| urea | <biochemistry> The final nitrogenous excretion product of many organisms. (18 Nov 1997) |
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| urea breath test | A test for the presence of the bacteria helicobacter pylori that causes inflammation and ulcers in the stomach. The breath test is based on the ability of h. Pylori to break down urea. Ten minutes after swallowing a capsule containing urea with labelled carbon, a breath sample is collected to detect labelled carbon in the exhaled breath. A positive test indicates active infection. The test turns negative after eradication of the bacteria from the stomach with antibiotics. (12 Dec 1998) |
| urea clearance | The volume of plasma (or blood) that would be completely cleared of urea by one minute's excretion of urine; originally calculated as urine flow multiplied by urine urea concentration divided by concentration of urea in whole blood rather than plasma, representing blood urea clearance rather than plasma urea clearance. (05 Mar 2000) |
| urea clearance test | A test of renal function based on urea clearance. (05 Mar 2000) |
| urea cycle | The metabolic pathway isfound in vertebrates and takes place in theliver, in it, urea is synthesised from amino acids and carbon dioxide. (09 Oct 1997) |
| urea peroxide | CH4N2O-H2O2;a white crystalline compound used in an aqueous solution as an oxidizing mouthwash. (05 Mar 2000) |
| urea stibamine | A urea derivative of stibanilic acid, used in the treatment of kala azar and certain other tropical diseases. (05 Mar 2000) |
| ureagenesis | Formation of urea, usually referring to the metabolism of amino acids to urea. Synonym: ureapoiesis. Origin: urea + G. Genesis, production (05 Mar 2000) |
| ureal | Relating to or containing urea. Synonym: ureic. (05 Mar 2000) |
| ureameter | <physiology> An apparatus for the determination of the amount of urea in urine, in which the nitrogen evolved by the action of certain reagents, on a given volume of urine, is collected and measured, and the urea calculated accordingly. Origin: Urea. Source: Websters Dictionary (01 Mar 1998) |
| ureaplasma | A microorganism that can infect peoples' bladders, ureaplasmas are similar to mycoplasmas. (09 Oct 1997) |
| ureaplasma infections | Infections with bacteria of the genus ureaplasma. (12 Dec 1998) |
| ureaplasma urealyticum | A species of gram-negative bacteria found in the human genitourinary tract, oropharynx, and anal canal. (12 Dec 1998) |
| ureapoiesis | Synonym: ureagenesis. Origin: urea + G. Poiesis, a making (05 Mar 2000) |
| urease | <enzyme> An enzyme that breaks urea downinto carbon dioxide and ammonia, itstypically used to measure ureaconcentrations. (09 Oct 1997) |
| blood urea nitrogen | Blood urea nitrogen (BUN) is a metabolic by product (in the liver) from the breakdown of blood, muscle and protein. Blood urea nitrogen can be measured from a simple venipuncture specimen. Abnormal elevation in the blood urea nitrogen can indicate renal disease, dehydration, congestive heart failure, gastrointestinal bleeding, starvation, shock or urinary tract obstruction (by tumour or prostate gland). Low BUN level can indicate liver disease, malnutrition or a low protein diet. Normal BUN levels should be between 7 and 20 mg/dl (milligrams per decilitre). (27 Sep 1997) |
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| maximum urea clearance | The urea clearance when the urine flow exceeds 2 ml/min; normal value is about 75 ml blood/min per 1.73 m2 body surface area. (05 Mar 2000) |
| herbicides, urea | Herbicides which owe their activity to the urea moiety in the molecule. (12 Dec 1998) |
| standard urea clearance | The value obtained when the square root of the urine flow (when below 2 ml/min) is multiplied by the urine urea concentration and divided by the whole blood urea concentration; represents an old empirical adjustment for the effect of low urine flow on urea excretion; sometimes corrected for body size by dividing by some function of body weight or surface area. Later, plasma concentration was substituted for blood concentration in the calculation. The normal value is about 54 ml/min per 1.73 m2 in an adult person. Synonym: Van Slyke's formula. (05 Mar 2000) |
| quinine and urea hydrochloride | Sclerosing agent for treatment of internal haemorrhoids, hydrocele, and varicose veins, containing not less than 58% and not more than 65% of anhydrous quinine. (05 Mar 2000) |