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Biomedical subjects

H Ohira

Publications and source records attributed to H Ohira.

At least 37 records · Page 2Linked to original sources
PubMed1999

Cytophagic histiocytic panniculitis improved by combined CHOP and cyclosporin A treatment.

In a 31-year-old Japanese man with cytophagic histiocytic panniculitis (CHP) remission was achieved by a combination of combined chemotherapy CHOP and cyclosporin A treatment. He was admitted to our hospital in January 1994 with recurrent high fever of 40.2 degrees C and tender and violaceous subcutaneous nodules on his trunk, arms and legs. He developed pancytopenia, hemorrhagic diathesis, liver dysfunction. Histological examination of the biopsied subcutaneous nodule revealed a lobular panniculitis with fat necrosis and a massive infiltration of histiocytes phagocytosing nuclear debris. He was treated initially with 40 mg/day prednisolone. However, following a reduction in prednisolone dosage, his symptoms reappeared. CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone) therapy was then initiated. Three courses of CHOP treatment alleviated his symptoms and cyclosporin A was used to maintain his condition for 15 months. His medication was then discontinued and he has been in complete remission for 10 months. Combined treatment of cyclosporin A and CHOP combined chemotherapy was shown to be effective for this patient with severe CHP.

Adult↗
PubMed1999

The type A behavior pattern and immune reactivity to brief stress: change of volume of secretory immunoglobulin A in saliva.

This article presents findings of a laboratory experiment on the association of the Type A behavior pattern with reactivity of secretory immune functioning to brief stress. 38 female undergraduate students classified as Type A (n = 19) or as Type B (n = 19) on the basis of their scores on the Kwansei Gakuin Type A scale performed a continuous arithmetic task in a situation in which they were exposed to aversive loud noise. Secretory immunoglobulin A (s-IgA) in saliva and autonomic measures (heart rate and frequency of eyeblink) were evaluated before and after the manipulation of stress. The volume of s-IgA at baseline was significantly higher for the Type A group than for the Type B group, suggesting that the former relative to the latter might be chronically higher in mucosal immune functioning. Also, the volume of s-IgA significantly increased after exposure to a brief stress for the Type B group but did not change for the Type A group, a finding which might indicate that the Type A group may have less immune reactivity to a brief stress.

Adult↗
PubMed1999

[The underlying mechanism for process dissociation in recognition: performance, response latency, and eyeblink in a three-process model].

Jacoby (1991) proposed a process-dissociation procedure to estimate contributions of conscious and unconscious processes to cognitive task performance. The present research examined the inner processing mechanism underlying the procedure. Thirty-two female undergraduates learned a list of visual stimulus words and another of auditory stimulus. They then performed recognition memory tasks in which conscious and unconscious memory components presumably either help or interfere with each other. Memory performance, response latency, and eyeblink activity were analyzed based on the framework of the process-dissociation procedure. A three-process model of recognition, with an underlying hypothetical processing mechanism, was proposed to explain the complicated results obtained of the three dependent measures.

Acoustic Stimulation↗
PubMed1999

Transient complete atrioventricular block provoked by ventricular pacing in a patient with nonsustained ventricular tachycardia.

A 75-year-old woman with complete left bundle branch block underwent electrophysiological study (EPS) to assess the conduction in the His-Purkinje conduction system and to further investigate the electrical instability in the ventricle, which was suggestive by the findings of nonsustained ventricular tachycardia in ambulatory monitoring. Transient complete atrioventricular (AV) block was provoked by ventricular pacing, and the intracardiac recordings proved that the site of AV block was distal to the His bundle. This phenomenon was not related to the rate or the duration of the ventricular pacing. The transient impairment of the conduction appeared to be due to the fatigue phenomenon in the His-Purkinje system.

Aged↗
PubMed1998

Analysis of peripheral blood mononuclear cell stimulated with pyruvate dehydrogenase complex, T-cell receptors from patients with primary biliary cirrhosis.

