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Biomedical subjects

T Iwasaka

Publications and source records attributed to T Iwasaka.

At least 271 records · Page 15Linked to original sources
PubMed1988

Heart with circulatory failure secretes and processes atrial natriuretic peptide in a manner different from normal heart.

The role of catecholamine in atrial natriuretic peptide (ANP) secretion and its secretory mechanism in normal humans is not well defined; therefore, we studied the relationship among ANP, catecholamine, and atrial pressures in 25 patients without cardiovascular disease and in 35 patients with chronic congestive heart failure (CHF, 20 in mitral valve disease and 15 in dilated cardiomyopathy). In patients without cardiovascular disease, right atrial pressure at rest showed a positive correlation (r = 0.80, p less than 0.001) with ANP concentration, whereas left atrial pressure did not. The relation narrowed (r = 0.82) when the bicycle ergometer exercise in the supine position was conducted. Neither adrenalin nor noradrenalin significantly correlated with ANP concentration. In patients with mitral valve disease and dilated cardiomyopathy, the significant relations (r = 0.56 p less than 0.001, r = 0.85 p less than 0.001, respectively) between left atrial pressures and ANP concentrations at rest were observed, and following exercise, induced more significant relations. Right atrial pressures did not correlate positively with ANP concentrations. The increments of ANP concentrations induced by exercise load were markedly reduced compared with those of patients without cardiovascular disease. Although concentrations of both noradrenalin and adrenalin in patients with mitral valve disease and dilated cardiomyopathy at rest were much higher than those without cardiovascular disease, only noradrenalin had a highly positive correlation with ANP concentrations (r = 0.88 p less than 0.001, r = 0.78 p less than 0.001, respectively). Furthermore, the circulating ANP molecular weight forms in all patients studied were analyzed by gel chromatography coupled with radioimmunoassay.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Combined herpes simplex virus type 2 and human papillomavirus type 16 or 18 deoxyribonucleic acid leads to oncogenic transformation.

Tumorigenic transformation was produced by combining herpes simplex virus type 2 and human papillomavirus type 16 or 18 deoxyribonucleic acid (each is associated with cervical carcinoma). Recombinant human papillomavirus type 16 and 18 deoxyribonucleic acid each containing a head-to-tail dimer of the full-length human papillomavirus respective genomes, induced morphologic transformation in an immortalized cell line (AE), obtained by transfection of Syrian hamster embryo cells with immortalizing sequences of herpes simplex virus type 2 deoxyribonucleic acid. These transformed cells were tumorigenic in nude mice. Deoxyribonucleic acid of both human papillomaviruses induced morphologically transformed foci in Syrian hamster embryo cell cultures, but these transformed cells were not tumorigenic. Southern blot analyses revealed transfected deoxyribonucleic acid in the human papillomavirus type 16 transformed cells, whereas viral deoxyribonucleic acid was not evident in the human papillomavirus type 18 transformed cells. These events suggest a "hit and run" oncogenesis.

Animals↗
PubMed1988

Malignant pericardial effusion in endometrial adenocarcinoma.

A case of endometrial adenocarcinoma in a 62-year-old woman with malignant pericardial effusion is presented. The patient underwent a total abdominal hysterectomy, bilateral salpingo-oophorectomy, pelvic node dissection, and paraaortic node biopsy. Postoperatively, she was placed on a combination chemotherapy regimen of cisplatin, doxorubicin, and cyclophosphamide. The patient developed cardiac tamponade during the course of chemotherapy. Although we first suspected cardiotoxic effect of doxorubicin, cytologic examination revealed adenocarcinoma cells in the pericardial fluid. A review of the literature revealed no other cases of cardiac metastasis from endometrial carcinoma diagnosed during life.

Adenocarcinoma, Papillary↗
PubMed1988

Preoperative diagnosis of ovarian malignancies with intravenous digital subtraction angiography.

