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Biomedical subjects

J Sato

Publications and source records attributed to J Sato.

At least 433 records · Page 24Linked to original sources
PubMed1984

Comparison of cytologic and biochemical properties between liver cells isolated from adult rats by trypsin perfusion and those isolated by collagenase perfusion.

Primary cultures of liver cells isolated from adult rats by trypsin and collagenase perfusion techniques were carried out to compare cytologic and biochemical properties between the differently prepared cells. Trypsin-dispersed cells consisted of comparatively smaller cells, whereas collagenase-dispersed cells consisted of larger cells. The cell attachment efficiency on culture day 1 was about twice as high in the liver cells prepared with collagenase than those prepared with trypsin. Mature hepatocytes isolated by collagenase perfusion could be maintained in the primary culture for a longer period than those isolated by trypsin perfusion. Epithelial-like clear cells started to grow much earlier in the primary culture of the trypsin-dispersed liver cells than in that of the collagenase-dispersed liver cells. Earlier proliferation of epithelial-like clear cells could not be induced by in vitro trypsinization of the collagenase-dispersed liver cells. Both kinds of enzymatically prepared liver cells showed albumin production and exhibited glucose 6-phosphatase (D-glucose-6-phosphate phosphohydrolase, EC 3.1.3.9, G6Pase) and tyrosine aminotransferase (L-tyrosine: 2-oxoglutarate amino-transferase, EC 2.6.1.5, TAT) activities for 1 week in the primary culture. Albumin production was higher in the liver cells prepared with collagenase than those prepared with trypsin, whereas G6Pase activity was almost the same between them. TAT activity up to culture day 2 was about 3-fold higher in the liver cells prepared with collagenase than in those prepared with trypsin. Combined supplementation of dexamethasone (1 X 10(-5)M) and insulin (10 micrograms/ml) consistently improved the cell attachment efficiency and was very effective in the maintenance of mature hepatocytes in both types. Furthermore, these hormones enhanced the albumin production and TAT activity in both types.

Albumins↗
PubMed1984

Preparation and primary culture of liver cells isolated from adult rats by dispase perfusion.

The dispase perfusion technique was used to isolate liver cells from adult rats. The optimum conditions for obtaining many isolated liver cells with high viability were an enzyme concentration of 2000 U/ml, a pH of 7.5 and a perfusion time of 20 min. The population of isolated liver cells prepared with dispase consisted of 43.6% cells with diameters less than 20 micron and 56.4% cells with diameters above 20 micron. The isolated liver cells were cultured in basal culture medium either supplemented with or without dexamethasone (1 X 10(-5)M) and insulin (10 micrograms/ml). The addition of hormones to the culture medium improved the attachment efficiency of the isolated liver cells and delayed the disappearance of mature hepatocytes. Epithelial-like clear cells proliferated early in primary culture even in the presence of hormones. Therefore, functioning mature hepatocytes and proliferating epithelial-like clear cells coexisted well in the hormone-containing medium. Furthermore, the number of cultured cells reached a maximal level earlier in the presence of hormones than in the absence of hormones. The level of TAT activity in primary cultured cells was higher up to 3 days after inoculation in the presence of hormones than in their absence. No difference between G6Pase activity in primary cultured cells in the presence of hormones and that in the absence of hormones was found.

Animals↗
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↗
PubMed1984

Intestinal-type alkaline phosphatase produced by human hepatoblastoma cell line HUH-6 clone 5.

Two enzyme forms of alkaline phosphatase have been partially purified from the medium spent for the culture of HUH-6 clone 5 cells, which were originally derived from hepatoblastoma tissue. The purification methods used are ammonium sulfate precipitation, ethanol precipitation, diethylaminoethyl cellulose chromatography, Affi-Gel Blue chromatography, and Sephadex G-200 gel filtration. These alkaline phosphatases have been characterized by thermostability, inhibition, and immunological and electrophoretic studies. Both are L-phenylalanine and L-tryptophan sensitive and L-homoarginine and L-leucylglycylglycine insensitive, and both react with an antiserum against intestinal alkaline phosphatase. The major enzyme form is a neuraminidase-cleavable, moderately thermostable isoenzyme which on polyacrylamide gel shows an electrophoretic mobility similar to that of liver alkaline phosphatase. The minor enzyme form is a neuraminidase-uncleavable, thermolabile isoenzyme which shows an intermediate electrophoretic mobility between liver and hepatoma alkaline phosphatases. The molecular weights of the major and minor enzymes have been estimated by gel filtration to be 170,000 and 110,000, respectively. These results support the conclusion that the two enzyme forms of HUH-6 alkaline phosphatase are intestinal in type, with the major enzyme form closely resembling hepatoma and oncoamnionic alkaline phosphatases, and the minor enzyme form resembling "intestine-like liver alkaline phosphatase." HUH-6 clone 5 cell line may be a useful in vitro model to study the regulatory mechanism for phenotypic expression of intestinal-type alkaline phosphatase isoenzymes in liver cancer cells.

Alkaline Phosphatase↗
PubMed1984

Improved assay for alcohol dehydrogenase activity in serum by centrifugal analysis.

We describe an improved method for determination of alcohol dehydrogenase (EC 1.1.1.1) activity in 60 microL of human serum, based on conversion of ethanol to acetaldehyde with simultaneous reduction of NAD+ in glycine NaOH buffer (pH 9.0) at 37 degrees C in a centrifugal analyzer. The final concentration of NAD+ was 10 mmol/L and ethanol was 20 mmol/L. The dilution curve was linear with enzyme activity up to 200 U/L, and results by this method correlated well with those by a manual method (N Engl J Med 279: 241-248, 1968). Within-run precision (CV) was 0.9 to 8.2% over the range of 4.5 to 88.1 U/L, and day-to-day precision was 5.4 to 5.6%. In sera from 198 healthy individuals, mean alcohol dehydrogenase activity was 1.6 (SD 1.2, range 0-5) U/L. To evaluate the clinical utility of determining alcohol dehydrogenase, we measured the activity of alanine aminotransferase and alcohol dehydrogenase in sera from 470 patients with various diseases in our hospital, and found that results for the two enzymes did not correlate well.

Adult↗
PubMed1984

[Clinical results of cefaclor treatment of infections of oral regions].

Cefaclor (CCL) is a cephem antibiotic for oral use. Thirty cases of infection of oral regions, in the First Department of Oral and Maxillofacial Surgery, School of Dentistry, the University of Tokushima, were treated with CCL at 750 mg/day. The results were as follows: The efficacy rate for all kinds of diseases was 80.0% in 3 days and 96.7% in 5 days and 86.7% as an overall assessment by the patients' doctors. With regard to the degree of symptoms, the efficacy rate for cases with moderate symptoms was less than that for mild cases in 3 days and according to the assessment by the patients' doctors. Some moderate cases required increased medication because no beneficial effect was observed. In sensitivity tests, CCL was shown to be effective on all 27 isolated clones of bacteria tested. CCL caused no detectable changes in laboratory data. No side effects were observed in any case. From these results, it is concluded that CCL is a highly effective antibiotic for use on infections of the oral regions.

Administration, Oral↗
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

Adult T-cell leukemia. Chromosome analysis of 15 cases.

Chromosome studies was conducted on 15 patients with adult T-cell leukemia. Cells with chromosomal abnormality were seen in 14 of the 15 patients. The modal chromosome number was near diploid range in all the patients. The most common abnormality was 14q+ marker chromosome and partial deletion of the long arm of chromosome 6, i.e., 6q-, which were seen in eight and seven cases, respectively. Donor chromosomes involved in the 14q+ marker chromosome varies, i.e., Yq, #5p, #5q, #9q, #10q or #12q, except for two patients whose donor chromosome origins were unable to determine. The break point in 14q+ marker chromosome was band at q32. The 6q- chromosome was due to a deletion in one patient and interstitial deletion in six patients. A 14q- chromosome having break point at q24 was found in one patient and duplication of Yq chromosome in two patients. In addition, four patients showed a 5q- chromosome or a 9q- chromosome which was due to a translocation or deletion. The significance of these chromosome abnormalities was discussed.

