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Biomedical subjects

S Watabe

Publications and source records attributed to S Watabe.

At least 163 records · Page 9Linked to original sources
PubMed1982

Characterization of cathepsin D in porcine adrenocortical lysosomes.

More than 95% of the apparent cathepsin D activity in the lysosomes of porcine adrenal cortex was due to a genuine cathepsin D that has a molecular weight of 42,800 +/- 800 (mean +/- standard deviation of the mean in 5 runs) as determined by Sephadex G-100 column chromatography. On CM-Sephadex C-50 column chromatography at pH 6.9, the enzyme was resolved into five peaks which were termed Fractions D1 through D5 in order of their elution from the column. Fraction D4 and Fraction D5 together constituted more than 70% of the total cathepsin D, and were purified through chromatographic procedures to constant specific activities. The content of lysosomal cathepsin D was estimated to be about 1% of the total cellular protein. On isoelectric focusing, Fraction D4 was resolved into one major band with pI of 7.34 (termed Form D4-1) and one minor band of 7.20 (Form D4-2), while Fraction D5 gave one major band with pI of 7.50 (Form D5-1) and two minor ones of 7.37 (Form D5-2) and of 7.20 (Form D5-3). All of these 5 bands were enzymatically active. On SDS-polyacrylamide gel electrophoresis, both Form D4-1 and Form D5-1 dissociated into three subunits with molecular weights of 27,400 +/- 500 (termed Subunit A), 24,600 +/- 400 (Subunit B) and 13,800 +/- 600 (Subunit C) (mean +/- standard deviation of the mean in 16 determinations). The three subunits all contained carbohydrates.

Adrenal Cortex↗
PubMed1981

Characterization of porcine adrenocortical lysosomes.

Porcine adrenocortical lysosomes were characterized by differential centrifugation, acid hydrolase contents, latency of cathepsin D, release of bound acid hydrolases in soluble form, and isopycnic density gradient centrifugation. Cathepsins D and B, beta-N-acetylglucosaminidase, beta-galactosidase and arylsulphatase were found exclusively in the lysosomes, while alpha-mannosidase and beta-glucuronidase were in both the lysosomal and microsomal fractions. The activity of cathepsin D was remarkably high, amounting to more than 6 times that in porcine liver and to more than 10 times that in liver of Sprague-Dawley rats in terms of units per g wet tissue. Porcine adrenocortical lysosomes showed a modal isopycnic density value of 1.155, but mitochondria a value of 1.145. The validity of these values was studied by investigating the possibilities of agglutination of organelles, damage to lysosomal membranes, disruption of mitochondria due to the hydrostatic pressure and by applying the same procedures of isopycnic centrifugation to hog and rat livers. After these validity tests, porcine adrenocortical lysosomes were concluded to be unique in their strikingly high content of cathepsin D as well as in their low modal isopycnic density which is very close to that of porcine adrenocortical mitochondria.

Acetylglucosaminidase↗
PubMed1981

Isopycnic density values for lysosomes and mitochondria in rat adrenal cortex.

Adrenocortical tissues of male adult Wistar rats were fractionated by isopycnic density gradient centrifugation. Fractions were analyzed for density, protein and marker enzymes for lysosomes and mitochondria with rat liver being used as a reference tissue for subcellular enzyme distribution. Both lysosomes and mitochondria of adrenal cortex showed unimodal distribution profiles of marker enzymes with their modal isopycnic density values at 1.165. This value was significantly lower than the corresponding ones for lysosomes and mitochondria in rat liver but was very close to those in porcine adrenal cortex. Modal isopycnic density as well as distribution profiles of marker enzymes for lysosomes and mitochondria remained unchanged 24 hr after 0.1 or 10 units of ACTH (Cortrosyn Z) administration. As in porcine adrenal cortex, lysosomes in rat adrenal cortex were characterized by a higher content of cathepsin D than those in rat liver.

Adrenal Cortex↗
PubMed1981

Inhibition of mouse natural killer activity by cholera toxin.

The treatment of mouse spleen cells with cholera toxin (CT) extracted from Vibrio cholerae greatly reduced natural killer (NK) activity. The inhibition of NK activity was rapidly induced by CT treatment and persisted in the absence of CT. Even a very small amount of CT, such as 0.1 ng/ml, was effective in inhibiting NK activity. The inhibitory effect of CT on NK activity was lost upon preabsorption of CT with brain tissues, but not upon preabsorption with liver or kidney tissues.

Animals↗
PubMed1979

Ammonia metabolism in the rat liver in biliary obstruction.

Arginine synthetase activity and ammonia removal in liver slices were determined in rats with obstructive jaundice or acute carbon tetrachloride (CCl4)-induced liver dysfunction and the following results were obtained: (1) Urea synthesis and ammonia removal in liver slices progressively decreased with prolonged biliary obstruction. The effects of ATP and/or ornithine addition were also markedly decreased, particularly in the group with 6 weeks of biliary obstruction. (2) Arginine synthetase activity also fell with prolongation of biliary obstruction and the fall was most pronounced in the 6-week group. (3) The CCl4-induced liver dysfunction group showed a significantly higher level of arginine synthetase activity than the group with 6 weeks of biliary obstruction, but ammonia removal was markedly decreased and the effects of ATP and ornithine addition were prominent. From the results, it is concluded that, due to a fall in the enzyme activity of the urea cycle in obstructive jaundice, liver dysfunction can easily occur with prolongation of the obstruction, while hepatic urea cycle dysfunction is brought about by severe metabolic disruption in the liver damaged by CCl4.

Adenosine Triphosphate↗
PubMed1978

Purification and characterization of tetrahydrofolate.protein complex in bovine liver.

