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Biomedical subjects

Kazuhiko Nakamura

Publications and source records attributed to Kazuhiko Nakamura.

At least 19 recordsLinked to original sources
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

Novel strategies for the treatment of inflammatory bowel disease: Selective inhibition of cytokines and adhesion molecules.

The etiology of inflammatory bowel disease (IBD) has not yet been clarified and immunosuppressive agents which non-specifically reduce inflammation and immunity have been used in the conventional therapies for IBD. Evidence indicates that a dysregulation of mucosal immunity in the gut of IBD causes an overproduction of inflammatory cytokines and trafficking of effector leukocytes into the bowel, thus leading to an uncontrolled intestinal inflammation. Such recent advances in the understanding of the pathogenesis of IBD created a recent trend of novel biological therapies which specifically inhibit the molecules involved in the inflammatory cascade. Major targets for such treatment are inflammatory cytokines and their receptors, and adhesion molecules. A chimeric anti-TNF-alpha monoclonal antibody, infliximab, has become a standard therapy for CD and it is also likely to be beneficial for UC. Several anti-TNF reagents have been developed but most of them seem to not be as efficacious as infliximab. A humanized anti-TNF monoclonal antibody, adalimumab may be useful for the treatment of patients who lost responsiveness or developed intolerance to infliximab. Antibodies against IL-12 p40 and IL-6 receptor could be alternative new anti-cytokine therapies for IBD. Anti-interferon-gamma and anti-CD25 therapies were developed, but the benefit of these agents has not yet been established. The selective blocking of migration of leukocytes into intestine seems to be a nice approach. Antibodies against alpha4 integrin and alpha4beta7 integrin showed benefit for IBD. Antisense oligonucleotide of intercellular adhesion molecule 1 (ICAM-1) may be efficacious for IBD. Clinical trials of such compounds have been either recently reported or are currently underway. In this article, we review the efficacy and safety of such novel biological therapies for IBD.

Animals↗
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 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

Safety advantage of endocut mode over endoscopic sphincterotomy for choledocholithiasis.

AIM: To evaluate whether an automatically controlled cut system (endocut mode) could reduce the complication rate of endoscopic sphincterotomy (EST) and serum hyperamylasemia after EST compared to the conventional blended cut mode. METHODS: From January 2001 to October 2003, 134 patients with choledocholithiasis were assigned to either endocut mode group or conventional blended cut mode group at the time of sphincterotomy. The two groups were retrospectively compared for the complications after EST and serum amylase level before and 24 h after the procedure. RESULTS: Of the 134 patients treated, 79 were assigned to conventional blended cut mode group and 55 to endocut mode group. There was no significant difference in age, sex, and serum amylase level before EST between the two groups. Complications were found in 5 patients of the endocut mode group (9%): hyperamylasemia (5 times higher than normal) in 4 and moderate pancreatitis in 1. Complications were found in 13 patients of the conventional blended cut mode group (16%): hyperamylasemia in 12 and moderate pancreatitis in 1. Serum amylase levels were elevated in both groups 24 h after EST (P<0.02). The average serum amylase level 24 h after EST in the conventional blended cut mode group was significantly higher than that in the endocut mode group (P<0.05). CONCLUSION: Endocut mode offers a safety advantage over conventional blended cut mode for pancreatitis after EST by reducing hyperamylasemia.

Aged↗
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

Acute pancreatitis associated with peroral double-balloon enteroscopy: a case report.

A 58-year-old Japanese man had tarry stool and severe anemia. Neither upper nor lower gastrointestinal (GI) endoscopy showed any localized lesions. Thus, the source of his GI bleeding was suspected to be in the small intestine, and he underwent peroral double-balloon enteroscopy (DBE) using EN-450T5 (Fujinon-Toshiba ES System Co., Tokyo, Japan). There were no lesions considered to be the source of GI bleeding. After the procedure, the patient began to experience abdominal pain. Laboratory tests revealed hyperamylasemia and abdominal computed tomography revealed an inflammation of the pancreas and the peripancreas. He was thus diagnosed to have acute pancreatitis. Conservative treatments resulted in both clinical and laboratory amelioration. He had no history of alcohol ingestion, gallstone disease or pancreatitis. Magnetic resonance cholangiopancreatography demonstrated no structural alterations and no stones in the pancreatobiliary ductal system. As his abdominal pain started after the procedure, his acute pancreatitis was thus thought to have been related to the peroral DBE. This is the first reported case of acute pancreatitis probably associated with peroral DBE.

