| gated blood pool imaging | Radionuclide ventriculography where scintigraphic data is acquired during repeated cardiac cycles at specific times in the cycle, using an electrocardiographic synchroniser or gating device. Analysis of right ventricular function is difficult with this technique; that is best evaluated by first-pass ventriculography (ventriculography, first-pass). (12 Dec 1998) |
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| venous blood | Blood which has passed through the capillaries of various tissues, except the lungs, and is found in the veins, the right chambers of the heart, and the pulmonary arteries; it is usually dark red as a result of a lower content of oxygen. (05 Mar 2000) |
| red blood cell | <haematology> Cell specialised for oxygen transport, having a high concentration of haemoglobin in the cytoplasm (and little else). Biconcave, anucleate discs, 7nm diameter in mammals, nucleus contracted and chromatin condensed in other vertebrates. Acronym: RBC (18 Nov 1997) |
| red blood cell cast | A urinary cast composed of a matrix containing red cells in various stages of degeneration and visibility, characteristic of glomerular disease or renal parenchymal bleeding. Synonym: red cell cast. (05 Mar 2000) |
| red blood cell count | A normal value is 4.6-6.2 million RBC's per cubic millimetre of blood. This number can increase in cases of dehydration (fluid loss) or severe lung disease. Interestingly, red blood cell counts are much higher in those who live at high altitude, because of the increased demand for oxygen carrying capacity. (27 Sep 1997) |
| red blood cell indices | Laboratory measurements of red blood cell volume, size and haemoglobin concentration. These values are used to point to the specific cause for anaemia (iron deficiency, B12 deficiency, etc.) (27 Sep 1997) |
| CDE blood group | See Rh blood group, Blood Groups appendix. (05 Mar 2000) |
| renal blood flow, effective | The amount of blood flowing to the parts of the kidney that are involved with the production of constituents of urine. It is that portion of the total renal blood flow that perfuses functional renal tissue (e.g., the glomeruli). It should be differentiated from renal plasma flow, effective which is based on the amount of plasma rather than on total renal blood. (12 Dec 1998) |
| p blood-group system | A blood group related to the abo, lewis and I systems. at least five different erythrocyte antigens are possible, some very rare, others almost universal. Multiple alleles are involved in this blood group. (12 Dec 1998) |
| retinal blood vessels | The blood vasculature of the retina, including the branches and tributaries of the central retinal artery and vein, respectively, and the vascular circle of the optic nerve. Synonym: vasa sanguinea retinae. (05 Mar 2000) |
| percutaneous umbilical blood sampling | See: PUBS. (12 Dec 1998) |
| Rhesus blood group | <haematology> Human blood group system with allelic red cell antigens C, D and E. The D antigen is the strongest. Red cells from a Rhesus positive foetus cross the placenta and can sensitise a Rehesus negative mother, expecially at parturition. The mother's antibody may then, in a subsequent pregnancy, cause haemolytic disease of the newborn if the foetus is Rhesus positive. The disease can be prevented by giving antiD IgG during the first 72 hours after parturition to mop up D red cells in the maternal circulation. 1st ed (18 Nov 1997) |
| rh-hr blood-group system | Erythrocyte isoantigens of the rh (rhesus) blood group system, the most complex of all human blood groups, because the genes differ by determining a different number of the over thirty antigens thus far described and do so with remarkably different quality. The major antigen rh or d is the most common cause of erythroblastosis foetalis. (12 Dec 1998) |
| peripheral blood stem cell transplantation | A procedure that is similar to bone marrow transplantation. Doctors remove healthy immature cells (stem cells) from a patient's blood and store them before the patient receives high-dose chemotherapy and possibly radiation therapy to destroy the leukaemia cells. The stem cells are then returned to the patient, where they can produce new blood cells to replace cells destroyed by the treatment. (12 Dec 1998) |
| Pfeiffer's blood agar | Solid agar with a few drops of human blood smeared on the surface. (05 Mar 2000) |