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Biomedical subjects

M Sawamura

Publications and source records attributed to M Sawamura.

At least 145 records · Page 8Linked to original sources
PubMed1985

Vectorcardiograms in dilated cardiomyopathy and triple vessel coronary artery disease: a comparative study by ventricular gradient.

An analysis using vectorcardiography and left ventriculography was made on forty patients, 17 of whom had dilated cardiomyopathy (DCM), 14 with triple vessel coronary artery disease (CAD) and 9 control subjects. QRS deflection area vector (Aqrs) was directed the most posteriorly in the DCM group and the second most posteriorly in the CAD group. Ventricular gradients (G) were smaller in the DCM and CAD groups than in the control group and directed more posteriorly in the DCM group than in the CAD and control groups. G/Aqrs was the smallest in the DCM group and the second smallest in the CAD group. Aqrs-At Angle was the widest in the DCM group and the second widest in the CAD group. Left ventricular ejection fraction (EF) showed high correlations with the azimuth of Aqrs (r = 0.659), with the magnitude of G (r = 0.720), with G/Aqrs (r = 0.785) and with Aqrs-At Angle (r = -0.855). From this evidence, we conclude that the magnitude of G, G/Aqrs and Aqrs-At Angle have a definable relationship with the impairment of left ventricular function and the Aqrs-At Angle is an especially useful parameter to detect the grade of myocardial damage in both the DCM and CAD groups.

Adult↗
PubMed1985

[Systemic chemotherapy with high-dose cisplatin and sodium thiosulfate rescue].

Intravenous bolus injection of an 80- to 120-mg/m2 dose of cisplatin followed by "rescue" with sodium thiosulfate (STS) was tried in the treatment of 7 patients with advanced tumor. STS was given continuously i.v. six hours after cisplatin injection, combined with methylprednisolone and metoclopramide as antiemetics. Four patients were evaluable, consisting of one CR, one PR and two NC. Severe nausea and emesis occurred in two patients and irreversible renal dysfunction occurred in one. The clinical use of the STS rescue regimen was discussed in conjunction with our basic investigation of "STS-rescue" in an animal model.

Adult↗
PubMed1985

[Systemic chemotherapy with super-high dose cisplatin and sodium thiosulfate (STS) rescue in mice].

We have devised a new systemic chemotherapy using cisplatin (DDP) with sodium thiosulfate (STS) rescue; basically, STS was given repeatedly 6 hours after DDP administration combined with metoclopramide. The effect of STS-rescue on the antitumor activity of DDP was studied using a BALB/c syngeneic fibrosarcoma (KKN-1). A graded dose of DDP was given i.p. with or without STS-rescue and its effects were evaluated according to N. C. I. protocol. A DDP dose-related antitumor activity was observed and the minimal effective doses were calculated as 8.2 and 9.8 mg/kg for groups treated with DDP alone and with STS-rescue, respectively. When STS-rescue was combined, however, super-high doses of DDP (9-16.5mg/kg) could be administered and this resulted in a 52% increase in chemotherapy index.

Animals↗
PubMed1984

Synergistic action of protein kinase C and calcium for histamine release from rat peritoneal mast cells.

When rat mast cells were stimulated by concanavalin A, phosphatidylinositol turnover was induced. Concurrently, several cytosol proteins were phosphorylated and histamine was released. 1-Oleoyl-2-acetyl-glycerol ( OAG ) and 12-O-tetradecanoylphorbol-13-acetate (TPA), known as direct activators of protein kinase C in intact cells, induced phosphorylation of the same spectrum of proteins. These proteins also served in vitro as preferable substrates for protein kinase C. The simultaneous addition of OAG or TPA and A23187 synergistically enhanced histamine release from mast cells. It is suggestive that protein kinase C activation and Ca2+ mobilization play essential roles for this cellular response.

Animals↗
PubMed1984

Effect on exercise tolerance and pharmacokinetics of conventional and sustained release preparations of propranolol in patients with angina pectoris--a double-blind cross-over study.

