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T Udagawa

Publications and source records attributed to T Udagawa.

59 records · Page 4Linked to original sources

Generation of the electrochemical potential of Na+ by the Na+-motive NADH oxidase in inverted membrane vesicles of Vibrio alginolyticus.

Inverted membrane vesicles prepared from Vibrio alginolyticus generated a membrane potential (positive inside) and accumulated Na+ by the oxidation of NADH. Generation of the membrane potential required Na+ and was inhibited by 2-heptyl-4-hydroxyquinoline N-oxide, a specific inhibitor of the Na+-dependent NADH oxidase. Collapse of the membrane potential by valinomycin stimulated the uptake of Na+. In contrast, accumulation of H+ was not detected under all the conditions tested. These results suggest that only Na+ is translocated by the Na+-dependent NADH oxidase of V. alginolyticus.

Cell Membrane↗

Photodynamic therapy based on combined use of 5-aminolevulinic acid with a pheophorbide-a derivative for murine tumors.

BACKGROUND: 5-Aminolevulinic acid (5-ALA)-based photodynamic therapy (PDT) appears to be a promising cancer treatment modality. Here, we investigated whether enhancement of 5-ALA-PDT by combining another photosensitizer, a pheophorbide-a derivative (PH-1126), is an option. MATERIALS AND METHODS: PH-1126 (2.5, 5 or 10 mg/kg.bw) and 5-ALA (168 mg/kg.bw) were injected i.p. into C3H/HeN mice bearing squamous cell carcinoma (SCC) or BALB/c nude mice bearing L5178Y lymphoma. Afterwards, these mice received laser irradiations (630 nm for 5-ALA and 650 nm for PH-1126) with a total dose of 88 J/cm2. The results showed that PDT with 5-ALA plus PH-1126 at a low dose (2.5 mg/kg.bw) were well tolerated by both animal models, with resultant synergistically enhanced inhibition of tumor growth and/or survival advantage for the treated animals. CONCLUSION: This study demonstrated the usefulness of the combination of a low dose PH-1126 with 5-ALA for PDT of experimental tumors in vivo.

Aminolevulinic Acid↗

Non-random primary and secondary chromosomal abnormalities in human gastric cancers.

By using Giemsa-banding and fluorescence in situ hybridization techniques, we have been able to identify primary and secondary cytogenetic abnormalities in four gastric tumors at different stages of development. Structural and numerical abnormalities were present in all four gastric tumors in chromosomes 3, 7, 11, and X. Other abnormalities involving chromosomes 1, 5, 6, 8, 13, 15, 17, 18, 19 and 22 were observed, but only in three advanced gastric tumors, suggesting that these were secondary/tertiary genetic defects. Based on these results it was possible for us to decipher primary and secondary genetic abnormalities in these four gastric tumors.

Biopsy↗