Search PubMed⌕ Search

Biomedical subjects

T Iwasaka

Publications and source records attributed to T Iwasaka.

At least 181 records · Page 10Linked to original sources
PubMed1994

Assessment of lectin binding for prognosis in endometrial carcinoma.

The binding of Ulex europeus agglutinin-I (UEA-I) and Peanut agglutinin (PNA) was studied in 56 endometrial carcinomas. The positive rates of UEA-I and PNA were 66%. Following neuraminidase treatment, the PNA positive rate increased from 66% to 98% and most tumors stained abundantly. UEA-I staining was unaffected. Using a combined grading system based on architectural and nuclear abnormalities, the PNA positive rates of grade 1, grade 2 and grade 3 tumors were 78%, 70% and 36%, respectively. There was no correlation between UEA-I binding and the grading systems. UEA-I binding correlated significantly with the presence of myometrial invasion and vessel permeation. Metastatic endometrial carcinomas showed a high affinity of tumor cells for UEA-I. Tissues that stained with UEA-I were those from patients with the worst prognosis. PNA and UEA-I reactivities relate to the biologic activity of endometrial carcinomas. UEA-I can serve as a prognostic marker for patients with endometrial carcinoma.

Adenocarcinoma↗
PubMed1994

The factor dominating the determination of left ventricular filling varies during the first five days after acute myocardial infarction.

BACKGROUND: Left ventricular diastolic dysfunction may occur after the onset of acute myocardial infarction. Left ventricular diastolic filling dynamics are related to many factors. To evaluate the influence of left ventricular filling pressure on Doppler-derived left ventricular diastolic flow profiles in patients with acute myocardial infarction, we studied serial changes in filling during the first 5 days after the onset of uncomplicated acute myocardial infarction. METHODS: The study population consisted of 14 patients with acute myocardial infarction and 15 normal subjects: Doppler echocardiographic studies (left ventricular transmitral inflow and outflow velocity patterns) were performed on admission, and on the third and fifth days after infarction. Hemodynamic parameters were measured simultaneously using Doppler echocardiography. RESULTS: The E wave was lower, the A wave and A:E ratio were higher, deceleration half time and isometric relaxation time were prolonged, and peak left ventricular ejection flow velocity was lower in myocardial infarction patients than in normal subjects. The E wave and pulmonary capillary wedge pressure were positively correlated on the first and the third day (r = 0.77, P < 0.001, and r = 0.67, P < 0.01, respectively), but not on the fifth day. The E wave and isometric relaxation time were negatively correlated on the fifth day (r = -0.72, P < 0.01), but not on the first and third day. CONCLUSION: Left ventricular filling pressure (preload) was an important mechanism for maintaining left ventricular filling during the first 3 days, but the relaxation of the ventricle began to play a dominant role on the fifth day.

Aged↗
PubMed1994

Residual left ventricular pump function following acute myocardial infarction in postmenopausal diabetic women.

BACKGROUND: The Framingham Study indicated that women with diabetes mellitus developed cardiac failure four times more often than those without diabetes mellitus after acute myocardial infarction. However, there is little information on residual left ventricular pump function after myocardial infarction in female diabetic patients. METHODS: To evaluate the difference between postmenopausal women and age-matched men in the impact of diabetes mellitus on left ventricular pump function during the first year after myocardial infarction, radionuclide angiography was performed during the third week after acute myocardial infarction and again 1 year later in 50 patients (21 women, 29 men) with diabetes mellitus and 62 patients (25 women, 37 men) without diabetes mellitus. RESULTS: Although the radionuclide angiographic indices did not change during the first year after myocardial infarction in non-diabetic patients, left ventricular end-diastolic volume increased, and the left ventricular ejection fraction, the regional ejection fraction of the non-infarcted area, and the ratio of arterial systolic blood pressure to left ventricular end-systolic volume (pressure:volume ratio) decreased in the diabetic patients. Furthermore, the degree of change in the left ventricular end-diastolic volume, the left ventricular ejection fraction, the regional ejection fraction of the non-infarcted area, and the pressure:volume ratio in diabetic women was larger than that in diabetic men. CONCLUSION: The increase in the left ventricular end-diastolic volume and the decrease in the regional ejection fraction of the non-infarcted area during the first year after myocardial infarction in postmenopausal women with diabetes mellitus indicate that female sex associated with diabetes mellitus may be important factors in left ventricular remodeling in postmenopausal women.

Aged↗
PubMed1994

Late potentials during left ventricular healing of acute myocardial infarction.

