Provided that a selective accumulation of (10)B-containing compounds is introduced in @entity5 cells, following irradiation by thermal neutrons produces high-LET alpha-particles ((4)He) and recoiling @entity1091 -7 ((7)Li) nuclei emitted during the capture of thermalized neutrons (0.025  eV) from (10)B. To estimate the biological effectiveness of this @entity9725 neutron capture [(10)B(n,a)(7)Li] reaction, the chromosome aberration assay and the flow cytometry apoptosis assay were applied. At the presence of the clinically used compounds @entity53838 (sodium borocaptate) and BPA ( @entity68451 ), @entity1 lymphocytes were irradiated by sub-thermal neutrons. For analyzing chromosome aberrations, @entity1 lymphocytes were exposed to thermally equivalent neutron fluences of 1.82  *  10(11) cm(-2) or 7.30  *  10(11) cm(-2) (corresponding to thermal neutron doses of 0.062 and 0.248  Gy, respectively) in the presence of 0, 10, 20, and 30  ppm of @entity53838 or BPA. Since the kerma coefficient of blood increased by 0.864  *  10(-12)  Gy  cm(2) per 10  ppm of (10)B, the kerma coefficients in blood increase from 0.34  *  10(-12) cm(2) (blood without @entity53838 or BPA) up to 2.93  *  10(-12) Gy  cm(2) in the presence of 30  ppm of (10)B. For the (10)B(n, a)(7)Li reaction, linear dose-response relations for dicentrics with coefficients a  =  0.0546      0.0081  Gy(-1) for @entity53838 and a  =  0.0654      0.0075  Gy(-1) for BPA were obtained at 0.062  Gy as well as a  =  0.0985      0.0284  Gy(-1) for @entity53838 and a  =  0.1293      0.0419  Gy(-1) for BPA at 0.248  Gy. At both doses, the corresponding (10)B(n, a)(7)Li reactions from @entity53838 and BPA are not significantly different. A linear dose-response relation for dicentrics also was obtained for the induction of apoptosis by the (10)B(n, a)(7)Li reaction at 0.248  Gy. The linear coefficients a  =  0.0249      0.0119  Gy(-1) for @entity53838 and a  =  0.0334      0.0064  Gy(-1) for BPA are not significantly different. Independently of the applied thermal neutron doses of 0.062  Gy or 0.248  Gy, the (10)B(n, a)(7)Li reaction from 30  ppm @entity53838 or BPA induced an apparent RBE of about 2.2 for the production of dicentrics as compared to exposure to thermal neutrons alone. Since the apparent RBE value is defined as the product of the RBE of a thermal neutron dose alone times a @entity9725 localization factor which depends on the concentration of a (10)B-containing compound, this localization factor determines the biological effectiveness of the (10)B(n, a)(7)Li reaction.

The effectiveness of the high-LET radiations from the XXXX neutron capture [(10)B(n,a) (7)Li] reaction determined for induction of chromosome aberrations and apoptosis in lymphocytes of @entity1 blood samples.

@entity1 :: ('9606', 'Species') :: ['human'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumor'] @entity9725 :: ('MESH:D001895', 'Chemical') :: ['boron'] @entity53838 :: ('CHEBI:64876', 'Chemical') :: ['BSH'] @entity1091 :: ('MESH:D008094', 'Chemical') :: ['lithium'] @entity68451 :: ('MESH:C033685', 'Chemical') :: ['p-boronophenylalanine']
@entity9725 :: (MESH:D001895,Chemical) :: ['boron']
