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Biomedical subjects

Yoshimoto Sekine

Publications and source records attributed to Yoshimoto Sekine.

At least 19 recordsLinked to original sources
PubMed2007

Acute and repeated administration of fluoxetine, citalopram, and paroxetine significantly alters the activity of midbrain dopamine neurons in rats: an in vivo electrophysiological study.

We examined the effect of the administration of the selective serotonin reuptake inhibitors (SSRIs) fluoxetine, citalopram, and paroxetine on the activity of spontaneously active dopamine (DA) neurons in the substantia nigra pars compacta (SNC) and ventral tegmental area (VTA) in anesthetized adult male Sprague-Dawley rats. This was accomplished using the technique of in vivo extracellular recording. A single injection of 2.5 mg/kg (i.p.) of fluoxetine significantly increased the number of spontaneously active SNC and VTA DA neurons. In contrast, a single injection of either 1 mg/kg (i.p.) of paroxetine or 5 mg/kg of fluoxetine significantly increased the number of spontaneously active VTA DA neurons. The repeated administration (one injection per day for 21 days) of all of the SSRIs produced a significant increase in the number of spontaneously active VTA DA neurons. Overall, our results indicate that the systemic administration of SSRI alters the activity of midbrain DA neurons with differential effects on VTA compared with SNC DA neurons.

Action Potentials↗
PubMed2006

Decreased serum levels of hepatocyte growth factor in male adults with high-functioning autism.

BACKGROUND: The mechanisms underlying the pathophysiology of autism are currently unknown. Given the role of hepatocyte growth factor (HGF) in brain development, we hypothesized that HGF plays a role in the pathophysiology of autism. In this study, we studied whether serum HGF levels are altered in subjects with high-functioning autism. METHODS: Using an enzyme-linked immunosorbent assay (ELISA), we measured serum levels of HGF in 17 male adults with high-functioning autism and age-matched 18 male healthy subjects. RESULTS: The serum levels (503.5+/-160.5 pg/mL (mean+/-SD)) of HGF in the subjects with high-functioning autism were significantly (Mann-Whitney U=34.0, p<0.001) lower than those (817.6+/-232.4 pg/mL (mean+/-SD)) of control subjects. However, there were no correlations between serum HGF levels and clinical variables in the patients. CONCLUSIONS: This study suggests that reduced HGF levels may play a role in the pathophysiology of high-functioning autism.

Adult↗
PubMed2006

Decreased serum levels of epidermal growth factor in adult subjects with high-functioning autism.

BACKGROUND: The neurobiological basis for autism remains poorly understood. Given the role of growth factors in brain development, we hypothesized that epidermal growth factor (EGF) may play a role in the pathophysiology of autism. In this study, we examined whether serum levels of EGF are altered in adult subjects with high-functioning autism. METHODS: We measured serum levels of EGF in the 17 male subjects with high-functioning autism and 18 age-matched healthy male subjects. RESULTS: The serum levels of EGF in the subjects with high-functioning autism (72.4 +/- 102.8 pg/mL [mean +/- SD]) were significantly lower (Mann-Whitney U = 22.0, p < .001) than those of normal control subjects (322.3 +/- 122.0 pg/mL [mean +/- SD]). However, there were no correlations between serum EGF levels and clinical variables in the subjects with autism. CONCLUSIONS: This study suggests that decreased levels of EGF might be implicated in the pathophysiology of high-functioning autism.

Adult↗
PubMed2006

Linkage disequilibrium analysis of the CHRNA7 gene and its partially duplicated region in schizophrenia.

Several previous studies have reported a significant linkage between markers in the alpha 7 nicotinic cholinergic receptor subunit (CHRNA7) gene and either schizophrenia or the P50 sensory gating deficit, a schizophrenia endophenotype. However, CHRFAM7A, a partially duplicated gene 1.6Mb upstream of the CHRNA7 gene, has complicated further genetic analysis. We genotyped 14 polymorphic markers throughout the full-length CHRNA7 gene and the duplicated region in 188 unrelated Han Chinese patients with schizophrenia and 188 controls. The duplicated regions were assessed by genotyping up- and down-stream polymorphic markers in the vicinity of each region and analyzing the linkage disequilibrium (LD) between each pair of markers. No evidence of risk variants for schizophrenia in either the CHRNA7 gene or the partially duplicated region was found in the LD analysis. A significant deviation from the Hardy-Weinberg equilibrium (HWE) was found only in the genotypic distribution of SNP9 (IVS4-1912) in patients (p=0.00829), but not in controls. In conclusion, our LD analysis did not reveal any association between schizophrenia in our Han Chinese population and the CHRNA7 gene or its partially duplicated region. However, we could not exclude the possibility of a weak genetic effect due to the small sample size. Analyses of larger samples and higher-density markers, particularly around SNP9 (IVS4-1912), are still needed.