BACKGROUND: Late potentials and left ventricular remodeling are important factors in the prognosis of acute myocardial infarction. However, the relationship between late potentials and ventricular remodelling has not been fully evaluated. METHODS: We evaluated clinical characteristics, coronary angiographic findings and radionuclide angiographic measures about 1 month after an acute myocardial infarction in patients with and without late potentials. RESULTS: Although the left ventricular ejection fraction of patients with late potentials was not different from that of patients without late potentials, the left ventricular end-diastolic volume of patients with late potentials was larger than that of patients without late potentials (P < 0.05). There was a significant positive correlation between the left ventricular end-diastolic volume and the filtered QRS duration (r = 0.53, P < 0.001). The root mean square of the voltage in the terminal 40 ms and the low-amplitude signal duration of < 40 microV in the terminal QRS sequence were also correlated with the left ventricular end-diastolic volume (r = 0.40, P < 0.02, and r = 0.39, P < 0.02, respectively). Patency of the infarct-related vessel in the late phase of an acute myocardial infarction was an important factor associated with the occurrence of late potentials (P < 0.01). CONCLUSION: A larger left ventricular end-diastolic volume in patients with late potentials might be associated with left ventricular remodeling during the first month after an acute myocardial infarction.

Coronary Angiography↗
PubMed1994

The effect of platelet-activating-factor antagonist TCV-309 on arrhythmias and functional recovery during myocardial reperfusion.

BACKGROUND: We investigated the effects of a platelet-activating-factor antagonist TCV-309, an antagonist of metabolites of ischemia, on arrhythmias and functional recovery during in-situ reperfusion in dogs. METHODS: Open-chest anesthetized dogs were subjected to ligation of the left anterior coronary artery. Ischemia was maintained for 20 min after which reperfusion was allowed. A cardiac surface ECG was recorded continuously with the II limb lead. Monophasic action potential, left ventricular segment shortening measured by sonomicrometer, and left ventricular pressure were recorded simultaneously under atrial pacing (group A, n = 14). In a second group of dogs, TCV-309 (1 mg/kg) was administered before coronary artery occlusion (group B, n = 12). The hearts were constantly paced through the right atrium at 120 beats/min throughout all experiments. Measurements were continuously obtained from before drug administration to 30 min after reperfusion. RESULTS: The 90% repolarization time of monophasic action potentials in group B revealed significant recovery compared with group A until the fifth minute after reperfusion (P < 0.02). Reduction of severe ventricular arrhythmias was observed during reperfusion in group B (P < 0.05). The percentage segment shortening and left ventricular pressure did not differ significantly between the groups. CONCLUSION: The platelet-activating-factor antagonist had beneficial effects on arrhythmias but not on functional recovery during reperfusion after brief coronary artery occlusion in situ in dogs.

Action Potentials↗
PubMed1994

Clinical significance of right ventricular dilatation in patients with right ventricular infarction.

BACKGROUND: Right ventricular infarction can be accurately diagnosed by ST-segment elevation in the right precordial leads. However, the clinical outcome of right ventricular infarction encompasses a wide spectrum, ranging from no hemodynamic compromise to cardiogenic shock. The present study examined the clinical significance of echocardiographic right ventricular dilatation in patients with right ventricular infarction. METHODS: We studied 60 consecutive patients with ECG evidence of right ventricular infarction (at least 1 mm ST-segment elevation and QS or QR in V4R) after their first acute Q-wave inferior infarction. They had been admitted to the coronary care unit within 24 h of the onset of chest pain. The presence of right ventricular dilatation was diagnosed when the end-diastolic ratio between right and left ventricle was more than 0.5 on two-dimensional echocardiogram. RESULTS: Of the 60 patients with ECG evidence of right ventricular infarction, 29 had right ventricular dilatation (group 1) and 31 did not (group 2). We used four clinical variables in multivariate analysis to determine the significant factors related to right ventricular infarction. Mean right atrial pressure and number of left ventricular segments with advanced asynergy were found to be the important factors. Furthermore, a significantly higher incidence of major complications (cardiogenic shock and need for temporary pacing) was observed in group 1 than in group 2. Right ventricular dilatation was found to be the significant factor related to major complications. CONCLUSION: Echocardiographic right ventricular dilatation is an important non-invasive sign obtained on admission in patients with right ventricular infarction, because it is associated with larger left ventricular infarct size and increased risk of major complications.

Aged↗
PubMed1994

Weight carrying effects on treadmill exercise response in persons without heart disease.

