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Biomedical subjects

T Miyatake

Publications and source records attributed to T Miyatake.

At least 307 records · Page 17Linked to original sources
PubMed1984

Degradation of myelin proteins by cathepsin B and inhibition by E-64 analogue.

Purified human brain myelin was isolated, heat-treated to inactivate the endogenous proteolytic activity and incubated with cathepsin B purified from rat liver, at pH 6.0. Incubation resulted in a marked reduction of myelin basic protein (BP) and partial breakdown of proteolipid protein or Wolfgram protein. Degradation of myelin proteins was inhibited by E-64 analogue (E-64-a). E-64 is a specific thiol protease inhibitor isolated from a solid culture of Aspergillus japonicus. The present study suggests that cathepsin B may play some role in demyelination.

Cathepsin B↗
PubMed1984

Isolation and characterization of a novel disialoganglioside from bovine adrenal medulla.

A novel GDlb ganglioside which contains only N-glycolylneuraminic acid was isolated from bovine adrenal medulla by DEAE-Sephadex A-25 and Iatrobeads column chromatography. The concentration of this ganglioside was 0.9 nmol lipid-bound sialic acid per gram fresh tissue, which accounted for 2.7% of the disialoganglioside fraction. The structure was elucidated by sugar analysis, neuraminidase digestion, and permethylation studies. The complete structure of this ganglioside was identified as GDlb (NeuGc)2 or II3 (NeuGc)2-GgOse4Cer.

Adrenal Medulla↗
PubMed1984

Ganglioside composition of chromaffin granule membrane in bovine adrenal medulla.

The ganglioside composition of chromaffin granule membranes of bovine adrenal medulla was investigated. Two major gangliosides, which accounted for over 95% of total gangliosides, were characterized as GM3 (NeuAc) and GM3 (NeuGc) by thin layer chromatography (TLC) and gas-liquid chromatography (GLC). Chromaffin granule membranes contained a relatively higher concentration of gangliosides than the membranes of other subcellular organelles; three times higher than microsomal membranes and seven times higher than mitochondrial membranes. This high concentration of ganglioside in chromaffin granule membranes could contribute to the high concentration of gangliosides in the adrenal medulla as compared to other extraneural tissues.

Adrenal Medulla↗
PubMed1984

Gangliosides and neutral glycolipids in guinea pig adrenal glands.

Glycolipids were isolated from the adrenal glands of seven strains of guinea pig by DEAE-Sephadex and Iatrobeads column chromatographies. The average lipid-bound sialic acid content of the adrenal glands was estimated to be 96.0 +/- 30.4 nmol/g fresh tissue. The ganglioside fraction contained two major gangliosides which accounted for 82% of the total lipid-bound sialic acid. They were identified as N-acetylneuraminylgalactosylceramide (GM4) and N-acetylneuraminyllactosylceramide (GM3). The neutral glycolipid fraction contained one major and three minor glycolipids. The major glycolipid was identified as galactosylceramide, which accounted for 81% of the total glycolipid. The other three glycolipids were identified as Forssman glycolipid (7%), lactosylceramide (5%), and gangliotriaosylceramide (7%). In all strains examined, the glycolipid patterns were similar.

Adrenal Glands↗
PubMed1984

Fatty acid elongation activity in fibroblasts from patients with adrenoleukodystrophy (ALD).

The activities of microsomal fatty acid elongation and cytoplasmic de novo fatty acid synthesis were measured in human cultured skin fibroblasts. Both activities in fibroblasts from normal controls and patients with adrenoleukodystrophy (ALD) were compared and slight but a significant increase of elongation activities in ALD fibroblasts was demonstrated. On the other hand, there were no significant differences in the fatty acid synthetase activities. In this study, we measured microsomal fatty acid elongation activities in the presence of N-ethylmaleimide, which completely inhibited the activity of contaminating fatty acid synthetase and also the degradation of fatty acids, and made accurate determination of the elongation activities possible.

Adrenoleukodystrophy↗
PubMed1984

Identification of myelin-associated glycoprotein (MAG) on the cell surface of mononuclear cells in human peripheral blood by a heterologous antiserum.

