| Ehret's phenomenon | A sudden throb felt by the finger on the brachial artery, as the pressure in the cuff falls during a blood pressure estimation; said to indicate fairly accurately the diastolic pressure. (05 Mar 2000) |
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| Ehrlich's phenomenon | The difference between the amount of diphtheria toxin that will exactly neutralise one unit of antitoxin and that which, added to one unit of antitoxin, will leave one lethal dose free is greater than one lethal dose of toxin; i.e., it is necessary to add more than one lethal dose of toxin to a neutral mixture of toxin and antitoxin to make the mixture lethal (the basis of the L+ dose). (05 Mar 2000) |
| toe phenomenon | <clinical sign> Extension of the great toe and abduction of the other toes instead of the normal flexion reflex to plantar stimulation, considered indicative of pyramidal tract involvement ("positive" Babinski). Synonym: Babinski reflex, Babinski's phenomenon, great-toe reflex, paradoxical extensor reflex, toe phenomenon. (05 Mar 2000) |
| tongue phenomenon | <clinical sign> In latent tetany, tapping the tongue causes its depression with a concave dorsum. Synonym: tongue phenomenon. (05 Mar 2000) |
| Tournay's phenomenon | Dilation of the pupil in the abducting eye on extreme lateral gaze. This is present in only a small percentage of the normal popupation and has no known association with disease. Synonym: Tournay sign. (05 Mar 2000) |
| erythrocyte adherence phenomenon | A phenomenon manifested by the adherence of antigen-antibody-complement complex to "indicator cells" (microorganisms, platelets, leukocytes, or erythrocytes), the reaction being sensitive and specific for the antigen and antibody in the complex. Synonym: erythrocyte adherence phenomenon, immune adherence phenomenon, red cell adherence phenomenon. (05 Mar 2000) |
| escape phenomenon | Failure of the pupil in an eye with optic neuritis to maintain constriction as both eyes are alternately stimulated with light. (05 Mar 2000) |
| Tullio's phenomenon | <neurology> Momentary vertigo caused by any loud noise, notably occurring in cases of active labyrinthine fistula. (05 Mar 2000) |
| jaw-winking phenomenon | <syndrome> An increase in the width of the eye lids during chewing, sometimes with a rhythmic elevation of the upper lid when the mouth is open and ptosis when the mouth is closed. Synonym: Gunn phenomenon, Gunn's syndrome, jaw-winking phenomenon, jaw-working reflex, Marcus Gunn phenomenon, Marcus Gunn syndrome. (05 Mar 2000) |
| Twort-d'Herelle phenomenon | The lysis of bacteria by bacteriophage. Synonym: bacteriophagia, d'Herelle phenomenon, Twort phenomenon. (05 Mar 2000) |
| Twort phenomenon | The lysis of bacteria by bacteriophage. Synonym: bacteriophagia, d'Herelle phenomenon, Twort phenomenon. (05 Mar 2000) |
| Jod-Basedow phenomenon | <endocrinology> Induction of thyrotoxicosis in a previously euthyroid individual as a result of exposure to large quantities of iodine. It occurs most often in areas of endemic iodine-deficient goiter and in patients with multinodular goiter. It can also can develop following use of iodine-containing agents for diagnostic studies. Synonym: iodine-induced hyperthyroidism. (05 Mar 2000) |
| Tyndall phenomenon | The visibility of floating particles in gases or liquids when illuminated by a ray of sunlight and viewed at right angles to the illuminating ray. Synonym: Tyndall effect. (05 Mar 2000) |
| facialis phenomenon | Facial spasm produced by light rubbing of the skin or a tap on the zygoma; sometimes percussion above the zygoma causes contraction of the lip only; observed in tetany and sometimes in exophthalmic goiter. (05 Mar 2000) |
| knee phenomenon | A sudden contraction of the anterior muscles of the thigh, caused by a smart tap on the patellar tendon while the leg hangs loosely at a right angle with the thigh. Synonym: knee jerk, knee phenomenon, knee reflex, knee-jerk reflex, patellar tendon reflex, quadriceps reflex. (05 Mar 2000) |