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Biomedical subjects

J Ono

Publications and source records attributed to J Ono.

At least 235 records · Page 13Linked to original sources
PubMed1979

Simple method for the collection of pancreatic islets by the use of Ficoll-Conray gradient.

Simple method for the collection of large numbers of viable pancreatic islets from normal rats is described. This method involves collagenase digestion of the pancreas, followed by the use of Ficoll-Conray discontinuous gradient for the separation of isolated islets from unwanted acinal debris. Ficoll-Conray A solution was prepared by mixing undialyzed 12.5% Ficoll and 33.4% Conray in the ratio 2 : 1, to make a specific gravity of 1.095 and osmolarity of 396 mOsm/l. The solution B, C, and D, with specific gravities 1.084, 1.072, and 1.048, respectively were obtained by diluting A solution with distilled water. Using Ficoll-Conray gradient, about 200 viable islets which maintained excellently their morphology and function, were collected consistently from a young adult rat pancreas.

Animals↗
PubMed1979

Studies of the functional and morphologic status of islets maintained at 24 C for four weeks in vitro.

Isolated rat islets were maintained in vitro at 24 C for 1-4 weeks in tissue culture medium containing D-glucose (1.5 mg/ml). The rate of insulin release at 24 C remained stable for three weeks (2.2 muU/islet/hr) and decreased to 1.2 muU/islet/hr during the fourth week. Increasing the temperature from 24 C to 37 C at the end of 1, 2, 3, or 4 weeks produced a 5--7-fold increase in the rate of insulin release in the presence of glucose (1.5 mg/ml). This rate of secretion was comparable to control islets maintained at 37 C for 1--4 weeks. Light- and electron-microscopic studies revealed minimal central necrosis of large islets maintained at 24 C for 3 weeks. In contrast, extensive central necrosis was present in large islets maintained at 37 C for only 1 week. Degranulation of B cells occurred at 24 C with almost complete degranulation at 28 days. Regranulation occurred when the temperature was increased to 37 C. These findings indicate that isolated islets maintained at 24 C remain functionally and morphologically intact for 4 weeks. Initial studies have shown that maintenance of islets at 24 C for 1 week in conjunction with a single injection of antilymphocyte serum will produce marked prolongation of survival of islet allografts. The finding that isolated islets will survive for prolonged periods of time at 24 C should be of importance to future studies on islet transplatation, immune rejection, and investigations on hormonal release from islets maintained under these conditions.

Animals↗
PubMed1978

Tryptophan and hepatic coma.

To clarify the involvement of tryptophan in the pathogenesis of hepatic coma, plasma and cerebrospinal fluid (CSF) tryptophan was studied in three patient groups (hepatic coma, stable cirrhosis, and control). An assessment of free fatty acids, some of the amino acids reported to compete with tryptophan for brain uptake, and albumin was also made. The data demonstrated that, whereas the elevated CSF tryptophan levels in cirrhotic patients compared to controls may have been attributable to decreased plasma branched chain amino acids, the elevated CSF tryptophan levels in hepatic coma compared to stable cirrhotic patients were probably attributable to increased plasma free tryptophan concentrations. Associated with the elevated plasma free tryptophan in coma patients was an increase in plasma free fatty acids and a marked decrease in serum albumin levels. Of all the amino acids investigated in the CSF, only tryptophan was significantly increased in patients in hepatic coma compared to cirrhotic patients not in coma.

Amino Acids↗
PubMed1977

Three glucose 6-phosphate dehydrogenase variants found in Japan.

Three Japanese glucose 6-phosphate dehydrogenase (G6PD) variants were investigated. G6PD 'Mediterranean-like' had markedly decreased activity, normal electrophoretic mobility, low Km G6P, low Km NADP, increased utilization of all three substrate analogues (2-deoxy-G6P, Gal-6P, and deamino-NADP) and slightly decreased heat stability and slightly biphasic pH curve. G6PD 'Ogori' had markedly decreased activity, but otherwise normal characteristics. G6PD 'Hofu' had moderately decreased activity, normal electrophoretic mobility, slightly reduced Km G6P, normal Km NADP, normal utilization of 2-deoxy-G6P and Gal-6P, but increased utilization of deamino-NADP and normal heat stability as well as normal pH curve.

