End-user verification results of two serum separator tubes for clinical chemistry analytes according to CLSI GP34-A and CLSI GP41-A6.

Tube manufacturers use different composition of gels and blood clot activator formulations in serum tube production. Our aim was to investigate the within-tube (repeatability) and between-tube variation, concordance between comparison results of BD and VacuSEL tubes. Blood samples were collected from control subjects (n = 20) and patients (n = 30) in accordance with the CLSI GP41-A6 and CLSI GP34-A guidelines. Twenty-three clinical chemistry parameters were analysed via Roche Cobas C702 Chemistry Analyzer on T0 (0 hour) and T24 (24 hour). Mean differences % were compared with Wilcoxon matched pair test. Clinical significance was evaluated based on desirable bias according to total allowable error (TEa). VacuSEL tubes demonstrated acceptable performance for the results of 20 parameters with regards to desirable bias % limits. Lactate dehydrogenase (LD) [mean difference % (%95 confidence intervals (CI) values of BD and VacuSEL tubes at T0 [6.41% (4.80-8.01%)]; sodium (Na) and total protein (TP) at T24 [-0.27% (-0.46 to -0.07%) and -1.39% (-1.87 to -0.91), respectively] were over the desirable bias limits (LD: 4.3%, Na: 0.23% and TP: 1.36%, respectively) but not exceeding total biological variation CV % [Na: 0.5 (0.0-1.0) % and TP: 2.6 (2.3-2.7) %). %95 confidence intervals (CI) of T0 LD values overlap with within-subject biological variation % (CI) limits (LD: 5.2 (4.9-5.4) %). The differences between two tubes were not medically significant and necessarily conclusive. VacuSEL serum tubes presented comparable performance with BD serum tubes.

Evaluation of Sensitive Analytes to Hemolysis Interference on an Automated Chemistry Analyzer.

BACKGROUND: Hemolysis is a common reason for specimen rejection in the laboratory. Our experience suggested that hemolysis (H) flag limits are too strict for some analytes leading to unnecessary specimen rejections. This study summarizes H flags for commonly rejected analytes on the Beckman Coulter DxC 700 AU analyzer. METHODS: We evaluated analytes with low-limit H flags and high rejection rates. These included: aspartate aminotransferase (AST), alanine aminotransferase (ALT), iron (IRN), potassium (K), direct bilirubin (DBIL), magnesium (Mg), amylase (AMY), sodium (Na), gamma-glutamyltransferase (GGT), phosphorus (PHOS), albumin (ALB), alkaline phosphatase (ALKP), and lactate dehydrogenase (LDH). Five patient plasma pools without hemolysis were made from 50 patient specimens. Neat pools were analyzed to establish baseline analyte concentrations. A hemolysate was created by diluting whole blood with distilled water. Each analyte was tested after spiking each pool with the hemolysate to specific hemoglobin concentrations corresponding to manufacturer's H flags. Percent differences were calculated between baseline pool means and each flag's pool mean. Acceptance limits were based upon the average of the 2019 CLIA and the method precision limits. Calculated percent differences greater than the acceptance limits were considered significant. RESULTS: Manufacturer-defined hemolysis flags can be updated to greater than 1+ for Na, K, and AST, greater than 3+ for ALKP, and greater than 4+ for AMY and Mg. No changes were noted for the remaining analytes. CONCLUSIONS: The hemolysis criteria set for ALKP, AMY, AST, Mg, K, and Na were updated in the Remisol Advance middleware, which led to a 56% reduction in rejected hemolyzed specimens.

An HPLC-UV Method to Assess Human Plasma 25(OH)D3.

The aim of this study was to validate an HPLC-UV method to assess vitamin D status by determining the linearity and precision of the 25-hydroxyvitamin D3 (25(OH)D3) calibration curve, the limits of detection, quantitation and robustness of the method, and its accuracy. A second stock solution of 25(OH)D3 was prepared (500 ng/mL), and working dilutions (5, 10, 20, 30, 40, and 50 ng/mL) were prepared for a calibration curve. The HPLC equipment had a UV-Vis diode-array detector and utilized an AcclaimTM 120 C18 column (5 µm, 4.6 × 250 mm) with a flow rate of 1.2 mL/min, a column temperature of 30 °C, and the standards and samples were maintained at 4 °C, with an injection volume of 100 µL. Detection of 25(OH)D3 was determined at 265 nm, with a retention time of 4.0 min. The validation was conducted according to the FDA Validation of Analytical Procedures: Guidance for Industry. Vitamin D was extracted from plasma samples using acetonitrile (ACN)-0.1% formic acid (2:1 v/v), and the percentage of recovery was calculated. The proposed method conditions gave excellent linearity (R2 = 0.9989) and the linearity coefficient was R2 > 0.99 for 25(OH)D3. The detection and quantification limits were 1.1703 ng/mL and 3.5462 ng/mL, respectively. Decreasing or increasing the reading temperature by 1 °C decreased the response units (AU) of vitamin D, 25(OH)D3. When the current flow rate decreased by 0.2 mL/min (1.0 mL/min), the retention time increased to 4.913 min, whereas an increase of 0.2 mL/min of the proposed flow rate (1.4 mL/min) decreased the retention time to 3.500 min. The percentage of recovery varied from 92.2% to 97.1%. The proposed method to quantify a vitamin D metabolite (25(OH)D3) in human plasma samples was reliable and validated.

Rapid label-free impedimetric detection of progesterone enhanced by immunomagnetic bead-based competitive immunoreaction.

Detecting progesterone (P4) concentration in cow serum is essential for monitoring the pregnancy progress after fertilization and is significant for the dairy farming industry and veterinary medicine. This study reports enzyme-free immunomagnetic beads (IMBs)-based competitive immunoassay for detecting P4 by P4-bovine serum albumin (BSA)-modified biosensors. The anti-P4 antibody-conjugated IMBs serve as collectors to capture P4 in undiluted serum samples to prevent the biosensor surface from biosample contamination and as insulated labels to report the electron-transfer resistance signal of electrochemical impedance spectroscopy (EIS) measurement. The IMBs and P4-containing samples were mixed for 15-30 min, capable of obtaining stable P4@IMB complexes. The 0.2-kGauss pulsed magnetic field (PMF) of the 20-s pulse width and 20-s relaxation time applied for 5 min can shorten the immunoreaction time between the P4@IMBs and the P4-BSA-modified biosensor and reduce the IMB's nonspecific adsorption on the biosensor surface. This competitive immunoassay's cut-off value and detection limit were 7.71 ng/mL and 7.33 ng/mL, respectively, which is lower than the serum's P4 plateau concentration (over 8 ng/mL) of dairy cows on days 6-16 of estrus cycles and that in pregnancy. The IMB-based immunoassay combining the PMF attraction and the label-free EIS measurement exhibits promising potential for rapidly detecting P4 in undiluted serum.

Vanadium-doped metal-organic framework@Znln2S4 core-shell heterojunction-attenuated photoelectrochemical immunoassay.

Considering that cancer has become the second leading cause of death in humans, it is essential to develop an analytical approach that can sensitively detect tumor markers for early detection. We report an attenuated photoelectrochemical (PEC) immunoassay based on the organic-inorganic heterojunction 10MIL-88B(FeV)/ZnIn2S4 (10M88B(FeV)/ZIS) as a photoactive material for monitoring carcinoembryonic antigen (CEA). The 10M88B(FeV)/ZIS heterojunctions have excellent light-harvesting properties and high electrical conductivity, which are attributed to the advantages of both organic and inorganic semiconductors, namely, remarkable photogenerated carrier separation efficiency and long photogenerated carrier lifetime. Horseradish peroxidase (HRP) in the presence of H2O2 can catalyze 3,3'-diaminofenamide (DAB) producing brown precipitates (oxDAB), which is then loaded onto the 10M88B(FeV)/ZIS heterojunction to reduce the photocurrent and enable the quantitative detection of CEA. Under optimal conditions, the photocurrent values of the PEC biosensor are linearly related to the logarithm of the CEA concentrations, ranging from 0.01 ng mL-1 to 100 ng mL-1 with a detection limit (LOD) of 4.0 pg mL-1. Notably, the accuracy of the PEC biosensor is in agreement with that of the human CEA enzyme-linked immunosorbent assay (ELISA) kit.

Comentarios a las infracciones por presencia de drogas en carretera y argumentos para establecer tasas mínimas de detección en sangre / Comments on offenses due to the presence of drugs on the road and arguments to establish minimum detection rates in blood

El presente trabajo tiene como objeto la revisión de la bibliografía científica relativa a la afectación de las drogas en la conducción así como la revisión de toda la legislación del Derecho comparado que regula las sanciones administrativas y penales por conducir bajo los efectos o con presencia de drogas en el organismo. Este documento hace especial referencia al caso español, criticando, mediante los principios de la ciencia, la lógica y el Derecho, el Auto del Pleno del Tribunal Constitucional español nº 174/2017 de 19 de diciembre, que declaró constitucional sancionar la mera presencia de una mínima cantidad de droga en el organismo cuando se está conduciendo, expresando que esto no vulnera derechos fundamentales de la persona usuaria de drogas a pesar de no acreditar la afectación a las capacidades psicofísicas. El estudio acaba dando unos consejos a ciudadanos y administraciones para intentar que la protección de la seguridad vial se realice de la manera más justa y proporcional posible y sin vulnerar derechos fundamentales de la persona usuaria de drogas, haciendo alusión a los puntos de corte o tasas, tanto en saliva como en sangre, que existen en los diferentes aparatos de detección de sustancias psicoactivas, ya sea con el aparato presuntivo de carretera (test de antígenos) que con la prueba confirmatoria en el laboratorio (GC-MS).(AU)

The purpose of this work is to review the scientific bibliography on the effects of drugs on driving as well as the review of all comparative law legislation that regulates administrative and criminal sanctions for driving under the influence or with the presence of drugs. in the body. This document makes special reference to the Spanish case, criticizing, through the principles of science, logic and law, the Order of the Plenary of the Spanish Constitutional Court No. 174/2017 of December 19, which declared it constitutional to sanction the mere presence of a minimum amount of drug in the body when driving, stating that this does not violate the fundamental rights of the person who uses drugs despite not proving the effect on psychophysical capacities. The study ends by giving some advice to citizens and administrations to try that the protection of road safety is carried out in the most fair and proportional way possible and without violating the fundamental rights of the person who uses drugs, referring to the cut-off points or rates, both in saliva and in blood, which exist in the different psychoactive substances detection devices, either with the presumptive road device (antigen test) or with the confirmatory laboratory test (GC-MS). (AU)

Seudohiperfosfatemia analítica como punto de partida en el diagnóstico de una disproteinemia / Role of pseudo-hyperphosphataemia in the diagnosis of dysproteinaemia

El fósforo es el segundo mineral más abundante en el organismo. Su homeostasis se consigue mantener a través de varios mecanismos mediados principalmente por el riñón, el intestino y el hueso. Se han descrito interferencias en la medición del fósforo que pueden provocar una seudohiperfosfatemia. La causa más frecuente es la presencia de una paraproteína en el suero de los pacientes con mieloma múltiple, macroglobulinemia de Waldenström y gammapatía monoclonal de significado incierto. En los casos de hiperfosfatemia sin causa aparente que la pueda justificar, es importante tener en cuenta la existencia de una seudohiperfosfatemia causada por la presencia de las paraproteínas en sangre en los autoanalizadores de química líquida. El sistema multicapa de Vitros(R) 5600 es un método rápido y fiable para solucionar este problema

