 3. Patients receiving any of the following medications are not eligible for study entry: a. Anti-cancer therapy or investigational agents b.Anti-coagulants except for heparin to maintain the patency of central venous catheters. c.Growth factors for white blood cell, red blood cell or platelet support d.Aspirin 81 mgday e.Non-steroidal anti-inflammatory drugs f.Clopidogrel Plavix, Dypiramidole Persantine, or any other drug that inhibits platelet function g. Anti-convulsants: patients on any anti-convulsant with the exception of VPA are eligible for study entry. It is strongly recommended that a neurology consult be obtained to enable discontinuation of all anti-convulsant other than VPA, whenever possible. 