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Biomedical subjects

T Miyatake

Publications and source records attributed to T Miyatake.

At least 343 records · Page 19Linked to original sources
PubMed1981

Partial characterization and studies of fibroblast and leucocyte neuraminidase activities towards sialyloligosaccharides in adult sialidosis and mucolipidosis II and III.

We describe the partial characterization and some properties of fibroblast and leucocyte neuraminidase towards 2 leads to 3 and 2 leads to 6 sialyllacose, and 2 leads to 3 and 2 leads to 6 sialylhexasaccharide which were isolated from the urine of a patient with adult sialidosis with partial beta-galactosidase deficiency. Neuraminidase activities were assayed using the radioactive-labeled derivatives of these saccharide substrates. These neuraminidases (acylneuraminyl hydrolase, EC 3.2.1.18) were partially inactivated by homogenization, sonication and freeze-thawing treatment. The leucocyte neuraminidase was more labile than that of fibroblasts. Fibroblast neuraminidase had about a 10-fold higher activity than leucocyte neuraminidase towards the respective substrates. The neuraminidase from fibroblasts and leucocytes were each able to hydrolyze 2 leads to 3 isomers 2-3 times faster than 2 leads to 6 isomers and the sialyllactoses 1.5-3.0-times faster than sialylhexasaccharides. Neuraminidase activities towards all four substrates were deficient in fibroblasts and leucocytes from the patients with adult sialidosis. Loss of activity was especially prominent in fibroblasts, while considerable residual activities (about 20-30%) remaining in leucocytes. In mucolipidosis II and III patients, these neuraminidase activities showed normal levels in leucocytes, although they were decreased in fibroblasts. The discrepancy between neuraminidase activities towards 2 leads to 3 and 2 leads to 6 isomers was not found in all the cases.

Adult↗
PubMed1981

Four positional isomers of sialyloligosaccharides isolated from the urine of a patient with sialidosis.

Four positional isomers of sialyloligosaccharides were isolated from the urine of an adult patient with sialidosis with partial deficiency of beta-galactosidase. From structural studies including compositional sugar analysis, exoglycosidase digestion, chemical ionization mass spectrometry, proton nuclear magnetic resonance spectrometry, and methylation analysis, their structures were deduced to be as follows: 1. AcNeu alpha 2 leads to 3 Gal beta 1 leads to 4GlcNac beta 1 leads to 2Man alpha 1 leads to 3Man beta 1 leads to 4GlcNac 2. AcNeu alpha 2 leads to 3Gal beta 1 leads to 4GlcNac beta 1 leads to 2Man alpha 1 leads to 6Man beta 1 leads to 4GlcNac 3. AcNeu alpha 2 leads to 6Gal beta 1 leads to 4GlcNac beta 1 leads to 2Man alpha 1 leads to 3Man beta 1 leads to 4GlcNac 4. AcNeu alpha 2 leads to 6Gal beta 1 leads to 4GlcNac beta 1 leads to 2Man alpha 1 leads to 6Man beta 1 leads to 4GlcNac Sialyloligosaccharides 1 and 3 have previously been found in the liver and urine of patients with mucolipidosis I, II, and variable forms, but sialyloligosaccharides 2 and 4 have not previously be found in human urine.

Carbohydrate Conformation↗
PubMed1981

Increased synthesis of hexacosanoic acid (C23:0) by cultured skin fibroblasts from patients with adrenoleukodystrophy (ALD) and adrenomyeloneuropathy (AMN).

We studied the metabolism of radioactive stearic acid by cultured skin fibroblasts from patients wtih adrenoleukodystrophy (ALD) and its variant, adrenomyeloneuropathy (AMN), to clarify the mechanism of the increased content of very long chain saturated fatty acids in cholesterol esters and sphingolipids, which are known to be the characteristic biochemical changes in ALD and AMN. A substantial amount of hexacosanoic acid (C26 : 0) wa synthesized from stearic acid by ALD and AMN fibroblasts, whereas only a trace amount of hexacosanoic acid was synthesized by control fibroblasts. This indicates that the primary biochemical defect in ALD and AMN may involved the elongation system of very long chain fatty acids.

