Biomedical subjects

Y Hiasa

Publications and source records attributed to Y Hiasa.

At least 109 records · Page 6Linked to original sources

PubMed1991

[Tolerance to a sustained release form of isosorbide dinitrate: comparison between 20 mg four times and 40 mg twice-daily administrations].

Attenuation of antianginal effects of oral isosorbide dinitrate in a sustained release from (ISDN-SR) were studied using the treadmill exercise test in eleven patients with stable exertional angina and a positive exercise test. We compared the four-time-daily administration of 20 mg with a twice-daily regimen of 40 mg for 10 days using the double-blind, crossover method. On the 1st day of the administration, with both regimens, the treadmill walking time, the time to 1mm and 2mm ST depression, and several hemodynamic parameters increased significantly. These improvements were reduced gradually on day 5 and day 10 after the administration. In the comparison between the four-time-daily and two-time-daily regimens, the former application showed clearer antianginal and hemodynamic effects than the latter regimen, but these effects were attenuated more markedly in the four-time daily administration. With both dosage regimens, the plasma ISDN concentrations increased gradually. With the long-term four-time-daily regimen, the time-to-time changes of the ISDN concentration were smaller each day. These data suggest that tolerance to oral ISDN-SR exists even if it is applied only two time daily, but its degree is less than when a four-time-daily dose in administered.

Administration, Oral↗

PubMed1991

[Wrapping operation for Stanford type A acute dissecting aneurysms].

Four cases of Stanford type A acute aortic dissection were treated by wrapping operation. After careful dissection between the dilated ascending aorta and right pulmonary artery, 8 mm woven Dacron vascular prosthesis was passed around the aorta and tightened. Further enforcement wrapping was carried out using several prostheses from aortic root to the innominate artery. We call this technique "wrapping operation". Emergent operations were performed on all patients because of cardiac tamponade, 6.8-33 hours after the onset of dissection. Three patients are doing well 17-39 months after the operation, but only 1 patient died early postoperative period because of DIC and multiple organ failure. And 2 patients was showed closure of entry of the ascending aorta by the postoperative aortography. We think that the wrapping operation is a useful technique for the patients of ruptured Stanford type A acute dissecting aneurysms.

Aortic Dissection↗

PubMed1991

[A case of left atrial giant thrombus which appeared in a short period].

We reported a case with left atrial giant thrombus (LAGT) which appeared over a period of six months. The patient was a 65-year-old woman who came to our hospital complaining of syncopal attack. Her electrocardiogram showed atrial fibrillation with very slow ventricular response, and there was cardiac arrest for 1500 ms, mitral stenosis and regurgitation, aortic and tricuspid regurgitations were recognized in the echocardiogram. By coronary angiography, 90% stenosis in the left circumflex artery (LCX) was found, and using transseptal left atrium heart catheterization, pressure gradient from the left atrium to the left ventricle was also measured. We diagnosed that her valvular diseases were mild. To protect her from unconsciousness and heart failure, a permanent pacemaker was implanted and PTCA for LCX lesion was performed. After six months, we found LAGT by echocardiography. It is very rare that LAGT is formed in a short period. We suggested that the changes of hemodynamics caused by transseptal left atrial catheterization or the permanent pacemaker implantation effected the formation of the LAGT.

Aged↗

PubMed1991

[The step to improve the operative outcome in patients with severe valvular heart disease].

In an effort to improve the operative outcome in severe valvular heart disease, we investigated the effects of low-dose infusion of dopamine and dobutamine up to the day of operation. New York Heart Association Functional Class was improved significantly before operation, as compared with at the time of admission. It was possible to perform operation on individual patients when their physical condition seemed to be at their best. In patients with fear of postoperative renal failure, hemodialysis was combined during cardiac surgery to prevent failing to renal dysfunction after operation. As the result of these procedures, we were able to obtain satisfactory result. In patients with severe valvular heart disease, the preoperative combined infusion of dopamine and dobutamine, and hemodialysis during cardiac surgery to prevent postoperative renal dysfunction seemed to improve the operative outcome.

