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Catherine Trumel - One of the best experts on this subject based on the ideXlab platform.
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The preanalytic phase in Veterinary Clinical Pathology.
Veterinary Clinical Pathology, 2015Co-Authors: Jean-pierre Braun, Anne Geffre, Didier Concordet, Nathalie Bourges-abella, Catherine TrumelAbstract:This article presents the general causes of preanalytic variability with a few examples showing specialists and practitioners that special and improved care should be given to this too often neglected phase. The preanalytic phase of Clinical Pathology includes all the steps from specimen collection to analysis. It is the phase where most laboratory errors occur in human, and probably also in Veterinary Clinical Pathology. Numerous causes may affect the validity of the results, including technical factors, such as the choice of anticoagulant, the blood vessel sampled, and the duration and conditions of specimen handling. While the latter factors can be defined, influence of biologic and physiologic factors such as feeding and fasting, stress, and biologic and endocrine rhythms can often not be controlled. Nevertheless, as many factors as possible should at least be documented. The importance of the preanalytic phase is often not given the necessary attention, although the validity of the results and consequent Clinical decision making and medical management of animal patients would likely be improved if the quality of specimens submitted to the laboratory was optimized.
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canine reference intervals for the sysmex xt 2000iv hematology analyzer
Veterinary Clinical Pathology, 2011Co-Authors: Nathalie Bourgesabella, Anne Geffre, Didier Concordet, J.p. Braun, Catherine TrumelAbstract:BACKGROUND: The laser-based Sysmex XT-2000iV hematology analyzer is increasingly used in Veterinary Clinical Pathology laboratories, and instrument-specific reference intervals for dogs are not available. OBJECTIVE: The purpose of this study was to establish canine hematologic reference intervals according to International Federation of Clinical Chemistry and Clinical and Laboratory Standards Institute guidelines using the Sysmex XT-2000iV hematology analyzer. METHODS: Blood samples from 132 healthy purebred dogs from France, selected to represent the most prevalent canine breeds in France, were analyzed. Blood smears were scored for platelet (PLT) aggregates. Reference intervals were established using the nonparametric method. PLT and RBC counts obtained by impedance and optical methods were compared. Effects of sex and age on reference intervals were determined. RESULTS: The correlation between impedance (I) and optical (O) measurements of RBC and PLT counts was excellent (Pearson r=.99 and .98, respectively); however, there were significant differences between the 2 methods (Student's paired t-test, P<.0001). Differences between sexes were not significant except for HCT, PLT-I, and PLT-O. WBC, lymphocyte, and neutrophil counts decreased significantly with age (ANOVA, P<.05). Median eosinophil counts were higher in Brittany Spaniels (1.87 × 10(9) /L), Rottweilers (1.41 × 10(9) /L), and German Shepherd dogs (1.38 × 10(9) /L) than in the overall population (0.9 × 10(9) /L). PLT aggregates were responsible for lower PLT counts by the impedance, but not the optical, method. CONCLUSION: Reference intervals for hematologic analytes and indices were determined under controlled preanalytical and analytical conditions for a well-characterized population of dogs according to international recommendations.
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canine reference intervals for the sysmex xt 2000iv hematology analyzer
Veterinary Clinical Pathology, 2011Co-Authors: Nathalie Bourgesabella, Anne Geffre, Didier Concordet, J.p. Braun, Catherine TrumelAbstract:BACKGROUND: The laser-based Sysmex XT-2000iV hematology analyzer is increasingly used in Veterinary Clinical Pathology laboratories, and instrument-specific reference intervals for dogs are not available. OBJECTIVE: The purpose of this study was to establish canine hematologic reference intervals according to International Federation of Clinical Chemistry and Clinical and Laboratory Standards Institute guidelines using the Sysmex XT-2000iV hematology analyzer. METHODS: Blood samples from 132 healthy purebred dogs from France, selected to represent the most prevalent canine breeds in France, were analyzed. Blood smears were scored for platelet (PLT) aggregates. Reference intervals were established using the nonparametric method. PLT and RBC counts obtained by impedance and optical methods were compared. Effects of sex and age on reference intervals were determined. RESULTS: The correlation between impedance (I) and optical (O) measurements of RBC and PLT counts was excellent (Pearson r=.99 and .98, respectively); however, there were significant differences between the 2 methods (Student's paired t-test, P<.0001). Differences between sexes were not significant except for HCT, PLT-I, and PLT-O. WBC, lymphocyte, and neutrophil counts decreased significantly with age (ANOVA, P<.05). Median eosinophil counts were higher in Brittany Spaniels (1.87 × 10(9) /L), Rottweilers (1.41 × 10(9) /L), and German Shepherd dogs (1.38 × 10(9) /L) than in the overall population (0.9 × 10(9) /L). PLT aggregates were responsible for lower PLT counts by the impedance, but not the optical, method. CONCLUSION: Reference intervals for hematologic analytes and indices were determined under controlled preanalytical and analytical conditions for a well-characterized population of dogs according to international recommendations.
