apheresis

apheresis , or hemapheresis , any procedure in which blood is drawn from a donor or patient and a component (platelets, plasma , or white blood cells) is separated out, the remaining blood components being returned to the body. Apheresis allows the donor's blood volume to replenish itself much more quickly than whole blood donation. One type of apheresis, plasmapheresis, is commonly used in commercial blood banks . In plasmapheresis the plasma (the liquid portion of the blood) is separated from donated blood, the red blood cells being returned to the donor. In some diseases, such as myasthenia gravis , plasmapheresis is used to attempt to remove the disease-causing substances from the blood.

APHAERESIS BrE, apheresis AmE [Stress: ‘a-FER-e-sis’]. The removal of an element from the beginning of a WORD, usually for informal economy of expression: copter and gator from helicopter and alligator. Sometimes aphaeresis and APOCOPE occur together: tec from detective, flu from influenza. The use of an APOSTROPHE to mark aphaeresis ('gator, 'phone, 'plane) is now rare, expect when used to mark novel or unusual forms, as in 'kyou for ‘thank you’. See APHESIS, CLIPPING, ELISION.