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Biomedical subjects

M Sekiguchi

Publications and source records attributed to M Sekiguchi.

At least 523 records · Page 29Linked to original sources
PubMed1985

Clinical spectrum and endomyocardial biopsy findings in eosinophilic heart disease.

Fourteen cases of heart disease with hypereosinophilia were analyzed employing conventional cardiologic methods, including echocardiography, cardiac catheterization, and endomyocardial biopsy. The cases were divided into four types: Acute carditic (endocarditis, myocarditis, pericarditis; five cases); ventricular dilation (three cases); restrictive (three cases); electric disturbance (three cases). Biopsy revealed significant changes in all cases. In one case of the ventricular dilation type, endomyocardial fibrosis with myocardial degeneration was seen, and in another case mural thrombus formation was shown to be present. In three cases of the restrictive type, endomyocardial fibrosis (EMF) was observed. In two cases of the electric disturbance type, minor right ventricular myocardial degeneration was observed. In two of the three cases of the carditic type and in three of eight cases in other categories, postmyocarditic changes were observed. The course of the disease compared with the type of disorder revealed a short course in the carditic type and a longer course, ranging from 2 to 24 years, with one exception, in the other types. It is also confirmed that the various histopathologic changes can be related to particular clinical presentations. We have shown that the basic changes in eosinophilic heart disease are not restricted to the endomyocardium and that they occur in various parts of the heart causing more widespread manifestations. The more comprehensive term "eosinophilic heart disease" is a preferable description.

Adolescent↗
PubMed1985

The induction of chromosome condensation in tsBN2, a temperature-sensitive mutant of BHK21, inhibited by the calmodulin antagonist, W-7.

The induction of premature chromosome condensation (PCC) in tsBN2 cells, a temperature-sensitive (ts) mutant of BHK21/13 which shows PCC at the non-permissive temperature, was almost completely inhibited by 40 microM W-7, an antagonist of calmodulin. The mitotic phosphorylation of histone H1 and H3 was also inhibited by W-7. W-5, a chlorine-deficient analogue of W-7 and which interacts weakly with calmodulin, did not inhibit the induction of PCC, even at a dose of 80 microM. The content of calmodulin in tsBN2 cells was increased by a temperature shift to 40.5 degrees C. All these results suggested that calmodulin is required for the chromosome condensation.

Animals↗
PubMed1985

Ability of various alkylating agents to induce adaptive and SOS responses: a study with lacZ fusion.

We used alkA'-lacZ' and umuC'-lacZ' fused genes and determined the ability of various alkylating agents to induce adaptive and SOS responses. The degree of induction of expression of these genes was quantitatively measured by a simple colorimetric assay of beta-galactosidase activity. SN1 type methylating agents, such as N-methyl-N'-nitro-N-nitrosoguanidine and N-methyl-N-nitrosourea, were more effective inducers for the alkA than for the umuC system, while SN1 type ethylating agents, such as N-ethyl-N'-nitro-N-nitrosoguanidine and N-ethyl-N-nitrosourea, were more potent inducers for the umuC than for the alkA system. Similar but less striking effects on the two systems were obtained with SN2 type alkylating agents.

Alkylating Agents↗
PubMed1985

Regulation of expression of the cloned ada gene in Escherichia coli.

The ada gene of Escherichia coli K12, the regulatory gene for the adaptive response of bacteria to alkylating agents, was cloned in multicopy plasmids. O6-Methylguanine-DNA methyltransferase and 3-methyladenine-DNA glycosylase II, which are known to be inducible as part of the adaptive response, were produced in ada- cells bearing ada+ plasmids, even without treatment with alkylating agents. When such cells had been treated with methyl methanesulfonate, even higher levels of the enzyme activities were produced. Maxicell experiments revealed that the ada gene codes for a polypeptide with a molecular weight of 38 000. We constructed a hybrid plasmid carrying an ada'-lacZ' fused gene, with the proper control region for ada expression. beta-Galactosidase synthesis from the fused gene was strongly induced only when cells were treated with low doses of methylating agents, but was weakly induced with relatively high doses of ethylating agents. The induction was autogenously regulated by the ada gene product, in a positive manner.

Alkylating Agents↗
PubMed1985

Molecular cloning of an activated human oncogene, homologous to v-raf, from primary stomach cancer.

