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1.
Nano Lett ; 21(19): 8160-8165, 2021 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-34543039

RESUMO

Airborne particular matter (PM) pollution is an increasing global issue and alternative sources of filter fibers are now an area of significant focus. Compared with relatively mature hazardous gas treatments, state of the art high-efficiency PM filters still lack thermal decomposition ability for organic PM pollutants, such as soot from coal-fired power plants and waste-combustion incinerators, resulting in frequent replacement, high cost, and second-hand pollution. In this manuscript, we propose a bottom-up synthesis method to make the first all-thermal-catalyst air filter (ATCAF). Self-assembled from ∼50 nm diameter TiO2 fibers, ATCAF could not only capture the combustion-generated PM pollutants with >99.999% efficiency but also catalyze the complete decomposition of the as-captured hydrocarbon pollutants at high temperature. It has the potential of in situ eliminating the PM pollutants from burning of hydrocarbon materials leveraging the burning heat.


Assuntos
Poluentes Atmosféricos , Poluentes Atmosféricos/análise , Catálise , Temperatura Alta , Centrais Elétricas
2.
Bioinformatics ; 36(9): 2813-2820, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-31971581

RESUMO

MOTIVATION: Gradual population-level changes in tissues can be driven by stochastic plasticity, meaning rare stochastic transitions of single-cell phenotype. Quantifying the rates of these stochastic transitions requires time-intensive experiments, and analysis is generally confounded by simultaneous bidirectional transitions and asymmetric proliferation kinetics. To quantify cellular plasticity, we developed Transcompp (Transition Rate ANalysis of Single Cells to Observe and Measure Phenotypic Plasticity), a Markov modeling algorithm that uses optimization and resampling to compute best-fit rates and statistical intervals for stochastic cell-state transitions. RESULTS: We applied Transcompp to time-series datasets in which purified subpopulations of stem-like or non-stem cancer cells were exposed to various cell culture environments, and allowed to re-equilibrate spontaneously over time. Results revealed that commonly used cell culture reagents hydrocortisone and cholera toxin shifted the cell population equilibrium toward stem-like or non-stem states, respectively, in the basal-like breast cancer cell line MCF10CA1a. In addition, applying Transcompp to patient-derived cells showed that transition rates computed from short-term experiments could predict long-term trajectories and equilibrium convergence of the cultured cell population. AVAILABILITY AND IMPLEMENTATION: Freely available for download at http://github.com/nsuhasj/Transcompp. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Algoritmos , Neoplasias da Mama , Adaptação Fisiológica , Células Cultivadas , Humanos
3.
Sensors (Basel) ; 21(23)2021 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-34883854

RESUMO

It is found that nodes in Delay Tolerant Networks (DTN) exhibit stable social attributes similar to those of people. In this paper, an adaptive routing algorithm based on Relation Tree (AR-RT) for DTN is proposed. Each node constructs its own Relation Tree based on the historical encounter frequency, and will adopt different forwarding strategies based on the Relation Tree in the forwarding phase, so as to achieve more targeted forwarding. To further improve the scalability of the algorithm, the source node dynamically controls the initial maximum number of message copies according to its own cache occupancy, which enables the node to make negative feedback to network environment changes. Simulation results show that the AR-RT algorithm proposed in this paper has significant advantages over existing routing algorithms in terms of average delay, average hop count, and message delivery rate.


Assuntos
Algoritmos , Simulação por Computador , Humanos
4.
J Hepatol ; 61(2): 260-269, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24583249

RESUMO

BACKGROUND & AIMS: There is increasing need for accurate assessment of liver fibrosis/cirrhosis. We aimed to develop qFibrosis, a fully-automated assessment method combining quantification of histopathological architectural features, to address unmet needs in core biopsy evaluation of fibrosis in chronic hepatitis B (CHB) patients. METHODS: qFibrosis was established as a combined index based on 87 parameters of architectural features. Images acquired from 25 Thioacetamide-treated rat samples and 162 CHB core biopsies were used to train and test qFibrosis and to demonstrate its reproducibility. qFibrosis scoring was analyzed employing Metavir and Ishak fibrosis staging as standard references, and collagen proportionate area (CPA) measurement for comparison. RESULTS: qFibrosis faithfully and reliably recapitulates Metavir fibrosis scores, as it can identify differences between all stages in both animal samples (p<0.001) and human biopsies (p<0.05). It is robust to sampling size, allowing for discrimination of different stages in samples of different sizes (area under the curve (AUC): 0.93-0.99 for animal samples: 1-16 mm(2); AUC: 0.84-0.97 for biopsies: 10-44 mm in length). qFibrosis can significantly predict staging underestimation in suboptimal biopsies (<15 mm) and under- and over-scoring by different pathologists (p<0.001). qFibrosis can also differentiate between Ishak stages 5 and 6 (AUC: 0.73, p=0.008), suggesting the possibility of monitoring intra-stage cirrhosis changes. Best of all, qFibrosis demonstrates superior performance to CPA on all counts. CONCLUSIONS: qFibrosis can improve fibrosis scoring accuracy and throughput, thus allowing for reproducible and reliable analysis of efficacies of anti-fibrotic therapies in clinical research and practice.


