[Experimental influenza caused by an incomplete form of the agent]

Incomplete form of the influenza virus obtained in accordance with Nayak's method was administered intranasally to mice CBA and C57BL. From the lung tissue of the infected mice the causative agent could be isolated for 45 days, and from the other internal organs--the first hours after the infection only. In morphological investigation of the lungs of animals infected with an incomplete form of the influenza virus a prevalence of the proliferative component against the background of inflammatory changes was noted. Three months after the infection limited lymphoid formations consisting of monomorphic cells with hyperchromic nuclei were defined in the lung tissue. Marked proliferation of the alveolar and bronchial epithelium was observed later; considerable anaplasia of the cells was noted in the papillomatous structure of the alveolar and bronchial epithelium. Glomangioma of the mesentery was observed among affections of other internal organs in 18.7% of mice CBA.