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: Furthermore , glomerulosclerosis index was significantly increased in the nitrendipine - treated group compared with the hypertensive controls ( 0 . 38 + / - 0 . 1 versus 0 . 13 + / - 0 . 04 ) .
### Output Text:
Furthermore , glomerulosclerosis index was significantly increased in the <span class="chemical">nitrendipine</span> - treated group compared with the hypertensive controls ( 0 . 38 + / - 0 . 1 versus 0 . 13 + / - 0 . 04 ) . 