Biomedical subjects

M Kojima

Publications and source records attributed to M Kojima.

1,138 records · Page 64Linked to original sources

PubMedDate not supplied

Glutathione related enzymes in cis-diamminedichloroplatinum (II)-sensitive and-resistant human ovarian carcinoma cells.

A cis-diamminedichloroplatinum (II) (CDDP)-resistant cell line (NOS2CR) demonstrated 7.4-fold greater resistance to CDDP compared with the parental cell line (NOS2) established from a patient with serous cystadenocarcinoma of the ovary. We investigated the role of enzyme systems associated with glutathione (GSH) in these cell lines. The GSH content was almost identical in both cell lines. Preincubation with 50 microM DL-buthionine-S, R-sulfoximine (BSO), an inhibitor of gamma-glutamyl cysteine synthetase, for 24 hr reduced the IC50 in both NOS2 and NOS2CR cells. Glutathione-S-transferase pi (GST-pi) activity and mRNA level in NOS2CR cells were higher than in NOS2 cells. However, gamma-glutamyltranspeptidase (GGT) activity in NOS2CR cells was 2.4-fold less than in NOS2 cells. The GST activity and mRNA level in both cell lines were constant when the cells were exposed to CDDP. Exposure to CDDP for 48 hr increased the GGT mRNA level 4.4 and 1.8 times in NOS2 and NOS2CR cells, respectively, compared with no exposure. By exposure to CDDP for 48 hr, the GGT activities in NOS2 and NOS2CR cells were increased 1.6-and 2.5-fold, respectively, compared with no exposure. The above data provide the first evidence that GGT activity and GGT mRNA are induced by CDDP in human carcinoma cell lines.

Blotting, Western↗

PubMedDate not supplied

Potentiating effect of amphotericin B on five platinum anticancer drugs in human cis-diamminedichloroplatinum (II) sensitive and resistant ovarian carcinoma cells.

We have determined an effect of amphotericin B (AMB), an antifungal drug, on the cytotoxicity of cis-diamminedichloro-platinum (II) (CDDP) and 4 CDDP analogues in a human ovarian carcinoma cell line (NOS2). Intracellular accumulation of CDDP was elevated significantly by treatment with AMB, and AMB significantly potentiated the cytotoxicity of CDDP by MTT assay. Intracellular accumulation of 4 CDDP analogues was also elevated by the treatment with AMB and the order of increasing accumulation rate of platinum drugs was consistent with that of dose modification factor (DMF). AMB also increased the intracellular CDDP accumulation in CDDP resistant cells (NOS2CR), derived from NOS2. The intracellular accumulations of 4 CDDP analogues were elevated slightly by the treatment with AMB in NOS2CR cells. DMFs of 5 platinum drugs in NOS2CR cells, however, were more than those in NOS2 cells. These results indicate that AMB sensitizes NOS2 and NOS2CR cells to platinum drugs, partially due to the increasing intracellular accumulation of these drugs. In addition, CDDP analogues are more effective in NOS2CR cells than CDDP, but the cytotoxicity of CDDP was most potentiated by AMB among the 5 platinum drugs under study.

Amphotericin B↗

PubMedDate not supplied

Market basket and duplicate portion estimation of dietary intakes of cadmium, mercury, arsenic, copper, manganese, and zinc by Japanese adults.

Daily intakes of selected metals from meals in Shiga Prefecture (Japan) were investigated by the duplicate portion method and market basket method. In 1991 and 1992, daily intakes of metals by women, determined by the duplicate portion method, were, respectively, 37 and 27 micrograms for Cd, 4.3 and 3.5 micrograms for Hg, 260 and 210 micrograms for As, 1200 and 1200 micrograms for Cu, 4700 and 3600 micrograms for Mn, and 8000 and 7200 micrograms for Zn. Those determined by the market basket method were, respectively, 32 and 35 micrograms for Cd, 4.3 and 9.9 micrograms for Hg, 160 and 280 micrograms for As, 1100 and 980 micrograms for Cu, 3600 and 4700 micrograms for Mn, and 8700 and 8500 micrograms for Zn. No wide differences between the 2 methods were found, except for Hg data in 1992. Daily intakes of Cd and Hg in Shiga Prefecture were lower than the provisional tolerable daily intakes of 57-72 micrograms for Cd and 43 micrograms for Hg, proposed by the Food and Agricultural Organization and the World Health Organization.

Adult↗

PubMedDate not supplied

Levels of Cd, Hg, As, Cu, Mn, and Zn in Japanese restaurant and box lunches.

Intakes of selected elements from restaurant and box lunches in Shiga Prefecture (Japan) were investigated in 1993 and 1994, respectively. Average intakes of these elements from restaurant and box lunches were, respectively, 14 and 12 micrograms for Cd, 4.6 and 4.5 micrograms for Hg, 85 and 91 micrograms for As, 461 and 561 micrograms for Cu, 1268 and 1235 micrograms for Mn, and 3612 and 2688 micrograms of Zn. There were no great differences between the intakes from the restaurant lunches in 1993 and the box lunches in 1994. The proportion of elements from the lunches constituted 25-38% of the daily intake for Cd, As, Mn, and Zn and 51-65% of the daily intake for Hg.

Arsenic↗