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 control ISO infusion with stenosis was performed , equihypotensive doses of CD - 832 ( 3 and 10 micrograms / kg / min , n = 7 ) , nifedipine ( 1 and 3 micrograms / kg / min , n = 9 ) or diltiazem ( 10 and 30 micrograms / kg / min , n = 7 ) were infused 5 min before and during the second and third ISO infusion .
### Output Text:
After the control <span class="chemical">ISO</span> infusion with stenosis was performed , equihypotensive doses of <span class="chemical">CD - 832</span> ( 3 and 10 micrograms / kg / min , n = 7 ) , <span class="chemical">nifedipine</span> ( 1 and 3 micrograms / kg / min , n = 9 ) or <span class="chemical">diltiazem</span> ( 10 and 30 micrograms / kg / min , n = 7 ) were infused 5 min before and during the second and third <span class="chemical">ISO</span> infusion . 