| alpha-aminoisobutyric acid | 2-amino-2-methylpropionic acid;a synthetic amino acid useful in the study of amino acid transport across cell membranes and in the study of cytokine effects; it is not metabolised by the cell. (05 Mar 2000) |
|---|---|
| alpha-aminosuccinic acid | <amino acid> One of the twenty naturally occurring amino acids. Has the following chemical characteristics: pKa1 pKa2 pKa3 pI Water Solubility (30deg C)2.09-3.86 9.82 2.97 0.6 (09 Oct 1997) |
| alpha-amylase | <enzyme> An enzyme that catalyses the endohydrolysis of 1,4-alpha-glycosidic linkages in starch, glycogen, and related polysaccharides and oligosaccharides containing 3 or more 1,4-alpha-linked d-glucose units. Pharmacological action: anti-inflammatory agents. Chemical name: 1,4-alpha-D-Glucan glucanohydrolase Registry number: EC 3.2.1.1 (12 Dec 1998) |
| alpha angle | The angle between the visual and optic axes as they cross at the nodal point of the eye, the angle between the visual line and the major axis of the corneal ellipse. (05 Mar 2000) |
| alpha-antitrypsin deficiency | <enzyme> A specific enzyme (alpha 1 antitrypsinase) that when absent genetically can result in panacinar emphysema (lung disease) and liver disease. There is no specific treatment for this condition other than supportive care for the liver and lung complications. Medications such as alpha-1proteinase inhibitor is given regularly to these patients. Incidence: approximately 1 in 10,000. (02 Jan 1998) |
| alpha,beta-ketoalkene reductase | <enzyme> Nadh is much less effective than NADPH; catalyses the reduction of the carbon-carbon double bond of five membered ring cpds which have two conjugated carbonyl groups on both sides of a double bond Registry number: EC 1.3.1.- Synonym: n-ethylmaleimide reducing enzyme, NADPH-linked alpha,beta-ketoalkene double bond reductase, n-ethylmaleimide reductase (26 Jun 1999) |
| alpha-blocker | An agent that competitively blocks alpha-adrenergic receptors; used in the treatment of hypertension. Synonym: alpha-blocker. (05 Mar 2000) |
| alpha blocking | The attenuation of the occipital alpha rhythm (8-14 Hz brain waves as seen on an electroencephalogram), produced by opening the eyes or by intense mental concentration. (05 Mar 2000) |
| alpha cell | <biology> A type of cell in the pancreas (in areas called the islets of Langerhans). Alpha cells make and release a hormone called glucagon, which raises the level of glucose (sugar) in the blood. (09 Oct 1997) |
| Alpha cells | Alpha cell's of pancreas or of anterior lobe of hypophysis. (05 Mar 2000) |
| alpha cells of anterior lobe of hypophysis | Acidophil cell's that constitute about 35% of the cell's of the anterior lobe. There are two varieties: one that elaborates somatotropin, another that elaborates prolactin. (05 Mar 2000) |
| alpha cells of pancreas | Cell's of the islets of Langerhans that secrete glucagon. (05 Mar 2000) |
| alpha chain disease | A vague or indefinite term; could be used for alpha-heavy-chain disease (a lymphoplasma cell proliferative disease usually seen in Mediterranean men, characterised by intestinal involvement with steatorrhoea, often progressive with fatal outcome) or a thalassaemia (a genetic abnormality in the alpha globin chain of haemoglobin). (05 Mar 2000) |
| alpha channeling | <radiobiology> Term for an idea (so far theoretical) in magnetic confinement fusion, the idea is that plasma waves can be used to control the alpha particles produced in a fusion reactor, to transfer their energy directly to fuel ions, and to help push them out of the plasma. This could potentially help to substantially improve the power output capabilities of fusion plasmas. (09 Oct 1997) |
| alpha-chloralose | A conjugate of chloral and glucose used as an anaesthetic in laboratory animals; it does not depress cardiovascular reflexes as much as most other anaesthetic agents. (05 Mar 2000) |