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Biomedical subjects

N Morooka

Publications and source records attributed to N Morooka.

At least 37 records · Page 2Linked to original sources
PubMed1985

2-Hydroxyemodin, an active metabolite of emodin in the hepatic microsomes of rats.

The hepatic microsomes derived from rats transformed emodin (1,3,8-trihydroxy-6-methyl-anthraquinone), an anthraquinone present in fungal metabolites and constituent of rhubarb, into at least 10 anthraquinoid metabolites. Metabolite d proved to be mutagenic to Salmonella typhimurium TA1537 in the absence of activation system. MS, NMR, UV and mutagenicity test analysis revealed that metabolite d was 2-hydroxyemodin (1,2,3,8-tetrahydroxy-6-methyl-anthraquinone) and exhibited mutagenicity in doses of 2-20 micrograms/plate. In addition to this active metabolite, TLC analysis revealed the formation of 4-hydroxyemodin (metabolite a), 5-hydroxyemodin (metabolite b), 7-hydroxyemodin (metabolite d') and others. No mutagenicity of these monohydroxyemodins was demonstrated in the absence of activation system.

Animals↗
PubMed1985

[Magnetic resonance imaging of cardiovascular diseases: advantages of coronal and sagittal planes].

The usefulness of coronal and sagittal sections of the cardiovascular system by magnetic resonance imaging was evaluated. Coronal, sagittal and transverse spin echo scans using ECG-non-gating and gating during systole and diastole were performed for five normal volunteers, 91 with heart diseases (25 valvular disease, 28 ischemic heart disease, 14 cardiomyopathies, 14 congenital malformations, four pericardial diseases, and six others) and 32 patients with aortic abnormalities (17 aneurysms, 10 dissections and five others) using a 2.5 KGauss unit. Cardiac gating necessitated six to eight min per scan, but it was mandatory to obtain clear images of the details. On the other hand, in most of the aortic abnormalities, diagnostic images were obtained by the ECG-non-gating technique which required only about 2.5 min per scan. Coronal and sagittal sections were useful for estimating the entire shape and size of each cardiac chamber and intracardiac thrombi, the extent of postinfarctional wall thinning and cardiac aneurysms, and hypertrophy or narrowing of both the ventricular outflow tracts and apex. These planes were particularly useful, and more contributory than transverse planes for detecting inferior myocardial damage such as infarction. A few coronal and sagittal scans were sufficient to diagnose extensive lesions of the aorta, such as atherosclerosis, dissections and the aortitis syndrome. Local lesions such as coarctation, supravalvular aortic stenosis, annulo-aortic ectasia and aneurysm, especially those originating in the inferior wall of the aortic arch were easily discovered. Since the main arteries, such as the innominate, left common carotid, left subclavian and renal arteries, were clearly demonstrated by coronal images, coronal scans were considered more useful than transverse ones for observing the relationship between these arteries and dissections or aneurysms of the arch and of the abdominal aorta.

Coronary Disease↗
PubMed1984

The usefulness of x-ray computed tomography for the diagnosis of myocardial infarction.

Conventional and enhanced computed tomographic (CT) examinations were performed in 103 patients with myocardial infarction for evaluation of the diagnostic usefulness of CT. After intravenous bolus injection of contrast material, an initial filling defect and late enhancement of the infarcted myocardium appeared on the cardiac CT images. These two findings were direct evidence of myocardial infarction; the former was found mostly in the patient with recent myocardial infarctions, and the latter was recognized both in those with recent and those with "remote" infarctions. Wall thinning at the site of infarction was found by enhanced CT mostly in patients with anteroseptal or extensive anterior infarctions, and was rarely found in patients with inferoposterior infarctions. Left ventricular aneurysms and ventricular thrombi were found by enhanced CT in 39 and 23 of the 103 subjects, respectively, and the sensitivity of CT in detecting intracardiac thrombi was higher than that of two-dimensional echocardiography. Calcification of the myocardium and pericardial effusion associated with myocardial infarction were also detected by conventional nonenhanced CT. Thus, cardiac CT was found to be a useful test in evaluating patients with myocardial infarction.

Adult↗
PubMed1984

Noninvasive diagnosis of thrombus in the heart and large vessels--usefulness of two-dimensional echocardiography and X-ray CT.

