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: Combined antiretroviral therapy causes cardiomyopathy and elevates plasma lactate in transgenic AIDS mice .
### Output Text:
Combined antiretroviral therapy causes cardiomyopathy and elevates plasma <span class="chemical">lactate</span> in transgenic AIDS mice . 