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Biomedical subjects

T Fujinami

Publications and source records attributed to T Fujinami.

At least 109 records · Page 6Linked to original sources
PubMed1986

Selectivity and contribution of lecithin: cholesterol acyltransferase to plasma cholesterol ester formation.

Selectivity factors (Vm/Km) for human and rat lecithin: cholesterol acyltransferases (LCAT) for the transfer of various acyl groups from the 2-position of phosphatidylcholine were determined. By multiplying these values by the proportions of acyl groups at the 2-position of phosphatidylcholine, one can predict the proportions of molecular species of cholesterol ester which will be synthesized by LCAT. In human subjects fasted overnight, the molecular composition of plasma cholesterol ester was found to reflect the LCAT selectivity relatively accurately. This result supports the concepts that hepatic acyl-CoA:cholesterol acyltransferase (ACAT) does not contribute significantly to the synthesis of plasma cholesterol ester and that removal of cholesterol ester from plasma is not selective with respect to molecular species under these conditions. In contrast to the results with humans, the molecular composition of plasma cholesterol ester formed in spontaneously hypertensive rats fed a high-cholesterol diet and then fasted overnight differs from that which is predicted from LCAT selectivity and the proportion of various fatty acids at the 2-position of phosphatidylcholine: these results suggest that cholesterol ester is formed mainly via the ACAT reaction.

Adult↗
PubMed1986

[Non-invasive estimation of aortic flow by local electrical impedance changes].

Aortic flow velocity was measured by catheter-tip flow transducer in 25 patients who underwent left cardiac catheterization for non-invasive estimates by the impedance method. Disk electrodes were attached to the skin at the levels of the second thoracic vertebra in the posterior median line and the V8 lead position for electrocardiography. Alternating current, 350 micro-amperes, 50 KHz constant, was applied to the outer electrode, and impedance changes were detected via the inner electrode. The e wave, or height of the first derivative dz/dt wave of the electrical impedance was lower in cases of old myocardial infarction and higher in cases of aortic valve regurgitation, as compared with the values of the healthy control group. The time lag between the start of the upward deflection and the peak value of the dz/dt wave coincided with that of the aortic flow curve as measured at the aortic arch and descending aorta. These time lags were about 20 to 30 msec as compared with the ascending aortic flow curve, and were -20 to -30 msec as compared with the abdominal aortic flow curve. There was a close correlation between the maximum flow velocity measured at the aortic arch and the height of the e waves. The regression equation was: Y = 0.21X - 1.53, r = 0.88, p less than 0.01. These data suggest that the first derivative of electrical impedance change as obtained by the disk electrode method reflects aortic flow at the arch and descending aorta.

Adult↗
PubMed1986

[Relation of mitral valve motion to left ventricular end-diastolic pressure assessed by M-mode echocardiography].

Left ventricular end-diastolic pressure (LVEDP) was estimated noninvasively using cardiac parameters obtained from simultaneous recordings of the echocardiograms, electrocardiograms and phonocardiograms in 30 patients who underwent diagnostic left cardiac catheterization. Special attention was paid to the mitral valve motion which reflects global left ventricular function. The interval from the onset of the Q wave of the ECG to the echocardiographic C point of mitral valve closure (Q-C), the interval from the aortic component of the second heart sound to the E point of the mitral echogram (IIa-E), and the time from the opening of the mitral valve (D point) to the E point (D-E) were measured. A good correlation with LVEDP was observed with Q-C/IIa-E (r = 0.87, p less than 0.001), and inversely with D-E time (r = -0.81, p less than 0.001). The correlation of Q-C/D-E and LVEDP was most significant (r = 0.89, p less than 0.001). The regression equations were LVEDP = 36.6 X (Q-C/IIa-E) -10.9 and LVEDP = 4.49 X (Q-C/D-E) +5.56. This noninvasive and easily repeated method for predicting LVEDP is very useful clinically.

Adult↗
PubMed1984

Evaluation of effects of aging, training and myocardial ischemia on cardiac reserve by exercise echocardiography.