Adolescent↗
PubMed1977

Preparation of single cells from pancreatic islets of adult rat by the use of dispase.

A high yield of viable single cells was attained from isolated pancreatic islets of adult rat by the sequential treatment with EDTA and Dispase. The percentage of single cells was consistently higher with EDTA-Dispase in comparison with EDTA-trypsin treatment, being 65.8 +/- 7.9% and 36.0 +/- 5.4% respectively, when more than 90% of total islet cells were viable. Excellent preservation of free islet cells dissociated with EDTA-Dispase was demonstrated morphologically by light and electron microscopy. The secretory response of dissociated B cells to glucose was stabilized earlier with EDTA-Dispase than with EDTA-trypsin treatment. The amount of insulin released into the medium was proportional to the number of cells inoculated, thus permitting the quantitative analysis of B-cell function in vitro.

Animals↗
PubMed1977

G6PD Ube, a glucose-6-phosphate dehydrogenase variant found in four unrelated Japanese families.

A total of 6,120 Japanese males were screened for glucose-6-phosphate dehydrogenase deficiency (G6PD). Five cases with the deficiency were discovered. Two of them and an additional two cases have the same variant, G6PD Ube, characterized by moderate enzyme deficiency, fast moving enzyme activity on electrophoresis, high Ki Nadph, utilization of substrate analogues, kinetics, pH optima, and stability. This variant was distinguished for G6PD A- and from other Oriental variants by biochemical parameters. Differences in the frequency and type of the variants between southern Asia and Japan, suggest that the Japanese who have been isolated on islands where malaria is not endemic, may have developed their own variant traits.

Adult↗
PubMed1976

Two new glucose 6-phosphate dehydrogenase variants associated with congenital nonspherocytic hemolytic anemia found in Japan: GD(-) Tokushima and GD(-) Tokyo.

Two new variants of glucose 6-phosphate dehydrogenase (G6PD) deficiency associated with chronic nonspherocytic hemolytic anemia were discovered in Japan. Gd(-) Tokushima was found in a 17-years-old male whose erythrocytes contained 4.4% of normal enzyme activity. Partially purified enzyme revealed a main band of normal electrophoretic mobility with additional two minor bands of different mobility; normal Km G6P, and Km NADP five-to sixfold higher than normal; normal utilization of 2-deoxy-G6P, galactose-6P, and deamino-NADP; marked thermal instability; a normal pH curve; and normal Ki NADPH. The hemolytic anemia was moderate to severe. Gd(-) Tokyo was characterized from a 15-year-old male who had chronic nonspherocytic hemolytic anemia of mild degree. The erythrocytes contained 3% of normal enzyme activity, and partially purified enzyme revealed slow electrophoretic mobility (90% of normal for both a tris-hydrochloride buffer system and a tris-EDTA-borate buffer system, and 70% of normal for a phosphate buffer system); normal Km G6P and Km NADP; normal utilization of 2-deoxy-G6P, galactose-6P, and deamino-NADP; greatly increased thermal instability; a normal pH curve; and normal Ki NADPH. These two variants are clearly different from hitherto described G6PD variants, including the Japanese variants Gd(-) Heian and Gd(-) Kyoto. The mothers of both Gd(-) Tokushima and Gd(-) Tokoyo were found to be heterozygote by an ascorbate-cyanide test.

Adolescent↗
PubMed1976

Fine structures of the spleen in hereditary elliptocytosis.

Light and electron microscopic studies of the spleen and liver from a patient with hereditary elliptocytosis have been reported. Characteristic findings are congestion of the cordal space, diminished variation of the erythrocyte shape in the cord, relatively empty sinuses and erythrophagocytosis by the cordal macrophages. The same basic defect of the red cell membrane as has been documented in hereditary sperocytosis might be a possible explanation on the pathogenesis of this rare hemolytic anemia.

Elliptocytosis, Hereditary↗