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BACKGROUND: A first pilot study showed that an image-guided navigation system could improve resection margin rates in locally advanced (LARC) and locally recurrent rectal cancer (LRRC) patients. Incremental surgical innovation is often implemented without reimbursement consequences, health economic aspects should however also be taken into account. This study evaluates the early cost-effectiveness of navigated surgery compared to standard surgery in LARC and LRRC. METHODS: A Markov decision model was constructed to estimate the expected costs and outcomes for navigated and standard surgery. The input parameters were based on pilot data from a prospective (navigation cohort n = 33) and retrospective (control group n = 142) data. Utility values were measured in a comparable group (n = 63) through the EQ5D-5L. Additionally, sensitivity and value of information analyses were performed. RESULTS: Based on this early evaluation, navigated surgery showed incremental costs of 3141 and 2896 in LARC and LRRC. In LARC, navigated surgery resulted in 2.05 Quality-Adjusted Life Years (QALYs) vs 2.02 QALYs for standard surgery. For LRRC, we found 1.73 vs 1.67 QALYs respectively. This showed an Incremental Cost-Effectiveness Ratio (ICER) of 136.604 for LARC and 52.510 for LRRC per QALY gained. In scenario analyses, optimal utilization rates of the navigation technology lowered the ICER to 61.817 and 21.334 for LARC and LRRC. The ICERs of both indications were most sensitive to uncertainty surrounding the risk of progression in the first year after surgery, the risk of having a positive surgical margin, and the costs of the navigation system. CONCLUSION: Adding navigation system use is expected to be cost-effective in LRRC and has the potential to become cost-effective in LARC. To increase the probability of being cost-effective, it is crucial to optimize efficient use of both the hybrid OR and the navigation system and identify subgroups where navigation is expected to show higher effectiveness.
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Recidiva Local de Neoplasia , Neoplasias Retais , Análise Custo-Benefício , Humanos , Margens de Excisão , Recidiva Local de Neoplasia/cirurgia , Projetos Piloto , Estudos Prospectivos , Anos de Vida Ajustados por Qualidade de Vida , Neoplasias Retais/cirurgia , Estudos RetrospectivosRESUMO
BACKGROUND: Various databases on genetically modified organisms (GMOs) exist, all with their specific focus to facilitate access to information needed for, e. g., the assistance in risk assessment, the development of detection and identification strategies or inspection and control activities. Each database has its unique approach towards the subject. Often these databases use different terminology to describe the GMOs. For adequate GMO addressing and identification and exchange of GMO-related information it is necessary to use commonly agreed upon concepts and terminology. RESULT: A hierarchically structured controlled vocabulary describing the genetic elements inserted into conventional GMOs, and GMOs developed by the use of gen(om)e-editing is presented: the GMO genetic element thesaurus (GMO-GET). GMO-GET can be used for GMO-related documentation, including GMO-related databases. It has initially been developed on the basis of two GMO databases, i.e. the Biosafety Clearing-House and the EUginius database. CONCLUSION: The use of GMO-GET will enable consistent and compatible information (harmonisation), also allowing an accurate exchange of information between the different data systems and thereby facilitating their interoperability. GMO-GET can also be used to describe genetic elements that are altered in organisms obtained through current targeted genome-editing techniques.
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Edição de Genes , Organismos Geneticamente Modificados , Plantas Geneticamente Modificadas , Vocabulário Controlado , Consenso , Bases de Dados Factuais , Plantas Geneticamente Modificadas/genéticaRESUMO
BACKGROUND: Compare antimicrobial efficacy of a quarternary ammonium silane (QAS)/k21 as an intracanal medicament against E. faecalis and C. albicans biofilms formed on root dentin. METHODOLOGY: Dentin blocks were sterilized and E. faecalis and C. albicans microbial colonies were counted for colony-forming-units against 2%k21, 2%CHX and Ca(OH)2 medicaments. Biofilm colonies after 7 days on dentin were analysed using confocal laser scanning microscopy with live/dead bacterial viability staining. TEM was done to study dentin collagen matrix. Dentin discs from 3rd day and 7th day well plate was used for Raman spectra and observed under fluorescent-microscope. Docking studies were carried out on MMP-2 S1 binding-domain with k21. RESULTS: There was reduction of E. faecalis/C. albicans when k21, chlorhexidine and calcium hydroxide were used with highest percentage in 2%k21 treated specimens. 2%k21 showed dense and regular collagen network with intact cross-banding and decreased Raman intensity for 2%k21 on 3rd day. NaOCl + k21 showed least adherence, whereas saline groups showed highest adherence of E. faecalis and C. albicans to root-canal dentin. Alizarin red staining of hDPSCs revealed calcium deposition in all groups with significant difference seen amongst 2%k21 groups. MMP-2 ligand binding was seen accurately indicating possible target sites for k21 intervention. CONCLUSION: 2%k21 can be considered as alternative intracanal medicament.
