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 the adriamycin - treated cells , the addition of adenosine increased the adenylate charge and , concomitant with this inrcease , the cells ' functional integrity , in terms of percentage of beating cells and rate of contractions , was maintained .
### Output Text:
In the <span class="chemical">adriamycin</span> - treated cells , the addition of <span class="chemical">adenosine</span> increased the adenylate charge and , concomitant with this inrcease , the cells ' functional integrity , in terms of percentage of beating cells and rate of contractions , was maintained . 