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In 2014, the International Society for Extracellular Vesicles (ISEV) introduced the Minimal Information for Studies of Extracellular Vesicles (MISEV) guidelines to establish standards for extracellular vesicle (EV) research. These guidelines aimed to enhance reliability and reproducibility, addressing the expanding field of EV science. EVs, membrane-bound particles released by cells, play crucial roles in intercellular communication and are potential biomarkers for various conditions. Over the years, the EV landscape witnessed a surge in publications, emphasizing their roles in cancer and immune modulation. In response, the MISEV guidelines underwent evolution, leading to the MISEV2018 update. This version, generated through community outreach, provided a comprehensive framework for EV research methodologies, emphasizing separation, characterization, reporting standards, and community engagement. The MISEV2018 guidelines reflected responsiveness to feedback, acknowledging the evolving EV research landscape. The guidelines served as a testament to the commitment of the scientific community to rigorous standards and the collective discernment of experts. The present article compares previous MISEV guidelines with its 2023 counterpart, highlighting advancements, changes, and impacts on EV research standardization. The 2023 guidelines build upon the 2018 principles, offering new recommendations for emerging areas. This comparative exploration contributes to understanding the transformative journey in EV research, emphasizing MISEV's pivotal role and the scientific community's adaptability to challenges.
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Vesículas Extracelulares , Vesículas Extracelulares/metabolismo , Humanos , Neoplasias/terapia , Neoplasias/imunologia , Guias como Assunto , Pesquisa Biomédica/métodos , Comunicação CelularRESUMO
BACKGROUND: The scratch assay is commonly used in cell biology to evaluate cell migration; however, it is not a standardized method; it produces highly variable gap dimensions. We design a printable device, comprising a single wounding tool and a guide, and compared the gap produced by our device and the traditional method. The deviceis printable in a standard 3D printer. Cells were seeded on a 24-well plate. After reaching full confluency, a gap was created using the traditional method (scratch assay with a pipette tip), a pipette tip and the guide of the device, or the single wounding tool and the guide. The gaps were observed for up to 48 h under a light microscope and analyzed. RESULTS: The results show that the traditional method produces irregular and not straight gaps, and had the worst cell migration rates compared to the other groups. The wounding tool produced scrape signs at the well surface. CONCLUSION: The guide and pipette tip delivered the best results for the scratch assay. SIGNIFICANCE: The use of the guide and the pipette tip for the scratch assay allows allows to perform reproducible cell migration experiments.
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With expansion of chimeric antigen receptor (CAR) T cell therapy and broader utilization of anti-cytokine directed therapeutics for toxicity mitigation, the routine assessment of cytokines may enhance understanding of toxicity profiles, guide therapeutic interventions, and facilitate cross-trial comparisons. As specific cytokine elevations can correlate with and provide insights into CAR T cell toxicity, mitigation strategies, and response, we explored the reporting of cytokine detection methods and assessed for the correlation of cytokines to cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) across clinical trials. In this analysis, we reviewed 21 clinical trials across 60 manuscripts that featured a US Food and Drug Administration-approved CAR T cell construct or one of its predecessors. We highlight substantial variability and limited reporting of cytokine measurement platforms and panels used across CAR T cell clinical trials. Specifically, across 60 publications, 28 (46.7%) did not report any cytokine data, representing 6 of 21 (28.6%) clinical trials. In the 15 trials reporting cytokine data, at least 4 different platforms were used. Furthermore, correlation of cytokines with ICANS, CRS, and CRS severity was limited. Considering the fundamental role of cytokines in CAR T cell toxicity, our manuscript supports the need to establish standardization of cytokine measurements as a key biomarker essential to improving outcomes of CAR T cell therapy.
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The evaluation of biopsied solid organ tissue has long relied on visual examination using a microscope. Immunohistochemistry is critical in this process, labeling and detecting cell lineage markers and therapeutic targets. However, while the practice of immunohistochemistry has reshaped diagnostic pathology and facilitated improvements in cancer treatment, it has also been subject to pervasive challenges with respect to standardization and reproducibility. Efforts are ongoing to improve immunohistochemistry, but for some applications, the benefit of such initiatives could be impeded by its reliance on monospecific antibody-protein reagents and limited multiplexing capacity. This perspective surveys the relevant challenges facing traditional immunohistochemistry and describes how mass spectrometry, particularly liquid chromatography-tandem mass spectrometry, could help alleviate problems. In particular, targeted mass spectrometry assays could facilitate measurements of individual proteins or analyte panels, using internal standards for more robust quantification and improved interlaboratory reproducibility. Meanwhile, untargeted mass spectrometry, showcased to date clinically in the form of amyloid typing, is inherently multiplexed, facilitating the detection and crude quantification of 100s to 1000s of proteins in a single analysis. Further, data-independent acquisition has yet to be applied in clinical practice, but offers particular strengths that could appeal to clinical users. Finally, we discuss the guidance that is needed to facilitate broader utilization in clinical environments and achieve standardization.
