Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 80
Filtrar
1.
Rev. chil. obstet. ginecol. (En línea) ; 87(4): 299-303, ago. 2022. ilus
Artigo em Espanhol | LILACS | ID: biblio-1407857

RESUMO

Resumen El embarazo ectópico roto es una emergencia quirúrgica cuyo diagnóstico, gracias a la interrelación de la cuantificación de la fracción beta de la hormona gonadotropina coriónica humana (HCG-β) y los hallazgos ultrasonográficos, se ha hecho más preciso. Sin embargo, el diagnóstico se vuelve difícil cuando clínicamente se encuentran datos sugestivos de embarazo ectópico con una HCG-β negativa. Presentamos el caso de una mujer de 25 años acude a valoración por referir 12,2 semanas de retraso menstrual, asociado a sangrado transvaginal y signos de irritación peritoneal, que cuenta con HCG-β negativa (< 5 mUI/ml). Se realizó un rastreo ultrasonográfico encontrando abundante líquido libre en cavidad, sin evidencia de embarazo intrauterino. Ante la alta sospecha de embarazo ectópico se realizó laparotomía exploradora, encontrando hallazgos sugestivos de embarazo ectópico roto, y se realizó salpingectomía. Finalmente, en el estudio posoperatorio se confirmó por histopatología un embarazo ectópico roto. Existen muy pocos reportes en la literatura internacional de pacientes con características clínicas de embarazo ectópico roto, con HCG-β negativa. Es importante la difusión de este tipo de casos con la finalidad de mejorar los abordajes diagnósticos y no restar importancia ante la sospecha clínica, a pesar de presentar una HCG-β negativa.


Abstract Broken ectopic pregnancy is a surgical emergency that due to the relation between the serum quantification of the of the beta subunit of human chorionic gonadotropin (β-HCG) and the ultrasonographic findings, there have been improvements to reach a precise diagnosis. However, there are very few reported cases in the literature where a broken ectopic pregnancy is described with negative serum results in β-HCG. We present a case report of a 25-year-old patient came to the evaluation for referring 12.2 weeks of menstrual delay, associated with transvaginal bleeding and data of peritoneal irritation, she had a negative β-HCG fraction (< 5 mIU/ml). A scan was performed ultrasound finding abundant free fluid in the cavity, without evidence of intrauterine pregnancy. Given the high suspicion of ectopic pregnancy, an exploratory laparotomy was performed, finding findings suggestive of a ruptured ectopic pregnancy, a salpingectomy was performed. Finally, in the postoperative study, a ruptured ectopic pregnancy was confirmed by histopathology. There are very few reported internationally were found a patient with clinical characteristics of broken ectopic pregnancy, with a β-HCG negative. It is important the scientific diffusion of this type of cases with the purpose of improving the diagnostic approaches and not underestimating importance to the clinical suspicion, despite presenting negative β-HCG results.


Assuntos
Humanos , Feminino , Gravidez , Adulto , Gravidez Ectópica/diagnóstico , Gonadotropina Coriônica Humana Subunidade beta/análise , Gravidez Ectópica/cirurgia , Ruptura Espontânea
2.
Biostatistics ; 24(1): 1-16, 2022 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-34467372

RESUMO

High-dimensional biological data collection across heterogeneous groups of samples has become increasingly common, creating high demand for dimensionality reduction techniques that capture underlying structure of the data. Discovering low-dimensional embeddings that describe the separation of any underlying discrete latent structure in data is an important motivation for applying these techniques since these latent classes can represent important sources of unwanted variability, such as batch effects, or interesting sources of signal such as unknown cell types. The features that define this discrete latent structure are often hard to identify in high-dimensional data. Principal component analysis (PCA) is one of the most widely used methods as an unsupervised step for dimensionality reduction. This reduction technique finds linear transformations of the data which explain total variance. When the goal is detecting discrete structure, PCA is applied with the assumption that classes will be separated in directions of maximum variance. However, PCA will fail to accurately find discrete latent structure if this assumption does not hold. Visualization techniques, such as t-Distributed Stochastic Neighbor Embedding (t-SNE) and Uniform Manifold Approximation and Projection (UMAP), attempt to mitigate these problems with PCA by creating a low-dimensional space where similar objects are modeled by nearby points in the low-dimensional embedding and dissimilar objects are modeled by distant points with high probability. However, since t-SNE and UMAP are computationally expensive, often a PCA reduction is done before applying them which makes it sensitive to PCAs downfalls. Also, tSNE is limited to only two or three dimensions as a visualization tool, which may not be adequate for retaining discriminatory information. The linear transformations of PCA are preferable to non-linear transformations provided by methods like t-SNE and UMAP for interpretable feature weights. Here, we propose iterative discriminant analysis (iDA), a dimensionality reduction technique designed to mitigate these limitations. iDA produces an embedding that carries discriminatory information which optimally separates latent clusters using linear transformations that permit post hoc analysis to determine features that define these latent structures.


