[A study of possibility to predict the sensitivity of different respiratory tract divisions to influenza]
To predict a potential value of a viral ID50 for a macro-organism of interest (e.g. humans), it is necessary to determine in vitro two parameters of the interaction of the virus with susceptible cells of the host, i.e. the probability of the virus' productive absorption on a susceptible cell and the average virus yield per cell. A different macroorganism (a model animal) and primary cells obtained from it can be used to determine the value of a scale factor, which accounts for the difference between the values of the probability of the virus' absorption measured in vivo and in vitro. An original mathematical model is used to convert the above-mentioned data to ID50 for the macroorganism of interest. It was shown that the method of cultivating influenza virus (A/ Aichi/2/68) in primary suspension culture of respiratory tract cells of rats and two breeds of mice may be used to estimate potential human susceptibility to novel influenza viruses. This work was sponsored by DAPRA, USA, and performed under the contract 450p to the International Science and Technology Center, Moscow.
- [Show abstract] [Hide abstract] ABSTRACT: Inability to preserve airway mucus in situ has limited our understanding of its structure and function. This light- and transmission electron-microscopic study of rat tracheal mucus used a nonaqueous fixative that retains mucus (epiphase) over a lucent layer (hypophase). The fixative is a 1% solution of osmium tetroxide dissolved in a perfluorocarbon. The mean thickness of rat tracheal epiphase was 5 μm, with significant variation (0.1-50 μm) around the tracheal circumference. Tracheal mucus was thickest at the trachealis muscle region and contained cells, cellular debris, and a variable amount of surfactant and lipid, estimated at 4-16% of the total epiphase in five rats, with a mean composition of 9%. Lipid was observed on the surface of the epiphase, embedded within mucus, and at the epiphase-hypophase interface. Refined study of developmental, physiological, and pathological alterations to the airway coat may benefit from this approach.0Comments 31Citations