| yellow spot | An oval area of the sensory retina, 3 by 5 mm, temporal to the optic disk corresponding to the posterior pole of the eye; at its centre is the central fovea, which contains only retinal cones. Synonym: area centralis, macula lutea, macular area, punctum luteum, Soemmerring's spot, yellow spot. (05 Mar 2000) |
|---|---|
| yellow vision | <ophthalmology> A form of chromatopsia in which objects looked at appear yellow. Origin: Gr. Opsis = vision (11 May 1997) |
| yellow wax | A yellowish, solid, brittle substance prepared from the honeycomb of the bee, Apis mellifera; the chief constituent is myricin (myricyl palmitate); others are cerotic acid (cerin), melissic acid, heptacosane, and hentriacontane; used in the preparation of ointments, cerates, plasters, and suppositories. (05 Mar 2000) |
| yellow yolk | The chief constituent of the yolk in a bird's egg; it consists of relatively coarse particles of stored food materials and is laid down in concentric zones with interposed thin layers of white yolk. (05 Mar 2000) |
| Leipzig yellow | A fine yellow powder used in paints and dyes. Synonym: lead chromate, Leipzig yellow, lemon yellow, Paris yellow. (05 Mar 2000) |
| lemon yellow | A fine yellow powder used in paints and dyes. Synonym: lead chromate, Leipzig yellow, lemon yellow, Paris yellow. (05 Mar 2000) |
| active methyl | A methyl group attached to a quaternary ammonium ion or a tertiary sulfonium ion that can take part in transmethylation reactions; e.g., methyl groups in choline and in S-adenosyl-l-methionine, which are thus methyl donors. (05 Mar 2000) |
| aklanonic acid methyl ester cyclase | <enzyme> Catalyses the formation of aklaviketone from aklanonic acid methyl ester; involved in daunomycin biosynthesis; see also daunorubicin-doxorubicin polyketide synthase Registry number: EC 5.- Synonym: aame cyclase, daud protein, daud gene product, dnrd protein, dnrd gene product (26 Jun 1999) |
| alpha-(4-O-methyl)-D-glucuronidase | <enzyme> Removes 4-o-methyl-glucopyranosyl uronic acid residues from the 2-position of fungal cell wall xylans Registry number: EC 3.2.1.- Synonym: 4-o-methyl-glucuronidase (26 Jun 1999) |
| alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid | <chemical> Alpha-amino-2,3-dihydro-5-methyl-3-oxo-4-isoxazolepropanoic acid. An ibotenic acid homolog and glutamate agonist. The compound is the defining agonist for the ampa subtype of glutamate receptors (receptors, ampa). It has been used as a radionuclide imaging agent but is more commonly used as an experimental tool in cell biological studies. Pharmacological action: excitatory amino acid agonists. Chemical name: 4-Isoxazolepropanoic acid, alpha-amino-2,3-dihydro-5-methyl-3-oxo- (12 Dec 1998) |
| alpha methyl dopa | <drug> An antihypertensive drug, preferred in pregnant patients. (18 Nov 1997) |
| angular methyl | A methyl group attached to carbon 10 (between rings A and B) or to carbon 13 (between rings C and D) of the steroid nucleus. (05 Mar 2000) |
| bevonium methyl sulfate | 2-(hydroxymethyl)-1,1-dimethylpiperidinium methyl sulfate benzylate;an anticholinergic agent. Synonym: pyribenzyl methyl sulfate. (05 Mar 2000) |
| Mann's methyl blue-eosin stain | <technique> A stain useful for anterior pituitary and viral inclusion bodies; a mixture of the two dyes stains alpha cell granules red, beta cell granules dark blue, chromophobes gray to pink, colloid red, erythrocytes orange-red, and collagen fibres blue; this method is also useful for enterochromaffin, goblet, Paneth, and pancreatic islet cells; Negri bodies appear red while their nuclei and central granules are blue. (05 Mar 2000) |
| receptors, n-methyl-d-aspartate | A class of ionotropic glutamate receptors characterised by affinity for n-methyl-d-aspartate. Nmda receptors have an allosteric binding site for glycine which must be occupied for the channel to open efficiently and a site within the channel itself to which magnesium ions bind in a voltage-dependent manner. The positive voltage dependence of channel conductance and the high permeability of the conducting channel to calcium ions (as well as to monovalent cations) are important in excitotoxicity and neuronal plasticity. (12 Dec 1998) |