Cathy L Bedwell

Publications of Cathy L Bedwell

• Select tissue mineral concentrations and chronic wasting disease status in mule deer from North-central Colorado.

  Authors: Lisa L Wolfe, Mary M Conner, Cathy L Bedwell, Paul M Lukacs, Michael W Miller

  Journal of wildlife diseases. 07/2010; 46(3):1029-34.

  Trace mineral imbalances have been suggested as having a causative or contributory role in chronic wasting disease (CWD), a prion disease of several North American cervid species. To begin exploringTrace mineral imbalances have been suggested as having a causative or contributory role in chronic wasting disease (CWD), a prion disease of several North American cervid species. To begin exploring relationships between tissue mineral concentrations and CWD in natural systems, we measured liver tissue concentrations of copper, manganese, and molybdenum in samples from 447 apparently healthy, adult (> or = 2 yr old) mule deer (Odocoileus hemionus) culled or vehicle killed from free-ranging populations in north-central Colorado, United States, where CWD occurs naturally; we also measured copper concentrations in brain-stem (medulla oblongata at the obex) tissue from 181 of these deer. Analyses revealed a wide range of concentrations of all three minerals among sampled deer (copper: 5.6-331 ppm in liver, 1.5-31.9 ppm in obex; manganese: 0.1-21.4 ppm in liver; molybdenum: 0.5-4.0 ppm in liver). Bayesian multiple regression analysis revealed a negative association between obex copper (-0.097; 95% credible interval -0.192 to -0.006) and the probability of sampled deer also being infected with CWD, as well as a positive association between liver manganese (0.158; 95% credible interval 0.066 to 0.253) and probability of infection. We could not discern whether the tendencies toward lower brain-stem copper concentrations or higher systemic manganese concentrations in infected deer preceded prion infection or rather were the result of infection and its subsequent effects, although the distribution of trace mineral concentrations in infected deer seemed more suggestive of the latter.

• Effects of selenium supplementation and sample storage time on blood indices of selenium status in bighorn sheep.

  Authors: Laura E Rosen, Daniel P Walsh, Lisa L Wolfe, Cathy L Bedwell, Michael W Miller

  Journal of wildlife diseases. 08/2009; 45(3):795-801.

  Periodic pneumonia outbreaks cause large-scale die-offs that threaten the viability of bighorn sheep (Ovis canadensis) populations. Bighorns are highly susceptible to pneumonia, and in some casesPeriodic pneumonia outbreaks cause large-scale die-offs that threaten the viability of bighorn sheep (Ovis canadensis) populations. Bighorns are highly susceptible to pneumonia, and in some cases this susceptibility may be exacerbated by trace mineral deficiencies. To evaluate responses to injectable selenium supplementation, eight captive bighorn sheep were treated with either an injectable sodium selenite supplement or a saline control. We collected 6-ml blood aliquots before and at 1, 6, and 12 wk posttreatment. We submitted one set of aliquots immediately to measure selenium (Se) and zinc (Zn) concentrations and glutathione-peroxidase (GSH-Px) activity; additional aliquots were held at about 22 C and then submitted at 1, 3, and 7 days postcollection to assess effects of storage on these measures. Neither Se nor GSH-Px were affected by selenite injections. Both Se and GSH-Px demonstrated small linear decays over the 7-day storage period (0.011 ppm/day [SE=0.0027] and 15.78 mmole/l/sec/day [SE=6.88], respectively); in contrast, Zn concentrations in stored samples increased logarithmically (0.35 ppm/day on the natural log scale). Blood Se and GSH-Px were not correlated in sampled bighorns; however, because all values for both measures were within normal limits, lack of correlation did not affect interpretation of these data in our study.