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Biomedical subjects

M Ishihara

Publications and source records attributed to M Ishihara.

At least 163 records · Page 9Linked to original sources
PubMed1996

[Efficacy and limitation of directional coronary atherectomy for acute myocardial infarction assessed by depth of tissue resection].

The efficacy and limitations of directional coronary atherectomy (DCA) for acute myocardial infarction were evaluated in 44 patients (left anterior descending artery : 27 lesions, left circumflex artery : 2 lesions, right coronary artery : 15 lesions) who underwent DCA within 24 hours after the onset of chest pain. Thirty-two patients underwent DCA for residual stenosis of > or = 75% with TIMI flow grade II or III after thrombolysis (immediate DCA), and 12 patients underwent DCA for suboptimal results after immediate percutaneous transluminal coronary angioplasty (rescue DCA). In all patients, DCA resulted in residual stenosis of <25% (15 +/- 8%), and the primary success rate was 100%. No major complications (death, emergency bypass grafting) occurred. Repeat angiography was performed in 41 patients before discharge (2.4 +/- 0.7 weeks later) and in 39 patients during follow-up (5 +/- 2 months later). Reocclusion was not found at the follow-up. Restenosis was not found before predischarge, but was found in 19 of the 39 patients (49%) at the follow-up. Histological analysis of atheroma samples was performed to evaluate the influence of subintimal resection on restenosis. Patients were divided into two groups according to the depth of tissue resection : intimal resection and subintimal resection. The restenosis rate associated with subintimal resection was significantly higher than that associated with intimal resection (80% vs 29%, p < 0.01). DCA is useful for persistent patency of the infarct-related coronary artery in patients with acute infarction, but subintimal resection may increase the restenosis rate during the follow-up period.

Adult↗
PubMed1996

[Evaluation of occult atherosclerosis in the left main coronary artery in patients with acute anterior myocardial infarction].

Intravascular ultrasound was performed in 30 patients with acute anterior myocardial infarction to evaluate occult atherosclerosis in the left main coronary artery which could not be detected by coronary angiography. The intravascular ultrasound catheter was positioned in the left main coronary artery after successful intracoronary thrombolysis, and cross-sectional coronary artery scanning was performed. Percentage area stenosis (%AS) was calculated as (plaque cross-sectional area/vessel cross-sectional area) x 100. Images of crescent-shaped eccentric plaque were obtained in all patients. The mean vessel cross-sectional area was 28.6 +/- 8.0 mm2, and mean plaque cross-sectional area was 7.7 +/- 4.2 mm2. Mean %AS was 27 +/- 15% (range from 6 to 58%). In five patients, intravascular ultrasound was repeated 3 months later, which showed increased %AS more than 15% in two patients. These findings indicate that occult atherosclerosis is present in the left main coronary artery in almost all the patients with acute anterior myocardial infarction and should be treated with caution when coronary intervention is performed.

Adult↗
PubMed1996

HLA class II genotyping of sarcoidosis patients in Hokkaido by PCR-RFLP.

To confirm the significant association of sarcoidosis with HLA-DR5, -DR6, and -DR8 associated DRB1 alleles, in sarcoidosis patients from the eastern Japan (Kanto) area found in our previous study, we used HLA class II genotyping of patients in another region-Hokkaido, in northern Japan. The annual incidence of sarcoidosis in Hokkaido is about three times that of eastern Japan, and Hokkaido has one of the world's highest incidences of this disease. For the HLA class II (HLA-DRB1, -DRB3, -DQA1, -DQB1) genotyping, we used the polymerase chain reaction restriction fragment polymorphism (PCR-RFLP) method with 150 subjects: 40 sarcoidosis patients and 110 healthy controls. The frequencies of DRB1*12, DRB1*14, DRB1*08, DQA1*0501, and DQB1*0301 were significantly increased in the patients, compared with the controls. Our finding of a high frequency of DRB1*08 (which lacks the DRB3 gene encoding the DR52 antigen) in patients living in both eastern Japan and in Hokkaido, confirms that it is the HLA-DRB1 locus, rather than that of the HLA-DRB3, -DQA1, or -DQB1, which determines the susceptibility to sarcoidosis.

Adolescent↗
PubMed1996

Seroepidemiological studies on Silk Road ethnic groups.

