strontium-radioisotopes and Wounds-and-Injuries

This study had a goal to evaluate the predictive capabilities of the National Council on Radiation Protection and Measurements (NCRP) wound model coupled to the International Commission on Radiological Protection (ICRP) systemic model for 90Sr-contaminated wounds using non-human primate data. Studies were conducted on 13 macaque (Macaca mulatta) monkeys, each receiving one-time intramuscular injections of 90Sr solution. Urine and feces samples were collected up to 28 d post-injection and analyzed for 90Sr activity. Integrated Modules for Bioassay Analysis (IMBA) software was configured with default NCRP and ICRP model transfer coefficients to calculate predicted 90Sr intake via the wound based on the radioactivity measured in bioassay samples. The default parameters of the combined models produced adequate fits of the bioassay data, but maximum likelihood predictions of intake were overestimated by a factor of 1.0 to 2.9 when bioassay data were used as predictors. Skeletal retention was also over-predicted, suggesting an underestimation of the excretion fraction. Bayesian statistics and Monte Carlo sampling were applied using IMBA to vary the default parameters, producing updated transfer coefficients for individual monkeys that improved model fit and predicted intake and skeletal retention. The geometric means of the optimized transfer rates for the 11 cases were computed, and these optimized sample population parameters were tested on two independent monkey cases and on the 11 monkeys from which the optimized parameters were derived. The optimized model parameters did not improve the model fit in most cases, and the predicted skeletal activity produced improvements in three of the 11 cases. The optimized parameters improved the predicted intake in all cases but still over-predicted the intake by an average of 50%. The results suggest that the modified transfer rates were not always an improvement over the default NCRP and ICRP model values.

Topics: Animals; Bayes Theorem; Biological Assay; Computer Simulation; Environmental Exposure; Humans; Kinetics; Macaca mulatta; Models, Biological; Radiation Injuries; Radiation Protection; Risk Assessment; Strontium Radioisotopes; Tissue Distribution; Wounds and Injuries

The changes in cardiac output (Q), regional blood blow (Qr) and regional vascular resistance, and arterial pressure were studied in rats subjected to moderate (LD0) or severe (LD50) traumatic shock. Q and Qr were determined using microspheres at 15, 60 and 180 min posttrauma. Arterial pressure decreased in both groups at 15 min and recovered by 3 hr after sublethal (LD0) trauma, while arterial pressure did not return to control levels after LD50 trauma. Q decreased in both groups at 15 min and returned to control only in the LD0 trauma group by 3 hr. Cerebral, coronary, and hepatic arterial flows and resistances were maintained in both groups. Renal, intestinal, and splenic flows decreased and resistances increased in both groups by 15 min and returned to control levels by 3 hr only in the LD0 trauma group. Total hepatic and hepatic portal flows decreased at 60 min and returned to control levels at 3 hr after LD0 trauma, while there was significant depression in these parameters 3 hr after LD50 trauma. Therefore, sublethal and severe trauma resulted in early redistribution of flow favoring the coronary, cerebral, and hepatic arterial beds. However, renal, intestinal, splenic, and portal flows remained depressed only in severely traumatized rats, suggesting that continued hypoperfusion is a factor in the multiple organ failure and death following severe traumatic injury.

Topics: Animals; Blood Pressure; Cardiac Output; Cerium Radioisotopes; Hemodynamics; Male; Mononuclear Phagocyte System; Rats; Regional Blood Flow; Shock, Traumatic; Strontium Radioisotopes; Wounds and Injuries

Topics: Absorption; Americium; Animals; Cerium Radioisotopes; Polonium; Radioisotopes; Rats; Skin; Skin Absorption; Strontium Radioisotopes; Time Factors; Wounds and Injuries