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Biomedical subjects

Kunio Tashiro

Publications and source records attributed to Kunio Tashiro.

At least 37 records · Page 2Linked to original sources

[Validity and clinical applicability of the Japanese version of amyotrophic lateral sclerosis--assessment questionnaire 40 (ALSAQ-40)].

We studied validity and clinical applicability of the Japanese version of amyotrophic lateral sclerosis (ALS) assessment questionnaire 40 (ALSAQ-40). The original version contains forty questions measuring five areas (domains) of health status: Physical Mobility, ADL/Independence, Eating and Drinking, Communication and Emotional Functioning. Data were obtained from 39 ALS patients and from their physicians at 15 centers in Japan. Patients completed the ALSAQ-40 and the SF-36, and provided information on their age and their status of ventilator use. Their physicians provided information on the date of diagnosis, type of disease and clinical characteristics, and ALSFRS-R. The patients' average age was 58.5 years, and 64% were men. The mean duration since diagnosis was 39.1 months. Forty four percent were classical ALS patients and 46% were receiving a respiratory intervention. Although there was much heterogeneity, the scores for Physical Mobility and ADL/Independence were higher(indicating worse health status)than the scores for the other domains. Item-scale correlations were strong, except for the item "felt embarrassed in social situations" in the Emotional Functioning domain. All the domains had very high internal consistency: Cronbach's alphas ranged 0.95 to 0.97. With regard to the cluster structure of the forty items, the Eating and Drinking domain and the Communication clustered together. The reason might be that the former consisted of only three items and both domains measure bulbar symptoms. Domain scores correlated significantly with scores of related dimensions in the SF-36 and ALSFRS-R, and did not correlate strongly with unrelated domains. The five items of the ALSAQ-5 correlated with all five domain scores on the ALSAQ-40. These results should be interpreted with caution because we analyzed together data from ALS patients with various characteristics. In conclusion, although we may need to add and remove some items and modify the wording of others, the Japanese version of the ALSAQ-40 had high validity and is likely to be useful in evaluating of QOL in ALS patients. Whether the ALSAQ-5 can be used in place of the ALSAQ-40 is a matter for further study.

Activities of Daily Living↗

The prevalence and clinical characteristics of MS in northern Japan.

In Japan, there is a low prevalence rate (PR) of multiple sclerosis (MS; 0.8-4.0/100,000) but a relatively high frequency of "optic-spinal form" MS (OS-MS). There have been no intensive epidemiologic frequency studies, however, in over 30 years. We performed a province-wide prevalence study of MS in the Tokachi province of Hokkaido, the northernmost island of Japan, and compared the observed clinical features with other populations in Japan and Western countries. Prevalence was determined on March 31, 2001. The primary sources for the case ascertainment were 13 hospitals that treated patients with neurologic diseases including MS in Tokachi. Patients were classified according to Poser's criteria. The prevalence rate of clinically definite or laboratory-supported definite MS (LSDMS) was 8.57 per 100,000 [31/361,726; male/female ratio=1:2.9, and age at onset=29.1+/-14.2 (mean+/-SD) years]. Out of the 31 patients, 5 (16%) were classified as OS-MS. The prevalence rate of MS in the Tokachi province was the highest reported in Orientals to date, although still low in comparison with Western communities at a similar latitude. In contrast to the previous reports in Japan, there was a relatively low frequency of OS-MS in Hokkaido.

Adolescent↗

Deficits of working memory during mental calculation in patients with Parkinson's disease.

Using the dual task paradigm, previous studies have suggested that working memory (WM) deficit is due to depleted attention resources in patients with Parkinson's disease (PD). The aim of this study is to establish whether the WM problems in PD are due to reduced attentional set-shifting resources rather than depletion of attention resources. The task design attempts to eliminate confounding of the deficits in dealing with novel material, a problem documented in PD, by concentrating on WM tasks of mental calculation that are familiar to subjects in daily living. We also administered attention tasks, the Trail Making Test (TMT) that relies primarily on attentional set-shifting and the Kana (Japanese syllabogram) Pick-out Test instead primarily depending on depleted attention resources for allocation. A total of 24 patients with PD and 24 normal controls participated in this study. The PD group showed deficits in mental calculation span and in attentional set-shifting in the TMT-b.Considering the common deficits in alternating processing of mental calculation and TMT-b in PD, the results suggested that the central executive dysfunction in PD during mental calculations was due to reduced attentional set-shifting resources for rapidly alternating operations, rather than the depletion of attentional resources.

