| haemadsorption | <haematology> The clumping together of red blood cells to other cells or particles, or to substrates. The sticking of red blood cells to cells which have been infected with certain types of haemagglutinating viruses. Similar to haemagglutination. (09 Oct 1997) |
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| haemadsorption test | <investigation> A clinical lab test which is used to detect the presence of haemagglutinating viruses (virus which causes haemadsorption) based on whether red blood cells will stick to cells from the infected tissue when a haemagglutinin is present. (09 Oct 1997) |
| haemadsorption virus | <virology> An older term for certain influenza viruses. The two types are: haemadsorption virus type I - mostly in children, symptoms include bronchitis and pneumonia. Now called parainfluenza 3. Haemadsorption virus type 2 - is sometimes present in children who have a respiratory disease that includes high fever. Now called parainfluenza 1. (09 Oct 1997) |
| haemadsorption virus test | A method for detecting haemagglutinating viruses that is based on adherence of erythrocytes to infected cells. (05 Mar 2000) |
| haemadsorption virus type 1 | parainfluenza virus type 3 |
| haemadsorption virus type 2 | parainfluenza virus type 1 |
| haemadynameter | haemadynamometer |
| haemafacient | <pharmacology> Refers to an agent or process that affects or promotes the formation of blood cells. (09 Oct 1997) |
| haemagglutinating cold autoantibody | A cold autoagglutinin. (05 Mar 2000) |
| haemagglutination | <haematology> Agglutination of red blood cells, often used to test for the presence of antibodies directed against red cell surface antigens or carbohydrate binding proteins or viruses in a solution. Requires that the agglutinin has at least two binding sites. (18 Nov 1997) |
| haemagglutination inhibition | A variation of the haemagglutination technique. Some viral antigens, when coated on erythrocytes, spontaneously cause agglutination in the absence of antibody. In these situations, the specific antigen-antibody reaction actually prevents the agglutination of reagent RBCs. Haemagglutination inhibition cannot differentiate between isotypes of specific antibodies (IgG, IgA or IgM) although positive haemagglutination inhibition analysis of specimens treated with Staphylococcus aureus Protein A (discussed above under coagglutination) to remove the IgG isotype antibodies has been used to imply the presence of specific IgM antibodies to the specific viral antigen. The crude quantitation of the specific antibodies is possible using serial dilution (titre). (05 Mar 2000) |
| haemagglutination inhibition test | <investigation> A clinical lab test used to detect the presence of a certain haemagglutinating virus or other haemagglutinin antigen based on whether the red blood cells in the sample lose the ability to clump together when the antibody to the virus or other antigen is added to it. If the virus or antigen is present, the antibody kills it and thereby stops it from being able to stick the red blood cells to each other. (09 Oct 1997) |
| haemagglutination inhibition tests | Serologic tests in which a known quantity of antigen is added to the serum prior to the addition of a red cell suspension. Reaction result is expressed as the smallest amount of antigen which causes complete inhibition of haemagglutination. (12 Dec 1998) |
| haemagglutination test | <investigation> A test in which an antigen and an antibody react to each other on the surface of a red blood cell. (09 Oct 1997) |
| haemagglutination tests | Sensitive tests to measure certain antigens, antibodies, or viruses, using their ability to agglutinate certain erythrocytes. (12 Dec 1998) |