The MMR immunity test is used to evaluate immunity to Measles, Mumps and Rubella. The MMR immunity test is often referred to as a titer test and is often necessary for students or when no vaccination records can be provided.
Most doctors only give platelet transfusions in cases where the patient is actively bleeding and the blood won't clot. The reason is that this treatment is of limited benefit and only lasts a very short time. The problem has to do with the life of the cells. Unlike red blood cells, which on average live about 120 days, platelets on average live only eight days. When you get a transfusion of blood from someone else, some of those cells are very old and some are brand-new, so you have to assume that the average platelet's going to last only four days.
Platelets are held within these internal membranes within the cytoplasm of megakaryocytes. There are two proposed mechanisms for platelet release. In one scenario, these proto-platelet processes break up explosively to become platelets. Alternatively, the cell may form platelet ribbons into blood vessels. The ribbons are formed via pseudopodia and they are able to continuously emit platelets into circulation. In either scenario, each of these proto-platelet processes can give rise to 2000-5000 new platelets upon breakup.