Search PubMed⌕ Search

Biomedical subjects

K Ihara

Publications and source records attributed to K Ihara.

At least 145 records · Page 8Linked to original sources
PubMed1990

[Studies on faint attack due to arrhythmias with Holter electrocardiogram].

Out of 1,400 Holter ECGs, 15 records revealed arrhythmias which would be responsible for faint attack, including 8 sick sinus syndrome with cardiac arrest, 4 non-sustained ventricular tachycardia (VT), 2 paroxysmal atrial fibrillation and 1 paroxysmal supraventricular tachycardia. All of cardiac arrest corresponding to faint attack lasted for longer than 4 sec, and an averaged duration of the arrest was 5.8 +/- 2.3 sec. This was significantly longer than that with no subjective symptoms, 3.4 +/- 0.7 sec. Duration and rate of VT did not show any significant relationship with faint attack. The result suggests that cardiac arrest is mostly responsible for arrhythmia-induced involvement of cerebral circulation and faint attack. It is also suggested that cardiac arrest longer than 4 sec should be extensively treated including pacemaker implantation.

Arrhythmias, Cardiac↗
PubMed1990

[Coronary revascularization with reduction of serum cholesterol level using LDL apheresis in patient with homozygous familial hypercholesterolemia].

We reported a case of a 48-year-old male with homozygous familial hypercholesterolemia who underwent coronary revascularization successfully. Coronary artery bypass grafting (CABG) utilizing internal mammary artery graft to LAD, and percutaneous transluminal angioplasty for residual stenosis after CABG was able to relieve symptomatic myocardial ischemia. LDL apheresis every two weeks in addition to combined drug treatment had maintained total cholesterol at an acceptable level (120-280 mg/dl) before and after CABG. It was confirmed by repetition of coronary angiography at one year after CABG that all grafts were widely patent, and the native coronary artery did not accelerate the atherosclerotic lesion. It was important in patients with homozygous familial hypercholesterolemia, to carry out active coronary revascularization with reduction of serum cholesterol level by using LDL apheresis.

Angioplasty, Balloon, Coronary↗
PubMed1990

[Congenital atresia of the left main coronary artery ostium--a case suffering from ventricular tachycardia].

A case of congenital atresia of the left main coronary ostium suffering from ventricular tachycardia underwent coronary artery bypass operation. The patient was 17 years old boy. When he was 9 years old he visited our department for the purpose of examining cardiac disease. The diagnostic impression was mitral regurgitation. At 16 years old he suddenly complained tachycardia during exercise. He admitted to our hospital and the tachycardia was proved to be ventricular tachycardia. Left ventriculogram demonstrated a small range of akinesis at the left ventricular apex. And coronary cineangiogram revealed atresia of the left main coronary artery. The left coronary artery was perfused with collateral circulations from right coronary artery. Electrophysiological study was performed. The ventricular tachycardia could be reproducibly initiated and terminated by programmed stimulation. The catheter endocardial mapping was also performed. The source of ventricular tachycardia was supposed to be at the left ventricular apex. At 18 years old coronary artery bypass operation was performed. Internal mammary artery graft was placed to the left anterior descending artery and a saphenous vein graft was placed from the ascending aorta to the left circumflex artery. A small size of myocardial infarction was recognized at the left ventricular apex. And epicardial mapping revealed that the source of arrhythmia was the same region as the myocardial infarction was recognized. Endocardial resection or cryoablation was not performed. Post-operative study was performed 8 months after surgery. The graft flow of the internal mammary artery to the left anterior descending artery was not sufficient.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

[A rare case of congenital tricuspid stenosis treated with modified Fontan operation].

