| gap phenomenon | A short period in the cycle of the atrioventricular or intraventricular conduction allowing passage of an impulse which at other times would be blocked in transit. Synonym: excitable gap. (05 Mar 2000) |
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| GAP protein | <molecular biology> Originally purified as a 125 kD protein from bovine brain (1044 amino acids), stimulates the GTPase activity of ras p21 and thereby switches it to the inactive state. GAP may itself be regulated by phospholipids and by phosphorylation on a tyrosine residue by growth factor receptors (PDGF R, EGF R). The neurofibromatosis type 1 gene NF1) codes for a protein homologous to GAP. GAP has both SH2 and SH3 domains. Another example is sar 1 (from yeast). (18 Nov 1997) |
| chromosomal gap | A localised area of thinning in a chromatid which may simulate a complete break. (05 Mar 2000) |
| silent gap | The period during which Korotkoff sounds indicating true systolic pressure fade away and reappear at a lower pressure point; responsible for errors made in recording falsely low systolic blood pressure, especially in hypertensive patients, of up to 25 mm Hg, and avoided by pumping the cuff 30 mm Hg beyond palpable systolic pressure. Synonym: silent gap. (05 Mar 2000) |
| DNA gap | A localised loss of one of the two strands in the double helix of DNA. (05 Mar 2000) |
| interocclusal gap | The space between the occluding surfaces of the maxillary and mandibular teeth when the mandible is in physiologic resting position. Synonym: interocclusal clearance, interocclusal distance, interocclusal gap, interocclusal rest space. (05 Mar 2000) |
| excitable gap | A short period in the cycle of the atrioventricular or intraventricular conduction allowing passage of an impulse which at other times would be blocked in transit. Synonym: excitable gap. (05 Mar 2000) |