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Biomedical subjects

N Morooka

Publications and source records attributed to N Morooka.

At least 19 recordsLinked to original sources
PubMed1997

Production of monoclonal antibody discriminating serological difference in Escherichia coli O9 and O9a polysaccharides.

A monoclonal antibody (mAb) with a unique antigenic specificity against Escherichia coli O9 was produced. The O9a mAb was reactive with a part of the strains in E. coli O9. The O9a mAb did not react with LPS from the E. coli O9 test strain Bi316-42. The distribution of the antigen defined by the O9a mAb in E. coli O9 was consistent with that of E. coli O9a present in E. coli O9 strains. The chemical structure of the repeating unit of the O-specific polysaccharide detected by the mAb was demonstrated to be a mannotetraose by two-dimensional nuclear magnetic resonance spectroscopy. It was confirmed that the mAb recognized E. coli O9a serotype in E. coli O9 serotype strains, suggesting that E. coli O9a serotype might be a dominant strain in E. coli O9.

Animals↗
PubMed1992

Evaluation of morphological changes of the atherosclerotic aorta by enhanced computed tomography.

Enhanced and non-enhanced computed tomography (CT) were performed in 405 subjects (222 men; 183 women; mean age 57 years). Intimal atherosclerotic changes of the aorta were quantified by enhanced CT, revealing the atheromatous intima to be projecting and thick-walled, while non-enhanced CT demonstrated aortic calcification. We measured the degree of aortic intimal changes at various segments of the aorta. In 224 cases, CT was performed from the aortic root to the bifurcation of the abdominal aorta. Intimal changes were found predominantly at the aortic arch, the middle descending thoracic and the infrarenal abdominal aorta. As for the intimal changes, aortic calcification and aortic pulse wave velocity were significant atherosclerotic characteristics. The aortic diameter did not show a significant association with intimal change. Among the various atherosclerotic risk factors, intimal change was significantly associated with age, systolic blood pressure, serum total cholesterol and diabetes mellitus, whereas gender, diastolic blood pressure, relative weight and cigarette use were not significantly related. For coronary artery disease and arteriosclerosis obliterans, aortic intimal changes constituted a significant atherosclerotic feature. In cerebrovascular disease, however, aortic intimal change did not play a significant role.

Adolescent↗
PubMed1992

Expansion rate of thoracic aortic aneurysms and influencing factors.

The risk of rupture of an aortic aneurysm increases with size and rapid expansion rate. We studied the expansion rate of thoracic aortic aneurysms and the factors influencing expansion rate, and compared the results with those of abdominal aortic aneurysms. Forty thoracic aortic aneurysms and 25 abdominal aortic aneurysms were serially examined with enhanced and nonenhanced computed tomography. The mean expansion rate of thoracic aortic aneurysms was 1.3 +/- 1.2 mm/yr and was significantly lower than 3.9 +/- 3.2 mm/yr of abdominal aortic aneurysms. The factors increasing expansion rate of thoracic aortic aneurysms were initial size of aneurysms, diastolic blood pressure, and presence of renal failure by univariate analysis. Multivariate analysis concerning the entire aortic aneurysms also revealed that the large size of the aneurysm and the presence of the aortic aneurysm in the abdomen increased expansion rate of aneurysms.

Aged↗
PubMed1992

Unoperated thoracic aortic aneurysms: survival rates of the patients and determinants of prognosis.

The purpose of this study was to evaluate the long-term prognosis of unoperated thoracic aortic aneurysms, and to detect the risk factors which determine the prognosis of unoperated patients. The subjects were 52 unoperated patients with 58 thoracic aortic aneurysms (22 of the ascending aorta, 36 of the descending aorta or the aortic arch) and 38 with abdominal aortic aneurysms. The survival rates of the patients with ascending aortic aneurysms at 3 years and 5 years and those of the patients with descending aortic aneurysms at 5 years were significantly higher than those of the patients with abdominal aortic aneurysms. The risk factors for rupture of thoracic aortic aneurysms were the large size of aneurysms and non-management by the cardiologist and the risk factors for death unrelated to the aneurysms were patient age, male gender and non-management by the cardiologist.

Age Factors↗
PubMed1991

[Successful mitral valve replacement in osteogenesis imperfecta--a case report].

