Biomedical subjects

Y Hiasa

Publications and source records attributed to Y Hiasa.

At least 127 records · Page 7Linked to original sources

PubMed1989

[Electrocardiograms during acute occlusion of the left circumflex artery as compared with that of the right coronary artery].

To assess the characteristic electrocardiographic (ECG) ST changes during acute occlusion of the left circumflex artery (LCX), we observed ECG changes during percutaneous transluminal coronary angioplasty (PTCA) of the LCX and compared the results with those obtained during right coronary angioplasty. Results were as follows: 1. In the 30 patients who had LCX angioplasty (group LCX), ST-segment elevation occurred most frequently in lead V6 (67.7%) and in lead III (46.7%), but rarely in leads and aVL. ST depression occurred most frequently in lead V3 (80.0%) and in lead V2 (73.3%), but rarely in other leads except for leads I and aVL (23.3%, 33.3%). 2. Four types of ST change in lead combinations were observed. These included: (1) ST elevation in the inferior leads (II, III and aVF), (2) ST elevation in the lateral leads (V5 and V6), (3) ST depression in the anterior leads (V2-V4) and (4) ST depression in the high lateral leads (I and aVL). In group LCX, nine cases (30.0%) manifested all four changes, and six cases (20.0%) revealed only ST depression in the anterior leads without ST changes in other leads. 3. ST depression in the anterior leads and ST elevation in the inferior and lateral leads were observed in nearly equal frequency in patients who received PTCA at the proximal site (Seg. 11) and at the distal site (Seg. 13) in the group LCX. However, ST depression in the high-lateral leads was more frequently observed in the distal than in the proximal cases (66.7% vs 33.3%).(ABSTRACT TRUNCATED AT 400 WORDS)

Acute Disease↗

PubMed1989

Chronic effects of nicorandil on exercise tolerance in patients with stable effort angina pectoris.

To examine the chronic effects of nicorandil, a new coronary vasodilator, on exercise tolerance, we gave this drug for ten days at 15 mg/day orally in three divided doses to 10 patients with stable effort angina. An increase in exercise capacity by more than 1 stage of modified Bruce's protocol was observed in 6 of 10 patients on the 5th and 10th day after the administration. The exercise duration was significantly prolonged from 294 +/- 86 sec (mean +/- SD) before the administration to 363 +/- 106 sec and 405 +/- 139 sec on the 5th and 10th day after the administration, respectively. With nicorandil administration, the time to 0.1 mV of ST-segment depression was also significantly delayed from 3.1 +/- 1.9 minutes to 4.5 +/- 2.6 minutes on the 10th day. On the other hand, systolic blood pressure, heart rate and pressure rate product did not demonstrate any significant change before and after the administration. These results indicate that oral nicorandil of 5 mg 3 times a day can chronically increase exercise tolerance without decreasing myocardial oxygen consumption in patients with stable effort angina.

Adult↗

PubMed1989

[Influence factors on coronary collateral development].

In order to evaluate the influence factors on coronary collateral development, we compared various factors between two groups. Group I consisted of the 69 patients performed coronary angiography within 6 hours after the onset of acute myocardial infarction (MI) and Group II consisted of the 56 patients without MI because having good collaterals nevertheless whose one coronary artery was totally occluded or had a 99% stenosis. Group I (24/69, 35%) had a higher frequency of Diabetes mellitus than Group II (11/56, 20%) and had a lower frequency (30/69, 43%) of multivessel disease than Group II (39/56, 70%). The patients having angina duration more than 6 months were more in Group II (37/56, 60%) than in Group I (18/69, 26%). No significant differences existed between these two groups in age, smoke, hyperlipidemia and hypertension. In conclusions, the patients with good collateral have high frequency of multivessel disease and long history of angina pectoris. Diabetes mellitus is a inhibit factor on coronary collateral development.

Adult↗

PubMed1989

[The effect of open heart surgery and an operation on thoracic aneurysm on organs and the prevention of an organ system failure: comparison between the group using ulinastatin and not using group].

We studied the effect of the open heart surgery and the thoracic aortic aneurysm surgery on renal, liver and respiratory function and the coagulofibrinolytic system. We also investigated as to whether ulinastatin was effective or not with regard to preventing an organ system failure. The renal function, liver function and the coagulofibrinolytic system were preserved, although there was a greater number of severe cases in the group which used ulinastatin (US group) than in the group that did not use ulinastatin (non-US group). In the US group, PaO2 did not decrease postoperatively. However, in the non-US group, PaO2 decreased significantly after the operation. The variables in relation to using ulinastatin, examined by a stepwise method, included kind of disease, emergency operation, PaO2, BUN and serum plasminogen. The multiple coefficient for these five variables was 0.623 (p less than 0.01) and the contribution was 38.8%. It was suggested that ulinastatin could prevent an organ system failure, especially respiratory failure, after open heart surgery and the thoracic aortic aneurysm surgery.

