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Biomedical subjects

Kenji Nakashima

Publications and source records attributed to Kenji Nakashima.

At least 37 records · Page 2Linked to original sources
PubMed2005

Triple stimulation technique in patients with spinocerebellar ataxia type 6.

OBJECTIVE: To establish further evidence that SCA6 may not be a pure cerebellar syndrome. METHODS: Seven patients with genetically confirmed SCA6 and 9 age-matched normal controls were studied. Recordings of the CMAP were obtained from the right first dorsal interosseus muscle. Transcranial magnetic stimulation of the left motor cortex was applied to the contralateral scalp with a plane figure-of-8 coil. Conventional transcranial magnetic stimulation (TMS), central motor conduction time (CMCT) by F-wave method and the triple stimulation technique (TST) amplitude ratio (TST test/TST control) were investigated. RESULTS: The mean resting motor threshold and mean CMCT did not show significant differences between normal controls and patients, but the mean TST amplitude ratio was significantly smaller in patients than in controls. CONCLUSIONS: An abnormal TST represents upper motor neuron loss, central axon lesions or conduction blocks, or inexcitability in response to TMS. The lack of pathological changes in the corticospinal tract of patients with SCA6 indicates that this abnormality may be caused by crossed cerebellar diaschisis, or a functional disorder in the brain resulting from CACNA1A mutations. SIGNIFICANCE: TST is a useful method for quantifying corticospinal tract dysfunction.

Aged↗
PubMed2005

Mouse motor neuron disease caused by truncated SOD1 with or without C-terminal modification.

Mutation of Cu/Zn superoxide dismutase (SOD1) contributes to a portion of the cases of familial amyotrophic lateral sclerosis (FALS). We previously reported on a FALS family whose members had a mutant form of SOD1 characterized by a 2-base pair (bp) deletion at codon 126 of the SOD1 gene. To investigate the cellular consequences of this mutation, we produced transgenic mice that expressed normal and mutated copies of human SOD1: wild-type SOD1 (W), wild-type SOD1 with a FLAG epitope at C-terminal (WF), mutated SOD1 with the 2-bp deletion (D), and SOD1 with the 2-bp deletion with FLAG (DF). The mice heterozygotic for the human mutated SOD1 (D and DF) showed distinct ALS-like motor symptoms, whereas the mice heterozygotic for the normal SOD1 (W and WF) mice did not. Homozygotes of D and DF lines showed the ALS symptoms at an earlier age and died earlier than the heterozygotes. By Northern blot analysis, the mRNAs for all human SOD1s were confirmed in these lines. All the human SOD1 proteins, except the D mutant, were detectable by immunoblot. The D protein was only confirmed when it was concentrated by immunoprecipitation. Neuropathologically, loss of spinal motor neurons and reactive gliosis were common features in the symptomatic lines. The remaining motor neurons in these mice also exhibited eosinophilic inclusions. The biochemical and pathological characteristics of these mice are quite similar to those of human FALS patients with same mutation. This intriguing model will provide an important source of information of the pathogenesis of FALS.

Animals↗
PubMed2005

Association of the insertion/deletion polymorphism of the angiotensin I-converting enzyme gene in patients of migraine with aura.

Recently, several angiotensin I-converting enzyme (ACE) inhibitors and an angiotensin II receptor blocker were demonstrated to have a clinically important prophylactic effect in migraine. ACE is one of the key enzymes in the rennin-angiotensin-aldosterone system, which modulates vascular tension and blood pressure. In humans, serum ACE levels are strongly genetically determined. Individuals who were homozygous for the deletion (D) allele showed increased ACE activity levels. To investigate the role of ACE polymorphism in headache, we analyzed the ACE insertion (I)/deletion (D) genotypes of 54 patients suffering from migraine with aura (MwA), 122 from migraine without aura, 78 from tension-type headache (TH), and 248 non-headache healthy controls. The ACE D allele were significantly more frequent in the MwA than controls (p<0.01). The incidence of the D/D genotype in MwA (25.9%) was significantly higher than that in controls (12.5%; p<0.01; odds ratio=5.26, 95% confidence interval: 1.69-16.34, adjusted for age and gender). No differences in the remaining groups were found. Our results support the conclusion that the D allele and the D/D genotype in the ACE gene is a genetic risk factor for Japanese MwA. There seems to be a possible relationship between ACE activity and the pathogenesis of migraine.

Adult↗
PubMed2005

L-dopa and dopamine enhance the formation of aggregates under proteasome inhibition in PC12 cells.

