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: At each time point , systolic blood pressure ( BP ) , urinary protein excretion and renal histopathological findings were evaluated , and morphometric image analysis was done .
### Output Text:
At each time point , systolic blood pressure ( BP ) , urinary protein excretion and renal histopathological findings were evaluated , and morphometric image analysis was done . 