Experimental studies on the treatment and pathological basis of combined radiation and burn injury.

Objective: To investigate therapeutics for and the pathological basis of combined radiation and burn injuries.
Methods: Combined radiation and burn injuries on mice and rats were inflicted by gamma ray irradiation from a (60)Co source and thermal radiation from a 5 kW bromotungsten lamp.
Results: The dysfunction of myocardium played an important role in the development of early stage shock. Transfusion of irradiated (in vitro, 20 Gy) or stored (4 degrees C, 7 days) blood after irradiation was done to promote the success of allo-transplantation of bone marrow. Decrease of IL-4 mRNA expression was the molecular basis of depression of intestinal mucosa immune and intervention of IL-4 showed an antagonistic effect on enterogenic infection. A new lipid component extracted from burn eschar was documented for the first time and its toxic effects were elucidated. The survival rate of alloskin grafts after removal of burn eschar from the recipient animals was obviously increased in combined injury due to reduction of immune rejection activity by the radiation effect. In contrast, in animal models with simple burn, the alloskin grafts were all rejected within ten days after the procedure. A successful therapeutic result (survival rate: 92% for 30 days and 67% for 100 days) was obtained by comprehensive management of treated animals, while the untreated control animals all died within 3 - 7 days after injury.
Conclusion: The pathogenesis of injury caused by simultaneous radiation and burn is extremely complicated and the treatment is very difficult. A comprehensive management program consisting of several therapeutic measures aimed at key links of the pathogenesis may achieve significantly improved results.