Adult↗

The writing of arabic numerals, kanji, and kana in brain-damaged patients.

This study investigated the neural mechanisms involved in the writing of Arabic numerals, kanji, and kana. Tasks involving writing numerals in Arabic, kanji, and, kana were administered to four patients with Gerstmann's syndrome and to five Wernicke aphasics. The results indicated that the ability to write Arabic numerals was well preserved in the Wernicke aphasics despite their serious phonological disturbances. The patients with Gerstmann's syndrome, who have a deficit with the concept of number, could write kanji numerals better than Arabic and kana numerals. Unlike Arabic numerals (ideogram) and kana (syllabogram), kanji (morphogram) have both semantic and phonetic values. The results suggested that Arabic numerals may be somesthetic and linked directly to the concept of number bypassing phonological analysis.

Aged↗

Effect of proteasome inhibitor on cultured mesencephalic dopaminergic neurons.

Proteasomal dysfunction has been implicated in the pathogenesis of Parkinson's disease (PD). We examined the effect of a selective proteasomal inhibitor, epoxomicin, on primary cultured mesencephalic neurons. Exposing rat cultured mesencephalic neurons to epoxomicin for 24 h resulted in neurotoxicity in a dose-dependent manner. Epoxomicin caused mitochondrial dysfunction, reduction in reduced glutathione (GSH), and increased generation of free radicals. Neuronal damage was significantly blocked by antioxidative/GSH-augmenting agents. Epoxomicin also increased the expression of Bax and decreased that of Bcl-2, which may cause mitochondrial dysfunction and release of free radicals. Dopaminergic neurons were preferentially resistant to the toxicity of epoxomicin. Inhibiting the synthesis of tetrahydrobiopterin (BH(4)), which has been reported to have antioxidative function, increased the susceptibility of dopaminergic neurons, whereas increasing BH(4) levels protected non-dopaminergic neurons. These findings suggest that BH(4) is at least in part a contributing factor to grand the resistance to dopaminergic neurons against epoxomicin neurotoxicity. Our results suggest that proteasome inhibition causes the neurotoxicity in mesencephalic neurons, but that is not sufficient to reproduce the selective damage to dopaminergic neurons, such as that seen in PD.

Animals↗

Brefeldin A-induced neurotoxicity in cultured spinal cord neurons.

Brefeldin A (BFA) is a fungus metabolite that is known to cause the disassembly of the Golgi complex and apoptosis in exposed cells, both of which have been suggested as playing roles in the pathogenesis of neurodegenerative diseases, particularly amyotrophic lateral sclerosis (ALS). This study showed that BFA caused neurotoxicity and apoptotic nuclear changes in cultured spinal neurons of rat spinal cord in a dose- and time-dependent manner. The spinal motor neurons were more vulnerable to this neurotoxicity. The cultured spinal neurons showed irreversible disassembly of the Golgi apparatus as early as 1 hr after exposure to BFA. BFA induced the expression and activation of caspase-12 beginning 8 hr after exposure. The level of the cleaved form of caspase-3 had increased 12 hr after the addition of BFA. Free radical generation and loss of mitochondrial membrane potential were observed in the later stages of neurotoxicity caused by BFA. Collectively, our data suggests that BFA is an excellent agent for reproducing the pathophysiological features of ALS. This in vitro model may be useful in attempts to study the mechanisms of this neurodegenerative disease and to examine therapeutic potentials.

Animals↗

Isatin, an endogenous MAO inhibitor, improves bradykinesia and dopamine levels in a rat model of Parkinson's disease induced by Japanese encephalitis virus.