Assuntos
Algoritmos , Humanos , Análise de Componente Principal
3.
Surg Innov ; 29(1): 66-72, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34325591

RESUMO

Introduction. Surgical technique videos are an important part of surgical fellows' education. YouTube has been identified as the preferred source of educational videos among trainees. The aim of this article is to objectively evaluate the quality of the 50 most viewed videos on YouTube concerning right laparoscopic hemicolectomy using LAParoscopic surgery Video Educational GuidelineS (LAP-VEGaS). We hypothesized that the number of likes or views will not necessarily reciprocate with the educational content. Materials and methods. This observational study started with a YouTube search under the words "laparoscopic right hemicolectomy", "right colectomy", and "right hemicolectomy". The 50 most viewed videos with an English title were chosen. Video characteristics and LAP-VEGaS score were analyzed by four colorectal surgery fellows from a tertiary center in Mexico City. Results. Right hemicolectomy videos were reviewed; there was no correlation between the LAP-VEGaS score and the view ratio, the like ratio, or the video power index. The LAP-VEGaS score was significantly higher among videos uploaded by medical associations, journals, or commercial when compared with videos uploaded by doctors/physicians or academic associations. Conclusion. Educational quality in right laparoscopic hemicolectomy videos did not reciprocate with their educational quality, but it agrees significantly with the video uploading source. Low educational quality was identified among the videos underscoring the need to endorse peer-reviewed video channels.


Assuntos
Cirurgia Colorretal , Laparoscopia , Mídias Sociais , Colectomia , Laparoscopia/métodos , Gravação em Vídeo
4.
Nat Med ; 27(11): 1885-1892, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34789871

RESUMO

The particularly interdisciplinary nature of human microbiome research makes the organization and reporting of results spanning epidemiology, biology, bioinformatics, translational medicine and statistics a challenge. Commonly used reporting guidelines for observational or genetic epidemiology studies lack key features specific to microbiome studies. Therefore, a multidisciplinary group of microbiome epidemiology researchers adapted guidelines for observational and genetic studies to culture-independent human microbiome studies, and also developed new reporting elements for laboratory, bioinformatics and statistical analyses tailored to microbiome studies. The resulting tool, called 'Strengthening The Organization and Reporting of Microbiome Studies' (STORMS), is composed of a 17-item checklist organized into six sections that correspond to the typical sections of a scientific publication, presented as an editable table for inclusion in supplementary materials. The STORMS checklist provides guidance for concise and complete reporting of microbiome studies that will facilitate manuscript preparation, peer review, and reader comprehension of publications and comparative analysis of published results.


Assuntos
Biologia Computacional/métodos , Disbiose/microbiologia , Microbiota/fisiologia , Estudos Observacionais como Assunto/métodos , Projetos de Pesquisa , Humanos , Ciência Translacional Biomédica
5.
PLoS Comput Biol ; 17(11): e1009442, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34784344

