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Biomedical subjects

E Mita

Publications and source records attributed to E Mita.

At least 37 records · Page 2Linked to original sources
PubMed1997

Urodynamic effects of intravesical instillation of lidocaine in patients with overactive detrusor.

PURPOSE: We evaluated the effects of intravesical administration of lidocaine on the overactive detrusor in patients with spinal cord injury and cerebrovascular disease. MATERIALS AND METHODS: Cystometry was performed before and 15 minutes after intravesical instillation of 20 ml. of 1 and/or 4% lidocaine in 48 patients with spinal cord injury and 67 with cerebrovascular disease. RESULTS: A significant increase in bladder capacity was observed following administration of 1 and 4% lidocaine in patients tested longer than 1 year after spinal cord injury. However, no significant increase was noted even with 4% lidocaine in those tested within 1 year after injury. A significant increase in bladder capacity was observed in patients with cerebrovascular disease with 4 but not 1% lidocaine. When comparing the percent increase in bladder capacity obtained with 4% lidocaine in the 2 groups, patients with spinal cord injury showed a significantly greater increase than those with cerebrovascular disease (91.6 versus 31.9%, respectively). Detrusor contractions disappeared in 37.5 versus 5.4% of patients, respectively. CONCLUSIONS: Intravesical administration of lidocaine appears to be useful in differentiating detrusor hyperactivity caused by lesions of the spinal cord versus those of the brain.

Administration, Intravesical↗
PubMed1997

[Apoptosis in human diseases: role of Fas system in liver cell injury by viral hepatitis].

Hepatitis C virus (HCV) and hepatitis B virus (HBV) are major causative agents of chronic liver disease. However, the mechanisms responsible for liver cell injury remain to be clarified. Cytotoxic T lymphocytes play a crucial role in liver cell injury by HCV or HBV infection. Recently, perforin and Fas ligand have been shown to be the only molecules causing T cell-mediated cytotoxicity in short term assays. Therefore, we examined the implication of the Fas system-mediated apoptosis in the liver cell injury. When examined by immunohistochemical method, Fas antigen expression in chronic hepatitis C or B was upregulated in accordance with the severity of liver inflammation. Furthermore, Fas ligand expression was detected in liver-infiltrating mononuclear cells obtained from patients with chronic hepatitis C. These observations suggest that the Fas system plays a dominant role in liver cell injury by viral hepatitis.

Apoptosis↗
PubMed1996

Hammerhead ribozyme-mediated inhibition of telomerase activity in extracts of human hepatocellular carcinoma cells.

Telomerase, a ribonucleoprotein that directs the synthesis of telomeric DNA repeats and compensates for the telomeric losses that occur with cell division, is absent from most mortal cells but is present in immortal cells. Telomerase activity is thought to be essential for continuous cell division as seen in malignant tumor cells, and its inhibition could be a strategy for anti-cancer therapy. We prepared a hammerhead ribozyme (teloRZ) directed against the RNA component of human telomerase and tried to find if it could serve as an inhibitor of telomerase. TeloRZ showed a specific cleavage activity against a synthesized portion of the telomerase RNA component used as the substrate. Furthermore, when added to cell extracts from HepG2 or Huh-7, human hepatocellular carcinoma derived lines, teloRZ inhibited the telomerase activity in both. These findings support the potential application of ribozymes capable of telomerase inhibition as new therapeutic agents directed against immortalized cancer cells.

Base Sequence↗
PubMed1996

Quantitative analysis of antibody to hepatitis C virus envelope 2 glycoprotein in patients with chronic hepatitis C virus infection.

