Biomedical subjects
M Iwahara
Publications and source records attributed to M Iwahara.
High affinity of hybrid liposomes for normal human epidermal keratinocytes in vitro.
A high affinity of hybrid liposomes towards normal human epidermal keratinocytes was observed. The fluorescence micrograph showed that hybrid liposomes may be incorporated into the keratinocytes by fusion.
Successful balloon mitral commissurotomy in a small child: use of small Inoue balloon catheter.
A 15-month-old girl weighing 5.8 kg, in whom congestive heart failure developed due to congenital mitral stenosis, was successfully treated by percutaneous transluminal mitral commissurotomy using a small Inoue balloon catheter. Percutaneous transluminal mitral commissurotomy using a small Inoue balloon catheter may be a first-choice treatment for small children with congenital mitral stenosis.
Development and evaluation of a novel sterilizer with rotary vibrators.
A novel steam-air sterilizer with rotary vibrators was developed with the aim of promoting heat transfer and the effective sterilization of foods. To evaluate the effects of the sterilizer, experiments to examine heat transfer and sterilization tests were carried out. In the experiments to examine heat transfer, heat penetration factors of sterilizer with vibration, j and fh values, were 1.70 and 1.50, respectively, while those of sterilizer without vibration were 1.83 and 2.32, respectively. In the sterilization with vibration, no surviving cells were detected after 3 min, whereas 7 min were required for sterilization without vibration. The rate of the amino carbonyl reaction was repressed by heat treatment with vibration.
Specific inhibitory effect of hybrid liposomes on growth of human lymphoma-human lymphocyte B hybridoma cells in vitro.
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Plasma endothelin concentration: relation with vascular resistance and comparison before and after balloon dilatation procedures.
Endothelin (ET) is a potent vasoconstrictor peptide with an as yet uncertain physiological role in cardiovascular disease. We measured blood plasma ET concentrations using a recently developed radioimmunoassay and analysed the relations between ET concentration, systemic arterial pressure and systemic vascular resistance. In addition, ET levels before and after percutaneous balloon valvuloplasty and angioplasty were measured. Fifty-one patients were studied: (1) 13 patients with small left-to-right shunting or Kawasaki heart disease (age ranged from 4 to 144 months); (2) 10 patients who had undergone balloon valvuloplasty or angioplasty (age ranged from 1 to 233 months) and (3) 28 healthy infants and children (age ranged from 3 to 152 months). Systemic vascular resistance was calculated by the formula (mean aortic pressure--mean right atrial pressure) X 80/cardiac output (dyne.sec.cm-5). Plasma ET concentrations in healthy children less than 2 years were significantly higher than those over 2 years (2.48 +/- 0.62 vs 1.31 +/- 0.53 pg/ml). In eight patients in groups 1 and 2, plasma ET concentration in the pulmonary artery (2.00 +/- 0.43 pg/ml) was significantly lower than that in the femoral vein (2.39 +/- 0.69 pg/ml) and aorta (2.23 +/- 0.59 pg/ml), suggesting ET secretion derived from endothelial cells in peripheral pulmonary vessels. There was a significant positive correlation between ET concentrations in the femoral vein and systemic vascular resistance (r = 0.55, p less than 0.05). After balloon dilatation ET concentration rose from 2.15 +/- 0.82 pg/ml to 2.61 +/- 1.38 pg/ml.(ABSTRACT TRUNCATED AT 250 WORDS)
Intermediate-term results of balloon valvuloplasty for isolated and complicated pulmonary valve stenosis.
UNLABELLED: The purpose of this study is to report our experience regarding the acute and intermediate-term results of balloon pulmonary valvuloplasty (BPV) in various types of congenital pulmonary valve stenosis. METHODS AND RESULTS: Twenty-four consecutive patients with a median age of 6.6 years (ranging from 1 month to 24 years old) underwent BPV between January 1988 and September 1991. These patients were divided into 2 groups; Group 1 consisting of 13 patients with isolated pulmonary valve stenosis, and Group 2 consisting of 11 patients with complicated pulmonary valve stenosis (supravalvular, subvalvular, valved conduit and post-right ventricular outflow reconstruction). Mean peak systolic pressure gradients from the right ventricle to the pulmonary artery were as follows: In group 1, 48 +/- 21 (mean +/- SD) mmHg before BPV, 18 +/- 8 mmHg immediately after BPV and 13 +/- 5 mmHg at the longest follow-up based on catheterization or Doppler echocardiographic studies. The gradients in group 2 were 65 +/- 28 mmHg before BPV, 46 +/- 25 mmHg immediately after BPV and 47 +/- 21 mmHg at the longest follow-up. CONCLUSIONS: BPV provides both acute and intermediate-term gradient relief in patients with isolated pulmonary valve stenosis. In complicated pulmonary valve stenosis, on the other hand, the effect of BPV was unsatisfactory and appears to depend on the mechanism of associated obstruction. Therefore accurate evaluation of the anatomy of associated obstruction in the pulmonary valve region is needed to determine that BPV is indicated.
Balloon occlusion aortography.
We review the validity of balloon occlusion aortography (BOA) on the basis of our personal experience with 18 patients with congenital heart disease (mean weight 4.55 g, including 8 neonates). Four of the 18 patients underwent aortic arch angiography using balloon occlusion of the descending aorta. Pulmonary angiography was also performed in 9 patients via a patent ductus arteriosus and in 3 patients via a Blalock-Taussig shunt. The remaining 2 patients underwent coronary arteriography by balloon occlusion of the ascending aorta. The information obtained was satisfactory in 17 of the 18 patients. However, in one patient with a double-outlet right ventricle and pulmonary stenosis, the pulmonary arteries were not clearly visualized because of dominant antegrade flow from the right ventricle. BOA is a safe and useful procedure which can be used to image the aortic arch, pulmonary artery, and coronary arteries in infants with congenital heart diseases. In children over 3 years of age, however, the balloon may not be able to occlude the appropriate site of the aorta, so selective angiography is required to obtain precise information.