A 34-year-old man with osteogenesis imperfecta who underwent successful mitral valve replacement due to mitral regurgitation was reported. Cardiac disease associated with osteogenesis imperfecta is very rare and only fifteen patients were operated under the extracorporeal circulation previously. While excessive hemorrhage due to tissue fragility was observed in 7 of 15 patients, perioperative course of the case reported here was completely uneventful. The difference of hemorrhagic tendency as well as etiology of osteogenesis imperfecta will be defined according to the advance of technology in collagen genetics and biochemistry in future.

Adult↗
PubMed1991

Prognosis of patients with medically treated aortic dissections.

The purpose of this study is to evaluate the long-term results of medical treatment for a dissecting aorta and to detect the risk factors that determine the prognosis of medically treated patients. During the past 10 years, 228 patients with aortic dissections were admitted to our hospital and affiliated hospitals. One hundred thirty-four patients, including 60 with proximal type (Stanford, type A) and 74 with peripheral type (Stanford, type B) dissections, were treated by medical means alone. The survival rates of medically treated patients with type A dissections at 24 hours, 2 weeks, and 5 and 10 years after the onset of the disease were 72, 43, 34, and 28%, respectively, and the survival rates in type B dissections were 100, 92, 76, and 56%, respectively. The risk factors that determine poor prognosis in the acute phase of dissections were type A dissection and serious complications (rupture of the aorta, shock, cerebral accident, myocardial infarction, severe aortic regurgitation, renal failure, mesenteric infarction, and arterial occlusion in the extremities). The risk factors in the chronic phase were serious complications, excluding shock and rupture in the acute phase, the large diameter of the dissecting aorta, and increasing age. These results show that emergency surgical intervention is indicated in the patients with acute type A dissections and in those who had acute type B dissections with these serious complications. Medical treatment may be tentatively recommended for the patients with uncomplicated type B dissections until the operative death rate in these patients becomes less than presently identified.

Aortic Dissection↗
PubMed1991

Clinical importance of coronary calcification detected by CT.

Coronary calcifications appear in advanced atheromatous lesions therefore fluoroscopy is useful for the detection of the atherosclerotic coronary artery disease (Aldrich et al., 1979). However, the detection of coronary calcification by fluoroscopy is difficult in the case of obesity or thick chest wall and also impaired by the background structures including bone and other intrathoracic calcifications. X-ray CT is more advantageous than fluoroscopy in the detection of coronary calcification. It can eliminate the interference from background structures and clearly demonstrates calcified sites of the coronary artery. Therefore, we investigated the clinical usefulness in the detection of coronary calcification with X-ray CT.

Adult↗
PubMed1990

Coronary artery calcification detected by CT: clinical significance and angiographic correlates.

Cardiac computed tomography (CT) to detect coronary calcification was performed on 161 patients undergoing coronary angiography for proven or suspected coronary artery disease. Among 108 patients in whom coronary calcifications was identified, 90% had significant coronary stenosis angiographically (greater than 75% stenosis), and 80% of 121 patients with significant coronary stenosis showed calcification by CT. The relationship between the calcification site and the significance in stenosis of each vessel was determined. Calcification was present in 133 arteries among 205 stenotic coronary arteries (sensitivity = 65%) as compared with 59 of 439 entire arteries with normal coronary angiograms (specificity = 87%). In the younger age group the sensitivity of calcification for stenosis of each coronary artery was lower and the specificity and predictive value were generally higher than those in the elderly group. These results demonstrate that CT is a valuable procedure for detecting coronary arterial disease, since this examination is easy to conduct, noninvasive, and widely applicable for screening a large population.

Adult↗
PubMed1990

[Progression to ischemic heart disease in subjects with coronary calcification as evaluated by computed tomography].