To evaluate the effect of weight carrying on dynamic exercise response, 12 normal subjects were studied during treadmill exercise using ear densitography in two ways: (1) no weight, (2) 10 kg weight in one hand. Although there were no significant differences in diastolic time (DT), tension-time index [TTI: systolic blood pressure x heart rate (HR) x left ventricular ejection time (LVET)] was significantly higher throughout the weight carrying exercise compared to dynamic exercise. The amount of change (delta) in TTI was significantly larger in the initial stage (control to 1 min) of weight carrying exercise compared to dynamic exercise, but there were no significant differences in the later stages (1-3 min and 3-6 min). A prolongation in LVET was observed despite increasing HR during the first minute of exercise in both type of exercise, but LVET was longer at any given HR in weight carrying compared to dynamic exercise. Thus, despite higher TTI throughout the weight carrying exercise, delta TTI was larger only in the initial stage which was caused by prolongation of LVET resulting from disproportionate increase in venous return of early exercise.

Adult↗
PubMed1994

Effect of gender on the left ventricular diastolic performance during isometric handgrip exercise in normal individuals.

To evaluate the effects of gender and isometric handgrip exercise on left ventricular diastolic function in normal individuals, atrial and rapid filling fraction were investigated using M-mode echocardiography in 35 postmenopausal women and 31 age-matched men. There were no significant differences in heart rate, mean blood pressure, atrial filling fraction, and rapid filling fraction at rest between women and men. When the amount of change in hemodynamic variable during exercise was compared, there were no significant differences in heart rate and mean blood pressure between women and men. But the increase in atrial filling fraction and the decrease in rapid filling fraction were significantly larger in women than in men. These data suggest that left ventricular diastolic function is restricted in postmenopausal women, and left atrial booster pump action is mobilized when afterload is increased during isometric handgrip exercise.

Aged↗
PubMed1994

Effect of ventriculoarterial coupling on residual left ventricular pump function in diabetic patients with myocardial infarction.

To study the ventriculoarterial coupling in diabetic patients with myocardial infarction (MI), 26 diabetic and 34 nondiabetic patients were investigated using radionuclide angiography in the 3rd week after acute MI. Effective arterial elastance was nearly one half of left ventricular end-systolic elastance in nondiabetic patients. On the other hand, effective arterial elastance was twice left ventricular end-systolic elastance in diabetic patients. These data suggest that a decrease in left ventricular contractility and an increase in effective arterial elastance lead to increased potential energy and decreased work efficiency in diabetic patients.

Arteries↗
PubMed1994

Cardioprotective effect of unstable angina prior to acute anterior myocardial infarction.

To evaluate the difference in the process of left ventricular functional recovery after successful percutaneous transluminal coronary angioplasty (PTCA), 25 patients with sudden onset of acute Q wave anterior myocardial infarction (MI [group 1]) and 28 patients with unstable angina prior to MI (group 2) were investigated in the late hospital phase. The circumferential extent of left ventricular dysfunction was significantly larger in group 1 than in group 2. The left ventricular ejection fraction (EF) and the ratio of systemic arterial systolic blood pressure to left ventricular end-systolic volume (P/V ratio) were significantly lower in group 1 compared with group 2. The P/V ratio had nonlinear relationships with left ventricular end-diastolic volume (LVEDV) in both groups and the P/V ratio in group 1 was significantly lower than those in group 2 at any given LVEDV. Thus, in patients with successful PTCA, unstable angina prior to acute MI had better left ventricular pump function in the course of left ventricular remodeling.

Angina, Unstable↗
PubMed1994

Effect of body characteristics on the variables of signal-averaged electrocardiograms in healthy subjects.

Late potentials have been reported to be affected by body size or left ventricular mass. To our knowledge, however, the effect of subadipose tissue, which is known to influence QRS amplitudes of the surface ECG on the variables of late potentials, has not been evaluated. The relationships between the variables of late potentials and various obesity indices were assessed in 45 men, aged 24 to 38 years, without structural heart disease and bundle branch blocks. QRS duration (DUR), root mean square voltage in the last 40 ms (RMS), and low-amplitude signals < 40 microV (LAS) were obtained by signal-averaged ECG. Left ventricular mass (LV mass) was determined by echocardiography. The DUR and RMS had no correlation with body height, weight, body mass index (BMI), sum of skin folds (triceps and subscapular), or LV mass. Positive linear correlations were found between LAS and weight (r = 0.48, p < 0.002), BMI (r = 0.54, p < 0.002), sum of skin folds (r = 0.57, p < 0.002), and percent BMI (r = 0.54, p < 0.002). Subadipose tissue may shift the onset of the 40-microV point of LAS to the left with a consequent prolongation of LAS by attenuation of the QRS complex. These data suggest that the use of LAS alone or as a combination in an obese population for the definition of positive late potentials is inappropriate.

Adult↗
PubMed1994

Prolonged survival in a patient with a single ventricle without pulmonary stenosis.