Asian People↗
PubMed2006

A novel scale including strabismus and 'cuspidal ear' for distinguishing schizophrenia patients from controls using minor physical anomalies.

The present study explored minor physical anomaly items relevant to schizophrenia in order to establish a scale that can distinguish schizophrenia from controls using newly identified items along with items from the refined Waldrop scale. Seven items were significantly more frequent among schizophrenia patients (N=218) than controls (N=226). Among these seven items, two novel features, strabismus and 'cuspidal ear' showed markedly different prevalence rates between schizophrenia and control groups. A six-item scale, including the newly identified strabismus and cuspidal ear, was selected for most accurately discriminating patients with schizophrenia from controls. This scale correctly classified 59.6% of patients and 78.9% of control subjects. This new scale is procedurally more exacting and quantitative, and more relevant to schizophrenia than the original Waldrop scale. The validity of this scale should be sound since it was tested on a larger number of cohorts than used in previous research. Our scale can be used as a biomarker for predicting risk for future development of schizophrenia. The scale may also facilitate the identification of schizophrenia susceptibility genetic/environmental factors by stratifying etiologically heterogeneous patients according to physical abnormalities.

Abnormalities, Multiple↗
PubMed2006

Increased levels of serum soluble L-selectin in unmedicated patients with schizophrenia.

OBJECTIVE: Numerous studies have linked schizophrenia with altered immune function. The selectin family of adhesion molecules plays a prominent role in immune/inflammatory responses. To further study the immunological processes in the pathophysiology of schizophrenia, we determined the serum levels of selectins in patients with schizophrenia. For specificity, we also investigated selectin levels in patients with major depression. METHOD: We studied 23 unmedicated patients with schizophrenia, 17 unmedicated patients with major depression, and 36 healthy subjects. The serum levels of three types of soluble-form selectin (sE-, sL- and sP-selectin) were determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: Serum sL-selectin levels were significantly higher in patients with schizophrenia than in either control subjects (p=0.005) or patients with major depression (p=0.02). No significant difference was found with regard to the level of either serum sE-selectin or sP-selectin. CONCLUSION: Elevated sL-selectin levels in patients with schizophrenia may represent immune system dysfunction and may be involved in the pathogenesis of the illness.

Adult↗
PubMed2006

Decreased serum levels of transforming growth factor-beta1 in patients with autism.

BACKGROUND: The neurobiological basis for autism remains poorly understood. Given the key role of transforming growth factor-beta1 (TGF-beta1) in brain development, we hypothesized that TGF-beta1 plays a role in the pathophysiology of autism. In this study, we studied whether serum levels of TGF-beta1 are altered in patients with autism. METHODS: We measured serum levels of TGF-beta1 in 19 male adult patients with autism and 21 age-matched male healthy subjects using enzyme-linked immunosorbent assay (ELISA). RESULTS: The serum levels (7.34+/-5.21 ng/mL (mean+/-S.D.)) of TGF-beta1 in the patients with autism were significantly (z=-5.106, p<0.001) lower than those (14.48+/-1.64 ng/mL (mean+/-S.D.)) of normal controls. However, there were no marked or significant correlations between serum TGF-beta1 levels and other clinical variables, including Autism Diagnostic Interview-Revised (ADI-R) scores, Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), aggression, Theory of Mind, and Intellectual Quotient (IQ) in patients. CONCLUSIONS: These findings suggest that decreased levels of TGF-beta1 may be implicated in the pathophysiology of autism.

Adolescent↗
PubMed2006

Reduced serum levels of brain-derived neurotrophic factor in adult male patients with autism.