It is well known that coronary artery calcification develops in patients with advanced coronary sclerosis. Currently, it can be easily detected by computed tomography (CT). We studied the correlation of CT-detected coronary calcification with its progression to myocardial infarction, and further with the prognosis in various patients who did not have symptoms suggesting ischemic heart disease. The subjects consisted of 241 patients (136 males, 105 females) with a mean age of 61 years, categorized as a calcified coronary artery group (82 patients) and a non-calcified coronary artery group (159 patients). In all the subjects nonenhanced serial cardiac-CT scans were performed with a GECT/T 9800 for detecting coronary calcification. The mean follow-up period was four years in both groups. Among the 82 patients with coronary calcification, four developed myocardial infarction (4.9%) and 14 patients died (17%). Among the 159 patients without coronary calcification, none progressed to myocardial infarction, but 17 patients died unrelatedly (11%). Although there was no significant difference in mortality between the two groups, there was a statistical significance (p less than 0.005) as to the incidence of progression to myocardial infarction. In males, there was no significant difference (13 vs 12%) in mortality between the two groups, but the calcified group had a higher incidence of progression to myocardial infarction than that of the non-calcified group (5.5 vs 0%). In females, the calcified group had higher mortality (26 vs 8.9%) and a more frequent incidence of myocardial infarction (3.7 vs 0%) than did the non-calcified group. In conclusion, patients with coronary artery calcification are likely to develop coronary artery disease rather rapidly, even though asymptomatic. Therefore, detection of coronary calcification by non-enhanced CT is helpful for estimating the prognosis of coronary artery disease.

Calcinosis↗
PubMed1990

[Echocardiography in patients with malignant metastatic neoplasms of the heart and great vessels].

Two-dimensional echocardiography was used to study malignant metastatic neoplasms of the heart and great vessels in 20 patients, 13 males and seven females, whose ages ranged from 15 to 72 years. Five patients had lung cancer; two each had breast cancer, malignant melanoma, hepatoma and one each had gastric cancer, urinary bladder cancer, adrenocortical carcinoma, malignant lymphoma, angiosarcoma, fibrosarcoma, leiomyosarcoma; and two had cancers with unknown primaries. Tumor invasion was demonstrated echocardiographically in the left atrium in one each with breast cancer, fibrosarcoma and gastric cancer; in the right atrium in two with hepatomas; in the right atrium and right ventricle in one patient with adrenocortical carcinoma; in the left ventricle in one with lung cancer; and in the pulmonary artery in one with malignant melanoma. Massive pericardial effusion was observed in 11 of 20 patients; two with pericardial tumors including malignant lymphoma and lung cancer. We conjectured that metastatic tumors in the right cardiac cavities came through the inferior vena cava, and other tumors in the left atrium, left ventricle and pericardium developed from direct extension of the primary lesions. There was an 80% mortality of the patients during the observation period, and the average survival period after the diagnosis of cardiac metastases was 5.5 months. However, one patient was still living after two years of radiation therapy and chemotherapy. Echocardiography proved a useful, non-invasive means for the detection and follow-up observation of metastatic cardiac tumors.

Adolescent↗
PubMed1987

Metabolic activation of emodin in the reconstituted cytochrome P-450 system of the hepatic microsomes of rats.

Studies were undertaken to elucidate further the mechanism by which emodin, an anthraquinoid mycotoxin and constituent of rhubarb, was converted into a direct-acting mutagen to Salmonella typhimurium TA1537 by the hepatic microsomes and the reconstituted cytochrome P-450 system. Emodin was activated into a mutagenic principle(s) in the reconstituted cytochrome P-450 system, and its mutagenicity was significantly higher with the fraction II (P-448 type) than the fraction I (P-450 type) derived from the hepatic microsomes of PCB-induced rats. Thin-layer chromatographic analysis revealed that the purified cytochrome II-a (maximal CO-differential spectrum at 448.0 nm and high-spin form) activity converted emodin into 2-hydroxy-emodin, a direct-acting mutagen.

Animals↗
PubMed1987

omega-Hydroxyemodin, a major hepatic metabolite of emodin in various animals and its mutagenic activity.