Adrenal Gland Diseases↗
PubMed1981

Abnormality of long-chain fatty acids in erythrocyte membrane sphingomyelin from patients with adrenoleukodystrophy.

We have devised an analytical method for the determination of fatty acid composition of erythrocyte membrane sphingomyelin by chemical ionization mass spectrometry combined with capillary column gas-liquid chromatography. Fatty acid composition of erythrocyte membrane sphingomyelin from 8 patients with adrenoleukodystrophy (ALD) and 16 healthy controls were examined by this method. The ratio of hexacosanoic acid (C26:0) to docosanoic acid (C22:0) in erythrocyte membrane sphingomyelin from ALD patients was 2.6-fold higher than that of the controls. This result suggests that biochemical diagnosis of ALD is possible by the analysis of fatty acid composition of erythrocyte membrane sphingomyelin. Furthermore, it demonstrates that biochemical abnormality in ALD is the generalized abnormal metabolism of very long-chain saturated fatty acids.

Chemical Phenomena↗
PubMed1981

Topographical distribution of gamma-aminobutyric acid within the cat thalamus in relation to the basal ganglia, as determined by mass fragmentometry.

Chemical ionization mass spectrometry was introduced for the assay of GABA in the cat brain. The method is quite simple, sensitive, and specific for quantitative analysis. Study of the regional distribution of the GABA content within the thalamus disclosed that the ventromedial nucleus (VM) of the thalamus had a high concentration of GABA. The VM receives the afferent projection from the zona reticulata of the substantia nigra. The result, together with the results obtained by physiological as well as pharmacological studies, supports the hypothesis that the transmitter substance of the nigrothalamic pathway is GABA.

Animals↗
PubMed1981

Urinary sialyloligosaccharides in adult type sialidosis: occurrence of two positional isomers.

Two positional isomers of sialyloligosaccharides were isolated from the urine of a patient with adult type sialidosis with partial deficiency of beta-galactosidase. From structural studies including sugar analysis, enzyme degradation and methylation analysis, the following structures are deduced; 1. alpha-AcNeu-(2 leads to 3)-beta-Gal-(1 leads to 4)-beta-GlcNAc-(1 leads to 2)-alpha-Man-(1 leads to 3)-beta-Man-(1 leads to 4)-GlcNAc 2. alpha-AcNeu-(2 leads to 3)-beta-Gal-(1 leads to 4)-beta-GlcNAc-(1 leads to 2)-alpha-Man-(1 leads to 6)-beta-Man-(1 leads to 4)-GlcNAc The sialyloligosaccharide 1 has previously been reported to be present in liver and urine of patients with mucolipidosis I, II and variant forms. The sialyloligosaccharide 2 was first demonstrated in human urine.

Chemical Phenomena↗
PubMed1980

Gangliosides and neutral glycolipids of human adrenal medulla.

Glycolipids were isolated from human adrenal medulla by DEAE-Sephadex A-25 and Iatrobeads column chromatography. The lipid-bound sialic acid was about 234 microgram/g fresh tissue. The glanglioside fraction contained two major gangliosides which accounted for 93% of the total lipid-bound sialic acid. They were identified as GM3, N-acetylneuraminylgalactosylglucosylceramide and GD3, N-acetylneuraminyl N-acetylneuraminylgalactosylglucosylceramide on the basis of cochromatography with authentic standards, sugar composition analysis, and neuraminidase digestion. GM3, N-acetylneuraminylgalactosylglucosylceramide and GD3, N-acetylneuraminyl N-acetylneuraminylgalactosylglucosylceramide occurred in a ratio of approximately 3 : 2, and the ratio seemed to be rather constant irrelevant of age and sex differences. The neutral glycolipid fraction consisted of GL1a, glucosylceramide (18%), GL1b, galactosylceramide (23%), GL2a, lactosylceramide (27%), GL3, digalactosylglucosylceramide (20%), and GL4, globoside (12%). The major fatty acids of all these glycolipids were 16 : 0, 18 : 0, 22 : 0, 24 : 0 and 24 :1.