The significance of circulating antibody to hepatitis C virus (HCV) envelope glycoprotein 2 (E2)/nonstructural protein 1 (NS1) glycoprotein was studied in 83 patients with chronic HCV infection diagnosed by polymerase chain reaction (PCR). E2/NS1 antibody was quantitatively examined by a passive hemagglutination test using recombinant E2/NS1 glycoprotein encompassing amino acids 388 to 664 of the HCV-H strain. The results were correlated with clinical and virological features such as genotypes and viremic levels assessed by a competitive reverse-transcription PCR assay. E2/NS1 antibody was found in 73 patients (88%), and its occurrence was related to viremic levels. E2/NS1 antibody titers were low in asymptomatic HCV carriers with low levels of viral replication; 9 of 17 such patients tested positive for E2/NS1 antibody (53%), compared with 64 of 66 chronic hepatitis C patients (97%) (P < .01). A significant direct relationship was observed between viremic levels and E2/NS1 antibody titers (r = .52, P < .01). Of the 13 patients with low viremic levels of < 10(6) copies/mL, only 5 tested positive for E2/NS1 antibody (38%), whereas 68 of the 70 patients with viremic levels of > or = 10(6) copies/mL had it (97%) (P < .01). As for the relation to HCV genotypes, no difference was seen in E2/NS1 antibody titers among genotypes examined (1b, 2a, and 2b). These findings suggest that the E2/NS1 antibody tested exhibits no neutralizing activity in chronic HCV infection but may serve as a serological indicator of active virus replication.

Adult↗
PubMed1996

[Molecular biology of Fas antigen-Fas ligand system].

Fas antigen is a type I membrane protein of 45 kDa that belongs to the tumor necrosis factor (TNF)/nerve growth factor receptor family. The binding of agonistic anti-Fas antibody or Fas ligand to Fas antigen induces apoptosis. The unique motif "death domain" in the cytoplasmic region of Fas antigen is essential for the initiation of apoptosis. Fas ligand is a type II membrane protein of 40 kDa that belongs to the TNF family. Fas ligand is predominantly expressed in activated T cells. Fas system plays an important role on the clonal deletion of autoreactive T cells and T cell-mediated cytotoxicity.

Animals↗
PubMed1995

Clinical characteristics and antibody profiles of chronic hepatitis C patients: relation to hepatitis C virus genotypes.

Genotyping of 179 consecutive Japanese chronic hepatitis C patients was carried out based on the variation in the hepatitis C virus (HCV) core gene. The results were correlated with clinical features and antibody responses toward specific HCV proteins deduced from the nucleotide sequence of genotype I/1a. Genotypes II/1b, III/2a, and IV/2b were identified in 138 (77%), 24 (13%), and 12 (7%) patients, respectively. Five patients had double infections. Genotype dependence was observed only for antibody response toward the NS4 (5-1-1) protein, which was infrequent in genotype III/2a patients (33%) compared with genotype II/1b (81%; P < 0.01) and genotype IV/2b (75%; P < 0.05). Following interferon-alpha therapy, sustained amniotransferase normalisation was achieved by 89% (eight of nine) patients without antibody to the 5-1-1 protein and 33% (17 of 51) with it (P < 0.01). These findings indicate that absence of antibody response to the 5-1-1 protein is frequent in genotype III/2a HCV carriers and may serve to predict responses to interferon therapy.

Adult↗
PubMed1995

Serial density analysis of hepatitis C virus particle populations in chronic hepatitis C patients treated with interferon-alpha.

In interferon treatment of chronic hepatitis C patients, the biochemical and virological responses mostly parallel each other. However, some patients who show persistent ALT normalization display continued viremia after cessation of therapy. High-density hepatitis C virus (HCV) particles, which are immune complex forms, are reported to be less infectious both in vitro and in vivo. To assess whether high-density HCV contributes to the response discrepancies and to clarify the association with patient outcome, sera were examined from chronic hepatitis C patients who were treated with interferon-alpha. This study included 10 sustained responders with viremia (SR + ve), 5 SR without viremia, 3 transient responders (TR), and 3 nonresponders (NR). The SR + ve patients were defined as those with continued ALT normalization and serum HCV-RNA positivity at 24 weeks after therapy completion. Serum samples obtained before and 24 weeks after therapy were ultracentrifuged on 35% sucrose. The ratio between high-density and low-density HCV was determined by quantification of HCV-RNA titers in the bottom and top fractions by competitive reverse transcription and by the polymerase chain reaction, and expressed as the bottom/top (B/T) ratio. The B/T ratios before therapy were 1:1 in all groups of patients, and 1:1 after therapy in TR and NR groups. Five out of 6 SR + ve patients who showed 1:1 ratio after therapy relapsed within 1 year. In contrast, all SR + ve patients whose ratios were 10-100:1 continued to show ALT normalization. These findings demonstrate that patients who have high-density HCV dominance after therapy show persistent ALT normalization despite viremia, which can be explained by predominance of the neutralized immune complex.