A rare case of congenital tricuspid stenosis treated with modified Fontan operation was reported. The patient was 13 years old boy and his chief complaint was cyanosis. Cyanosis appeared in his neonatal period and squatting developed in his childhood. He underwent Blalock's shunt operation at 5 years of age. His exercise tolerance was limited at the admission for the radical operation. Angiocardiography showed the annular stenosis of tricuspid valve and the moderate hypoplasia of right ventricle. The right ventricular volume was 56 ml (equivalent to 35% of the normally expected right ventricular volume) and the diameter of tricuspid annulus was 13 mm (equivalent to 58% of the normally expected diameter). Atrial septal defect was associated with but pulmonary stenosis did not exist. His left ventricular function was good and pulmonary vascular resistance was not raised. A diagnosis of tricuspid stenosis was made and Fontan's repair was considered to be possible for his correction. Operative findings showed normal architecture of tricuspid valve with the three leaflets but tricuspid annulus was narrow. Tricuspid valve stenosis was considered to be caused by the hypoplasia of tricuspid ring and surgical dilatation was found to be difficult. Therefore, modified Fontan operation (RA-RV connection) was performed. His cyanosis disappeared and exercise tolerance was improved after the operation. Cardiac catheterization and angiocardiography were performed 8 months and 28 months after the operation. His righ ventricular volume was increased to 123 ml (equivalent to 57% of the normally expected volume) followed by RA-RV connection.

Adolescent↗
PubMed1990

[Changes in the ECG and myocardial blood flow of the right and left ventricular walls under acute pulmonary arterial stenosis].

For studying the effect of regional myocardial blood flow changes on the epicardial ECG of right and left ventricular walls under acute right ventricular pressure overload, we mapped the epicardial using 64-channel shock electrodes, and estimated the myocardial blood flow with radioactive microspheres. In 9 anesthetized open-chest dogs, the main pulmonary artery was gradedly constricted to the level of mild (peak RV pressure: PRVP, 50-70 mmHg), moderate (PRVP, 70-80 mmHg) and severe stenosis (PRVP, over 80 mmHg). Labeled microspheres were injected into the left atrium before and after the PA constriction, and the epicardial ECGs were recorded continuously. After the completion of the experiment, 9 areas of each right and left ventricular wall were excised. The myocardium was divided into three layers and the flow data were compared to the changes of ECG parameters. In the cases where there was severe PA stenosis, the right ventricular myocardial blood flow decreased to a significantly greater degree (63% reduction from the control), especially in the subepicardial layer, than the flow in the left ventricle (37% reduction from the control). ST potential, STT and QRST Area Map increased in the right ventricle but decreased in the left ventricle. Activation Recovery Time of the right ventricle decreased due to the severe ischemia of the right ventricle. The value of QRS Area Map of the left ventricle decreased significantly in parallel with the decrease in cardiac output.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1990

[A case of successful surgery in ruptured aneurysm of the aortic arch under profound hypothermic selective cerebral perfusion].

We experienced a case of surgery for ruptured aneurysm of the aortic arch. A 51-year-old man who had been admitted complaining of back pain was diagnosed as ruptured aortic arch aneurysm by chest X-ray film and computed tomography. The aortic arch and descending aorta was replaced with a Dacron graft under profound hypothermic selective cerebral perfusion (PHSCP). The post operative course was well without neurological complications. Since 1982 we have utilized PHSCP in four cases of thoracic aortic aneurysms including this case. The average of PHSCP time was 143 minutes. Perfusion rate of carotid arteries was 400-800 ml/min during PHSCP. The average of lowest blood temperature was 15.5 degrees C. It was suggested that PHSCP was a safe and effective method for surgical treatment of thoracic aortic aneurysms.

Aged↗
PubMed1989

[Sequential changes in blood pressure and electrocardiographic findings over seventeen years in three different regions in Okayama Prefecture].

