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Biomedical subjects

H Shinzawa

Publications and source records attributed to H Shinzawa.

At least 55 records · Page 3Linked to original sources
PubMed1997

Detection of hepatitis G virus RNA in patients with hepatitis B, hepatitis C, and non-A-E hepatitis by RT-PCR using multiple primer sets.

Hepatitis G virus(HGV)/GB virus C(GBV-C) is a newly identified virus associated with human hepatitis. The preliminary prevalence studies of HGV infection in Japan were entirely based on the detection of HGV RNA by RT-PCR. However, the selection of the different primer sets in such assay may influence sensitivity of the test because of the extensive genetic heterogeneity of HGV, and influence the estimation of the prevalence of HGV. To address this potential problem, we designed two primer sets from well conserved domains in the 5'NC and NS5 regions of HGV genome, and tested them together with the NS3-derived primer set in RT-PCR for their ability to detect HGV RNA in serial dilution of synthetic viral RNA templates. Subsequently, we used these three primer sets to detect HGV RNA in the sera of 371 Japanese patients with hepatitis B, hepatitis C, and non-A-E hepatitis. The results indicated that the primer set derived from the 5'NC region appeared to be most effective in detecting HGV RNA. The results also showed that only two out of the 126 patients (1.6%) with non-A-E hepatitis were positive for HGV RNA although the RNA were detected more frequently in patients with hepatitis B (2/38; 5.3%) and hepatitis C (17/207; 8.2%), suggesting that HGV is not a common causative agent for non-A-E hepatitis in Japan.

Base Sequence↗
PubMed1996

Sequence of hepatitis G virus genome isolated from a Japanese patient with non-A-E-hepatitis: amplification and cloning by long reverse transcription-PCR.

The nucleotide sequence of hepatitis G virus (HGV) genome was determined by analysis of cDNA clones obtained by long reverse transcription-polymerase chain reaction (long RT PCR) and 5'- and 3'-rapid amplification of cDNA ends (RACE) from a Japanese patient (Iw) with non A-E hepatitis. The HGV-Iw genome, consisting of 9375 nucleotides, contains a long open reading frame encoding 2873 amino acid residues. Comparison of HGV-Iw with two American isolates of HGV and one African isolate of GB virus C (GBV-C) indicates that although the nucleotide sequences of these isolates were considerably divergent (86.2% to 93.3%), the deduced amino acid sequences shared an extremely high degree of identity (96.1% to 100%). It was also found that HGV-Iw was more closely related to the HGV isolates from USA than to the GBV-C isolate from Africa.

Cloning, Molecular↗
PubMed1996

Effect of alcohol on tumor growth of hepatocellular carcinoma with type C cirrhosis.

To investigate the influence of alcohol intake on tumor growth of hepatocellular carcinoma (HCC) in patients with type C cirrhosis, we examined the tumor volume doubling time (TVDT) of 35 nodules from 35 cases of HCC, calculated through ultrasonographic imaging. The patients were divided into two groups according to their drinking habit; 21 habitual drinkers (alcohol group; 80g ethanol/day for 5 years), and 14 patients without alcohol abuse (non alcoholic group). The average value of TVDT in the alcoholic group was 78 +/- 47 days, although that of the non alcoholic group was 142 +/- 60 days. A statistically significant difference (p < 0.01) was found between the two groups. Of the 21 habitual alcohol drinkers, 8 refrained from drinking after detection of HCC; their TVDT was about 30 days shorter than those who continued alcohol intake. In conclusion we found that alcohol intake was closely related to the tumor growth of HCC in patients with type C cirrhosis.

Adult↗
PubMed1996

Prevalence of inhabitants with anti-hepatitis C virus antibody in an area following an acute hepatitis C epidemic: age-and area-related features.

