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: Other end points were an increase in the creatinine concentration of 0 . 5 mg per deciliter or more , an increase of 1 . 0 mg per deciliter or more , and a change in the creatinine concentration from day 0 to day 7 .
### Output Text:
Other end points were an increase in the <span class="chemical">creatinine</span> concentration of 0 . 5 mg per deciliter or more , an increase of 1 . 0 mg per deciliter or more , and a change in the <span class="chemical">creatinine</span> concentration from day 0 to day 7 . 