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Biomedical subjects

H Sunagawa

Publications and source records attributed to H Sunagawa.

At least 55 records · Page 3Linked to original sources
PubMed1987

[Hypocholesterolemic effect of catechol estrogen 2-monomethyl ether].

The hypocholesterolemic effect of 2-methoxyestrone (2-MeOE1), 2-methoxyestriol (2-MeOE3) and estradiol-17 beta (E2-17 beta) was investigated in two experimental systems of normocholesterolemic and dietary hypercholesterolemic rats that had undergone oophorectomy. Each compound was subcutaneously administered for 6 consecutive days at a dose of 10 micrograms per day in the former systems and at 300 micrograms per day in the latter system, respectively. The hypocholesterolemic effect was in the following relation: 2-MeOE3 = E2 - 17 beta greater than 2-MeOE1. In the latter system, the serum total cholesterol level of individual rats in both 2-MeOE3- and E2-17 beta-administered groups returned to normal. No uterotrophic activity was exhibited by either 2-MeOE1 or 2-MeOE3, while E2-17 beta exhibited an anomalous activity. The effect of 2-MeOE1 and 2-MeOE3 on body weight was not exhibited, while E2-17 beta reduced it slightly. The results suggest that catechol estrogen 2-monomethyl ether plays an important role in lipid metabolism through estrogen receptor independent mechanisms and has a pharmacologically important effect on hyperlipidemia and atherosclerosis.

Animals↗
PubMed1987

To what extent does the size of a ventricular septal defect correlate with haemodynamic data derived from cardiac catheterisation?

A simplified model based on Gorlin's formula was used to derive an index of the cross sectional area of ventricular septal defects from commonly used cardiac catheterisation data. This index was compared with the area of the defect measured during operation and expressed as a ratio to the cross sectional area of the aorta. The highly significant linear relation (r = 0.94) between this index of the defect area and the size of the defect measured at operation means that the severity of a ventricular septal defect can be assessed from haemodynamic data obtained at cardiac catheterisation.

Adolescent↗
PubMed1987

Primary repair of interrupted aortic arch and severe aortic stenosis in neonates.

Two infants, aged 36 days old (Case 1) and 18 days old (Case 2) with interrupted aortic arch types B and A, respectively, and with severe aortic stenosis, were successfully operated on by use of pulsatile cardiopulmonary bypass. The great arteries were normally related in Case 1 and were transposed in Case 2. Repair involved the following procedure: ligation of the patent ductus arteriosus, restoration of aortic continuity with an 8 mm polytetrafluoroethylene graft, placement of an internal patch to tunnel all left ventricular blood from the left ventricle through the ventricular septal defect into the pulmonary artery in Case 1 and patch closure of the ventricular septal defect in Case 2, transection of the main pulmonary artery, anastomosis between the proximal pulmonary artery and the ascending aorta, and interposition of a valved conduit between the right ventricle and the distal pulmonary artery. The operative field could be approached easily through a median sternotomy. Postoperative cardiac catheterization revealed satisfactory anatomical and hemodynamic results in both cases.

Aorta↗
PubMed1986

Estimation of exercise capacity from oxygen consumption in the recovery phase of submaximal exercise.

We analyzed the transient response of oxygen consumption (VO2) after the sudden termination of exercise. The study population consisted of 20 male athletes (age 13 to 15.9 years) and 87 male patients, 59 of whom (age 4.8 to 17.8 years) were considered to be normal subjects, and 28 of whom (age 6 to 14.8 years) had restricted physical activity because of underlying heart diseases (restricted group). The exercise tests were performed according to Bruce's protocol and terminated at signs of exhaustion. As soon as exercise ceased, the examinee sat on a chair and took rested completely. VO2 was measured every 30 seconds throughout the test. We characterized the rate of the initial decay of the VO2 transient as the ratio of the 30 second VO2 right after the exercise to that at the end of the exercise (Irv). This index did not differ significantly among the groups. On the other hand, Exc, the Irv normalized by the end-exercise VO2, was a sensitive index for separating the restricted group from the control and athlete groups. Should the Exc remain sensitive enough to quantify exercise capacity regardless of the intensity of the exercise imposed, even the submaximal exercise test should enable us to safely evaluate the exercise capacity of patients with impaired cardiac function.

