Factors associated with whole carcass condemnation rates in provincially-inspected abattoirs in Ontario 2001-2007: implications for food animal syndromic surveillance

Background  

Ontario provincial abattoirs have the potential to be important sources of syndromic surveillance data for emerging diseases of concern to animal health, public health and food safety. The objectives of this study were to: (1) describe provincially inspected abattoirs processing cattle in Ontario in terms of the number of abattoirs, the number of weeks abattoirs process cattle, geographical distribution, types of whole carcass condemnations reported, and the distance animals are shipped for slaughter; and (2) identify various seasonal, secular, disease and non-disease factors that might bias the results of quantitative methods, such as cluster detection methods, used for food animal syndromic surveillance.     

Structural organization of the beta-globin locus of B-haplotype sheep

Goats and some sheep synthesize a juvenile hemoglobin, Hb C (alpha 2 beta C2), at birth and produce this hemoglobin exclusively during severe anemia. Sheep that synthesize this juvenile hemoglobin are of the A haplotype. Other sheep, belonging to a separate group, the B haplotype, do not synthesize hemoglobin C and during anemia continue to produce their adult hemoglobin. To understand the basis for this difference we have determined the structural organization of the beta- globin locus of B-type sheep by constructing and isolating overlapping genomic clones. These clones have allowed us to establish the linkage map 5' epsilon I-epsilon II-psi beta I-beta B-epsilon III-epsilon IV- psi beta II-beta F3' in this haplotype. Thus, B sheep lack four genes, including the BC gene, and have only eight genes, compared with the 12 found in the goat globin locus. The goat beta-globin locus is as follows: 5' epsilon I-epsilon II-psi beta X-beta C-epsilon III-epsilon IV-psi beta Z-beta A-epsilon V-epsilon VI-psi beta Y-beta F3'. Southern blot analysis of A-type sheep reveals that these animals have a beta- globin locus similar to that of goat, i.e., 12 globin genes. Thus, the beta-globin locus of B-haplotype sheep resembles that of cows and may have retained the duplicated locus of the ancestor of cows and sheep. Alternatively, the B-sheep locus arrangement may be the result of a deletion of a four-gene set from the triplicated locus.      

Uncoupled expression of mRNAs for alpha 1(I) and alpha 2(I) procollagen chains in chemically transformed Syrian hamster fibroblasts

Syrian hamster embryo fibroblasts transformed by 4-nitroquinoline-1-oxide (NQT-SHE cells) failed to synthesize the pro-alpha 1(I) subunit of type I procollagen but continued to synthesize altered forms of the other subunit, pro-alpha 2(I) (Peterkofsky, B., and Prather, W. (1986) J. Biol. Chem. 261, 16818-16826). This was unusual, since synthesis of the two subunits generally is coordinately regulated. Present experiments using cell-free translation and hybridization of RNA from normal and transformed Syrian hamster fibroblasts with labeled pro-alpha 1(I) DNA probes show that mRNA for pro-alpha 1(I) is absent from the transformant. In contrast, dot-blot and Southern blot hybridizations of cellular DNAs with pro-alpha 1(I) DNA probes demonstrated that the transformed cells contained pro-alpha 1(I) gene sequences and that the gross structure of the gene was unchanged by transformation. mRNA for the other type I procollagen subunit, pro-alpha 2(I), was present in transformed cells and the major collagenous polypeptide translated from this RNA migrated like the normal pro-alpha 2 subunit during sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The translated procollagen chain was cleaved to an alpha 2(I)-sized collagen chain by pepsin at 4 degrees C. These studies provide a molecular basis for the observed collagen phenotype of NQT-SHE cells.     

A [4,5-3H]lysine:[14C]lysine dual-label method to measure lysine hydroxylation in collagen

A new method has been developed to determine the extent of lysine hydroxylation in newly synthesized collagen. This method relies on the measurement of changes in the ratio of [3H]lysine:[14C]lysine in collagenase digests, resulting from loss of tritium from the C-5 position of lysine during hydroxylation. Lysine hydroxylation can be measured in the presence of large amounts of noncollagen proteins, and simultaneous quantitation of the relative rates of collagen and non-collagen protein production is obtained. The dual-label lysine method is simple, rapid, and accurate. There was a very good correlation between this method and column chromatography procedures currently used for the measurement of lysine hydroxylation.