Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
2.
Nat Biomed Eng ; 5(6): 533-545, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34131321

RESUMO

Regular screening for the early detection of common chronic diseases might benefit from the use of deep-learning approaches, particularly in resource-poor or remote settings. Here we show that deep-learning models can be used to identify chronic kidney disease and type 2 diabetes solely from fundus images or in combination with clinical metadata (age, sex, height, weight, body-mass index and blood pressure) with areas under the receiver operating characteristic curve of 0.85-0.93. The models were trained and validated with a total of 115,344 retinal fundus photographs from 57,672 patients and can also be used to predict estimated glomerulal filtration rates and blood-glucose levels, with mean absolute errors of 11.1-13.4 ml min-1 per 1.73 m2 and 0.65-1.1 mmol l-1, and to stratify patients according to disease-progression risk. We evaluated the generalizability of the models for the identification of chronic kidney disease and type 2 diabetes with population-based external validation cohorts and via a prospective study with fundus images captured with smartphones, and assessed the feasibility of predicting disease progression in a longitudinal cohort.


Assuntos
Aprendizado Profundo , Diabetes Mellitus Tipo 2/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/estatística & dados numéricos , Fotografação/estatística & dados numéricos , Insuficiência Renal Crônica/diagnóstico por imagem , Retina/diagnóstico por imagem , Área Sob a Curva , Glicemia/metabolismo , Estatura , Índice de Massa Corporal , Peso Corporal , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Progressão da Doença , Feminino , Fundo de Olho , Taxa de Filtração Glomerular , Humanos , Masculino , Metadados/estatística & dados numéricos , Pessoa de Meia-Idade , Redes Neurais de Computação , Fotografação/métodos , Estudos Prospectivos , Curva ROC , Insuficiência Renal Crônica/metabolismo , Insuficiência Renal Crônica/patologia , Retina/metabolismo , Retina/patologia
3.
Oral Oncol ; 117: 105268, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33848724

RESUMO

BACKGROUND: Restoring anatomical contour and position of the malar eminence and orbital rim following ablative mid-face procedures is critical in maintaining facial contour and orbit position. OBJECTIVE: To report our reconstructive approach using the scapular tip free-flap (STFF) for orbito-zygomatic defects, evaluating contour and overall shape restoration. METHODS: The study included 2 series: a clinical cohort of 15 consecutive patients who underwent an orbito-zygomatic reconstruction with a STFF and a cohort of 10 patients who had CT scan imaging but did not have orbito-zygomatic surgical resection or reconstruction. Using a 3D software, overall conformance (OC) and contour conformance (CC) with respect to the mirrored contralateral (clinical cohort) or native zygoma (preclinical cohort) were analyzed. Postoperative orbital volumes were also measured in the clinical cohort. Mean, median, root-mean-square (RMS), minimum and maximum measurements were obtained both for OC and CC. Conformance values of clinical and preclinical cohort were compared to objectively evaluate the quality of reconstruction in terms of orbito-zygomatic framework restoration (Mann-Whitney test). RESULTS: All measurements for OC and CC between scapular tip and the zygoma showed no differences, both on the clinical (RMS: OC 3.29 mm vs CC 3.32 mm -p = NS-) and preclinical (RMS: OC 2.03 mm and CC 2.31 mm -p = NS-) cohorts. Moreover, there were no differences in post-operative orbital volumes in the clinical cohort. Clinical outcomes of the case-series are also reported. CONCLUSION: The STFF is highly effective in restoring facial projection and orbital volume in orbito-zygomatic reconstruction.


Assuntos
Retalhos de Tecido Biológico , Órbita , Procedimentos de Cirurgia Plástica , Zigoma , Estudos de Coortes , Face , Humanos , Órbita/diagnóstico por imagem , Órbita/cirurgia , Zigoma/diagnóstico por imagem , Zigoma/cirurgia
4.
Nat Biomed Eng ; 5(6): 509-521, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33859385