The usefulness of two dimensional echocardiography (2-D echocardiography) and x-ray computed tomography (CT) for the diagnosis of thrombi in the cardiac cavity and large vessels was studied by comparing them with the findings of invasive methods. Among 56 subjects with mitral stenosis, left atrial thrombi were noted in 12 cases (16 regions) by CT and 8 cases (9 regions) by 2-D echocardiography. In 16 subjects who underwent operations, one false negative case by CT and 3 false negative and one false positive cases by 2-D echocardiography were found. In 80 subjects with myocardial infarction 2-D echocardiography, CT and left ventriculography (LVG) were performed at approximately the same time. Thrombi were detected in 10 subjects (12.5%) by 2-D echocardiography, in 15 (18.8%) by CT and in 14 (17.5%) by LVG. Although mural thrombi in abdominal aortic aneurysm were detected very easily, thin thrombi surrounding the false lumen of the dissecting aneurysm were not detected ultrasonographically. These thrombi were only detected by the enhanced CT. Our results show the usefulness of both methods for detecting thrombi in the heart and large vessels. CT can distinguish the thrombi more clearly than 2-D echocardiography, but 2-D echocardiography is performed more easily, safely and economically than CT.

Adult↗
PubMed1983

[Positron computed tomography for the assessment of myocardial infarction].

Positron computed tomography (PCT) was performed on 2 normal subjects and 3 patients with myocardial infarction. The PCT device "Positologica-II" developed at the National Institute of Radiological Science Japan was used in this study (Fig. 1). This is a whole body positron CT consisting of 3 detector rings that provide 5 sliced images simultaneously. The radiopharmaceutical 13N-ammonia (13NH3) synthesized by the cyclotron at the institute was used as an indicator of myocardial blood flow. Immediately after the intravenous administration of 13NH3, five serial 1-min PCT scans were performed with 3 additional scans that provided 15 static images spaced 6 mm apart. Cardiac blood pool images were obtained from the first scan. A patient with extensive anterior myocardial infarction revealed an outward bulging of the blood pool compatible with aneurysmal formation (Fig. 2). Three additional late scans provided high quality cross-sectional images of the distribution of 13N in the left ventricular myocardium. Although 13N distribution in myocardium was uniform in normal subjects (Figs. 3 & 4), the patients with myocardial infarction revealed defects in the accumulation of 13N at the sites corresponding to the infarction (Figs. 5, 6, 7 & 8). The conclusions are as follows: (1) serial PCT scans with 13NH3 provide cardiac blood pool images, and (2) myocardial 13N tissue concentration seems to reflect myocardial blood flow.

Adult↗
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

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

[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↗
PubMed1981

[Measurement of cardiac volume by computed tomography (author's transl)].

Noninvasive cardiac volume measurement by computed tomography (CT) was attempted in this study. It was found that non-gated CT images were very close to the end-diastolic images by ECG-gated CT. Ten to fifteen non-gated scannings were obtained serially from the upper atria to the left diaphragm in 9 normal subjects and 72 patients (6 hypertensives, 7 aortic valvular diseases, 22 mitral valvular diseases, 5 shunt lesions and 33 ischemic heart diseases). To demarcate each chamber, contrast enhancement CT was performed by drip infusion in most cases, but it was done by 4-6 times bolus injections at the level of the left ventricle (LV) to visualize LV lumen in ischemic cardiac patients who had ventriculography. The volume was calculated by summing each slice's volume which was obtained from the area times slice thickness (Fig. 2). The total cardiac volume and the volume of each chamber (LA, RA, RV and LV) were calculated. The interventricular septum and LV wall were included into LV volume. There was a good relationship (r = 0.90) between the total cardiac volume by CT and that by chest X-ray (PA and lateral views) (Fig. 4). Each volume by CT in 9 normal subjects was: 353 +/- 30 ml/m2 in total, RA: 53 +/- 17 ml/m2, LA: 54 +/- 21 ml/m2, RV: 90 +/- 15 ml/m2, and LV: 123 +/- 15 ml/m2 (mean +/- SD), respectively, and an increment of each volume was shown according to the hemodynamic features of various heart diseases: the total volume was increased significantly in valvular disease (Fig. 5), RA and RV volumes in mitral valvular disease with tricuspid regurgitation and ASD (Figs. 6, 7) LA volume in mitral valvular disease and shunt lesion (Fig. 8) and LV volume in aortic valvular disease and mitral regurgitation (Fig. 9). Between the left ventricular lumen volume by Ct and its end-diastolic volume by ventriculography (area-length method), there was a good relationship (r - 0.81) in 17 cases without cardiac aneurysms out of 22 ischemic cardiac patients examined by ventriculography (RAO and LAO views) (Fig. 11). The cardiac CT was found very useful for measurements of cardiac volume, since it is noninvasive and quite simple yet reasonably accurate.