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reference value advisor a new freeware set of macroinstructions to calculate reference intervals with microsoft excel
Veterinary Clinical Pathology, 2011Co-Authors: Anne Geffre, Didier Concordet, J.p. Braun, Catherine TrumelAbstract:International recommendations for determination of reference intervals have been recently updated, especially for small reference sample groups, and use of the robust method and Box-Cox transformation is now recommended. Unfortunately, these methods are not included in most software programs used for data analysis by Clinical laboratories. We have created a set of macroinstructions, named Reference Value Advisor, for use in Microsoft Excel to calculate reference limits applying different methods. For any series of data, Reference Value Advisor calculates reference limits (with 90% confidence intervals [CI]) using a nonparametric method when n≥40 and by parametric and robust methods from native and Box-Cox transformed values; tests normality of distributions using the Anderson-Darling test and outliers using Tukey and Dixon-Reed tests; displays the distribution of values in dot plots and histograms and constructs Q-Q plots for visual inspection of normality; and provides minimal guidelines in the form of comments based on international recommendations. The critical steps in determination of reference intervals are correct selection of as many reference individuals as possible and analysis of specimens in controlled preanalytical and analytical conditions. Computing tools cannot compensate for flaws in selection and size of the reference sample group and handling and analysis of samples. However, if those steps are performed properly, Reference Value Advisor, available as freeware at http://www.biostat.envt.fr/spip/spip.php?article63, permits rapid assessment and comparison of results calculated using different methods, including currently unavailable methods. This allows for selection of the most appropriate method, especially as the program provides the CI of limits. It should be useful in Veterinary Clinical Pathology when only small reference sample groups are available.
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comparison of plasma serum urea and creatinine concentrations in the dog a 5 year retrospective study in a commercial Veterinary Clinical Pathology laboratory
Journal of Veterinary Medicine Series A-physiology Pathology Clinical Medicine, 2004Co-Authors: C Medaille, Didier Concordet, Catherine Trumel, Francois Vergez, J.p. BraunAbstract:Serum/plasma urea (S/P-urea) and creatinine (S/P-creatinine) concentrations are routinely assayed as indirect markers of glomerular filtration rate and have been reported to be highly correlated. The aim of this study was to evaluate the relationship between the two analytes in a large number of unselected samples submitted to a commercial laboratory. In 4799 pairs of results, the correlation was high (r = 0.795) and was not affected by sex or age. The relationship between the two analytes was best represented by a second-order polynomial equation. However, the dispersion of results was large and there was a high percentage of cases (27.5%) where S/P-urea was increased and S/P-creatinine normal (< or =120 micromol/l for this laboratory), while there was a low percentage of cases where S/P-creatinine (1.6%) was increased and S/P-urea normal (< or =8 mmol/l for this laboratory). The discrepancy between increases in S/P-urea and S/P-creatinine might not only reflect a high incidence of non-renal factors of variation for S/P-urea but also an effect of the size or muscle mass of the dogs on the limit of decision for S/P-creatinine. In dogs with normal S/P-urea, there was a significant effect of the size on the 0.975 quantile of S/P-creatinine, ranging from 106 micromol/l in very small dogs to 133 micromol/l in large and very large dogs. This study shows that isolated increases in S/P-urea could be misleading for the diagnosis of renal diseases and that the reference intervals of S/P-creatinine should be re-evaluated according to breed or muscle mass of dogs.
J.p. Braun - One of the best experts on this subject based on the ideXlab platform.
