Light and electron microscopy were used to study somatic cell reduction division occurring spontaneously in tetraploid populations of rat kangaroo Potorous tridactylis (PtK2) cells in vitro. Light microscopy coupled with time-lapse photography documented the pattern of reduction division which includes an anaphase-like movement of double chromatid… (More)
1. Pulmonary consolidation may be produced in normal mice by the inhalation of Friedländer's bacillus or Streptococcus haemolylicus. 2. The initial lesion is in both instances interstitial in character and the spread is by way of the interstitial tissue, though the ultimate consolidation may come to resemble in the gross a lobar pneumonia. 3. The lesions… (More)
The results of these experiments support the previous observations that mice react in different ways to the inhalation of different bacteria. If normal mice are sprayed with hemolytic streptococci or Friedländer's bacillus, these organisms may be recovered from the lungs and heart's blood for a number of days after exposure. A large number of mice so… (More)
1. When mice are passively immunized by the intraperitoneal injection of antipneumococcus horse serum or actively by the injection of heat-killed pneumococcus cultures, and are then alcoholized and sprayed with a culture of pneumococci of the same type as that of the bacteria employed in immunization, a considerable number die with localized lesions in the… (More)
1. The administration of alcohol produces no evident histological changes in the lungs of mice. 2. Following inhalations of pneumococci the organisms are not visible histologically in the lungs of mice either in the bronchi or alveoli. 3. In partially immunized mice which have been exposed to a pneumococcus spray while alcoholized, true lobar pneumonia not… (More)
1. The serial section examination of 71 partially immune alcoholised mice which were killed at intervals following the inhalation of virulent pneumococci showed pulmonary localisation in 7 or 9%. 2. In the case of the mouse the initial lesion of pneumococcus pneumonia is in the alveolar wall and the exudate into the alveolar lumen occurs secondarily.
1. Non-immune mice which are alcoholized and die of septicemia following exposure to a spray of virulent pneumococci rarely show any localization of infection in the lung. 2. Mice which have been partially immunized by previous inhalations of living or killed pneumococci and which while alcoholized are exposed to an atmosphere of virulent pneumococci often… (More)
1. Rabbits are very susceptible to infection by inhalation of Type I pneumococci. 2. When rabbits are exposed to a pneumococcus spray the bacteria readily penetrate into the lower respiratory tract. The pneumococci which reach the periphery of the lungs as a result of this procedure usually disappear within a few hours but a generalized and fatal septicemia… (More)