Adult↗

PubMed1990

Differentiation between left circumflex and right coronary artery occlusions: studies on ST-segment deviation during percutaneous transluminal coronary angioplasty.

To distinguish between acute occlusion of the right coronary artery (RCA) and the left circumflex artery (LCx) by electrocardiography, we studied ST-segment deviation during balloon inflation in percutaneous transluminal angioplasty. The composite electrocardiographic criteria based on ST-segment deviations increased the diagnostic specificity: that is, the finding of inferior infarction (ST-segment elevation in leads II, III, aVF) without lateral infarction (ST-segment elevation in leads V5,6) was highly suggestive of RCA occlusion (sensitivity and specificity: 35 of 43 cases, 81.4%; and 33 of 36 cases, 91.7%), whereas ST-segment elevation in leads V5,6 (LCx: 23 of 36 cases; 63.9%, RCA: 5 of 43 cases; 11.6%) or isolated ST-segment depression in leads V2-4 (LCx: 9 of 36 cases; 25.0%, RCA: none of 43 cases) was highly suggestive of LCx occlusion. These results indicate that the composite electrocardiographic criteria were useful in predicting the artery involved in acute myocardial infarction, although any single criterion was not sensitive or specific enough to differentiate right from left circumflex coronary artery occlusion.

Angioplasty, Balloon, Coronary↗

PubMed1990

Hemangioblastomas of the central nervous system--immunohistochemical and ultrastructural study.

Immunohistochemical studies using immunoperoxidase staining for glial fibrillary acidic protein (GFAP), S-100 protein, and factor VIII-related antigen (VIII-RAg) were performed on 10 hemangioblastomas of the central nervous system to determine the origin of stromal cells. No cytoplasmic immunoreactivity for anti-GFAP, anti-S-100 protein, or anti-VIII-RAg was detected in most stromal cells. A small number of GFAP-positive cells were found only in the periphery of the tumor; they were thought to be trapped astrocytes or stromal cells taking up GFAP. Most stromal cells had abundant, clear cytoplasm with some microfilaments and lipid vacuoles. Cylindrical cytoplasmic processes and intermediate junctions were observed in some stromal cells, but most cells did not possess any junctional device. No stromal cell possessed any feature clearly suggesting endothelial cells or pericytes. Our immunohistochemical and ultrastructural investigations did not support the theories of stromal cell origin from astrocytes or endothelial cells. We concluded that stromal cells can be regarded as an aberrant cell type of angiogenic mesenchymal derivation.

Adolescent↗

PubMed1990

[Three dimensional culture of human salivary gland using irradiated collagen gel embedding technique].

Embedding culture was performed on normal salivary gland cells from five subjects using 0.2% irradiated collagen gel. Collagen was collected from rat tail tendon and gelatinized at the final concentration of 0.2%. D-MEM added BSA (5mg/ml), insulin (10 micrograms/ml) and EGF (5 micrograms/ml) was used as a serum-free medium. Within the collagen gel, the cells were found to grow in a branch-like pattern, and then to form a lot of radial duct-like structures containing alcian blue positive secretions. Immunohistochemical observation of myoepithelial cells with monoclonal antibody from human mammalian cancer suggested that these cells play an important role in the process of glandular ducts formation. Salivary gland cells being able to grow in collagen gel in a very similar fashion to in-vivo condition, the present collagen gel embedding culture is useful for morphological or functional studies on salivary gland cells.

Animals↗

PubMed1990

Production of monoclonal antibody against human prostatic adenocarcinoma and its immunohistochemical properties.

