Performance evaluation of the high sensitive troponin I assay on the Atellica IM analyser

The Fourth Universal Definition of Myocardial Infarction Global Taskforce recommends the use of high sensitive troponin (hs-Tn) assays in the diagnosis of acute myocardial infarction. We evaluated the analytical performance of the Atellica IM High-sensitivity Troponin I Assay (hs-TnI) (Siemens Healthcare Diagnostics Inc., Tarrytown, USA) and compared its performance to other hs-TnI assays (Siemens Advia Centaur, Dimension Vista, Dimension EXL, and Abbott Architect (Wiesbaden, Germany)) at one or more sites across Europe. Precision, detection limit, linearity, method comparison, and interference studies were performed according to Clinical and Laboratory Standards Institute protocols. Values in 40 healthy individuals were compared to the manufacturer’s cut-offs. Sample turnaround time (TAT) was examined. Imprecision repeatability CVs were 1.1–4.7% and within-lab imprecision were 1.8–7.6% (10.0–25,000 ng/L). The limit of blank (LoB), detection (LoD), and quantitation (LoQ) aligned with the manufacturer’s values of 0.5 ng/L, 1.6 ng/L, and 2.5 ng/L, respectively. Passing-Bablok regression demonstrated good correlations between Atellica IM analyser with other systems; some minor deviations were observed. All results in healthy volunteers fell below the 99th percentile URL, and greater than 50% of each sex demonstrated values above the LoD. No interference was observed for biotin (≤ 1500 µg/L), but a slight bias at 5.0 g/L haemoglobin and 50 ng/L Tn was observed. TAT from was fast (mean time = 10.9 minutes) and reproducible (6%CV). Real-world analytical and TAT performance of the hs-TnI assay on the Atellica IM analyser make this assay fit for routine use in clinical laboratories

Cerium oxide nanoparticles display antilipogenic effect in rats with non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide, ranging from steatosis to non-alcoholic steatohepatitis (NASH). Recently, cerium oxide nanoparticles (CeO₂NPs) have emerged as a new antioxidant agent with hepatoprotective properties in experimental liver disease. The aim of the current investigation was to elucidate whether CeO₂NPs display beneficial effects in an experimental model of NAFLD.Therefore, fifteen Wistar rats were subjected to a methionine and choline deficient diet (MCDD) for 6 weeks and intravenously treated with CeO₂NPs or vehicle during the weeks three and four of the diet. The effect of CeO₂NPs on serum biochemistry, hepatic steatosis, inflammation, fatty acid content and expression of reactive oxygen species (ROS) and lipid metabolism related genes was assessed. MCDD fed rats showed increased inflammation, enhanced hepatic lipid accumulation of both saturated and unsaturated fatty acids (FAs) and overexpression of genes related to fatty liver and ROS metabolism. Treatment with CeONPs was able to reduce the size and content of hepatocyte lipid droplets, the hepatic concentration of triglyceride- and cholesterol ester-derived FAs and the expression of several genes involved in cytokine, adipokine and chemokine signaling pathways. These findings suggest that CeO₂NPs could be of beneficial value in NAFLD

Estudio de la incertidumbre asociada a los resultados obtenidos con ciertos procedimientos de medida bioquímico-clínicos