Phosphorus is the second most important mineral in the body. Its homeostasis is maintained through several mechanisms mediated mainly by the kidney, intestine, and bone. Interferences have been described in the measurement of phosphorus that could suggest a pseudo-hyperphosphataemia. The most frequent cause was the presence of a paraprotein in the serum of patients with multiple myeloma, Waldenström macroglobulinaemia, or monoclonal gammopathy of uncertain significance, was described as the most frequent cause of interference in phosphorus assay using liquid chemistry autoanalysers. When hyperphosphataemia is present, and no apparent cause can justify it, it is important to consider the possibility of a pseudo-hyperphosphataemia caused mainly by the presence of a paraprotein. The Vitros(R) 5600 multilayer system can be used as a fast and reliable method to avoid this interference

Associação entre desnutrição, escore prognóstico de Glasgow modificado e índice inflamatório nutricional em pacientes com câncer / Association between malnutrition, modified Glasgow prognostic score and nutritional inflammatory index in cancer patients

Introdução: A desnutrição é um achado comum em pacientes oncológicos e sua etiologia é multicausal, sendo influenciada significativamente pela resposta inflamatória sistêmica. Os indicadores de inflamação podem ser ferramentas úteis na avaliação nutricional dos pacientes com câncer. Objetivo: Avaliar a associação entre o Escore Prognóstico de Glasgow modificado e o Índice Inflamatório Nutricional (IIN) com a presença e o grau de desnutrição em pacientes com câncer. Método: Pacientes admitidos em um hospital universitário, com diagnóstico confirmado de câncer, participaram deste estudo. Exames laboratoriais de albumina e proteína C-reativa foram realizados para obtenção do EPGm e do IIN. A avaliação nutricional foi realizada por meio da Avaliação Subjetiva Global. Resultados: Foram avaliados 70 pacientes com idade média de 58,51±14,85 anos, dos quais 50 (71,5%) apresentaram algum grau de desnutrição, enquanto 27 (38,6%) apresentaram desnutrição grave. As categorias de risco do EPGm e do IIN estiveram presentes em 41 (58,6%) e 39 (55,7%) pacientes, respectivamente. O EPGm e o IIN associaram-se à presença da desnutrição (p<0,05). Conclusão: O EPGme o IIN mostraram-se ferramentas úteis, de fácil interpretação, com possibilidade de complementar a avaliação nutricional do paciente oncológico, uma vez que se associaram com a desnutrição.(AU)

Introduction: Malnutrition is a common finding in patients with cancer; its etiology is multifactorial and significantly influenced by the systemic inflammatory response. Inflammation indicators can be useful tools in the nutritional assessment of patients with cancer. Objective: We intended to evaluate the association of the modified Glasgow Prognostic Score (mGPS) and the InflammatoryNutritional Index (INI) with the presence and degree of malnutrition in cancer patients. Methods: We evaluated patients who were admitted to university hospital with a confirmed diagnosis of cancer participated in this study. Laboratory tests for albumin and C-reactive protein were conducted to obtain mGPS and INI scores. Nutritional assessment was carried out by subjective global assessment. Results: A total of 70 patients with a mean age of 58.51±14.85 years were evaluated, of which 50 (71.5%) presented some degree of malnutrition, while 27 (38.6%) presented severe malnutrition. The risk categories of mGPS and INI were present in 41 (58.6%) and 39 (55.7%) patients, respectively. Conclusion: Them GPS Score and the INI are simple tools, easy to interpret, with the possibility of complementing the nutritional evaluation of cancer patients, since they were associated with malnutrition.(AU)

Estudio de la validez en la medición de los valores de lactato sanguíneo entre los dos modelos existentes de LactatePro / Validity of blood lactate measurements between the two LactatePro versions

Introducción: La medición de la concentración de lactato sanguíneo ([La-]) para el control de la intensidad del esfuerzo, tanto en laboratorio como sobre el terreno, es muy habitual en la fisiología del ejercicio y en el control del entrenamiento. El objeto de este estudio es analizar la validez y concordancia en la medición de [La-] entre los dos modelos existentes de LactatePro en el mercado. Métodos: Han participado 34 deportistas voluntarios (3 ciclistas, 17 remeros, 10 corredores de larga distancia y 4 de montaña), los cuales llevaron a cabo un test Escalonado Progresivo Incremental Máximo (EPIM) con escalones de 3 minutos hasta el agotamiento subjetivo, con toma de una muestra sanguínea con un capilar heparinizado, la cual se analizó simultáneamente ambos modelos. Resultados y conclusión: El análisis mostró una alta correlación entre aparatos (r = 0,991 y r2 = 0,983; p <0.001), con concordancia alta para la media de resultados (0,31 mmol/l), siendo ligeramente más alta en el modelo LactatePro LT-1710. El tramo (0 - 5,0 mmol/l) muestra una alta correlación entre aparatos (r = 0,965 y r2= 0,931; p <0,001). El tramo de lactato medios (5,1 - 10,0 mmol/l) determina una alta correlación entre ambos (r = 0,921 y r2= 0,848; p <0,001) y concordancia alta (0,54 mmol/l). En el tramo de valores de lactato (10,1 - 20,0 mmol/l) la correlación es alta, similar a la del tramo medio (r = 0,926 y r2= 0,858). La concordancia en este grupo es alta para la media de los resultados (0,40 mmol/l). Para los de [La] mayor (>10 mmol/l) la correlación y la concordancia son altas. El cambio en la medición de los valores de [La-], sustituyendo el modelo antiguo de LactatePro LT-1710 por el nuevo LT 1730 del mismo fabricante (Akray Factory Inc. KDK Corporation, Siga, Japan), es posible dada la alta correlación y concordancia tanto para todo el conjunto como para los grupos