Prolonged survival of the patient with a single ventricle is rare. We report the case of a 57-year-old man who has type A3 of Van Praagh's classification of single ventricle with pulmonary hypertension without pulmonary stenosis. Favorable streaming, a large bulboventricular foramen, and intact atrioventricular valves may have contributed to his long-term survival.

Echocardiography, Transesophageal↗
PubMed1994

[Influence of age on cardiac pump function during laparoscopic cholecystectomy--measurements by ear densitography].

Using ear densitography, consisting of photoelectric plethysomography and Holter electrocardiography, we measured systolic time intervals (STI) in 21 patients, ASA class 1 and 2, undergoing laparoscopic cholecystectomy using CO2 insufflation under general anesthesia (neuroleptanesthesia with isoflurane in air, FIO2 0.5). The patients were divided into two groups: Y-group (10 patients under 59 years of age) and O-group (11 patients over 60 years of age). We investigated the influence of age on cardiac pump function during pneumoperitoneum non-invasively. Y-group showed improvement of cardiac pump function (reduction of PEP/LVET) from 30 minutes after the beginning of insufflation and quick recovery of cardiac function immediately after deflation. O-group showed a tendency of increasing PaCO2 and arterial diastolic pressure, and delayed recovery of cardiac function (elongation of PEP at 60 minutes, and increase of PEP/LVET at 60 and 90 minutes, respectively, after insufflation). Hypertension and tachycardia were apparent immediately after pneumoperitoneum in the O-group. We conclude that special care and monitoring are mandatory for the aged patients with impaired cardiac or respiratory function during laparoscopic surgery.

Aged↗
PubMed1994

[Anesthetic management of a patient with 21-hydroxylase deficiency].

21-hydroxylase deficiency was described as a fatal disease in infancy manifested by severe adrenal insufficiency with lack of differentiation of the external genitalia in males. Patients are in adrenal insufficiency or receiving long term corticosteroid therapy and are unable to respond normally to surgery or other forms of stress. Therefore, supplementation with corticosteroids and various regimens are required for surgery and anesthetic management. A 3 year 10 months correction of 6] old phenotypic female [correction of male] with 21-hydroxylase deficiency and congenital adrenal hyperplasia was scheduled for critroplasty. Anesthesia was induced with sevoflurane, nitrous oxide and oxygen. After endotracheal intubation, a caudal epidural catheter was placed. At the induction of anesthesia, the patient received a bolus of hydrocortisone 30 mg i.v. followed by a continuous infusion of hydrocortisone. The patient's general condition was good during surgery without any major complications. Caudal epidural anesthesia is considered to be effective for anesthetic management of these patients.

Adrenal Hyperplasia, Congenital↗
PubMed1993

Disturbance of pulmonary gas exchange in patients with acute myocardial infarction-associated pericardial effusion.

To elucidate the effect of pericardial effusion on pulmonary gas exchange in patients with infarction-associated pericardial effusion, 294 consecutive patients with their first Q-wave anterior wall acute myocardial infarction were examined carefully by echocardiography, chest radiography and hemodynamic monitoring. A pericardial effusion was detected in 77 patients and was absent in 217 (group 1). Of the 77 patients with pericardial effusion, it was mild in 57 (group 2) and moderate in 20 (group 3). Patients with pericardial effusion (groups 2 and 3) had significantly greater pulmonary artery wedge pressure and more left ventricular segments with advanced asynergy than did those in group 1. Although there were no significant differences in pulmonary artery wedge pressure and number of left ventricular segments with advanced asynergy between groups 2 and 3, group 3 had significantly greater right atrial pressure, alveolar arterial oxygen difference and incidence of high radiographic score. Thus, accumulation of pericardial effusion to a moderate amount may contribute to the greater incidence of increase in extravascular lung water, and disturbance of pulmonary gas exchange.

Aged↗
PubMed1993

Correlation between HPV positivity and state of the p53 gene in cervical carcinoma cell lines.

Human papillomavirus (HPV) infection is clearly associated with cervical carcinomas, yet it is also true that there are cervical carcinomas in which HPV DNA is absent. We examined eight established cell lines derived from cervical carcinomas for the presence of mutations of the p53 antioncogene in relation to the presence of HPV DNA sequences. Of these eight cell lines, seven were positive for HPV DNA and the remaining one was negative for HPV DNA. Single-strand conformation polymorphism analyses revealed a point mutation of the p53 gene in the cell line in which HPV DNA was absent. Sequencing analysis revealed a single-base mutation at codon 273 from CGT to CAT(Arg-->His) and immunocytochemical studies provided evidence that the p53 protein was overexpressed in this cell line. Our observations suggest that the loss of normal p53 gene function may be linked to the oncogenesis of cervical carcinoma.

Adenocarcinoma↗