PubMed Health⌕ Search

Biomedical subjects

B Schechter

Publications and source records attributed to B Schechter.

At least 55 records · Page 3Linked to original sources
PubMed1976

The requirement for tetravalency of soybean agglutinin for induction of mitogenic stimulation of lymphocytes.

The mitogenic activity of soybean agglutinin was found to depend on the presence of lectin aggregates formed in lectin preparations stored in the lyophilized state. Such soybean agglutinin preparations gave maximal stimulation of untreated pig lymph node cells and neuraminidase-treated mouse spleen cells at relatively high concentrations, ranging from 100 to 2000 mug/ml. After separation into unaggregated (divalent) and polymeric (tetra-and multivalent) fractions, it was found that the unaggregated lectin did not stimulate the cells, while the tetravalent and multivalent fractions were active and gave maximal stimulation at a concentration of 10 mug/ml. These results suggest that soybean agglutinin must have at least four sugar binding sites in order to be able to stimulate lymphocytes.

Acetylgalactosamine↗
PubMed1976

Specific cytotoxicity in vitro of lymphocytes sensitized in culture against tumor cells.

The production of tumor-specific cell-mediated cytotoxicity following in vitro sensitization of C57BL spleen cells against a syngeneic 3LL Lewis lung carcinoma was studied. Lymphocytes were sensitized on monolayers of the tumor cells for 4-5 days. The cytotoxicity was assayed by measuring the reduction in 3H-leucine and 3H-thymidine incorporation by target cells after interaction with the sensitized lymphocytes. Spleen lymphocytes sensitized on monolayers of 3LL tumor cells caused a high extent of lysis; such cells tested on C57BL or C3H fibroblast targets evoked only a low level of cytotoxicity. C57BL spleen cells sensitized on C57BL fibroblasts caused a low level of cytotoxicity when tested on a 3LL target. Thus cytotoxicity appeared to be tumor specific. The reduced incorporation into protein and DNA of target tumor cells caused by the sensitized lymphocytes was a measure of cell injury, which was more sensitive than direct cell count or uptake of 51CR. Lymphocytes from syngeneic tumor-bearing mice, tested 13-25 days after tumor inoculation, did not manifest in vitro cytotoxicity. On the contrary, such lymphocytes sometimes appeared to have a promoting effect on the tumor cells.

Animals↗
PubMed1976

An in vitro assay of cell-mediated cytotoxicity. Terminal labeling with 3h-leucine.

A method is described for measuring cell-mediated cytotoxicity, based on the incorporation of labeled leucine into actively synthesized proteins in viable target cells which have survived interaction with effector lymphocytes. The method was studied with in vitro or in vivo sensitized lymphocytes in xenogeneic or allogeneic systems. This method was found to be applicable to quantitative determination of cell-mediated cytotoxicity by in vitro sensitized lymphocytes against a syngeneic tumor.

Animals↗
PubMed1976

Sensitization of T lymphocytes in vitro by syngeneic macrophages fed with tumor antigens.

We investigated the interaction between T lymphocytes and macrophages in the vitro sensitization of lymphocytes against tumor cells. Spleen cells were sensitized in vitro by syngeneic peritoneal macrophages that had been fed with cell-free antigen preparation of syngeneic tumor cells. The sensitized T lymphocytes acquired specific cytotoxic cells. The sensitized T lymphocytes acquired specific cytotoxic activity in vitro and the capacity to inhingeneic fibroblasts, or the antigen preparation by itself were not able to sensitize the lymphocytes against the tumor.

Animals↗