[Time of tooth eruption in children born preterm in the arid climatic zone]. / Sroki prorezyvaniia zubov u detei, rodivshikhsia nedonoshennymi v usloviiakh aridnoi zony.

Dental examinations were carried out in 2768 preschool children in the city of Tashkent. 407 (14.7%) of these children were born preterm. The time of tooth eruption was evaluated from analysis of 295 case histories and 112 infants were observed from the age of 3 months till 2 years. The terms of decidual teeth eruption in preterm children are different in comparison with children born after full-term gestation and depend on the baby's maturity by birth. Diseases of the first months of life have a negative impact on the time of tooth eruption.

[Inhibition of the growth of a syngeneic weakly immunogenic tumor in mice resulting from exposures affecting T lymphocyte activity]. / Tormozhenie rosta singennoi slaboimmunogennoi opukholi u myshei v rezul'tate vozdeistvii, vliiaiushchikh na aktivnost' T-limfotsitov.

Adult BALB/c mice were thymectomized, lethally irradiated and reconstituted with cells of syngeneic embryonic liver (B-mice). The growth of the syngeneic low-immunogenic tumor of spontaneous origin (Acatol) was strongly inhibited in B-mice as compared to that in intact recipients. The transplantation of the tumor to adult-thymectomized hosts 3 months after operation also resulted in marked retardation of tumor growth as compared to intact or sham-operated animals. The same effect was observed in mice preimmunized with spleen cells from tumor-bearers but not from intact donors. It is inferred that BALB/c mice possess strong non-specific factors of tumor resistance. However, they are actively suppressed by the mature immune system. Apparently, tumor cells, regardless of low immunogeneity are antigenic enough for the syngeneic host and induce a series of immune reactions, bringing about activation of T suppressors. It is assumed that attempts at immunizing a tumor host with autochthonous T suppressors might lead to a promising approach to cancer immunotherapy.

[Effect of the joint use of BCG and antithymocyte serum on the growth of a syngeneic tumor in mice]. / Effekt sovmestnogo primeneniia BTsZh i antitimotsitarnoi syvorotki na rost singennoi opukholi u myshei.

The growth of the syngeneic tumor Acatol in BALB/c mice was retarded if the animals were pretreated with BCG or antilymphocyte serum (ATS). Combined use of BCG and ATS led to a significantly more powerful retardation as compared to the effect produced by each factor alone. Using the adoptive transfer of splenocytes from treated mice it was shown that tumor growth suppression is effected by the cell types other than T lymphocytes and macrophages. It is probable that the effector cells within the given system are K cells and natural killer cells. The results attest to a possibility of search for a two-directional action on the immune system of the tumor host, which would stimulate antitumor effector cells and inhibit the activity of suppressors, particularly that of T suppressors.

[Effect of preliminary administration of cyclophosphamide and pretransplantation irradiation on the growth of syngeneic tumors in mice]. / Vliianie predvaritel'nogo vvedeniia tsiklofosfamida i pretransplantatsionnogo oblucheniia na rost singennoi opukholi u myshei.

The growth of the syngeneic tumor Acatol was retarded and the minimal number of tumor cells necessary for inoculation was increased in BALB/c mice preinjected with cyclophosphamide (100 mg/kg) and/or totally irradiated (5 Gy). Administration of spleen cells from intact mice abolished the antitumor effect of the above factors. The natural killer activity of spleen cells was estimated within 2-9 days after tumor inoculation. The natural killer activity in intact recipients was elevated on the 2nd day and then decreased to the control level. In irradiated recipients, the natural killer activity remained high throughout the entire observation period.

[Use of heterologous antireceptor antibodies for specific reversal of acute homologous disease in mice]. / Ispol'zovanie geterologichnykh antiretseptornykh antitel dlia spetsificheskoi otmeny ostroi gomologichnoi bolezni u myshei.

Antireceptor antibodies anti- (CBA-anti-C57BL/6) and anti-(C57BL/6-anti-BALB/c) were obtained in a heterologous system by immunization of rabbits with alloimmune mouse lymphocytes and intensive absorption of immune rabbit sera. In the complement-dependent cytotoxic assay, these antireceptor antibodies were able to lyse only T-lymphoblasts with corresponding idiotypic specificity but not T-lymphoblasts of other idiotypes and normal T- and B- lymphocytes of various strains. It was also shown that antireceptor antibodies specifically inhibit the lethal graft-versus-host disease after injection of allogenic parental spleen cells into irradiated F1-recipients. These results suggest that heterologous antireceptor antibodies are capable of inhibiting specifically the immune responses to allogenic transplantation antigens.