| haemolytic anaemia | <disease, haematology> Anaemia resulting from reduced red cell survival time and haemolysis, either due to an intrinsic defect in the erythrocyte (hereditary spherocytosis or ellipsocytosis, enzyme defects, haemoglobinopathy) or an extrinsic damaging agent. For example autoantibody (autoimmune haemolytic anaemia), iso antibody, parasitic invasion of the cells (malaria), bacterial or chemical haemolysins, mechanical damage to erythrocytes. Origin: Gr. Haima = blood (18 Nov 1997) |
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| haemolytic anaemia of newborn | <haematology> A condition which develops in the foetus due to an incompatibility between the mother's blood type (RH factor) and the baby's. Maternal antibodies, which enter the foetal circulation during delivery attack the baby's red blood cells leading to haemolysis (rupture of the cells). Symptoms include an infant with an enlarged liver and spleen, swelling, jaundice and anaemia. (27 Sep 1997) |
| haemolytic chain | The haemolysis that occurs when complement is activated by the previously formed union of erythrocytes and specific antibody. (05 Mar 2000) |
| haemolytic disease of newborn | <haematology> A condition which develops in the foetus due to an incompatibility between the mother's blood type (RH factor) and the baby's. Maternal antibodies, which enter the foetal circulation during delivery attack the baby's red blood cells leading to haemolysis (rupture of the cells). Symptoms include an infant with an enlarged liver and spleen, swelling, jaundice and anaemia. (27 Sep 1997) |
| haemolytic disease of the newborn | Abnormal breakup of red blood cells in the foetus or newborn. This is usually due to antibodies made by the mother directed against the baby's red cells. It is typically caused by rh incompatibility, that is differences between the mother and baby uinvolving the rh blood group. (12 Dec 1998) |
| haemolytic gas | A poisonous gas, such as arsine, inhalation of which causes haemolysis with haemoglobinuria, jaundice, gastroenteritis, and nephritis. (05 Mar 2000) |
| haemolytic jaundice | <haematology> Haemolytic jaundice is a type of jaundice, where the skin takes on a yellowish hue, which occurs when red blood cells have been destroyed (by haemolysis). (09 Oct 1997) |
| haemolytic plaque assay | <investigation> A haemolytic plaque assay is a lab technique used to show that certain antibodies are secreted by antibody-making cells when these cells are mixed with red blood cells. The mixture is spread onto a plate of agar, if a plaque appears, it means that the red blood cells have been destroyed (by haemolysis) by the antibodies. (09 Oct 1997) |
| haemolytic splenomegaly | Splenomegaly associated with congenital haemolytic jaundice. (05 Mar 2000) |
| haemolytic streptococci | Those that produce active haemolysins (O and S) which cause a zone of clear haemolysis on the blood agar medium in the area of the colony; beta-haemolytic streptococci are divided into groups (A to O) on the basis of cell wall C carbohydrate (see Lancefield classification); Group A (in the strains pathogenic for man) comprises more than 50 types (designated by Arabic numerals) determined by cell wall M protein, which seems to be associated closely with virulence and is produced chiefly by strains with matt or mucoid colonies, in contrast to nonvirulent, glossy colony-producing strains; other surface protein antigens such as R and T (T substance), and the nucleoprotein fraction (P substance) seem to be of less importance. The more than 20 extracellular substances elaborated by strains of beta-haemolytic streptococci include erythrogenic toxin (elaborated only by lysogenic strains), deoxyribonuclease (streptodornase), haemolysins (streptolysins O and S), hyaluronidase, and streptokinase. Synonym: haemolytic streptococci. (05 Mar 2000) |
| haemolytic system | <haematology> A haemolytic system is composed of red blood cells covered with antibodies which are genetically identical to the surface proteins (antigens) of the red blood cells. It is used to measure how much complement is left after a round of complement fixation. (09 Oct 1997) |
| haemolytic unit | The smallest quantity (highest dilution) of inactivated immune serum (haemolysin) that will sensitise the standard suspension of erythrocytes so that the standard complement will cause complete haemolysis. Synonym: amboceptor unit. (05 Mar 2000) |
| haemolytic uraemic syndrome | <haematology, syndrome> A pathologic condition with involves the rupture (haemolysis) of red blood cells, subsequent anaemia, low platelet count and kidney failure. It is a syndrome of haemolytic anaemia, thrombocytopenia, and acute renal failure, with pathological finding of thrombotic microangiopathy in kidney and renal cortical necrosis. See: haemolytic anaemia. (12 Dec 1998) |
| haemolyzation | The production or occurrence of haemolysis. (05 Mar 2000) |
| haemolyze | To produce haemolysis or liberation of the haemoglobin from red blood cells. (05 Mar 2000) |