| photodynamic sensitization | The action by which certain substances, notably fluorescing dyes (acridine, eosin, methylene blue, rose bengal) absorb visible light and emit the energy at wavelengths that are deleterious to microbes or other organisms in the dye-containing suspension, or selectively destroy cancer cells sensitised by intravenous porphyrin and exposed to red laser light. Synonym: photosensitization. (05 Mar 2000) |
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| photodynamic | Relating to the energy or force exerted by light. Origin: photo-+ G. Dynamis, force (05 Mar 2000) |
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| photodynamic radiation therapy | <oncology, technique> A light sensitive drug is given through a vein and concentrates in the tumour. Then, during a surgical procedure, a special light activates the drug. The activated drug kills tumour cells. (31 Dec 1997) |
| photodynamic therapy | <oncology, technique> Cancer treatment that uses the interaction between laser light and a substance that makes cells more sensitive to light. When light is applied to cells that have been treated with this substance, a chemical reaction occurs and destroys cancer cells. (31 Dec 1997) |
| autoerythrocyte sensitization | See: autoerythrocyte sensitization syndrome. (05 Mar 2000) |
| autoerythrocyte sensitization syndrome | <syndrome> A condition, usually occurring in women, in which the individual bruises easily (purpura simplex) and the ecchymoses tend to enlarge and involve adjacent tissues, resulting in pain in the affected parts; so-called because similar lesions are produced by inoculation of the individual's blood or various components of red blood cells and it is thought to be a form of localised autosensitization, although no specific antibodies have been demonstrable; in some individuals, there seems to be a psychogenic mechanism. Synonym: Gardner-Diamond syndrome, psychogenic purpura. (05 Mar 2000) |
| repression-sensitization | Defense mechanisms involving approach and avoidance responses to threatening stimuli. The sensitizing process involves intellectualization in approaching or controlling the stimulus whereas repression involves unconscious denial in avoiding the stimulus. (12 Dec 1998) |
| covert sensitization | Aversive conditioning or training to rid onself of an unwanted behaviour during which the patient is taught to imagine unpleasant and related aversive consequences while engaging in the unwanted habit. (05 Mar 2000) |
| sensitization | Immunization, especially with reference to antigens (immunogens) not associated with infection; the induction of acquired sensitivity or of allergy. (05 Mar 2000) |