The northern district of R Town, Yamagata Prefecture, Japan, experienced an epidemic of acute hepatitis C during the 6 years following 1967. A mass survey health examination for hepatitis C virus (HCV) infection was performed on the inhabitants of this district aged 6 or over (4,655 people). Of the 3,094 inhabitants (66.5%) examined, 602 (19.5%) were anti-HCV antibody (anti-HCV) positive. Of the 602 anti-HCV positive subjects, 444 (73.7%) showed an anti-HCV cutoff index of over 4.0 (high titer), 54 (9.0%) showed 3.0 approximately 4.0 (middle titer), and 104 (17.3%) showed an index of under 3 (low titer). One hundred and sixty subjects, randomly selected, were examined for HCV RNA by nested polymerase chain reaction, and positive reactions were detected in 125 subjects (78.1%). The anti-HCV positive rate differed greatly between subjects younger than 40 years (18/1,289; 1.4%) and those 40 or over (584/1,805; 32.4%). Those who had lived in this district since before the acute hepatitis C epidemic had a high rate of positive anti-HCV. Among the 47 hamlets in this farming district, the hamlet with the highest rate (71.4%) was surrounded by other hamlets where the rates decreased as the distance from the high rate hamlet increased. The study suggested a marked regional accumulation of HCV infection in this district and an age-related difference in HCV infection rates. The cause of the accumulation was not identified, although the HCV infection in this district may have been spread during or before the acute hepatitis C epidemic and produced many HCV carriers.

Adolescent↗
PubMed1996

An evaluation of hepatic ultrasound speed in injury models in rats: correlation with tissue constituents.

The speed of sound through the livers of 32 male Sprague-Dawley rats was measured. The study population consisted of four experimental groups: control, acute liver injury induced by carbon tetrachloride, fatty liver induced by a choline-deficient diet, and liver cirrhosis induced by administration of N-diethylnitrosamine. To examine possible correlations between the speed of sound and liver histology, biochemical measurements of the water, fat, and collagen content were made. The aim of the present study was to determine the effects of the characteristics of diseased liver tissue on the speed of sound, by studying the tissue constituents biochemically and by using a more accurate measurement of the speed of sound. The sound speed was 1591.6 +/- 6.7 m/s in the acute liver injury group, 1531.4 +/- 18.4 m/s in the fatty liver group, and 1624.9 +/- 6.7 m/s in the liver cirrhosis group. No significant correlation existed between the speed of sound and the water content in all groups taken together, whereas a good correlation was found in the fatty liver group (P < 0.0001, r = -0.858) and in cirrhosis (P < 0.0001, r = 0.760) when the groups were examined separately. These results indicate that the speed of sound is useful for diagnosing fatty liver for predicting the fat content.

Animals↗
PubMed1995

Interleukin-6 down-regulates expressions of the aldolase B and albumin genes through a pathway involving the activation of tyrosine kinase.

Interleukin-6 plays a key role in mediating acute-phase protein synthesis in hepatocytes. However, the mechanism of how interleukin-6 regulates aldolase B and albumin syntheses in hepatocytes is not completely understood. In this study, using primary cultured rat hepatocytes, we have shown that interleukin-6 down-regulates expressions of the aldolase B and albumin genes in a dose- and time-dependent manner. We examined whether the decrease in aldolase B and albumin mRNA expressions by interleukin-6 reflected transcriptional down-regulation or stability of the mRNA. Actinomycin D and cycloheximide did not affect the interleukin-6-mediated decrease in the expressions of both genes. These results suggest that the decreased expressions of both genes induced by interleukin-6 is controlled at the transcriptional level, and that it is due neither to increased degradation of mRNA nor to synthesis of new proteins. Protein kinases play a fundamental role in the intracellular signal transduction. To examine the interleukin-6 signal pathway(s) leading to the decrease of aldolase B and albumin mRNA expressions, we tested various kinds of protein kinase inhibitors in this system. Herbimycin A, an inhibitor of tyrosine kinase(s), prevented the decrease in the expression of aldolase B and albumin mRNAs by interleukin-6. H-7, an inhibitor of protein kinase C, prevented the decrease in the expression of albumin mRNA by interleukin-6, but did not induce recovery of that of aldolase B mRNA. These results suggest that a tyrosine kinase(s) or a herbimycin A-sensitive kinase(s) constitutes a common pathway for interleukin-6-mediated reduction of aldolase B and albumin mRNA expressions and that distinct pathways exist for the modes of expression of the two mRNAs.

