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: Incidence of increased aspartate aminotransferase and / or alanine aminotransferase > 3 times the upper limit of normal was < 0 . 3 % .
### Output Text:
Incidence of increased <span class="chemical">aspartate</span> aminotransferase and / or <span class="chemical">alanine</span> aminotransferase > 3 times the upper limit of normal was < 0 . 3 % . 