Isatin, an endogenous monoamine oxidase (MAO) inhibitor, has an important role in the control of neurotransmitter concentration. We previously reported that exogenously administered isatin significantly increased acetylcholine (ACh) and dopamine (DA) levels in the rat striatum. In order to test the possibility of treating Parkinson's disease by isatin, we evaluated DA levels in the striatum and bradykinesia using a rat model of Parkinson's disease induced by the Japanese encephalitis virus (JEV).We have already reported that in adult Fischer rats infected with JEV at day 13, there was a marked decrease of tyrosine hydroxylase-positive neurons in the bilateral substantia nigra after 12 weeks. Effects of isatin were investigated in JEV-induced post-encephalitic parkinsonism rats by a pole test and high performance liquid chromatograph (HPLC) with an electrochemical detector (ECD). Isatin (100 mg/kg per day for 1 week, intraperitoneal injection) improved the bradykinesia observed in the JEV-induced parkinsonism rats. Dopamine (DA) concentrations in the JEV-infected rats were profoundly reduced in the striatum as compared with controls. Isatin also increased DA in the striatum of parkinsonism rats. These results suggest that isatin could be a possible treatment for Parkinson's disease as well as for post-encephalitic parkinsonism.

Animals↗

Spinocerebellar ataxia type 14 caused by a mutation in protein kinase C gamma.

BACKGROUND: We previously discovered spinocerebellar ataxia type 14 (SCA14) in a single Japanese family with an autosomal dominant neurodegenerative disorder characterized by cerebellar ataxia and intermittent axial myoclonus. The latter manifestation is selectively observed in patients with early onset. We mapped the locus to chromosome 19q13.4-qter, but the etiologic gene was not known. Recently, a mutation in the protein kinase C gamma gene (PRKCG) was identified in a US family of English and Dutch ancestry with autosomal dominant SCA whose disease mapped to a region overlapping that of the SCA14 locus. Different PRKCG mutations were found in another family with SCA and in a sporadic case from the United States. Axial myoclonus was not observed in any of these US families. OBJECTIVES: To determine whether a mutation in the PRKCG gene is responsible for SCA14 and to investigate the prevalence of PRKCG mutations in Japanese patients with autosomal dominant SCA. PATIENTS AND METHODS: Direct nucleotide sequencing analysis of the 18 coding exons of the PRKCG gene was performed in the 19 members of the original Japanese family with SCA14 and in 24 Japanese probands with SCA. After identifying a PRKCG mutation, DNA samples from 72 patients with multiple system atrophy and 50 healthy individuals were examined for the mutation as controls. RESULTS: Sequence analysis revealed a novel missense mutation, Gln127Arg, in all affected members of the family with SCA14. This mutation was not found in 122 control individuals. No mutations in the PRKCG gene were detected in the group of 24 probands with SCA of unknown type. CONCLUSIONS: These findings document that SCA14 is caused by mutations in the PRKCG gene. The observation that all 4 PRKCG mutations identified in patients with SCA to date are located in exon 4 suggests a critical role for this region of the gene in cerebellar function. Mutations in the same region of the gene can result in myoclonus in some families but not in others.

Adult↗

Positional vertigo and macroscopic downbeat positioning nystagmus in spinocerebellar ataxia type 6 (SCA6).

To investigate the frequency of positioning nystagmus in degenerative ataxic disorders, we examined downbeat positioning nystagmus (DPN) in 25 patients with spinocerebellar ataxia type 6 (SCA6) and 58 patients with other types of degenerative ataxia. DPN was observed in 21 of the 25 patients with SCA6 (84 %) versus only 3 of the 58 patients (5.2 %) with other types of degenerative ataxia, including multiple system atrophy, SCA1, SCA2, SCA3/Machado-Joseph disease, and non-SCA6 late-onset pure cerebellar ataxia. Our findings indicated that DPN is a distinct part of the clinical presentation of SCA6, showing that vestibular cerebellum is more affected in SCA6 than other types of degenerative ataxia.

Adult↗

C-C chemokine receptor 2 gene polymorphism in Japanese patients with multiple sclerosis.