Immunosuppressive therapy in the management of acute myocarditis in children: a clinical trial.
To assess whether steroid therapy influenced the clinical course of myocarditis in a pediatric population, findings in 13 consecutive infants and children (8 female, 5 male) with biopsy-proved myocarditis were reviewed. The mean age was 5.7 +/- 4.8 years (range 1.1 to 14.8). Congestive heart failure was present in all as were ST-T wave changes, cardiomegaly and pulmonary edema on chest roentgenogram. Echocardiography demonstrated pericardial effusion in five patients and mitral regurgitation in eight. Mean left ventricular ejection fraction was 34 +/- 12%. Prednisone was administered to all patients; one patient also received azathioprine. There was one death. All survivors showed clinical improvement with normalization of ECG changes, heart size and systolic function. No significant side effects occurred. Repeat myocardial biopsy in eight patients demonstrated improvement in all eight and elimination of the inflammatory infiltrate in six. Immunosuppressive therapy in this pediatric population appeared useful in improving the clinical course and cardiac function in acute myocarditis with no adverse side effects.
Purification and some properties of a thermostable metal proteinase produced by Thermomicrobium sp. KN-22 strain.
An extreme thermophile that produces a heat-stable proteinase was isolated from hot-spring water and classified as Thermomicrobium sp. KN-22 (growth temperature, 50-83 degrees C; and optimum growth temperature, 70 degrees C). The proteinase was purified from the culture broth of this strain by fractionation with ammonium sulfate, chromatography on columns of DEAE-cellulose and CM-Sepharose CL-6B, and HPLC on TSKgel CM-5PW. The purified enzyme gave a single band on SDS-polyacrylamide gel electrophoresis and a single peak after HPLC (yield 8.8%). The enzyme had maximum activity at pH 8.5 and at 75 degrees C and it was stable up to 60 degrees C. The molecular weight of the enzyme was 35,000 by SDS-PAGE. Since the enzymatic activity was completely inhibited by EDTA, o-phenanthroline, and phosphoramidon, it appears that the enzyme is a metal proteinase.
Indications for aortocoronary bypass surgery after Kawasaki disease.
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Myocarditis in Kawasaki disease.
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Clinical features of aortic arch anomaly with malalignment ventricular septal defect.
The clinical features and outcome after various surgical procedures on 9 patients with coarctation or interruption of the aortic arch and malalignment ventricular septal defect (group 1) were compared with those of 9 patients with the arch anomaly without malalignment ventricular septal defect (group 2). Cardiomegaly and metabolic acidosis were prominent in group 1. Five of the 9 patients in group 1 died in the immediate postoperative period (56% mortality), but no operative deaths occurred among 8 patients in group 2 (p less than 0.01). The ratio of left ventricular outflow tract to ascending aortic diameter was 0.59 +/- 0.09 in group 1 and 1.03 +/- 0.11 in group 2 (p less than 0.01). Three of 4 patients with a ratio of less than 0.6 died, but no operative deaths occurred among the 6 patients who had a palliative operation and in whom the ratio was more than 0.6. These data suggest that left ventricular outflow tract obstruction is critical when the ratio of left ventricular outflow tract to ascending aortic diameter is 0.6 or less. The presence of severe left ventricular outflow tract obstruction necessitates modification of the present surgical strategy.
Advanced atrioventricular block in a neonate with lupus erythematosus and anti-SS-A antibodies.
Recent studies suggested that the involvement of anti-SS-A and anti-SS-B antibodies in the pathogenesis of neonatal lupus erythematosus and congenital heart block. We here describe a female neonate with lupus erythematosus, advanced atrioventricular block, and a positive test for anti-SS-A antibodies. The findings of His-bundle recordings are presented.
Progressive vascular lesions in Williams-Beuren syndrome.
We report two patients with Williams-Beuren syndrome. The first patient showed no evidence of coarctation of the aorta at the first examination. Seven years later, she developed coarctation of the aorta. In the second patient, we found the progression of renal artery stenosis by serial angiography. We report that vascular lesions may be progressive in Williams-Beuren syndrome.
Aortocoronary bypass surgery for Kawasaki disease.
A case of Kawasaki disease with precordial pain in a 6-year-old boy is described. Coronary arteriography revealed large aneurysms with subtotal obstruction of the left anterior descending artery and long-segment narrowings of the right coronary artery. The left ventriculogram revealed an old myocardial infarction of the inferoposterior wall of the left ventricle. The patient was given aortocoronary bypasses using both a left internal mammary artery and a fresh saphenous vein graft to the left anterior descending artery. Serial angiographic study, performed 6 weeks after the operation, revealed these grafts were both patent. Using the two techniques together may have the potential benefit of the saphenous vein bypass graft functioning as a temporary measure to ensure survival with the hope that the internal mammary artery supply will continue to grow.
Infantile hypertrophic cardiomyopathy with QT prolongation.
An infant who died at 5 months with hypertrophic cardiomyopathy accompanied by QT prolongation was examined at autopsy. At the age of 16 days, serum IgM level was elevated (226 mg/dl). Microscopic examination revealed characteristics of hypertrophic cardiomyopathy with myocardial cell hypertrophy with disarray and healed myocarditis with patchy fibrosis and mononuclear cell infiltration. The histological findings were compatible with those of postmyocarditic cardiomegaly developing during the fetal period.
Progressive vascular lesions in Williams syndrome.
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