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Biomedical subjects

K Nishimura

Publications and source records attributed to K Nishimura.

At least 1,153 records · Page 64Linked to original sources
PubMed1982

[Study on tricuspid regurgitation in Ebstein's anomaly using pulsed Doppler technique combined with two-dimensional echocardiography].

To investigate the localization of tricuspid regurgitant flow in Ebstein's anomaly, pulsed Doppler echocardiography (PDE) was performed on nine patients with or without associated cardiac lesions. The equipment used was characterized by the real time frequency analysis of Doppler signals obtained from the sampling sites confirmed on the cross-sectional images. We employed the apical four-chamber view or right ventricular inflow view in order to facilitate the sampling of Doppler signals from the three-sided heart chambers of this lesion. Doppler signals were recorded from several points in the functional right ventricle, atrialized right ventricle and right atrium. The PDE recording was made in conjunction with M-mode echocardiography at a paper speed of 50 mm per second. In eight of the nine patients, a systolic disturbed flow of wide band pattern was maximally located in the atrialized right ventricle in the vicinity of the tricuspid valve leaflets and had a delayed onset, which were seemed to be the findings characteristic of tricuspid regurgitation in Ebstein's anomaly. In the remaining one, a turbulent flow due to this lesion was obscured by a systolic jet of the associated ventricular septal defect in the vicinity of the tricuspid valve leaflet. In the right atrium, no disturbed flow of wide band pattern existed or only a faint abnormal blood flow was observed during systole. In the functional right ventricle, a smooth blood flow of the right ventricular inflow was recognized in diastole. In contrast, 15 patients with secondary tricuspid regurgitation revealed a holosystolic disturbed flow of wide band pattern maximally in the right atrium in the vicinity of the tricuspid valve leaflets. In eight healthy subjects, there was no systolic disturbed flow in the right atrium. Pulsed Doppler technique combined with two-dimensional echocardiography is thought useful to detect the localization of the disturbed flow in Ebstein's anomaly, thus contributing to the differentiation of various causes of tricuspid regurgitation.

Adult↗
PubMed1981

Cross-sectional echocardiographic study on the mitral valve prolapse associated with secundum atrial septal defect: pre- and post-operative comparison.

Cross-sectional echocardiography was performed on 77 patients with secundum atrial septal defect (ASD). Mitral valve prolapse (MVP) was recognized in 41 out of the 77 (53.2%); anterior MVP was found in 36 patients, three cases revealed posterior MVP, and two were diagnosed as having both anterior and posterior MVP. Pre- and post-operative study was carried out on 53 cases; anterior MVP decreased in incidence from 28 patients to 17 following closure of ASD, whereas posterior MVP remained unchanged, as did both anterior and posterior MVP. The left ventricular distortion ratio (LVDR) was measured in the short axis view in 45 cases. After the repair of ASD, the LVDR decreased both in end-systole and end-diastole (p less than 0.01), that is, the left ventricle became more circular in configuration. Pre- and post-operatively, MVP patients revealed a significantly greater LVDR than those without it in end-systole, and post-operatively in end-diastole as well (p less than 0.01). Prior to operation, the short axis area of the left ventricle (LVSAA) was statistically larger in patients with MVP than without it in end-diastole (p less than 0.05). However, there existed no relationship between the presence of MVP and the pulmonic to systemic flow ratio, right ventricular dimension index, right ventricular systolic pressure and size of ASD at the time of operation.

Adolescent↗
PubMed1981

A new potent inhibitor of converting enzyme: (2R,4R)-2-(2-hydroxyphenyl)-3-(3-mercaptopropionyl)-4-thiazolidinecarboxylic acid(SA446).

