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: These data suggest a similarity between postalcoholic Wernicke - Korsakoff syndrome and the patient with tolazamide - induced Wernicke ' s encephalopathy from the standpoint of transketolase abnormality .
### Output Text:
These data suggest a similarity between postalcoholic Wernicke - Korsakoff syndrome and the patient with <span class="chemical">tolazamide</span> - induced Wernicke ' s encephalopathy from the standpoint of transketolase abnormality . 