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Biomedical subjects

W C Chang

Publications and source records attributed to W C Chang.

310 records · Page 18Linked to original sources

[The antiarrhythmic effect of (-)-U-50,488 in rats with acute ischemia and reperfusion of heart is mediated by kappa1-opioid receptor activation].

Pretreatment with a selective kappa1 opioid receptor (OR) agonist (-)-U-50,488 (1 mg/kg, i.v.) prevented the development of arrhythmias induced by occlusion (10 min) and reperfusion (10 min) in ketamine anesthetized rats, while the treatment with a less active enantiomer (+)-U-50,488 in the same dose produced no such effects. Preliminary intravenous administration of a selective kappa1 OR antagonist norbinaltorphimine (9 mg/kg) fully abolished the antiarrhythmic effect of (-)-U-50,488, while the kappa2 OR antagonist quadazocine (3 mg/kg) did not eliminate this effect. The injections of norbinaltorphimine or quadazocine alone did not influence the incidence of model arrhythmias caused by the occlusion and reperfusion. It was concluded that kappa1 OR stimulation favors an increase in cardiac tolerance to the arrhythmogenic action of occlusion and reperfusion.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗

Absent pulmonary valve syndrome associated with DiGeorge syndrome: report of one case.

A female infant presented with cyanosis, respiratory distress and unique to-and-fro murmur which she had since the age of 1-month-old. Absent pulmonary valve syndrome was diagnosed by echocardiography. She developed seizure disorders with hypocalcemia and pneumonia at the age of 2-month-old. The patient died from sepsis, intractable respiratory and heart failure. The postmortem study confirmed the diagnosis of congenital absent pulmonary valve associated with DiGeorge syndrome.

DiGeorge Syndrome↗

Inhibitory effect of crocetin on benzo(a)pyrene genotoxicity and neoplastic transformation in C3H10T1/2 cells.

Crocetin is a major component in the fruit of Gardenia jasminoides Ellis, a Chinese herbal medicine. In the work, we investigate the protective action and mechanism against benzo(a)pyrene [B(a)P]-induced genotoxicity and neoplastic transformation with a non-toxic dose of crocetin (0.01-0.10 mM) for 1 hour prior to the administration of 0.1 mM B(a)P. B(a)P genotoxicity was inhibited significantly by crocetin in a dose responsive manner. Pretreating C3H10T1/2 cells with crocetin (0.1 mM) also caused a decrease in the covalent binding of B(a)P-diol-epoxide to DNA, to about half that of cells without crocetin treatment. Crocetin also inhibited B(a)P-induced transformations. When the culture was treated with crocetin (0.01, 0.05 and 0.10 mM) for 7 days, the transformation frequencies were lower than that of the culture without crocetin treatment. Furthermore, pretreating cells with crocetin (0.01-0.10 mM) also caused an increase in the activity of GSH S-transferase (GST) to 18-71% that of the cells without crocetin treatment. These results suggest that the inhibition by crocetin of B(a)P-induced genotoxicity and neoplastic transformation in C3H10T1/2 cells is due to a mechanism that increases the activity of GST and decreases the formation of a B(a)P-DNA adduct.

Anticarcinogenic Agents↗