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T Miyatake

Publications and source records attributed to T Miyatake.

At least 253 records · Page 14Linked to original sources
PubMed1988

[Mitochondrial angiopathy in the cerebral blood vessels of MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and strokelike episodes)].

MELAS is a distinctive syndrome manifested by mitochondrial myopathy, encephalopathy, lactic acidosis, and recurrent stroke-like episodes such as seizures, alternating hemiparesis, hemianopsia, or cortical blindness. Pathologically the disorder is characterized by multiple, solitary or continuous foci of necrosis (infarct or softening), varying in size and stage, predominantly involving the bilateral cerebral cortices and to a lesser degree cerebral white matter, basal ganglia, brainstem and cereblum. The distribution of the lesions does not correspond to vascular territories, suggesting that they are not due to usual thrombotic or embolic process. The exact nature and pathogenesis of these lesions with characteristic distribution pattern remain to be elucidated. We studied systematically cerebral blood vessels from two autopsied patients with MELAS by electron microscopy. All the main cerebral arteries including anterior, middle and posterior cerebral, basilar and vertebral arteries were examined at their proximal portions at the cerebral base and at their peripheral portions at the cortical surface as well as within brain parenchyma. We found marked accumulation of mitochondria in the cell bodies of smooth muscle cells and endothelial cells and numerous smooth muscle cells showing degeneration or necrosis, sporadically or in clusters in the tunica media. These abnormalities were most prominent in the walls of pial arterioles and small arteries up to 250 mu in diameter, and less frequent and severe in the larger pial arteries and intracerebral arterioles and small arteries. These vascular changes are different from any of those described in various disorders known to involve the cerebral blood vessels and are thus characteristic to the cerebral blood vessels of MELAS. We think that these peculiar vascular changes called mitochondrial angiopathy are caused by primary mitochondrial dysfunction in the vascular smooth muscle cells and endothelial cells themselves, as is the same in the skeletal and cardiac muscles in this disease, and that they constitute the pathogenic base of the brain lesions with unusual distribution pattern and nature in MELAS.

Acidosis, Lactic↗
PubMed1987

Characterization of tumor-associated fucogangliosides from PC 12 pheochromocytoma cells.

PC 12h pheochromocytoma cells were subcutaneously transplanted into rat. We found the transplanted tumors accumulated some fucogangliosides associated with PC 12 cells. These gangliosides were isolated and purified by DEAE-Sephadex A-25 and Iatrobeads column chromatographies. Their structures were determined by fast atom bombardment mass spectrometry, proton nuclear magnetic resonance spectrometry, permethylation study, and sequential degradation using various exoglycosidases and mild acid hydrolysis. Two tumor-associated fucogangliosides were found to possess the blood group B determinant as follows: G6: IV2Fuc alpha, IV3Gal alpha, II3NeuAc, GgOse4Cer; G11: IV2Fuc alpha, IV3Gal alpha, II3 (NeuAc)2, GgOse4Cer. A ganglioside with the similar structure as ganglioside G6 was isolated from rat hepatoma cells (Holmes, E.H., and Hakomori, S-I. (1982) J. Biol. Chem. 257, 7698-7703). However, ganglioside G11 has not previously been reported in the literature. These fucogangliosides reacted with the monoclonal antibody prepared by immunizing mice with PC 12h cells. Other fucogangliosides were also found to accumulate in the transplanted tumor tissues. They were identified as fucosyl-GM1 and fucosyl-GDlb. These fucogangliosides did not react with the monoclonal antibody against PC 12h cells.

Adrenal Gland Neoplasms↗
PubMed1987

Murine monoclonal antibodies to the myelin-associated glycoprotein (MAG) recognize Leu-7-reactive molecules on human mononuclear cells.

It is known that the antibody to human myelin-associated glycoprotein (MAG) reacts with a subset of human mononuclear cells (MNC) mediating a natural killer (NK) activity. The properties of the target molecule of the anti-MAG antibody, however, have not yet been elucidated. Three (GC-J4, MC-P2, and MC-P4) of five murine monoclonal antibodies (mAb) to MAG bound to human MNC. Moreover, MC-P2 and MC-P4 inhibited the binding of 125I-labeled anti-Leu-7 to MNC in a dose-dependent fashion. Conversely, anti-Leu-7 inhibited the binding of MC-P2 and MC-P4 to MNC, but did not inhibit the binding of GC-J4. Therefore, it is possible that MC-P2 and MC-P4 bind directly to or close to the Leu-7 epitope, and that GC-J4 binds to the epitope which is distinct from the Leu-7 epitope. The electrophoretic patterns of immunoprecipitates with GC-J4, MC-P2 and anti-Leu-7 from detergent lysates of surface-labeled human MNC were very similar. The target molecules of anti-Leu-7 and anti-MAG mAb have apparent m.w. of 205, 170, 150, 135, 110, 85, 65, and 55 kDa. All of the molecules precipitated by these mAb are monomeric or noncovalently associated proteins, because the electrophoretic mobilities of the proteins remained unchanged whether the samples were reduced or not. MC-P4 may have a higher affinity for the 65 kDa molecule than the other mAb, and precipitates the 58 kDa molecule as well. Therefore, the fine antigenic specificity of MC-P4 is slightly different from those of anti-Leu-7 or MC-P2. The implication of these results is that mAb, whose specificity is directed to the carbohydrate part of human MAG, reacts with the Leu-7 reactive molecules on human MNC, and that at least two epitopes detected by anti-MAG mAb coexist on the surface molecules with various apparent m.w.

