| TAB vaccine | A suspension of killed typhoid and paratyphoid A and B bacilli. See: typhoid vaccine. Synonym: TAB vaccine. (05 Mar 2000) |
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| folic acid | <biochemistry> Pteridine derivative that is abundant in liver and green plants and is a growth factor for some bacteria. The biochemically active form is tetrahydrofolate (see folate). (12 Nov 1997) |
| folic acid antagonist | <pharmacology> A chemical which inhibits a cells capacity to use folic acid and so prevent cell division, for example methotrexate. See: chemotherapy. (12 Nov 1997) |
| folic acid antagonists | Inhibitors of the enzyme, dihydrofolate reductase (tetrahydrofolate dehydrogenase), which converts dihydrofolate (fh2) to tetrahydrofolate (fh4). They are frequently used in cancer chemotherapy. (12 Dec 1998) |
| folic acid conjugate | A folate with three molecules of glutamic acid (pteropterin) instead of one, or with seven (pteroylheptaglutamic acid or vitamin Bc conjugate). (05 Mar 2000) |
| folic acid deaminase | <enzyme> Chemotaxis regulating enzyme; splits folic acid into 6-hydroxymethylpterin and p-aminobenzoylglutamic acid Registry number: EC 3.5.4.- Synonym: folic acid inactivating enzyme, folic acid c9-n10 cleaving enzyme (26 Jun 1999) |
| folic acid deficiency | A nutritional condition produced by a deficiency of folic acid in the diet. Many plant and animal tissues contain folic acid, abundant in green leafy vegetables, yeast, liver, and mushrooms but destroyed by long-term cooking. Alcohol interferes with its intermediate metabolism and absorption. Folic acid deficiency may develop in long-term anticonvulsant therapy or with use of oral contraceptives. This deficiency causes anaemia, macrocytic anaemia, and megaloblastic anaemia. It is indistinguishable from vitamin b 12 deficiency in peripheral blood and bone marrow findings, but the neurologic lesions seen in b 12 deficiency do not occur. (merck manual, 16th ed) (12 Dec 1998) |
| folic acid deficiency anaemia | Anaemia due to deficiency of folic acid, characterised by large-sized red blood cells (macrocytosis) and presence of large nuclei in erythroid precursor cells (megaloblasts) in the bone marrow. (05 Mar 2000) |
| folic acid oxidase | <enzyme> Enzyme from human red blood cell membranes; catalyses oxidation of folic acid to pterin-6-aldehyde plus p-aminobenzoylglutamic acid in presence of h2o2; singlet oxygen is involved Registry number: EC 1.11.- (26 Jun 1999) |
| Rambourg's chromic acid-phosphotungstic acid stain | <technique> A stain for glycoproteins, used with an electron microscope, with which ultrathin tissue sections reveal complex carbohydrates in the same locations as shown by Rambourg's periodic acid-chromic methenamine-silver stain. (05 Mar 2000) |
| a1-acid glycoprotein | <biology> Plasma protein of mammals and birds, 38% carbohydrate. In humans a single chain glycoprotein of 39 kD. Increased levels are associated with inflammation, pregnancy and various diseases. (18 Nov 1997) |
| abscisic acid | <biochemistry> A lipid hormone that inhibits cell growth in plants, it is associated with fruit drop, leaf death and seed dormancy. It is synthesised in the plastids from carotenoids. This hormone helps plants deal with water loss, and its effects can be reversed with gibberellins. (06 May 1997) |
| abscisic acid 8'-hydroxylase | <enzyme> Catalyses conversion of abscisic acid to 8'-hydroxyabscisic acid, which rearranges to phaseic acid Registry number: EC 1.14.99.- Synonym: aba 8'-hydroxylase (26 Jun 1999) |
| acetic acid | <chemical> The acid most commonly associated with vinegar, it is the most commercially important organic acid and is used to manufacture a wide range of chemical products, such as plastics and Acetobacter but, except for making vinegar, is usually made through synthetic processes. Derivatives of acetic acid which may be formed by substitution reactions. Mono- and di-substituted, as well as, halogenated compounds have been synthesised. Experimentally, alpha- and n2- substituted acetic acids have been examined for their anti-inflammatory activity and effect on the central nervous system respectively. Additionally, limited exposure data has been collected on dibromo and dichloroacetic acids to determine whether they pose health effects. Synonym: ethanoic acid. (26 Jun 1999) |
| acetoacetic acid | CH3COCH2COOH;one of the ketone bodies, formed in excess and appearing in the urine in starvation or diabetes. Synonym: diacetic acid. (05 Mar 2000) |