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Biomedical subjects

M Matsuda

Publications and source records attributed to M Matsuda.

At least 1,297 records · Page 72Linked to original sources
PubMed1983

Action of tetanus toxin on cholinergic neuroblastoma X glioma hybrid cells: selective blockade of Ca spikes.

We examined the effect of tetanus toxin on clonal neuroblastoma X glioma hybrid cells, NG108-15, by intracellular microelectrode studies of passive membrane electrical properties and action potentials generated under various conditions. Binding of tetanus toxin to the surface of the cells was demonstrated by indirect immunofluorescent staining but no morphological alteration was observed in tetanus toxin-treated cells under a phase contrast microscope. These is no significant difference between the tetanus toxin-treated and untreated cells in their passive electrical membrane properties, i.e. resting membrane potentials, input resistances, time constants and input capacities. Cells in 120 mM Na+, 2 mM Ca2+ salt solution showed Na spikes, and cells in high Ca2+ (30 mM), Na+-free salt solution showed Ca spikes in response to depolarizing current pulses. While the Na spike was not affected by tetanus toxin, the Ca spike was blocked by the toxin. The minimum dose of tetanus toxin for maximum suppression of the peak potential level of the Ca spike was 250 ng/ml. Addition of tetraethyl ammonium (TEA) to extracellular fluid enhanced the Ca spike in untreated cells. In toxin-treated cells, TEA did not alter the effect of tetanus toxin on the Ca spike. Blockade of the Ca spike by tetanus toxin could be detected even at low extracellular Ca2+ concentration (10 mM) by adding TEA to the extracellular fluid and adjusting the membrane potential to a steady hyperpolarized level (-80 mV) to ensure optimal and uniform electrical responses. The usefulness of NG108-15 hybrid cells for in vitro investigations on the mechanism of action of tetanus toxin was discussed.

Action Potentials↗
PubMed1983

[Effect of cepharanthin on peripheral leukocytopenia caused by antineoplastic agents].

One of the problems in administration of anticancer drugs is a decrease of peripheral blood leucocytes which causes reduction of defense mechanism against various infections. In this study, for the purpose of protecting leucopenia after administration of anticancer drugs, an effect of cepharanthine which is a kind of alkaroid materials was examined in normal and tumor-bearing mice. Peripheral leucocytes of both normal and tumor-bearing mice receiving anticancer drugs gradually decreased during first two weeks, and in third and forth week they decreased rapidly. On the other hand, leucopenia was improved by simultaneous administration of anticancer drugs and cepharanthin; however, a complete repairment was hardly expected when anticancer drugs were continuously administered. A significant recovery of leucocytes was observed in mice receiving cepharanthin compared to those receiving only anticancer drugs. In any process of decreasing and recovering from peripheral leucocytes, proportions of differential counts of leucocytes were approximately identical. On the colony forming experiment for granulocytic stem cell (CFU-C) using bone marrow cells of normal, anticancer drugs-treated, and anticancer drugs plus cepharanthin-treated mice, it has been suggested that cepharanthin might have some influencing activity on hematopoietic cells or cell-mediated activity on hematopoiesis only in vivo.

Alkaloids↗
PubMed1983

[Evaluation of regional pulmonary function test using 11C02, 11C0 and 13N2].

