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Biomedical subjects

S Iino

Publications and source records attributed to S Iino.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Future outlook for treatment of chronic hepatitis C: IFN + ribavirin combination therapy].

Japan has over 2 million patients infected with HCV and is currently facing a crisis of rapid increase in the number of patients with HCV-related liver cirrhosis and hepatocellular carcinoma. To overcome this situation, reliance is placed mainly on IFN therapy with the addition of various therapies to treat symptoms. The knowledge gained to date with IFN monotherapy and the expectations for efficacy to be achieved with IFN + ribavirin combination therapy have been presented.

Antiviral Agents↗
PubMed2000

Annexin XI may be involved in Ca2+ - or GTP-gammaS-induced insulin secretion in the pancreatic beta-cell.

The aim of this study was to investigate possible involvement of annexin XI in the insulin secretory machinery. In fluorescence immunocytochemistry, annexin XI was found in the cytoplasm of pancreatic endocrine cells and a pancreatic beta-cell line, MIN6, in a granular pattern. MIN6 cells also possessed weak and diffused annexin XI immunoreactivity in the cytoplasm. Immunoelectron microscopy revealed annexin XI in the insulin granules. Insulin secretion from streptolysin-O-permeabilized MIN6 cells was inhibited by anti-annexin XI antibody, when the release was stimulated by either Ca2+ or GTP-gammaS, but not by a protein kinase C-activating phorbol ester. Inhibition of insulin release by anti-annexin XI antibody was reproduced in permeabilized rat islets. These findings suggest that annexin XI may be involved in the regulation of insulin secretion from the pancreatic beta-cells.

Animals↗
PubMed2000

Virologic analysis of non-B, non-C hepatocellular carcinoma in Japan: frequent involvement of hepatitis B virus.

Serum and liver tissues from hepatitis B surface antigen-negative/anti-hepatitis C virus (HCV)-negative (non-B, non-C) hepatocellular carcinoma (HCC) patients in Japan were examined for the presence of hepatitis B virus (HBV), HCV, and TT virus (TTV) by polymerase chain reaction. The studies evaluated the contribution of these viruses to pathogenesis of HCC. HBV DNA was detected in the sera of 20 (47.6%) of 42 non-B, non-C HCC patients, which was significantly higher than in age-matched controls without liver disease (P<.001). In 8 of 12 patients with liver tissues available, HBV DNA was detected in cancerous and adjacent noncancerous liver tissues. No HCV RNA was detected. The positivity for TTV DNA was not significantly different between HCC patients and controls. These results indicate that HBV is associated with a substantial proportion of non-B, non-C HCC cases in Japan. The role of HBV in hepatocarcinogenesis in such patients needs to be clarified.

Adult↗
PubMed2000

Amino acid mutations in the interferon sensitivity determining region and serum virus load in hepatitis C virus carriers with long-term normal ALT levels.

The amino acid mutations in a part of the non-structural region 5A (NS5A) of the hepatitis C virus (HCV) genome, called the interferon sensitivity determining region (ISDR), can affect the response to interferon (IFN) treatment. We analyzed the serial changes of the amino acid substitutions in the ISDR during the natural course of patients with sustained long-term normal alanine aminotransferase (ALT) levels in relation to the changes in virus load, and assessed the clinical significance of ISDR in the natural course and IFN treatment. The subjects were nine patients infected with HCV (genotype 1b) who had been examined for serum ALT levels every month for more than 1 year and had well-sustained normal levels. The amino acid sequence of the ISDR was determined by the direct sequencing method, and the number of amino acid mutations was evaluated in comparison with the prototype (HCV-J). Quantitation of serum HCV RNA levels was conducted by the Amplicor-monitor method (Nihon Roche). On the initial analysis of the ISDR, six patients were determined to have no mutations, and three patients had one or two mutations. However, an increased number in amino acid mutations compared with the wild type during the follow-up period was confirmed in only one patient, and that increase was limited to within two amino acids. Virus load changed regardless of the changes in amino acid substitutions in the ISDR. The ISDR was therefore inferred to be a stable region unrelated to the virus load in patients with well-sustained normal ALT levels. Additional changes of amino acid sequence in this region were not a sensitive marker for determining whether IFN treatment is indicated.

Journal Article↗
PubMed2000

Mutations in the non-structural protein 5A gene in patients with chronic hepatitis C virus 1b infection during repeated interferon treatment.