RESUMO

It is challenging to associate features such as human health outcomes, diet, environmental conditions, or other metadata to microbial community measurements, due in part to their quantitative properties. Microbiome multi-omics are typically noisy, sparse (zero-inflated), high-dimensional, extremely non-normal, and often in the form of count or compositional measurements. Here we introduce an optimized combination of novel and established methodology to assess multivariable association of microbial community features with complex metadata in population-scale observational studies. Our approach, MaAsLin 2 (Microbiome Multivariable Associations with Linear Models), uses generalized linear and mixed models to accommodate a wide variety of modern epidemiological studies, including cross-sectional and longitudinal designs, as well as a variety of data types (e.g., counts and relative abundances) with or without covariates and repeated measurements. To construct this method, we conducted a large-scale evaluation of a broad range of scenarios under which straightforward identification of meta-omics associations can be challenging. These simulation studies reveal that MaAsLin 2's linear model preserves statistical power in the presence of repeated measures and multiple covariates, while accounting for the nuances of meta-omics features and controlling false discovery. We also applied MaAsLin 2 to a microbial multi-omics dataset from the Integrative Human Microbiome (HMP2) project which, in addition to reproducing established results, revealed a unique, integrated landscape of inflammatory bowel diseases (IBD) across multiple time points and omics profiles.


Assuntos
Biologia Computacional , Microbioma Gastrointestinal , Análise Multivariada , Simulação por Computador , Humanos , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/metabolismo , Doenças Inflamatórias Intestinais/patologia
6.
Nature ; 598(7879): 103-110, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34616066

RESUMO

Single-cell transcriptomics can provide quantitative molecular signatures for large, unbiased samples of the diverse cell types in the brain1-3. With the proliferation of multi-omics datasets, a major challenge is to validate and integrate results into a biological understanding of cell-type organization. Here we generated transcriptomes and epigenomes from more than 500,000 individual cells in the mouse primary motor cortex, a structure that has an evolutionarily conserved role in locomotion. We developed computational and statistical methods to integrate multimodal data and quantitatively validate cell-type reproducibility. The resulting reference atlas-containing over 56 neuronal cell types that are highly replicable across analysis methods, sequencing technologies and modalities-is a comprehensive molecular and genomic account of the diverse neuronal and non-neuronal cell types in the mouse primary motor cortex. The atlas includes a population of excitatory neurons that resemble pyramidal cells in layer 4 in other cortical regions4. We further discovered thousands of concordant marker genes and gene regulatory elements for these cell types. Our results highlight the complex molecular regulation of cell types in the brain and will directly enable the design of reagents to target specific cell types in the mouse primary motor cortex for functional analysis.


Assuntos
Epigenômica , Perfilação da Expressão Gênica , Córtex Motor/citologia , Neurônios/classificação , Análise de Célula Única , Transcriptoma , Animais , Atlas como Assunto , Conjuntos de Dados como Assunto , Epigênese Genética , Feminino , Masculino , Camundongos , Córtex Motor/anatomia & histologia , Neurônios/citologia , Neurônios/metabolismo , Especificidade de Órgãos , Reprodutibilidade dos Testes
7.
Foods ; 10(7)2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34202798

RESUMO

Basil (Ocimum basilicum L.) is found worldwide and is used in the food, pharmaceutical, and cosmetic industries; however, the nutritional and functional properties of the seeds are scarcely known. Basil seeds contain high concentrations of proteins (11.4-22.5 g/100 g), with all the essential amino acids except S-containing types and tryptophan; dietary fiber (soluble and insoluble) ranging from 7.11 to 26.2 g/100 g lipids, with linoleic (12-85.6 g/100 g) and linolenic fatty acids (0.3-75 g/100 g) comprising the highest proportions; minerals, such as calcium, potassium, and magnesium, in high amounts; and phenolic compounds, such as orientine, vicentine, and rosmarinic acid. In addition, their consumption is associated with several health benefits, such as the prevention of type-2 diabetes, cardio-protection, antioxidant and antimicrobial effects, and anti-inflammatory, antiulcer, anticoagulant, and anti-depressant properties, among others. The focus of this systematic review was to study the current state of knowledge and explore the enormous potential of basil seeds as a functional food and source of functional ingredients to be incorporated into foods.

