373 research outputs found

    Lack of association of human leukocyte antigen-B7 with COPD and rate of decline in lung function

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    SummaryBackground: Although variation in the human leukocyte antigen (HLA) locus is associated with various diseases, there have been a limited number of studies that have examined the possible role of HLA in chronic obstructive pulmonary disease (COPD). Only HLA-B7 has been shown to be correlated with low forced expiratory volume in 1s (FEV1) in Caucasians; however, this finding has not been replicated. The aim of this study was to investigate the contribution of the HLA-B7 allele to COPD and to rate of decline of lung function.Methods: We determined the prevalence of HLA-B7 in a group of COPD patients and a non-obstructed control group of smokers by using a polymerase chain reaction-based genotyping assay. We also determined the prevalence of HLA-B7 in smokers selected from the National Heart Lung and Blood Institute, Lung Health Study for having the fastest and slowest decline of lung function.Results: No significant difference was found in the frequency of HLA-B7 between the COPD and non-obstructed groups. There was also no significant association of HLA-B7 with rate of decline of lung function.Conclusion: These data indicate that HLA-B7 does not contribute to COPD or rate of decline of FEV1 in smokers

    Pathogenic uromodulin mutations result in premature intracellular polymerization

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    AbstractSeveral renal diseases involve mutations in the gene encoding uromodulin, the predominant protein in urine. We investigated the intracellular processing of wild-type uromodulin, and three mutants: p.V93_G97del/ins AASC; C155R; and C150S. A renal biopsy from a patient harboring the C155R mutation revealed intracellular protein accumulation. Wild-type uromodulin was efficiently trafficked to the cell surface in transfected tsA 201 cells, whereas the mutants were partially retained within the cell, and incompletely processed. Atomic force microscopy imaging revealed that the intracellular mutant proteins contained fibrillar structures similar to urinary uromodulin. We suggest that premature intracellular polymerization underlies the pathology of uromodulin diseases

    “Dogged” Search of Fresh Nakhla Surfaces Reveals New Alteration Textures

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    Special Issue: 74th Annual Meeting of the Meteoritical Society, August 8-12, 2011, London, U.K.International audienceCarbonaceous chondrites are considered as amongst the most primitive Solar System samples available. One of their primitive characteristics is their enrichment in volatile elements.This includes hydrogen, which is present in hydrated and hydroxylated minerals. More precisely, the mineralogy is expected to be dominated by phyllosilicates in the case of CM chondrites, and by Montmorillonite type clays in the case of CI. Here, in order to characterize and quantify the abundance of lowtemperature minerals in carbonaceous chondrites, we performed thermogravimetric analysis of matrix fragments of Tagish Lake, Murchison and Orgueil

    Coordinated Microanalyses of Seven Particles of Probable Interstellar Origin from the Stardust Mission

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    Stardust, a NASA Discovery-class mission, was the first sample-return mission to return solid samples from beyond the Moon. Stardust was effectively two missions in one spacecraft: it returned the first materials from a known primitive solar system body, the Jupiter-family comet Wild 2; Stardust also returned a collector that was exposed to the contemporary interstellar dust stream for 200 days during the interplanetary cruise. Both collections present severe technical challenges in sample preparation and in analysis. By far the largest collection is the cometary one: approximately 300 micro g of material was returned from Wild 2, mostly consisting of approx. 1 ng particles embedded in aerogel or captured as residues in craters on aluminum foils. Because of their relatively large size, identification of the impacts of cometary particles in the collection media is straightforward. Reliable techniques have been developed for the extraction of these particles from aerogel. Coordinated analyses are also relatively straightforward, often beginning with synchrotron-based x-ray fluorescence (S-XRF), X-ray Absorption Near-Edge Spectoscopy (XANES) and x-ray diffraction (S-XRD) analyses of particles while still embedded in small extracted wedges of aerogel called ``keystones'', followed by ultramicrotomy and TEM, Scanning Transmission X-ray Microscopy (STXM) and ion microprobe analyses (e.g., Ogliore et al., 2010). Impacts in foils can be readily analyzed by SEM-EDX, and TEM analysis after FIB liftout sample preparation. In contrast, the interstellar dust collection is vastly more challenging. The sample size is approximately six orders of magnitude smaller in total mass. The largest particles are only a few pg in mass, of which there may be only approx.10 in the entire collection. The technical challenges, however, are matched by the scientific importance of the collection. We formed a consortium carry out the Stardust Interstellar Preliminary Examination (ISPE) to carry out an assessment of this collection, partly in order to characterize the collection in sufficient detail so that future investigators could make well-informed sample requests. The ISPE is the sixth PE on extraterrestrial collections carried out with NASA support. Some of the basic questions that we asked were: how many impacts are there in the collector, and what fraction of them have characteristics consistent with extraterrestrial materials? What is the elemental composition of the rock-forming elements? Is there crystalline material? Are there organics? Here we present coordinated microanalyses of particles captured in aerogel, using S-FTIR, S-XRF, STXM, S-XRD; and coordinated microanalyses of residues in aluminum foil, using SEMEDX, Auger spectroscopy, STEM, and ion microprobe. We discuss a novel approach that we employed for identification of tracks in aerogel, and new sample preparation techniques developed during the ISPE. We have identified seven particles - three in aerogel and four in foils - that are most consistent with an interstellar origin. The seven particles exhibit a large diversity in elemental composition. Dynamical evidence, supported supported by laboratory simulations of interstellar dust impacts in aerogel and foils, and numerical modeling of interstellar dust propagation in the heliosphere, suggests that at least some of the particles have high optical cross-section, perhaps due to an aggregate structure. However, the observations are most consistent with a variety of morphologie
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