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Biomedical subjects

Akira Sano

Publications and source records attributed to Akira Sano.

At least 19 recordsLinked to original sources
PubMed2006

Brain-specific transcript variants of 5' and 3' ends of mouse VPS13A and VPS13C.

Mutations in vacuolar protein sorting 13A (VPS13A) gene are responsible for chorea-acanthocytosis (ChAc). We previously determined the full-length sequence and exon-intron structure of mouse VPS13A and generated a ChAc model mouse by using the gene targeting technique. In the process, we found diverse 5' and 3' transcript variants. Since ChAc is a rare neurodegenerative disorder, the mouse model should be useful for investigation of ChAc molecular pathogenesis, and the model's brain specific variants of VPS13A will be indispensable in these investigations. In the present study, we investigated mouse VPS13A transcript variants. We found brain-specific variants of mouse VPS13A, which may be involved in the brain-specific pathology of ChAc. In addition, we identified for the first time mouse VPS13C cDNA sequences and brain-specific variants of VPS13C.

3' Untranslated Regions↗
PubMed2006

In vivo distribution and localization of chorein.

Chorea-acanthocytosis (ChAc) is a hereditary neurodegenerative disorder caused by loss of function mutations in the VPS13A gene encoding chorein. In this study, we produced an antibody against chorein and examined its protein-level expression and localization in mouse. Immunoblot analysis revealed that chorein was expressed in a gene dose-dependent manner in the VPS13A deletion-mice that we recently developed, which confirms the sensitivity of the antibody. Chorein was highly expressed in testis, kidney, spleen, and brain, and was expressed ubiquitously in various brain regions. Subcellular analysis of the brain showed high levels of chorein in microsomal and synaptosomal fractions. Immunohistochemically, chorein-like immunoreactivity was ubiquitously observed in the brain in the neuronal perinuclear region, cytoplasm and fibers. In testis and kidney, clear cell-specific patterns of chorein-like immunoreactivity were detected. Our findings provide basic information on chorein in vivo and may contribute to taking the first step toward understanding molecular pathogenesis of ChAc.

Animals↗
PubMed2006

Chorein deficiency leads to upregulation of gephyrin and GABA(A) receptor.

Chorea-acanthocytosis (ChAc) is a hereditary neurodegenerative disorder caused by loss of function mutations in the VPS13A gene encoding chorein. Recently, using a gene-targeting technique to delete exons 60-61, we produced a ChAc-model mouse that corresponds to a human disease mutation. In this study, a comparative microarray analysis of gene expression in the striatum revealed an increased level of gephyrin gene expression in the ChAc-model mice compared with wild type mice. Since gephyrin is known as a GABA(A) receptor-anchoring protein, we compared the protein-level expression and localization of gephyrin and the GABA(A) receptor alpha1 (GABRA1) and gamma2 (GABRG2) subunits. Gephyrin and GABRG2 immunoreactivities in the striatum and hippocampus of the ChAc-model mice were significantly higher than those in the wild types. Our results suggest that chorein functional loss may lead to a compensatory upregulation of gephyrin and GABRG2 in the pathologic condition in ChAc.

Animals↗
PubMed2006

Association of AKT1 haplotype with the risk of schizophrenia in Iranian population.

AKT-glycogen synthase kinase 3beta (GSK3beta) signaling is a target of lithium and has been implicated in the pathogenesis of mood disorders and schizophrenia. AKT1 protein level is decreased in the peripheral lymphocytes and brains of schizophrenic patients. The SNP2/3/4 TCG haplotype of AKT1 was associated with schizophrenia in patients with Northern European origin. In the present study, we genotyped five single nucleotide polymorphisms (SNP1-5) of AKT1 gene according to the original study in Iranians comprising of 321 schizophrenic patients and 383 controls, all residing in Mashhad city, Northeastern Iran. Haplotype analysis showed that the frequency of a five-SNP haplotype (AGCAG) was significantly higher in schizophrenic patients (0.068) than that of controls (0.034) (P = 0.03 after Bonferroni correction, OR = 2.04, CI = 1.2-3.4). In stratified analysis by schizophrenia subtypes, the frequency of the same haplotype was significantly higher in disorganized subtype (n = 78, frequency of haplotype=0.081) when compared with normal controls (P = 0.04 after Bonferroni correction, OR = 2.59, CI = 1.3-5.2). Our findings did not confirm the association of AKT1 SNP2/3/4 TCG haplotype with the risk of schizophrenia as reported in the original study but showed the evidence of association with a different haplotype, AKT1 five-SNP AGCAG haplotype, with the risk of schizophrenia in Iranian population.