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canine reference intervals for the sysmex xt 2000iv hematology analyzer
Veterinary Clinical Pathology, 2011Co-Authors: Nathalie Bourgesabella, Anne Geffre, Didier Concordet, J.p. Braun, Catherine TrumelAbstract:BACKGROUND: The laser-based Sysmex XT-2000iV hematology analyzer is increasingly used in Veterinary Clinical Pathology laboratories, and instrument-specific reference intervals for dogs are not available. OBJECTIVE: The purpose of this study was to establish canine hematologic reference intervals according to International Federation of Clinical Chemistry and Clinical and Laboratory Standards Institute guidelines using the Sysmex XT-2000iV hematology analyzer. METHODS: Blood samples from 132 healthy purebred dogs from France, selected to represent the most prevalent canine breeds in France, were analyzed. Blood smears were scored for platelet (PLT) aggregates. Reference intervals were established using the nonparametric method. PLT and RBC counts obtained by impedance and optical methods were compared. Effects of sex and age on reference intervals were determined. RESULTS: The correlation between impedance (I) and optical (O) measurements of RBC and PLT counts was excellent (Pearson r=.99 and .98, respectively); however, there were significant differences between the 2 methods (Student's paired t-test, P<.0001). Differences between sexes were not significant except for HCT, PLT-I, and PLT-O. WBC, lymphocyte, and neutrophil counts decreased significantly with age (ANOVA, P<.05). Median eosinophil counts were higher in Brittany Spaniels (1.87 × 10(9) /L), Rottweilers (1.41 × 10(9) /L), and German Shepherd dogs (1.38 × 10(9) /L) than in the overall population (0.9 × 10(9) /L). PLT aggregates were responsible for lower PLT counts by the impedance, but not the optical, method. CONCLUSION: Reference intervals for hematologic analytes and indices were determined under controlled preanalytical and analytical conditions for a well-characterized population of dogs according to international recommendations.
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canine reference intervals for the sysmex xt 2000iv hematology analyzer
Veterinary Clinical Pathology, 2011Co-Authors: Nathalie Bourgesabella, Anne Geffre, Didier Concordet, J.p. Braun, Catherine TrumelAbstract:BACKGROUND: The laser-based Sysmex XT-2000iV hematology analyzer is increasingly used in Veterinary Clinical Pathology laboratories, and instrument-specific reference intervals for dogs are not available. OBJECTIVE: The purpose of this study was to establish canine hematologic reference intervals according to International Federation of Clinical Chemistry and Clinical and Laboratory Standards Institute guidelines using the Sysmex XT-2000iV hematology analyzer. METHODS: Blood samples from 132 healthy purebred dogs from France, selected to represent the most prevalent canine breeds in France, were analyzed. Blood smears were scored for platelet (PLT) aggregates. Reference intervals were established using the nonparametric method. PLT and RBC counts obtained by impedance and optical methods were compared. Effects of sex and age on reference intervals were determined. RESULTS: The correlation between impedance (I) and optical (O) measurements of RBC and PLT counts was excellent (Pearson r=.99 and .98, respectively); however, there were significant differences between the 2 methods (Student's paired t-test, P<.0001). Differences between sexes were not significant except for HCT, PLT-I, and PLT-O. WBC, lymphocyte, and neutrophil counts decreased significantly with age (ANOVA, P<.05). Median eosinophil counts were higher in Brittany Spaniels (1.87 × 10(9) /L), Rottweilers (1.41 × 10(9) /L), and German Shepherd dogs (1.38 × 10(9) /L) than in the overall population (0.9 × 10(9) /L). PLT aggregates were responsible for lower PLT counts by the impedance, but not the optical, method. CONCLUSION: Reference intervals for hematologic analytes and indices were determined under controlled preanalytical and analytical conditions for a well-characterized population of dogs according to international recommendations.
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reference value advisor a new freeware set of macroinstructions to calculate reference intervals with microsoft excel
Veterinary Clinical Pathology, 2011Co-Authors: Anne Geffre, Didier Concordet, J.p. Braun, Catherine TrumelAbstract:International recommendations for determination of reference intervals have been recently updated, especially for small reference sample groups, and use of the robust method and Box-Cox transformation is now recommended. Unfortunately, these methods are not included in most software programs used for data analysis by Clinical laboratories. We have created a set of macroinstructions, named Reference Value Advisor, for use in Microsoft Excel to calculate reference limits applying different methods. For any series of data, Reference Value Advisor calculates reference limits (with 90% confidence intervals [CI]) using a nonparametric method when n≥40 and by parametric and robust methods from native and Box-Cox transformed values; tests normality of distributions using the Anderson-Darling test and outliers using Tukey and Dixon-Reed tests; displays the distribution of values in dot plots and histograms and constructs Q-Q plots for visual inspection of normality; and provides minimal guidelines in the form of comments based on international recommendations. The critical steps in determination of reference intervals are correct selection of as many reference individuals as possible and analysis of specimens in controlled preanalytical and analytical conditions. Computing tools cannot compensate for flaws in selection and size of the reference sample group and handling and analysis of samples. However, if those steps are performed properly, Reference Value Advisor, available as freeware at http://www.biostat.envt.fr/spip/spip.php?article63, permits rapid assessment and comparison of results calculated using different methods, including currently unavailable methods. This allows for selection of the most appropriate method, especially as the program provides the CI of limits. It should be useful in Veterinary Clinical Pathology when only small reference sample groups are available.