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Compostos de Amônio , Silanos , Biofilmes , Hidróxido de Cálcio , Clorexidina/farmacologia , Cavidade Pulpar , Dentina , Enterococcus faecalis , Humanos , Irrigantes do Canal Radicular/farmacologiaRESUMO
In the original publication, the starting point in time for the three feeding trials.
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In 2012, a controversial study on the long-term toxicity of a Roundup herbicide and the glyphosate-tolerant genetically modified (GM) maize NK603 was published. The EC-funded G-TwYST research consortium tested the potential subchronic and chronic toxicity as well as the carcinogenicity of the glyphosate-resistant genetically modified maize NK603 by performing two 90-day feeding trials, one with GM maize inclusion rates of 11 and 33% and one with inclusion rates of up to 50%, as well as a 2-year feeding trial with inclusion rates of 11 and 33% in male and female Wistar Han RCC rats by taking into account OECD Guidelines for the testing of chemicals and EFSA recommendations on the safety testing of whole-food/feed in laboratory animals. In all three trials, the NK603 maize, untreated and treated once with Roundup during its cultivation, and the conventional counterpart were tested. Differences between each test group and the control group were evaluated. Equivalence was assessed by comparing the observed difference to differences between non-GM reference groups in previous studies. In case of significant differences, whether the effects were dose-related and/or accompanied by changes in related parameters including histopathological findings was evaluated. It is concluded that no adverse effects related to the feeding of the NK603 maize cultivated with or without Roundup for up to 2 years were observed. Based on the outcome of the subchronic and combined chronic toxicity/carcinogenicity studies, recommendations on the scientific justification and added value of long-term feeding trials in the GM plant risk assessment process are presented.
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Ração Animal/normas , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/etiologia , Alimentos Geneticamente Modificados , Glicina/análogos & derivados , Herbicidas/toxicidade , Plantas Geneticamente Modificadas/efeitos dos fármacos , Zea mays , Animais , Testes de Carcinogenicidade , Resistência a Medicamentos/genética , Feminino , Glicina/toxicidade , Masculino , Plantas Geneticamente Modificadas/genética , Ratos Wistar , Testes de Toxicidade Crônica , Testes de Toxicidade Subcrônica , Zea mays/efeitos dos fármacos , Zea mays/genética , GlifosatoRESUMO
In most countries, systems are in place to analyse food products for the potential presence of genetically modified organisms (GMOs), to enforce labelling requirements and to screen for the potential presence of unauthorised GMOs. With the growing number of GMOs on the world market, a larger diversity of methods is required for informative analyses. In this paper, the specificity of an extended screening set consisting of 32 screening methods to identify different crop species (endogenous genes) and GMO elements was verified against 59 different GMO reference materials. In addition, a cost- and time-efficient strategy for DNA isolation, screening and identification is presented. A module for semiautomated analysis of the screening results and planning of subsequent event-specific tests for identification has been developed. The Excel-based module contains information on the experimentally verified specificity of the element methods and of the EU authorisation status of the GMO events. If a detected GMO element cannot be explained by any of the events as identified in the same sample, this may indicate the presence of an unknown unauthorised GMO that may not yet have been assessed for its safety for humans, animals or the environment.
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Produtos Agrícolas/genética , DNA de Plantas/genética , Alimentos Geneticamente Modificados , Plantas Geneticamente Modificadas/genética , Reação em Cadeia da Polimerase/métodos , DNA de Plantas/isolamento & purificação , Análise de Alimentos/métodos , Reação em Cadeia da Polimerase/economiaRESUMO
The emergence of high-throughput, massive or next-generation sequencing technologies has created a completely new foundation for molecular analyses. Various selective enrichment processes are commonly applied to facilitate detection of predefined (known) targets. Such approaches, however, inevitably introduce a bias and are prone to miss unknown targets. Here we review the application of high-throughput sequencing technologies and the preparation of fit-for-purpose whole genome shotgun sequencing libraries for the detection and characterization of genetically modified and derived products. The potential impact of these new sequencing technologies for the characterization, breeding selection, risk assessment, and traceability of genetically modified organisms and genetically modified products is yet to be fully acknowledged. The published literature is reviewed, and the prospects for future developments and use of the new sequencing technologies for these purposes are discussed.
