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Biomedical subjects

T Miyatake

Publications and source records attributed to T Miyatake.

At least 289 records · Page 16Linked to original sources

Metabolism of [17,18-3H2]hexacosanoic acid and [15,16-3H2]lignoceric acid in cultured skin fibroblasts from patients with adrenoleukodystrophy (ALD) and adrenomyeloneuropathy (AMN).

We have studied the metabolism of [17,18-3H2]hexacosanoic acid and [15,16-3H2]lignoceric acid in cultured skin fibroblasts from patients with adrenoleukodystrophy (ALD) and adrenomyeloneuropathy (AMN). The successful solubilization of the very long chain fatty acids as albumin conjugates was confirmed by analysis using glycerol density gradient centrifugation. The composition of radioactive fatty acids in total lipids of fibroblasts after culture for 7 days in the presence of [17,18-3H2] hexacosanoic acid or [15,16-3H2]lignoceric acid was analyzed by radio-gas chromatography. Most of the fatty acids added to the culture media were degraded to shorter-chain fatty acids both by control, and ALD or AMN fibroblasts. However, the content of the remaining radioactive hexacosanoic acid or lignoceric acid was much higher in ALD or AMN fibroblasts, and the content of radioactive shorter-chain fatty acids was much lower in ALD or AMN fibroblasts. These results indicate that the degradation of very long chain fatty acids is decreased in ALD, but also that there is a substantial amount of residual activity of their degradation in ALD fibroblasts.

Adrenoleukodystrophy↗

Human natural killer cell activity is reduced by treatment of anti-myelin-associated glycoprotein (MAG) monoclonal mouse IgM antibody and complement.

Human mononuclear cells could be stained by anti-myelin-associated glycoprotein (MAG) monoclonal mouse IgM antibody. The remaining human natural killer (NK) cell activity examined by using K-562 cells at 20:1 as effector:target ratio after treatment of anti-MAG monoclonal mouse or anti-Leu-7 (HNK-1) antibody and complement revealed 13.4% and 15.1%, respectively (untreated NK activity was 40.8%). However, human NK activity could be abrogated by anti-Leu-11 and complement. The remaining NK activity shown as lytic units after treatment with anti-MAG, anti-Leu-7 or anti-Leu-11 and complement was 6.1, 5.3 and below 1.0, respectively (untreated NK cells showed 15.4). When NK activity was examined in another target cell, MOLT-4, the remaining activity shown as lytic units was also decreased with anti-MAG antibody (4.3) or with anti-Leu-7 (3.0) (untreated NK activity was 8.3). Our findings suggest that NK cells may be influenced by anti-MAG antibody if it is found in the sera as anti-lymphocytotoxic antibody.

Animals↗

An interspecies comparison of gangliosides and neutral glycolipids in adrenal glands.

Gangliosides and neutral glycolipids of adrenal glands of mouse, rat, guinea pig, rabbit, cat, pig, cow, monkey, and chicken were analyzed by thin layer chromatography (TLC). The major gangliosides common to all species had lactosylceramide in their core structure. GM3 containing N-acetylneuraminic acid (NeuAc) was the major ganglioside in rat, guinea pig, rabbit, and cat, whereas GM3 containing N-glycolylneuraminic acid (NeuGc) was the major one in mouse, cow, and monkey. GD3 was also detected in all species except mouse and GD3(NeuAc)2 was the major in pig adrenal gland. GM4(NeuAc) was detected in the adrenal glands of guinea pig and chicken but not in those of the other species. In the neutral glycolipid fractions, galactosylceramide, glucosylceramide, lactosylceramide, globotriaosylceramide and globotetraosylceramide were detected and the proportions of these glycolipids varied among the species. Guinea pig and chicken adrenal glands contained large amounts of galactosylceramide, this being consistent with the presence of GM4 in these two species. Globopentaosylceramide was detected in mouse, guinea pig, cat, and chicken by the TLC-immunostaining procedure.

Adrenal Glands↗

Two positional isomers of sialylheptasaccharides isolated from the urine of a patient with sialidosis.

We describe the structures of two positional isomers of sialylheptasaccharide isolated from the urine of a patient with sialidosis with partial deficiency of beta-galactosidase. Based on 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: AcNeu alpha 2----6Gal beta 1----4GlcNac beta 1----2Man alpha 1----3(Man alpha 1----6)Man beta 1----4GlcNac; AcNeu alpha 2----6Gal beta 1----4GlcNac beta 1----2Man alpha 1----6(Man alpha 1----3)Man beta 1----4GlcNac. Sialyloligosaccharide 1 has previously been found in the urine and liver of patients with mucolipidosis I and II and sialidosis, but sialyloligosaccharide 2 has not been found yet in human urine. These two sialyloligosaccharides could not be completely separated by any chromatographic procedures tested. The analytical techniques, including methylation study and NMR spectroscopy, could not clearly detect the differences between them. However, alpha-mannosidase treatment gave important information for the structural analyses of these sialyloligosaccharides.

Carbohydrate Metabolism, Inborn Errors↗

Antibody to glycolipid in a patient with IgM paraproteinemia and polyradiculoneuropathy.

Serum from a patient with IgM paraproteinemia and polyradiculoneuropathy, diagnosed as malignant lymphoma reacted specifically with a lipid component in a crude ganglioside fraction isolated from human peripheral nerve, but did not react with myelin proteins including myelin-associated glycoprotein (MAG). The reactive glycolipid migrated between GM1 and GD1a gangliosides on TLC, and there was no distinct band corresponding to this glycolipid on examination with resorcinol reagent. Antibody to glycolipid in this case may play a role in the pathogenesis of neuropathy.

Aged↗

Human peripheral lymphocytes defined by anti-myelin-associated glycoprotein antiserum in healthy individuals and in patients with multiple sclerosis.

We investigated both the association between MAG-positive cells and active natural killer cells stained by anti-Leu-11 and the percentage of MAG-positive cells in patients with multiple sclerosis (MS) by indirect immunofluorescence study. Eighty percent of MAG-positive cells were stained with anti-Leu-11. The percentage of MAG-positive cells of 41 healthy individuals was from 5.1 to 16.1% (8.5 +/- 2.7%). The percentage of Leu-7-positive cells (13.8 +/- 4.9%) was always greater than that of MAG-positive cells. In 5 of 17 samples from 14 patients with MS, the percentage of MAG-positive cells was reduced. This finding was not related to disease activity and was not a pathognomonic feature of MS. The percentage of Leu-7-positive cells in patients with MS was not statistically different from that in healthy individuals; however, 4 patients showed a normal number of Leu-7-positive cells and a reduced number of MAG-positive cells. These studies suggest that MAG-positive cells are closely related to active natural killer cells and that "MAG" is a useful marker of human natural killer cells.

Adolescent↗

Morphological studies of peripheral nerves and skeletal muscles of an adult case with adrenoleukomyeloneuropathy.

A 53-year-old patient with adrenoleukomyeloneuropathy, showing symptoms of mental deterioration, cerebellar ataxia, spastic tetraparesis, and polyneuropathy, was reported. The myelinated fiber densities were decreased in the anterior spinal root and sciatic nerve. Most of the myelinated fibers showed segmental demyelination and a few fibers showed axonal degeneration. Electron microscopy showed numerous lipid inclusions in the cytoplasm of the Schwann cells. The muscles showed neurogenic changes. Numerous lipid bodies and intracytoplasmic crystalline arrays were found in the sarcolemma.

Adrenoleukodystrophy↗

Type 3 (adult) GM1 gangliosidosis: case report.

GM1 gangliosidosis is usually a pediatric disease caused by hereditary acid beta-galactosidase deficiency. There have been a few cases in adults. We saw a 51-year-old Japanese man with type 3 GM1 gangliosidosis who was manifesting dementia, dysarthria, gait disturbance, and limb rigidity. Radiologic studies showed platyspondylia, acetabular hypoplasia, and flattened femoral heads. Biochemical analysis revealed generalized acid beta-galactosidase deficiency.

G(M1) Ganglioside↗

Myasthenia gravis associated with lipodystrophy.

Patients with partial lipodystrophy frequently show hypocomplementemia but rarely have associated autoimmune diseases. We report here a patient of myasthenia gravis associated with limb lipodystrophy, a variant form of partial lipodystrophy, and hypocomplementemia.

Adult↗

31P-NMR studies on the energy metabolism of the living rat brain using a surface coil method.

