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Biomedical subjects

E J Collins

Publications and source records attributed to E J Collins.

46 records · Page 3Linked to original sources

Cell-mediated immunity to hepatitis B virus antigens in mice: correlation of in vivo and in vitro assays.

Cell mediated immunity (CMI) to hepatitis B viral antigens was studied in BALB/mice after immunization with purified hepatitis B surface antigen (HBsAg), or core antigen (HBcAg), with adjuvants. The two in vitro assays for cell-mediated immunity (CMI), utilizing lymph node cells, were release of interferon after exposure to antigen, and blast transformation of lymphocytes, and the in vivo assay was ear swelling at 24 h after local injection of antigen. Immunization with HBsAg or HBcAg with adjuvants induced antigen-specific cutaneous reactivity; if no adjuvants were given, immunization with HBcAg, but not HBsAg, induced cutaneous reactivity. CMI could be adoptively transferred by lymph node cells, but for only a limited period after immunization with HbsAg or HBcAg. The ability of lymph node cells from mice immunized with HBV antigens to transfer adoptively CMI correlated well with their production of interferon after challenge with antigen in vitro, but less well with blastogenesis after challenge with antigen in vitro, or with cutaneous reactivity to antigen in the donor mouse. Reliable antigen-specific lymphokine release assays, rather than blast transformation of lymphocytes or cutaneous reactivity after antigen challenge, are required to assess CMI to HBV antigens in the mouse and, by inference, in man.

Adjuvants, Immunologic↗

Assessment of delayed-type hypersensitivity in man: a comparison of the "Multitest" and conventional intradermal injection of six antigens.

Recall of delayed type hypersensitivity (DTH) as a test for cell-mediated immune competence was assessed in 254 subjects using the Multitest device which delivers seven skin-test antigens intradermally; 77 subjects were tested concurrently by Multitest and a conventional panel of six antigens. Similar results were obtained with Multitest and the conventional panel (R = 0.65). Reproducibility of Multitest between three observers, who independently assessed the aggregate size of reactions (the reaction score) in 45 subjects, was high (R = 0.89). Twenty-four subjects were tested twice 3 months apart; the correlation for the reaction score was high (R = 0.88), demonstrating the suitability of Multitest for serial studies of immune function. Anergy was infrequent (1%) among 110 healthy male controls but was more frequent (8%) among a group of 101 healthy male homosexuals (P less than 0.05). The response rate to particular test antigens differed for the three Australian groups tested and a previously studied French group. Hence there is a need to establish normal profiles of DTH responsiveness for different geographic areas, as well as among subjects of known age and sex, when assessing cell-mediated immunity by the level of DTH responsiveness to multiple skin test antigens.

Adolescent↗

Giant-cell centrioles.

The giant cell of osteoclastic origin and the giant cell produced in response to foreign bodies are characterized by multiple nuclei. Electron microscopy of these multinucleated cells reveals a special centrosphere in the osteoclast, which is not typical of other types of giant cells.

Animals↗