RESUMO
BACKGROUND: Small (< 4 cm) clear cell renal cell carcinoma (ccRCC) is the most common type of small renal cancer and its prognosis is poor. However, conventional radiological characteristics obtained by computed tomography (CT) are not sufficient to predict the nuclear grade of small ccRCC before surgery. METHODS: A total of 113 patients with histologically confirmed ccRCC were randomly assigned to the training set (n = 67) and the testing set (n = 46). The baseline and CT imaging data of the patients were evaluated statistically to develop a clinical model. A radiomics model was created, and the radiomics score (Rad-score) was calculated by extracting radiomics features from the CT images. Then, a clinical radiomics nomogram was developed using multivariate logistic regression analysis by combining the Rad-score and critical clinical characteristics. The receiver operating characteristic (ROC) curve was used to evaluate the discrimination of small ccRCC in both the training and testing sets. RESULTS: The radiomics model was constructed using six features obtained from the CT images. The shape and relative enhancement value of the nephrographic phase (REV of the NP) were found to be independent risk factors in the clinical model. The area under the curve (AUC) values for the training and testing sets for the clinical radiomics nomogram were 0.940 and 0.902, respectively. Decision curve analysis (DCA) revealed that the radiomics nomogram model was a better predictor, with the highest degree of coincidence. CONCLUSION: The CT-based radiomics nomogram has the potential to be a noninvasive and preoperative method for predicting the WHO/ISUP grade of small ccRCC.
Assuntos
Carcinoma de Células Renais , Carcinoma de Células Pequenas , Neoplasias Renais , Neoplasias Pulmonares , Carcinoma de Pequenas Células do Pulmão , Humanos , Carcinoma de Células Renais/diagnóstico por imagem , Carcinoma de Células Renais/cirurgia , Nomogramas , Tomografia Computadorizada por Raios X , Neoplasias Renais/diagnóstico por imagem , Neoplasias Renais/cirurgia , Organização Mundial da Saúde , Estudos RetrospectivosRESUMO
PURPOSE: To develop a radiomics nomogram based on computed tomography (CT) to estimate progression-free survival (PFS) in patients with small cell lung cancer (SCLC) and assess its incremental value to the clinical risk factors for individual PFS estimation. METHODS: 558 patients with pathologically confirmed SCLC were retrospectively recruited from three medical centers. A radiomics signature was generated by using the Pearson correlation analysis, univariate Cox analysis, and multivariate Cox analysis. Association of the radiomics signature with PFS was evaluated. A radiomics nomogram was developed based on the radiomics signature, then its calibration, discrimination, reclassification, and clinical usefulness were evaluated. RESULTS: In total, 6 CT radiomics features were finally selected. The radiomics signature was significantly associated with PFS (hazard ratio [HR] 4.531, 95% confidence interval [CI] 3.524-5.825, p < 0.001). Incorporating the radiomics signature into the radiomics nomogram resulted in better performance for the estimation of PFS (concordance index [C-index] 0.799) than with the clinical nomogram (C-index 0.629), as well as high 6 months and 12 months area under the curves of 0.885 and 0.846, respectively. Furthermore, the radiomics nomogram also significantly improved the classification accuracy for PFS outcomes, based on the net reclassification improvement (33.7%, 95% CI 0.216-0.609, p < 0.05) and integrated discrimination improvement (22.7%, 95% CI 0.168-0.278, p < 0.05). Decision curve analysis demonstrated that in terms of clinical usefulness, the radiomics nomogram outperformed the clinical nomogram. CONCLUSION: A CT-based radiomics nomogram exhibited a promising performance for predicting PFS in patients with SCLC, which could provide valuable information for individualized treatment.
