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: After the administration of NG , 5 - FU and CY neither a statistically significant increase in creatinine concentration nor an increase in creatinine clearance was observed compared to the group receiving no cytostatics .
### Output Text:
After the administration of <span class="chemical">NG</span> , <span class="chemical">5 - FU</span> and <span class="chemical">CY</span> neither a statistically significant increase in <span class="chemical">creatinine</span> concentration nor an increase in <span class="chemical">creatinine</span> clearance was observed compared to the group receiving no cytostatics . 