Progressive destruction of the intrahepatic bile ducts in patients with primary biliary cirrhosis (PBC) is thought to be mediated by cytotoxic T cells which recognize certain epitopes, such as the pyruvate dehydrogenase complex (PDC). To clarify the T-cell repertoire in PBC, we analyzed T-cell receptor (TCR) Vbeta-chain messages expressed in peripheral blood mononuclear cells (PBMCs) stimulated with PDC and in liver biopsy specimens. PBMCs from 12 PBC patients and 6 healthy controls were examined. The TCR Vbeta repertoires of unstimulated PBMCs and PBMCs stimulated with PDC purified from bovine heart were analyzed, using the reverse transcriptase-polymerase chain reaction (RT-PCR) and single-strand conformation polymorphism (SSCP). Liver biopsy specimens from 5 PBC patients were also analyzed. In the PBC patients, several different T-cell clones, some of which showed the same mobility, were evident in both the PDC-stimulated and unstimulated PBMCs, as demonstrated by SSCP analysis. In addition, TCR clonality of infiltrating lymphocytes in the liver was also observed in PBC patients, showing common clonal T-cell accumulation with that seen in PBMCs stimulated with PDC. These data indicate that common clonal T-cell accumulation specific for PDC may be present in both peripheral PBMCs and the liver of patients with PBC.

Case-Control Studies↗
PubMed1998

New electrophysiologic features and catheter ablation of atrioventricular and atriofascicular accessory pathways: evidence of decremental conduction and the anatomic structure of the Mahaim pathway.

INTRODUCTION: Several modalities of catheter ablation have been proposed to eliminate Mahaim pathway conduction. However, limited research has been reported on the electrophysiologic nature of this pathway in its entity. METHODS AND RESULTS: In seven patients, electrophysiologic study was performed, and radiofrequency energy was applied to investigate the electrophysiologic clues for successful ablation. In all seven patients, the Mahaim pathway was diagnosed as a right-sided atriofascicular or atrioventricular pathway with decremental properties. In two patients, two different kinds of electrograms were recorded through the ablation catheter positioned at the Mahaim pathway location: one was suggestive of conduction over the decremental portion, demonstrating a dulled potential; and the other of nondecremental conduction, demonstrating a spiked potential. All but one of the Mahaim pathways were eliminated successfully at the atrial origin where the spiked Mahaim potential was recorded. Radiofrequency energy application was performed at the slow potential site resulting in failure to eliminate the conduction over the Mahaim pathway. Conduction block at the site between the slow and fast potential recording sites was provoked by intravenous administration of adenosine, concomitant with a decrease in the amplitude of the Mahaim potential. In one patient, the clinical arrhythmia was a sustained monomorphic ventricular tachycardia originating from the ventricular end of the Mahaim fiber. CONCLUSION: The identification of Mahaim spiked potentials may be the optimal method to permit their successful ablation. Detailed electrophysiologic assessment is indispensable for successful ablation of tachycardias associated with Mahaim fibers because tachycardias unassociated with Mahaim fibers can occur despite complete elimination of the Mahaim fiber.

Adolescent↗
PubMed1998

Monitoring the local electrogram at the ablation site during radiofrequency application for common atrial flutter.

Recent studies have suggested that the attenuation of the local electrogram amplitude recorded from the ablation electrode during radiofrequency (RF) application predicts lesion growth. This study examined the time course of local electrogram amplitude during ongoing RF delivery in patients with common atrial flutter (AFl). In 71 patients with AFl. RF energy was applied to the anatomical isthmus. Termination of AFl was noted during 68 of 625 applications of RF energy. The changes in local atrial electrogram amplitude observed at all successful sites were analyzed. With increasing duration of the RF delivery, the electrogram amplitude decreased exponentially to reach a steady state within a mean duration of 17+/-3 sec, which was significantly longer than that of the steady-state temperature. The average decrease in the amplitude was 67+/-13%. In 16 patients in whom an increase in the power of RF energy had resulted in AFl termination, there was a dose-response relationship between the power and the amplitude decrease. The decrease in local electrogram amplitude appears to be a reliable marker for the efficacy of tissue heating and may be useful as an endpoint for individual applications. Local electrogram monitoring may offer an optimal energy strategy in AFl ablation.

