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1.
Talanta ; 207: 120349, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31594572

RESUMO

In this work, for the first time, the direct usability of natural products, catechins (CT) and cocoa powder (CO), as electrochemical mediators able to modify a carbon black modified screen-printed electrode (SPE-CB) is proved, and, as proof of applicability, free (GSH) and total glutathione (GSH + GSSG) in blood samples is successfully determined. Noteworthy, the cocoa powder (naturally rich in catechins), dissolved in DMSO, was able to give rise to a useful highly redox-active catechol-quinone surface-confined system onto a carbon black nanoparticles modified screen-printed electrode (SPE-CB-CO - Cocoatrode), giving rise to a similar behaviour obtained with pure catechins (SPE-CB-CT). The electrodeposition process has been carefully studied, the resulting immobilized natural mediator (obtained using both CT and CO) features investigated, and the performance of the resulting sensors (SPE-CB-CT and Cocoatrode) tested and compared. Both modified electrodes (SPE-CB-CT and Cocoatrode) have a good inter-electrodes precision (RSD ip,a ≤ 4.2%, n = 3) and intra-electrodes repeatability (RSD ip,a ≤ 3.9%, n = 20), indicating a robust and stable 'fabrication' strategy. Finally, SPE-CB-CT and Cocoatrode have been employed for the detection of free (GSH) and total (GSH+GSSG) glutathione in blood samples, using differential pulse voltammetry decrease in the mediator's reduction peak (Δi %), as analytical signal. Analytical curves (R2 ≥ 0.998), for the GSH detection, have been determined both with SPE-CB-CT and Cocoatrode in the 2.5 × 10-8-6.0 × 10-5 M and 5.0 × 10-8-1.0 × 10-4 M concentration ranges, respectively. Limits of detections (LODs) were ≤2.6 × 10-8 M. GSH (free and total) determined in blood samples, by the proposed CT and CO sensors, showed a good intra-electrode repeatability (RSD ip,a ≤ 9.0%, n = 3), with good recoveries (from 88.3% to 117.7%). The values obtained were in agreement with a classical spectrophotometric method (GSH and GSSG concentration relative error between -4.7 and +9.8%). The SPE-CB-CT and the Cocoatrode platforms demonstrated high potentiality in sensing and biosensing scenario, opening new gates to the natural/food products employment as unconventional, eco-friendly and economically affordable analytical active tools.


Assuntos
Análise Química do Sangue/instrumentação , Catequina/química , Chocolate , Glutationa/sangue , Impressão , Fuligem/química , Eletroquímica , Eletrodos , Glutationa/química
2.
Fish Physiol Biochem ; 45(5): 1551-1562, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31583489

RESUMO

Portable clinical analysers are gradually being involved in on-site assessment of haematic parameters in fish. The purpose of this study was to evaluate the i-STAT portable clinical analyser (i-STAT PCA) for accuracy and reliability of measuring blood pH, partial pressure of oxygen (pO2), haematocrit, haemoglobin, sodium, potassium and calcium in Atlantic cod (Gadus morhua). Haematological parameters detected with the i-STAT PCA were compared with conventional laboratory techniques (CLTs). Two types of disposable cartridges were used (CHEM8+ and CG4+) with the i-STAT PCA, and experiments were performed at two different temperature regimes (5 °C and 15 °C) and four different carbon dioxide (CO2) levels (0%, 0.1%, 0.5% and 1%). All blood parameters measured with the i-STAT PCA showed heterogeneous inaccuracy under the tested conditions, but the highest discrepancies were registered in blood pO2. The i-STAT PCA systematically overestimated the pO2 measurements. Our research suggests that i-STAT PCA is not an appropriate tool for pO2 measurements especially in coldwater fish species. The i-STAT PCA consistently underestimated the pH and haematocrit values especially at a lower temperature, although those parameters indicate significant high correlation at 15 °C. Furthermore, the analysed ions showed overestimation of sodium and underestimation of potassium and calcium.