Assuntos
Hepatite B Crônica/complicações , Cirrose Hepática Experimental/diagnóstico , Animais , Biópsia , Colágeno/análise , Modelos Animais de Doenças , Humanos , Fígado/patologia , Cirrose Hepática Experimental/patologia , Ratos
5.
Genomics ; 101(2): 101-12, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23195410

RESUMO

We developed a model of influenza virus infection of neutrophils by inducing differentiation of the MPRO promyelocytic cell line. After 5 days of differentiation, about 20-30% of mature neutrophils could be detected. Only a fraction of neutrophils were infected by highly virulent influenza (HVI) virus, but were unable to support active viral replication compared with MDCK cells. HVI infection of neutrophils augmented early and late apoptosis as indicated by annexin V and TUNEL assays. Comparison between the global transcriptomic responses of neutrophils to HVI and low virulent influenza (LVI) revealed that the IFN regulatory factor and IFN signaling pathways were the most significantly overrepresented pathways, with activation of related genes in HVI as early as 3 h. Relatively consistent results were obtained by real-time RT-PCR of selected genes associated with the type I IFN pathway. Early after HVI infection, comparatively enhanced expression of apoptosis-related genes was also elicited.


Assuntos
Apoptose , Influenza Humana/imunologia , Interferon Tipo I/imunologia , Neutrófilos/virologia , Transdução de Sinais , Animais , Linhagem Celular , Cães , Humanos , Vírus da Influenza A Subtipo H3N2/fisiologia , Células Madin Darby de Rim Canino , Neutrófilos/citologia , Transcriptoma , Replicação Viral
6.
medRxiv ; 2024 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-39148849

RESUMO

Background: Developing medicine from scratch to governmental authorization and detecting adverse drug reactions (ADR) have barely been economical, expeditious, and risk-averse investments. The availability of large-scale observational healthcare databases and the popularity of large language models offer an unparalleled opportunity to enable automatic high-throughput drug screening for both repurposing and pharmacovigilance. Objectives: To demonstrate a general workflow for automatic high-throughput drug screening with the following advantages: (i) the association of various exposure on diseases can be estimated; (ii) both repurposing and pharmacovigilance are integrated; (iii) accurate exposure length for each prescription is parsed from clinical texts; (iv) intrinsic relationship between drugs and diseases are removed jointly by bioinformatic mapping and large language model - ChatGPT; (v) causal-wise interpretations for incidence rate contrasts are provided. Methods: Using a self-controlled cohort study design where subjects serve as their own control group, we tested the intention-to-treat association between medications on the incidence of diseases. Exposure length for each prescription is determined by parsing common dosages in English free text into a structured format. Exposure period starts from initial prescription to treatment discontinuation. A same exposure length preceding initial treatment is the control period. Clinical outcomes and categories are identified using existing phenotyping algorithms. Incident rate ratios (IRR) are tested using uniformly most powerful (UMP) unbiased tests. Results: We assessed 3,444 medications on 276 diseases on 6,613,198 patients from the Clinical Practice Research Datalink (CPRD), an UK primary care electronic health records (EHR) spanning from 1987 to 2018. Due to the built-in selection bias of self-controlled cohort studies, ingredients-disease pairs confounded by deterministic medical relationships are removed by existing map from RxNorm and nonexistent maps by calling ChatGPT. A total of 16,901 drug-disease pairs reveals significant risk reduction, which can be considered as candidates for repurposing, while a total of 11,089 pairs showed significant risk increase, where drug safety might be of a concern instead. Conclusions: This work developed a data-driven, nonparametric, hypothesis generating, and automatic high-throughput workflow, which reveals the potential of natural language processing in pharmacoepidemiology. We demonstrate the paradigm to a large observational health dataset to help discover potential novel therapies and adverse drug effects. The framework of this study can be extended to other observational medical databases.

