Biomedical subjects

H Ohira

Publications and source records attributed to H Ohira.

At least 19 recordsLinked to original sources

PubMed1997

Enhanced interleukin-8 production by cultured Chang liver cells subjected to ethanol exposure and subsequent stimulation with tumor necrosis factor-alpha.

We investigated the production of interleukin-8 (IL-8) and chemotactic activity released from Chang liver cells subjected to long-term treatment with ethanol (Et) and subsequent stimulation with tumor necrosis factor-alpha (TNF-alpha). Chang liver cells were cultured in the presence of 5, 50 or 100 mmol/l Et for 4 weeks and then treated with recombinant TNF-alpha (1, 10, 100 U/ml). The culture supernatants were assayed for IL-8 using a sandwich ELISA and chemotactic activity was measured using a chemotactic chamber. Total RNA was also extracted from these cells and IL-8 mRNA was assayed by RT-PCR. In addition, TNF-receptor expression on the Et-treated cells was analyzed by flow cytometry. IL-8 levels in supernatants of cells stimulated with 100 U/ml of TNF-alpha for 48 h rose significantly with increasing concentrations of Et and values obtained were as follows: 4,918 +/- 244.4 pg/ml at 0 mmol/l Et, 5,335 +/- 266.2 pg/ml at 5 mmol/l Et, 8,726 +/- 873.4 pg/ml at 50 mmol/l Et and 9,134 +/- 866.0 pg/ml at 100 mmol/l Et. The chemotactic activity also increased with increasing concentrations of Et and was almost completely suppressed by anti-IL-8 antibody. Using semiquantitative analysis of radioactivity of IL-8 mRNA using a 32P gamma ATP-labeled primer for IL-8 mRNA, Et-treated cells were shown to have markedly higher levels of radioactivity than untreated cells. In addition, TNF-receptor expression was significantly higher in cells treated with 100 mmol/l Et. These data suggest that long-term Et treatment of Chang liver cells stimulated with TNF-alpha may enhance transcription of the IL-8 gene with up-regulation of the TNF receptor.

Antibodies↗

PubMed1996

Electrophysiologic effects of ischemic preconditioning on QT dispersion during coronary angioplasty.

OBJECTIVES: The aim of this study was to examine the effect of ischemic preconditioning on the manner of ventricular repolarization by assessing the change in QT dispersion during coronary angioplasty. BACKGROUND: QT interval dispersion reflects regional variations in ventricular repolarization and cardiac electrical instability. Previous studies have suggested that increased QT dispersion is associated with an increased incidence of malignant ventricular arrhythmias, whereas brief episodes of myocardial ischemia can render the heart more resistant to subsequent ischemic episodes, a phenomenon called ischemic preconditioning. METHODS: To assess the effects of ischemic preconditioning on myocardial repolarization by examining the change in QT dispersion during coronary angioplasty, we studied 47 consecutive patients (39 men and 8 women; mean age 57 +/- 16 years). QT dispersion was measured after each balloon inflation during coronary angioplasty. Statistical analysis was performed by using repeated measurement of analysis of variance. RESULTS: There were significant differences in QT dispersion as the number of balloon inflations increased (mean +/- SD 52 +/- 14, 42 +/- 11, 36 +/- 9, 31 +/- 10 and 29 +/- 11 ms, respectively [p < 0.01], for the first, second, third, fourth and fifth balloon inflations). The magnitude of decrease in QT dispersion was significant in the first and second balloon inflations, then became insignificant with later inflations. CONCLUSIONS: These data indicate that the gradual decrease in QT dispersion provoked by coronary artery occlusion and reperfusion during coronary angioplasty may be associated with electrophysiologic effects of ischemic preconditioning on myocardium in the human heart.

Angioplasty, Balloon, Coronary↗

PubMed1996

Ventricular tachycardia with narrow QRS duration, a right bundle branch block pattern, and right axis deviation abolished by catheter manipulation.

A 25-year-old women underwent electrophysiologic evaluation for sustained normal QRS complex tachycardia with a pattern of right bundle branch block and right axis deviation. Ventricular tachycardia was diagnosed by demonstrating fusion beats, atrioventricular dissociation, and bundle of His potential activation, which began before the onset of each QRS complex. A single ventricular extrastimulus was capable of easily provoking the tachycardia. There was an inverse relationship between the coupling interval of the first extrastimulus and the interval of the first tachycardia beat, suggesting reentry as the mechanism. The tachycardia was unexpectedly abolished during catheter manipulation in the left ventricle and has never recurred during 1 year of follow-up evaluation. The tachycardia was thought to be an unusual form of interfascicular tachycardia or microreentrant fascicular tachycardia.

