Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Magn Reson Imaging ; 57(4): 1185-1196, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36190656

RESUMO

BACKGROUND: Dual-phenotype hepatocellular carcinoma (DPHCC) is highly aggressive and difficult to distinguish from hepatocellular carcinoma (HCC). PURPOSE: To develop and validate clinical and radiomics models based on contrast-enhanced MRI for the preoperative diagnosis of DPHCC. STUDY TYPE: Retrospective. POPULATION: A total of 87 patients with DPHCC and 92 patients with non-DPHCC randomly divided into a training cohort (n = 125: 64 non-DPHCC; 61 DPHCC) and a validation cohort (n = 54: 28 non-DPHCC; 26 DPHCC). FIELD STRENGTH/SEQUENCE: A 3.0 T; dynamic contrast-enhanced MRI with time-resolved T1-weighted imaging sequence. ASSESSMENT: In the clinical model, the maximum tumor diameter and hepatitis B virus (HBV) were independent risk factors of DPHCC. In the radiomics model, a total of 1781 radiomics features were extracted from tumor volumes of interest (VOIs) in the arterial phase (AP) and portal venous phase (PP) images. For feature reduction and selection, Pearson correlation coefficient (PCC) and recursive feature elimination (RFE) were used. Clinical, AP, PP, and combined radiomics models were established using machine learning algorithms (support vector machine [SVM], logistic regression [LR], and logistic regression-least absolute shrinkage and selection operator [LR-LASSO]) and their discriminatory efficacy assessed and compared. STATISTICAL TESTS: The independent sample t test, Mann-Whitney U test, Chi-square test, regression analysis, receiver operating characteristic curve (ROC) analysis, Pearson correlation analysis, the Delong test. A P value < 0.05 was considered statistically significant. RESULTS: In the validation cohort, the combined radiomics model (area under the curve [AUC] = 0.908, 95% confidence interval [CI]: 0.831-0.985) showed the highest diagnostic performance. The AUCs of the PP (AUC = 0.879, 95% CI: 0.779-0.979) and combined radiomics models were significantly higher than that of clinical model (AUC = 0.685, 95% CI: 0.526-0.844). There were no significant differences in AUC between AP or PP radiomics model and combined radiomics model (P = 0.286, 0.180 and 0.543). CONCLUSION: MRI radiomics models may be useful for discriminating DPHCC from non-DPHCC before surgery. EVIDENCE LEVEL: 4 TECHNICAL EFFICACY: Stage 2.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Imageamento por Ressonância Magnética/métodos , Fenótipo , Estudos Retrospectivos
3.
Microb Ecol ; 77(4): 967-979, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30357425

RESUMO

Titanium ions significantly promote plant growth, but the mechanism is still unclear. Cut flowers are ideal materials for the study of plant growth and senescence. In this study, freshly cut Gerbera jamesonii were used to study the effects of titanium ions (8 mg/L) on the flower longevity. Flowering observation showed that the gerbera vase life was significantly prolonged in the presence of titanium ions. Plate colony counts showed that the amounts of bacteria in the vase solution of the control group were approximately 1700 times more than that of titanium ion treatment group. High-throughput sequencing was used to determine the sequences of 16S rRNA gene V3-V4 variable regions of the vase solutions to analyze bacterial species, their average proportions, and absolute abundance. The results showed that the titanium ions reduced the entire bacterial counts as well as altered the absolute abundance of different bacterial species in the vase solution. The most prevalent bacteria were mainly Enterobacteriaceae, Pseudomonas veronii, Pseudomonas sp., Delftia sp., Agrobacterium sp., Sphingobacterium multivorum, Acinetobacter johnsonii, and Clostridiaceae. In combination with plate colony counts, we demonstrated that all the bacterial growths were significantly inhibited by titanium ions, regardless of their average proportions increased or decreased. These results showed that titanium ions could extend effectively the longevity of gerberas and possess the broad-spectrum antibacterial properties. This study provides a basis for further mechanism exploration of titanium ions action and its applications in cut flower preservation and agricultural production.