Exercise tolerance and heart response were examined by cross-sectional echocardiography before and during exercise tests to assess the effects of aging, training and myocardial ischemia on the cardiac reserve of 40 healthy men, 20 athletes and 25 patients with angina on effort. The cardiac response to exercise can be divided into 4 types according to parameters derived from a short axis section echocardiogram. Type A: The left ventricular end-diastolic volume (LVEDV) increased slightly in the early stage of exercise, and thereafter, the cardiac response was maintained by a gradual increase of myocardial contractility and heart rate. Type B: Initial response to exercise was similar to Type A, but cardiac output was maintained only by an increase of heart rate under additional exercise load. Type C: LVEDV, LVESV (left ventricular end-systolic volume) and contractility remained virtually unchanged throughout the exercise. Type D: The contractility decreased from the early stage of the exercise, and LVEDV and LVESV increased. Most young subjects and all athletes showed Type A response, while in the aged healthy subjects the Type B response was more frequent. Anginal cases tolerating 125-watt load responded as Type B or C, and those tolerating only 75 watts showed Type C or D. All patients in Type D had multi-vessel disease.

Adult↗
PubMed1982

[Evaluation of cardiac reserve in patients with angina pectoris by dynamic exercise echocardiography].

To evaluate cardiac reserve in patients with angina pectoris, 10 healthy control subjects and 15 patients with angina pectoris were examined by exercise echocardiography. Exercise on the bicycle ergometer in supine position was imposed at 25 watts per min initially and the exercise was increased by 25 watts every 3 min until attainment of either maximal predicted heart rate or ST segment depression in the electrocardiogram (ECG) or appearance of severe chest pain. Blood pressure, two-dimensional echocardiogram at the level of the papillary muscle in the short-axis view (Fig. 1) and 12 leads ECG were recorded at the end of each exercise level. Cardiac response to the exercise was evaluated by blood pressure, areas of left ventricular cavity at the end diastole and end systole, percent change of the area, ejection fraction and mVCF, as shown in Figs. 2, 3 and 4. From these parameters, the behavior of cardiac response to exercise was divided into four types (cf. Fig. 5). Type A: left ventricular volume was increased slightly at the initial stage of exercise, and thereafter, the cardiac response was maintained by a gradual increase of myocardial contractility. Type B: initial response to exercise was similar to type A, but cardiac output was maintained only with an increase of heart rate in further exercise load. Type C: left ventricular contractility and increased left ventricular volume were observed from 25 watts load of exercise. Most of the control subjects responded as type A. Patients with angina who underwent 125 watts exercise showed type B response, while those who tolerated only 75 watts exercise revealed type C or type D (Table 1). The latter indicates decreased cardiac reserve to exercise. From the results of 10 patients who showed ST depression during exercise, deterioration of left ventricular contractile function appeared before ST segment depression, indicating that a change in mechanical pump function preceded electrical function of the myocardium (Fig. 6). It may be concluded that serial changes of cardiac parameters obtained from dynamic exercise echocardiography with an area-based method is useful to identify decreased cardiac reserve in patients with angina pectoris.

Angina Pectoris↗
PubMed1979

Impedance cardiography for the assessment of cardiac function during exercise.

1. Impedance cardiography proved valuable to estimate the stroke volume and other cardiac parameters noninvasively, when the electrical resistivity of the blood was corrected with hematocrit. 2. Cardiac response to graded exercise on a bicycle ergometer up to the maximal load in healthy young and active middle-aged subjects was divided into four phases from the changes in cardiac parameters such as stroke volume, cardiac output, ejection index and height of the atrial wave. 3. The ischemic patients did not tolerate well the exercise after the second phase or drift phase of exercise. 4. Physical training enhanced the cardiac function in work through increase in cardiac output and work load.

Adult↗
PubMed1978

Impedance cardiography for estimating cardiac output during submaximal and maximal work.

Impedance cardiography was used to estimate cardiac output in 10 men during rest and within 5 s after exercise on a bicycle ergometer, including work up to and including maximal aerobic capacity. An indwelling venous catheter permitted simultaneous sampling of venous blood for observing changes in hematocrit associated with each exercise level. Cardiac output, calculated from a standard equation which assumes a constant value of 150 omega.cm for the electrical resistivity of blood, was compared with corresponding calculations in which blood resistivity was individually determined as a function of hematocrit. It is concluded that many of the discrepancies in the literature related to values for cardiac output obtained during exercise by the impedance method may be inherent in calculations that do not consider the changing electrical resistivity of the blood with a changing hematocrit.

Adult↗