Material and methods
Fourteen healthy volunteer as well as 14 otherwise healthy subject is symptom consistency with URI 4 man and 10 women mean age 30 were recruited for the study which was approved by the institutional review board of Albert Einstein hospital Montefior medical center. All participation were no smoker without a history of symptom suggestive of gastroesophageal reflex . Healthy volunteer denied recently without 4 weeks symptom of respiratory tracts infection seasonal allergies or postnasal drip syndrome.