Alleles↗
PubMed2006

Gene expression and association analysis of LIM (PDLIM5) in major depression.

LIM (PDLIM5) is a small protein that interacts with protein kinase C-epsilon and the N-type calcium channel alpha-1B subunit and modulates neuronal calcium signaling. Recently, the LIM mRNA expression in postmortem brains and immortalized lymphoblastoid cells from mood disorder patients was reported to be changed and seems to be involved in its pathophysiology. We hypothesized that the expression of the LIM mRNA in the native peripheral leukocytes may be a good candidate for the biological marker for mood disorders. Twenty patients with major depression and age- and sex-matched control subjects were included in this expression study. The LIM mRNA levels in the peripheral leukocytes from drug-naive depressive patients were significantly lower than those from control subjects and increased significantly after 4-week paroxetine treatments, to almost the same level as controls'. Hamilton depressive scores (HAM-D) were improved about 50% after 4-week treatment but neither paroxetine concentrations nor the changes of HAM-D scores showed significant correlation with the change of the mRNA levels. Then, we genotyped three single nucleotide polymorphic markers of LIM gene, which were reported to be associated with bipolar disorder in patients with major depression and control subjects (n=130, each), but there were no associations between these SNPs and major depression. Our investigation indicates that the lower expression levels of LIM mRNA in the peripheral leukocytes are associated with the depressive state and that its recovery after treatment may be an adaptive change induced by the antidepressant.

Adaptor Proteins, Signal Transducing↗
PubMed2005

Changes in expression of prosaposin in the rat facial nerve nucleus after facial nerve transection.

Prosaposin is the precursor of saposins A, B, C and D, which are activators of sphingolipid hydrolases. In addition, unprocessed prosaposin functions as a neurotrophic factor in the central and peripheral nervous systems by acting to prevent neuronal apoptosis, to elongate neurites and to facilitate myelination. In this study, the expression pattern of prosaposin in the facial nerve nucleus after facial nerve transection was examined by immunohistochemistry and in situ hybridization. Prosaposin immunoreactivity in the neurons on the operated side facial nerve nucleus showed a biphasic pattern: it was significantly increased on day 3 after transection, decreased dramatically on day 7, started to increase gradually on day 14 and reached another peak on day 21 after transection. Significant increases in the levels of prosaposin mRNA were identified in the neurons on the operated side, suggesting that prosaposin was synthesized vigorously by the neurons themselves in the case of facial nerve transection. The diverse changes in prosaposin immunoreactivity during the process of facial nerve regeneration may reflect the diverse neurotrophic activities of prosaposin in facial motoneurons.

Animals↗
PubMed2005

Hemoptysis from collateral arteries 12 years after a fontan-type operation.

A 20-year-old patient who had a single ventricle and pulmonary stenosis presented with recurrent hemoptysis 12 years after a Fontan-type operation. He was referred to us because of unsuccessful treatment with a tentative diagnosis of lung tuberculosis for 3 months. He had been relatively well for the prior 12 years, although he had attacks of paroxysmal supraventricular tachycardia and had underwent successful catheter ablation 3 years ago. Aortography revealed multiple collateral arteries as a cause of hemoptysis and coil embolization of these collateral arteries successfully stopped the hemoptysis. This case illustrates that collateral arteries may stay open or develop, and these collateral arteries can become a source of hemoptysis long after a Fontan-type operation.

Abnormalities, Multiple↗
PubMed2005

A gene-targeted mouse model for chorea-acanthocytosis.

Chorea-acanthocytosis (CHAC) is a hereditary neurodegenerative disorder with autosomal recessive transmission, in which selective degeneration of striatum has been reported in brain pathology. Clinically, CHAC shows Huntington's disease-like neuropsychiatric symptoms and red blood cell acanthocytosis. Recently, we identified the gene, CHAC, encoding a novel protein, chorein, in which a deletion mutation was found in Japanese families with CHAC. In the present study, we have identified the mouse CHAC cDNA sequence and the exon-intron structures of the gene and produced a CHAC model mouse introducing no. 60-61 exon deletion corresponding to a human disease mutation by a gene-targeting technique. The mice began to show acanthocytosis and motor disturbance in old age. In behavioral observations, locomotor activity was significantly decreased and the contact time at social interaction test was decreased significantly in the model mice. In the brain pathology, many apoptotic cells were observed in the striatum of the mutant mice. In neurochemical determinations, the dopamine metabolite, homovanillic acid, concentration decreased significantly in the portion including the midbrain of the mutant mice. These findings are consistent with the human results reported elsewhere and indicate that the CHAC model mice showed a mild phenotype with late adult onset. The CHAC model mouse therefore provides a good model system to study the human disease.