7.
Front Bioinform ; 4: 1450146, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39497739

RESUMO

Background: Microscopy of regenerated tissue shows different morphologies between the healing of acute wounds and chronic wounds. This difference can be seen manually by biologists, but computational methods are needed to automate the characterization of morphology and regenerative quality in regenerated muscle tissue. Results: From the detected edge segments, we computed several imaging biomarkers of interest, such as median tortuosity, number of edge segments normalized by area, median edge segment distance and interquartile range of orientation angles of edge segments of the microscope images of successful and unsuccessful muscle regeneration. We observed that muscle fibers in saline-treated pressure ulcers had a larger interquartile range of orientation angles of the edge segments (p = 0.05) and shorter edge segment distances (p = 0.003) compared to those of acute cardiotoxin injuries. Conclusion: Our edge detection method was able to identify statistically significant differences in some of the imaging biomarkers between saline-treated pressure ulcers and cardiotoxin injuries, suggesting that chronic pressure ulcers have increased muscle fiber malformations compared to cardiotoxin injuries.

8.
Funct Integr Genomics ; 12(1): 105-17, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21874528

RESUMO

Investigating the relationships between critical influenza viral mutations contributing to increased virulence and host expression factors will shed light on the process of severe pathogenesis from the systems biology perspective. We previously generated a mouse-adapted, highly virulent influenza (HVI) virus through serial lung-to-lung passaging of a human influenza H3N2 virus strain that causes low virulent influenza (LVI) in murine lungs. This HVI virus is characterized by enhanced replication kinetics, severe lung injury, and systemic spread to major organs. Our gene microarray investigations compared the host transcriptomic responses of murine lungs to LVI virus and its HVI descendant at 12, 48, and 96 h following infection. More intense expression of genes associated with cytokine activity, type 1 interferon response, and apoptosis was evident in HVI at all time-points. We highlighted dysregulation of the TREM1 signaling pathway (an amplifier of cytokine production) that is likely to be upregulated in infiltrating neutrophils in HVI-infected lungs. The cytokine gene expression changes were corroborated by elevated levels of multiple cytokine and chemokine proteins in the bronchoalveolar lavage fluid of infected mice, especially at 12 h post-infection. Concomitantly, the downregulation of genes that mediate proliferative, developmental, and metabolic processes likely contributed to the lethality of HVI as well as lack of lung repair. Overall, our comparative transcriptomic study provided insights into key host factors that influence the dynamics, pathogenesis, and outcome of severe influenza.


Assuntos
Citocinas/metabolismo , Vírus da Influenza A Subtipo H3N2/patogenicidade , Pulmão/metabolismo , Glicoproteínas de Membrana/metabolismo , Infecções por Orthomyxoviridae/metabolismo , Receptores Imunológicos/metabolismo , Transcriptoma , Animais , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Líquido da Lavagem Broncoalveolar , Quimiocinas/genética , Quimiocinas/metabolismo , Citocinas/genética , Feminino , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Interações Hospedeiro-Patógeno , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H3N2/fisiologia , Pulmão/imunologia , Pulmão/patologia , Pulmão/virologia , Glicoproteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos BALB C , Infecções por Orthomyxoviridae/genética , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/virologia , Receptores Imunológicos/genética , Transdução de Sinais , Biologia de Sistemas , Receptor Gatilho 1 Expresso em Células Mieloides , Virulência/genética
9.
PLoS Comput Biol ; 7(7): e1002119, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21799663