Animals↗
PubMed1987

Mitochondrial angiopathy in cerebral blood vessels of mitochondrial encephalomyopathy.

We studied cerebral blood vessels of two autopsied patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). All the main cerebral arteries in the proximal portion at the brain base and more distal portion at the cortical surface, as well as within the brain parenchyma were examined by electron microscopy. There was a striking increase in number of mitochondria in the smooth muscle and endothelial cells, which were most prominent in the pial arterioles and small arteries up to 250 micron in diameter and less frequent and severe in the larger pial arteries and intracerebral arterioles and small arteries. These vascular changes have not hitherto been described in MELAS, or in other disorders affecting blood vessels of the brain and other organs. It is suggested that the vascular changes are caused by primary mitochondrial dysfunction in the vascular smooth muscle and endothelial cells of the brain and that they constitute the pathogenic base of the brain lesions and their unusual distribution pattern in MELAS.

Adolescent↗
PubMed1987

An autopsy case of a syndrome with muscular atrophy, decreased subcutaneous fat, skin eruption and hyper gamma-globulinemia: peculiar vascular changes and muscle fiber degeneration.

This is the first autopsy case report of a syndrome with autosomal recessive inheritance, muscular atrophy, contracture, skin eruption, hyper gamma-globulinemia, decreased subcutaneous fat, mental retardation and abnormal ECG findings. Skeletal muscles showed severe, discrete, multifocal muscular fibrosis which replaced several primary fasciculi. The tongue, heart and extraocular muscles showed identical but less severe findings. In the involved muscle fasciculi, veins and venules as well as arteries and arterioles showed medial hyperplasia and luminal constriction. Degeneration of endothelial cells of arterioles and narrowing of the lumen of terminal arterioles by the debris were observed. The peripheral nerves in the muscles were relatively well preserved. The correlation and pathogenesis of these findings are discussed.

Central Nervous System↗
PubMed1987

Morphometry of the degenerative process in the hypoglossal nerves in amyotrophic lateral sclerosis.

The peripheral hypoglossal nerves in 13 cases of amyotrophic lateral sclerosis (ALS) and five control cases were examined using morphometrical methods to demonstrate the degenerative process of motor nerve degeneration. The total number of myelinated fibers and their histograms were analyzed according to the degree of severity of the degeneration. Reduction of the total number of myelinated fibers in ALS hypoglossal nerves were graded in three groups: mild 65%-75%, moderate 50%-65% and severe 30%-50% of the myelinated fibers in controls. Each histogram of the remaining myelinated fibers showed different patterns corresponding to the degree of the degeneration and disclosed that the progressive reduction of large myelinated fibers was the fundamental change. Small myelinated fibers were not reduced, but increased, especially in the group with a moderate grade of degeneration. In plastic section, there were clusters of regenerated myelinated fibers. The transient increase of small myelinated fibers may be a reflexion of myelinated fiber regeneration during the progressive degenerative process of the motor neurons. The correlation between the degree of severity of the hypoglossal nerve degeneration and the atrophy of the tongue muscle and the duration of bulbar symptoms was examined and discussed.

Amyotrophic Lateral Sclerosis↗
PubMed1987

Developmental changes of myelin-associated glycoprotein in rat brain: study on experimental hyperphenylalaninemia.

We examined developmental changes of myelin-associated glycoprotein (MAG), basic protein (BP), and proteolipid protein (PLP) in central nervous system myelin isolated from experimental hyperphenylalaninemic rats (PKU rats) and controls. Higher amounts of MAG, including high-molecular-weight MAG in myelin, were found in 12- to 21-day-old control rats than in adult rats. MAG in developing myelin was at a maximum in 18-day-old rats and began to decrease in 21-day-old rats, while PLP and BP in developing myelin increased at these developmental stages. The level of high-molecular-weight MAG decreased in myelin prepared from 21-day-old rats. These results suggest that the decreasing high-molecular-weight MAG is important for compaction of myelin in the early stage of myelination. In myelin from 12- to 18-day-old PKU rats, the ratio of each protein such as MAG, PLP, or BP to that of control was about 0.5 at 12 days, and increased to almost 1.0 at 18 days. The myelination seems to be initially delayed but to be close to that of controls in PKU rats about 18 days old.

Animals↗
PubMed1987

A mitochondrial encephalomyopathy with cardiomyopathy. A case revealing a defect of complex I in the respiratory chain.

