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K Kyogoku

Publications and source records attributed to K Kyogoku.

At least 19 recordsLinked to original sources

Cloning and sequencing of a new holin-encoding gene of Bacillus licheniformis.

A Bacillus licheniformis DNA fragment which exhibits homology with the upstream region of the cell-wall hydrolase-encoding gene, cwlL, was cloned into Escherichia coli (Ec). Nucleotide sequencing indicated that there are two open reading frames (tentatively designated as xpaG1 and xpaG2) which encode polypeptides of 89 and 88 amino acids (aa) (10044 and 9764 Da, respectively). Ec cells harboring two compatible plasmids (pMWB1 and pHSGKH) containing the Bacillus subtilis cell-wall hydrolase-encoding gene, cwlA, and xpaG1-G2, respectively, exhibited higher extra-cellular cell-wall hydrolase activity than did cells harboring pMWB1 and a control plasmid, pHSG398. The aa sequence homology of XpaG2 with other polypeptides indicated that xpaG2 is a holin-encoding gene. Moreover, Ec C600 harboring a plasmid containing xpaG1-xpaG2 led to leakage of beta-galactosidase into the extracellular fraction.

Amidohydrolases↗

Effect of an anti-ulcer agent, 2'-carboxymethoxy-4, 4'-bis (3-methyl-2-butenyloxy) chalcone (SU-88), on the biosynthesis of gastric sulfated mucosubstances in restrained and water-immersed rats.

2'-Carboxymethoxy-4,4'-bis(3-methyl-2-butenyloxy) chalcone (SU-88) has an anti-ulcer effect which is considered to increase the resistant factors of the gastric mucosa. In order to clarify the mechanism of the action of SU-88, the biosynthesis of gastric sulfated mucosubstances (SMS) in vivo and in vitro was investigated in rats with gastric erosion induced by restraint and water-immersion. The incorporation of 35S-sulfate into gastric SMS was significantly reduced 18 hr after the onset of stress. Pretreatment with SU-88 (500 mg/kg, p.o., X 10 days) prevented a reduction in the incorporation of 35S-sulfate due to stress when 35S-sulfate was administered in vivo. On the contrary, the incorporating activity of 35S-sulfate into the SMS in the isolated rat gastric mucosa with erosion was significantly increased 12 hr after the onset of stress, as compared with that of the control group in vitro. The incorporation of 35S-sulfate into the SMS was still further increased by the oral administration of SU-88. The mode of action of SU-88 on the biosynthesis of SMS was discussed.

Animals↗

Cytoprotective effect of SU-88, an anti-ulcer agent, in the rat.

The gastric cytoprotective action of SU-88, an anti-ulcer agent, was studied in rats. SU-88 dose-dependently prevented the formation of gastric lesions induced by absolute ethanol as observed by PGE2. The efficacy of SU-88 when given i.p. was more potent than the p.o. administration. Indomethacin (5mg/kg, p.o.) given 30 min prior to SU-88 dosing blocked this protective effect, whereas it was not affected when indomethacin was given 30 min after the SU-88 dosing. Cimetidine, on the other hand, failed to exert a protective effect against the ethanol-induced lesions and caused a significant increase in the lesions induced by 0.6N HCI. Pretreatment with SU-88 prior to cimetidine resulted in a marked reduction in the lesions. SU-88 was found to increase the synthesis of gastric glycoproteins and to prevent the reduction of glycoprotein synthesis caused by the administration of absolute ethanol. However, no increase in the synthesis was observed 5 min after the SU-88 dosing, although the lesion was significantly suppressed at that time. These findings indicate that SU-88 possesses a cytoprotective effect and that this effect seems to be mediated by the increase in endogenous PG.

Animals↗

[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↗

[Studies on the anti-ulcer effects of isoprenyl flavonoids (1). The anti-ulcer effects of isoprenyl chalcone extracted from Sophora subprostrata (author's transl)].

A series of extracted fractions from sophora subprostrata was screened by determining anti-ulcer effects in pylorus ligated and stressed rats. Fr. [C-2] had the most potent anti-ulcer effects of all fractions extracted. Sophoradin and sophoranone which were isolated from Fr. [C-2] were also found to have inhibitory effects on ulcer formation in pylorus ligated and stressed rats. The anti-ulcer effect of sophoradin was relatively potent in comparison with that of sophoranone and/or Fr. [C-2]. The anti-ulcer effect of sophoranone was approximately the same as that of Fr. [C-2]. The authors examined the effects of sophoradin and sophoranone on gastric secretion in pylorus ligated rats. Sophoradin and sophoranone significantly reduced the volume of gastric juice. Sophoradin but not sophoranone inhibited the free and total acid output of gastric juice. The effect of sophoradin was examined on various secretagogues which induced gastric secretions in rats with acute fistula. Sophoradin showed a tendency to inhibit tetragastrin- and insulin-induced gastric acid secretion, but there were no effects on methacholine- and histamine-induced secretions. These results suggest that sophoradin may have marked anti-ulcer and inhibitory effects on gastric secretion.

Animals↗