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Biomedical subjects

E Pick

Publications and source records attributed to E Pick.

At least 91 records · Page 5Linked to original sources
PubMed1977

A simple method for the production of migration inhibitory factor by concanavalin A - stimulated lymphocytes.

A simple method for preparing culture supernatants containing macrophage migration inhibitory factor (MIF) by pulse exposure to guinea pig lymphocytes to concanavalin A (ConA), is described. The method is based on the property of originally nonadherent lymphocytes to attach to the flask surface in the presence of Con A. The Con A-induced lymphocyte 'monolayer' can be easily rinsed, allowing the removal of free Con A without repeated, cell damaging centrifugation. The Con A-pulsed lymphocytes are cultured for 24 h in medium and supernatants containing MIF but free of undesired Con A are regularly obtained.

Animals↗
PubMed1975

Participation of immunoglobulin-bearing lymphocytes in the production of macrophage migration inhibitory factor.

The role of immunoglobulin-bearing cells in the production of macrophage migration inhibitory factor (MIF) by tuberculin-stimulated lymphocytes of guinea pigs, immunized with complete Freund's adjuvant, was studied. It was found that: (1) pretreatment of lymphocytes with rabbit anti-guinea pig IgG (anti-IgG) does not block antigen-induced MIF production. (2) Passage of lymphocytes through double layer IgG-anti-IgG gelatin bead columns (the preparation of which is described) abolishes MIF formation by the eluted cells. Cells retained on the columns can be recovered and where shown to produce MIF, when stimulated by antigen. (3) Pulsing of lymphocytes with anti-IgG, for 2 h at 37degreesC, results in MIF synthesis by the cells cultured in medium, in the absence of specific antigen. These findings indicate that cells bearing Ig or Ig fragments are either able to secrete MIF themselves, upon stimulation with antigen or anti-IgG, or are required for MIF production by a different cell type.

Animals↗
PubMed1975

Studies on the inhibition of macrophage migration induced by soluble antigen-antibody complexes.

Mixtures of serum of Freund's complete adjuvant (FCA) immunized guinea-pigs and tuberculin PPD consistently inhibited the in vitro migration of peritoneal exudate cells (PEC) of normal guinea-pigs. It is shown that this inhibitory effect is due to a soluble complex between an IgG2 antibody and PPD. By separation of PPD on Sephadex G-200 two peaks were obtained, corresponding respectively to molecular weights of at least 800,000 and 25,000, separated by a plateau. Material derived from both peaks and from the plateau was able to form inhibitory complexes with anti-PPD IgG2. When a mixture of small molecular weight PPD and anti-PPD IgG2 was fractionated on Sephadex G-200, the inhibitory activity was recovered in the void region only. The detection of both IgG2 and PPD in the latter was taken as evidence for the presence of a high molecular weight antigen-antibody complex. When the mechanism of complex-induced inhibition of migration was examined it was found that: (1) complexes act directly on macrophages present in the peritoneal exudate; (2) removal of the Fc fragment of IgG2 by pepsin abolishes its ability to form migration inhibitory complexes; (3) passive sensitization of macrophages with anti-PPD IgG2, followed by exposure to PPD does not result in inhibition of migration; (4) in order to obtain migration inhibition, the complexes must be present during the entire migration period. A 2-hr pulse with complexes does not induce permanent inhibition; (5) the migration inhibitory activity of antigen--antibody complexes can be abolished by certain concentrations of puromycin and aminophylline.

Aminophylline↗