2,453 research outputs found

    Survival of the fittest: Retrospective cohort study of the longevity of Olympic medallists in the modern era

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    Objective: To determine whether Olympic medallists live longer than the general population. Design: Retrospective cohort study, with passive follow-up and conditional survival analysis to account for unidentified loss to follow-up. Setting and participants: 15 174 Olympic athletes from nine country groups (United States, Germany, Nordic countries, Russia, United Kingdom, France, Italy, Canada, and Australia and New Zealand) who won medals in the Olympic Games held in 1896-2010. Medallists were compared with matched cohorts in the general population (by country, age, sex, and year of birth). Main outcome measures Relative conditional survival. Results: More medallists than matched controls in the general population were alive 30 years after winning (relative conditional survival 1.08, 95% confidence interval 1.07 to 1.10). Medallists lived an average of 2.8 years longer than controls. Medallists in eight of the nine country groups had a significant survival advantage compared with controls. Gold, silver, and bronze medallists each enjoyed similar sized survival advantages. Medallists in endurance sports and mixed sports had a larger survival advantage over controls at 30 years (1.13, 1.09 to 1.17; 1.11, 1.09 to 1.13) than that of medallists in power sports (1.05, 1.01 to 1.08). Conclusions: Olympic medallists live longer than the general population, irrespective of country, medal, or sport. This study was not designed to explain this effect, but possible explanations include genetic factors, physical activity, healthy lifestyle, and the wealth and status that come with international sporting glory. © BMJ Publishing Group Ltd 2012

    Quality determination and the repair of poor quality spots in array experiments.

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    BACKGROUND: A common feature of microarray experiments is the occurrence of missing gene expression data. These missing values occur for a variety of reasons, in particular, because of the filtering of poor quality spots and the removal of undefined values when a logarithmic transformation is applied to negative background-corrected intensities. The efficiency and power of an analysis performed can be substantially reduced by having an incomplete matrix of gene intensities. Additionally, most statistical methods require a complete intensity matrix. Furthermore, biases may be introduced into analyses through missing information on some genes. Thus methods for appropriately replacing (imputing) missing data and/or weighting poor quality spots are required. RESULTS: We present a likelihood-based method for imputing missing data or weighting poor quality spots that requires a number of biological or technical replicates. This likelihood-based approach assumes that the data for a given spot arising from each channel of a two-dye (two-channel) cDNA microarray comparison experiment independently come from a three-component mixture distribution--the parameters of which are estimated through use of a constrained E-M algorithm. Posterior probabilities of belonging to each component of the mixture distributions are calculated and used to decide whether imputation is required. These posterior probabilities may also be used to construct quality weights that can down-weight poor quality spots in any analysis performed afterwards. The approach is illustrated using data obtained from an experiment to observe gene expression changes with 24 hr paclitaxel (Taxol) treatment on a human cervical cancer derived cell line (HeLa). CONCLUSION: As the quality of microarray experiments affect downstream processes, it is important to have a reliable and automatic method of identifying poor quality spots and arrays. We propose a method of identifying poor quality spots, and suggest a method of repairing the arrays by either imputation or assigning quality weights to the spots. This repaired data set would be less biased and can be analysed using any of the appropriate statistical methods found in the microarray literature.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Understanding stroke survivors' and informal carers' experiences of and need for primary care and community health services--a systematic review of the qualitative literature: protocol.

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    INTRODUCTION: Despite the rising prevalence of stroke, no comprehensive model of postacute stroke care exists. Research on stroke has focused on acute care and early supported discharge, with less attention dedicated to longer term support in the community. Likewise, relatively little research has focused on long-term support for informal carers. This review aims to synthesise and appraise extant qualitative evidence on: (1) long-term healthcare needs of stroke survivors and informal carers, and (2) their experiences of primary care and community health services. The review will inform the development of a primary care model for stroke survivors and informal carers. METHODS AND ANALYSIS: We will systematically search 4 databases: MEDLINE, EMBASE, PsycINFO and CINAHL for published qualitative evidence on the needs and experiences of stroke survivors and informal carers of postacute care delivered by primary care and community health services. Additional searches of reference lists and citation indices will be conducted. The quality of articles will be assessed by 2 independent reviewers using a Critical Appraisal Skills Programme (CASP) checklist. Disagreements will be resolved through discussion or third party adjudication. Meta-ethnography will be used to synthesise the literature based on first-order, second-order and third-order constructs. We will construct a theoretical model of stroke survivors' and informal carers' experiences of primary care and community health services. ETHICS AND DISSEMINATION: The results of the systematic review will be disseminated via publication in a peer-reviewed journal and presented at a relevant conference. The study does not require ethical approval as no patient identifiable data will be used.National Institute for Health Research (PTC-RP-PG-0213-20001)

    Reprogramming of Trypanosoma cruzi metabolism triggered by parasite interaction with the host cell extracellular matrix.

