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Biomedical subjects

Yuji Tanaka

Publications and source records attributed to Yuji Tanaka.

At least 37 records · Page 2Linked to original sources

Incidence of invasive aspergillosis after allogeneic hematopoietic stem cell transplantation with a reduced-intensity regimen compared with transplantation with a conventional regimen.

To evaluate the clinical characteristics of invasive aspergillosis (IA) after reduced-intensity stem cell transplantation (RIST) compared with those after conventional stem cell transplantation (CST), we examined the medical records of 486 CST and 178 RIST recipients. The overall incidence of IA after allogeneic transplantation was 35 (5.3%) of 664, which gave a 3-year cumulative incidence of 5.6%. The estimated 3-year incidence of IA in CST and RIST was 4.5% and 8.2% (P = .045), respectively, but the mortality rates were similar (76% and 86%). The median onset of IA after RIST (day 127) occurred significantly later than that after CST (day 97). A multivariate analysis revealed that IA was associated with age older than 50 years (relative risk, 2.12; 95% confidence interval, 1.08-4.17; P = .03) and the presence of acute and/or chronic GVHD (relative risk, 6.2; 95% confidence interval, 2.4-16.4; P = .0002). IA remains an important complication after allogeneic transplantation, regardless of the type of conditioning regimen.

Adolescent↗

Modulation of organic anion transporting polypeptide 1 and multidrug resistance protein 3 expression in the liver and kidney of Gunn rats.

Background: Gunn rat is an animal model of Crigler-Najjar syndrome (CNS) type I that develops jaundice due to defect of bilirubin conjugation. Bilirubin UDP-glucuronosyltransferase (UGT1A1), which plays a critical role in bilirubin glucuronidation, has been reported to be deficient in CNS type 1. On the other hand, little is known about the expression of organic anion transporters in Gunn rats. In the present study, we evaluated expressions of organic anion transporting polypeptide (oatp) 1 and 2, multidrug resistance-associated protein (mrp) 2 and mrp3 in the liver and kidney of Gunn rats. Methods: Serum samples, liver and kidney tissues were obtained from Gunn rats and normal SD rats ( [Formula: see text], in each group). Semi-quantitative mRNA expression of oatp1, oatp2, mrp2, and mrp3 mRNA was evaluated by constructed reverse transcription-polymerase chain reaction (RT-PCR). Protein expressions were determined by Western blotting and by immunohistochemistry. Results: Marked elevation of serum unconjugated bilirubin concentration ( [Formula: see text] micromol/l) was observed in Gunn rats. Hepatic expression of oatp1 and oatp2 mRNA was 44% ( [Formula: see text] ) and 35% ( [Formula: see text] ) lower in Gunn rats than in SD rats, respectively. Hepatic oatp1 protein expression was 37% ( [Formula: see text] ) lower in Gunn rats than in SD rats. In contrast to oatp1, hepatic expression of mrp3 mRNA and protein was 76% ( [Formula: see text] ) and 557% ( [Formula: see text] ) higher in Gunn rats than in SD rats, respectively. Hepatic expression of oatp2 and mrp2 protein was not significantly different between Gunn rats and SD rats. Like the Western blot analysis, immunohistochemical staining disclosed decrease of oatp1 and increase of mrp3 protein expressions in the liver of Gunn rats. Decrease of oatp1 and increase of mrp3 expressions were also observed in the kidney of Gunn rats. Conclusion: Decreased expression of oatp1 and increased expression of mrp3 were observed in the liver and kidney of Gunn rats. Deficient UGT1A1 activity-associated retention of unconjugated bilirubin in the hepatocytes may modulate the expressions of these transporters in Gunn rats.

Journal Article↗

Comparative analysis of clinical outcomes after allogeneic bone marrow transplantation versus peripheral blood stem cell transplantation from a related donor in Japanese patients.

