2,412 research outputs found

    Paradoxical Immune Responses in Non-HIV Cryptococcal Meningitis

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    The fungus Cryptococcus is a major cause of meningoencephalitis in HIV-infected as well as HIV-uninfected individuals with mortalities in developed countries of 20% and 30%, respectively. In HIV-related disease, defects in T-cell immunity are paramount, whereas there is little understanding of mechanisms of susceptibility in non-HIV related disease, especially that occurring in previously healthy adults. The present description is the first detailed immunological study of non-HIV-infected patients including those with severe central nervous system (s-CNS) disease to 1) identify mechanisms of susceptibility as well as 2) understand mechanisms underlying severe disease. Despite the expectation that, as in HIV, T-cell immunity would be deficient in such patients, cerebrospinal fluid (CSF) immunophenotyping, T-cell activation studies, soluble cytokine mapping and tissue cellular phenotyping demonstrated that patients with s-CNS disease had effective microbiological control, but displayed strong intrathecal expansion and activation of cells of both the innate and adaptive immunity including HLA-DR+ CD4+ and CD8+ cells and NK cells. These expanded CSF T cells were enriched for cryptococcal-antigen specific CD4+ cells and expressed high levels of IFN-gamma as well as a lack of elevated CSF levels of typical T-cell specific Th2 cytokines -- IL-4 and IL-13. This inflammatory response was accompanied by elevated levels of CSF NFL, a marker of axonal damage, consistent with ongoing neurological damage. However, while tissue macrophage recruitment to the site of infection was intact, polarization studies of brain biopsy and autopsy specimens demonstrated an M2 macrophage polarization and poor phagocytosis of fungal cells. These studies thus expand the paradigm for cryptococcal disease susceptibility to include a prominent role for macrophage activation defects and suggest a spectrum of disease whereby severe neurological disease is characterized by immune-mediated host cell damage

    Outcome measures in rheumatoid arthritis randomised trials over the last 50 years

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    BACKGROUND: The development and application of standardised sets of outcomes to be measured and reported in clinical trials have the potential to increase the efficiency and value of research. One of the most notable of the current outcome sets began nearly 20 years ago: the World Health Organization and International League of Associations for Rheumatology core set of outcomes for rheumatoid arthritis clinical trials, originating from the OMERACT (Outcome Measures in Rheumatology) Initiative. This study assesses the use of this core outcome set by randomised trials in rheumatology. METHODS: An observational review was carried out of 350 randomised trials for the treatment of rheumatoid arthritis identified through The Cochrane Library (up to and including September 2012 issue). Reports of these trials were evaluated to determine whether or not there were trends in the proportion of trials reporting on the full set of core outcomes over time. Researchers who conducted trials after the publication of the core set were contacted to assess their awareness of it and to collect reasons for non-inclusion of the full core set of outcomes in the study. RESULTS: Since the introduction of the core set of outcomes for rheumatoid arthritis, the consistency of measurement of the core set of outcomes has improved, although variation in the choice of measurement instrument remains. The majority of trialists who responded said that they would consider using the core outcome set in the design of a new trial. CONCLUSIONS: This observational review suggests that a higher percentage of trialists conducting trials in rheumatoid arthritis are now measuring the rheumatoid arthritis core outcome set. Core outcome sets have the potential to improve the evidence base for health care, but consideration must be given to the methods for disseminating their availability amongst the relevant communities

    The PhoBR two-component system regulates antibiotic biosynthesis in Serratia in response to phosphate

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    <p>Abstract</p> <p>Background</p> <p>Secondary metabolism in <it>Serratia </it>sp. ATCC 39006 (<it>Serratia </it>39006) is controlled via a complex network of regulators, including a LuxIR-type (SmaIR) quorum sensing (QS) system. Here we investigate the molecular mechanism by which phosphate limitation controls biosynthesis of two antibiotic secondary metabolites, prodigiosin and carbapenem, in <it>Serratia </it>39006.</p> <p>Results</p> <p>We demonstrate that a mutation in the high affinity phosphate transporter <it>pstSCAB-phoU</it>, believed to mimic low phosphate conditions, causes upregulation of secondary metabolism and QS in <it>Serratia </it>39006, via the PhoBR two-component system. Phosphate limitation also activated secondary metabolism and QS in <it>Serratia </it>39006. In addition, a <it>pstS </it>mutation resulted in upregulation of <it>rap</it>. Rap, a putative SlyA/MarR-family transcriptional regulator, shares similarity with the global regulator RovA (regulator of virulence) from <it>Yersina </it>spp. and is an activator of secondary metabolism in <it>Serratia </it>39006. We demonstrate that expression of <it>rap</it>, <it>pigA-O </it>(encoding the prodigiosin biosynthetic operon) and <it>smaI </it>are controlled via PhoBR in <it>Serratia </it>39006.</p> <p>Conclusion</p> <p>Phosphate limitation regulates secondary metabolism in <it>Serratia </it>39006 via multiple inter-linked pathways, incorporating transcriptional control mediated by three important global regulators, PhoB, SmaR and Rap.</p

    Report on Interstate 476 (The Blue Route)