RESUMO

Advances in proteomic technologies continue to substantially accelerate capability for generating experimental data on protein levels, states, and activities in biological samples. For example, studies on receptor tyrosine kinase signaling networks can now capture the phosphorylation state of hundreds to thousands of proteins across multiple conditions. However, little is known about the function of many of these protein modifications, or the enzymes responsible for modifying them. To address this challenge, we have developed an approach that enhances the power of clustering techniques to infer functional and regulatory meaning of protein states in cell signaling networks. We have created a new computational framework for applying clustering to biological data in order to overcome the typical dependence on specific a priori assumptions and expert knowledge concerning the technical aspects of clustering. Multiple clustering analysis methodology ('MCAM') employs an array of diverse data transformations, distance metrics, set sizes, and clustering algorithms, in a combinatorial fashion, to create a suite of clustering sets. These sets are then evaluated based on their ability to produce biological insights through statistical enrichment of metadata relating to knowledge concerning protein functions, kinase substrates, and sequence motifs. We applied MCAM to a set of dynamic phosphorylation measurements of the ERRB network to explore the relationships between algorithmic parameters and the biological meaning that could be inferred and report on interesting biological predictions. Further, we applied MCAM to multiple phosphoproteomic datasets for the ERBB network, which allowed us to compare independent and incomplete overlapping measurements of phosphorylation sites in the network. We report specific and global differences of the ERBB network stimulated with different ligands and with changes in HER2 expression. Overall, we offer MCAM as a broadly-applicable approach for analysis of proteomic data which may help increase the current understanding of molecular networks in a variety of biological problems.


Assuntos
Análise por Conglomerados , Bases de Dados de Proteínas , Proteômica/métodos , Algoritmos , Humanos , Modelos Biológicos
10.
Mol Cell Proteomics ; 9(11): 2558-70, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20631208

RESUMO

The rate of discovery of post-translational modification (PTM) sites is increasing rapidly and is significantly outpacing our biological understanding of the function and regulation of those modifications. To help meet this challenge, we have created PTMScout, a web-based interface for viewing, manipulating, and analyzing high throughput experimental measurements of PTMs in an effort to facilitate biological understanding of protein modifications in signaling networks. PTMScout is constructed around a custom database of PTM experiments and contains information from external protein and post-translational resources, including gene ontology annotations, Pfam domains, and Scansite predictions of kinase and phosphopeptide binding domain interactions. PTMScout functionality comprises data set comparison tools, data set summary views, and tools for protein assignments of peptides identified by mass spectrometry. Analysis tools in PTMScout focus on informed subset selection via common criteria and on automated hypothesis generation through subset labeling derived from identification of statistically significant enrichment of other annotations in the experiment. Subset selection can be applied through the PTMScout flexible query interface available for quantitative data measurements and data annotations as well as an interface for importing data set groupings by external means, such as unsupervised learning. We exemplify the various functions of PTMScout in application to data sets that contain relative quantitative measurements as well as data sets lacking quantitative measurements, producing a set of interesting biological hypotheses. PTMScout is designed to be a widely accessible tool, enabling generation of multiple types of biological hypotheses from high throughput PTM experiments and advancing functional assignment of novel PTM sites. PTMScout is available at http://ptmscout.mit.edu.


Assuntos
Ensaios de Triagem em Larga Escala , Internet , Processamento de Proteína Pós-Traducional , Proteômica/métodos , Software , Sequência de Aminoácidos , Bases de Dados de Proteínas , Dados de Sequência Molecular , Proteínas/química , Proteínas/genética
11.
Artigo em Inglês | MEDLINE | ID: mdl-35270766

RESUMO

The first wave of COVID-19 in China began in December 2019. The outbreak was quickly and effectively controlled through strict infection prevention and control with multipronged measures. By the end of March 2020, the outbreak had basically ended. Therefore, there are relatively complete and effective infection prevention and control (IPC) processes in China to curb virus transmission. Furthermore, there were two large-scale updates for the daily reports by the National Health Commission of the People's Republic of China in the early stage of the pandemic. We retrospectively studied the transmission characteristics and IPC of COVID-19 in China. Additionally, we analyzed and modeled the data in the two revisions. We found that most cases were limited to Hubei Province, especially in Wuhan, and the mortality rate was lower in non-Wuhan areas. We studied the two revisions and utilized the proposed transmission model to revise the daily confirmed cases at the beginning of the pandemic in Wuhan. Moreover, we estimated the cases and deaths for the same stage and analyzed the effect of IPC in China. The results show that strong and effective IPC with strict implementation was able to effectively and quickly control the pandemic.


