adjusted regression models, age, urine output and a history of depression remained significant. Conclusions: These data suggest that both the BDI-II and PHQ-9 are sufficiently unidimensional to warrant the use of a total score. Younger age, lower urine output and a history of depression appear consistent correlates of depression severity among HD patients.Peer reviewedFinal Accepted Versio
Multidrug-Resistant Organism Infections in US Nursing Homes: A National Study of Prevalence, Onset, and Transmission across Care Settings, October 1, 2010-December 31, 2011
Objective.To understand the prevalence of multidrug-resistant organism (MDRO) infections among nursing home (NH) residents and the potential for their spread between NHs and acute care hospitals (ACHs).Methods.Descriptive analyses of MDRO infections among NH residents using all NH residents in the Long-Term Care Minimum Data Set (MDS) 3.0 between October 1, 2010 and December 31, 2011.Results.Analysis of MDS data revealed a very high volume of bidirectional patient flow between NHs and ACHs, indicating the need to study MDRO infections in NHs as well as in hospitals. A total of 4.24% of NH residents had an active MDRO diagnosis on at least 1 MDS assessment during the study period. This rate significantly varied by sex, age, urban/rural status, and state. Approximately 2% of NH discharges to ACHs involved a resident with an active diagnosis of infection due to MDROs. Conversely, 1.8% of NH admissions from an ACH involved a patient with an active diagnosis of infection due to MDROs. Among residents who acquired an MDRO infection during the study period, 57% became positive in the NH, 41% in the ACH, and 2% in other settings (eg, at a private home or apartment).Conclusion.Even though NHs are the most likely setting where residents would acquire MDROs after admission to an NH (accounting for 57% of cases), a significant fraction of NH residents acquire MDRO infection at ACHs (41%). Thus, effective MDRO infection control for NH residents requires simultaneous, cooperative interventions among NHs and ACHs in the same community.</jats:sec
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