Search PubMed⌕ Search

Biomedical subjects

Y Kano

Publications and source records attributed to Y Kano.

At least 325 records · Page 18Linked to original sources
PubMed1980

Effects of a tumor promoter and an anti-promoter on spontaneous and UV-induced 6-thioguanine-resistant mutations and sister-chromatid exchanges in V79 Chinese hamster cells.

The effects of a tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) and/or an anti-promoter antipain (protease inhibitor) on spontaneous and ultraviolet-induced sister-chromatid exchanges (SCEs) and 6-thioguanine-resistant (6TGr) recessive mutations were examined in V79 Chinese hamster cells in culture. TPA and/or antipain neither significantly altered base-line and UV-induced immediate SCE frequencies, nor decreased the level of delayed SCEs which persisted 6-7 days after irradiation. TPA and/or antipain appeared to enhance the recovery of UV-induced 6TGr colonies at the plateau expression phase despite non-mutagenicity by themselves and unaltered metabolic cooperation. Thus, the results conceivably imply that the 6TGr-recessive mutation expression, but not fixation, can be modulated at the cell level by TPA and/or antipain. Our results, together with the recent results of Loveday and Latt, may argue against the notion that TPA enhances the antipain-suppressible SCEs as an index of mitotic recombination in relevance with a tumor-promotion mechanism.

Animals↗
PubMed1980

Characterization of gangliosides in human leucocytes.

Lipids extracted from leucocyte pellets with chloroform-methanol were applied to a DEAE-Sephadex column an the gangliosides were eluted with 0.2M sodium acetate in methanol. The eluate was desalted by Sephadex G-50 column chromatography. The purified ganglioside was spotted on the high-performance than-layer plate. The plate was developed and sprayed with resorcinol reagents and heated. Seventeen bands of gangliosides were demonstrated in normal human leucocytes. The composition of these gangliosides was different in the various kinds of leucocytes. Amounts of GM3 ganglioside were apparently greater in normal lymphocytes and leukaemic cells than in granulocytes. Among the acute-leukaemic cells, some kinds of complex gangliosides were much more abundant in myelogenous cells than in lymphocytic cells. These changes in ganglioside composition are suggested as new biochemical markers for leukaemic cells.

Chromatography, Thin Layer↗
PubMed1980

[The clinical values fro chemical constituents of blood in normal miniature Shiba goats (author's transl)].

Using the both methods. RaBA-Super System (Rapid Blood Analyzer System), the clinical values for chemical constituents of blood in Shiba goats bred in Stock Farm, University of Tokyo, were determined on the following items: total protein, albumin, TTT, glucose, BUN, total bilirubin, total cholesterol, triglyceride, GOT, GPT, ALP, LDH, CPK, cholinesterase, calcium and inorganic phosphorus. The results obtained were summarized as follows: 1) All items determined were to be analyzed by means of the RaBA-Super System, although the values for total cholesterol, TTT, ALP and CPK varied considerably with individuals. 2) The values of adult female goats were significantly higher than those of young ones in total protein and albumin, and lower in glucose, cholinesterase, ALP and CPK. 3) The values of GPT and BUN of adult female goats in summer were significantly lower than those in winter and autumn. 4) The values for triglyceride and albumin of adult female goats using the RaBA-Super System were inconsistent with those analyzed simultaneously by the manual method, but a significant linear correlation was recognized between the both methods.

Age Factors↗
PubMed1980

Quantitative estimation of nucleolar cistrons (rDNA) in proliferating normal and tumor cells.

The saturating hybridization levels of DNA with rRNA (hereafter abbreviated as rDNA/DNA) in adult liver, bone marrow, and fetuses in Long-Evans rats were 0.042, 0.036, and 0.029 approximately 0.033%, respectively, showed a lower level in rapidly growing tissues. We consider that the lower rDNA/DNA in rapidly growing tissues might be due to the replication of rDNA in the late S phase, or in other words, to the depression of rDNA/DNA in each S phase. Based on these findings, the relative levels of rDNA per G1 geome were estimated in cells of these normal tissues and 4 diploid tumors by multiplying rDNA/DNA and DNA/genome. By this procedure, rDNA/genome was shown to be constant in normal G1 cells, while a 31 approximately 48% increase was found in the tumor cell genome. Direct measurement of rDNA in synchronized #2 trisomy leukemia cells confirmed the replication of rDNA in the late S phase, with a 21.4% increase of rDNA per G1 genome.