Albumins↗
PubMed1995

In vivo regulation of rat neutrophil apoptosis occurring spontaneously or induced with TNF-alpha or cycloheximide.

We previously demonstrated that human TNF-alpha induces rapid apoptosis of human neutrophils. To understand better the in vivo significance of neutrophil apoptosis, we examined spontaneous, recombinant human and mouse TNF-alpha- or cycloheximide-induced apoptosis of normal peripheral blood neutrophils (PBN), PBN from rats injected i.p. with proteose peptone or a streptococcus preparation, OK-432 (inflammatory PBN), peritoneally exudated neutrophils (PEN) obtained after a proteose peptone injection, and normal bone marrow neutrophils. The following observations were made. 1) Normal PBN responded to TNF-alpha, but PEN, normal bone marrow neutrophils, and inflammatory PBN at 12 h after stimulation did not. 2) The sensitivity to TNF-alpha of the inflammatory PBN started to decrease at 3 h, was lowest at 12 h, and was almost restored at 52 h after stimulation. 3) Spontaneous apoptosis of normal and inflammatory PBN reached 25% at 12 h after in vitro incubation, but that of PEN and normal bone marrow neutrophils was very low over this period. 4) The sensitivity to cycloheximide (6 h incubation) was high for normal PBN and bone marrow neutrophils, but low for PEN and inflammatory PBN after 12 h. 5) 125I-rhTNF-alpha binding of bone marrow neutrophils was significantly lower than that of normal and inflammatory PBN and PEN. 6) TNF-alpha-induced apoptosis of normal or inflammatory PBN and bone marrow neutrophils was enhanced by treatment with low doses of cycloheximide that alone were barely able to induce neutrophil apoptosis; however, apoptosis of PEN was not. The mechanisms and in vivo significance of these phenomena are discussed.

Animals↗
PubMed1994

Ascorbic acid radical, superoxide, and hydroxyl radical are detected in reperfusion injury of rat liver using electron spin resonance spectroscopy.

Using electron spin resonance (ESR) spectroscopy, we examined whether reactive oxygen intermediates (ROIs) are produced after reperfusion of isolated, perfused rat livers subjected to global ischemia (10, 30, 60, and 90 min of ischemia). A few drops of effluent (200 microliters) flowed from reperfused liver was mixed immediately with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO, final concentration 1 M), and ESR measurements were then performed. Immediately after reperfusion, a small amount of ascorbic acid radical and DMPO-OOH, which was formed by the reaction of superoxide with DMPO, was detected. The amount of ascorbic acid radical peaked immediately after reperfusion, but became hardly detectable at 6 min after reperfusion, irrespective of the period of ischemia. Six minutes after reperfusion, not only DMPO-OOH but also DMPO-OH, which was formed by the reaction of hydroxyl radical with DMPO, was detected. Thereafter, DMPO-OOH and DMPO-OH gradually declined and became hardly detectable at 40 min after reperfusion. In accordance with the duration of ischemia, the concentrations of DMPO-OOH and DMPO-OH were highest after 60 min of ischemia, and then after 30, 90, and 10 min of ischemia in decreasing order. These results directly demonstrate that the production of ROIs occurs at an early stage of reperfusion in ischemic liver and that the amount of ROI production is closely related to the duration of ischemia.

Animals↗
PubMed1994

Treatment of symptomatic hepatic cysts by percutaneous instillation of minocycline hydrochloride.