RESUMO

Common lung diseases are first diagnosed using chest X-rays. Here, we show that a fully automated deep-learning pipeline for the standardization of chest X-ray images, for the visualization of lesions and for disease diagnosis can identify viral pneumonia caused by coronavirus disease 2019 (COVID-19) and assess its severity, and can also discriminate between viral pneumonia caused by COVID-19 and other types of pneumonia. The deep-learning system was developed using a heterogeneous multicentre dataset of 145,202 images, and tested retrospectively and prospectively with thousands of additional images across four patient cohorts and multiple countries. The system generalized across settings, discriminating between viral pneumonia, other types of pneumonia and the absence of disease with areas under the receiver operating characteristic curve (AUCs) of 0.94-0.98; between severe and non-severe COVID-19 with an AUC of 0.87; and between COVID-19 pneumonia and other viral or non-viral pneumonia with AUCs of 0.87-0.97. In an independent set of 440 chest X-rays, the system performed comparably to senior radiologists and improved the performance of junior radiologists. Automated deep-learning systems for the assessment of pneumonia could facilitate early intervention and provide support for clinical decision-making.


Assuntos
COVID-19/diagnóstico por imagem , Bases de Dados Factuais , Aprendizado Profundo , SARS-CoV-2 , Tomografia Computadorizada por Raios X , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Índice de Gravidade de Doença
5.
Precis Clin Med ; 4(3): 149-154, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35693215

RESUMO

To assess the impact of the key non-synonymous amino acid substitutions in the RBD of the spike protein of SARS-CoV-2 variant B.1.617.1 (dominant variant identified in the current India outbreak) on the infectivity and neutralization activities of the immune sera, L452R and E484Q (L452R-E484Q variant), pseudotyped virus was constructed (with the D614G background). The impact on binding with the neutralizing antibodies was also assessed with an ELISA assay. Pseudotyped virus carrying a L452R-E484Q variant showed a comparable infectivity compared with D614G. However, there was a significant reduction in the neutralization activity of the immune sera from non-human primates vaccinated with a recombinant receptor binding domain (RBD) protein, convalescent patients, and healthy vaccinees vaccinated with an mRNA vaccine. In addition, there was a reduction in binding of L452R-E484Q-D614G protein to the antibodies of the immune sera from vaccinated non-human primates. These results highlight the interplay between infectivity and other biologic factors involved in the natural evolution of SARS-CoV-2. Reduced neutralization activities against the L452R-E484Q variant will have an impact on health authority planning and implications for the vaccination strategy/new vaccine development.

6.
Precis Clin Med ; 4(2): 85-92, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35694155

RESUMO

Anterior segment eye diseases account for a significant proportion of presentations to eye clinics worldwide, including diseases associated with corneal pathologies, anterior chamber abnormalities (e.g. blood or inflammation), and lens diseases. The construction of an automatic tool for segmentation of anterior segment eye lesions would greatly improve the efficiency of clinical care. With research on artificial intelligence progressing in recent years, deep learning models have shown their superiority in image classification and segmentation. The training and evaluation of deep learning models should be based on a large amount of data annotated with expertise; however, such data are relatively scarce in the domain of medicine. Herein, the authors developed a new medical image annotation system, called EyeHealer. It is a large-scale anterior eye segment dataset with both eye structures and lesions annotated at the pixel level. Comprehensive experiments were conducted to verify its performance in disease classification and eye lesion segmentation. The results showed that semantic segmentation models outperformed medical segmentation models. This paper describes the establishment of the system for automated classification and segmentation tasks. The dataset will be made publicly available to encourage future research in this area.

7.
Precis Clin Med ; 4(1): 62-69, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35693121

RESUMO

Within COVID-19 there is an urgent unmet need to predict at the time of hospital admission which COVID-19 patients will recover from the disease, and how fast they recover to deliver personalized treatments and to properly allocate hospital resources so that healthcare systems do not become overwhelmed. To this end, we have combined clinically salient CT imaging data synergistically with laboratory testing data in an integrative machine learning model to predict organ-specific recovery of patients from COVID-19. We trained and validated our model in 285 patients on each separate major organ system impacted by COVID-19 including the renal, pulmonary, immune, cardiac, and hepatic systems. To greatly enhance the speed and utility of our model, we applied an artificial intelligence method to segment and classify regions on CT imaging, from which interpretable data could be directly fed into the predictive machine learning model for overall recovery. Across all organ systems we achieved validation set area under the receiver operator characteristic curve (AUC) values for organ-specific recovery ranging from 0.80 to 0.89, and significant overall recovery prediction in Kaplan-Meier analyses. This demonstrates that the synergistic use of an artificial intelligence (AI) framework applied to CT lung imaging and a machine learning model that integrates laboratory test data with imaging data can accurately predict the overall recovery of COVID-19 patients from baseline characteristics.

