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Biomedical subjects

K Matsui

Publications and source records attributed to K Matsui.

At least 793 records · Page 44Linked to original sources

Differential control of synergistic effect with polyene macrolide antibiotics upon Chinese hamster cells in vitro.

An amphotericin B-resistant cell (AMBR-1), which was isolated from aneuploid Chinese hamster cells (V79), was found to show much higher resistance than the parent V79 cells to other polyene antibiotics, such as pentamycin and filipin. To obtain the 50 to 60% inhibition of the control protein synthesis activity by a synergistic combination of fusidic acid and amphotericin B, 50 microgram fusidic acid per ml were combined with 10 microgram amphotericin B in V79 cells, whereas in AMBR cells 50 microgram fusidic acid per ml were combined with 100 microgram polyene antibiotic per ml. Bleomycin (10 microgram/ml), which alone did not affect cellular DNA synthesis, inhibited DNA synthesis of V79 cells by more than 90% of the control activity when combined with only 1 microgram pentamycin per ml, whereas a similar extent of inhibition in AMBR cells was observed by combination with more than 5 microgram pentamycin per ml.

Amphotericin B↗

A mouse leukemia cell mutant resistant to blasticidin S.

After nitrosoguanidine mutagenesis we isolated from mouse leukemia L5178Y cells a mutant cell (Bla-R) resistant to blasticidin S, an inhibitor of protein synthesis. Neither growth nor leucine incorporation into hot-acid insoluble fraction of Bla-R cell was inhibited by 5 to 20 microgram/ml blasticidin S, which almost completely blocked protein synthesis as well as growth of the parental L5178Y cells. However, other inhibitors such as fusidic acid, cycloheximide, ricin D or L-asparaginase blocked protein synthesis in Bla-R cells to the same extent as in L5178Y cells. Protein synthesis in vitro using S-30 extracts from the parental cell line L5178Y was almost completely blocked in the presence of the antibiotic, while no inhibition by blasticidin S occurred when S-30 extracts -rom Bla-R mutant cells were used. Protein synthesis assays were made by using the S100 fraction from rat liver together with ribosomes from either L5178Y cells or Bla-R cells. Blasticidin S inhibited protein synthesis when ribosomes were derived from L5178Y cells, but not from Bla-R mutant.

Animals↗