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Proteínas , Proteômica , Proteômica/métodos , Reprodutibilidade dos Testes , Espectrometria de Massas , AnticorposRESUMO
BACKGROUND: Blood transcriptomic analysis is widely used to provide a detailed picture of a physiological state with potential outcomes for applications in diagnostics and monitoring of the immune response to vaccines. However, multi-species transcriptomic analysis is still a challenge from a technological point of view and a standardized workflow is urgently needed to allow interspecies comparisons. RESULTS: Here, we propose a single and complete total RNA-Seq workflow to generate reliable transcriptomic data from blood samples from humans and from animals typically used in preclinical models. Blood samples from a maximum of six individuals and four different species (rabbit, non-human primate, mouse and human) were extracted and sequenced in triplicates. The workflow was evaluated using different wet-lab and dry-lab criteria, including RNA quality and quantity, the library molarity, the number of raw sequencing reads, the Phred-score quality, the GC content, the performance of ribosomal-RNA and globin depletion, the presence of residual DNA, the strandness, the percentage of coding genes, the number of genes expressed, and the presence of saturation plateau in rarefaction curves. We identified key criteria and their associated thresholds to be achieved for validating the transcriptomic workflow. In this study, we also generated an automated analysis of the transcriptomic data that streamlines the validation of the dataset generated. CONCLUSIONS: Our study has developed an end-to-end workflow that should improve the standardization and the inter-species comparison in blood transcriptomics studies. In the context of vaccines and drug development, RNA sequencing data from preclinical models can be directly compared with clinical data and used to identify potential biomarkers of value to monitor safety and efficacy.
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Perfilação da Expressão Gênica , Vacinas , Humanos , Animais , Camundongos , Coelhos , Fluxo de Trabalho , Transcriptoma , RNA , Sequenciamento de Nucleotídeos em Larga EscalaRESUMO
Insulin-like growth factor 1 (IGF-1), primarily synthesized in the liver, was initially discovered due to its capacity to replicate the metabolic effects of insulin. Subsequently, it emerged as a key regulator of the actions of growth hormone (GH), managing critical processes like cell proliferation, differentiation, and apoptosis. Notably, IGF-1 displays a longer half-life compared to GH, making it less susceptible to factors that may affect GH concentrations. Consequently, the measurement of IGF-1 proves to be more specific and sensitive when diagnosing conditions such as acromegaly or GH deficiency. The recognition of the existence of IGFBPs and their potential to interfere with IGF-1 immunoassays urged the implementation of various techniques to moderate this issue and provide accurate IGF-1 results. Additionally, in response to the limitations associated with IGF-1 immunoassays and the occurrence of discordant IGF-1 results, modern mass spectrometric methods were developed to facilitate the quantification of IGF-1 levels. Taking advantage of their ability to minimize the interference caused by IGF-1 variants, mass spectrometric methods offer the capacity to deliver robust, reliable, and accurate IGF-1 results, relying on the precision of mass measurements. This also enables the potential detection of pathogenic mutations through protein sequence analysis. However, despite the analytical challenges, the discordance in IGF-1 reference intervals can be attributed to a multitude of factors, potentially leading to distinct interpretations of results. The establishment of reference intervals for each assay is a demanding task, and it requires nationwide multicenter collaboration among laboratorians, clinicians, and assay manufacturers to achieve this common goal in a cost-effective and resource-efficient manner. In this comprehensive review, we examine the challenges associated with the standardization of IGF-1 measurement methods, the minimization of pre-analytical factors, and the harmonization of reference intervals. Particular emphasis will be placed on the development of IGF-1 measurement techniques using "top-down" or "bottom-up" mass spectrometric methods.