It has been previously reported that the non-structural region 5A (NS5A) of the hepatitis C virus (HCV) includes an interferon sensitivity determining region (ISDR) and that amino acid substitutions in this region are closely associated with the response to interferon (IFN) treatment. We assessed the clinical significance of serial changes of amino acid sequences in the ISDR during repeated IFN treatment in patients with chronic hepatitis C (genotype 1b), related to serum HCV RNA load. During treatment, additional amino acid substitutions in the ISDR were observed in four of eight patients (50% 2/5 of complete responders (CR); 2/3 of non-responders (NR). However, comparing these amino acid substitutions to wild-type ISDR, the number of amino acid mutations was limited to only one amino acid identified in two CRs. The virus load changed regardless of the amino acid substitutions in the ISDR during treatment, and the wild-type and intermediate type (with less than three amino acid substitutions) showed wide variations in virus load. These data indicate that amino acid mutations in the ISDR, which indicate the switch to mutant-type do not occur easily even during repeated IFN treatment, and the additional amino acid substitutions in the ISDR are not a sensitive marker during repeated IFN treatment. In cases where virus load is used as a marker of response to repeated UN treatment, serial examinations are necessary to determine the precise virus load levels.

Journal Article↗
PubMed2000

Emergence of the precore mutant late in chronic hepatitis B infection correlates with the severity of liver injury and mutations in the core region.

OBJECTIVE: The reason that precore negative mutants (e-minus DNA) gradually become predominant in some patients during chronic hepatitis B virus infection is not clear. Theoretically, as long as both e-plus and e-minus DNA share the same epitopes in the core region, HBcAg-specific cytotoxic T lymphocytes (CTLs) cannot distinguish between the target peptides expressed by e-plus and e-minus DNA. Therefore, e-minus DNA may be accompanied by additional mutations in the core region, which may affect cytotoxic T lymphocyte recognition. To examine this possibility, the sequences of the precore and the entire core region of the hepatitis B virus genome were analyzed from paired serum samples in CH-B patients who experienced HBeAg to anti-HBe seroconversion (SC). METHODS: Patients were divided into two groups. Group A patients (n = 17) genome-converted to e-minus DNA in the precore region, which abolished HBeAg secretion within 3-4 yr after SC. Group B patients (n = 16) retained precore wild-type DNA for more than 3-4 yr after SC. To investigate the impact of the emergence of precore mutant type DNA on liver injury, alanine aminotransferase (ALT) levels were also examined. RESULTS: ALT flares were more severe among patients in group A than in group B. The average mean ALT level during the HBeAg negative phase of chronic infection was 54 +/- 38 in group A and 28 +/- 24 in group B. The average maximal ALT level during the HBeAg negative phase was 235 +/- 249 in group A and 83 +/- 106 in group B. Furthermore, all 17 patients in group A developed new core mutants during genome conversion. The average number of mutations in the core gene was 0.9 +/- 1.2 before genome conversion (e-plus DNA dominant phase) and increased to 2.8 +/- 1.3 for the 3-4 yr during genome conversion (e-minus DNA dominant phase). In contrast, only 56% (nine of 16) of patients in group B developed new core mutations after the loss of HBeAg. The average number of mutations in the core gene was 1.8 +/- 1.3 before SC (HBeAg-positive and e-plus DNA dominant phase), and decreased to 1.1 +/- 1.1 for 3-4 yr after seroconversion (anti-HBe-positive and e-plus DNA dominant phase). CONCLUSIONS: These data indicate that the emergence of a predominant precore negative genotype late in chronic hepatitis B virus infection is associated with the selection of additional mutations in the core gene, as well as with liver injury.

Adolescent↗
PubMed2000

Comparison of vectorcardiographic and 12-lead electrocardiographic detections of abnormalities in repolarization properties due to preexcitation in patients with Wolff-Parkinson-White syndrome: proposal of a novel concept of a "remodeling gradient".

Repolarization abnormalities after radiofrequency ablation in patients with manifest Wolff-Parkinson-White syndrome (WPW) have been attributed to cardiac memory of pre-existing changes in repolarization properties. We compared spatial ventricular gradient (VG) from vectorcardiograms with QRST values of 12-lead ECG in 41 patients with WPW (group A, manifest WPW due to left-sided accessory pathway (n = 20); group B, manifest WPW due to right-sided accessory pathway (n = 12); group C, concealed WPW (n = 9)) before and after ablation. Group N (n = 607) served as control. In groups A and B, the abnormalities of spatial VG and QRST values of 12-lead ECG that existed before and 1 day after ablation significantly decreased 1 week after ablation. In group C, spatial VG and QRST values of 12-lead ECG showed no significant changes. The diagnostic ability of spatial VG is almost equivalent to that of the QRST value of ECG in detecting repolarization abnormalities in patients with WPW before and after ablation. We propose a new concept of a "remodeling gradient" directing from the preexcited area to the opposite side of the ventricle as a result of preexcitation-induced electrical remodeling.

