| ACTH suppression test | <investigation> A test that measures the response of the adrenal glands to ACTH. In this case, dexamethasone is given to the patient and then blood cortisol levels are measured. Under normal conditions, cortisol levels should drop in response to dexamethasone. In this test one milligram of dexamethasone is administered in the morning and then the blood is drawn for analysis the following morning. Abnormal test results can indicate Cushing's syndrome. (27 Sep 1997) |
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| adhesion test | The diagnostic application of the immune adhesion phenomenon. Synonym: erythrocyte adherence test, immune adhesion test, red cell adherence test. (05 Mar 2000) |
| Adler's test | A test for blood; the suspected fluid is treated with glacial acetic acid and ether, and the latter is then decanted and treated with hydrogen peroxide and a solution of benzidine in acetic acid; the presence of blood is indicated by a bluish colour turning to purple. Synonym: Adler's test. (05 Mar 2000) |
| Adson's test | A test for thoracic outlet syndrome; the patient is seated, with head extended and turned to the side of the lesion; with deep inspiration there is a diminution or total loss of radial pulse on the affected side. Not all patients with a positive Adson's test have thoracic outlet syndrome. Synonym: Adson manoeuvre. (05 Mar 2000) |
| agglutination test | <investigation> A serologic test to demonstrate the presence of antibodies in the blood. It is dependent on the clumping of cells, microorganisms, or particles when mixed with specific antiserum. See: agglutination. (04 Jul 1999) |
| AIDS test | <investigation> A test which is performed on a standard venipuncture blood specimen which detects the presence of antibodies to HIV (virus). This test may not be positive for 3 to 6 months after infection with HIV. (27 Sep 1997) |
| Albarran's test | A test for renal insufficiency wherein the drinking of large quantities of water will cause a proportionate increase in the volume of urine if the kidneys are sound, but not if the epithelium of the secreting tubules is damaged. Synonym: polyuria test. (05 Mar 2000) |
| alkali denaturation test | A test for haemoglobin F (Hb F), based on the fact that haemoglobins, with the exception of Hb F, are denatured by alkali to alkaline haematin; the test is sensitive to 2% or more Hb F. (05 Mar 2000) |
| Allen-Doisy test | A test for oestrogenic activity; the material to be investigated is injected repeatedly into immature or spayed rats or mice; the disappearance of leukocytes from the vaginal smear and the appearance of cornified cells constitutes a positive reaction. (05 Mar 2000) |
| Allen's test | For phenol: upon the addition of 5 or 6 drops of hydrochloric acid and then 1 of nitric acid to the suspected fluid, a red colour develops. For strychnine: fluid is extracted with ether, which is then evaporated by means of "drop-by-drop" pipetting into a warmed porcelain dish or crucible; the residue is treated with a small bit of manganese dioxide and dilute sulfuric acid; a red-blue or violet colour develops if strychnine is present. Origin: A.H. Allen A test for radial or ulnar patency; either the radial or ulnar artery is digitally compressed by the examiner after blood has been forced out of the hand by clenching it into a fist; failure of the blood to diffuse into the hand when opened indicates that the artery not compressed is occluded. Origin: Edgar Van Nuys Allen (05 Mar 2000) |
| allergy skin test | Test done on the skin to identify the allergy substance (allergen) triggering the allergic reaction. A small amount of the suspected allergy substance is placed on the skin. The skin is then gently scratched through the small drop with a special sterile needle. If the skin reddens and, more importantly, swells, then allergy to that substance is probable. (12 Dec 1998) |
| Almen's test for blood | Glacial acetic acid, gum guaiac solution, and hydrogen peroxide are added to an aqueous suspension of the suspected stain; if occult blood or blood pigment is present, a blue colour develops. Synonym: guaiac test, Schonbein's test, van Deen's test. (05 Mar 2000) |
| alternate binaural loudness balance test | ABLB test, a test for recruitment in one ear; the comparison of relative loudness of a series of intensities presented alternately to either ear. (05 Mar 2000) |
| alternate cover test | A test to detect phoria or strabismus; attention is directed to a small fixation object, and one eye is covered for several seconds; then the cover is moved quickly to the other eye; if the eye moves when it is uncovered, a strabismus or phoria is present. (05 Mar 2000) |
| alternating light test | Test to detect a relative afferent defect in one eye by watching pupillary movements. With the patient fixing in the distance, the light is held on each eye for about a second, and quickly moved to the other eye. Assuming no defect of the innervation to the iris sphincter in one eye (which would produce an anisocoria in light), the eye with the weaker light response has a relative afferent pupillary defect. This asymmetry of pupillomotor input can be estimated by holding neutral density filters in front of the better eye until the pupillary responses of the two eyes are balanced. Synonym: swinging light test. (05 Mar 2000) |