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Fator de Crescimento Insulin-Like I , Humanos , Fator de Crescimento Insulin-Like I/análise , Fator de Crescimento Insulin-Like I/metabolismo , Imunoensaio/métodos , Espectrometria de Massas/métodos , Peptídeos Semelhantes à InsulinaRESUMO
Distributed network studies and multisite studies assess drug safety and effectiveness in diverse populations by pooling information. Targeting groups of clinical or policy interest (including specific sites or site combinations) and applying weights based on effect measure modifiers (EMMs) prior to pooling estimates within multisite studies may increase interpretability and improve precision. We simulated a 4-site study, standardized each site using inverse odds weights (IOWs) to resemble the 3 smallest sites or the smallest site, estimated IOW-weighted risk differences (RDs), and combined estimates with inverse variance weights (IVWs). We also created an artificial distributed network in the Clinical Practice Research Datalink (CPRD) Aurum consisting of 1 site for each geographic region. We compared metformin and sulfonylurea initiators with respect to mortality, targeting the smallest region. In the simulation, IOWs reduced differences between estimates and increased precision when targeting the 3 smallest sites or the smallest site. In the CPRD Aurum study, the IOW + IVW estimate was also more precise (smallest region: RD = 5.41% [95% CI, 1.03-9.79]; IOW + IVW estimate: RD = 3.25% [95% CI, 3.07-3.43]). When performing pharmacoepidemiologic research in distributed networks or multisite studies in the presence of EMMs, designation of target populations has the potential to improve estimate precision and interpretability. This article is part of a Special Collection on Pharmacoepidemiology.
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Hipoglicemiantes , Metformina , Farmacoepidemiologia , Compostos de Sulfonilureia , Humanos , Farmacoepidemiologia/métodos , Compostos de Sulfonilureia/uso terapêutico , Hipoglicemiantes/uso terapêutico , Metformina/uso terapêutico , Estudos Multicêntricos como Assunto , Estados Unidos , Simulação por ComputadorRESUMO
External validity is an important part of epidemiologic research. To validly estimate effects in specific external target populations using a chosen effect measure (ie, "transport"), some methods require that one account for all effect measure modifiers (EMMs). However, little is known about how including other variables that are not EMMs (ie, non-EMMs) in adjustment sets affects estimates. Using simulations, we evaluated how inclusion of non-EMMs affected estimation of the transported risk difference (RD) by assessing the impacts of covariates that (1) differ (or not) between the trial and the target, (2) are associated with the outcome (or not), and (3) modify the RD (or not). We assessed variation and bias when covariates with each possible combination of these factors were used to transport RDs using outcome modeling or inverse odds weighting. Inclusion of variables that differed in distribution between the populations but were non-EMMs reduced precision, regardless of whether they were associated with the outcome. However, non-EMMs associated with selection did not amplify bias resulting from omission of necessary EMMs. Including all variables associated with the outcome may result in unnecessarily imprecise estimates when estimating treatment effects in external target populations.
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Viés , Humanos , Simulação por ComputadorRESUMO
In this paper, we advocate and expand upon a previously described monitoring strategy for efficient and robust estimation of disease prevalence and case numbers within closed and enumerated populations such as schools, workplaces, or retirement communities. The proposed design relies largely on voluntary testing, which is notoriously biased (e.g., in the case of coronavirus disease 2019) due to nonrepresentative sampling. The approach yields unbiased and comparatively precise estimates with no assumptions about factors underlying selection of individuals for voluntary testing, building on the strength of what can be a small random sampling component. This component enables the use of a recently proposed "anchor stream" estimator, a well-calibrated alternative to classical capture-recapture (CRC) estimators based on 2 data streams. We show that this estimator is equivalent to a direct standardization based on "capture," that is, selection (or not) by the voluntary testing program, made possible by means of a key parameter identified by design. This equivalency simultaneously allows for novel 2-stream CRC-like estimation of general mean values (e.g., means of continuous variables like antibody levels or biomarkers). For inference, we propose adaptations of Bayesian credible intervals when estimating case counts and bootstrapping when estimating means of continuous variables. We use simulations to demonstrate significant precision benefits relative to random sampling alone.
