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Biomedical subjects

Y Oike

Publications and source records attributed to Y Oike.

14 recordsLinked to original sources
PubMed1992

[Continuous monitoring of coronary venous oxygen saturation during PTCA and its relation to electrocardiographic ST changes].

The purpose of this study was to investigate change in coronary venous oxygen saturation (CSO2-Sat) during percutaneous transluminal coronary angioplasty (PTCA) and to compare the results with those of standard 12-lead ECGs (s-ECG) and epicardial ECG induced using an intracoronary guidewire (ic-ECG). CSO2-Sat was measured continuously in 10 patients undergoing PTCA; 5 patients with lesions in the left anterior descending coronary artery (LAD), one with lesions in the left circumflex artery (LCX), and 4 with right coronary artery (RCA) lesions. The results were as follows: 1. In all 6 patients with stenotic lesions in the left coronary artery, CSO2-Sat decreased by 5 to 22% immediately after balloon inflation. Significant changes in ic-ECG (ST deviation > or = 0.1 mV) were observed in 5 of the 6 patients, while significant changes in s-ECG (ST deviation > or = 0.1 mV) were observed in only 3 of the 6 patients. The s-ECG did not seem to be sensitive enough to represent myocardial ischemia in the LCX. 2. The interval from the balloon inflation to the significant change was shorter for CSO2-Sat than for the ECGs in 4 of the 5 patients with LAD lesions, except Case 4. The recovery time of CSO2-Sat to the basal level on balloon deflation was longer than the recovery times of ic-ECG and s-ECG. 3. There was no significant change in the CSO2-Sat in 3 of the 4 patients undergoing PTCA for RCA lesions, while significant changes were observed in the ic-ECG and s-ECG in all 4 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1992

[Inverse relationship between coronary flow velocity and myocardial oxygen extraction during intracoronary infusion of papaverine].

The relationship between coronary blood flow velocity (CBFV) and myocardial oxygen extraction (O2-Ext) was investigated during rapid changes of CBFV after intracoronary papaverine infusion. In 6 patients without stenosis of the left anterior descending artery (LAD), one with hypertrophic cardiomyopathy, 2 with syndrome X and 3 with effort angina pectoris, simultaneous measurements of CBFV using the Doppler catheter system and coronary venous oxygen saturation using the fiberoptic catheter system were continuously performed before and during intracoronary infusion of papaverine. When O2-Ext was related to CBFV in every cardiac cycle, there was a good, inverse linear relationship, both in the increase (r = 0.81 +/- 0.24) and decrease (r = 0.93 +/- 0.04) phases of CBFV. The increase in cross-sectional area of segment 6 in the LAD as observed on orthogonal coronary angiograms was 6.0 +/- 2.0%. These results imply that the increase in CBFV during intracoronary papaverine infusion seems parallel to that of coronary blood flow, and that papaverine induces no significant change in myocardial oxygen consumption. Myocardial oxygen extraction in response to changes in coronary flow is regulated readily to meet the myocardial oxygen demand.

Adult↗
PubMed1992

[Are the first repetitive reentrant VPCs a trigger or an initiation of reentrant circuit for VPCs?: Evaluation by Holter ECG in patients with reentrant sustained ventricular tachycardia].

To evaluate whether the first repetitive reentrant VPCs are a trigger or an initiation of a reentrant circuit for VPCs, we studied Holter ECGs in 13 patients with sustained ventricular tachycardia, the morphology of reentrant VPCs, the relationship between the coupling interval (N-V) and the first ventricular cycle length (V-V), and the relationship of the coupling interval (N-V) between single VPC and repetitive VPCs. In 7 patients who showed episodes of repetitive VPCs more than twice on one recording of Holter ECG, most of VPCs in the first and second beats were the same in shape (1195 out of 1466 episodes, 82%). No obvious relationship between the coupling interval (N-V) and the first ventricular cycle length (V-V) was found in 5 patients, whereas a weak inverse relationship (r = 0.32) was found in one patient, and a weak positive relationship (r = 0.38) was found in another patient. In addition, the coupling interval in repetitive VPCs was longer than that in single VPCs in 4 out of 7 patients. These results imply that, in most cases, the first VPC is the expression of initiation of a reentrant circuit for repetitive reentrant VPCs developing spontaneously.

Adult↗
PubMed1992

[Evaluation of myocardial oxygen extraction dynamics in syndrome X by continuous measurement of coronary sinus oxygen saturation and its relation to clinical features].

