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Biomedical subjects

B C Yang

Publications and source records attributed to B C Yang.

78 records · Page 5Linked to original sources
PubMed1990

A comparative study of alkaline phosphatases among human placenta, bovine milk, hepatopancreases of shrimp Penaeus monodon (Crustacea: Decapoda) and clam Meretrix lusoria (Bivalvia: Veneidae): to obtain an alkaline phosphatase with improved characteristics as a reporter.

1. Alkaline phosphatases were purified from human placenta, bovine milk, shrimp and clam with a final spec. act. of 67,000, 32,000, 22,000 and 15,000 U/mg of protein respectively. 2. The alkaline phosphatase from Meretrix lusoria is unique with its thermostability at 65 degrees C for 30 min; whereas the remaining enzymes studied, including the human placental alkaline phosphatase, are inactivated and have negligible activities. 3. The alkaline phosphatase from Penaeus monodon can be differentiated by its pH optimum at 9.0; the remaining enzymes studied have their optimal pH at 10.0. 4. The alkaline phosphatases from shrimp and clam are proposed to be applied as "reporters" in the study of mammalian cells.

Alkaline Phosphatase↗
PubMed1990

A sialidase from the hepatopancreas of the shrimp Penaeus japonicus (Crustacea: Decapoda): reversible binding with the acidic beta-galactosidase.

1. The sialidase purified from the hepatopancreas of Penaeus japonicus is able to bind the acidic beta-galactosidase in vitro. No protective protein, Mr 32,000, was detected in either purified enzyme preparation. 2. The specific activity of the isolated sialidase is 55.0 mU/mg of protein. After polyacrylamide gel electrophoresis under denaturing conditions, the purified shrimp enzyme was found to consist of monomers of Mr 32,000. 3. The sialidase from shrimp has an isoelectric point (pI) of 4.6 +/- 0.1. 4. The shrimp enzyme has the pH optimum at 5.0 and its Km was 5.5 microM with 2'-(4-methylumbelliferyl)-alpha-D-N-acetylneuraminic acid as substrate. The enzyme activity was inhibited by either Hg2+ or Cu2+ ions.

Animals↗
PubMed1987

Protective effects of ginsenosides on anoxia/reoxygenation of cultured rat myocytes and on reperfusion injuries against lipid peroxidation.

Lactic acid dehydrogenases (LDH) release from cultured rat myocytes during anoxia and reoxygenation were significantly reduced by ginsenosides (G) and its components Rb+Ro, both in 83 micrograms/ml, but not by Rg. G in higher concentration (250 micrograms/ml) enhanced the LDH release. G and Rb+Ro both 8.3 micrograms/ml in the perfusate, also significantly reduced CPK release from isolated rat heart. Rb component 50 mg/kg protected rat myocardial infarct in vivo against lipid peroxidation signified by significant reduction of malondialdehyde (MDA) and increase of superoxide dismutase (SOD) in rat myocardium. It was concluded that G in adequate dose can protect myocyte anoxia and reoxygenation as well as reperfusion damage in isolated rat heart, and the mechanism of protection may partly attribute to its action on oxygen free radical formation and lipid peroxidation. The active components of myocardial protection are Rb+Ro, and not Rg.

Animals↗
PubMed1980

Comparative distribution of Baker's antifolate (NSC 139105) in rat tissues after subcutaneous and intravenous injections.

The tissue distribution of BAF was compared by intravenous and subcutaneous injections in rats bearing Walker 256 carcinoma. Following a single dose (6 mg/kg containing 30 microCi 4,6-di-14C-BAF), the drug concentrations were determined by radiochemical and dihydrofolate reductase assays. The two methods gave comparable results. No metabolites were found by paper chromatographic separations.

Animals↗
PubMedDate not supplied

Exogenous dehydroepiandrosterone modified the expression of T helper-related cytokines in NZB/NZW F1 mice.

The onset of lupus-like disease in NZB/NZW F1 mice was correlated with the expression of IL-10 at 4 m of age, and with a sequential enhanced expression of IFN-gamma and IL-6 between 6 to 8 m of age. The expression of IFN-gamma and IL-6 was associated with exacerbation of disease symptom, production of anti-DNA antibody, and increase in total serum IgG1. Exogenous dehydroepiandrosterone (DHEA) given in animal diet significantly prolonged survival, and delayed formation of autoantibody of NZB/NZW F1 mice as compared to mice fed on control diet. The effect of DHEA paralleled a delay in the expression of IL-10 and IL-6 and an earlier detection of IL-12 transcripts. Moreover, DHEA-fed mice had higher serum IgG2a level than control diet-fed mice. Collectively, DHEA may modify the activation of distinct subset of T helper cells in NZB/NZW F1 mice at different phases of disease progression.

Animals↗