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Biomedical subjects

R Ueda

Publications and source records attributed to R Ueda.

At least 91 records · Page 5Linked to original sources
PubMed1999

Amino acid substitutions in NS5A region of GB virus C and response to interferon therapy.

GB virus C (GBV-C) is related to hepatitis C virus (HCV) and has a similar genomic structure. Some predictors for the efficacy of interferon (IFN) therapy on HCV have been reported: genotype, viral load, IFN dose, and the amino acid substitutions in the NS5A region, designated as the interferon sensitivity determining region (ISDR). To evaluate the correlation between the amino acid substitutions in the GBV-C NS5A region and the response to IFN therapy, single-strand conformation polymorphism (SSCP) analysis was performed in the 12 concomitantly GBV-C-and HCV-infected patients who received IFN therapy at three time points: before, end-point, and after the IFN therapy. The region in the GBV-C NS5A studied includes the amino acids that exhibit some homology to the ISDR and the various substitutions. By SSCP analysis, amplicons were separated into 1-4 bands, which indicated the existence of heterogeneity in each host. However, the deduced amino acid sequences in these bands exhibited no characteristic differences among these strains irrespective of response to IFN therapy. Of the 32 strains separated by SSCP, 7 strains were responders, and 25 were nonresponders. The mean amino acid substitution, compared with the consensus sequence of nonresponders, was 1.00+/-0.93 among responders, and 1.40+/-0.85 among non-responders (P= NS). No correlation between the amino acid sequence in the GBV-C NS5A region and response to IFN therapy was found, indicating that the GBV-C NS5A region dose not act as the ISDR.

Adult↗
PubMed1999

Association of cyclin D1 expression with factors correlated with tumor progression in human hepatocellular carcinoma.

The amplification and/or rearrangement of the cyclin D1 gene, a positive regulatory element of the G1 to S phase of the cell cycle, has been reported in various human tumors, suggesting an oncogenic role of this gene. In this study, we investigated the expression of cyclin D1 in the formalin-fixed and paraffin-embedded human hepatocellular carcinoma (HCC) tissues of 25 patients, using monoclonal antibody 5D4 raised against cyclin D1. Two distinct patterns of staining were observed in HCC cells, nuclear and cytoplasmic. The nuclear staining pattern of cyclin D1 was detected in the tissues of only 2 of the 25 HCC patients (8%) examined and no particular clinicopathological characteristics were found in these patients. In contrast, the cytoplasmic staining pattern, without nuclear staining, was detected in 8 of the 25 patients with HCC (32%). A significant correlation was found between the expression of cytoplasmic cyclin D1 and patients with tumor thrombus in the portal vein (Vp), as well as those with intrahepatic metastasis (IM). These results indicate that the cytoplasmic cyclin D1 expression appears to be related to the prognosis of HCC. The Ag nucleolar organizer regions (NORs) counts in cyclin D1-positive and -negative patients were not significantly different, suggesting that immunostaining for cyclin D1 has the potential to be a unique prognostic marker in human HCC. Simultaneous immunohistochemical study with p53 antibody in the same series of HCC revealed that 88% of the patients positive for cyclin D1 also expressed p53 and that in 91% of the patients negative for p53, cyclin D1 was not expressed. These results suggest that cyclin D1 is expressed later than the alteration of p53 in the progression of human HCC.

Adult↗
PubMed1999

High prevalence and phylogenetic analysis of TT-virus infection in Mongolia.

A novel DNA virus, TT-virus (TTV), was isolated from a post-transfusion hepatitis patient in Japan. The prevalence of TTV infection was investigated among patients with chronic liver disease and normal alanine aminotransferase (ALT) volunteers as controls in Mongolia. Polymerase chain reaction (PCR) was employed to detect TTV DNA using specific primers derived from open reading frame 1 (ORF1) of the TTV genome. Nucleotide sequences of samples positive for TTV DNA were determined. The sequences were analyzed by a molecular evolutionary method. Fifty (60.2%) hepatitis patients and 12 (42.9%) volunteers were positive for TTV DNA. The serum ALT levels did not differ significantly between patients with single TTV infection and without TTV, HBV and HCV infection. Similarly, the serum ALT levels did not differ significantly between controls with and without TTV infection. Dual infection of TTV with either HBV or HCV did not affect the ALT levels of hepatitis patients. The molecular evolutionary tree showed that TTV was a heterogeneous virus and all strains could be divided into three genotypes in Mongolia. A new genotype was identified that was distinct from those previously reported.