9.
Cell ; 181(6): 1423-1433.e11, 2020 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-32416069

RESUMO

Many COVID-19 patients infected by SARS-CoV-2 virus develop pneumonia (called novel coronavirus pneumonia, NCP) and rapidly progress to respiratory failure. However, rapid diagnosis and identification of high-risk patients for early intervention are challenging. Using a large computed tomography (CT) database from 3,777 patients, we developed an AI system that can diagnose NCP and differentiate it from other common pneumonia and normal controls. The AI system can assist radiologists and physicians in performing a quick diagnosis especially when the health system is overloaded. Significantly, our AI system identified important clinical markers that correlated with the NCP lesion properties. Together with the clinical data, our AI system was able to provide accurate clinical prognosis that can aid clinicians to consider appropriate early clinical management and allocate resources appropriately. We have made this AI system available globally to assist the clinicians to combat COVID-19.


Assuntos
Inteligência Artificial , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Tomografia Computadorizada por Raios X , COVID-19 , China , Estudos de Coortes , Infecções por Coronavirus/patologia , Infecções por Coronavirus/terapia , Conjuntos de Dados como Assunto , Humanos , Pulmão/patologia , Modelos Biológicos , Pandemias , Projetos Piloto , Pneumonia Viral/patologia , Pneumonia Viral/terapia , Prognóstico , Radiologistas , Insuficiência Respiratória/diagnóstico
10.
Signal Transduct Target Ther ; 5(1): 3, 2020 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-32296024

RESUMO

The ability to identify a specific type of leukemia using minimally invasive biopsies holds great promise to improve the diagnosis, treatment selection, and prognosis prediction of patients. Using genome-wide methylation profiling and machine learning methods, we investigated the utility of CpG methylation status to differentiate blood from patients with acute lymphocytic leukemia (ALL) or acute myelogenous leukemia (AML) from normal blood. We established a CpG methylation panel that can distinguish ALL and AML blood from normal blood as well as ALL blood from AML blood with high sensitivity and specificity. We then developed a methylation-based survival classifier with 23 CpGs for ALL and 20 CpGs for AML that could successfully divide patients into high-risk and low-risk groups, with significant differences in clinical outcome in each leukemia type. Together, these findings demonstrate that methylation profiles can be highly sensitive and specific in the accurate diagnosis of ALL and AML, with implications for the prediction of prognosis and treatment selection.


Assuntos
Biomarcadores Tumorais/genética , Metilação de DNA/genética , Leucemia/genética , Prognóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Ilhas de CpG/genética , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Lactente , Leucemia/classificação , Leucemia/diagnóstico , Leucemia/patologia , Aprendizado de Máquina , Masculino , Pessoa de Meia-Idade , Regiões Promotoras Genéticas/genética , Adulto Jovem
11.
Proc Natl Acad Sci U S A ; 117(8): 4328-4336, 2020 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-32029582

RESUMO

Epigenetic alterations and metabolic dysfunction are two hallmarks of aging. However, the mechanism of how their interaction regulates aging, particularly in mammals, remains largely unknown. Here we show ELOVL fatty acid elongase 2 (Elovl2), a gene whose epigenetic alterations are most highly correlated with age prediction, contributes to aging by regulating lipid metabolism. Impaired Elovl2 function disturbs lipid synthesis with increased endoplasmic reticulum stress and mitochondrial dysfunction, leading to key accelerated aging phenotypes. Restoration of mitochondrial activity can rescue age-related macular degeneration (AMD) phenotypes induced by Elovl2 deficiency in human retinal pigmental epithelial (RPE) cells. We revealed an epigenetic-metabolism axis contributing to aging and potentially to antiaging therapy.