Adult↗
PubMed1983

Effects of dibutyryl cyclic AMP on the syntheses of dolichol-linked saccharides and glycoproteins in cultured hepatoma cells. Correlation with the effect on the adhesiveness of the cells.

When the hepatoma cells (AH 70Btc, Clone 10-5) were cultured in the presence of 1 mM-dibutyryl cyclic AMP for 2 days, the incorporation of [14C]glucosamine into protein was increased over 2-fold. At the same time, dibutyryl cyclic AMP increased the incorporation of [14C]glucosamine into dolichol-linked N-acetylglucosamine and NN'-diacetylchitobiose about 1.5-fold and into dolichol-linked oligosaccharides about 3-fold. Analysis of cellular glycoproteins by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis after reduction showed that dibutyryl cyclic AMP specifically enhanced the glycosylation of a fibronectin-like glycoprotein with an apparent mol.wt. of 220 000 and two other high-molecular-weight glycoproteins (apparent mol.wts. 270 000 and 185 000). Increased glycosylation of the glycoproteins with mol.wts. of 220 000 and 185 000 was shown to be linked to increased synthesis of the polypeptide portion. In addition to the above effects, dibutyryl cyclic AMP enhanced the adhesiveness of AH 70Btc cells to glass surfaces. Both the effects on the glycosylation pathway and on adhesiveness of cells were reversed by further treatment of the cells with 1 microgram of tunicamycin/ml. The results indicated that dibutyryl cyclic AMP increased the synthesis of dolichol-linked oligosaccharides and N-glycosylation of proteins in AH 70Btc cells. The enhancement of adhesiveness may be mediated by the increased synthesis of dolichol-linked oligosaccharides and also may be related to the increased synthesis of fibronectin.

Animals↗
PubMed1983

Production of fibronectin by HUH6 C15 cell line established from a human hepatoblastoma.

Fibronectin was detected by indirect immunofluorescence on the cell surfaces of HUH6 C15 cells, established from a human hepatoblastoma and maintained with serum-free RPMI 1640 medium. Fibronectin synthesized by HUH6 Cl5 was purified by gelatin-Sepharose affinity chromatography and compared with human plasma fibronectin in respect to molecular weight, electrophoretic mobility and antigenicity. Fibronectin synthesized by this cell line was proved to be identical with human plasma fibronectin.

Carcinoma, Hepatocellular↗
PubMed1983

Effect of quinidine on digoxin distribution and elimination in guinea pigs.

The effect of quinidine on the distribution and elimination of digoxin was examined by comparing the change in the steady-state volume of distribution (Vdss), determined both from in vivo plasma elimination and tissue distribution and in vitro serum binding studies, with that in the total body clearance (CLtot) determined from biliary, renal, and metabolic clearances in guinea pigs. The plasma disappearance of digoxin after a 250-micrograms/kg iv dose followed a triexponential decline in both the control and quinidine-treated guinea pigs. In the quinidine-treated guinea pigs, the pharmacokinetic parameters Vdss and CLtot significantly decreased to approximately half of that for the control guinea pigs. The tissue-to-plasma partition coefficients (Kp) of all tissues studied, i.e. liver, heart, muscle, and brain, at 6 hr after bolus injection of digoxin decreased in the presence of quinidine. The serum free fraction and the plasma-to-blood concentration ratio of digoxin in the therapeutic range did not show a significant alteration in the presence of quinidine. This suggested that the decrease of Kp is due mainly to the inhibition of tissue distribution of digoxin by quinidine. The biliary clearance (CLB) and renal clearance (CLR) also significantly decreased in the presence of quinidine. It was concluded that quinidine caused a inhibition of digoxin in the tissue binding or uptake, which significantly decreased the Kp values of digoxin; this result may explain the significant decrease of Vdss. Moreover quinidine may be the cause of a reduction of biliary, renal, and metabolic clearances, which significantly decrease the CLtot of digoxin.