Assuntos
Análise Química do Sangue/instrumentação , Dióxido de Carbono , Gadus morhua/sangue , Temperatura Ambiente , Animais , Cálcio/sangue , Hematócrito , Concentração de Íons de Hidrogênio , Pressão Parcial , Potássio/sangue , Reprodutibilidade dos Testes , Sódio/sangue
3.
Analyst ; 144(18): 5449-5454, 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31424465

RESUMO

A simple-to-use device to measure drugs in saliva, blood plasma, and whole blood for point-of-care analysis and treatment of overdose patients has been investigated. A rudimentary flow strip has been developed to separate opioids from these biofluids for analysis by surface-enhanced Raman spectroscopy (SERS). The strips are based on lateral flow assays, in which the antibodies have been substituted by SERS-active pads for detection. Samples of codeine and fentanyl, artificially added to these biofluids, were measured using the strips by a field-usable Raman spectrometer. We report measurement of these drugs in these biofluids from 0.5 to 5 µg mL-1 in 5 minutes. Calculated limits of detection for the spectra suggest that these drugs could be measured at 5 to 20 ng mL-1 with improvements in the strips' separation capability.


Assuntos
Análise Química do Sangue/instrumentação , Codeína/análise , Fentanila/análise , Saliva/química , Análise Espectral Raman/instrumentação , Codeína/sangue , Codeína/isolamento & purificação , Fentanila/sangue , Fentanila/isolamento & purificação , Humanos , Limite de Detecção , Sistemas Automatizados de Assistência Junto ao Leito , Fatores de Tempo
4.
Malar J ; 18(1): 262, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31366365

RESUMO

BACKGROUND: The Mindray BC-6800 haematology analyzer (BC-6800) provides a dedicated flag 'Infected RBC' (InR) and the number of InR (InR#)/the permillage of InR (InR‰) in routine blood testing as a screening tool for malaria in endemic areas. This study sought to evaluate the effectiveness of the BC-6800 flag parameter for aiding the diagnosis of malaria. METHODS: A total of 181 samples were tested using the Mindray BC-6800 haematology analyzer, including 117 malaria-infected samples collected from Yunnan, China, and 64 samples from healthy controls. Microscopy examination was conducted as reference when stained thick blood film revealed the presence of malaria parasites identified as Plasmodium vivax and Plasmodium falciparum. The receiver operating characteristic (ROC) curve analysis was developed using Analyse-it v4.92.3. The Kappa value was determined to evaluate the agreement between BC-6800 and light microscopy. RESULTS: The sensitivity of InR‰ generated by BC-6800 for P. vivax and P. falciparum was 88.3 and 24.1%, respectively; specificity of InR‰ for malaria parasites was 84.3 and 84.3%, respectively; positive predictive value and negative predictive value was 89.4 and 82.7% for P. vivax, and 52.8 and 60.3% for P. falciparum. There was a strong correlation between ΔWBC and InR‰ (R2 = 0.9731 for P. vivax and R2 = 0.9757 for P. falciparum). There was also a significant correlation between parasitaemia and InR# in P. vivax-infected samples (R2 = 0.734). InR# was evaluated using ROC curve analysis, the area under the ROC curve is 0.95 with a 95% confidence interval of 0.926 to 0.974, and the cut-off value is 0.01 × 109/L for P. vivax. However, the ring stage and the early trophozoite stage of Plasmodium cannot be detected easily on BC-6800, possibly because of the small size and low nucleic acid content of these stages. CONCLUSIONS: The findings suggest that the flag 'InR' and the parameters 'InR#/InR‰' provided by the BC-6800 haematology analyzer could be used to screen for malaria in a clinical setting.


Assuntos
Análise Química do Sangue/métodos , Sangue/parasitologia , Hematologia/métodos , Malária Falciparum/diagnóstico , Malária Vivax/diagnóstico , Plasmodium falciparum/isolamento & purificação , Plasmodium vivax/isolamento & purificação , Adolescente , Adulto , Idoso , Análise Química do Sangue/instrumentação , Criança , Pré-Escolar , China/epidemiologia , Feminino , Hematologia/instrumentação , Humanos , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Malária Vivax/epidemiologia , Malária Vivax/parasitologia , Masculino , Pessoa de Meia-Idade , Parasitemia/diagnóstico , Parasitemia/epidemiologia , Parasitemia/parasitologia , Prevalência , Curva ROC , Sensibilidade e Especificidade
5.
Ann Biol Clin (Paris) ; 77(4): 447-452, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31339492

RESUMO

The complement system is composed of a set of plasma or membrane proteins. Complement protein deficiencies can be inherited or acquired, through the presence of autoantibodies or through consumption. We evaluated the analytical performance of the Optilite® analyser for the determination of the C3 and C4 levels and for the evaluation of the total complement activity. The intra- and inter-series CVs were evaluated and have showed satisfactory results, the concordances with analysers currently used in the laboratory (BNII® and BCT®, Siemens) are very good, as is the agreement between the serum and plasma samples. We also determined the reference values for the different parameters tested in view of a routine use of Optilite® analyser in the laboratory.


