Differentiating the cellular and humoral components of neuromuscular blocking agent-induced anaphylactic reactions in patients undergoing anaesthesia.

Background: The significance of IgE antibodies to neuromuscular blocking agent (NMBA)-induced anaphylactic reactions during anaesthesia is unclear. We investigated the relevance of IgE to rocuronium using an in vitro technique.

Methods: Serum samples from 61 patients with anaphylactic reactions during anaesthesia were investigated.

Fine-mapping of the B-cell epitope domain at the N-terminus of the preS2 region of the hepatitis B surface antigen.

In this study, we report the exact localization and substitutional characterization of a B-cell epitope domain at the N-terminus of the preS2 region of the hepatitis B surface antigen. A set of deletion variants containing preS2 sequences of different length was generated on the basis of frCP as a carrier. It was found after Western blot analysis that three monoclonal antibodies (MAbs) (2-11B1, 3-11C2, HB.

Anti-HBs after hepatitis B immunization with plasma-derived and recombinant DNA-derived vaccines: binding to mutant HBsAg.

The G145R mutant of the small S-protein is a major escape mutant of hepatitis B virus observed in natural infection, after immunization and HBIG therapy. In a previous study we found that plasma-derived and recombinant DNA-derived vaccine HBsAg reacted differently with monoclonal antibodies sensitive for the G145R change. In the present study we investigated the binding of polyclonal anti-HBs obtained after immunization with plasma vaccine and recombinant DNA vaccine to synthetic peptides (adw(2), adr) and rHBsAg (HepG2) (ayw(3); wild type and a 145R mutant).

Vaccine- and hepatitis B immune globulin-induced escape mutations of hepatitis B virus surface antigen.

Hepatitis B virus surface antigen (HBsAg) vaccination has been shown to be effective in preventing hepatitis B virus (HBV) infection. The protection is based on the induction of anti-HBs antibodies against a major cluster of antigenic epitopes of HBsAg, defined as the 'a' determinant region of small HBsAg. Prophylaxis of recurrent HBV infection in patients who have undergone liver transplantation for hepatitis B-related end-stage liver disease is achieved by the administration of hepatitis B immune globulins (HBIg) derived from HBsAg-vaccinated subjects.

Anti-HBs characteristics after hepatitis B immunisation with plasma-derived and recombinant DNA-derived vaccines.

Hepatitis B surface antigen derived from chronic hepatitis B carriers has been replaced almost completely by recombinant DNA-derived HBsAg for use as hepatitis B vaccine. Similarly, recombinant DNA-derived HBsAg is replacing plasma-derived HBsAg in standard anti-HBs assays. We analysed the influence of a change from plasma-derived HBsAg to recombinant DNA-derived HBsAg on antigen presentation in immunoassays and the characteristics of the anti-HBs antibodies after immunisation.

Characterization of the reactivity pattern of murine monoclonal antibodies against wild-type hepatitis B surface antigen to G145R and other naturally occurring "a" loop escape mutations.

The hepatitis B surface antigen (HBsAg) "a" domain harbors major B-cell epitopes. Viruses with mutations in this region emerge after vaccination or during hepatitis B immune globulin (HBIg) prophylaxis. A strain with G145R replacement has been almost invariably isolated as a major escape mutant.

Localization of a unique hepatitis B virus epitope sheds new light on the structure of hepatitis B virus surface antigen.

In a search for monoclonal antibodies (MAbs) that can bind hepatitis B virus surface antigen (HBsAg) with amino acid substitutions in the immune dominant 'a' region (escape mutants) we investigated the epitope recognition site of the human MAb 4-7B. Pepscan analysis and experiments with alanine substitution as well as substitutions known from nature pointed to residues 178-186 in the small S protein with the amino acid sequence PFVQWFVGL (key amino acids in bold) as the minimal epitope. Single amino acid substitutions at positions 122(R/K)(d/y), 134(Y/F), 145(G/R), 148(T/A) and 160(K/R)(w/r), representing 'a' region variants in recombinant HBsAg COS-I cells, did not influence binding of MAb 4-7B.

In vivo activity of a mixture of two human monoclonal antibodies (anti-HBs) in a chronic hepatitis B virus carrier chimpanzee.

A 35-year-old female hepatitis B virus carrier chimpanzee was infused with one dose of a mixture of human monoclonal antibodies 9H9 and 4-7B (antibodies against hepatitis B virus surface antigen; HBsAg). Blood samples were taken before and up to 3 weeks after infusion. HBsAg and antibodies against HBsAg (anti-HBs) were quantified by radioimmunoassay and enzyme immunoassay.

Characteristics of the early phase of chronicity in acute hepatitis B infection.

The mechanism of development of chronicity after acute hepatitis B infection has not been elucidated fully. Following a single source outbreak of hepatitis B among 79 adult women, three patients (4%) became chronic carriers of hepatitis B virus (HBV). We compared features of the virus and antibody response of the latter three patients with those of 12 HBeAg-positive cases with resolving infection.

Analysis of hepatitis B virus populations in an interferon-alpha-treated patient reveals predominant mutations in the C-gene and changing e-antigenicity.

It is largely unknown whether hepatitis B virus (HBV) sequence variation during chronic infection hampers HBV immune recognition or the antiviral effect of cytokines on HBV production. Here we have analyzed which region of the HBV genome changes most drastically during an interferon-alpha (IFNalpha)-stimulated immune response. In addition, we have investigated whether the mutations affect viral replication, gene expression, and immune recognition of the mutant viral proteins.

HBV-specific lymphoproliferative and cytokine responses in patients with chronic hepatitis B.

Background/aims: Hepatitis B virus specific T cell responses are crucial for viral elimination but their nature is not fully understood.

Methods: We studied the regulation of proliferation and cytokine production after antigenic stimulation in peripheral blood mononuclear cells from chronically HBV-infected patients and subjects with natural immunity after recovery from an acute infection. Proliferation and production of interferon-gamma, IL-10 and tumor necrosis factor-alpha were determined after stimulation with HBcAg, HBeAg or HBsAg in the absence or presence of IL-12 or neutralizing antibodies to IL-12, interferon-gamma, IL-4, IL-10 or tumor necrosis factor-alpha.

Epitope mapping and serodiagnosis using Ata- and (Lys)7 peptides.

The general applicability of the new peptide immobilization strategy in which the peptide of interest is N-terminally extended with an acetyl-thio-acetyl group or (poly)-Lys extension during synthesis, has been demonstrated in epitope-mapping experiments and serodiagnosis. Ala-scanning experiments and minimal epitope determination showed that the antigenicity of Ata-extended peptides derived from the human chorionic gonadotropin (hCG) and hepatitis B virus (HBV) amino acid sequence, was superior to the free parent peptides. Further, it could be shown that the choice of the epitope-mapping procedure (peptide in solution or immobilized on a solid support) may lead to a different perception of which residues constitute the epitope.

The effect of copper on the embryonic development and hatching of Sepia officinalis L.

The influence of copper on embryonic development and hatching of Sepia offinalis was investigated. Copper exerts a profound effect on both hatching stage and time-to-hatching. At high copper concentrations (50-200 ppb Cu2+), the embryos hatch earlier than the controls but have a lower survival potential.