107 research outputs found

    A normed measures of variability among proportions

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    A measure of variability among a set of proportions is developed. There are no distributional assumptions, so the measure, H, is applicable in a wide variety of situations. H is scaled so that its range is zero (all proportions are equal) to one (maximum variability among the proportions, given the weighted average). The measure can be interpreted as a distance: the value of H indicates the position of the proportions relative to the possible extremes of no variability or maximum variability. Any set of constant weights can be applied to the proportions: the weights are used to compute the weighted average proportion and are also used to determine the extent to which each proportion affects the variability measure. Comparisons are made to other measures of variability and a numerical example is given.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27023/1/0000011.pd

    ELISA Measurement of Specific Non-antigen-bound Antibodies to Ab1-42 Monomer and Soluble Oligomers in Sera from Alzheimer\u27s Disease, Mild Cognitively Impaired, and Noncognitively Impaired Subjects

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    The article presents a study for enzyme-linked immunosorbent assay (ELISA) measurement of specific non-antigen-bound antibodies to Aβ1-42 monomer and soluble oligomers in Alzheimer\u27s disease (AD), mild cognitively impaired (MCI), and noncognitively impaired (NCI) sera. In the study, serum samples were obtained from the Rush Alzheimer\u27s Disease Center, Chicago, Illinois

    Effects of External Beam Radiation on \u3ci\u3eIn Vitro\u3c/i\u3e Formation of Abeta1-42 Fibrils and Preformed Fibrils

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    Plaques containing fibrillar amyloid-beta (Abeta) are a characteristic finding in Alzheimer\u27s disease. Although plaque counts correlate poorly with the extent of cognitive deficits in this disorder, fibrillar Abeta can promote neuronal damage through a variety of mechanisms. External beam radiotherapy has been reported to be an effective treatment for tracheobronchial amyloidosis, in which amyloid is deposited as submucosal plaques and tumor-like masses in the trachea and/or bronchi. Radiotherapy\u27s effectiveness in this disorder is thought to be due to its toxicity to plasma cells, but direct effects of radiotherapy on amyloid may also be involved. On this basis, whole-brain radiotherapy has been suggested as a treatment for Alzheimer\u27s disease. The objective of this study was to determine the effects of external beam radiation on preformed Abeta1-42 fibrils and on the formation of these fibrils. Using the Thioflavin-T assay, no effects of radiation were found on either of these parameters. Our results in this in vitro study suggest that whole-brain irradiation is unlikely to directly reduce plaque counts in the Alzheimer\u27s disease brain. This treatment might still lower plaque counts indirectly, but any potential benefits would need to be weighed against its possible neurotoxic effects, which could induce further cognitive deficits

    The use of telehealth for diabetes management: a qualitative study of telehealth provider perceptions

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    BACKGROUND: Monitoring and Messaging Devices (MMDs) are telehealth systems used by patients in their homes, and are designed to promote patient self-management, patient education, and clinical monitoring and follow-up activities. Although these systems have been widely promoted by health care systems, including the Veterans Health Administration, very little information is available on factors that facilitate use of the MMD system, or on barriers to use. METHODS: We conducted in-depth qualitative interviews with clinicians using MMD-based telehealth programs at two Veterans Affairs Medical Centers in the Midwestern United States. RESULTS: Findings suggest that MMD program enrollment is limited by both clinical and non-clinical factors, and that patients have varying levels of program participation and system use. Telehealth providers see MMDs as a useful tool for monitoring patients who are interested in working on management of their disease, but are concerned with technical challenges and the time commitment required to use MMDs. CONCLUSION: Telehealth includes a rapidly evolving and potentially promising range of technologies for meeting the growing number of patients and clinicians who face the challenges of diabetes care, and future research should explore the most effective means of ensuring successful program implementation

    Double Blind Study Investigating the Effect of Different Voice Prostheses on Ease of Swallowing and Residue Post Laryngectomy.

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    Voice prostheses have been examined for their effect on voice production but there is little datum on their effect on swallow function. This study investigated the difference between six commonly available voice prostheses in terms of swallowing. Laryngectomy patients had up to six voice prostheses placed in a random order over two visits. Swallowing was evaluated for each prosthesis using FEES (Fibreoptic Endoscopic Evaluation of Swallowing). After each prosthesis trial, patients self-evaluated their experience of swallowing. Three independent experts indicated which prosthesis they considered best for swallowing for each patient and judged residue on the voice prosthesis and in the upper esophagus. Raters were blinded to participant details, voice prosthesis type and scores of other raters. On patient self-evaluation, scores were equally distributed across all prostheses for swallowing. Experts most frequently chose the Blom Singer Low pressure and Blom Singer Classic Indwelling voice prostheses as best for swallowing but consensus was poor for most patients. Experts found that the Blom Singer Classic Indwelling and the Provox Vega had least residue on the voice prosthesis on thin liquid (p ≤ 0.001) and soft (p = 0.001), respectively. Experts also found that the Blom Singer Low Pressure had least residue in the upper esophagus on soft consistency (p ≤ 0.001). While self-evaluation by patients did not identify a consistently preferred prosthesis for swallow, many patients expressed personal preferences, suggesting benefits to involving patients in the choice of prosthesis. Some voice prostheses may be associated with lower levels of residue on the prosthesis and upper esophagus with certain consistencies