Assuntos
Complemento C3/análise , Complemento C4/análise , Proteínas do Sistema Complemento/análise , Testes Hematológicos/instrumentação , Adulto , Artefatos , Automação Laboratorial/instrumentação , Automação Laboratorial/normas , Análise Química do Sangue/instrumentação , Análise Química do Sangue/métodos , Análise Química do Sangue/normas , Coagulação Sanguínea/fisiologia , Complemento C3/metabolismo , Complemento C4/metabolismo , Proteínas do Sistema Complemento/metabolismo , Contaminação de Equipamentos , Testes Hematológicos/métodos , Testes Hematológicos/normas , Humanos , Padrões de Referência , Reprodutibilidade dos Testes
6.
Anal Sci ; 35(7): 739-743, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31292353

RESUMO

An electrochemical phosphate sensor based on zirconium and reduced graphene oxide modified pencil graphite electrode (Zr/rGO-PGE) is proposed. The XRD, CV and EIS confirmed that GO was partially reduced on the PGE. Scanning electron microscopy (SEM) exhibited the layered and wrinkled structures for the rGO-PGE and Zr/rGO-PGE, respectively. Cyclic voltammetry showed the immobilized rGO was highly stable and had high activity toward zirconium adsorption. The prepared electrode was used for the electrochemical determination of phosphate. Based on the optimum condition using differential pulse voltammetry, the limit of detection and sensitivity for phosphate was obtained as [0.011(± 0.004) µM] (S/N = 3) and [622.4(± 9.6) µA µM-1 cm-2], respectively. The sensor was successfully evaluated for phosphate determination in human serum samples. In practical terms, the construction of this sensor was exceptionally simple, fast, cost effective and reproducible.


Assuntos
Análise Química do Sangue/instrumentação , Grafite/química , Óxidos/química , Fosfatos/sangue , Zircônio/química , Eletroquímica , Eletrodos , Humanos , Oxirredução , Fosfatos/química
7.
J Vet Med Sci ; 81(9): 1301-1304, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31308294

RESUMO

The aim of this study was to evaluate the accuracy and precision of portable blood glucose meters, such as i-STAT 1 and Precision Xceed, for use in calves. Whole blood and plasma samples were obtained from eleven calves that received 2.5 or 5.0% dextrose-containing polyelectrolyte isotonic solutions. Measurements using the i-STAT 1 (r2=0.99, P<0.0001) and Precision Xceed (r2=0.96, P<0.0001) were well correlated with those by the hexokinase method, which is the gold standard. Although the accuracy of i-STAT 1 was equivalent to that of the hexokinase method, there was an autocorrelation in the residuals between the results from the Precision Xceed and the hexokinase method. Thus, the i-STAT 1 can be used to measure the blood glucose concentration in cattle.


Assuntos
Análise Química do Sangue/veterinária , Glicemia/análise , Bovinos/sangue , Animais , Análise Química do Sangue/instrumentação , Glucose/administração & dosagem , Soluções Isotônicas/administração & dosagem , Sistemas Automatizados de Assistência Junto ao Leito
8.
Talanta ; 204: 379-385, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31357309

RESUMO

Fabricating simple, accurate and user-friendly diagnostic device for "point of care testing" (POCT) applications is one of the most challenging objectives in the analytical field. Hemin detection is important for drugs monitoring, diagnosis, and forensic latent bloodstain imaging. Herein is developed, luminol chemiluminescence biosensor for hemin detection using artesunate as coreactant. A possible mechanism to account for the chemiluminescence reaction is discussed. Hemin was detected using both photomultiplier tube (PMT) and smartphone as detector. The detection limit for hemin using smartphone as detector is 20 nM, enabling the visual detection of hemin in blood sample with a dilution factor of blood up to 120,000. While PMT detector is used, the system is able to detect hemin down to 0.22 nM. In addition to high sensitivity, this sensing system exhibit high selectivity. It can successfully distinguish bloodstain from other stains while applying the system for point of care testing using smart phone as detector. Moreover, the system can detect artesunate with a linear range from 0.1 nM to 1.0 µM with a limit of detection of 0.078 nM.