Aged↗

PubMed1989

[The results of an investigation of the various factors influencing the late patency ratio of coronary bypass grafting].

The purpose of this communication was to find out the factors influencing the late patency ratio of coronary artery bypass grafts of 42 patients in our institution. The following results were obtained: 1. The size of the measured diameters of coronary arteries and the graft flow rates were correlated well to the late patency ratio (p less than 0.05). 2. The regular physical exercise trainings were significantly important to keep patent grafts (p less than 0.01). 3. In blood serum studies, serum uric acid levels were significantly lower (p less than 0.05), the average mean HDL cholesterol levels were much higher (p less than 0.001) and the ratio of total cholesterol to HDL cholesterol were significantly lower in the group with late patent grafts than with grafts occluded. Therefore, we found out the variables affecting graft patency ratio which were examined by a stepwise method were the diameter of the coronary artery, regular physical exercise training, the average of lower serum uric acid levels and higher HDL cholesterol levels. The multiple coefficient for these four variables was 0.562 (p less than 0.001) and the contribution was 31.6%. According to the base of this studies, we have concluded that postoperative regular physical exercise, low fat and restricted calorie intake were very important to keep the late patent grafts in long-term follow up period after coronary bypass surgery.

Adult↗

PubMed1989

[Correlation of arteriosclerosis obliterans of the lower extremity with coronary artery disease].

To ascertain the correlation between arteriosclerosis obliterans (ASO) of the lower extremities and coronary artery disease (CAD), 69 patients with lower extremity ASO were observed. Based on clinical symptoms, the patients were categorized as group A: 52 with intermittent claudication and group B: 17 with angina pectoris. All patients underwent angiography of both lower extremities and the heart. Results were as follows: 1. In group A, 33 patients had significant coronary stenosis with single (16 cases), double (12 cases) and triple (five cases) vessel disease. Sixteen patients had histories of myocardial infarction and two had vasospastic angina. In group B, 15 patients had significant coronary stenosis with single (five cases), double (six cases) and triple (four cases) vessel disease including two cases involving the left main trunk. Six patients had histories of myocardial infarction and two had vasospastic angina. 2. Electrocardiography revealed that 37 patients in group A and 14 patients in group B had abnormal ECGs as abnormal Q waves and ST-T changes. However, 10 patients in group A and three patients in group B had significant coronary stenosis despite their normal ECGs. 3. According to the sites of stenotic lesions, all 69 patients with ASO were classified in four types; as diffuse, pelvic, ilio-femoral and femoral. The incidence of CAD did not differ among these four types. 4. In group A, 38 patients experienced revascularization of ASO; 36 cases by bypass grafting, and two by percutaneous transluminal angioplasty (PTA). Ten patients received cardiac revascularization including three cases with coronary artery bypass graft (CABG) and seven cases with percutaneous transluminal coronary angioplasty (PTCA). In group B, 13 patients received revascularization of ASO with bypass grafting. Eleven patients had coronary revascularization including seven cases with CABG and four cases with PTCA. 5. Fourteen of the 69 patients received revascularization for both ASO and CAD. In conclusion, there is a highly significant coincidence of CAD in patients with ASO, and CAD is often silent. These data indicate that routine coronary angiography is necessary for detecting and preventing CAD in all patients with ASO. Coronary artery revascularization, especially PTCA, can be indicated prior to lower extremity revascularization.

Aged↗

PubMed1988

Effects of trisodium nitrilotriacetate monohydrate, nitrilotriacetic acid and ammonium chloride on urinary bladder carcinogenesis in rats pretreated with N-bis(2-hydroxypropyl) nitrosamine.

