| contact | A mutual touching of two bodies or persons. Origin: L. Contactus = a touching together (18 Nov 1997) |
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| contact allergy | A delayed type IV allergic reaction of the skin with varying degrees of erythema, oedema, and vesiculation resulting from cutaneous contact with a specific allergen. Synonym: contact allergy. (05 Mar 2000) |
| contact area | That part of the proximal surface of a tooth which touches the adjacent tooth mesially or distally. Synonym: contact point, point of proximal contact. (05 Mar 2000) |
| contact ceptor | A nerve ceptor in the surface layer of skin or mucous membrane by means of which impulses contributed by direct physical impact are received. (05 Mar 2000) |
| contact cheilitis | Inflammation of the lips resulting from contact with a primary irritant or specific allergen, including ingredients of lipsticks. (05 Mar 2000) |
| contact dermatitis | <pathology> A type of immune-mediated inflammatory skin rash that results from an allergy to a particular substance (for example jewelry dermatitis, poison ivy, neomycin ointment, etc.). (27 Sep 1997) |
| contact following | Behaviour shown by individual slime mould cells when they join a stream moving towards the aggregating centre. Contact sites A at front and rear of cell may be involved in Dictyostelium. (18 Nov 1997) |
| contact guidance | Directed locomotory response of cells to an anisotropy of the environment, for example the tendency of fibroblasts to align along ridges or parallel to the alignment of collagen fibres in a stretched gel. (18 Nov 1997) |
| contact hypersensitivity | <pathology> A type of immune-mediated inflammatory skin rash that results from an allergy to a particular substance (for example jewelry dermatitis, poison ivy, neomycin ointment, etc.). (27 Sep 1997) |
| contact illumination | Illumination of the eye by means of an instrument in contact with the cornea or bulbar conjunctiva. Critical illumination, the precise focusing of the light source directly upon the object being examined. Dark-field illumination, a procedure in which a black circular shield is used to block the majority of the vertically directed rays of light (e.g., the field is dark), and a circumferential, suitably angled, mirrored surface is used to direct the peripheral rays horizontally against the object, thereby reflecting the light vertically through the objective lens and along the optical axis; thus, the object is well illuminated in a contrasting dark background. Synonym: dark-ground illumination. (05 Mar 2000) |
| contact induced spreading | The response in which contact between two epithelial cells leads to a stabilised contact and the increased spreading of the cells so that the area covered is greater than that covered by the two cells in isolation. (18 Nov 1997) |
| contact inhibition | The inhibition of continued growth and division of a cell or colony due to physical contact with other cells or colonies. The stopping of continued growth when a certain density of cells has been reached. The momentary stopping of all movement when a mobile cell runs into another cell. (09 Oct 1997) |
| contact inhibition of growth | See: density dependent inhibition. (18 Nov 1997) |
| contact inhibition of movement | Reaction in which the direction of motion of a cell is altered following collision with another cell. In heterologous contacts both cell may respond (mutual inhibition) or only one (nonreciprocal). Type I contact inhibition involves paralysis of the locomotory machinery, Type II is a consequence of adhesive preference for the substratum rather than the dorsal surface of the other cell. (18 Nov 1997) |
| contact inhibition of phagocytosis | Phenomenon described in sheets of kidney epithelial cells that, when confluent, lose their weak phagocytic activity, probably because of a failure of adhesion of particles to the dorsal surface in the absence of ruffles. (18 Nov 1997) |