To clarify the origin of the Japanese, the Jomom and/or Yayol, we screened for HTLV-1 and -II antibodies among inhabitants of the Silk Road, the Han, Uygur and Kazaks. We also screened for HIV, HBV, and HCV. The HTLV-I, -II, HIV, and HCV antibody tests were uniformly negative in all the studied groups. In contrast, a significantly higher incidence of HBs antigen was observed in all the groups tested (Northern Han: 11.9%, Uygur: 6.0%, Kazak: 9.1%). These results indicate that these ethnic groups are not the origin of the indigenous Japanese (the Jomon), and that HBV is prevalent in the various groups along the Silk Road.

Antigens, Viral↗
PubMed1995

An IRF-1-dependent pathway of DNA damage-induced apoptosis in mitogen-activated T lymphocytes.

Lymphocytes are particularly susceptible to DNA damage-induced apoptosis, a response which may serve as a form of 'altruistic suicide' to counter their intrinsic high potential for mutation and clonal expansion. The tumour suppressor p53 has been shown to regulate this type of apoptosis in thymocytes, but an as yet unknown, p53-independent pathway(s) appears to mediate the same event in mitogen-activated mature T lymphocytes. Here we show DNA damage-induced apoptosis in these T lymphocytes is dependent on the antioncogenic transcription factor interferon regulatory factor (IRF)-1. Thus two different anti-onco-genic transcription factors, p53 and IRF-1, are required for distinct apoptotic pathways in T lymphocytes. We also show that mitogen induction of the interleukin-1 beta converting enzyme (ICE) gene, a mammalian homologue of the Caenorhabditis elegans cell death gene ced-3, is IRF-1-dependent. Ectopic overexpression of IRF-1 results in the activation of the endogenous gene for ICE and enhances the sensitivity of cells to radiation-induced apoptosis.

Animals↗
PubMed1995

Microsatellite polymorphism between the tumor necrosis factor and HLA-B genes in Behçet's disease.

Behçet's disease is associated with the HLA-B51 antigen. However, it has not yet been clarified if the HLA-B51 gene itself is the susceptibility gene related to this disease or if it is some other non-HLA gene in linkage disequilibrium with HLA-B51. Therefore, we screened one of the HSP70 genes, HUM70t (HSP70-Hom), around the class III region and the microsatellite sequence located between the HLA-B and TNF genes for genetic polymorphism in BD. A comparison between patients with BD and healthy controls revealed no significant difference in the frequency of the HUM70t polymorphism. In the microsatellite sequence, Tau-a, in the region between the HLA-B and TNF genes, the frequency of 14 repetitions of GT was increased significantly and that of 11 repetitions was decreased significantly in the patient group. Further, the allelic distributions of the B51 antigen-associated microsatellite polymorphism differed significantly between patients and healthy controls, and in the B51 antigen-negative subjects, analysis of the microsatellite polymorphism also revealed a significant difference in the haplotype frequency between the patient and control groups. These results suggest that the HLA-B51 gene may not be the primary locus responsible for BD, and implicate some other gene(s) located between the TNF and HLA-B genes.

Base Sequence↗
PubMed1995

Molecular epidemiology of Salmonella enteritidis. An outbreak and sporadic cases studied by means of pulsed-field gel electrophoresis.

Large outbreaks of diarrhoea due to Salmonella enteritidis in Aichi-ken, Japan, provided the opportunity to investigate aspects of the molecular epidemiology of this and related organisms. This was performed by comparing the plasmid profile types, phage types, antimicrobial resistance, and the restriction fragment length polymorphisms (RFLPs) by pulsed-field gel electrophoresis (PFGE) of S. enteritidis from outbreaks and sporadic cases. Among the isolates studied, 10 distinctive RFLP types were found with XbaI and four with NotI, while 12 combination types were identified among the 68 isolates from 16 Health Centres in Aichi-ken, Japan. A total of 22 isolates from four outbreaks, however, had the same RFLP and phage types. The RFLP type was subdivided by means of the plasmid profile and phage type. Conversely, plasmid profile and phage type were separated by means of RFLP. This PFGE method may prove useful for subclassifying S. enteritidis and differentiating isolates of the same plasmid profile and phage type.

Bacteriophage Typing↗
PubMed1995

Importance of 6-O-sulfate groups of glucosamine residues in heparin for activation of FGF-1 and FGF-2.

