| CysLT1 | cysteinyl leukotriene 1 |
|---|---|
| LT | heat-labile toxin; laminar tomography; left; left thigh; less than; lethal time; leukotriene; Levin ... |
| LTA | leukotriene A; lipoate transacetylase; lipotechoic acid; local tracheal anesthesia; long-term archiv... |
| LTB | laryngotracheobronchitis; leukotriene B |
| LTC | large transformed cell; leukotriene C; lidocaine tissue concentration; long-term care |
| antagonist | <pharmacology> A substance that tends to nullify the action of another, as a drug that binds to a cell receptor without eliciting a biological response. Origin: Gr. Antagonistes = an opponent (18 Nov 1997) |
|---|---|
| associated antagonist | One of two muscles or groups of muscles which pull in nearly opposite directions, but which, when acting together, move the part in a path between their diverging lines of action. (05 Mar 2000) |
| beta-adrenoreceptor antagonist | A class of drugs that compete with beta-adrenergic agonists for available receptor sites; some compete for both b1 and b2 receptors (e.g., propranolol) while others are primarily either b1 (e.g., metoprolol) or b2 blockers; used in the treatment of a variety of cardiovascular diseases where beta-adrenergic blockade is desirable. Synonym: beta-adrenergic receptor blocking agent, beta-adrenoreceptor antagonist, beta-blocker. (05 Mar 2000) |
| calcium antagonist | calcium channel-blocking agent |
| calcium channel antagonist | <pharmacology> A class of drugs that act by selective inhibition of calcium ion influx through or across cell membranes or on the release and binding of calcium in intracellular pools. Calcium channel blockers are used primarily in the treatment of certain heart conditions and stroke. As they are inducers of vascular and other smooth muscle relaxation, they are also used in the treatment of hypertension and cerebrovascular spasms, as myocardial protective agents, and in the relaxation of uterine spasms. Synonym: calcium antagonist, calcium channel-blocker, slow channel-blocking agent. (12 May 2002) |
| mixed opioid agonist-antagonist | <pharmacology> A compound that has an affinity for two or more types of opioid receptors and blocks opioid effects on one receptor type while producing opioid effects on a second receptor type. (13 Nov 1997) |
| competitive antagonist | An antimetabolite. (05 Mar 2000) |
| muscarinic antagonist | Drugs which bind with muscarinic cholinergic receptors but do not activate them, thus preventing access to acetylcholine; examples include atropine, scopolamine, propantheline, and pirenzepine. (05 Mar 2000) |
| H2 antagonist | <pharmacology> A class of anti-ulcer medication which work through the inhibition of basal and nocturnal gastric acid secretion by competitive inhibition of the action of histamine at histamine H2 receptor sites on the parietal cells. Drugs of this type block gastric acid secretion and are therefore clinically useful in treating duodenal ulcers. Examples include cimetidine (Tagamet), famotidine (Pepcid), nizatidine (Axid) and ranitidine (Zantac). (27 Sep 1997) |
| insulin antagonist | Something that opposes or fights the action of insulin. Insulin lowers the level of glucose (sugar) in the blood, whereas glucagon raises it, therefore, glucagon is an antagonist of insulin. (09 Oct 1997) |
| oestrogen antagonist | <pharmacology> A drug or compound which inhibit or antagonise the action or biosynthesis of oestrogen. Tamoxifen also has agonist or stimulatory actions as well as blocking effects. There are also selective oestrogen-receptor modulators (SERMs). For example, raloxifene (trade name Evista) is classified as a SERM because it prevents bone loss (like oestrogen) and lowers serum cholesterol (like oestrogen) but (unlike oestrogen) does not stimulate the endometrial lining of the uterus. (12 May 2002) |
| enzyme antagonist | An antimetabolite or inhibitor of enzyme action. (05 Mar 2000) |
| folate antagonist | <pharmacology> One of a group of substances which blocks the formation of nucleotides that require the presence of folate (one of the B vitamins) before they can be made. The substance does this by blocking key steps in the reaction sequence. These substances are often used to treat cancer because fast-growing cancerous cells usually need to use the blocked reactions more than normal cells. (09 Oct 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) |
| acetylcholine receptor antibodies | <neurology, investigation> A test used to measure the amount of antibodies to acetylcholine receptors on nerve endings. This is a diagnostic test for myasthenia gravis. A normal value is no antibodies in the bloodstream. Acetylcholine receptor (AChR) binding autoantibodies (i.e. Antibodies reactive with several epitopes other than the binding site for acetylcholine or alpha-bungarotoxin) are present in approximately 88% of patients with generalised myasthenia gravis, 70% of ocular myasthenia and in approximately 80% of myasthenia gravis in remission. Although serum concentrations of AChR binding autoantibodies do not in general correlate well with severity of weakness, there is typical decrease in concentration as weakness improves with immunosuppressive therapy. AChR blocking autoantibodies (i.e., antibodies reactive with the AChR binding site) are present in about 50% of patients with myasthenia gravis, 30% with ocular myasthenia gravis and 20% of myasthenia gravis in remission, AChR blocking autoantibodies are the only AChR autoantibodies present in about 1% of myasthenia gravis. AChR modulating autoantibodies (i.e., autoantibodies which cross-link AChRs and cause their removal from muscle membrane surfaces) are present in more than 90% of myasthenia gravis and occasionally are the only AchR autoantibodies detectable in mild, recent onset or ocular-restricted myasthenia gravis. Results for AChR modulating autoantibodies can be transiently false-positive due to curare-like drugs used during general anesthesia. AChR autoantibodies of one or more types are found in at least 80% of ocular myasthenia gravis. Although generally absent in neurological conditions other than myasthenia gravis(and consequently unlikely to cause confusion in neurodiagnosis), false-positive results for AChR autoantibodies occasionally occur in primary biliary cirrhosis, tardive dyskinesia, autoimmune thyroiditis, the elderly, amyotrophic lateral sclerosis patients treated with cobra venom and patients with thymoma in the absence of myasthenia gravis. Approximately 1% of patients with rheumatoid arthritis treated with D-penicillamine develop AChR autoantibodies and myasthenia gravis, both of which disappear when the drug is discontinued. Babies born to ~10% of myasthenia gravis mothers have a transient neonatal form of myasthenia gravis that responds well to anticholinesterase therapy and usually remits within 1 month as maternal IgG disappears. (29 Dec 1997) |