9.
Bioinformatics ; 36(Suppl_1): i102-i110, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32657377

RESUMO

MOTIVATION: Advances in sequencing technology, inference algorithms and differential testing methodology have enabled transcript-level analysis of RNA-seq data. Yet, the inherent inferential uncertainty in transcript-level abundance estimation, even among the most accurate approaches, means that robust transcript-level analysis often remains a challenge. Conversely, gene-level analysis remains a common and robust approach for understanding RNA-seq data, but it coarsens the resulting analysis to the level of genes, even if the data strongly support specific transcript-level effects. RESULTS: We introduce a new data-driven approach for grouping together transcripts in an experiment based on their inferential uncertainty. Transcripts that share large numbers of ambiguously-mapping fragments with other transcripts, in complex patterns, often cannot have their abundances confidently estimated. Yet, the total transcriptional output of that group of transcripts will have greatly reduced inferential uncertainty, thus allowing more robust and confident downstream analysis. Our approach, implemented in the tool terminus, groups together transcripts in a data-driven manner allowing transcript-level analysis where it can be confidently supported, and deriving transcriptional groups where the inferential uncertainty is too high to support a transcript-level result. AVAILABILITY AND IMPLEMENTATION: Terminus is implemented in Rust, and is freely available and open source. It can be obtained from https://github.com/COMBINE-lab/Terminus. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Perfilação da Expressão Gênica , Software , Algoritmos , RNA-Seq , Análise de Sequência de RNA
10.
Bioinformatics ; 36(18): 4682-4690, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32618995

RESUMO

MOTIVATION: Genomic data repositories like The Cancer Genome Atlas, Encyclopedia of DNA Elements, Bioconductor's AnnotationHub and ExperimentHub etc., provide public access to large amounts of genomic data as flat files. Researchers often download a subset of data files from these repositories to perform exploratory data analysis. We developed Epiviz File Server, a Python library that implements an in situ data query system for local or remotely hosted indexed genomic files, not only for visualization but also data transformation. The File Server library decouples data retrieval and transformation from specific visualization and analysis tools and provides an abstract interface to define computations independent of the location, format or structure of the file. We demonstrate the File Server in two use cases: (i) integration with Galaxy workflows and (ii) using Epiviz to create a custom genome browser from the Epigenome Roadmap dataset. AVAILABILITY AND IMPLEMENTATION: Epiviz File Server is open source and is available on GitHub at http://github.com/epiviz/epivizFileServer. The documentation for the File Server library is available at http://epivizfileserver.rtfd.io.


Assuntos
Genoma , Genômica , Computadores , Armazenamento e Recuperação da Informação , Software
11.
Microbiome ; 8(1): 35, 2020 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-32169095

RESUMO

BACKGROUND: There are a variety of bioinformatic pipelines and downstream analysis methods for analyzing 16S rRNA marker-gene surveys. However, appropriate assessment datasets and metrics are needed as there is limited guidance to decide between available analysis methods. Mixtures of environmental samples are useful for assessing analysis methods as one can evaluate methods based on calculated expected values using unmixed sample measurements and the mixture design. Previous studies have used mixtures of environmental samples to assess other sequencing methods such as RNAseq. But no studies have used mixtures of environmental to assess 16S rRNA sequencing. RESULTS: We developed a framework for assessing 16S rRNA sequencing analysis methods which utilizes a novel two-sample titration mixture dataset and metrics to evaluate qualitative and quantitative characteristics of count tables. Our qualitative assessment evaluates feature presence/absence exploiting features only present in unmixed samples or titrations by testing if random sampling can account for their observed relative abundance. Our quantitative assessment evaluates feature relative and differential abundance by comparing observed and expected values. We demonstrated the framework by evaluating count tables generated with three commonly used bioinformatic pipelines: (i) DADA2 a sequence inference method, (ii) Mothur a de novo clustering method, and (iii) QIIME an open-reference clustering method. The qualitative assessment results indicated that the majority of Mothur and QIIME features only present in unmixed samples or titrations were accounted for by random sampling alone, but this was not the case for DADA2 features. Combined with count table sparsity (proportion of zero-valued cells in a count table), these results indicate DADA2 has a higher false-negative rate whereas Mothur and QIIME have higher false-positive rates. The quantitative assessment results indicated the observed relative abundance and differential abundance values were consistent with expected values for all three pipelines. CONCLUSIONS: We developed a novel framework for assessing 16S rRNA marker-gene survey methods and demonstrated the framework by evaluating count tables generated with three bioinformatic pipelines. This framework is a valuable community resource for assessing 16S rRNA marker-gene survey bioinformatic methods and will help scientists identify appropriate analysis methods for their marker-gene surveys.


