For these employees, when a holiday falls on a nonworkday -- Saturday or Sunday -- the holiday usually is observed on Monday (if the holiday falls on Sunday) or Friday (if the holiday falls on Saturday).
CK-MB. 1  A creatine kinase-MB (CK-MB) test may be used as a follow-up test to an elevated creatine kinase (CK) in order to determine whether the increase is due to heart damage or skeletal muscle damage.
Creatine kinase (CK) is an enzyme found in the heart, brain, skeletal muscle, and other tissues. Increased amounts of CK are released into the blood when there is muscle damage. This test measures the amount of creatine kinase in the blood. The small amount of CK that is normally in the blood comes primarily from skeletal muscles. Any condition that causes muscle damage and/or interferes with muscle energy production or use can cause an increase in CK.