| beta-amyloid | <protein> The protein which forms thick deposits, or plaques, in the brains of people with Alzheimer's disease, a disease where memory skills gradually deteriorate with age. (13 Nov 1997) |
|---|---|
| beta angle | The angle formed by a line connecting the bregma and hormion meeting the radius fixus. (05 Mar 2000) |
| beta-aspartyl(acetylglucosamine) | Misnomer for 1-(beta-asparagino)-N-acetylglucosamine or 1-(beta-aspartamido)-N-acetylglucosamine, or, formally, 1-(beta-l-aspartamido)-N-2-acetamido-1,2-dideoxy-beta-d-glucose; a compound of N-acetylglucosamine and asparagine, linked via the amide nitrogen of the latter and carbon-1 of the former. An important structural linkage in many glycoproteins. (05 Mar 2000) |
| beta-aspartyldipeptidase | <enzyme> Catalyses the hydrolytic cleavage of a beta-linked aspartic residue from the n-terminus of a polypeptide; formetly EC 3.4.13.10 Registry number: EC 3.4.19.5 Synonym: beta-aspartylpeptidase, isoaspartyl dipeptidase, beta-aspartyl-peptidase, l-beta-aspartyl dipeptidase (26 Jun 1999) |
| beta-blocker | <pharmacology> A large group of medications that act to block specific receptors in the nervous system. A drug that induces adrenergic blockade at either á1 or á2 adrenergic receptors or at both. The effect of beta-blockade results in slowing of the heart rate, reduction in blood pressure and reduced anxiety. Beta-blockers are used in the treatment of angina, heart arrhythmias, high blood pressure, mitral valve prolapse and other conditions. (06 Oct 1997) |
| beta blockers | A class of drugs that block the action of adrenaline (a beta adrenergic substance) and can relieve stress to the heart muscle. Beta blockers are often used to slow the heart rate or lower the blood pressure. (12 Dec 1998) |
| beta-carboline-2-N-methyltransferase | <enzyme> Brain enzyme may have a role in development of idiopathic parkinson disease by forming n-methylated beta-carbolinium cations Registry number: EC 2.1.1.- Synonym: betac-2-nmt (26 Jun 1999) |
| beta-carotene | An antioxidant which protects cells against oxidation damage that can lead to cancer. Beta carotene is converted, as needed, to vitamin A. A yellow carotenoid pigment that gives a reddish colour to plants such as carrots and tomatoes. It is often used as a vitamin supplement because the liver can convert it into Vitamin A. Food sources of beta-carotene include vegetables such as carrots, sweet potatoes, spinach and other leafy green vegetables; and fruit such as cantaloupes and apricots. Excessive carotene in the diet can temporarily yellow the skin, a condition called carotenaemia, commonly seen in infants fed largely mushed carrots. (12 Dec 1998) |
| beta-carotene 15,15'-dioxygenase | <enzyme> An enzyme catalyzing the reaction of beta-carotene plus O2 producing two retinals. Synonym: beta-carotene cleavage enzyme, carotenase, carotinase. (05 Mar 2000) |
| beta-carotene cleavage enzyme | <enzyme> An enzyme catalyzing the reaction of beta-carotene plus O2 producing two retinals. Synonym: beta-carotene cleavage enzyme, carotenase, carotinase. (05 Mar 2000) |
| beta-carotene hydroxylase | <enzyme> O2-dependent NADPH-dependent monooxygenase from erwinia herbicola; forms zeaxanthin; amino acid sequence has been determined; genbank m87280 Registry number: EC 1.14.13.- Synonym: beta-carotene monooxygenase, crtz gene product (26 Jun 1999) |
| beta cell | 1. <pathology> Cells of the pancreas within discrete endocrine islands (Islets of Langerhans) embedded in the major exocrine tissue of vertebrate pancreas. The B or beta cells (originally distinguished by differential staining from A, C and D), are responsible for synthesis and secretion of insulin, a hormone that controls the level of glucosein the blood. 2. Also refers to the beta cells of the anterior lobe of hypophysis. These are a population of functionally diverse cell's that contain basophilic granules and secrete hormones such as ACTH, lipotropin, thyrotropin, and the gonadotropins. Synonym: basophil cell of anterior lobe of hypophysis. (05 Mar 2000) |
| beta-cell src-homology tyrosine kinase | <enzyme> A murine frk (fyn-related kinase) homolog; genbank l36132; do not confuse with brain-specific kinase bsk Registry number: EC 2.7.1.- Synonym: beta-cell sh tk, bsk protein, sh tk, bsk gene product, sh tk (26 Jun 1999) |
| beta-chlorovinyldichloroarsine | C2H2AsCl3; dichloro(2-chlorovinyl)arsine;a war gas. It is a vesicant, a lung irritant like mustard gas, a systemic poison entering the circulation through the lungs or skin, and a mitotic poison arresting mitosis in the metaphase; dimercaprol is the antidote. Synonym: beta-chlorovinyldichloroarsine. Origin: W. Lee Lewis, U.S. Chemist 1898-1943 (05 Mar 2000) |
| beta conformation | A polypeptide chain (often a secondary structure of a protein) arranged as along zig-zag. (09 Oct 1997) |