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Biomedical subjects

S E Li

Publications and source records attributed to S E Li.

At least 19 recordsLinked to original sources
PubMed1991

Studies on DNA sequence specific binding proteins for 5' flanking upstream region of CPSI gene.

Two specific carbamyl phosphate synthetase I gene binding nuclear proteins (M. W. 109 kD and 74 kD) have been determined in the rat liver by the protein blotting technique (Southwestern blot assay). The result shows that they are not present in the normal rat spleen and F-26 rat hepatoma cell. The Bal31 nuclease deletion in the CPSI gene 5' upstream region proves that the binding sites for 109 kD and 74 kD are respectively located in the regions of -38 bp to -4 bp and -113 bp to -38 bp. The binding proteins may be the liver-specific ones of the CPSI gene, which are related to hepatocyte differentiation and hepatocarcinogenesis.

Animals↗
PubMed1988

[Proliferative activity of the hepatocytes at different times of day during prolonged hypokinesia].

The white male Wistar rats were exposed to hypokinesia during 10 days. Essential oppression of the mitotic division of hepatocytes in the rats' liver at the hypokinesia was revealed. The cellular division was exposed to the daily oscillations. The quantity of mitoses prevailed in the day and evening. In these conditions the quantity of binucleate cells increased as compared with the control. The deficit of mitoses stipulates the delay of postnatal weight of liver at the hypokinesia. Binucleate hepatocytes are the analog of the polyploid cells and their large population compensates for the increased organism's need in liver function in the experiment.

Animals↗
PubMed1988

Cloning of cDNA coding for carbamyl phosphate synthetase I and changes in levels of CPS1 mRNA during hepatocarcinogenesis.

cDNA coding for carbamyl phosphate synthetase I was cloned from recombinant plasmid with insert complementary to the mRNA for CPS1 followed by hybrid-selected translation screening. The length of the insert CPS1 cDNA was approximately 800 base pairs. Using this cDNA as a probe, it was found by dot-blot analysis of the total RNAs and poly(A)+-RNAs isolated from rat livers with different pathological lesions induced by diethylnitrosamine that the levels of CPS1 mRNA were decreased, the decrease being correlated with the malignancy of hepatocytes during carcinogenesis.

Animals↗
PubMed1988

Studies on the mechanism of carcinogenesis (IX)--Differential expression of proliferating and tissue-specific enzyme genes during hepatocarcinogenesis.

With cDNA fragments of CPS1, OCT and ACT as probes, dot and Northern blot analyses of poly(A)+-RNA from rat liver with different pathological lesions during carcinogenesis induced by diethylnitrosamine were conducted. It was shown that the level of mRNA of tissue-specific enzymes, CPSI and OCT decreased while that of the proliferating enzyme ACT mRNA increased, and the alteration was correlated with the degree of pathological changes in each case. The relative changes in the mRNA level of these enzymes during hepatocarcinogenesis were correlated with that of enzyme activities. Implication of these findings in the mechanism of carcinogenesis in terms of cell proliferation and differentiation was discussed.

Animals↗
PubMed1985

[Changes in the immunity indices of intact and partially hepatectomized mice undergoing the transplantation of splenic cells from hypokinetic donors].

Male (CBA X C57B1/6)F1 mice subjected to a 17-hour movement restrain showed a decrease in splenic and thymic weights and in the number of immunocompetent cells in the blood. Suspension of splenocytes from hypokinetic mice was transplanted to intact and to partly hepatectomized syngeneic animals. One day after transplantation there was a reduction in the weight of the spleen and thymus in intact but not in partly hepatectomized recipients. Seven days after transplantation the number of E-RFC and EAC-RFC dropped in both intact and hepatectomized mice.

Animals↗
PubMed1984

[Appearance of the signs of stress in mice as affected by lymphoid cells from syngeneic hypokinetic animals].

Lymphoid cells of the spleen were transferred from F1(CBA X C57BL/6) mice exposed to hypokinesia for 17 hours to unoperated and partially hepatectomized syngeneic recipients. It caused (on days 2, 3 and 7) changes in the body weight, thymus, spleen, adrenals and in proliferative activity of hepatocytes in the intact and regenerating liver, with these changes being similar to those induced by stress alone.

Animals↗