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    Trypanosoma cruzi, the etiological agent of Chagas' disease, affects 8 million people predominantly living in socioeconomic underdeveloped areas. T. cruzi trypomastigotes (Ty), the classical infective stage, interact with the extracellular matrix (ECM), an obligatory step before invasion of almost all mammalian cells in different tissues. Here we have characterized the proteome and phosphoproteome of T. cruzi trypomastigotes upon interaction with ECM (MTy) and the data are available via ProteomeXchange with identifier PXD010970. Proteins involved with metabolic processes (such as the glycolytic pathway), kinases, flagellum and microtubule related proteins, transport-associated proteins and RNA/DNA binding elements are highly represented in the pool of proteins modified by phosphorylation. Further, important metabolic switches triggered by this interaction with ECM were indicated by decreases in the phosphorylation of hexokinase, phosphofructokinase, fructose-2,6-bisphosphatase, phosphoglucomutase, phosphoglycerate kinase in MTy. Concomitantly, a decrease in the pyruvate and lactate and an increase of glucose and succinate contents were detected by GC-MS. These observations led us to focus on the changes in the glycolytic pathway upon binding of the parasite to the ECM. Inhibition of hexokinase, pyruvate kinase and lactate dehydrogenase activities in MTy were observed and this correlated with the phosphorylation levels of the respective enzymes. Putative kinases involved in protein phosphorylation altered upon parasite incubation with ECM were suggested by in silico analysis. Taken together, our results show that in addition to cytoskeletal changes and protease activation, a reprogramming of the trypomastigote metabolism is triggered by the interaction of the parasite with the ECM prior to cell invasion and differentiation into amastigotes, the multiplicative intracellular stage of T. cruzi in the vertebrate host

    Uterine selection of human embryos at implantation

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    Human embryos frequently harbor large-scale complex chromosomal errors that impede normal development. Affected embryos may fail to implant although many first breach the endometrial epithelium and embed in the decidualizing stroma before being rejected via mechanisms that are poorly understood. Here we show that developmentally impaired human embryos elicit an endoplasmic stress response in human decidual cells. A stress response was also evident upon in vivo exposure of mouse uteri to culture medium conditioned by low-quality human embryos. By contrast, signals emanating from developmentally competent embryos activated a focused gene network enriched in metabolic enzymes and implantation factors. We further show that trypsin, a serine protease released by pre-implantation embryos, elicits Ca2+ signaling in endometrial epithelial cells. Competent human embryos triggered short-lived oscillatory Ca2+ fluxes whereas low-quality embryos caused a heightened and prolonged Ca2+ response. Thus, distinct positive and negative mechanisms contribute to active selection of human embryos at implantation

    The professionals speak: Practitioners’ perspectives on professional election campaigning

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    Faced with some fundamental changes in the socio-cultural, political and media environment, political parties in post-industrialized democracies have started to initiate substantial transformations of both their organizational structures and communicative practices. Those innovations, described as professionalization, become most obvious during election campaigns. In recent times, the number of empirical studies measuring the degree of political parties’ campaign professionalism has grown. They have relied on a broad spectrum of indicators derived from theory which have not been tested for their validity. For the first time, we put these indicators to a ‘reality check’ by asking top-ranked party secretaries and campaign managers in 12 European countries to offer their perceptions of professional election campaigning. Furthermore, we investigate whether any differences in understanding professionalism among party campaign practitioners can be explained by macro (country) and meso (party) factors. By and large, our results confirm the validity of most indicators applied in empirical studies on campaign professionalism so far. There are some party- and country-related differences in assessing campaign professionalism too, but the influence of most factors on practitioners’ evaluations is weak. Therefore, we conclude that largely there is a far-reaching European Union-wide common understanding of professional election campaigning

    CD4 T lymphocyte autophagy is upregulated in the salivary glands of primary Sjögren’s syndrome patients and correlates with focus score and disease activity