Nine patients with 16 symptomatic nonneoplastic congenital hepatic cysts were treated prospectively by ultrasonically guided percutaneous minocycline hydrochloride injection, and the usefulness of this treatment was evaluated. Seven of the patients had multiple hepatic cysts, and two solitary cysts. All the patients were women, ranging in age from 36 to 81 years. After cystic fluid had been aspirated with a 21-gauge PTC needle, minocycline hydrochloride was injected into all the cysts. The minocycline hydrochloride was dissolved in saline at a concentration of 200 mg in 9 ml, and mixed with 1 ml of 2% mepivacaine hydrochloride. The total quantity of minocycline hydrochloride injected varied from 100 mg to 1200 mg per hepatic cyst, depending on its size. Total or subtotal regression of the cysts was observed in all patients during follow-up periods ranging from 15 to 35 months. Seven patients became symptom-free, one showed symptom reduction, and one showed no change in symptoms. Minor side effects, eg, transient abdominal pain, slight right shoulder pain, and temperature elevation, were noted in three patients respectively. On the basis of these results, we conclude that ultrasonically guided percutaneous minocycline hydrochloride injection is useful for the treatment of symptomatic hepatic cysts.

Adult↗
PubMed1994

[Interferon therapy of compensated type C cirrhosis].

Interferon (IFN) has been demonstrated to be effective against chronic hepatitis C. However, it has been believed that IFN treatment is generally ineffective in cases that have already progressed to cirrhosis. It is highly important to develop a treatment modality that will stop the progression of compensated to decompensated cirrhosis. We have carried out a randomized controlled study of human lymphoblastoid interferon in patients with compensated type C cirrhosis. There were no serious side effects, and treatment with 3 MU IFN daily for 2 wk and three times weekly for 24 wk thereafter is more effective than treatment with 1 MU, or no treatment. IFN administration can be effective and safe in patients with compensated type C cirrhosis, and it would be worthwhile to evaluate IFN therapy for such patients further.

Female↗
PubMed1994

A randomized, controlled trial of human lymphoblastoid interferon in patients with compensated type C cirrhosis.

OBJECTIVE: To determine the efficacy of human lymphoblastoid interferon (L-IFN) in the treatment of compensated type C cirrhosis, 30 patients were assigned randomly to three groups, consisting of 10 patients each, who were treated as follows. METHODS: The 1- and 3-megaunit (MU) groups received 1 or 3 MU of L-IFN, respectively, daily for 2 wk, and three times weekly for 24 wk thereafter. The control group received no treatment. All of the patients had positive C100-3 hepatitis C virus antibody (anti-HCV) titers. RESULTS: The serum alanine aminotransferase (ALT) levels decreased 26 wk after L-IFN treatment was began, in both treatment groups. In the 3-MU group, the ALT levels became normal [complete response (CR)] in 40%, improved to less than twice the upper limit of the normal value [partial response (PR)] in 10%, and remained unchanged [no change (NC)] in 50%. In the 1-MU group, a PR occurred in 30%. There was NC in 70%, and NC occurred in the control group. Twenty-four weeks after stopping L-IFN, the CR and NC rates in the 3-MU group were 10% and 90%, respectively, and NC was observed in all of the 1-MU and control patients. 2',5'-Oligoadenylate synthetase activities increased in both treatment groups (p < 0.05), but not in the control group. The anti-HCV titers decreased in the 3-MU group (p < 0.05), but not in the 1-MU and control groups. Higher doses of L-IFN were more effective. No serious side effects occurred. CONCLUSIONS: These findings suggest that IFN administration can be effective and safe in patients with compensated type C cirrhosis, and that it would be worthwhile to evaluate IFN therapy for cirrhotic patients further.

2',5'-Oligoadenylate Synthetase↗
PubMed1993

Inhibition of Corynebacterium parvum-primed and lipopolysaccharide-induced hepatic necrosis in rats by selective depletion of neutrophils using a monoclonal antibody.

To examine whether neutrophils are involved in the pathogenesis of experimental liver dysfunction, we observed the effect of selective in vivo neutrophil depletion by a monoclonal antibody (RP-3) on the pathogenesis of acute experimental hepatic necrosis in rats induced by a preparative injection of heat-killed Corynebacterium parvum and a challenging dose of lipopolysaccharide (LPS) (positive control group). The serum transaminase titer 8 h after LPS injection was reduced by selective depletion of peripheral blood neutrophils as a result of RP-3 treatment (RP-3 group). A kinetic study showed that the serum transaminase titer of the RP-3 group was significantly lower than that of the positive control group from 4 to 24 h after LPS injection. The transaminase level was significantly lower in the group with less than 400/mm3 peripheral blood neutrophils than in the group with a greater number. The effect of RP-3 on the transaminase level was due neither to the injection of cancer ascites nor to RP-3 injection with the accompanying decrease in complement titer. These results suggest that neutrophils play an important role in the induction of liver dysfunction in this system.