Adult↗

PubMed1996

Antibodies to E1 and E2/Protein X components of pyruvate dehydrogenase complex in sera of patients with primary biliary cirrhosis.

AIMS/METHODS: Using purified E1 component of pyruvate dehydrogenase complex (PDC) from bovine heart, we measured the levels of anti-E1 antibodies in PBC sera using ELISA and determined the degree of inhibition that these antibodies exerted on E1 enzyme activity. We also estimated levels of anti-E2/Protein X (Pro-X) antibodies in PBC sera using purified E2 and Pro-X of PDC which were copurified with E1. RESULTS/CONCLUSIONS: Anti-E1 antibodies were detected in 87.5% (35/40) of PBC sera. Some of these sera inhibited E1 enzyme activity but inhibition did not correlate with levels of anti-E1 antibodies. A high positive correlation (r = 0.918) was found between levels of anti-E1 and anti-E2/Pro-X antibodies, suggesting that anti-PDC antibody production was stimulated by PDC itself. Levels of IgG class anti-E2/Pro-X antibodies were significantly higher in sera of symptomatic PBC patients than in those of asymptomatic PBC patients. It was also found that patients who were positive for only IgM class anti-E2/Pro-X antibodies had early-stage PBC.

Animals↗

PubMed1996

Interleukin-6 induces proliferation of rat hepatocytes in vivo.

BACKGROUND/AIMS: The aim of this study was to assess the effect of interleukin-6 (IL-6) on the proliferation of hepatocytes and to study the interaction between IL-6 and hepatocyte growth factor (HGF) in vivo. METHODS: IL-6 was injected at a dose of 200 micrograms/mg subcutaneously into rats every day for 14 days. Liver and blood samples were obtained at 1, 3, 7 and 14 days during IL-6 administration. Hepatocyte proliferative activity of sera was measured using 3H-thymidine incorporation into cultured rat hepatocytes. To evaluate the proliferative activity of the hepatocytes in tissue sections, hepatic DNA content and immunostaining of the liver tissue sections for proliferating cell nuclear antigen (PCNA) were performed. Plasma HGF levels were measured using specific EIA. In addition, total RNA was extracted from the liver and expression of HGF mRNA was detected by RT-PCR. RESULTS: The DNA contents of liver taken from IL-6-treated rats were increased during IL-6 administration compared with untreated rats. Sera taken from IL-6-treated rats at various intervals during administration also significantly increased 3H-thymidine incorporation by cultured rat hepatocytes compared with sera from untreated rats, suppressing 3H-thymidine incorporation at day 1 and 3 by anti-HGF antibody. IL-6 itself did not increase 3H-thymidine incorporation. Increased expression of PCNA in these hepatocytes was noted from 1 day after IL-6 administration, and at 14 days, the number of PCNA-positive cells was sevenfold greater than in the livers of untreated rats. However, plasma HGF levels showed a peak at day 1, decreased gradually from day 3, and became undetectable by day 14. HGF mRNA expression in livers of IL-6-treated rats was suppressed from day 3 to day 14 of IL-6 administration. CONCLUSIONS: These data show that IL-6 induces an early phase of liver cell growth in vivo and suggest that an increase level of HGF mediates this effect.

Animals↗

PubMed1996

Radiofrequency ablation for WPW syndrome with monitoring the local electrogram at the ablation site.

Catheter ablation for septal accessory pathways is occasionally associated with complications, such as atrioventricular block, since the septal region is a complex anatomical structure containing the atrioventricular conduction system. Therefore, we designed a signal separator composed of an inductance-capacitance network with which the local electrogram at the ablation site could be continuously monitored during the delivery of radiofrequency (RF) energy. We tested the safety and efficacy of RF catheter ablation using a signal separator in 17 patients with septal accessory pathways (10 anteroseptal and 7 midseptal cases). RF energy (520 KHz) was applied at an output of 20-40 W for 30-120 sec. to the atrioventricular annulus where the shortest atrioventricular interval or accessory pathway potential was recorded on the electrogram using a large tip ablation electrode. In ablation for the anteroseptal or midseptal accessory pathways, the atrial to ventricular amplitude ratio on the local electrogram was maintained at 1 or less during the delivery of RF energy. In all 17 cases, the interruption of accessory pathways was successful without atrioventricular block. In one patient, accessory pathway conduction recurred which could be treated by the second session. There were no late complications during the 4 to 46 month follow-up period. In conclusion, RF catheter ablation using a signal separator is a safe and reliable method for treating patients with septal accessory pathways.