Animals↗
PubMed1979

Evidence for endonucleolytic cleavage at the 5'-proximal segment of the trp messenger RNA in Escherichia coli.

The 5'-proximal trp leader RNA segment (about 5S) decays at 2 to 3 times slower rates than the distal trp mRNA sequence. This has been demonstrated by employing the deletion mutants which lack a large portion of the structural genes but retain the promoter-proximal region of the trp operon. Relative stability of the leader RNA is not merely due to the presence of an untranslatable region in the segment; the internal untranslatable segment of trp mRNA downstream from the nonsense alteration site of a double mutant trpAD28.trpE9758 decays as fast as the normal trp mRNA sequence. These results suggest that the trp mRNA is endonucleolytically cleaved to yield the small 5'-proximal leader RNA segment before the distal mRNA decays and that the leader RNA sequence is not subject to usual mode of mRNA decay in the 5' to 3' direction.

DNA, Viral↗
PubMed1979

In vivo enhancement of general and specific transcription in Escherichia coli by DNA gyrase activity.

The effect of drugs which inhibit DNA gyrase, including nalidixic acid, oxolinic acid and coumerycin, on transcription of Escherichia coli bacteria, phage and plasmid genomes was studied. Quantitative estimates of the synthesis of RNA under drug-treatment conditions showed that synthesis of many RNA species, including trp mRNA, was subject to inhibiton by the drug. Transcription directed by the lambda promoter pR was selectively less sensitive to the drug action than transcription initiated at the lambda promoter pL. Evidence was obtained showing that diminished transcription resulted from less frequent RNA chain initiation rather than a premature arrest of the chain elongation. Inhibiton of transcription by these DNA gyrase inhibitors was observed even in the absence of DNA replication. The inhibition by oxolinic acid or coumerycin was not observed in an E. coli strain bearing a nalAr mutation or a cour mutation, respectively. The reduction of trp mRNA synthesis in oxolinic acid-treated cells cannot be attributed to the increase in the rate of nascent mRNA degradation. These results indicate that DNA gyrase is generally required for intracellular RNA synthesis, and suggest that the supercoiling of DNA by this winding enzyme enhances the initiation of transcription.

Bacteriophage lambda↗
PubMed1979

Cellular cooperation in lymphocyte activation. III. B-cell helper effect in the enhancement of T-cell response.

T and B cells were purified from human tonsil and peripheral blood by the removal of phagocytic cells, followed by filtration through a nylon fiber column (NC) and E-rosette formation. Purified T and B cells contained less than 1% of other cell types. The responses of T cells to concanavalin A (Con A) and soluble protein A were greatly enhanced in the presence of autologous B cells. Participation of B cells in T-cell enhancement was confirmed by the following observations: (a) purified B copulation, which was separated further from adherent B cells, retained its enhancing activity. (b) Another adherent cell-free B-cell preparation, which was purified from the NC-passed fraction, and (c) no T lymphoid but some B lymphoid cell lines, elicited strong T-cell enhancement. It was also found that the enhancing capacity of B cells required no metabolic activity, but rather an intact cell form and direct cell-to-cell contact with responding cells. The stimulatory determinants on B cells were resistant to trypsin and neuraminidase treatment. In this paper a hypothesis will be presented that at least two signals are prerequisite for the effective activation of T cells.

B-Lymphocytes↗
PubMed1979

[Cross-sectional anatomy of miniature "Shiba" goat].

The anatomical relations of visceral organs and other tissues in the thoracic, abdominal and pelvic cavities of the male miniature "Shiba" goat are illustrated as thirteen semi-diagramatic representations of cross sections.

Animals↗