In the present study an attempt was made to evaluate the regional pulmonary function tests using positron gases and comparative studies of pulmonary functions were made using these positron gases and the conventional radioisotopes. In this study, 11CO2, 11CO, and 13N2 were used as positron study and then both 133Xe and 99mTc-MAA were used as conventional study. As fundamental tests, we measured the full width at half maximum (FWHM) of the line source of these nuclides and then measured the depth response of energy of these nuclides using the source in water. The subjects comprised normal control subjects, chronic obstructive pulmonary diseases (COPD), pulmonary fibrosis etc. as clinical tests. A single image or sequence of dynamic images were photographed by scintillation camera (Searle Pho-Gamma LFOV) equipped with a high energy collimator for positron and simultaneously the data were collected by computer. The detector of the scintillation camera was positioned in the posterior projection of the chest in a sitting position. A single breath method was used and after a short period of breath holding (10-20 min.), the inspired gas washed out for rebreathing room air. From the dynamic images, wash out curve and clearance rate were extracted with the aid of computer. The right lung field was divided into two zones, the upper and lower zones and upper/lower ratio (U/L ratio) of pulmonary distribution or clearance rate (C.R.) were calculated. As fundamental evaluation, resolving distance between positron and 133Xe were similar. But positron was best depth response of gamma-ray energy of the used nuclides. Clinically, 13N2 study and 133Xe study were similar.(ABSTRACT TRUNCATED AT 250 WORDS)

Carbon Dioxide↗
PubMed1983

Evaluation of left ventricular reserve in left ventricular diseases: non-invasive analysis of its determinants by dynamic exercise echocardiography.

To analyze the determinants of left ventricular (LV) reserve non-invasively, LV echocardiograms were taken during ergometer exercise in 52 LV disease patients (19 with hypertension [HT], 22 with aortic regurgitation [AR] and 11 with dilated cardiomyopathy [DCM] with various severities. In mild cases [HT], at exercise, fractional shortening (FS) increased, and at higher-grade exercise, an increase of LV enddiastolic diameter (Dd) was added to more increase of FS, to increase stroke volume (SV). In moderately severe cases [HT, AR or DCM], FS did not change or decreased at exercise. In severe cases [AR or DCM], FS was low at rest, and at exercise decreased further with an increase of LV systolic stress and no significant increase of Dd, resulting in a decrease of SV. The responses of LV parameters in volume-overload (AR) or dilated myocardial (DCM) hearts were poorer than in pressure-overload (HT) hearts, in moderately severe cases. In conclusion, exercise echocardiography can show non-invasively that the interrelationship among the determinants of LV reserve is different by the severities and the types of LV diseases, and this method is useful, especially in discriminating mild cases objectively.

Adult↗
PubMed1983

The influence of exercise on left ventricular outflow tract obstruction, left ventricular performance and electrocardiogram in hypertrophic cardiomyopathy.

To investigate exertional changes in hypertrophic cardiomyopathy (HCM), 42 patients with HCM were studied by echocardiography and ECG at a supine ergometer exercise. In 12 cases with left ventricular (LV) outflow tract obstruction at rest (Group I), systolic anterior movement (SAM) of mitral valve was intensified during exercise; and among 30 cases without obstruction at rest (Group II), in 6 cases (Group IIA) SAM appeared during exercise. SAM might be further intensified 1 minute after exercise. Inverted T-wave was seen at rest especially in Group IIB (no SAM both at rest and during exercise), and tended to become less deep during exercise with an increase of LV wall motion. In conclusion, in HCM, LV outflow tract obstruction may be produced or intensified during exercise. Inverted T-wave in HCM may become less deep during exercise, with accelerated LV function.

Adolescent↗
PubMed1983

[Cellular changes in malignant pleural effusion induced by intrapleural injection of BCG-CWS].

The intrapleural injection of BCG cell wall skeleton (BCG-CWS) is thought to be beneficial in the treatment of malignant pleural effusion. The study of cancer cells in pleural effusion after the intrapleural injectin of CWS showed that nuclear damage to cancer cells was slight and delayed compared to findings obtained after the intrapleural injection of Mitomycin C. After the intrapleural injection of CWS, the ratio of granulocytes in pleural effusion was rapidly elevated. This suggests that CWS induces an inflammatory response in the pleural cavity. After the inflammatory reaction, adhesive pleuritis was induced, the pleural space was reduced, leading to the disappearance of effusion. On the other hand, after the intrapleural injection of CWS, no elevation of the ratio of macrophages, and no increase of macrophage and cancer cell adherence were observed. This suggests that the immunopotentiating effect of CWS is not high.

Adenocarcinoma↗