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Biomedical subjects

Y Inagaki

Publications and source records attributed to Y Inagaki.

At least 361 records · Page 20Linked to original sources
PubMed1983

[Diagnostic value of CT in congenital disorders of the great vessels].

Computed tomographic (CT) studies of the cardiovascular system were performed on 850 cases at our institute during the last five years. The aorta was clearly demonstrated by CT from the aortic root to the bifurcation of the iliac artery, and in most cases the main aortic branches including the coronary, brachiocephalic, common carotid, subclavian, celiac, superior mesenteric, renal and iliac arteries were satisfactorily evaluated (Fig. 1-3). Therefore CT renders us encouraging to detect the abnormality of these arteries. This paper described the CT findings of congenital anomalies of the great vessels in 14 patients with 16 anomalies including two cases of l-corrected transposition of the great vessels, two of double aortic arch, one of aneurysm of the sinus of Valsalva, six of patent ductus arteriosus (PDA) and five of right-sided descending aorta, two of which had double aortic arch aforementioned and the remaining three had dextrocardia. The diagnosis of these abnormalities except for PDA were made only by CT. For instance, l-corrected transposition of the great vessels was diagnosed easily by observing the side-to-side relationship of the great vessels, the aorta is situated to the left and anterior to the pulmonary artery. In the case of double aortic arch, not only the left and right aortic arch, but also the degree of narrowing as well as compression of the trachea and esophagus were well evaluated. The diagnosis of aneurysm of the sinus of Valsalva was made by the characteristically marked dilatation of the aorta at the level of sinus of Valsalva on CT. Only in one case of PDA, the ductus connecting the descending aorta to the left pulmonary artery was demonstrated by CT. Plain CT was well tolerable, but enhanced CT was much more informative to detect cardiovascular abnormalities, and moreover, dynamic CT was rewarding in the detailed evaluation of blood flow in the cardiovascular system.

Adult↗
PubMed1983

[Diagnosis of myocardial infarction by CT: the study of an initial filling defect and late enhancement of the infarcted myocardium after injection of contrast material].

Several animal experimental studies have shown that the enhanced CT gives the direct evidence of acute myocardial infarction characterized by an initial filling defect and late enhancement in the site of the damaged myocardium. Therefore, we studied experimentally and clinically the diagnostic value of these CT findings in detecting and quantitating recent and remote myocardial infarctions. Sixteen mongrel dogs with anterior myocardial infarction were subjected to the present study. The cardiac infarction within one month after coronary arterial ligation was visualized as a filling defect by early CT scan after intravenous injection of contrast material. The delayed scan after the injection showed late enhancement of the infarcted area in both acute and chronic phases. Post mortem histologic studies confirmed that the area of filling defect coincided with the necrotic myocardium and late enhancement coincided with the totally infarcted myocardium including healed scar. The total infarct size measured from CT images was closely correlated with histo-pathological infarct volume (r = 0.96). In the clinical study, the enhanced CT was performed on 112 patients with myocardial infarction and 12 patients with angina pectoris. The filling defect and late enhancement of the infarcted myocardium in the antero-septal or apical wall were detected as clearly as in the animal experiment; the former was found in 85% of the patients with recent infarction, and the latter was detected in about a half of the patients with both recent and remote infarctions. However, these CT findings were not clearly recognized in the patients with infero-posterior infarction, subendocardial infarction or angina pectoris. These results indicate the usefulness of CT in the noninvasive diagnosis and a follow-up study of myocardial infarction.

Animals↗
PubMed1983

[Evaluation of constrictive pericarditis by computed tomography].