    A Complex Systems Science Perspective for Whole Systems of Complementary and Alternative Medicine Research

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    Whole systems complementary and alternative medicine (WS-CAM) approaches share a basic worldview that embraces interconnectedness; emergent, non-linear outcomes to treatment that include both local and global changes in the human condition; a contextual view of human beings that are inseparable from and responsive to their environments; and interventions that are complex, synergistic, and interdependent. These fundamental beliefs and principles run counter to the assumptions of reductionism and conventional biomedical research methods that presuppose unidimensional simple causes and thus dismantle and individually test various interventions that comprise only single aspects of the WS-CAM system. This paper will demonstrate the superior fit and practical advantages of using complex adaptive systems (CAS) and related modeling approaches to develop the scientific basis for WS-CAM. Furthermore, the details of these CAS models will be used to provide working hypotheses to explain clinical phenomena such as (a) persistence of changes for weeks to months between treatments and/or after cessation of treatment, (b) nonlocal and whole systems changes resulting from therapy, (c) Hering\u27s law, and (d) healing crises. Finally, complex systems science will be used to offer an alternative perspective on cause, beyond the simple reductionism of mainstream mechanistic ontology and more parsimonious than the historical vitalism of WS-CAM. Rather, complex systems science provides a scientifically rigorous, yet essentially holistic ontological perspective with which to conceptualize and empirically explore the development of disease and illness experiences, as well as experiences of healing and wellness

    Clustered Coding Variants in the Glutamate Receptor Complexes of Individuals with Schizophrenia and Bipolar Disorder

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    Current models of schizophrenia and bipolar disorder implicate multiple genes, however their biological relationships remain elusive. To test the genetic role of glutamate receptors and their interacting scaffold proteins, the exons of ten glutamatergic ‘hub’ genes in 1304 individuals were re-sequenced in case and control samples. No significant difference in the overall number of non-synonymous single nucleotide polymorphisms (nsSNPs) was observed between cases and controls. However, cluster analysis of nsSNPs identified two exons encoding the cysteine-rich domain and first transmembrane helix of GRM1 as a risk locus with five mutations highly enriched within these domains. A new splice variant lacking the transmembrane GPCR domain of GRM1 was discovered in the human brain and the GRM1 mutation cluster could perturb the regulation of this variant. The predicted effect on individuals harbouring multiple mutations distributed in their ten hub genes was also examined. Diseased individuals possessed an increased load of deleteriousness from multiple concurrent rare and common coding variants. Together, these data suggest a disease model in which the interplay of compound genetic coding variants, distributed among glutamate receptors and their interacting proteins, contribute to the pathogenesis of schizophrenia and bipolar disorders

    Expert Panel Curation of 113 Primary Mitochondrial Disease Genes for the Leigh Syndrome Spectrum

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    OBJECTIVE: Primary mitochondrial diseases (PMDs) are heterogeneous disorders caused by inherited mitochondrial dysfunction. Classically defined neuropathologically as subacute necrotizing encephalomyelopathy, Leigh syndrome spectrum (LSS) is the most frequent manifestation of PMD in children, but may also present in adults. A major challenge for accurate diagnosis of LSS in the genomic medicine era is establishing gene-disease relationships (GDRs) for this syndrome with >100 monogenic causes across both nuclear and mitochondrial genomes. METHODS: The Clinical Genome Resource (ClinGen) Mitochondrial Disease Gene Curation Expert Panel (GCEP), comprising 40 international PMD experts, met monthly for 4 years to review GDRs for LSS. The GCEP standardized gene curation for LSS by refining the phenotypic definition, modifying the ClinGen Gene-Disease Clinical Validity Curation Framework to improve interpretation for LSS, and establishing a scoring rubric for LSS. RESULTS: The GDR with LSS across the nuclear and mitochondrial genomes was classified as definitive for 31/114 gene-disease relationships curated (27%); moderate for 38 (33%); limited for 43 (38%); and 2 as disputed (2%). Ninety genes were associated with autosomal recessive inheritance, 16 were maternally inherited, 5 autosomal dominant, and 3 X-linked. INTERPRETATION: GDRs for LSS were established for genes across both nuclear and mitochondrial genomes. Establishing these GDRs will allow accurate variant interpretation, expedite genetic diagnosis of LSS, and facilitate precision medicine, multi-system organ surveillance, recurrence risk counselling, reproductive choice, natural history studies and eligibility for interventional clinical trials. This article is protected by copyright. All rights reserved
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