The formation of inclusion bodies in dopaminergic neurons is associated with the pathogenesis of Parkinson's disease. In order to clarify the role of dopamine/L-dopa in the formation of protein aggregates, we investigated dopamine/L-dopa-related aggregation using an experimental inclusion model. The inhibition of tyrosine hydroxylase (TH) by alpha-methyltyrosine dramatically decreased MG132-induced aggregate formation. In addition, the inhibition of TH caused the upregulation of proteasomes in cultured cells and the dopamine/L-dopa induced non-enzymatic polymerization of ubiquitin. This inhibition did not affect cell viability. These results suggest that dopamine/L-dopa might enhance aggregate formation, and that intracellular aggregates may not be toxic to cells.

Animals↗
PubMed2005

Pro-apoptotic protein glyceraldehyde-3-phosphate dehydrogenase promotes the formation of Lewy body-like inclusions.

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) has long been recognized as a classical glycolytic protein; however, previous studies by our group and others have demonstrated that GAPDH is a general mediator initiating one or more apoptotic cascades. Our most recent findings have elucidated that an expression of a pro-apoptotic protein GAPDH is critically regulated at the promoter region of the gene. Apoptotic signals for its subsequent aggregate formation and nuclear translocation are controlled by the respective functional domains harboured within its cDNA component. In this study, coexpression of GAPDH with either wild-type or mutant (A53T) alpha-synuclein and less likely with beta-synuclein in transfected COS-7 cells was found to induce Lewy body-like cytoplasmic inclusions. Unlike its full-length construct, the deleted mutant GAPDH construct (C66) abolished these apoptotic signals, disfavouring the formation of inclusions. The generated inclusions were ubiquitin- and thioflavin S-positive appearing fibrils. Furthermore, GAPDH coimmunoprecipitated with wild-type alpha-synuclein in this paradigm. Importantly, immunohistochemical examinations of post mortem materials from patients with sporadic Parkinson's disease revealed the colocalized profiles immunoreactive against these two proteins in the peripheral zone of Lewy bodies from the affected brain regions (i.e. locus coeruleus). Moreover, a quantitative assessment showed that about 20% of Lewy bodies displayed both antigenicities. These results suggest that pro-apoptotic protein GAPDH may be involved in the Lewy body formation in vivo, probably associated with the apoptotic death pathway.

Acetates↗
PubMed2005

Increased plasma transforming growth factor-beta1 in migraine.

BACKGROUND AND OBJECTIVES: Migraine is characterized by the peripheral and central sensitization of pain perceptive neural systems, and neurogenic inflammation is a key step in the development of migraine headache. We focused on transforming growth factor-beta1 (TGF-beta1), which is a multifunctional proinflammatory cytokine. To address the possibility of TGF-beta1 involvement in migraine, we investigated the plasma level of TGF-beta1 in patients with migraine headache during headache-free periods. SUBJECTS AND METHODS: Sixty-eight subjects with migraine participated: 23 with migraine with aura (MWA) and 45 without aura (MWoA). We recruited 58 healthy subjects without headache as controls. In addition, we examined 12 subjects with episodic tension-type headache. Platelet poor plasma (PPP) was obtained from subjects during headache free-periods. TGF-beta1 levels in PPP were determined by enzyme-linked immunosorbent assay. RESULTS: The TGF-beta1 level in PPP was 2.62*+/- 0.23 (mean +/- SE) ng/mL in migraine, 2.08 +/- 0.20 ng/mL in tension-type headache, and 1.80 +/- 0.09 ng/mL in controls (P= .007, ANOVA; *P < .01, post hoc tests vs. the controls). CONCLUSION: TGF-beta1 in PPP was significantly increased in patients with migraine during headache-free periods. TGF-beta1 may play some role in the development of migraine headache.

Adult↗
PubMed2005

Approximate entropy in the electroencephalogram during wake and sleep.

Entropy measurement can discriminate among complex systems, including deterministic, stochastic and composite systems. We evaluated the changes of approximate entropy (ApEn) in signals of the electroencephalogram (EEG) during sleep. EEG signals were recorded from eight healthy volunteers during nightly sleep. We estimated the values of ApEn in EEG signals in each sleep stage. The ApEn values for EEG signals (mean +/- SD) were 0.896 +/- 0.264 during eyes-closed waking state, 0.738 +/- 0.089 during Stage I, 0.615 +/- 0.107 during Stage II, 0.487 +/- 0.101 during Stage II, 0.397 +/- 0.078 during Stage IV and 0.789 +/- 0.182 during REM sleep. The ApEn values were found to differ with statistical significance among the six different stages of consciousness (ANOVA, p<0.001). ApEn of EEG was statistically significantly lower during Stage IV and higher during wake and REM sleep. We conclude that ApEn measurement can be useful to estimate sleep stages and the complexity in brain activity.

