36 research outputs found

    Interferon-Alpha Administration Enhances CD8+ T Cell Activation in HIV Infection

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    Type I interferons play important roles in innate immune defense. In HIV infection, type I interferons may delay disease progression by inhibiting viral replication while at the same time accelerating disease progression by contributing to chronic immune activation.To investigate the effects of type I interferons in HIV-infection, we obtained cryopreserved peripheral blood mononuclear cell samples from 10 subjects who participated in AIDS Clinical Trials Group Study 5192, a trial investigating the activity of systemic administration of IFNα for twelve weeks to patients with untreated HIV infection. Using flow cytometry, we examined changes in cell cycle status and expression of activation antigens by circulating T cells and their maturation subsets before, during and after IFNα treatment.The proportion of CD38+HLA-DR+CD8+ T cells increased from a mean of 11.7% at baseline to 24.1% after twelve weeks of interferon treatment (p = 0.006). These frequencies dropped to an average of 20.1% six weeks after the end of treatment. In contrast to CD8+ T cells, the frequencies of activated CD4+ T cells did not change with administration of type I interferon (mean percentage of CD38+DR+ cells = 2.62% at baseline and 2.17% after 12 weeks of interferon therapy). As plasma HIV levels fell with interferon therapy, this was correlated with a "paradoxical" increase in CD8+ T cell activation (p<0.001).Administration of type I interferon increased expression of the activation markers CD38 and HLA DR on CD8+ T cells but not on CD4+ T cells of HIV+ persons. These observations suggest that type I interferons may contribute to the high levels of CD8+ T cell activation that occur during HIV infection

    Exploring new physics frontiers through numerical relativity

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    The demand to obtain answers to highly complex problems within strong-field gravity has been met with significant progress in the numerical solution of Einstein's equations - along with some spectacular results - in various setups. We review techniques for solving Einstein's equations in generic spacetimes, focusing on fully nonlinear evolutions but also on how to benchmark those results with perturbative approaches. The results address problems in high-energy physics, holography, mathematical physics, fundamental physics, astrophysics and cosmology

    Synaptic versus extrasynaptic NMDA receptor signalling: implications for neurodegenerative disorders

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    There is a long-standing paradox that N-methyl-D-aspartate receptors (NMDARs) can both promote neuronal health and kill neurons. Recent studies show that NMDAR-induced responses depend on the receptor location: stimulation of synaptic NMDARs, acting primarily through nuclear Ca(2+) signaling, leads to the build-up of a neuroprotective ‘shield’, whereas stimulation of extrasynaptic NMDARs promotes cell death. These differences result from the activation of distinct genomic programmes and opposing actions on intracellular signalling pathways. Perturbations in the balance between synaptic and extrasynaptic NMDAR activity contribute to neuronal dysfunction in acute ischaemia and Huntington’s disease and could be a common theme in the aetiology of neurodegenerative diseases. Neuroprotective therapies should aim to both enhance the effect of synaptic activity and disrupt extrasynaptic NMDAR-dependent death signalling

    Cardiopoietic cell therapy for advanced ischemic heart failure: results at 39 weeks of the prospective, randomized, double blind, sham-controlled CHART-1 clinical trial

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    Cardiopoietic cells, produced through cardiogenic conditioning of patients' mesenchymal stem cells, have shown preliminary efficacy. The Congestive Heart Failure Cardiopoietic Regenerative Therapy (CHART-1) trial aimed to validate cardiopoiesis-based biotherapy in a larger heart failure cohort

    Longitudinal Assessment of the Enhanced Liver Fibrosis Score in the Era of Contemporary HIV and Hepatitis C Virus Treatment

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    BACKGROUND: The trajectory of liver fibrosis is not well understood in the contemporary era of human immunodeficiency virus (HIV) and hepatitis C virus (HCV) therapy. METHODS: We assessed the Enhanced Liver Fibrosis (ELF) score, aspartate transaminase-to-platelet ratio index (APRI) and Fibrosis-4 (FIB-4) in 116 women with HIV/HCV coinfection over a 4-year period. Random-effects linear regression models examined the rate of fibrosis change 1-2 years before starting HCV treatment, within 1 year before starting (peri-HCV treatment), within 1 year after and 1-2 years post-HCV treatment in unadjusted and adjusted models including age, race, and changes from pretreatment of factors that might affect fibrosis (eg, alcohol, integrase strand inhibitor [INSTI] use, waist circumference, CD4 count). RESULTS: INSTI use nearly doubled from pre- to peri-HCV treatment. In unadjusted analysis, there was a 3.3% rate of rise in ELF pre-HCV treatment, 2.2% and 3.6% rate of decline during the peri- and 1-year post-HCV treatment period, respectively, followed by a 0.3% rise. Similar findings were observed for APRI and FIB-4. There was little effect on the estimated fibrosis trajectories after adjustment. CONCLUSIONS: The apparent lack of decline in biomarkers of liver fibrosis beyond 1 year after HCV cure suggests that continued monitoring of liver fibrosis and interventions to mitigate progression in people with HIV after HCV cure remains essential
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