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Biomedical subjects

K Okamura

Publications and source records attributed to K Okamura.

At least 577 records · Page 32Linked to original sources
PubMed1977

Purification and characterization of two types of esterase from rat liver microsomes.

It was found that about 90% of the triacylglycerol lipase activity of a rat liver microsomal fraction was released by heparin treatment. The residual microsomal fraction contained about 95% of the esterase activity but little triacylglycerol lipase activity. Two kinds of esterase (esterases I and II) were purified from this residual fraction by DEAE-cellulose chromatography, hydroxyapatite chromatography, isoelectric focusing and Sephadex G-200 chromatography. The final preparations of esterases I and II, which were puri fied 70-and 140-fold, respectively, gave single protein bands on polyacrylamide gel and sodium dodecyl sulfate-gel electrophoreses. The molecular weights of esterases I and II were calculated to be about 70 000 and 160 000 by gel filtration of Sephadex G-200. Their isoelectric points were 5.82 and 6.32. Both esterases completely hydrolyzed short-chain triacylglycerols, such as tributyrylglycerol, but did not hydrolyze long-chain triacylglycerols. They preferentially hydrolyzed medium-chain-length 1-monoacylglycerols, such as 1-monocaprylylglycerol. Esterase I differed immunologically from esterase II and it was found to constitute about 30% of the total esterase activity in the microsomal fraction; esterase II constituted 50--60%. These results show the existence of two isozymes of esterase in the microsomal fraction.

Animals↗
PubMed1976

Congenital oculoskeletal myopathy with abnormal muscle and liver mitochondria.

We report a 22-year-old very thin man, who showed various symptoms and signs of oculoskeletal muscle weakness, episodes of myalgia, prolonged diarrhea, severe myopia, perceptive deafness, electrocardiographic and electroencephalographic abnormalities, and endocrinological abnormality. The onset was at about 3 months of age and a positive family history was strongly suggested. The light-microscopic, histochemical and electron-microscopic findings showed abnormal mitochondria not only in the skeletal muscle, but also in liver cells. From the clinical as well as morphological points of view, this case was suspected to be one of congenital oculoskeletal myopathy probably due to an unidentified systemic metabolic disorder.

Heart↗
PubMed1976

The role of C1 esterase inhibitor in the activation of C1r, a subcomponent of the first component of complement from human plasma.

Clr was isolated from human serum by DEAE-cellulose column chromatography in the presence of EDTA. The isolated Clr did not hydrolyze N(alpha)-acetyl-L-arginine methyl ester, unless activated by brief treatment with trypsin [EC 3.4.21.4]. On thecolumn, the C1 esterase inhibitor activity was found to coincide with Clr but not C1s (another subcomponent of the first component) C1r was isolated from the euglobulin fraction of human serum by DEAE-cellulose column chromatograph. On Sephadex G-200 column chromatography, Clr was eluted in the void volume, whereas Clr was eluted in a position corresponding to a molecular weight of 140,000-160,000. The results indicated that, on activation, Clr was converted to an enzyme of lower molecular weight...

Chromatography, Ion Exchange↗
PubMed1976

A study on Mallory bodies. Isolation, ultrastructure and preliminary biochemical characterization of Mallory bodies from livers of alcoholic cirrhosis and malignant hepatoma.

Mallory bodies (MBs) were isolated from the livers of 8 alcoholic patients and a malignant hepatoma occurring in a non-alcoholic patient. MBs were isolated in large quantity and high purity. The isolates were devoid of liver cell organelles except in the case of malignant hepatoma where dense and membranous material resembling nuclear substances and endoplasmic reticulum were found. The "nuclear" material had continuity with MBs. Electron microscopic examination suggested the presence of a dense body and very fine filaments within in situ and isolated MBs in addition to the tubular structure of so-called MB fibers. Amino acid analysis indicated that the major component of MBs is a protein which does not contain unusual amino acids or any particular amino acid in a large quantity to characterize this protein. The isolated fractions were solubilized in 6 M guaindine hydrochloride by sonication or in 1% sodium dodecyl sulfate (SDS) with 2 mercaptoethanol and 8 M urea. The solubilized MB protein produced 3 peaks by Sephadex G 100 chromatography and at least five intense protein bands by SDS polyacrylamide gel electrophoresis. Serum sample and the fractions from control livers contained several protein bands which were similar to the major components of isolated MB protein. These morphological and biochemical findings suggest that MBs are not homogeneous protein, but they are probably complexes of various proteins and that some components of MBs are present in normal hepatocytes.

Aged↗