The sequential changes in blood pressure and electrocardiographic findings of populations living in three districts of Okayama prefecture, with differing environments and life styles, were analyzed during the seventeen year period from 1966 to 1982. Furthermore, factors influencing the causes of mortality among these populations were evaluated in 790 males and 1, 118 females (total 1,908), aged from 35 to 65 years at the beginning of the survey (1966). During the survey period 94 subjects moved out of the district and 210 subjects died, so that in 1982, 975 subjects (61.1%) could be examined. Cerebrovascular disease, cancer, and cardiac disease were the major causes of death in all these districts. A higher mortality from cerebrovascular disease was recorded in the mountainous district, with harsh weather and living conditions, in contrast to the other two lowland district. There was no significant difference in mortality due to cardiac disease among the three districts. In the mountainous district, the incidence of hypertension, especially systolic hypertension, was higher than in the other two districts throughout the whole of this survey. However, after 1980, the difference in the incidence of hypertension among the districts diminished sequentially. The incidence of hypertension was higher in the elderly than in younger subjects. However, even this age difference in incidence was seen to diminish sequentially, (especially for diastolic hypertension). The ratio of the number of people who were actually treated to the population who needed hypertensive therapy increased gradually, and in 1978 there was no significant difference concerning this ratio among the three districts. Finally over 80% of the subjects who qualified for antihypertensive therapy were treated continuously. The appearance ratio of abnormal ECG findings, (Minnesota Code, Code 3, Code 3 + 4, 5 and especially Code 4 and 5), increased in proportion to the increase of blood pressure in the hypertensive group. The sequential appearance ratios for the borderline hypertension and stage I hypertension groups showed an inverse relationship to that of the normal group. However the appearance ratios of stage II & III hypertension groups increased sequentially with no relation to that of the normal group. Subjects whose ECG showed ST-T changes without subjective symptoms apparently increased sequentially in all districts. The incidence ratios of angina pectoris and myocardial infarction showed no significant sequential changes. These results suggested that high blood pressure (both systolic and diastolic) was controlled fairly well in all age groups by therapy.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1989

Exercise body surface mapping in patients with left ventricular hypertrophy: comparison with stress thallium scans (SPECT).

To evaluate exercise-induced myocardial ischemia in patients with electrocardiographic evidence of left ventricular hypertrophy (LVH), including ST.T changes, body surface maps (QRST area maps) were recorded using 87 lead points before and after exercise. The patterns of the subtraction QRST area maps (S-maps) were compared with the findings of stress thallium (T1) scans in 31 patients with hypertrophic cardiomyopathy and in five with essential hypertension. All 18 patients whose S-maps revealed changes less than -40 muVS or only an increase over the anterior chest region showed no positive findings on the stress T1 scans. However, there were clearly positive findings on stress T1 scans in eight (89%) of nine patients whose S-maps revealed changes greater than -40 muVS over a wide precordial region or in six (67%) of nine patients whose S-maps revealed increases over the anterior chest region and had accompanying changes greater than -40 muVS somewhere over the precordial region. These results suggested that exercise QRST area maps could differentiate exercise-induced myocardial ischemia from LVH with ST.T changes.

Aged↗
PubMed1989

[Idiopathic chylothorax in an adult--a case report and a review of 14 cases in Japan].

A 30-year-old female with an idiopathic chylothorax who underwent successful surgical treatment was reported. The patient was referred to our hospital because of massive right pleural effusion found by chance on the X-ray. Thoracocentesis revealed chyle but the etiology was not known by examinations. Conservative treatments such as fasting, intravenous hyper-alimentation and a continuous drainage were performed for 10 weeks without remarkable improvement. A right thoracotomy revealed nothing abnormal except for the oozing of lymph from mediastinal pleura, which was sutured by 3-0 nylon. Postoperative course was uneventful and no recurrent pleural effusion has been recognized for 3 years since then. Adult chylothorax with unknown etiology like this is rare and only 13 cases have been reported in Japan. Such "idiopathic chylothorax" cases, including our case, were reviewed and discussed.

Adult↗
PubMed1989

[Progressive pulmonary hypertension following repair of pseudotruncus arteriosus with major aorto-pulmonary collateral arteries in a 20-year-old patient].