Although cross-reactivity between T cells and nervous tissue elements has been reported previously, the antigenic determinants of the cross-reactivity are still unknown. In this study, using immunofluorescence, we demonstrate that the same antigenic determinant as myelin-associated glycoprotein (MAG) exists on the cell surface of mononuclear cells in human peripheral blood. MAG positive cells of thirteen healthy individuals were from 6.1 percent to 14.0 percent (mean +/- standard deviation: 9.1 +/- 2.0% of total mononuclear cells in human peripheral blood). The percentage of MAG positive cells was diminished from 9.3% to 1.3% by preincubation with Leu-7, a monoclonal antibody against human natural killer cells. The percentage of Leu-7 positive cells was not changed by preincubation with anti-MAG antiserum. MAG may be one of the specific antigens which exist in both human peripheral blood mononuclear cells and nervous tissues, and may also be a marker of human natural killer cells.

Antibodies, Monoclonal↗
PubMed1984

Characterization of gangliosides by direct inlet chemical ionization mass spectrometry.

Permethylated derivatives of N-acetylneuraminic acid-containing GM3, N-glycolylneuraminic acid-containing GM3, GD1a, and GD1b, were analyzed by direct inlet ammonia chemical ionization (CI) mass spectrometry. These compounds were found to yield simple fragmentations, prominent fragment ions in the high mass region, and characteristic fragment ions corresponding to the cleavage of glycosidic linkages. This method also provides detailed information on the carbohydrate sequence and lipophilic composition in gangliosides.

Adrenal Glands↗
PubMed1984

[An electrophoretic study of the muscle proteins in nemaline myopathy: a new method using type-defined freeze-dried sections].

The characteristic features observed in the muscle fibers of nemaline myopathy are the presence of rods mainly in type I fibers, and the predominance and atrophy of type I fibers. In order to detect the abnormal proteins in the rods and clarify whether type I or II fibers have abnormal structural protein, we examined proteins in the muscles of patients with nemaline myopathy by one and two-dimensional gel electrophoresis (2-D). These freshly frozen muscles were cut to 20 microns thick and freeze-dried. Pieces were chosen and teased under a dissecting microscope with reference to the stained specimens of the same part, and electrophoresed. At first, we examined the proteins of the type I and II fibers in normal and type grouping fibers of patients with motor neuron disease by SDS gel electrophoresis and found no abnormality of the protein pattern in this disease. Then we examined each of the following fibers of the nemaline muscle; type I fibers with many rods and type II fibers with no rods. Each of the electrophoresed gel patterns of the nemaline muscle was compared with those of grouping type I and II fibers. The SDS gel electrophoresis showed and increase of the intensity of 55 K band in nemaline myopathy, especially in type I fibers with rods, which was thought as desmin. In 2-D, the pattern of type I fibers with rods were identical to that of the grouping type I fibers except the 55 K spot which showed a slow form of tropomyosin alpha-subunit (TM-alpha), troponin-C (TN-C) and myosin light chains (LC) although both contained small amounts of fast form LC2 and LC3.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1983

Gangliosides of hog skeletal muscle.

The ganglioside content of hog skeletal muscle was 27 nmol/g wet weight when calculated as lipid-bound sialic acid. The elution profile on DEAE-Sephadex A-25 column chromatography showed that the monosialoganglioside fraction (61% of total lipid-bound sialic acid) contained at least seven major gangliosides and that the disialoganglioside fraction (25%) contained four major ones. These gangliosides were purified by latrobeads column chromatography, and from the results of sugar analysis, specific enzymatic hydrolysis, a permethylation study and CrO3 oxidation, the structures of these gangliosides were determined to be as follows: A, GM3(NeuAc); B, GM3(NeuGc); C, sialosylparagloboside(NeuAc); D sialosylparagloboside (NeuGc); E, GM1(NeuAc); F, GM1(NeuGc); G, sialosyllactosaminylparagloboside(NeuAc) (monosialogangliosides) and H, GD1a(NeuAc, NeuAc); I, GD1a(NeuAc, NeuGc); J, GD1a(NeuGc, NeuGc); K, GD1b(NeuAc, NeuAc) (disialogangliosides), where NeuAc is N-acetylneuraminic acid and NeuGc is N-glycolylneuraminic acid as sialyl groups. The major fatty acids of gangliosides A, D and G were mainly C16:0, but those of the others, E, F, H, J and K, were C16:0, C18:0, C22:0 and C24:0. The long-chain bases were predominantly C18:1 sphingosine in all gangliosides.

