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: PATIENTS AND METHODS : One hundred eighty - four chemotherapy - naive patients receiving high - dose cisplatin ( 81 to 120 mg / m2 ) were randomized to receive one of four granisetron doses ( 5 , 10 , 20 , or 40 micrograms / kg ) administered before chemotherapy .
### Output Text:
PATIENTS AND METHODS : One hundred eighty - four chemotherapy - naive patients receiving high - dose <span class="chemical">cisplatin</span> ( 81 to 120 mg / m2 ) were randomized to receive one of four <span class="chemical">granisetron</span> doses ( 5 , 10 , 20 , or 40 micrograms / kg ) administered before chemotherapy . 