Acanthocytes↗
PubMed2004

Observation of "partial coherence" in an Aharonov-Bohm interferometer with a quantum dot.

We report experiments on the interference through spin states of electrons in a quantum dot (QD) embedded in an Aharonov-Bohm (AB) interferometer. We have picked up a spin-pair state, for which the environmental conditions are ideally similar. The AB amplitude is traced in a range of gate voltage that covers the pair. The behavior of the asymmetry in the amplitude around the two Coulomb peaks agrees with the theoretical prediction that the spin-flip process in a QD is related to the quantum dephasing of electrons. These results constitute evidence of "partial coherence" due to an entanglement of spins in the QD and in the interferometer.

Journal Article↗
PubMed2004

Chemo-affinity of titania for the column-switching HPLC analysis of phosphopeptides.

A column-switching high-performance liquid chromatography (HPLC) system for the determination of phosphopeptides has been developed. The method is based on the selective adsorption of phosphopeptides on a titania (TiO2) precolumn and successive HPLC separation of the phosphopeptides on an anion-exchange column with a UV detector (215 nm). The recoveries of phosphopeptides were tested using authentic phosphopeptides [Gln-Ile-Ser(p)-Val-Arg, Ile-Ser(p)-Val-Arg and Lys-Gln-Ile-Ser(p)-Val-Arg] at an injection amount of 1 microg. The recoveries were 74.3, 79.6, and 82.6%, respectively, while the corresponding dephosphopeptides were not retained on the titania precolumn.

Chromatography, Affinity↗
PubMed2004

Titania as a chemo-affinity support for the column-switching HPLC analysis of phosphopeptides: application to the characterization of phosphorylation sites in proteins by combination with protease digestion and electrospray ionization mass spectrometry.

A method for the determination of phosphorylation sites in phosphoproteins based on column-switching high-performance liquid chromatography (HPLC) has been developed. The HPLC system consisted of a titania precolumn for the selective adsorption of phosphopeptides, an anion-exchange analytical column and a UV detector (215 nm). Rabbit muscle phosphorylase a (RPa) and porcine stomach pepsin (PSP) were tested as model phosphoproteins. After protease digestion, the resulting phosphopeptides were successfully isolated by column-switching HPLC. The phosphopeptide fractions were analyzed by electrospray ionization mass spectrometry with a positive or negative ion mode after purification by reversed-phase HPLC. Pseudo-molecular ion peaks corresponding to Gln-Ile-Ser(p)-Val-Arg (MW 681.7) and Glu-Ala-Thr-Ser(p)-Gln-Glu-Leu (MW 856.8) were detected from the tryptic digest of RPa and chymotryptic digest of PSP, respectively, which agreed with the theoretically expected phosphopeptide fragments.

Alkaline Phosphatase↗
PubMed2004

Stem durability testing of interdental brush.

The purpose of the present study was to determine the ability of interdental brush to withstand repeated use and to relate this property to clinically observed fractures of such brushes. The stem durability test was conducted according to ISO (International Standards Organization) standard by using a bending at 90 degrees under a 500-g controlled load (ISO/TC106/SC7/ WG3). Two sizes (ss, m) of each of the five commercially available interdental brushes (D, B, P, I, S) were used. The cycle number at the time of fracture was noted for all interdental brushes. The fractured surfaces of the stem wire following the stem durability test were also observed under a scanning electron microscope. The specimens, when ranked in decreasing order of the number of cycles at which fracture occurred, were D-m, D-ss, B-ss, B-m > P-m, P-ss, I-ss, I-m, S-m, S-ss (P < 0.05). L-type interdental brushes (P-m, P-ss, I-ss, I-m, S-m, and S-ss) showed significantly decreased fracture resistance when compared with straight-type interdental brushes (D-m, D-ss, B-ss, B-m). In all cases, the fracture was found to be of ductile nature.

Dental Devices, Home Care↗
PubMed2004

[Hereditary chorea--update].