Introduction: The blood lactate concentration to measure the exercise intensity in the lab or in the field is very usual in the exercise physiology and training control. The main aim was to measure the validity and the concordance in the measurement between two lactate-pro models in the market. Methods: 34 voluntary sportmen (3 cyclist, 17 rowers, 10 long distance runners and 4 mountains runners) performed a staggered, progressive, intervallic, maximal test of effort. Constant increases of intensity (every 3 min) were done. The peripheral blood lactate was measured at the same time in both models by a heparinized capilar during the 10 next second after the step. Results and Conclusion: A high correlation between devices was presented (r = 0,991 and r2= 0,983; p <0.001), with a high concordance for the medium results (0,31 mmol/l), being a little beat higher in the model LactatePro LT-1710. The stretch of values (0 -5,0 mmol/l) presented a high correlation between devices (r = 0,965 and r2= 0,931; p <0.001). The stretch of medium values (5,1 - 10,0 mmol/l) determined a high correlation between them (r = 0,921 and r2= 0,848; p <0.001) and high concordance (0,54 mmol/l). In the stretch (10,1 - 20,0 mmol/l) the correlation is high, similar than the medium group (r = 0,926 and r2= 0,858). The concordance in this group is for the mean results (0,40 mmol/l). For high [La-] (>10 mmol/l), the correlations and the concordance are high. The measurements of the [La-] values by the old model LactatePro LT-1710 versus the new one LT 1730 (Akray Factory Inc. KDK Corporation, Siga, Japan) is possible, given that the correlation and the concordance for the total data as well as groups are high

Intervenção nutricional sobre medidas antropométricas, percentual de gordura corporal e parâmetros bioquímicos / Nutritional intervention on anthropometric, percentage of body fat and biochemical parameters

Objetivo: Avaliar a eficácia da intervenção nutricional sobre medidas antropométricas, percentual de gordura corporal (%G) e parâmetros bioquímicos de pacientes, maiores de 18 anos, atendidos em uma Clínica de Nutrição do município de Passos, MG. Método: Trata-se de um estudo de intervenção realizado com pacientes que procuraram o Centro de Atendimento Nutricional (CAN) da Universidade Estadual de Minas Gerais, unidade de Passos, e possuíam desvios nutricionais. Como instrumento de medida, utilizou-se a anamnese alimentar ou história dietética. Analisou- se, antes e após a intervenção nutricional, peso, índice de massa corporal, %G, circunferência abdominal, triglicérides, colesterol total e glicose de jejum. Realizou-se análise estatística descritiva e o teste T Student pareado. O nível de significância adotado foi de 5%. Participaram do estudo 19 indivíduos, com média de idade de 35±17 anos, sendo 84% do sexo feminino. Resultados: Verificou-se redução significativa no %G (t=2,469; p=0,024), triglicérides (t=2,551; p=0,020) e colesterol total (t=2,526; p=0,021) após a intervenção nutricional. Conclusões: Os resultados sugerem que a intervenção nutricional contribuiu para a redução do %G, dos parâmetros bioquí- micos e para qualidade de vida dos pacientes.(AU)

Objective: To evaluate the effectiveness of nutritional intervention on anthropometric measure- ments, body fat and biochemical parameters of patients, older than 18 years-old, attended in a Nutrition Clinic in Passos (Minas Gerais). Methods: This is an intervention study of patients who sought the Service Center Nutrition at the State University of Minas Gerais, Passos unit, and had nutritional problems. The measurement instrument was used food history or diet history analyzed before and after nutritional intervention, weight, body mass index, %G, waist circumference, triglycerides, total cholesterol and fasting glucose. A descriptive statistical analysis and paired Student T test. The study included 19 subjects with a mean age of 35±17 years, 84% female. Results: It was found significant reduction in% body fat, triglycerides and total cholesterol after nutritional intervention. Conclusions: The results suggest that dietary intervention contributed to the reduction in body fat C, biochemical parameters and quality of life of patients.(AU)

Assessment of two glycated hemoglobin immunoassays / Evaluación de 2 inmunoensayos para hemoglobina glucosilada

INTRODUCTION: Glycated hemoglobin (HbA1c) level reflects chronic glycemic status if reliable tests are used, however, in some regions worldwide high performing assays might not be readily available. This study aimed to asses two HbA1c immunoassays, comparing them with high-performance liquid chromatography (HPLC) assay, three methods available in Ecuador. MATERIAL AND METHODS: HbA1c were measured in 114 fresh whole blood-samples by DCA-Vantage point-of-care analyzer, I-Chroma portable fluorescent scanner immunoassay and BioRad Variant II Turbo HPLC. Normal and pathological HbA1c ranges were included. Blood samples with variants of hemoglobin were excluded. HbA1c values were expressed in National Glycohemoglobin Standardization Program percentages and mmol/mol, as mean±standard deviation. RESULTS: HbA1c results by HPLC and DCA-Vantage were similar: 6.3 ± 1.7% (45 ± 18.6 mmol/mol) vs.6.3 ± 1.8% (45 ± 19.7 mmol/mol), respectively, P = 0.057; while HbA1c values by I-Chroma were lower than HPLC, 5.8 ± 1.9% (40 ± 20.8 mmol/mol), P < 0.001. The coefficient of variation was below 2% for high and low HbA1c levels, in all methods studied. HbA1c values by HPLC and DCA-Vantage were highly correlated (Spearman's Rank Correlation [SRC]: 0.916), while the correlation among HPLC and I-Chroma was weak (SRC: 0.368). The mean bias between DCA-Vantage and HPLC was -0.02 ± 0.29% (-0.2 ± 3.2 mmol/mol), while for I-Chroma and HPLC mean bias was -0.50 ± 1.62% (- 5.5 ± 17.7mmol/mol). CONCLUSIÓN: HbA1c immunoassays DCA-Vantage was comparable to HPLC assay, showing good correlation, appropriate precision and low bias, whereas I-Chroma assay was precise but inaccurate. Therefore, DCA-Vantage has better performance than I-Chroma. These findings suggest that is convenient to assess the HbA1c immunoassays commercially available in our country, Ecuador

