title: Influence of cell position relative to planar alpha-particle sources on survival and preneoplastic transformation of primary rat tracheal epithelial cells.
abstract: Rat tracheal epithelial cells exposed directly on planar 210Po sources exhibited exponential cell killing; however, no significant increase in induction of preneoplastic transformation was observed over a range of alpha-particle fluences (0.017-0.050 micron-2). In contrast, up to 10-fold increases in frequencies of preneoplastic transformants, above control levels, were observed after exposure of rat tracheal epithelial cells to similar alpha-particle fluences on 238Pu and 241Am sources. Two alternative hypotheses are evaluated as an explanation for this apparent difference in the biological effect of alpha particles emitted from different sources: (a) possible interactions between effects produced by alpha particles and by low-energy photons, which occur with 238Pu and 241Am but not with 210Po; and (b) the influence of spatial relationships between exposed cells and the surface of the planar source. The data suggest that cell-to-source spatial relationships affect both survival and transformation markedly.
authors.affiliation: Biology Division, Oak Ridge National Laboratory, Tennessee 37831-8080, USA.
authors.forename: M
authors.initials: M
authors.lastname: Terzaghi-Howe
authors.forename: J R
authors.initials: JR
authors.lastname: Ford
authors.forename: J E
authors.initials: JE
authors.lastname: Turner
mesh_terms: D000512:Alpha Particles; D000576:Americium; D000818:Animals; D002470:Cell Survival / Q000528:radiation effects; D002471:Cell Transformation, Neoplastic / Q000528:radiation effects*; D002478:Cells, Cultured; D004307:Dose-Response Relationship, Radiation; D004848:Epithelium / Q000528:radiation effects; D018499:Linear Energy Transfer; D008297:Male; D011005:Plutonium; D011059:Polonium; D051381:Rats; D011916:Rats, Inbred F344; D014132:Trachea / Q000166:cytology
chemical_list: D011005:Plutonium; D011059:Polonium; D000576:Americium