| azatadine maleate | An antihistamine with anticholinergic and antiserotonin properties. Chemical name: 6,11-Dihydro-11-(1-methyl-4-piperidylidene)-5H-benzo[5,6]cyclohepta[1,2-b]pyridine dimaleate. (05 Mar 2000) |
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| azathioprine | <chemical> An immunosuppressive agent used in combination with cyclophosphamide and hydroxychloroquine in the treatment of rheumatoid arthritis. According to the fourth annual report on carcinogens (ntp 85-002, 1985), this substance has been listed as a known carcinogen. (merck index, 11th ed) Pharmacological action: antimetabolites, antimetabolites, antineoplastic, antirheumatic agents, carcinogens, immunosuppressive agents. Chemical name: 6-((1-methyl-4-nitro-1h-imidazol-5-yl)thio)-1h-purine. (12 Dec 1998) |
| azauridine | <chemical> A triazine nucleoside used as an antineoplastic antimetabolite. It interferes with pyrimidine biosynthesis thereby preventing formation of cellular nucleic acids. As the triacetate, it is also effective as an antipsoriatic. Pharmacological action: antimetabolites, antimetabolites, antineoplastic, dermatologic agents. Chemical name: 1,2,4-Triazine-3,5(2H,4H)-dione, 2-beta-D-ribofuranosyl- (12 Dec 1998) |
| azedarach | 1. <botany> A handsome Asiatic tree (Melia azedarach), common in the southern United States; called also, Pride of India, Pride of China, and Bead tree. 2. <medicine> The bark of the roots of the azedarach, used as a cathartic and emetic. Origin: F. Azedarac, Sp. Acederaque, Pers. Azaddirakht noble tree. Source: Websters Dictionary (01 Mar 1998) |
| azeotrope | A mixture of two or more liquids that boils without change in proportion of the liquids, either in the liquid or the vapor phase; e.g., 95% ethanol (actually 94.9% by volume, the rest being water). Origin: G. A-priv. + zeein, to boil, + tropos, a turning (05 Mar 2000) |
| azeotropic | Denoting or characteristic of an azeotrope. (05 Mar 2000) |
| azeotropic mixture | <chemistry> This is a mixture of liquids in which the composition of the vapor is the same as that of the liquid phase, so it can be distilled without any change in composition. (12 Mar 1998) |
| azetidinecarboxylic acid | <chemical> 2-azetidinecarboxylic acid. A proline analog. Acts as a stoichiometric replacement of proline causing the production of abnormal proteins having impaired biological activity. Chemical name: 2-Azetidinecarboxylic acid (12 Dec 1998) |
| azide | <chemical> Usually the sodium salt NaN3, an inhibitor of electron transport that blocks electron flow from cytochrome oxidase to oxygen. (18 Nov 1997) |
| azidothymidine | aZT |
| azimuth | <radiobiology> An angle measured clockwise relative to some reference point on a circle (for example, south or north). (09 Oct 1997) |
| azimuthal | <radiobiology> Generally an angle, measured around an object. In spherical geometries, the angle which is not the polar angle. On the earth, one incarnation of the azimuthal angle is the longitude of a location relative to the prime meridian through Greenwich, England. In toroidal geometries, the longitude idea still applies, but the other angle is the poloidal angle, not the polar angle. The azimuthal direction is the long way around a torus. See: poloidal. (12 Mar 1998) |
| azin dyes | Dye derivatives of phenazine, C6H4-N2-C6H4 that include important histologic stains, such as neutral red, azocarmine G., and safranin O. (05 Mar 2000) |
| azinphosmethyl | <chemical> An organothiophosphorus cholinesterase inhibitor. It has been used as an acaricide and as an insecticide. Pharmacological action: cholinesterase inhibitor, insecticide, organothiophosphate. Chemical name: Phosphorodithioic acid, O,O-dimethyl S-((4-oxo-1,2,3-benzotriazin-3(4H)-yl)methyl) ester (12 Dec 1998) |
| aziridines | Saturated azacyclopropane compounds. Any substitutions on carbon or nitrogen atoms are permitted. (12 Dec 1998) |