Adolescent↗

PubMed1996

Eyeblink activity in a word-naming task as a function of semantic priming and cognitive load.

Eyeblink activity was examined based on a discrete-trial paradigm in which 17 subjects engaged in a semantic priming task. They were presented a series of pairs of words (prime and target) associatively related or associatively unrelated and were required to name them as quickly as possible. Cognitive load or difficulty of naming of the target word was also manipulated. The latency data for naming of the target word showed a typical priming effect, namely, facilitation of naming speed by the associatively relate prime word. The eyeblink rate changed synchronically to onset of stimuli as a function of prime-target relationship and cognitive load during the task. Specifically, the eyeblink rate was suppressed during presentation of the target word and peaked just after that. This study showed that suppression of eyeblinks was longer on trials with high cognitive loads than on those with low cognitive loads and the peak of eyeblink rate was higher on trials for which the prime and target were unrelated than on those for which they were related. These results suggested that the eyeblink activity is influenced by inner cognitive processes of word recognition.

Adult↗

PubMed1996

A case of idiopathic portal hypertension complicated with narrowing of intrahepatic bile ducts.

A 37-year-old woman who had portal hypertension followed by splenomegaly, developed collateral blood flow of spleno-renal shunt and paraesophageal veins, esophageal varices and further with narrowing of intrahepatic bile ducts shown by endoscopic retrograde cholangiography was described. Liver function was almost normal except the slight elevation of serum alkaline phosphatase and gamma-glutamyl transpeptidase levels. However, endoscopic retrograde cholangiography revealed the narrowing of the intrahepatic bile ducts. The histological examination of biopsied specimen showed no prominent change in portal tracts and bile ducts without cell infiltration or fibrosis in the portal area. This case will be considered as idiopathic portal hypertension complicated by narrowing of the intrahepatic bile ducts.

Adult↗

PubMed1995

Detection of antibodies to 65 KD heat shock protein and to human superoxide dismutase in autoimmune hepatitis-molecular mimicry between 65 KD heat shock protein and superoxide dismutase.

The antibody to 65 KD mycobacterial heat shock protein (HSP65) and antibody to human superoxide dismutase (H-SOD) were measured by ELISA in patients with autoimmune hepatitis (AIH), and results were compared with those of patients with chronic active hepatitis C (CAH-C) or systemic lupus erythematosus (SLE) and normal subjects (NS). Patients with AIH had significantly higher OD values of anti-HSP65 antibody and anti-H-SOD antibody compared with those of patients with CAH-C or SLE and NS. OD values of anti-HSP65 antibody were correlated with those of anti-SOD antibody. Affinity-purified anti-SOD antibody reacted with HSP65. Analysis of the amino acid sequence of human SOD showed that 7 segments, corresponding to r to 25 amino acid residues, exhibited 50 to 71% homology with that of my mycobacterial HSP65.

Amino Acid Sequence↗

PubMed1995

Primary sclerosing cholangitis with marked eosinophilic infiltration in the liver.

A 16-year-old boy was diagnosed as having primary sclerosing cholangitis (PSC), based on retrograde cholangiography showing mixed features of narrowing and dilatation of the common hepatic and intrahepatic bile ducts. However, periductal fibrosis was not observed in the needle biopsy liver specimen. The liver biopsy specimen obtained 11 years previously, at the onset of the disease had disclosed a marked infiltration of eosinophils in the portal tract with eosinophilic catinonic protein immunostaining, with marked eosinophilia (54%) being noted. In Japanese reports, eosinophilia of more than 7% was reported in 13 of 32 (40.6%) PSC patients. However, the early stage of PSC, with marked eosinophilia and eosinophilic infiltration in the liver, such as in the present case, has rarely been reported. The findings in this case suggest that eosinocytes are related to the pathogenesis of PSC.

Adolescent↗

PubMed1995

Association of primary sclerosing cholangitis, thymoma and hypogammaglobulinemia.

A 64-year-old Japanese woman with thymoma has been suffering from diarrhea and increased alkaline phosphatase levels without jaundice. Her serum immunoglobulin levels of IgM and IgG were less than half of the normal levels, with an increase in CD8 (suppressor/cytotoxic) T cell percentage and a decrease in CD4 (helper) T cell percentage, resulting in a lower CD4/CD8 ratio of 0.31. These immunological features are in accordance with those of hypogammaglobulinemia complicating thymoma. Cholangiography and a liver biopsy specimen disclosed the presence of primary sclerosing cholangitis (PSC). PSC has been recognized in various immunodeficiency syndromes and this case shows that thymoma complicated by hypogammaglobulinemia is associated with PSC.

