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: He was hospitalized for a myocardial infarction with pulmonary edema , treated with high - dose diuretics .
### Output Text:
He was hospitalized for a myocardial infarction with pulmonary edema , treated with high - dose diuretics . 