Animals↗
PubMed1983

Effect of acetazolamide on the anticonvulsant potency of several antiepileptic drugs in mice.

Effect of acetazolamide (AZA) on the anticonvulsant potency of several antiepileptics was investigated in mice by maximal electroshock seizure test. By the coadministration of AZA, a remarkable increase in the anticonvulsant activity was brought about not only for the barbiturates including barbital (BA), mephobarbital (MB) and metharbital (MET), but also for the other antiepileptics such as phenytoin (PHT), valproic acid (VPA) and trimethadione (TMO). This potentiating effect of AZA, however, was relatively weak for PHT, MET and TMO (about 2.5 fold) in contrast to those for phenobarbital (PHB), BA, MB and VPA (4-5 fold). The brain-serum concentration ratio (B/S) of PHB was elevated by the coadministration of AZA, while the B/S of PHT was not changed. Thus it was inferred that the difference in the potentiating effect of AZA on the activity of the antiepileptics was due to the difference in its effect on the brain levels of the antiepileptic drugs. However, the potentiating effect of AZA was still observed for PHT, VPA and MET, as well as PHB, in reserpinized mice. Therefore, some pharmacodynamic effect of AZA other than its increasing effect on the brain levels of the antiepileptic drugs may partly contribute to the potentiation of the activity of the antiepileptic drugs.

Acetazolamide↗
PubMed1983

Effect of acetazolamide on barbiturate-induced sleeping time in mice. III. Pharmacokinetics of serum elimination and brain distribution.

Effects of acetazolamide (AZA) on the serum elimination and brain distribution of barbital (BA), phenobarbital (PHB), pentobarbital (PEB) and hexobarbital (HB) were studied in mice. When the barbiturates were administered intraperitoneally to mice, the pretreatment of AZA reduced the serum BA and PHB levels, and significantly increased these brain levels. While relatively small and no effects of AZA were observed for the PEB and HB levels, respectively. After the intravenous administration, the serum elimination of these barbiturates were described by the two compartment model. Although the pretreatment of AZA tended to increase the volumes of central compartment and decrease the elimination rate constants for BA, PHB and PEB, the elevated brain levels of the barbiturates could not be explained as the simulated peripheral concentrations. However, it appeared that the prolongation effect of AZA on the BA, PHB and PEB sleeps in mice was associated with the elevated brain barbiturate levels with AZA.

Acetazolamide↗
PubMed1983

Effect of 3'-methyl-N,N-dimethyl-4-aminoazobenzene in the presence or absence of liver microsomes on the liver cells having low tumor-producing capacity in culture.

A cell strain having low tumor-producing capacity was exposed in culture to 3'-methyl-N,N-dimethyl-4-aminoazobenzene (3'-Me-DAB) in the presence or absence of liver microsomes, and whether or not the cells will progress to those having high tumor-producing capacity was examined. When transplanted into rats, the cells treated with 3'-Me-DAB four (Exp-I) or thirteen times (Exp-II) formed larger tumors than untreated control cells, the latter treatment being more efficient in this regard. Furthermore, the tumors formed by the cells treated with 3'-Me-DAB in the presence of liver microsomes were considerably larger than those formed by the cells treated with 3'-Me-DAB alone. The subcutaneous tumors produced by the cells treated with 3'-Me-DAB with S-15 Mix showed poorly differentiated histology compared with those produced by control and 3'-Me-DAB-treated cells. The frequency of lung metastasis tended to increase by 3'-Me-DAB with S-15 Mix. The cells treated with 3'-Me-DAB in the presence or absence of liver microsomes differed from untreated control cells in vitro in some properties, including the size of aggregates in rotation culture, plating efficiency in liquid medium and morphology. These observations suggest that cell malignancy was promoted by 3'-Me-DAB alone as well as by 3'-Me-DAB in the presence of liver microsomes.

Animals↗