Adolescent↗
PubMed1985

Cardiodynamic effects of experimental right bundle branch block in canine hearts with normal and hypertrophied right ventricles.

Cardiodynamic effects of acute experimental right bundle branch block (RBBB) were studied in canine hearts: group A included 15 normal hearts; group B-1 had seven hearts with mild right ventricular hypertrophy (RVH), and group B-2 had 11 hearts with marked RVH. The main sequential changes following RBBB were marked prolongation of the Q upstroke interval of the right ventricle and striking shortening of right ventricular systolic time that affected right and left ventricular interaction, particularly in the hearts with RVH. Hemodynamic changes were: the right ventricular end-diastolic pressure was elevated markedly (4.4 +/- 2.2----9.8 +/- 2.6 mm Hg, p less than 0.001) in group B-2, moderately (p less than 0.01) in group B-1, and not at all in group A. The right ventricular positive peak dp/dt decreased remarkably (1036 +/- 151----827 +/- 152 mm Hg/sec, p less than 0.001) in group B-2 and negligibly in the other groups. A significant correlation existed between the percentage of decrease in right ventricular peak dp/dt and the QRS duration of RBBB in each group (p less than 0.01). The left ventricular peak negative dp/dt decreased distinctly (2570 +/- 326----+/- 2055 +/- 362 mm Hg/sec, p less than 0.01) in group B-2 and not at all in the other groups. The stroke volume showed 12% decrease in group B-2 (p less than 0.001), 8% decrease in group B-1 (NS), and no decrease in group A. In the presence of RVH, acute RBBB causes significant impairment of right and left ventricular function. The magnitude of the impairment invariably depends upon both the prior degree of RVH and the width of the QRS complex.

Animals↗
PubMed1985

Heat resistance, spore germination, and enterotoxigenicity of Clostridium perfringens.

Heat resistance at 95 C, heat activation at 75 C, and germination response were determined for spores of 10 serotype strains of Clostridium perfringens type A, including five heat-resistant and five heat-sensitive strains. The D95-values ranged from 17.6 to 63.0 and from 1.3 to 2.8 for the heat-resistant and the heat-sensitive strains, respectively. The heat-activation values, the ratios between the heated and unheated viable counts of spore suspensions, ranged from 0.0035 to 0.65 and from 6.5 to 60.0 for the heat-sensitive and the heat-resistant strains, respectively. Spores of these strains were divided into two distinct germination types on the basis of their germination response; spores of the heat-resistant strains germinated in KC1 medium after heat activation (K-type), and spores of the heat-sensitive strains germinated in a mixture of L-alanine, inosine, and CaCl2 in the presence of CO2 without heat activation (A-type). The strains were tested for enterotoxigenicity by a reversed passive latex-agglutination (RPLA) test. All the heat-resistant strains were RPLA-positive, whereas the heat-sensitive strains were all RPLA-negative. A total of 37 strains of the organism isolated from food-poisoning outbreaks were tested for spore germination and enterotoxin formation. All of the 20 heat-resistant strains showed K-type spore germination and, except for three strains, were RPLA-positive, whereas all of the 17 heat-sensitive strains showed A-type spore germination and, except for only one strain, were RPLA-negative.

Alanine↗
PubMed1985

Direct estimation of cardiac reserve through analysis of relation between oxygen consumption and heart rate during exercise testing.

