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Biomedical subjects

T Miyatake

Publications and source records attributed to T Miyatake.

At least 199 records · Page 11Linked to original sources
PubMed1991

[Mixed connective tissue disease--various neuromuscular complications prior to the elevation of antibody to RNP].

A 47-year-old woman with mixed connective tissue disease (MCTD) was reported. She developed various neuromuscular complications including carpal tunnel syndrome, narrowing of visual field, dysesthesia on face and extremities and weakness before elevation of antibody to RNP. On the examination of biopsied specimens of muscle and peripheral nerve, myositis and demyelination were suspected, respectively. Electroencephalography showed diffuse slowing which was without clinical evidence of the central nervous system involvement and was normalized by the treatment with prednisolone. Present case seems to provide some insights into the neuromuscular complications in MCTD.

Autoantibodies↗
PubMed1991

[A case of distal lower motor neuron syndrome associated with IgM anti-GM1 antibodies].

A 34-year-old man had noted progressive weakness in his right hand. On admission at age 39, cranial nerves were not involved. Fasciculations were observed in his upper limb girdles. Neurological examination revealed severe wasting and weakness of arms and the right hand, whereas mild in the left hand. The deep tendon reflexes were absent in the upper extremities, but normal in the lower extremities. No sensory disturbances were observed. Motor and sensory nerve conduction velocities were normal, and multifocal conduction block was not observed. EMG showed neuropathic changes in all 4 limbs and sternocleidomastoideus muscles. Serum immunoelectrophoresis failed to detect an M protein. High-performance thin-layer chromatography with immunostaining revealed that his serum IgM reacted with GM1, but not reacted with GM2, GD1a, GD1b, and asialo-GM1.

Adult↗
PubMed1991

[A case of cerebrotendinous xanthomatosis with spastic paraparesis, epilepsy, and bradykinesia].

A 26-year-old female developed mental deterioration, general convulsion, cataract and spastic gait in order since her entrance into elementary school. A diagnosis of cerebrotendinous xanthomatosis (CTX) was made because of hypercholestanolemia. At the time of admission, cataract, a mild thickening of Achilles tendons, mental deterioration, spastic paraparesis, truncal ataxia, and bradykinesia were noted. Bilateral slowing of 2 to 7 Hz was recorded in EEG, and brain CT and MRI revealed mild cerebellar atrophy. HVA and 5-HIAA levels in CSF were low. Oral administration of chenodeoxycholic acid, 300 mg per day, resulted in improvement of bradykinesia and EEG abnormality, increase of HVA and 5-HIAA levels in CSF, and decrease of serum cholesterol level in two weeks. Bradykinesia observed in the present case is a rare clinical finding of CTX, and the improvement of bradykinesia soon after the treatment with chenodeoxycholic acid has not been reported yet. This case is important for elucidating the mechanism of neurological disorders in CTX.

Adult↗
PubMed1990

Suppressive effect of E-64c on ischemic degradation of cerebral proteins following occlusion of the middle cerebral artery in rats.

Microtubule-associated protein 2 (MAP2) levels in the left cerebral hemisphere decreased significantly 3 days after occlusion of the left middle cerebral artery in rats to 29 +/- 16.3% of control levels. Since MAP2 is one of the substrates of calpain, E-64c, a synthetic calpain inhibitor, was administered at a dose of 400 mg/kg twice a day for 3 days, with the first dose being given before the production of ischemia. This depletion was significantly inhibited in vivo by E-64c (P less than 0.05) to increase MAP2 levels to 55 +/- 25.7% of control levels. E-64c had no significant effect on the ischemia-induced depletion of myelin-associated glycoprotein. Sham-operated rats were used as controls. Our results suggest that calpain is partially involved in the degradation of MAP2, and that the use of calpain inhibitors can be a useful clinical approach to cerebral ischemia.

Animals↗
PubMed1990

Molecular cloning of two species of cDNAs for human alpha-N-acetylgalactosaminidase and expression in mammalian cells.

Two species of cDNAs for human alpha-N-acetylgalactosaminidase were isolated from a human fibroblast cDNA library. The two species differ each other by a 70 bp insertion in the coding region. Transient expression study in COS cells demonstrated that only the cDNA without the 70 bp insertion expressed alpha-N-acetylgalactosaminidase activity. Analysis of mRNA species utilizing polymerase chain reaction revealed that the majority of the mRNA does not contain the 70 bp insertion, and the mRNA containing the 70 bp insertion is present only in a minor amount in human brain.

Acetylglucosaminidase↗
PubMed1990

Induction of myelin-associated glycoprotein mRNA in experimental remyelination.

