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Biomedical subjects

T Iida

Publications and source records attributed to T Iida.

At least 415 records · Page 23Linked to original sources
PubMed1987

The characteristics of luteinizing hormone and its beta-subunit secretion in dispersed rat anterior pituitary cells.

Secretion of luteinizing hormone (LH) and its beta-subunit (LH-beta) by luteinizing hormone-releasing hormone (LH-RH) were studied in perifused rat anterior pituitary cells. LH release was dose related between 10(-10) and 10(-6)M LH-RH. Every 5-minute pulse of 10(-8)M LH-RH induced almost similar response to the initial LH release; neither the self-priming effect nor desensitization were significant. Continuous administration of 10(-8)M LH-RH caused an initial LH release, followed by distinct desensitization, which could not be overcome by subsequent pulses of 10(-8)M LH-RH. The results were quite similar in LH-beta release. The perifusion study is shown to be useful in analyzing the characteristics of LH and LH-beta release, and the present results suggest that LH-RH receptor-mediated regulation may be also involved in LH-beta release.

Animals↗
PubMed1987

Clinical reports on plasma exchange in the Kidney Center, Tokai University School of Medicine.

There were 72 patients (19 with hepatic failure, 10 with fulminant hepatitis, eight with paraquat poisoning, eight with rheumatoid arthritis, five with myasthenia gravis, four with hyperlipidemia, four with systemic arteriosclerosis including brain infarction, three with pemphigus vulgaris, two with multiple myeloma, two with systemic lupus erythematosus, two cases non-specific Ig-G antibody, two cases medication with an anticancer drug, one with multiple sclerosis, one with Crohn's disease with amyloid kidney and one with chronic myeloblastic leukemia) treated by plasma exchange in the Kidney Center, Tokai University School of Medicine from Jan. 1983 to Dec. 1986. We performed plasma exchange using fresh frozen plasma in 40 cases and Lactate-Ringer's solution containing albumin (4.0-5.0%) in 20 cases as the replacement fluid. In 17 cases, we performed double filtration plasma exchange with the recycle system and no replacement fluid. Although PE therapy did not constitute a basic therapy for hyperlipidemia, pemphigus vulgaris, rheumatoid arthritis, myasthenia gravis, and systemic lupus erythematosus, it was effective in relieving severe clinical symptoms. At the present time, conventional plasma exchange does not improve the survival rate of patients with hepatic failure and fulminant hepatitis. Developments of a new artificial liver support apparatus and identity of many toxic substances in hepatic failure are necessary. No hypotension, hypovolemic shock or other significant complications were experienced.

Adult↗
PubMed1986

Studies on lipoxygenase inhibitors. II. KF8940 (2-n-heptyl-4-hydroxyquinoline-N-oxide), a potent and selective inhibitor of 5-lipoxygenase, produced by Pseudomonas methanica.

Pseudomonas methanica KY4634 was found to produce 5-lipoxygenase inhibitor designated KF8940, MY12-62a and MY12-62c. The inhibitors were purified by solvent extraction, silica gel column chromatography, reversed-phase low pressure liquid chromatography and crystallization. The chemical structures of KF8940, MY12-62a and MY12-62c were determined to be 2-n-heptyl-4-hydroxyquinoline-N-oxide, 2-n-heptyl-4-hydroxyquinoline and 3-n-heptyl-3-hydroxy-1,2,3,4-tetrahydroquinoline-2,4-dione, respectively, on the basis of their physico-chemical properties. Among them, KF8940 was the most potent inhibitor. The compound inhibited 5-lipoxygenase of rat basophilic leukemia cells in a dose-dependent manner and the half maximal inhibitory concentration (IC50) was 1.5 X 10(-7) M. At this concentration, KF8940 did not inhibit bovine platelet 12-lipoxygenase and cyclooxygenase, and the IC50 values for these enzyme were 3.5 X 10(-5) M and 1.7 X 10(-4) M, respectively. The results indicated that KF8940 is a potent and selective inhibitor of 5-lipoxygenase. The IC50 value of MY12-62c for 5-lipoxygenase was 1.9 X 10(-5) M and that of MY12-62a was 1.9 X 10(-5) M.

Arachidonate Lipoxygenases↗
PubMed1986

Studies on lipoxygenase inhibitors. I. MY3-469 (3-methoxytropolone), a potent and selective inhibitor of 12-lipoxygenase, produced by Streptoverticillium hadanonense KY11449.

Streptoverticillium hadanonense KY11449 was found to produce a 12-lipoxygenase inhibitor MY3-469. The compound was purified by chromatography on Diaion HP-10, charcoal, Sephadex LH-20 and crystallization. The chemical structure of MY3-469 was determined to be 3-methoxytropolone on the basis of its physico-chemical properties. The half maximal inhibitory concentration (IC50) of MY3-469 against bovine platelet 12-lipoxygenase was 1.8 X 10(-6)M. The compound did not inhibit bovine platelet cyclooxygenase at 10(-3)M and showed weak inhibition (IC50 2.8 X 10(-4)) against 5-lipoxygenase of rat basophilic leukemia cells. The results indicate that MY3-469 is a potent and selective inhibitor of 12-lipoxygenase.

Actinomycetales↗
PubMed1985

High performance liquid chromatographic separation of stereoisomeric bile acids as their UV-sensitive esters.

High performance liquid chromatographic separation of a series of mono-, di- and trihydroxylated 5 beta-cholanic acids, which differ only in position and configuration of hydroxyl groups at positions C-3, C-7 and/or C-12, is reported. The C-24 free acids were derivatized to four different classes of UV-sensitive esters, i.e., p-bromophenacyl (BP), m-methoxyphenacyl (MP), 4-nitrophthalimidemethyl (NPM) and 9-anthrylmethyl (AM) esters, and chromatographed on two variants of C18 reversed-phase columns (Nova-Pak C18 and Zorbax ODS) with methanol-water systems as mobile phase. Separation efficiency and elution order of some isomeric pairs were influenced by both the structure of the C-24 ester groups and the nature of the columns used. Excellent chromatographic properties were found for those derivatives, particularly for the NPM esters.

Bile Acids and Salts↗