Animals↗
PubMed1992

Electron microscopic study of hepatitis B virus-associated antigens on the infected liver cell membrane in relation to analysis of immune target antigens in chronic hepatitis B.

To clarify the characteristics of cell surface Pre-S2 Ag, HBcAg and HBeAg immunohistochemically and to explore their relationship with a cellular immune target antigen, 31 liver biopsy specimens from chronic HBV carriers were examined by immunoperoxidase staining. By immune light microscopy, Pre-S2 Ag was detected on the liver cell membrane in 18 (58%) of the 31 cases, HBcAg in 4 cases (13%) and HBeAg in 4 cases (13%). Pre-S2 Ag frequently showed a honeycomb-like membrane expression pattern which was present regardless of liver inflammation, whereas HBcAg and HBeAg exhibited a scattered membrane expression pattern detected in areas of marked inflammation. Of the 18 cases showing a honeycomb-like Pre-S2 Ag expression, 3 concomitantly showed a scattered membrane expression pattern. Immunoelectron microscopy revealed these two distinct membrane expression patterns. In areas showing a honeycomb-like membrane expression pattern, Pre-S2 Ag was demonstrated in the intercellular space and on the basolateral membranes of hepatocytes, but was not detected on the cell membranes in areas of the intercellular space lacking an immunoreaction. Cytoplasmic expression of Pre-S2 Ag was less extensive in these hepatocytes. These findings suggest that the honeycomb-like membrane expression of Pre-S2 Ag results from attachment of extracellular antigen to the liver cell membrane. In contrast, in areas showing a scattered membrane expression pattern, Pre-S2 Ag, HBcAg and HBeAg were each detected as single-layered linear deposits along the cell membrane, but were absent in the intercellular space. Each antigen was also expressed abundantly in the cytoplasm, and the immunoproducts appeared to fuse with the cell membrane. These findings suggest that the scattered membrane expression of these antigens results from intrahepatic transfer of antigen synthesized in the liver cell to the cell membrane, possibly serving as a target for the host immune-mediated response in connection with inflammation.

Adult↗
PubMed1991

Superoxide is involved in the pathogenesis of paraquat-induced injury in cultured rat liver slices.

We examined whether superoxide is a factor responsible for paraquat-induced liver injury in terms of superoxide dismutase using cultured rat liver slices exposed to various concentrations of paraquat. The degree of liver injury was assessed by measurement of percentage of lactate dehydrogenase leakage into the medium and lipid hydroperoxides in the liver slices and by direct histopathological observation. Paraquat produced concentration- and time-related liver injury in the cultured rat liver slices. Notably, after exposure to 5 mmol/L paraquat, a significant increase of the percentage of lactate dehydrogenase leakage occurred from 4 hr (p less than 0.05 vs. control group), and this gradually increased up to 8 hr (p less than 0.01 and p less than 0.001 vs. control group at 6 and 8 hr, respectively). Changes in lipid hydroperoxides in the liver slices were similar to those in percentage of lactate dehydrogenase leakage (p less than 0.05 and p less than 0.01 vs. control group at 6 and 8 hr, respectively). Liver injury was located around the central vein at 6 hr and gradually spread at 8 hr. Paraquat-induced liver injury was aggravated both biochemically and histopathologically by pretreatment with 5 mmol/L diethyldithiocarbamate, an inhibitor of copper- and zinc-containing superoxide dismutase activity (percentage of lactate dehydrogenase leakage: p less than 0.01 and p less than 0.001 vs. paraquat group at 6 and 8 hr, respectively; lipid hydroperoxides: p less than 0.01 vs. paraquat group at 8 hr). Incubation of liver slices with liposome-encapsulated superoxide dismutase increased the augmentation of superoxide dismutase in the liver slices.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