11561
METHODS: During a double-blind placebo-controlled crossover study , 200 micrograms fluticasone propionate aqueous nasal spray (in the active treatment period ) and placebo (in the placebo treatment period ) were administered twice daily for 2 weeks to 22 patients allergic to house dust mite .
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Locate the role in the text that participated in the event based on the event type and return it in the event list. 
 Option: Event type: RNA,cell type,protein,cell line,DNA, Arguments type: . 
Text: {0} 
Answer:
 None