In order to elucidate fundamental relationship between exercise and cardiac reserve, we investigated the parameters of regression equation (VO2 = A X HR + B) between oxygen consumption (VO2 ml/kg/min) and heart rate (HR) during exercise test (Bruce). 62 male children were divided into 3 groups based on history and clinical evaluation. HR related linearly with VO2 (average r = 0.967, range 0.90-0.993). Both of the parameters A and [B] were significantly high in Athlete (A = 0.465 +/- 0.043, [B] = 36 +/- 6.07), low in Failed (0.297 +/- 0.055, 17.4 +/- 6.1) and middle in Ordinary group (0.366 +/- 0.078, 23.5 +/- 8.6) (p less than 0.005). Based on our result of linear VO2-HR relation, and on the previously reported studies that cardiac output linearly and consistently relates with VO2, we considered the meaning of the parameters as follows; A determines the possible maximum stroke volume (SV), and B determines the HR where SV reaches plateau. In conclusion, since the SV is considered as a measure of cardiac function, measuring the parameters of VO2-HR relation allows us to isolate cardiac functional reserve through the exercise tolerance test.

Adolescent↗
PubMed1985

Left ventricular diastolic pressure-volume and stress-strain relationship in children.

Diastolic pressure and volume (P-V) curves were approximately exponential and fitted the equation, dP/dV = aP + b, where a was left ventricular volume elastic constant. Stress and strain (sigma-epsilon) curves were expressed by the equation, d sigma/d epsilon = k sigma + c, where k was wall stiffness constant. These exponential curves have been fitted over the whole diastole, but theoretically, the mid-diastole should reflect diastolic elastic properties best. In the present study, therefore, special attention was paid to the mid-diastole in each patient, and both P-V and sigma-epsilon relationships were analyzed by fitting the data to the above mentioned curves during this period of time. This analysis was made in two separate groups of patients. One was the control group consisting of 2 patients with normal hearts, 2 patients with mild pulmonary stenosis, and 25 patients with post mucocutaneous lymph node syndrome. The other group consisted of patients with postoperative congenital heart disease, that is, 8 patients with atrial septal defect and 5 patients with tetralogy of Fallot. The elastic constant (a) could not be compared if the size of the hearts differed. The results of the present study, however, demonstrated that the size of the heart was closely related to the constant, a. In the control group, the constant (a) was exponentially related to the size of the heart, and expressed as follows: a = 0.30e-0.037EDV + 0.045 (r = 0.94, p less than 0.01) In contrast, the wall stiffness constant (k) was not related to the size of the heart. After surgical repair of congenital heart disease, the stiffness constant in the left ventricle was normal in patients with postoperative atrial septal defect, while it was significantly increased in patients with postoperative tetralogy of Fallot.

Cardiac Volume↗
PubMed1984

Physiological significance of the slope of the regression equation between oxygen consumption and heart rate in exercise testing.

The relationship between oxygen consumption (VO2) and heart rate (HR) was studied in 62 male children. Based on clinical evaluation and history, they were divided into three groups, i.e., athlete, ordinary and failed. There was a high linear correlation between HR and VO2 in each individual. The averaged values of the slope and standard deviations were 2.09 +/- 0.189 in the athlete group (n = 17), 2.60 +/- 0.140 in the ordinary group (n = 16) and 3.17 +/- 0.591 in the failed group (n = 29). The statistical differences were confirmed among the groups (p less than 0.005). The results suggested that the slope of the HR vs. VO2 relation was related to an inotropic state of cardiac function. We concluded that the slope was a more suitable and more direct evaluation of cardiac function during exercise. Moreover, the method was non-invasive and safe because it required no potentially hazardous maximum work load for the patients.

Child↗
PubMed1980

Left ventricular performance and compliance following acute febrile mucocutaneous lymphnode syndrome.

Right and left heart catheterizations and biplane cineangiographies were performed on 115 post-MCLS cases to study the left ventricular performance and compliance, and the following conclusions were obtained: 1) The left ventricular performance of the post-MCLS cases with macroscopic cardiac lesions such as coronary aneurysms and stenosis declined compared with the others. 2) The left ventricular contractility of the post-MCLS cases without macroscopic cardiac lesions were within normal limits. 3) The diastolic compliance of the post-MCLS cases seemed to be decreased but the value could be regarded as normal for children.

Child↗