Search PubMed⌕ Search

Biomedical subjects

T Miyatake

Publications and source records attributed to T Miyatake.

At least 361 records · Page 20Linked to original sources

Biochemical study on myelin in adrenoleukodystrophy.

Two myelin fractions, heavy and light, were isolated from white matter of a patient with adrenoleukodystrophy. Morphologically, heavy myelin fraction showed compact lamellar structures, and light myelin fraction consisted of loose lamellar structures and rod-like clear space. Analytical studies demonstrated that the chemical composition of heavy myelin fraction was almost the same as that of normal myelin and that light myelin fraction consisted mainly of cholesterol. Long chain saturated fatty acids, C25:0 and C26:0, were increased and C24:1 was decreased in sphingoglycolipids of heavy myelin fraction of the patient.

Brain Chemistry↗

Adrenoleukodystrophy. A correlative analysis of computed tomography and radionuclide studies.

A discrepancy in location of abnormality has been noted between computed tomography (CT) and radionuclide studies in patients with adrenoleukodystrophy (ALD). Radionuclide concentration occurs only in the periphery of the lesion or area of acute demyelinating process and no concentration is seen in the area af gliosis whereas gliosis appears as a low-density lesion in the CT scan. Forward migration of radionuclide uptake in the follow-up study is another characteristic feature of this disease.

Child↗

Characterization of trimethylsilyl derivatives of cerebrosides by direct inlet-chemical ionization mass spectrometry.

Submicrogram quantities of trimethylsilyl derivatives of cerebrosides obtained from the spleen of a patient with Gaucher's disease and from bovine brain were analyzed by direct probe inlet-chemical ionization mass spectrometry, using isobutane as the reagent gas. Quasimolecular ions (QM+, M + 73) and other recognizable fragment ions produced by the successive elimination of trimethylsilanol and sugar residue gave useful information about fatty acid compositions. These ions could also be utilized for qualitative analyses of the molecular species of cerebrosides. Cerebrosides with non-hydroxy and hydroxy fatty acids could be discriminated from each other by comparing the intensities of their quasimolecular ions. Cerebrosides with saturated and monounsaturated fatty acids could also be discrimnated from each other, because the mass number decreased by two mass units in cerebrosides with monounsaturated fatty acids. It was concluded that structural information and molecular species determination could be obtained from small amounts of purified cerebrosides.

Animals↗

HLA and Japanese MS.

Determination of HLA-A, -B and -C types in 43 Japanese patients with multiple sclerosis (MS) and of DR type in 25 MS patients was carried out using antisera from the 7th International Histocompatibility Workshop. The results were compared with 46 controls typed simultaneously. Twenty-three patients were also tested for HLA-Dw2. The conclusions were: 1) There were no significantly higher occurrences of HLA-A3, B7, Dw2 or DRw2 in Japanese MS. 2) Japanese MS might nevertheless be associated with the human major histocompatibility complex, because HLA-B40 was significantly less frequent in MS and two anti HLA-DRw sera, 7w008 and 034, reacted positively more often against lymphocytes from MS patients.

Epitopes↗

The use of tears for diagnosis of GM1 gangliosidosis.

The properties of beta-galactosidase of tears were investigated and the standard assay system was accomplished. The pH optimum was 4.2. The enzyme had a KM of 8.3 X 10(-4) M. The activity was stimulated by chloride ions and slightly stabilized by bovine serum albumin. The activities of normal individuals were 205 +/- 80 (S.D.) nmol/h/ml. The activity in the tears of the patient with GM1 gangliosidosis decreased to about 20% of normal control and this disease could be diagnosed by the assay of beta-galactosidase in tears.

Adolescent↗

Partial purification and characterization of beta-galactosidase from rat brain hydrolyzing glycosphingolipids.

Adult rat brain beta-galactosidase was partially purified with the use of lactosylceramide, galactosyl-N-acetylgalactosaminyl-galactosyl-glucosylceramide, galactosyl-N-acetylgalactosaminyl-(N-acetylneuraminyl)galactosyl-glucosylceramide, and 4-methylumbelliferyl theta-galactoside as substrates. Approximately 50-fold purification was achieved by solubilization, ammonium sulfate fractionation, Sephadex G-200 and DEAE-cellulose column chromatography. Activities toward the above four substrates behaved essentially identically throughout the pruification procedure. Considerable differences were noted between the apparent properties determined with whole homogenate and those of the purer enzyme preparations. Based on these studies, assay procedures for the purified preparation for the three glycosphingolipid substrates were standardized. Inhibition studies with the use of varieties of simple sugars, oligosaccharide chains prepared from glycosphingolipids, and intact sphingolipids suggested that the enzyme which cleaves lactosylceramide may be different from the enzyme(s) which is active toward the other two glycosphingolipids. The oligosaccharide chains of the glycosphingolipids were much poorer inhibitors for the respective glycosphingolipid beta-galactosidases than the original intact glycosphingolipids or ceramide, and in some instances, even unrelated sphingolipids. These findings indicated the importance of the lipophilic groups and perhaps of the entire molecular configuration of glycosphingolipids in determining the specificity of these glycosphingolipid theta-galactosidases.

Animals↗