24974
Interaction of PVA HNP with mammalian cells was investigated using flow cytometry , viability screening , and measurements of nitric oxide production by cultured macrophages .
 Chemical: PVA; Chemical: nitric oxide
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: PVA; Chemical: nitric oxide