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Biomedical subjects

K Onodera

Publications and source records attributed to K Onodera.

At least 271 records · Page 15Linked to original sources
PubMed1991

[Coronary venous oxygen saturation dynamics during intracoronary infusion of ergonovine or acetylcholine in vasospastic angina].

We investigated changes in coronary venous oxygen saturation (CSO2-Sat) dynamics during intracoronary infusion of ergonovine (ERG) or acetylcholine (ACh) in patients with vasospastic angina. In 16 patients with suspected vasospasm in the left coronary artery, intracoronary ERG injection provoked vasospasm in 4 out of 6 patients, and intracoronary ACh in 6 out of 11 patients. A gradual decrease in CSO2-Sat, anteceding angina and ischemic ECG evidence, was characteristic in ERG-induced vasospastic patients, while no significant change of CSO2-Sat was observed in non ERG-induced patients. Intracoronary infusion of ACh was followed in all 11 patients by a transient increase in CSO2-Sat, suggesting decreased myocardial oxygen extraction due to increased coronary blood flow with ACh. However, earlier and sudden decreases in CSO2-Sat below the control levels were characteristic in 6 patients with ACh-induced vasospastic angina. These findings suggest that effects of ERG and ACh on coronary flow dynamics are essentially different although both drugs can provoke vasospasm.

Acetylcholine↗
PubMed1990

Developmental immunohistochemistry of membrane proteins in the brain coded by a gene on human chromosome 21.

A monoclonal antibody, OK-2, against membrane proteins coded by a gene on chromosome 21 was obtained using hamster/human hybrid cells as an antigen, and used for a developmental study on the brains of Down's syndrome (DS) cases. The membrane proteins recognized by OK-2 were expressed earlier in neurons and vessels of DS brains than in normal brains, the difference being more marked in the temporal lobe than in the frontal lobe. This over-expression of the membrane proteins in DS brains, especially in the temporal lobe, may be related to the pathogenesis of or predisposition to Alzheimer type dementia in elderly DS cases.

Adult↗
PubMed1990

Immunohistochemistry of superoxide dismutase-1 in developing human brain.

The developmental changes in superoxide dismutase (SOD)-1 were studied in brains ranging in age from human fetuses to adults by immunohistochemistry. SOD-positive neurons and glial cells appeared with maturation in each region, and increased progressively with gestational and postnatal age. This phenomenon implies a relationship between SOD-1 gene expression and the anti-oxidant defence mechanism in developing neurons and glia.

Adult↗
PubMed1990

Distribution of glial fibrillary acidic protein (GFAP) in the intermediate filaments of the cultured cells from a patient with tuberous sclerosis.

We established a cell line (TS) from adenoma sebaceum of a patient with tuberous sclerosis. Through our previous studies, the abnormal cell division and dysfunction of TS cells were indicated. Glial fibrillary acidic protein (GFAP) and 55 kd protein had been to be major cytoskeletal proteins in these cells. This time we have examined the structure and distribution of cytoskeletons in TS cells with immunoelectron microscopy. TS cells were found to coexpress GFAP and vimentin-like substance; both structures seem to be closely related. The coexistence of a few kinds of proteins integrated in the cytoskeletons might lead to the abnormal behavior of the nucleus during the process of cell division.

Adenoma↗
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

Changes in vascular wall production of prostacyclin and thromboxane A2 in spontaneously hypertensive rats during maturation and the concomitant development of hypertension.

The purpose of this study was to clarify how the metabolism of vascular prostacyclin (PGI2) and thromboxane (TX) A2 in spontaneously hypertensive rats (SHR) is involved in aging and development of hypertension. We removed the aortic walls from 5-week-old and 20 to 25-week-old SHR and age-matched Wistar Kyoto rats (WKY). At 5 weeks of age, there was no significant difference in basal and maximal (arachidonic acid 0.1 mM) 6-keto-PGF1 alpha production between SHR and WKY, but the TXB2 generation in the SHR aortic wall was markedly enhanced as compared with that in WKY. At 20 to 25 weeks of age, the SHR aortic wall synthesized about 1.5 times more 6-keto-PGF1 alpha in the basal condition and twice as much as in the maximal condition as did the WKY wall. However there was no significant difference in TXB2 production between SHR and WKY. Age-dependent increase of vascular 6-keto-PGF1 alpha was greater in SHR than in WKY. Moreover, the maximal/basal 6-keto-PGF1 alpha production ratio increased with age in SHR, but not in WKY. The synthesis of vascular TXB2 was enhanced with age in WKY, but did not change with age in SHR. These data suggest that not only the enhanced basal generation of vascular 6-keto PGF1 alpha but also a much greater reservoir of 6-keto-PGF 1 alpha synthesis in SHR was induced by both hypertension and maturity. The increased production of vascular TXB2 in young SHR may affect the development of hypertension.