INTRODUCCIÓN: El nivel de hemoglobina glucosilada (HbA1c) refleja el estado glucémico crónico si se utilizan pruebas confiables. En algunas regiones del mundo los métodos de alto desempeño para medir la HbA1c no son fácilmente accesibles. Nuestros objetivos fueron evaluar 2 inmunoensayos, comparándolos con la cromatografía líquida de alta resolución (HPLC, por sus siglas en inglés), 3 ensayos disponibles en Ecuador. MATERIALES Y MÉTODOS: En 114 muestras de sangre entera medimos la HbA1c por DCA Vantage (R), escáner fluorescente i-Chroma (R) y HPLC Bio-Rad Variant II® Turbo. Incluimos valores normales y patológicos de HbA1c. Excluimos muestras con variantes de la hemoglobina. La HbA1c fue expresada en porcentaje según el Programa Nacional de Estandarización de la Glicohemoglobina y en mmol/mol (media± desviación estándar). RESULTADOS: La HbA1c medida por HPLC y DCA Vantage (R) fue semejante: 6,3 ± 1,7% (45 ± 18,6 mmol/mol) y 6,3 ± 1,8% (45 ± 19,7 mmol/mol), respectivamente, p = 0,057; pero la cuantificada por i-Chroma(R) fue menor a HPLC, 5,8 ± 1,9% (40 ± 20,8 mmol/mol), p < 0,001. El coeficiente de variación fue menor al 2% en los 3 ensayos estudiados. Los valores de HbA1c obtenidos por HPLC y DCA Vantage(R) estuvieron fuertemente correlacionados (correlación de Spearman [CS]: 0,916), mientras que la correlación entre HPLC y i-Chroma (R) fue débil (CS: 0,368). El sesgo medio entre DCA Vantage ® y HPLC fue -0,02 ± 0,29% (- 0,2 ± 3,2 mmol/mol), en cambio, entre i-Chroma(R) y HPLC fue -0,50 ± 1,62% (-5,5 ± 17,7mmol/mol). CONCLUSIÓN: El inmunoensayo DCA Vantage (R) fue comparable a HPLC, mostrando buena correlación, apropiada precisión y bajo sesgo, mientras que i-Chroma (R) fue preciso, pero inexacto. Por lo tanto, DCA Vantage (R) tiene mejor desempeño que i-Chroma (R). Estos hallazgos sugieren que es conveniente evaluar los inmunoensayos comercialmente disponibles en nuestro país, Ecuador

Veracidad de un analizador de gasometria para determinar glucemia, respecto a un metodo de laboratorio convencional / Reliability of a gas analyzer to determine glycemia compared to the conventional laboratory method

Objetivos:Determinar el grado de veracidad en los resultados de glucosa, medidos en un equipo de gasometría, mediante lacomparación con un procedimiento de uso habitual en el laboratorio, siguiendo el procedimiento indicado en la guía EP9–A2 delClinical and Laboratory Standards Institute(CLSI).Diseño:Estudio descriptivo con muestreo no probabilístico.Institución:HospitalEdgardo Rebagliati Martins, EsSalud, Lima, Perú.Material:Muestra sanguínea de 234 sujetos provenientes de los servicios deemergencia y la unidad de cuidados intensivos.Métodos:Se procesó glucemia en los equipos ADVIA1800 y el gasómetro ABL800.Se comparó los resultados de ambos analizadores siguiendo las directrices de la mencionada guía, además del análisis gráfico deBland-Altman y el cálculo del coeficiente de concordancia correlación (CCC) de Lin.Principales medidas de resultados:Concentraciónde glucosa sérica.Resultados:La media de glucemia obtenida fue 1,6 mg/dL mayor para ABL800 que para el ADVIA1800. Los dosmétodos de medida seguían una relación lineal, obteniéndose un coeficiente de correlación de 0,9995, con un intervalo de confianza(IC) al 95% de 0,9994a 0,9996. Los resultados de glucosa del método de estudio fueron aceptables según los requerimientos decalidad, lo cual se confirmó con los análisis estadísticos de Bland-Altman y el valor del CCCL de 0,9995, con un IC de 95% de 0,9993a 0,9996.Conclusiones:El analizador ABL800 resultó adecuado para la monitorización de glucemia; presentó una buena asociaciónlineal y veraz, cuando fue comparado con el método de referencia del laboratorio.

