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Biomedical subjects

Y Oike

Publications and source records attributed to Y Oike.

At least 37 records · Page 2Linked to original sources
PubMed1994

The effect of radix Salviae Miltiorrhizae Composita on peroxidation of low density lipoprotein due to copper dichloride.

It is well known that plasma lipoprotein, particularly oxidized LDL, plays an important role in the pathogenesis of atherosclerosis and atherosclerotic diseases. We used oxidized LDL generated by incubating LDL from healthy persons with copper dichloride as a model to investigate the antioxidate property of Radix Salviae Miltiorrhizae Composita (RSMC). On photos, the spot X1 and the spot X2 were clearly found in the control group after the dialysis into copper dichloride for 24 and 48 hours, but they could not found in the RSMC group. The analysis of the constituents of lipids in LDL (by charring method) showed that after dialysis the percentages of the spot X1 and the spot X2 in the RSMC group were significantly lower than those in the control group (P < 0.01). The results suggest that RSMC plays a potential role in antioxidation of lipids or LDL.

Adult↗
PubMed1993

Evaluation of oxidized low-density lipoprotein and large molecular size low-density lipoproteins in atherosclerosis.

To study the roles of modified low-density lipoprotein (LDL) and the molecular size of LDL in atherogenesis, the following studies were carried out. Eight white male rabbits fed a standard oriental diet with 1% cholesterol were used to isolate LDL and to observe changes in the molecular size of LDL due to cholesterol feeding. The tissue LDLs in the aorta were analyzed to confirm the existence of modified LDL (namely, LDL with peroxidized cholesteryl ester) by thin-layer chromatography. In addition, plasma LDLs were isolated from 18 patients with myocardial infarction and 11 patients with angina pectoris to confirm the existence of LDL with peroxidized cholesteryl ester. Each LDL separated consisted of 3 fractions; namely, IDL (1.006-1.018), LDL1 (1.019-1.052) and LDL2 (1.053-1.063) by sequential ultracentrifugation. The molecular sizes of LDL were measured by a planimeter from electron microscopic photographs, with negative staining. The estimation of peroxidized cholesteryl linoleate in LDL was performed using our method. The modified LDLs with peroxidized cholesteryl ester were poorly estimated in the LDL separated from the plasma of cholesterol-fed rabbits and from the aorta extraction after 16 weeks of feeding. The peroxidized cholesteryl ester was clearly identified in the plasma LDLs of the patients with myocardial infarction and angina pectoris, and in whole extracts from human aortic atheroma, although it was not clearly identified in the tissue LDL fraction. The molecular sizes of LDL1 enlarged week by week with cholesterol feeding, but two fractions of IDL and LDL2 did not change in size. The infusion of cholesterol-rich LDL of large molecular size or LDL with peroxidized cholesteryl ester into the vessels led to fixation, on the surface of the arteries of many platelets, red cells, and white cells, and to marked irregularities in the endothelial folds. The evidence suggests that atheromas, formed in a short period in rabbits with cholesterol feeding, are caused mainly by the increase in LDL1 of large molecular size, and that foam cells, formed in human atheromas, are caused mainly by the production of modified LDL with peroxidized cholesteryl ester.

Animals↗
PubMed1993

Fatal angioedema associated with enalapril.

A 37-year-old female with a history of hypertension for 5 years was brought to the emergency room with swelling of the tongue and neck after the second dose of enalapril. After administration of hydrocortisone by her physician, she went to the emergency room. Her dyspnea and dysarthria were relieved. However, she experienced recurrence of the symptoms followed by respiratory arrest. She suffered severe anoxic brain damage and died three days later. Although angioedema is a rare occurrence with the use of enalapril, it is potentially life threatening.

Adult↗
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↗
PubMed1991

[Coronary collateral function evaluated by coronary hemodynamics and myocardial lactate metabolism during rapid atrial pacing].

To elucidate coronary collateral function in the ischemic myocardium, we studied coronary hemodynamics and myocardial lactate metabolism of the collateral-dependent myocardium before and during rapid atrial pacing. Subjects consisted of 38 patients who were categorized into 3 groups according to their coronary and coronary collateral arteriographic findings: 14 patients with normal coronary arteriograms (Group A), 15 with significant stenosis in the left anterior descending coronary artery (LAD) without collaterals (Group B), and 9 with LAD stenosis and collaterals (Group C). Estimates of cross-sectional area (CSA) obtained from the orthogonal coronary arteriograms, and the great cardiac vein flow (GCVF) and myocardial lactate extraction ratio (MLER) before and during rapid atrial pacing were used as parameters to evaluate coronary stenosis. The results were as follows: 1. The cross-sectional areas in Groups B and C were 86% and 91% of that in Group A, respectively. 2. In Group B, there was a good linear relationship between cross-sectional area and % delta GCVF, as shown in % delta GCVF = 2.90 + 36.22 x CSA (r = 0.61, p < 0.05). This relationship was modified in Group C, increasing % delta GCVF against CSA. 3. Myocardial lactate extraction ratio in Groups B and C decreased significantly after rapid atrial pacing, while, it remained unchanged in Group A. This ratio after rapid atrial pacing did not differ significantly between the 2 groups. 4. In 3 of 4 patients with total LAD occlusions, GCVF and anterior coronary resistance before and during rapid atrial pacing were similar to those of Group A.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Pacing, Artificial↗
PubMed1991

[Correlations between redistribution areas observed on exercise thallium-201 myocardial SPECT images and the coronary collateral circulations in patients with myocardial infarction].

The significance of coronary collateral circulation for redistribution in the infarcted zone was evaluated in 16 patients with history of myocardial infarction and severe stenosis (> or = 90%) of the coronary artery. Redistribution areas were quantitatively measured using the redistribution ratios and redistribution indices on the infarction-redistribution map obtained by thallium-201 scintigraphy with single photon emission computed tomography. Coronary collateral findings were categorized in 4 classes according to the Rentrop's grading. There was good, positive linear correlation between the redistribution ratio (Y) and collateral grading (X) (Y = 0.21X + 0.10, r = 0.92, p < 0.01). The redistribution index (X) also correlated well with the collateral grading (Y) using a good, positive quadratic equation (Y = 0.32X2 + 0.24X + 0.04, r = 0.89, p < 0.01). These results suggest that the measurements of the redistribution areas in the ischemic zone in myocardial infarction correlated well with collateral perfusion. Collateral perfusion severer than Rentrop's grade 2 markedly reduces the severity of ischemia and increases redistribution areas.

Collateral Circulation↗
PubMed1991

[A case of Schönlein-Henoch purpura with myocardial complications].

A rare case of Schönlein-Henoch purpura with myocardial complications was reported. A 64-year-old man was admitted to our hospital for further examination of hematuria, associated with arthralgia, proteinuria, and previous episodes of anasarca and orthopnea. The examinations revealed moderate renal dysfunction due to mesangial proliferative glomerulonephritis secondary to Schönlein-Henoch purpura. In addition, the patient proved to have cardiac dilatation and dysfunction of the left ventricle. The histological examination of the right ventricular subendocardium sampled by myocardial biopsy showed myocardial damage, suggesting the invasion of microvasculitis in Schönlein-Henoch purpura to the peripheral coronary vessels. These findings indicate that myocardial damage induced in the patient may be one of the complications caused by Schönlein-Henoch purpura.

Cardiac Catheterization↗
PubMed1990

Acceleration of platelet aggregability due to modulation of native LDL.

The aim of this experiment was to clarify whether low density lipoprotein (LDL) causes an acceleration of platelet aggregability. Native LDL was separated into two fractions by filtered tap-water dialysis, namely, water-soluble LDL (WS-LDL) and non-water-soluble LDL. Although native LDL did not enhance the platelet aggregability, WS-LDL made it markedly increased. WS-LDL consisted of the lipid constituents that were not found in native LDL. Namely, in thin-layer chromatography of WS-LDL, an unknown spot between triolein and free fatty acid was clearly stained. This unknown spot in the WS-LDL was produced by the peroxidation of cholesteryl ester in native LDL. It was confirmed that the spot has the same Rf value as the peroxidate of cholesteryl linolate in thin-layer chromatography. If native LDL is modulated by divalent metal ions and oxygen in the fluids, LDL with biological activity such as an increase of platelet aggregability is produced.

Chromatography, Thin Layer↗
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↗
PubMed1990

[Continuous monitoring of coronary sinus oxygen saturation during pacing loading in patients with syndrome X].

To determine whether patients with syndrome X suffer from myocardial ischemia, coronary sinus oxygen saturation was continuously measured during pacing loading in 31 patients. Subjects were categorized by groups as syndrome X (11 patients), effort angina (14), and old myocardial infarction and valvular heart disease (6). Pacing loading induced evidence of ischemia in all syndrome X patients and in eight of the 11 patients with effort angina, while there was no such evidence in those with old myocardial infarction and valvular heart disease. Coronary sinus oxygen saturation in syndrome X decreased significantly from 44.2 +/- 5.8% to 33.5 +/- 4.4% (p less than 0.01), and it decreased from 47.0 +/- 4.9% to 31.2 +/- 4.0% (p less than 0.01) in effort angina with induced ischemic evidence, indicating that a significant reduction in coronary sinus oxygen saturation reflects the presence of myocardial ischemia. In the group with old myocardial infarction and valvular heart disease, coronary sinus oxygen saturation remained nearly unchanged during pacing. The pattern of depression of coronary sinus oxygen saturation during pacing was steeper in effort angina than in syndrome X. Therefore, we conclude that, although syndrome-X may not be a homogeneous group of patients, most of them may develop myocardial ischemia due to reduced vasodilator reserves of the small coronary artery.

Adolescent↗