Assuntos
Artesunato/química , Hemina/análise , Substâncias Luminescentes/química , Luminol/química , Artesunato/análise , Análise Química do Sangue/instrumentação , Análise Química do Sangue/métodos , Manchas de Sangue , Calibragem , Humanos , Limite de Detecção , Medições Luminescentes/instrumentação , Medições Luminescentes/métodos , Smartphone
9.
Analyst ; 144(17): 5223-5231, 2019 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-31360940

RESUMO

Reagent sensors in diagnostic assays are used in medical laboratories to obtain patient results. However, interference during the analysis of blood samples is a constant problem with reagent sensors and leads to inaccurate results. Interference in blood analysis is frequently caused by hemolysis and icterus. This study analyzed the effects of interferents on reagent sensors and devised a method to improve the measurement accuracy using an interference index detection (IID) system to minimize the interference effect. The IID system can be easily applied using only two wells and an optical component for sample measurement. After applying the IID system, the interference rates from bilirubin and hemoglobin improved dramatically. A comparison of results obtained for clinical samples showed that the IID system had a positive effect on the accuracy.


Assuntos
Técnicas Biossensoriais/métodos , Análise Química do Sangue/métodos , Confiabilidade dos Dados , Hemólise , Icterícia , Bilirrubina/sangue , Bilirrubina/química , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/estatística & dados numéricos , Análise Química do Sangue/instrumentação , Análise Química do Sangue/estatística & dados numéricos , Nitrogênio da Ureia Sanguínea , Cloretos/sangue , Hemoglobinas/análise , Hemoglobinas/química , Humanos , Análise de Regressão , gama-Glutamiltransferase/sangue
10.
Clin Chim Acta ; 495: 507-511, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31152696

RESUMO

BACKGROUND: The pneumatic tube system (PTS) is widely established in clinical laboratories. We aimed to evaluate the impacts of PTS on high-sensitivity cardiac troponin T (hs-cTnT) assays. METHODS: The hemolysis distribution of hs-cTnT PTS specimens from emergency department (ED) were determined by hemolysis index (HI). Grouped samples from 15 healthy volunteers were delivered to the laboratory via manual delivery (MD) or PTS. Interference studies were conducted to access the influence of different hemolysis degrees on hs-cTnT assays. RESULTS: 7.26% PTS specimens from ED were hemolyzed in clinic. Compared with MD samples, we found highly elevated free plasma hemoglobin (Hb) in PTS samples. Hs-cTnT was interfered negatively with free Hb (R = -0.625, P < .001), and it was also validated in interference studies (R ≥ -0.820, all P ≤ .001). Clinically significant bias occurred in each hs-cTnT concentration at 100 mg/dl free Hb (Bias≥ - 13.85%, all P < .05). Moreover, bias of hs-cTnT assays at 50 mg/dl free Hb was approaching 10%, especially at 30 ng/l hs-cTnT concentration (Bias: -11.72%, P < .001). CONCLUSIONS: PTS could increase the frequency of specimen hemolysis which might cause false decrease in hs-cTnT assays. Hence, clinicians should be aware of the increased measurement bias in hs-cTnT from hemolyzed PTS samples with free Hb ≥50 mg/dl.


Assuntos
Análise Química do Sangue/instrumentação , Limite de Detecção , Miocárdio/metabolismo , Troponina T/sangue , Reações Falso-Negativas , Feminino , Voluntários Saudáveis , Humanos , Masculino , Troponina T/metabolismo , Adulto Jovem
11.
J Clin Lab Anal ; 33(6): e22921, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31131509