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Projetos de Pesquisa , Humanos , Teorema de Bayes , BiomarcadoresRESUMO
Precise determination of circulating parathyroid hormone (PTH) concentration is crucial to diagnose and manage various disease conditions, including the chronic kidney disease-mineral and bone disorder. However, the lack of standardization in PTH assays is challenging for clinicians, potentially leading to medical errors because the different assays do not provide equivalent results and use different reference ranges. Here, we aimed to evaluate the impact of recalibrating PTH immunoassays by means of a recently developed LC-MS/MS method as the reference. Utilizing a large panel of pooled plasma samples with PTH concentrations determined by the LC-MS/MS method calibrated with the World Health Organization (WHO) 95/646 International Standard, five PTH immunoassays were recalibrated. The robustness of this standardization was evaluated over time using different sets of samples. The recalibration successfully reduced inter-assay variability with harmonization of PTH measurements across different assays. By recalibrating the assays based on the WHO 95/646 International Standard, we demonstrated the feasibility for standardizing PTH measurement results and adopting common reference ranges for PTH assays, facilitating a more consistent interpretation of PTH values. The recalibration process aligns PTH results obtained from various immunoassays with the LC-MS/MS method, providing more consistent and reliable measurements. Thus, establishing true standardization across all PTH assays is crucial to ensure consistent interpretation and clinical decision-making.
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Distúrbio Mineral e Ósseo na Doença Renal Crônica , Insuficiência Renal Crônica , Humanos , Cromatografia Líquida/métodos , Espectrometria de Massas em Tandem , Hormônio Paratireóideo , Insuficiência Renal Crônica/diagnósticoRESUMO
International consensus supports the development of standardized protocols for measured glomerular filtration rate (mGFR) to facilitate the integration of mGFR testing in both clinical and research settings. To this end, the European Kidney Function Consortium convened an international group of experts with relevant experience in mGFR. The working group performed an extensive literature search to inform the development of recommendations for mGFR determination using 1-compartment plasma clearance models and iohexol as the exogenous filtration marker. Iohexol was selected as it is non-radio labeled, inexpensive, and safe, can be assayed at a central laboratory, and the other commonly used non-radio-labeled tracers have been (inulin) or are soon to be (iothalamate) discontinued. A plasma clearance model was selected over urine clearance as it requires no urine collection. A 1 compartment was preferred to 2 compartments as it requires fewer samples. The recommendations are based on published evidence complemented by expert opinion. The consensus paper covers practical advice for patients and health professionals, preparation, administration, and safety aspects of iohexol, laboratory analysis, blood sample collection and sampling times using both multiple and single-sample protocols, description of the mGFR mathematical calculations, as well as implementation strategies. Supplementary materials include patient and provider information sheets, standard operating procedures, a study protocol template, and support for mGFR calculation.
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Cardiovascular research relies heavily on the veracity of in vitro cardiomyocyte models, with H9c2 and HL-1 cell lines at the forefront due to their cardiomyocyte-like properties. However, the variability stemming from nonstandardized culturing and transfection methods poses a significant challenge to data uniformity and reliability. In this study, we introduce meticulously crafted protocols to enhance the culture and transfection of H9c2 and HL-1 cells, emphasizing the reduction of cytotoxic effects while improving transfection efficiency. Through the examination of polymer-based and lipid-based transfection methods, we offer a comparative analysis that underscores the heightened efficiency and reduced toxicity of these approaches. Our research provides an extensive array of step-by-step procedures designed to foster robust cell cultures and outlines troubleshooting practices to rectify issues of low transfection rates. We discuss the merits and drawbacks of both transfection techniques, equipping researchers with the knowledge to choose the most fitting method for their experimental goals. By offering a definitive guide to these cell lines' culturing and transfection, our work seeks to set a new standard in procedural consistency, ensuring that the cardiovascular research community can achieve more dependable and reproducible results, thereby pushing the boundaries of current methodologies toward impactful clinical applications.NEW & NOTEWORTHY We have developed standardized protocols that significantly reduce cytotoxicity and enhance transfection efficiency in H9c2 and HL-1 cardiomyocyte cell lines. Our detailed comparative analysis of polymer-based and lipid-based transfection methods has identified optimized approaches with superior performance. Accompanying these protocols are comprehensive troubleshooting strategies to address common issues related to low transfection rates. Implementing these protocols is expected to yield more consistent and reproducible results, driving the field of cardiovascular research toward impactful clinical breakthroughs.
