| constitutional reaction | A generalised reaction in contrast to a focal or local reaction; in allergy the immediate or delayed response, following the introduction of an allergen, occurring at sites remote from that of injection. (05 Mar 2000) |
|---|---|
| constitutional symptom | A symptom indicating a systemic effect of a disease; e.g., weight loss. (05 Mar 2000) |
| constitutional thrombopathy | <haematology> A form of congenital platelet functional defect that result in prolongation of the bleeding time. Characteristics include mucosal and post-operative bleeding that may be severe. (17 Dec 1997) |
| constitutional ulcer | An ulcer due to systemic disease, such as tuberculosis. Synonym: symptomatic ulcer. (05 Mar 2000) |
| constitutive | Constantly present, whether there is demand or not. Thus some enzymes are constitutively produced, whereas others are inducible. (18 Nov 1997) |
| constitutive enzyme | <enzyme> An enzyme that is constantly produced by the cell regardless of the growth conditions. Compare: induced enzyme. (05 Mar 2000) |
| constitutive gene | A gene which is continuously expressed without any regulation (transcription can be neither suppressed nor encouraged). These genes generally encode housekeeping functions and are expressed at low levels in all cells. (09 Oct 1997) |
| constitutive heterochromatin | <protein> Regions on chromosomes which are permanently condensed and genetically inactive in every cell in the body. The condensed portions are always in the same position on both homologous chromosomes. An example is the centromeres. Compare: facultative heterochromatin. (09 Oct 1997) |
| constitutive mutant | An organism with a mutation in a regulatory gene, so that the genes which its flawed regulatory product are supposed to suppress become constitutive genes, or impossible to turn off. Thus, the products of the uncontrolled genes are produced to excess. (09 Oct 1997) |
| constriction | The act of constricting. (12 Dec 1998) |
| constriction ring | The equatorial ring of microfilaments that diminishes in diameter probably both by contraction and disassembly as cytokinesis proceeds. (18 Nov 1997) |
| constriction, pathologic | The condition of an anatomical structure's being constricted beyond normal dimensions. (12 Dec 1998) |
| constrictions of ureter | Normal physiological narrowings of the ureter observable in a pyelogram; the uppermost occurs at the origin of the ureter from the renal pelvis; a second occurs as the ureter crosses the iliac vessels and pelvic brim; the inferiormost occurs as the ureter penetrates the wall of the urinary bladder. (05 Mar 2000) |
| constrictive bronchiolitis | Obliteration of bronchioles by scarring following bronchiolitis obliterans. Compare: proliferative bronchiolitis. (05 Mar 2000) |
| constrictive endocarditis | Thickening of the endocardium due to inflammation of any origin that restricts the diastolic relaxation of one or both ventricles producing diastolic ventricular failure. (05 Mar 2000) |