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Biomedical subjects

S Terao

Publications and source records attributed to S Terao.

At least 91 records · Page 5Linked to original sources

Thromboxane synthetase inhibitors (TXSI). Design, synthesis, and evaluation of a novel series of omega-pyridylalkenoic acids.

A novel series of omega-pyridylalkenoic acids has been prepared by applying the Wittig reaction. Modifications were made in the omega-aryl moiety, the alkylene chain length, the alpha-methylene group adjacent to the carbonyl group, and the carboxyl group of the molecule. The compounds were tested as inhibitors of thromboxane synthetase in an in vitro assay and in ex vivo experiments with the rat. Most members of this new class of thromboxane synthetase inhibitors (TXSI) showed good activity in both assay systems. (E)-7-Phenyl-7-(3-pyridyl)-6-heptenoic acid (9c; CV-4151) was one of the most potent compounds in in vitro enzyme inhibition (IC50 = 2.6 X 10(-8) M) and, when orally administered, the most potent and long acting in the inhibition of blood thromboxane A2 production in the rat. New conceptual models I-III for the enzyme-substrate (prostaglandin H2, PGH2) and the enzyme-TXSI interactions are proposed for understanding the molecular design and structure-activity relations.

Animals↗

Enzyme immunoassay of thromboxane B2.

An immunoassay for thromboxane B2 was developed in which the hapten molecule was labeled with beta-galactosidase. The immunoprecipitate formed after competition between enzyme-labeled and unlabeled thromboxane B2 was subjected to a fluorometric assay of beta-galactosidase. Thromboxane B2 was detectable in the range of 0.1-30 pmol. Both enzyme immunoassay and radioimmunoassay showed essentially the same cross-reactivities with other prostaglandins and their metabolites when the same antibody was used. Known amounts of thromboxane B2 were added to human plasma, and the sample was applied to an octadecyl silica column. The extract was analyzed by enzyme immunoassay to examine the correlation between the added (x) and measured (y) thromboxane B2 (y = 1.09x + 11.07 pmol/ml, r = 0.99). A satisfactory correlation was observed between radioimmunoassay (x) and enzyme immunoassay (y) (y = 0.92x + 4.64 pmol/ml, r = 0.96). The validity of enzyme immunoassay was also confirmed by gas chromatography-mass spectrometry of a dimethylisopropylsilyl ether derivative of thromboxane B2 methyl ester. The method was applicable to the assay of thromboxane B2 produced from endogenous precursor during thrombin-induced aggregation of human platelets.

Cross Reactions↗

Pharmacological profile of AA-861, a 5-lipoxygenase inhibitor.

AA-861, a selective 5-lipoxygenase inhibitor, suppressed A23187-induced formations of 5-HETE and LTB4 in rat peritoneal macrophages. Immunologically-stimulated generation of SRS-A was also inhibited in guinea pig lung and rat peritoneal cavity. AA-861 had no effects on histamine release from rat mast cells or passive cutaneous anaphylaxis in rats. Essentially no antagonistic activity to LTD4 or histamine was observed. This compound exerted an obvious inhibition of allergic bronchoconstriction in guinea pigs and a moderate reduction of carrageenin-induced paw edema and pleurisy in rats. These findings suggest that SRS-A plays an important role in asthmatic and inflammatory reactions.

Animals↗

2,3,5-Trimethyl-6-(12-hydroxy-5,10-dodecadiynyl)-1,4-benzoquinone (AA861), a selective inhibitor of the 5-lipoxygenase reaction and the biosynthesis of slow-reacting substance of anaphylaxis.

2,3,5-Trimethyl-6-(12-hydroxy-5,10-dodecadiynyl)-1,4-benzoquinone (AA861) inhibited 5-lipoxygenase of guinea pig peritoneal polymorphonuclear leukocytes (ID50, 0.8 microM). The inhibition was of competitive type. 12-Lipoxygenases and fatty acid cyclooxygenase were not affected below 10 microM. The formation of slow-reacting substance of anaphylaxis by the sensitized guinea pig lung was almost fully suppressed by the compound at 10 microM.

Animals↗

8-14 translocation in a Japanese Burkitt's lymphoma.

Chromosome analysis was performed on cells obtained from the pleural effusion of a Japanese patient with Burkitt's lymphoma. Two modal chromosomal numbers were found: 45 and 46. Five different karyotypes were present, all having a t (8q-;14q+) translocation. This case illustrates that Burkitt's lymphomas of Japanese are no exception to the frequent association of this chromosomal abnormality with Burkitt's lymphomas.

Adolescent↗

Chromosome 14q+ in a Japanese patient with Burkitt's lymphoma.

Cytogenetic studies were performed on a biopsy specimen of a jaw tumor and on a bone marrow aspirate from a Japanese patient with Epstein-Barr virus-negative Burkitt's lymphoma. A 14q + chromosome was found in cells from either source, although each contained a different clone. Other karyotypic abnormalities present in common included 2dir dup (1q) (q21 leads to q32), 3q+, 6p--, +12, +mar.

Asian People↗