| finger phenomenon | A sign of organic hemiplegia; with the patient's elbow resting on a table, the patient's wrist is grasped by the examiner's hand, the thumb of which is used to exert pressure on the radial side of the patient's pisiform bone; if the hemiplegia is organic, some or all of the patient's fingers become extended and spread out in a fanlike form. Synonym: Gordon's sign. (05 Mar 2000) |
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| Flynn phenomenon | A pupillary response to light, the reverse of that expected; e.g., contraction of the pupil in response to turning the lights off. Synonym: Flynn phenomenon, paradoxical pupillary phenomenon. (05 Mar 2000) |
| Friedreich's phenomenon | The tympanitic percussion sound over a pulmonary cavity is slightly raised in pitch on deep inspiration. (05 Mar 2000) |
| Leclef phenomenon | Enhanced phagocytosis by leukocytes of microorganisms in the presence of immune serum. (05 Mar 2000) |
| Leede-Rumpel phenomenon | Appearance of petechiae in an area following application of vascular constriction, such as by a tourniquet, usually after 10 minutes but can appear after shorter period, such as following application of tourniquet to draw blood specimen or use of blood pressure cuff. Due to capillary fragility or abnormal platelet numbers (e.g. Thrombocytopenia) or function. (05 Mar 2000) |
| leg phenomenon | In tetany, spasm both of the extensor muscles of the knee and of the calf muscles when the extended leg is flexed at the hip. Synonym: leg phenomenon, Pool-Schlesinger sign, Schlesinger's sign. In tetany, contraction of the arm muscles following the stretching of the brachial plexus by elevation of the arm above the head with the forearm extended, resembles the contraction resulting from stimulation of the ulnar nerve. Synonym: arm phenomenon. (05 Mar 2000) |
| Leichtenstern's phenomenon | <clinical sign> Tapping gently one of the bones of the extremities causes the patient to draw back violently, sometimes with a loud cry; noted in cases of cerebrospinal meningitis. Synonym: Leichtenstern's phenomenon. (05 Mar 2000) |
| LE phenomenon | The formation of LE cells in bone marrow or blood on adding serum from patients with disseminated lupus erythematosus. (05 Mar 2000) |
| Lucio's leprosy phenomenon | An acute form occurring in pure diffuse lepromatous leprosy presenting irregularly shaped, intensely erythematous, tender plaques, especially of the legs, with tendency to ulceration and scarring. Synonym: lazarine leprosy, Lucio's leprosy phenomenon. (05 Mar 2000) |
| Abbe test plate | <equipment> A long, wedge-shaped coverslip about 0.20 mm thick at one end and 0.10 to 0.12 mm at the other end coated chemically with a silver film on which are ruled horizontal lines. at each variation in thickness of 0.01 mm there are vertical lines. By means of oblique illumination and by focusing on different portions of the plate, it is possible to determine the optimum coverslip thickness for any objective and also, for microscopes with drawtubes, the tube length for best objective performance. The approximate freedom from spherical and chromatic aberrations can also be estimated. Small isolated bits of silver near the edges of the lines form good objects for the star test (05 Aug 1998) |
| acetone test | A test for ketonuria; the suspected urine is shaken up with a few drops of sodium nitroprusside, and strong ammonia water is then gently poured over the mixture; if acetone is present, a magenta ring forms at the line of contact; tablets containing sodium nitroprusside and alkali are now more commonly used. (05 Mar 2000) |
| achievement test | A standardised test used to measure acquired learning, e.g., competence in a specific subject area such as reading or arithmetic, in contrast to an intelligence test which is a useful index of potential ability or learning. (05 Mar 2000) |
| acidified serum test | Lysis of the patient's red cells in acidified fresh serum, specific for paroxysmal nocturnal haemoglobinuria. Synonym: Ham's test. (05 Mar 2000) |
| acid loading test | <nephrology> This is a test used in the diagnosis of renal tubular acidosis. The patient takes ammonium chloride capsules for 3 days to acidify the blood (lower blood pH). A sample of the urine and the blood is then collected and the results are interpreted. (27 Sep 1997) |
| acid perfusion test | <gastroenterology, investigation> A test used to diagnosis gastrooesophageal reflux disease. This investigation requires that the patient swallow 3 tiny tubes into the stomach. A mixture of hydrochloric acid (like stomach acid) and saline are alternatively injected into the tubes. The patient then reports any symptoms they may have. Some patients may vomit. (13 Nov 1997) |