RESUMO

BACKGROUND: Protein induced by vitamin K antagonist-II (PIVKA-II), in addition to alpha-fetoprotein, is a useful tumor marker for diagnosis of hepatocellular carcinoma (HCC). We evaluated the analytical performance of the HISCL-5000 analyzer (Sysmex Corporation) in the measurement of serum PIVKA-II. METHODS: We evaluated the precision and linearity of PIVKA-II assays using the HISCL-5000 analyzer. Methods using HISCL-5000, LUMIPULSE G1200 (Fujirebio Diagnostics), and ARCHITECT i2000 (Abbott Diagnostics) were compared according to the guidelines of the Clinical and Laboratory Standards Institute. A total of 501 subjects (median age 59 years, age range 24-90 years) were enrolled. Among them, 335 were HCC patients, 46 were patients with non-HCC liver disease, and 120 were healthy individuals. Non-HCC liver disease included liver cirrhosis, chronic hepatitis, HBV or HCV carrier, hepatic adenoma, and intrahepatic cholangiocarcinoma. RESULTS: Repeatability (%CV) in low- and high-level controls and pooled serum was 2.81%-10.30%, and within-laboratory precision was 4.24%-8.86%. In a linearity test, the coefficient of determination (R2 ) was 0.9957, ranging from 11 to 69 897 mAU/mL. In comparison, the coefficient of correlation (r) was 0.9561-0.9644, agreement was 93.4%-97.6%, and the κ value was 0.855-0.945 among the three analyzers. About 99.2% of healthy individuals and 84.8% of non-HCC liver disease patients were below the cutoff value (40 mAU/mL) on HISCL-5000. CONCLUSIONS: A PIVKA-II assay using HISCL-5000 showed acceptable analytical performance including precision, linearity, and method comparison. This indicates that HISCL-5000 can be potentially helpful in clinical laboratories.


Assuntos
Biomarcadores/sangue , Análise Química do Sangue/instrumentação , Precursores de Proteínas/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise Química do Sangue/métodos , Ensaio de Imunoadsorção Enzimática/instrumentação , Feminino , Humanos , Hepatopatias/sangue , Masculino , Pessoa de Meia-Idade , Protrombina , Reprodutibilidade dos Testes , Adulto Jovem
12.
J Clin Lab Anal ; 33(6): e22913, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31090232

RESUMO

BACKGROUND: To conduct a comprehensive performance evaluation of a fully automated analyzer for measuring thrombomodulin (TM), thrombin-antithrombin complex (TAT), plasmin-α2-antiplasmin complex (PAP), and t-PA: PAI-1 complex (tPAI-C). METHODS: According to the Clinical and Laboratory Standards Institute (CLSI) EP05-A2, EP06-A specifications, TM, TAT, PAP, and tPAI-C were analyzed to evaluate intraassay variability and interassay variability, linear range, carryover rate, reference range, sample stability, and interferences. RESULTS: The intraassay variability and interassay variability of the four factors were all below 5%. The carryover rates were below 1%. Linear verification analysis revealed correlation coefficients of 0.998-0.999. The recommended reference ranges of TM, TAT, and PAP were appropriate for our laboratory, whereas the reference of tPAI-C should be established by each laboratory. Stability assessment revealed that TM is stable for 2 days at room temperature but lacks stability at colder temperatures. In contrast, TAT is stable for 5 days at 4°C and -20°C but has poor stability at room temperature. PAP and tPAI-C are stable for 3 days at all three temperatures. The measurement of TM, TAT, PAP, and tPAI-C is not altered by the presence of 510 mg/dL hemoglobin, 1490 FTU triglycerides, or 21.1 mg/dL conjugated and free bilirubin. CONCLUSION: The determination of TM, TAT, PAP, and tPAI-C using a high-sensitivity chemiluminescence analyzer performs well in terms of precision, carryover rate, linear range, and interference. Thus, this method is suitable for the detection of these substances in clinical specimens.


Assuntos
Análise Química do Sangue/instrumentação , Fibrinolisina/análise , Peptídeo Hidrolases/sangue , Inibidor 1 de Ativador de Plasminogênio/sangue , Trombomodulina/sangue , Ativador de Plasminogênio Tecidual/sangue , alfa 2-Antiplasmina/análise , Antitrombina III , Automação , Análise Química do Sangue/métodos , Calibragem , Humanos , Medições Luminescentes/instrumentação , Medições Luminescentes/métodos , Valores de Referência
13.
Anesth Analg ; 129(1): 92-98, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30973383

RESUMO

Minutes count in the operating room when it comes to treatment guidance and therapies. On a daily basis, anesthesiologists make hundreds of decisions, some based on laboratory results, when guiding patient therapies. When time is crucial, point-of-care testing is often utilized for expediency. However, point-of-care testing has its limitations. Providers should be aware of the limitations, including the potential for error in results-errors that could lead to improper treatment and possible patient harm. This article outlines the technical aspects and summarizes pitfalls in accuracy for 2 of the most commonly utilized point-of-care testing devices: glucose meters and hemoglobin meters.