Objectives: To determine the glucose reliability results measured in a gas equipment as compared with a reference method commonly used in the laboratory. The Clinical and Laboratory Standards Institute (CLSI) guide EP9- A2 instructions were followed. Design: Descriptive study with non-probability sampling. Setting: Hospital Edgardo Rebagliati Martins, EsSalud, Lima, Peru. Materials: Blood sample of 234 subjects from the emergency services and intensive care unit. Methods: Blood glucose was processed with the ADVIA1800 equipment and the ABL800 gasometer. Results of both analyzers were compared following the mentioned guide directives, the Bland-Altman plot analysis and the Lin’s concordance correlation coefficient (CCC) calculation. Main outcome measures: Serum glucose concentration. Results: Average blood glucose levels obtained were 1.6 mg/dL higher for ABL800 than for ADVIA1800. Both methods showed a high positive correlation (beta coefficient 0.9995 and 95 per cent, 95 per cent CI 0.9994 to 0.9996). Glucose results for the method studied were acceptable, as confirmed with the Bland-Altman statistical analysis (0.9995 CCC value, 95 per cent CI 0.9993 to 0.9996). Conclusions: The ABL800 analyzer is suitable for blood glucose monitoring, presenting an excellent correlation with the reference laboratory method.

¿Cuál es la rentabilidad diagnóstica del frotis de sangre periférica? / What is the diagnostic yield of the peripheral blood smear?

Fundamento y objetivo. A pesar de que el frotis de sangre periférica es una herramienta muy útil en el diagnóstico de diversas enfermedades, para que aporte beneficio es crucial que el encargado de examinarlo conozca datos clínicos del paciente y sepa qué tiene que buscar o descartar. El objetivo de nuestro trabajo fue evaluar el beneficio real que aporta el frotis y los factores que predicen su impacto en la práctica clínica. Pacientes y métodos. Se analizaron de forma prospectiva todos los frotis consecutivos (n = 618) solicitados en un mes por 6 hospitales de la comunidad de Madrid y revisados en nuestro laboratorio. En cada frotis se evaluó la información previa aportada por el médico peticionario y la serie hematológica alterada. Clasificamos cada frotis, según lo que aportó al clínico, en: a) sin información relevante; b) confirma diagnóstico ya conocido, y c) aporta información relevante para el diagnóstico o pronóstico. Resultados. No se obtuvo ninguna información relevante en 402 frotis (65,04%). En los frotis útiles se observó mayor proporción de sospechas diagnósticas previas (20%) en comparación con los no diagnósticos (5,1%) (p < 0,001) y menos peticiones con hemograma normal (3,8 vs 42,7%, p < 0,001). Conclusiones. En nuestra experiencia, 2 de cada 3 frotis solicitados no aportan ninguna información relevante. Conocer la sospecha diagnóstica y tener al menos una de las 3 series alteradas tiene impacto significativo en la rentabilidad del frotis(AU)

Background and objetive. Although examination of peripheral blood smear is a very helpful tool in the diagnosis of several pathologies, it is essential that the person who performs it knows the patient clinical data and what to look for in order to obtain the highest benefit. The aim of this study is to determine the proportion of useful blood smears in clinical practice and to identify possible predictive factors. Patients and methods. We prospectively analysed 618 consecutive peripheral blood smears performed in our laboratory, requested by 6 hospitals in Madrid. Clinical features provided by the physician and abnormalities in complete blood count (none / white cells / red cells / platelets / all of them) were evaluated in each case. According to the information obtained from them, blood smears were classified into: a) non-diagnostic; b) a previously-known diagnosis is confirmed, and c) new relevant information provided. Results. No useful information was obtained by 402 (65.04%) blood smears. A higher proportion of previous clinical suspicions was observed in helpful blood smears compared to non-diagnostic ones (20% vs 5.1%, P<.001), and also less for completely normal blood counts (3.8% vs 42.7%, P <.001). Conclusions. In our experience, two thirds of requested peripheral blood smears provide no useful information at all. Clinical suspicion and the presence of at least one abnormality in complete blood count showed a significant impact in blood smear yield(AU)

Utilidad de la determinación cualitativa de troponina I y creatinfosfocinasa isoenzima MB en los síndromes isquémicos coronarios agudos / Usefulness of rapid bedside assay of cardiac troponin I and creatine phosphokinase-MB in acute ischemic coronary syndromes

Recently, a rapid bedside assay for quantitative determination of cTI and CPK-MB has been developed that provides a positive or negative result in 10 to 15 minutes allowing for a better therapeutic approach. The objective of our study was to validate the diagnostic usefulness of cardiac troponin I in patients with chest pain. We determined sensitivity, specificity, positive and negative predictive values in 40 patients that arrived to the hospital with chest pain. These patients were assigned to four different groups: Group A: Patients with acute myocardial infarction. Group B: Patients with unstable angina and normal ECG. Group C: Patients with atypical chest pain and normal ECG. Group D: Control. Eighteen (45%) patients were woman and 22 (55%) were men; age 54.1 +/- 26, range 32 to 85 years. In Group A, sensitivity, specificity, positive and negative predictive values for cTI were 95%, for CPK-MB, they were 40, 50, 90, 7.1%. For Group B, cTI: 64, 90, 90, 64%; CPK-MB: 50, 90, 87, 56%. Group C, cTI and CPK MB 25, 95, 50, 86%. Group D, cTI and CPK-MB: 50, 95, 50, 95%. This study suggests that the rapid bedside qualitative test through cardiac troponin I assessment is a test with higher predictive value for early diagnosis of acute myocardial infarction than CPK-MB.