Transfection with high molecular weight DNA from a primary stomach cancer induced foci of transformed NIH 3T3 cells, and the transformed cells were tumorigenic in nude mice. By screening with a human Alu-family probe, we isolated the human DNA sequence from the secondary transformant cells. This transforming sequence encompasses about 60 kilobase pairs and is unrelated to known human transforming genes. Examination of homologies between this sequence and retroviral oncogenes revealed that the human transforming sequence is closely related to the v-raf oncogene of murine transforming retrovirus 3611-MSV.

Animals↗
PubMed1985

Phosphorylation of nonhistone proteins during premature chromosome condensation in a temperature-sensitive mutant, tsBN2.

In tsBN2 cells, a temperature-sensitive (ts) mutant of the BHK21 cell line, with a ts-defect in its regulatory system for chromosome condensation, antigens that react with mitotic specific mouse monoclonal antibody MPM-2 were produced when premature chromosome condensation (PCC) was induced by a temperature shift. The polypeptides of antigens recognized by MPM-2 in tsBN2 cells with PCC were identical to those of antigens in mitotic cells. These antigens appeared concomitantly with chromosome condensation, which suggests that these mitotic-specific antigens may be related to chromosome condensation. As the production of mitotic-specific antigens was inhibited by W-7, a specific and potent antagonist of calmodulin, calmodulin may function in the mitotic phosphorylation of nonhistone protein.

Animals↗
PubMed1985

A Japanese survey on first attempts of percutaneous transluminal coronary angioplasty.

Experiences of the initial application of percutaneous transluminal coronary angioplasty (PTCA) in Japan performed during 1980-1981 at the multicenter level were analyzed. A survey in 72 cases which were collected from 12 centers showed an overall success rate of 64.7%, unimproved stenotic lesions in 8.1% and unpassable lesions in 24.3% of the cases. Complications were death of the patient in 2(2.8%), acute myocardial infarction in 6(8.3%) and dissection of the coronary artery in 3 cases (4.2%). Aortocoronary bypass graft surgery was performed in 8 cases (11.1%).

Adult↗
PubMed1985

Our experience of coronary intervention. Intracoronary guide wire recanalization and percutaneous transluminal coronary angioplasty.

Our old and new trials of coronary intervention therapy are introduced and analyzed. A method using intracoronary guide wire recanalization (Endo's method) is introduced. Two unusual cases of percutaneous transluminal coronary angioplasty (PTCA) from our initial experience of 18 cases are also presented. One is a 60-year-old patient who had transient complete right bundle branch block in a post-PTCA treadmill test. The other is a 45-year-old patient with unstable angina who developed myocardial infarction right after the PTCA but in whom post-PTCA coronary arteriography showed no apparent stenosis at the site of the PTCA.

Angioplasty, Balloon↗
PubMed1985

On the interstitial fibrotic changes in acute and convalescent myocarditis obtained by serial endomyocardial biopsy.

In order to determine the characteristics of the interstitial fibrotic change of the myocardium in cases with viral or idiopathic myocarditis, right ventricular endomyocardial biopsy findings in 9 cases where serial endomyocardial biopsy had been performed at the acute (5-10 days after the onset of the disease), subacute (11-21 days) and convalescent stages (22-167 days) and in 1 case at the acute stage were analyzed. They were then compared with right ventricular endomyocardial biopsy findings from 58 cases with chronic right ventricular overloading and which were of various kinds of congenital and valvular heart diseases. The following results were obtained: Interstitial fibrosis was seen at the acute stage along with an increase in fibroblasts, macrophages and lymphocytes. An analysis of the interstitial changes revealed that, at the acute stage, thin collagenous fibers were prominent as well as interstitial edema and at the convalescent stage, the edema became less prominent and instead, thick collagenous fibers increased. Comparison with the 58 cases with chronic right ventricular overloading revealed that diffuse and/or subendocardial fibrosis and endocardial thickening were more frequent and statistically more significant in cases with myocarditis.

Acute Disease↗
PubMed1985

Improved myocardial ischemia and left ventricular function during exercise after successful percutaneous transluminal coronary angioplasty.

