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: Effects of a new calcium antagonist , CD - 832 , on isoproterenol - induced myocardial ischemia in dogs with partial coronary stenosis .
### Output Text:
Effects of a new <span class="chemical">calcium</span> antagonist , <span class="chemical">CD - 832</span> , on <span class="chemical">isoproterenol</span> - induced myocardial ischemia in dogs with partial coronary stenosis . 