We investigated the relation of myocardial oxygen extraction dynamics to pathophysiology and clinical features in syndrome X. In patients with syndrome X who underwent cardiac catheterization, coronary sinus oxygen saturation (n = 21) during rapid atrial pacing loading was continuously measured using a fiberoptic catheter system, and global and regional left ventricular function (n = 14) was evaluated before and immediately after pacing loading. Results were as follows: 1) In 5 of 21 patients with syndrome X, coronary sinus oxygen saturation during pacing loading fell less than 5% below the baseline without any impairments of global and regional left ventricular function. 2) In 16 patients with syndrome X, coronary sinus oxygen saturation during the pacing loading continuously fell over 5% below the baseline accompanied by impairment of both global and regional left ventricular function. The decrease in regional wall motion of the left ventricle was mainly observed in the apical area. These findings imply that changes in myocardial oxygen extraction dynamics in syndrome X during rapid atrial pacing may show the extent of a patchy area where myocardial oxygen demand-supply imbalance occurs due to coronary microcirculatory disturbances.

Adult↗
PubMed1990

Isolation and characterization of human fibroblast tenascin. An extracellular matrix glycoprotein of interest for developmental studies.

We have developed a biochemical method for purifying human tenascin from cultured fibroblasts or the culture medium. The method is a series of biochemical procedures including gel filtration, gelatin gel affinity chromatography and ion-exchange high performance liquid chromatography. The final preparation was identified as tenascin from its immunological cross-reactivity to antibody against chicken tenascin, strong hemagglutination activity which has been reported to be one of the biological functions of chicken tenascin, and from the electron microscopic study demonstrating a six-armed structure. Gel chromatography showed that intact human tenascin has an apparent molecular weight of over one million. Analysis of the purified tenascin with SDS-PAGE under reducing conditions demonstrated that tenascin consists of two kinds of subunits (250K and 190K). We established rat x mouse heterohybridoma cell lines which produce tenascin-specific antibodies. One monoclonal antibody (RCB1) was selected for immunohistochemical study and partially characterized. RCB1 bound native tenascin but not reduced and alkylated tenascin. Immunohistochemistry of normal and neoplastic tissues demonstrated that RCB1 bound the connective tissues surrounding the cancer nests and various normal tissues including interstitium of renal distal tubule, periosteum, endosteum, smooth muscles of digestive tract and media of arteries and arterioles.

Antibodies, Monoclonal↗
PubMed1990

[Estimation of left ventricular diastolic characteristics in patients with myocardial ischemia by pulsed Doppler echocardiography: transmitral blood flow velocity in postextrasystolic beats].

To investigate diastolic dynamics of the left ventricle in postextrasystolic (PES) beats during myocardial ischemia induced by rapid atrial pacing (RAP), transmitral blood flow velocity was evaluated using pulsed Doppler echocardiography in 13 subjects. The subjects consisted of eight patients with ischemic heart disease and five healthy subjects. An atrial extrasystole was artificially induced before and immediately after RAP, while the transmitral flow velocity was recorded continuously. The ratio of the early peak diastolic velocity to the peak atrial velocity (A/E) on PES beat was less than that in a basic beat without an extrasystole. The A/E increased in the PES beat in four patients who experienced myocardial ischemia; whereas, other patients and the normals showed a decrease in the A/E in the PES beat even after RAP. These findings indicated that left ventricular dynamics coupled with left atrial contraction are quite different in myocardial ischemic and nonischemic situations, and that postextrasystolic potentiation may be a useful means of detecting the ventricular diastolic dysfunction.

Blood Flow Velocity↗
PubMed1979

A clinical study on urinary kallikrein in patients with renal diseases.

The urinary kallikrein activity (KA) was measured to investigate its significance in the renal diseases by using tosyl-arginine methyl ester (TAME) as a substrate. The examinees were 94 patients with renal diseases and 25 normal persons. The daily urinary kallikrein excretion (KE, KE=KAxdaily urinary volume) is less in chronic glomerulonephritis and outstandingly less in chronic renal failure than in the normal controls. The KE also shows a positive correlation moderately to 15-min PSP excretion and relatively to creatinine clearance. KE is closely related to renal function and decreases with the degree of renal damage. KA has no relation to the concentration of urine protein, but it was parallel, in general, to the urokinase activity. In nephrotic syndrome, KA tends to show a negative correlation to the urinary alpha 1-antitrypsin. alpha 1-antitrypsin may have a function as an inhibitor to the urinary kallikrein.

Adolescent↗