Animals↗
PubMed1983

Lysosomal sialidase deficiency in sialidosis with partial beta-galactosidase deficiency.

We analyzed the subcellular localization of sialidases in human lymphocytes from a patient with adult type sialidosis with partial beta-galactosidase deficiency and normal controls. Sialidase activities were measured with alpha,2 leads to 3 NeuAc-lactitol, 4-methylumbelliferyl-NeuAc and GM3 ganglioside as substrates. Sialidases in the lysosomes were sonication-labile and hydrolyzed mainly hydrophilic substrates such as NeuAc-lactitol and 4-methylumbelliferyl-NeuAc, but hydrolyzed subsidiarily GM3 ganglioside. On the other hand, sialidases in the plasma membrane were sonication-stable and hydrolyzed both hydrophilic substrates and GM3 ganglioside. In sialidosis with partial beta-galactosidase deficiency, the sialidases of the lysosomes showed 3-5% activity toward hydrophilic substrates and 25% activity toward GM3 ganglioside as compared with sialidase activities of the controls. However, there are no differences in the activities of the sialidases in the plasma membrane. These results demonstrate that the essential defect in this disease is the deficiency of a lysosomal sialidase.

Carbohydrate Metabolism, Inborn Errors↗
PubMed1983

Degradation of myelin basic protein by calcium-activated neutral protease (CANP) in human brain and inhibition by E-64 analogue.

A calcium-activated neutral protease (CANP) was extracted from human brain and partially purified. The activity was measured using alkali-denatured casein (Hammersten) as a substrate. The optimum pH was around 7.0. The activity required the presence of calcium ions, maximum activity was obtained with over 5 mM calcium ions. The Km for the casein concentration was about 1.62 mg/ml. The activity of CANP was inhibited by one of the thiol protease inhibitors, E-64 analogue (E-64-a). The rate of inhibition was about 50% at an E-64-a concentration of 10(-5)M. This CANP degraded selectively basic protein in myelin proteins and the degradation was inhibited by E-64-a or EGTA. The role of the brain CANP in the process of demyelination was suggested by this study.

Brain↗
PubMed1983

Anti-acetylcholine receptor antibody in aged individuals and in patients with Down's syndrome.

Anti-acetylcholine receptor (AChR) antibodies were found in 9 of 50 sera from old patients with cerebrovascular disease (CVD) and in 9 of 38 sera from patients with Down's syndrome. Only one of 30 sera from young patients with CVD was positive. There were age-related changes in the positive rate and titers among Down's syndrome subjects. Anti-AChR antibody appeared associated with aging as did other autoantibodies.

Acetylcholine↗
PubMed1983

Interspecies comparison of muscle gangliosides by two-dimensional thin-layer chromatography.

Skeletal muscle gangliosides prepared from ten species of animals (human, monkey, bovine, hog, dog, cat, rabbit, guinea pig, mouse, and chicken) were studied by two-dimensional thin-layer chromatography. Densitometric quantification of spots on the chromatograms was carried out with an image analysis system equipped with a computer system. In about thirty-five resorcinol-positive spots, sixteen components could be identified by comparison with authentic standards we had previously obtained. GM3 ganglioside was found as a major component in all examined animals, but there were remarkable species variations in the minor gangliosides. In bovine and hog muscle gangliosides, more than fifteen minor components were detected owing to the presence of N-glycolyl neuraminic acid species. In contrast to this, muscle gangliosides of human, dog, cat, rabbit, and chicken showed relatively simple patterns because of the absence or the small amounts of N-glycolyl type gangliosides. The presence of lactosamine containing gangliosides was characteristic of muscle gangliosides of the examined species.

Animals↗
PubMed1983

Quantitative analysis of stance in ataxic myxoedema.

Postural abnormalities in a 66-year-old woman with ataxic myxoedema were recorded by stabilography during treatment. After replacement therapy, 3 Hz power in the sagittal plane was greater than before treatment; this peak shifted to a higher frequency and finally its ratio became normal. This is the first report of recovery of a 3 Hz body oscillation in ataxic myxoedema.

Aged↗