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: Also , BCNU administration increased serum tumor necrosis factor - alpha ( TNFalpha ) , hippocampal MT and malondialdehyde ( MDA ) contents as well as caspase - 3 activity in addition to histological alterations .
### Output Text:
Also , <span class="chemical">BCNU</span> administration increased serum tumor necrosis factor - alpha ( TNFalpha ) , hippocampal <span class="chemical">MT</span> and <span class="chemical">malondialdehyde</span> ( <span class="chemical">MDA</span> ) contents as well as caspase - 3 activity in addition to histological alterations . 