Biomedical subjects

F H Gao

Publications and source records attributed to F H Gao.

10 recordsLinked to original sources

PubMed2001

Nuclear matrix in developing rat spermatogenic cells.

The nonchromatin structure or nuclear matrix in developing spermatogenic cells of the rat was studied using a biochemical fractionation in concert with resinless section electron microscopy. Observations demonstrated that the nuclear matrix of spermatogenic cells consisted of a three-dimensional network of filaments of variable thicknesses. In spermatogonia and spermatocytes the nuclear matrix consisted of relatively thin filaments, while that of round spermatids consisted of a thicker interconnecting network of filament. In elongating spermatids, the interior of the nuclear matrix consisted of a network of dense filaments bounded by a peripheral lamina. The protein composition of the nuclear matrix in spermatogenic cells was examined by high-resolution two-dimensional gel electrophoresis and correlated with morphological changes characteristic of each stage. The results showed that the proteins of nuclear matrix changed in a cell stage-specific manner. These stage-specific changes corresponded to the major transitions of chromatin structure and function during spermatogenesis. Furthermore, immunocytochemical and immunoblotting analysis of DNA topoisomerase II (topo II) revealed that this enzyme exhibited stage-specific variations and was associated with the nuclear matrix. These results suggest that the nuclear matrix in spermatogenic cells may be involved in mediating DNA modifications and maintaining nuclear organization during spermatogenesis. Mol. Reprod. Dev. 59:314-321, 2001.

Animals↗

PubMed2001

[Efficacy of ablendazole emulsion in treatment of 212 patients with cystic echinococcosis].

OBJECTIVE: To verify the efficacy of abendazole emulsion, a new formulation of abendazole, in treatment of human cystic echinococcosis. METHODS: 212 patients with liver cystic echinococcosis were treated orally with albendazole emulsion at a daily dose of 10 mg/kg or 12.5 mg/kg for 3 to 12 months or over one year. The therapeutic efficacy was mainly evaluated by image feature examined with B ultrasound examination, a short-term efficacy at the completion of treatment and a long-term efficacy followed-up for 1-4 years. RESULTS: In 212 patients treated with albendazole emulsion at a daily dose of 10 mg/kg and 12.5 mg/kg, the average cure rate, improved rate and the rate of no avail were 74.5%, 99.1% and 0.9% respectively after termination of the treatment, and the average long-term rates were 83.1%, 89.3% and 0.6% respectively. Recurrence occurred in 18 patients(10.2%). The results indicated that the best efficacy was seen in patients treated with albendazole 12.5 mg/kg daily for 9 months. Better response was also found when the recurrent patients were re-treated with albendazole. CONCLUSION: The efficacy of albendazole emulsion on patients with liver cystic echinococcosis is much better than that of albendazole tablet or capsule and mebendazole. Meanwhile, the efficacy of albendazole emulsion is stable with less adverse effects. The results suggest that albendazole emulsion could be the drug of choice for treatment of cystic hydatid disease.

Albendazole↗

PubMed1991

Mechanism of action of the peptide antibiotic nisin in liposomes and cytochrome c oxidase-containing proteoliposomes.

The interaction of the peptide antibiotic nisin with liposomes has been studied. The effect of this interaction was analyzed on the membrane potential (inside negative) and the pH gradient (inside alkaline) in liposomes made from Escherichia coli phosphatidylethanolamine and egg phosphatidylcholine (9:1, wt/wt). The membrane potential and pH gradient were generated by artificial ion gradients or by the oxidation of ascorbate, N,N,N',N'-tetramethyl-p-phenylenediamine, and cytochrome c by the beef heart cytochrome c oxidase incorporated in the liposomal membranes. Nisin dissipated the membrane potential and the pH gradient in both types of liposomes and inhibited oxygen consumption by cytochrome c oxidase in proteoliposomes. The dissipation of the proton motive force in proteoliposomes was only to a minor extent due to a decrease of the oxidase activity by nisin. The results in these model systems show that a membrane potential and/or a pH gradient across the membrane enhances the activity of nisin. Nisin incorporates into the membrane and makes the membrane permeable for ions. As a result, both the membrane potential and pH gradient are dissipated. The activity of nisin was found to be influenced by the phospholipid composition of the liposomal membrane.

Animals↗

PubMed1991

[Studies on tissue schizonticide of malaria parasite: synthesis of 2-substituted benzyloxy (or methoxy)-5-substituted phenoxy analogues of primaquine].

2-Chloro-6-methoxy-8-nitroquinoline was reacted with substituted benzyl alcohols (or sodium methanol) and then brominated to give 2-substituted benzyloxy-6-methoxy- and 2,6-dimethoxy-5-bromo-8-nitroquinolines (compounds 5-8 in Table 1). These products were condensed with substituted phenols to form corresponding 5-substituted phenoxy compounds (9-19 in Tables 1 and 2) which were subsequently reduced to afford 2-substituted benzyloxy-6-methoxy- and 2,6-dimethoxy-5-substituted phenoxy-8-aminoquinolines (20-28, 47 and 48 in Tables 3 and 6). Condensation with 4-bromophthalimidopentane yielded corresponding 8-(4-phthalimido-1-methylbutyl)aminoquinolines (29-37, 49 and 50 in Tables 4 and 6) which were subsequently treated with hydrazine hydrate to give 2-substituted benzyloxy-6-methoxy- and 2,6-dimethoxy-5-substituted phenoxy-8-(4-amino-1-methylbutyl)amino-quinolines, compounds III and IV (38-46, 51 and 52 in Tables 5 and 6), the analogues of primaquine. Compounds III and IV were tested against Plasmodium yoenii in mice infected with sporozoites. The parasitaemia of 80% and 90% of tested mice was negative at an oral single dose of 100 mg/kg of compounds 39 and 45, respectively. The results of further studies on compound 45 showed that the parasitaemia of 80% of mice was negative at a single dose of 20 mg/kg, and the acute toxicity in mice was less than that of primaquine.

Animals↗

PubMed1984