Adult↗
PubMed1999

Microsatellite instability associated with hepatocarcinogenesis.

BACKGROUND/AIMS: The biological and clinicopathological significance of microsatellite instability in hepatocellular carcinoma still remains to be determined. The aim of this study was to assess the role of microsatellite instability in hepatocarcinogenesis. METHODS: Genomic DNA extracted from 38 fresh samples of hepatocellular carcinoma was amplified by polymerase chain reaction using 29 fluorescence-labeled microsatellite markers and analyzed using a semi-automated laser scanning system. Associations between the incidence of replication error and the clinicopathological features of hepatocellular carcinoma were evaluated. Since reference DNA was extracted from corresponding fresh samples of non-cancerous liver tissue, the incidence of microsatellite instability in non-cancerous liver tissues was not assessed in this study. RESULTS: Four (11%) hepatocellular carcinomas had a replication error in one or two microsatellite markers; they were all poorly differentiated hepatocellular carcinomas. The incidence of replication error correlated significantly with the histological differentiation of the tumor (p<0.05) and with portal vein involvement (p<0.05). All four hepatocellular carcinomas with replication errors showed loss of heterozygosity in one or more of the 29 markers we examined. No replication errors were detected in six markers in the coding regions of the BAX, insulin-like growth factor II receptor, transforming growth factor-beta type II receptor, E2F-4, hMSH3 and hMSH6 genes. CONCLUSIONS: The results of this study indicate that: (1) microsatellite instability is a rare event during hepatocarcinogenesis and may be specifically associated with progression of hepatocellular carcinoma; and (2) frame-shift mutation in the above six genes is not a common mechanism involved in progression of this cancer.

Aged↗
PubMed1999

High prevalance of TT virus infection in Japanese patients with liver diseases and in blood donors.

BACKGROUND/AIMS: Although a novel DNA virus, TT virus (TTV), has been isolated from a patient with cryptogenic post-transfusion hepatitis, its pathogenic role remains unclear. To elucidate its prevalence and clinical impact in patients with liver diseases, the presence of TTV DNA was assessed in patients with liver diseases and blood donors (BDs) in Japan using two primer sets, one conventional and the other new and highly sensitive. METHODS: We studied 261 samples, 72 with chronic hepatitis associated hepatitis C virus (HCV-CH), 57 with hepatocellular carcinoma associated HCV (HCV-HCC), 12 with HCC without either HCV or hepatitis B virus (NBNC-HCC), and 120 of BDs. RESULTS: Using two primer sets, TTV DNA was detected in 68 (94.4%), 53 (93.0%), 12 (100%), and 98 (81.7%) HCV-CH, HCV-HCC, NBNC-HCC, and BDs, respectively. The prevalence was not significantly different between HCV-CH and HCV-HCC, or between HCV-HCC and NBNC-HCC. Comparison between patients with and without TTV revealed no significant differences in backgrounds or biochemical findings. Histopathological findings in patients with HCV-CH, and number, maximum diameter, and histological differentiation of HCC also did not demonstrate any relation to TTV infection. TTV strains can be divided into five groups using phylogenetic analysis, but no disease-specific group appears to exist. CONCLUSIONS: Our data suggest that: 1) TTV is very prevalent among patients with liver diseases and even among BDs in Japan, 2) TTV infection does not impact on liver damage with HCV infection, and 3) TTV infection also does not affect the development or progression of HCC.

Adult↗
PubMed1999

Seroprevalence of hepatitis B virus, hepatitis C virus and GB virus-C infections in Siberia.

