Biological Effects of Protracted Exposure to Ionizing Radiation: Review,Analysis, and Model Development

摘要

Two basic approaches are developed to mathematically model biological responsesto ionizing radiation exposure, including upper gastrointestinal (UG) distress (nausea, vomiting), lower gastrointestinal (LG) distress (diarrhea, fluid loss), and GI-syndrome lethality. Models are constructed to accommodate arbitrary histories of protracted exposure. Sets of coupled differential equations are employed to simulate dynamics of the biological processes involved. The modeling approaches are guided by a comprehensive review and analysis of relevant literature, including radiation-induced symptomatology, response dynamics, physiological changes, morphological changes, cell/tissue damage and recovery mechanisms, and existing radiobiological injury and recovery models. The upper gastrointestinal distress model (UGIDM) is a two-compartment toxicokinetic model to simulate radiation-induced production and clearing of humoral substances involved in triggering UG distress.