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Biomedical subjects

T Kumada

Publications and source records attributed to T Kumada.

At least 163 records · Page 9Linked to original sources
PubMed1985

Inhomogeneous contribution of late diastolic filling to filling volume in patients with isolated disease of the left anterior descending coronary artery: assessment with radionuclide ventriculography.

Contributions of late diastolic filling (slow filling and atrial systolic phases) to total filling volume in both global and regional left ventricle were analyzed using radionuclide techniques in 21 patients with isolated left anterior descending coronary artery disease without previous myocardial infarction. A computer program subdivided the image of the left ventricle into four regions at a geometric center of the area. The time-activity and its first-derivative curves of the global and regional left ventricles were computed. In the global left ventricle, the percent contributions of late diastolic filling to total filling volume were significantly increased in patients with one-vessel disease than in control subjects (20 +/- 5%, 28 +/- 4%; p less than 0.001). In the regional left ventricle, in patients with one-vessel disease, the percent contributions of late diastolic filling to total filling volume were significantly increased in the septal (25 +/- 5%, 34 +/- 8%; p less than 0.001) and in the apical regions (21 +/- 4%, 28 +/- 4%; p less than 0.001) which were perfused by stenosed vessel. In contrast, there were no significant differences in this value between the two groups in the normally perfused lateral region (22 +/- 6%, 25 +/- 5%; p = NS). These results indicate that the late diastolic filing makes a larger contribution to the left ventricular filling in the affected regions than in the normally perfused regions, and that the increased late diastolic filling in the affected regions are the cause for the increased late diastolic filling in the global left ventricle in patients with one-vessel disease.

Adult↗
PubMed1985

Immunohistochemical detection of alpha-fetoprotein, carcinoembryonic antigen, and ferritin in formalin-paraffin sections from hepatocellular carcinoma.

Paraffin sections of livers from 20 patients with hepatocellular carcinoma were examined by a method using peroxidase antiperoxidase for the detection of alpha-fetoprotein, carcinoembryonic antigen, and ferritin. Ferritin was detected in 70% of the cases, alpha-fetoprotein was in 50% and carcinoembryonic antigen in 30%. The incidence of the detection of these antigens was in accordance with the incidence of these antigens in the sera of patients with hepatocellular carcinoma. Moreover, these antigens were mainly expressed in the well differentiated type of hepatocellular carcinoma by the Edmondson's criteria. Our results also revealed that different antigens were usually present in different tumor cells, although some cells displayed two or more antigens simultaneously. These findings suggest that hepatocellular carcinoma cells are functionally heterogeneous, even if they appear histologically monomorphic.

Aged↗
PubMed1984

Purification and some properties of rat alpha 2-plasmin inhibitor.

alpha 2-Plasmin inhibitor was purified from rat plasma by the procedures including sequential lysine-Sepharose chromatography, ammonium sulfate precipitation and plasminogen-Sepharose, DEAE-Sephadex, concanavalin A-Sepharose, and Sephadex G-200 chromatographies. The final preparation was homogeneous as judged by sodium dodecyl sulfate polyacrylamide gel- and immuno-electrophoresis. It was a single polypeptide chain with a molecular weight of about 7.1 X 10(4) daltons and was found to possess fast-acting antiplasmin activity. There existed other molecular forms of alpha 2-plasmin inhibitor-related antigen with molecular weight of 6.3 X 10(4) and 6.1 X 10(4) daltons. The latter was found to be inactive in binding to plasminogen and in inhibiting plasmin activity. Normal plasma level of alpha 2-plasmin inhibitor in rats was immunologically determined to be 7.9 +/- 0.8 mg/dl. Indirect evidence was obtained that rat alpha 2-plasmin inhibitor was incorporated into cross-linked fibrin during blood clotting.

Animals↗
PubMed1984

Physiological role of alpha 2-plasmin inhibitor in rats.

For understanding the physiological role of rat alpha 2-plasmin inhibitor (alpha 2-PI), the effect of alpha 2 PI deficiency on the fibrinolytic system was studied in rats in vitro and in vivo. Selective removal of alpha 2 PI from plasma was achieved in vitro and in vivo by immune complex formation with specific anti-rat alpha 2 PI rabbit gamma-globulin and the F(ab')2 fragments derived from specific anti-rat alpha 2 PI rabbit IgG, respectively. Depletion of alpha 2 PI from plasma resulted in almost complete loss of the fast-acting antiplasmin activity of the plasma and in a marked acceleration of urokinase-induced plasma clot lysis. A similar acceleration of thrombus dissolution was also observed, when a thrombus isolated from a thrombosed rat was incubated in alpha 2 PI-deficient serum in vitro. The effect was found to be inversely proportional to the alpha 2 PI levels in plasma or serum. When alpha 2 PI deficiency was induced in rats with experimental venous thrombosis, thrombus size was markedly decreased in association with elevation of serum fibrin degradation products and reduction of plasma plasminogen, indicating enhanced fibrinolysis in vivo. In addition, alpha 2 PI deficiency for a longer period induced a mild bleeding tendency at the sites of venipuncture. These results indicate that alpha 2 PI plays an important role as a stabilizer of fibrin in rats, as in humans.