A reduced incidence of graft versus host disease (GvHD) has been documented among Japanese allogeneic bone marrow transplantation (BMT) patients, as the Japanese are genetically more homogeneous than western populations. To clarify whether this ethnic difference affects the results of allogeneic peripheral blood stem cell transplantation (PBSCT), we conducted a nationwide survey to compare clinical outcomes of allogeneic PBSCT (n = 214) and BMT (n = 295) from a human leucocyte antigen-identical-related donor in Japanese patients. The cumulative incidence of grades II-IV acute GvHD was 37.4% for PBSCT and 32.0% for BMT. The cumulative incidence of extensive chronic GvHD at 1 year was significantly higher after PBSCT than BMT (42% vs. 27%; P < 0.01). The organ involvement patterns of GvHD were different between the two groups. By multivariate analyses, the incidence of chronic GvHD was significantly increased in PBSCT, whereas the stem cell source did not affect the incidence of acute GvHD, transplant-related mortality, relapse or survival. We concluded that Japanese PBSCT patients have an increased risk of chronic GvHD compared with BMT patients, but the incidence of acute GvHD was still lower than in western populations. Thus, the choice of haematopoietic stem cell source should be considered based on data for individual ethnic populations.

Acute Disease↗

Increased hepatic and renal expressions of multidrug resistance-associated protein 3 in Eisai hyperbilirubinuria rats.

BACKGROUND AND AIM: Eisai hyperbilirubinuria rats (EHBR) are animal models of Dubin-Johnson syndrome, which suffer from jaundice due to impaired biliary excretion of bilirubin glucuronides. In EHBR, deficiency of multidrug resistance-associated protein 2 (mrp2) causes defective biliary excretion of numerous organic anions. However, little is known about the expression of other organic anion transporters in this mrp2-deficient model. The aim of the present study was to investigate adaptive expressions of mrp1, mrp3, mrp6, organic anion transporting polypeptide 1 (oatp1) and oatp2 in liver and kidney of EHBR. METHODS: For the present study, EHBR (n = 5) were used. Hepatic and renal mRNA expression of the aforementioned transporters was determined by constructed semiquantitative reverse transcription polymerase chain reaction assay. Their protein expression was determined by western blotting. Localization of hepatic and renal mrp3 was confirmed by immunohistochemistry. Sprague-Dawley (SD) rats (n = 5) were used as normal controls. RESULTS: Deficiency of mrp2 protein was confirmed in EHBR. Hepatic and renal expression of mrp3 mRNA was 53.6% (P < 0.001) and 82.9% (P < 0.001), and its protein expression was 298.9% (P < 0.001) and 245.0% (P = 0.001) higher in EHBR than in SD rats, respectively. Hepatic and renal expression of mrp1 and mrp6 mRNA was not significantly different between EHBR and SD rats. The mrp1 and mrp6 proteins were expressed in very low amounts in the liver and kidney of both EHBR and SD rats. In contrast to mrp3, hepatic expression of oatp1 and oatp2 mRNA was 33.9% (P = 0. 001) and 38.6% (P < 0.001), and their protein expression was 57.4% (P < 0.05) and 51.0% (P < 0.01) lower in EHBR than in SD rats, respectively. Hepatic and renal mrp3 protein was localized at the basolateral membrane. CONCLUSIONS: Mrp3 plays an important role in the compensation of mrp2 deficiency in liver and kidney of EHBR. Hepatic expressions of mrp3, oatp1 and oatp2 changed adaptively in this animal model. This is a compensatory mechanism for reducing injury to hepatocytes from cytotoxic materials that increase in mrp2 deficiency.

ATP Binding Cassette Transporter, Subfamily B↗

Psychoneurological symptoms during interferon therapy in patients with chronic hepatitis: prospective study on predictive use of Cornell Medical Index and electroencephalogram.

