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Biomedical subjects

M Ziff

Publications and source records attributed to M Ziff.

At least 163 records · Page 9Linked to original sources

Studies on the anti-inflammatory action of 6-mercaptopurine.

The mechanism of action of 6-mercaptopurine (6-MP) on an egg albumin-induced inflammatory lesion in the skin has been studied in rabbits treated with 6-MP in a daily dosage of 18 mg/kg. Relative to control animals, significant decreases in the numbers of large lymphocytes and monocytes in the blood were observed in the 6-MP-treated animals by the 9th day of treatment, without significant decrease in the numbers of polymorphonuclear leukocytes and small and medium lymphocytes. Concurrently, a significant decrease was also seen in the percentage of tissue mononuclear cells in the inflammatory skin lesion. There was a highly significant correlation between the numbers of monocytes in the blood and the per cent of mononuclear cells in the lesion. A mean of 52% of the mononuclear cells in the tissue lesion phagocytosed carbon offering further evidence that the major cell involved was the blood monocyte. In vitro incorporation of (3)H-Tdr by blood mononuclear cells was significantly reduced in the 6-MP-treated animals as determined by scintillation counting and radioautography. The large lymphocyte was the predominant cell type which was labeled in vitro. Small lymphocytes and monocytes were rarely labeled. The data obtained suggest that the anti-inflammatory effect of 6-MP, reflected in these experiments by a decrease in mononuclear cells in a tissue lesion, results from suppression of a bone marrow response to local inflammation, affecting principally proliferating precursors of blood monocytes and large lymphocytes. The possible importance of this action of 6-MP in the treatment of inflammatory and immunologically mediated disease is discussed.

Animals↗

Suppression of adjuvant disease in the rat by heterologous antilymphocyte globulin.

The effect of antilymphocyte globulin (ALG) on adjuvant arthritis, an immunologically induced disease in the rat, was studied. ALG was prepared from the serum of rabbits immunized against rat lymphocytes. Adjuvant arthritis was induced in rats by a single intracutaneous injection of Freund's complete adjuvant; after 9 to 12 days, all control rats developed polyarthritis. Administration of antilymphocyte globulin about the time of adjuvant injection produced marked inhibition of clinical disease. Some suppression was apparent even when ALG was started after the onset of arthritis. Rats receiving ALG remained conspicuously healthy compared to controls. Urinary findings and renal histology showed no evidence of nephritis. The results of serum corticosterone determinations made it unlikely that adrenal stimulation contributed to the actions of ALG. Antilymphocyte preparations lowered peripheral lymphocyte counts and suppressed primary antibody responses to sheep erythrocytes, but had little effect on the skin reaction to PPD, even in rats protected from arthritis. All rats given ALG developed antibodies to rabbit globulin; there was no evidence that ALG inhibited the appearance of antibodies to itself, and prior hyperimmunization of rats with rabbit globulin did not interfere with the biological activity of ALG subsequently injected. Antisera produced separately against lymph node and thymus cells had identical properties with regard to agglutination of lymphocytes and thymus cells. Administered to rats, these preparations were equally potent in lowering lymphocyte counts and suppressing both adjuvant arthritis and the primary antibody response to sheep erythrocytes. It is concluded that ALG, as used in these experiments, is a potent immunosuppressive agent without obvious toxic effects.

Agglutination Tests↗

In vitro synthesis of immunoglobulin by rheumatoid synovial membrane.

A technique for the in vitro culture of rheumatoid synovial tissue with (14)C-amino acids and isolation and quantitation of the newly synthesized immunoglobulins has been developed. This technique has been used to compare immunoglobulin synthesis of 12 rheumatoid synovia with that of synovia from nonarthritic patients and with that of normal human lymph nodes and spleen. In addition, the spleen of a patient with Felty's syndrome has also been examined. Immunoglobulin synthesis in rheumatoid synovia has been shown to be quantitatively and qualitatively similar to that of normal human spleen and lymph nodes although somewhat less active than the Felty's syndrome spleen examined. 79% of the immunoglobulin produced in rheumatoid synovia was of the IgG type, whereas IgM comprised 10% and IgA, 11% of the total. Less than 10% of the IgM synthesized was found to be rheumatoid factor. A fraction containing approximately 90% of its radioactivity in the form of IgG has been obtained for further studies.

Amino Acids↗