Since extensive studies of constrictive pericarditis by CT have not been reported, we performed a plain and contrast enhanced CT on 4 patients of constrictive pericarditis diagnosed by cardiac catheterization or echocardiography and confirmed at the time of surgical operation. The CT findings were as follows: The normal pericardium was smooth, could be visualized in the right and anterior regions of the heart, and was approximately or less 2 mm in thickness. On the other hand, the pericardium in constrictive pericarditis was irregularly thickened, was visualized even in the left and posterior regions of the heart, and was more than 2 mm in thickness. The mean CT value of the pericardium in constrictive pericarditis was significantly increased as compared with that of the normal pericardium. The contrast enhanced CT image revealed a marked dilatation of superior and inferior caval veins (SVC and IVC) even in the cases with normal size of each cardiac chamber. The ECG gated CT performed on one case demonstrated the impaired ventricular expansion. After pericardiectomy, the ventricular chambers showed a tendency to dilate, and the dimension of the SVC and IVC were reduced. Thus, CT is thought to be a useful noninvasive technique in evaluating the thickness of the pericardium, its pathology and the degree of dilatation in each cardiac chamber or the vena cavae.

Adult↗
PubMed1982

ECG synchronized computed tomography in clinical evaluation of total and regional cardiac motion: comparison of postmyocardial infarction to normal hearts by rapid sequential imaging.

Computed tomograph (CT) of the heart was performed using the JEOL Dynamic Scanner, which provides CT cardiac images with minimal radiation and within a short period of time. ECG-synchronized CT was undertaken at various phases of the cardiac cycle every 0.04 second. Approximately 30 minutes of scanning was necessary to obtain a series of CT images of one complete cardiac cycle. In contract to 24 normal subjects, 38 patients with recent or remote myocardial infarction (MI) demonstrated hypokinetic, akinetic, or paradoxical movement of the ventricular segment corresponding to the MI sites predicted by ECG. The sequential cardiac area curve was useful in evaluating instantaneous changes of cardiac dimension, extent of ventricular contraction, and regional dyssynergy. ECG-synchronized CT studies using Somatom contrast dye enhancement in selected patients allowed sequential assessment of left ventricular cavity size and wall motion.

Aged↗
PubMed1982

Changes in Scatchard plots for insulin binding to mammary epithelial cells from cycling, pregnant, and lactating mice.

Insulin binding to its receptors was studied in collagenase-dissociated mammary cells prepared from mice that were cycling, pregnant, or lactating. Mammary cells (3 X 10(6)) were incubated in medium 199 (0.4 ml) supplemented with iodinated insulin (0.8-1 ng/ml) for 45 min at room temperature. The dissociation of iodinated insulin from its receptors was accelerated by the presence of native insulin. The specific binding of insulin at a physiological concentration (1 ng/ml) increased on day 0 of pregnancy and on day 3 of lactation. The Scatchard plots showed predominantly high affinity binding during estrous cycles and in early pregnancy, and low affinity binding in late pregnancy and lactation. Scatchard plots were further analyzed for evidence of negative cooperativity and of two independent receptors. The negative cooperativity model gave well fitted curves for unconstrained parameters. However, dissociation constants for insulin binding to empty sites were too high during lactation. The independent two-receptor model gave also well fitted curves for unconstrained parameters at each stage. The dissociation constants for high affinity and low affinity receptors, which were optimal throughout the entire stage, were 1.0 and 20.0 nM, respectively. There was no significant difference between these dissociation constants and any of unconstrained constants at each stage. When dissociation constants were constrained throughout entire stages, the number of receptors for high affinity binding increased on day 0 of pregnancy and in early lactation, and the number for low affinity binding showed one peak on day 3 of lactation. Changes in these receptors were independent. From these results, we propose that at least two species of insulin receptors are present in mouse mammary epithelial cells; the high affinity receptor may be associated with the stimulation of DNA synthesis.

Animals↗
PubMed1982

Estimation of pulmonary water distribution and pulmonary congestion by computed tomography.

Computed tomography (CT) of the lung in normal subjects and patients with congestive heart failure was performed in the supine position with deep inspiration to obtain pulmonary CT values and images. The mean CT value in normal subjects was higher in the posterior than anterior lung field, presumably because blood vessels were more dilated in the former than the latter due to the effects of gravity. The mean pulmonary CT value in patients with congestive heart failure was significantly increased possibly due to an increase in blood flow per unit lung volume arising from either pulmonary congestion or pulmonary interstitial and alveolar edema. The mean pulmonary CT value increased parallel to the severity of pulmonary congestion, interstitial or alveolar edema and was well correlated with the pulmonary arterial wedge pressure, indicating that such a correlation was a valuable tool in assessing therapeutic effects. The results of the present study indicate that pulmonary CT is useful for the noninvasive estimation of intrapulmonary water content and its distribution, thereby providing an effective diagnostic clue to various conditions in congestive heart failure.

