17789
RATIONALE : Histamine H3 receptor antagonists , such as ABT - 288 , have been shown to possess cognitive - enhancing and wakefulness - promoting effects .
 Chemical: Histamine; Chemical: ABT - 288
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: Histamine; Chemical: ABT - 288