Adult↗
PubMed1995

Tumor necrosis factor-alpha and interferon-gamma inhibit synergistically viral replication in hepatitis B virus-replicating cells.

The effects of tumor necrosis factor-alpha and/or interferon-gamma on the replication of hepatitis B virus were examined using HB611 cells. These cells were derived from human hepatoblastoma cells, Huh6, by integrating hepatitis B virus DNA, and produce hepatitis B virus continuously. Each of the cytokines inhibited hepatitis B virus replication in the cells assessed as the amount of episomal hepatitis B virus DNA, without a decrease in cell viability. When the two cytokines were administered together, the inhibitory effect became greater. Incubation of the cells with 1,000 U/ml tumor necrosis factor-alpha decreased HBV DNA replicative intermediates by 55%, and that with 1,000 U/ml interferon-gamma decreased these by 51%. Furthermore, incubation with 1,000 U/ml tumor necrosis factor-alpha and 1,000 U/ml interferon-gamma in combination decreased HBV DNA replicative intermediates by 71%. In contrast, the amount of hepatitis B virus RNA and secretion of hepatitis B e antigen were not apparently reduced by the cytokines, and 2',5'-oligoadenylate synthetase activity was not detected in the supernatant. These results suggest that tumor necrosis factor-alpha and interferon-gamma inhibit hepatitis B virus replication by blocking some step in reverse transcription and that the 2',5'-oligoadenylate synthetase is not involved in the mechanism underlying the inhibition by these two cytokines.

2',5'-Oligoadenylate Synthetase↗
PubMed1995

Hepatitis C viral complexity detected by single-strand conformation polymorphism and response to interferon therapy.

BACKGROUND/AIMS: Hepatitis C virus (HCV) genome heterogeneity by sequence analysis in association with interferon (IFN) inefficacy has been reported. This study was performed to establish a convenient method for detecting the HCV quasispecies complexity and to determine the correlation between the complexity and the responsiveness to IFN therapy in patients with chronic hepatitis C. METHODS: The quasispecies complexity of HCV hypervariable region 1 in patients treated with IFN-alpha was analyzed by polymerase chain reaction-mediated single-strand conformation polymorphism (SSCP). RESULTS: Seven of 25 patients (28%) with low complexity (SSCP band number of < or = 2) were HCV RNA negative after treatment, whereas in 24 patients with high complexity (SSCP band number of > or = 3), the response to IFN was almost insignificant because only 1 patient (4.5%) remained HCV RNA negative after treatment (P < 0.05). Among type 1b patients, IFN therapy was only effective for patients with low amounts of HCV RNA (< or = 10(7.5) copies/mL serum) and low complexity. In contrast, most type 2a patients tended to respond to the therapy with exceptions being those with high amounts of HCV RNA and high complexity. CONCLUSIONS: The complexity of the hypervariable region 1 quasispecies may be a factor for predicting IFN inefficacy in patients with chronic hepatitis C.

Amino Acid Sequence↗
PubMed1995

Density analysis of hepatitis C virus particle population in the circulation of infected hosts: implications for virus neutralization or persistence.

Hepatitis C virus has a low buoyant density in sucrose, but high-density particles are often observed in hepatitis C virus infection. To investigate the characteristics of circulating hepatitis C virus particles and their association with liver disease progression, we examined sera from two histologically normal hepatitis C virus carriers, 20 chronic hepatitis patients and five acute hepatitis C patients. The supernatants obtained after immunoprecipitation with anti-immunoglobulins antibody were subjected to sucrose equilibrium centrifugation. HCV-RNA positive fractions separated after the treatments were further examined for immunoprecipitation with anti-core hepatitis C virus antibody. We separated hepatitis C virus particle populations according to the density difference on 35% sucrose with centrifugation. The proportions of high and low density particles in hepatitis C virus populations were determined by means of competitive reverse transcription and polymerase chain reaction. Circulating hepatitis C virus particles in chronically infected patients could be separated into two populations: those immunoglobulin-bound with high densities and -unbound with low densities. Patients with severe liver inflammation had high-density hepatitis C virus that did not precipitate with anti-immunoglobulins but with anti-core hepatitis C virus antibodies. Thus, hepatitis C virus particle populations consist of low-density virions and high-density immune complexes and/or nucleocapsids. Among the chronic hepatitis patients, the dominant population shifted from low-density to high-density particles with the progression of liver disease. In acute hepatitis patients, this density shift was observed with alanine aminotransferase normalizations. Therefore, the major hepatitis C virus populations change from virion to immune complex and/or nucleocapsid with the progression of liver disease or inflammation.

