[Optimal conditions of gamma type irradiation for inactivating HIV in bone fragments. Consequences in biomechanical resistance of the bone tissue].

In order to determine bone-dependent penetration differences, we conducted a dosimetric study of gamma radiation using 2.5 mega rads on cancellous bone fragments at 4 degrees C and below 0 degrees with or without a surrounding solution. Variations in dose received inside and outside the femoral head were independent of radiation temperature but varied with the presence or absence of a surrounding solution. We then verified the gamma radiation effect on femoral heads infected with HIV: as free virus and in chronically infected cells. we evaluated infectious capacity after radiation by visualizing syncitia formation and by reverse transcriptase assay. The results for the controls were negative for free virus and positive for chronically infected cells. The virus was still after radiation. At the same time, we studied the effect of gamma radiation at different doses (0, 2.5, 5 mega rads) on biomechanical characteristics of bone, particularly crush resistance. Statistical analysis of the compression curves showed that resistance declined after high radiation at 5 mega rads, but the mean values obtained were within the range of values commonly accepted for human bone crush resistance.