Impaired repair capacity of DNA breaks induced in mammalian cellular DNA by accelerated heavy ions. [Argon-, carbon-, and neon-ion beams; cultured human kidney T-1 cells]
The capacity of human kidney T-1 cells to rejoin DNA breaks induced by accelerated heavy-ion beams of C/sup 6 +/, Ne/sup 10 +/, and A/sup 18 +/ (308 to 500 MeV/amu) was studied. Cell monolayers were irradiated on ice with 2000 rad at various positions in the unmodified Bragg ionization curve. The data show that as the LET increases, the rate of rejoining becomes substantially slower than that normally found for x rays. The impaired rejoining capacity becomes maximal in the 100 to 200 keV/..mu..m range where 25% (+-6.8%) of the initial number of breaks per cell do not rejoin. In comparison, the induction of a maximal number of unrejoined breaks cell/sup -1/ rad/sup -1/ and cell-inactivation studies made under the same experimental conditions show a maximal biological effectiveness at about 100 keV/..mu..m. The data were evaluated both in terms of ionization densities expressed as LET (keV/..mu..m) and in terms of the factor (Z*)/sup 2//..beta../sup 2/, where Z* is the charge of the stripped nucleus and ..beta.. is the ratio of its velocity to the velocity of light.
- Research Organization:
- Univ. of California, Berkeley
- OSTI ID:
- 6355126
- Journal Information:
- Radiat. Res.; (United States), Vol. 78:1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BIOLOGICAL REPAIR
ENERGY DEPENDENCE
DNA
STRAND BREAKS
ION BEAMS
LET
ANIMAL CELLS
ARGON IONS
BIOLOGICAL RADIATION EFFECTS
CARBON IONS
CELL CULTURES
EXPERIMENTAL DATA
GRAPHS
IN VITRO
IRRADIATION
ISOLATED VALUES
NEON IONS
ATOMIC IONS
BEAMS
BIOLOGICAL EFFECTS
BIOLOGICAL RECOVERY
CHARGED PARTICLES
DATA
DATA FORMS
ENERGY TRANSFER
INFORMATION
IONS
NUCLEIC ACIDS
NUMERICAL DATA
ORGANIC COMPOUNDS
RADIATION EFFECTS
RECOVERY
REPAIR
560121* - Radiation Effects on Cells- External Source- (-1987)