21 research outputs found

    Varicellovirus UL49.5 Proteins Differentially Affect the Function of the Transporter Associated with Antigen Processing, TAP

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    Cytotoxic T-lymphocytes play an important role in the protection against viral infections, which they detect through the recognition of virus-derived peptides, presented in the context of MHC class I molecules at the surface of the infected cell. The transporter associated with antigen processing (TAP) plays an essential role in MHC class I–restricted antigen presentation, as TAP imports peptides into the ER, where peptide loading of MHC class I molecules takes place. In this study, the UL49.5 proteins of the varicelloviruses bovine herpesvirus 1 (BHV-1), pseudorabies virus (PRV), and equine herpesvirus 1 and 4 (EHV-1 and EHV-4) are characterized as members of a novel class of viral immune evasion proteins. These UL49.5 proteins interfere with MHC class I antigen presentation by blocking the supply of antigenic peptides through inhibition of TAP. BHV-1, PRV, and EHV-1 recombinant viruses lacking UL49.5 no longer interfere with peptide transport. Combined with the observation that the individually expressed UL49.5 proteins block TAP as well, these data indicate that UL49.5 is the viral factor that is both necessary and sufficient to abolish TAP function during productive infection by these viruses. The mechanisms through which the UL49.5 proteins of BHV-1, PRV, EHV-1, and EHV-4 block TAP exhibit surprising diversity. BHV-1 UL49.5 targets TAP for proteasomal degradation, whereas EHV-1 and EHV-4 UL49.5 interfere with the binding of ATP to TAP. In contrast, TAP stability and ATP recruitment are not affected by PRV UL49.5, although it has the capacity to arrest the peptide transporter in a translocation-incompetent state, a property shared with the BHV-1 and EHV-1 UL49.5. Taken together, these results classify the UL49.5 gene products of BHV-1, PRV, EHV-1, and EHV-4 as members of a novel family of viral immune evasion proteins, inhibiting TAP through a variety of mechanisms

    Neurons and neuronal activity control gene expression in astrocytes to regulate their development and metabolism

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    The influence that neurons exert on astrocytic function is poorly understood. To investigate this, we first developed a system combining cortical neurons and astrocytes from closely related species, followed by RNA-seq and in silico species separation. This approach uncovers a wide programme of neuron-induced astrocytic gene expression, involving Notch signalling, which drives and maintains astrocytic maturity and neurotransmitter uptake function, is conserved in human development, and is disrupted by neurodegeneration. Separately, hundreds of astrocytic genes are acutely regulated by synaptic activity via mechanisms involving cAMP/PKA-dependent CREB activation. This includes the coordinated activity-dependent upregulation of major astrocytic components of the astrocyte-neuron lactate shuttle, leading to a CREB-dependent increase in astrocytic glucose metabolism and elevated lactate export. Moreover, the groups of astrocytic genes induced by neurons or neuronal activity both show age-dependent decline in humans. Thus, neurons and neuronal activity regulate the astrocytic transcriptome with the potential to shape astrocyte-neuron metabolic cooperation

    Obeticholic acid for the treatment of non-alcoholic steatohepatitis: interim analysis from a multicentre, randomised, placebo-controlled phase 3 trial

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    BACKGROUND Non-alcoholic steatohepatitis (NASH) is a common type of chronic liver disease that can lead to cirrhosis. Obeticholic acid, a farnesoid X receptor agonist, has been shown to improve the histological features of NASH. Here we report results from a planned interim analysis of an ongoing, phase 3 study of obeticholic acid for NASH. METHODS In this multicentre, randomised, double-blind, placebo-controlled study, adult patients with definite NASH, non-alcoholic fatty liver disease (NAFLD) activity score of at least 4, and fibrosis stages F2-F3, or F1 with at least one accompanying comorbidity, were randomly assigned using an interactive web response system in a 1:1:1 ratio to receive oral placebo, obeticholic acid 10 mg, or obeticholic acid 25 mg daily. Patients were excluded if cirrhosis, other chronic liver disease, elevated alcohol consumption, or confounding conditions were present. The primary endpoints for the month-18 interim analysis were fibrosis improvement (≥1 stage) with no worsening of NASH, or NASH resolution with no worsening of fibrosis, with the study considered successful if either primary endpoint was met. Primary analyses were done by intention to treat, in patients with fibrosis stage F2-F3 who received at least one dose of treatment and reached, or would have reached, the month 18 visit by the prespecified interim analysis cutoff date. The study also evaluated other histological and biochemical markers of NASH and fibrosis, and safety. This study is ongoing, and registered with ClinicalTrials.gov, NCT02548351, and EudraCT, 20150-025601-6. FINDINGS Between Dec 9, 2015, and Oct 26, 2018, 1968 patients with stage F1-F3 fibrosis were enrolled and received at least one dose of study treatment; 931 patients with stage F2-F3 fibrosis were included in the primary analysis (311 in the placebo group, 312 in the obeticholic acid 10 mg group, and 308 in the obeticholic acid 25 mg group). The fibrosis improvement endpoint was achieved by 37 (12%) patients in the placebo group, 55 (18%) in the obeticholic acid 10 mg group (p=0·045), and 71 (23%) in the obeticholic acid 25 mg group (p=0·0002). The NASH resolution endpoint was not met (25 [8%] patients in the placebo group, 35 [11%] in the obeticholic acid 10 mg group [p=0·18], and 36 [12%] in the obeticholic acid 25 mg group [p=0·13]). In the safety population (1968 patients with fibrosis stages F1-F3), the most common adverse event was pruritus (123 [19%] in the placebo group, 183 [28%] in the obeticholic acid 10 mg group, and 336 [51%] in the obeticholic acid 25 mg group); incidence was generally mild to moderate in severity. The overall safety profile was similar to that in previous studies, and incidence of serious adverse events was similar across treatment groups (75 [11%] patients in the placebo group, 72 [11%] in the obeticholic acid 10 mg group, and 93 [14%] in the obeticholic acid 25 mg group). INTERPRETATION Obeticholic acid 25 mg significantly improved fibrosis and key components of NASH disease activity among patients with NASH. The results from this planned interim analysis show clinically significant histological improvement that is reasonably likely to predict clinical benefit. This study is ongoing to assess clinical outcomes. FUNDING Intercept Pharmaceuticals

    Diagnosing small bowel malabsorption: a review

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    Malabsorption encompasses dysfunctions occurring during the digestion and absorption of nutrients. A small proportion of patients presents with chronic diarrhoea. A clinical history supportive of malabsorption may guide investigations toward either the small bowel or pancreas. Serological testing for coeliac disease will determine most cases without invasive investigations. In the clinical context of persisting weight loss and malnutrition, small bowel enteropathy may be investigated with small intestinal biopsies. Small bowel absorptive capacity and permeability might be measured by oral sugar-mix ingestion. Further, approaches to the investigation of malabsorption might also involve the detection in faeces of a substance that has not been absorbed. A variation of the latter is the use of breath testing which relies on the breakdown of the malabsorbed test substance by colonic flora. Measurement of protein absorption is difficult and unreliable; it is, therefore, rarely advocated in clinical settings. No single biological marker confirming a diagnosis of small bowel malabsorption or small bowel integrity is presently available in clinical practice. Plasma citrulline concentration, an amino acid not incorporated into endogenous or exogenous proteins, has been extensively used in research studies and supportive results are establishing its concentration as a reliable quantitative biomarker of enterocyte absorptive capacity

    Effect of biosolids from municipal sewage sludge composted with rice husk on soil functionality

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    Two different biosolids were obtained composting anaerobic (A) and aerobic (B) municipal sewage sludge (SS) with rice husk. Higher amounts of SS (1:1 v/v) could be used in this composting process than in conventional ones. The two biosolids were characterized by chemical analysis and compared with a conventional green manure plus municipal solid waste and municipal SS compost. The effect of these products on soil functionality was studied in a 14- week incubation experiment by their addition to two different soils (silty clay—Ustic Endoaquert—and sandy loam—Aquic Xeropsamment). The total organic C ranged from 20 to 26 % and total N from 1.6 to 2.5 % in the two biosolids. The most relevant difference was due to dissolved organic C that was lower in the anaerobic biosolid (1 mgCkg−1) than in the other products (5–6 mgCkg−1). The total trace elements (Cd, Cr, Cu, Ni, Pb and Zn) contents were under the limits fixed by the European legislation for soil application of SS (EC Directive 86/278/EEC, 1986). The three biosolids did not show strong negative effects on soil functionality during the incubation experiment, although some significant differences were found. The aerobic biosolid B mainly increased cumulative N release, microbial activity, basal respiration rate, microbial biomass-C-tototal organic C ratio, β-glucosidase, alkaline phosphomonoesterase and aryl-sulphatase activities. The anaerobic one (B) decreased basal respiration rate, microbial biomass-C-to-total organic C ratio and aryl-sulphatase activity. DTPA soil bioavailable heavy metals were not affected by biosolids additions

    Defining appropriate outcome measures in pulmonary arterial hypertension related to systemic sclerosis: A Delphi consensus study with cluster analysis Participants of the Delphi Survey are shown in Appendix A .

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    Objective Outcome measures for pulmonary arterial hypertension associated with systemic sclerosis (PAH-SSc) are only partially validated. The aim of the present study was to establish an expert consensus regarding which outcome measures are most appropriate for clinical trials in PAH-SSc. Methods Sixty-nine PAH-SSc experts (rheumatologists, cardiologists, pulmonologists) rated a list of disease domains and measurement tools in an Internet-based 3-stage Delphi consensus study. In stages 2 and 3, the medians of domains and measurement tools and frequency distributions of ratings, along with requests for re-ratings, were distributed to respondents to provide feedback. A final score of items was identified by means of cluster analysis. Results The experts judged the following domains and tools as most appropriate for randomized controlled trials in PAH-SSc: lung vascular/pulmonary arterial pressure and cardiac function both measured by right heart catheterization and echocardiography, exercise testing measured by 6-minute walking test and oxygen saturation at exercise, severity of dyspnea measured on a visual analog scale, discontinuation of treatment measured by (serious) adverse events, quality of life/activities of daily living measured by the Short Form 36 and Health Assessment Questionnaire disability index, and global state assessed by physician measured by survival. Conclusion Among experts in PAH-SSc, a core set of outcome measures has been defined for clinical trials by Delphi consensus methods. Although these outcome measures are recommended by this expert group to be used as an interim tool, it will be necessary to formally validate the present measures, as well as potential research measures, in further studies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/60213/1/23718_ftp.pd
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