Adult↗
PubMed1982

[Amyl nitrite test in the evaluation of left ventricular function: application to ischemic heart disease and Duchenne's progressive muscular dystrophy].

The effect of amyl nitrite (AN) inhalation on the left ventricular function was evaluated by mechanocardiography and echocardiography. The patient's group consisted of 110 cases with ischemic heart disease (IHD) and 25 cases of dystrophia musculorum progressiva (DMP) of Duchenne type. The former was a representative of impairment of blood supply and myocardial involvement, and the latter was of predominant myocardial disease. The control was age-matched 32 normals for IHD group and 17 cases for DMP group. Left ventricular function was mainly evaluated by systolic time intervals (STI) and the echocardiographic correlates. Fifty-five cases of IHD group were tested by coronary angiography and left ventriculography and these data were compared with the noninvasive measures. The results were as follows: I. IHD group: The ratio of ejection time (ET) to pre-ejection period (PEP), ET/PEP, did not change so much as in controls after AN inhalation, and this percent change was much smaller in cases with lesions of the left anterior descending artery (LAD) than in cases with lesions of the right coronary artery (RCA). On the other hand, mean posterior wall velocity (mPWV) and posterior wall excursion (PWE) changed greater in patients with LAD lesion than in those with RCA lesion. In cases with LAD stenosis, percent change in ET/PEP was smaller in cases with asynergy than in cases without it, disclosing more significant impairment of the left ventricle in the former. II. DMP group: In severe cases, ET/PEP was small even at rest, and percent change by AN inhalation was smaller than control in mild cases and smallest in severe cases. This seems to be useful in evaluating the severity of the diseased process. The mPWV and PWE showed impairment of left ventricular motion even at rest, but it was clearly showed in severe cases after AN inhalation. These results indicate that impairment of left ventricular function induces the poor response to AN inhalation and this, in turn, results in the lack of hyperactivity of the heart produced by this drug.

Adolescent↗
PubMed1982

[Pulse wave].

Explore the source record for details and available documents.

Adult↗
PubMed1982

[Assessment of an intracardiac mural thrombus by contrast enhanced computed tomography].

The usefulness of computed tomography (CT) in the diagnosis of an intracardiac mural thrombus was examined by comparing with two-dimensional echocardiography (2-DE), left ventricular cineangiography (LVG), and operative findings. The following results were obtained: 1) Left atrial thrombi: Among 43 cases of valvular disease with mitral stenosis, left atrial thrombi were noted in 10 cases (13 regions) by CT. Out of these 13 regions, 2-DE detected six regions (Fig. 2). Among 11 patients who underwent operation, thrombi were present in four (six regions). Of these six regions, thrombus was suspected in one region and another one was undetectable, but detected in the remaining four regions by CT and was in good accord with the operative findings (Table 1). Left atrial thrombi were detected in two of 138 cases of coronary heart disease, and in one of 26 cases of cardiomyopathy by CT. 2) Left ventricular thrombi: Left ventricular thrombi were detected in 26 of 122 cases of myocardial infarction (21%) by CT, and had a particularly high incidence in the cases having a ventricular aneurysm (Fig. 4). Of 81 cases in which 2-DE was performed, left ventricular thrombi were detected in 13 cases by both CT and 2-DE, and were not detected in 59 cases by both methods. In nine cases 2-DE diagnosis was not consistent with CT (Table 2). Of 76 cases in which left ventricular cineangiography was performed, left ventricular thrombi were detected in 12 cases by both CT and LVG, and were not detected in 58 cases by both methods. There were six cases of disaccord between 2-DE and CT (Table 2). In two of five cases of congestive cardiomyopathy, left ventricular thrombi were noted by CT. CT was able to detect thrombi in the left atrial appendage, the left atrial lateral wall (Fig. 6), and the regions near the left ventricular apex, which were difficult to be investigated by 2-DE (Fig. 8). CT was, in particular, superior in depicting the size, location and property of thrombi. In addition, CT was able to depict clearly a small thrombus in the left ventricular apex to the extent of, or better than, left ventriculography. Therefore, contrast enhanced CT is a useful diagnostic method for the detection of intracardiac mural thrombi.

