[Acid hydrolase activity of the blood in immunodepression].

Immunosuppressants reduce the activity of acid RNase and acid phosphatase in the blood serum of mice and patients with kidney allografts. In reversible graft rejection crises, the activity of both enzymes ascends in the period preceding the crisis or at its height. However, following intensive immunosuppressive therapy it drops again.

[Effect of the inhibitor-antioxidant belonging to the 3-hydroxypyridine series on immunocompetent and stem cells].

The effect of the synthetic inhibitor-antioxidant belonging to the 3-hydroxypyridine series (compound OP-6) on the functions of immunocompetent and stem cells of mice was studied. Use was made of the models of synthesis of antibodies to sheep red blood cells (local hemolysis and hemagglutination), of endogeneic and exogeneic colony-formation in (CBA X C57BL)F1 mice as well as skin homotransplantation to CBA mice from C57BL/6 donors. Compound OP-6 was shown to exert an immunodepressant effect on both the humoral and cell immunity, not to decrease the colony-forming capacity of the stem cells and to protect them from irradiation.

[Effect of purine derivatives on regeneration and the immunologic reactivity of animals].

The effect of azathioprine and of KI-7 (the new purine derivative) on the immunogenesis and regeneration in mammals was studied comparatively, KI-7 with a lesser toxicity than azathioprine proved to suppress the synthesis of antibodies to the SRBC in mice in case of administration of the preparation one day before or on the day of immunization; it also considerably prolonged the survival of skin allografts in rabbits in comparison with control. At the same time it was shown that under conditions of suppression of the immunogenesis system hepatic regeneration did occur in rats, but the correlation of the proliferation processes and cellular hypertrophy differed from that under ordinary restoration conditions, depending on the immunodepressor used. Thus, in difference from azathioprine, KI-7 not only inhibited the mitotic activity of the regenerating liver, but even stimulated it somewhat.

[Use of an immunothermistographic method for detecting humoral antibodies in the allotransplantation of skin and cornea in rabbits].

Humoral antibodies were investigated by the method of immunothermistography in 43 rabbits after allotransplantation of the skin and cornea. The method of immunothermistography is based on the changes in thermoconduction of the medium as a result of the antigen-antibody reaction. The antibodies were discovered in the blood serum 3 to 5 days after the skin transplantation.