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: Fully developed cyclophosphamide - induced cystitis is characterized by nearly complete detachment of the urothelium , severe submucosal edema owing to damage to the microvascular bed and focal muscle necroses .
### Output Text:
Fully developed <span class="chemical">cyclophosphamide</span> - induced cystitis is characterized by nearly complete detachment of the urothelium , severe submucosal edema owing to damage to the microvascular bed and focal muscle necroses . 