Biomedical subjects
Publications and source records attributed to N Ohkoshi.
A patient with hereditary neuropathy presented with asymmetric distal weakness. On nerve biopsy, there was demyelination and onion-bulb formation, and molecular analysis revealed that the patient was heterozygous for an MPZ mutation. The patient improved with corticosteroid treatment.
The authors present three novel missense mutations in the UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE) gene, the causative gene for hereditary inclusion body myopathy, in Japanese patients with distal myopathy with rimmed vacuoles. Seven out of nine patients had homozygous V572L mutation, one was a compound heterozygote with C303V and V572L mutations, and the remaining patient bore homozygous A631V mutation.
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Individual vulnerability to reactive intermediates and oxidative stress accompanying metabolism of endogenous toxic compounds in the brain may promote the development of PD. Phase II detoxification enzymes such as glutathione S-transferase M1 (GSTM1), NAD(P)H:quinone oxidoreductase 1 (NQO1) and dihydronicotinamide riboside (NRH):quinone oxidoreductase 2 (NQO2) are important as cellular defenses against catecholamine-derived quinones and the oxidative stress that arises as a consequence of their metabolism. We conducted a study of the potential association between idiopathic Parkinson's disease and polymorphisms of GSTM1, NQO1, and NQO2. DNA samples from 111 unrelated outpatients with idiopathic PD and 100 unrelated healthy volunteers were analyzed. GSTM1 deletion polymorphism exhibited no positive association with PD (P = 0.596, odds ratio: 1.135), although GSTM1 were grouped into three genotypes (deletion/deletion, deletion/nondeletion, and nondeletion/nondeletion). In addition, polymorphism of the NQO1 gene caused by a C to T substitution in exon 3 presented no association with PD (P = 0.194, odds ratio: 1.31). However, polymorphism in the form of an insertion/deletion (I/D) of 29 base pairs (bp) nucleotides in the promoter region of the NQO2 gene, which contains four repeats of the putative core sequence (GGGCGGG) of the Sp1-binding cis-element, did associate with PD. The frequency of the D allele was significantly higher in patients with PD than in controls (P < 0.0001, odds ratio: 3.463). Our data suggested that the deletion of 29-bp nucleotides in the promoter region of the NQO2 gene associates with the development of PD.
In the presence of a catalytic amount of ruthenium(II) complexes, [RuCl(2)(cod)](n)(), RuCl(2)(cod)(MeCN)(2), [RuCl(2)(nbd)](n)(), [RuCl(2)(CO)(3)](2), and Cp*Ru(cod)Cl, 1,6-dienes were effectively converted into the corresponding exo-methylenecyclopentanes in good to excellent yields with good isomer purity in i-PrOH at 90 degrees C. The alcoholic solvent was essential for the present catalytic cyclization, and the efficiency increased in the following order: t-BuOH << EtOH < or = i-PrOH. In contrast, a Ru(0) complex, (C(6)Me(6))Ru(cod), catalyzed the cycloisomerization only in 1,2-dichloroethane. The unusual isomer-selectivity occurred when a 1,7-octadiene was subjected to cyclization to give a similar exo-methylenecyclopentane isomer as the major product. The identical isomer selectivity was observed for the cyclization of unsymmetrical 1,6-dienes having one terminal- and one internal-alkene termini. On the basis of the results from the studies using the known ruthenium hydrides and deuterium-labeling substrates, the novel mechanism via the Ru(II) <--> Ru(IV) system involving a ruthenacyclopentane(hydrido) intermediate was proposed, which better explains the particular regiochemistry of the present cyclization than other previous mechanisms.
Aggregations of the alpha1A-calcium channel protein have been previously demonstrated in spinocerebellar ataxia type 6 (SCA6). Here the authors show that small aggregates, labeled by a monoclonal antibody 1C2 that preferentially detects expanded polyglutamine larger than that in SCA6 mutation, are present mainly in the cytoplasm but also in the nucleus of Purkinje cells. Although the length of expansion is small in SCA6, the current finding might indicate that SCA6 conforms to the pathogenic mechanism(s) in other polyglutamine diseases.
