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Asger Lundorff Jensen

Publications and source records attributed to Asger Lundorff Jensen.

5 recordsLinked to original sources
PubMed2003

Evaluation of a commercially available human C-reactive protein (CRP) turbidometric immunoassay for determination of canine serum CRP concentration.

BACKGROUND: Serum C-reactive protein (CRP) is an acute phase marker in dogs that is useful for the diagnosis and monitoring of inflammatory disease. Rapid, reliable, and automated assays are preferable for routine evaluation of canine serum CRP concentration. OBJECTIVE: The aim of this study was to evaluate whether canine serum CRP concentration could be measured reliably using an automated turbidometric immunoassay (TIA) designed for use with human serum. METHODS: A commercially available TIA for human serum CRP (Bayer, Newbury, UK) was used to measure canine serum CRP concentration. Cross-reactivity of antigen was evaluated by the Ouchterlony procedure. Intra- and interassay imprecision was investigated by multiple measurements on canine serum samples and serum pools, respectively. Assay inaccuracy was investigated by linearity under dilution and comparison of methodologies (canine CRP ELISA, Tridelta Development Ltd, Kildare, UK). Then the assay was applied to serum samples from 14 clinically healthy dogs, 11 dogs with neoplasia, 13 with infections, 8 with endocrine or metabolic diseases, and 10 with miscellaneous diseases. RESULTS: Cross-reactivity between canine serum CRP and the anti-human CRP antibody was found. Intra- and interassay imprecision ranged from 5.2% to 10.8% and 3.0% to 10.2%, respectively. Serum CRP concentration was measured in a linear and proportional manner. There was no significant disagreement and there was linear correlation of the results in the comparison of methodologies, except for a slight proportional discrepancy at low CRP concentrations (<10 microg/mL). Dogs with infections had a significantly higher concentration of serum CRP than did all other dogs, and dogs with neoplasia had a significantly higher concentration of serum CRP than did clinically healthy dogs. CONCLUSIONS: Canine serum CRP concentration can be measured reliably using the commercially available TIA designed for human CRP.

Animals↗
PubMed1999

Biological variation of canine serum thyrotropin (TSH) concentration.

The aim of the present study was to estimate the between-dog, within-dog and analytical components of variance for serum thyrotropin (TSH) in healthy dogs, and to use these components of variance to 1) estimate the critical difference for significance between serial results; 2) assess the utility of the conventional population-based reference interval; 3) set a desirable performance standard for analytical imprecision; and 4) estimate the number of samples required for determination of the true mean value for an individual dog. Using the Immulite test system, TSH was measured in serum samples collected weekly for five weeks from eight clinically healthy dogs. Results were subjected to nested analysis of variance. Between-dog variation was 43.6%, within-dog variation was 13.6%, analytical variation was 8.8%, the one-sided critical difference was 37.8%, the index of individuality was 0.4, the maximum allowable analytical imprecision was 6.8%, and the number of samples required to determine the true mean value in a single dog was 40. In practical terms, the present study indicated that the analytical imprecision of canine serum TSH measurement should be < 7%, and that comparing a single serum TSH measurement from an individual dog to the conventional population-based reference range may be too insensitive to detect small but important changes in the serum TSH level of that particular dog. In addition, when treating a hypothyroid dog, serum TSH, measured on a weekly basis, should decrease by at least one-third before any effect of exogenous thyroxine supplementation can be said to have influenced the serum TSH level.

Journal Article↗
PubMed1999

Evaluation of analytical performance assisted by total error criteria of a commercial enzyme immunometric assay for canine serum thyrotropin.

The aim of the present study was to evaluate analytical performance using total error criteria of a commercial enzyme immunometric assay for the determination of endogenous canine thyrotropin (TSH). The allowable total error for this assay (22.6%) was estimated using previously reported data on biological variation. Inaccuracy and imprecision of the assay (0% and 5.7% for the low control material; 6.8% and 3.0% for the high control material) were estimated by measuring the same lot of control material for 21 consecutive weeks, during which time the assay was considered stable and in control. Analytical performance was assessed using a MEDx chart, a graphical tool for comparing inaccuracy and imprecision, with an analytical quality requirement stated in the form of allowable total error. The results of the present study showed that the canine TSH assay had good to excellent analytical performance.

Journal Article↗
PubMed1996

Evaluation of thyroid function in dogs by hormone analysis: effects of data on biological variation.

The purpose of the present study was to investigate commercially available ELISA methods designed for the determination of total and unbound thyroxine (TT(4) and FT(4)) and total triiodothyronine (TT(3)) in human serum for their usefulness in evaluating thyroid function in dogs when data describing the biological variation were included in the characterization of the assays. The TT(3) analysis was evaluated with intraassay coefficients of variation (CV%) ranging between 12% and 20%, and interassay CV% ranging between 5 and 17% at naturally occurring TT(3) concentrations. At concentrations around the limit of detection (0.27 nmol/l) CV% was considerably higher (99%). The analysis exhibited a satisfying accuracy since the recovery of added TT(3) was not different from unity and since parallelism between the dose-response curve and plasma dilutions could be verified. Determination of TT(4), TT(3) and FT(4) in eight normal dogs during 4 weeks resulted in a significant variation between dogs and between weeks in the individual animals (p < 0.01 in all cases). From the inter- and intraindividual CV%, quality goals for the maximally allowed analytical variation could be computed to be 8.4, 10.0, and 10.1% for individual testing of animals, and 12.0, 12.9, and 15.8% for screening for diseased animals in healthy populations for TT(4), TT(3) and FT(4), respectively. A comparison between quality goals derived from the inter- and intraindividual CV% and the measured analytical CV% (4.0, 17.3, and 6.7%, respectively) evidenced that TT(4) and FT(4) analyses fulfilled the requirements for analytical precision, whereas the TT(3) analysis could not be accepted as an effective tool for the evaluation of thyroid function in dogs due to too high analytical variation.

Journal Article↗