Agammaglobulinemia↗

PubMed1995

Primary biliary cirrhosis (PBC)-CREST (calcinosis, Raynaud's phenomenon, esophageal dysfunction, sclerodactyly and telangiectasia) overlap syndrome complicated by Sjögren's syndrome and arthritis.

A 36-year-old woman with primary biliary cirrhosis (PBC)-CREST (calcinosis, Raynaud's phenomenon, esophageal dysfunction, sclerodactyly and telangiectasia) overlap syndrome complicated by Sjögren's syndrome and arthritis is reported. She had suffered from Raynaud's phenomenon, sclerodactyly, morning stiffness, arthralgia and sicca symptoms since 34 years of age. She exhibited an increased level of alkaline phosphatase and hyperglobulinemia at 2.8 g/dl without any symptoms, and histological findings from the biopsy specimen of the liver were consistent with those of PBC. Her human leukocyte antigen (HLA) typing was DR8 homozygous.

Adult↗

PubMed1995

Analysis of eyeblink activity during self-referent information processing in mild depression.

This study was designed to assess characteristics of self-referent information processing in mildly depressed persons using the eyeblink response measured in a discrete-trial paradigm. 7 mildly depressed and 9 nondepressed subjects (classified by scores on Beck's inventory) performed a self-reference task for positive and negative trait adjectives. The eyeblink was suppressed before and during presentation of stimuli and a burst pattern of the eyeblink was observed just after exposure. The pattern of the eyeblink burst after trait adjectives could be interpreted to reflect cognitive effort, cognitive load, or amount of attentional resource. Present results suggested that depressed individuals should have less cognitive load or allocate less attentional resource to negative stimuli than to positive ones during self-referent information processing.

Blinking↗

PubMed1995

Leukocyte adhesion molecules in the liver and plasma cytokine levels in endotoxin-induced rat liver injury.

BACKGROUND: The interactions between polymorphonuclear neutrophils (PMNs) and sinusoidal endothelial cells (SECs) have been known to be involved in the pathogenesis of acute liver injury. It has been also reported that tumor necrosis factor-alpha (TNF-alpha) up-regulates ICAM-1 expression on SECs and that interleukin-8 (IL-8) provokes rapid activation of CD11/CD18 on PMNs. These findings expand into the relationship between the expression of leukocyte adhesion molecules (ICAM-1, CD11a/CD18 and CD11b/CD18) in liver tissues and plasma TNF and IL-8 levels after lipopolysaccharide (LPS)-induced liver injury in rats. METHODS: Male Wistar rats weighing 200-250 g were treated with 2 mg LPS/kg intravenously in a 0.2- to 0.25-ml volume. Liver and blood samples were obtained at 1, 3, 8, and 12 h after LPS exposure. Plasma TNF and IL-8 levels were measured using bioassay and specific enzyme-linked immunosorbent assay, respectively. Liver samples were fixed and studied by immunohistochemistry using specific monoclonal antibodies against ICAM-1, CD11a, and CD11b. RESULTS: The TNF level showed a peak at 1 h (23.3 +/- 11.4 IU/ml), and the IL-8 level showed a peak at 3 h (343.1 +/- 110.5 ng/ml) after LPS exposure. An increase in the number of PMNs in the liver was observed as early as 1 h and continued until 12 h after LPS exposure. PMNs adhered to degenerated SECs and hepatocytes. ICAM-1 on SECs was diffusely and strongly expressed at 8 h, and PMNs adhered to SECs expressed both CD11a and CD11b. ICAM-1 was also observed on hepatocytes. CONCLUSION: These data suggest that PMN-SEC and PMN-hepatocyte interactions via leukocyte adhesion molecules, related to inflammatory cytokines such as TNF and IL-8, exist and play an important role in the pathogenesis of acute liver injury.

Animals↗

PubMed1995

[Detected Epstein-Barr virus genome using polymerase chain reaction in peripheral mononuclear cells--subacute necrotizing lymphadenitis].