(2R, 4R)-2-(2-Hydroxyphenyl)-3-(3-mercaptopropionyl)-4-thiazolidinecarboxylic acid (SA446) is a novel potent converting enzyme inhibitor having a sulfhydryl group in the molecule. SA446 inhibited the activity of semi-purified rabbit lung converting enzyme (IC50 = 6 nM). The contractile response of isolated guinea pig ileum to angiotensin I (AI) was markedly inhibited by SA446 (IC50 = 28 nM). On the other hand, SA446 augmented the contraction to bradykinin (BK) (AC50 = 0.7 nM), but did not affect the contraction caused by angiotensin II (AII), acetylcholine and histamine. These in vitro potencies of SA446 were 4 to 5 times larger than those of captopril. SA446 inhibited the pressor response to AI in rats (ID50 = 0.06 mg/kg, i.v., 0.48 mg/kg, p.o.) and dogs (ID50 = 0.01 mg/kg, i.v.). SA446 augmented the depressor response to BK (AD50 = 0.009 mg/kg, i.v.), but did not affect the pressor responses to AII and norepinephrine in rats. These in vivo activities of SA446 in dogs were more potent than those of captopril, but the reverse was seen in rats. Oral administration of SA446 had a hypotensive effect on two-kidney, one-clip renal hypertensive rats and spontaneously hypertensive rats, at doses over 3 and 10 mg/kg, respectively. However, the blood pressure of normotensive and DOCA-salt hypertensive rats was not affected by SA446, in doses up to 100 mg/kg. These results indicate that oral SA446 is a potent active inhibitor of converting enzyme and may be classed as an antihypertensive agent.

3-Mercaptopropionic Acid↗
PubMed1981

Enzyme deviation patterns in primary rat hepatomas induced by sequential administration of two chemically different carcinogens.

Enzyme deviation patterns were examined in primary rat hepatomas induced by short-term sequential administration of two chemical carcinogens from among 2-fluorenylacetamide (FAA), diethylnitrosamine (DENA), and 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) or by FAA or 3'-Me-DAB followed by phenobarbital as a promoter. The purpose was to discern how the patterns are influenced by different administration schedules of carcinogens and which of the two carcinogens in the sequence affects the pattern more. Biochemical differentiation of hyperplastic hepatic nodules and hepatomas was determined by simultaneous assays of activities and isozyme composition of glucose-adenosine triphosphate phosphotransferase, pyruvate kinase, glucose-6-phosphatase, fructose-1,6-bisphosphatase, and gamma-glutamyltransferase with consideration of histological classification of nodules and tumors. Poorly differentiated hepatomas were predominantly induced by 3'-Me-DAB followed by FAA or DENA except for hepatomas induced by 3'-Me-DAB followed by phenobarbital, which were mainly well and moderately differentiated; well and moderately differentiated hepatomas were predominantly induced by FAA followed by 3'-Me-DAB or phenobarbital. The degree of enzyme deviation of the hepatomas induced by DENA as the first carcinogen was intermediate between those of hepatomas induced by FAA or 3'-Me-DAB, although the degree tended to increase with increased dose or term of DENA. These results indicate that deviations of some enzymes, such as pyruvate kinase and fructose-1,6-bisphosphatase, as well as histological differentiation of the primary hepatomas are more strongly influenced by the first carcinogen than by the second under our administration schedules and that the degree of enzyme deviation shown by hepatomas produced by a particular carcinogen treatment regimen principally related to the potential of that regimen to induce the more anaplastic tumors.

2-Acetylaminofluorene↗
PubMed1981

Familial primary biliary cirrhosis. Immunological and genetic study.

A 53-year old male and his daughter (38 years old) had primary biliary cirrhosis. The daughter had a high titer of antimitochondrial and other autoantibodies. Nine members, including, four living sibs, mother and two of the daughter's healthy offspring have been examined for liver function, the presence of autoimmune antibodies, cell mediated immunity and histocompatibility antigens. The eldest and second sons, mother and sisters of the affected daughter had multiple autoimmune reactions including antismooth-muscle antibodies and decreased peripheral T lymphocyte but liver tests were normal except in the eldest son. Histocompatibility antigens HL-A9 and HL-B5 were present in both patients and the elder son. Thus the findings suggest a similar genetic predisposition to immunologic abnormalities among the family members of the patients with primary biliary cirrhosis.

Adult↗