The brain isoenzyme of creatine kinase (CK) (EC 2.7.3.2) has been identified in the serum of 21 of 950 patients tested. Samples were received over a period of about 20 months. Analysis was performed by electrophoresis on agarose gel with isoenzyme bands visualized by fluorescence after enzyme coupled reactions producing NADH. Specialized substrate preparations were used to rule out the possibil...

We describe a sensitive, specific radioimmunoassay for the BB isoenzyme of creatine kinase (CK-BB) in serum. A sequential saturation assay was used to achieve sufficient sensitivity to detect the isoenzyme in 100-microliter serum samples of all healthy persons and patients tested. Bound and free antigen were separated by a second antibody system. Large excesses of purified isoenzyme MM did not ...

We studied the effect of prostate resection on serum creatine kinase (EC 2.7.3.2) and lactate dehydrogenase (EC 1.1.1.27) isoenzymes in 22 patients. Two hours after their operations, two-thirds of these patients had increased total creatine kinase activity. The MB isoenzyme was demonstrated in sera of 66% of the patients and the BB isoenzyme in 76%. MB content varied from 1 to 7% of total creat...

We have adapted to a microcentrifugal analyzer an immunoinhibition assay for measuring the activity of creatine kinase MB by using an inhibitory antibody for the M monomer. The method actually measures half the MB activity, but results are not multiplied by two because atypical isoenzymes of creatine kinase, including BB, IgG-BB, and the isoenzyme derived from mitochondria, are also detected, i...

We determined the decay constant and distribution space of the MB isoenzyme of creatine kinase after intravenous injection of 440 to 720 U, in a group of seven adult baboons. The rate of decay of the isoenzyme was monoexponential, with a mean decay constant of 0.00175 min-1 (SD, 0.00019). The mean distribution volume obtained by extrapolation of the monoexponential curve to zero time was 5.22% ...

Analytical interference in laboratory assays is not only unpredictable but also an underestimated problem. Not recognising these interferences can lead to misdiagnosis and mismanagement of patients. We present a case of a patient with chest pain and ischaemic risk factors with incongruent biochemical results. These results were discovered to be due to the presence of macro-creatine kinase (macr...