6-Ketoprostaglandin F1 alpha↗
PubMed1990

Effects of thiamine administration on hypothermia and hypothalamic histamine levels in dietary-induced thiamine deficient rats.

The rats maintained on a thiamine-deficient diet for 30 days showed hypothermia, and their histamine levels increased significantly in both the anterior and posterior hypothalamus. When these rats were administered, thiamine disulfide and/or provided with thiamine-added diet for a further 30 days, the rats recovered from hypothermia, and histamine levels were decreased to the normal level. Thus, it is probable that the increased histamine levels in the hypothalamus, especially those in its anterior region, are closely related to the hypothermia in thiamine-deficient rats.

Animals↗
PubMed1990

Epidemiological study on hypertension in northern Japan.

Aging for 5 years, from 50 to 55 years of age, influenced the various markers in a normotensive group but a similar correlation could not be seen in a hypertensive group. This suggests an impaired control of physiological homeostasis in hypertensive subjects. An increase in body mass index (BMI) is an important predictor in understanding the pathogenesis of hypertension, although the mechanism is uncertain. A reduction in BMI may reduce the risk of high blood pressure.

Age Factors↗
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↗
PubMed1990

[Evaluation of left ventricular mechanical energy efficiency and ventriculo-arterial coupling in humans using the conductance catheter technique].

To evaluate left ventricular mechanical energy efficiency and ventriculo-arterial coupling in humans, left ventricular pressure-volume relations were determined using the conductance catheter technique in 20 patients undergoing cardiac catheterization. The results were as follows: 1. A convex, curvilinear relationship was observed between end-systolic pressure-volume relations (Emax) and left ventricular ejection fraction (EF), as shown in the equation of EF = 28.5 x log (Emax) + 39.6 (r = 0.67, p less than 0.01, n = 20); EF remained nearly constant in the range of Emax greater than or equal to 4 mmHg/ml/m2, whereas, EF decreased markedly under the Emax of 4 mmHg/ml/m2. 2. A convex, curvilinear relationship was observed between Emax and mechanical energy efficiency (EW/PVA), as shown in the equation of EW/PVA = 30.5 x log (Emax) + 54.8 (r = 0.83, p less than 0.01, n = 16). 3. A concave, curvilinear relationship was observed between Emax and ventriculo-arterial coupling (Ea/Emax), as shown in the equation of Ea/Emax = -0.8 x (Emax)0.5 + 2.6 (r = -0.85, p less than 0.01, n = 16). Accordingly, EW/PVA was markedly decreased with changes in Emax in the range less than 4 mmHg/ml/m2, although it remained slightly increased above 4 mmHg/ml/m2. Ea/Emax was maintained constant (p less than 0.5) in the range of Emax above 4 mmHg/ml/m2 but was abruptly decreased when Emax was reduced below 4 mmHg/ml/m2. These results indicate that depressed left ventricle attempts to work effectively at the risk of mechanical energy efficiency and with suitable matching by aortic property. Application of pressure-volume relationships provides a new framework for evaluation and treatment of the failing heart.

Adolescent↗
PubMed1990

[Two cases of pulmonary alveolar proteinosis with increased CEA].

Two cases of pulmonary alveolar proteinosis (PAP) with increased CEA were reported. Case 1 was a 62-year-old male with suspected pulmonary fibrosis, who was transferred to our hospital. Laboratory findings on admission revealed 31.3 ng/ml of CEA. Because he had severe dyspnea, lung biopsy was not carried out. His condition gradually deteriorated and he died of respiratory failure. Autopsy revealed he had PAP and no malignancy. Case 2 was a 48 year-old male referred to our hospital because of dyspnea. Serum CEA was 52.8 ng/ml. Microscopic examination of a transbronchial lung biopsy showed PAP. The level of CEA in bronchoalveolar lavage fluid was 151 ng/ml. Unilateral whole lung lavage was performed twice. With the improvement of chest X-ray findings, serum levels of CEA fell to normal level. The molecular weight of CEA in bronchoalveolar lavage fluid was 180,000. Immunochemical staining of CEA in lung revealed nonspecific findings.

Carcinoembryonic Antigen↗
PubMed1990

[Estimation of myocardial oxygen extraction dynamics in effort angina by continuous measurement of coronary venous saturation].

To estimate myocardial oxygen extraction dynamics in the situation of increased myocardial oxygen requirement, we made a continuous measurement of coronary venous oxygen saturation (CSO2-Sat) using the fiberoptic catheter system and a measurement of myocardial lactate extraction ratio (MLER) in 14 patients. Ten patients showed ischemic ST depression and/or anginal episodes during the pacing loading, while 4 patients did not. Although transient decreases in CSO2-Sat were observed in the non-ischemic 4 patients immediately after the initiation of pacing or with the increase in pacing rate. CSO2-Sat and MLER remained almost unchanged from the start of pacing to the time of maximal pacing. However, in the 10 patients who developed ischemia, CSO2-Sat fell from 39.5 +/- 1.8% before pacing to 32.9 +/- 2.8% at the time of maximal pacing (p less than 0.05), with an average decrease of 6.6 +/- 2.8%. Data of MLER obviously indicated the appearance of myocardial ischemia (32.1 +/- 4.7% to 9.2 +/- 10.3%, p less than 0.05). These findings suggest that myocardial oxygen extraction will increase transiently or continuously to meet the myocardial oxygen demand when increase in coronary blood flow is limited. Continuous measurement of coronary venous saturation may be useful for the early detection of myocardial ischemia.

Adult↗
PubMed1990

Electron microscopic findings in benign deoxycorticosterone and 11-deoxycortisol-producing adrenal tumor.

The ultrastructural characteristics of a benign adrenal adenoma that produces deoxycorticosterone and 11-deoxycortisol were examined by transmission electron microscopy. Both large, round mitochondria with a few cristae in the peripheral portion and spherical or oval mitochondria with sacrotubular cristae were observed in adenoma cells. The development of agranular or granular endoplasmic reticulum varied from cell to cell. In some cells, many vacuoles and collagenous fibers were also seen. Thus, the adrenal tumor we examined was composed of the cells derived from the fascicular zone, which are associated with Cushing's syndrome, and the cells of the glomerular zone observed in association with primary aldosteronism.

17-Hydroxycorticosteroids↗
PubMed1989

Mechanism of selective killing by dilinoleoylglycerol of cells transformed by the E1A gene of adenovirus type 12.

Rat 3Y1 fibroblasts transformed by the E1A gene of adenovirus type 12 (E1A-3Y1 cells) are highly sensitive to the cell-killing effect of 1,3-dilinoleoylglycerol (DLG) administered in a culture medium, whereas the parental 3Y1 cells are less sensitive (H. Shimura et al., Cancer Res., 48: 578-583, 1988). The selective cytotoxicity of DLG to E1A-3Y1 cells was markedly reduced by the simultaneous administration of nonspecific antioxidants such as vitamin E, butylated hydroxytoluene, and ascorbic acid. Specific scavengers for oxygen radicals had no effect. Lipoxygenase inhibitors (nordihydroguaiaretic acid, esculetin, and baicalein) reduced the DLG-mediated selective cytotoxicity, whereas cyclooxygenase inhibitors (acetylsalicylic acid and indomethacin) showed no effect. The intracellular and extracellular contents of the products from lipid peroxidation as measured by the thiobarbituric acid test were significantly greater in E1A-3Y1 cells than in the parental 3Y1 cells. In comparison with DLG, linoleic acid and monolinoleoylglycerol were equally toxic to E1A-3Y1 and parental 3Y1, and trilinoleoylglycerol was weakly toxic to both types of cells. Scanning electron microscopy revealed that numerous holes about 0.2 micron in diameter were scattered all over the surface of the E1A-3Y1 cells after treating the cultures with DLG. These results suggest that; (a) the DLG-mediated cytotoxicity to the E1A-transformed cells is attributable to lipid peroxidation; (b) the structural property of DLG is essential to the E1A specificity of cytotoxicity; and finally (c) the destruction of the cell membrane is the basis of cytotoxicity of DLG.

Adenovirus Early Proteins↗