13.
Nat Med ; 25(3): 433-438, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30742121

RESUMO

Artificial intelligence (AI)-based methods have emerged as powerful tools to transform medical care. Although machine learning classifiers (MLCs) have already demonstrated strong performance in image-based diagnoses, analysis of diverse and massive electronic health record (EHR) data remains challenging. Here, we show that MLCs can query EHRs in a manner similar to the hypothetico-deductive reasoning used by physicians and unearth associations that previous statistical methods have not found. Our model applies an automated natural language processing system using deep learning techniques to extract clinically relevant information from EHRs. In total, 101.6 million data points from 1,362,559 pediatric patient visits presenting to a major referral center were analyzed to train and validate the framework. Our model demonstrates high diagnostic accuracy across multiple organ systems and is comparable to experienced pediatricians in diagnosing common childhood diseases. Our study provides a proof of concept for implementing an AI-based system as a means to aid physicians in tackling large amounts of data, augmenting diagnostic evaluations, and to provide clinical decision support in cases of diagnostic uncertainty or complexity. Although this impact may be most evident in areas where healthcare providers are in relative shortage, the benefits of such an AI system are likely to be universal.


Assuntos
Aprendizado Profundo , Diagnóstico por Computador , Registros Eletrônicos de Saúde , Processamento de Linguagem Natural , Pediatria , Adolescente , Inteligência Artificial , Criança , Pré-Escolar , China , Feminino , Humanos , Lactente , Recém-Nascido , Aprendizado de Máquina , Masculino , Estudo de Prova de Conceito , Reprodutibilidade dos Testes , Estudos Retrospectivos
14.
Cell Res ; 29(4): 337, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30670814

RESUMO

In the initial published version of this article, we inadvertently stated that "all procedures were conducted with the approval and under the supervision of the Institutional Animal Care and Use Committee (IACUC) at the University of California, San Diego". Given that all animal work that was conducted for this project was performed at the City University of Hong Kong and Guangzhou Women and Children's Medical Center, we would like to instead, acknowledge these programs for their oversight of the animal studies. This correction does not affect the description of the results or the conclusions of this work.

15.
Precis Clin Med ; 2(4): 213-220, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35693877

RESUMO

Uveal melanoma is the most common intraocular cancer in the adult eye. R183 and Q209 were found to be mutational hotspots in exon 4 and exon 5 of GNAQ and GNA11 in Caucasians. However, only a few studies have reported somatic mutations in GNAQ or GNA11 in uveal melanoma in Chinese. We extracted somatic DNA from paraffin-embedded biopsies of 63 Chinese uveal melanoma samples and sequenced the entire coding regions of exons 4 and 5 in GNAQ and GNA11. The results showed that 33% of Chinese uveal melanoma samples carried Q209 mutations while none had R183 mutation in GNAQ or GNA11. In addition, seven novel missense somatic mutations in GNAQ (Y192C, F194L, P170S, D236N, L232F, V230A, and M227I) and four novel missense somatic mutations in GNA11 (R166C, I200T, S225F, and V206M) were found in our study. The high mutation frequency of Q209 and the novel missense mutations detected in this study suggest that GNAQ and GNA11 are common targets for somatic mutations in Chinese uveal melanoma.

16.
Cell ; 172(5): 1122-1131.e9, 2018 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-29474911

RESUMO

The implementation of clinical-decision support algorithms for medical imaging faces challenges with reliability and interpretability. Here, we establish a diagnostic tool based on a deep-learning framework for the screening of patients with common treatable blinding retinal diseases. Our framework utilizes transfer learning, which trains a neural network with a fraction of the data of conventional approaches. Applying this approach to a dataset of optical coherence tomography images, we demonstrate performance comparable to that of human experts in classifying age-related macular degeneration and diabetic macular edema. We also provide a more transparent and interpretable diagnosis by highlighting the regions recognized by the neural network. We further demonstrate the general applicability of our AI system for diagnosis of pediatric pneumonia using chest X-ray images. This tool may ultimately aid in expediting the diagnosis and referral of these treatable conditions, thereby facilitating earlier treatment, resulting in improved clinical outcomes. VIDEO ABSTRACT.