Gel filtration of bovine liver extract on a Sephadex G-200 column resolved three macromolecular fractions with dihydropteridine reductase-dependent cytochrome c reducing activity. One of the active fractions was purified from the extract through the steps of solvent fractionation, chromatography on DEAE-Sephadex, and gel filtration. Biochemical and microbiological analyses showed that the purified complex consists of a Mr = 70,000 protein and tetrahydropteroyldiglutamate. In contrast to the extreme lability of free tetrahydropteridines the complex was quite stable against autooxidation under aerobic conditions.

Animals↗
PubMed1977

A new enzyme, NADPH-dihydropteridine reductase in bovine liver.

An enzyme designated as NADPH-dihydropteridine reductase was found in the extract of bovine liver and partially purified. In contrast to NADH-dpendent dihydropteridine reductase [EC 1.6.99.7], the enzyme catalyzes the reduction of quinonid-dihydropterin to tetrahydropterin in the presence of NADPH. The two enzymes were separated by column chromatography on DEAE-sephadex. Tyrosine formation in the phenylalanine hydroxylation system was also stimulated by NADPH-dihydropteridine reductase. The existence of these two dihydropteridine reductases suggests that the tetrahydro from ofpteridine cofactor may be regenerated in two different ways in vivo.

Animals↗
PubMed1976

Clinical significance of Congo red test.

Clinical significance of Congo red test was studied, especially on its relation to the liver function and amyloidosis. No significant relationship was observed between Congo red test and Indocyanin green test in cases of various liver diseases except liver cirrhosis. Histological studies also revealed that there were no pathologic features specifically affecting Congo red index (CRI), even though CRI in cases of various liver diseases tended to be increased as compared with other diseases. As a cause of increased CRI which was seen most remarkably in cases of liver cirrhosis, obstructive change of the liver blood flow followed by the hepatic tissue damage is suspected. The concept that Congo red test is a kind of the hepatic excretory function test does not have, from our data, enough evidence. The present study confirmed our previous data on the fate of Congo red injected intravenously, which indicated that this test is one of the best tests available for RES function and this test is related mainly to Kupffer's cell rather than to the so-called hepatic excretory function. There were no cases which showed notable decrease of CRI in experimental amyloidosis and in clinical amyloidosis, and it can be said that Congo red test is not the best test for the diagnosis of amyloidosis.

Acute Disease↗
PubMed1976

Erythrocyte rosette forming activity of macrophage.

Erythrocyte rosette forming activities of the rat lung macrophage, peritoneal macrophage, Kupffer cells and expressed splenic cells were studied. The erythrocytes employed were fresh human red blood cell (RBC), fresh sheep RBC (SRBC), and tanned SRBC coated with bovine albumin or with bovine gamma-globulin. The macrophages were mixed with RBC at a ratio of 1 to 100 or 200 in gelatin veronal buffer or phosphate buffered saline. The experiments were carried out at 4 degrees C. No autologous serum nor anti-RBC serum was added to the experimental system. 10 to 20 per cent of the lung macrophages formed rosette and their entire surfaces were covered with RBC. The peritoneal macrophage and Kupffer cells were also capable of forming rosette with fresh SRBC as well as with SRBC coated with bovine albumin or with bovine gamma-globulin. Examinations for cell surface immunoglobulin of alveolar macrophage, peritoneal macrophage, Kupffer cells and splenic cells revealed that alveolar and peritoneal macrophages apparently possessed surface gamma-globulin and that almost all of these macrophages possessed surface immuno-globulin. In order to examine the effect of different natures of SRBC on in vivo phagocytosis, rats were immunized with SRBC by injecting various SRBC into the femoral or the portal vein and the hemagglutinin titer was studied. The maximum hemagglutinin titer was observed in the rat injected with fresh SRBC into the femoral vein and the minimum hemagglutinin titer was observed in the splenectomized rat injected with fresh SRBC and in the rat injected with SRBC coated with albumin or gamma-globulin into the femoral or portal vein. Immunological role of Kupffer cells was discussed.

Animals↗
PubMed1975

Postoperative bronchopleural fistula: clinical and experimental study.

It is a well-known fact that in pulmonary tuberculosis patients treated by resection, the quality of the suture material used for closing the bronchial stump plays an important role in the pathogenesis of postoperative bronchopleural fistula. Of 426 cases treated surgically and in whom silk suture thread was used, 23 developed bronchopleural fistula, whereas none of the 220 cases sutured with nylon monofilament developed abnormality. Statistical analysis of 100 surgical cases with silk thread suture and of 100 cases with nylon monofilament suture showed that the two groups had no marked differences as to background factors. Howevers, as compared with the silk-thread suture group, the nylon-monofilament suture group revealed more consistently favorable postoperative bronchoscopic findings. Experimental studies with dogs showed a similar lack of complications when the monofilament suture material was used, as contrasted were conducted in hospital by the same surgical personnel using the same procedures, it can be said that, to insure prevention of complications, the suture material for bronchial stump closure should be of non-irritating nature and preferably of monofilament strength and quality, such as nylon monofilament.

Animals↗
PubMed1975

Lympho-reticuloendothelial activity of early gastric carcinoma.

The lympho-reticuloendothelial activities of 54 cases of early gastric carcinoma were studied. Morphological blastoid transformation of lymphocyte by the addition of phytohemagglutinin-P (PHA-P) was disturbed in half of the patients. The DNA synthesizing activity of lymphocyte was not stimulated by PHA-P in the cases of advanced carcinoma but it was stimulated in the cases of early carcinoma. The tuberculin reaction was negative in 30% of the cases of early carcinoma. The reticuloendothelial system (RES) activity studied through the congo red method revealed that 86% of the cases of early carcinoma had disturbed RES function.

Adolescent↗