Biological Radiation Effects

Reaction intermediates and redox state changes in a blue laccase from Steccherinum ochraceum observed by crystallographic high/low X-ray dose experiments

“…The buildup of this energy leads to sample heating and then to the breakage of bonds often resulting in the formation of radical species both from protein components and solvent water molecules [26]. These reactive radicals, together with the electrons released from the protein atoms, are responsible for the structural changes observed in disulfide bonds, in carboxyl groups of acidic residues, in tyrosine residues and in chromophoric and metal redox centers unit [24,25,27,28].…”

“…As a matter of fact the interaction of the X-ray photons with the atoms in the crystal causes ionizations and electronic excitations, which are directly proportional to the energy of the X-rays and to its dose i.e. to the quantity of energy deposited per unit [24,25]. The buildup of this energy leads to sample heating and then to the breakage of bonds often resulting in the formation of radical species both from protein components and solvent water molecules [26].…”

Estimation of hydroxyl radical generation by salicylate hydroxylation method in multiple organs of mice exposed to whole-body X-ray irradiation

“…In addition, low LET ionizing radiation generate hydroxyl radicals in line with the track and it is possible to perform uniform whole-body irradiation of mice with these X-rays [19]. Moreover, it is easy to control hydroxyl radical generation by using the on -off switch of the X-ray generator.…”

“…To evaluate the hydroxyl radical generation, the ratios of 2,3-DHBA to SA were compared between the irradiated mice and the control mice. Moreover, to estimate the amount of increase in hydroxyl radicals corresponding to 2,3-DHBA in the samples, we derived two linearregression equations from our in vitro experiments and G-value of hydroxyl radical (2.7/100 eV) by g-radiolysis of water at neutral pH [19]. Using these linearregression equations, the equivalent amounts of hydroxyl radicals in the samples were calculated as follows: (1) the expected values of hydroxyl radicals generated by 24 Gy irradiation were calculated from the concentration of SA in the samples, and (2) the equivalent amounts of hydroxyl radicals corresponding to the 2,3-DHBA increases in the samples were calculated by subtracting the background (un-irradiated samples) from the concentrations of 2,3-DHBA in the samples.…”

Estimation of hydroxyl radical generation by salicylate hydroxylation method in kidney of mice exposed to ferric nitrilotriacetate and potassium bromate

“…Further, to estimate the amount of increase in ×OH corresponding to the 2,3-DHBA increase in the samples, we derived two linear-regression equations from our in vitro experiments and the G-value of ×OH (2.7/100eV) by gamma-radiolysis of water at neutral pH [21]. Using these linear-regression Estimation of hydroxyl radical generation by salicylate hydroxylation method 1247 Free Radic Res Downloaded from informahealthcare.com by Nyu Medical Center on 06/12/15 equations, the equivalent amounts of ×OH in the samples were calculated as follows assuming a specific gravity of 1 [16]:…”