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: Use of argatroban and catheter - directed thrombolysis with alteplase in an oncology patient with heparin - induced thrombocytopenia with thrombosis .
### Output Text:
Use of <span class="chemical">argatroban</span> and catheter - directed thrombolysis with alteplase in an oncology patient with <span class="chemical">heparin</span> - induced thrombocytopenia with thrombosis . 