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    For fifty years Pennsylvanians have been discussing the idea of constructing a new north-south highway in the central part of Delaware County, the suburban county immediately west of the City of Philadelphia. Such a highway originally was conceived as a parkway. The notion never got very far until the mid-1950\u27s. When the federal Interstate Highway System was conceived, a facility in central Delaware County was proposed to connect the Pennsylvania Turnpike (I-276) in Plymouth Meeting, Montgomery County, with the Delaware Expressway (I-95) in Ridley Township, Delaware County. This facility was designated I-476. As conceived, it would constitute the western part of a planned circumferential freeway network around Philadelphia. I-476 is commonly known as the Blue Route and also as the Mid County Expressway. As an interstate highway project, 90% of the cost of I-476 would be covered by federal interstate highway funds allocated to the Pennsylvania Department of Transportation (PennDOT) by the Federal Highway Administration (FHWA). The remaining 10% of the project\u27s cost would be paid for by PennDOT (either construction bonds or revenues from the State Motor Fund). Construction of the Blue Route commenced in 1967 but all con­struction on the main stretch of the road--the 16.9 mile section be­ tween I-95 and the Schuylkill Expressway (I-76)--was halted in 1973. Construction of this portion cannot resume until the project undergoes an environmental impact assessment under the provisions of federal law. The project also must undergo a so-called 4(f) assessment analyzing the facility\u27s impact on parkland and historical resources. The requirements of these federal statutes are summarized in an appen­dix to this report. Because of the uncertainty surrounding completion of the Blue Route, and because the project has aroused considerable controversy in Delaware County, U.S. Representative Robert W. Edgar in March 1977 organized a Transportation Advisory Committee to un­dertake a comprehensive analysis of the project. [...] This report is submitted to the Congressman as the Committee\u27s recommendation

    Multiplex meta-analysis of RNA expression to identify genes with variants associated with immune dysfunction

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    ObjectiveWe demonstrate a genome-wide method for the integration of many studies of gene expression of phenotypically similar disease processes, a method of multiplex meta-analysis. We use immune dysfunction as an example disease process.DesignWe use a heterogeneous collection of datasets across human and mice samples from a range of tissues and different forms of immunodeficiency. We developed a method integrating Tibshirani's modified t-test (SAM) is used to interrogate differential expression within a study and Fisher's method for omnibus meta-analysis to identify differentially expressed genes across studies. The ability of this overall gene expression profile to prioritize disease associated genes is evaluated by comparing against the results of a recent genome wide association study for common variable immunodeficiency (CVID).ResultsOur approach is able to prioritize genes associated with immunodeficiency in general (area under the ROC curve = 0.713) and CVID in particular (area under the ROC curve = 0.643).ConclusionsThis approach may be used to investigate a larger range of failures of the immune system. Our method may be extended to other disease processes, using RNA levels to prioritize genes likely to contain disease associated DNA variants

    MEPicides: Potent antimalarial prodrugs targeting isoprenoid biosynthesis

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    AbstractThe emergence of Plasmodium falciparum resistant to frontline therapeutics has prompted efforts to identify and validate agents with novel mechanisms of action. MEPicides represent a new class of antimalarials that inhibit enzymes of the methylerythritol phosphate (MEP) pathway of isoprenoid biosynthesis, including the clinically validated target, deoxyxylulose phosphate reductoisomerase (Dxr). Here we describe RCB-185, a lipophilic prodrug with nanomolar activity against asexual parasites. Growth of P. falciparum treated with RCB-185 was rescued by isoprenoid precursor supplementation, and treatment substantially reduced metabolite levels downstream of the Dxr enzyme. In addition, parasites that produced higher levels of the Dxr substrate were resistant to RCB-185. Notably, environmental isolates resistant to current therapies remained sensitive to RCB-185, the compound effectively treated sexually-committed parasites, and was both safe and efficacious in malaria-infected mice. Collectively, our data demonstrate that RCB-185 potently and selectively inhibits Dxr in P. falciparum, and represents a promising lead compound for further drug development.</jats:p

    A Precise Water Abundance Measurement for the Hot Jupiter WASP-43b

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    The water abundance in a planetary atmosphere provides a key constraint on the planet's primordial origins because water ice is expected to play an important role in the core accretion model of planet formation. However, the water content of the Solar System giant planets is not well known because water is sequestered in clouds deep in their atmospheres. By contrast, short-period exoplanets have such high temperatures that their atmospheres have water in the gas phase, making it possible to measure the water abundance for these objects. We present a precise determination of the water abundance in the atmosphere of the 2 MJupM_\mathrm{Jup} short-period exoplanet WASP-43b based on thermal emission and transmission spectroscopy measurements obtained with the Hubble Space Telescope. We find the water content is consistent with the value expected in a solar composition gas at planetary temperatures (0.4-3.5x solar at 1 σ\sigma confidence). The metallicity of WASP-43b's atmosphere suggested by this result extends the trend observed in the Solar System of lower metal enrichment for higher planet masses.Comment: Accepted to ApJL; this version contains three supplemental figures that are not included in the published paper. See also our companion paper "Thermal structure of an exoplanet atmosphere from phase-resolved emission spectroscopy" by Stevenson et a
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