Acute Disease↗
PubMed2006

Adult case of an omphalomesenteric cyst resected by laparoscopic-assisted surgery.

This report describes an extremely rare adult case of an omphalomesenteric cyst resected by laparoscopic-assisted surgery. A 29-years-old Japanese man was referred and admitted to Kyushu University Hospital because of an abdominal mass and an elevated serum CEA (carcinoembryonic antigen) level (21.3 ng/mL) in August 2001. Abdominal CT and US demonstrated a cystic mass with septum and calcification. Laparoscopy showed a large mass to be attached to his abdominal wall, measuring 110 mm x 70 mm x 50 mm and filled with mucus. The mass was resected by laparoscopic-assisted surgery. The histological findings of its wall showed fibromuscular tissue, adipose tissue, calcification, and an intestinal structure. It was finally diagnosed to be an omphalomesenteric cyst.

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

The acute and chronic administration of (+/-)-8-hydroxy-2-(Di-n-propylamino)tetralin significantly alters the activity of spontaneously active midbrain dopamine neurons in rats: an in vivo electrophysiological study.

This study examined the effect of the acute and chronic systemic administration of (+/-)-8-Hydroxy-2-(Di-n-propylamino)Tetralin(8-OH-DPAT) on the number and firing pattern of spontaneously active dopamine (DA) neurons in the ventral tegmental area (VTA or A10) and substantia nigra pars compacta (SNC or A9) in anesthetized male rats. These parameters were measured using extracellular in vivo electrophysiology. A single s.c. injection of 0.01, 0.1, or 1 mg/kg of 8-OH-DPAT did not significantly alter the number of spontaneously active SNC DA neurons compared to vehicle-treated animals (controls). The acute administration of 0.01 or 0.1 mg/kg of 8-OH-DPAT did not significantly alter, whereas the 1 mg/kg dose significantly decreased the number of spontaneously active VTA DA neurons compared to controls. The acute administration of 8-OH-DPAT significantly increased the percentage of VTA DA neurons firing in a bursting pattern. In contrast, there was a significant decrease in the percentage of SNC DA neurons firing in a bursting pattern following the acute administration of 8-OH-DPAT. The number of spontaneously active SNC DA neurons was not significantly altered by the chronic s.c. administration of 8-OH-DPAT (0.01, 0.1, or 1 mg/kg s.c.) as compared to controls. However, the chronic s.c. administration of all doses of 8-OH-DPAT significantly decreased the number of spontaneously active VTA DA neurons compared to controls. The i.v. administration of (+)-apomorphine (50 microg/kg) did not reverse the 8-OH-DPAT-induced decrease in the number of spontaneously active VTA DA neurons, suggesting that this effect is unlikely due to depolarization blockade. The percentage of VTA DA neurons exhibiting burst firing was significantly increased by 0.01 and 0.1 mg/kg, but significantly decreased by 1 mg/kg of 8-OH-DPAT. Overall, the systemic administration of 8-OH-DPAT preferentially affects the activity of spontaneously active A10 DA neurons in rats.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed2006

An inverse correlation of human peripheral blood regulatory T cell frequency with the disease activity of ulcerative colitis.

Evidence suggests that CD4+CD25+ regulatory T cells play a crucial role in the suppression of intestinal inflammation. However, their role in the suppression of inflammatory bowel disease has not yet been addressed. We examined the proportion of regulatory T cells in inflammatory bowel disease. First, we isolated CD4+CD45RO+CD25+ T cells from the peripheral blood of healthy persons and showed that these cells suppressed T cell proliferation profoundly and expressed FoxP3 abundantly, revealing that they are regulatory cells. Then the proportion of CD45RO+CD25+ in peripheral blood CD4+ T cells was analyzed in patients and healthy controls by flow cytometry. CD4+CD45RO+CD25+ T cell frequency was significantly lower in active ulcerative colitis than in the control and inactive ulcerative colitis. CD4+CD45RO+CD25+ T cell frequency was inversely correlated with the clinical and endoscopic severity of ulcerative colitis. These results suggest that a deficiency of regulatory T cells is associated with the progression of ulcerative colitis.

Adolescent↗