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Biomedical subjects

S Ohbayashi

Publications and source records attributed to S Ohbayashi.

30 records · Page 2Linked to original sources
PubMed1988

[A quantitative measurement of the cerebral infarct focus induced by arachidonate infusion and the relationship between measured values and stroke signs].

A method for measuring the organic infarct focus induced by arachidonate infusion into rat brain was devised, and the statistical relationship between the measured values and stroke signs in the rat was studied. By the infusion of arachidonate, a high incidence of cerebral infarction was found in the live rats with uniformly necrotized foci. The size of these foci (infarction rate) were measured by transcripting them to a graduated brain sheet. The relationship between the independent parameter of the infarction rate and the dependent parameter of stroke signs was fully analyzed by multidimensional quantification. Many animals showed no stroke signs despite having lesions (false negative). By contract, no animal without any lesion showed stroke signs (false positive). When each parameter of these signs were quantified and normalized, the stumbling and abnormal posture signs showed a wide range of values, relatively accurately reflecting the infarction degree. Moreover, the highest partial correlation ratio between the various parameters was found to be that between the stumbling and abnormal posture stroke signs. Thus, it may be said that the stumbling and the abnormal posture stroke signs can be considered relatively good parameters for evaluating the degree of an infarction. These parameters should be useful for the testing of anti-infarction drugs.

Animals↗
PubMed1983

[Experimental studies on gastric ulcer (5). Endoscopical evaluation of healing processes of acetic acid ulcer in rats (1). Ulcer reducing process].

The following results were obtained as the result of the sequential observations with an endoscope of the gastric ulcer produced by submucosal injection of acetic acid in rats. 1) The size of the ulcer produced by acetic acid injection observed on the 3rd day after ulcer induction depended on the concentration and volume of acetic acid. 2) The natural reducing rates of the size of ulcers in the region between the fundus and pylorus on the anterior wall (A) and in the glandular region on the greater curvature (B) were compared. The reducing rate of B ulcer was significantly faster than that of A ulcer. 3) No significant difference was observed in the reducing processes of untreated ulcers in 7 weeks old rats and 25 weeks old rats. 4) The ulcer reducing rate of female rats was found to be slightly faster than that of male rats. 5) The ulcer reducing rates of the aldioxa (ALD) and sucralfate (SUC) treated group were significantly faster than that of the control group. However, no difference in the ulcer reducing process between the cimetidine (CIM) treated group and the control group was observed. 6) The ulcer indices (UI) of both the combinations of ALD and SUC and of ALD and CIM were found to be significantly less than that of the control group on the 20th day. Treatment with drug combinations shortened the healing period of ulcers more than treatment with one drug alone. The percent healing by the combination of ALD and SUC was the highest among the groups treated. 7) An approximately linear relationship exists between the logarithm of the days after ulcer induction (x) and logarithm of UI (y), and the following equation was obtained: log y = a log x + b. Slope (a) indicates the ulcer reducing rate in evaluating the ulcer reducing process.

Acetates↗
PubMed1982

Infusion-free hemodiafiltration: simultaneous hemofiltration and dialysis with no need for infusion fluid.

A new simultaneous hemofiltration and dialysis system was developed which has no need of infusion fluid. The system employs two hemodiafilters in a direct series. An ultrafiltration rate and dialysate flow rate control system was employed to control the dialysate flow at the inlet and outlet, and the difference in volume was arranged to be the amount of water removed from the body. When the blood circuit was narrowed between the two hemodiafilters, the ultrafiltration was performed at the first hemodiafilter; at the second one, the dialysate moved to the blood side as a dilution fluid. To remove pyrogens and bacteria, tap water was subjected to activated charcoal, ion exchange and reverse osmosis treatment, followed by preparation of the dialysate. In clinical evaluation, this system showed marked improvement in clearance of middle and large molecules.

Adult↗
PubMed1980

Effects of ticlopidine on thrombotic obstruction of A-V shunts and on dialysance of artificial kidneys.

Administration of ticlopidine, a new inhibitor of platelet aggregation, during hemodialysis to two patients with thrombotic occlusion of external A-V shunts markedly suppressed the obstruction of the shunt and improved anemia. Consequently, it was concluded that this drug may be useful for maintaining good blood flow and good patency of shunts in patients undergoing dialysis. In order to determine the dialyzer efficiency during dialysis, the reduction rate of the dialyzer was determined in vitro. The dialyzer reduction rates for urea, creatinine, uric acid, and phosphoric acid were all lowered after dialysis, and the administration of ticlopidine resulted in a suppression of the drop in the reduction rate. Based on the inhibitory effect of ticlopidine on platelet aggregation, it was assumed that a close correlation may exist between adhesion and aggregation of platelets and the drop in the efficiency of the dialyzer during dialysis as well as thrombotic obstruction of shunts.

Adult↗