Adolescent↗
PubMed2000

Muscular innervation of the proximal duodenum of the guinea pig.

We investigated the muscular structure and innervation of the gastroduodenal junction in the guinea pig. In the gastroduodenal junction, the innermost layer of the circular muscle contained numerous nerve fibers and terminals. Since this nerve network continued onto the deep muscular plexus (DMP) of the duodenum, we surmised that the numerous nerve fibers in the gastroduodenal junction were specialized DMP in the most proximal part of the duodenum. The innermost layer containing many nerve fibers was about 1,000 microm in length and 100 microm in thickness in the proximal duodenum. This layer contained numerous connective tissue fibers composed of collagen and elastic fibers. Five to 30 smooth muscle cells lay in contact with each other and were surrounded by fine connective tissue. The nerve fibers in the proximal duodenum contained nerve terminals immunoreactive for choline acetyltransferase, dynorphin, enkephalin, galanin, gastrin-releasing peptide, nitric oxide synthase, substance P, and vasoactive intestinal polypeptide. Adrenergic fibers which contained tyrosine hydroxylase immunoreactivity were rare in the proximal duodenum. In the innermost layer of the proximal duodenum, there were numerous c-Kit immunopositive cells that were in contact with nerve terminals. This study allowed us to clarify the specific architecture of the most proximal portion of the duodenum. The functional significance of the proximal duodenum in relation to the electrical connection and neural cooperation of the musculature between the antrum and the duodenum is also discussed.

Actins↗
PubMed2000

Congenital hepatic fibrosis with fatal cholestatic liver damage.

A 23-year-old male with congenital hepatic fibrosis died because of progressive cholestatic liver damage. Pathologically, marked extension of fine fibers along the sinusoids in addition to fibrosis in Glisson's sheath, miniaturization and pseudo-glandular formation of hepatocytes as parenchymal damage, and nodular regenerative hyperplasia were considered as the cause of rapid aggravation of liver damage or portal hypertension.

Adolescent↗
PubMed2000

[Hepatitis virus and malignant lymphoma].

Hepatitis virus, especially hepatitis C virus(HCV), is suggested to be associated with lymphomagenesis. A high prevalence(33%) of HCV among non-Hodgkin's lymphoma(NHL) patients has been reported mainly in Italy, but the prevalence is low in other countries. HCV-related NHL is varied histopathologically, including diffuse large B cell lymphoma, immunocytoma or follicular lymphoma(REAL). The HCV genotypes involved are 1b, 2a or 2c(Simmonds). Although HCV RNA + strand has been detected in lymphoma tissue in various studies, there are not many studies in which HCV RNA-strand has been detected. Recent studies have shown that BCL-2 plays an important role in lymphoproliferation by suppressing apoptosis, that HCV core protein regulates c-myc transcription and that BCL-2 and c-myc work together in lymphomagenesis. It seems difficult to provide reasonable explanations regarding these puzzling epidemiological findings and lymphomagenesis.

B-Lymphocytes↗
PubMed1999

Immunohistochemical demonstration of a neuronal calmodulin-binding protein, NAP-22, in the rat spinal cord.

Neuron-enriched acidic protein having a molecular mass of 22 kDa, NAP-22, is a newly isolated calmodulin-binding protein and is phosphorylated with protein kinase C (PKC). This protein is localized to biological membrane via myristoylation and found in the membrane fraction of the brain and in the synaptic vesicle fraction. To reveal the NAP-22 distribution in vivo, we investigated the spinal cord of the 4-5-week old rats using light and electron microscopy. NAP-22 immunoreactivity was observed in the gray matter with dorsoventral gradient of reactivity. Distinct reactivity was demonstrated in the nerve terminals and dendritic spines. Some reactions were also observed in the thin nerve fibers. NAP-22 immunoreactivity was associated mainly with pre- and postsynaptic membranes, synaptic vesicles and outer mitochondrial membranes. In the nerve terminals, NAP-22 was colocalized with synaptic vesicle proteins such as synapsin I or synaptobrevin 2. About 80% of the nerve terminals having immunoreactivity for synapsin I or synaptobrevin 2 showed NAP-22 immunoreactivity. From these results, NAP-22 is confirmed to be distributed in the synaptic region of the spinal cord and is involved in the synaptic function relating to PKC.

