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: In addition , antithrombin treatment markedly suppressed puromycin aminonucleoside - induced apoptosis of renal tubular epithelial cells .
### Output Text:
In addition , antithrombin treatment markedly suppressed <span class="chemical">puromycin aminonucleoside</span> - induced apoptosis of renal tubular epithelial cells . 