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Lipídeos , Miócitos Cardíacos , Transfecção , Miócitos Cardíacos/metabolismo , Linhagem Celular , Animais , Lipídeos/toxicidade , Lipídeos/química , Ratos , Sobrevivência Celular , Polímeros/toxicidade , CamundongosRESUMO
Gold nanoparticles (GNPs) are largely employed in diagnostics/biosensors and are among the most investigated nanomaterials in biology/medicine. However, few GNP-based nanoformulations have received FDA approval to date, and promising in vitro studies have failed to translate to in vivo efficacy. One key factor is that biological fluids contain high concentrations of proteins, lipids, sugars, and metabolites, which can adsorb/interact with the GNP's surface, forming a layer called biomolecular corona (BMC). The BMC can mask prepared functionalities and target moieties, creating new surface chemistry and determining GNPs' biological fate. Here, the current knowledge is summarized on GNP-BMCs, analyzing the factors driving these interactions and the biological consequences. A partial fingerprint of GNP-BMC analyzing common patterns of composition in the literature is extrapolated. However, a red flag is also risen concerning the current lack of data availability and regulated form of knowledge on BMC. Nanomedicine is still in its infancy, and relying on recently developed analytical and informatic tools offers an unprecedented opportunity to make a leap forward. However, a restart through robust shared protocols and data sharing is necessary to obtain "stronger roots". This will create a path to exploiting BMC for human benefit, promoting the clinical translation of biomedical nanotools.
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Nanopartículas Metálicas , Nanopartículas , Coroa de Proteína , Humanos , Nanopartículas Metálicas/química , Ouro/química , Coroa de Proteína/química , Nanopartículas/química , Proteínas , NanomedicinaRESUMO
Interlaboratory agreement of viral load assays depends on the accuracy and uniformity of quantitative calibrators. Previous work demonstrated poor agreement of secondary cytomegalovirus (CMV) standards with nominal values. This study re-evaluated this issue among commercially produced secondary standards for both BK virus (BKV) and CMV, using digital polymerase chain reaction (dPCR) to compare the materials from three different manufacturers. Overall, standards showed an improved agreement compared to prior work, against nominal values in both log10 copies/mL and log10 international unit (IU)/mL, with bias from manufacturer-assigned nominal values of 0.0-0.9 log10 units (either copies or IU)/mL. Standards normalized to IU and those values assigned by dPCR rather than by real-time PCR (qPCR) showed better agreement with nominal values. The latter reinforces prior conclusions regarding the utility of using such methods for quantitative value assignment in reference materials. Quantitative standards have improved over the last several years, and the remaining bias from nominal values might be further reduced by universal implementation of dPCR methods for value assignment, normalized to IU. IMPORTANCE: Interlaboratory agreement of viral load assays depends on accuracy and uniformity of quantitative calibrators. Previous work, published in JCM several years ago, demonstrated poor agreement of secondary cytomegalovirus (CMV) standards with nominal values. This study re-evaluated this issue among commercially produced secondary standards for both BK virus (BKV) and CMV, using digital polymerase chain reaction (dPCR) to compare the materials from three different manufacturers. Overall, standards showed an improved agreement compared to prior work, against nominal values, indicating a substantial improvement in the production of accurate secondary viral standards, while supporting the need for further work in this area and for the broad adaption of international unit (IU) as a reporting standard for quantitative viral load results.
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Vírus BK , Infecções por Citomegalovirus , Humanos , Citomegalovirus/genética , Infecções por Citomegalovirus/diagnóstico , Reação em Cadeia da Polimerase em Tempo Real/métodos , Carga Viral/métodos , Vírus BK/genética , DNA ViralRESUMO
Guidelines recommend monitoring of Epstein-Barr virus (EBV) and BK virus (BKV) in solid organ and hematopoietic stem cell transplant patients. The majority of quantitative DNA testing for EBV and BKV employs unstandardized individual laboratory-developed testing solutions (LDTs), with implications for accuracy, reproducibility, and comparability between laboratories. The performance of the cobas EBV and cobas BKV assays was assessed across five laboratories, using the World Health Organization International Standards (WHO IS) for EBV and BKV, and the National Institute of Standards and Technology Quantitative Standard for BKV, and results were compared with the LDTs in use at the time. Methods were also compared using locally sourced clinical specimens. Variation was high when laboratories reported EBV or BKV DNA values using LDTs, where quantitative values were observed to differ by up to 1.5 log10 unit/mL between sites. Conversely, results from the cobas EBV and cobas BKV assays were accurate and reproducible across sites and on different testing days. Adjustment of LDTs using the international standards led to closer alignment between the assays; however, day-to-day reproducibility of LDTs remained high. In addition, BKV continued to show bias, indicating challenges with the commutability of the BKV International Standard. The cobas EBV and cobas BKV assays are automated, aligned to the WHO IS, and have the potential to reduce the variability in viral load testing introduced by differences in LDTs. Standardization of reporting values may eventually allow different centers to compare data to allow clinical decision thresholds to be established supporting improvements in patient management.IMPORTANCEThe application of center-specific cut-offs for clinical decisions and the variability of LDTs often hinder interpretation; thus, the findings reported here support the need for standardization in the field of post-transplant monitoring of EBV and BKV to improve patient management. Alongside the choice of assay, it is also important to consider which standard to use when deciding upon a testing methodology. This is a call to action for standardization, as treatment for EBV and BKV is driven by viral load test results, and the more accurate and comparable the test results are across institutions, the more informed and better the treatment decisions can be.
