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: RESULTS : After granisetron doses of 5 , 10 , 20 , and 40 micrograms / kg , a major response ( < or = two vomiting or retching episodes , and no antiemetic rescue ) was recorded in 23 % , 57 % , 58 % , and 60 % of patients , respectively , and a complete response ( no vomiting or retching , and no antiemetic rescue ) in 18 % , 41 % , 40 % , and 47 % of patients , respectively .
### Output Text:
RESULTS : After <span class="chemical">granisetron</span> doses of 5 , 10 , 20 , and 40 micrograms / kg , a major response ( < or = two vomiting or retching episodes , and no antiemetic rescue ) was recorded in 23 % , 57 % , 58 % , and 60 % of patients , respectively , and a complete response ( no vomiting or retching , and no antiemetic rescue ) in 18 % , 41 % , 40 % , and 47 % of patients , respectively . 