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 : Short - term losartan treatment , besides antihypertensive effect , improved glomerular filtration rate and ameliorated glomerulosclerosis resulting in decreased proteinuria .
### Output Text:
RESULTS : Short - term <span class="chemical">losartan</span> treatment , besides antihypertensive effect , improved glomerular filtration rate and ameliorated glomerulosclerosis resulting in decreased proteinuria . 