Two forms of myelin-associated glycoprotein (MAG) mRNA are produced by alternative splicing of the exon 12 portion. Expression of the two forms of MAG mRNA was studied here in experimentally introduced demyelination and remyelination by Cuprizone intoxication. During the demyelinating stage, both forms of MAG mRNA decreased markedly. When feeding with Cuprizone was stopped, MAG mRNA began to increase. One form of MAG mRNA without the exon 12 portion, which appears in normal development at the period of active myelination, was characteristically induced during the remyelinating stage. The other form containing the exon 12 portion was also induced but recovered only to the level in normal development.

Animals↗
PubMed1990

Acetazolamide inhibits the recovery from triethyl tin intoxication: putative role of carbonic anhydrase in dehydration of central myelin.

The vacuolar degeneration of central myelin was produced in Sprague-Dawley rats by oral administration of triethyl tin. The wet weight of brain stems which seems to reflect the degree of accumulation of water increased during the administration of the toxin, whereas the activity of 2', 3'-cyclic nucleotide 3'-phosphodiesterase altered less remarkably. When TET was withdrawn from the drinking water, the rats showed a dramatic clinical improvement along with reduction in wet weight of brain stems. Treatment with acetazolamide following TET inhibited the clinical improvement and reduction in wet weight of brain stems. The present results indicates that central myelin has plasticity in recovering from the vacuolar degeneration by removing the accumulated fluid and carbonic anhydrase is possibly involved in the dehydration of myelin in such a recovery phase.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1990

Stability of messenger RNA in postmortem human brains and construction of human brain cDNA libraries.

We studied stabilities of poly(A)(+)-RNA in postmortem mouse and human brains for up to 12 hours. The yields of total RNA were not changed significantly during postmortem periods either in mouse brains or human brains. Cell-specific cDNA probes were used to evaluate postmortem stability of poly(A)(+)-RNA in each cell type in the central nervous system. We used neuron-specific enolase (NSE), S-100 beta (S-100), and myelin-associated glycoprotein (MAG) for molecular markers of neuron, astrocyte, and oligodendrocyte, respectively. There was no detectable degradation of mRNAs coding for NSE, S-100, and MAG during the postmortem periods on Northern blot hybridization analyses. These results indicate that intact mRNAs expressed in neuron, astrocyte, or oligodendrocyte can be isolated from postmortem brains for up to 12 hours after death. Using poly(A)(+)-RNA thus isolated from two postmortem human brains, we constructed directional cDNA libraries and demonstrated the presence of full-length cDNAs for NSE, S-100, and MAG on Southern blot hybridization analysis. The present data should encourage studies on altered gene expressions in human brain in various neurologic diseases.

Aged↗
PubMed1990

The large isoform of myelin-associated glycoprotein is scarcely expressed in the quaking mouse brain.

Two polypeptide isoforms of myelin-associated glycoprotein (MAG) with molecular masses of 72 and 67 kDa are produced by alternative splicing of the exon 12 portion. Our previous work has demonstrated that in the quaking mouse brain this alternative splicing is lacking and that the mRNA coding the large MAG isoform (L-MAG) is scarcely expressed, whereas that of small MAG isoform (S-MAG) is overexpressed. In the present study, we prepared antisera specific to the S-MAG and L-MAG amino acid residues, respectively. Immunoblots showed that the L-MAG band was scarcely detectable in the quaking mouse brain, whereas the S-MAG band had an apparently higher molecular mass than in the normal control. Our immunohistochemical study also showed that L-MAG was scarcely stained in the quaking mouse brain. These results seemed to reflect a reduction in content of L-MAG mRNA and abnormal glycosylation in the quaking mouse brain.

Animals↗
PubMed1990

Changes in the concentrations of cerebral proteins following occlusion of the middle cerebral artery in rats.

Using an immunoblotting technique, we investigated changes in the concentrations of microtubule-associated protein 2, 200-kDa neurofilament, tubulin, myelin-associated glycoprotein, and 2':3'-cyclic nucleotide 3'-phosphodiesterase in the brains of 40 rats following occlusion of the left middle cerebral artery or sham operation. Compared with those 4 hours after surgery, concentrations of all proteins decreased significantly in the left hemisphere 3 days after surgery (p less than 0.01). Microtubule-associated protein 2 was the most susceptible to ischemia, and its mean +/- SEM concentration decreased to 23 +/- 9.4% of that in concurrent sham-operated controls. Degradation products of microtubule-associated protein 2 and myelin-associated glycoprotein were detected on the blots. Furthermore, in the contralateral hemisphere (where calpain might be activated), concentrations of these two proteins decreased to 57 +/- 12.0% and 83 +/- 4.3% of those in concurrent sham-operated controls, respectively, 3 days after surgery. Changes in the concentrations of cerebral proteins in the contralateral hemisphere are important for understanding clinical symptoms not attributable solely to the ipsilateral lesion following a focal cerebral stroke.

Animals↗
PubMed1990

Rapid diagnosis of tuberculous meningitis by polymerase chain reaction (PCR).