We have generated a monoclonal antibody against prostatic adenocarcinoma, PC-Ab (IgM) was derived from a fusion using the fresh prostatic tissue of adenocarcinoma as the immunogen. Initial screening was performed by enzyme-linked immunosorbent assay (ELISA) on the soluble fraction of the immunogen. The specific analysis was performed by the avidin-biotin-complex immunoperoxidase method on paraffin-embedded sections of normal, benign and malignant neoplastic tissues from the prostate and various organs. PC-Ab reacted with well differentiated adenocarcinoma (83.3%), moderately differentiated adenocarcinoma (92.2%), and poorly differentiated adenocarcinoma (90.2%), respectively. According to classification by stage, the reaction rates with stage T0, T1, T2, T3 and T4 were 77.3%, 80.0%, 95.2%, 91.3% and 92.9%, respectively but no significant differences in the stages were seen among these groups. PC-Ab reacted with the epithelium of the normal prostate and benign prostatic adenoma, and human fetal tissues. Molecular weight and isoelectric point of the antigen recognized by this PC-Ab was estimated to be 57,000 daltons and 7.0, respectively. These results indicate that PC-Ab reacts with the antigen associated with human prostatic adenocarcinoma.

Adenocarcinoma↗

PubMed1990

[Primary coronary artery dissection: its incidence and genesis studied by clinical and coronary angiographic findings].

The incidence and genesis of primary coronary artery dissection which occurred spontaneously in the coronary artery system were elucidated in this study. We examined clinical and coronary angiographic features of the patients who presented this dissection. Primary coronary artery dissection was observed in 23 (0.43%) of 5,400 consecutive patients with ischemic heart disease undergoing coronary angiography. The basic diseases were myocardial infarction in 17 cases and angina pectoris in 6. Sixteen patients (70%) had smoking habits, which might be related to this disease. The dissection of the right coronary artery in 12 cases, of the left anterior descending artery in 10, and of the left circumflex artery in only one was found. All lesions occurred in the proximal positions of the coronary branches. Seven (30%) of all cases had fixed coronary stenosis in other coronary branches. The other cases had "one-vessel" disease. Seventeen patients were treated medically, 5 had PTCA therapy and one had CABG operation. All the patients, except one who died of cancer are surviving in a 3.8-year follow-up. Patients can be divided etiologically into three groups. The first was comprised of those in the post- or peri-partum period. The second was those associated with coronary vasospasm, and the third was those with atherosclerotic coronary artery disease. The third group was the most frequent.

Adult↗

PubMed1990

[Immunohistochemical study of placental form of glutathione S-transferase in human brain tumors and fetal brains].

The activity of glutathione S-transferase placental form (GST-pi) was examined in 100 cases including various histologic subtypes and grading of human brain tumors and 10 cases of fetal brains by immunohistochemical studies. The 69% of cases with brain tumors were shown to be positive for GST-pi. This activity in neuroepithelial tumors tended to increase in order to tumor grading, however, medulloblastoma and primitive neuroectodermal tumor (PNET) were not immunoreactive with GST-pi. Embryonal carcinoma showed strong staining, although fetal brains were negative. The metastatic brain tumors showed the same reactivity with GST-pi as those of original carcinomas. Moreover, the difference of GST-pi activity was investigated on some brain tumors treated with or without antitumor drug, such as 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU). The 85% of recurrent cases showed strong staining with GST-pi, and GST-pi activity seemed to be increased after treated with ACNU. The present study indicated that GST-pi might be a useful marker for human brain tumor, as the same conclusion was applicable to other neoplastic lesions examined previously. It is suggested that the increased GST-pi activity with malignancy of tumor may indicate the tendency to recurrence. The presence of such activity in tumor cells may also imply their acquired multidrug resistance. Our findings suggest that the evaluation of GST-pi activity in brain tumors will offer a predictive value for eventual behavior of the tumor.

Biomarkers, Tumor↗

PubMed1990

[Coronary artery disease in patients with abdominal aortic aneurysm].

