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: We measured diazepam - induced anxiolysis with the elevated plus - maze test , diazepam - induced sedation by recording the vigilance states , and picrotoxin - and pentylenetetrazol - induced seizures after i . p . injections .
### Output Text:
We measured <span class="chemical">diazepam</span> - induced anxiolysis with the elevated plus - maze test , <span class="chemical">diazepam</span> - induced sedation by recording the vigilance states , and <span class="chemical">picrotoxin</span> - and <span class="chemical">pentylenetetrazol</span> - induced seizures after i . p . injections . 