We have examined the changes of the energetic metabolic state of rat and mouse brains under hypoxic hypoxia or ischemia using a 31P-NMR spectrometer with a surface coil. The NMR spectrometer has a super-conducting magnet providing a homogeneous magnetic field of 6.3 tesla. A probe was remodelled to accommodate an experimental animal in it. The animals were anesthetized with 1.0% or 1.5% halothane throughout the experiments. The optimal measurement conditions were a 90 degrees pulse width of 20 microsecond, and a 2 sec pulse repetition time. 200 acquisitions of FIDs was required for high spatially resolved signals. The Pcr/ATP ratio of the live, anesthetized rat brains was 1.76 +/- 0.46 (n = 8) for cerebra and 1.63 +/- 0.11 (n = 4) for cerebella. That of gerbil brains was 1.23 +/- 0.09 (n = 4). The Pcr/ATP ratio did not show any significant changes under both the conditions of hypoxic hypoxia or ischemia. The value of Pcr/Pi ratio decreased in the hypoxic conditions. The level of Pcr. of rat cerebrum decreased by 76.8 +/- 10.5% at 10% oxygen and by 57.3 +/- 15.7% at 5% oxygen compared with the value of 20% oxygen. The ATP level in the rat brain also decreased according to the degree of hypoxia. Cerebral ischemia was produced in the gerbil by ligation of the common carotid artery. The levels of Pcr. and ATP were severely depressed in the ischemic hemisphere but those of the intact side remained normal.

Adenosine Triphosphate↗

Carrier detection of sialidosis with partial beta-galactosidase deficiency by the assay of lysosomal sialidase in lymphocytes.

Lysosomal and plasma membrane sialidase activities in lymphocytes were studied in four patients with sialidosis with partial beta-galactosidase deficiency, four obligate heterozygotes, and three siblings of a patient. Lysosomal sialidase activity in homozygotes was absent, and that in heterozygotes was significantly decreased to 70% of control level. The results indicate that carriers can be detected by the assay of lysosomal sialidase activity of lymphocytes.

Adult↗

Medullasin activity in granulocytes of patients with multiple sclerosis.

Medullasin activity in mature granulocytes was measured in the blood of 22 patients with multiple sclerosis (definite type, 16; probable type, 6). The activity was elevated in every patient in relapse; it decreased to nearly normal levels at the beginning of improvement and further decreased to normal levels with remission. Serial determinations of the level of medullasin activity in 3 patients revealed that activity increased several days before the onset of acute exacerbation. Medullasin activity level in mature granulocytes obtained from patients with neurological diseases other than multiple sclerosis was largely within the normal range, except in 2 patients with spinocerebellar degeneration. Measurement of medullasin activity in mature granulocytes may become useful in both diagnosis and evaluation of multiple sclerosis.

Endopeptidases↗

Adrenal medulla gangliosides.

The gangliosides were examined in adrenal glands of mouse, rat, guinea pig, rabbit, monkey, pig, ox and chicken. GM3 ganglioside was predominant in all examined animals except pig. In pig GD3 ganglioside was the major one. GM4 ganglioside was found in guinea pig and chicken. The distribution of sialic acid varied in each species. NeuNGly containing gangliosides were not detected in rat, guinea pig, rabbit and chicken. The other animals have both NeuNAc and NeuNGly containing gangliosides. Chromaffin granules from bovine adrenal medulla contain gangliosides at concentrations 3 and 7 times as great as microsomal and mitochondrial fractions, respectively. These gangliosides were NeuNAc-containing GM3 and NeuNGly containing GM3 in the same amount.

Adrenal Medulla↗

Adrenoleukodystrophy: a clinical variant presenting as olivopontocerebellar atrophy.

A case of adrenoleukodystrophy showing neurological features of olivopontocerebellar atrophy is described. A CT scan demonstrated marked atrophy in both cerebellum and pons. ACTH stimulation produced no rise in the plasma cortisol level but a significant rise in the plasma aldosterone level. The ratios of C26:0 to C22:0 in fatty acids of sphingomyelin from erythrocyte membrane and plasma were increased.

Adrenocorticotropic Hormone↗

Conversion of myelin-associated glycoprotein (MAG) to a smaller derivative by calcium activated neutral protease (CANP)-like enzyme in myelin and inhibition by E-64 analogue.

Using the immunoblot technique, we found that an incubation of purified human myelin in 10 mM Tris-HCl buffer at pH 7.5 resulted in the conversion of the myelin-associated glycoprotein (MAG) to a smaller derivative (dMAG). Exogenously added 5 mM CaCl2 accelerated the conversion of MAG. In buffer containing more than 100 microM of EGTA, the conversion was inhibited. In addition, the existence of endogenous calcium in purified myelin was confirmed using atomic absorption spectroscopy. The conversion was also inhibited partially by one of the thiol protease inhibitors, E-64 analogue (E-64-a). These observations suggest that the conversion of MAG is mediated by calcium-activated neutral protease (CANP)-like enzyme.

Calpain↗