| iodine stain | <technique> A stain to detect amyloid, cellulose, chitin, starch, carotenes, and glycogen, and to stain amoebas by virtue of their glycogen; faeces and other wet preparations are stained directly with Lugol's iodine solution; smears are treated with Schaudinn's fixative and then stained with alcoholic iodine, followed by Heidenhain's iron haematoxylin. (05 Mar 2000) |
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| iodine test | A test for detecting the presence of starch based on its reaction with iodine. (05 Mar 2000) |
| iodine tincture | A hydroalcoholic solution containing 2% elemental iodine and 2.4% potassium iodide to facilitate dissolution and 47% alcohol; used as an antiseptic/germicide on the skin surface for cuts and scratches. Has been used as a skin disinfectant before surgery but is now largely replaced by organic forms of iodine. (05 Mar 2000) |
| iodine uptake test | A test of thyroid function in which 131I-iodide is given orally; after 24 hours, the amount present in the thyroid gland is measured and compared with normal values. Synonym: radioactive iodide uptake test, RAI test. (05 Mar 2000) |
| iodine value | An indication of the quantity of unsaturated fatty acids present in a fat; it represents the number of grams of iodine absorbed by each 100 g of fat. See: hydrogen number. Synonym: iodine value. (05 Mar 2000) |
| tamed iodine | A combination of iodine with a surfactant carrier, usually polyvinylpyrrolidone. Commercial preparations generally contain 1% "available" iodine, which is slowly released to take effect against microorganisms; used as skin disinfectants, particularly for surgical scrubs. Synonym: tamed iodine. Origin: iodine + G. Phora, a carrying (05 Mar 2000) |
| undecoylium chloride-iodine | A complex of iodine with undecoylium chloride; a cationic detergent used topically as a germicidal agent. (05 Mar 2000) |
| Lugol's iodine solution | An iodine-potassium iodide solution used as an oxidizing agent, for removal of mercurial fixation artifacts, and also in histochemistry and to stain amoebas. (05 Mar 2000) |
| active | Characterised by action, not passive, not expectant. (18 Nov 1997) |
| active acetate | <enzyme> Condensation product of coenzyme A and acetic acid, symbolised as CoAS~COCH3; intermediate in transfer of two-carbon fragment, notably in its entrance into the tricarboxylic acid cycle and in fatty acid synthesis. This coenzyme plays a huge role in intermediary metabolism, in which cells synthesise, break down or use nutrient molecules for energy production, growth, etc. Acetyl-coenzyme A synthase is found in bacteria and plants and catalyses the reaction in which acetate enters metabolic pathways and forms acetyl-coenzyme A. Synonym: acetyl-coenzyme A, active acetate. (05 Mar 2000) |
| active aldehyde | Any aldehyde derivative of thiamin pyrophosphate. (05 Mar 2000) |
| active anaphylaxis | Reaction following inoculation of antigen in a subject previously sensitised to the specific antigen, in contrast to passive anaphylaxis. (05 Mar 2000) |
| active biomass | <cell biology> The amount of a given culture that is actively growing. (06 May 1997) |
| active carbon dioxide | Activated carbon dioxide, a complex of N-carboxybiotin (biotin + CO2) and an enzyme; the form in which carbon dioxide is added to other molecules in carboxylations; e.g., to methylcrotonyl-CoA to form beta-methylglutaconyl in the catabolism of leucine, and to acetyl-CoA to form malonyl-CoA. See: acetyl-CoA carboxylase. (05 Mar 2000) |
| active caries | Microbial-induced lesions of teeth that are increasing in size. (05 Mar 2000) |