| reactivation | The restoration of activity to something that has been inactivated. (18 Nov 1997) |
|---|---|
| reactive arthritis | Reiter's syndrome is also called reactive arthritis since it is thought to involve the immune system which is reacting to the presence of bacterial infections in the genital, urinary, or gastrointestinal systems. Accordingly, certain people's immune systems are genetically primed to react aberrantly when these areas are exposed to certain bacteria. The aberrant reaction of the immune system leads to inflammation in the joints and eyes. (12 Dec 1998) |
| reactive astrocyte | <cell biology> A round to oval astrocyte cell with abundant cytoplasm containing glial filaments and an eccentric nucleus; may contain two nuclei in the cell hypertrophy of astrocytes. Synonym: gemistocyte, gemistocytic cell, reactive astrocyte, reactive cell. (05 Mar 2000) |
| reactive attachment disorder | Markedly disturbed and developmentally inappropriate social relatedness that begins before age 5 and is associated with grossly pathological child care. The child may persistently fail to initiate and respond to social interactions in a developmentally appropriate way (inhibited type) or there may be a pattern of diffuse attachments with nondiscriminate sociability (disinhibited type). (12 Dec 1998) |
| reactive cell | <cell biology> A round to oval astrocyte cell with abundant cytoplasm containing glial filaments and an eccentric nucleus; may contain two nuclei in the cell hypertrophy of astrocytes. Synonym: gemistocyte, gemistocytic cell, reactive astrocyte, reactive cell. (05 Mar 2000) |
| reactive depression | A psychological state occasioned directly by an intensely sad external situation (frequently loss of a loved person), relieved by the removal of the external situation (e.g., reunion with a loved person). (05 Mar 2000) |
| reactive hyperaemia | Hyperaemia following the arrest and subsequent restoration of the blood supply to a part. (05 Mar 2000) |
| reactive inhibition | Tendency toward a lessened strength of response due to practice or activity. It is independent of the effect of reward and is a direct function of time interval since the last response and the number of preceding responses. (12 Dec 1998) |
| reactive oxygen species | Reactive intermediate oxygen species including both radicals and non-radicals. These substances are constantly formed in the human body and have been shown to kill bacteria and inactivate proteins, and have been implicated in a number of diseases. Scientific data exist that link the reactive oxygen species produced by inflammatory phagocytes to cancer development. (12 Dec 1998) |
| reactive perforating collagenosis | A rare skin disorder characterised by extrusion of collagen fibres through the epidermis; usually begins in infancy or childhood and appears clinically as recurrent umbilicated papules that resolve spontaneously. The condition may be inherited or acquired, the latter differing from Kyrle's disease because follicular involvement is absent. (05 Mar 2000) |
| reactive schizophrenia | Those forms of severe schizophrenic disorders which are distinguished from process schizophrenia by their more acute onset, greater relation to environmental stress, and better prognosis. (05 Mar 2000) |
| reactivity | The process or property of reacting. (18 Nov 1997) |