Search results for "Hepadnaviridae"
showing 10 items of 57 documents
Ortervirales: New Virus Order Unifying Five Families of Reverse-Transcribing Viruses
2018
International audience; Reverse-transcribing viruses, which synthesize a copy of genomic DNA from an RNA template, are widespread in animals, plants, algae, and fungi (1, 2). This broad distribution suggests the ancient origin(s) of these viruses, possibly [...]
Beyond malaria: The inhibition of viruses by artemisinin-type compounds
2018
Abstract Natural products represent valuable chemical scaffolds for drug development. A recent success story in this context was artemisinin, which is not only active against malaria but also to other diseases. This raised the interest of artemisinin's potential for drug repurposing. On the present review, we give an overview on artemisinin's antiviral activity. There is good in vitro and in vivo evidence for the activity of artemisinin and its derivatives against DNA viruses of the Herpesviridae and Hepadnaviridae families such as cytomegaloviruses, human herpesvirus 6, herpes simplex viruses 1 and 2, Epstein-Barr virus and Hepatitis B virus. The evidence is weaker for Polyomaviruses and p…
Use of the polymerase chain reaction to demonstrate hepatitis B virus DNA in serum of children with chronic hepatitis B.
1992
The polymerase chain reaction was used to investigate the presence of hepatitis B virus DNA in sera of 61 children with chronic hepatitis B and negative results on dot biot hybridization tests. Our results demonstrate that most chronic carriers of hepatitis B surface antigen in childhood have hepatitis B virus DNA detectable by polymerase chain reaction in their serum and must be considered infectious.
Active immunization of homosexual men using a recombinant hepatitis B vaccine
1989
Twenty homosexual men [13 anti-human immunodeficiency virus (HIV)-positive, seven anti-HIV negative] without HBsAg, anti-HBs, and anti-HBc were vaccinated with three 20 micrograms doses of a recombinant hepatitis B vaccine. All anti-HIV-positive homosexuals were nonresponders independent of the initial number of CD4-positive cells. Among seven anti-HIV-negative individuals, five responded. After three doses of the vaccine, CD4-positive cells fell in anti-HIV positive individuals by 22.4%. A similar fall in CD4-positive cells of an average 24.9% was noted in 17 matching, but nonvaccinated, anti-HIV-positive homosexuals. The study indicates that the efficacy of vaccination in anti-HIV-positiv…
Smouldering hepatitis B virus replication in patients with chronic liver disease and hepatitis delta virus superinfection
1991
Hepatitis B virus deoxyribonucleic acid (HBV-DNA) was studied by Southern blot analysis in liver biopsy specimens from 75 HBsAg-positive patients with chronic liver disease living in southern Italy. Twenty-seven of the patients were hepatitis delta virus (HDV) superinfected. Intrahepatic HBV-DNA was detected in 54 (72%) patients, 32 (59%) of them with replicative forms. The presence of replicative forms was directly related to liver HBcAg and inversely related to liver HDAg, as shown by multivariate analysis. However, 14 patients with intrahepatic HBV-DNA non-replicative pattern and about half of HDV-infected patients were liver HBcAg and/or serum HBV-DNA positive, mostly in low amounts. Hi…
Selection of a precore mutant after vertical transmission of different hepatitis B virus variants is correlated with fulminant hepatitis in infants
1995
The incidence of perinatal transmission of hepatitis B virus (HBV) depends on the HBeAg/anti-HBe status of the mother. While children of HBeAg-positive mothers have a 90% probability of acquiring a chronic hepatitis B virus carrier state, babies of anti-HBe-positive mothers are more likely to develop fulminant hepatitis within the first 3 to 4 months of life. There is evidence that precore (pre-C) mutations of the HBV can be associated with fulminant hepatitis. The pre-C region was therefore examined in sera from nine infants with fulminant hepatitis after vertical transmission, one HBeAg-positive and seven anti-HBe-positive mothers by polymerase chain reaction (PCR) and direct sequence ana…
HBV-DNA suppression and disease course in HBV cirrhosis patients on long-term lamivudine therapy
2005
In hepatitis B virus (HBV) cirrhosis patients on long-term lamivudine (LAM), the relationships between HBV suppression, development of viral resistance and disease outcome are unclear. We analysed the dynamic of serum HBV-DNA and its relationship with the clinical course of 59 patients (52 males, mean age 51.4 ±8.4 years, 12 HBeAg positive and 47 HBeAg negative, and 57 genotype D and two genotype A) with cirrhosis (45 in Child-Turcotte-Pugh class A) and high levels of serum HBV-DNA (median 14.7x107 genomes/ml) treated with LAM [median (range): 44 (15–78) months]. A total of 50 patients (84.7%) achieved a virological response (serum HBV-DNA negative by PCR) during the first 6 months of ther…
Quantitative and functional analysis of core-specific T-helper cell and CTL activities in acute and chronic hepatitis B
2008
Aims/background CD4+ T-helper cell (Th) responses to hepatitis B virus (HBV) core antigen (HBc) are increased during exacerbations in acute and chronic hepatitis B (AHB, CHB) and might influence the induction of CD8+ cytotoxic T lymphocytes (CTL) that are important for viral clearance. Methods HBc-specific proliferative responses and cytokine release of blood mononuclear cells (PBMC) were studied in patients with AHB or CHB, as well as responders and non-responders to interferon-alpha treatment (IFN-R, IFN-NR), by [3H]-thymidine-uptake, enzyme-linked immunosorbent assay (ELISA) and Elispot assay and were compared to peptide HBc18 27-specific CTL precursor frequencies among CD8+ T cells deri…
Regulation of the neutralizing anti-hepatitis B surface (HBs) antibody response in vitro in HBs vaccine recipients and patients with acute or chronic…
1996
Abstract Antibodies directed to the HBs antigen indicate viral clearance and the development of life-long immunity in patients that recovered from HBV infection. In HBs antigen vaccine recipients anti-HBs antibodies provide protective immunity. However, little is known about the regulation of this HBs-specific antibody response. The existence of anti-HBs-secreting B cells was demonstrated using the highly sensitive ELISPOT technique compared with conventional ELISA in serum and cell culture supernatants. In the peripheral blood of patients with acute self-limited hepatitis B, HBs-specific B cells were demonstrated with a high frequency despite undetectable anti-HBs serum antibodies. HBV-imm…
Can the serological status of anti-HBc alone be considered a sentinel marker for detection of occult HBV infection?
2008
Some individuals have “occult” infection with hepatitis B virus (HBV), defined as presence of HBV genome in the serum or liver tissue without HBV surface antigen (HBsAg) in the serum. The aim of this study was to investigate whether serum antibodies against HBV core antigen in isolation (“anti-HBc alone”) are a useful marker of “occult” HBV in patients with or without hepatitis C virus (HCV) infection. “Anti-HBc alone” was detected in the sera of 119/6,544 (1.8%) asymptomatic outpatients referred to the diagnostic laboratory for routine testing for viral hepatitis, 62/607 (10.2%) drug users, and 42/195 (21.5%) patients with hepatocellular carcinoma. Using three in-house nested-PCR amplifica…