Assuntos
Análise Química do Sangue/instrumentação , Glicemia/metabolismo , Hemoglobinas/metabolismo , Sistemas Automatizados de Assistência Junto ao Leito , Testes Imediatos , Biomarcadores/sangue , Humanos , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Fatores de Tempo , Fluxo de Trabalho
14.
Int J Biol Macromol ; 132: 748-758, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30940584

RESUMO

Early stage diagnosis of breast cancer by monitoring the proteins in human biological fluids is the best method and the first section toward efficient therapy, delaying metastasis and hindrance mortality. In this study, graphite ink was synthesized and combined with CA 15-3 antibody in order to develop a novel immunosensor for detection of CA 15-3, breast cancer biomarker. Conductivity of bioink was examined by designing various conductive patterns on paper using a rollerball pen. Electrochemical behavior of engineered immunosensor was evaluated through employing sensitive diagnostic technique, DPV (differential pulse voltammetry). Under optimal conditions, the linear concentration range and low limit of quantification (LLOQ) of designed immunosensor was 15-250 U/mL and 15 U/mL, respectively. The process was successfully applied to assay of breast cancer biomarker (CA15-3) in unprocessed human plasma specimens.


Assuntos
Análise Química do Sangue/instrumentação , Neoplasias da Mama/sangue , Imunoensaio/instrumentação , Tinta , Mucina-1/sangue , Nanotecnologia/instrumentação , Papel , Biomarcadores Tumorais/sangue , Eletroquímica , Humanos , Reprodutibilidade dos Testes , Fatores de Tempo
15.
J Chromatogr A ; 1596: 226-232, 2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-30853166

RESUMO

The effect of membrane thickness on extraction performance was systematically examined in extractions through supported liquid membranes (SLM), which were in-line coupled to capillary electrophoresis (CE). Three porous polypropylene membranes with different thickness (25, 100 and 170 µm) were used as supports for SLM extractions of model basic drugs (nortriptyline, papaverine, haloperidol and loperamide) from complex samples. The analytes were transferred through the SLMs by a pH gradient and were in-line injected, separated and quantified using a commercial CE instrument with ultraviolet (UV) detection. Transfers of the model drugs through SLM decreased with the increased membrane thickness (in the order: 25 > 100 > 170 µm) and highest transfers were achieved for the thinnest membrane. Interferences from complex sample matrices were efficiently eliminated, moreover, impregnation of the 25 µm membrane required significantly reduced volume of organic solvent. Mechanical stability of the impregnated 25 µm membrane was excellent during in-line injections, which necessitated direct contact of CE separation capillary with the SLM. Repeatability of the hyphenated SLM-CE-UV method (using the 25 µm membrane) was lower than 11% (RSD values of peak areas) and calibration curves were strictly linear in 0.5-30 µg/mL concentration range (coefficients of determination ≥ 0.997). Transfers of the basic drugs from donor solutions (standard and undiluted human urine/plasma) through the SLMs ranged from 45 to 231% and limits of detection were between 0.02 and 0.15 µg/mL.


Assuntos
Análise Química do Sangue/métodos , Líquidos Corporais/química , Eletroforese Capilar , Membranas Artificiais , Urinálise/métodos , Análise Química do Sangue/instrumentação , Humanos , Solventes/química , Urinálise/instrumentação
16.
J Clin Lab Anal ; 33(5): e22885, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30924550

RESUMO

BACKGROUND: Blood gas analysis and blood lactate measurement have important roles in patient management. Point-of-care (POC) testing simplifies and provides rapid blood gas and lactate measurements. This study aimed to compare pH, pCO2 , pO2 , and lactate measurements between a POC device and a benchtop blood gas analyzer typically used in a hospital central laboratory, and to evaluate the inter-device variability of the POC device. METHODS: A cross-sectional study was conducted with a sample size of 100. Each sample was measured for pH, pCO2 , pO2 , and lactate using a Nova pHOx plus L® benchtop blood gas analyzer in the central laboratory and an i-STAT® handheld POC device. The results of both devices were compared using Pearson or Spearman correlation coefficients and Bland-Altman tests. Testing of the inter-device variability was done by using three different i-STAT® devices, and the results were compared statistically. RESULTS: Strong correlations were observed for all test results. In Bland-Altman analysis, ≥95% of the results were within the limits of agreement, with the exception of lactate, which had only 93%. The results that were beyond the limits were primarily lactate levels >8 mmol/L. Biases between the benchtop analyzer and the i-STAT® were not clinically significant, except pH. No significant inter-device variability was observed between the i-STAT® analyzers. CONCLUSION: This comparison study of pH, pCO2 , pO2 , and lactate measurements between Nova pHOx plus L® and i-STAT® analyzers showed good agreement. However, lactate measurement results >8 mmol/L on the i-STAT® analyzer should be interpreted with caution.


