Search

Chronic wasting disease (CWD) is a contagious, rapidly spreading transmissible spongiform encephalopathy (TSE), or prion disease, occurring in cervids such as white tailed-deer (WTD), mule deer or elk in North America. Despite efficient horizontal transmission of CWD among cervids natural transmission of the disease to other species has not yet been observed. Here, we report for the first time a direct biochemical demonstration of pathological prion protein PrPTSE and of PrPTSE-associated seeding activity, the static and dynamic biochemical markers for biological prion infectivity, respectively, in skeletal muscles of CWD-infected cervids, i. e. WTD for which no clinical signs of CWD had been recognized. The presence of PrPTSE was detected by Western- and postfixed frozen tissue blotting, while the seeding activity of PrPTSE was revealed by protein misfolding cyclic amplification (PMCA). Semi-quantitative Western blotting indicated that the concentration of PrPTSE in skeletal muscles of CWD-infected WTD was approximately 2000-10000 -fold lower than in brain tissue. Tissue-blot-analyses revealed that PrPTSE was located in muscle-associated nerve fascicles but not, in detectable amounts, in myocytes. The presence and seeding activity of PrPTSE in skeletal muscle from CWD-infected cervids suggests prevention of such tissue in the human diet as a precautionary measure for food safety, pending on further clarification of whether CWD may be transmissible to humans. [ABSTRACT FROM AUTHOR]

The article discusses the future of animal agriculture in North America. The opportunities and challenges facing the livestock sector are discussed as well as the driving forces behind them. Key policy alternatives and business strategies for change are proposed. The role of animal identification and traceability systems in the future of the North American animal agriculture industry was also discussed.

The section presents an overview of articles which focus on animal agriculture in North America. Cross-cutting issues that will affect the future of animal agriculture in North America were discussed. The consumer demand and related forces driving changes in animal agriculture were addressed. The role of animal welfare issues in wealthy countries were also considered.

Objectives: This article provides a detailed understanding of the differences in selected formulary submission guidelines supplied by various health technology assessment (HTA) agencies and indicates how these differences can impact the evidence base used to populate the HTA., Methods: Detailed summaries of the recommended methods for evidence generation, organized by topic areas relevant for clinical and economic data, for twelve countries in Europe, North America, and Australia where HTA processes are well developed were prepared. Using these summaries, we provide examples of the likely impact these differences in recommended methods could have on the evidence base used to evaluate new health technologies., Results: Areas where recommendations differed included methodologies for systematic literature reviews (e.g., preferred databases and study designs for inclusion); selection of appropriate comparators; guidance on critical appraisal and synthesis of clinical evidence; appropriate sources for health value measures, resource use, and cost data; and approaches to uncertainty analyses. Performing literature searches that capture all relevant studies and then creating subsets of the literature based on a listing of country-specific requirements could allow for direct comparison of the evidence bases associated with the different guidelines., Conclusions: If the formulary submission guidelines were followed as written, different (although overlapping) bodies of evidence likely would be generated for each country, which could contribute to disparate assessments and recommendations. This comparison of the formulary submission guidelines could contribute to an understanding of why clinical and reimbursement decisions vary across countries.