We studied the seroprevalence of hepatitis B virus (HBV), hepatitis C virus (HCV) and GB virus-C (GBV-C) infections in 348 Siberian natives who lived in the Kamchatka Peninsula of Russia. Of 348 samples studied, the seroprevalence of HBsAg and anti-HBs were 11.8% (41 of 348 samples) and 35.9% (125 of 348 samples), respectively. The prevalence of HCV infection was 1.4% (5 of 348 samples), and that of GBV-C RNA, using RT-PCR methods, was 7.5% (26 of 348 samples). In Siberia, the prevalences of HBV and GBV-C infections were about tenfold higher than those in Japan. The prevalence of HBsAg in subjects under 50 years of age was significantly higher than that in those over 50 years old (P < 0.05). Because HBV infection is highly endemic in Siberia, we propose that the community-based mass immunization must be conducted as soon as possible in this area.

Adolescent↗
PubMed1999

Prevalence of TT virus and GBV-C infections among patients with liver diseases and the general population in Shanghai, China.

To determine the prevalence of TT virus (TTV) and GB virus C/hepatitis G virus (GBV-C) infections among patients with liver disease and the general population in Shanghai, China, we studied 90 patients with liver diseases (acute hepatitis, 28; chronic hepatitis, 27; liver cirrhosis, 20; hepatocellular carcinoma, 15) and 90 age, sex matched healthy blood donors as controls. There were no significant differences in the clinical and demographic characteristics between the two groups, except for liver function test values. There was a statistical difference between the patient group and the control group with regard to the prevalence of TTV DNA (23.5% in patient group, 11.1% in control group, P < 0.05), although no differences in clinical features could be found between TTV DNA-positive and negative subjects. Also, no differences in TTV DNA prevalence among various categories of liver diseases were noted (P = NS). The prevalence of HBsAg was significantly different between the patient group (36.7%) and the control group (3.3%) (P0.01), whereas the prevalence of anti-HCV and GBV-C RNA were not significantly different between the two groups. The nucleotide sequences were determined in the TTV DNA-positive samples and evaluated using phylogenetic analysis which suggested that they could be divided into two main genotypes designated as genotype 1 and 2. There were five samples clustered into 3 hitherto unknown subtypes of genotype 2. We concluded that (1) although TTV infection is widespread among both groups and there is a statistical difference of TTV infection between them, no hepatic damaging evidence and correlation with certain liver disease could be found in this study, suggest that TTV may not be major cause of liver disease, (2) GBV-C infection is frequent, but the virus is not the cause of liver diseases, and (3) new subtypes of TTV may exist in Shanghai, China.

Adult↗
PubMed1999

Myofibroblasts and S-100 protein positive cells in idiopathic pulmonary fibrosis and rheumatoid arthritis-associated interstitial pneumonia.

The aim of this study was to investigate whether idiopathic pulmonary fibrosis (IPF) can be distinguished from rheumatoid arthritis (RA)-associated interstitial pneumonia (RA-IP) by means of quantitatively assessing myofibroblasts and S-100 protein positive dendritic cells. Seven patients with IPF and twelve with RA, in whom the pathological findings were consistent with usual interstitial pneumonia (UIP) were studied. Antibodies to vimentin, alpha-smooth muscle actin (alpha-SMA) and S-100 protein were used for immunohistochemical studies performed using the streptavidin/biotin/peroxidase complex method, applied to dewaxed sections from each case. In fibrosis of RA-IP, appearance of both vimentin- and alpha-SMA-positive cells, namely myofibroblasts, was widely observed, together with the pathological patterns of honeycombing, UIP and bronchiolitis obliterans-organizing pneumonia (BOOP). Fibrosis, in cases of chronic IPF, was found to be characterized mainly by vimentin-positive but alpha-SMA-negative fibroblasts. Pulmonary tissues from RA-IP patients especially when associated with a BOOP pattern, contained many cells positive for S-100 protein. However, such cells were generally hard to find in cases of IPF. These findings suggests that idiopathic pulmonary fibrosis and rheumatoid arthritis-associated interstitial pneumonia can be differentiated from each other, to some extent, based on the appearance of myofibroblasts and the presence of S-100-positive dendritic cells.

Actins↗
PubMed1999

Accurate quantitation of residual tumor burden at bone marrow harvest predicts timing of subsequent relapse in patients with common ALL treated by autologous bone marrow transplantation. Nagoya BMT Group.