Adult↗
PubMed1980

Microbial acetyl conjugation of T-2 toxin and its derivatives.

The acetyl conjugation of T-2 toxin and its derivatives, the 12,13-epoxytrichothecene mycotoxins, was studied by using mycelia of trichothecene-producing strains of Fusarium graminearum, F. nivale, Calonectria nivalis, and F. sporotrichoides, T-2 toxin was efficiently converted into acetyl T-2 toxin by all strains except a T-2 toxin-producing strain of F. sporotrichoides, which hydrolyzed the substrate to HT-2-toxin and neosolaniol. HT-2 toxin was conjugated to 3-acetyl HT-2 toxin as an only product by mycelia of F. graminearum and C. nivalis, but was also resistant to conjugation by both F. nivale and F. sporotrichoides. Neosolaniol was also biotransformed selectively into 3-acetyl neosolaniol by F. graminearum. However, 3-acetyl HT-2 toxin was not acetylated by any of the strains under the conditions employed, but was hydrolyzed to HT-2 toxin by F. graminearum and F. nivale. This is the first report on the biological 3 alpha-O-acetyl conjugation of T-2 toxin and its derivatives.

Acetylation↗
PubMed1979

The tissue distribution and the pattern of excretion of [14C]-13-labeled 12, 13-epoxytrichothec-9-ene in mice and rats.

The distribution in the mouse tissues of 13-[14C]-12,13-epoxtrichothec-9-ene administered intravenously was determined by whole-body autoradiography and by tracing the radioactivity of the tissues oxidized in an Auto Sample Oxidizer. The appearance of the label in urine and feces was also followed by the tracer technique. The distributions of radioactivity in tissues as determined by the two methods were almost identical. On the autoradiograms of mice killed 10 min after the injection, marked blackening of the film was observed at the sites corresponding to the liver, kidney, and bladder with urine, and much less darkening at other sites. The radioactivities contained in the liver, kidney, urine and small intestine were 13.3, 2.3, 2.6 and 10.2% of the dose, respectively. The labeled toxin was rapidly excreted into urine and feces, 56.0 and 4.9% in 6 hr and 66.7 and 28.0% in 24 hr after injection, respectively. Oral administration of the labeled toxin to mother mice resulted in the appearance of radioactivity in the stomach contents of 7-day suckling mice, thus demonstrating indirectly the secretion of the toxin into the milk. An attempt to show a respiratory route of excretion in rats given the radioactive compound orally or intravenously failed to detect any radioactivity in the expired CO2 collected for 6 hr, suggesting that the 14C in the epoxy ring was intact.

Animals↗
PubMed1977

Emetic and refusal activity of deoxynivalenol to swine.

The minimum emetic dose of deoxynivalenol to swine weighing 9 to 10 kg was 0.05 mg/kg of body weight intraperitoneally and 0.1 to 0.2 mg/kg orally. There was no emesis by undosed pigs consuming vomitus from pigs orally dosed with deoxynivalenol or penned with such pigs without access to vomitus. Analysis by gas-liquid chromatography of a sample of Gibberella zeae-infected corn containing about 25% visually damaged kernels indicated 12 ppm of deoxynivalenol. Deoxynivalenol added to feed reduced feed consumption of 20- to 45-kg pigs, ranging from a 20% decrease with 3.6 ppm to 90% reduction with 40 ppm. Loss in weight was associated with feed refusal. Feed refusal, however, was much greater for naturally infected corn samples than for feeds with equal concentrations of the pure compound added, indicating the involvement of an additional factor(s) in the swine refusal response.

Animals↗