| essential gene | <genetics> Any gene that, if it does not workcorrectly, kills the organism. (09 Oct 1997) |
|---|---|
| essential hypertension | Hypertension without known cause. Synonym: idiopathic hypertension, primary hypertension. (05 Mar 2000) |
| essential oils | Plant products, usually somewhat volatile, giving the odours and tastes characteristic of the particular plant, thus possessing the essence, e.g., citral, pinene, camphor, menthane, terpenes; usually, the steam distillates of plants or oils of plants obtained by pressing out the rinds of a particular plant. See: volatile oil. (05 Mar 2000) |
| essential phthisis bulbi | A softening of the eyeball (ophthalmomalacia) and reduction in size, not due to inflammation. (05 Mar 2000) |
| essential progressive atrophy of iris | Progressive atrophy of the iris without inflammatory signs, characterised by patchy loss of all layers of the iris with hole formation, migration of the pupil, degeneration of the corneal endothelium, peripheral anterior synechiae, and secondary glaucoma; usually unilateral, predominantly affecting women in their middle years. (05 Mar 2000) |
| essential pruritus | Itching that occurs independently of skin lesions. (05 Mar 2000) |
| essential tachycardia | Persistent rapid action of the heart due to no discoverable organic lesion. (05 Mar 2000) |
| essential telangiectasia | Localised capillary dilation of undetermined origin. Synonym: angioma serpiginosum. (05 Mar 2000) |
| essential thrombocythaemia | A rare condition related to polycythaemia rubra vera characterised by the production of large numbers of abnormal platelets. Symptoms include haemorrhage, blood clots and enlargement of the spleen. Treatment varies according to the severity of the disease. (13 Nov 1997) |
| essential thrombocytopenia | A primary form of thrombocytopenia, in contrast to secondary forms that are associated with metastatic neoplasms, tuberculosis, and leukaemia involving the bone marrow, or with direct suppression of bone marrow by the use of chemical agents, or with other conditions. (05 Mar 2000) |
| essential tremor | <neurology> A tremor that is associated with purposeful movement or motor activity. Essential tremor is the most common form of tremor with no identifiable cause. Stress, anxiety and the use of stimulants (for example caffeine, decongestants) can often make the tremor worse. Treatment is usually not necessary for this benign condition. (27 Sep 1997) |
| fatty acids, essential | Fatty acids that cannot be synthesised by the human body and must be obtained from dietary sources, e.g., linoleic acids and linolenic acids. (12 Dec 1998) |
| acetyl-activating enzyme | A ligase that catalyses the reaction of acetate and CoA and ATP to form AMP, pyrophosphate, and acetyl-CoA. A key step in the activation of acetate. Synonym: acetate thiokinase, acetate-CoA ligase, acetyl-activating enzyme, acetyl-CoA synthetase. (05 Mar 2000) |
| acyl-activating enzyme | <enzyme> Fatty acid thiokinase (long-chain), a ligase forming acyl-CoA, AMP, and pyrophosphate from long-chain fatty acids, ATP, and coenzyme A. Activity is independent of phosphatidylcholine Registry number: EC 6.2.1.3 Synonym: acyl-activating enzyme, dodecanoyl-CoA synthetase, fatty acid thiokinase (long chain), acid-coenzyme a ligase, fatty acid-CoA ligase, acyl-CoA synthetase, acyl-CoA ligase, coash ligase, ciprofibroyl-CoA synthetase, pristanoyl-CoA synthetase, palmityl CoA synthetase, palmitoyl CoA synthetase, palmitoyl CoA ligase, fatty acyl-CoA synthetase, very long chain fatty acid acyl-CoA synthetase, vlcfa acyl-CoA synthetase, nafenopin-CoA ligase, palmitoyl-CoA synthase, faa2 gene product, faa2p protein, vlacs enzyme (26 Jun 1999) |
| adaptive enzyme | Inducible enzyme, an enzyme that can be detected in a growing culture of a microorganism, after the addition of a particular substance (inducer) to the culture medium, but was not detectable prior to the addition and can act on the inducer. A prototype is the beta-galactosidase of Escherichia coli, synthesised upon the addition of various galactosides, whether or not these are good substrates. Compare: constitutive enzyme. Synonym: adaptive enzyme. (05 Mar 2000) |