Transportation and handling of blood samples prior to ammonia measurement in the real life of a large university hospital.

Background: Hyperammonemia is neurotoxic and as such can be a medical emergency. Preanalytical factors greatly influence the blood ammonia concentration results.

Aims And Methods: Ammonia concentrations measured in the real life setting of a large hospital after pneumatic transport of blood samples and various time periods before centrifugation were compared to those based on the indications of the reagent manufacturer.

High-Sensitivity Cardiac Troponin T: a Preanalytical Evaluation.

Background: Little is known about the effects of preanalytical conditions on high-sensitivity cardiac troponin T (hs-cTnT) concentrations.

Methods: Variations of hs-cTnT concentrations were evaluated under the following preanalytical conditions: 1) serum vs. lithium-heparin (Li-Hep) plasma, with or without separator gel; 2) centrifugation time (15-minutes vs.

Stability of Routine Biochemical Analytes in Whole Blood and Plasma From Lithium Heparin Gel Tubes During 6-hr Storage.

Background: The stability of biochemical analytes has already been investigated, but results strongly differ depending on parameters, methodologies, and sample storage times. We investigated the stability for many biochemical parameters after different storage times of both whole blood and plasma, in order to define acceptable pre- and postcentrifugation delays in hospital laboratories.

Methods: Twenty-four analytes were measured (Modular® Roche analyzer) in plasma obtained from blood collected into lithium heparin gel tubes, after 2-6 hr of storage at room temperature either before (n = 28: stability in whole blood) or after (n = 21: stability in plasma) centrifugation.

Hemolysis indexes for biochemical tests and immunoassays on Roche analyzers: determination of allowable interference limits according to different calculation methods.

Objectives: To determine the hemolysis interference on biochemical tests and immunoassays performed on Roche Diagnostics analyzers, according to different maximum allowable limits.

Design And Methods: Heparinized plasma and serum pools, free of interferences, were overloaded by increasing amounts of a hemoglobin-titrated hemolysate. This interference was evaluated for 45 analytes using Modular(®) and Cobas(®) analyzers.

Oxidative stress implication after prolonged storage donor heart with blood versus crystalloid cardioplegia and reperfusion versus static storage.

Several factors are known to limit cardiac transplantation, such as number of donors, quality of cardiac graft preservation, and ischemia-reperfusion injury. Some mechanisms of reperfusion injury are now recognized; they include oxygen free radical (OFR), white blood cells activation, changes in calcium influx, alteration of microvascular blood flow, and sympathetic activation. The goal of this study was to assess the effects of two types of cardioplegia with long-term storage, either static or continuous perfusion, in 30 isolated sheep hearts as a model for heart transplantation.

Oxidative stress implication in a new ex-vivo cardiac concordant xenotransplantation model.

Xenotransplantation (XT) reveals a growing interest for the treatment of cardiomyopathy. The major barrier is an acute vascular rejection due to an acute humoral rejection. This pathogenesis is a difficult issue and in order to elaborate means for its prevention, we analysed the implication of oxidative stress (OS) on hearts from mini-pigs followed by reperfusion with either autologous or human blood in an attempt to simulate xenotransplantation.