Atrial Flutter↗
PubMed1998

Alternation in the flutter wave morphology during radiofrequency catheter ablation for common atrial flutter.

A linear lesion created at the right atrial isthmus by radiofrequency current application can successfully eliminate common atrial flutter (AF). The mechanism of unsuccessful cases has not yet been well delineated. This study sought to investigate the cause of unsuccessful cases of radiofrequency catheter ablation of AF. Sixty-six patients with refractory common AF were referred for radiofrequency catheter ablation. Radiofrequency current was applied to the right atrial isthmus between the inferior vena cava and tricuspid annulus or between the coronary sinus orifice and tricuspid annulus. In 5 (8%) of the 66 patients, a morphological change of the flutter wave was observed in the 12-lead ECG concomitant with the change of the atrial excitation sequence during the delivery of radiofrequency energy without the termination of atrial flutter. In 8 (12%) patients, the morphology of the new AF wave, which was provoked electrically after the termination of the original AF, was different, and the average flutter cycle length also differed in 3 cases (2%). The results of radiofrequency application could be misinterpreted as unsuccessful when the occurrence of another, different type of AF has been overlooked following the elimination of the original AF during the radiofrequency catheter ablation procedure. It is possible that the flutter circuit can take an alternative pathway despite the complete conduction block at the right atrial isthmus.

Adult↗
PubMed1998

Mixed connective tissue disease with severe pulmonary hypertension and extensive subcutaneous calcification.

The results of the autopsy of a 38-year-old female with mixed connective tissue disease who had suffered from painful subcutaneous calcification in her buttocks and extremities for 14 years and died from rapidly progressive pulmonary hypertension are reported. On autopsy, her heart and lungs revealed changes of severe pulmonary hypertension with intimal thickening and plexiform lesions in the small pulmonary arteries which had resulted in the collapse of both lungs and caused marked dilatation and hypertrophy of the right ventricle of the heart. Microscopic examinations of the subcutaneous calcified tissues indicated that the calcification may have been caused by repeated panniculitis.

Adult↗
PubMed1998

An autopsy case of Wegener's granulomatosis with pachymeningitis.

A 61-year-old woman presented with high fever, headache and left facial palsy with diplopia. Histopathological examination of the biopsied specimens taken from nasal mucosa and kidney revealed a granulomatous angiitis with giant cell infiltration. Ga-DTPA-enhanced magnetic resonance imaging (MRI) revealed a thickening of dura mater in the middle cranial fossa and tentorium cerebelli. The observed left facial and occulomotor palsy was considered to be caused by pachymeningitis associated with Wegener's granulomatosis (WG). Cyclophosphamide combined with prednisolone effectively improved the symptoms. However, the patient died of acute interstitial pneumonitis, presumably caused by cyclophosphamide. The pathohistology obtained in the autopsy revealed a fibrous thickening of the dura mater in the left meningen with a segmental scarring of the arteries and a necrotizing arteritis in the kidney.

Anti-Inflammatory Agents↗
PubMed1998

Antineutrophil cytoplasmic antibody in patients with antinuclear antibody-positive chronic hepatitis C.

