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Biomedical subjects

L Ye

Publications and source records attributed to L Ye.

132 records · Page 8Linked to original sources

The diagnostic value of a hepatoma-specific band of serum gamma-glutamyl transferase.

Using a vertical slab electrophoretic apparatus loaded with polyacrylamide stage gel plate, we observed a total of II bands of gamma-glutamyl transferase (EC 2.3.2.2,GGT) on a gel plate and designated these GGT I-XI by order of distance beginning at the positive pole. Positive GGT II was found in 81 (90%) of 90 cases of primary hepatic carcinoma (PHC), in 9(90%) of 10 cases of secondary hepatic carcinoma (SHC), and in only 4 (3.1%) of a total of 128 cases of acute and chronic liver disease. There was one case with positive GGT II among 45 cases of cancer of ampulla of Vater, but the possibility of hepatic metastasis could not be excluded. No GGT II was found in a total of 250 healthy persons and 21 pregnant women. PHC patients with negative alpha-fetoprotein (AFP) had a positive GGT II rate of 84.6%, whereas in those with negative GGT II the positive rate for AFP was only 44.4%.

Adult↗

Effectiveness of transient immunosuppression using cyclosporine for xenomyoblast transplantation for cardiac repair.

We studied the survival of human myoblast for cellular myocardial reconstruction in a porcine model of chronic myocardial ischemia with immune tolerance using transient immunosuppression. A porcine model of chronic cardiac ischemia was created in 10 pigs (DMEM medium-injected n = 4; myoblast transplanted n = 6) by clamping ameroid ring around left circumflex coronary artery. Three weeks later, 3 x 10(8) human myoblasts carrying lac-z reporter gene were transplanted in multiple sites (0.25 mL each) into the left ventricular wall. Immunosuppression was achieved with 5 mg/kg cyclosporine for 6 weeks after cell transplantation. After animals were euthanized between 6 and 30 weeks after cell transplantation; the heart was removed for histological studies. Discontinuation of immunosuppression after 6 weeks of cell transplantation did not result in donor cell rejection. The lac-z-positive donor cells were detected in porcine host cardiac tissue for up to 30 weeks posttransplantation, expressing human skeletal myosin heavy chain. The results highlight the effectiveness of transient immunosuppression for myoblast transplantation for cardiac repair.

Animals↗

Transcriptional activation by the Werner syndrome gene product in yeast.

Werner syndrome (WS) is characterized by the premature occurrence of many age-related features. Before the cloning of the gene for WS (WRN), several reports suggested that transcriptional defects of genes may relate to the mechanisms of the occurrence of WS and natural aging. Because WRN, which encodes a helicase (WRN-H), has been cloned, we are attempting to clarify the mechanism of the transcriptional abnormalities found in WS cells, using WRN and WRN-H. In this article, we studied transcriptional activation of a promoter by WRN-H in a yeast assay system as a first step. The results showed that WRN-H functions as a transcriptional activator in the system. Furthermore, we performed additional transcriptional assays using various parts of WRN to define the critical region of WRN-H for transcriptional activation in yeast. The results revealed the critical region for the activation most likely mapped to the region of 315 to 403 aa. The region of 404 to 1309 aa may also effect activation in the presence of the critical region. The two regions contain an acidic domain, and the region of 404 to 1309 aa also contains a helicase domain. If this transcriptional activation by WRN-H occurs also in human cells in vivo, direct activation of the promoters by WRN-H could explain the results of somatic cell hybrid studies as well as the overexpressed genes detected in WS cells. However, our results should be interpreted with caution, because thus far, the transcriptional activation by WRN-H were only demonstrated using one promoter in a yeast system.

DNA Helicases↗