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Biomedical subjects

Y Matsushima

Publications and source records attributed to Y Matsushima.

At least 19 recordsLinked to original sources
PubMed1979

Tagging of sugars with a fluorescent compound, 2-aminopyridine.

Potential aldehyde groups of several monosaccharides and oligosaccharides were coupled with 2-aminopyridine by reductive amination with sodium cyanoborohydride. The product was isolated by adsorption on a Dowex 50 (H+) column, followed by washing, elution with aqueous ammonia and evaporation. The specimen was analyzed by paper electrophoresis at pH 5.0. Each sugar derivative gave a single spot in addition to one corresponding to excess 2-amino-pyridine when the paper was scanned under a UV lamp. The migration rates of these fluorescent sugars were related to their molecular weights and were independent of their linkage points and anomeric configurations. The reducing end sugar units of oligosaccharide derivatives could be identified by gas-liquid chromatography after hydrolysis of the 2-aminopyridine derivatives of the oligosaccharides.

Aminopyridines↗
PubMed1979

Comparative studies of three exo-beta-glycosidases of Aspergillus oryzae.

beta-Glucosidase [beta-D-glucoside glucohydrolase EC 3.2.1.21] and beta-galactosidase [beta-D-galactoside galactohydrolase, EC 3.2.1.23] of Takadiastase were purified by acetone fractionation, DEAE-cellulose, and hydroxylapatite chromatography. Purity was confirmed by disc electrophoresis, ultracentrifugation and measurement of other glycosidase activities which coexisted in Takadiastase. Molecular weight of the beta-glucosidase was 218,000 by sedimentation equilibrium and 110,000-116,000 by SDS-disc electrophoresis. Molecular weight of the beta-galactosidase was 112,000 by sedimentation and 56,000-59,000 by SDS-disc electrophoresis. These values showed that both enzymes consisted of two subunits. Taka-beta-N-acetylglucosaminidase also consisted of two subunits. Both enzymes were glycoproteins containing glucosamine and neutral sugar. Stability, pH optima, isoelectric points, and some specificities were observed.

Acetylglucosaminidase↗
PubMed1979

Analyses of oligosaccharides by tagging the reducing end with a fluorescent compound. I. Application to glycoproteins.

The reducing end sugar of an oligosaccharide and 2-aminopyridine were linked by means of reductive amination with sodium cyanoborohydride. The fluorescent derivative of the oligosaccharide thus obtained, which had a positive charge, was subjected to two-dimensional paper electrophoresis. In the first direction, the sugar derivative moved according to its degree of polymerization, and in the second direction, it moved according to the structure of the borate complex. In this way fluorescent derivatives of saccharides were mapped on a sheet of paper. The method was applied to some known mono- and oligosaccharides and to the saccharides obtained by nitrous deamination of the oligosaccharide portions of glycoproteins (fetuin, Take-amylase A, and ovalbumin). The fingerprints thus obtained were characteristic of the chemical structures of the original oligosaccharides.

Aminopyridines↗
PubMed1979

Cell wall-bridge maintaining three dimensional structure of cell packets formed by the localized suppression of cell separation of a Micrococcus lysodeikticus (luteus) mutant.

Cell packets of Micrococcus lysodeikticus (luteus) mutant strain MT grown in medium supplemented with trypsin consisted of a tetrad as the unit structure. An interstice was observed between the unit-tetrads, and a three dimensional structure of cell packets was maintained by the cell wall-bridge along the rim of the cell packets which linked each unit-tetrad. This unique structure of strain MT cell packets seemed to occur when the cell separation was suppressed locally, i.e., when the cross wall inside the initial site of cell separation was cut off, while the wall outside the initial site of separation was not cut off but remained as a joint of the daughter cells. The mechanism of cell wall-bridge formation is discussed in connection with cell separation.

Amino Acids↗
PubMed1979

Effect of hypophysectomy and growth hormone administration on somatostatin content in the rat hypothalamus.

The effect of hypophysectomy and bovine GH administration on somatostatin (SRIF) content in the rat hypothalamus was investigated. SRIF content was determined by a specific radioimmunoassay method described elsewhere. The total SRIF content of the rat hypothalamus as well as its content per milligram wet weight had decreased 4 weeks after hypophysectomy but was restored significantly in those rats which were subjected to bovine GH administration for 7 days 3 weeks after hypophysectomy. Furthermore, in nonoperated rats, increase of hypothalamic SRIF content was observed after 7 days GH administration. These results indicate that growth hormone may influence the SRIF content of hypothalamus and it seems likely that a feedback mechanism between pituitary GH and hypothalamic SRIF exists.

Animals↗
PubMed1979

Changes in pancreatic somatostatin content in spontaneously diabetic mice, as determined by radioimmunoassay and immunohistochemical methods.

