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Hidenao Sasaki

Publications and source records attributed to Hidenao Sasaki.

At least 19 recordsLinked to original sources
PubMed2007

Role of p53 in neurotoxicity induced by the endoplasmic reticulum stress agent tunicamycin in organotypic slice cultures of rat spinal cord.

The endoplasmic reticulum (ER) is important for maintaining the quality of cellular proteins. Various stimuli can disrupt ER homeostasis and cause the accumulation of unfolded or misfolded proteins, i.e., a state of ER stress. Recently, ER stress has been reported to play an important role in the pathogenesis of neurological disorders such as cerebral ischemia and neurodegenerative diseases, but its involvement in the spinal cord diseases has not been fully discussed. We conducted this study using tunicamycin (Tm) as an ER stress inducer for rat spinal cord in organotypic slice culture, a system that we have recently established. Tm was shown to induce ER stress by increased expression of GRP78. The viability rate of spinal cord neurons decreased in a dose-dependent manner with Tm treatment, and dorsal horn interneurons were more vulnerable to Tm-induced neurotoxicity. A p53 inhibitor significantly increased the viability of dorsal horn interneurons, and immunofluorescence studies showed nuclear accumulation of p53 in the dorsal horns of Tm-treated spinal cord slices. These findings suggest that p53 plays an important role in the killing of dorsal horn interneurons by Tm. In contrast, motor neurons were not protected by the p53 inhibitor, suggesting that the role of p53 may vary between different cell types. This difference might be a clue to the mechanism of the stress-response pathway and might also contribute to the potential application of p53 inhibitors for the treatment of spinal cord diseases, including amyotrophic lateral sclerosis.

Animals↗
PubMed2006

MSA-C is the predominant clinical phenotype of MSA in Japan: analysis of 142 patients with probable MSA.

We investigated the clinical features and mode of disease progression in 142 patients with probable multiple system atrophy (MSA) according to the Consensus Criteria. The subjects included 84 men and 58 women with a mean age at onset of 58.2+/-7.1 years (range: 38-79 years). Cerebellar signs were detected in 87.3% of these patients at the time of initial examination, and were found in 95.1% of them at latest follow-up. MSA-C was diagnosed in 83.8% of the patients at their first examination. Parkinsonism was initially detected in 28.9% of the patients, increasing to 51.4% at the latest follow-up. Among all of the subjects, only 16.2% were classified as having MSA-P on initial examination. At the latest follow-up, parkinsonian features had become predominant over cerebellar features in 24.6% of the 65 patients with MSA-C who were followed for more than 3 years. Although parkinsonism usually masked the signs of cerebellar involvement in MSA-C patients, none of the patients with MSA-P at an early stage showed predominance of cerebellar features at the latest follow-up. Parkinsonism is the predominant feature of MSA among Western patients, even at an early stage, but this study showed that cerebellar deficits are the main feature in Japanese patients. This difference of disease manifestations between ethnic groups suggests that genetic factors may influence the clinical phenotype of MSA.

Adult↗
PubMed2006

Four mutations of the spastin gene in Japanese families with spastic paraplegia.

Hereditary spastic paraplegia (HSP) is a group of genetically heterogeneous neurodegenerative disorders characterized by slowly progressive spasticity and weakness of the lower limbs. HSP is caused by failure of development or selective degeneration of the corticospinal tracts, which contain the longest axons in humans. The most common form of HSP is caused by mutations of the spastin gene (SPAST), located on chromosome 2p21-p22, which encodes spastin, one of the ATPases associated with diverse cellular activities (AAA). In this study, we detected four causative mutations of SPAST among 14 unrelated patients with spastic paraplegia. Two missense mutations (1447A-->G, 1207C-->G) and two deletion mutations (1465delT, 1475-1476delAA) were located in the AAA cassette region. Three of these four mutations were novel. Previous reports and our results suggest that the frequency of SPAST mutations is higher among Japanese patients with autosomal dominant HSP, although SPAST mutations are also observed in patients with sporadic spastic paraplegia.

Adenosine Triphosphatases↗
PubMed2006

Brain activation during detrusor overactivity in patients with Parkinson's disease: a positron emission tomography study.

