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: Treatment was consisted of withdrawal of nicergoline and intravenous methylprednisolone , and his renal function was completely recovered .
### Output Text:
Treatment was consisted of withdrawal of <span class="chemical">nicergoline</span> and intravenous <span class="chemical">methylprednisolone</span> , and his renal function was completely recovered . 