polonium and Tracheal-Neoplasms

Rat tracheal epithelial cells exhibited exponential cell killing when exposed to 210Po alpha particles as single cell suspensions or in the intact tissue. Survival of cells in the intact tissue was not significantly different from that observed with cell suspensions. Comparison of survival of cells exposed in suspension to 300 kVpX rays yielded an RBE of 6.3. Measurements of basal cell nuclei were used to determine that a single traversal of a cell nucleus had a high probability of causing cell inactivation. This was also observed in mink lung cells and CHO cells exposed in an identical manner. There were no significant increases in frequencies of preneoplastic transformation observed for a range of exposures (0.0007 to 0.05 alpha particles/micron2). Examination of intact tracheal transplants which were irradiated with alpha particles also failed to reveal any preneoplastic or neoplastic changes.

Topics: Alpha Particles; Animals; Cell Line; Cell Survival; Cell Transformation, Neoplastic; Cells, Cultured; CHO Cells; Cricetinae; Epithelium; Male; Neoplasms, Radiation-Induced; Polonium; Precancerous Conditions; Rats; Rats, Inbred F344; Suspensions; Trachea; Tracheal Neoplasms

Topics: Alpha Particles; Animals; Carcinoma; Carcinoma, Squamous Cell; Cricetinae; Disease Models, Animal; Female; Lung Neoplasms; Lymphoma; Mesocricetus; Neoplasm Metastasis; Neoplasms, Radiation-Induced; Polonium; Tracheal Neoplasms

Topics: Adenocarcinoma; Animals; Benzopyrenes; Bronchial Neoplasms; Carcinogens; Carcinoma; Carcinoma, Squamous Cell; Cricetinae; Dose-Response Relationship, Drug; Dose-Response Relationship, Radiation; Female; Hyperplasia; Intubation, Intratracheal; Lung Neoplasms; Male; Neoplasms, Experimental; Neoplasms, Radiation-Induced; Papilloma; Polonium; Respiratory Tract Neoplasms; Time Factors; Tracheal Neoplasms