BACKGROUND: The precise mechanisms underlying the pathophysiology of autism are currently unknown. Given the key role of brain-derived neurotrophic factor (BDNF) in brain development, we hypothesized that BDNF may play a role in the pathophysiology of autism. In this study, we studied whether serum levels of BDNF are altered in patients with autism. METHODS: We measured serum levels of BDNF in 18 adult male patients with autism and 18 age-matched healthy male control subjects. RESULTS: The serum levels of BDNF in patients with autism (25.6+/-2.15 ng/ml (mean+/-S.D.)) were significantly (z = -4.42, p < 0.001) lower than those of normal controls (61.6+/-10.9 ng/ml (mean+/-S.D.)). Nevertheless, we found no correlations between BDNF levels and clinical variables in autistic patients. CONCLUSIONS: This study suggests that reduced BDNF levels may play a role in the pathophysiology of autism.

Adolescent↗
PubMed2006

Increased serum levels of glutamate in adult patients with autism.

BACKGROUND: Precise mechanisms underlying the pathophysiology of autism are currently unknown. Given the major role of glutamate in brain development, we have hypothesized that glutamatergic neurotransmission plays a role in the pathophysiology of autism. In this study, we studied whether amino acids (glutamate, glutamine, glycine, D-serine, and L-serine) related to glutamatergic neurotransmission are altered in serum of adult patients with autism. METHODS: We measured serum levels of amino acids in 18 male adult patients with autism and age-matched 19 male healthy subjects using high-performance liquid chromatography. RESULTS: Serum levels (mean = 89.2 microM, S.D. = 21.5) of glutamate in the patients with autism were significantly (t = -4.48, df = 35, p < 0.001) higher than those (mean = 61.1 microM, S.D. = 16.5) of normal controls. In contrast, serum levels of other amino acids (glutamine, glycine, d-serine, l-serine) in the patients with autism did not differ from those of normal controls. There was a positive correlation (r = 0.523, p = 0.026) between serum glutamate levels and Autism Diagnostic Interview-Revised (ADI-R) social scores in patients. CONCLUSIONS: The present study suggests that an abnormality in glutamatergic neurotransmission may play a role in the pathophysiology of autism.

Adolescent↗
PubMed2006

Association analysis of delta-opioid receptor gene polymorphisms in methamphetamine dependence/psychosis.

The role of the delta-opioid receptor (OPRD1) in methamphetamine (MAP) addiction was investigated using association analysis between OPRD1 gene polymorphisms and MAP dependence/psychosis. DNA samples from Japanese patients with MAP dependence/psychosis were analyzed to find polymorphisms in OPRD1 gene exons and exon-intron boundaries. One novel single nucleotide polymorphism (SNP) in intron 1 and two SNPs in exon 3 were identified. The two SNPs in exon 3 were in linkage disequilibrium. No significant difference was observed in either genotypic or allelic frequencies of these SNPs between controls (n = 260) and MAP dependent/psychotic patients (n = 170). Global analyses using the three SNPs and subcategory analyses on clinical parameters also showed no significant differences. These results suggest that the OPRD1 gene variants may not be a factor in vulnerability to MAP dependence/psychosis.

Adult↗
PubMed2006

Association analysis of SOD2 variants with methamphetamine psychosis in Japanese and Taiwanese populations.

SOD2 (superoxide dismutase 2) plays a crucial role in protecting the cells against damage caused by free radicals, by catalyzing their detoxification. On the other hand, cell damage caused by free radical generation following methamphetamine administration has been postulated as one of the possible pathophysiological mechanisms for methamphetamine psychosis. Hence, we investigated the association of SOD2 polymorphisms with the development of methamphetamine psychosis, in two independent populations of Japan and Taiwan. We recruited 116 patients with methamphetamine psychosis and 189 controls in Japan, and 135 patients with methamphetamine psychosis and 204 controls in Taiwan. The methamphetamine group was divided into two clinical subtypes: a transient type of psychosis (i.e., good prognosis) and a prolonged type of psychosis (i.e., poor prognosis), according to the course of the manifestation of psychosis. With reference to the genotypic and allelic frequencies of Ala/Val functional polymorphism in exon 2, we found significant differences between individuals with prolonged methamphetamine psychosis and control samples from Japan and Taiwan in the genotypic (P value 0.014 and 0.016, respectively) and in the allelic (P value 0.004 and 0.047, respectively) frequencies. Our results suggest that Ala/Val polymorphism of the SOD2 gene could be associated with the risk of developing methamphetamine psychosis.

