[Histopathological observations on the trachea of the germ free, conventional and sulfur-dioxide-exposed rats].
D000818:Animals; D001485:Basement Membrane / Q000473:pathology; D002356:Cartilage / Q000473:pathology; D004781:Environmental Exposure; D005856:Germ-Free Life; D008214:Lymphocytes; D009092:Mucous Membrane / Q000473:pathology; D051381:Rats; D013458:Sulfur Dioxide; D014132:Trachea / Q000473:pathology*
D013458:Sulfur Dioxide