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: As granisetron dose increased , appetite return increased ( P = . 040 ) .
### Output Text:
As <span class="chemical">granisetron</span> dose increased , appetite return increased ( P = . 040 ) . 