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: Pretreatment with RAMH ( 5 microg i . c . v . ) could partially reverse such effects of THP ( 3 . 75 mg / kg i . p . ) .
### Output Text:
Pretreatment with <span class="chemical">RAMH</span> ( 5 microg i . c . v . ) could partially reverse such effects of <span class="chemical">THP</span> ( 3 . 75 mg / kg i . p . ) . 