The hepatic microsomes derived from various animal species transformed emodin (1,3,8-trihydroxy-6-methylanthraquinone), an anthraquinoid pigment present in fungal metabolites and a constituent of plant medicines, into an unidentified anthraquinone h, along with 2-hydroxy-, 4-hydroxy- and 7-hydroxyemodins. TLC, UV, MS and NMR clarified this unidentified major metabolite as omega-hydroxy-emodin (1,3,8-trihydroxy-6-hydroxymethylanthraquinone). Among 7 animal species, the highest activity to produce this omega-hydroxyemodin was observed in the hepatic microsomes of guinea pig and rat, followed by mouse and rabbit. The microsomal activity to convert emodin into omega-hydroxyemodin was accelerated by the pretreatment of animals with phenobarbital, and inhibited by SKF 525A. The microsomal hydroxylation reactions of the methyl residue and the anthraquinoid nucleus of emodin were presumed to be catalyzed regiospecifically by multiple forms of cytochrome P-450. omega-Hydroxyemodin was not mutagenic to Salmonella typhimurium in the absence of S9, but exhibited mutagenicity in the presence of an activating system. This genotoxic potential was comparable to 2-hydroxyemodin, a direct-acting mutagen.

Animals↗
PubMed1987

Generation of free radical and hydrogen peroxide from 2-hydroxyemodin, a direct-acting mutagen, and DNA strand breaks by active oxygen.

Among several hydroxylated metabolites of emodin, a fungal anthraquinone and constituent of rhubarb, 2-hydroxyemodin was a direct-acting mutagen showing a large electron-spin resonance (ESR) signal in the presence of DNA, especially at alkaline pH. Coupled with generation of free radical, hydrogen peroxide but not superoxide was formed. The active oxygen produced from 2-hydroxyemodin induced strand breaks in phi X 174 replicative form I DNA (supercoiled covalently closed circular duplex DNA). These results suggest a possible role of active oxygen in the process of mutagenesis.

Anthraquinones↗
PubMed1987

[Diagnostic evaluation of ischemic heart disease by X-ray computed tomography and magnetic resonance imaging].

To assess the usefulness of X-ray computed tomography (CT) and magnetic resonance imaging (MRI) in detecting and evaluating ischemic heart disease, conventional and enhanced CT were performed for 180 patients (150 with transmural infarction, 12 with subendocardial infarction, and 18 with angina pectoris). MRI examinations were performed for 38 patients (31 with transmural infarction, three with subendocardial infarction, and four with angina pectoris). With enhanced CT, two findings in the myocardium were direct evidence of myocardial infarction: 1. filling defects on the early scans, and 2. late enhancement of the myocardium on the delayed scans. The former were observed mainly at the sites of recent anterior myocardial infarction and the latter were seen in about half of the patients with recent and remote anterior myocardial infarctions. However, these findings were inadequately imaged in patients with inferoposterior infarction and subendocardial infarction. Among 137 patients with transmural infarction, enhanced CT revealed left ventricular aneurysms in 51 (37%) and ventricular thrombi in 26 (19%). ECG-gated MRI apparatus having a superconducting magnetic operating at 0.25 Tesla was used, and data for this study were collected using the single-slice spin echo technique. In eight of nine patients with acute myocardial infarction, gated MRI demonstrated the infarcted myocardium as regions of high signal intensity relative to that of the adjacent normal myocardium. Such a difference in MRI signal intensity was scarcely recognized in the chronic stage of myocardial infarction, but the indirect findings of infarction, such as regional wall thinning, wall motion disturbances, left ventricular aneurysms, and ventricular thrombi were easily detected using MRI. No characteristic finding was obtained by CT or MRI in patients with angina pectoris.

Aged↗
PubMed1987

[Problems related to tracer concentration and wall thickness: pitfalls in positron CT diagnosis].

Positron emission computed tomography (PET) is regarded an excellent technique for quantitative measurements. However, its accuracy is related to the spatial resolution of the system. The relation between myocardial wall thicknesses as measured by X-ray CT or MRI and the radioactivity as measured using PET was studied in 37 patients. 1. In patients with transmural infarction, the infarcted myocardium was imaged as a region of low radioactivity. However, the myocardium usually exhibited wall thinning, so that partial volume effects must be taken into account in evaluating the radioactivity. 2. In the infarcted regions, the regions of the low radioactivity tended to be larger than those of wall thinning. 3. There were cases with the regional low radioactivity without wall thinning in myocardial infarction and in hypertrophic cardiomyopathy. Because patients with myocardial infarction frequently had regional wall thinning, it seems necessary to correct partial volume effects for the infarcted regions which differ from the normal. It was concluded that, to estimate regional myocardial blood flow or metabolism using PET, it is necessary to supplement another morphological diagnostic method to evaluate myocardial wall thickness.

Ammonia↗