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Biomedical subjects

S Ochi

Publications and source records attributed to S Ochi.

At least 91 records · Page 5Linked to original sources
PubMed1992

[A new analytical method for simultaneous measurement of iothalamate and iohexol].

Glomerular filtration rate (GFR) is believed to be the overall index of renal function, and the renal clearance of inulin (Cin) obtained during constant intravenous infusion has long been accepted as the gold standard of GFR measurement. Because of a number of technical difficulties inherent in the assay of inulin concentration in urine and plasma, its utility in clinical practice is limited. Iothalamate, urographic contrast medium, which behaves and is excreted in a fashion similar to inulin, has been accepted as a good filtration marker. We examined whether GFR could be estimated by ionic contrast media, "iothalamate" and non-ionic contrast media, "iohexol", when the high-performance liquid chromatography (HPLC) system was used as the analytic method. In our HPLC system, iothalamate and iohexol could be simultaneously determined. The assay results gave linearity within the wide range of concentrations tested. In seventeen subjects, the renal clearances of creatinine, iothalamate, and iohexol (Ccr, Ciot, and Cioh) were compared with that of inulin. The slopes with zero intercept of Ccr vs Cin, Ciot vs Cin, and Cioh vs Cin were 1.24 +/- 0.02, 1.06 +/- 0.02, and 0.83 +/- 0.02, respectively. In conclusion, an excellent correlation of renal clearance of iothalamate with that of inulin was obtained in patients with a wide range of renal function and normal volunteers. This justifies the use of the single injection of iothalamate and HPLC system as the analytic method in the measurement of GFR.

Chromatography, High Pressure Liquid↗
PubMed1991

Enzyme-linked immunosorbent assay for rapid detection of toxins from Clostridium perfringens.

An enzyme-linked immunosorbent assay (ELISA) with antibodies specific to beta, epsilon and iota ib toxins of Clostridium perfringens was developed to detect beta, epsilon and iota ib toxins, respectively. The ELISA was sensitive enough to detect as little as 1.0 ng/ml of purified beta and iota ib toxins and 0.1 ng/ml of purified epsilon toxin. By means of the ELISA method, 192 isolates of C. perfringens from food samples in Japan and Thailand, and 58 isolates from patients suffering from gas gangrene or gastroenteritis were examined. One isolate from food samples in Japan, three from food samples in Thailand and five from stools of patients with gastroenteritis were C. perfringens type D. One type B and one type C were detected from the stools of patients with gastroenteritis.

ADP Ribose Transferases↗
PubMed1991

Signal transduction mechanism of interleukin 6 in cultured rat mesangial cells.

Interleukin 6 (IL-6) is one of the potent autocrine growth factors for mesangial cells. We investigated the signal transduction mechanism of IL-6 in cultured rat mesangial cells. IL-6 induced a transient increase of inositol 1,4,5-trisphosphate (Ins 1,4,5-P3) followed by a transient and sustained increase of intracellular calcium concentration, suggesting that IL-6 stimulates phosphoinositide turnover. IL-6 also stimulated prostaglandin E2 (PGE2) production. The IL-6-concentration dependency in PGE2 production was similar to that in Ins 1,4,5-P3 production. We concluded that the action of IL-6 on mesangial cells is exerted at least partially through the enhancement of phosphoinositide turnover and PGE2 production.

Animals↗
PubMed1991

Partial agonist activity of celiprolol, a cardioselective beta-antagonist.

The beta-antagonistic effects of celiprolol were assessed in isolated guinea-pig preparations. The pA2 values obtained were 7.84 +/- 0.07, 7.79 +/- 0.06 and 6.45 +/- 0.11 against the positive chronotropic and inotropic effects in the atria and relaxant effects in the trachea induced by isoproterenol, respectively, indicating that celiprolol is a cardioselective beta-antagonist. Celiprolol produced slight positive chronotropic and inotropic effects in atrial preparations and a uniquely strong relaxant effect in tracheal preparations. All these effects were attenuated by pretreatment with 10(-6) M atenolol or 10(-6) M propranolol. In pithed rats, celiprolol produced pressor responses at doses lower than 0.03 mg/kg and hypotensive responses at doses higher than 0.3 mg/kg. It produced sustained increases in heart rate in all doses applied. These effects were attenuated by pretreatment with 1 mg/kg of propranolol. The pressor response might be taken to be a reflection of an increase in cardiac function mediated by cardiac beta 1-receptor stimulation, while the hypotension may be ascribed mainly to stimulation of beta 2-adrenoceptors in the vascular system. It is concluded that celiprolol exerts a uniquely strong partial agonist activity at beta 2-adrenoceptors.

