In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: RESULTS : Of the 246 admitted patients , 34 ( 14 % ) met CK - MB criteria for MI and 38 ( 16 % ) had cTnI elevations .
### Output Text:
RESULTS : Of the 246 admitted patients , 34 ( 14 % ) met CK - MB criteria for MI and 38 ( 16 % ) had cTnI elevations . 