1,721,027 research outputs found
National survey on the pre-analytical variability in a representative cohort of Italian laboratories
No full textHarmonization of contemporary-sensitive troponin I immunoassays: calibration may only be a part of the problem.
No full textBackground. Standardization of cardiac troponin I (cTnI) immunoassays remains an unmet target and comparability of current commercial methods is modest. We hence planned a study to investigate whether realignment of cTnI data by means of reference samples may improve comparability among different cTnI methods.Methods. Seventy six routine serum samples were collected in one center, centrifuged, aliquoted and shipped to participant centers, along with four additional reference serum samples with defined cTnI concentrations. The centers performed blind measurement of thawed aliquots and reference samples using four widespread contemporary-sensitive immunoassays (Ortho-Clinical Diagnostics Vitros cTnI ES, Beckman Coulter DXI 800 AccuTnI, Siemens Healthcare Diagnostics Dimension Vista cTnI and Abbott Diagnostics Architect STAT cTnI). Test results were analyzed as provided by the centers, and also after data alignment by means of polynomial regression parameters obtained on reference sera.Results. In five out of six circumstances the Deming fit improved after harmonization. The median inter-assay variability increased from 22% to 53% after alignment with polynomial regression parameters. A reduction of bias was observed in half of the circumstances, whereas in the remaining the bias increased. After harmonization, the agreement at diagnostic thresholds decreased in 4 out of 6 circumstances.Conclusions. These results show that calibration may only be a minor contributor of inter-assay variability of commercial cTnI immunoassays. Harmonization by means of reference sera was also counterproductive for improving methods agreement around a diagnostic threshold
Reference range of hemolysis index in serum and lithium-heparin plasma measured with two analytical platforms in a population of unselected outpatients.
No full textBACKGROUND: The hemolysis index (HI) is now available in several laboratory analyzers, but doubts remain about the thresholds for suppressing test results, the degree of standardization among different instrumentations and the use of different reference ranges in different biological matrices. This study was hence planned to establish the reference ranges of HI in serum and lithium-heparin plasma in a population of unselected outpatients, using two analytical platforms.
MATERIALS AND METHODS: We analyzed the HI in serum and lithium-heparin samples collected from 135 unselected outpatients, and we also defined the relative reference ranges according to Clinical and Laboratory Standards Institute (CLSI) recommendations. Samples were collected in the morning by expert nurses, using straight needle venipuncture. The HI in serum and lithium-heparin plasma was assessed with Roche Cobas c501 and Siemens Dimension Vista 1500.
RESULTS: The median concentration of cell-free hemoglobin was significantly higher in serum than in lithium-heparin plasma when measured with Cobas c501, but not with Dimension Vista 1500. After categorizing values according to cell-free hemoglobin thresholds, the agreement between instruments was 0.75 (p<0.01) for serum and 0.95 (p<0.01) for lithium-heparin plasma. The upper limits calculated according to CLSI document C28-A3 were 0.22g/L for Roche Cobas c501 and 0.25g/L for Siemens Dimension Vista 1500 in serum, whereas they were 0.13g/L for Cobas c501 and 0.10g/L for Dimension Vista 1500 in lithium-heparin plasma.
CONCLUSIONS: According to our data, different thresholds of cell-free hemoglobin should be used between serum and lithium-heparin plasma for monitoring phlebotomy practice
Overview on self-monitoring of blood glucose.
No full textThe self-monitoring of blood glucose (SMBG), traditionally performed by "point-of-care" (POC) devices called portable glucose monitors (PGM) is now considered an integral part of managed care of diabetic patients, especially type I diabetics and those on insulin therapy. In patients with type 2 diabetes, SMBG can help to achieve a better glycaemic control, although there is not sufficient evidence to attest that strict monitoring in these patients is associated with an improved outcome. The outcome of several clinical studies, especially in diabetics on insulin therapy, has shown that SMBG plays a key role in preventing complications in the short, medium and long term. According to the current recommendations, SMBG is aimed to achieve and maintain glycaemic control, prevent and identify hypoglycaemia, prevent severe hyperglycaemia, adjust lifestyle changes and establish the need to begin treatment with insulin in gestational diabetes mellitus. However, as clearly highlighted by the American Diabetes Association (ADA) and the National Academy of Clinical Biochemistry (NACB), patients and healthcare personnel should be trained on the appropriate use of the device, as well as on the correct interpretation of data. Moreover, definite analytical targets and appropriate acceptance criteria for performance should be fulfilled before a new device is introduced in the hospital environment, or recommended to the patients. Performance limitations such as hematocrit extremes and analytical interferences should be clearly acknowledged by the operators, before taking test results for granted. The current article aims to review the current indications for SMGB and highlight the most important criteria for the appropriate use of PGMs
Comparison of estimated glomerular filtration rate (eGFR) using the MDRD and CKD-EPI equations for CKD screening in a large population
No full textBackground/Aims Recently, the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) proposed a new equation for estimating glomerular filtration rate (eGFR), which could potentially replace the Modified Diet for Renal Disease Study (MDRD) equation in routine clinical use Our aim was to evaluate the correlation between them and to compare the prevalence of each CKD stage using these two equations Methods We measured serum creatinine in 38,188 consecutive patients and calculated eGFR using the CKD-EPI and MDRD equations We also compared the distribution of CKD stages for both equations Results There was very good correlation between eGFR estimated by CKD-EPI and MDRD at values < 60 ml/min x 1 73 m(2), but not at higher values Estimated prevalence of CKD (eGFR < 60 ml/min x 1 73 m2) was 5 9% with CKD-EPI and 7 5% with MDRD Furthermore, the prevalence of CKD Stage 2 was lower with CKD-EPI (33 8% vs 49 1% with MDRD) Conclusion The use of the CKD-EPI equation results in a lower estimated prevalence of CKD, compared to the MDRD equation This may have important implications for public health and clinical practice, as well as for future modification of guidelines for laboratorie
PHARMACOKINETICS OF SUBCUTANEOUS RECOMBINANT INTERLEUKIN-2 ADMINISTRATION IN CANCER-PATIENTS
No full textData from a clinical trial with recombinant Interleukin (rIL-2) subcutaneousy administered are here reported. Five patients with cancer were administered with r-IL2. Serum levels were measured on serial samples by immunoenzymatic method. This method is easier than biological methods, allowing to measure rIL-2 only as antigen. Therefore, immunoenzymatic method can be on support in the comprehensive study of IL-2 farmacokynetic. rIL-2 was detectable in serum in all the patient treated, with different levels and time
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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