2,242 research outputs found

    Five years MIQE guidelines: The case of the Arabian countries

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    The quantitative real time polymerase chain reaction (qPCR) has become a key molecular enabling technology with an immense range of research, clinical, forensic as well as diagnostic applications. Its relatively moderate instrumentation and reagent requirements have led to its adoption by numerous laboratories, including those located in the Arabian world, where qPCR, which targets DNA, and reverse transcription qPCR (RT-qPCR), which targets RNA, are widely used for region-specific biotechnology, agricultural and human genetic studies. However, it has become increasingly apparent that there are significant problems with both the quality of qPCR-based data as well as the transparency of reporting. This realisation led to the publication of the Minimum Information for Publication of Quantitative Real-Time PCR Experiments (MIQE) guidelines in 2009 and their more widespread adoption in the last couple of years. An analysis of the performance of biomedical research in the Arabian world between 2001-2005 suggests that the Arabian world is producing fewer biomedical publications of lower quality than other Middle Eastern countries. Hence we have analysed specifically the quality of RT-qPCR-based peer-reviewed papers published since 2009 from Arabian researchers using a bespoke iOS/Android app developed by one of the authors. Our results show that compliance with 15 essential MIQE criteria was low (median of 40%, range 0-93%) and few details on RNA quality controls (22% compliance), assays design (12%), RT strategies (32%), amplification efficiencies (30%) and the normalisation process (3%). These data indicate that one of the reasons for the poor performance of Arabian world biomedical research may be the low standard of any supporting qPCR experiments and identify which aspects of qPCR experiments require significant improvements

    Housekeeping genes for quantitative expression studies in the three-spined stickleback Gasterosteus aculeatus

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    Background During the last years the quantification of immune response under immunological challenges, e.g. parasitation, has been a major focus of research. In this context, the expression of immune response genes in teleost fish has been surveyed for scientific and commercial purposes. Despite the fact that it was shown in teleostei and other taxa that the gene for beta-actin is not the most stably expressed housekeeping gene (HKG), depending on the tissue and experimental treatment, the gene has been us Results To establish a reliable method for the measurement of immune gene expression in Gasterosteus aculeatus, sequences from the now available genome database and an EST library of the same species were used to select oligonucleotide primers for HKG, in order to perform quantitative reverse-transcription (RT) PCR. The expression stability of ten candidate reference genes was evaluated in three different tissues, and in five parasite treatment groups, using the three algorithms BestKeeper, geNorm and N Conclusion As they were the most stably expressed genes in all tissues examined, we suggest using the genes for the L13a ribosomal binding protein and ubiquitin as alternative or additional reference genes in expression analysis in Gasterosteus aculeatus.

    Reducción de la cobertura social para los fármacos antiartrósicos sintomáticos de acción lenta: una iniciativa de desinversión en Argentina, 2015-2017

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    In April 2016, the National Institute of Social Services for Retirees and Pensioners discontinued its policy of 100% coverage for 159 drugs (the “social subsidy”), including symptomatic slow-acting drugs for osteoarthritis (SYSADOAs), due to insufficient evidence of significant clinical benefit. We evaluated the effect of this measure on the use of SYSADOAs as well as non-steroidal anti-inflammatory drugs (NSAIDs), which were unaffected by this policy change. We compared outpatient dispensations of SYSADOAs and NSAIDs from 2015 to 2017, measuring dispensed units, retail price, and out-of-pocket expenses for beneficiaries each month. After the change in coverage, there was a 61.6% total decrease in SYSADOA units dispensed, and a 63.4% decrease in the final sales price to the public, measured in constant values. Dispensation was not reoriented towards NSAIDs, which fell by 6.1%. The incidence of new treatments decreased (from 6.4 to 3.3 treatments per 1,000 beneficiaries per month), as did their continuity. Beneficiaries’ out-of-pocket spending on SYSADOAs increased by 75.8% (at constant values). Disinvestment in interventions with questionable therapeutic value is an important tool in working toward the sustainability of health systems.En abril de 2016, el Instituto Nacional de Servicios Sociales para Jubilados y Pensionados excluyó del subsidio social la cobertura al 100% de 159 fármacos, entre ellos, los antiartrósicos sintomáticos de acción lenta o symptomatic slow-acting drugs for osteoarthritis (SySADOA), por insuficiente evidencia de beneficio clínico significativo. Evaluamos el efecto de esta medida sobre la utilización de SySADOA y de los antiinflamatorios no esteroides (AINE), no afectados por la medida. Se compararon las dispensas ambulatorias de los SySADOA y los AINE de 2015 a 2017, midiendo unidades dispensadas, precio de venta al público y gasto de bolsillo del beneficiario para cada mes. Luego de la medida, descendieron un 61,6% los envases de SySADOA dispensados y un 63,4% el monto total del precio de venta al público, medido en valores constantes. La dispensa no se reorientó hacia los AINE, que descendieron un 6,1%. Disminuyó tanto la incidencia de nuevos tratamientos (de 6,4 a 3,3 tratamientos por 1.000 beneficiarios por mes) como su continuidad. El gasto de bolsillo de los beneficiarios en SySADOA aumentó un 75,8% (a valores constantes). La desinversión en intervenciones de valor terapéutico cuestionable es una herramienta valiosa para la sustentabilidad de los sistemas de salud

