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Biomedical subjects

H Bazin

Publications and source records attributed to H Bazin.

At least 271 records · Page 15Linked to original sources
PubMed1980

Fc receptors of rat peritoneal macrophages: immunoglobulin class specificity and sensitivity to drugs affecting the microfilament or microtubule system.

Macrophage-cytophilic antibody activity of various immunoglobulin classes and subclasses was tested in two different rosetting systems. Cytophilic antibody activity of IgM, IgG2a and IgG1 was verified in the SRBC system, while IgM, IgG2a and IgG2c were found to be active in the trypanosome system. Sensitivity to cytochalasin B treatment of SRBC rosette formation was dependent on the class of antibody and decreased in the following order: IgM > IgG1 > IgG2a. Trypanosome rosette formation was prevented by the same drug regardless the type of antibody. Vinblastin caused an enhancement of rosette formation in the SRBC system in low concentration, except when the antibody belonged to subclass IgG1. The enhancing effect was less pronounced in the trypanosome system.

Animals↗
PubMed1980

Homocytotropic antibody responses during murine schistosomiasis. A follow-up study of both total immunoglobulins and Schistosoma mansoni specific antibodies.

Mice infected with Schistosoma mansoni develop a high increase of homocytotropic antibodies, thought to be involved in protection. IgE and IgG1 rise differently during the course of infection. Total serum IgE levels rise between days 20 and 30 and the maximum is observed around day 50. IgG1 levels remain almost unchanged until day 50 after which they increase dramatically, reaching a peak at day 100. S. mansoni specific IgE antibodies measured by passive cutaneous anaphylaxis parallel to variations of total IgE. On the contrary, S. mansoni specific IgG1 antibodies, also measured by passive cutaneous anaphylaxis, do not parallel total IgG1; they reach a peak between days 30 and 40 and remain high until day 100.

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PubMed1979

Identification of secretory component as an IgA receptor on rat hepatocytes.

Secretory component (SC) was found to be synthesized by isolated rat hepatocytes. SC was detected by radioimmunoassay and cultured hepatocytes were found to synthesize 0.078 microgram SC/10(6) hepatocytes in a 48-h period. SC was also present on the surface of hepatocytes as detected by the specific binding of radiolabeled anti-SC antibodies as well as by the detection of specific membrane staining in indirect immunofluorescence tests using specifically purified anti-SC antibodies. Rat SC was detected on hepatocytes and intestinal epithelial cells but not on peripheral blood lymphocytes, unfractionated spleen cells, or erythrocytes. Specific binding of radiolabeled rat dimeric IgA to rat hepatocytes was also observed and evidence was obtained to indicate that such binding was mediated by SC. Thus, prior incubation of hepatocytes with anti-SC prevented binding of radiolabeled IgA. Moreover, prior incubation of radiolabeled IgA with rat SC prevented binding of the IgA to isolated hepatocytes. Cells treated with 0.25% trypsin lost their ability to bind to radiolabeled dimeric IgA.

Animals↗
PubMed1979

[Production of monoclonal anti-Schistosoma mansoni antibodies. Preliminary study of their biological activities].

Monoclonal antibodies against Schistosoma mansoni have been produced by fusion of splenic lymphocytes from S. mansoni infected Rats and P3-X63-Ag8 BALB/c cells. In vitro and in vivo studies of the biological activities of these antibodies have led to the identification of IgE antibodies with a high reaginic activity and antibodies which in a complement dependent or eosinophil dependent system were shown to have a marked cytotoxicity for schistosomula in vitro. This methodology seems to open new perspectives for the study of antibody function in immunity against parasites as well as for the isolation of the corresponding target antigens.

Animals↗
PubMed1979

Rat immunoglobulins.

Five immunoglobulin isotypes (or classes) have been identified in the human as well as in the rat species. The homologies between the human and the rat immunoglobulin classes have been well defined with the help of the monoclonal immunoglobulins produced by the LOU immunocytomas (plasmocytomas,myeloma tumours). The LOU rat immunocytomas model, the physicochemical and the biological properties of the rat immunoglobulins are described in this review.

Animals↗
PubMed1979

Biliary transport of IgA: role of secretory component.

Biliary transport of rat immunoglobulin was studied by perfusion of isolated rat liver with blood containing radiolabeled immunoglobulin. Transport to bile was selective for polymeric IgA. Between 15 and 27% of polymeric IgA was transported from blood to bile during a 210-min perfusion period, and approximately 60% of the IgA transported to bile bore secretory component. Small quantities of IgM (0.12%) were transported; transport of IgG2 alpha, IgE, or monomeric IgA was not detected. Purification of radiolabeled polymeric IgA by affinity chromatography on human secretory component-Sepharose yielded a fraction that was transported more efficiently (i.e., up to 40% transported). In contrast, secretory IgA (colostral or biliary) was transported 1/25th to 1/12th as well as polymeric IgA myeloma protein. Complexes of 125I-labeled secretory component and polymeric IgA formed in vitro were transported poorly (0.1%) compared to polymeric IgA (26%). It was concluded that biliary transport of polymeric IgA requires combination of it with secretory component in the liver. In support of this hypothesis, rabbit IgG anti-rat secretory component antibodies were also transported to bile but normal rabbit IgG was not.

Animals↗
PubMed1979

Relation between total serum IgE levels and IgE antibody production in rats.

Five different rat strains were immunized with 100 microgram ovalbumin and 1 mg Al (OH)3. A good correlation was found between the total serum IgE level of a rat strain before immunization and the IgE antibody production. Good IgE antibody-producing strains had high total serum IgE levels and vice versa. A discordance between the evolution of the total serum IgE level after immunization and the changes in IgE antibody level was found in all strains.

Animals↗
PubMed1979

The influence of antigen dose on IgE production in different rat strains.

Strain differences in total serum IgE levels and IgE antibody responses to various amounts of antigen were studied in rats. Five inbred strains (BN, Wistar R/A, DA, LEW, PVG), (Wistar R/A x BN)F1 and (LEW x BN) F1 hybrids were immunized twice at an interval of 28 days by intraperitoneal injection of 10 ng, 100 ng, 1 microgram, 10 microgram, 100 microgram or 1 mg ovalbumin and 1 mg A1(OH)3 in a volume of 0.5 ml. Total serum IgE and IgE antibody levels were followed. Both parameters were measured with a solid phase radioimmunoassay. A significant difference was observed in total IgE levels between the different strains. The IgE antibody response depended both on the strain and on the amount of antigen used for immunization. There was an optimal antigen dose for IgE antibody formation, differing from strain to strain. F1 hybrids had total IgE levels and IgE responses intermediary between those of the two parent strains. A good correlation existed between the total serum IgE level before immunization and the magnitude of the optimum IgE antibody responses in the different strains. These results suggest that there may be a genetic influence on both parameters, the total IgE level and the specific IgE antibody response. The IgE antibody response is also dependent on the dose of antigen.

Animals↗
PubMed1979

Ontogeny of the cells synthesizing IgE reaginic antibodies.

IgE and IgD antibodies to ovalbumin were analyzed in animals immunized by three different techniques. The results showed that IgE and IgD immune responses could be induced more or less independently by different immunization schedules. Moreover, the triggering of the IgD membrane receptors of the IgE-B lymphoid cells which seems necessary to obtain a primary reaginic immune response, does not necessarily seem to induce an IgD immune response at the same time. We conclude IgE and IgD circulating antibodies are synthesized by two different B lymphoid cell lines.

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