A specific RIA for somatostatin (SRIF) was used to determine the SRIF content of the pancreas and hypothalamus in spontaneously diabetic C57BL/KsJ dbdb and C57BL/6J obob mice. In addition, SRIF- and glucagon-containing cells were examined in the pancreatic islets with an immunohistochemical technique. In dbdb mice, immunoassayable pancreatic SRIF content was increased, as was the number of SRIF- or glucagon-containing cells. In obob mice, immunoassayable pancreatic SRIF content was also increased, but no increase was noted in the number of SRIF- or glucagon-containing cells. The hypothalamic SRIF content of either strain was not different from that of controls. These results regarding pancreatic SRIF content were in accord with some but not all previous reports. These differences may be related to the age of the mice or to the conditions in which they were bred. The pancreatic SRIF increase in both dbdb and obob mice may be attributable to hyperglucagonemia, hyperglycemia, or a decrease in insulin action. Further work is necessary to clearly delineate the mechanism.

Animals↗
PubMed1979

Divalent cation transport in kidney slices. I. Properties of calcium transport in slices of rat kidney cortex and the effects of diuretics.

Correlative studies on transports of Ca2+ and Na+ and the properties of Ca2+ transport were carried out in rat kidney cortex slices. Ouabain had no effect on the Ca2+ transport but did inhibit the Na+ transport extensively. With addition of 2,4-dinitrophenol to the incubation medium, or under the anaerobic conditions, the effluxes of Ca2+ and Na+ were inhibited while the Ca2+ influx was enhanced significantly. Sulfhydryl inhibitors such as ethacrynic acid, mersalyl and p-chloromercuribenzoic acid suppressed Ca2+ efflux and stimulated Ca2+ influx. When the slices of kidney cortex were treated with these inhibitors, there was a reduction in the content of cellular ATP. The present results suggest that Ca2+ transport may be partly independent of Na+ transport, and that Ca2+ efflux may require energy-yielding processes.

Adenosine Triphosphate↗
PubMed1979

Complex formed from 3-hydroxy-4-formylpyridine, glutamic acid, and technetium--a possible cholescintigraphic agent.

In order to obtain a technetium-99m-labeled cholescintigraphic agent suitable for kit preparation, reactions of a variety of aromatic aldehydes, amino acids, and [99mTc] pertechnetate were examined under mild conditions. Aqueous solutions of the three reactants were heated in a boiling-water bath and the products analyzed by means of thin-layer chromatography for the formation of organic technetium complexes. 3-Hydroxy-4-formylpyridine (HFP) and 1-methyl-3-hydroxy-4-formylpyridinium chloride (N-Me-HFP) formed the complex with excellent yields, whereas 3-hydroxy-2-formylpyridine, 4-nitrosalicylaldehyde, salicylaldehyde, and isonicotinaldehyde did not. The complex is concluded to be the Tc-99m chelate of the Schiff base formed from the aldehyde and amino acbbits administered with the complex of HFP, glutamic acid and Tc-99m. The results indicate that it is promising as a cholescintigraphic agent.

Animals↗
PubMed1978

[The effect of Ritalin, CB-154 and various drugs of serum GH in acromegalics (author's transl)].

The present study was undertaken to investigate the effects of dopaminergic agents and hypothalamic-releasing hormones on the GH release in acromegalics and normal volunteers. In the methylphenidate (Ritalin) test, nine normal volunteers and four acromegalics were examined. In other tests, five acromegalics were examined. The dopaminergic agents were administered to the subjects orally early in the morning after overnight fasting, but the hypothalamic-releasing hormones were given intravenously at the same time. The results were as follows: (1) The oral administration of 20 mg of Ritalin failed to have any effect on the GH release in normal subjects, and caused a decrease of serum GH level in only one of four acromegalics, the same case which showed an increased GH response to 1-DOPA. In the other three patients, Ritalin did not effect the GH release. Long-term administration of this drug to the acromegalics who showed depression of GH levels resulted in only slightly depressed GH levels. (2) Each oral administration of 2.5 mg of CB-154 or 500 mg of 1-DOPA caused a significant decrease of serum GH level in acromegalics, but CB-154 showed a longer and more stable suppression of serum GH level in all acromegalics. Furthermore, long-term administration of this drug resulted in a continuing inhibited serum GH level without the existence of any serious side effects. It thus seems likely that CB-154 might be a safe and effective drug for the medical treatment of acromegalics. However, while 1-DOPA also caused a significant decrease of serum GH level in four out of five acromegalics, its effect was of much shorter duration. (3) The intravenous administration of 500 microgram of TRH showed a significant increase of serum GH level in four out of five acromegalics, but LH-RH did not have any effect on GH release in any of the acromegalic cases. It seems likely from these results that dopaminergic agents, especially CB-154, may be beneficial for the medical treatment of acromegaly.

Acromegaly↗