PURPOSE: Patients with Parkinson's disease often have urine storage symptoms, such as urinary urgency, frequency and incontinence, which are induced by detrusor overactivity. However, little is known of the mechanisms inducing detrusor overactivity in this disease. We have previously examined the human brain response to bladder filling in healthy male volunteers using positron emission tomography. We hypothesized that brain activation patterns in response to bladder filling would be different in patients with Parkinson's disease. MATERIALS AND METHODS: Nine male patients with Parkinson's disease were catheterized via the urethra for bladder filling and intravesical pressure monitoring. We performed positron emission tomography, consisting of tasks 1 and 2. For task 1 the bladder was maintained empty via the urethral catheter. For task 2 room temperature water was dripped for bladder filling until the onset of detrusor overactivity. Data acquisition for task 2 was done during detrusor overactivity. Data on each scan were summed on a computer and further analyzed using a statistical parametric mapping procedure. RESULTS: Significant brain activation during detrusor overactivity was found in the periaqueductal gray, supplementary motor area, cerebellar vermis, insula, putamen and thalamus. The most prominent activation was found in the cerebellum. The pons was not activated during detrusor overactivity. CONCLUSIONS: Alteration in brain activation sites in response to bladder filling may be related to the pathophysiology of detrusor overactivity in patients with Parkinson's disease.

Aged↗
PubMed2006

Brain SPECT analysis by 3D-SSP and clinical features of Parkinson's disease.

OBJECTIVE: The aim of the present study is to investigate the association of symptoms in Parkinson's disease (PD) with cerebral perfusion on single photon emission computed tomography (SPECT). The clinical features of PD were compared with SPECT images of the brain obtained by three-dimensional stereotactic surface projection (3D-SSP) analysis. PATIENTS AND METHODS: Thirty-eight patients who had PD without dementia (17 men and 21 women with a mean age of 68.6 +/- 4.7 years) were enrolled in this study. Their symptoms were rated using the unified Parkinson's disease rating scale (UPDRS). Within a week, all patients were examined by SPECT with 1-123, and reconstructed images were analyzed with 3D-SSP using an image-analysis software, iSSP ver. 3.5. Data on brain surface perfusion extracted by 3D-SSP analysis were compared between the PD patients and the normal control group. The same comparisons were made for subgroups of PD patients with severe symptoms, such as tremor, gait disturbance, bradykinesia, and the UPDRS motor score. RESULTS: Cerebral perfusion was decreased at the anterior cingulate cortex and occipital lobe of the PD patients compared with the normal controls. In the subgroups with severe gait disturbance and severe bradykinesia, additional hypoperfusion was seen at the lateral frontal association and lateral temporal association and the medial frontal gyrus, and by the pixel-by-pixel comparison, perfusion was significantly decreased (p < 0.05) at the medial frontal gyrus and anterior cingulate cortex compared with the normal control group. CONCLUSION: In PD patients, severe gait disturbance and bradykinesia may be correlated with hypoperfusion of the medial aspect of the frontal lobe. This suggests that functional disturbance of the supplementary motor area and other parts of the frontal lobe are involved in the development of gait disturbance and bradykinesia in PD.

Aged↗
PubMed2005

Brain SPECT analysis by 3D-SSP and phenotype of Parkinson's disease.

OBJECTIVES: We hypothesize that the regional pattern of blood flow reduction in the brain is different between tremor-dominant Parkinson's disease (PD) and postural instability gait difficulty (PIGD)-dominant PD. We therefore investigated the association of phenotypes in untreated PD with brain perfusion on SPECT using three-dimensional stereotactic surface projection (3D-SSP) technique. PATIENTS AND METHODS: Thirty-three patients who had PD without dementia (12 men and 21 women with a mean age of 67.1+/-6.4 years) were included in this study. Their symptoms were rated using the Unified Parkinson's Disease Rating Scale (UPDRS). Patients were grouped in two phenotypes: tremor and PIGD-dominant groups based on UPDRS components. Around the same time, all patients were examined by N-isopropyl-p[123I] iodoamphetamine single photon emission computed tomography (123I-IMP SPECT), and obtained images were analyzed with 3D-SSP using an image-analysis software, NEUROSTAT. Data on brain surface perfusion extracted by 3D-SSP analysis were compared between the PD patients and the normal control group. The same comparisons were made for subgroups of PD patients. RESULTS: Cerebral perfusion was decreased at the anterior cingulate cortex and primary visual cortex of the PD patients, and especially by the pixel-by-pixel comparison, perfusion was significantly decreased at the right anterior cingulate cortex compared with the normal controls. In the PIGD-dominant group, more severe hypoperfusion was seen at the same regions. In the tremor-dominant group, significant hypoperfusion was not seen compared with the normal controls. CONCLUSIONS: The regional pattern of blood flow reduction in the brain was found to be different between tremor-dominant PD and PIGD-dominant PD. These regional differences were considered to suggest different and disease-specific combinations of underlying pathophysiological and neurochemical processes.

