—_ Ay tere o _2- \ of injury and the clinical manifestations are ~roportionate to the dose, is particularly true of the symdromes of whole body radiation. I repeat, highly dependent on doseand time after exposure, description, This The latter is and There 4s no simple The problem is subtle and complex and one must always bear dose and time in mind. THE SYNDROMES FRCM TOTAL BODY PENETRATING RADIATIONS The dose dependent syndromes resulting from total body exposure in the mammal have been described in detail and I shall only simmarize them here. further details one is referred to the following references (1-12). For After large doses (approximately 6000 r or nore) the central nervous system syndrome wiich can be abbreviated CNS is produced. being irradiated or after some hours. Death may occur under the beam while “he clinical picture is characterized by hyperexcitability, disorders of equilibriun, incoordination, respiretory distress and intermittent stupor. Convulsions may preceed death. this syndrome are elways uniformly fatal. Doses capable of producing If an occasional animal, and presumably man, survives this CNS he has yet to experience the gastrointestinal syndrome (GIS), which when produced by doses in excess of 1500 r is always fatal within three to nine days for mammals, laboratory animals. Presumably man also will respond in a comparable manner es The GIS is so named because of the marked nausea, vomiting, diarrhea, and denudation of the lining of the small bowel. fatal syndrome in most laboratory animals. The GIS is a uniformly If the short duration GIS of a few hours resulting from lower doses, does not produce the three to nine day death, the survivors of this syndrome have yet to experience the sequelae of bone marrow depression which has been termed the hemopoietic syndrome (HS). The HS 4s not necessarily fatal. It is the clinical -icture that is seen in the lethal range for all mammals and in general the 50% lethal dose values reported, represent the Lp? for the sequela of hemopoietic depression ~ namely granulocytopenia, depressed defenses ageinst infection, -thrombopenia, and anenia with the pcssible resulting infections, diffuse pur-

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