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Vírus BK , Infecções por Vírus Epstein-Barr , Herpesvirus Humano 4 , Carga Viral , Humanos , Vírus BK/isolamento & purificação , Vírus BK/genética , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/isolamento & purificação , Carga Viral/normas , Carga Viral/métodos , Reprodutibilidade dos Testes , Infecções por Vírus Epstein-Barr/diagnóstico , Infecções por Vírus Epstein-Barr/virologia , Infecções por Polyomavirus/diagnóstico , Infecções por Polyomavirus/virologia , DNA Viral/genética , DNA Viral/análise , Técnicas de Diagnóstico Molecular/normas , Técnicas de Diagnóstico Molecular/métodos , Infecções Tumorais por Vírus/diagnóstico , Infecções Tumorais por Vírus/virologiaRESUMO
Advancements in data acquisition and computational methods are generating a large amount of heterogeneous biomedical data from diagnostic domains such as clinical imaging, pathology, and next-generation sequencing (NGS), which help characterize individual differences in patients. However, this information needs to be available and suitable to promote and support scientific research and technological development, supporting the effective adoption of the precision medicine approach in clinical practice. Digital biobanks can catalyze this process, facilitating the sharing of curated and standardized imaging data, clinical, pathological and molecular data, crucial to enable the development of a comprehensive and personalized data-driven diagnostic approach in disease management and fostering the development of computational predictive models. This work aims to frame this perspective, first by evaluating the state of standardization of individual diagnostic domains and then by identifying challenges and proposing a possible solution towards an integrative approach that can guarantee the suitability of information that can be shared through a digital biobank. Our analysis of the state of the art shows the presence and use of reference standards in biobanks and, generally, digital repositories for each specific domain. Despite this, standardization to guarantee the integration and reproducibility of the numerical descriptors generated by each domain, e.g. radiomic, pathomic and -omic features, is still an open challenge. Based on specific use cases and scenarios, an integration model, based on the JSON format, is proposed that can help address this problem. Ultimately, this work shows how, with specific standardization and promotion efforts, the digital biobank model can become an enabling technology for the comprehensive study of diseases and the effective development of data-driven technologies at the service of precision medicine.
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Bancos de Espécimes Biológicos , Medicina de Precisão , Humanos , Reprodutibilidade dos Testes , GenômicaRESUMO
PURPOSE: Several reconstruction methods for MR-based electrical properties tomography (EPT) have been developed. However, the lack of common data makes it difficult to objectively compare their performances. This is, however, a necessary precursor for standardizing and introducing this technique in the clinical setting. To enable objective comparison of the performances of reconstruction methods and provide common data for their training and testing, we created ADEPT, a database of simulated data for brain MR-EPT reconstructions. METHODS: ADEPT is a database containing in silico data for brain EPT reconstructions. This database was created from 25 different brain models, with and without tumors. Rigid geometric augmentations were applied, and different electrical properties were assigned to white matter, gray matter, CSF, and tumors to generate 120 different brain models. These models were used as input for finite-difference time-domain simulations in Sim4Life, used to compute the electromagnetic fields needed for MR-EPT reconstructions. RESULTS: Electromagnetic fields from 84 healthy and 36 tumor brain models were simulated. The simulated fields relevant for MR-EPT reconstructions (transmit and receive RF fields and transceive phase) and their ground-truth electrical properties are made publicly available through ADEPT. Additionally, nonattainable fields such as the total magnetic field and the electric field are available upon request. CONCLUSION: ADEPT will serve as reference database for objective comparisons of reconstruction methods and will be a first step toward standardization of MR-EPT reconstructions. Furthermore, it provides a large amount of data that can be exploited to train data-driven methods. It can be accessed from https://doi.org/10.34894/V0HBJ8.