La incertidumbre (u) es un parámetro asociado al resultado de una medición que caracteriza la dispersión de los valores que razonablemente pueden atribuirse a una magnitud particular. Esta dispersión de valores es debido a la existencia de errores aleatorios producidos en las distintas fases en las que se divide el proceso de medida y que están originados por diversos factores de variabilidad.Todo proceso de evaluación de la incertidumbre consta de cuatro pasos: especificación de la magnitud, identificación de los componentes de incertidumbre, cuantificación de estos componentes de incertidumbre y el cálculo de la incertidumbre combinada (uc).El objetivo de esta tesis ha sido el cálculo de la incertidumbre producida durante la fase premetrológica (PM), la fase metrológica (M), en la valoración de los calibradores (Cal) y por las magnitudes influyentes (Inf). Este estudio se ha realizado en un conjunto de magnitudes que se encuentran entre las más solicitadas en el laboratorio de bioquímica clínica. El modelo de función usado en todos los casos ha sido y = CM + Cte PM + Cte Cal +Cte Int . En esta ecuación, CM representa el resultado de medida observado, y los valores de las diversas Cte son términos de corrección asociados con la fase premetrológica (CtePM), la valoración de los calibradores (CteCal), y el efecto de las magnitudes interferentes (CteInt). Si se asume que los resultados de las mediciones han sido corregidos de todas los posibles errores sistemáticos significativos, estas constantes son igual a 0. Sin embargo las incertidumbres asociadas a cada uno de estos términos difiere en general de 0 y por tanto contribuirá a la incertidumbre de y. De manera que teniendo en cuenta este modelo de función, la función de la incertidumbre combinada para estos procedimientos ha sido uc = ¡Ì sM 2+ sPM 2 + sCal2 + sInt2En el caso de la incertidumbre premetrológica se ha estudiado el efecto de le extracción a cargo de distintos flebotomistas, la extracción en distintos brazos y el efecto del tratamiento premetrológico de la muestra diferido en el tiempo. En el caso de incertidumbre metrológica la imprecisión interdiaria es un importante factor de esta incertidumbre. Con respecto a la imprecisión interdiaria, el fenómeno denominado heterocedasticidad debería ser tomado en cuenta. La variancia metrológica interserial depende del valor del mensurando. Para calcular la relación matemática entre la variancia y el valor del mensurando, se ha usado el programa desarrollado por Sadler y colaboradores Variance Function Program Versión 2. Para cada magnitud, la variancia ha sido estimada a partir de los resultados de 20 replicados, realizados en 20 días de trabajo correlativos en siete mezclas de suero cuyos valores comprenden el intervalo más amplio posible del intervalo de medida del procedimiento. Se ha estudiado además la intercambiabilidad de la imprecisión interdiaria entre materiales de control y mezclas de suero. En el estudio de la incertidumbre de las magnitudes influyentes se ha estudiado el efecto de la concentración de bilirrubina, la concentración de hemoglobina y la concentración de triglicérido.Resultados y conclusión La incertidumbre premetrológica generalmente no es despreciable. No existe siempre intercambiabilidad en la imprecisión entre materiales de control y muestras de suero. La variancia de la imprecisión interdiaria es heteroced¨¢stica en todos los procedimientos estudiados mientras que el tipo de relaci¨®n entre el coeficiente de variación y la concentración del constituyente varía dependiendo del procedimiento.Las interferencias potenciales conocidas son un componente notable de la incertidumbre.Uncertainty (u) of measurement is a parameter associated with the result of a measurement that characterises the dispersion of the values that could reasonably be attributed to the measurand. This dispersion of values is due to the random errors produced in the different parts of the procedure of measurement, originating from different factors of variability.The following steps summarise the tasks that need to be performed in order to obtain an estimate of the uncertainty associated with a measurement: specification of the quantity, identification of uncertainty components, quantification of uncertainty components and calculation of total uncertainty (uc).The aim of this work has been to estimate the uncertainty generated in the premetrological part (PM), in the metrological part (M), in the process of assignation of values to the calibrators (Cal) and that originated by the interference quantities(Int). This work has been carried out on those quantities most frequently measured in a clinical chemistry laboratory. If y is the result of any measurement, its relationship with the values of the different parts of the whole measurement procedure can be expressed as follows: y = CM + Ct PM + Ct Cal +Ct Inf y. In this equation, CM represents the observed measurement result, and the different Ct values are correction terms associated with the premetrological phase (Ct PM), the traceability chain (CtCal), and the effects of the interference quantities (Ct Int). It is assumed that correction for all significant systematic errors has been applied to all results of a measurement. Therefore, these constants (Ct) should be equal to 0. However, the associated uncertainties will, in general, differ from 0 and will, therefore, contribute to the uncertainty of y. Considering this model function, the total uncertainty can be expressed as follows: uc = ¡Ì sM 2+ sPM 2 + sCal2 + sInt2For the premetrological phase, the following contributing factors have been considered: differences in sample taking procedures between phlebotomits, the extractions in different arms and the day-to-day differences in sample pretreatment.For the metrological phase, day-to-day imprecision is an important contributing factor to the uncertainty. With regards to day-to-day imprecision, the phenomenon called heterocedasticity should be taken into account. Day-to-day metrological variance depends on the value of the measurand. In order to calculate the mathematical relationship between variance and measurement value, the Variance Function Program Version 2 developed by Sadler et al has been applied. For each individual quantity, variances have been estimated from 20 replicated results, taken once daily in aliquots of seven serum pools with values representing the entire measurement range. The interchangeability of estimates of day-to-day imprecision between commercial control materials and serum pools has also been studied. The effect of bilirrubin, heamoglobin and triglyceride has been evaluated in the study of interfering quantities. Results and conclusionThe premetrological uncertainty is not, generally, negligible. Interchangeability is not always demonstrated between commercial control materials and serum pools.Variance of day-to-day imprecision is heterocedastic for every procedure studied. The relationship between the coefficient of variation and the measurand value is not the same across all different procedures.The known interferences are an important component of the uncertainty

Cerium oxide nanoparticles display antilipogenic effect in rats with non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide, ranging from steatosis to non-alcoholic steatohepatitis (NASH). Recently, cerium oxide nanoparticles (CeO₂NPs) have emerged as a new antioxidant agent with hepatoprotective properties in experimental liver disease. The aim of the current investigation was to elucidate whether CeO₂NPs display beneficial effects in an experimental model of NAFLD.Therefore, fifteen Wistar rats were subjected to a methionine and choline deficient diet (MCDD) for 6 weeks and intravenously treated with CeO₂NPs or vehicle during the weeks three and four of the diet. The effect of CeO₂NPs on serum biochemistry, hepatic steatosis, inflammation, fatty acid content and expression of reactive oxygen species (ROS) and lipid metabolism related genes was assessed. MCDD fed rats showed increased inflammation, enhanced hepatic lipid accumulation of both saturated and unsaturated fatty acids (FAs) and overexpression of genes related to fatty liver and ROS metabolism. Treatment with CeONPs was able to reduce the size and content of hepatocyte lipid droplets, the hepatic concentration of triglyceride- and cholesterol ester-derived FAs and the expression of several genes involved in cytokine, adipokine and chemokine signaling pathways. These findings suggest that CeO₂NPs could be of beneficial value in NAFLD