Assuntos
Biologia Computacional/métodos , Análise de Dados , Microbiota/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA/métodos , Adulto , Ensaios Clínicos como Assunto , Feminino , Marcadores Genéticos , Humanos , Masculino , Software , Adulto Jovem
12.
JCO Clin Cancer Inform ; 4: 71-88, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31990579

RESUMO

PURPOSE: In this work, we introduce CDGnet (Cancer-Drug-Gene Network), an evidence-based network approach for recommending targeted cancer therapies. CDGnet represents a user-friendly informatics tool that expands the range of targeted therapy options for patients with cancer who undergo molecular profiling by including the biologic context via pathway information. METHODS: CDGnet considers biologic pathway information specifically by looking at targets or biomarkers downstream of oncogenes and is personalized for individual patients via user-inputted molecular alterations and cancer type. It integrates a number of different sources of knowledge: patient-specific inputs (molecular alterations and cancer type), US Food and Drug Administration-approved therapies and biomarkers (curated from DailyMed), pathways for specific cancer types (from Kyoto Encyclopedia of Genes and Genomes [KEGG]), gene-drug connections (from DrugBank), and oncogene information (from KEGG). We consider 4 different evidence-based categories for therapy recommendations. Our tool is delivered via an R/Shiny Web application. For the 2 categories that use pathway information, we include an interactive Sankey visualization built on top of d3.js that also provides links to PubChem. RESULTS: We present a scenario for a patient who has estrogen receptor (ER)-positive breast cancer with FGFR1 amplification. Although many therapies exist for patients with ER-positive breast cancer, FGFR1 amplifications may confer resistance to such treatments. CDGnet provides therapy recommendations, including PIK3CA, MAPK, and RAF inhibitors, by considering targets or biomarkers downstream of FGFR1. CONCLUSION: CDGnet provides results in a number of easily accessible and usable forms, separating targeted cancer therapies into categories in an evidence-based manner that incorporates biologic pathway information.


Assuntos
Antineoplásicos/uso terapêutico , Biomarcadores Tumorais/genética , Medicina Baseada em Evidências , Redes Reguladoras de Genes , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológico , Medicina de Precisão , Biomarcadores Tumorais/antagonistas & inibidores , Humanos , Neoplasias/genética , Neoplasias/patologia , Seleção de Pacientes
13.
F1000Res ; 9: 601, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32742640

RESUMO

The rich data produced by the second phase of the Human Microbiome Project (iHMP) offers a unique opportunity to test hypotheses that interactions between microbial communities and a human host might impact an individual's health or disease status. In this work we describe infrastructure that integrates Metaviz, an interactive microbiome data analysis and visualization tool, with the iHMP Data Coordination Center web portal and the HMP2Data R/Bioconductor package. We describe integrative statistical and visual analyses of two datasets from iHMP using Metaviz along with the metagenomeSeq R/Bioconductor package for statistical analysis of differential abundance analysis. These use cases demonstrate the utility of a combined approach to access and analyze data from this resource.


Assuntos
Análise de Dados , Microbiota , Interpretação Estatística de Dados , Humanos , Projetos de Pesquisa
14.
Bioinformatics ; 36(7): 2195-2201, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-31782758

RESUMO

MOTIVATION: Integrative analysis of genomic data that includes statistical methods in combination with visual exploration has gained widespread adoption. Many existing methods involve a combination of tools and resources: user interfaces that provide visualization of large genomic datasets, and computational environments that focus on data analyses over various subsets of a given dataset. Over the last few years, we have developed Epiviz as an integrative and interactive genomic data analysis tool that incorporates visualization tightly with state-of-the-art statistical analysis framework. RESULTS: In this article, we present Epiviz Feed, a proactive and automatic visual analytics system integrated with Epiviz that alleviates the burden of manually executing data analysis required to test biologically meaningful hypotheses. Results of interest that are proactively identified by server-side computations are listed as notifications in a feed. The feed turns genomic data analysis into a collaborative work between the analyst and the computational environment, which shortens the analysis time and allows the analyst to explore results efficiently.We discuss three ways where the proposed system advances the field of genomic data analysis: (i) takes the first step of proactive data analysis by utilizing available CPU power from the server to automate the analysis process; (ii) summarizes hypothesis test results in a way that analysts can easily understand and investigate; (iii) enables filtering and grouping of analysis results for quick search. This effort provides initial work on systems that substantially expand how computational and visualization frameworks can be tightly integrated to facilitate interactive genomic data analysis. AVAILABILITY AND IMPLEMENTATION: The source code for Epiviz Feed application is available at http://github.com/epiviz/epiviz_feed_polymer. The Epiviz Computational Server is available at http://github.com/epiviz/epiviz-feed-computation. Please refer to Epiviz documentation site for details: http://epiviz.github.io/.


