| blood component transfusion | The transfer of blood components such as erythrocytes, leukocytes, platelets, and plasma from a donor to a recipient or back to the donor. This process differs from the procedures undertaken in plasmapheresis and types of cytapheresis (plateletpheresis and leukapheresis) where, following the removal of plasma or the specific cell components, the remainder is transfused back to the donor. (12 Dec 1998) |
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| blood corpuscle | <haematology> There are three main types of cell in the blood stream. The red cell, which carries oxygen, the white cell, which fights infections and the platelet, which helps prevent bleeding. The correct balance between each cell type must be maintained for the body to remain healthy. (13 Nov 1997) |
| blood crisis | The appearance of a large number of nucleated red blood cells in the peripheral blood, accompanied by reticulocytosis and occurring in "exhausted" bone marrow in pernicious anaemia and in haemolytic icterus, a suddenly appearing leukocytosis, indicating a change for the better in the course of a grave blood disease. (05 Mar 2000) |
| blood crystals | <haematology> A substance which appears to be identical to the red-orange bile pigment bilirubin, but which is produced from haemoglobin in tissues rather than within the liver and usually when oxygen tension is low. (09 Oct 1997) |
| blood culture | <investigation, microbiology> A test which involves the incubation of a blood specimen overnight to determine if bacteria are present. (27 Sep 1997) |
| blood cyst | A cyst containing blood or resulting from the encapsulation of a haematoma. Synonym: blood cyst, haematocele, haematocyst, sanguineous cyst. (05 Mar 2000) |
| blood disk | <haematology> A discoid cell (3m diameter) found in large numbers in blood, important for blood coagulation and for haemostasis by repairing breaches (small breaks) in the walls of blood vessels. Platelet _ granules contain lysosomal enzymes, dense granules contain ADP (a potent platelet aggregating factor) and serotonin (a vasoactive amine). They also release platelet-derived growth factor which presumably contributes to later repair processes by stimulating fibroblast proliferation. Synonym: thrombocytes. (09 Oct 1997) |
| blood dust | 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 dyscrasia | <haematology> A general term which is used to describe any abnormality in the blood or bone marrow's cellular components, such as low white blood cell count, low red blood cell count or low platelet count. Medications known to cause thrombocytopenia or leukopenia as a side effect include: pyrimethamine, chloramphenicol, levamisole, sulphamethoxazole and trimethoprim, sulphapyridine, sulphasalazine, antihistamines, appetite suppressants, anticonvulsants, tricyclic antidepressants, decongestants and antihistamines, benzodiazepines, chloroquine, clozapine, dapsone, glutethimide, hydroxychloroquine, isoniazid, meprobamate and aspirin, methazolamide, perphenazine and amitriptyline, phenacemide, pimozide, rifampin, thioxanthenes, trimethobenzamide, trimethoprim and trimetaphan. (27 Sep 1997) |
| blood flow velocity | A value equal to the total volume flow divided by the cross-sectional area of the vascular bed. (12 Dec 1998) |
| blood gas analysis | <investigation> A test which analyses arterial blood for oxygen, carbon dioxide and bicarbonate content in addition to blood pH. Used to test the effectiveness of respiration. (27 Sep 1997) |
| blood gases | A clinical expression for the determination of the partial pressures of oxygen and carbon dioxide in blood. (05 Mar 2000) |
| blood gas monitoring, transcutaneous | The noninvasive measurement or determination of the partial pressure (tension) of oxygen and/or carbon dioxide locally in the capillaries of a tissue by the application to the skin of a special set of electrodes. These electrodes contain photoelectric sensors capable of picking up the specific wavelengths of radiation emitted by oxygenated versus reduced haemoglobin. (12 Dec 1998) |
| blood glucose | The main sugar that the body makes from the three elements of food--proteins, fats, and carbohydrates--but mostly from carbohydrates. Glucose is the major source of energy for living cells and is carried to each cell through the bloodstream. However, the cells cannot use glucose without the help of insulin. (09 Oct 1997) |
| blood glucose meter | A machine that helps test how much glucose (sugar) is in the blood. A specially coated strip containing a fresh sample of blood is inserted in a machine, when then calculates the correct level of glucose in the blood sample and shows the result in a digital display. Some meters have a memory that can store results from multiple tests. (09 Oct 1997) |