Aged↗
PubMed2005

Heredity in multiple system atrophy.

We investigated the family histories of 157 Japanese patients with probable or possible multiple system atrophy (MSA). A family history of neurodegenerative disorders was only detected in three MSA patients (1.9%). We evaluated these patients by careful neurological examination, neuroimaging studies, and genetic studies to exclude hereditary spinocerebellar ataxia with a similar clinical phenotype to MSA. The results indicated that one of them had a family history of MSA. Although the familial presence of neurodegenerative disorders is rare in MSA patients, the existence of such cases suggests that MSA may have a genetic background.

Adult↗
PubMed2005

Proteasome inhibition induces selective motor neuron death in organotypic slice cultures.

A dysfunctional ubiquitin-proteasome system recently has been proposed to play a role in the pathogenesis of neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS). We have shown previously that spinal motor neurons are more vulnerable to proteasome inhibition-induced neurotoxicity, using a dissociated culture system. To confirm this toxicity, we used organotypic slice cultures from rat neonatal spinal cords, which conserve the structure of the spinal cord in a horizontal plane, enabling us to identify motor neurons more accurately than in dissociated cultures. Furthermore, such easy identifications make it possible to follow up the course of the degeneration of motor neurons. When a specific proteasome inhibitor, lactacystin (5 microM), was applied to slice cultures, proteasome activity of a whole slice was suppressed below 30% of control. Motor neurons were selectively damaged, especially in neurites, with the increase of phosphorylated neurofilaments. They were eventually lost in a dose-dependent manner (1 microM, P < 0.05; 5 microM, P < 0.01). The low capacity of Ca(2+) buffering is believed to be one of the factors of selectivity for damaged motor neurons in ALS. In our system, negative staining of Ca(2+)-binding proteins supported this notion. An intracellular Ca(2+) chelator, BAPTA-AM (10 microM), exerted a significant protective effect when it was applied with lactacystin simultaneously (P < 0.01). We postulate that proteasome inhibition is an excellent model for studying the mechanisms underlying selective motor neuron death and searching for new therapeutic strategies in the treatment of ALS.

Acetylcysteine↗
PubMed2005

CSF pleocytosis and expansion of spinal lesions in Japanese multiple sclerosis with special reference to the new diagnostic criteria.

New diagnostic criteria for multiple sclerosis (MS) were recently proposed from the international panel on the diagnosis of MS, and they include exclusion criteria, such as lesions extending over more than two vertebral segments on spinal MRI and CSF pleocytosis of more than 50/mm3. We reviewed the clinical features of 158 patients who satisfied the diagnostic criteria for MS except for having the above atypical paraclinical findings. All patients exhibited two or more clinical attacks and objective clinical evidence of multiple lesions without any evidence of other disorders. Thirty-three (20.9%) patients had one or both atypical paraclinical findings. Twenty-one out of the 33 patients were classified as having optico-spinal MS (OSMS), and the other 12 as non-OSMS patients with atypical large expanding or destructive cerebral, cerebellar or brainstem lesions on MRI as well as one or both atypical paraclinical findings. Based on this heterogeneity in clinical findings in MS, there is an urgent need to develop a common general concept of the "MS" syndromes, and the ethnic-related heterogeneity should be considered in the revised criteria for the diagnosis of MS.

Adolescent↗
PubMed2005

Brain 3D-SSP SPECT analysis in dementia with Lewy bodies, Parkinson's disease with and without dementia, and Alzheimer's disease.

