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Biomedical subjects

M Kitagawa

Publications and source records attributed to M Kitagawa.

At least 559 records · Page 31Linked to original sources
PubMed1981

Changes of alpha-tocopherol levels in red blood cells and plasma with respect to hemolysis induced by dialuric acid in vitamin E-deficient rats.

The plasma and red blood cell (RBC) levels of alpha-tocopherol in rats were determined in association with hemolysis induced by dialuric acid for a 7-week period of tocopherol deprivation following a 2-week period on tocopherol-containing diet. The patterns of decreases in plasma and RBC levels during the 7-week period were similar, differing in one respect. The RBC levels were characterized by a prompt decrease to non-detectable levels in the 4th week, while at that time a plasma level of 100 microgram/dl, albeit low, was maintained during the subsequent two weeks. Consequently, tocopherol ratios of RBC to plasma lowered throughout the experimental course. As for the relationship between these levels and hemolysis values, non-hemolysis was recorded in animals whose minimum RBC and plasma levels were 40 microgram/dl packed cell and 180 microgram/dl, respectively. This experiment showed that the plasma tocopherol level which has traditionally been accepted as the only index of hemolysis values does not always reflect them, and that in animals with hemolysis, only RBC tocopherol levels were found to reflect hemolysis values.

Animals↗
PubMed1979

Regulatory functions of hapten-reactive helper and suppressor T lymphocytes. III. Amplification of a generation of tumor-specific killer T-lymphocyte activities by suppressor T-cell-depleted hapten-reactive T lymphocytes.

2,4.6-trinitrophenyl (TNP)-reactive T-cell activities were raised in mice by immunization with TNP-isologous mouse gamma globulin. After establishing that TNP-reactive T lymphocytes can serve as amplifier cells for induction of killer T lymphocytes in allogeneic system, we explored the possibility of this hapten-reactive T-cell system to amplify tumor-specific killer T-lymphocyte activity in the syngeneic system. We utlized relatively weak immunogenic syngeneic plasmacytoma X5563 in C3H/He mice. Analysis of the TNP-reactive T-cell activities revealed that such T lymphocytes express the biological functions of both major subtypes of regulatory T cells, namely suppressors and helpers, and that TNP-reactive suppressor and helper T lymphocytes, respectively, differ in their relative susceptibility to specific inactivation by TNP conjugates of the nonimmunogenic D-amino acid copolymer, D-glutamic acid, and D-lysine (D-GL). By taking advantage of the relative susceptibility-difference to TNP-D-GL, selective inactivation of TNP-reactive suppressor T cells was induced by appropriate treatment with TNP-D-GL, and the generation of TNP-reactive helper T-cell activity was amplified. The supplement of augmented TNP-reactive helper T-cell activity to the system at the immunization with syngeneic X5563 with TNP-haptenation, resulted in a striking augmentation of induction of tumor-specific killer T-lymphocyte activity, and a considerable number of hosts survived after the challenge with lethal dose of viable tumor cells. Thus, appropriate manipulations designed to induce potent hapten-reactive helper T-lymphocytes provided the potential for a very effective mode of immunoprophylaxis against tumor.

Animals↗