A 23-year old woman was admitted to our hospital because of fever, leukocytopenia, thrombocytopenia and cervical lymphadenopathy. From pathological findings of the cervical lymphnode she was diagnosed as subacute necrotizing lymphadenitis (SNL). Bone marrow aspiration was hypocellular with proliferation of mature histiocytes with hemophagocytosis. Lactate dehydrogenase was elevated to 1863 IU/l and mild liver dysfunction was observed. Hepatosplenomegaly, lymphnode swelling in abdominal cavity, pleural effusion and pericardial effusion were detected. After glucocorticoid therapy all such disorders were normalized. In this course, Epstein-Barr (EB) virus genome was detected by a polymerase chain reaction method from peripheral mononuclear cells. After normalization, EB virus genome became not to be detected. From present case we concluded that EB virus was expanded in clinical course and was associated with pathogenesis of SNL.

Adult↗

PubMed1995

Effect of ethanol on DNA synthesis and c-met induction in Chang liver cells with long-term culture.

This investigation was performed to determine whether ethanol affects induction on Chang liver cells of the c-met protooncogene product (c-met), a cell-surface receptor for hepatocyte growth factor (HGF). These cells were cultured for 4 weeks with 5, 50, or 100 mmol/L ethanol, or 10, 100, or 200 mumol/L acetaldehyde. Ethanol was found to inhibit [3H]thymidine incorporation by cells in a dose-dependent manner. In addition, acetaldehyde at 100 mumol/L also inhibited [3H]thymidine uptake. Treatment with recombinant HGF led to enhanced [3H]thymidine incorporation by cells treated with ethanol or acetaldehyde as well as by those left untreated, with no significant differences in the rates of increase among these three cell groups. The amount of c-met messenger RNA, however, was unaffected by treatment with ethanol or acetaldehyde. Expression of c-met as measured by cell ELISA was also unchanged by both treatments. These results suggest that ethanol has no effect on c-met induction on Chang liver cells and that HGF may not be involved in the ethanol induced inhibition of DNA synthesis.

Cells, Cultured↗

PubMed1994

Transplantation of allogeneic peripheral blood stem cells after myeloablative treatment of a patient in blastic crisis of chronic myelocytic leukemia.

A 48-year-old man in blastic crisis of chronic myelocytic leukemia received a transplant of allogeneic peripheral blood stem cells. The donor was his HLA-identical sister, who refused to donate bone marrow cells, but agreed to donate peripheral blood stem cells. The patient received standard transplant conditioning with cyclophosphamide (120 mg/kg) and busulfan (16 mg/kg). Peripheral blood stem cells were mobilized with granulocyte colony stimulating factor and collected by apheresis. After transplantation, the white blood cell count and the result of microscopic analysis of the bone marrow became normal, and the leukocyte karyotype became 46XX. DNA fingerprinting showed complete chimerism. Graft-versus-host disease was suppressed with cyclosporine and methyl-prednisolone. The patient died of recurrence of leukemia on day 102+.

Blast Crisis↗

PubMed1994

Radiofrequency thermal balloon coronary angioplasty: a new device for successful percutaneous transluminal coronary angioplasty.

OBJECTIVES: The purpose of this study was to evaluate the effects of thermal balloon percutaneous transluminal coronary angioplasty using radiofrequency energy in the treatment of patients with failed coronary angioplasty and complex lesions. In addition, we evaluated restenosis after radiofrequency thermal balloon applications. BACKGROUND: The efficacy of coronary angioplasty is limited by the relatively low success rate in complex lesions and the high frequency of restenosis. Few reports have studied the combined effects of pressure and laser thermal energy. This study describes a new device for coronary angioplasty using radiofrequency thermal energy. METHODS: Thirty-two patients with failed conventional coronary angioplasty or complex lesions were treated with radiofrequency thermal balloon coronary angioplasty. Radiofrequency energy was delivered up to 11 times in exposures ranging from 30 to 60 s in duration. This combined effect allowed the vascular wall to be heated to temperatures ranging from 60 to 70 degrees C. Follow-up coronary angiography was performed, on average, 6 months after the procedure. RESULTS: Successful radiofrequency coronary angioplasty was achieved in 28 (82%) of 34 lesions. There was one abrupt coronary artery occlusion (3%) and no death, perforation or dissection. Angiographic restenosis occurred in 14 (56%) of 25 lesions. CONCLUSIONS: In patients with failed coronary angioplasty and difficult complex lesions, radiofrequency coronary angioplasty could potentially improve angioplasty success rates and may have important implications for bailout cases with abrupt occlusion. However, restenosis remains a significant problem.

Angioplasty, Balloon, Coronary↗