[Structure and properties of lipoteichoic acid of group A Streptococcus type M 29].

Lipoteichoic acid (LTA) of group A streptococci, type M 29 was studied. Chemical and 13C NMR spectroscopic analysis showed that the polymer contained poly(glycerophosphate) chain consisting of 12-14 glycerophosphate elements united by the 1----3 type phosphodiether bond and diglucosylglyceride. Oleic, stearic, palmitic and palmitoleic fatty acids predominated in the polymer composition.

[Mechanism of the nonspecific protective action of Shigella antigens].

The mechanism promoting the nonspecific action of antigens obtained from S. flexneri and S. sonnei by a sparing method has been studied.

[Reaction between syngeneic hematopoietic stem cells and lymphocytes in leukemic AKR mice].

The syngeneic donor-recipient model was used to examine the influence of T lymphocytes from AKR mice with spontaneous leukemia on colony-formation and differentiation of hemopoietic stem cells. It was shown that in the stage of the neoplastic process development, the cells of lymph nodes and the thymus inhibited the colony-forming capacity in all the three hemopoietic lines (erythroid, myeloid, megakaryocytic) of the syngeneic normal and autologous bone marrow. In the late stages of leukemia aggravated by generalized infection, T lymphocytes stimulated the exo- and endogenous growth of the granuloid colonies, changing the erythroid-myeloid index to 1:1-1:2.

[Suppression of bone marrow colony-forming capacity by syngeneic T-lymphocytes in AKR strain mice with lymphoblastic leukemia].

The effect of lymphocytes from the lymph nodes and thymus on bone marrow colony-forming capacity was studied in AKR mice in the preleukemic and leukemic periods in vivo in the syngeneic donor-recipient system. In the pre-leukemic period, the lymphocytes do not change in the syngeneic stem cell colony-forming index, while in spontaneous lymphoblastic leukemia they suppress bone marrow proliferative activity both in normal and leukemic mice and 62-100%.