Acute Disease↗
PubMed1995

Hepatitis C viral quasispecies in hepatitis C virus carriers with normal liver enzymes and patients with type C chronic liver disease.

Hepatitis C virus (HCV) has been reported to conform to a quasispecies nature, which is most evident in hypervariable regions of the putative envelope 2 domain. The aim of this study was to determine the relationship between the nucleotide complexity and diversity of hypervariable region 1 and various stages of the carrier states. The subjects studied were 20 HCV carriers with normal alanine aminotransferase (ALT) levels, 50 patients with chronic hepatitis who showed elevated ALT levels, 22 with cirrhosis, and 24 with hepatocellular carcinoma. The quasispecies complexity was analyzed by means of polymerase chain reaction-mediated single strand conformation polymorphism (PCR-SSCP). The value of nucleotide diversity was calculated by PCR cloning and sequencing. The number of SSCP bands ranged from 1 to 7, with no significant differences in the mean numbers among the stages of HCV infection. There was no correlation between the amounts of serum HCV RNA and the numbers of SSCP bands. No significant difference was found in the values of nucleotide diversity between carriers with normal ALT levels (mean, 6.6 x 10(-2) per site) and patients with chronic hepatitis (7.7 x 10(-2). These findings suggest that the quasispecies complexity of hypervariable region 1 is independent of the stage of chronic HCV infection.

Adolescent↗
PubMed1995

In vivo transfection of hepatitis C virus complementary DNA into rodent liver by asialoglycoprotein receptor mediated gene delivery.

An in vivo model of hepatitis C virus (HCV) infection is needed to enable investigation of the mechanism of the liver injury that it causes. In this study, we used asialoglycoprotein receptor mediated gene delivery to obtain expression of the complementary DNA (cDNA) coding the core and part of the envelope 1 protein of HCV because selective delivery to the hepatocytes has been reported to be attained with this method. The optimum carrier-DNA ratio was examined using in vitro transfection and found to be important for the efficiency of this method. In transfection in vivo, microautoradiographical examination showed that the transfected plasmids were delivered selectively to the liver parenchymal cells. To obtain an immunohistochemically detectable level of protein expression in rodent liver, some modifications for increasing the in vivo transfection efficiency were performed; a lysosomal enzyme inhibitor, chloroquine, was used and the administration route of the carrier-DNA complex was changed from the tail vein to the portal vein. On the bases of these results, in vivo transfection with expression vector of HCV core/E1 region was performed. In rat liver transfected by intraportal injection with chloroquine, the transcript RNA and the core protein were detected. These results indicated that the HCV core/E1 expression vector was not merely delivered but also successfully expressed in the liver using asialoglycoprotein receptor mediated gene delivery. The number of the HCV core expressing cells in the transfected liver was similar to that in patients with hepatitis C. These in vivo transfected animals should be useful for investigating the role of this region in the liver injury caused by HCV.

Animals↗
PubMed1995

Expression of the hepatitis C virus genome in rat liver after cationic liposome-mediated in vivo gene transfer.