The effects of trisodium nitrilotriacetate monohydrate (Na3 NTA.H2O) nitrilotriacetic acid (H3NTA) and ammonium chloride (NH4Cl) on two-stage urinary bladder carcinogenesis were examined. Carcinogenesis was initiated by administration of 0.2% N-bis (2-hydroxypropyl)-nitrosamine (DHPN) to male Wistar rats in the drinking water for 2 weeks, and then the animals were treated with basal diet containing Na3NTA.H2O, Na3NTA.H2O plus NH4Cl, H3NTA, H3NTA plus NH4Cl, or without these chemicals for 28 weeks. Na3NTA.H2O increased significantly the resultant incidence of neoplastic and preneoplastic lesions of the urinary bladder. Moreover, treatment with Na3NTA.H2O, without the initiation, itself induced papillary or nodular (PN)-hyperplasia. H3NTA produced only a slight increase in the incidence of preneoplastic urinary bladder lesions (PN-hyperplasia) in rats initiated by DHPN, and this was not statistically significant. Elevation of both pH and sodium ion concentration in the urine were correlated with promotion of tumor development. These data showed that Na3NTA.H2O was more effective than H3NTA with regard to promoting potential, and that changes in both urinary pH and concentration of sodium played important roles in enhancement of urinary bladder tumorigenesis by these chemicals.

Acetates↗

PubMed1988

Promotive effect of 4,4'-methylenebis(N,N-dimethyl)benzenamine on N-bis(2-hydroxypropyl)nitrosamine-induced thyroid tumors in Wistar rats.

The promotive effect of 4,4'-methylenebis(N,N-dimethyl)benzenamine (MDBA) on 2-stage thyroid tumorigenesis induced by N-bis(2-hydroxypropyl)nitrosamine (DHPN) in Wistar male rats was investigated. Animals were given i.p. injections of DHPN, and then a basal diet containing 0.0375% MDBA for 19 weeks. In addition, localization of the thyroid-stimulating hormone (TSH) in the pituitary gland was investigated. Levels of TSH and T4 in serum were measured by radioimmunoassay (RIA). The addition of MDBA to the diet significantly increased the incidence and numbers of preneoplastic lesion (focal hyperplasia), adenoma and carcinoma of the thyroid. TSH was usually localized in the thyroidectomy-cell in the anterior lobe of the pituitary gland, and the number of TSH-positive cells increased in the group treated with MDBA. Mean circulating levels of TSH were elevated in all MDBA-treated groups, and mean T4 levels in groups treated with MDBA were significantly lower different (P less than 0.05) than those in control groups.

Aniline Compounds↗

PubMed1988

ST-segment depression in inferior ECG leads during percutaneous transluminal coronary angioplasty for left anterior descending artery.

The mechanism of inferior ST depression during percutaneous transluminal coronary angioplasty (PTCA) for the left anterior descending artery (LAD) was studied in 108 patients with isolated LAD lesion. In 49 patients (Group I) ST depression in inferior leads was observed, and 59 patients (Group II) showed no inferior ST depression. In the lateral lead (I or a VL), the incidence (43 cases; 88% vs. 5 cases; 9%) and degree (1.5 +/- 0.8 mm vs. 0.2 +/- 0.4) of ST elevation were significantly greater in Group I than in Group II. There was a significant inverse correlation (r = -0.57, p less than 0.01) between ST depression in the inferior lead and ST elevation in the lateral lead, but no correlation was found between anterior leads (V2-4) and the inferior leads. Elevation of diastolic pressure of the pulmonary artery (8.7 +/- 4.8 vs. 5.7 +/- 2.8 mmHg) and lowering of systolic pressure of the femoral artery (-25.7 +/- 24.3 vs. -11.8 +/- 8.3 mmHg) were significantly greater in Group I. These findings suggest that ST depression in the inferior leads during LAD angioplasty was due to a purely electrical phenomenon and not to the concomitant ischemia of the inferior wall. However, this change was more frequently seen in patients with larger myocardial ischemia and, presumably, was more often related to ST elevation in the lateral lead, which is reciprocal in position.

Angioplasty, Balloon↗

PubMed1988

Enhancement of DHPN induced hepatocellular, cholangiocellular and pancreatic carcinogenesis by Opisthorchis viverrini infestation in Syrian golden hamsters.

Infection with 100 Opisthorchis viverrini (OP) metacercariae prior to two injections of dihydroxy-di-n-propyl nitrosamine (DHPN) (1000 mg/kg body weight) brought about significant enhancement of resultant preneoplastic lesion development in Syrian hamster liver and pancreas tissue. Thus combined treatment with carcinogen and parasite was associated with pancreatic atypical (dysplastic) foci, hepatocellular nodules, cholangiofibrosis and cholangiocarcinomas. No such lesions were observed in carcinogen alone, parasite alone or untreated control groups. In addition, parasite induced hyperplastic gall bladder epithelium was found to include areas of putative preneoplastic cells only in the DHPN-OP combined group. The results strongly suggest that pancreatitis and biliary cirrhosis associated with liver fluke infestation are responsible for the observed enhancement of carcinogenesis, and that the resultant increased proliferation plays a major role in tumorigenesis.

