ABBR,MEANING CAT,Computer-Assisted (or Axial) Tomography CDC,"(U.S.) Centers for Disease Control and Prevention; previously known as the Communicable Disease Center" IAS,"Insulin autoimmune syndrome (a rare cause of reversible autoimmune hypoglycemia)" pr,per the rectum PT,prothrombin time PTT,partial thromboplastin time pulv,powder PV,per the vagina q,every q12h,every 12 hours qd,daily q1d,daily q2h,every 2 hours q3h,every 3 hours q4h,every 4 hours XTP,xanthosine 5'-triphosphate XXX,Triple X Syndrome (disorder)