OBJECTIVES: Cerebral blood flow was compared among patients with dementia with Lewy bodies (DLB), Parkinson's disease with dementia (PDD), Parkinson's disease without dementia (PD), and Alzheimer's disease (AD) using three-dimensional stereotactic surface projection (3D-SSP) analysis. PURPOSE: We attempt to clarify the difference of reduction pattern on SPECT among patients having DLB, PDD, PD, AD. PATIENTS AND METHODS: Six patients with DLB, 7 patients with PDD who were matched with the DLB patients for age, unified Parkinson's disease rating scale-III (UPDRS-III) score, and degree of cognitive function disorders, 21 patients with PD who were matched with the DLB patients for age, UPDRS-III score, 12 patients with AD who were matched with the DLB patients for age and degree of cognitive function disorders, and 12 control subjects. All patients were examined by N-isopropyl-p[123I] iodoamphetamine single photon emission computed tomography (123I-IMP SPECT), and obtained images were analyzed with 3D-SSP using an image-analysis software, iSSP ver. 3.5. RESULTS: Although DLB and PDD showed similar cerebral perfusion reduction pattern at the lateral parietal association and lateral temporal association and precuneus on SPECT by the pixel-by-pixel comparison, greater perfusion reduction was observed in DLB than in PDD. Cerebral perfusion was decreased at the occipital lobe of the DLB patients compared with the AD patients. CONCLUSIONS: The regional pattern of blood flow reduction in the brain was found to be different among DLB, PD, and AD. Greater blood flow reduction was observed in DLB, although DLB and PDD showed similar reduction pattern. These regional differences were considered to suggest different and disease-specific combinations of underlying pathological and neurochemical processes.

Aged↗
PubMed2005

TNF-related apoptosis inducing ligand (TRAIL) gene polymorphism in Japanese patients with multiple sclerosis.

TNF-related apoptosis inducing ligand (TRAIL) has been reported to induce apoptosis of autoreactive T cells and other inflammatory cells, and thus, it is a strong candidate gene for involvement in the development of autoimmune diseases. We investigated single nucleotide polymorphisms (SNPs) in the coding region of the gene at position 1595 in exon 5 in 128 Japanese patients with conventional/classical multiple sclerosis (MS) and 158 healthy controls. Patients with optico-spinal MS (OSMS) or atypical clinical attacks were excluded from the study. The frequency of CC genotype at position 1595 was significantly different between patients and controls (p=0.0027), and the C allele was more prevalent in the patients than in the controls (p=0.0138, OR=1.546, 95% CI=1.092-2.188). Logistic analysis, adjusted for HLA-DRB1*1501-positivity, revealed the independent association of the CC genotype with susceptibility to MS (p=0.0006, OR=2.393, 95% CI=1.453-3.943). There were no significant associations between +1595 polymorphism and the clinical features of MS. The results indicate that the presence of the CC genotype at position 1595 in exon 5 represents a higher risk of MS.

Adolescent↗
PubMed2005

Treatment of cerebellar ataxia with 5-HT1A agonist.

Effective, pharmacologic approaches to the treatment of cerebellar ataxia are lacking or inadequate. We recently reported preliminary evidence that tandospirone citrate (tandospirone), a 5-HT1A agonist, improved cerebellar ataxia in patients with Machado-Joseph disease (MJD). In the course of that study, we found that such treatment also alleviated the pain associated with cold sensations in the legs, insomnia, anorexia, and depression, all of which are thought to be mediated through activation of the 5-HT1A receptor. In this paper, we reviewed the few published clinical trials that involved the use of 5-HT1A receptor agonists for the treatment of cerebellar ataxia, and discussed the current theories regarding their mechanism of action. Cortical cerebellar atrophy (CCA) was reported, in a double-blind study, to be amenable to treatment with tandospirone. Other types of spinocerebellar degeneration (SCD) i.e., olivopontocerebellar atrophy (OPCA) and Machado-Joseph disease (MJD) have also been reported to respond to the drug, but these have been small studies. Responsive patients exhibited only mild ataxia. The doses of 5-HT1A agonists that have been used successfully ranged from 12.5 mg/day to 60 mg/day (or 1 mg/kg), and were well tolerated by most patients.

Buspirone↗
PubMed2005

Degeneration of the inferior olive in spinocerebellar ataxia 6 may depend on disease duration: report of two autopsy cases and statistical analysis of autopsy cases reported to date.

This report concerns a clinicopathological study of two autopsied patients with spinocerebellar ataxia 6 (SCA6), and a statistical analysis between neuronal loss of the inferior olive and disease duration of 15 SCA6 autopsy cases reported to date, including the two cases reported in this study. Cases 1 and 2 came from independent Japanese families. Case 1 developed gait disturbance at age 35 years and died at age 78 years; she had a CAG-repeat expansion of the SCA6 gene (25/13). Case 2 presented with gait disturbance at age 68 years and died at age 78 years; he had an expanded CAG-repeat of the SCA6 gene (22/13). Neuropathological examination of both cases disclosed not only neuronal loss of the Purkinje cells and inferior olive, but also some unnoticed features, including cactus-like expansion of the dendrite of Purkinje cells and relative preservation of Golgi cells in the granular layer of the cerebellum. Exploratory statistical analysis between 11 SCA6 autopsy cases with neuronal loss in the inferior olive (average disease duration: 27 years) and four SCA6 autopsy cases without neuronal loss in the olive (average disease duration: 14.5 years) was investigated by Kaplan-Meier estimates of survival and log-rank test, retrospectively. Kaplan-Meier estimates of survival revealed an obvious difference between the two groups. Survival of 10 years after the disease onset was 90.9% in the former 11 SCA6 autopsy cases, but was 50% in the latter four SCA6 autopsy cases. Furthermore, a log-rank test on the two groups disclosed a significant difference (P=0.0450). We postulate that the neuronal loss of the inferior olive in SCA6 may depend on disease duration.

Adult↗
PubMed2005

Herpes simplex virus encephalitis presenting with cerebral infarction-like signs and neuroimages.

A patient with an atypical presentation of herpes simplex virus (HSV) encephalitis mimicking acute cerebral infarction was reported. A 48-year-old man developed left-sided hemiparesis, convulsive seizures, and loss of consciousness. Brain magnetic resonance imaging revealed high intensity areas in the right frontal to parietal lobes on T2-weighted and diffusion-weighted images. Soon after admission with suspected cerebral infarction of the right middle cerebral artery region, the patient had high fever with frequent seizures and severe loss of consciousness. Laboratory findings including cerebrospinal fluid established a diagnosis of HSV encephalitis, and a state of apalic syndrome persisted despite aggressive antiviral therapy.

Brain↗
PubMed2004

CTLA-4 gene polymorphism is not associated with conventional multiple sclerosis in Japanese.

We investigated the polymorphisms of exon 1 (+49A/G) and promoter (-318C/T and -651C/T) regions of the CTLA-4 gene in 133 Japanese patients with conventional/classical multiple sclerosis (MS) and 156 healthy controls. Patients with optico-spinal MS (OSMS) or atypical clinical attacks were excluded from the study. There was no significant difference in the distribution of polymorphisms between patients and controls. Furthermore, there were no associations between polymorphisms and clinical characteristics, such as age at onset, disease prognosis, and HLA profiles. Our results suggest that CTLA-4 gene polymorphisms are neither conclusively related to susceptibility nor to the clinical characteristics of MS, especially in Japanese patients with conventional/classical form and clinical features identical to those of their counterparts in Western countries.

Adolescent↗
PubMed2004

Attack-related severity: a key factor in understanding the spectrum of idiopathic inflammatory demyelinating disorders.

Understanding the spectrum of idiopathic inflammatory demyelinating disorders (IIDD) is a fundamental issue for the diagnosis and treatment of these disorders as well as for the approach to their pathogenesis. The spectrum of IIDD is usually classified according to clinical course and lesion distribution. We compared the demographic features, clinical characteristics, laboratory findings, and genetic backgrounds between 193 Japanese patients with and without clinically or radiographically fulminant attacks who all satisfied the diagnostic criteria for multiple sclerosis (MS). "Fulminant attacks" in the current study represent attack-related clinically or radiologically severe relapses but do not necessarily mean severe disability. Patients with fulminant attacks were clinically and immunogenetically distinct from those free of such attacks, and the previously described characteristics of the opticospinal form of MS (OSMS) or neuromyelitis optica (NMO) were mostly shared by patients with fulminant attacks. HLA profiles were similar among patients with fulminant attacks irrespective of the lesion distributions. The GG homozygous and G alleles of the CTLA4 gene A/G coding SNP at position 49 in exon 1 were significantly more common in patients with fulminant attacks than in those without. Attack-related severity may be an important factor if validated by prospective studies defining criteria and establishing relationships to disease course and treatment regimens.

Adolescent↗