Assuntos
Genômica , Software , Genoma , Projetos de Pesquisa
15.
BMC Bioinformatics ; 20(1): 421, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31409274

RESUMO

BACKGROUND: Ultra-fast pseudo-alignment approaches are the tool of choice in transcript-level RNA sequencing (RNA-seq) analyses. Unfortunately, these methods couple the tasks of pseudo-alignment and transcript quantification. This coupling precludes the direct usage of pseudo-alignment to other expression analyses, including alternative splicing or differential gene expression analysis, without including a non-essential transcript quantification step. RESULTS: In this paper, we introduce a transcriptome segmentation approach to decouple these two tasks. We propose an efficient algorithm to generate maximal disjoint segments given a transcriptome reference library on which ultra-fast pseudo-alignment can be used to produce per-sample segment counts. We show how to apply these maximally unambiguous count statistics in two specific expression analyses - alternative splicing and gene differential expression - without the need of a transcript quantification step. Our experiments based on simulated and experimental data showed that the use of segment counts, like other methods that rely on local coverage statistics, provides an advantage over approaches that rely on transcript quantification in detecting and correctly estimating local splicing in the case of incomplete transcript annotations. CONCLUSIONS: The transcriptome segmentation approach implemented in Yanagi exploits the computational and space efficiency of pseudo-alignment approaches. It significantly expands their applicability and interpretability in a variety of RNA-seq analyses by providing the means to model and capture local coverage variation in these analyses.


Assuntos
Algoritmos , Transcriptoma , Processamento Alternativo , Animais , Área Sob a Curva , Drosophila/genética , Humanos , RNA/química , RNA/metabolismo , Curva ROC , Análise de Sequência de RNA
16.
Bioinformatics ; 35(19): 3870-3872, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30821316

RESUMO

SUMMARY: We developed the metagenomeFeatures R Bioconductor package along with annotation packages for three 16S rRNA databases (Greengenes, RDP and SILVA) to facilitate working with 16S rRNA databases and marker-gene survey feature data. The metagenomeFeatures package defines two classes, MgDb for working with 16S rRNA sequence databases, and mgFeatures for marker-gene survey feature data. The associated annotation packages provide a consistent interface to the different databases facilitating database comparison and exploration. The mgFeatures-class represents a crucial step in the development of a common data structure for working with 16S marker-gene survey data in R. AVAILABILITY AND IMPLEMENTATION: https://bioconductor.org/packages/release/bioc/html/metagenomeFeatures.html. SUPPLEMENTARY INFORMATION: Supplementary material is available at Bioinformatics online.


Assuntos
Bases de Dados de Ácidos Nucleicos , Software , RNA Ribossômico 16S , Inquéritos e Questionários
17.
F1000Res ; 8: 1769, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32148761

RESUMO

An increasing emphasis on understanding the dynamics of microbial communities in various settings has led to the proliferation of longitudinal metagenomic sampling studies. Data from whole metagenomic shotgun sequencing and marker-gene survey studies have characteristics that drive novel statistical methodological development for estimating time intervals of differential abundance. In designing a study and the frequency of collection prior to a study, one may wish to model the ability to detect an effect, e.g., there may be issues with respect to cost, ease of access, etc. Additionally, while every study is unique, it is possible that in certain scenarios one statistical framework may be more appropriate than another. Here, we present a simulation paradigm implemented in the R Bioconductor software package microbiomeDASim available at http://bioconductor.org/packages/microbiomeDASim microbiomeDASim. microbiomeDASim allows investigators to simulate longitudinal differential abundant microbiome features with a variety of known functional forms with flexible parameters to control desired signal-to-noise ratio. We present metrics of success results on one particular method called metaSplines.


