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: PR3 - ANCA titer was 250 and 1 , 070 EU in pleural effusions on right and left side , respectively .
### Output Text:
PR3 - ANCA titer was 250 and 1 , 070 EU in pleural effusions on right and left side , respectively . 