Immunofluorescence assays with fixed tissue sections were used to characterize antibody reactivity in sera obtained from duck hepatitis B virus-infected ducks. Under conditions of experimental infection, antibody to core antigen but not to surface antigen was detectable. A majority of the ducks infected at 8 days after hatching and a minority of those infected at 1 day after hatching showed a t...

Tree squirrel hepatitis B virus (THBV)-associated particles isolated from the livers of naturally infected animals share one or more antigenic determinants with hepatitis B surface antigen in solid-phase immunoassays. Characterization of THBV-associated polypeptides by sodium dodecyl sulfate/polyacrylamide gel electrophoresis reproducibly demonstrated major components with apparent sizes of 15....

BACKGROUND The aim of the evaluation was to investigate the relevance of the HCV-core antigen testing for the diagnosis and monitoring of HCV infections in the daily routine. Up to now, most of the serological diagnostics was performed as determination of antibodies while the determination of activity and the monitoring of antiviral therapy were checked by HCV RNA PCR. METHODS The routine req...

The specific roles that immunoproteasome variants play in MHC class I antigen presentation are unknown at present. To investigate the biochemical properties of different immunoproteasome forms and unveil the molecular mechanisms of PA28 activity, we performed in vitro degradation of full-length proteins by 20S, 26S, and PA28αβ-20S immunoproteasomes and analyzed the spectrum of peptides released...

background: hepatitis b virus (hbv) infection is the most common cause of end-stage liver disease in iran. more than 70% of cases are negative for the hepatitis b e antigen (hbeag) and have a long-term response to antiviral therapy, as well as a high relapse rate after discontinuing lamivudine or interferon. these features could be due, in part, to genetic variation of the hbv genome. materials...

Salmonella enterica serovar Typhi causes typhoid fever in humans. Central to the pathogenicity of serovar Typhi is its capacity to invade intestinal epithelial cells. The role of lipopolysaccharide (LPS) in the invasion process of serovar Typhi is unclear. In this work, we constructed a series of mutants with defined deletions in genes for the synthesis and polymerization of the O antigen (wbaP...

Routine use of the automated chemiluminescent microparticle immunoassay Abbott ARCHITECT anti-HBc for diagnosis of hepatitis B is limited in case of borderline reactive sera with low signal close to the cut-off index. In order to determine the significance of anti-HBc detection when borderline reactivity occurs using the ARCHITECT anti-HBc assay, a comparative study was designed. 3540 serum sam...