Assuntos
Microbiota , Software , Análise de Sequência de DNA
18.
BMC Genomics ; 19(1): 799, 2018 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-30400812

RESUMO

BACKGROUND: Count data derived from high-throughput deoxy-ribonucliec acid (DNA) sequencing is frequently used in quantitative molecular assays. Due to properties inherent to the sequencing process, unnormalized count data is compositional, measuring relative and not absolute abundances of the assayed features. This compositional bias confounds inference of absolute abundances. Commonly used count data normalization approaches like library size scaling/rarefaction/subsampling cannot correct for compositional or any other relevant technical bias that is uncorrelated with library size. RESULTS: We demonstrate that existing techniques for estimating compositional bias fail with sparse metagenomic 16S count data and propose an empirical Bayes normalization approach to overcome this problem. In addition, we clarify the assumptions underlying frequently used scaling normalization methods in light of compositional bias, including scaling methods that were not designed directly to address it. CONCLUSIONS: Compositional bias, induced by the sequencing machine, confounds inferences of absolute abundances. We present a normalization technique for compositional bias correction in sparse sequencing count data, and demonstrate its improved performance in metagenomic 16s survey data. Based on the distribution of technical bias estimates arising from several publicly available large scale 16s count datasets, we argue that detailed experiments specifically addressing the influence of compositional bias in metagenomics are needed.


Assuntos
Algoritmos , Biologia Computacional/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Metagenômica/métodos , Microbiota , RNA Ribossômico 16S/genética , Teorema de Bayes
19.
Microbiome ; 6(1): 197, 2018 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-30396371

RESUMO

The Mid-Atlantic Microbiome Meet-up (M3) organization brings together academic, government, and industry groups to share ideas and develop best practices for microbiome research. In January of 2018, M3 held its fourth meeting, which focused on recent advances in biodefense, specifically those relating to infectious disease, and the use of metagenomic methods for pathogen detection. Presentations highlighted the utility of next-generation sequencing technologies for identifying and tracking microbial community members across space and time. However, they also stressed the current limitations of genomic approaches for biodefense, including insufficient sensitivity to detect low-abundance pathogens and the inability to quantify viable organisms. Participants discussed ways in which the community can improve software usability and shared new computational tools for metagenomic processing, assembly, annotation, and visualization. Looking to the future, they identified the need for better bioinformatics toolkits for longitudinal analyses, improved sample processing approaches for characterizing viruses and fungi, and more consistent maintenance of database resources. Finally, they addressed the necessity of improving data standards to incentivize data sharing. Here, we summarize the presentations and discussions from the meeting, identifying the areas where microbiome analyses have improved our ability to detect and manage biological threats and infectious disease, as well as gaps of knowledge in the field that require future funding and focus.


Assuntos
Armas Biológicas , Biologia Computacional/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Metagenômica/métodos , Humanos , Microbiota/fisiologia , Análise de Sequência de DNA/métodos
20.
F1000Res ; 7: 1096, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30135734

RESUMO

Interactive and integrative data visualization tools and libraries are integral to exploration and analysis of genomic data. Web based genome browsers allow integrative data exploration of a large number of data sets for a specific region in the genome. Currently available web-based genome browsers are developed for specific use cases and datasets, therefore integration and extensibility of the visualizations and the underlying libraries from these tools is a challenging task. Genomic data visualization and software libraries that enable bioinformatic researchers and developers to implement customized genomic data viewers and data analyses for their application are much needed. Using recent advances in core web platform APIs and technologies including Web Components, we developed the Epiviz Component Library, a reusable and extensible data visualization library and application framework for genomic data. Epiviz Components can be integrated with most JavaScript libraries and frameworks designed for HTML. To demonstrate the ease of integration with other frameworks, we developed an R/Bioconductor epivizrChart package, that provides interactive, shareable and reproducible visualizations of genomic data objects in R, Shiny and also create standalone HTML documents. The component library is modular by design, reusable and natively extensible and therefore simplifies the process of managing and developing bioinformatic applications.


Assuntos
Gráficos por Computador , Bases de Dados de Ácidos Nucleicos , Genômica , Software , Navegador
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA