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Biomedical subjects

K Miyano

Publications and source records attributed to K Miyano.

At least 91 records · Page 5Linked to original sources
PubMed1984

Phenotypical stability of a human hepatoma cell line, HuH-7, in long-term culture with chemically defined medium.

A chemically defined medium containing selenium was further improved, and the improved medium showed excellent ability to support growth and colony formation of a human hepatoma cell line, HuH-7. The improved defined medium (designated as IS-RPMI) contained small amounts of unsaturated fatty acids, inorganic trace elements including selenium, and HEPES buffer. Many of these additions exert only a small individual effect on the growth of cells, but their cumulative effects were substantial. HuH-7 cells replicated continuously with a doubling time of 47-51 hr in IS-RPMI. A conditioned medium from a semiconfluent population increased the colony-forming ability of HuH-7 cells in IS-RPMI. The addition of insulin to the medium gave good colony growth, thus duplicating the effect of the conditioned medium. Although some alterations of morphological and growth characteristics of HuH-7 cells were observed, the differentiated liver functions, as revealed by production of plasma proteins including high levels of alpha 1-fetoprotein, were maintained for a period of more than 3 years and through 70 passages under the above culture conditions.

Animals↗
PubMed1983

Expression of gamma-glutamyltranspeptidase in cultures of spontaneously and chemically transformed rat liver cells.

The expression of gamma-glutamyltranspeptidase (gamma-GTP) and the relationship between this enzyme activity and tumorigenicity were studied in 38 tumorigenic and non-tumorigenic epithelial cell lines derived from livers of normal and aminoazo-dye-fed rats. Nine of 22 non-tumorigenic epithelial cell lines exhibited gamma-GTP-positive cells, whereas 9 of 16 tumorigenic epithelial cell lines did not exhibit gamma-GTP-positive cells. This finding revealed that no correlation existed between the acquisition of gamma-GTP activity and tumorigenicity. None of 10 spontaneously transformed epithelial cell lines, which consisted of 8 tumorigenic and 2 non-tumorigenic cell lines, exhibited gamma-GTP-positive cells. On the other hand, 16 of 28 transformed epithelial cell lines, which were derived from aminoazo-dye-fed rat livers and aminoazo-dye-treated cultures of normal rat liver cells, included gamma-GTP-positive cells in various percentages. As described above, in contrast to in vitro spontaneous transformation of rat liver cells, it is obvious that the carcinogen-induced transformation of rat liver cells in vitro as well as in vivo was frequently accompanied by the acquisition of gamma-GTP-activity. Therefore, it is concluded that the expression of gamma-GTP in liver cells may be mainly associated with exposure to chemical carcinogens.

Animals↗
PubMed1983

[Clinical effect of a cephalosporin derivative, cefotiam, on otorhinolaryngologic infections].

CTM was administered at dose levels of 1 to 3 g a day to 77 cases of otorhinolaryngological infections, and the following results were obtained: The effect of the drug was determined in 75 cases. The responders were 3 out of 5 (60.0%) in acute suppurative otitis media, 4 out of 11 (36.4%) in chronic suppurative otitis media, 39 out of 43 (90.7%) in tonsillitis and peritonsillar abscess and 12 out of 16 (75.0%) in other diseases, a total of 58 out of 75 cases (77.3%). The bacteriological effect of CTM was evaluated in 53 cases, and bacterial eradication was demonstrated in 41 cases (77.4%). Also, its antibacterial potency was 2 to 4 times superior in comparison to that of CEZ against isolated bacteria in which MICs were measurable. Side effects which were neither severe nor specific were recognized in 3 out of 77 cases (3.9%). In the cases with abnormal laboratory values, none was determinable to be attributed to CTM.

Adolescent↗
PubMed1982

Effect of 3'-methyl-4-dimethylaminoazobenzene on liver cells from adult rat in primary culture.