Assuntos
Análise Química do Sangue/instrumentação , Gasometria/instrumentação , Ácido Láctico/sangue , Sistemas Automatizados de Assistência Junto ao Leito , Análise Química do Sangue/métodos , Gasometria/métodos , Dióxido de Carbono/sangue , Estudos Transversais , Humanos , Concentração de Íons de Hidrogênio , Oxigênio/sangue , Testes Imediatos
17.
J Clin Lab Anal ; 33(4): e22856, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30779463

RESUMO

BACKGROUND: In vitro hemolysis is still the most common source of pre-analytical nonconformities. This study aimed to investigate the hemolytic effects on commonly used biochemical tests as well as to determine the hemolysis index (HI) thresholds on Siemens Advia 2400 chemistry analyzer. METHODS: Peripheral blood samples were collected from forty healthy volunteers. Hemolysis was achieved using syringes. Five hemolysis levels were produced including the no hemolysis group, slight hemolysis group, mild hemolysis group, moderate hemolysis group, and heavy hemolysis group. We then used the bias from baseline (no hemolysis) and HI to construct regression functions. The HI corresponding to the bias limits was considered as HI thresholds. We chose the total allowable error (TAE) as the bias limit. RESULTS: Of the twenty-eight analytes, ten analytes had clinical significance. Creatine kinase-MB, creatine kinase, potassium, aspartate aminotransferase, and hydroxybutyrate dehydrogenase were all positively affected; the corresponding HI threshold was 45.2, 99.96, 4.07, 10.16, and 7.94, respectively. Lactate dehydrogenase was also positively interfered, but we failed to calculate the HI threshold. Total bile acid, uric acid, and sodium were all negatively affected, and the HI threshold was 42.23, 500 and 501.8, respectively. Glucose was also negatively interfered, but it failed to achieve the HI threshold. CONCLUSIONS: When the HI value was higher than its threshold, the corresponding analyte was considered inappropriate for reporting. The implementation of the assay-specific HI thresholds could provide an accurate method to identify analytes interfered by hemolysis, which would improve clinical interpretations and further boost laboratory quality by reducing errors associated with hemolysis.


Assuntos
Análise Química do Sangue/instrumentação , Análise Química do Sangue/métodos , Hemólise , Testes Hematológicos/instrumentação , Hemoglobinas/análise , Humanos
18.
J Clin Lab Anal ; 33(4): e22851, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30811634

RESUMO

BACKGROUND: The most clinically useful blood ketone in the diagnosis, management, and recovery of diabetes ketoacidosis in both adults and children is 3-hydroxybutyrate. In the absence of laboratory routine methods, several point-of-care methods are in use, but very few clinical evaluations are published. METHODS: This study evaluates linearity and reproducibility of two handheld point-of-care meters for blood 3-hydroxybutyrate measurement for hospital use, Nova StatStrip, and FreeStyle Precision Pro. Whole blood from healthy volunteers was spiked with different concentrations of a 3-hydroxybutyrate solution and tested on the point-of-care instruments. The results were compared with plasma 3-hydroxybutyrate that was analyzed with a laboratory enzymatic end point spectrophotometric reference method. RESULTS: Blood 3-hydroxybutyrate on StatStrip was linear with the reference method up to approximately 4 mmol/L, and FreeStyle was linear up to 6 mmol/L. At higher concentrations, the point-of-care instruments gave falsely too low results, especially the StatStrip meter. The FreeStyle meter had better precision and less bias than StatStrip. CONCLUSION: In the acute setting of diabetes ketoacidosis, blood 3-hydroxybutyrate in the higher ranges should be interpreted with caution as the point-of-care meters are less accurate there.