Ten patients with effort angina were studied in a randomized double-blind cross-over trial in order to investigate the effect of sustained release propranolol (LA) and conventional propranolol (Prop) formulations on exercise tolerance. LA was given once daily and Prop three times daily. Treadmill exercise tests were performed using the Bruce protocol and the plasma propranolol levels were measured. The following results were obtained: LA proved to have an anti-anginal effect similar to Prop. No adverse reactions were observed after administration of either of the drugs. Similar suppressive effect of the heart rate, blood pressure and double product at rest and on exercise was seen after LA and Prop while the exercise capacity was increased. The plasma level of propranolol was higher at 2 hours after Prop than LA administration, but there was no difference between LA and Prop at 4 and 24 hours after administration. The plasma propranolol level at 4 hours after LA correlated with the percent reduction in exercise heart rate and with the percent reduction in the double product. Our study suggested that once-a-day administration of LA could improve patients' compliance and adds another choice to the list of clinically useful beta-blockers for the treatment of angina pectoris on effort.

Aged↗
PubMed1984

Relationship between ventricular gradient and the impairment of wall motion of the left ventricle in coronary artery disease.

Fifty patients with or without coronary artery disease were studied. Twelve of them showed no coronary artery obstruction, while 38 demonstrated obstruction of the left anterior descending artery (LAD). Of the latter 38, 16 had obstruction at LAD alone, 6 at LAD and right coronary artery (RCA), 8 at LAD and left circumflex artery (LCx) and 8 at LAD, RCA and LCx. Vectorcardiography, selective coronary cineangiography and left ventricular cineangiography were undertaken in all subjects. The vectorcardiogram (VCG) was recorded on a magnetic tape and QRS area vector (Aqrs), T area vector (At) and ventricular gradient (G) were calculated by micro-computer. From left ventriculogram (LVG) "score" was computed to express the grade of impairment of the wall motion. Correlations between various vector-cardiographic parameters and this score were examined. The score correlated significantly (p less than 0.001) with azimuth of Aqrs (r = -0.545), azimuth of At (r = 0.661), magnitude of G (r = -0.705), azimuth of G (r = 0.533), G/Aqrs (r = -0.645), spatial angles between Aqrs and At (r = 0.591) and between max R and max T (r = 0.595) and X component of G (r = -0.758). These results suggested the usefulness of ventricular gradient to grasp the grade of coronary artery disease.

Cineangiography↗
PubMed1983

Synergistic functions of protein phosphorylation and calcium mobilization in platelet activation.

When human platelets were stimulated by synthetic diacylglycerol such as 1-oleoyl-2-acetyl-glycerol, which was a potent activator in vitro of Ca2+-activated, phospholipid-dependent protein kinase (protein kinase C) (Mori, T., Takai, Y., Yu, B., Takahashi, J., Nishizuka, Y., and Fujikura, T. (1982) J. Biochem. (Tokyo) 91, 427-431), a protein having Mr approximately 40,000 (40-kilodalton protein) was rapidly phosphorylated, just as it was by natural extracellular messengers such as thrombin. Fingerprint analysis appeared to indicate that protein kinase C was indeed responsible for this 40-kilodalton protein phosphorylation in intact platelets. Under these conditions, neither inositol phospholipid breakdown nor endogenous diacylglycerol formation was observed, indicating that the synthetic diacylglycerol intercalated into the membrane and directly activated protein kinase C without interaction with cell surface receptors. During this process, the diacylglycerol was converted in situ to the corresponding phosphatidate, 1-oleoyl-2-acetyl-glyceryl-3-phosphoric acid. Experiments with the synthetic diacylglycerol and Ca2+ ionophore A23187 suggested that the protein phosphorylation catalyzed by protein kinase C was a prerequisite requirement for the release of serotonin, and that the receptor-linked protein phosphorylation and Ca2+ mobilization acted synergistically to elicit the full physiological cellular response.

Anti-Bacterial Agents↗
PubMed1983

Myopericarditis associated with ECHO virus type 3 infection--A case report.

A case with myopericarditis caused by type 3 ECHO virus was reported. The diagnosis was based on a significantly increased hemagglutination-inhibiting antibody titer (from 4:6 to 4:516) against type 3 ECHO virus in the acute and the convalescent phase. A 29-year-old male was hospitalized for chest pain and fever. The patient had congestive heart failure, pericardial effusion and temporarily appearing abnormal Q waves on his electrocardiogram in the acute phase all of which gradually improved within about 3 weeks. Cardiac catheterization performed on the 21st day of hospitalization disclosed normal coronary arteries, but a partially hypokinetic region was found in the left ventricular free wall. A right ventricular endomyocardial biopsy study revealed histological features of a small number of mononuclear cell infiltrations, myocardial cell necrosis and early fibrosis associated with an increased number of fibroblasts and ultrastructural changes including myocytolysis, vacuolation in sarcoplasm and dissociation of some intercalated discs. The endomyocardial biopsy study, and the electrocardiographic and cineangiographic findings in this case suggest that viral infection may induce clinical signs of myocardial infarction in the heart with normal coronary arteries.

