The clinical and pathological response of goats to whole-body irradiation by gamma-rays and fision neutrons.

Abstract

SummaryFifty adult male British Saanen goats in equal numbers were given acute whole-body irradiation with either fission neutrons or gamma-rays of 2·5 mev mean energy. The LD 50/30 was about 505 rad for neutrons and 395 r for gamma-rays, giving an RBE of 0·8.Higher doses resulted in a fatal ‘gastro-intestinal’ syndrome characterized by severe to absolute anorexia, fluid intake greatly reduced to absent, progressive haemoconcentration from 48 hours and diarrhoea from 4 days after exposure. At post-mortem there were mucus casts within the lumen of the small intestine. Deaths in the third and fourth weeks were commonly the result of widespread haemorrhage with severe thrombocytopenia following bone-marrow damage. Severe anaemia was seen only once and that in a survivor. Although few deaths could be confidently attributed to infection and blood-cultures were sterile, bacterial aggregates were nearly always found in the tissues, most commonly in the intestines, liver and lungs, and fever occurred invariably i...