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teaching Veterinary Clinical Pathology to undergraduate students an integrated european project
Veterinary Clinical Pathology, 2007Co-Authors: Jose J Ceron, J.p. Braun, Tibor Gaal, Jeanmarie Godeau, C M Knottenbelt, Hugh A Larkin, George Lubas, Andreas Moritz, Kostas Papasouliotis, Satu SankariAbstract:Background: Veterinary Clinical Pathology is a relatively new and emerging discipline in Europe that has gained momentum with the recent establishment of a specialty college. In this situation, Veterinary faculties may face challenges in understanding and defining what Clinical Pathology is and how it can best be integrated into existing curricula. In addition, many schools in Europe may not yet have available a critical mass of suitably qualified faculty capable of teaching in all areas of clin-ical Pathology. Objective: The main purpose of this report is to describe the goals, procedures adopted, teaching material produced, and proposed future activities of a major European initiative designed to develop a Veterinary Clinical Pathology curriculum. Methods: Four working subgroups were formed to establish a list of course objectives and topics and prepare a series of lectures. These contents were reviewed and discussed several times at a series of general meetings. Results: An undergraduate course on Veterinary Clinical Pathology was designed with course objectives, a list of topics and a CD-ROM consisting of 24 lectures. Conclusions: The results of this project could be useful in the establishment or improvement of training programs in Veterinary Clinical Pathology at the undergraduate level in Europe and in other places around the world. The provision of teaching resources for faculty could help to instill in Veterinary students a strong understanding of the discipline and promote development of advanced training programs and career opportunities in Clinical Pathology in Europe. ©2007 American Society for Veterinary Clinical Pathology.
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establishment of the european college of Veterinary Clinical Pathology ecvcp and the current status of Veterinary Clinical Pathology in europe
Veterinary Clinical Pathology, 2007Co-Authors: Peter J Obrien, J.p. Braun, S. Paltrinieri, Kathleen P Freeman, C Fournelfleury, A P Bolliger, J Archer, H Tvedten, Zoe S Polizopoulou, A L JensenAbstract:After 5 years of development, the European College of Veterinary Clinical Pathology (ECVCP) was formally recognized and approved on July 4, 2007 by the European Board of Veterinary Specialisation (EBVS), the European regulatory body that oversees specialization in Veterinary medicine and which has approved 23 colleges. The objectives, committees, basis for membership, constitution, bylaws, information brochure and certifying examination of the ECVCP have remained unchanged during this time except as directed by EBVS. The ECVCP declared full functionality based on the following criteria: 1) a critical mass of 65 members: 15 original diplomates approved by the EBVS to establish the ECVCP, 37 de facto diplomates, 7 diplomates certified by examination, and 5 elected honorary members; 2) the development and certification of training programs, laboratories, and qualified supervisors for residents; currently there are 18 resident training programs in Europe; 3) administration of 3 annual board-certifying examinations thus far, with an overall pass rate of 70%; 4) European consensus criteria for assessing the continuing education of specialists every 5 years; 5) organization of 8 annual scientific congresses and a joint journal (with the American Society for Veterinary Clinical Pathology) for communication of scientific research and information; the College also maintains a website, a joint listserv, and a newsletter; 6) collaboration in training and continuing education with relevant colleges in medicine and Pathology; 7) development and strict adherence to a constitution and bylaws compliant with the EBVS; and 8) demonstration of compelling rationale, supporting data, and the support of members and other colleges for independence as a specialty college. Formal EBVS recognition of ECVCP as the regulatory body for the science and practice of Veterinary Clinical Pathology in Europe will facilitate growth and development of the discipline and compliance of academic, commercial diagnostic, and industry laboratories in Veterinary Clinical Pathology. Future needs are in developing sponsorship for resident positions, increasing employment opportunities, increasing compliance with laboratory, training, and continuing education standards, and advancing relevant science and technology.
