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: Baseline , liver function tests were elevated in two patients ( fourth patient : ALT : 122 IU / l , AST : 111 IU / l , tenth patient : ALT : 294 IU / l , AST : 274 IU / l , with minimal changes in the liver biopsy in both ) .
### Output Text:
Baseline , liver function tests were elevated in two patients ( fourth patient : ALT : 122 IU / l , AST : 111 IU / l , tenth patient : ALT : 294 IU / l , AST : 274 IU / l , with minimal changes in the liver biopsy in both ) . 