title: Validation study of the OHIO Chamber in patients with Japanese cedar pollinosis.
abstract: BACKGROUND
  An artificial exposure chamber (OHIO Chamber), which allows dispersal of a fixed concentration of Japanese cedar (JC) pollen under stable conditions, was constructed. This study was conducted to identify the exposure conditions assuring validity of the clinical tests conducted using this chamber.
  
  
  METHODS
  Twenty-four adult patients with JC pollinosis were exposed to different concentrations of JC pollen: 0 (only during the summer period), 4,000, 8,000 and 12,000 grains/m3, and the nasal and ocular symptoms were self-assessed during a 4-hour period of exposure. The amount of nasal discharge was measured and the sneezing frequency was recorded. This study was conducted twice during the summer and winter periods, i.e. non-pollen seasons. The reproducibility of the symptoms between the two seasons was assessed.
  
  
  RESULTS
  None of the subjects developed any symptom at the pollen concentration of 0 grains/m3. No significant differences in the time to the onset of symptoms were found between the summer and winter study, regardless of the pollen concentration. There were no significant differences between the summer and winter study in the total symptom score and total nasal symptom score at any pollen concentration, suggesting the very favorable reproducibility of symptoms.
  
  
  CONCLUSIONS
  Efficient and reproducible results are obtained in patients exposed to JC pollen in the OHIO Chamber. The results suggest the conditions of JC pollen exposure have scientific validity and the OHIO Chamber has the potential to contribute significantly to basic and clinical studies of JC pollinosis.
authors.affiliation: Kitasato Institute Hospital, Department of Otolaryngology, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8642, Japan. hashiguc@insti.kitasato-u.ac.jp
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Hashiguchi
authors.forename: Huaipeng
authors.initials: H
authors.lastname: Tang
authors.forename: Toshio
authors.initials: T
authors.lastname: Fujita
authors.forename: Kiyochika
authors.initials: K
authors.lastname: Suematsu
authors.forename: Shigekazu
authors.initials: S
authors.lastname: Tsubaki
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Nagakura
authors.forename: Sei
authors.initials: S
authors.lastname: Kitajima
authors.forename: Minoru
authors.initials: M
authors.lastname: Gotoh
authors.forename: Kimihiro
authors.initials: K
authors.lastname: Okubo
mesh_terms: D000328:Adult; D000485:Allergens / Q000276:immunology*; D001273:Atmosphere Exposure Chambers; D018592:Cross-Over Studies; D032485:Cryptomeria / Q000276:immunology*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D019570:Inhalation Exposure; D008297:Male; D008875:Middle Aged; D011058:Pollen / Q000276:immunology*; D015203:Reproducibility of Results; D006255:Rhinitis, Allergic, Seasonal / Q000175:diagnosis* / Q000276:immunology
chemical_list: D000485:Allergens