title: Effects of monoenergetic X-rays with resonance energy of bromine K-absorption edge on bromouracil-labelled E. coli cells.
abstract: In order to examine enhanced killing that might be induced by Auger cascades in the incorporated atoms in cells, bromouracil(BrU)-labelled E. coli cells were irradiated with monoenergetic X-rays at 13.49 and 12.40keV, just above and below the K-absorption edge of bromine. In both cases BrU-labelled cells were more sensitive for killing than were normal cells. However, when the degree of BrU-sensitization was compared between the two energies of X-rays, the enhanced killing at 13.49 keV was only small, 2 +/- 8 per cent based on the D0 value in saline. By the addition of DMSO, which is believed to suppress radical-mediated effects, killing of BrU-labelled cells was enhanced at 13.49 keV by 8 +/- 4 per cent as compared with 12.40 keV, based on D0. These results have been examined in terms of absorbed energy in BrU-labelled cells and in terms of the number of induced Auger events.
authors.affiliation: Department of Radiation Oncology, School of Medicine, Tokai University, Kanagawa, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Maezawa
authors.forename: K
authors.initials: K
authors.lastname: Hieda
authors.forename: K
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Y
authors.initials: Y
authors.lastname: Furusawa
authors.forename: T
authors.initials: T
authors.lastname: Mori
authors.forename: K
authors.initials: K
authors.lastname: Suzuki
authors.forename: T
authors.initials: T
authors.lastname: Ito
mesh_terms: D001976:Bromouracil / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects*; D004926:Escherichia coli; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology*
chemical_list: D011838:Radiation-Sensitizing Agents; D001976:Bromouracil