Percutaneous transluminal coronary angioplasty (PTCA) was performed in 42 patients with effort angina, 28 (67%) of them underwent successful angioplasty. Treadmill exercise testing, thallium-201 myocardial scintigraphy and radionuclide ventriculography were performed before and after PTCA for evaluation of the improvement of myocardial ischemia and left ventricular function at rest and during exercise. The average exercise duration by treadmill testing in 14 successful cases increased from 14 +/- 4 (mean +/- S.D.) to 16 +/- 2 minutes (p less than 0.05). Sixteen of 28 the patients were studied by thallium-201 myocardial scintigraphy. Before PTCA, regions of decreased thallium-201 uptake after exercise were observed in 12 of the 16 patients. After angioplasty, no distinct defects were recognizable in 9 of the 12 patients, and in the remaining three, a significant decrease in defects was recognized. Fifteen of the 28 patients were studied by radionuclide ventriculography. The mean ejection fraction was 61 +/- 5% at rest and 56 +/- 11% during exercise (N.S.) before PTCA. After angioplasty, the ejection fraction was unchanged at rest (61 +/- 5 to 62 +/- 4%), but increased significantly during exercise (62 +/- 4 to 74 +/- 4%, p less than 0.001). In conclusion, left ventricular function was improved by successful PTCA due to improvement of myocardial ischemia. The long term results require further study.

Adult↗
PubMed1985

Experience of emergency coronary artery bypass grafting surgery and operative transluminal coronary angioplasty.

Our experience of performing emergency coronary artery bypass surgery in 9 patients with acute myocardial infarction (AMI) and of intraoperative transluminal coronary angioplasty (OTCA) during bypass surgery in another 28 patients was reviewed. Data were evaluated in conjunction with the recent application of intracoronary thrombolytic therapy and percutaneous transluminal coronary angioplasty. In 4 of the 9 cases where the emergency coronary artery bypass grafting (CABG) was performed within 2 hours after the onset of AMI, no new Q waves appeared in electrocardiograms (3 cases), and remarkable improvement of left ventriculographic findings was noted when pre- and postoperative ventriculograms were compared in 2 of these 4 cases. Intraoperative transluminal coronary angioplasty was successful in only 51.6% of the cases when evaluated at the post bypass period and this was less successful than our experience with PTCA. The low success rate was considered to be due to the greater amount of intimal fibrosis in the more distal portion, where the OTCA is performed, than is found in the proximal portion of the coronary arteries.

Adult↗
PubMed1985

Characterization of a human rhabdomyosarcoma cell strain in tissue culture.

A new human rhabdomyosarcoma cell strain, designated KYM-1, has been established from a neck tumor found in a 9-month-old infant. The cultured cells were round and mainly free-floating or in a moniliform pattern with a population doubling time of 75 hours. In stained preparations, the cells were pleomorphic and had a single round or oval nucleus in non-striated cytoplasm. However, the intracellular presence of myogenic markers was clearly shown by enzyme-immunochemical stains. An ultrastructural feature of the KYM-1 cells was the presence of numerous intermediate filaments in the perinuclear area and around the Golgi complexes which were associated with abundant cell organelles and aggregates of glycogen granules. High viscosity of the spent culture medium was attributed to hyaluronic acid, identified by electrophoresis and hyaluronidase digestion, and immunological and biochemical analyses revealed that the increased concentration of plasminogen activator activity found in the culture medium was almost wholly of the tissue plasminogen activator type. The KYM-1 cells also contained high concentrations of alkaline phosphatase activity. Tumorigenicity of the cells was confirmed by heterotransplantation into hamsters treated with anti-thymocyte serum.

Animals↗
PubMed1985

Macrophage migration inhibition test of peritoneal exudate cells of Litomosoides carinii-infected cotton rats by direct method in agar plate.

The macrophage migration inhibition test (MIT) was successfully made in agar plates using peritoneal exudate cells (PEC) of cotton rats, Sigmodon hispidus, during infection with Litomosoides carinii. It was found that 1% Bacto agar plate containing heat-inactivated serum was most suitable for the migration of PEC of the cotton rat induced by liquid paraffin injection. Ten percent normal cotton rat serum mixed in agar plate was best for PEC migration as compared with the various concentrations of horse, fetal and newborn calf sera. Migration areas of PEC from normal cotton rats increased with the number of cells per well and 2 X 10(6) cells/well was optimal. With concentrations of greater than or equal to 20 micrograms/ml of adult L. carinii antigen, significant migration inhibition of PEC from infected animals was observed from 18 hours after incubation at 37 degrees C with 5% CO2 gas phase, as compared with the migration of PEC from non-infected animals. Comparative analyses of the different aspects of infection showed that there was no correlation between the degree of migration inhibition and the duration of infection or the number of live worms recovered from the pleural cavity. Cell-mediated immunity against L. carinii as indicated by MIT still existed in 18 months after infection, although adult worms had died and were absorbed in the pleural cavity of the cotton rat.

Animals↗