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Biomedical subjects

S Takeuchi

Publications and source records attributed to S Takeuchi.

At least 883 records · Page 49Linked to original sources

Fluorescein mercuric acetate as a probe of the dynamic structure of double-helical DNA.

Fluorescein mercuric acetate causes the unwinding of DNA and binds to the separated bases. The kinetics of this unwinding process were studied using both untreated DNA and sonicated DNA at various pH values (6.8--9.3) and Na+ concentrations (10--250 mM). The unwinding process is explained by assuming a nucleation in the middle of DNA (as a function of time) as well as at the helix ends (immediately after addition of this reagent) and the subsequent growth of the nuclei. The frequency of the nucleation in the middle of DNA appears to be markedly affected by pH and Na+ concentration. In contrast, the reaction rate of this reagent with heat-denatured DNA was almost insensitive to these environmental variables. The growth rate of the unwinding nuclei in double-stranded DNA also appears insensitive. The most important implication of this study is that in the low pH range (6.8--7.5) the reactivity of thermally-induced locally open regions in the middle of double-helical DNA toward this reagent appears much higher than that of heat-denatured DNA. Since this reagent is negatively charged, these findings are discussed in view of its electrostatic interaction with the locally open regions.

Chemical Phenomena↗

Dynamics of kallikreinogen under hemodialysis.

There are many complications due to hemodialysis, causes of which seem to lie under disorders of the coagulation system, fibrinolytic system, and kinin system. Therefore, it is important to understand the dynamics of these systems during hemodialysis. Accordingly, kallikreinogen, plasminogen, plasmin inhibitors, contact factor, antithrombin, and prothrombin were assayed during the experimental dialysis, experimental ultrafiltration and clinical hemodialysis. Plasmin inhibitors decreased remarkably by dialysis. They then recovered the pre-dialytic values as time went on. Kallikreinogen did not show any definite tendency immediately after the beginning of dialysis, but two hours later its value rather increased relative to thepre-dialytic value. It was supposed that this increase was caused by reactive hyperproduction due to gradual consumption of kallikreinogen. Contact factor slightly decreased by dialysis, whereas prothrombin and antithrombin decreased apparently. When hemodialysis is practiced, it is necessary to fully realize that the coagulation system, fibrinolytic system, and kinin system might lose their balance.

Antithrombins↗

A case of mesenteric cyst diagnosed by ultrasound examination and a review of Japanese literatures.

Mesenteric cyst is relatively rare, and its diagnosis is difficult. We carried out an ultrasound examination on a 6-year-old boy who showed intestinal obstruction. This examination revealed an abdominal mass, and he was diagnosed as mesenteric cyst. Later it was confirmed by operation. The histopathological examination revealed that it was a lymphangioma. A review was also carried out on 288 cases of mesenteric cyst in Japan.

Child↗

Surgical correction of double outlet left ventricle associated with hypoplastic right ventricle: direct anastomosis of right atrial appendage and pulmonary artery.

This reports concerns a 9 years old boy, who had situs solitus and atrioventricular concordance with double outlet left ventricle, pulmonary stenosis, tricuspid stenosis, ventricular septal defect, secundum atrial septal defects and hypoplastic right ventricle. Previous Blalock-Taussig shunt was created at the age of 11 months. Total correction consisted of closure of atrial septal defect and tricuspid valve orifice, and direct anastomosis of right atrial appendage to pulmonary trunk. Though atrial pacing was required for the immediate post operative period, the patient regained sinus rhythm 3 days after operation. He is doing well at present, one year after the operation.

Cardiac Catheterization↗

Protection against hemorrhagic pneumonia of mink by Pseudomonas aeruginosa multicomponent vaccine.

An attempt to prevent epidemics of hemorrhagic pneumonia in mink due to Pseudomonas aeruginosa was made in the course of epidemics with injection of the multicomponent vaccine consisting of common protective antigen (OEP) of P. aeruginosa mixed with toxoids of protease and elastase of the bacillus. Enzootics of hemorrhagic pneumonia, due to P. aeruginosa serotype 8, broke out from August to October 1977 in a total of 13 sheds of 3 farms (A, B and C) which were located in the northeast area of Hokkaido. These farms were raising 7,452, 2,553 and 10,639 mink respectively. The mortality rate of the mink on farms A, B and C were 11.8%, 13.0% and 1.0% respectively. The vaccination was performed on the 3 farms 5, 8 and 21 days after the onset of the disease. Inoculation of each mink with 200 micrograms or 100 micrograms of each of the three components of the multicomponent vaccine was effective in most of the male and female groups of mink. The period required for revealing the effect of the vaccination was very short, in some cases only a few days. Administration of the vaccine 21 days after the onset of the enzootic was also effective.

Animals↗

Diagnosis of Corynebacterium pyogenes infection in pigs by immunodiffusion test with protease antigen.

A protease antigen was prepared from the culture supernatant of Corynebacterium pyogenes by concentrating with a flash evaporator and ultrafiltration. It was adjusted to the concentration of 32 units by the single radial immunodiffusion with a tentative standard serum. In the immunodiffusion test, the antigen of 4 units reacted enough with sera having an antibody titer ranging from 1 to 128. As a result, it was decided that the antigen of 4 units should be used in the immunodiffusion test for the detection of protease antibody. By the immunodiffusion test, protease antibody was demonstrated in about 35% of 443 sera from pigs collected at random. The antibody titer showed the distribution of 2 peaks. The summits of the two peaks were seen at 4 and 32 of antibody titer, respectively. The valley between the two peaks was seen at 16 of titer. From the result, a diagnostic criterion of the immunodiffusion test was decided provisionally as follows: above 16 of antibody titer is positive, 1 to 8 suspect, and less than 1 negative. On the other hand, protease antibody was demonstrated in sera from 13 of 14 pigs carrying abscesses from which C. pyogenes had been isolated. Its titer was 8 (in 2 pigs), 16 (in 1), 32 (in 3), 64 (in 6), and 128 (in 1). From these results, it was proposed that the immunodiffusion test with protease antigen be used for the diagnosis of C. pyogenes infection in pigs.

Animals↗