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Genoma , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Organismos Geneticamente Modificados , Transcriptoma , TransgenesRESUMO
With the increased global production of different genetically modified (GM) plant varieties, chances increase that unauthorized GM organisms (UGMOs) may enter the food chain. At the same time, the detection of UGMOs is a challenging task because of the limited sequence information that will generally be available. PCR-based methods are available to detect and quantify known UGMOs in specific cases. If this approach is not feasible, DNA enrichment of the unknown adjacent sequences of known GMO elements is one way to detect the presence of UGMOs in a food or feed product. These enrichment approaches are also known as chromosome walking or gene walking (GW). In recent years, enrichment approaches have been coupled with next generation sequencing (NGS) analysis and implemented in, amongst others, the medical and microbiological fields. The present review will provide an overview of these approaches and an evaluation of their applicability in the identification of UGMOs in complex food or feed samples.
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DNA/genética , Organismos Geneticamente Modificados/genética , Passeio de Cromossomo , Alimentos Geneticamente Modificados , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Hibridização de Ácido Nucleico , Reação em Cadeia da PolimeraseRESUMO
Species identification using DNA barcodes has been widely adopted by forensic scientists as an effective molecular tool for tracking adulterations in food and for analysing samples from alleged wildlife crime incidents. DNA barcoding is an approach that involves sequencing of short DNA sequences from standardized regions and comparison to a reference database as a molecular diagnostic tool in species identification. In recent years, remarkable progress has been made towards developing DNA metabarcoding strategies, which involves next-generation sequencing of DNA barcodes for the simultaneous detection of multiple species in complex samples. Metabarcoding strategies can be used in processed materials containing highly degraded DNA e.g. for the identification of endangered and hazardous species in traditional medicine. This review aims to provide insight into advances of plant and animal DNA barcoding and highlights current practices and recent developments for DNA metabarcoding of food and wildlife forensic samples from a practical point of view. Special emphasis is placed on new developments for identifying species listed in the Convention on International Trade of Endangered Species (CITES) appendices for which reliable methods for species identification may signal and/or prevent illegal trade. Current technological developments and challenges of DNA metabarcoding for forensic scientists will be assessed in the light of stakeholders' needs.
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Animais Selvagens/genética , DNA/genética , Alimentos , Genética Forense , Plantas/genética , Animais , Biologia Computacional , Código de Barras de DNA Taxonômico , Sequenciamento de Nucleotídeos em Larga Escala/métodosRESUMO
The GRACE (GMO Risk Assessment and Communication of Evidence; www.grace-fp7.eu ) project was funded by the European Commission within the 7th Framework Programme. A key objective of GRACE was to conduct 90-day animal feeding trials, animal studies with an extended time frame as well as analytical, in vitro and in silico studies on genetically modified (GM) maize in order to comparatively evaluate their use in GM plant risk assessment. In the present study, the results of a 1-year feeding trial with a GM maize MON810 variety, its near-isogenic non-GM comparator and an additional conventional maize variety are presented. The feeding trials were performed by taking into account the guidance for such studies published by the EFSA Scientific Committee in 2011 and the OECD Test Guideline 452. The results obtained show that the MON810 maize at a level of up to 33 % in the diet did not induce adverse effects in male and female Wistar Han RCC rats after a chronic exposure.
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Ração Animal , Alimentos Geneticamente Modificados/toxicidade , Nível de Saúde , Plantas Geneticamente Modificadas/toxicidade , Zea mays/genética , Ração Animal/normas , Ração Animal/toxicidade , Animais , Feminino , Masculino , Ratos Endogâmicos , Medição de Risco , Testes de Toxicidade CrônicaRESUMO
BACKGROUND: Data analysis of omics data should be performed by multivariate analysis such as principal component analysis (PCA). The way data are clustered in PCA is of major importance to develop some classification systems based on multivariate analysis, such as soft independent modeling of class analogy (SIMCA). In a previous study a one-class classifier based on SIMCA was built using microarray data from a set of potatoes. The PCA grouped the transcriptomic data according to varieties. The present work aimed to use PCA to verify the clustering of the proteomic profiles for the same potato varieties. RESULTS: Proteomic profiles of five potato varieties (Biogold, Fontane, Innovator, Lady Rosetta and Maris Piper) were evaluated by two-dimensional gel electrophoresis (2-DE) performed on two immobilized pH gradient (IPG) strip lengths, 13 and 24 cm, both under pH range 4-7. For each strip length, two gels were prepared from each variety; in total there were ten gels per analysis. For 13 cm strips, 199-320 spots were detected per gel, and for 24 cm strips, 365-684 spots. CONCLUSION: All four PCAs performed with these datasets presented clear grouping of samples according to the varieties. The data presented here showed that PCA was applicable for proteomic analysis of potato and was able to separate the samples by varieties. © 2016 Society of Chemical Industry.
