Studies comparing a new method with an established method, to assess whether the new measurements are comparable with existing ones, are frequently conducted in clinical pathology laboratories. Assessment usually involves statistical analysis of paired results from the 2 methods to objectively investigate sources of analytical error (total, random, and systematic). In this review article, the types of errors that can be assessed in performing this task are described, and a general protocol for comparison of quantitative methods is recommended. The typical protocol has 9 steps: 1) state the purpose of the experiment, 2) establish a theoretical basis for the method comparison experiment, 3) become familiar with the new method, 4) obtain estimates of random error for both methods, 5) estimate the number of samples to be included in the method comparison experiment, 6) define acceptable difference between the 2 methods, 7) measure the patient samples, 8) analyze the data and 9) judge acceptability. The protocol includes the essential investigations and decisions needed to objectively assess the overall analytical performance of a new method compared to a reference or established method. The choice of statistical methods and recommendations of decision criteria within the stages are discussed. Use of the protocol for decision-making is exemplified by the comparison of 2 methods for measuring alanine aminotransferase activity in serum from dogs. Finally, a protocol for comparing simpler semiquantitative methods with established methods that measure on a continuous scale is suggested. (Vet Clin Pathol. 2006;35:276-286)

Telomeres are specialized DNA-protein complexes that cap the ends of linear chromosomes and protect them from degradation and end to end fusions. Due to the ''end replication problem,'' telomeres undergo progressive shortening with each cell division. Shortening to a critical length triggers cell growth arrest and cellular senescence pathways, thereby acting as a means for regulating cellular lifespan. The enzyme telomerase is a ribonucleoprotein complex that adds nucleotides to the 3 end of telomeres, thus maintaining telomere length and bypassing cellular senescence. Telomerase activity is absent from most adult so-matic cells, with expression limited to activated lymphocytes, germ cells and stem cells. In contrast, up to 90% of cancers possess telomerase activity, suggesting that telomerase activity within cells represents the acquisition of an immortal phenotype. Telomerase is composed of an RNA component, TR, a reverse transcriptase catalytic subunit, TERT, and associated proteins. Whilst TR is present in some somatic cells, the finding that TERT is only present in those cells possessing telomerase activity and that telomerase activity can be induced in telomerase-negative cells through the addition of TERT alone suggests that tel-omerase activity is regulated primarily through regulation of the TERT catalytic subunit. Our group has recently sequenced and characterized the canine TERT gene and identified approximately 5Kb of the upstream regulatory region. The purpose of this study was to sequence the promoter of the canine TERT gene and to identify the core region of the promoter essential for activity. PCR amplification and cloning of selected regions of the canine TERT promoter followed by luciferase assays revealed that core promoter activity is contained within a region extending approximately 300bp upstream of the ATG codon. Transient transfections in telomerase-positive canine cell lines and telo-merase negative fibroblasts showed that the promoter is only active in telomerase positive cell lines. Sequence analysis demonstrated that the 5 regulatory region is GC-rich and contains no TATA or CAAT box, similar to the human TERT promoter. Motif searches revealed the presence of multiple transcription factor binding sites common to both the human and canine TERT promoters, including a single E-box, Sp1, AP1, MZF-2 and ER/Sp1 binding sites. These findings suggest that the canine TERT gene shares similar transcriptional control to the human TERT gene. Identifying the core promoter necessary for activity will enable the development of telomerase-targeted therapies in canine cancer patients similar to those investigated in human patients. 401 2005 ACVIM Abstracts acterization of the Mik-red cell antigen. Screening feline blood donors and patients for the presence of this apparently common red cell antigen and corresponding alloantibody may prove necessary in clinical practice. Thromboelastography (TEG) enables global assessment of hemostatic function in whole blood with evaluation of both plasma and cellular...

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Postoperative measurements of SAA, fibrinogen, and iron may be useful for comparing surgical trauma associated with new and established surgical techniques. Moreover, knowledge of the normal postoperative acute phase response is essential, if acute phase reactants are to be used for monitoring occurrence of postoperative infections.

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Canine serum CRP concentration can be measured reliably using the commercially available TIA designed for human CRP.

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