• Journal of Life Science
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• v.8 no.5
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• pp.486-491
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• 1998

Previously, we have cloned and characterized two ADP-ribosyltransferases (Yac-1 and Yac-2) from mouse Iym-phocyte. Yac-2 transferase contains significant NAD glycohydrolase activity as well as ADP-ribosyltransferase acti-vity. Yac-2 has an arginine at position 221 between two conserved glutamic acids. To investigate the significance of Arg-221 on enzyme activities, Arg-221 was mutagenized to Glu (R221E) and to Ala (R221A). Mutants R221E and R221A were active as wild type for ADP-ribosyltransferase and NAD glycohydrolase activity, suggesting that the arginine 221 in Yac-2 does not play a major role in enzyme activities.

• YAKHAK HOEJI
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• v.46 no.1
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• pp.69-74
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• 2002

The effects of genistein on murine thymocytes for inducing apoptotic cell death and phagocytic activity of peritoneal macrophage were studied in vitro. Addition of genistein (10 and 50$\mu$M) to cultured thymocytes from BALB/c mice definitely promoted DNA fragmentation. Also, cytofluorometric analysis of these cells demonstrated a reduction in mitochondrial transmembrane potential ($\Delta$Ψm). But, repeated administration of genistein (1 mg/mouse/day) to mice for 7 days did not cause any detectable DNA fragmentation. Genistein decreased lucigenin chemiluminescence and engulfment of fluorescein-conjugated E. coli particles in peritoneal macrophage. These results suggest that genistein induce an apoptosis of thymocyte via reduction in $\Delta$Ψm and decrease phagocytic activity of peritoneal macrophage in vitro.

• Biomedical Science Letters
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• v.2 no.1
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• pp.13-20
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• 1996

A Recent discovery of surface antigens in cells has led to the success of quantitative measurement of T-cell subpopulations, and this has especially opened the way for an epoch-making development in the understanding and classification of cellular immune mechanisms. It is known that phenotypes of T-cell subpopulations exist in many forms according to the variation of species or animal experimental models. In Korea, Clonorchis sinensis still gives rise to public concern as it infects more than eighty million people and threatens the public by causing cirrhosis of the liver, or liver cancer when liver infection becomes prolonged and chronic. Up until now there has been much progress in research and improvement in the classification system of Clonorchis sinensis in the area of humoral immunity, but as for research in the area of cellular immune mechanisms, there is almost none. Knowing all these circumstances, the authors delved for the characterization of Iymphocyte subpopulations with mice as Clonorchis sinensis in the area of cellular immunity, and obtained the following results. That is, we injected Clonorchis sinensis antigens mixed in Freund's ajuvant solution intraperitoneally in mice and measured the T-cell subpopulation characterization of spleen lymphocytes with flow cytometry. The results of these measurements showed that CD2, CD5 and CD8 decreased early following injections but then in-creased again seven weeks after the injections. CD4, however, showed a slight increase shortly after the injection but then a fair increase seven weeks after the injection.