| digoxin toxicity | A result of the over-accumulation of digitalis glycosides in the body. Kidney insufficiency can be a contributing factor. Symptoms include nausea, vomiting, visual changes, blurred vision, anorexia and palpitations. Treatment is emergent as life-threatening cardiac arrhythmias are possible with higher blood levels. (27 Sep 1997) |
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| drug toxicity | The systemic effects of a drug that are related to the overall level of the medication in the bloodstream. Drug toxicity may occur with overdosage of a medication, accumulation of the drug in the body over time or the inability of the patients body to eliminate the drug. (27 Sep 1997) |
| oxygen toxicity | A body disturbance resulting from breathing high partial pressures of oxygen; characterised by visual and hearing abnormalities, unusual fatigue while breathing, muscular twitching, anxiety, confusion, incoordination, and convulsions; although the mechanism for development of the condition is obscure, a disruption of enzymatic activity is likely, perhaps as a result of free radical formation. Synonym: oxygen poisoning. (05 Mar 2000) |
| toxicity | The quality of being poisonous, especially the degree of virulence of a toxic microbe or of a poison. (18 Nov 1997) |
| toxicity test | <investigation> Controlled laboratory test to determine the toxicity of a chemical to an organism in terms of specific chemical concentrations. An acute toxicity test establishes the concentration required to kill a predetermined proportion of test organisms within a relatively short period of time, typically 4 days or less. A chronic toxicity test reveals the effects of a sublethal concentration applied throughout all or part of the life cycle. (12 Jan 1998) |
| toxicity tests | Tests that determine the toxicity of a substance. These include tests of clinical drugs, foods, environmental pollutants, etc. (12 Dec 1998) |
| ep toxicity | A test defined by the federal Environmental Protection Agency to check a substance for the presence of arsenic, barium, cadmium, chromium, lead, mercury, selenium, or silver. 40 CFR 261.24 defines the concentrations constituting hazardous waste and the test procedure. (05 Dec 1998) |
| active carbon dioxide | Activated carbon dioxide, a complex of N-carboxybiotin (biotin + CO2) and an enzyme; the form in which carbon dioxide is added to other molecules in carboxylations; e.g., to methylcrotonyl-CoA to form beta-methylglutaconyl in the catabolism of leucine, and to acetyl-CoA to form malonyl-CoA. See: acetyl-CoA carboxylase. (05 Mar 2000) |
| anomeric carbon | The reducing carbon of a sugar; C-1 of an aldose, C-2 of a 2-ketose. (05 Mar 2000) |
| arteriovenous carbon dioxide difference | <physiology> The difference in carbon dioxide content (in ml per 100 ml blood) between arterial and venous blood. (05 Mar 2000) |
| carbon | <chemistry, element> Sixth element (Z=6) in the periodic table, has 6 protons, often described as the basis of life on earth because of its chemical properties, has potential for use with silicon as a low-activation structural material for fusion reactors, in the form silicon carbide. Carbon tiles are often used in plasma-facing components because its low Z makes carbon a relatively nice impurity. It is also useful as a neutron moderator. See: low-activation materials, plasma-facing components. Abbreviation: C (13 Nov 1997) |
| carbon-11 | A cyclotron-produced, positron-emitting radioisotope of carbon with a half-life of 20.3 minutes; used in positron-emitting tomography. (05 Mar 2000) |
| carbon-12 | The standard of atomic mass, 98.90% of natural carbon. (05 Mar 2000) |
| carbon-13 | A stable natural isotope, 1.1% of natural carbon. (05 Mar 2000) |
| carbon-14 | A beta-emitter with a half-life of 5715 years, widely used as a tracer in studying various aspects of metabolism; naturally occurring 14C, arising from cosmic ray bombardment, is used to date relics containing natural carbonaceous materials. (05 Mar 2000) |