Fig. 1.

All animal experiments shown in the figure were reviewed and approved by the IACUC of the University of Tennessee Health Science Center and the California National Primate Research Center. A: Kaplan-Meier survival curve from a study conducted under Good Laboratory Practice standards using partial body irradiation (PBI) and dosing of either vehicle or OTP (3 mg/kg sc) beginning 24 h after 15.62 Gy exposure in female C57/BL6 mice >12 weeks (P < 0.0001, log-rank test). Median survival time was 17 days for OTP-treated animals and 7 days for vehicle-treated animals. Taken from study report: BARDA Contract HHSO100201100036C. B: Kaplan-Meier survival curve from a study with male Rhesus macaques at the California National Primate Research Center under RC-2 grant 1RC2AI087550. This model used 11.5 Gy PBI with 5% bone marrow shielding (PBI-BM5) and treatment with vehicle or OTP (0.1 mg/kg sc) beginning 4 h after radiation (P = 0.02, log-rank test). C: Ki67 immunohistological staining of a jejunum section taken on postirradiation day from a vehicle-treated Rhesus macaque after PBI-BM5 (11.5 Gy). Note the lack of crypts and uneven villus lengths in this section. D: A jejunum section from an OTP-treated Rhesus macaque (0.1 mg/kg for 5 days starting at 4 h after irradiation) from the same study as shown in C. Note the robust labeling of regenerating crypts uniformly lining the gut wall. E: Hematoxylin-eosin stained duodenum section from a vehicle-treated Rhesus macaque exposed to 11.5 Gy irradiation as in C and D taken 8 days after radiation exposure. Note the atrophic Brunner gland with extensive fibrosis. E: Hematoxylin-eosin stained duodenum section from a Rhesus macaque treated with OTP 0.3 mg/kg for 5 days starting at 24 h postirradiation and euthanized on day 8. Note that the Bunner glands show normal cellularity and no sign of fibrosis. Taken from the final grant report to NIAID on award AI 87550.