1 Select the Triggers tab, and then select New. 2  Set your time and frequency, and then select OK. 3  Open Windows Defender by clicking the Start button. In the search box, type Defender and then, in the list of results, click Windows Defender.  Click Tools, and then click Options.
â Platelet refractoriness is the inability to get an adequate increase in platelet count after transfusion (Arch Pathol Lab Med 2003;127:409, Haematologica 2005;90:247) â Immune causes: anti-platelet or anti-HLA antibodies after multiple exposures from transfusion, pregnancy or transplantation (Transfusion 2005;45:761)
Platelet: An irregular, disc-shaped element in the blood that assists in blood clotting. During normal blood clotting, the platelets clump together (aggregate). Although platelets are often classed as blood cells, they are actually fragments of large bone marrow cells called megakaryocytes. Search MedTerms: