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Biomedical subjects

K Tsuchida

Publications and source records attributed to K Tsuchida.

At least 217 records · Page 12Linked to original sources
PubMed1982

Effect of concanavalin A on the activity of membrane-bound and detergent-solubilized Mg2+ -ATPase.

Plasma membranes were isolated after binding liver and hepatoma cells to polylysine-coated polyacrylamide beads, and the effect of concanavalin A on the membrane-bound Mg2+ -ATPase and the Mg2+ -ATPase solubilized by octaethylene glycol monododecyl ether (C12E8) was studied. In the experiment of membrane-bound Mg2+ -ATPase, plasma membranes were pretreated with Concanavalin A and the activity was assayed. Concanavalin A stimulated the activity of both liver and hepatoma enzymes assayed above 20 degrees C. Concanavalin A abolished the negative temperature dependency characteristic of liver plasma membrane Mg2+ -ATPase. On the other hand, Concanavalin A prevented the rapid inactivation due to storage at -20 degrees C, which was characteristic of hepatoma plasma membrane Mg2+ -ATPase. With solubilized Mg2+ -ATPase from liver plasma membranes, the negative temperature dependency was not observed. Concanavalin A, which was added to the assay medium, stimulated the activity of the enzyme solubilized in C12E8 at a high ionic strength. However, Concanavalin A failed to show any effect on the enzyme solubilized in C12E8 at a low ionic strength. With solubilized Mg2+ -ATPase from hepatoma plasma membranes, Concanavalin A could not prevent the inactivation of the enzyme during incubation at -20 degrees C.

Adenosine Triphosphatases↗
PubMed1982

Toward the total synthesis of Sinefungin.

Among many attempts toward the total synthesis of Sinefungin one of the most promising approach was found to be the transglycosylation of the amino acid-D-ribofuranosyl portion of 15 to N6-acyladenine. The key intermediate (15) was prepared from uridine in 12 steps. Thus, treatment of 2',3'-O-isopropylidene-uridine 5'-aldehyde (5) with methyl 4-nitrobutanoate gave rise to an aldol adduct (6) which was led to 4-nitro-4-(5'-deoxy-2', 3'-O-isopropylideneuridin-5'-yl)-butanal (10) via 8. A four-component condensation involving 10 afforded N,N-disubstituted alpha-aminocarboxamide derivative (11). The transglycosylation involving 8 and N6-benzoyladenine was successfully achieved. A parallel transglycosylation involving 15 and N6-benzoyladenine is under way to obtain 16.

Adenosine↗
PubMed1981

[Pharmacological study on hydrocortisone 17-butyrate 21-propionate (author's transl)].

The topical and systemic anti-inflammatory activities of hydrocortisone 17-butyrate 21-propionate (HBP) were studied. The systemic anti-inflammatory activities of HBP and reference steroids were examined for their effects on dinitrochlorobenzene dermatitis, carrageenin edema, cotton pellet granuloma and adjuvant arthritis in rats and by the delayed allergic edema test in mice. The topical anti-inflammatory activities of these steroids were examined for their effects on croton oil dermatitis, croton oil ear edema, carrageenin edema and cotton pellet granuloma in rats. Furthermore, effects of these steroids on liver glycogen deposition in mice, thymolysis, and decrease of serum corticosterone level in rats were examined. Systemically administered HBP was less potent than betamethasone 17-valerate (BV), but was almost equal to hydrocortisone 17-butyrate (HB) in anti-inflammatory activity, and its effects on liver glycogen deposition, thymolysis, and the decrease of serum corticosterone level. However, the topical anti-inflammatory activity of HBP was more potent than that of BV and HB, although in the same experiment, thymolytic activity of HBP was less potent than that of BV, but was almost equal to HB. The inhibitory effect of HBP on hypotonic induced hemolysis was weaker than that of BV, but was stronger than that of HB in vitro. The affinity of HBP was higher than that of BV and HB to polymorphonuclear leucocytes used as the inflammatory cells in vitro. On the other hand no marked difference was observed in the affinity to erythrocytes used as the non-inflammatory cells in vitro. These results suggest that HBP is a useful drug which has superior topical anti-inflammatory activity, but has a weak systemic effect.

Animals↗
PubMed1981

Clinical significance of gingival fluid measurement by "Periotron".

The accuracy of gingival fluid measurement with an electric device was compared with such clinical parameters as Gingival Index scores and pocket depths, and the treatment effect was evaluated by changes in the gingival fluid amount. After the initial examination 10 patients received oral hygiene instruction, scaling, root planing and soft tissue curettage. The operated areas were protected by a periodontal dressing for 1 week and all patients used a 0.2% chlorhexidine mouthrinse twice daily during that period and for the next week. Four weeks later the patients were reexamined for the same factors that were evaluated at the initial examination. The amount of gingival fluid correlated with the Gingival Index (r = 0.65), the pocket depth (r = 0.74) and the total amount of acid phosphatase in the gingival fluid (r = 0.92). Following treatment, a significant improvement in periodontal status was demonstrated by all of the parameters utilized.

Gingival Crevicular Fluid↗
PubMed1981

[Studies on antigenicity, phototoxicity and other specific toxicities of hydrocortisone 17-butyrate 21-propionate (HBP) (author's transl)].

The present experiments were undertaken to determine the antigenicity and other toxicities of HBP; such as phototoxicity, photosensitivity, ulcerogenicity, adrogenic-myotropic, estrogenic and progestational activities, and mutagenicity. No antibody formation and delayed type skin reaction of HBP were seen in rabbits. Active systemic anaphylaxis was not observed in guinea pigs challenged by HBP. In the phototoxicity and photosensitivity test, 0.1% HBP ointment, 0.1% HBP cream and 10% HBP acetone solution did not show any skin reaction with or without irradiation of ultraviolet light. Repeated subcutaneous administration of HBP irritated the gastric and intestinal mucosa dose dependently in rats as hydrocortisone 17-butyrate and betamethasone 17-valerate (BV). HBP had neither androgenic-myotropic nor estrogenic activity, but antiestrogenic activity was observed. The progestational activity of HBP in immature rabbit pretreated with estrone was less potent than BV. In the mutagenicity test os HBP investigated by the reverse mutation according to the method by Ames, no significant increase in the number of revertants was observed in the presence or absence of S9 mixture.

Administration, Topical↗