7838
Hepatocellular altered foci , detected by glutathione S - transferase - placental type ( pi ) immunohistochemistry , were present beginning with the high dose group at 8 weeks and extending to all MEG groups at 16 weeks .
 glutathione, S, MEG
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 glutathione, S, MEG