Selective coronary angiography to determine the prevalence of coronary artery disease (CAD) has been performed in patients with abdominal aortic aneurysm (AAA). Thirty patients in this series consisted of 26 men and 4 women with an age range of 48-87 years (mean +/- SD: 67.5 +/- 8.2 years). As the atherosclerotic risk factors, cigarette smoking was present in 19 patients (63.3%), hypertension was in 18 (60%), hypercholesteremia was in 10 (33.3%), and diabetes mellitus was in 2 (6.7%). Cerebral vascular disease was present in 11 patients (36.7%). Regarding CAD, angina pectoris or old myocardial infarction was found in 9 patients (30%), and abnormal electrocardiography (ECG) was in 16 patients (53.3%). Coronary angiography prior to operation of AAA was performed to 22 patients (73.3%), and 15 patients (68.2%) among them had significant coronary artery stenosis, and 9 patients underwent myocardial revascularization (4 CABG, 5 PTCA). CAD was frequently complicated both in patients without symptoms or ECG abnormalities and in less than 65-year patients. In order to prevent fatal myocardial infarction, we recommend routine coronary angiography to patients with AAA. And if necessary, myocardial revascularization must be indicated prior to aneurysmectomy.

Aged↗

PubMed1990

[A case of myonephropathic-metabolic syndrome after urgent aortic valve re-replacement due to prosthetic valve thrombosis].

Acute cardiac failure due to prosthetic valve thrombosis is a rare, but lethal complication after cardiac valve replacement. A 40-year-old female admitted to our hospital, because of cardiac failure after aortic valve replacement with a #21 Björk-Shiley valve in 1975. After admission, echocardiography showed thrombotic obstruction of the prosthetic valve, and we underwent urgent aortic valve re-replacement. Postoperative period, she was complicated with myonephropathic-metabolic syndrome (MNMS). But, we performed intermittent veno-venous hemofiltration (IVVH) in early period, and successfully could save her life and her lower limb.

Adult↗

PubMed1989

Greater inhibitory effects for testosterone than castration in rat thyroid tumorigenesis initiated by N-bis(2-hydroxypropyl)nitrosamine.

The effects of testosterone and castration on thyroid tumorigenesis subsequent to initiation by N-bis(2-hydroxypropyl)nitrosamine (DHPN) were investigated in male Wistar rats. Following 2 weekly i.p. injections of DHPN at the dose of 210 mg/100 g body weight, testosterone was administered in the diet at concentrations of 0.15% or 0.03% for 28 weeks. Castration was performed on a separate group of animals 1 week after the final injection of DHPN. The incidence of thyroid adenomas and carcinomas were 69% (9/13) and 15% (2/13), respectively, in rats treated with DHPN alone, 0% (0/15) and 6% (1/15) in rats treated with DHPN and 0.15% testosterone, 13% (2/15) and 13% (2/15) in rats treated with DHPN and 0.03% testosterone and 33% (5/15) and 33% (5/15) in the castrated animals initiated by DHPN. The reduction in adenoma development associated with testosterone treatment was significant at both concentrations. In contrast, only a tendency for decrease of thyroid tumor incidence was observed in rats castrated.

Animals↗

PubMed1989

Effect of ethanol on hepatocarcinogenesis initiated in rats with 3'-methyl-4-dimethylaminoazobenzene in the absence of liver injuries.

In this study special care was taken to discriminate between the direct effect of ethanol on hepatocarcinogenesis and secondary effects such as choline deficiency or fatty liver. Rats were divided into 2 groups, D and N. Group D was initiated using 3'-Me-DAB, while the control group N was not initiated. Groups N and D were divided into 4 sub-groups. Each subgroup was given, in the drinking water, one of the following ethanol solutions: 0, 5, 10 or 15% for 45 weeks. Liver tumors were induced only in D groups. Evidence obtained indicates that: (a) in the N group, ethanol did not cause any apparent disorders in histology and lipid metabolism, and (b) in the D group no significant differences were observed in the incidence of HCCs and other liver lesions. Ethanol thus does not appear to enhance hepatocarcinogenesis, at least in the absence of liver injury.

Animals↗

PubMed1989

Acute myocardial infarction due to coronary spasm associated with L-thyroxine therapy.

