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Alsius-Serra A.,Bioquimica Catlab | Ballbe-Anglada M.,Bioquimica Catlab | Lopez-Yeste M.L.,Calidad Catlab | Buxeda-Figuerola M.,Laboratorio Of Urgencias | And 4 more authors.
Revista de Calidad Asistencial

Objective To describe the study of the comparability of the measurements levels of biological tests processed in biochemistry in Catlab's 4 laboratories. Material and methods Quality requirements, coefficients of variation and total error (CV% and TE %) were established. Controls were verified with the precision requirements (CV%) in each test and each individual laboratory analyser. Fresh serum samples were used for the comparability study. The differences were analysed using a Microsoft Access® application that produces modified Bland-Altman plots. Results The comparison of 32 biological parameters that are performed in more than one laboratory and/or analyser generated 306 Bland-Altman graphs. Of these, 101 (33.1%) fell within the accepted range of values based on biological variability, and 205 (66.9%) required revision. Data were re-analysed based on consensus minimum specifications for analytical quality (consensus of the Asociación Española de Farmacéuticos Analistas (AEFA), the Sociedad Española de Bioquímica Clínica y Patología Molecular (SEQC), the Asociación Española de Biopatología Médica (AEBM) and the Sociedad Española de Hematología y Hemoterapia (SEHH), October 2013). With the new specifications, 170 comparisons (56%) fitted the requirements and 136 (44%) required additional review. Taking into account the number of points that exceeded the requirement, random errors, range of results in which discrepancies were detected, and range of clinical decision, it was shown that the 44% that required review were acceptable, and the 32 tests were comparable in all laboratories and analysers. Conclusions The analysis of the results showed that the consensus requirements of the 4 scientific societies were met. However, each laboratory should aim to meet stricter criteria for total error. © 2015 SECA. Published by Elsevier Espaa, S.L.U. All rights reserved. Source

Algarra M.,University of Porto | Campos B.B.,University of Porto | Gomes D.,University of Porto | Alonso B.,Autonomous University of Madrid | And 6 more authors.

A nanocomposite obtained by a thiol DAB-dendrimer (generation 5), coated with fluorescent ZnSe quantum dots, was successfully synthesized for the selective recognition of C-reactive protein. The procedure presented was carried out by a novel, cheap and non-toxic bottom up synthesis. The nanocomposite showed an excitation at 180 nm, with two emission bands at 411 and 465 nm, with a full-width at half-maximum of 336 nm. The Stokes shift was influenced by the presence of coating molecules and the intensity was dependent on pH due to the presence of a charge transfer process. The transmission electron microscopy images demonstrated that the spherical nanoparticles obtained displayed a regular shape of 30 nm size. The fluorescence intensity was markedly quenched by the presence of C-reactive protein, with a dynamic Stern-Volmer constant of 0.036 M-1. The quenching profile shows that about 51% of the ZnSe QDs are located in the external layer of the thiol dendrimer accessible to the quencher. The precision of the method obtained as relative standard deviation was 3.76% (4 mg L-1, n=3). This water soluble fluorescent nanocomposite showed a set of favorable properties to be used as a sensor for the C-reactive protein in serum samples, at concentrations of risk levels. © 2012 Elsevier B.V. Source

Gomes D.,University of Porto | Algarra M.,University of Porto | Diez De Los Rios M.J.,Laboratorio Of Urgencias | Arrebola M.M.,Laboratorio Of Urgencias | And 3 more authors.

A fluorescence chemical sensor for C-reactive protein (CRP) was developed based on the selective interaction with CdSe and ZnSe quantum dots (QDs) coated with O-phosphorylethanolamine (PEA). Synthesis procedure and analytical parameters such as pH and ionic strength were studied. The decrease in the fluorescence emission intensity was explained due to the specific interaction of the QDs-PEA with CRP, and a correlation was observed between the quenching of the fluorescence and the concentration of CRP. The accuracy of the proposed method was 0.37% as RSD. The proposed method was applied to screen serum samples, and showed to be sensible at the C-reactive protein concentrations of risks levels. © 2012 Elsevier B.V. All rights reserved. Source

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