Assuntos
Neoplasias Pulmonares , Carcinoma de Pequenas Células do Pulmão , Humanos , Nomogramas , Neoplasias Pulmonares/diagnóstico por imagem , Carcinoma de Pequenas Células do Pulmão/diagnóstico por imagem , Intervalo Livre de Progressão , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodosRESUMO
OBJECTIVES: Mucosal healing (MH) is currently the gold standard in Crohn's disease (CD) management. Noninvasive assessment of MH in CD patients is increasingly a concern of clinicians. METHODS: This retrospective study included 106 patients with confirmed CD who were divided into a training cohort (n = 73) and a testing cohort (n = 33). Patient demographics were evaluated to establish a clinical model. Radiomics features were extracted from computed tomography enterography (CTE) images. A radiomics signature was constructed, and a radiomics score (Rad-score) was calculated by using the radiomics signature-based formula. A clinical radiomics nomogram was then built by incorporating the Rad-score and significant clinical features. The diagnostic performance of the three models was evaluated using receiver operating characteristic (ROC) curve analysis. RESULTS: Of the 106 patients with CD, 37 exhibited MH after 26 weeks of infliximab (IFX) treatment. The area under the ROC curve (AUC) of the clinical radiomics nomogram for distinguishing MH from non-MH, which was based on the disease duration and Rad-score, was 0.880 (95% confidence interval [CI]: 0.809-0.943) in the training cohort and 0.877 (95% CI: 0.745-0.983) in the testing cohort. Decision curve analysis (DCA) confirmed the clinical utility of the clinical radiomics nomogram. CONCLUSIONS: This is a preliminary study suggesting that this CTE-based radiomics model has potential value for predicting MH in CD patients. A nomogram constructed by combining radiomics signatures and clinical features can help clinicians select appropriate therapeutic strategies for CD patients. KEY POINTS: ⢠The disease duration (odds ratio (OR) = 0.969, 95% confidence interval (CI) = 0.943-0.995, p = 0.021) was an independent predictor of MH in the clinical model. ⢠The AUC of the radiomics model constructed by the five radiomics features was 0.846 (95% CI: 0.759-0.921) in the training cohort and 0.817 (95% CI: 0.665-0.945) in the testing cohort for differentiating MH from non-MH. ⢠The AUC of the clinical radiomics nomogram was 0.880 (95% CI: 0.809-0.943) in the training cohort and 0.877 (95% CI: 0.745-0.983) in the testing cohort for distinguishing MH from non-MH.
Assuntos
Doença de Crohn , Nomogramas , Doença de Crohn/diagnóstico por imagem , Doença de Crohn/tratamento farmacológico , Humanos , Infliximab/uso terapêutico , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodosRESUMO
BACKGROUND: Disruption of the postsynaptic density protein-95 (PSD95)-neuronal nitric oxide synthase (nNOS) coupling is an effective way to treat ischemic stroke, however, it still faces some challenges, especially lack of satisfactory PSD95-nNOS uncouplers and the efficient high throughput screening model to discover them. RESULTS: Herein, the multifunctional metal-organic framework (MMOF) nanoparticles as a new screening system were innovatively fabricated via layer-by-layer self-assembly in which His-tagged nNOS was selectively immobilized on the surface of magnetic MOF, and then PSD95 with green fluorescent protein (GFP-PSD95) was specifically bound on it. It was found that MMOF nanoparticles not only exhibited the superior performances including the high loading efficiency, reusability, and anti-interference ability, but also possessed the good fluorescent sensitivity to detect the coupled GFP-PSD95. After MMOF nanoparticles interacted with the uncouplers, they would be rapidly separated from uncoupled GFP-PSD95 by magnet, and the fluorescent intensities could be determined to assay the uncoupling efficiency at high throughput level. CONCLUSIONS: In conclusion, MMOF nanoparticles were successfully fabricated and applied to screen the natural actives as potential PSD95-nNOS uncouplers. Taken together, our newly developed method provided a new material as a platform for efficiently discovering PSD95-nNOS uncouplers for stoke treatment.
