Reflections on Some Recent Progress in Human Radiobiology

Biological effects of space radiation and development of effective countermeasures

“…hemorrhage, at death has been frequently observed in irradiated mammals, including humans. There is extensive evidence that widespread hemorrhages occurred in the Hiroshima and Nagasaki atomic bomb casualties, even in the relatively low radiation dose groups (311), with the estimated LD 50 values of approximately 2.5 (312, 313). Other information about hemorrhaging in humans after irradiation comes from accidental exposures in Norway (314) and Brazil (315, 316) in which several people were accidently exposed to whole body irradiation at doses near the human LD 50 and widespread hemorrhages were observed.…”

Is Disseminated Intravascular Coagulation the Major Cause of Mortality from Radiation at Relatively Low Whole Body Doses?

“…As the commonly used treatments for potentially lethal radiation injury have beneficial effects, human LD 50 values are imprecise, with estimates ranging from 3–4 Gy for young adults without medical intervention. However, human LD 50 values for the very young or the old maybe lower (7), (between 2–3 Gy) with estimates as low as 2.43 Gy [reviewed by Lushbaugh (8)].…”

“…There is evidence that humans exhibit bleeding in response to radiation at doses of 2–4 Gy (7). There is extensive evidence that widespread hemorrhages occurred in the Hiroshima and Nagasaki casualties, even in the relatively low-radiation dose groups (13); the estimated LD 50 values for those irradiated in Hiroshima and Nagasaki are approximately 2.5 Gy (8, 14). Other information about hemorrhaging after human radiation exposures comes from accidental whole-body irradiation (e.g., the radiation accidents in Norway (15) and Brazil (16, 17).…”

Etude prospective de la symptomatologie clinique précoce après irradiation corporelle totale thérapeutique de 2 Gy

“…La dose d'irradiation susceptible de provoquer des vomissements chez la moitié des sujets (ED50) a pu être évaluée à 2 Gy ou 2,3 Gy selon les équipes [14,21]. L'effet protecteur des sétrons, même s'il n'est que partiel, semble désormais clairement établi : après traitement préventif par granisétron, 62 % de nos patients n'ont eu aucun vomissement au cours des 10 heures post-ICT ; Feuvret et al rapportent le chiffre de 85 % dans les mêmes conditions [9] tandis que Anno et al estiment qu'un patient sur deux ne bénéficiant pas de prophylaxie antiémétique vomit précocement après ICT de 2 Gy [1].…”