BACKGROUND/AIMS: We assessed the usefulness of the Cornell Medical Index (CMI) and electroencephalogram (EEG) in the prediction and early detection of psychoneurological symptoms associated with interferon (IFN) therapy for chronic viral hepatitis. METHODS: Forty-eight consecutive patients received IFN for chronic viral hepatitis for 8-24 weeks. CMI was measured before IFN therapy. Serial EEGs were recorded before IFN therapy, 2, 4 weeks, and thereafter every 4 weeks in the therapy. RESULTS: Psychoneurological symptoms including insomnia, depression, and restlessness were seen in 11 (23%) of 48 patients. Five (13%) of 40 patients with CMI I and II and six (75%) of eight with CMI III developed psychoneurological symptoms (P<0.001). Sensitivity, specificity, and predictive accuracy of CMI III were 55%, 95%, and 75%, respectively. Abnormal EEG such as slow basic rhythm, appeared in 13 patients (27%) during IFN therapy. Psychoneurological symptoms were seen in six (46%) of the 13 patients with abnormal EEG, and in five (14%) of 35 in whom EEG remained normal (P<0.05). CONCLUSIONS: CMI is useful for the prediction of IFN-induced psychoneurological symptoms in patients with chronic viral hepatitis. Serial EEGs contribute to the screening and auxiliarily assessing the adverse effects of IFN on the central nervous system.

Adult↗

Heart rate variability and ambulatory blood pressure monitoring in young patients with hypertrophic cardiomyopathy.

BACKGROUND: Sudden cardiac death commonly occurs in young patients with hypertrophic cardiomyopathy (HCM); however, their heart rate variability (HRV) and blood pressure (BP) response to daily life activities is not well known. METHODS AND RESULTS: HRV and ambulatory BP monitoring were performed in 20 patients (age range: 7-21 years) and 57 age-matched healthy volunteers (age range: 10-22 years). Time domain variables and spectral data were obtained at hourly intervals throughout the day. To determine the BP response to daily life activities, the ratios of the mean BP and pulse pressure in the morning, afternoon, and night to those during sleeping were calculated. The association between the BP level and HRV was also evaluated. The HCM patients showed significantly increased sympathovagal imbalance and decreased parasympathetic activity in the early morning, around noon, and in the early evening. This abnormality was independent of cardiac symptoms. Symptomatic patients showed a significantly lower systolic BP response in the morning, and a higher incidence of dissociation between sympathetic activity and BP response than asymptomatic patients. CONCLUSION: An abnormal BP response in the presence of impaired HRV appears to be predictive for cardiac events in young patients with HCM.

Adolescent↗

Promotion of beta-cell differentiation by conophylline in fetal and neonatal rat pancreas.

Conophylline is a vinca alkaloid extracted from the tropical plant Ervatamia microphylla and has been shown to induce differentiation of pancreatic AR42J cells. In the present study, we investigated the effect of conophylline on the differentiation of pancreatic precursor cells. In the rat pancreatic rudiment in organ culture, conophylline inhibited the formation of cystic structure and increased the number of insulin-positive cells. Conophylline also markedly increased the expression of mRNA for insulin and the number of pancreatic duodenal homeobox-1-positive cells. These effects of conophylline were similar to those of activin A. We also examined the effect of conophylline on neonatal rats treated with streptozotocin, a model of type 2 diabetes. Treatment with conophylline significantly reduced the plasma glucose concentration and improved glucose tolerance in response to glucose loading. The insulin content and the beta-cell mass at 2 months were significantly increased by conophylline. The number of islet-like cell clusters and pancreatic duodenal homeobox-1-positive ductal cells was greater in conophylline-treated rats. These results suggest that conophylline induces differentiation of pancreatic precursor cells and increases the formation of beta-cells.

Activins↗

[Changes in national insurance reimbursement with introduction of the DPC package payment system for 131I therapy for hyperthyroidism].

The inpatient DPC package payment system lowers national insurance reimbursement as compared to the former fee-for-service payment system for inpatients, when an inpatient with hyperthyroidism or toxic multinodular goiter (TMNG) is admitted for 2-day radioiodine therapy. The differentials are 29,970 yen and 48,870 yen for a 2-day hospital stay for administration of 555 MBq and 925 MBq, respectively. We request the Health and Labor Ministry to newly establish the fee for 131I internal therapy for hyperthyroidism. Furthermore, the fee should be paid according to the fee-for-service payment system.

Adult↗

The human frizzled-3 (FZD3) gene on chromosome 8p21, a receptor gene for Wnt ligands, is associated with the susceptibility to schizophrenia.