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    Background: Primary Sjögren’s syndrome (pSS) is a common chronic autoimmune disease characterized by lymphocytic infiltration of exocrine glands and peripheral lymphocyte perturbation. In the current study, we aimed to investigate the possible pathogenic implication of autophagy in T lymphocytes in patients with pSS. Methods: Thirty consecutive pSS patients were recruited together with 20 patients affected by sicca syndrome a nd/or chronic sialoadenitis and 30 healthy controls. Disease activity and damage were evaluated according to SS disease activity index, EULAR SS disease activity index, and SS disease damage index. T lymphocytes were analyzed for the expression of autophagy-specific markers by biochemical, molecular, and histological assays in peripheral blood and labial gland biopsies. Serum interleukin (IL)-23 and IL-21 levels were quantified by enzyme-linked immunosorbent assay. Results: Our study provides evidence for the first time that autophagy is upregulated in CD4+ T lymphocyte salivary glands from pSS patients. Furthermore, a statistically significant correlation was detected between lymphocyte autophagy levels, disease activity, and damage indexes. We also found a positive correlation between autophagy enhancement and the increased salivary gland expression of IL-21 and IL-23, providing a further link between innate and adaptive immune responses in pSS. Conclusions: These findings suggest that CD4+ T lymphocyte autophagy could play a key role in pSS pathogenesis. Additionally, our data highlight the potential exploitation of T cell autophagy as a biomarker of disease activity and provide new ground to verify the therapeutic implications of autophagy as an innovative drug target in pSS

    Use of flucinolone acetonide for patients with diabetic macular oedema:patient selection criteria and early outcomes in real world setting

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    Introduction: Fluocinolone acetonide slow release implant (Iluvien®) was approved in December 2013 in UK for treatment of eyes which are pseudophakic with DMO that is unresponsive to other available therapies. This approval was based on evidence from FAME trials which were conducted at a time when ranibizumab was not available. There is a paucity of data on implementation of guidance on selecting patients for this treatment modality and also on the real world outcome of fluocinolone therapy especially in those patients that have been unresponsive to ranibizumab therapy. Method: Retrospective study of consecutive patients treated with fluocinolone between January and August 2014 at three sites were included to evaluate selection criteria used, baseline characteristics and clinical outcomes at 3-month time point. Results: Twenty two pseudophakic eyes of 22 consecutive patients were included. Majority of patients had prior therapy with multiple intravitreal anti-VEGF injections. Four eyes had controlled glaucoma. At baseline mean VA and CRT were 50.7 letters and 631 μm respectively. After 3 months, 18 patients had improved CRT of which 15 of them also had improved VA. No adverse effects were noted. One additional patient required IOP lowering medication. Despite being unresponsive to multiple prior therapies including laser and anti-VEGF injections, switching to fluocinolone achieved treatment benefit. Conclusion: The patient level selection criteria proposed by NICE guidance on fluocinolone appeared to be implemented. This data from this study provides new evidence on early outcomes following fluocinolone therapy in eyes with DMO which had not responded to laser and other intravitreal agents

    X-ray Structures of the Signal Recognition Particle Receptor Reveal Targeting Cycle Intermediates

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    The signal recognition particle (SRP) and its conjugate receptor (SR) mediate cotranslational targeting of a subclass of proteins destined for secretion to the endoplasmic reticulum membrane in eukaryotes or to the plasma membrane in prokaryotes. Conserved active site residues in the GTPase domains of both SRP and SR mediate discrete conformational changes during formation and dissociation of the SRP·SR complex. Here, we describe structures of the prokaryotic SR, FtsY, as an apo protein and in two different complexes with a non-hydrolysable GTP analog (GMPPNP). These structures reveal intermediate conformations of FtsY containing GMPPNP and explain how the conserved active site residues position the nucleotide into a non-catalytic conformation. The basis for the lower specificity of binding of nucleotide in FtsY prior to heterodimerization with the SRP conjugate Ffh is also shown. We propose that these structural changes represent discrete conformational states assumed by FtsY during targeting complex formation and dissociation

    Evidence of seasonality in the diagnosis of monocytic leukaemia

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    Evidence of seasonality in the diagnosis of monocytic leukaemia in England and Wales is presented, with a maximum diagnosis rate in February/March and a minimum in August/September. Previous published results for monocytic leukaemia are of small sample size yet appear consistent with this finding
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