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Biomedical subjects

S Kimata

Publications and source records attributed to S Kimata.

At least 55 records · Page 3Linked to original sources
PubMed1987

Natural history of atrial fibrillation.

The clinical significance of atrial fibrillation was analyzed in cases with chronic or acute heart disease and its significance at the acute and chronic stages of the disease was investigated in various disease groups. The types of disease, number of patients, and incidence of atrial fibrillation were: atrial septal defect (92, 14.1%), mitral valve disease (128, 79.7%), nonrheumatic valvular disease (32, 56.2%), aortic regurgitation (71, 2.8%), aortic stenosis (10, 10.0%), hypertrophic cardiomyopathy (181, 11.6%), dilated cardiomyopathy (111, 37.8%), acute myocardial infarction (823, 9.0%), healthy subjects (31,886, 0.3%). A histopathological and electron-microscopic evaluation of the atrial heart muscle revealed that the advancement of the morphological changes was closely related to the occurrence of atrial fibrillation. Decrease in size of F waves in the electrocardiogram correlated well with the extent of right and left atrial fibrosis. Also, it was noteworthy that the atrial fibrillation in cases with dissecting aneurysm (n = 60) was an expression of the myocardial damage due to the infiltration of the bleeding into the right atrium. Intra-atrial electrogram in 48 patients with various heart diseases revealed that the electric potentials obtained from various parts of the atrium varied to a great extent and finally the patient's condition transformed to that of atrial standstill. We conclude that atrial fibrillation is an expression of some important aspect of the progression of heart disease and is not directly associated with hemodynamic overloading to the atrium. A strategy for quinidine treatment was also introduced.

Age Factors↗
PubMed1986

Microanalysis of free fatty acids in plasma of experimental animals and humans by high-performance liquid chromatography.

A high-performance liquid chromatographic (HPLC) method was developed for microanalysis of thirteen free fatty acids using 200 microliter of plasma. Fatty acids were derivatized with 9-anthryldiazomethane for HPLC analysis. Use of an ODS minicolumn for pretreatment of plasma gave a more accurate determination of free fatty acids in plasma than by chloroform extraction. Using this method, thirteen free fatty acids in the plasma of normal human, dog, rabbit, guinea pig and rat were determined.

Animals↗
PubMed1986

Expression of myosin isozymes during the developmental stage and their redistribution induced by pressure overload.

Cardiac muscles contain at least two isozymes--referred to as alpha(HC alpha) and beta(HC beta)--of the myosin heavy chain. The proportional ratio of these isozymes varies depending upon the developmental stage and the physiological and/or the hormonal milieu of the cell. Using monoclonal antibodies (MoAb) specific for human cardiac HC alpha and HC beta, we have examined the expression of these isozymes in fetal through adult cardiac tissues and investigated whether isozymic redistribution occurs in pressure overloaded human ventricles. We found that although HC alpha was expressed in the atrium from the early embryonic stage, in embryonic ventricular myofibers, only HC beta was expressed without expression of HC alpha, but some myofibers replace HC beta by HC alpha after birth, and these HC alpha containing ventricular myofibers were found to be decreased by pressure overload, which suggested that isozymic redistribution from HC alpha to HC beta also occurred in the ventricles, as well as the atrium. In addition, we also found two subtypes of HC beta (beta 1, beta 2) in the human heart. In the ventricle, both beta 1 and beta 2 was present in all myofibers; in contrast, some myofibers contained beta 1 or beta 2 or both with or without expression of HC alpha in the atrium. beta 1 and beta 2 were distinctive in their expression during the developmental stage, since beta 1 was present in the embryonic heart from the early developmental stage, whereas beta 2 was not present in the early embryonic heart, but began to be expressed in the late embryonic stage.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Hemodynamic and clinical effects of a new inotropic agent TA-064 in patients with refractory heart failure due to cardiomyopathy with special reference to dose-response effects.

A new hydroxybenzyl alcohol derivative TA-064 exerts a positive inotropic action in experimental preparations. To assess the acute effects in man, we made a cardiac catheterization study of the hemodynamic responses to TA-064 (20 mg and/or 40 mg given orally) in eleven patients with refractory heart failure due to cardiomyopathy (nine patients with dilated cardiomyopathy and one with amyloidosis). All patients were already receiving full digitalis and diuretics therapy. The following statistically significant (P less than 0.05-0.01) effects were noted: Upon administration of 20 mg of the drug, the cardiac index (CI) increased from a mean +/- 1 SD of 1.6 +/- 0.4 to 2.1 +/- 0.6 l/min/m2; pulmonary capillary wedge pressure (PCW) fell from 25 +/- 5 to 21 +/- 5 mm Hg; right atrial pressure (RA) fell from 12 +/- 3 to 10 +/- 4 mm Hg. In contrast, when 40 mg TA-064 were administered orally, the CI increased from 1.7 +/- 0.4 to 2.4 +/- 0.9 l/min/m2; PCW fell from 25 +/- 8 to 20 +/- 6 mm Hg; pulmonary arterial mean pressure fell from 35 +/- 11 to 29 +/- 9 mm Hg. Neither systemic arterial mean pressure nor heart rate increased. No toxicity was observed. The plasma concentration of TA-064 increased dose-dependently and reached a peak value 0.5-1.5 h after oral administration. Plasma catecholamine levels revealed no significant changes before and after use of the drug; therefore, the mechanism of action may not have been mediated by catecholamine.

Adult↗