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: Isoproterenol delivered by osmotic minipump implantation in adult C3Heb / FeJ mice resulted in a 46 % increase in heart weight and a 19 . 3 % increase in cardiomyocyte area .
### Output Text:
<span class="chemical">Isoproterenol</span> delivered by osmotic minipump implantation in adult C3Heb / FeJ mice resulted in a 46 % increase in heart weight and a 19 . 3 % increase in cardiomyocyte area . 