Neurodevelopmental abnormalities have been reported in studies on the pathogenesis of schizophrenia. The Wnt-signaling pathway has been implicated in a variety of processes in neurodevelopment, and the frizzled proteins have been identified as receptors for Wnt ligands. Of the frizzled proteins, frizzled-3 (FZD3) is required for formation of the neural crest and for development of major fiber tracts in the CNS. The human FZD3 gene is located on chromosome 8p21, a positive linkage locus for schizophrenia. We analyzed polymorphisms of the FZD3 gene in patients with schizophrenia and control subjects in the Japanese population. We found a significant association between schizophrenia and the FZD3 gene in single nucleotide polymorphisms and haplotype analyses. Our data suggest that dysregulation of the Wnt-signaling pathway may be involved in the susceptibility to schizophrenia.

Adult↗

No association between the sigma receptor type 1 gene and schizophrenia: results of analysis and meta-analysis of case-control studies.

BACKGROUND: Several lines of evidence have supported possible roles of the sigma receptors in the etiology of schizophrenia and mechanisms of antipsychotic efficacy. An association study provided genetic evidence that the sigma receptor type 1 gene (SIGMAR1) was a possible susceptibility factor for schizophrenia, however, it was not replicated by a subsequent study. It is necessary to evaluate further the possibility that the SIGMAR1 gene is associated with susceptibility to schizophrenia. METHODS: A case-control association study between two polymorphisms of the SIGMAR1 gene, G-241T/C-240T and Gln2Pro, and schizophrenia in Japanese population, and meta-analysis including present and previous studies. RESULTS: There was no significant association of any allele or genotype of the polymorphisms with schizophrenia. Neither significant association was observed with hebephrenic or paranoid subtype of schizophrenia. Furthermore, a meta-analysis including the present and previous studies comprising 779 controls and 636 schizophrenics also revealed no significant association between the SIGMAR1 gene and schizophrenia. CONCLUSION: In view of this evidence, it is likely that the SIGMAR1 gene does not confer susceptibility to schizophrenia.

Asian People↗

No association between the dihydropyrimidinase-related protein 2 (DRP-2) gene and bipolar disorder in humans.

Several susceptibility loci for both of schizophrenia and bipolar disorder (BPD) have been found to overlap on several chromosomes including 8p21. Expression of dihydropyrimidinase-related protein 2 (DRP-2), which gene is located on 8p21, was found to be reduced in the brains of individuals with schizophrenia and BPD. Recently, we demonstrated a significant association between the DRP-2 gene and schizophrenia. Based on the rationale, we investigated the genetic association of the DRP-2 gene with BPD using a case-control study in the Japanese population. However, no significant associations were found between five polymorphisms of the DRP-2 gene (-975C>G, 352G>A, 426C>T, 1506T>C, and *2236T>C), and BPD, nor were associations detected between either of the polymorphisms and any subtype of BPD, bipolars I and II. The present study did not provide any evidence for a contribution of the DRP-2 gene to susceptibility to BPD.

Adult↗

Expressions of hepatobiliary organic anion transporters and bilirubin-conjugating enzyme in differentiating embryonic stem cells.

Mouse embryonic stem (ES) cells are clonal cell lines derived from the inner cell mass of developing blastocysts and have multi-lineage differentiation ability. We previously reported that ES cells can be made to differentiate into hepatocytes possessing high metabolic activities by transfection of hepatocyte nuclear factor-3beta (HNF-3beta). In the present study, we investigated the expression of hepatobiliary organic anion transporters and bilirubin uridine diphosphate glucuronosyltransferase (ugt1a1) in undifferentiated and differentiating HNF-3beta-transfected ES (HNF-3beta-ES) cells. The expression of organic anion transporting polypeptide 1 (oatp1), multidrug resistance-associated protein 1 (mrp1), mrp2, mrp3, and ugt1a1 was not seen in the undifferentiated HNF-3beta-ES cells by RT-PCR, whereas all were expressed in differentiating HNF-3beta-ES cells. Protein expression for oatp1, mrp1, mrp2, mrp3, and ugt1a1 was also observed in the differentiating HNF-3beta-ES cells by Western blotting. An immunofluorescence examination revealed that oatp1 was co-located with desmoplakin, a marker for the basolateral (sinusoidal) membrane, and mrp2 was co-localized with CD26, a marker for the apical (canalicular) membrane, though they were both expressed throughout most of the cell membranes.