Assuntos
COVID-19 , Pandemias , COVID-19/epidemiologia , China/epidemiologia , Humanos , Pandemias/prevenção & controle , Estudos Retrospectivos , SARS-CoV-2
12.
Nat Commun ; 13(1): 7652, 2022 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-36496454

RESUMO

Metformin, a diabetes drug with anti-aging cellular responses, has complex actions that may alter dementia onset. Mixed results are emerging from prior observational studies. To address this complexity, we deploy a causal inference approach accounting for the competing risk of death in emulated clinical trials using two distinct electronic health record systems. In intention-to-treat analyses, metformin use associates with lower hazard of all-cause mortality and lower cause-specific hazard of dementia onset, after accounting for prolonged survival, relative to sulfonylureas. In parallel systems pharmacology studies, the expression of two AD-related proteins, APOE and SPP1, was suppressed by pharmacologic concentrations of metformin in differentiated human neural cells, relative to a sulfonylurea. Together, our findings suggest that metformin might reduce the risk of dementia in diabetes patients through mechanisms beyond glycemic control, and that SPP1 is a candidate biomarker for metformin's action in the brain.


Assuntos
Demência , Diabetes Mellitus Tipo 2 , Metformina , Humanos , Metformina/farmacologia , Metformina/uso terapêutico , Reposicionamento de Medicamentos , Farmacologia em Rede , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/complicações , Compostos de Sulfonilureia , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Demência/tratamento farmacológico , Demência/etiologia , Prontuários Médicos
13.
Neuroimage Clin ; 25: 102186, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32000101

RESUMO

Functional modules in the human brain support its drive for specialization whereas brain hubs act as focal points for information integration. Brain hubs are brain regions that have a large number of both within and between module connections. We argue that weak connections in brain functional networks lead to misclassification of brain regions as hubs. In order to resolve this, we propose a new measure called ambivert degree that considers the node's degree as well as connection weights in order to identify nodes with both high degree and high connection weights as hubs. Using resting-state functional MRI scans from the Human Connectome Project, we show that ambivert degree identifies brain hubs that are not only crucial but also invariable across subjects. We hypothesize that nodal measures based on ambivert degree can be effectively used to classify patients from healthy controls for diseases that are known to have widespread hub disruption. Using patient data for Alzheimer's Disease and Autism Spectrum Disorder, we show that the hubs in the patient and healthy groups are very different for both the diseases and deep feedforward neural networks trained on nodal hub features lead to a significantly higher classification accuracy with significantly fewer trainable weights compared to using functional connectivity features. Thus, the ambivert degree improves identification of crucial brain hubs in healthy subjects and can be used as a diagnostic feature to detect neurological diseases characterized by hub disruption.


Assuntos
Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/fisiopatologia , Transtorno do Espectro Autista/diagnóstico por imagem , Transtorno do Espectro Autista/fisiopatologia , Córtex Cerebral/diagnóstico por imagem , Conectoma/métodos , Aprendizado Profundo , Rede Nervosa/diagnóstico por imagem , Adolescente , Adulto , Idoso , Córtex Cerebral/fisiopatologia , Criança , Humanos , Imageamento por Ressonância Magnética , Rede Nervosa/fisiopatologia , Adulto Jovem
14.
PLoS One ; 13(5): e0195518, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29734327

RESUMO

Research on temporal characteristics of human dynamics has attracted much attentions for its contribution to various areas such as communication, medical treatment, finance, etc. Existing studies show that the time intervals between two consecutive events present different non-Poisson characteristics, such as power-law, Pareto, bimodal distribution of power-law, exponential distribution, piecewise power-law, et al. With the occurrences of new services, new types of distributions may arise. In this paper, we study the distributions of the time intervals between two consecutive visits to QQ and WeChat service, the top two popular instant messaging services in China, and present a new finding that when the value of statistical unit T is set to 0.001s, the inter-event time distribution follows a piecewise distribution of exponential and power-law, indicating the heterogeneous character of IM services users' online behavior in different time scales. We infer that the heterogeneous character is related to the communication mechanism of IM and the habits of users. Then we develop a combination model of exponential model and interest model to characterize the heterogeneity. Furthermore, we find that the exponent of the inter-event time distribution of the same service is different in two cities, which is correlated with the popularity of the services. Our research is useful for the application of information diffusion, prediction of economic development of cities, and so on.


