1. The immunological response to incompatibility in a transplanted organ. 2. A refusal to accept, recognize, or grant; a denial. 3. Elimination of small ultrasonic echoes from display. [L. rejectio, a throwing back]
accelerated r. a transplant r. manifested in less than three days.
acute r. acute cellular r
acute cellular r. graft r. which usually begins within 10 days after a graft has been transplanted into a genetically dissimilar host. Lesions at the site of the graft characteristically are infiltrated with large numbers of lymphocytes and macrophages which cause tissue damage. See primary r.acute r;
allograft r. (al´lo-graft) the r. of tissue transplanted between two genetically different individuals of the same species. R. is caused by T lymphocytes responding to the foreign major histocompatibility complex of the graft.homograft;
chronic r. a transplant r. occurring after a few or many months, mainly from persisting serum antibody action.
chronic allograft r. immunologically mediated damage to the allograft, typically a kidney allograft, manifested by diffuse interstitial fibrosis glomerular changes, typically membranous and sclerotic in nature, as well as intimal fibrosis of the blood vessels with tubular atrophy and loss of tubular structures.
first-set r. allograft transplantation between two organisms not previously sensitized to the graft tissue. Necrosis of the graft usually occurs within 10 days of transplantation.
hyperacute r. 1. a r. that usually develops in less than one hour from the implantation of a vascular graft; 2. a form of antibody-mediated, usually irreversible damage to a transplanted organ, particularly the kidney, manifested predominantly by diffuse thrombotic lesions, usually confined to the organ itself and only rarely disseminated; 3. for skin allograft rejection of this type, see white graft.
parental r. a child's denying, withholding, or unacceptance of affection or attention to or from a parent, or its obverse from a parent to or from a child.
primary r. a r. occurring more than seven days after transplantation, mainly from a cellular immune response.
second set r. an accelerated r. of a transplant that occurs when an individual has been previously sensitized to the graft.
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