Intravenous digital subtraction angiography was performed on 59 patients with ovarian tumors. Dilatation of the uterine artery and its ovarian branch was relatively frequent in both benign and malignant tumor groups, while dilation of the ovarian artery, and hypervascularity from the uterine artery or the ovarian artery were fairly specific to the malignant tumor group. These five abnormal vascular patterns were evaluated by a scoring system and approximately 75% of malignant and 87% of benign ovarian tumors were correctly diagnosed preoperatively by digital subtraction angiography alone. Intravenous digital subtraction angiography can be applied as an easy, safe, and valuable diagnostic method for ovarian malignancies and can replace conventional pelvic angiography.

Adult↗
PubMed1988

[Hemodynamic response to diurnal activities of patients with myocardial infarction evaluated by ambulatory monitoring of systolic time intervals using ear densitography].

The purpose of this study was (1) to assess the hemodynamic changes during daily activities by 24-hour continuous ear-densitographic monitoring (Holter EDG) in 14 patients with acute myocardial infarction (MI), and (2) to define the changes in left ventricular performance during and after acute upright posture in 35 patients with old MI. Ninety-seven percent of the daily activities could be reliably measured by ambulatory monitoring of systolic time intervals (STI) and the most significant change in STI was observed during defecation. The ratio of preejection period to left ventricular ejection time (PEP/LVET) increased significantly during defecation (0.42 +- 0.09----0.50 +- 0.09, p less than 0.05), but heart rate either increased (5 patients) or decreased (4 patients). Though there was no change in PEP/LVET during sleep, walking and washing the face and hands, it tended to increase during eating and urinating. Acute upright posture caused sudden acceleration of the heart rate, and increased PEP/LVET immediately (0.36 +- 0.05----0.39 +- 0.06, p less than 0.005). The latter further increased immediately after sitting (0.36 +- 0.05----0.41 +- 0.07, p less than 0.001) and 1 min after sitting (0.36 +- 0.05----0.43 +- 0.07, p less than 0.001), but it was stable thereafter. Thus, abrupt changes in these parameters indicate that changes both in neural activity and venous return are virtually instantaneous. We concluded that the Holter EDG will facilitate the evaluation of daily activities of patients, and that the information obtained in this study could be valuable in understanding the physiology and hemodynamics of patients recovering from acute MI.

Activities of Daily Living↗
PubMed1988

The factors associated with fascicular block in acute anteroseptal infarction.

To elucidate the genesis and effect of fascicular block, 131 patients with acute Q-wave anteroseptal infarction were studied. Thirty-seven patients had new onset of fascicular block in the coronary care unit. The hospital mortality rate was 16%. Multivariate analysis was performed to determine the important variables related to the occurrence of fascicular block and hospital mortality based on 17 clinical variables obtained at the time of hospital admission. Serum potassium level and heart rate were the significant factors predicting the occurrence of fascicular block, whereas cardiac output and arterial oxygen tension were important for hospital mortality. Therefore, not only the rise in the heart rate but also the effect of the serum potassium level on the conduction system are independent factors related to the occurrence of fascicular block, and fascicular block in itself has no significant influence on the hospital mortality.

Aged↗
PubMed1988

[Antiemetic efficacy of high-dose metoclopramide, diphenhydramine, methylprednisolone and diazepam on chemotherapy-induced emesis in gynecological malignancy].

The antiemetic efficacy of high-dose metoclopramide (MCP), diphenhydramine (DPH), methylprednisolone (MPL), and diazepam (DZP) was investigated in 40 gynecologic cancer patients for a total of 98 chemotherapy courses, treated with cisplatin (50 mg/m2). With MPL (500 mg i.v. x 2) plus DZP (5 mg i.m. x 2), no vomiting occurred in 0% and mild emesis (vomiting 1-2 times) occurred in 20% of 25 courses. With MCP (2 mg/kg i.v. x 5) plus DPH (40 mg i.v. x 3), no vomiting occurred in 35% and mild emesis occurred in 10% of 20 courses. With a combination of MCP plus DPH and MPL plus DZP, no vomiting occurred in 51% and mild emesis occurred in 25% of 53 courses. These results indicate that high-dose MCP plus DPH are effective in preventing cisplatin-induced vomiting. Furthermore, the antiemetic efficacy of MCP plus DPH (0-2 vomiting episodes: 45%) was significantly enhanced (p less than 0.05) by the combined use of MPL plus DZP (0-2 vomiting episodes: 76%).