We have investigated whether the extent of residual leukemia at bone marrow harvest can predict subsequent relapse after autologous bone marrow transplantation (BMT). A total of 29 pre- and post-purged marrow samples from 15 patients with high-risk common acute lymphoblastic leukemia were examined. An accurate quantitation of residual disease was achieved by phage library assay using polymerase chain reaction to amplify the third complementarity determining region of the immunoglobulin gene. The estimated rate of disease-free survival at 3 years was significantly higher for the patients with less than 5% residual disease among total B cells than for those with greater than 5% before purging (87.5% vs 0%, P = 0. 0013). Furthermore, among patients with subsequent relapse, there was a linear correlation between the quantitated residual tumor burden of pre-purged marrow and remission duration after BMT (r2 = 0. 888). An accurate quantitative assessment of residual disease in the autograft has a high predictive value for subsequent relapse. A serial assay of residual disease would help us to individualize the treatment for each patient after induction or consolidation therapy.

Adult↗
PubMed1999

Selective usage of D-type cyclins in lymphoid malignancies.

Three D-type cyclins, cyclin D1, D2 and D3, belong to the G1 cyclin, which regulates the G1/S transition of the cell cycle, and feature highly homologous amino acid sequences. The cyclin D1 gene was found to be transcriptionally activated in B-lymphoid malignancies with t(11;14), but available information is limited regarding expression of cyclin D2 and D3 in hematopoietic malignancies. We examined the expressions of three D-type cyclins to investigate how these homologous genes are differentially used. Northern blot hybridization with densitometric analyses was performed to examine 64 cell lines and 159 patients with various hematopoietic malignancies. Among lymphoid malignancies, cyclin D1 overexpression was exclusively detected in B cell malignancies accompanied by a genetic event consisting of 11q13 chromosomal translocation, consisting of 13 of 19 (68%) patients with mantle cell lymphoma, two of 11 (18%) with B-chronic lymphocytic leukemia, and one of six (17%) with multiple myeloma. The cyclin D2 expression was significantly higher in T cell malignancies than in B cell malignancies (P = 0.003 for cell lines and P < 0.0001 for patient samples, respectively). In the T cell malignancies, cyclin D2 overexpression was predominantly recognized in those with mature phenotype. Furthermore, cyclin D2 expression was upregulated by phytohemagglutinin (PHA) stimulation of normal T-lymphocytes, suggesting that this simply represents the proliferation status of mature T cells. Although cyclin D3 was ubiquitously expressed, its expression was reduced in lymphoid malignancies with cyclin D1 or D2 overexpression. In myeloid leukemias, although three D-type type cyclins were differentially expressed, no preference for particular D-type cyclins was found. This selective usage of D-type cyclins in lymphoid malignancies suggests an existence of a regulatory mechanism among three D-type cyclins.

Cell Lineage↗
PubMed1999

Molecular and immunological dissection of diffuse large B cell lymphoma: CD5+, and CD5- with CD10+ groups may constitute clinically relevant subtypes.

Diffuse large B cell lymphoma (DLBL) constitutes the greatest percentage of adult non-Hodgkin's lymphomas and represents a diverse spectrum of lymphoid neoplasms. Clinicopathologic, phenotypic and genotypic findings were correlated and compared for 63 DLBL cases to investigate whether they represent clinically relevant subtypes. They were all cyclin D1 negative and were phenotypically divided into three groups, ie group I (CD5+ type, n=11), group II (CD5- CD10+ type, n=19), and group III (CD5- CD10- type, n=33). Data were correlated by observing the respective gene rearrangement and expression of BCL2 and BCL6. In clinical aspects, the group I cases demonstrated a significantly inferior survival than those of the other two groups (log-rank test, P = 0.016). Although rearrangement of BCL2 and BCL6 did not show any inclination to a specific subgroup, the immunohistochemical detection of BCL2 was less frequent, at a statistically significant level (P=0.011), in group II (50%) than in group I (82%) and III (82%) cases. This appears to confirm the unique aspect of the CD5- CD10+ type DLBL, indicating a certain relationship with the normal germinal center cells which usually lack BCL2 expression. The BCL6 protein expression was detected in most of the present DLBL cases (92%) irrespective of this grouping. These data suggest that the phenotypic delineation by the detection of CD5 and CD10 will improve our understanding of DLBL and be helpful in a future subgrouping of DLBL.