Huiping Xie - One of the best experts on this subject based on the ideXlab platform.
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sex specific reference intervals of hematologic and biochemical analytes in sprague dawley rats using the nonparametric rank percentile method
PLOS ONE, 2017Co-Authors: Keliang Liu, Fangcheng Zhang, Yong Jiang, Jun Gao, Lida Liu, Zhongren Jiang, Minwu Jin, Huiping XieAbstract:Background Hematologic and biochemical analytes of Sprague-Dawley rats are commonly used to determine effects that were induced by treatment and to evaluate organ dysfunction in toxicological safety assessments, but reference intervals have not been well established for these analytes. Reference intervals as presently defined for these analytes in Sprague-Dawley rats have not used internationally recommended statistical method nor stratified by sex. Thus, we aimed to establish sex-specific reference intervals for hematologic and biochemical parameters in Sprague-Dawley rats according to Clinical and Laboratory Standards Institute C28-A3 and American Society for Veterinary Clinical Pathology guideline. Methods Hematology and biochemistry blood samples were collected from 500 healthy Sprague-Dawley rats (250 males and 250 females) in the control groups. We measured 24 hematologic analytes with the Sysmex XT-2100i analyzer, 9 biochemical analytes with the Olympus AU400 analyzer. We then determined statistically relevant sex partitions and calculated reference intervals, including corresponding 90% confidence intervals, using nonparametric rank percentile method. Results We observed that most hematologic and biochemical analytes of Sprague-Dawley rats were significantly influenced by sex. Males had higher hemoglobin, hematocrit, red blood cell count, red cell distribution width, mean corpuscular volume, mean corpuscular hemoglobin, white blood cell count, neutrophils, lymphocytes, monocytes, percentage of neutrophils, percentage of monocytes, alanine aminotransferase, aspartate aminotransferase, and triglycerides compared to females. Females had higher mean corpuscular hemoglobin concentration, plateletcrit, platelet count, eosinophils, percentage of lymphocytes, percentage of eosinophils, creatinine, glucose, total cholesterol and urea compared to males. Sex partition was required for most hematologic and biochemical analytes in Sprague-Dawley rats. We established sex-specific reference intervals, including corresponding 90% confidence intervals, for Sprague-Dawley rats. Conclusions Understanding the significant discrepancies in hematologic and biochemical analytes between male and female Sprague-Dawley rats provides important insight into physiological effects in test rats. Establishment of locally sex-specific reference intervals allows a more precise evaluation of animal quality and experimental results of Sprague-Dawley rats in our toxicology safety assessment.
Didier Concordet - One of the best experts on this subject based on the ideXlab platform.
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The preanalytic phase in Veterinary Clinical Pathology.
Veterinary Clinical Pathology, 2015Co-Authors: Jean-pierre Braun, Anne Geffre, Didier Concordet, Nathalie Bourges-abella, Catherine TrumelAbstract:This article presents the general causes of preanalytic variability with a few examples showing specialists and practitioners that special and improved care should be given to this too often neglected phase. The preanalytic phase of Clinical Pathology includes all the steps from specimen collection to analysis. It is the phase where most laboratory errors occur in human, and probably also in Veterinary Clinical Pathology. Numerous causes may affect the validity of the results, including technical factors, such as the choice of anticoagulant, the blood vessel sampled, and the duration and conditions of specimen handling. While the latter factors can be defined, influence of biologic and physiologic factors such as feeding and fasting, stress, and biologic and endocrine rhythms can often not be controlled. Nevertheless, as many factors as possible should at least be documented. The importance of the preanalytic phase is often not given the necessary attention, although the validity of the results and consequent Clinical decision making and medical management of animal patients would likely be improved if the quality of specimens submitted to the laboratory was optimized.
