Search results for "hepatitis B virus"
showing 10 items of 295 documents
Relationship of pre-S encoded antigens in liver and clinical manifestations of chronic hepatitis B infection.
2008
Pre-S1 and pre-S2 encoded antigens of hepatitis B virus were localized in liver tissue using monoclonal antibodies. They were found to be exclusively expressed in the cytoplasm of liver cells. Cell bound pre-S1 encoded protein was often detected in patients with chronic liver disease and viremia. Only a small number of the HBsAg positive cells also contained pre-S1 antigen. There was no correlation with nuclear HBcAg. Livers of non-viremic HBsAg carriers contained many HBsAg expressing liver cells, that were frequently also positive for pre-S2 encoded protein but contained no detectable pre-S1 encoded protein at all. It remains open whether cell bound pre-S2 containing proteins of middle si…
Hepatic expression patterns of the large and middle hepatitis B virus surface proteins in viremic and nonviremic chronic hepatitis B.
1990
The envelope of hepatitis B virus consists of large, middle, and small hepatitis B surface proteins. Recent data from in vitro studies suggest that intracellular expression and distribution of the three polypeptides may be variable. These observations in artificial expression systems prompted this analysis of the occurrence and distribution of the three hepatitis B surface proteins in the liver tissue of substantial viremic (hepatitis B virus DNA- and hepatitis B e antigen-positive) and low-viremic or nonviremic (hepatitis B virus DNA-negative, anti-hepatitis B e antigen-positive) carriers by specific monoclonal antibodies against large, middle, and small proteins. Patients with an active f…
HBV-specific immune defect in chronic hepatitis B (CHB) is correlated with a dysregulation of pro- and anti-inflammatory cytokines.
1999
SUMMARY The aim of this study was to examine the immunomodulating effects of rhIL-12 on the immune response induced by hepatitis B virus (HBV) antigens in clinical subgroups of patients with HBV infection. Peripheral blood mononuclear cells (PBMC) of 80 patients were stimulated with HBsAg, HBcAg, pre-S1Ag and tetanus toxoid in the absence or presence of IL-12 (0.01, 0.1 and 1 ng/ml). Stimulation by anti-CD3 + anti-CD28 and lipopolysaccharide (LPS) were used as controls. Proliferation and cytokine production were determined by 3H-thymidine uptake and ELISA after 72 h. After stimulation with HBV antigens only, production of tumour necrosis factor-alpha (TNF-α) or IL-10 was observed in all pat…
Kinetics of Anti-Hepatitis B Surface Antigen Titers in Nurse Students after a Two-Year Follow-Up
2020
Infection caused by hepatitis B virus (HBV) can be prevented through a safe and effective vaccine. This study analysed the kinetics of serum antibodies against hepatitis B surface antigen (HBsAg) (anti-HBs) titers in relation to previous vaccine boosters in Italian nursing students who were followed up for two years. Serum anti-HBs titers were evaluated at the first visit, after vaccine booster (if required) and at visit after two years. Overall, 483 students (mean age = 21.7 years
Enhancement of Gene Expression by Somatic Hybridization with Primary Cells: High-Level Synthesis of the Hepatitis B Surface Antigen in Monkey Vero Ce…
1990
Vero cells transfected with the S gene encoding the surface antigen (HBsAg) of the hepatitis B virus (HBV) synthesize HBsAg at low levels. We have obtained a large increase in S gene expression by somatic hybridization of Vero cells with primary hepatocytes, which are the natural target cells for HBV infection. Fusion with cells other than hepatocytes did not enhance expression of the S gene. The Vero/hepatocyte hybrid clones analyzed are stable and have maintained a high level of HBsAg synthesis over prolonged periods. Hybrid cell lines may be of general interest for the high-level synthesis of proteins using cloned genes.
Immunohistochemical Characterization of 130 Cases of Primary Hepatic Carcinomas
1987
Primary liver carcinoma (PLC) may express a certain number of markers. Here we communicate results of an analysis of five such markers (alpha-1-antitrypsin--AAT--, carcino-embryonic antigen --CEA--, alpha-fetoprotein --AFP--, and superficial --HBsAg-- and core --HBcAg-- antigens of hepatitis B virus) by means of PAP techniques in 130 cases of PLC, comparing the neoplastic tissue and the non-tumorous liver. Three variants of PLC are distinguished: hepatocarcinoma (HC) (108 cases); cholangiocarcinoma (CC) (19 cases); and three cases of hepatocholangiocarcinoma (HCC). AAT was positive in 29 HC, 2 HCC, and negative in all 19 CC. CEA appeared positive in 16 HC, 16 CC and only one HCC. AFP was po…
Polyalbumin receptors, hepatitis B surface antigen (HBsAg), and HBsAg/IgM complexes in HBsAg positive patients with and without delta superinfection.
1985
Receptors for polymerized human albumin are found at high litres during high-level hepatitis B virus (HBV) replication and in small amounts in chronic low-level infection. Complexes between hepatitis B surface antigen (HBsAg) and IgM without specificity for HbsAg are expressed in a pattern similar to that of receptors. Anti-albumin antibodies could be involved in their formation. Delta infection depresses the synthesis of gene products of HBV. To assess whether delta modifies the expression of receptors on HBsAg and the level of HBsAg/IgM complexes, and if anti-albumin antibodies are actually part of the complex, we tested sera from 86 subjects with acute and chronic HBV infection. Our find…
Prophylaxis and treatment of hepatitis B in immunocompromised patients.
2007
The literature on hepatitis B virus (HBV) in immunocompromised patients is heterogeneous and referred mainly to the pre-antivirals era. Today a rational approach to the problem of hepatitis B in these patients provides for: (a) the evaluation of HBV markers and of liver condition in all subjects starting immunosuppressive therapies (baseline), (b) the treatment with antivirals (therapy) of active carriers, (c) the pre-emptive use of antivirals (prophylaxis) in inactive carriers, especially if they are undergoing immunosuppressive therapies judged to be at high risk, (d) the biochemical and hepatitis B surface antigen (HBsAg) monitoring (or universal prophylaxis, in case of high risk immunos…
Knowledge, attitudes and risk of HIV, HBV and HCV infections in hairdressers of Palermo city (South Italy)
2009
Background: The hairdressing trade may potentially expose its practitioners and their customers to blood-borne infections. Methods: Knowledge, attitudes and behaviours towards occupational risk of HIV, HBV and HCV infections were evaluated in a cross-sectional survey, conducted during spring 2008, in 105 out of 112 randomly selected hairdressers of Palermo. Participants were queried by answering to an anonymous questionnaire. Results: Most of hairdressers (93.3%) knew that HIV and hepatitis are transmitted through parenteral route and could also be transmitted by razors. The availability of gloves was inadequate, up to 30% of the participants never used them and up to 50% usually reused the…
Long-term efficacy of hepatitis B vaccine, booster policy, and impact of hepatitis B virus mutants
2005
The long-term efficacy of hepatitis B vaccine, long-term effectiveness of hepatitis B immunisation programmes, immune memory induced by hepatitis B vaccine, current booster policies, and impact of hepatitis B virus mutants on immunisation programmes were reviewed at the Viral Hepatitis Prevention Board (VHPB) meeting in Sevilla, Spain, March 2004. The main focus was on universal vaccination programmes with data being presented from Italy, Saudi Arabia, Singapore, Spain, Taiwan, Thailand, The Gambia, and USA (Alaska).