| signal transduction | The cascade of processes by which an extracellular signal (typically a hormone or neurotransmitter) interacts with a receptor at the cell surface, causing a change in the level of a second messenger for example calcium or cyclic AMP) and ultimately effects a change in the cells functioning (for example: triggering glucose uptake or initiating cell division). Can also be applied to sensory signal transduction, for example of light at photoreceptors. (18 Nov 1997) |
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| signal void | In magnetic resonance imaging, a region emitting no radiofrequency signal, either because there are no activated protons in the region (such as flowing blood) or because a different element predominates, particularly calcium. (05 Mar 2000) |
| nuclear localization signal | Short, predominantly basic amino acid sequences identified as nuclear import signals for some proteins. These sequences are believed to interact with specific receptors at nuclear pores. (12 Dec 1998) |
| accessory symptom | A symptom that usually but not always accompanies a certain disease, as distinguished from a pathognomonic symptom. Synonym: assident symptom, concomitant symptom. (05 Mar 2000) |
| accidental symptom | Any morbid phenomenon coincidentally occurring in the course of a disease, but having no relation with it. (05 Mar 2000) |
| assident symptom | A symptom that usually but not always accompanies a certain disease, as distinguished from a pathognomonic symptom. Synonym: assident symptom, concomitant symptom. (05 Mar 2000) |
| Baumes symptom | Pain behind the sternum in angina pectoris. (05 Mar 2000) |
| Bezold's symptom | Inflammatory oedema at the tip of the mastoid process in mastoiditis. Synonym: Bezold's sign. (05 Mar 2000) |
| Bolognini's symptom | A feeling of crepitation on gradually increasing pressure on the abdomen in cases of measles. Cardinal symptom, the primary or major symptom of diagnostic importance. (05 Mar 2000) |
| Macewen's symptom | <clinical sign> Percussion of the skull gives a cracked-pot sound in cases of hydrocephalus. Synonym: Macewen's symptom. (05 Mar 2000) |
| rainbow symptom | A yellowish white ring surrounding the optic disk, indicating atrophy of the choroid in glaucoma. Synonym: glaucomatous ring. A halo surrounding lights, caused by corneal oedema in glaucoma. Synonym: rainbow symptom. (05 Mar 2000) |
| reflex symptom | A disturbance of sensation or function in an organ or part more or less remote from the morbid condition giving rise to it; e.g., muscle spasm due to joint inflammation. Synonym: sympathetic symptom. (05 Mar 2000) |
| pathognomonic symptom | A symptom that, when present, points unmistakably to the presence of a certain definite disease. (05 Mar 2000) |
| Gordon's symptom | The occurrence of an appreciable interval after the production of a reflex before relaxation, e.g., the leg remains up for a time after a knee jerk. Synonym: Gordon's symptom. (05 Mar 2000) |
| Griesinger's symptom | Oedema of the superficial tissues at the tip of the mastoid process in cases of thrombosis of the sigmoid sinus. (05 Mar 2000) |