UNLABELLED: Hepatitis C viral (HCV) infection has been shown to lead to autoimmune phenomena. Antineutrophil cytoplasmic antibodies (ANCA) have been known to be present in several autoimmune liver diseases. This study aimed to evaluate the prevalence of ANCA in sera of patients with antinuclear antibody (ANA)-positive chronic hepatitis C (CH-C) and to characterize ANCA antigens by Western blot compared with HCV-negative autoimmune hepatitis (AIH). METHODS: Ninety sera obtained from 20 patients with ANA-positive CH-C, 20 patients with ANA-negative CH-C, 20 patients with AIH, 6 patients with primary screlosing cholangitis (PSC) and 24 healthy controls were tested using an indirect immunofluorescence assay, cell ELISA and Western blotting to detect ANCA. RESULTS: In the indirect immunofluorescence assay, ANCA was found in 60% (12/20) of patients with ANA-positive CH-C, 100% (20/20) of patients with AIH and 33.3% (2/6) of patients with PSC, but in none of patients with ANA-negative CH-C (n = 20) or healthy controls (n = 24). The staining pattern observed in sera of these patients was a peculiar mixture of both cytoplasmic and perinuclear patterns. The mean ANCA titer by cell ELISA was significantly (p < 0.01) higher in patients with AIH compared with ANA-positive or ANA-negative CH-C patients or healthy controls. However, no correlation was found between ANCA titers and ANA titers, serum alanine amino transferase (ALT) or IgG levels in either ANA-positive CH-C or AIH. Western blots of ANCA-positive sera from ANA-positive CH-C patients revealed two bands corresponding to molecular weights of 72 and 46 kDa and there was no differencies in ANCA antigens compared with that from AIH patients. CONCLUSIONS: We found an increased incidence of ANCA in ANA-positive CH-C patients. ANCA in ANA-positive CH-C patients is thought to be one of autoimmune phenomena lead by HCV infection because no difference was observed in the epitope of ANCA antigens between patients with CH-C and AIH.

Adult↗
PubMed1998

Two sister cases of autoimmune hepatitis.

Two sister cases of autoimmune hepatitis are described. Case 1 involved a 49-year-old woman who suffered from bleeding gums and general fatigue. Her laboratory data showed a marked increase in transaminase levels, an elevated IgG level with titers 1:80 or more of both antinuclear and smooth muscle antibodies and thrombocytopenia. Histology of the biopsied liver revealed chronic active hepatitis with a moderate infiltration of mononuclear cells. A complication of idiopathic thrombocytopenic purpura was determined based on higher titers of PA-IgG and a normal bone marrow findings. Case 2 involved a 54-year-old woman, an elder sister of case 1, who suffered from general fatigue with jaundice. Her laboratory data showed a severe damage of liver function and an elevated IgG level with positive antibodies to nuclear and smooth muscle antigen. Histology of the biopsied liver revealed chronic active hepatitis. Both patients were negative to markers of hepatotrophic agents. Under diagnosis of autoimmune hepatitis, they have been treated with prednisone followed by a significant clinical improvement. HLA types of two patients were Bw54-DR4 and DR4. Among 4 other siblings, the eldest sister suffered from rheumatoid arthritis. The occurrence of two sister cases of type-1 autoimmune hepatitis has rarely reported and the fact would support a role of enviromental factors besides genetic factors for the onset of this disease.

Female↗
PubMed1997

Radiofrequency ablation of tachyarrhythmias in patients with Ebstein's anomaly.

We performed radiofrequency catheter ablation in five patients associated with Ebstein's anomaly to cure their refractory tachyarrhythmias. The presenting arrhythmias were four cases of orthodromic circus movement tachycardia using accessory pathways as a requisite limb, including one case of a Mahaim fiber and one of atrial flutter of common variety. All accessory pathways, including the Mahaim fiber, were ablated by RF energy delivered through the catheter placed at the AV annulus rather than the displaced anatomical AV groove. Interestingly, the antegrade or retrograde conduction interval over these accessory pathways was relatively longer than that of usual accessory pathways, and the accessory pathway potential was fractionated in some cases. The location of the atrioventricular node was displaced from the usual position to the postero-inferior area of Koch's triangle in one case. The configuration of the flutter wave was larger than usual in height as well as in width. All tachyarrhythmias were cured by RF catheter ablation. In the case of RF catheter ablation for patients with Ebstein's anomaly, close attention is indispensable in order to accomplish it safely and successfully, because of the anatomical and functional differences peculiar to Ebstein's anomaly.

