Michael Linn Russell

The primary focus of my research is reactive gas dosimetry. The main body of work has involved using O-labeled nitrogen oxide to perform dosimetric analysis on rodents. O is a radioisotope with a half-life of 2.04 minutes produced in the DUMC cyclotron. This N1502 is exposed to mice, rats guinea pigs and hamsters, either free breathing or on mechanical ventilation. A number of bronchoalveolar lavage studies have been performed demonstrating the high solubility of radiolabeled N02 in the aqueous but not lipid fraction of lung tissue. the distribution of N 1502 uptake throughout the entire respiratory tract has been mapped. Similar studies will be performed using )-labeled ozone. Additional studies have been performed using phosgene, which is a highly reactive chemical intermediate used in industry. Microdissection of lung tissue at the junction between the bronchial and the alveolar region demonstrated that this gas produced a toxic thickening in the epithelium, in the most proximal regions of the alveolar regions. This effect dissipated as the gas moved distally. This indicates that the highly reactive gas was taken up in the proximal regions leaving a lower concentration in the distal regions. This affect is magnified by the fact that the surface area of the alveolar region increases moving distally. Future work will involve looking at injury in the alveolar region induced by inhaled particles and dosimetry of inhaled particles throughout the respiratory tract