Assuntos
Aprendizado Profundo , Diagnóstico por Imagem , Pneumonia/diagnóstico , Criança , Humanos , Redes Neurais de Computação , Pneumonia/diagnóstico por imagem , Curva ROC , Reprodutibilidade dos Testes , Tomografia de Coerência Óptica
17.
Precis Clin Med ; 1(1): 5-20, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35694125

RESUMO

Retinal degenerative diseases are a major cause of blindness. Retinal gene therapy is a trail-blazer in the human gene therapy field, leading to the first FDA approved gene therapy product for a human genetic disease. The application of Clustered Regularly Interspaced Short Palindromic Repeat/Cas9 (CRISPR/Cas9)-mediated gene editing technology is transforming the delivery of gene therapy. We review the history, present, and future prospects of retinal gene therapy.

18.
Nat Mater ; 16(11): 1155-1161, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-29035356

RESUMO

An effective blood-based method for the diagnosis and prognosis of hepatocellular carcinoma (HCC) has not yet been developed. Circulating tumour DNA (ctDNA) carrying cancer-specific genetic and epigenetic aberrations may enable a noninvasive 'liquid biopsy' for diagnosis and monitoring of cancer. Here, we identified an HCC-specific methylation marker panel by comparing HCC tissue and normal blood leukocytes and showed that methylation profiles of HCC tumour DNA and matched plasma ctDNA are highly correlated. Using cfDNA samples from a large cohort of 1,098 HCC patients and 835 normal controls, we constructed a diagnostic prediction model that showed high diagnostic specificity and sensitivity (P < 0.001) and was highly correlated with tumour burden, treatment response, and stage. Additionally, we constructed a prognostic prediction model that effectively predicted prognosis and survival (P < 0.001). Together, these findings demonstrate in a large clinical cohort the utility of ctDNA methylation markers in the diagnosis, surveillance, and prognosis of HCC.


Assuntos
Biomarcadores Tumorais , Carcinoma Hepatocelular , DNA Tumoral Circulante , Metilação de DNA , Neoplasias Hepáticas , Modelos Biológicos , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/genética , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/genética , DNA Tumoral Circulante/sangue , DNA Tumoral Circulante/genética , Feminino , Humanos , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/genética , Masculino , Prognóstico
19.
Proc Natl Acad Sci U S A ; 114(28): 7414-7419, 2017 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-28652331

RESUMO

The ability to identify a specific cancer using minimally invasive biopsy holds great promise for improving the diagnosis, treatment selection, and prediction of prognosis in cancer. Using whole-genome methylation data from The Cancer Genome Atlas (TCGA) and machine learning methods, we evaluated the utility of DNA methylation for differentiating tumor tissue and normal tissue for four common cancers (breast, colon, liver, and lung). We identified cancer markers in a training cohort of 1,619 tumor samples and 173 matched adjacent normal tissue samples. We replicated our findings in a separate TCGA cohort of 791 tumor samples and 93 matched adjacent normal tissue samples, as well as an independent Chinese cohort of 394 tumor samples and 324 matched adjacent normal tissue samples. The DNA methylation analysis could predict cancer versus normal tissue with more than 95% accuracy in these three cohorts, demonstrating accuracy comparable to typical diagnostic methods. This analysis also correctly identified 29 of 30 colorectal cancer metastases to the liver and 32 of 34 colorectal cancer metastases to the lung. We also found that methylation patterns can predict prognosis and survival. We correlated differential methylation of CpG sites predictive of cancer with expression of associated genes known to be important in cancer biology, showing decreased expression with increased methylation, as expected. We verified gene expression profiles in a mouse model of hepatocellular carcinoma. Taken together, these findings demonstrate the utility of methylation biomarkers for the molecular characterization of cancer, with implications for diagnosis and prognosis.


Assuntos
Metilação de DNA , Neoplasias/diagnóstico , Neoplasias/genética , Alelos , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Estudos de Casos e Controles , Estudos de Coortes , Neoplasias do Colo/diagnóstico , Neoplasias do Colo/genética , Ilhas de CpG , Feminino , Humanos , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/genética , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Masculino , Metástase Neoplásica , Neoplasias/mortalidade , Prognóstico , Risco , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA