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Biomedical subjects

S Kimoto

Publications and source records attributed to S Kimoto.

At least 19 recordsLinked to original sources

[Hepatic arteriography under temporary hepatic venous occlusion].

Hepatic arteriography with and without temporary segmental hepatic vein occlusion was performed in 10 patients, five of whom had chronic liver injury. Hepatic arteriograms obtained during hepatic venous obstruction demonstrated significantly more peripheral and definite arterial branches in the occluded area and fewer peripheral branches in the non-occluded segment. A prolonged, dense hepatogram (sinusoidogram) showing hepatofugal opacification of the portal vein was obtained in the occluded area. Only one case with a large veno-venous anastomosis did not show these findings. Hepatic arteriograms in two cases with hepatocellular carcinoma provided clear visualization of peripheral portal branches that could act as efferent tumor vessels during regional temporary hepatic vein occlusion. Temporary hepatic venous occlusion may cause a sudden increase of hepatic arterial flow in the occluded area and transsinusoidal arterioportal communication there. This method can be useful for the diagnosis and arterial infusion or embolization therapy of hepatic diseases.

Adult

A comparative study of dynamic CT and ultrasonic pulsed Doppler method for estimation of the portal blood flow.

A new dynamic CT method for evaluating the portal blood flow is described. Thirty healthy volunteers were injected with non-ionic hypo-osmotic iodine contrast medium to estimate the portal blood flow. Time density curves (TD-curves) for the abdominal aorta and the main trunk of the portal vein were determined on the basis of data obtained by dynamic CT. From the TD-curves, portal blood flow coefficient and circulation time to flow into the portal vein (P-P time) were calculated. More detailed data of the TD-curves could be obtained by the new dynamic CT than by the previous methods. Subjects were simultaneously studied by an ultrasonic pulsed Doppler method which has been clinically accepted. There was a significant correlation between our dynamic CT method (portal blood flow coefficient) and the ultrasonic pulsed Doppler method concerning the measurement of portal blood flow. Therefore, it may be concluded that this CT method is reliable and clinically acceptable.

Adult

[Evaluation of renal function by dynamic CT].

Dynamic CT scans of the kidney were conducted in 57 persons with varied renal function. The results of dynamic CT were used to obtain time-density curves for renal cortex, medulla and aorta. Various parameters were calculated from these time-density curves. Among them, CA ratio, the ratio of the area under the renal cortex curve to the area under the aortic curve, showed the best correlation with creatinine clearance. With these parameters, dynamic CT studies are believed to be useful in evaluating renal function.

Adult

Studies of an aspect of renal function with the aid of dynamic CT and renogram.

Dynamic CT scans were conducted on 94 persons who had been randomly selected among the patients and the volunteers. The test results were used to obtain the time-density curve. A part of the subjects (20 cases) underwent the renogram examination for the comparative studies. The cortico-aortic (CA) ratio derived from the time-density curve demonstrated good correlation between the dynamic CT and the renal function (r = 0.68). When the dynamic CT studies and the renogram were compared, the vascular phase of the renogram showed strong correlation with CA ratio. Consequently the dynamic CT study the CA ratio was believed to demonstrate the renal function.

Adolescent

Plasma endothelin levels in hypertension and chronic renal failure.

Endothelin-1 is a novel endothelium-derived vasoconstrictive peptide. Using a highly specific and sensitive radioimmunoassay for endothelin-1, plasma levels of immunoreactive endothelin-1 were measured in 32 research subjects with normal renal function (21 normal subjects and 11 patients with essential hypertension), 24 patients with nondialyzed chronic renal failure, and 51 patients undergoing maintenance hemodialysis. Although there was no significant difference in plasma immunoreactive endothelin-1 levels among the three groups, patients with essential hypertension had significantly higher plasma endothelin-1 levels than normal subjects (2.29 +/- 1.09 vs. 1.41 +/- 0.50 pg/ml, p less than 0.025). When nondialyzed and hemodialyzed patients were divided into hypertensive and normotensive groups, the nondialyzed hypertensive group (n = 17) had higher plasma endothelin-1 levels than the comparable normotensive group (n = 7) (3.08 +/- 3.43 vs. 0.73 +/- 0.34 pg/ml, p less than 0.05), and the hemodialyzed hypertensive group (n = 18) had higher plasma endothelin-1 levels than the comparable normotensive group (n = 33) (2.66 +/- 1.92 vs. 1.35 +/- 0.73 pg/ml, p less than 0.005). Plasma atrial natriuretic factor, arginine vasopressin, renin activity, and aldosterone concentration did not show significant differences between hypertensive and normotensive individuals or a correlation with plasma endothelin-1 levels. These data suggest that circulating endothelin-1 may be partly involved in the development or maintenance of hypertension in humans.

Endothelins

[Follow-up study on anti-HBs levels in vaccinees after two and three doses of HB vaccine. (2)].

An HB prophylaxis vaccination that included a primary and secondary vaccination was carried out on persons working at the university hospital. In the primary vaccination group, the subjects were inoculated the second time with a vaccine derived from human blood plasma obtained from the Kitazato Therapeutic Research Institute. The third time, they were inoculated with a vaccine from the Chemo-Sero Therapeutic Research Institute derived from a second-generation vaccine organized ferment. The vaccine used for the second inoculation group was obtained from the Chemo-Sero Therapeutic Research Institute. Results were summarized as follows: 1) The primary vaccination group: (1) The number of the 153 subjects inoculated with the primary vaccination at the time of the second inoculation, 49 subjects (32%) tested positive for antibodies 3-4 months following inoculation. Thirty-two subjects (20%) tested positive 15-16 months following inoculation with a high rate among females. (2) Among 104 subjects inoculated the third time with the primary vaccination (those who tested negative the second inoculation of the above vaccine), 61 subjects (58.7%) tested positive for antibodies 8-9 months following inoculation with a generally high rate among females. Twenty-eight subjects (26%) tested 15-16 months after inoculation with a high rate among females between 20 and 30 years and among males between 40 and years. 2) The secondary group: Among the 38 subjects who were inoculated the second time with the secondary vaccination, 8 subjects (21%) tested positive for antibodies 5-6 months following inoculation, with a high rate among females in their 20's. 3) The rate of antibodies formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

[Effects of indomethacin on calcium release from cultured rat calvaria].

The bone-resorbing action of lipopolysaccharides (LPS) in vitro has unknown mechanism of action. In order to evaluate the effect of LPS on rat calvaria and the influence of LPS on the bone-resorbing activity of macrophages, the following experiments were conducted. The addition of macrophages 10(6)/ml to a culture system composed of rat calvaria increased calcium release from the cultured bone. Addition of macrophages 10(6)/ml preincubated with 10(-2) mg/ml LPS caused a more pronounced release of calcium from the cultured bone. Combined use of Indomethacin, a prostaglandin synthesis inhibitor, with macrophages and macrophages preincubated with LPS inhibited calcium release, suggesting a possible participation of prostaglandins in osteoclast mediated bone resorption.

Animals

Identification of osteoblast-specific monoclonal antibodies.

A series of four antibodies against rat osteoblasts have been produced using the hybridoma technique. After bone cells isolated from newborn rat calvariae by a sequential digestion procedure were cultured for 3 days, the cells were trypsinized and further maintained in rotation cultures overnight. Out of the cultured bone cells alkaline phosphatase-positive cells were sorted by flow cytometry and used as immunogens. The clones secreting the antibodies were selected on the basis of the abilities of these antibodies to bind to the bone cells but not to fibroblasts from neonatal rat head skins, in an enzyme-linked immunosorbent assay. Clones of two hybridomas, designated AOB-1 and AOB-2, were used to characterize the antigenic determinant(s) in osteogenic cells. The antibody showed the reactivity with isolated alkaline phosphatase-positive cells, osteogenic tissue cells in newborn rat calvaria, and mandibula, but not with the cells in head skin, lung, kidney, liver, or stomach as determined by immunofluorescence study. Western blot analysis has identified the antigenic determinants possessing apparent molecular weights of 210,000, 110,000, 65,000, 58,000, 40,000, 36,000, 32,000, 28,000, 25,000, 17,000, and 15,000 of osteoblast-rich monolayer cultured cells. According to the cell surface detection with biotin-avidin protein blotting technique, these fractions appear to be present as components of the cell surface of the osteoblast.

Animals

Actions of a newly synthesized compound (711389-S) on various types of experimentally induced arrhythmias in mammalian species in situ.

We examined effects of 711389-S, a new antiarrhythmic agent, on ouabain-induced arrhythmias in dogs and guinea-pigs, aconitine-induced arrhythmias in dogs and mice, adrenaline-induced arrhythmias in dogs under an anesthetized condition, and arrhythmias induced by coronary artery ligation and occlusion by a glass bead in dogs under conscious and un-restrained conditions. 711389-S (1-3 mg/kg, i.v.) decreased the number of ventricular extrasystoles induced by ouabain in dogs, and the doses of ouabain required to induce various types of arrhythmias were increased by pretreatment of guinea-pigs with intraduodenal application of 711389-S (5-10 mg/kg). In mice, 711389-S (3 mg/kg, i.v. or 10 mg/kg, p.o.) significantly prolonged the time to onset of arrhythmias induced by aconitine infusion. Atrial fibrillation induced by a topical application of aconitine on the atrium was blocked by 711389-S (1 mg/kg, i.v.) in dogs. 711389-S (1-3 mg/kg, i.v.) depressed arrhythmias induced by adrenaline and restored the sinus rhythm by significantly decreasing the number of ventricular ectopic beats induced by coronary ligation or occlusion in dogs. Oral administration of 711389-S (10-30 mg/kg) in dogs markedly depressed the ventricular ectopic beats induced by coronary ligation. The half decay time of 711389-S after a single bolus injection of 711389-S ranged from 60 to 80 min. Results indicate that 711389-S has similar antiarrhythmic effects to those of other Class I antiarrhythmic agents in situ, and they suggest that this compound might have potential usefulness as a new type of antiarrhythmic agent for clinical use.

Aconitine