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canine reference intervals for the sysmex xt 2000iv hematology analyzer
Veterinary Clinical Pathology, 2011Co-Authors: Nathalie Bourgesabella, Anne Geffre, Didier Concordet, J.p. Braun, Catherine TrumelAbstract:BACKGROUND: The laser-based Sysmex XT-2000iV hematology analyzer is increasingly used in Veterinary Clinical Pathology laboratories, and instrument-specific reference intervals for dogs are not available. OBJECTIVE: The purpose of this study was to establish canine hematologic reference intervals according to International Federation of Clinical Chemistry and Clinical and Laboratory Standards Institute guidelines using the Sysmex XT-2000iV hematology analyzer. METHODS: Blood samples from 132 healthy purebred dogs from France, selected to represent the most prevalent canine breeds in France, were analyzed. Blood smears were scored for platelet (PLT) aggregates. Reference intervals were established using the nonparametric method. PLT and RBC counts obtained by impedance and optical methods were compared. Effects of sex and age on reference intervals were determined. RESULTS: The correlation between impedance (I) and optical (O) measurements of RBC and PLT counts was excellent (Pearson r=.99 and .98, respectively); however, there were significant differences between the 2 methods (Student's paired t-test, P<.0001). Differences between sexes were not significant except for HCT, PLT-I, and PLT-O. WBC, lymphocyte, and neutrophil counts decreased significantly with age (ANOVA, P<.05). Median eosinophil counts were higher in Brittany Spaniels (1.87 × 10(9) /L), Rottweilers (1.41 × 10(9) /L), and German Shepherd dogs (1.38 × 10(9) /L) than in the overall population (0.9 × 10(9) /L). PLT aggregates were responsible for lower PLT counts by the impedance, but not the optical, method. CONCLUSION: Reference intervals for hematologic analytes and indices were determined under controlled preanalytical and analytical conditions for a well-characterized population of dogs according to international recommendations.
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canine reference intervals for the sysmex xt 2000iv hematology analyzer
Veterinary Clinical Pathology, 2011Co-Authors: Nathalie Bourgesabella, Anne Geffre, Didier Concordet, J.p. Braun, Catherine TrumelAbstract:BACKGROUND: The laser-based Sysmex XT-2000iV hematology analyzer is increasingly used in Veterinary Clinical Pathology laboratories, and instrument-specific reference intervals for dogs are not available. OBJECTIVE: The purpose of this study was to establish canine hematologic reference intervals according to International Federation of Clinical Chemistry and Clinical and Laboratory Standards Institute guidelines using the Sysmex XT-2000iV hematology analyzer. METHODS: Blood samples from 132 healthy purebred dogs from France, selected to represent the most prevalent canine breeds in France, were analyzed. Blood smears were scored for platelet (PLT) aggregates. Reference intervals were established using the nonparametric method. PLT and RBC counts obtained by impedance and optical methods were compared. Effects of sex and age on reference intervals were determined. RESULTS: The correlation between impedance (I) and optical (O) measurements of RBC and PLT counts was excellent (Pearson r=.99 and .98, respectively); however, there were significant differences between the 2 methods (Student's paired t-test, P<.0001). Differences between sexes were not significant except for HCT, PLT-I, and PLT-O. WBC, lymphocyte, and neutrophil counts decreased significantly with age (ANOVA, P<.05). Median eosinophil counts were higher in Brittany Spaniels (1.87 × 10(9) /L), Rottweilers (1.41 × 10(9) /L), and German Shepherd dogs (1.38 × 10(9) /L) than in the overall population (0.9 × 10(9) /L). PLT aggregates were responsible for lower PLT counts by the impedance, but not the optical, method. CONCLUSION: Reference intervals for hematologic analytes and indices were determined under controlled preanalytical and analytical conditions for a well-characterized population of dogs according to international recommendations.
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reference value advisor a new freeware set of macroinstructions to calculate reference intervals with microsoft excel
Veterinary Clinical Pathology, 2011Co-Authors: Anne Geffre, Didier Concordet, J.p. Braun, Catherine TrumelAbstract:International recommendations for determination of reference intervals have been recently updated, especially for small reference sample groups, and use of the robust method and Box-Cox transformation is now recommended. Unfortunately, these methods are not included in most software programs used for data analysis by Clinical laboratories. We have created a set of macroinstructions, named Reference Value Advisor, for use in Microsoft Excel to calculate reference limits applying different methods. For any series of data, Reference Value Advisor calculates reference limits (with 90% confidence intervals [CI]) using a nonparametric method when n≥40 and by parametric and robust methods from native and Box-Cox transformed values; tests normality of distributions using the Anderson-Darling test and outliers using Tukey and Dixon-Reed tests; displays the distribution of values in dot plots and histograms and constructs Q-Q plots for visual inspection of normality; and provides minimal guidelines in the form of comments based on international recommendations. The critical steps in determination of reference intervals are correct selection of as many reference individuals as possible and analysis of specimens in controlled preanalytical and analytical conditions. Computing tools cannot compensate for flaws in selection and size of the reference sample group and handling and analysis of samples. However, if those steps are performed properly, Reference Value Advisor, available as freeware at http://www.biostat.envt.fr/spip/spip.php?article63, permits rapid assessment and comparison of results calculated using different methods, including currently unavailable methods. This allows for selection of the most appropriate method, especially as the program provides the CI of limits. It should be useful in Veterinary Clinical Pathology when only small reference sample groups are available.