Understanding molecular genetical background of hereditary chorea has recently been progressed so far. Triplet repeat expansion diseases including, Huntington disease, in which CAG expansion has been identified in the IT-15 or Huntingtin gene, and Huntington disease like-2, in which CTG expansion in junctophilin-3 (JPH3) gene occurs, causes selective degeneration of striatum in the brain. Octapeptide repeat expansion in the prion gene in Huntington disease like-1 has been also identified. Neuroacanthocytosis syndromes including McLeod syndrome and chorea-acanthocytosis cause acanthocytosis in the red blood cells and chorea due to the degeneration of caudate nucleus in the brain. The XK gene on the X chromosome is mutated to lose its function in McLeod syndrome. CHAC gene coding chorein is mutated to lead loss of function in chorea-acanthocytosis. Selective degeneration in the striatum, especially in the caudate nucleus might be associated with the molecular cascade of expanded polyglutamine or polyleucine or octapeptide and the loss of function of the XK protein and of chorein protein.

Chorea↗
PubMed2003

Relationship between functional dopamine D2 and D3 receptors gene polymorphisms and neuroleptic malignant syndrome.

Our previous study has suggested that the TaqI A polymorphism of dopamine D2 receptor gene (DRD2) is associated with the predisposition to neuroleptic malignant syndrome (NMS). However, the specificity of this polymorphism as a predictor of NMS dose not seem to be sufficient enough. Meanwhile, it has been shown that the non-carriers of Del allele of the -141C Ins/Del polymorphism in the promoter region of DRD2 have lower dopamine D2 receptor in the brain than the carriers. In addition, dopamine D3 receptor gene has a Ser(9)Gly polymorphism, which may alter the receptor function. The present study examined the association between these three polymorphisms and the development of NMS to investigate if a combination of these polymorphisms could increase the specificity as markers for NMS. The subjects were 17 psychiatric patients who had developed NMS (13 patients with schizophrenia, 3 with major depression, and 1 with dementia of the Alzheimer's type) and 163 schizophrenic patients who had never developed this syndrome. The frequency of the A1 allele was significantly (P = 0.012) higher in the patients who had developed NMS (59%) than in the patients who had not (35%). The proportion of the A1 carriers was significantly (P = 0.003) higher in the patients with NMS (16/17: 94%) than in those without the syndrome (93/163: 57%). However, no significant differences were found in the allele and genotype frequencies of the other two polymorphisms between the two groups. The present study suggests that only the TaqI A polymorphism is at least partly useful as a predictor of NMS, but the -141 C Ins/Del and Ser(9)Gly polymorphisms are not.

Adult↗
PubMed2003

Long-term outcomes and complications of metallic stents for malignant esophageal stenoses.

Thirty patients with malignant esophageal stenosis underwent Ultraflex esophageal stent deployment and were followed up for a maximum of 29 months from June 1995 to August 2001 in Tenri Hospital. Twelve stents were in the upper esophagus, and nine each in the middle and lower esophagus. The procedures were successful and dysphagia scores improved from 2.9 to 0.7. Major complications such as esophagorespiratory fistula, hematemesis, or airway compression occurred in 9 patients, more often in the upper esophagus than in other parts of the esophagus, with no statistical difference. There was a significant difference in the onset of major complications between the upper and middle esophagus, as well as between the upper and middle-lower esophagus (p < 0.05), but no difference in mean survival time between locations, or patients with or without major complications. These results demonstrate that esophageal stent deployment is effective for relieving dysphagia and associating malnutrition. But major complications may occur in the upper esophagus more often and earlier than in other parts.

Aged↗
PubMed2002

The silencer activity of the novel human serotonin transporter linked polymorphic regions.

Enhancer/silencer activity of each allelic variant of the human serotonin transporter linked polymorphic region (5-HTTLPR) including newly found ones was measured in several cell lines including raphe-nucleus-derived RN46A. 5-HTTLR variants ligated in pGL-3 promoter vector increased luciferase activity in COS-7 cells and PC12 cells, where no significant differences among the variants were observed. In RN46 cell lines, however, 5-HTTLPRs decreased luciferase activity to 80-30%, acting as silencers not as enhancers. Some allelic variants (15, 19, 20 and 22) showed even significantly stronger silencer activities than others in RN46A. We also examined relationship between allelic frequencies, the enhancer/silencer activities and incidents of mood disorder. The categorized genotypic or allelic frequencies was not significantly different between the mood disorder and the control. No significant difference was detected either when analyzed by silencer activities of each allelic variant.

Animals↗