Assuntos
Bactérias/metabolismo , Titânio/metabolismo , Microbiologia da Água , Asteraceae/crescimento & desenvolvimento , Bactérias/classificação , Bactérias/efeitos dos fármacos , Flores/crescimento & desenvolvimento , Íons/metabolismo , RNA Bacteriano/análise , RNA Ribossômico 16S/análise
4.
Front Plant Sci ; 8: 1519, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29209335

RESUMO

Plant cytochrome P450s are involved in a wide range of biosynthetic reactions that generate various biomolecules, including a variety of defensive compounds. Perennial ryegrass (Lolium perenne) and tall fescue (Festuca arundinacea) are two major species of turf and forage grasses that usually experience low temperature below -10°C and high temperature over 38°C around the world. In this study, we re-analyzed transcriptome of perennial ryegrass and tall fescue treated with heat and cold stress. Thus, we can evaluate P450 composition in these species and confirm whether P450 genes response to temperature stress. We identified 277 and 319 P450 transcripts with open reading frames larger than 300 bp, respectively. These P450 transcripts were mainly classed in the CYP71, 51, 94, 89, 72, and 734 families. In perennial ryegrass and tall fescue, a total of 66 and 62 P450 transcripts were up-regulated, and 65 and 117 transcripts were down-regulated when subjected to heat stress, respectively. When exposed to cold stress, 60 and 73 transcripts were up-regulated, and 59 and 77 transcripts were down-regulated in perennial ryegrass and tall fescue. Among these differentially expressed transcripts, 64 and 87 of them showed expression level changes that followed the same trend, and these temperature-responsive genes primarily belong to the CYP71, 72 and 99 families. Besides, heat and cold stress altered phenylalanine and brassinosteroid involved P450 transcripts in perennial ryegrass and tall fescue. P450 transcripts involved in the metabolism of these compounds showed a strong response to heat and/or cold stress, indicating that they likely play important roles in temperature acclimation in these two species. The CYPome provide a genetic base for the future functional studies, as well as genetic studies that may improve stress tolerance for perennial ryegrass and tall fescue to extreme temperature.

5.
BMC Genomics ; 17: 423, 2016 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-27260799

RESUMO

BACKGROUND: Plant microRNAs (miRNAs) are involved in various biological pathways and stress responses as negative regulators at the posttranscriptional level. Abscisic acid (ABA) is a key signaling molecule that mediates plant stress response by activating many stress-related genes. Although some miRNAs in plants are previously identified to respond to ABA, a comprehensive profile of ABA-responsive miRNAs has not yet been elucidated. RESULTS: Here, we identified miRNAs responding to exogenous application of ABA, and their predicted target genes in the model plant organism tomato (Solanum lycopersicum). Deep sequencing of small RNAs from ABA-treated and untreated tomatoes revealed that miRNAs can be up- or down-regulated upon treatment with ABA. A total of 1067 miRNAs were detected (including 365 known and 702 candidate novel miRNAs), of those, 416 miRNAs which had an abundance over two TPM (transcripts per million) were selected for differential expression analysis. We identified 269 (180 known and 89 novel) miRNAs that respond to exogenous ABA treatment with a change in expression level of |log2FC|≥0.25. 136 of these miRNAs (90 known and 46 novel) were expressed at significantly different levels |log2FC|≥1 between treatments. Furthermore, stem-loop RT-PCR was applied to validate the RNA-seq data. Target prediction and analysis of the corresponding ABA-responsive transcriptome data uncovered that differentially expressed miRNAs are involved in condition stress and pathogen resistance, growth and development. Among them, approximately 90 miRNAs were predicted to target transcription factors and pathogen resistance genes. Some miRNAs had functional overlap in biotic and abiotic stress. Most of these miRNAs were down-regulated following exposure to exogenous ABA, while their related target genes were inversely up-regulated, which is consistent with their negative regulatory role in gene expression. CONCLUSIONS: Exogenous ABA application influences the composition and expression level of tomato miRNAs. ABA mainly down-regulates miRNAs that their target genes involve in abiotic stress adaption and disease resistance. ABA might increase expression of stress-related genes via miRNA-mediated posttranscriptional regulation, and our results indicate that ABA treatment has the potential to improve both abiotic stress tolerance and pathogen resistance. This study presents a comprehensive profile of ABA-regulated miRNAs in the tomato, and provides a robust database for further investigation of ABA regulatory mechanisms.


Assuntos
Ácido Abscísico/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genoma de Planta , Genômica , MicroRNAs/genética , Solanum lycopersicum/efeitos dos fármacos , Solanum lycopersicum/genética , Biologia Computacional/métodos , Perfilação da Expressão Gênica , Genômica/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Anotação de Sequência Molecular , Interferência de RNA , RNA Mensageiro/genética , Reprodutibilidade dos Testes , Transcriptoma
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...