Adenoma, Bile Duct↗

PubMed1988

Early lesions induced by DHPN in Syrian golden hamsters: influence of concomitant Opisthorchis infestation, dehydroepiandrosterone or butylated hydroxyanisole administration.

The effects of concomitant Opisthorchis infestation and dehydroepiandrosterone (DHEA) or butylated hydroxyanisole (BHA) administration on dihydroxy-di-n-propylnitrosamine (DHPN) induction of preneoplastic lesions were investigated in Syrian golden hamsters. Whereas parasite infection was primarily associated with first-order ductular proliferation in the liver and a secondary appearance of cholangiofibrotic lesions, DHEA treatment brought about increased carcinogen toxicity and enhanced generation of glutathione-S-transferase P (GST-P)-positive hepatocellular foci, liver cysts and focal proliferative changes in the pancreas. BHA also exerted an enhancing influence on pancreatic but not liver carcinogenesis. The results suggest that whereas alteration of DHPN metabolism by DHEA and BHA treatment effected changes at the initiation level, opisthorchiasis principally exerted an enhancing influence subsequent to carcinogen withdrawal.

Animals↗

PubMed1988

Generation of high yields of Syrian hamster cholangiocellular carcinomas and hepatocellular nodules by combined nitrite and aminopyrine administration and Opisthorchis viverrini infection.

Combined administration of 0.1% nitrite and 0.1% aminopyrine in the drinking water for eight to ten weeks resulted in subsequent development of both hepatocellular nodules and cholangiofibrotic lesions/cholangiocellular carcinomas in Syrian golden hamsters. Additional prior dosing with Opisthorchis viverrini metacercariae (100/animal) induced inflammatory and proliferative changes in the livers of infected hamsters and was associated with a significant increase in yields of hepatocellular and cholangiocellular preneoplastic and neoplastic lesions. Thus, environmental factors thought to be casually related to the high levels of human liver cancer observed in the Northeastern provinces of Thailand were sufficient to bring about development of equivalent tumors in experimental animals. The results indicate that parasite associated liver injury and non-specific compensatory regeneration may play an important role in generation of both hepatocellular and cholangiocellular carcinomas in man.

Adenoma, Bile Duct↗

PubMed1988

The promoting effects of food dyes, erythrosine (Red 3) and rose bengal B (Red 105), on thyroid tumors in partially thyroidectomized N-bis(2-hydroxypropyl)-nitrosamine-treated rats.

The effects of erythrosine (Red 3), rose bengal B (Red 105) and thyroidectomy on the development of thyroid tumor were examined in male Wistar rats treated with N-bis(2-hydroxypropyl)nitrosamine (DHPN). Red 3 and Red 105 were used at 4% in the basal diet and were administered for 19 weeks from week 2 to 20. Thyroidectomy was performed by resection of the left lobe at week 4. Single injection of DHPN was performed intraperitoneally at 280 mg per 100 g body weight at the beginning of the experiment. Red 3 and Red 105 significantly promoted the development of thyroid tumors in thyroidectomized rats given DHPN, but had no significant effect in non-thyroidectomized rats. The incidence of thyroid tumors was 91% in rats with partial thyroidectomy, Red 3 and DHPN, 100% in rats with partial thyroidectomy, Red 105 and DHPN, and 64% in rats with partial thyroidectomy and DHPN. Serum TSH was 5.5 +/- 3.1 ng/ml in rats with partial thyroidectomy, Red 3 and DHPN, 2.1 +/- 2.2 ng/ml in rats with partial thyroidectomy, Red 105 and DHPN, and 1.5 +/- 0.5 ng/ml in rats with partial thyroidectomy and DHPN.

Animals↗

PubMed1988

A morphological study of the left bundle branch in the normal human heart.

To clarify the distribution pattern of the left bundle branch (LBB) in the human heart, the AV conduction system was studied in 13 autopsied hearts obtained from subjects aged 50 to 80 years. Vertical serial sections (7 micron) of the bundle of His and LBB were prepared and every 20th section was stained alternately with hematoxylin-eosin (HE) or by the elastica van Gieson (EVG) method and examined by light microscopy. Reconstruction was performed using a two-dimensional system in order to histologically differentiate the bundle cells from Purkinje cells. The LBB bifurcated into the anterior and posterior radiations and the cells in the septal portion were almost all Purkinje cells except in two cases showing a septal branch between the two radiations. The LBB usually branched widely from the bundle of His. An extremely anterior fascicle of the LBB was found in all cases. The distribution of the LBB at the top of the ventricular septum was divided into network and continuous types. Purkinje cells were present on both the atrial and apical sides of the two main radiations. It was suggested that these findings resulted from the fact that we morphologically differentiated the bundle cells from Purkinje cells by light microscopy.

