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 group I , cyclosporine was given before the procedure at a loading dose of 17 . 5 mg / kg and then continued after the procedure to keep a whole blood level about 1000 ng / ml .
### Output Text:
In group I , <span class="chemical">cyclosporine</span> was given before the procedure at a loading dose of 17 . 5 mg / kg and then continued after the procedure to keep a whole blood level about 1000 ng / ml . 