The lack of a small animal model of hepatitis C virus (HCV) infection has impeded elucidation of the pathogenesis of HCV. The aim of this study was to develop an HCV-expressing animal model by means of cationic liposome-mediated in vivo gene transfer. To examine the feasibility of this strategy, pActLacZ, an expression vector composed of the LacZ gene driven by the beta-actin promoter, complexed with lipofectin, was injected retrogradely into the common bile ducts of adult rats. X-Gal histochemical staining clearly showed that the LacZ gene was expressed in hepatocytes, but not in biliary epithelial cells. Maximal expression was observed at a DNA to lipofectin ratio of 1:4. Based on this observation, pAGS3M091, an expression vector containing the full length of HCV complementary DNA (cDNA) preceded by the beta-actin promoter, was evaluated. Two days after in vivo intrabiliary administration of pAGS3M091 complexed with lipofectin, polymerase chain reaction (PCR) amplification of reverse-transcribed liver RNA demonstrated the 5' and 3' portions of HCV transcripts derived from pAGS3M091. Immunohistochemical analysis showed the HCV core protein in a small number of hepatocytes scattered in the hepatic lobules. We conclude that the full-length HCV genome was successfully expressed in adult rat liver by means of cationic liposome-mediated in vivo gene transfer. This model will be useful for determining the immunopathological role of HCV in vivo.

Animals↗
PubMed1994

Role of Fas ligand in apoptosis induced by hepatitis C virus infection.

To investigate the role that Fas ligand plays in the apoptosis of hepatocytes induced by hepatitis C virus infection, we isolated a cDNA clone for human Fas ligand and examined the expression of Fas ligand in liver-infiltrating mononuclear cells obtained from patients with chronic hepatitis C. The amino acid sequence of human Fas ligand showed 76% and 77% identity with those of rat and mouse Fas ligand, respectively. When the expression of Fas ligand transcripts was tested by reverse transcription-polymerase chain reaction, the amplified signal was detected in liver-infiltrating mononuclear cells and peripheral blood mononuclear cells, whereas only a weak signal or none at all was detected in liver tissues. These findings suggest that the Fas ligand-Fas antigen system may play an important role in liver cell injury by hepatitis C virus infection.

Amino Acid Sequence↗
PubMed1994

Increased expression of c-met messenger RNA following acute gastric injury in rats.

The aim of the present study was to evaluate messenger RNA expression of c-met, a hepatocyte growth factor receptor gene, after gastric mucosal injury in rats. Male Sprague-Dawley rats were fasted for 24 hours, received 0.6 N hydrochloric acid (HCl), and served for polyadenylated RNA extraction from the oxyntic gastric mucosa. The transcripts of rat c-met gene were analyzed by reverse-transcript polymerase chain reaction and Northern blotting. Although it was detected even before the HCl administration, the c-met expression increased 6, 24 and 48 hours after the HCl administration. Thereafter, gastric mucosal injury diminished and the c-met expression declined. Hepatocyte growth factor reportedly plays an important role in gastric cell proliferation. The increased c-met expression indicates that this gene may participate in the healing process of gastric mucosa after injury.

Amino Acid Sequence↗
PubMed1994

Aberration of genomic DNA in association with human hepatocellular carcinomas detected by 2-dimensional gel analysis.

Alterations of genomic DNAs in primary hepatocellular carcinomas (HCCs) were examined by restriction landmark genomic scanning (I. Hatada et al., Proc. Natl. Acad. Sci. USA, 88: 9523-9527, 1991) which is a 2-dimensional gel analysis that allows detection of deletion, amplification, or other rearrangements of genomic DNA. Sixteen HCC samples together with their normal counterparts were tested in this manner. Each HCC sample was micromanipulated to minimize possible carryover from non-malignant cells. DNAs from HCCs and their normal counterparts were cleaved with the restriction enzyme NotI, end labeled with 32P, and size fractionated by 2-dimensional electrophoresis using HinfI as the second cleavage enzyme. The resulting spots (about 2000) in HCC samples were compared with their normal counterparts. Five spots were more intense in 10-14 of the 16 HCCs (63-88%). The intensity of several spots was reduced to about half, suggesting the loss of one of two alleles. Some of these decreases were observed frequently in different HCC samples, whereas others were sporadic. Sixty of these spots reproducibly decreased in > 2 cases, with 27 showing a decrease in > 50% of the informative cases. The highest incidence was observed in 14 of 16 samples (88%). No significant correlations were observed between these changes in spots and hepatitis B virus or hepatitis B virus infection. The use of landmarks that show a reproducible increase or decrease in intensity is discussed in conjunction with future studies of genomic alterations inherent in HCC.

Carcinoma, Hepatocellular↗