title: Low-dose hypersensitivity of V79 cells under exposure to gamma-rays and 4He ions of different energies: survival and chromosome aberrations.
abstract: OBJECTIVE
  To examine the low-dose sensitivity of V79 cells under exposure to gamma-rays and 4He ions of different energies.
  
  
  METHODS
  Cell survival and cytogenetic analysis using the Giemsa technique were studied following irradiation to doses of 0-3 Gy at the INFN-LNL facilities.
  
  
  RESULTS
  Low-dose hyper-radiosensitivity (HRS) of V79 was demonstrated after irradiation with gamma-rays and alpha-particles of various linear energy transfers (LET) (58.9, 79.3 and 101.7 keV microm(-1)). Cytogenetic analysis showed an LET dependence of aberrations at a dose of 1Gy; the frequency of chromatid fragments appeared to vary with the number of alpha-particles traversing the cell nucleus. The results of both studies fit together to give a better understanding of so-called 'induced radioresistance' phenomenon.
  
  
  CONCLUSIONS
  The mechanism of induced cellular radioresistance appears to be initiated after a certain amount of energy is deposited in the cell nucleus. This amount depends on both radiation quality and the number of particles traversing the cell.
authors.affiliation: Institute of Nuclear Physics, NCSR Demokritos, Aghia Paraskevi 153 10, Athens, Greece. ktsoulou@mail.democritos.gr
authors.forename: E
authors.initials: E
authors.lastname: Tsoulou
authors.forename: L
authors.initials: L
authors.lastname: Baggio
authors.forename: R
authors.initials: R
authors.lastname: Cherubini
authors.forename: C A
authors.initials: CA
authors.lastname: Kalfas
mesh_terms: D000818:Animals; D002460:Cell Line / Q000187:drug effects / Q000528:radiation effects; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects*; D002869:Chromosome Aberrations; D006224:Cricetinae; D003412:Cricetulus; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D006371:Helium / Q000494:pharmacology*
chemical_list: D006371:Helium