Adult↗
PubMed1999

Detection of MUM1/IRF4-IgH fusion in multiple myeloma.

MUM1 (multiple myeloma oncogene 1)/IRF4 (interferon regulatory factor 4) gene has been identified as an oncogene transcriptionally activated by t(6;14)(p25;q32) chromosomal translocation in multiple myeloma (MM). The significance of this alteration in MM remains unknown, as it is not detectable by means of conventional cytogenetic analysis. To address this issue, we established diagnostic procedures based on pulsed-field gel electrophoresis (PFGE) analysis and double color fluorescence in situ hybridization (DCFISH) using DNA probes derived from the MUM1 and the immunoglobulin heavy chain (IgH) gene loci. Among a panel of 17 MM cell lines, three (17.6%) showed fusions between these two loci, which resulted in the juxtaposition of the MUM1 to the IgH 3' alpha-enhancer region by virtue of t(6;14) or insertion of the IgH sequences into the vicinity of the MUM1 gene and in the concomitant overexpression of the MUM1 mRNA. With similar results, fusions between MUM1 and IgH loci were observed by means of interphase DCFISH in eight (21.1%) out of the 38 MM cases, although no definite relationships between MUM1 status and specific clinical findings could be established.

Aged↗
PubMed1999

DCRY is a Drosophila photoreceptor protein implicated in light entrainment of circadian rhythm.

BACKGROUND: Light is the major environmental signal for the entrainment of circadian rhythms. In Drosophila melanogaster, the period(per) and timeless (tim) genes are required for circadian behavioural rhythms and their expression levels undergo circadian fluctuations. Light signals can entrain these rhythms by shifting their phases. However, little is known about the molecular mechanism for the perception and transduction of the light signal. The members of the photolyase/cryptochrome family contain flavin adenine dinucleotide (FAD) as chromophore and are involved in two diverse functions, DNA repair and photoreception of environmental light signals. RESULTS: We report the cloning of a new member of this family, dcry, from Drosophila. Northern blot analysis shows that this gene is expressed in various tissues. The dcry mRNA is expressed in a circadian manner in adult heads, while such rhythmic fluctuation is abolished in the clock-defective per0 and tim0 mutants. The circadian expression is dampened down in constant darkness. The over-expression of the dcry gene alters the light-induced phase delay in the locomotor activity rhythms of flies. CONCLUSION: These results suggest that DCRY is a circadian photoreceptor and that its expression is regulated by circadian clock genes.

Age Factors↗
PubMed1999

TT virus infection among IVDUs in south western China.

To elucidate the prevalence and clinical implications of infection with the newly described TT virus (TTV) among intravenous drug users (IVDUs) in Yunnan, southwest China, serum samples from 158 IVDUs (129 M, 29 F; mean age 26.1 +/- 5.5 years) were examined for TTV DNA by semi-nested polymerase chain reaction (PCR) using primers derived from the open reading frame (ORFI) of TTV DNA. The seroprevalence of viral markers of HIV, HBV, HCV and GB virus C/hepatitis G virus (GBV-C) infection was also examined. A molecular evolutionary analysis was performed. Thirty one (20%) of the IVDUs were positive for TTV DNA, and 34 (22%), 6 (4%), 98 (62%), 76 (48%), 136 (86%) and 65 (41%) were positive for anti-HIV, HBsAg, anti-HBs, anti-HBc, anti-HCV and GBV-C RNA, respectively. When all the subjects were classified according to TTV DNA positivity, no significant differences were observed in demographic, biochemical or virological characteristics between the 2 groups. TTV infection was in all cases associated with co-infection with 1 or more of the other aforementioned viruses. There were no significant differences in the various combinations of co-infection between TTV positive and negative groups. Phylogenetic analysis revealed that the TTV isolates obtained in the study could be grouped mainly into TTV genotype 1, and that some of the isolates belonged to subgroups other than those previously described. These results indicate that: 1) TTV infection is prevalent among IVDUs in China; 2) TTV probably has minor liver pathogenicity; and 3) new subgroups of genotype 1 and 2 exist in China.

