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Biomedical subjects

P Perlmann

Publications and source records attributed to P Perlmann.

At least 325 records · Page 18Linked to original sources
PubMed1968

Immunological studies in ulcerative colitis. IV. Origin of autoantibodies.

The incidence and height of antibody titers to colon, assayed by indirect hemagglutination with a heat stable colon extract from germ free rats, is significantly higher in sera from patients with ulcerative colitis than in those from healthy controls or from patients with amebic liver abscess or dysentery. While sera from ulcerative colitis patients and controls are indistinguishable in regard to incidence and height of antibody titers to Forsman antigen, Staphylococcus aureus S 209, Clostridium difficile, and several common strains of E. coli, they have elevated titers and increased incidence of antibodies to a heat stable antigen of E. coli O14. Patients with amebic dysentery have normal titers of such antibodies. Absorption of patients' sera with E. coli O14 antigen inhibits the colon directed hemagglutination reaction in approximately 30% of the cases tested. Likewise, the anti-E. coli O14 reaction can sometimes be inhibited with the colon extract. Other E. coli strains and other bacteria are inactive or have only weak inhibitory activity. Hemagglutination inhibition experiments show that germ free rat colon and E. coli O14 contain common structures, depicted by antibodies in the patients' sera. This pattern of reactivity closely resembles that seen in rats made autoimmune to colon by injection of newborn rabbit colon. E. coli O14 is known to carry a heterogenetic antigen present in lower concentration (or activity) in most Enterobacteriaceae. Hemagglutination inhibition experiments with rabbit antisera to E. coli O14 suggest that the antigen common for E. coli O14 and colon is related to this heterogenetic antigen. The findings imply that this antigen, which is constantly present in low concentrations in the human colon, may give rise to anticolon antibody formation in ulcerative colitis through breakage of tolerance. Since this antigen is present in healthy individuals as well, additional factors are required to explain the induction of anti-colon autoimmunity in ulcerative colitis.

Animals↗
PubMed1968

Cytotoxic action of stimulated lymphocytes on allogenic and autologous erythrocytes.

Fowl erythrocytes are lysed when exposed to an excess of fowl blood lymphocytes in the presence of phytohemagglutinin. No significant cell damage is seen in the absence of phytohemagglutinin, or when the lymphocytes are replaced by malignant lymphoid cells, thymus cells, or nonlymphoid cells. The lymphocytes remain viable during the reaction. Differences in histocompatibility between lymphocytes and erythrocytes are not required. Autologous lymphocytes are cytotoxic to the same extent as allogenic lymphocytes over a wide range of experimental conditions.

Allergy and Immunology↗
PubMed1967

Cytotoxic potential of stimulated human lymphocytes.

Viable and immunologically competent lymphocytes from unsensitized donors damage allogeneic tissue culture cells in the presence of phytohemagglutinin (PHA). This cytotoxicity is specific since syngeneic tissue culture cells are not at all or only slightly damaged under similar experimental conditions. In this investigation, the relation between the stimulation of human lymphocytes and their cytotoxicity was studied. Chang cells (human liver) served as target cells in all experiments. Cell damage was quantitated by measuring the release of isotope from target cells labeled with chromate-(51)Cr. The cytotoxicity of the lymphocytes was dependent on the concentration of PHA in the incubation medium. Cell damage was maximal at concentrations of 4-8 microl PHA/ml. Higher concentrations were inhibitory although aggregation was increased and no injury of the lymphocytes was noted. Stimulation of DNA and RNA synthesis in PHA-treated lymphocytes each followed dose response curves which were similar to that of cytotoxicity. In order to establish whether stimulation without mixed aggregation of lymphocytes and target cells would suffice for cytotoxicity, a series of nonagglutinating stimulants were investigated. Lymphocytes pretreated with a crude filtrate of Staphylococcus aureus for periods of 0.5-72 hr damaged Chang cells even in the absence of PHA. Lymphocytes from a tuberculin-positive donor were strongly cytotoxic after prestimulation with PPD while those from a negative donor were inactive. Moreover, strong cytotoxic effects were also obtained with lymphocytes which had been stimulated by preincubation with allogeneic lymphocytes in mixed culture. When two stimulants were applied at the same time, additive cytotoxic effects were seen. Addition of PHA to the lymphocyte/Chang cell mixtures potentiated the cytotoxicity of prestimulated lymphocytes. The cytotoxic potential of the lymphocytes was in all cases correlated to the degree of stimulation recorded as transformation into blast cells, and was independent both of the degree of aggregation and of the stimulating factor. These findings are compatible with the assumption that injury of the Chang cells reflected an immunologically nonspecific activity of lymphocytes enhanced by stimulation. The possible importance of this activity for a number of tissue-damaging immune reactions in vivo is pointed out.

Culture Techniques↗