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comparison of plasma serum urea and creatinine concentrations in the dog a 5 year retrospective study in a commercial Veterinary Clinical Pathology laboratory
Journal of Veterinary Medicine Series A-physiology Pathology Clinical Medicine, 2004Co-Authors: C Medaille, Didier Concordet, Catherine Trumel, Francois Vergez, J.p. BraunAbstract:Serum/plasma urea (S/P-urea) and creatinine (S/P-creatinine) concentrations are routinely assayed as indirect markers of glomerular filtration rate and have been reported to be highly correlated. The aim of this study was to evaluate the relationship between the two analytes in a large number of unselected samples submitted to a commercial laboratory. In 4799 pairs of results, the correlation was high (r = 0.795) and was not affected by sex or age. The relationship between the two analytes was best represented by a second-order polynomial equation. However, the dispersion of results was large and there was a high percentage of cases (27.5%) where S/P-urea was increased and S/P-creatinine normal (< or =120 micromol/l for this laboratory), while there was a low percentage of cases where S/P-creatinine (1.6%) was increased and S/P-urea normal (< or =8 mmol/l for this laboratory). The discrepancy between increases in S/P-urea and S/P-creatinine might not only reflect a high incidence of non-renal factors of variation for S/P-urea but also an effect of the size or muscle mass of the dogs on the limit of decision for S/P-creatinine. In dogs with normal S/P-urea, there was a significant effect of the size on the 0.975 quantile of S/P-creatinine, ranging from 106 micromol/l in very small dogs to 133 micromol/l in large and very large dogs. This study shows that isolated increases in S/P-urea could be misleading for the diagnosis of renal diseases and that the reference intervals of S/P-creatinine should be re-evaluated according to breed or muscle mass of dogs.
Anne Geffre - One of the best experts on this subject based on the ideXlab platform.
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The preanalytic phase in Veterinary Clinical Pathology.
Veterinary Clinical Pathology, 2015Co-Authors: Jean-pierre Braun, Anne Geffre, Didier Concordet, Nathalie Bourges-abella, Catherine TrumelAbstract:This article presents the general causes of preanalytic variability with a few examples showing specialists and practitioners that special and improved care should be given to this too often neglected phase. The preanalytic phase of Clinical Pathology includes all the steps from specimen collection to analysis. It is the phase where most laboratory errors occur in human, and probably also in Veterinary Clinical Pathology. Numerous causes may affect the validity of the results, including technical factors, such as the choice of anticoagulant, the blood vessel sampled, and the duration and conditions of specimen handling. While the latter factors can be defined, influence of biologic and physiologic factors such as feeding and fasting, stress, and biologic and endocrine rhythms can often not be controlled. Nevertheless, as many factors as possible should at least be documented. The importance of the preanalytic phase is often not given the necessary attention, although the validity of the results and consequent Clinical decision making and medical management of animal patients would likely be improved if the quality of specimens submitted to the laboratory was optimized.
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canine reference intervals for the sysmex xt 2000iv hematology analyzer
Veterinary Clinical Pathology, 2011Co-Authors: Nathalie Bourgesabella, Anne Geffre, Didier Concordet, J.p. Braun, Catherine TrumelAbstract:BACKGROUND: The laser-based Sysmex XT-2000iV hematology analyzer is increasingly used in Veterinary Clinical Pathology laboratories, and instrument-specific reference intervals for dogs are not available. OBJECTIVE: The purpose of this study was to establish canine hematologic reference intervals according to International Federation of Clinical Chemistry and Clinical and Laboratory Standards Institute guidelines using the Sysmex XT-2000iV hematology analyzer. METHODS: Blood samples from 132 healthy purebred dogs from France, selected to represent the most prevalent canine breeds in France, were analyzed. Blood smears were scored for platelet (PLT) aggregates. Reference intervals were established using the nonparametric method. PLT and RBC counts obtained by impedance and optical methods were compared. Effects of sex and age on reference intervals were determined. RESULTS: The correlation between impedance (I) and optical (O) measurements of RBC and PLT counts was excellent (Pearson r=.99 and .98, respectively); however, there were significant differences between the 2 methods (Student's paired t-test, P<.0001). Differences between sexes were not significant except for HCT, PLT-I, and PLT-O. WBC, lymphocyte, and neutrophil counts decreased significantly with age (ANOVA, P<.05). Median eosinophil counts were higher in Brittany Spaniels (1.87 × 10(9) /L), Rottweilers (1.41 × 10(9) /L), and German Shepherd dogs (1.38 × 10(9) /L) than in the overall population (0.9 × 10(9) /L). PLT aggregates were responsible for lower PLT counts by the impedance, but not the optical, method. CONCLUSION: Reference intervals for hematologic analytes and indices were determined under controlled preanalytical and analytical conditions for a well-characterized population of dogs according to international recommendations.
