A pilot study to evaluate the application of a generic protein standard panel for quality control of biomarker detection technologies.

BACKGROUND: Protein biomarker studies are currently hampered by a lack of measurement standards to demonstrate quality, reliability and comparability across multiple assay platforms. This is especially pertinent for immunoassays where multiple formats for detecting target analytes are commonly used. FINDINGS: In this pilot study a generic panel of six non-human protein standards (50 - 10^7 pg/mL) of varying abundance was prepared as a quality control (QC) material. Simulated "normal" and "diseased" panels of proteins were prepared in pooled human plasma and incorporated into immunoassays using the Meso Scale Discovery® (MSD®) platform to illustrate reliable detection of the component proteins. The protein panel was also evaluated as a spike-in material for a model immunoassay involving detection of ovarian cancer biomarkers within individual human plasma samples. Our selected platform could discriminate between two panels of the proteins exhibiting small differences in abundance. Across distinct experiments, all component proteins exhibited reproducible signal outputs in pooled human plasma. When individual donor samples were used, half the proteins produced signals independent of matrix effects. These proteins may serve as a generic indicator of platform reliability.Each of the remaining proteins exhibit differential signals across the distinct samples, indicative of sample matrix effects, with the three proteins following the same trend. This subset of proteins may be useful for characterising the degree of matrix effects associated with the sample which may impact on the reliability of quantifying target diagnostic biomarkers. CONCLUSIONS: We have demonstrated the potential utility of this panel of standards to act as a generic QC tool for evaluating the reproducibility of the platform for protein biomarker detection independent of serum matrix effects.

Analysis and interpretation of data from real-time PCR trace detection methods using quantitation of GM soya as a model system.

Recent years have seen an increased interest in DNA trace detection methods involved in many areas of bioanalytical research, such as quantitation of genetically modified (GM) ingredients in food products. There is little in the way of standardisation of data handling from these methods, and the data generated needs to be analysed appropriately if the results are to be interpreted correctly. This paper describes particular aspects of real-time PCR trace detection methods in order to increase the understanding of data generated using this bioanalytical technique. Using the specific example of GM soya detection and quantitation, it focuses on the production of calibration curves based on the mean and individual data values, the interpretation of correlation coefficients, regression techniques, and discusses suitable data analysis arising from simple and more complex experimental designs following transformation. By using the approaches outlined in this paper, more accurate analysis of data from real-time PCR and GM trace detection methods could be achieved.

Uso de moclobemida en el tratamiento de la depresión infantil / The use of moclobemide in treatment of depression in children

Objetivo: La depresión en niños se acompaña por trastornos del humor y la conducta, además de enuresis y encopresis. Se evaluó la utilidad de la moclobemida en niños con depresión. Método: 6 pacientes con depresión fueron evaluados según los criterios de Herzog y Rothbun para depresión infantil. Los pacientes tenían entre 5 y 9 años (promedio 7.6 años). La Impresión Clínica Global (ICG) inicial fue de 4.3. Tres presentaban enuresis, 1 enuresis-encopresis, 1 se autolesionaba y 1 mutismo electivo. Todos presentaron ruptura del vínculo filial y fracaso escolar. Dos varones eran tratados como homosexuales. eL tratamiento con la moclobemida duró de 20 a 480 días de 150 a 450 mg/día. Cuatro habían recibido tratamiento previo. Resultados: Al final del estudio, la ICG fue de 1.6. Hubo mejoría de la conducta y la ansiedad a la primera semana y del humor a la 2a. y 3a. semanas. En todos los casos se controló la enuresis y se atenuó la encopresis. Todos mejoraron conducta y rendimiento escolar. Conclusión: La moclobemida puede ser eficaz en el tratamiento de la depresión infantil.

Osteomielitis crónica hematógena / Chronic hematogenus osteomielitis

Presentamos el estudio de 37 casos de Osteomielitis Crónica Hematógena, hospitalizados en la Clínica Hortencia Espinoza de Salinas de Arequipa entre Enero 86 y Agosto 87. El 78% son varones, de mayor incidencia entre los 7-12 años (68%), siendo su localización preferencial tibia y fémur (78%), a focos multiples en el 11% de los casos, procedentes de toda la región Sur del Perú.En cuanto a la etiología el 92% son piogenos, con cultivo de estafilococo (48.7%), estreptococo (2,7%) y negativo a gérmenes comunes (37.8%); osteomielitis tífica (5.4%) y tuberculosa (2.7%). Fueron sometidos a intervención quirúrgica el 78.1%; las complicaciones más importantes son fractura patológica (8.1%) uno de los cuales evolucionó a pseudoartrosis y dos casos de osteortritis de colera