Animals↗
PubMed1999

An antagonist of cADP-ribose inhibits arrhythmogenic oscillations of intracellular Ca2+ in heart cells.

Oscillations of Ca2+ in heart cells are a major underlying cause of important cardiac arrhythmias, and it is known that Ca2+-induced release of Ca2+ from intracellular stores (the sarcoplasmic reticulum) is fundamental to the generation of such oscillations. There is now evidence that cADP-ribose may be an endogenous regulator of the Ca2+ release channel of the sarcoplasmic reticulum (the ryanodine receptor), raising the possibility that cADP-ribose may influence arrhythmogenic mechanisms in the heart. 8-Amino-cADP-ribose, an antagonist of cADP-ribose, suppressed oscillatory activity associated with overloading of intracellular Ca2+ stores in cardiac myocytes exposed to high doses of the beta-adrenoreceptor agonist isoproterenol or the Na+/K+-ATPase inhibitor ouabain. The oscillations suppressed by 8-amino-cADP-ribose included intracellular Ca2+ waves, spontaneous action potentials, after-depolarizations, and transient inward currents. Another antagonist of cADP-ribose, 8-bromo-cADP-ribose, was also effective in suppressing isoproterenol-induced oscillatory activity. Furthermore, in the presence of ouabain under conditions in which there was no arrhythmogenesis, exogenous cADP-ribose was found to be capable of triggering spontaneous contractile and electrical activity. Because enzymatic machinery for regulating the cytosolic cADP-ribose concentration is present within the cell, we propose that 8-amino-cADP-ribose and 8-bromo-cADP-ribose suppress cytosolic Ca2+ oscillations by antagonism of endogenous cADP-ribose, which sensitizes the Ca2+ release channels of the sarcoplasmic reticulum to Ca2+.

Action Potentials↗
PubMed1999

Mutation patterns for two flaviviruses: hepatitis C virus and GB virus C/hepatitis G virus.

We studied the mutation patterns of hepatitis C virus (HCV) and GB virus C/hepatitis G virus (HGV). Although the mutation patterns of the two viruses were similar to each other, they were quite different from that of HIV. In particular, the similarity of the patterns between HCV or HGV and human nuclear pseudogenes was statistically significant whereas there was no similarity between HIV and human nuclear pseudogenes. This finding suggests that the mutation patterns of HCV and HGV are similar to the patterns of spontaneous substitution mutations of human genes, implying that nucleotide analogues which are effective against HCV and HGV may have a side effect on the normal cells of humans.

Flaviviridae↗
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

Morphological investigation of the enteric nervous system in Hirschsprung's disease and hypoganglionosis using whole-mount colon preparation.

BACKGROUND/PURPOSE: A suction rectal mucosal biopsy with positive staining for acetylcholinesterase is a useful test for diagnosis of Hirschsprung's disease (HD). However, hypoganglionosis has not been diagnosed by a rectal mucosal biopsy. The authors morphologically examined the enteric nervous systems in HD and hypoganglionosis patients using whole-mount preparations. METHODS: Six HD patients, two hypoganglionosis patients, and 10 with normally innervated colons were examined. Colonic specimens were incubated with the primary antibodies against protein gene product 9.5 (PGP 9.5) mixed with S-100b protein, tyrosine hydroxylase (TH), calcitonin gene-related peptide (CGRP), substance P (SP), and neurofilament protein 200 kDa (NFH). They were observed by histochemical technique using light-microscopy in whole-mount preparations. RESULTS: The aganglionic distal colon had thick nerve strands stained with PGP 9.5 mixed with S100 or NFH located in the layer between the longitudinal muscle and the circular one, and the submucosal layer. The nerve strands in the myenteric layer contained few CGRP- and SP-positive fibers and ran along the long axis of the intestine. Ganglion cells appeared along with those thick nerve strands in the transitional zone of HD. In hypoganglionosis, we found small myenteric ganglia with no thick nerve strands. CONCLUSIONS: The enteric nervous system in oligoganglionic segments of HD morphologically differed from the one in hypoganglionosis. A suction rectal mucosal biopsy would be of no use in the diagnosis of hypoganglionosis.

Child, Preschool↗