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PURPOSE: Riluzole possesses various synaptic effects including an inhibitory action on glutamate release. The drug has been shown to inhibit kindled seizures, while its effect on the acquisition of kindling has not been reported. We investigated effects of riluzole on the kindling development in addition to effects on kindled seizures. METHODS: A bipolar electrode was implanted in the right amygdala of rats. Riluzole was injected intraperitoneally 30 min before kindling stimulation. To investigate effects of riluzole on the kindling development, rats were stimulated once daily for the drug session of 14 days at a current of 200 microA, 60 Hz, 1 ms for 2 s and thereafter stimulated without drugs (drug-free session) until completion of kindling. Seizure ranks and after discharge duration were observed every day. To investigate effects of riluzole on kindled seizures, fully-kindled rats were stimulated at the current of generalized seizure threshold (GST) before and after the administration of riluzole. Seizure ranks and after discharge duration were measured. GST after the treatment was also determined. RESULTS: The number of stimuli required for the first appearance of stage five seizure was significantly larger in rats treated with 8 mg/kg of riluzole than in vehicle controls. Riluzole at a dose of 8 mg/kg significantly retarded the development of seizure stages in the drug session. By comparison, effects on the duration of after discharge was relatively mild, though significantly different from the vehicle control. Riluzole at a dose of either 4 or 8 mg/kg markedly inhibited behavioral seizures and reduced the duration of after discharge in kindled seizures provoked by GST. The drug also significantly increased GST at both doses, suggesting that the anticonvulsant effects were attributed to the increase in GST. CONCLUSION: It was demonstrated that inhibitory effects of riluzole on both kindled seizures and the development of behavioral seizures in kindling acquisition with relatively mild correlation to afterdischarge duration. These effects might be attributed to inhibitory actions of riluzole on glutamate release and NMDA-receptor mediated events.
The expression of dystrophin and alpha1-syntrophin in rat tibialis anterior muscles were evaluated during a cycle of regeneration after myonecrosis induced by the injection of cardiotoxin. Immunohistochemical studies were performed in cryosections of muscles on days 1, 3, 5, 7, 10, 14, 21 and 28 after injection of cardiotoxin. Western blot analysis was also examined in muscle on days 1, 3, 5, 7, 10, 14, 21 and 28. In immunohistochemical studies, dystrophin was stained weakly at the sarcolemma of some regenerating muscle fibers on day 3, and by day 10 it was stained strongly on almost all regenerating muscle fibers. Alpha1-syntrophin was stained weakly at the sarcolemma of some regenerating fibers on day 5, and by day 14 it was detected on all regenerating muscle fibers. In Western blot analysis, dystrophin (DYS1) and alpha1-syntrophin (alpha1S) were completely absent on day 1. Re-expression of DYS1 and alpha1S was visible by day 5 and accelerated thereafter. The Western blots of DYS1 and alpha1S were densitometrically analyzed on each day. The protein levels on each day were converted to the percentage of the protein level on day 28, which was taken as 100%. From the sequential line based on these data, the following results were obtained on the chronological course of DYS1 and alpha1S. DYS1: 25% of the protein level on day 28 was reached by 3.5 days, 50% was reached by 5.3 days, and 90% was reached by 6.9 days. Alpha1S: 25% of the protein level on day 28 was reached by 4.6 days, 50% was reached by 6.0 days, and 90% was reached by 12.5 days. In this study, DYS1 regenerated earlier than alpha1S at the sarcolemma of regenerating muscle fibers.