Adrenergic beta-Agonists↗
PubMed1991

Stimulatory effect of thrombin on endothelin-1 production in isolated glomeruli and cultured mesangial cells of rats.

To determine whether endothelin-1 (ET-1) is released in close proximity to its binding sites on glomerular mesangial cells, and also to elucidate the regulatory factors responsible for its release, we measured immunoreactive ET-1 (ir-ET-1) in the incubation media of isolated glomeruli and cultured mesangial cells of rats using enzyme immunoassay under both basal and thrombin-stimulated conditions. ir-ET-1 was released time-dependently, from isolated glomeruli and cultured mesangial cells. Thrombin (2 U/ml) stimulated the release from both preparations. The release of immunoreactive big endothelin-1 (ir-big ET-1), which was assayed by using enzyme immunoassay, was also time-dependent, and the release was increased by thrombin (2 U/ml; at 4 h, 8 h, and 24 h) in cultured mesangial cells. The releases of big ET-1 and its converted product ET-1 from mesangial cells, an established target for ET-1, suggests that ET-1 acts as an autocrine factor for the cells.

Animals↗
PubMed1991

Effect of Clostridium perfringens alpha toxin on contraction of isolated guinea-pig diaphragm.

The effect of Clostridium perfringens alpha toxin on contraction induced by electric stimulation of isolated guinea-pig diaphragm was investigated. The toxin inhibited electrically stimulated contraction of the tissue in a dose- and incubation time-dependent manner. Tetrodotoxin resulted in no effect of the action of the toxin. Nifedipine dose-dependently delayed the action of the toxin, but verapamil and diltiazem did not. On the other hand, treatment of the toxin with N-acetylimidazole caused significant reduction of the inhibitory activity of the toxin on contraction, but did not cause significant loss of phospholipase C activity (PN activity) as measured by hydrolysis of p-nitrophenylphosphorylcholine. The data showed that the toxin impairs contraction of isolated guinea-pig diaphragm.

Animals↗
PubMed1991

[The relationship between the aortic pulse wave velocity and osteoporosis in elderly women].

The relationship between arteriosclerosis and osteoporosis (OP) was assessed in 20 elderly women. The aortic pulse wave velocity (PWV) was used as the index of arteriosclerosis and bone mineral content (BM) of the vertebral body, which was measured by quantitative computed tomography, was used as an index of OP. PWV and BM showed a significant correlation with aging (PWV and age: r = 0.466, p less than 0.05, BM and age: r = -0.487, p less than 0.05). In the group in which the serum alkaline phosphatase (ALP) was higher than 180 IU/l (n = 11), there was a significant inverse correlation between PWV and BM (r = -0.728, p less than 0.02). On the other hand, there was no correlation between PWV and BM in the group in which ALP was lower than 180 IU/l (n = 9). These results suggest that in cases with OP and high levels of ALP, calcium (Ca) seems to be released from the bone system and transferred to the wall of the aorta. The mechanism and pathogenesis of this Ca transference is unknown and should be investigated.

Aged↗
PubMed1991

Endothelin-1 stimulates prostaglandin E2 production in an extracellular calcium-independent manner in cultured rat mesangial cells.

To study a possible role of endothelin-1 (ET-1) in the regulation of glomerular function, we examined the presence of receptors for, and the biological action of, ET-1 in cultured rat mesangial (M) cells. The first-subcultured M cells prepared from isolated glomeruli of Sprague-Dawley rats were used. ET-1 binding was assayed by using 125I-ET-1. Inositol 1,4,5-trisphosphate (IP3) was determined by IP3-specific binding assay. Intracellular calcium (iCa2+) was measured in fura-2 loaded cells. Prostaglandin E2 (PGE2) was measured by radioimmunoassay. In M cells there existed two classes of binding sites specific for ET-1 (Kd was 0.24 and 4.4 nmol/L, Bmax was 130 and 1070 fmol/mg, respectively). ET-1 (10(-7) mol/L) induced a rapid and transient increase in IP3, followed by transient and sustained increases in iCa2+. Nicardipine (10(-6) mol/L) inhibited only the sustained increase in iCa2+. ET-1 (10(-9) mol/L to 10(-7) mol/L) significantly stimulated PGE2 production with the concentration dependency. Nicardipine (10(-6) mol/L) and diltiazem (10(-6) mol/L) did not inhibit the PGE2 production. We conclude that M cells have specific ET-1 receptors linked to phosphoinositide turnover and PGE2 production, and PGE2 production by ET-1 may be through an extra-cellular calcium-independent mechanism. Our results suggest that ET-1 plays an important role in the regulation of glomerular functions by modulating PGE2 production in M cells.

Animals↗
PubMed1990

Restrictive cardiomyopathy following acute myocarditis--a case report.

A fifty-five-year-old man developed intractable heart failure four weeks after upper respiratory infection. His central venous pressure was as high as 300 mmH2O. Two-dimensional echocardiogram revealed no muscular hypertrophy of the ventricles, no pericardial thickness, and no pericardial effusion. On catheterization, hemodynamic data were compatible with restrictive cardiomyopathy. Transvenous endomyocardial biopsy of the left ventricle was performed. Histologic examination strongly suggested that cardiomyopathy developed after acute myocarditis.

Biopsy↗
PubMed1990

[Pharmacological studies of celiprolol: I. Beta-blocking effect, intrinsic sympathomimetic activity, vasodilating and hypotensive effects].

The beta-blocking effect, intrinsic sympathomimetic activity (ISA), and vasodilating and hypotensive effects of celiprolol were tested. 1. Celiprolol competitively antagonized the isoproterenol-induced positive chronotropic and inotropic effects in guinea pig right atrial and papillary muscles and isoproterenol-induced guinea pig tracheal relaxation with pA2 values of 8.03, 7.98 and 6.43, respectively. 2. In dogs, isoproterenol-induced increases in cardiac contractility and heart rate were markedly inhibited by celiprolol (83.1 and 84.8%, respectively), while isoproterenol-induced hypotension was suppressed only by 16.8%. 3. Celiprolol increased the beating rate of the right atrium and relaxed the trachea isolated from normal and reserpinized guinea pigs. Celiprolol also potentiated the contractility of the left atrium isolated from reserpinized animals. These effects of celiprolol were antagonized by propranolol. 4. Celiprolol concentration-dependently relaxed rat femoral arteries contracted by methoxamine. The concentration-relaxation curve was shifted to the right by pretreatment with propranolol. 5. Orally administered celiprolol produced long lasting hypotension in conscious SHR without any heart rate change. 6. These results indicate that celiprolol is a highly cardioselective beta-blocker with a significant ISA, which contributes to its vasodilatory and hypotensive effects.

Adrenergic beta-Antagonists↗
PubMed1990

[Pharmacological studies of celiprolol: III. Effects of celiprolol on the cardiovascular system and renal function, and its antiarrhythmic effects].

Effects of celiprolol on the cardiovascular system and renal function, and its antiarrhythmic effects were studied. 1. In anesthetized dogs, celiprolol (0.01-3 mg/kg, i.v.) dose-dependently depressed the maximum rate of rise of left ventricular pressure, cardiac output and cardiac work less severely than propranolol and atenolol. 2. Celiprolol (0.01 mg/kg, i.v.) decreased the myocardial oxygen consumption in anesthetized dogs as potently as propranolol. 3. Celiprolol (0.03-3 mg/kg, i.v.) tended to increase femoral blood flow. Celiprolol (1 mg/kg, i.v.) increased common carotid blood flow. 4. Celiprolol decreased urine volume and urinary excretion of Na+ and Cl- at doses of 1 and 10 mg/kg and increased the sodium reabsorption rate at a dose of 10 mg/kg in anesthetized dogs, whereas it produced no change in plasma renin activity. 5. Celiprolol inhibited both halothane-adrenaline arrhythmia in dogs and ouabain-induced arrhythmia in rabbits. Its antiarrhythmic effects were 1/10-1/3 as potent as those of propranolol. 6. Celiprolol suppressed the maximum rate of rise of action potential at a concentration of 3 x 10(-4) M, which was 30 times as high as that of propranolol. Celiprolol (3 x 10(-5)-3 x 10(-4) M) dose-dependently shortened the effective refractory period (ERP), but it produced no change in the ratio of ERP to action potential duration. 7. These results suggest that celiprolol may be a useful drug for the treatment of ischemic heart disease and some types of arrhythmia, and that it has only a little influence on renal function.

Action Potentials↗
PubMed1990

[High flow medullary venous malformation with aneurysm on the proximal artery--a case report].

Medullary Venous Malformation with an aneurysm is uncommon and only 4 cases have been reported in previous papers. We reported a case of a medullary venous malformation (MVM) of the frontal lobe with an aneurysm on its proximal artery. A 48 year old female with numbness of right fingers visited our hospital. On the CT scan, an abnormal enhanced area was found inside the left frontal lobe. The left carotid angiography showed both of an aneurysm around A com A in early arterial phase, and "MVM with early blush" in capillary-early venous phase. MRI showed linear signal void crossing the cortex to join paraventricular low intensity area (LIA) with slight cortical atrophy on sagittal slice. The CBF study by Xe-SPECT proved a high flow lesion, with mean CBF 69 (left), 59 (right) mg/100 g brain/min, Protective operation only for aneurysm was performed. The MVM in our case was proved to be a "high flow-low resistance system" by CBF study, although MVM has been considered a "low flow system". Reviewing papers, there were 3 cases of "high flow MVMs" confirmed by the measurement of CBF, all of them were large sized (greater than 4 cm) and with early blush angiographically. We conclude that large sized MVM with early blush needs hemodynamic inspection and special care to prevent "high flow MVMs" from hemorrhage and the steal.

Cerebral Angiography↗
PubMed1990

[Renal pelvic tumor in chronic renal failure: report of a case].

A 44-year-old female was admitted because of gross hematuria six years after beginning hemodialysis for chronic renal failure. There was a past history of hematuria one year before admission. Retrograde pyelography, computed tomographic scan and angiography had been performed, and a probable malignant tumor of left renal pelvis had been found in 1986. We recommended surgery at the time, but she refused treatment and was followed up. On June 22, 1987, the patient had a second attack of gross hematuria resulting in bladder tamponade, and hematuria from the left ureteric orifice was confirmed at cystoscopy. Ultrasound showed left obstructive nephropathy. Left nephrectomy was performed because of the presumptive diagnosis of malignant tumor. The histological diagnosis was transitional cell carcinoma of the left renal pelvis. Two courses of M-VAC (methotiexate, vinblastine, adriamycin and cisplatin) chemotherapy were accordingly given postoperatively. The incidence of renal pelvic tumor and its chemotherapy in patients with chronic renal failure are discussed.

Adult↗
PubMed1989

Peritoneovenous shunting as compared with medical treatment in patients with alcoholic cirrhosis and massive ascites. Veterans Administration Cooperative Study on Treatment of Alcoholic Cirrhosis with Ascites.

The optimal management of severe ascites in patients with alcoholic cirrhosis has not been defined. in a 5 1/2-year study, we randomly assigned 299 men with alcoholic cirrhosis, who had persistent or recurrent severe ascites despite a standard medical regimen, to receive either intensive medical treatment or peritoneovenous (LeVeen) shunting. We identified three risk groups: Group 1 had normal or mildly abnormal results on liver-function tests, Group 2 had more severe liver dysfunction or previous complications, and Group 3 had severe prerenal azotemia without kidney disease. For the patients who received the medical treatment and those who received the surgical treatment combined, the median survival times were 1093 days in Group 1, 222 days in Group 2, and 37 days in Group 3 (P less than or equal to 0.01) for all comparisons). For all the groups combined, the median time to the resolution of ascites was 5.4 weeks for medical patients and 3.0 weeks for surgical patients (P less than 0.01). Within each risk group, mortality during the initial hospitalization and median long-term survival were similar among patients receiving either treatment. However, the median time to the recurrence of ascites in Group 1 was 4 months in medical patients, as compared with 18 months in surgical patients (P = 0.01); in Group 2 it was 3 months in medical patients as compared with 12 months in surgical patients (P = 0.04). The median duration of hospitalization was longer in medical patients than in surgical patients (6.1 vs. 2.4 weeks in Group 1 [P less than 0.001] and 5.0 vs. 3.1 weeks in Group 2 [P less than 0.01]). Group 3 was too small to permit a meaningful comparison. During the initial hospitalization, the incidence of infections, gastrointestinal bleeding, and encephalopathy was similar among the medical and surgical patients. We conclude that peritoneovenous shunting alleviated disabling ascites more rapidly than medical management. However, survival was closely related to the severity of the illness at the time of randomization and was not altered by shunting.

Ascites↗