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: We report the case of a 70 - year - old hypertensive man with a solitary kidney and chronic renal insufficiency who developed two episodes of transient anuria after losartan administration .
### Output Text:
We report the case of a 70 - year - old hypertensive man with a solitary kidney and chronic renal insufficiency who developed two episodes of transient anuria after <span class="chemical">losartan</span> administration . 