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Produtos Agrícolas/química , Regulação da Expressão Gênica de Plantas , Modelos Biológicos , Proteínas de Vegetais Comestíveis/análise , Proteínas de Plantas/metabolismo , Tubérculos/química , Solanum tuberosum/química , Análise por Conglomerados , Produtos Agrícolas/metabolismo , Perfilação da Expressão Gênica , Países Baixos , Proteínas de Plantas/genética , Proteínas de Vegetais Comestíveis/biossíntese , Tubérculos/metabolismo , Análise de Componente Principal , Proteoma/biossíntese , Proteômica/métodos , Solanum tuberosum/metabolismo , Especificidade da Espécie , Eletroforese em Gel Diferencial BidimensionalRESUMO
In January 2014, an international meeting sponsored by the International Life Sciences Institute/Health and Environmental Sciences Institute and the Canadian Food Inspection Agency titled "Genetic Basis of Unintended Effects in Modified Plants" was held in Ottawa, Canada, bringing together over 75 scientists from academia, government, and the agro-biotech industry. The objectives of the meeting were to explore current knowledge and identify areas requiring further study on unintended effects in plants and to discuss how this information can inform and improve genetically modified (GM) crop risk assessments. The meeting featured presentations on the molecular basis of plant genome variability in general, unintended changes at the molecular and phenotypic levels, and the development and use of hypothesis-driven evaluations of unintended effects in assessing conventional and GM crops. The development and role of emerging "omics" technologies in the assessment of unintended effects was also discussed. Several themes recurred in a number of talks; for example, a common observation was that no system for genetic modification, including conventional methods of plant breeding, is without unintended effects. Another common observation was that "unintended" does not necessarily mean "harmful". This paper summarizes key points from the information presented at the meeting to provide readers with current viewpoints on these topics.
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Produtos Agrícolas/genética , Alimentos Geneticamente Modificados , Plantas Geneticamente Modificadas/genética , Qualidade de Produtos para o Consumidor , Humanos , Medição de RiscoRESUMO
PURPOSE: Many conditions and characteristics are cross-sectionally associated with nocturia. However, to our knowledge longitudinal associations of frequency-volume chart based nocturia have not yet been studied. We identify (modifiable) determinants of nocturia in older men in a longitudinal setting. MATERIALS AND METHODS: A longitudinal, community based study was conducted among 1,688 men age 50 to 78 years in Krimpen aan den IJssel, The Netherlands with planned followup rounds at 2, 4 and 6 years. Men without a history of radical prostatectomy, transurethral surgery, or bladder or prostate cancer were included in the study. Data were obtained using frequency-volume charts, from which the nocturnal voiding frequency, maximum voided volume and (nocturnal) urine production were determined. Nocturia was defined as a nocturnal voiding frequency of 2 or more episodes. Polyuria was defined as greater than 2,800 ml voided per 24 hours. For nocturnal polyuria we used the 2 definitions of 1) greater than 33% of 24-hour voided volume and 2) nocturnal urine production of greater than 90 ml per hour. Conditions and characteristics were determined via medical examinations and questionnaires. A generalized linear mixed effect model was used to determine factors longitudinally associated with nocturia. RESULTS: Age (50 to 55 years vs greater than 60 years), maximum voided volume (greater than 300 ml vs less than 300 ml), 24-hour polyuria, nocturnal polyuria (both definitions) and lower urinary tract symptoms were all longitudinally associated with an increased prevalence of nocturia in older men. CONCLUSIONS: A smaller maximum voided volume, lower urinary tract symptoms, 24-hour polyuria and nocturnal polyuria are significant and potentially modifiable determinants of nocturia. The finding that both definitions for nocturnal polyuria are independent significant determinants may indicate a 2-step etiologic process for nocturnal polyuria.