Assuntos
Estruturas Metalorgânicas , Nanopartículas , Acidente Vascular Cerebral , Animais , Proteína 4 Homóloga a Disks-Large/metabolismo , Óxido Nítrico Sintase Tipo I/metabolismo , Ratos , Ratos Sprague-Dawley , Fatores de TranscriçãoRESUMO
Ligand binding to the cell surface receptors initiates signaling cascades that are commonly transduced through a protein-protein interaction (PPI) network to activate a plethora of response pathways. However, tools to capture the membrane PPI network are lacking. Here, we describe a cross-linking-aided mass spectrometry workflow for isolation and identification of signal-dependent epidermal growth factor receptor (EGFR) proteome. We performed protein cross-linking in cell culture at various time points following EGF treatment, followed by immunoprecipitation of endogenous EGFR and analysis of the associated proteins by quantitative mass spectrometry. We identified 140 proteins with high confidence during a 2 h time course by data-dependent acquisition and further validated the results by parallel reaction monitoring. A large proportion of proteins in the EGFR proteome function in endocytosis and intracellular protein transport. The EGFR proteome was highly dynamic with distinct temporal behavior; 10 proteins that appeared in all time points constitute the core proteome. Functional characterization showed that loss of the FYVE domain-containing proteins altered the EGFR intracellular distribution but had a minor effect on EGFR proteome or signaling. Thus, our results suggest that the EGFR proteome include functional regulators that influence EGFR signaling and bystanders that are captured as the components of endocytic vesicles. The high-resolution spatiotemporal information of these molecules facilitates the delineation of many pathways that could determine the strength and duration of the signaling, as well as the location and destination of the receptor.
Assuntos
Mapeamento de Interação de Proteínas/métodos , Proteoma/metabolismo , Transdução de Sinais , Linhagem Celular , Fator de Crescimento Epidérmico/metabolismo , Receptores ErbB/metabolismo , Humanos , Imunoprecipitação , Espectrometria de Massas , Transporte Proteico , Fatores de Tempo , Fluxo de TrabalhoRESUMO
KEY MESSAGE: Here, a functional characterization of a wheat MSR has been presented: this protein makes a contribution to the plant's tolerance of abiotic stress, acting through its catalytic capacity and its modulation of ROS and ABA pathways. The molecular mechanism and function of certain members of the methionine sulfoxide reductase (MSR) gene family have been defined, however, these analyses have not included the wheat equivalents. The wheat MSR gene TaMSRA4.1 is inducible by salinity and drought stress and in this study, we demonstrate that its activity is restricted to the Met-S-SO enantiomer, and its subcellular localization is in the chloroplast. Furthermore, constitutive expression of TaMSRA4.1 enhanced the salinity and drought tolerance of wheat and Arabidopsis thaliana. In these plants constitutively expressing TaMSRA4.1, the accumulation of reactive oxygen species (ROS) was found to be influenced through the modulation of genes encoding proteins involved in ROS signaling, generation and scavenging, while the level of endogenous abscisic acid (ABA), and the sensitivity of stomatal guard cells to exogenous ABA, was increased. A yeast two-hybrid screen, bimolecular fluorescence complementation and co-immunoprecipitation assays demonstrated that heme oxygenase 1 (HO1) interacted with TaMSRA4.1, and that this interaction depended on a TaHO1 C-terminal domain. In plants subjected to salinity or drought stress, TaMSRA4.1 reversed the oxidation of TaHO1, activating ROS and ABA signaling pathways, but not in the absence of HO1. The aforementioned properties advocate TaMSRA4.1 as a candidate for plant genetic enhancement.