Primary mass cultures of isolated liver cells, which prepared from normal adult rat by a collagenase-liver-perfusion technique, were treated with 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) to study the production of transformed liver cells. Enzymatically isolated liver cells had high sensitivity to 3'-Me-DAB in primary culture. By 2- or 6-day treatment, mature hepatocytes remarkably decreased in their numbers due to cytotoxic effect of 3-Me-DAB, but thereafter active proliferation of epithelial-like clear cells was observed. Six-day treatment induced epithelial-like clear cells with gross chromosomal abnormalities, although 2-day treatment failed to induce transformed cells. However, the transformed epithelial-like clear cells with chromosomal abnormalities were negative for gamma-glutamyl-transpeptidase (GGT).

Animals↗
PubMed1982

Selective growth of epithelial-like clear cells from adult rat liver by short-term exposure to glucocorticoids in primary culture.

Isolated liver cells, which were prepared from adult rats by a trypsin-liver-perfusion technique, were treated with dexamethasone or hydrocortisone at a concentration of 7.7 X 10(-6) M for 8 days in primary culture. The treated cultures displayed homogeneous population consisting of epithelial-like clear cells, while the untreated cultures displayed mixed population consisting of epithelial-like clear cells and fibroblast-like cells. The epithelial-like clear cells, which proliferated in the cultures treated with glucocorticoids for 8 days in primary culture, did not show any morphological changes following cultivation in glucocorticoid-free medium. After continuous glucocorticoid-treatment for more than 1 month, the treated cultures showed relatively low cell densities at confluence. The surface area of individual epithelial-like clear cells in the cultures treated with glucocorticoids for long periods of time was evidently greater than that in the cultures treated for only 8 days. The epithelial-like clear cells had glucose 6-phosphatase and tyrosine aminotransferase activities even though the levels of these enzyme-activities were very low compared with those in rat liver homogenates.

Animals↗
PubMed1982

Novel dimeric derivatives of leucomycins and tylosin, sixteen-membered macrolides.

The reductive amination of an aldehyde group on the aglycon moiety of leucomycins A3 and A5 and tylosin with sodium cyanoborohydride in the presence of NH(CH3)2 or NH2CH3 afforded the corresponding amine derivative. The use of NH3 as an amine source in the reduction of leucomycin A3 and tylosin afforded a novel dimeric derivative, 18,18'-dideoxo-18,18'-iminodileucomycin A3 and 20,20'-dideoxo-20,20'-iminoditylosin, respectively. The structures of the dimers were elucidated by field desorption mass spectral analysis. The dimeric derivative of tylosin possesses considerable antibacterial activity. The binding activity of the dimer of Escherichia coli ribosome was approximately the same as for tylosin.

Bacteria↗
PubMed1982

Growth of human hepatoma cells lines with differentiated functions in chemically defined medium.

A human hepatoma cell line, HuH-7, which was established from a hepatocellular carcinoma, was found to replicate continuously in a chemically defined medium when the medium was supplemented with Na2SeO3. The cells grew better in this medium than in serum-containing medium without any adaptation period. Other established human hepatoma and hepatoblastoma cell lines, HuH-6 cl-5, PLC/PRF/5, huH-1, and huH-4, also grew in the defined medium. Although HLEC-1 cells failed to proliferate continuously with Na2SeO3 alone, they grew if a cell-free conditioned medium from HuH-7 cells was added to the medium. These cell lines, except the HLEC-1 cell line, produced the following human plasma proteins among those examined: albumin, prealbumin, alpha 1-antitrypsin, ceruloplasmin, fibrinogen, fibronectin, haptoglobin, hemopexin, beta-lipoprotein, alpha 2-macroglobulin, beta 2-microglobulin, transferrin, lipoprotein, alpha 2-macroglobulin, beta 2-microglobulin, transferrin, Complement Components 3 and 4, and alpha 1-fetoprotein. Beside plasma proteins, the media from HuH-7, HuH-6 cl-5, PLC/PRF/5, and huH-1 contained anti-carcinoembryonic antigen-reactive proteins, and those from PLC/PRF/5, huH-1, and huH-4 medium contained hepatitis B surface antigen. These proteins were detected during periods of serial cultivation over 9 months under the above culture conditions. The hepatoma cell lines grown in the fully defined synthetic medium may provide a new approach for investigating the growth and metabolism of human hepatoma cells in vitro.