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Noctúria/complicações , Noctúria/etiologia , Idoso , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-IdadeRESUMO
The ever-increasing production of genetically modified crops generates a demand for high-throughput DNA-based methods for the enforcement of genetically modified organisms (GMO) labelling requirements. The application of standard real-time PCR will become increasingly costly with the growth of the number of GMOs that is potentially present in an individual sample. The present work presents the results of an innovative approach in genetically modified crops analysis by DNA based methods, which is the use of a microfluidic dynamic array as a high throughput multi-detection system. In order to evaluate the system, six test samples with an increasing degree of complexity were prepared, preamplified and subsequently analysed in the Fluidigm system. Twenty-eight assays targeting different DNA elements, GM events and species-specific reference genes were used in the experiment. The large majority of the assays tested presented expected results. The power of low level detection was assessed and elements present at concentrations as low as 0.06 % were successfully detected. The approach proposed in this work presents the Fluidigm system as a suitable and promising platform for GMO multi-detection.
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Beta vulgaris/genética , DNA de Plantas/isolamento & purificação , Glycine max/genética , Técnicas Analíticas Microfluídicas/instrumentação , Plantas Geneticamente Modificadas , Zea mays/genética , Calibragem , Primers do DNA , DNA de Plantas/genética , Ensaios de Triagem em Larga Escala , Humanos , Limite de Detecção , Reação em Cadeia da PolimeraseRESUMO
The growing number of biotech crops with novel genetic elements increasingly complicates the detection of genetically modified organisms (GMOs) in food and feed samples using conventional screening methods. Unauthorized GMOs (UGMOs) in food and feed are currently identified through combining GMO element screening with sequencing the DNA flanking these elements. In this study, a specific and sensitive qPCR assay was developed for vip3A element detection based on the vip3Aa20 coding sequences of the recently marketed MIR162 maize and COT102 cotton. Furthermore, SiteFinding-PCR in combination with Sanger, Illumina or Pacific BioSciences (PacBio) sequencing was performed targeting the flanking DNA of the vip3Aa20 element in MIR162. De novo assembly and Basic Local Alignment Search Tool searches were used to mimic UGMO identification. PacBio data resulted in relatively long contigs in the upstream (1,326 nucleotides (nt); 95 % identity) and downstream (1,135 nt; 92 % identity) regions, whereas Illumina data resulted in two smaller contigs of 858 and 1,038 nt with higher sequence identity (>99 % identity). Both approaches outperformed Sanger sequencing, underlining the potential for next-generation sequencing in UGMO identification.
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Agricultura/legislação & jurisprudência , Proteínas de Bactérias/genética , Gossypium/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Plantas Geneticamente Modificadas/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , Zea mays/genética , Contaminação de Alimentos/legislação & jurisprudênciaRESUMO
The GMO Risk Assessment and Communication of Evidence (GRACE; www.grace-fp7.eu ) project is funded by the European Commission within the 7th Framework Programme. A key objective of GRACE is to conduct 90-day animal feeding trials, animal studies with an extended time frame as well as analytical, in vitro and in silico studies on genetically modified (GM) maize in order to comparatively evaluate their use in GM plant risk assessment. In the present study, the results of two 90-day feeding trials with two different GM maize MON810 varieties, their near-isogenic non-GM varieties and four additional conventional maize varieties are presented. The feeding trials were performed by taking into account the guidance for such studies published by the EFSA Scientific Committee in 2011 and the OECD Test Guideline 408. The results obtained show that the MON810 maize at a level of up to 33 % in the diet did not induce adverse effects in male and female Wistar Han RCC rats after subchronic exposure, independently of the two different genetic backgrounds of the event.
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Ração Animal , Alimentos Geneticamente Modificados/toxicidade , Plantas Geneticamente Modificadas/toxicidade , Zea mays/genética , Administração Oral , Ração Animal/normas , Ração Animal/toxicidade , Animais , Peso Corporal , Qualidade de Produtos para o Consumidor , Dieta , Feminino , Masculino , Tamanho do Órgão , Ratos Endogâmicos , Projetos de Pesquisa , Medição de Risco , Testes de Toxicidade SubcrônicaRESUMO
An important part of the current hazard identification of novel plant varieties is comparative targeted analysis of the novel and reference varieties. Comparative analysis will become much more informative with unbiased analytical approaches, e.g. omics profiling. Data analysis estimating the similarity of new varieties to a reference baseline class of known safe varieties would subsequently greatly facilitate hazard identification. Further biological and eventually toxicological analysis would then only be necessary for varieties that fall outside this reference class. For this purpose, a one-class classifier tool was explored to assess and classify transcriptome profiles of potato (Solanum tuberosum) varieties in a model study. Profiles of six different varieties, two locations of growth, two year of harvest and including biological and technical replication were used to build the model. Two scenarios were applied representing evaluation of a 'different' variety and a 'similar' variety. Within the model higher class distances resulted for the 'different' test set compared with the 'similar' test set. The present study may contribute to a more global hazard identification of novel plant varieties.
