# Micronuclei induced by fast-neutrons versus 60Co γ-rays in human peripheral blood lymphocytes

Anne Vral (UGent) , Hubert Thierens (UGent) and Leo De Ridder (UGent)
(1994) 65(3). p.321-328
Author
Organization
Abstract
Here we compared the effectiveness of neutrons ([E] = 5.5 MeV) versus Co-60 gamma-rays in producing micronuclei (MN) in human lymphocytes. To obtain dose-response data, blood samples of six donors were irradiated with doses ranging from 0.1 to 5 Gy for gamma-rays and 0.1-3 Gy for neutrons. A linear dependence of MN yield with dose was found for fast neutrons while for gamma-rays a nonlinear dependence existed. For both radiation qualities no significant interindividual differences were found. Derived relative biological effectiveness Values decreased with increasing dose. The MN frequency distributions were overdispersed with respect to the Poisson distribution, with neutrons showing higher dispersion values than with gamma-rays. To compare the repair kinetics of both radiation qualities split-dose experiments were performed. A dose of 4 Gy gamma-rays (3 Gy neutrons) was delivered either as a single exposure or in two equal fractions separated by time intervals ranging from 30 min to 10 h (30 min to 7 h for neutrons). The data showed for gamma-rays a significant decline (30% +/- 10%) in MN yield with interfraction time due to repair of DNA damage. This repair is a continuous process starting almost immediately after the first of the two doses and lasting 3-5 h. For fast neutrons no decline was observed indicating irreparable damage.
Keywords
CHROMOSOME-ABERRATIONS, IRRADIATED HUMAN-LYMPHOCYTES, DOSE-RESPONSE, X-RAYS, BIOLOGICAL DOSIMETRY, ALPHA-PARTICLES, INVITRO, ASSAY, INDUCTION, PROTONS

## Citation

Chicago
Vral, Anne, Frans Verhaegen, Hubert Thierens, and Leo De Ridder. 1994. “Micronuclei Induced by Fast-neutrons Versus 60Co Γ-rays in Human Peripheral Blood Lymphocytes.” International Journal of Radiation Biology 65 (3): 321–328.
APA
Vral, A., Verhaegen, F., Thierens, H., & De Ridder, L. (1994). Micronuclei induced by fast-neutrons versus 60Co γ-rays in human peripheral blood lymphocytes. INTERNATIONAL JOURNAL OF RADIATION BIOLOGY, 65(3), 321–328.
Vancouver
1.
Vral A, Verhaegen F, Thierens H, De Ridder L. Micronuclei induced by fast-neutrons versus 60Co γ-rays in human peripheral blood lymphocytes. INTERNATIONAL JOURNAL OF RADIATION BIOLOGY. 1994;65(3):321–8.
MLA
Vral, Anne, Frans Verhaegen, Hubert Thierens, et al. “Micronuclei Induced by Fast-neutrons Versus 60Co Γ-rays in Human Peripheral Blood Lymphocytes.” INTERNATIONAL JOURNAL OF RADIATION BIOLOGY 65.3 (1994): 321–328. Print.
@article{197395,
abstract     = {Here we compared the effectiveness of neutrons ([E] = 5.5 MeV) versus Co-60 gamma-rays in producing micronuclei (MN) in human lymphocytes. To obtain dose-response data, blood samples of six donors were irradiated with doses ranging from 0.1 to 5 Gy for gamma-rays and 0.1-3 Gy for neutrons. A linear dependence of MN yield with dose was found for fast neutrons while for gamma-rays a nonlinear dependence existed. For both radiation qualities no significant interindividual differences were found. Derived relative biological effectiveness Values decreased with increasing dose. The MN frequency distributions were overdispersed with respect to the Poisson distribution, with neutrons showing higher dispersion values than with gamma-rays. To compare the repair kinetics of both radiation qualities split-dose experiments were performed. A dose of 4 Gy gamma-rays (3 Gy neutrons) was delivered either as a single exposure or in two equal fractions separated by time intervals ranging from 30 min to 10 h (30 min to 7 h for neutrons). The data showed for gamma-rays a significant decline (30\% +/- 10\%) in MN yield with interfraction time due to repair of DNA damage. This repair is a continuous process starting almost immediately after the first of the two doses and lasting 3-5 h. For fast neutrons no decline was observed indicating irreparable damage.},
author       = {Vral, Anne and Verhaegen, Frans and Thierens, Hubert and De Ridder, Leo},
issn         = {0955-3002},
journal      = {INTERNATIONAL JOURNAL OF RADIATION BIOLOGY},