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Processamento de Imagem Assistida por Computador , Neoplasias , Humanos , Condutividade Elétrica , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Encéfalo/diagnóstico por imagem , Tomografia/métodos , Imagens de Fantasmas , AlgoritmosRESUMO
This manuscript describes the ISMRM OSIPI (Open Science Initiative for Perfusion Imaging) lexicon for dynamic contrast-enhanced and dynamic susceptibility-contrast MRI. The lexicon was developed by Taskforce 4.2 of OSIPI to provide standardized definitions of commonly used quantities, models, and analysis processes with the aim of reducing reporting variability. The taskforce was established in February 2020 and consists of medical physicists, engineers, clinicians, data and computer scientists, and DICOM (Digital Imaging and Communications in Medicine) standard experts. Members of the taskforce collaborated via a slack channel and quarterly virtual meetings. Members participated by defining lexicon items and reporting formats that were reviewed by at least two other members of the taskforce. Version 1.0.0 of the lexicon was subject to open review from the wider perfusion imaging community between January and March 2022, and endorsed by the Perfusion Study Group of the ISMRM in the summer of 2022. The initial scope of the lexicon was set by the taskforce and defined such that it contained a basic set of quantities, processes, and models to enable users to report an end-to-end analysis pipeline including kinetic model fitting. We also provide guidance on how to easily incorporate lexicon items and definitions into free-text descriptions (e.g., in manuscripts and other documentation) and introduce an XML-based pipeline encoding format to encode analyses using lexicon definitions in standardized and extensible machine-readable code. The lexicon is designed to be open-source and extendable, enabling ongoing expansion of its content. We hope that widespread adoption of lexicon terminology and reporting formats described herein will increase reproducibility within the field.
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Meios de Contraste , Imageamento por Ressonância Magnética , Reprodutibilidade dos Testes , Imageamento por Ressonância Magnética/métodos , Perfusão , Imagem de PerfusãoRESUMO
PURPOSE: Urodynamic testing (UDS) is an important tool in the management of pediatric lower urinary tract conditions. There have been notable efforts to standardize pediatric UDS nomenclature and technique, but no formal guidelines exist on essential elements to include in a clinical report. We sought to identify ideal structure and elements of a pediatric UDS assessment based on expert consensus. MATERIALS AND METHODS: Pediatric urologists regularly performing UDS were queried using a Delphi process. Participants were invited representing varied geographic, experience, and societal involvement. Participants underwent 3 rounds of questionnaires between November 2022 and August 2023 focusing on report organization, elements, definitions, and automated electronic health record clinical decision support. Professional billing requirements were also considered. Consensus was defined as 80% agreeing either in favor of or against a topic. Elements without consensus were discussed in subsequent rounds. RESULTS: A diverse sample of 30 providers, representing 27 institutions across 21 US states; Washington, District of Columbia; and Canada completed the study. Participants reported interpreting an average number of 5 UDS reports per week (range 1-22). The finalized consensus report identifies 93 elements that should be included in a pediatric UDS report based on applicable study conditions and findings. CONCLUSIONS: This consensus report details the key elements and structure agreed upon by an expert panel of pediatric urologists. Further standardization of documentation should aid collaboration and research for patients undergoing UDS. Based on this information, development of a standardized UDS report template using electronic health record implementation principles is underway, which will be openly available for pediatric urologists.
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Consenso , Técnica Delphi , Urodinâmica , Humanos , Criança , Urologia/normas , Pediatria/normas , Masculino , Inquéritos e QuestionáriosRESUMO
Liquid chromatography/tandem mass spectrometry is firmly established today as the gold standard technique for analysis of vitamin D, both for vitamin D status assessments as well as for measuring complex and intricate vitamin D metabolic fingerprints. While the actual mass spectrometry technology has seen only incremental performance increases in recent years, there have been major, very impactful changes in the front- and back-end of MS-based vitamin D assays; for example, the extension to new types of biological sample matrices analyzed for an increasing number of different vitamin D metabolites, novel sample preparation techniques, new powerful chemical derivatization reagents, as well the continued integration of high resolution mass spectrometers into clinical laboratories, replacing established triple-quadrupole instruments. At the same time, the sustainability of mass spectrometry operation in the vitamin D field is now firmly established through proven analytical harmonization and standardization programs. The present review summarizes the most important of these recent developments.