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Perfilação da Expressão Gênica , Modelos Teóricos , Plantas Geneticamente Modificadas/toxicidade , Solanum tuberosum/genética , TranscriptomaRESUMO
This commentary focuses on the potential added value of and need for (sub)-chronic testing of whole genetically modified (GM) foods in rodents to assess their safety. Such routine testing should not be required since, due to apparent weaknesses in the approach, it does not add to current risk assessment of GM foods. Moreover, the demand for routine testing using animals is in conflict with the European Union (EU) Commission's efforts to reduce animal experimentation. Regulating agencies in the EU are invited to respect the sound scientific principles applied to the risk assessment of foods derived from GM plants and not to interfere in the risk assessment by introducing extra requirements based on pseudo-scientific or political considerations.
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Alimentos Geneticamente Modificados/efeitos adversos , Legislação sobre Alimentos , Animais , Exposição Ambiental , União Europeia , Inocuidade dos Alimentos , Ratos , Medição de Risco/métodosRESUMO
BACKGROUND: Patient online access to medical records is assumed to foster patient empowerment and advance patient-centred healthcare. Since July 2020, patients in the Netherlands have been legally entitled to electronically access their medical record in general practice. Experience from pioneering countries has shown that despite high patient interest, user rates often remain low. How to best support implementation depends on individual needs and expectations of patient populations, which are as yet unknown in the Dutch context. OBJECTIVE: To understand Dutch patients' needs and expectations with regard to online access to their medical record in general practice. METHOD: Twenty participants completed semi-structured individual interviews via video or telephone call. Transcripts of interviews underwent template analysis combining deductive and inductive coding using Atlas.ti software. RESULTS: Patients' needs and expectations ranged across three overlapping areas: (i) prerequisites for getting online access; (ii) using online access; and (iii) the impact on interaction with healthcare providers. Patients expected benefits from online access such as better overview, empowerment and improved communication with their general practitioner but identified needs regarding technological difficulties, data privacy and complex medical language in their record. CONCLUSION: The concerns and obstacles participants identified point towards the need for organisational changes in general practice, for example, adjusted documentation practices, and the key role of the general practitioner and staff in promoting and facilitating online access. IMPLICATIONS: Implementation strategies addressing needs identified in this study may help to unlock the full potential of online access to achieve desired outcomes of patient involvement and satisfaction.
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BACKGROUND: With the increasing number of GMOs on the global market the maintenance of European GMO regulations is becoming more complex. For the analysis of a single food or feed sample it is necessary to assess the sample for the presence of many GMO-targets simultaneously at a sensitive level. Several methods have been published regarding DNA-based multidetection. Multiplex ligation detection methods have been described that use the same basic approach: i) hybridisation and ligation of specific probes, ii) amplification of the ligated probes and iii) detection and identification of the amplified products. Despite they all have this same basis, the published ligation methods differ radically. The present study investigated with real-time PCR whether these different ligation methods have any influence on the performance of the probes. Sensitivity and the specificity of the padlock probes (PLPs) with the ligation protocol with the best performance were also tested and the selected method was initially validated in a laboratory exchange study. RESULTS: Of the ligation protocols tested in this study, the best results were obtained with the PPLMD I and PPLMD II protocols and no consistent differences between these two protocols were observed. Both protocols are based on padlock probe ligation combined with microarray detection. Twenty PLPs were tested for specificity and the best probes were subjected to further evaluation. Up to 13 targets were detected specifically and simultaneously. During the interlaboratory exchange study similar results were achieved by the two participating institutes (NIB, Slovenia, and RIKILT, the Netherlands). CONCLUSIONS: From the comparison of ligation protocols it can be concluded that two protocols perform equally well on the basis of the selected set of PLPs. Using the most ideal parameters the multiplicity of one of the methods was tested and 13 targets were successfully and specifically detected. In the interlaboratory exchange study it was shown that the selected method meets the 0.1% sensitivity criterion. The present study thus shows that specific and sensitive multidetection of GMO targets is now feasible.