Adult↗
PubMed1999

Beta-catenin accumulation and mutation of exon 3 of the beta-catenin gene in hepatocellular carcinoma.

A study was conducted to clarify the contribution of beta-catenin accumulation and mutation of the beta-catenin gene to hepatocarcinogenesis. Beta-catenin accumulation was examined immunohistochemically in 38 paired samples of hepatocellular carcinoma (HCC) and corresponding non-cancerous liver tissue. Gene mutation was analyzed by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and direct sequencing using intronic primers encompassing exon 3. Neither accumulation nor mutation was detected in non-cancerous liver tissues that showed no remarkable histological features, chronic hepatitis or liver cirrhosis. Accumulation of beta-catenin was seen in the nucleus, cytoplasm or cell membrane in 15 of 38 (39%) HCC samples, and gene mutation was seen in 9 of 38 (24%) HCC samples. Although there was a significant correlation between accumulation and mutation (P<0.01), six HCCs without mutation also showed accumulation. Samples of early HCC showed neither accumulation nor mutation, and accumulation and mutation were each correlated significantly with portal vein tumor involvement (P<0.05). The present results indicate that (1) mutation of exon 3 of the beta-catenin gene can lead to beta-catenin accumulation, although other mechanisms of accumulation may also operate in HCC, and (2) beta-catenin accumulation and mutation of the beta-catenin gene are not early events in hepatocarcinogenesis, and may be associated with the malignant progression of HCC.

Adult↗
PubMed1999

The Drosophila Bruton's tyrosine kinase (Btk) homolog is required for adult survival and male genital formation.

We isolated a Drosophila fickleP (ficP) mutant with a shortened copulatory duration and reduced adult-stage life span. The reduced copulatory duration is ascribable to incomplete fusion of the left and right halves of the apodeme that holds the penis during copulation. ficP is an intronic mutation occurring in the Btk gene, a gene which encodes two forms (type 1 and type 2) of a Bruton's tyrosine kinase (Btk) family cytoplasmic tyrosine kinase as a result of alternative exon usage. The ficP mutation prevents the formation of the type 2 isoform but leaves expression of the type 1 transcript intact. Ubiquitous overexpression of the wild-type cDNA by using a heat shock 70 promoter during the late larval or pupal stages rescued the life span and genital defects in the mutant, respectively, establishing the causal relationship between the ficP phenotypes and the Btk gene mutation. The stage specificity of the rescuing ability suggests that the Btk gene is required for the development of male genitalia and substrates required for adult survival.

Agammaglobulinaemia Tyrosine Kinase↗
PubMed1999

Vitamin D receptor gene polymorphism in patients with sarcoidosis.

The active form of vitamin D, 1,25-dihydroxyvitamin D(3), is known to be produced at sites of granulomatous reactions in sarcoidosis. 1, 25-dihydroxyvitamin D(3) has multiple immunomodulatory effects, and acts as a promoter of multinucleated giant cell formation. Polymorphism of the vitamin D receptor (VDR) gene has recently been shown to be related to bone mineral density, and also associated with hyperparathyroidism and risk of prostatic carcinoma. Considering that this might affect sarcoidosis, we investigated polymorphism of the VDR gene in 101 patients with sarcoidosis and 105 healthy control subjects. Their genotypes were determined using polymerase chain reaction (PCR) and restriction fragment length polymorphism. In the patients with sarcoidosis, the BB, Bb, and bb genotypes accounted for 1.0%, 37.6%, and 61.4%, whereas in healthy control subjects the figures were 1.0%, 20.0%, and 79.0%, respectively. The difference in the genotype distribution between healthy control subjects and sarcoidosis patients was significant (p < 0.05) with the frequency of the B allele being elevated (p < 0.05). From the result, we suggest that in VDR gene polymorphism the B allele might be a genetic risk factor for sarcoidosis.

Alleles↗