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canine reference intervals for the sysmex xt 2000iv hematology analyzer
Veterinary Clinical Pathology, 2011Co-Authors: Nathalie Bourgesabella, Anne Geffre, Didier Concordet, J.p. Braun, Catherine TrumelAbstract:BACKGROUND: The laser-based Sysmex XT-2000iV hematology analyzer is increasingly used in Veterinary Clinical Pathology laboratories, and instrument-specific reference intervals for dogs are not available. OBJECTIVE: The purpose of this study was to establish canine hematologic reference intervals according to International Federation of Clinical Chemistry and Clinical and Laboratory Standards Institute guidelines using the Sysmex XT-2000iV hematology analyzer. METHODS: Blood samples from 132 healthy purebred dogs from France, selected to represent the most prevalent canine breeds in France, were analyzed. Blood smears were scored for platelet (PLT) aggregates. Reference intervals were established using the nonparametric method. PLT and RBC counts obtained by impedance and optical methods were compared. Effects of sex and age on reference intervals were determined. RESULTS: The correlation between impedance (I) and optical (O) measurements of RBC and PLT counts was excellent (Pearson r=.99 and .98, respectively); however, there were significant differences between the 2 methods (Student's paired t-test, P<.0001). Differences between sexes were not significant except for HCT, PLT-I, and PLT-O. WBC, lymphocyte, and neutrophil counts decreased significantly with age (ANOVA, P<.05). Median eosinophil counts were higher in Brittany Spaniels (1.87 × 10(9) /L), Rottweilers (1.41 × 10(9) /L), and German Shepherd dogs (1.38 × 10(9) /L) than in the overall population (0.9 × 10(9) /L). PLT aggregates were responsible for lower PLT counts by the impedance, but not the optical, method. CONCLUSION: Reference intervals for hematologic analytes and indices were determined under controlled preanalytical and analytical conditions for a well-characterized population of dogs according to international recommendations.
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reference value advisor a new freeware set of macroinstructions to calculate reference intervals with microsoft excel
Veterinary Clinical Pathology, 2011Co-Authors: Anne Geffre, Didier Concordet, J.p. Braun, Catherine TrumelAbstract:International recommendations for determination of reference intervals have been recently updated, especially for small reference sample groups, and use of the robust method and Box-Cox transformation is now recommended. Unfortunately, these methods are not included in most software programs used for data analysis by Clinical laboratories. We have created a set of macroinstructions, named Reference Value Advisor, for use in Microsoft Excel to calculate reference limits applying different methods. For any series of data, Reference Value Advisor calculates reference limits (with 90% confidence intervals [CI]) using a nonparametric method when n≥40 and by parametric and robust methods from native and Box-Cox transformed values; tests normality of distributions using the Anderson-Darling test and outliers using Tukey and Dixon-Reed tests; displays the distribution of values in dot plots and histograms and constructs Q-Q plots for visual inspection of normality; and provides minimal guidelines in the form of comments based on international recommendations. The critical steps in determination of reference intervals are correct selection of as many reference individuals as possible and analysis of specimens in controlled preanalytical and analytical conditions. Computing tools cannot compensate for flaws in selection and size of the reference sample group and handling and analysis of samples. However, if those steps are performed properly, Reference Value Advisor, available as freeware at http://www.biostat.envt.fr/spip/spip.php?article63, permits rapid assessment and comparison of results calculated using different methods, including currently unavailable methods. This allows for selection of the most appropriate method, especially as the program provides the CI of limits. It should be useful in Veterinary Clinical Pathology when only small reference sample groups are available.
