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: After 7 days , PAN treatment induced significant proteinuria , hypoalbuminemia , decreased urinary sodium excretion , and extensive ascites .
### Output Text:
After 7 days , <span class="chemical">PAN</span> treatment induced significant proteinuria , hypoalbuminemia , decreased urinary <span class="chemical">sodium</span> excretion , and extensive ascites . 