Assuntos
Internet , Modelos Estatísticos , Comportamento Social , Envio de Mensagens de Texto/estatística & dados numéricos , Humanos , Fatores de Tempo
15.
Sci Rep ; 8(1): 16016, 2018 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-30375454

RESUMO

Current liver fibrosis scoring by computer-assisted image analytics is not fully automated as it requires manual preprocessing (segmentation and feature extraction) typically based on domain knowledge in liver pathology. Deep learning-based algorithms can potentially classify these images without the need for preprocessing through learning from a large dataset of images. We investigated the performance of classification models built using a deep learning-based algorithm pre-trained using multiple sources of images to score liver fibrosis and compared them against conventional non-deep learning-based algorithms - artificial neural networks (ANN), multinomial logistic regression (MLR), support vector machines (SVM) and random forests (RF). Automated feature classification and fibrosis scoring were achieved by using a transfer learning-based deep learning network, AlexNet-Convolutional Neural Networks (CNN), with balanced area under receiver operating characteristic (AUROC) values of up to 0.85-0.95 versus ANN (AUROC of up to 0.87-1.00), MLR (AUROC of up to 0.73-1.00), SVM (AUROC of up to 0.69-0.99) and RF (AUROC of up to 0.94-0.99). Results indicate that a deep learning-based algorithm with transfer learning enables the construction of a fully automated and accurate prediction model for scoring liver fibrosis stages that is comparable to other conventional non-deep learning-based algorithms that are not fully automated.


Assuntos
Diagnóstico por Imagem , Processamento de Imagem Assistida por Computador/métodos , Cirrose Hepática/diagnóstico por imagem , Algoritmos , Animais , Biomarcadores , Biópsia , Colágeno/metabolismo , Aprendizado Profundo , Diagnóstico por Imagem/métodos , Processamento de Imagem Assistida por Computador/normas , Cirrose Hepática/patologia , Aprendizado de Máquina , Imageamento por Ressonância Magnética , Masculino , Microscopia , Redes Neurais de Computação , Ratos , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios X
16.
Annu Int Conf IEEE Eng Med Biol Soc ; 2016: 3887-3890, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28269135

RESUMO

Quantitative co-localization analysis with fluorescent microscopy is a common approach to assess the spatial co-ordination of molecules and thus to understand their functions in biological processes. However, the co-localization analysis results might not be consistent due to various imaging conditions and different quantification methods used. We propose a novel method to separate a co-localization event into two aspects: co-occurrence and intensity correlation, which are usually combined as one parameter in other quantitative co-localization analyses. By examining co-localization through both co-occurrence and intensity correlation, the co-localization analysis provides accurate and interpretable results. Furthermore, the co-occurrence pixels can be visualized in an additional image channel to provide an intuitive impression of the quantity and locations of the co-localization events occurring.


Assuntos
Processamento de Imagem Assistida por Computador , Microscopia de Fluorescência , Algoritmos , Animais , Computadores , Células-Tronco Embrionárias/citologia , Humanos , Camundongos , Distribuição Normal , Software
17.
Aerosp Med Hum Perform ; 86(7): 606-13, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26102140

RESUMO

INTRODUCTION: Shoulder injuries due to working inside the space suit are some of the most serious and debilitating injuries astronauts encounter. Space suit injuries occur primarily in the Neutral Buoyancy Laboratory (NBL) underwater training facility due to accumulated musculoskeletal stress. We quantitatively explored the underlying causal mechanisms of injury. METHODS: Logistic regression was used to identify relevant space suit components, training environment variables, and anthropometric dimensions related to an increased propensity for space-suited injury. Two groups of subjects were analyzed: those whose reported shoulder incident is attributable to the NBL or working in the space suit, and those whose shoulder incidence began in active duty, meaning working in the suit could be a contributing factor. RESULTS: For both groups, percent of training performed in the space suit planar hard upper torso (HUT) was the most important predictor variable for injury. Frequency of training and recovery between training were also significant metrics. The most relevant anthropometric dimensions were bideltoid breadth, expanded chest depth, and shoulder circumference. Finally, record of previous injury was found to be a relevant predictor for subsequent injury. The first statistical model correctly identifies 39% of injured subjects, while the second model correctly identifies 68% of injured subjects. DISCUSSION: A review of the literature suggests this is the first work to quantitatively evaluate the hypothesized causal mechanisms of all space-suited shoulder injuries. Although limited in predictive capability, each of the identified variables can be monitored and modified operationally to reduce future impacts on an astronaut's health.