Animals↗
PubMed1984

Clinical characteristics of left ventricular pressure decline during isovolumic relaxation in normal and diseased hearts.

To compare two expressions of the time constant for ventricular relaxation, 39 patients with various heart diseases (six normal, six angina pectoris [AP], 13 myocardial infarction [MI], eight hypertrophic cardiomyopathy [HCM], and six congestive cardiomyopathy [CCM]) were studied. One time constant was obtained by the method of Weiss et al. (T1) and the other was the ratio of left ventricular pressure at peak (-) dP/dt (Pm) to peak (-) dP/dt (T2). The deviation of T2 from T1 was expressed as 100 X (T2 - T1)/T1 (delta %). In normal subjects, T1 was nearly equal to T2 (32 +/- 3 and 32 +/- 6 msec, respectively), resulting in a low value of delta (-1 +/- 9). However, delta values in AP (20 +/- 23, p less than 0.05), MI (24 +/- 26, p less than 0.05), HCM (37 +/- 21, p less than 0.001), and CCM (46 +/- 24, p less than 0.001) were significantly higher than in normal subjects. Thus T1, T2, or delta separated the patient groups from the control subjects, and there were significant differences between T1 and T2 among the types of heart disease.

Adult↗
PubMed1984

Regional left ventricular contraction abnormality during early systole in patients with angina pectoris. Assessment with radionuclide ventriculography.

To determine the presence and prevalence of regional contraction abnormalities in patients with angina pectoris, radionuclide ventriculography gated to an electrocardiogram was carried out in 22 control subjects (group 1) and in 22 patients with angina pectoris (group 2) with isolated stenosis of the left anterior descending coronary artery. No patients had had previous myocardial infarctions. A computer program subdivided the left ventricle into four regions at a geometric centre, and time-activity curves (30-40 ms/frame) of the global, septal, apical, and lateral regions were computed. There was no significant difference in the ejection fraction in the global or in any of the regions between the two groups. End systole in each region occurred close to global end systole in both groups. In the global region the percentage stroke volume ejected during the first third of systole was not significantly less in group 2 than in group 1. Regional analysis of the segments perfused by the stenosed vessel showed that the percentage stroke volume ejected during the first third of systole in group 2 was significantly less in the septal region and in the apical region compared with that in group 1. In contrast, in the normally perfused lateral region, there was no significant difference in the percentage stroke volume at the first third of systole between the two groups. This indicates that early contraction abnormalities are present in the region perfused by the stenosed vessel in patients with angina pectoris without previous myocardial infarction. Thus analysing the regional change in left ventricular volume during ejection in patients with coronary artery disease can show localised areas of contraction abnormalities during early systole that are not apparent when ventricular contraction is assessed as a whole.

Aged↗
PubMed1984

Asynchronous left ventricular diastolic filling in patients with isolated disease of the left anterior descending coronary artery: assessment with radionuclide ventriculography.

To study the relationship between global and regional filling of the left ventricle, we conducted resting gated radionuclide ventriculographic studies in 15 control subjects (group 1) and 22 patients with isolated disease of the left anterior descending coronary artery (group 2). None had had a previous myocardial infarction. A computer program subdivided the image of the left ventricle into four regions. The time-activity and first-derivative curves of the global and regional left ventricles were computed. In the global left ventricle, the normalized peak filling rate (PFR) was decreased (p less than .01) and the ratio of the time to PFR (time interval from global end-systole to PFR) to the diastolic time, TPFR/DT, was greater (p less than .02) in group 2 than in group 1. In the regional left ventricle, in the side perfused by the stenosed vessel (septal and apical), PFR was slightly decreased in the apical (p less than .05), but not the septal region (p = NS); TPFR/DT was greater in the apical (p less than .02) and in the septal region (p less than .01) in group 2. In the normally perfused lateral side, there were no significant differences in PFR or in TPFR/DT between group 1 and group 2. Total delta t/DT, which was defined as the ratio of the sum of the absolute values of the time differences from global PFR to regional PFR (septal, apical, and lateral) to the diastolic time, was significantly greater in group 2 (0.09 +/- 0.05 vs 0.16 +/- 0.05; p less than .001). This indicates the existence of asynchronous diastolic filling in the different regions of the left ventricle in group 2. A negative correlation existed between total delta t/DT and global PFR (r = -.64, p less than .001). Thus, in patients with one-vessel disease, asynchronous diastolic filling occurs due to the filling disturbance in the affected regions, which may cause impairment of the filling of the global left ventricle.