Desarrollo de m¨¦todos r¨¢pidos y sencillos para la purificaci¨®n de haptoglobina y ceruloplasmina porcina / Development of fast and simple methods for porcine haptoglobin and ceruloplasmin purification

Two fast and simple methods for porcine haptoglobin (Hp) and ceruloplasmin (Cp) purification are described in this paper. Hp was purified by ammonium sulphate fractionation and a FPLC Superdex-200 gel chromatography. The protein obtained showed two bands with a Mr (molecular mass) of about 44 kDa and 12.9 kDa corresponding to heavy (¦Â) and light (¦Á) chains of Hp respectively, on sodium dodecyl sulphate-polyacrilamide gel electrophoresis, under reducing conditions. Ceruloplasmin (Cp) was isolated by one step of chromatography on amino-ethyl-derivatized Sepharose followed by gel filtration on a Superdex-200 column. The Mr of the protein, as estimated by SDS-PAGE was approximately 150 kDa. In conclusion, two new protocols have been developed for porcine Hp and Cp purification, being less time-consuming and technically demanding than those previously reported. This paper could represent an interesting guideline and be of help to obtain pure protein to use as specie-specific standard material and to produce specific antibodies(AU)

En el presente trabajo se describen dos m¨¦todos sencillos y r¨¢pidos para la purificaci¨®n de la haptoglobina (Hp) y ceruloplasmina (CP). La Hp fue purificada mediante precipitaci¨®n con amonio sulfato y poserior cromatograf¨ªa en gel mediante un sistema de FPLC y columna de Superdex-200. La prote¨ªna obtenida mostr¨® en cromatograf¨ªa en gel de poliacrilamida, bajo condiciones reductoras, dos bandas con un peso molecular de 44 kDa y 12,9 kDa correspondientes a las dos cadenas pesadas (¦Â) y las dos cadenas ligeras (¦Á) de las estructura de la Hp, respectivamente. La ceruloplasmina (CP) fue purificada en un paso de cromatograf¨ªa de afinidad en gel de sefarosa modificada, seguida de filtraci¨®n en gel en columna de Superdex-200. El peso molecular de la prote¨ªna, estimado por electroforesis en gel de poliacrilamida, fue de aproximadamente 150 kDa. En conclusi¨®n, han sido desarrollados dos nuevos protocolos para la purificaci¨®n de la Hp y Cp porcina, siendo m¨¢s r¨¢pidos y menos exigentes t¨¦cnicamente que los anteriormente descritos. Este trabajo puede representar una interesante gu¨ªa y ser de ayuda para obtener prote¨ªna pura para ser usada como material est¨¢ndar especie-espec¨ªfico y para la producci¨®n de anticuerpos espec¨ªficos(AU)

Hemoglobin measured by Hemocue and a reference method in venous and capillary blood: a validation study

Objective. To assess the comparability of hemoglobin concentration (Hb) in venous and capillary blood measured by Hemocue and an automated spectrophotometer (Celldyn) and to document the influence of type of blood (capillary or venous) and analysis method on anemia prevalence estimates. Material and Methods. Between February and May 2000, capillary and venous samples were collected from 72 adults and children at Hospital del Niño Morelense (Morelos State Children's Hospital) in Cuernavaca, Morelos, Mexico, and assessed for Hb using the Hemocue and Celldyn methods. Estimated Hb levels were compared using the concordance correlation coefficient and Student's t test for paired data. The sensitivity and specificity for anemia diagnosis were estimated and compared between type of blood and method of assessment. Results. Capillary blood had higher Hb (+0.5g/dl) than venous blood in adults and children, as did samples assessed by Celldyn compared to Hemocue (+0.3g/dl). Specificity to detect anemia was adequate (>0.90) but sensitivity was low for capillary blood assessed by Hemocue (<0.80). Conclusions. The difference in Hb between venous and capillary blood is likely related to biological variability. Hemoglobin concentration in capillary blood assessed by Hemocue provides an adequate estimation of population anemia prevalence but may result in excess false negative diagnoses among individuals. The results of this study stress the importance of sample collection technique, particularly for children. Method of analysis and sampling site need to be taken into consideration in field studies.

Objetivo. Evaluar la comparabilidad de la concentración de hemoglobina (Hb) en sangre venosa y capilar medida por Hemocue y por espectrofotómetro automatizado (Celldyn), así como documentar la influencia del tipo de sangre (capilar o venosa) y del método de análisis sobre la prevalencia de anemia. Material y métodos. De febrero a mayo de 2000, se recolectaron muestras de sangre capilar y venosa en 72 adultos y niños en el Hospital del Niño Morelense, Cuernavaca, Morelos, México. Se determinaron los niveles de Hb con los métodos Hemocue y Celldyn. Las cifras de Hb estimadas se compararon con el coeficiente de concordancia y la prueba pareada de t de Student. También se comparó la sensibilidad y especificidad para el diagnóstico de anemia, utilizando sangre de los dos tipos y métodos de análisis. Resultados. La Hb fue mayor en sangre capilar comparada con sangre venosa (+0.5g/dl) en adultos y niños, y en las determinaciones por Celldyn comparadas con las de Hemocue (+0.3 g/dl). La especificidad para el diagnóstico de anemia fue adecuada (>0.90), mientras que la sensibilidad fue baja para las muestras capilares medidas por Hemocue (<0.80). Conclusiones. Es probable que la diferencia en la Hb entre sangre venosa y capilar refleje variabilidad biológica. La Hb en sangre capilar medida por Hemocue provee una estimación adecuada de la prevalencia de anemia en poblaciones, pero podría resultar en un exceso de diagnósticos falsos negativos. Los resultados de este estudio ponen énfasis en la importancia de la técnica de recolección de la muestra, particularmente en niños. Los métodos de análisis y tipos de muestra de sangre deben ser tomados en cuenta en estudios de campo.