Adolescent↗
PubMed2006

Evidence that variation in the peripheral benzodiazepine receptor (PBR) gene influences susceptibility to panic disorder.

Panic disorder (PD) is the repeated sudden occurrence of panic attacks, episodes characterized by psychological symptoms. Peripheral benzodiazepine receptor (PBR) is closely associated with personality traits for anxiety tolerance, and that it holds promise as a biological marker of stressful conditions. We have performed association analyses using the polymorphism to determine the PBR in PD. We screened the subjects for sequence variations within the 5' region, the coding region (exons 2-4), and the 3' noncoding region. One novel missense variant in exon 4, derived from the nucleotide transition in codon 162 (CGT --> CAT:485G > A) resulting in an arginine-to-histidine (Arg --> His) change, was detected in these subjects. The 485G > polymorphism of the PBR gene was analyzed in 91 PD patients and 178 controls. The genotypic and allelic analyses of the 485G > A revealed significant differences between the panic patients and the comparison subjects (P = 0.021 and 0.014, respectively). The present study provides new and important evidence that variation in the PBR gene influences susceptibility to PD.

Adult↗
PubMed2006

Genetic variant of prodynorphin gene is risk factor for methamphetamine dependence.

Previous studies have indicated that genetic factors substantially affect development of substance use disorders, including methamphetamine dependence. Prodynorphin (PDYN) is an opioid peptide precursor that yields dynorphins, endogenous kappa opioid-receptor agonists that play important roles in substance abuse. A physiologically active polymorphism of 1-4 repeats of a 68-bp element in the promoter region of the PDYN gene has been identified. We analyzed this polymorphism of the PDYN gene by a case-control association study in 143 patients with methamphetamine dependence and 209 healthy controls in the Japanese population. A 3- or 4-repeat allele in the PDYN gene promoter was found significantly more frequently in patients with methamphetamine dependence than in controls (chi(2)=9.45, p=0.0021). A 3- or 4-repeat allele in the PDYN gene promoter, which was shown to produce significantly higher transcription activity of the PDYN gene than a 1- or 2-repeat allele, is a genetic risk factor for development of methamphetamine dependence (odds ratio: 1.83, 95% CI=1.24-2.68).

Adult↗
PubMed2006

Brain serotonin transporter density and aggression in abstinent methamphetamine abusers.

CONTEXT: In animals, methamphetamine is known to have a neurotoxic effect on serotonin neurons, which have been implicated in the regulation of mood, anxiety, and aggression. It remains unknown whether methamphetamine damages serotonin neurons in humans. OBJECTIVE: To investigate the status of brain serotonin neurons and their possible relationship with clinical characteristics in currently abstinent methamphetamine abusers. DESIGN: Case-control analysis. SETTING: A hospital research center. PARTICIPANTS: Twelve currently abstinent former methamphetamine abusers (5 women and 7 men) and 12 age-, sex-, and education-matched control subjects recruited from the community. INTERVENTIONS: The brain regional density of the serotonin transporter, a structural component of serotonin neurons, was estimated using positron emission tomography and trans-1,2,3,5,6,10-beta-hexahydro-6-[4-(methylthio)phenyl]pyrrolo-[2,1-a]isoquinoline ([(11)C](+)McN-5652). Estimates were derived from region-of-interest and statistical parametric mapping methods, followed by within-case analysis using the measures of clinical variables. MAIN OUTCOME MEASURES: The duration of methamphetamine use, the magnitude of aggression and depressive symptoms, and changes in serotonin transporter density represented by the [(11)C](+)McN-5652 distribution volume. RESULTS: Methamphetamine abusers showed increased levels of aggression compared with controls. Region-of-interest and statistical parametric mapping analyses revealed that the serotonin transporter density in global brain regions (eg, the midbrain, thalamus, caudate, putamen, cerebral cortex, and cerebellum) was significantly lower in methamphetamine abusers than in control subjects, and this reduction was significantly inversely correlated with the duration of methamphetamine use. Furthermore, statistical parametric mapping analyses indicated that the density in the orbitofrontal, temporal, and anterior cingulate areas was closely associated with the magnitude of aggression in methamphetamine abusers. CONCLUSIONS: Protracted abuse of methamphetamine may reduce the density of the serotonin transporter in the brain, leading to elevated aggression, even in currently abstinent abusers.

