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S Kanoh

Publications and source records attributed to S Kanoh.

133 records · Page 8Linked to original sources
PubMed1977

Studies on pyrogenic tolerance to bacterial lipopolysaccharide in rabbits.

The development of pyrogenic tolerance was studied in rabbits treated with varying doses of E. coli lipopolysaccharide (LPS). The following results were obtained. 1) Development of pyrogenic tolerance seemed to proceed in two steps: that is, the first in which tolerance appeared rapidly and the second in which tolerance proceeded more gradually or steadily in response to repeated injections of a constant dose. 2) Tolerance induced by the latter method was not absolute; the rabbits were still sensitive to increased doses of LPS. 3) Rabbits immunized with E. coli vaccine lost their pyrogenic sensitivity of parent LPS to some extent. 4) Following intracisternal injection of LPS into tolerant rabbit, pyrogenic response was not decreased but rather enhanced in comparison with control. 5) The contents of nor-epinephrine and serotonin in the brain did not differ between normal and tolerant rabbits. 6) The mechanisms of endotoxin tolerance remain to be further studied.

Animals↗
PubMed1975

[Mechanisms of release of leucocytic pyrogen].

Mechanisms of the production and release of leucocytic pyrogen (LP) from peritoneal polymorphonuclear leucocytes (PMN) from rabbits were studied in vitro. The following results were obtained. 1) The fever curves of the microsomal and the lysosomal fractions had a later onset and were longer lasting than those from the extracellular fluid. The fever curves of the supernatant of 105,000 g showed the typical response of endogenous pyrogen characterized by a rapid onset and short lasting fever, as shown by the extracellular fluid. 2) The pyrogenicity of LP was the most potent at 60 min while the 105,000 g supernatant was most potent at 30 min after PMN incubation at 37 degrees C. 3) The extracellular protein attained the maximum level at 30 min after incubation of PMN, while the protein content in the supernatant of 105,000 g of PMN decreased gradually to the constant level at 30 min. 4) It was observed that the lysosomal degradation was stimulated with bacterial pyrogen (LPS) at 37 degrees C but LPS did not directly affect the lysosomal fraction of PMN.

Animals↗
PubMed1968

Pyrogenic principle of the ribonucleic acid from the yeast Candida utilis.

Experiments were performed to characterize the pyrogenic principle of ribonucleic acid (RNA) from the yeast Candida utilis. It was shown that ribonuclease hydrolysis of the RNA does not lead to inactivation of the pyrogenicity. Pyrogenicity was, however, destroyed by treatment with sodium deoxycholate. On column chromatography with Biogel under sterile and pyrogen-free conditions, the pyrogenic principle of yeast RNA was eluted together with the RNA. After treatment of the RNA with ribonuclease, it was possible to separate the pyrogenic activity from the RNA (hydrolysis products) to a great extent. Column chromatography of Escherichia coli endotoxin showed that the endotoxin was eluted in the same fractions as the pyrogenic activity of yeast RNA. On the basis of the behavior of the pyrogen, it may very well be that the fever reaction is produced not by the nucleic acid but by pyrogenic contaminants of the RNA preparation.

Animals↗
PubMedDate not supplied

Effects of reactive oxygen species on intracellular calcium in bovine tracheal epithelium: modulation by nitric oxide.

We studied the effects of reactive oxygen species (ROS) on intracellular Ca2+ concentration ([Ca2+]i) and their possible modulation by nitric oxide (NO) in fura-2-loaded cultured bovine tracheal epithelium. Hypoxanthine (HX) and xanthine oxidase (XO), which generate superoxide anion (O2-) and hydrogen peroxide (H2O2), dose dependently increased [Ca2+]i. The increase in [Ca2+]i was reduced in the presence of superoxide dismutase (SOD, 200 U/mL) and catalase (200 U/mL) by 29% and 43%, respectively. The iron chelator o-phenanthroline and the hydroxyl radical (.OH) scavenger dimethylthiourea (DMTU) more potently inhibited the response of [Ca2+]i. H2O2-derived .OH generated by the Fenton reaction caused a marked [Ca2+]i elevation, but exogenous H2O2 did not. Sodium nitroprusside (100 microM), an NO donor, potentiated HX-XO-induced [Ca2+]i rise by 50%, an effect that was abolished in the presence of SOD or DMTU. These results suggest that .OH formed by interaction of O2- and H2O2 in the presence of iron may play a major role in the HX-XO-induced disruption of airway epithelial Ca2+ homeostasis, and that NO potentiates ROS-induced [Ca2+]i response, presumably by reacting with O2- and producing .OH.

Animals↗