We investigated clinical and pathological features of the sural nerves of 5 patients with the ataxic form of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and compared these features with those of chronic ataxic neuropathies due to other causes. The CIDP patients presented with slowly progressive ataxia with deep sensory impairment. The durations of the symptoms from onset were relatively short in CIDP (4-8 months) and cancer (3 and 10 months), but long in chronic idiopathic ataxic neuropathy (24-260 months). Corticosteroid therapy elicited a good response in all the patients with CIDP, but a poor response in the patients with other ataxic neuropathies. Sural nerve biopsy of CIDP patients showed a slight or moderate loss of myelinated fiber. This report suggests that ataxic form of CIDP is a steroid-responsive ataxic neuropathy, and large myelinated fibers of the sural nerves in ataxic form of CIDP were better preserved than those in nerves with other chronic ataxic neuropathies.
A 35-year old Japanese male with adult Sandhoff disease was described, who was presented as a motor neuron disease phenotype with slow progression. At the age of 15, he first noticed weakness in his thigh. At the age of 28, his upper and lower motor neuron disturbances were disclosed. He was diagnosed as atypical amyotrophic lateral sclerosis. At the age of 34, a slight sensory disturbance appeared in the lower extremities. When he was admitted to our hospital, he displayed marked atrophy and weakness in his quadriceps femoris muscles, but no signs of mental deterioration and cerebellar ataxia. Because of the atypical course of motor neuron disease, hexosaminidase activity in peripheral leukocytes was determined. The assay of total hexosaminidase, hexosaminidase A and hexosaminidase B activities demonstrated low levels of these activities (7-15% of controls), leading the diagnosis of Sandoff disease. He was a member of non-consanguineous family, and the abnormal patterns of hexasaminidase activities were different between his father and mother. These data appear to show that he is a compound heterozygote in the locus of the hexosaminidase B gene. This is the first Japanese case of adult Sanhoff disease presented as a motor neuron disease phenotype.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
A 50-year-old man had been well until three months earlier, when he felt general fatigue, and cutaneous rash with itching. Thereafter a general muscular weakness developed and the patient could not walk for a month. Four weeks before referral to our hospital, he had high fever and could not role over in the bed. On admission, the patient was able to walk. He had no skin rash. Neurologically, he showed mild weakness in proximal muscles. Hematologic examination showed mild eosinophilia and serum creatine kinase was mildly elevated. Needle electromyogram revealed a diffuse myogenic pattern in extremities. Eosinophilic myositis was diagnosed by a biopsy of the left calf muscle showing mild infiltration of eosinophilis which was identified using antibodies against eosinophilic granule protein.
We report a case of a 70-year-old man who developed Churg-Strauss syndrome (CSS), diagnosed by characteristic histological findings, clinical presentations of mononeuritis multiplex, and multiple small intestinal ulcers with perforations, after discontinuation of corticosteroid therapy. The patient had developed asthma at age of 45, treated with oral prednisolone (10-20 mg daily) from that time. At the age of 70 he developed pneumonia. The condition responded to antibiotics, and the corticosteroid was quickly tapered and discontinued. He was never given leukotriene receptor antagonists during the course of treatment. Approximately two weeks after discontinuation of steroid therapy, he developed severe abdominal pain and mononeuritis multiplex, confirmed by nerve conduction studies. Laboratory evaluation revealed an eosinophil count of 30,450/microliter, and P-antineutrophil cytoplasmic antibody (ANCA) was positive. An abdominal CT scan revealed free air in the abdominal cavity. Laparotomy revealed multiple small intestinal ulcers with perforations. Histologic examination of the intestine showed eosinophilic vasculitis and fibrinoid necrosis. Treatment with systemic corticosteroid (prednisolone 60 mg daily) led to a clinical improvement of neurological and gastroenterological deficits. The prednisolone dose was tapered to 20 mg daily without disease flares. Recently, there have been several reports of CSS that manifested after withdrawal of steroid therapy. CSS can be precipitated in patients with adult-onset, steroid-dependent bronchial asthma after corticosteroid withdrawal.