The Specificity of Biochemical Markers of Cardiac Damage: a Problem Solved

Abstract

The UF-100 analyser is a fully automated instrument that stains the DNA and the membranes of the formed elements in native urine. The sample then passes as a laminar flow through a laser beam and light scattering, fluorescence and impedance are measured. The main purpose of the present work was to assess the analytical performance and the accuracy of the measurements of the UF-100 analyser. No carryover was observed, while the linearity was higher then the upper limit (40000 total particles microl(-1)) suggested by the manufacturer. The within-run imprecision was low, ranging from 17.7 % to 2.4% and was up to threefold better than manual microscopy. Comparison of results obtained by sediment microscopy (performed according to National Committee for Clinical Laboratory Standards (NCCLS) recommendations) and by the UF-100 analyser showed a linear correlation with r = 0.833 for erythrocytes, r = 0.934 for leukocytes, r = 0.880 for epithelial cells and r = 0.40 for casts. To evaluate the reliability of the UF-100 analyser in detecting bacteria we compared the results with the microbial culture (n = 608). Using a cut-off value of bacterial count above 1800 degrees l(-1) and at leukocyte count above 45 microl(-1), the analyser detected positive cultures with a sensitivity of 87 % and a specificity of 80 %. In conclusion, the UF-100 analyser can improve the work flow, increasing the output of urinalysis by reducing the number of specimens submitted for microscopy. Also the method provides reliable information for the identification of urinary tract inflammation and bacterial infection.

Biochemical Measurement of Muscle Injury Created by Lumbar Surgery

“…20 There is an extensive literature on application of biochemistry for cardiac muscle injury and there has been a strong clinical impact. [21][22][23][24][25][26][27] A large literature also exists in exercise physiology on changes in circulating levels of all of these tissue proteins in response to heavy exercise. 16,17,[28][29][30][31][32] That line of research may provide a model of muscle injury related to exertion.…”

Évaluation des pratiques professionnelles (EPP) : prise en charge (PEC) de la douleur thoracique aiguë aux urgences

“…• de prouver que l'ensemble des praticiens respecte bien la recommandation de ne prescrire que la seule troponine dans la suspicion de SCA (score à 100 %), ce qui était le premier point à vérifier lors de cette étude [6,12,13] ; • de monter qu'en cas de FRCV chez un patient l'ECG est systématiquement réalisé et correctement interprété (score à 100 %) ; • de démonter que les délais de réponse pour le dosage de TnT par le laboratoire (54 minutes) sont en moyenne conforment aux recommandations de la HAS qui sont de délais inférieur à une heure [1].…”

“…Il semble, plus particulièrement pour la TnT que ce test soit utilisé aussi comme test d'exclusion de maladie coronarienne devant des situations cliniques peu claires (souvent des patients âgées, polypathologiques et difficilement interrogeables) peut être à cause de sa grande cardio-spécificité (100 % en cas de lésion cardiaque quelle qu'en soit la cause : ischémie, souffrance ou lésion traumatique) [9,[12][13][14]. Cependant cette pratique est sans preuves évidentes de légitimité dans cette indication.…”

“…3). La connaissance du seuil de décision de la TnT est partagée entre 95 et 99 e percentile [9][10][11][12][13][14]. Cette notion ne semble pas majoritairement assimilée (Fig.…”

Cardiac Troponins in Suspected Acute Coronary Syndrome

“…The cardiac troponins (cTn) are sensitive [1]and specific [2, 3]markers of myocardial necrosis. Many clinical trials have addressed the role of cTn measurement in acute coronary syndrome without ST elevation (ACS) [4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25].…”