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: Thus , AE RBCs appear to have an increased sensitivity to oxidant stress both in vitro and in vivo , since dapsone does not cause hemolytic anemia at this dose in hematologically normal individuals .
### Output Text:
Thus , AE RBCs appear to have an increased sensitivity to oxidant stress both in vitro and in vivo , since <span class="chemical">dapsone</span> does not cause hemolytic anemia at this dose in hematologically normal individuals . 