We describe a 16-year-old Japanese girl with a mitochondrial encephalomyopathy who presented with progressive dementia, limb weakness and atrophy, episodic vomiting, generalized convulsions, myoclonic seizures, and hypertrophic cardiomyopathy. CT scan revealed transient focal low density areas in her occipital and parietal lobes, and cerebellar atrophy. The clinical features were consistent with mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes (MELAS). Microscopically, most of muscle fibers in the skeletal muscles and heart were occupied by markedly increased mitochondria. Polarographic studies on mitochondria isolated from postmortem heart muscle showed severe impairment of oxidation of NADH-linked substrates in contrast to normal succinate oxidation. The rotenone-sensitive NADH-coenzyme Q reductase activity was markedly decreased in heart, skeletal muscle and liver mitochondria. The biochemical investigations have led to the identification of a defect of complex I in the respiratory chain. Reported cases of a defect of complex I have revealed pure myopathy, encephalopathy or encephalomyopathy. The reason for a varied clinical expression of a single defect remains to be clarified.

Adolescent↗
PubMed1987

Antibody to sialosyllactosaminylparagloboside 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 ganglioside, sialosyllactosaminylparagloboside (SLPG), in human peripheral nerve but not with myelin-associated glycoprotein (MAG). This finding demonstrates the existence of anti-SLPG antibody in the patient's serum, suggesting that this antibody may play a role in the pathogenesis of neuropathy.

Aged↗
PubMed1987

Shared carbohydrate antigenic determinant between the myelin-associated glycoprotein (MAG) and lung cancers. An immunohistochemical study by an anti-MAG IgM monoclonal antibody.

An immunochemical study has shown that monoclonal anti-myelin-associated glycoprotein (MAG) antibodies identify some membrane glycoproteins from cell lines of small cell lung cancer. We investigated immunohistochemically 85 specimens of lung cancer from resection and autopsy using one of the monoclonal antibodies against MAG. One adenocarcinoma was highly reactive with the anti-MAG antibody, and in three small cell carcinomas immunostained tumor cells were distributed either singly or in occasional small clusters. These results show that a shared antigenic determinant with MAG appears on the tumor cells. MAG is believed to play the role of antigen in the development of carcinomatous polyneuropathy, and contributes to cancer development by its reduction of natural killer (NK) cell activity.

Antibodies, Monoclonal↗
PubMed1987

Human placental sialidase: partial purification and characterization.

A sialidase [EC 3.2.1.18] has been partially purified from human placenta by means of procedures comprising Con A-Sepharose adsorption, ammonium sulfate precipitation, sucrose density gradient centrifugation, and high-pressure liquid chromatography on a Shim pack Diol 300 column. On high-pressure liquid chromatography, most of the beta-galactosidase that comigrated with the sialidase on sucrose density gradient centrifugation was removed. The sialidase was purified 3,600-fold from the preparation obtained by Con A-Sepharose adsorption. The enzyme liberated the sialic acid residues from (alpha 2-3) and (alpha 2-6) sialyllactose, colomic acid, fetuin, and transferrin, but not from bovine submaxillary mucin. The enzyme also hydrolyzed gangliosides GM3, GD1a, and GD1b in the presence of sodium cholate as a detergent, but GM1 and GM2 were less susceptible to the enzyme. The optimum pHs for 4-methylumbelliferyl-N-acetylneuraminate, sialyllactose, fetuin, and GM3 lay between 4.0 and 5.0.

Chromatography, Affinity↗
PubMed1987

Neutral protease in cerebrospinal fluid from patients with multiple sclerosis and other neurological diseases.

Neutral protease activity was significantly elevated in the cerebro-spinal fluid of patients with multiple sclerosis (MS) in exacerbation and in the acute phase of acute viral meningoencephalitis (AME) compared with that of MS in remission, amyotrophic lateral sclerosis or psychosomatic disease. Since in each relapse of MS, protease activity was higher in exacerbation than in remission, this activity may be one good marker of disease activity in MS. One hundred micro molar of FOY305, synthetic protease inhibitor, inhibited in vitro increased neutral protease activity in MS in exacerbation, which suggests the possibility of a clinical application of this protease inhibitor for MS.

Amyotrophic Lateral Sclerosis↗
PubMed1987

Hyperornithinemia, hyperammonemia, and homocitrullinuria: case report and biochemical study.

Two siblings with hyperornithinemia, hyperammonemia, and homocitrullinuria are reported. The clinical picture included protein intolerance, mental retardation, seizures, and stuporous episodes. One patient had cerebellar ataxia, myoclonus, convulsive seizure, and muscular weakness in both legs. Isolated liver mitochondria in the patient revealed that ornithine transport and citrulline synthesis were decreased, but urea cycle enzymes and ornithine aminotransferase were normal. Ornithine metabolism was decreased in cultured skin fibroblasts.

Adolescent↗
PubMed1987

Dihydrobiopterin synthesis defect: an adult with diurnal fluctuation of symptoms.

A deficiency of dihydrobiopterin synthesis was found in a 27-year-old man with mild mental retardation, rigid spasticity, hyperreflexia, dystonia, myoclonus, and delay in the initiation of action, since age 10. Symptoms improved after sleep. Urine contained large amounts of neopterin and a trace of biopterin. Dihydropteridine reductase activity in red blood cells was normal. CSF levels of HVA and 5-HIAA were low. Tetrahydrobiopterin administration lowered serum phenylalanine and improved the symptoms.

Adult↗