Blood↗
PubMed1982

[The determination of 210Pb in lead (author's transl)].

Since lead contains more or less 210Pb, the selection for lead materials has to be done before construction of the low level radiation shield. In this paper, a method for determination of 210Pb is based on radioanalytical separation such as DDTC (sodium diethyl dithio carbamate) extraction followed by beta ray counting of 210Bi. Fourteen commercial lead samples and three old lead samples were analysed for 210Pb. The concentration for 210Pb in commercial samples was found to range from 0.063 to 11 Bq/g (1.7 to 300 pCi/g) and in old samples was less than 0.01 Bq/g (0.3 pCi/g). These results will be useful to the selection of shielding material. The detection limit and the time required for 210Pb determination was 0.003 Bq/g (0.1 pCi/g) and 5.5 hours, respectively.

Bismuth↗
PubMed1980

Chromosome analysis in a human hepato-blastoma cell line producing alpha-fetoprotein.

Analysis of the chromosomes of a cloned human hepato-blastoma cell line, HUH-6-clone 5 by Q-, G- and C-banding revealed numerical and structural chromosome aberrations. The modal number of chromosomes was 49. Trisomies #12 and 20 were present in most of the cells, and 8q isochromosome was detected in all of the cells analyzed. High levels of alpha-fetoprotein production by this cell strain were also demonstrated.

Carcinoma, Hepatocellular↗
PubMed1980

Chromosome analysis of a brain malignant lymphoma cell line.

Chromosome studies of a malignant lymphoma cell line derived from the brain were made by Q- and G-banding techniques. The modal number of chromosomes was 45. Complex structural rearrangements were present, but the 14q+ marker chromosome frequently seen in malignant lymphomas was not identified in the cell line. The main karyotype in cells analyzed was 45, X, -Y, del (2) (q21q23), t (3;?) (p25;?), t (p12;?), -8, 11q+, 18q+, +mar. Absence of the 14q+ may be explained by: firstly, clones which possessed 14q+ marker chromosome in brain tumor cells may have been selected out with increasing culture time and repeated passages; or secondly, the presence of the 14q+ marker chromosome depends on the type of lymphoma.

Adult↗
PubMed1980

Chromosome 14q+ in a Japanese patient with Burkitt's lymphoma.

Cytogenetic studies were performed on a biopsy specimen of a jaw tumor and on a bone marrow aspirate from a Japanese patient with Epstein-Barr virus-negative Burkitt's lymphoma. A 14q + chromosome was found in cells from either source, although each contained a different clone. Other karyotypic abnormalities present in common included 2dir dup (1q) (q21 leads to q32), 3q+, 6p--, +12, +mar.

Asian People↗
PubMed1978

Primary culture of adult rat liver cells. III. Hormonal effects on cytological and biochemical properties of primary cultured cells.

The effect of various hormones on cytological and biochemical properties of cultured hepatic cells were investigated in order to obtain long-term survival of the hepatocytes with adult liver functions in primary culture. Insulin supplementation of the culture medium enhanced the attachemnt efficiency of cells in primary culture without affecting either maintenance of morphological characters of epithelial cells or retention of liver-specific functions in cultured cells. A combination of dexamethasone and insulin was apparently effective in stimulating the formation of a monolayer of polygonal cells with granular cytoplasm and in maintenance of liver-specific functions for relatively longer periods. Supplementation with either dexamethasone or hydrocortisone alone enhanced tyrosine aminotransferase activities in cultured cells for at least 4 days postinoculation. These steroid hormones also allowed growth of small epithelial cells with clear cytoplasm and maintenance of increased albumin production for 8 days after inoculation. The roles of these hormones in the primary culture of isolated hepatic cells are discussed in the present paper.

Animals↗