Animals↗

The human dihydropyrimidinase-related protein 2 gene on chromosome 8p21 is associated with paranoid-type schizophrenia.

BACKGROUND: The dihydropyrimidinase-related protein (DRP) family, also called the collapsin response mediator protein, is implicated in the developmental process of the nervous system. Dysfunction of DRPs may result in neurodevelopmental abnormalities, which may be a factor in the pathogenesis of schizophrenia. The expression of one member of DRP-2 in humans has been reported to be decreased in the brains of people with schizophrenia. In addition, the DRP-2 gene (Dihydropyrimidinase-like 2; DPYSL2) is located on chromosome 8p21, a region that has been implicated in schizophrenia in genetic linkage studies. METHODS: We investigated a genetic association between five polymorphisms of the DRP-2 gene and schizophrenia in the Japanese population. RESULTS: The *2236T>C polymorphism in the 3' untranslated region (3'UTR) exhibited significant differences with respect to the distribution of the genotype and allele in patients compared with control subjects. The frequency of the *2236C allele was significantly higher in control subjects than patients with schizophrenia (p =.0097) and paranoid-type schizophrenia (p =.0083). CONCLUSIONS: Our results suggest that the *2236C allele in the 3'UTR of the DRP-2 gene, or an unknown mutation in linkage disequilibrium with this allele, may reduce the susceptibility to schizophrenia, especially the paranoid subtype.

Alleles↗

Inducible PC12 cell model of Huntington's disease shows toxicity and decreased histone acetylation.

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by the abnormal expansion of a polyglutamine tract in the huntingtin protein. We have developed PC12 cell lines in which the expression of an N-terminal truncation of huntingtin (N63) with either wild type (23Q) or expanded polyglutamine (148Q) can be induced by the removal of doxycycline. Differentiated PC12 cells induced to express N63-148Q showed cellular toxicity reaching up to 50% at 6 days post-induction. Histone acetyltransferase (HAT) activity and global histone acetylation was significantly decreased in cells expressing truncated huntingtin with mutant but not normal huntingtin. These data suggest that altered chromatin modification via reduction in coactivator activity may cause neuronal transcriptional dysregulation and contribute to cellular toxicity.

Acetylation↗

Association study of the brain-derived neurotrophic factor (BDNF) gene with bipolar disorder.

Brain-derived neurotrophic factor (BDNF) belongs to a family of neurotrophic factors and has been demonstrated to promote the survival, differentiation, and maintenance of a broad variety of central nervous system neurons. Several reports have suggested that the BDNF gene is a plausible functional candidate gene underlying the predisposition for developing bipolar disorder (BPD). In the present study, we investigated the possible role of the BDNF gene in the etiology of BPD using a matched case-control association design in a Japanese population. There was no evidence for an allelic or genotypic association of two polymorphisms (-1360C>T and 196G>A) of the BDNF gene with BPD. Furthermore, no significant association was observed between these polymorphisms and either of two diagnostic subtypes (bipolars I and II disorder). The results suggest that the BDNF gene is unlikely to confer susceptibility to BPD.

Bipolar Disorder↗

Association study between the fibronectin gene and schizophrenia.

Fibronectin is one of the cell adhesion proteins. Adhesion molecules play an important role in neural and synaptic genesis, and their dysfunction may result in neurodevelopmental abnormalities, which have been assumed to be a factor in the pathogenesis of schizophrenia. To examine the possible involvement of fibronectin in the etiology of schizophrenia, we analyzed six polymorphisms, located in introns 2, 21, 24, and 26, and exons 20 and 28, in the human fibronectin gene (FN1) of schizophrenic patients in the Japanese population (n = 104) and age-and gender-matched controls (n = 104). No significant positive association was observed between either of the polymorphisms and schizophrenia, nor was an association found between either of the polymorphisms and any subtypes of schizophrenia. These data did not provide evidence for a contribution of the FN1 gene to susceptibility to schizophrenia.

Adult↗