Adult↗
PubMed2006

A transient lesion in splenium of the corpus callosum in a patient with childhood-onset anorexia nervosa.

OBJECTIVE: Although a transient lesion in the splenium of the corpus callosum (SCC) has been reported predominantly regarding patients with epilepsia, it is of rare occurrence, and its underlying biological basis remains unknown. This is a report of an SCC lesion in a patient with anorexia nervosa (AN). METHOD: The patient was a 15-year-old girl with childhood-onset (11 years) and a protracted course of AN. On admission, the patient showed no apparent neurological abnormalities. Magnetic resonance imaging (MRI) scans revealed a circumscribed lesion in the SCC. We treated her with nutritional rehabilitation supplemented with B vitamins. RESULTS: One month later, the lesion completely disappeared, but her weight was not restored. CONCLUSION: Treatment with B-vitamin supplementation may be beneficial for the treatment of patients with AN, in cases in which the disorder develops at an early age before brain maturation (i.e., childhood-onset cases), along with an enduring course of malnutrition.

Adolescent↗
PubMed2006

An association study between catechol-O-methyl transferase gene polymorphism and methamphetamine psychotic disorder.

OBJECTIVE: A series of methamphetamine psychosis reveals two kinds of clinical courses of methamphetamine psychosis: transient type and prolonged type. Furthermore, paranoid psychosis sometimes recurs without methamphetamine reuse, referred to as spontaneous relapse. Dysfunction of central dopaminergic neurotransmission has been implicated in the pathogenesis of these psychiatric states. Catechol-O-methyl transferase appears to play a unique role in regulating synaptic dopaminergic activity. This study aimed to investigate whether a functional polymorphism of the catechol-O-methyl transferase gene would be involved in the development of these psychiatric states. BASIC METHODS: We examined the functional polymorphism of val 158 met (catechol-O-methyl transferase) in 143 patients with methamphetamine psychosis and 200 healthy controls in Japan. The patients were divided into subgroups by several characteristic clinical features. MAIN RESULTS: We found a significant difference in the catechol-O-methyl transferase allele frequency between patients with spontaneous relapse and the controls (P=0.018, odds ratio=1.67). Odds ratio implied that the patients with spontaneous relapse had a nearly 1.7-fold higher rate of the low activity alleles (met) than the controls. CONCLUSIONS: Our results indicate that the met allele frequency of the catechol-O-methyl transferase is associated with patients who experienced methamphetamine psychosis and spontaneous relapse, suggesting that patients with a met allele appear to be at increased risk of an adverse response to methamphetamine.

Adult↗
PubMed2006

Association between gene polymorphisms of SLC22A3 and methamphetamine use disorder.

BACKGROUND: Methamphetamine (MAP) is one of the most frequently used illegal substances in Japan, and family and twin studies have suggested that genetic factors contribute to psychostimulant dependence, including MAP dependence. Organic cation transporter 3 (OCT3) has been reported to be involved in the disposition of MAP as well as MAP-induced behavioral changes in animals. Moreover, SLC22A3 (which encodes OCT3) is a candidate gene for MAP dependence because it is located within a chromosomal region associated with substance dependence. METHODS: Using 96 healthy control subjects, linkage disequilibrium (LD) within the SLC22A3 was investigated, and 5 single-nucleotide polymorphisms (SNPs) were selected as haplotype tag SNPs to search for an association with MAP dependence. Single-marker analyses and haplotype analyses of these SNPs were performed in 213 subjects with MAP dependence and 443 healthy controls. RESULTS: SLC22A3 polymorphisms were not significantly associated with MAP dependence in any of the single-marker and haplotype analyses. When subjects with MAP dependence were divided into polysubstance and single-MAP users, genotype and allele frequency of SNP2 (p=0.024, p=0.011, respectively), allele frequency of SNP3 (p=0.037), and haplotypic frequencies for these 2 SNPs (p=0.0438) differed significantly between groups. CONCLUSIONS: These results suggest that polymorphisms of SLC22A3 are related to the development of polysubstance use in Japanese patients with MAP dependence.

Adult↗