Aged↗

PubMed1987

The nature of ventricular arrhythmias during ergonovine-induced vasospastic angina pectoris.

The peak incidence of ventricular fibrillation in acute myocardial infarction usually occurs during the first hours after the onset. Electrophysiological changes immediately after the onset have been studied in animal models, but are still incompletely understood in humans. For clarification of the characteristic features of ventricular arrhythmias during acute myocardial ischemia, ventricular arrhythmias were studied in 81 patients with vasospastic angina pectoris induced by ergonovine. Ventricular arrhythmias occurred in 45 of these patients, including ventricular tachycardia in 15, and ventricular fibrillation requiring repeated DC defibrillation in two patients. Most ventricular extrasystoles occurred before the ST segment reached maximum elevation, while reperfusion arrhythmias were less common. In many patients the coupling intervals varied, and the configuration was multiform. It is concluded that ventricular arrhythmias occurring during ergonovine-induced coronary spasm show different characteristics from those occurring during chronic ischemia. As the arrhythmias in this study seem, in some ways, to resemble arrhythmias occurring at the onset of myocardial infarction, the results might provide useful information on ventricular arrhythmias in myocardial ischemia in humans.

Angina Pectoris, Variant↗

PubMed1987

Inverted U wave in ergonovine-induced vasospastic angina.

The relationship between inverted U wave in leads V5 and II and the location of myocardial ischemia was studied in 52 positive patients and in 50 negative patients with ergonovine provocation test. Development of a biphasic or negative U wave, or increased negativity of U wave (inverted U wave) was observed in 15 of 17 patients with spasm in only the right coronary artery (RCA), in 6 of 8 with spasm in only the left anterior descending artery (LAD), in 2 of 8 with spasm in only the left circumflex artery (LCx), and in 23 of 24 with spasm in two or more vessels. Of 52 positive patients in the ergonovine provocation test, 46 (88.5%) had inverted U wave. Of these, 17 (32.7%) had inverted U wave without discernible ST deviation. Of 50 negative patients, 2 had inverted U wave. Inverted U wave in lead V5 was frequently seen in patients with spasm of LAD, but this finding was not uncommon in spasm of RCA or LCx. On the other hand, inverted U wave in lead II was frequently seen in spasm of RCA and LCx, but not in spasm of LAD. These findings suggest that inverted U wave in lead V5 is not specific for myocardial ischemia due to spasm of LAD and that inverted U wave in lead II is specific for spasm of RCA and LCx.

Adult↗

PubMed1987

Vector U loop in patients with right ventricular overloading.

The U loop of the vectorcardiogram (VCG) was examined qualitatively and quantitatively in 126 normal subjects, 15 subjects with complete right bundle branch block (CRBBB group) and 58 patients with right ventricular overloading (RVO group), using a direct-writing vectorcardiograph with memory function. In normal subjects the U loop was directed similarly to the T loop, i.e., to the left, anteriorly and inferiorly. In the CRBBB group, maximum U vector was smaller, but its direction was not significantly different from that in normal subjects. In the RVO group, the U loop tended to be displaced posteriorly and to the left and was significantly greater in magnitude than that in normal subjects in the horizontal (P less than 0.01) and frontal (P less than 0.001) planes. In the RVO group, a good correlation was found between the direction of maximum U vector and right ventricular systolic pressure. In some cases of the RVO group, the U loop was the only abnormality suggesting right ventricular overloading. These findings suggest that abnormality of the U loop is a good indicator in a diagnosis of right ventricular overloading.

Adolescent↗

PubMed1987

Experimental induction of renal tumors.

Renal tumors have been reported to be induced by natural products, chemical carcinogens, viruses, or radiation. Species or strain specificity and sex also appear to play significant roles in their development. In man, it is also likely that the heredity existence of other diseases, smoking, food habits, and irradiation may be etiological factors. It also appears that hormonal, chemical, and other environmental factors can play a role. Nephrotoxin modifies two-stage chemical carcinogenesis in rat kidney. Some nephrotoxins without carcinogenicity promote the development of renal tumors in rats pretreated with subcarcinogenic doses of chemical carcinogens. The importance of nephrotoxin in development of renal adenocarcinomas needs elucidation. Preneoplastic lesions in the kidneys can be recognized by histochemical methods with specific antibodies. It is hoped that further research will be continued, so that data obtained from experimental work will provide a better understanding of the etiology and induction of renal cancer in man.

Animals↗