18 research outputs found

    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

    GWAS meta-analysis of over 29,000 people with epilepsy identifies 26 risk loci and subtype-specific genetic architecture

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    Epilepsy is a highly heritable disorder affecting over 50 million people worldwide, of which about one-third are resistant to current treatments. Here we report a multi-ancestry genome-wide association study including 29,944 cases, stratified into three broad categories and seven subtypes of epilepsy, and 52,538 controls. We identify 26 genome-wide significant loci, 19 of which are specific to genetic generalized epilepsy (GGE). We implicate 29 likely causal genes underlying these 26 loci. SNP-based heritability analyses show that common variants explain between 39.6% and 90% of genetic risk for GGE and its subtypes. Subtype analysis revealed markedly different genetic architectures between focal and generalized epilepsies. Gene-set analyses of GGE signals implicate synaptic processes in both excitatory and inhibitory neurons in the brain. Prioritized candidate genes overlap with monogenic epilepsy genes and with targets of current antiseizure medications. Finally, we leverage our results to identify alternate drugs with predicted efficacy if repurposed for epilepsy treatment

    Experimental and numerical investigation of reactive species transport around a small rising bubble

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    In this article, we present experimental and numerical techniques to investigate the transfer, transport, and reaction of a chemical species in the vicinity of rising bubbles. In the experiment, single oxygen bubbles of diameter d b =0.55…0.85mm are released into a measurement cell filled with tap water. The oxygen dissolves and reacts with sulfite to sulfate. Laser-induced fluorescence is used to visualize the oxygen concentration in the bubble wake from which the global mass transfer coefficient can be calculated. The ruthenium-based fluorescent dye seems to be surface active, such that the rise velocity is reduced by up to 50% compared to the experiment without fluorescent dye and a recirculation zone forms in the bubble wake. To access the local mass transfer at the interface, we perform complementary numerical simulations. Since the fluorescence tracer is essential for the experimental method, the effect of surface contamination is also considered in the simulation. We employ several improvements in the experimental and numerical procedures which allow for a quantitative comparison (locally and globally). Rise velocity and mass transfer coefficient agree within a few percents between experiment, simulation and literature results. Because the fluorescence tracer is frequently used in mass transfer experiments, we discuss its potential surface activity. © 2019 The Author

    IL-33 receptor (T1/ST2) signalling is necessary to prevent the development of encephalitis in mice infected with Toxoplasma gondii

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    T1/ST2 is an immunoregulatory protein of the IL-1 receptor family that has recently been reported as being a component of the IL-33 receptor. IL-33 is a newly described cytokine known to amplify the Th2 response and reduce production of Th1 cytokines. The function of T1/ST2 during Toxoplasma gondii infection is as yet undescribed. Given the requirement of a balanced type 1/type 2 response for effective control of parasite number and immunopathology, it is likely that T1/ST2 may play a part in aiding this process. Accordingly, we have shown that T1/ST2 mRNA transcripts are upregulated in the brains of mice infected with T. gondii and that mice deficient in T1/ST2 demonstrated increased susceptibility to infection with T. gondii that correlated with increased pathology and greater parasite burden in the brains. Real-time PCR analysis of cerebral cytokine levels revealed increased mRNA levels of iNOS, IFN-gamma and TNF-alpha in infected T1/ST2(-/-) mice. These effects were independent of changes in IL-10 production. This study provides the first evidence of a specific role for IL-33 receptor signalling in the brain as well as highlighting the requirement of this mechanism in limiting infection with an intracellular parasite

    TG-interacting factor 1 (Tgif1)-deficiency attenuates bone remodeling and blunts the anabolic response to parathyroid hormone

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    Parathyroid hormone (PTH) is used to treat osteoporosis, but its therapeutic mechanism remains unclear. Here, the authors show that Tgif1 is a PTH target gene, and that its deletion impairs the function of osteoblasts and PTH-induced bone formation in mice

    Organ-Specific Metastatic Tumor Cell Adhesion and Extravasation of Colon Carcinoma Cells with Different Metastatic Potential

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    Adhesive and invasive characteristics appear to be crucial for organ-specific metastasis formation. Using intravital microscopy we investigated the relation between the metastatic potential of colon carcinoma cells and their adhesive and invasive behavior during early steps of metastasis within microvasculatures of rat liver, lung, intestine, skin, muscle, spleen, and kidney in vivo. Colon carcinoma cells with low (HT-29P), intermediate (KM-12C), and high (HT-29LMM, KM-12L4) metastatic potential were injected into nude or Sprague-Dawley rats. Initial interactions with host organ microvasculatures were semiquantitatively analyzed throughout 20 to 30 minutes. Circulating cells passed microvessels in all observed organs without size restriction. All cell lines showed high adhesion rates, independent from their metastatic potential, within liver and lung but very rarely in other organs. Diameters of involved microvessels were larger than diameters of adherent tumor cells. Cell extravasation of highly metastatic HT-29LMM and KM-12L4 cells into liver parenchyma was significantly higher compared to low metastatic cells (P < 0.05). Our results indicate that colon carcinoma cells can arrest in target organs without size restriction. Cell adhesion of circulating tumor cells occurred in metastatic target organs only, likely attributable to specific interactions. Migration into target organs correlated with their metastatic potential
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