Using a rapid and highly sensitive method for the diagnosis of tuberculous meningitis by polymerase chain reaction (PCR), we detected the Mycobacterium tuberculosis genome in CSF of 5 of 6 patients with clinically diagnosed tuberculous meningitis. The genome was not present in CSF from 10 patients with other types of meningitis and 10 normal controls.

Adult↗
PubMed1990

Acute axonal polyneuropathy associated with anti-GM1 antibodies following Campylobacter enteritis.

We report 2 patients with Guillain-Barré syndrome (GBS) following Campylobacter jejuni enteritis. Electrophysiologic studies indicated that the predominant process was axonal degeneration of motor nerves, and clinical recovery was poor. Serum testing by thin-layer chromatography and enzyme-linked immunosorbent assay revealed that the sera from both patients contained high titers of IgG antibody against GM1 ganglioside. These cases may represent a subgroup of GBS as acute axonal polyneuropathy following C jejuni enteritis associated with anti-GM1 antibodies.

Adult↗
PubMed1990

A common mitochondrial DNA mutation in the t-RNA(Lys) of patients with myoclonus epilepsy associated with ragged-red fibers.

Nucleotide sequence analyses of muscle mitochondrial DNA (mtDNA) from a patient with myoclonus epilepsy associated with ragged-red fibers (MERRF) revealed 33 single base substitutions, including 23 in coding regions for mitochondrial polypeptides and 10 in non-coding regions, as compared with the normal human mtDNA sequence. Three substitutions, in COI, ND4, and Cytb, would result in amino acid substitutions, which are conserved among species. Of three patients with MERRF, all had an identical A to G base substitution only at nucleotide position 8344 in the t-RNA(Lys) region. The substitution was not found in 15 controls. Various degrees of the combined enzymic defects in the oxidative phosphorylation system of mitochondria were found in the MERRF patients. The defects could be explained by altered function or processing of the mutant t-RNA(Lys). This mutation in the t-RNA(Lys) is the most probable cause of MERRF.

Adult↗
PubMed1990

Biochemical and clinical analysis of accumulated glycolipids in symptomatic heterozygotes of angiokeratoma corporis diffusum (Fabry's disease) in comparison with hemizygotes.

Angiokeratoma corporis diffusum (Fabry's disease) is an X-linked disorder of glycosphingolipid catabolism. Heterozygous females, although usually asymptomatic, are occasionally as severely afflicted as hemizygous males; recently we identified a heterozygous patient with cardiomyopathy and severe pain in the extremities. In order to elucidate the difference of the clinical features, we analyzed the glycolipid composition of the heart, liver, and kidney obtained from the patient and from a hemizygote. Gas-liquid chromatography revealed that globotriaosylceramide (Gb3) was markedly increased in the heart (32.4 times higher than control) and increased to a lesser extent in the liver and kidney (3.74 and 6.79 times, respectively). The pattern of Gb3 accumulation in the heterozygote, where the highest increases were seen in the heart, was distinct from that in the hemizygote, where elevated levels of Gb3 and Ga2 were found in the kidney. Furthermore, the alpha-galactosidase activity in the heart, liver, and kidney of the heterozygote was 17%, 26%, and 36%, respectively, of normal controls, which correlated well with the accumulation of glycosphingolipid in the heart and with the disease's clinical manifestations. Two other hemizygotic patients, who were identified by low alpha-galactosidase activities, demonstrated the cardiac involvement.

Adolescent↗
PubMed1990

[A case of rigid spine syndrome with rimmed vacuole].

A case of rigid spine syndrome associated with rimmed vacuoles in muscle biopsy is reported. A 36-year-old man was admitted to our hospital because of gait disturbance and limited mortality of the spine. His family was free from any neuromuscular disorders. He was born in normal pregnancy and delivery. His physical development was normal. At age 7, he was unable to run fast. At age 36, he had right hemiparesis and dysarthria. He was diagnosed as cerebral infarction of the left basal ganglia by brain CT. Neurological examination revealed moderate proximal dominant muscular atrophy and weakness. His spine was straight, showing loss of physiological cervical and lumbar lordosis. The neck flexion was limited but the extension was full. And he had contracture of bilateral ankle joint. Laboratory findings were all normal. The electrocardiogram showed negative T wave in V4, V5 and QT interval elongation. The echocardiogram showed diffuse decrease of ventricular wall motion. Respiratory function test revealed decrease of vital capacity. Arterial blood gases on room air showed that the PaO2 and PaCO2 were 70 mmHg and 49 mmHg, respectively. The findings of electromyogram were compatible with myopathic change. Biopsy specimen of the biceps brachii muscle showed marked variation in fiber size, type 1 fiber predominancy and atrophy, and type 2B fiber deficiency. Numerous rimmed vaculoes were found in the same muscle. Four cases of the rigid spine syndrome with rimmed vacuoles have been described. Among them, three patients died in young ages and two suffered from constrictive respiratory failure. In rigid spine syndrome with rimmed vacuole formation, the cardiac and respiratory problems must be taken account intensively.

Adult↗