Persistent creatine kinase MB isoenzyme without cardiac disease.

Although the creatine kinase MB isoenzyme may be useful in the diagnosis of myocardial injury, it is also found in the sera of patients with a number of noncardiac diseases. It may also occur in apparently normal individuals, as described in this case report. Hence, the diagnosis of myocardial injury should never be based solely on the presence of creatine kinase MB isoenzyme in the serum, but should be supported by additional clinical and laboratory data.

Yersinia colitis.

A 2-year-old child with a febrile, non-bloody diarrheal illness of acute onset with repeatedly negative stool and blood cultures for pathogenic bacteria is presented. Sigmoidoscopic and roentgenographic studies revealed an inflammatory colitis. Unfortunately, diagnostic perserverance and a high index of suspicion resulted in a positive stool culture for Yersinia enterocolitica.