A 63-year-old man with hypothyroidism is described. He had been receiving L-thyroxine therapy following mitral valve surgery. About three weeks into the therapy regimen, he complained of severe retrosternal chest oppression. Electrocardiographic findings and laboratory data indicated a diagnosis of acute myocardial infarction due to the L-thyroxine therapy. Emergency selective coronary angiography was performed. Comparing his coronary angiograms with those obtained before surgery indicated a severely spastic left coronary artery. We believe this is the first report of myocardial infarction due to coronary spasm, demonstrated by angiography associated with L-thyroxine therapy.

Angiography↗

PubMed1989

Promoting effect of 2,4-diaminoanisole sulfate on rat thyroid carcinogenesis.

Two experiments were conducted to examine the effects of 2,4-diaminoanisole sulfate (2,4-DAAS) on thyroid function and carcinogenesis in male Wistar rats. In experiment 1, feeding with 2,4-DAAS resulted in significantly elevated levels of thyroid stimulating hormone (TSH), reduced thyroxine (T4) and triiodothyronine (T3) in the serum, although the latter had almost recovered to normal levels by week 6. However, skin application did not affect serum levels. In experiment 2, administration of 0.5% 2,4-DAAS in the diet for 19 weeks, a week after a single 210 mg/100 g body weight i.p. injection of N-bis(2-hydroxypropyl)nitrosamine (DHPN), significantly increased the incidence and numbers of preneoplastic lesions (focal hyperplasia), adenomas and carcinomas developing in the thyroid gland. Histologically, brown pigment was usually observed within follicular epithelial cells in non-tumorous regions, but not in the tumors themselves.

Adenoma↗

PubMed1989

Magnetocardiographic studies of ventricular repolarization in old inferior myocardial infarction.

Isomagnetic maps of 50 normal subjects (control group) and 23 patients with old inferior myocardial infarction (IMI group) were recorded in order to analyse T wave abnormalities in inferior myocardial infarction. The T wave of the magnetocardiogram (MCG) in the control group showed negative deflections in the left upper portion and positive deflections in the right lower portion, thus resulting in a T vector directed leftward and inferiorly. The T wave of the IMI group was flat or positive in the left upper portion and flat or negative in the right lower portion, suggesting a T vector directed superiorly. In addition, opposing dipoles were observed in 36.4% of the IMI group; i.e. one directed superiorly, presumably due to inferior myocardial ischaemia, and the other directed inferiorly due to normal repolarization. Localized T vector abnormalities could be detected by the MCG in some cases, in which coronary T waves of the standard electrocardiogram had returned to normal. Furthermore, multiple dipoles were more frequently observed in the isomagnetic map than in the isopotential map (5 vs. 15; P less than 0.01). These results suggest that the MCG is helpful in diagnosing myocardial ischaemia when this is not detectable on the electrocardiogram.

Adult↗

PubMed1989

Monoclonal antibody against rat renal cell tumor-associated antigen as a new tool for the analysis of renal tumorigenesis.

A monoclonal antibody, NR-2 MAb, against one of the rat renal cell tumor-associated antigens was developed. NR-2 MAb belonged to IgM class and recognized a polypeptide of 81,000 daltons designated as NR-2 antigen, which is of non-glycoprotein nature with a pI of 4.6. NR-2 MAb was employed to probe the histogenesis of renal cell tumors in rats treated with N-ethyl-N-hydroxyethylnitrosamine followed by trisodium nitrilotriacetate monohydrate. Immunohistochemical analysis indicated that NR-2 antigen was expressed in simple hyperplasia, adenomatous hyperplasia and renal cell tumors. Both clear cells and basophilic cells of the simple hyperplasia showed equally strong positive reactions with NR-2 MAb, whereas the vacuolated epithelium was negative. Furthermore, the proximal tubules in nontumorous areas also expressed NR-2 antigen, suggesting that the hyperplastic lesions which eventually lead to renal cell tumors may derive from epithelia of proximal tubules and not directly from vacuolated epithelium. Such NR-2 antigen-positive epithelia of proximal tubules seem to be initiated cells. NR-2 MAb also cross-reacted with preneoplastic liver lesions.

Animals↗