Fiabilidad de la determinación de la glucemia a la cabecera del paciente en pacientes críticos / Reliability of the measurement of glucose at the bedside of critical patients

Introducción. El objetivo de este estudio es determinar la fiabilidad de tres métodos de determinación, a pie de cama, de la glucemia en el paciente crítico comparados con la determinación de glucemia en el laboratorio central. Material y métodos. Estudio observacional prospectivo desarrollado en una Unidad polivalente de 18 camas durante 4 meses. Se incluyeron pacientes que portaban catéter arterial. Se compararon con la glucemia plasmática (patrón oro) 8 muestras obtenidas a la cabecera del paciente: tres en sangre capilar, 4 en sangre arterial y una de sangre arterial en jeringa de gases. Las determinaciones a la cabecera fueron realizadas con tiras reactivas MediSense® Optium™ Plus y glucómetro MediSense® Optium™. Se realizó una comparación de medias mediante la prueba de la «t» de Student y análisis de Bland y Altman. Resultados. Obtuvimos 630 muestras en 70 pacientes. La glucemia media (desviación estándar [DE]) en mg/dl fue: a) muestras capilares: 149 (38), 149 (35), 147 (37); b) muestras arteriales: 140(34), 142 (35), 143 (35), 142 (34); muestra arterial en jeringa de gases: 143 (33); c) glucemia plasmática: 138 (33). Hubo diferencias significativas (p < 0,001) entre la glucemia plasmática y las muestras capilares, pero no con las muestras arteriales (p = 0,2). En las muestras arteriales la presencia de algunos factores, como fármacos vasoactivos, perfusión de soluciones glucosadas, perfusión de insulina y concentración plasmática de hemoglobina, aumenta el error y la dispersión respecto al patrón oro. Conclusiones. En enfermos críticos la medida de la glucemia a pie de cama es más fiable en muestras arteriales que en muestras capilares

Introduction. The objective of this study is to measure the reliability of three measurement methods at the bedside of the patient, of glucose in the critical patient compared with the measurement of glucose in the central laboratory. Material and methods. Observational, perspective study developed in a polyvalent unit of 18 beds for four months. Patients who had arterial catheter were included. Eight samples obtained at the patient's bedside were compared with the plasma glucose (gold Standard): three in capillary blood, four in arterial blood and one in arterial blood gases from a syringe. The measurements at bedside were conducted with reactive strips MediSense® Optium™ Plus and glucometer MediSense® Optium™. A comparison was made of the means used in the Student's T test and Bland and Altman analysis. Results. We obtained 630 samples in 70 patients. Mean glucose (SD) in mg/dl was: a) capillary samples: 149 (38), 149 (35), 147 (37); b) arterial samples: 140 (34), 142 (35), 143 (35), 142 (34); arterial gas sample syringe: 143 (33); c) plasma glucose: 138(33). There were significant differences (p < 0.001) between plasma glucose and capillary samples but not with arterial samples (p=0.2). In the arterial samples, the presence of some factors, such as vasoactive drugs, glycated solution perfusion, insulin perfusion and plasma concentration of hemoglobin, increase error and dispersion regarding the gold standard. Conclusions. The measurement of glucose at bedside in critical patients is more reliable in arterial samples than in capillary ones

Glicemia capilar medida por dois aparelhos de automonitorizaçäo: quanto eles podem estimar a glicemia plasmática na rotina médica? / Capillary blood glucose measurement by tho self-monitoring equipment: how can they to estimate a plasma blood grucose in medical routine?

O desenvolvimento de monitores portáteis para automonitorização da glicose sangüínea tem fácil aceitação pelos pacientes e médicos, sendo amplamente utilizado atualmente, o que torna essencial avaliar o quanto esses resultados correspondem à glicemia plasmática. Assim, avaliamos a acurácia e precisão de dois monitores digitais à disposição no mercado: um utiliza a glicose desidrogenase (Ap1) e o outro a glicose oxigenase (Ap2) na mensuração da glicemia capilar

Comparison of outpatient point of care glucose testing vs venous glucose in the clinical laboratory

The purpose of this study was to evaluate the accuracy of glucometers in assessing glucose levels in outpatients. The investigation consisted in the analysis of retrospective validation data (obtained at the Clinical Laboratory of the Puerto Rico Medical Services Administration) and the analysis of data obtained from forty outpatients. Glucose concentration was obtained from these outpatient samples using the patients' glucometers and a clinical laboratory analyzer (hexokinase method). Statistical analysis included descriptive and correlation measures and t-test. Results revealed that accurate glucose values were obtained by the glucometers utilized in both the validation process and the outpatients (POCT) procedure. The investigation also demonstrated the need by outpatients to receive proper training in handling their glucometers.

Proyecto Urea: estado actual de su determinación / Urea project: current status of urea measurement

Se diseñó un proyecto para investigar las causas del pobre rendimiento de los laboratorios clínicos en la determinación de urea. El proyecto contempló la evaluación de la influencia de la calidad del calibrador y de la calidad de la preparación enzimática sobre el estado actual de la determinación de urea. Cada uno de los laboratorios participantes en este proyecto recibió en las etapas previstas: una solución calibradora externa, y un estuche de reactivos para la determinación de urea, según la reacción de Berthelot, validado de acuerdo con la metodología elaborada en el Centro Nacional de Referencia, Hospital clínico-Quirúrgico "Hermanos Ameijerias". El efecto de la sustitución del calibrador interno y de la preparación enzimática empleados habitualmente en el laboratorio participante por los suministrados por el laboratorio de referencia, se evaluó mediante ensayo paralelo de dos sueros controles con niveles diferentes de urea. El comportamiento de la mayoría de los laboratorios participantes fue insensible a la sustitución del calibrador interno o del protocolo de trabajo definido localmente. Las causas del pobre rendimiento de los laboratorios en la determinación de urea, pueden ser variadas e independientes en su presentación, y representan, probablemente, fallas en la interacción operatorio-protocolo de trabajo. La observación de que la variabilidad interlaboratorio puede reducirse significativamente si se emplea una metodología única validada por un laboratorio de referencia, indica que la actividad de los laboratorios debe orientarse primariamente al mejoramiento continuo de la calidad de los protocolos de trabajo definidos localmente