Adrenal Medulla↗
PubMed1980

Characterization of gangliosides in human leucocytes.

Lipids extracted from leucocyte pellets with chloroform-methanol were applied to a DEAE-Sephadex column an the gangliosides were eluted with 0.2M sodium acetate in methanol. The eluate was desalted by Sephadex G-50 column chromatography. The purified ganglioside was spotted on the high-performance than-layer plate. The plate was developed and sprayed with resorcinol reagents and heated. Seventeen bands of gangliosides were demonstrated in normal human leucocytes. The composition of these gangliosides was different in the various kinds of leucocytes. Amounts of GM3 ganglioside were apparently greater in normal lymphocytes and leukaemic cells than in granulocytes. Among the acute-leukaemic cells, some kinds of complex gangliosides were much more abundant in myelogenous cells than in lymphocytic cells. These changes in ganglioside composition are suggested as new biochemical markers for leukaemic cells.

Chromatography, Thin Layer↗
PubMed1980

Characterization of glycosphingolipids by direct inlet chemical ionization mass spectrometry.

Permethylated derivatives of cerebrosides and ceramide di-, tri-, tetra-, and penta-hexosides were analyzed by the direct inlet ammonia chemical ionization (CI) mass spectrometry. In the CI mass spectra, the fragment ions produced by the loss of methanol from the protonated molecular ion were observed in all of the glycosphingolipids. Other fragment ions due to the cleavage of glycosidic moiety were major ones under the CI conditions. These ions provide information on the molecular species of glycosphingolipids and the sugar sequence of their oligosaccharides. Glycosphingolipids with hydroxy fatty acids could also be differentiated from those with nonhydroxy fatty acids by comparing the intensities of characteristic fragment ions. The CI method should be particularly useful in structural studies of glycosphingolipids from natural sources.

Animals↗
PubMed1979

Adult type neuronal storage disease with neuraminidase deficiency.

We describe a patient with adult-onset neuronal storage disease characterized by myoclonus, cerebellar ataxia, convulsive seizures, cherry-red spots, skeletal dysplasia, mild gargoyle features, inguinal hernia, and angiokeratoma. Cytoplasmic inclusions consistent with lysosomal storage disease were demonstrated in neurons of the autonomic nervous system. Accumulation of GM3 and GM2 gangliosides was found in sympathetic ganglia but a catabolic disturbance of these gangliosides was ruled out by normal levels of GM3 ganglioside sialidase and N-acetyl-beta-hexosaminidase A activities. beta-Galactosidase activity was decreased in leukocytes and fibroblasts, but not in serum. GM1 gangliosidosis was ruled out by lipid analyses, and mucopolysaccharidosis by normal excretion of mucopolysaccharide in urine. Sialyl oligosaccharides were increased in urine and alpha-neuraminidase was deficient in fibroblasts. This disorder is considered to be an inherited metabolic disorder of sialyl glycoproteins and oligosaccharides due to deficiency of an alpha-neuraminidase.

Galactosidases↗
PubMed1979

Myopathy and primary aldosteronism: electronmicroscopic study.

We studied two patients with myopathy and primary aldosteronism. Necrosis and vacuolation of muscle fibers were found on light microscopy. Ultrastructurally, the necrotic areas were characterized by dissolution of myofilaments with degenerative vacuoles. In muscle fibers that did not show necrosis, there were membrane-bound vacuoles, dilation of the sarcoplasmic reticulum, widening of the T-system, and a "honeycomb" appearance of T-tubules. These ultrastructural features suggest that the necrosis of muscle fibers may originate from membrane vulnerability of the sarcoplasmic reticulum and the T-system.

Adenoma↗