Connell. 1969. Investigator studied effects of ragweed inhalation on nasal membranes after unilateral nasal challenge. Found that membranes are 'primed', which results in acute rhinitis even after smaller doses of allergen. Also found priming to be nonspecific, with reactions occurring in primed membranes when small quantities of allergen that was previously not reactive were administered. Additionally, found that priming can take days to weeks for recovery.