Adult↗
PubMed2005

Spontaneous haemophilus influenzae type B meningoventriculitis with intraventricular debris.

Here we report the first case of spontaneous occurrence of Haemophilus influenzae type B meningoventriculitis. A 47-year-old man suffered from fever and headache. He had neck stiffness, and his cerebrospinal fluid (CSF) was turbid and yellowish. Gram staining and latex agglutination test of his CSF indicated that Haemophilus influenzae type B was the causative organism. Cranial CT and MRI revealed right ventricular debris accumulation, periventricular hyperintense signal, and periventricular ependymal enhancement. He was treated with intravenous administration of antibiotics, and his clinical condition and MRI findings gradually improved. Six weeks after onset, he was discharged without sequelae.

Anti-Bacterial Agents↗
PubMed2005

[Genetic analysis of migraine headache: a review].

Recent advances in genetic analysis of migraine headache are reviewed. Point mutations of P/Q -type Ca2+ channel alpha1 subunit(CACNA1A) gene and Na-K ATPase, alpha2 (ATP1A2) gene have been identified in the familial hemiplegic migraine (FHM-1 and FHM-2, respectively). Mutations in notch-3 gene cause the cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), which is an autosomal dominant inherited disorder often accompanying with migraine like headache. Serotonin (5-HT) related genes, dopamine D2 receptors (DRD2) gene, methylenetetrahydrofolate reductase (MTHFR) gene, and angiotensin converting enzyme (ACE) gene have been noticed as the susceptible genes for migraine pathogenesis. Genetic study of migraine is promising and will provide further understanding of the migraine pathophysiology. Discovery of the responsible or susceptible genes will open an avenue to develop new therapeutic strategy.

CADASIL↗
PubMed2005

[Migraine update].

Migraine is one of the common diseases suffering 8.4 million patients in Japan. The pathophysiology of migraine remains unclear. The genetic and basic studies of the familial hemiplegic migraine, a specific subtype of migraine with aura, have demonstrated the dysfunction of mutant brain-expressed calcium ion channel and/or the Na+/K+ ion transporter and suggested the association between cortical spreading depression (CSD) and migraine with aura. It is suggested that the CSD, neurogenic inflammation and vasodilatation caused by unknown triggers may activate the 'brainstem migraine generator' and amplified back way. In consequence, headache and/or aura will be appeared and strengthened. Our etiological data of headache in Daisen located in Western Japan clarified as follows; 1) Overall prevalence of migraine in Daisen was 6.0%. Women observed a 5.9-fold higher risk of migraine than men. 2) Fatigue, mental stress, and lack of sleep were the main headache triggers. 3) Only 7.3% of those with migraine with aura and 5.3% of those with migraine without aura had consulted a physician. 4) Migraineurs consume significantly more fatty/oily foods, coffee, and tea than nonheadache subjects of the same community. Migraineurs consume significantly fewer fish than nonheadache residents. As a conclusion, only a few Japanese migraineurs receive benefits of medical services and recent advances of headache medicine. The Japanese guideline for chronic headache treatment has declared in 2002. The International Classification of headache disorders has reedited to the 2nd edition. Public education concerning headaches is one of the most urgent issues in Japan.

Adult↗
PubMed2004

A novel presenilin 1 mutation (Y154N) in a patient with early onset Alzheimer's disease with spastic paraparesis.

Early onset familial Alzheimer's disease with spastic paraparesis (FAD-SP) has been associated with mutations of the presenilin 1 gene (PSEN1). We report a pedigree of FAD-SP due to a novel missense mutation of PSEN1 (Y154N). The symptoms of the proband were characterized by presenile dementia in her 40s, preceded by spastic paraparesis in her 30s, whereas the mother of the proband presented with spastic paraparesis in her 40s, followed by symptoms of dementia in her mid 60s. The mutation was found only in the proband, and not in a normal family member, normal Japanese control subjects, patients with sporadic Alzheimer's disease or patients with familial spastic paraparesis without dementia. Thus, Y154N is a novel PSEN1 mutation responsible for FAD-SP of Japanese origin.

Alzheimer Disease↗
PubMed2004

Myasthenia gravis with thymus hyperplasia and pure red cell aplasia.

A case of myasthenia gravis (MG) with thymus hyperplasia and pure red cell aplasia (PRCA) is reported. A 57-year-old woman was diagnosed as having MG and was treated with thymectomy 26 years ago. The histology of the resected thymus was thymic lymphoid follicular hyperplasia. She developed rapidly progressive anemia and a bone marrow examination revealed PRCA. Her hematological results improved with oral administration of cyclosporine A. Cases of MG, thymoma and PRCA have been reported in the literature. We report the first case of MG without thymoma and PRCA.

Cyclosporine↗