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: Diabetes of 4 months duration also resulted in decreases in body weight , and increases in fluid consumption , urine volume , frequency of micturition , and average volume per micturition , effects which were reversed by insulin treatment for the final 2 months of the study .
### Output Text:
Diabetes of 4 months duration also resulted in decreases in body weight , and increases in fluid consumption , urine volume , frequency of micturition , and average volume per micturition , effects which were reversed by insulin treatment for the final 2 months of the study . 