Developing and comparing models of hematopoietic-acute radiation syndrome in Göttingen and Sinclair minipigs

PURPOSE

Current animal models of hematopoietic-acute radiation syndrome (H-ARS) are resource intensive and have limited translation to humans, thereby inhibiting the development of effective medical countermeasures (MCM)s for radiation exposure.

MATERIALS AND METHODS

To improve the MCM pipeline, we developed models of H-ARS in male Göttingen and Sinclair minipigs. Weight matched Göttingens and Sinclairs received total body irradiation (TBI; 1.50-2.10 Gy and 1.94-2.90 Gy, respectively), were observed for up to 45 days with blood collections for clinical pathology analysis, and were examined during gross necropsy.

RESULTS

The lethal dose for 50% of the population over the course of 45 days (LD_50/45) with 'field' supportive care (primarily antibiotics and hydration support) and implanted vascular access ports was 1.89 and 2.53 Gy for Göttingens and Sinclairs, respectively. Both minipig strains exhibited prototypical H-ARS characteristics, experiencing thrombocytopenia and neutropenia, and nadirs approximately 14 days following irradiation, slightly varying with dose. Both strains experienced increased bruising, petechia, and signs of internal hemorrhage in the lungs, GI, heart, and skin. All observations were noted to correlate with dose more closely in Sinclairs than in Göttingens.

CONCLUSION

The results of this study provide a template for future MCM development in an alternate species, and support further development of the Göttingen and Sinclair minipig H-ARS models.

Radioactive materials in biosolids: dose modeling

The Interagency Steering Committee on Radiation Standards (ISCORS) has recently completed a study of the occurrence within the United States of radioactive materials in sewage sludge and sewage incineration ash. One component of that effort was an examination of the possible transport of radioactivity from sludge into the local environment and the subsequent exposure of humans. A stochastic environmental pathway model was applied separately to seven hypothetical, generic sludge-release scenarios, leading to the creation of seven tables of Dose-to-Source Ratios (DSR), which can be used in translating from specific activity in sludge into dose to an individual. These DSR values were then combined with the results of an ISCORS survey of sludge and ash at more than 300 publicly owned treatment works, to explore the potential for radiation exposure of sludge workers and members of the public. This paper provides a brief overview of the pathway modeling methodology employed in the exposure and dose assessments and discusses technical aspects of the results obtained.