[Morphofunctional status of the thymus in guinea pigs exposed to thymus and bone marrow preparations]

Study of the effect of the polypeptide thymic factor (thymalin) and the polypeptide bone marrow factor (hemalin) on the morphofunctional status of the thymus in guinea-pigs has shown that injection of thymalin into animals increases the count of small lymphocytes whereas injection of hemalin the count of medium-sized lymphocytes and lymphoblasts. Injection of thymalin magnifies the size of the nuclei of the reticuloendothelial cells.

[Effect of thymalin on the function of the blood kallikrein-kinin system in thymectomized rats]

The effects of thymus ablation and injection of thymalin on the blood plasma kallikrein-kinin system were studied. Thymus ablation was followed by activation of kinin formation, evidenced by an elevation of the total kallikrein activity and drop of the kininogen level. Injection of thymalin into thymectomized animals makes the characteristics under study return to normal.

[Isolation and evaluation of the specificity of an antiserum to the thymic polypeptide factor]

The specificity of antisera, obtained by the immunization of rabbits with the conjugated antigenic preparations of the thymic factor, have been evaluated by the method of immunochemical analysis. To carry out the comparative study, polypeptides isolated from the pineal body, cortex and white matter of the brain, Thy-1 antigen from the cerebral cortex and insulin have been used. The polypeptides of the thymus and the brain have been found to differ in their amino acid composition and molecular weight. The thymic factor possesses specific antigenic determinants which are absent in the tested preparations of cerebral polypeptides and insulin. The rabbit antisera obtained in this investigation are highly specific and can be used for the immunochemical determination of the thymic factor in the blood and other biological fluids.

[Role of polypeptide factors of the hypothalamus and epiphysis in regulating the function of stem cell precursors of granulomonopoiesis]

The claster- and colony-formation capacity of the offls--precursors of granulomonopoiesis in 29 normal subjects was studied in a bilayer agar system. Parallel cultures were used to investigate the effects of polypeptide factors of the hypothalamus and epiphysis. It was found that polypeptide factors of the hypothalamus and epiphysis have a regulatory influence on granulomonopoiesis at the level of precursor cells.

[Use of thymalin in the complex treatment of frostbite]

The use of thymalin in the complex therapy of 19 patients with frostbites was shown by the authors to promote the stimulation of cell immunity, decrease the intensity of intravascular blood coagulation, to increase fibrinolysis, to improve the development of reparative processes in the wound and outcomes of autoplasty. It also decreased the percentage of infectious complications.

[Effect of thymalin on the thymus and immunologic indices of irradiated animals]

The intramuscular injection of thymaline (1 mg/kg/day during 5 days) enhanced the regenerative processes in the thymus and favored the normalization of some immunological indices of irradiated guinea pigs.

[Participation of the cyclase system in the molecular mechanisms of differentiation control of immunocompetent cells]

The effects of polypeptide thymic and bone marrow factors on the cyclase system of rat thymus and spleen lymphocytes were studied. It was shown that the induction of maturation of rat T-lymphocyte precursors into immunocompetent T-cells under effects of the thymic factor is accompanied by the activation of the adenylate cyclase system and the elevation of the cAMP/cGMP ratio. The observed increase in the cGMP level in splenic lymphocytes suggests the presence of cAMP- and cGMP-dependent steps of in the reaction of T-lymphocyte maturation. The bone marrow factor causes an elevation of the cAMP level only in splenic lymphocytes, which points to differences in the lymphocyte subpopulations that are sensitive to thymus and bone marrow factors. Impairments in T-lymphocyte maturation in patients with immunodeficiencies are concomitant with shifts in the isoenzyme spectrum of lactate dehydrogenase in peripheral blood lymphocytes as well as with changes in the sensitivity of the cAMP system to the thymic factor and isoproterenol. These disturbances are relieved by administration of the thymic factor. The roles of the cyclase system and polypeptide thymic and bone marrow factors in the molecular mechanisms of immunocompetent cell maturation are discussed.

[Effect of vascular wall polypeptides on the hemostatic system]

It has been demonstrated in experiments on rats that polypeptide factor isolated from the vascular wall of the cattle (vasonin) increases the time of blood coagulation and the platelet count, prolongs the time of the occurrence of aggregation, and raises deaggregation activity of the vascular wall.