External conduit operation was performed for a 20 year-old woman with pseudotruncus arteriosus with major aorto-pulmonary collateral arteries (MAPCAs). Immediate postoperative pulmonary to systemic peak pressure ratio was 0.70, and decreased to 0.53 on the second postoperative day. She had episodes of pulmonary hypertensive crisis soon after the operation, and injection of tolazoline hydrochloride was effective on them. Seven months after surgery, cardiac catheterization revealed severe pulmonary hypertension (PH) above the systemic level. Pulmonary arterial pressure did not respond to any drug nor to inhalation of oxygen. The progression of PH may be due to the pulmonary obstructive disease, and its causes were thought to be the repetition of constriction of pulmonary arterioles, hypoxia due to the giant bullae, diminished pulmonary vascular beds due to ligation of arborized MAPCAs, and relatively high age at operation.

Adult↗
PubMed1989

[A case of primary lung cancer associated with diffuse panbronchiolitis].

Pulmonary resection was performed for primary lung cancer of a 72-year-old patient which was associated with diffuse panbrochiolitis that required home oxygen therapy. The preoperative total pulmonary vascular resistance at rest was 564 dyne.sec.cm-5/m2, but thoracotomy and reduction surgery were possible by strict respiratory and circulatory control. The troublesome postoperative pulmonary phthisis was dealt with through extended control by means of total parenteral nutrition and use of the Heimlich valve.

Aged↗
PubMed1988

Proteoliposomes with right-side-out oriented purple membrane/bacteriorhodopsin require cations inside for proton pumping.

Proteoliposomes were prepared by sonication of phospholipids and blue membranes (cation-free purple membranes carrying little activity of light-driven proton pumping) in an acidic medium of very low ionic strength. The majority of the bacteriorhodopsin population in these proteoliposomes was in the right-side-out (as in living cells) orientation as judged from the resultant polypeptides after papain digestion. By raising the pH of sonication, the population of right-side-out oriented bacteriorhodopsin decreased, and consequently that of the inversely oriented one increased. In KCl and NaCl up to certain concentrations or in choline chloride even at high concentrations, in the light, the proteoliposomes with right-side-out bacteriorhodopsin did not pump protons, whereas those with inversely oriented bacteriorhodopsin did. The former began to pump only after cations were likely incorporated/permeated into the proteoliposome and reached the carboxyl terminal (cytosol) side of bacteriorhodopsin/purple membrane.

Bacteriorhodopsins↗
PubMed1988

Effect of sodium intake on urinary renin excretion in rats.

The present study was carried out to investigate the effect of sodium intake on urinary renin excretion in rats. Renin activity was measured before and after acidification, by radioimmunoassay of angiotensin I generated by incubation with partially purified homologous renin substrate. The molecular weight of renin was determined by gel filtration. Low sodium intake for 4 weeks resulted in a 16-fold increase in urinary renin excretion and led to a 15-fold increase in plasma renin activity. A 2.5-fold increase in renal renin content was simultaneously observed. In contrast, high sodium intake for 4 weeks decreased urinary renin excretion, plasma renin activity and renal renin content to about 20%, 25% and 35% of the control level, respectively. No significant change in renin activity after acidification was observed in all the urine samples. The molecular weight of renin in the urine from rats on low or high sodium intake was 40,000, the value being identical with that from control rats. These results indicate that urinary renin excretion is well correlated with plasma renin activity, and that only active renin with a molecular weight of 40,000 is excreted in the urine of rats, even under conditions of altered sodium intake.

Animals↗
PubMed1987

The halobacterial H+-translocating ATP synthase relates to the eukaryotic anion-sensitive H+-ATPase.

The H+-translocating ATP synthase of Halobacterium halobium (Y. Mukohata and M. Yoshida (1987) J. Biochem. 102, 797-802) includes a catalytic moiety of 320 kDa which is isolated as an azide-insensitive ATPase (T. Nanba and Y. Mukohata (1987) J. Biochem. 102, 591-598). The polyclonal antibody against this archaebacterial ATPase cross-reacts with the anion-sensitive H+-ATPase of red beet, Beta vulgaris, tonoplast as well as with another archaebacterial ATPase from Sulfolobus acidocaldarius. The affinity is much higher than to F1-ATPase from spinach chloroplasts or to Ca2+-ATPase from sarcoplasmic reticulum of rabbit skeletal muscle.

Archaea↗