Adult↗
PubMed1983

Long-term effects of molsidomine on exercise tolerance in patients with exertional angina pectoris.

Molsidomine is a derivative of the sydnonimines and is a long-acting vasodilator that may be effective in the treatment of chronic stable angina pectoris. To evaluate the therapeutic efficacy and drug tolerance, eight men with stable angina pectoris performed a symptom-limited maximal exercise test on a computer-assisted treadmill. After ingesting either placebo or molsidomine administered in single blind fashion 90 min before the exercise test on the first day of treatment, molsidomine decreased the average systolic blood pressure response from 154 +/- 3 (SEM) to 135 +/- 4 mmHg (p less than 0.01). However it did not significantly change the average heart rate response (117 +/- 7 to 124 +/- 8 beats/min) and the rate-pressure product (18.1 +/- 1.2 X 10(3) to 16.8 +/- 1.1 X 10(3]. The average time up to the onset of ischemia at which significant ST-segment deviation (0.1 mV) first appeared was increased from 9.0 +/- 1.7 to 12.8 +/- 1.2 min (p less than 0.001) after molsidomine. At peak exercise after molsidomine, the mean value of ST-segment deviation in V5 or aVF was decreased (p less than 0.001). This result was obtained even though the average exercise duration was increased from 11.4 +/- 1.7 to 13.6 +/- 1.2 min (p less than 0.001). The treadmill score according to Hollenberg was also improved from -47 +/- 24 to 1 +/- 14 after molsidomine administration. After six weeks of continued therapy with molsidomine the favorable effect on exercise tolerance was significantly decreased in terms of exercise duration, the time up to the onset of ischemia, and the treadmill score.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1983

[Detection of regional left ventricular wall motion abnormality by ultrasonic cardiotomography: comparison with phase images of RI angiocardiography].

Left ventricular (LV) wall motion abnormality evaluated by LV contrast angiography was compared with that of RI angiography and ultrasonic cardiotomography (UCT). Phase images and UCT were performed in 15 patients with akinesis or dyskinesis (Group I), 17 with localized hypokinesis (Group II), and 11 without abnormality (Group III). In the RAO phase image, the LV was divided into apical, antero-lateral, and inferior segments. When there was a difference of more than 15 degrees in the mean of pixel phase values in each segment, the motion abnormality was judged to be present. The sensitivity was 90% in Group I and 25% in Group II, respectively, and the specificity was 86% in Group III. In the LAO phase images, when the standard deviation of phase values within the LV was more than 10 degrees, the motion abnormality was judged to be present. The sensitivity was 100% in Group I and 71% in Group II, respectively, and the specificity was 91% in Group III. In UCT, the sensitivity was 73% in Group I and 12% in Group II, respectively, and the specificity was 100% in Group III. Thus, the RAO phase image is rewarding in evaluating the site of the motion abnormality, and the LAO phase image is also helpful in the detection. On the other hand, it was difficult to detect the abnormality of wall motion of the apical region by UCT.

Adolescent↗
PubMed1981

Morphological transformation, sister chromatid exchange and mutagenesis assay of betel constituents.

Betel quid, a masticatory widely used in Sri Lanka, consists of Jaffna tobacco, the nuts and leaves of betel plants and calcium hydroxide. An ethyl acetate extract of Jaffna tobacco induced morphological transformation of hamster embryo cells. The extract also induced sister chromatid exchanges inn virally transformed and phytohaemagglutinin (PHA)-stimulated human lymphocytes. The induction of sister chromatid exchanges was potentiated by addition of rat liver homogenate. The extract did not induce ouabain-resistant mutation of V79 cells. Extracts of betel nuts and leaves gave negative results in assay of morphological transformation, sister chromatid exchange and mutagenesis.

Areca↗