Cineangiography↗
PubMed1982

[Estimation of infarct size with 201Tl by multiprojection analysis].

Since mortality resulting from cardiac arrhythmia has been decreased by an introduction of CCU, power failure has become the major cause of death in patients with acute myocardial infarction. The power failure is assumed to be related to an infarct size. Therefore, noninvasive quantification of the infarct size is required for proper assessment of prognosis and treatment. Recently, a scintigraphic technique using radionuclide thallium-201 has developed, which is accumulated not in myocardial necrosis but in the intact myocardium. In this study, we tested two different parameters expressing the infarct size based on 5-projection myocardial scintigrams. One parameter is the ratio of the defect area to the total myocardium (% area), and the other is the ratio of a count decrease by the defect to total counts (% loss counts) in the planar image. Each parameter was obtained from uni- and multi-projection analysis. Six items were selected in the study including % area of 1-projection analysis, % area of 3-projection analysis, % area of 5-projection analysis, % loss counts of 1-projection analysis, % loss counts of 3-projection analysis, and % loss counts of 5-projection analysis. In 56 patients with the first attack of acute myocardial infarction, these parameters showed a clinically acceptable correlation with ejection fractions obtained by contrast ventriculography performed about 4 weeks later, with pulmonary end-diastolic pressure shortly after the onset, and with peak-CPK and sigma CPK obtained by 4 or 6 hourly measurements. Correlation coefficients between two parameters among 6 items showed no difference from each other. Scintigraphy was performed more than twice in 11 patients and the infarct size of these patients was decreased with the clinical course. Validity for estimates of the infarct size obtained with two parameters (% loss counts and % area) in different projection analysis was examined by a phantom model experiment and the clinical implications were discussed. In conclusion, an infarct size estimated by 201Tl scintigraphy provides useful informations about the size of necrosis and cardiac function in patients with acute myocardial infarction.

Adult↗
PubMed1981

Characteristics of 106 spontaneous mammary tumours appearing in Sprague-Dawley female rats.

Pathological studies were undertaken on 106 mammary tumours (89 benign, 17 malignant) appearing spontaneously in 95 normal female Sprague-Dawley rats which were killed at Day 756. The benign tumours comprised those with a predominant acinar hyperplasia and those with adenomatous or fibroadenomatous pattern. No significant differences were found histochemically between the acinar cells of the benign tumours and of the lactating gland, except that the amount of fibrous interstitial connective tissue was larger in the former. 3H- or 35S-glycosaminoglycan synthesis by the benign tumours was found to be much higher. The prolactin value in the plasma of the benign-tumour-bearing rats was about 27 times that of 6-month-old virgin rats, and similar to that of rats on the 7th day post partum. Carcinomatous proliferation of tubuloacinar cells could be seen in 5 of the 89 benign tumours. The incidence of benign tumours increases with the age of the rats.

Animals↗
PubMed1981

A method for the iodination of insulin and its binding to dissociated mouse mammary cells.

The iodination of insulin was accomplished by a modification of the lactoperoxidase method. The use of a low concentration of hydrogen peroxide (1.5 ng/ul) followed by Sephadex gel filtration and purification on a cellulose column yielded iodoinsulin with an activity equal to that of native insulin in stimulation of glucose oxidation in rat epididymal fat cells and with high specific binding to collagenase-dissociated mouse mammary cells from pregnant and lactating mice. Other hormones tested did not displace the binding. Analysis of displacement curves and scatchard plots suggests that both the affinity and the number of sites for insulin binding differ between pregnant and lactating mammary cells.

Animals↗