| blood group | <haematology> An inherited feature on the surface of the red blood cell. A series of related blood groups make up a blood group system such as the ABO system or the Rh system. Erythrocytic allotypes (or phenotypes) defined by one or more cellular antigenic structural groupings under the control of allelic genes. Blood groups, especially for man, are identified by agglutinins supported by specific human or animal antisera and by lectins extracted from certain plants. See: blood group antigen. (25 Jun 1999) |
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| blood group antigen | <haematology, immunology> The set of cell surface antigens found chiefly, but not solely, on blood cells. More than fifteen different blood group systems are recognised in humans. There may be naturally occurring antibodies without immunisation, especially in the case of the ABO system and matching blood groups is important for safe transfusion. In most cases the antigenic determinant resides in the carbohydrate chains of membrane glycoproteins or glycolipids. See: Rhesus, Duffy, Kell, Lewis and MN. (25 Jun 1999) |
| blood group incompatibility | A mismatch between donor and recipient blood. Antibodies present in the recipient's serum are directed against antigens in the donor product. Such a mismatch may result in a transfusion reaction in which, for example, donor blood is haemolyzed. (12 Dec 1998) |
| blood grouping | The classification of blood samples by means of laboratory tests of their agglutination reactions with respect to one or more blood groups. In general, a suspension of erythrocytes to be tested is exposed to a known specific antiserum; agglutination of the erythrocytes indicates that they possess the antigen for which the antiserum is specific. Certain antisera require special testing conditions. (05 Mar 2000) |
| blood grouping and crossmatching | Testing erythrocytes to determine presence or absence of blood-group antigens, testing of serum to determine the presence or absence of antibodies to these antigens, and selecting biocompatible blood by crossmatching samples from the donor against samples from the recipient. Crossmatching is performed prior to transfusion. (12 Dec 1998) |
| blood group substance | Blood group-specific substances A and B, solution of complexes of polysaccharides and amino acids that reduces the titre of anti-A and anti-B isoagglutinins in serum from group O persons; used to render group O blood reasonably safe for transfusion into persons of group A, B, or AB, but does not affect any incompatibility that results from various other factors, such as Rh. (05 Mar 2000) |
| blood haemopathies | A group of disease states which primarily involve the bone marrow and the production blood cells. Examples include polycythaemia vera, leukaemia, myelofibrosis and primary thrombocytopenia. (27 Sep 1997) |
| blood island | An aggregation of splanchnic mesodermal cells on the embryonic yolk sac, with the potentiality of forming vascular endothelium and primitive blood cells. Synonym: blood islet. (05 Mar 2000) |
| blood islet | An aggregation of splanchnic mesodermal cells on the embryonic yolk sac, with the potentiality of forming vascular endothelium and primitive blood cells. Synonym: blood islet. (05 Mar 2000) |
| blood loss, surgical | Loss of blood during surgery. (12 Dec 1998) |
| blood lymph | Lymph exuded from the blood vessels and not derived from the fluid in the tissue spaces. (05 Mar 2000) |
| blood mole | A uterine mass occurring after foetal death and consisting of blood clots, foetal membranes, and placenta. Synonym: blood mole, carneous mole. (05 Mar 2000) |
| blood money | 1. Money paid to the next of kin of a person who has been killed by another. 2. Money obtained as the price, or at the cost, of another's life; said of a reward for supporting a capital charge, of money obtained for betraying a fugitive or for committing murder, or of money obtained from the sale of that which will destroy the purchaser. Source: Websters Dictionary (01 Mar 1998) |
| blood motes | Small refractive particles in the circulating blood, probably lipid material associated with fragmented stroma from red blood cells. Synonym: blood dust, blood motes, dust corpuscles. Origin: haemo-+ G. Konis, dust (05 Mar 2000) |
| blood patch, epidural | The injection of autologous blood into the epidural space either as a prophylactic treatment immediately following an epidural puncture or for treatment of headache as a result of an epidural puncture. (12 Dec 1998) |