Cardiac Catheterization↗
PubMed1997

Immunocytochemical localization of vitamin D receptors in the shell gland of immature, laying, and molting hens.

It is accepted that vitamin D is involved in the control of egg calcification in hens. The goal of this study was to localize the vitamin D receptors (VDR) in hen shell gland and to determine whether their localization was dependent on reproductive function. Frozen sections of the shell gland of immature, laying, and molting hens were immunostained for VDR, and the VDR in these tissues were also examined by Western blot analysis. Both apical and basal cells of the mucosal epithelium as well as tubular gland cells showed a strong immunoreaction for VDR in the shell gland of laying hens. In the magnum and isthmus, the basal cells of the mucosal epithelium showed a moderately strong immunoreaction for VDR, whereas the immunoreactions in the apical cells of the mucosal epithelium and tubular gland cells were weak. In the shell gland of immature birds, both the mucosal epithelium and tubular gland cells showed a moderately strong VDR immunoreaction. In molting hens, the mucosal epithelial cells and tubular gland cells showed a strong VDR immunoreaction although the mucosal tissue was regressed. Western blot analysis indicated that the mucosal tissue of the shell gland of immature, laying, and molting hens contained two forms of immunoreactive VDR, which were approximately 58 and 60 kDa. Because VDR were richer in the shell gland than in other oviductal segments, these results suggest that in laying hens the shell gland tissues are one of the significant targets for vitamin D. It is likely that the amount of shell gland VDR increases during sexual maturation and immunoreactive VDR remain even during the molting phase.

Animals↗
PubMed1997

Radiofrequency catheter ablation for AV nodal reentrant tachycardia associated with persistent left superior vena cava.

Slow AV nodal pathway ablation using RF is highly effective for patients with refractory AV nodal reentrant tachycardia (AVNRT). We report three catheter ablation cases using RF current in patients associated with persistent left superior vena cava (PLSVC). Three patients with drug refractory AVNRT of common variety were involved in this study. An electrode catheter introduced through the left subclavian vein inserted directly into the coronary sinus, a typical anatomical finding of PLSVC. The ablation procedure was initially performed at the posteroinferior region of Koch's triangle. A slow pathway potential could not be found from that area; nonsustained junctional tachycardia (NSJT) did not occur during the delivery of RF current; there was failure to eliminate slow AV nodal pathway conduction. The catheter then was moved into the bed of the proximal portion of the markedly enlarged coronary sinus. A slow AV nodal pathway potential was recorded through the ablation catheter, and the delivery of RF current caused NSJT in two patients. Complete elimination of slow AV nodal pathway conduction was accomplished in these two patients by this method. No adverse effects were provoked by this procedure. Catheter ablation of the slow AV nodal pathway guided by a slow pathway potential and the appearance of NSJT was feasible and safe in the area of the coronary sinus ostium in patients associated with PLSVC.

Adult↗
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↗
PubMed1997

[Two cases of personal identification from dental information].

We describe two cases in which unknown bodies were positively identified from dental information and biochemical examination using tooth materials. In one case, a charred body was positively identified with little effort by comparison of antemortem dental records (dental chart and dental X-ray film) with postmortem data. In the other case, although the unknown individual had dental treatment, the police were unable to obtain the antemortem dental records of the victim. We then conducted biochemical analysis of teeth, facilitating personal identification using DNA analysis and age estimation based on aspartic acid racemization. The mutation obtained from the sequence of mtDNA and the genotypes of HLADQ alpha, HPRTB and ABO blood groups including the data for estimated age supported the kinship between the unknown individual and his mother. The data for maternally inherited mtDNA were of great importance in this case, since it was possible to obtain DNA from the mother. Dental identification in one of the most accurate methods of personal identification if suitable antemortem records are available. In the absence of such records, biochemical analysis of teeth also makes it possible to increase the probability of correct personal identification.

Adult↗