Search PubMed⌕ Search

Biomedical subjects

S Takeuchi

Publications and source records attributed to S Takeuchi.

At least 937 records · Page 52Linked to original sources
PubMed1977

An extraluminal force transducer for recording contractile activity of the gastrointestinal smooth muscle in the conscious dogs: its construction and implantation.

An extraluminal strain-gauge force transducer has been developed for recording contractile activity of the gastrointestinal smooth muscle. The details of its construction and implantation were described. The transducer unit allows for continuous long-term recordings (more the 5 months) from conscious experimental animals. It could be constructed in any laboratory and easily implanted in animals if it is done in aseptic technique. Since it is sutured onto the outside of the gut, it does not interfere passage of the contents. The only disadvantages are that it only measures muscle contractions and it is hard to determine movements of intraluminal contents especially in the digestive state.

Animals↗
PubMed1977

Inhibitory effect of pentagastrin and feeding natural and motilin-induced interdigestive contractions in the stomach of conscious dogs.

The interaction between motilin, pentagastrin and feeding was investigated during the interdigestive gastric motor state in 4 healthy conscious dogs. We confirmed previous reports that an i.v. infusion of synthetic motilin always induced a pattern precisely like that of the naturally-occurring interdigestive contractions of the stomach. Pentagastrin inhibited the occurrence of the interdigestive contractions at dose between 0.2-1.6 microgram/kg-hr; this inhibition had a dose-related relationship to the occurrence of the motilin-induced contractions. The ingestion of food strongly inhibited the occurrence of not only the natually-occurring contractions but also the motilin-induced contractions in the stomach and changed the motor pattern to the digestive one. These findings strongly support our hypothesis that the interdigestive contractions in the dog are, at least in part, under the control of motilin. Furthermore, it should be emphasized that pentagastrin not always stimulates gastric motor activity but conversely, in the interdigestive state it inhibits movements characteristic of that condition and replaces them with the digestive pattern.

Animals↗
PubMed1977

Use of fluorescein mercuric acetate as a probe in studies of thiol-containing proteins.

The reaction of fluorescein mercuric acetate (FMA) with thiol groups is inhibited by barbital (Veronal). However, barbital has no effect on the reaction of 5,5'-dithiobis(2-nitrobenzoic acid) with thiol groups. Complex formation between FMA and barbital was shown by an increase in the fluorescence polarization of FMA in the presence of barbital. These findings indicate that the inhibitory effect of barbital is due to its interaction with FMA. The extent of this inhibition, which depends on the nature of the thiol-containing substance, presumably reflects the structure surrounding the thiol groups. Furthermore, the absorption and fluorescence properties of FMA conjugated with thiol groups are sensitive to the environment. Because of these properties, FMA can be used to investigate the environment of thiol groups.

Acetylcysteine↗
PubMed1977

Precipitating antibody against protease of Corynebacterium pyogenes in pigs.

Antibody in sera from pigs carrying an abscess associated with Corynebacterium pyogenes and healthy pigs was examined by the agar gel diffusion test. In the test, the concentrated culture fluid containing the protease of C. pyogenes was used as antigen. As a result, precipitating antibody was demonstrated in sera from 25 of 30 abscessed pigs and a few of the healthy pigs. When the relationship between precipitating antibody and protease was examined by the immunoelectrophoresis and gel filtration of the concentrated culture fluid, the antibody was shown in the same position as the protease. From the result, it was clear that the precipitating antibody was against the protease of C. pyogenes. All the proteases produced by 27 strains of C. pyogenes of porcine and bovine origin were serologically identical with one another. They were, however, serologically different from those of Staphylococcus aureus, Bacillus cereus, and B. subtilis. In the inhibition test, the proteolytic activity of C. pyogenes was inhibited by the serum of the abscessed pig. It was also inhibited by healthy pig serum. From the results, it seems that the determination of precipitating antibody may be useful for the diagnosis of C. pyogenes infection.

Abscess↗
PubMed1976

Interaction of a fluorescent reagent, fluorescein mercuric acetate, with nucleic acids.

Fluorescein mercuric acetate (fluorescein Hg Ac), which is a fluorescent thiol reagent, was shown to bind to various nucleic acids by measuring the changes in its absorption and fluorescence properties. Up to a critical concentration of free fluorescein Hg Ac (1-10(-7) M for calf thymus DNA, with 42% GC, and 2-10(-7) M for Micrococcus lysodeikticus DNA, with 72% GC) this reagent appears to bind selectively to single-stranded sections in DNA. Above this critical concentration, cooperative binding to double helical DNA occurs, and denatured DNA is obtained after removal of bound fluorescein Hg Ac by dialysis against 1 M KCl. These facts indicate that fluorescein Hg Ac causes the denaturation of double helical DNA prior to binding as has been shown in the case of methylmercuric hydroxide. The binding of fluorescein Hg Ac to DNA is much stronger than that of methylmercuric hydroxide. The number of total binding sites for fluorescein Hg Ac is close to the number of base pairs for both calf thymus DNA and M. lysodeikticus DNA. Furthermore, it was shown that fluorescein Hg Ac binds to thymidine, deoxyguanosine, poly(U) and poly(G). Since fluorescence quenching of fluorescein Hg Ac accompanies its complex formation with DNA and the affinity is markedly high as indicated by the association constant of 6.8-10(7) M(-1) for single-stranded calf thymus DNA, fluorescein Hg Ac can be used for the structural studies of small amounts of nucleic acids.

Binding Sites↗