Treatment of the pyridinium salts of heparin with N-methyltrimethylsilyl-trifluoroacetamide (MTSTFA) in pyridine for 2 h at various temperatures caused specific 6-O-desulfations from trisulfated disaccharide units to various degrees without detectable depolymerization or other chemical changes. In order to assess the importance of 6-O-sulfate groups in N-sulfated glucosamine (GlcNS) residues to promote FGF-1 and FGF-2 activities, various 6-O-desulfated (6-O-DS-) heparins were quantitatively examined for activity as enhancers or inhibitors of specific FGF-1- and FGF-2-induced proliferation of BALB/c3T3 clone A31 (A31) cells and the chlorate-treated cells. The present results suggested that a high content of 6-O-sulfate groups in GlcNS residues was required for activation of FGF-1, but not FGF-2. However, complete 6-O-desulfation of trisulfated disaccharide units in heparin resulted in loss of the ability to activate FGF-2, although the desulfated product bound strongly to FGF-2.

Animals↗
PubMed1995

Clinical features of sarcoidosis in relation to HLA distribution and HLA-DRB3 genotyping by PCR-RFLP.

BACKGROUND: Susceptibility to the development of sarcoidosis has been demonstrated to be associated with HLA-DR5, -DR6, and -DR8 encoded by the DRB1 gene. However, involvement of the DRB3 (HLA-DR52) gene in the development of sarcoidosis remains unclear. METHODS: HLA-DRB3 genotyping was performed using the PCR-RFLP method and the clinical features of the patients with and without the DR3, 5, 6, 8 group antigens were compared. RESULTS: HLA-DRB3 genotyping indicated an association between DRB3*0101 and sarcoidosis. The DR8 haplotype lacking the DRB3 gene has been found to be increased significantly in sarcoidosis, suggesting that the HLA-DRB3 gene is not a primary determinant of predisposition to sarcoidosis. The association of DRB3*0101 with sarcoidosis is attributable to linkage disequilibrium with DR5- and DR6-associated alleles. There were significant decreases in the DR3, 5, 6, 8 group (DR5, DR6, or DR8) antigen frequencies in patients with retinal perivasculitis, high intraocular pressure (or secondary glaucoma), and optic nerve and/or macular lesion. Correlations were observed among the DR3, 5, 6, 8 group antigens, early onset sarcoidosis and disease with fewer intraocular lesions. CONCLUSION: This established a molecular basis for some of the clinical heterogeneity observed in sarcoidosis.

Adolescent↗
PubMed1995

Effects of various doses of intracoronary diltiazem on coronary resistance vessels in humans.

We investigated the vasodilative effects of various doses of intracoronary diltiazem on coronary resistance vessels. Nine patients with normal angiograms were studied. A coronary Doppler guide wire was inserted into the left anterior descending coronary artery. Diltiazem, in doses of 0.1 mg, 0.5 mg, 1.0 mg, 2.0 mg and 4.0 mg, was injected into the left coronary artery at 10 min intervals and coronary blood flow velocity was measured. The coronary artery was pretreated with intracoronary nitroglycerin to avoid changes in the cross-sectional area. As a measure of the change in coronary vascular resistance, a coronary vascular resistance index (CVRI) was calculated as mean aortic pressure/coronary blood flow velocity. An injection of diltiazem into the left coronary artery caused a significant dose-dependent decrease in CVRI. A dose of 2.0 mg was the lowest dose on the plateau of the dose-response curve. In conclusion, the injection of diltiazem into the left coronary artery causes a dose-dependent dilatation of coronary resistance vessels, and the maximal effect can be produced with a dose of 2.0 mg.

Aged↗
PubMed1995

[Usefulness of 3-dimensional image analysis of skull base lesions].

We have evaluated three-dimensional (3D) images of the skull base lesions for planning cranial base surgery. Fifty 3D images were reconstructed from computed tomographies (CT), and/or magnetic resonance (MR) images or MR angiographic images of 30 patients with skull base lesions. These images have provided useful information for pre-operative evaluation. The 3D image reconstructed from CT provides clear information concerning the bone. Conversely, the 3D image from MR images demonstrates soft tissue very clearly, and that from MR angiography provides a detailed description of the vasculature. For skull base lesions, it is essential to evaluate 3D images from the different modalities, especially CT scan and MR image.

Adolescent↗