Biomedical subjects

R P Eady

Publications and source records attributed to R P Eady.

4 recordsLinked to original sources

PubMed1978

Anaphylactic bronchoconstriction in rats immunized with antigen-coated latex particles.

Studies have been carried out on the immunization of rats with antigen-coated latex particles. These studies confirmed that a significant lung blood eosinophilia is induced by a repeat intravenous injection of antigen-coated latex particles. Rats treated with antigen-coated latex particles also become sensitive to antigen such that on antigen challenge the animals show bronchoconstriction. Studies show that the bronchoconstriction is specific for antigen, but is unlikely to be mediated by tissue-fixing antibodies. Experiments comparing different immunization schedules involving latex particles indicate a strong association between the level of eosinophilia and degree of antigen-induced bronchoconstriction. These studies suggest that eosinophils may contribute to the anaphylactic bronchoconstriction.

Anaphylaxis↗

PubMed1976

Anti-idiotype sera raised against surface immunoglobulin of human neoplastic lymphocytes.

The idiotypic determinants of surface immunoglobulins on B-cell lymphomas and lymphocytic leukemias represent tumor-specific antigens, individually unique for each tumor. As such they have both diagnostic and therapeutic potential, particularly for those neoplasms with no serum monoclonal immunoglobulin arising from synthesis of the protein for export. We describe the raising in animals of anti-idiotype sera directed against two examples of a nonexporting neoplasm, human chronic lymphocytic leukemia. The procedure involves exposing the cells to papain so as to remove the Fab fragments (containing the idiotypic determinants) from the surface immunoglobulin, recovering the Fab on cellulose immunosorbent particles, and immunizing animals with the immunosorbent-Fab complex.

Aged↗

PubMed1975

The specificity of a solid phase radioimmunoassay for human immunoglobulins.

The specificity of a solid phase radioimmunoassay for immunoglobulin antigens, human Fab-mu in the case illustrated, has been assessed. The anti-Fab-mu serum available reacted well on gel diffusion with all Fab-mu- and light chain-containing proteins. In contrast the radioimmunoassay, in which unlabelled test antigen competes with radiolabelled Fab-mu for anti-Fab-mu coupled to Sephadex beads, was sensitive only to proteins containing entire Fab-mu regions. A double antibody radioimmunoassay showed comparable or greater sensitivity for Fab-mu-containing proteins, but was much less specific. By using Fab-gamma as the labeled antigen, with only light chain determinants reacting with the anti-Fab-mu, the solid phase assay was rendered polyspecific in being sensitive to all proteins containing light chain. Reasons for the specificity of the solid phase assay are discussed: steric factors can be expected in some cases to permit strong binding of antigen by multiple bonds, in others to restrict the number of molecular determinants simultaneously available to antibody.

Ammonium Sulfate↗

PubMed1975

Surface immunoglobulin of guinea-pig leukaemic lymphocytes.

The surface immunoglobulin of the transplantable L2C leukaemia of strain 2 guinea-pigs has been investigated. The immunoglobulin is seen to be synthesized when the cells are maintained in culture, indicating its intrinsic origin. Immunolabelling of the cell surface and immunochemical study of the Fab released by limited surface proteolysis indicate the presence of immunoglobulin of class IgM. IgG and free light chains were not detected, and there is unlikely to be an appreciable amount of immunoglobulin of any other class. The amount of immunoglobulin present, in terms of 4-chain monomers, is approximately 100,000 molecules per cell. Its half-life, calculated from the rate of reappearance in vitro of surface Fab after proteolytic clearing, is approximately 5 hours. Immunoglobulin secreted into the environment appears to arise predominantly or entirely from the cell surface: there is no evidence of an appreciable export of immunoglobulin which does not have a surface phase. Papain at 0.06 mg/ml rapidly removes the surface Fab. Residual Fcmu can then be detected by immunofluorescence, suggesting that papain cleaves surface IgM at a hinge region with the molecule in situ on the membrane. The released Fab is only moderately susceptible to degradation by papain at the enzyme: substrate ratio prevailing. It has been possible to isolate it from the papain digest by immuno-adsorption, with a notional yield of 75 mug per 10-10 cells, and then to prepare antisera against it.

Animals↗