Adult↗
PubMed1984

Hemodynamic effects of nitroprusside on cardiovascular system.

The effects of nitroprusside (NP) on hemodynamics, especially on venous flow velocity of the inferior vena cava (IVC) were evaluated in 20 remote myocardial infarction patients. NP was given beginning at 10 micrograms/min, with subsequent increments of 10 micrograms/min every 5 minutes until the systolic blood pressure was reduced to about 30 mmHg. Pressure was measured by a catheter-tip micromanometer. Flow velocity of IVC was measured by a catheter-tip flow velocity probe. NP significantly decreased left ventricular systolic pressure, left ventricular end-diastolic pressure, mean aortic pressure, right ventricular systolic pressure, right ventricular end-diastolic pressure, mean pulmonary arterial pressure, mean pulmonary capillary wedge pressure, systemic vascular resistance index (SVRI) and left ventricular volume. Cardiac index (CI) was unchanged and stroke volume index was decreased. IVC pressure was unchanged, while right atrial (RA) pressure decreased. Subsequently, the pressure difference between IVC and RA increased significantly. The amplitude of IVC flow velocity decreased significantly. Twenty patients were classified into two groups according to whether or not the CI increased by NP. CI increased in 9 patients (group I) and decreased in 11 patients (group D). Compared to group D, control CI and the slope of end-systolic pressure-volume relation were less and the difference between IVC pressure and RA pressure was greater in group I. The patients with higher control SVRI had greater increase in CI during NP. In our study, the greater the depression of cardiac performance and the higher the SVRI, the greater the improvement of left ventricular pumping function during NP.

Adult↗
PubMed1984

Clinical significance of serum ferritin determination for hepatocellular carcinoma.

The clinical significance of serum ferritin as a serological marker of hepatocellular carcinoma (HCC) was studied. Fasting serum ferritin levels were measured in 343 patients with diseases of the liver, using a radioimmunoassay ferritin kit. Elevated ferritin levels were obtained in various liver diseases but hyperferritinemia could be more clearly interpreted by classifying ferritin levels according to serum iron or transaminase values. Significantly higher values were obtained in HCC than liver cirrhosis. Sensitivity for diagnosis of HCC increased by serial and simultaneous determinations of ferritin and alpha-fetoprotein because high ferritin levels were observed more often in low alpha-fetoprotein-producing HCC and also in HBsAg negative, alcohol related, small-sized HCC. Therefore, simultaneous determination of alpha-fetoprotein and ferritin seems to be useful for detection of HCC in high risk patients such as those with liver cirrhosis.

Alanine Transaminase↗
PubMed1983

Importance of left atrial function in patients with myocardial infarction.

Left atrial function was evaluated in patients with and without remote myocardial infarction. The simultaneous left atrial pressure recording and left atrial and left ventricular cineangiograms were obtained with a catheter-tip micromanometer. The pressure-volume curve of the left atrium was composed of an A-loop and a V-loop. The ratio of active atrial emptying to left ventricular stroke volume in patients with myocardial infarction was significantly larger than that in normal subjects (42 +/- 12% vs 29 +/- 10%, p less than 0.05). The left atrial work was also significantly greater in patients with myocardial infarction (1690 +/- 717 mm Hg X ml) than in normal subjects (940 +/- 426 mm Hg X ml, p less than 0.05). The ratio of active atrial emptying to left ventricular stroke volume and left atrial work were significantly related in both normal subjects and patients with myocardial infarction (gamma = 0.72, p less than 0.01). The left ventricular ejection fraction correlated inversely with left atrial work (gamma = -0.5, p less than 0.05). Left atrial work also showed a significant linear correlation with left atrial volume before active atrial emptying (gamma = 0.82, p less than 0.01). We conclude that the left atrial contribution to left ventricular function is increased in patients with remote myocardial infarction. This left atrial contribution to the left ventricle is attributed to the Frank-Starling mechanism in the left atrium.

Adult↗
PubMed1983

The inhibitory effect of lipid peroxide on the activity of the membrane-bound and the solubilized lipoprotein lipase.

The effects of lipid peroxide (15-hydroperoxy arachidonic acid) on the activity of lipoprotein lipase was investigated. The activities were examined in 2 enzyme species: the lipoprotein lipase bound to the coronary vessels of the rat heart and that solubilized in the human post-heparin plasma. As a substrate, 3H-labelled human chylomicron was used. Lipid peroxide decreased the maximal velocity of the reaction between the chylomicron and lipoprotein lipase on the vascular surface. In the post-heparin plasma, the lipid peroxide decreased the maximal hydrolysis rate, but did not change the half life time in the unsaturated reaction. It is suggested that lipid peroxide directly damages a part of the membrane-bound lipoprotein lipase, and that the degeneration of cell membranes and the vasoconstriction caused by lipid peroxide will additionally disturb the hydrolysis of the plasma triglyceride on the vascular surface.

Animals↗