Acute and Subacute Effects of Injury on the Canine Alveolar Septum: Methods (5)
Septal continuity, however, was maintained by the alveolar epithelium, usually by a type 2 cell. Less commonly, continuity was maintained by the nucleated portion of a type 1 cell, and least commonly, by a thin single or double layer of type 1 cell cytoplasm. All septal discontinuities, all alveolar macrophages and all epithelial cell types were identified as to location on each alveolar profile, and the relationship of these cell types to septal gaps was noted. Those cells and gaps that bordered on or were within 10 p.m of an alveolar wall junction were classified as belonging to alveolar junctional zones. If the septal gap appeared on more than one alveolar profile, the number of successive profiles on which each gap and associated cell appeared was also identified. Areas about which there was doubt were photographically enlarged to resolve the issue.
The approximate surface areas of the alveoli contained within each of these specimens were determined by a map mileage reading device, calibrated in centimeters, with appropriate adjustments for magnification as previously reported. The circumference of each of the alveolar montages was determined by running a calibrated map mileage reader around each alveolar circumference. This value was multiplied by either 0.8 or 1.6 jim (depending on the interval between each montaged section) to give the estimated surface area of each segment of the alveolar wall. The sum of the surface areas of these segments was taken to be an approximation of that portion of the surface areas of each alveolus that had been serially sectioned and studied. flovent inhaler
Cell counts and surface areas from the two control groups (three animals) were summed and compared with the cell counts and surface areas in experimental groups by the chi square test with the Yates correction for continuity. The probability value was considered significant if it was <0.01.