    A versatile panel of reference gene assays for the measurement of chicken mRNA by quantitative PCR

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    Quantitative real-time PCR assays are widely used for the quantification of mRNA within avian experimental samples. Multiple stably-expressed reference genes, selected for the lowest variation in representative samples, can be used to control random technical variation. Reference gene assays must be reliable, have high amplification specificity and efficiency, and not produce signals from contaminating DNA. Whilst recent research papers identify specific genes that are stable in particular tissues and experimental treatments, here we describe a panel of ten avian gene primer and probe sets that can be used to identify suitable reference genes in many experimental contexts. The panel was tested with TaqMan and SYBR Green systems in two experimental scenarios: a tissue collection and virus infection of cultured fibroblasts. GeNorm and NormFinder algorithms were able to select appropriate reference gene sets in each case. We show the effects of using the selected genes on the detection of statistically significant differences in expression. The results are compared with those obtained using 28s ribosomal RNA, the present most widely accepted reference gene in chicken work, identifying circumstances where its use might provide misleading results. Methods for eliminating DNA contamination of RNA reduced, but did not completely remove, detectable DNA. We therefore attached special importance to testing each qPCR assay for absence of signal using DNA template. The assays and analyses developed here provide a useful resource for selecting reference genes for investigations of avian biology

    Impact of Reference Gene Selection for Target Gene Normalization on Experimental Outcome Using Real-Time qRT-PCR in Adipocytes

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    Background: With the current rise in obesity-related morbidities, real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) has become a widely used method for assessment of genes expressed and regulated by adipocytes. In order to measure accurate changes in relative gene expression and monitor intersample variability, normalization to endogenous control genes that do not change in relative expression is commonly used with qRT-PCR determinations. However, historical evidence has clearly demonstrated that the expression profiles of traditional control genes (e.g., b-actin, GAPDH, a-tubulin) are differentially regulated across multiple tissue types and experimental conditions. Methodology/Principal Findings: Therefore, we validated six commonly used endogenous control genes under diverse experimental conditions of inflammatory stress, oxidative stress, synchronous cell cycle progression and cellular differentiation in 3T3-L1 adipocytes using TaqMan qRT-PCR. Under each study condition, we further evaluated the impact of reference gene selection on experimental outcome using examples of target genes relevant to adipocyte function and differentiation. We demonstrate that multiple reference genes are regulated in a condition-specific manner that is not suitable for use in target gene normalization. Conclusion/Significance: Data are presented demonstrating that inappropriate reference gene selection can have profound influence on study conclusions ranging from divergent statistical outcome to inaccurate data interpretation of significan

    Applicability of RNA standards for evaluating RT-qPCR assays and platforms

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    The availability of diverse RT-qPCR assay formats and technologies hinder comparability of data between platforms. Reference standards to facilitate platform evaluation and comparability are needed. We have explored using universal RNA standards for comparing the performance of a novel qPCR platform (Fluidigm® BioMark™) against the widely used ABI 7900HT system. Our results show that such standards may form part of a toolkit to evaluate the key performance characteristics of platforms
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