Assuntos
Acidentes de Trabalho/estatística & dados numéricos , Medicina Aeroespacial/métodos , Traumatismos do Braço/epidemiologia , Astronautas/estatística & dados numéricos , Lesões do Ombro , Voo Espacial/instrumentação , Trajes Espaciais/estatística & dados numéricos , Traumatismos do Braço/etiologia , Humanos , Modelos Logísticos , Modelos Teóricos , Curva ROC , Trajes Espaciais/efeitos adversos
18.
J Biophotonics ; 8(10): 804-15, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25597396

RESUMO

Cancer initiating cells (CICs) have been the focus of recent anti-cancer therapies, exhibiting strong invasion capability via potentially enhanced ability to remodel extracellular matrices (ECM). We have identified CICs in a human breast cancer cell line, MX-1, and developed a xenograft model in SCID mice. We investigated the CICs' matrix-remodeling effects using Second Harmonic Generation (SHG) microscopy to identify potential phenotypic signatures of the CIC-rich tumors. The isolated CICs exhibit higher proliferation, drug efflux and drug resistant properties in vitro; were more tumorigenic than non-CICs, resulting in more and larger tumors in the xenograft model. The CIC-rich tumors have less collagen in the tumor interior than in the CIC-poor tumors supporting the idea that the CICs can remodel the collagen more effectively. The collagen fibers were preferentially aligned perpendicular to the CIC-rich tumor boundary while parallel to the CIC-poor tumor boundary suggesting more invasive behavior of the CIC-rich tumors. These findings would provide potential translational values in quantifying and monitoring CIC-rich tumors in future anti-cancer therapies. CIC-rich tumors remodel the collagen matrix more than CIC-poor tumors.


Assuntos
Neoplasias da Mama/patologia , Matriz Extracelular/patologia , Células-Tronco Neoplásicas/patologia , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Transformação Celular Neoplásica , Colágeno/metabolismo , Doxorrubicina/metabolismo , Doxorrubicina/farmacologia , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/metabolismo , Feminino , Humanos , Camundongos , Camundongos SCID , Microscopia , Mitoxantrona/metabolismo , Mitoxantrona/farmacologia , Invasividade Neoplásica , Células-Tronco Neoplásicas/efeitos dos fármacos
19.
Sci Rep ; 4: 4636, 2014 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-24717650

RESUMO

The accurate staging of liver fibrosis is of paramount importance to determine the state of disease progression, therapy responses, and to optimize disease treatment strategies. Non-linear optical microscopy techniques such as two-photon excitation fluorescence (TPEF) and second harmonic generation (SHG) can image the endogenous signals of tissue structures and can be used for fibrosis assessment on non-stained tissue samples. While image analysis of collagen in SHG images was consistently addressed until now, cellular and tissue information included in TPEF images, such as inflammatory and hepatic cell damage, equally important as collagen deposition imaged by SHG, remain poorly exploited to date. We address this situation by experimenting liver fibrosis quantification and scoring using a combined approach based on TPEF liver surface imaging on a Thioacetamide-induced rat model and a gradient based Bag-of-Features (BoF) image classification strategy. We report the assessed performance results and discuss the influence of specific BoF parameters to the performance of the fibrosis scoring framework.


Assuntos
Cirrose Hepática/diagnóstico , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Animais , Progressão da Doença , Processamento de Imagem Assistida por Computador , Fígado/patologia , Cirrose Hepática/classificação , Masculino , Ratos , Ratos Wistar , Tioacetamida
20.
Artigo em Inglês | MEDLINE | ID: mdl-22255707

RESUMO

Neutrophils derived from induced-differentiated mouse promyleocyte (MPRO) cell lines provide an alternative source of mouse neutrophils for in vitro experiments, substituting for primary mouse neutrophils that are normally obtained by sacrificing mice. One issue with using induced-differentiated MPRO cells (or NEUTs) is that they are usually composed of not only mature neutrophils, but also neutrophil precursors. Here, we report on an assessment of an automated image analysis system to estimate mature neutrophil proportion in giemsa-stained NEUTs, and compare the accuracy with manual cell counting and flow cytometry results.


Assuntos
Contagem de Células/métodos , Rastreamento de Células/métodos , Citometria de Fluxo/métodos , Células Precursoras de Granulócitos/citologia , Interpretação de Imagem Assistida por Computador/métodos , Neutrófilos/citologia , Reconhecimento Automatizado de Padrão/métodos , Algoritmos , Animais , Diferenciação Celular , Linhagem Celular , Aumento da Imagem/métodos , Camundongos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
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