277 research outputs found
Distribution of TT virus (TTV), TTV-like minivirus, and related viruses in humans and nonhuman primates
AbstractTT virus (TTV) and TTV-like minivirus (TLMV) are small DNA viruses with single-stranded, closed circular, antisense genomes infecting man. Despite their extreme sequence heterogeneity (>50%), a highly conserved region in the untranslated region (UTR) allows both viruses to be amplified by polymerase chain reaction (PCR). TTV/TLMV infection was detected in 88 of 100 human plasma samples; amplified sequences were differentiated into TTV and TLMV by analysis of melting profiles, showing that both viruses were similarly prevalent. PCR with UTR primers also detected frequent infection with TTV/TLMV-related viruses in a wide range of apes (chimpanzees, gorillas, orangutans, gibbons) and African monkey species (mangabeys, drills, mandrills). These findings support the hypothesis for the co-evolution of TTV-like viruses with their hosts over the period of primate speciation, potentially analogous to the evolution of primate herpesviruses
Neutralizing antibody response during acute and chronic hepatitis C virus infection
Little is known about the role of Abs in determining the outcome of hepatitis C virus (HCV) infection. By using infectious retroviral pseudotypes bearing HCV glycoproteins, we measured neutralizing Ab (nAb) responses during acute and chronic HCV infection. In seven acutely infected health care workers, only two developed a nAb response that failed to associate with viral clearance. In contrast, the majority of chronically infected patients had nAbs. To determine the kinetics of strain-specific and crossreactive nAb emergence, we studied patient H, the source of the prototype genotype 1a H77 HCV strain. An early weak nAb response, specific for the autologous virus, was detected at seroconversion. However, neutralization of heterologous viruses was detected only between 33 and 111 weeks of infection. We also examined the development of nAbs in 10 chimpanzees infected with H77 clonal virus. No nAb responses were detected in three animals that cleared virus, whereas strain-specific nAbs were detected in six of the seven chronically infected animals after approximately 50 weeks of infection. The delayed appearance of high titer crossreactive nAbs in chronically infected patients suggests that selective mechanism(s) may operate to prevent the appearance of these Abs during acute infection. The long-term persistence of these nAbs in chronically infected patients may regulate viral replication
HCVerso3: An Open-Label, Phase IIb Study of Faldaprevir and Deleobuvir with Ribavirin in Hepatitis C Virus Genotype-1b-Infected Patients with Cirrhosis and Moderate Hepatic Impairment
This study evaluated the interferon-free, oral combination of deleobuvir (non-nucleoside HCV NS5-RNA-polymerase inhibitor) and faldaprevir (HCV NS3/4A-protease inhibitor) with ribavirin in patients with HCV genotype-1b and moderate (Child-Pugh B [CPB], n = 17) or mild hepatic impairment (Child-Pugh A [CPA], n = 18). Patients received faldaprevir 120 mg and deleobuvir (600 mg [CPA], 400 mg [CPB]) twice-daily with weight-based ribavirin for 24 weeks. Baseline characteristics were similar between groups. Among CPA patients, 13/18 completed treatment; discontinuations were for adverse events (AEs, n = 1), lack of efficacy (n = 3) and withdrawal (n = 1). Among CPB patients, 8/17 completed treatment; discontinuations were for AEs (n = 6), withdrawal (n = 1) and 'other' (n = 2). Sustained virologic response at post-treatment Week 12 (SVR12) was achieved by 11 (61%) CPA patients (95% confidence interval: 38.6%-83.6%) and 9 (53%) CPB patients (95% confidence interval: 29.2%-76.7%), including most CPA (11/16) patients with Week 4 HCV RNA <25 IU.mL-1 (target detected or not detected) and most CPB (8/9) patients with Week 4 HCV RNA <25 IU.mL-1 (target not detected); 0/4 CPB patients with Week 4 HCV RNA <25 IU.mL-1 (target detected) achieved SVR12. The most common AEs in both groups were nausea, diarrhoea and vomiting. Serious AEs were observed in 9 (53%) CPB patients and 1 (6%) CPA patient. Plasma trough concentrations of deleobuvir and faldaprevir were not substantially different between the CPA and CPB groups. In conclusion, in this small study the safety and efficacy profiles for 24 weeks of treatment with faldaprevir+deleobuvir+ribavirin in patients with mild or moderate hepatic impairment were consistent with the safety and efficacy profile of this regimen in non-cirrhotic patients. Faldaprevir+deleobuvir+ribavirin resulted in SVR12 in 53-61% of patients: proportions achieving SVR4 but not SVR12 were higher than in non-cirrhotic patients and overall response rates were lower than rates reported with other all-oral regimens in patients with cirrhosis
POSITION PAPER OF THE CATALAN SOCIETY OF GASTROENTEROLOGY ABOUT HEPATIC ELASTOGRAPHY 2022
After almost 20 years using transient elastography (TE) for the non-invasive diagnosis of liver fibrosis, its use has been extended to population screening, evaluation of steatosis and complications of cirrhosis. For this reason, the "Catalan Society of Digestology" commissioned a group of experts to update the first Document carried out in 2011.The working group (8 doctors and 4 nurses) prepared a panel of questions based on the online survey "Hepatic Elastography in Catalonia 2022" following the PICO structure and the Delphi method.The answers are presented with the level of evidence, the degree of recommendation and the final consensus after being evaluated by 2 external reviewers.TE uses the simplest and most reliable elastographic method to quantify liver fibrosis, assess steatosis, and determine the risk of complications in patients with cirrhosis.Copyright Ā© 2022 Elsevier EspaƱa, S.L.U. All rights reserved
Primary herpes simplex virus type 1 infection with acute liver failure in solid organ transplantation: Report of three cases and review
Herpes virus infections is not uncommon in solid organ transplantation patients. We report 3 cases with primary Herpes simplex virus type-1 (HSV1) infection with acute liver failure (ALF). This is a rare and potentially fatal entity that could be a donor-derived infection. Although the initial clinical presentation is non-specific, it should be considered as a differential diagnosis in HSV-negative serology patients with liver failure and empirical treatment must be started in combination with a drastic reduction of immunosuppression. A strategy of HSV prophylaxis for pre-transplant HSV seronegative patients must be stablished in order to reduce the risk of clinical disease.Ā© 2022 Published by Elsevier Ltd
Sofosbuvir and Ribavirin Prevent Recurrence of HCV Infection After Liver Transplantation: An Open-Label Study
Background & AimsPatients with detectable hepatitis C virus (HCV) RNA at the time of liver transplantation universally experience recurrent HCV infection. Antiviral treatment before transplantation can prevent HCV recurrence, but existing interferon-based regimens are poorly tolerated and are either ineffective or contraindicated in most patients. We performed a trial to determine whether sofosbuvir and ribavirin treatment before liver transplantation could prevent HCV recurrence afterward.MethodsIn a phase 2, open-label study, 61 patients with HCV of any genotype and cirrhosis (ChildāTurcotteāPugh score, ā¤7) who were on waitlists for liver transplantation for hepatocellular carcinoma, received up to 48 weeks of sofosbuvir (400 mg) and ribavirin before liver transplantation. The primary end point was the proportion of patients with HCV-RNA levels less than 25 IU/mL at 12 weeks after transplantation among patients with this HCV-RNA level at their last measurement before transplantation.ResultsSixty-one patients received sofosbuvir and ribavirin, and 46 received transplanted livers. The per-protocol efficacy population consisted of 43 patients who had HCV-RNA level less than 25 IU/mL at the time of transplantation. Of these 43 patients, 30 (70%) had a post-transplantation virologic response at 12 weeks, 10 (23%) had recurrent infection, and 3 (7%) died (2 from nonfunction of the primary graft and 1 from complications of hepatic artery thrombosis). Of all 61 patients given sofosbuvir and ribavirin, 49% had a post-transplantation virologic response. Recurrence was related inversely to the number of consecutive days of undetectable HCV RNA before transplantation. The most frequently reported adverse events were fatigue (in 38% of patients), headache (23%), and anemia (21%).ConclusionsAdministration of sofosbuvir and ribavirin before liver transplantation can prevent post-transplant HCV recurrence. ClinicalTrials.gov: NCT01559844
Peptide based amphiphiles
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Experimental free energy measurements of kinetic molecular states using fluctuation theorems
Recent advances in non-equilibrium statistical mechanics and single molecule
technologies make it possible to extract free energy differences from
irreversible work measurements in pulling experiments. To date, free energy
recovery has been focused on native or equilibrium molecular states, whereas
free energy measurements of kinetic states (i.e. finite lifetime states that
are generated dynamically and are metastable) have remained unexplored. Kinetic
states can play an important role in various domains of physics, such as
nanotechnology or condensed matter physics. In biophysics, there are many
examples where they determine the fate of molecular reactions: protein and
peptide-nucleic acid binding, specific cation binding, antigen-antibody
interactions, transient states in enzymatic reactions or the formation of
transient intermediates and non-native structures in molecular folders. Here we
demonstrate that it is possible to obtain free energies of kinetic states by
applying extended fluctuation relations. This is shown by using optical
tweezers to mechanically unfold and refold DNA structures exhibiting
intermediate and misfolded kinetic states.Comment: main paper (16 pages, 5 figures) and supplementary information (22
pages, 14 figures
Air pollution exposure during pregnancy and childhood autistic traits in four European population-based cohort studies : the ESCAPE project
Background: Prenatal exposure to air pollutants has been suggested as a possible etiologic factor
for the occurrence of autism spectrum disorder.
Objectives: We aimed to assess whether prenatal air pollution exposure is associated with
childhood autistic traits in the general population.
Methods: Ours was a collaborative study of four European population-based birth/child cohortsā
CATSS (Sweden), Generation R (the Netherlands), GASPII (Italy), and INMA (Spain). Nitrogen
oxides (NO2, NOx) and particulate matter (PM) with diameters of ā¤ 2.5 Ī¼m (PM2.5), ā¤ 10 Ī¼m
(PM10), and between 2.5 and 10 Ī¼m (PMcoarse), and PM2.5 absorbance were estimated for birth
addresses by land-use regression models based on monitoring campaigns performed between 2008
and 2011. Levels were extrapolated back in time to exact pregnancy periods. We quantitatively
assessed autistic traits when the child was between 4 and 10 years of age. Children were classified
with autistic traits within the borderline/clinical range and within the clinical range using
validated cut-offs. Adjusted cohort-specific effect estimates were combined using random-effects
meta-analysis.
Results: A total of 8,079 children were included. Prenatal air pollution exposure was not associated
with autistic traits within the borderline/clinical range (odds ratio = 0.94; 95% CI: 0.81, 1.10
per each 10āĪ¼g/m3 increase in NO2 pregnancy levels). Similar results were observed in the different
cohorts, for the other pollutants, and in assessments of children with autistic traits within the
clinical range or children with autistic traits as a quantitative score.
Conclusions: Prenatal exposure to NO2 and PM was not associated with autistic traits in children
from 4 to 10 years of age in four European population-based birth/child cohort studies.NonePublishe
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