Assuntos
Ácido 3-Hidroxibutírico/sangue , Análise Química do Sangue/métodos , Análise Química do Sangue/instrumentação , Humanos , Sistemas Automatizados de Assistência Junto ao Leito , Reprodutibilidade dos Testes
19.
Int J Lab Hematol ; 41(2): 298-303, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30689284

RESUMO

INTRODUCTION: Laboratory quality assurance (QA) includes internal quality control (IQC), external quality assurance (EQA) and quality improvement (QI). EQA identifies quality deviations and training needs. D-dimers are breakdown products of thrombus and results guide various clinical decisions. METHODS: The National Health Laboratory Service (NHLS) in South Africa performs the pathology tests for more than 80% of the population. The NHLS Quality Assurance Department distributed 301 questionnaires to laboratories enquiring about D-dimer testing. Two levels of STAGO® and Siemens® commercial D-dimer assay control material were distributed for analysis and returned results analysed. RESULTS: A total of 64 (21.2%) completed questionnaires were returned and 26 (40.6%) laboratories were performing D-dimers with 25 (97%) subscribing to an EQA scheme. All laboratories reported results in D-dimer units with a negative result cut-off of ≤0.25 mg/L but various testing platforms were in use. All returned interpretations of analyses on the blinded control material were correct. The results were also within the respective reference ranges of the controls apart from three outliers. One laboratory obtained a result on STAGO® pathological control that was above the cut-off of the control reference range but the reason for this error could not be identified. Another obtained results on the STAGO® and on the Siemens® normal controls that were both below the cut-off of the control reference range due to transcription errors. CONCLUSION: The study demonstrated the feasibility of a local EQA scheme for D-dimers based on commercial control material that could mitigate against the cost of international EQA scheme participation.


Assuntos
Análise Química do Sangue/normas , Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Garantia da Qualidade dos Cuidados de Saúde , Inquéritos e Questionários , Análise Química do Sangue/instrumentação , Análise Química do Sangue/métodos , Feminino , Humanos , Masculino , Projetos Piloto , África do Sul
20.
Clin Biochem ; 66: 76-82, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30695682

RESUMO

OBJECTIVES: New user-friendly diagnostic tests for detection of individuals infected by Mycobacterium leprae (M. leprae), the causative pathogen of leprosy, can help guide therapeutic and prophylactic treatment, thus positively contributing to clinical outcome and reduction of transmission. To facilitate point-of-care testing without the presence of phlebotomists, the use of fingerstick blood (FSB) rather than whole blood-derived serum is preferred. This study is a first proof-of-principle validating that previously described rapid serum tests detecting antibodies and cytokines can also be used with FSB. METHODS: Quantitative detection of previously identified biomarkers for leprosy and M. leprae infection, anti-M. leprae PGL-I IgM antibodies (αPGL-I), IP-10 and CRP, was performed with lateral flow (LF) strips utilizing luminescent up-converting reporter particles (UCP) and a portable reader generating unbiased read-outs. Precise amounts of FSB samples were collected using disposable heparinized capillaries. Biomarker levels in paired FSB and serum samples were determined using UCP-LF test strips for leprosy patients and controls in Bangladesh, Brazil, South-Africa and the Netherlands. RESULTS: Correlations between serum and FSB from the same individuals for αPGL-I, CRP and IP-10 were highly significant (p < .0001) even after FSB samples had been frozen. The αPGL-I FSB test was able to correctly identify all multibacillary leprosy patients presenting a good quantitative correlation with the bacterial index. CONCLUSIONS: Reader-assisted, quantitative UCP-LF tests for the detection of humoral and cellular biomarkers for M. leprae infection, are compatible with FSB. This allows near-patient testing for M. leprae infection and immunomonitoring of treatment without highly trained staff. On site availability of test-result concedes immediate initiation of appropriate counselling and treatment. Alternatively, the UCP-LF format allows frozen storage of FSB samples compatible with deferred testing in central laboratories.


Assuntos
Anticorpos/sangue , Análise Química do Sangue/métodos , Proteína C-Reativa/análise , Quimiocina CXCL10/sangue , Hanseníase/diagnóstico , Resinas Acrílicas/química , Animais , Anticorpos/imunologia , Antígenos de Bactérias/imunologia , Biomarcadores/sangue , Análise Química do Sangue/instrumentação , Feminino , Cabras , Humanos , Raios Infravermelhos , Masculino , Camundongos , Mycobacterium leprae/imunologia , Nanopartículas/química , Nanopartículas/efeitos da radiação , Testes Imediatos
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