C-C chemokine receptor 2 (CCR2) is a receptor for chemoattractant protein-1 (MCP-1) and associated with infiltrating lymphocytes in chronic active multiple sclerosis (MS) lesions. To study the role of CCR2 gene in the development of MS, we investigated the CCR2-64I polymorphism in 122 MS patients and 112 healthy controls in a Japanese population. We also analysed the influence of CCR2-64I polymorphism on the clinical course, age at disease onset, and severity. The distribution of the CCR2-64I allele was significantly different between patients and controls (p=0.0187), and the 64I/64I homozygote was significantly less common in MS than in control. Logistic analysis, adjusted for HLA-DRB1*1501-positivity, revealed negative association between the CCR2-64I and MS (p=0.0204). There were no significant associations between CCR2 polymorphism and the clinical features of MS. Our results indicate that the presence of CCR2-64I allele seems to provide protection against the development of MS.

Adolescent↗

Glycation--a sweet tempter for neuronal death.

Glycation, one of the post-translational modifications of proteins, is a nonenzymatic reaction initiated by the primary addition of a sugar aldehyde or ketone to the amino groups of proteins. In the early stage of glycation, the synthesis of intermediates leading to the formation of Amadori compounds occurs. In the late stage, advanced glycation end products (AGE) are irreversibly formed after a complex cascade of reactions. Several AGEs have been characterized chemically, while other new compounds remain to be identified. To date, studies of the contribution of glycation to diseases have been primarily focused on its relationship to diabetes and diabetes-related complications. However, glucose-induced damage is not limited to diabetic patients. Although it does not cause rapid or remarkable cell damage, glycation advances slowly and accompanies every fundamental process of cellular metabolism. It has recently become clear that glycation also affects physiological aging and neurodegenerative diseases such as Alzheimer's disease and amyotrophic lateral sclerosis. Glycation alters the biological activity of proteins and their degradation processes. Protein cross-linking by AGE results in the formation of detergent-insoluble and protease-resistant aggregates. Such aggregates may interfere with both axonal transport and intracellular protein traffic in neurons. In addition, glycation reactions lead to the production of reactive oxygen species. Conversely, glycation is promoted by oxidative stress. We speculate on the presence of synergism between glycation and oxidative stress. In this review, we provide an outline of glycation and propose some possible mechanisms of its cytotoxicity and defense systems against it.

Animals↗

Genetic polymorphisms of osteopontin in association with multiple sclerosis in Japanese patients.

Osteopontin (OPN) exhibits pleiotropic functions and abundant transcripts for OPN are present in brains of patients with multiple sclerosis (MS). The aim of this study was to investigate the role of OPN genes in the pathogenesis of MS. Polymorphisms at the 8090th, 9250th and 9583rd positions in OPN were detected by PCR-RFLP from DNAs of 116 MS Japanese patients and 124 healthy controls. The C/C genotype at the 8090th position in exon 6 was more prevalent in MS than in control (p<0.0001), and C allele was more prevalent in MS than in control (p<0.0001, OR=2.57, 95% CI=1.65-4.00). For the 9583rd position polymorphism in exon 7, patients with G/G genotype (age; 32.1+/-12.5 years, mean+/-S.D.) showed a later disease onset than G/A (age; 25.9+/-7.8 years, p=0.01) and A/A (age; 25.2+/-8.9 years, p=0.01) genotypes. There were no significant correlations between OPN gene polymorphisms and disease progression. Our results suggest that the 8090th polymorphism might be associated with susceptibility to MS, while the 9583rd polymorphism might be associated with age of onset of MS.

Adult↗

Primary CD30/Ki-1 positive anaplastic large cell lymphoma of the central nervous system occurring in a patient with a seventeen-year history of essential thrombocythemia.

We present a rare case of central nervous system lymphoma that occurred in a patient who had essential thrombocythemia for 17 years. MRI examinations disclosed multiple ring-enhanced lesions that had shown bilateral spreading in the different period. Pathological examinations confirmed CD30/Ki-1-positive ALK negative anaplastic large cell lymphoma. The possible pathogenic mechanisms of this disease are discussed.

Brain Neoplasms↗