Adult↗
PubMed1987

Effect of exercise on ventricular diastolic time in coronary artery disease.

To evaluate diastolic time during uninterrupted upright exercise, 28 normal volunteers (group 1) and 12 men with coronary artery disease (group 2) were studied by ear densitography. Electromechanical systole-heart rate and diastolic time-heart rate regression equations during upright exercise were obtained from group 1. Electromechanical systole-heart rate had an inverse linear relation (electromechanical systole = 480 - 1.4 heart rate) and diastolic time-heart rate had an inverse nonlinear relation (diastolic time = 1206e-0.02 heart rate). Although there were no significant differences in electromechanical systole and diastolic time at 1 minute of exercise between patients with and without CAD, at peak exercise prolongation of electromechanical systole and consequent shortening of diastolic time in patients with CAD were observed. This disproportionate shortening of diastole with lengthening of systole at peak exercise tends to decrease myocardial perfusion and, hence, oxygen supply, while increasing myocardial oxygen demand, contributing to aggravation of ischemia in patients with CAD.

Coronary Disease↗
PubMed1987

The role of atrial pressure in secreting atrial natriuretic polypeptides.

The role of atrial pressure and catecholamines in secreting human atrial natriuretic polypeptides (hANP) were investigated in patients with acute or old myocardial infarction (AMI or OMI). No differences were observed in hANP levels obtained from brachial vein, right atrium, pulmonary artery and femoral artery, suggesting that hANP degradation in the pulmonary circulation has little clinical significance in hANP measurement. Plasma hANP levels in 10 patients with AMI were higher than those in controls and significantly correlated to both mean right atrial pressure (mRA) and pulmonary wedge pressure (PCW) (r = 0.76, p less than 0.05; r = 0.95; p less than 0.01, respectively). In 12 patients with OMI, plasma hANP levels were normal at rest and were significantly increased (p less than 0.01) with bicycle ergometer exercise associated with significant elevations of plasma catecholamine levels, mRA, and PCW. However, the increments of hANP correlated only to those of PCW. These results suggest that the elevation of atrial (principally left atrial) pressure rather than catecholamine stimulates hANP secretion.

Aged↗
PubMed1987

Supraventricular arrhythmias in the late hospital phase of acute Q-wave myocardial infarction. Supraventricular arrhythmia in myocardial infarction.

To assess the correlates of supraventricular arrhythmia (SA) in the late hospital phase of acute Q-wave myocardial infarction (MI), continuous 24-h ambulatory electrocardiographic monitoring, gated cardiac pool scan, modified exercise test, and chest x-ray were reviewed in 102 patients. Supraventricular tachyarrhythmias were seen in 11 patients, atrial premature beats in 42 patients; 49 patients did not have SA. Multiple discriminant analysis was used to determine the important variables contributing to the occurrence of SA. Variable included age, sex, history of previous MI, hypertension, location of MI, moist rales at time of admission, cardiothoracic ratio, ejection fraction, wall motion abnormality, exercise test result, duration of exercise and use of digitalis. Moist rales, digitalis, age and cardiothoracic ratio were the predictors of SA. Aging, hemodynamic change imposed on the left ventricle, and arrhythmic effects of digitalis are the major factors associated with SA in the late hospital phase of acute MI.

Atrial Fibrillation↗
PubMed1987

Antitumor activities of human recombinant interferon-gamma against cervical tumor transplanted into nude mice.

This study examines the antitumor effects of recombinant interferon-gamma (ReIFN-gamma), by comparing various routes for its administration in nude mice transplanted with human cervical tumor cells. Daily intratumoral injection of ReIFN-gamma showed the best inhibitory effect, although intramuscular daily administration of this IFN also showed a significant antitumor effect. Furthermore, the earlier treatment was initiated after tumor inoculation, the better was the antitumor effect of the IFN. Histologic examination of the transplanted tumors after treatment with ReIFN-gamma showed a sparse or reticular arrangement of the tumor cells, and very large multinucleated giant cells. Unlike the original tumor, 'pearl' formation and isolated cell keratinization were frequently observed in the transplanted tumors obtained from IFN-treated groups.

Animals↗