Assuntos
Heme Oxigenase-1/metabolismo , Metionina Sulfóxido Redutases/metabolismo , Transdução de Sinais , Estresse Fisiológico , Triticum/enzimologia , Ácido Abscísico/metabolismo , Arabidopsis/enzimologia , Arabidopsis/genética , Arabidopsis/fisiologia , Secas , Perfilação da Expressão Gênica , Heme Oxigenase-1/genética , Metionina Sulfóxido Redutases/genética , Oxirredução , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Salinidade , Tolerância ao Sal , Plântula/enzimologia , Plântula/genética , Plântula/fisiologia , Triticum/genética , Triticum/fisiologia , Técnicas do Sistema de Duplo-HíbridoRESUMO
In animals, the Sep15 protein participates in disease resistance, growth, and development, but the function of its plant homologues remains unclear. Here, the function of maize Sep15 was analysed by characterization of two independent Sep15-like loss-of-function mutants. In the absence of ZmSep15-like, seedling tolerance to both water and salinity stress was compromised. The mutants experienced a heightened level of endoplasmic reticulum stress, and over-accumulated reactive oxygen species, resulting in leaf necrosis. Characterization of Arabidopsis thaliana atsep15 mutant as well as like with ectopic expression of ZmSep15-like indicated that ZmSep15-like contributed to tolerance of both osmotic and salinity stress. ZmSep15-like interacted physically with UDP-glucose: glycoprotein glucosyltransferase1 (UGGT1). When the interaction was disrupted, the response to both osmotic and salinity stresses was impaired in maize or Arabidopsis. Co-expressing ZmUGGT1 and ZmUGGT2 enhanced the tolerance of A. thaliana to both stressors, indicating a functional interaction between them. Together, the data indicated that plants Sep15-like proteins promote osmotic and salinity stress resistance by influencing endoplasmic reticulum stress response and reactive oxygen species level.
Assuntos
Glucosiltransferases/metabolismo , Osmorregulação , Pressão Osmótica/fisiologia , Zea mays , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Retículo Endoplasmático/metabolismo , Regulação da Expressão Gênica de Plantas , Glucosiltransferases/genética , Osmorregulação/genética , Osmorregulação/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Estresse Salino/fisiologia , Estresse Fisiológico , Zea mays/metabolismoRESUMO
Despite the importance of taste in determining nutrient intake, our understanding of the processes that control the development of the peripheral taste system is lacking. Several early regulators of taste development have been identified, including sonic hedgehog, bone morphogenetic protein 4 and multiple members of the Wnt/ß-catenin signaling pathway. However, the regulation of these factors, including their induction, remains poorly understood. Here, we identify a crucial role for the Wilms' tumor 1 protein (WT1) in circumvallate (CV) papillae development. WT1 is a transcription factor that is important in the normal development of multiple tissues, including both the olfactory and visual systems. In mice, WT1 expression is detectable by E12.5, when the CV taste placode begins to form. In mice lacking WT1, the CV fails to develop normally and markers of early taste development are dysregulated compared with wild type. We demonstrate that expression of the WT1 target genes Lef1, Ptch1 and Bmp4 is significantly reduced in developing tongue tissue derived from Wt1 knockout mice and that, in normal tongue, WT1 is bound to the promoter regions of these genes. Moreover, siRNA knockdown of WT1 in cultured taste cells leads to a reduction in the expression of Lef1 and Ptch1. Our data identify WT1 as a crucial transcription factor in the development of the CV through the regulation of multiple signaling pathways that have established roles in the formation and patterning of taste placodes.
Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Papilas Gustativas/embriologia , Paladar/fisiologia , Língua/embriologia , Proteínas WT1/metabolismo , Animais , Fator 1 de Ligação ao Facilitador Linfoide/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores Patched , Receptor Patched-1 , Fenótipo , Receptores de Superfície Celular/metabolismo , Transdução de Sinais , Fatores de TempoRESUMO
DNA replication and repair in mammalian cells involves three distinct DNA ligases: ligase I (Lig1), ligase III (Lig3) and ligase IV (Lig4). Lig3 is considered a key ligase during base excision repair because its stability depends upon its nuclear binding partner Xrcc1, a critical factor for this DNA repair pathway. Lig3 is also present in the mitochondria, where its role in mitochondrial DNA (mtDNA) maintenance is independent of Xrcc1 (ref. 4). However, the biological role of Lig3 is unclear as inactivation of murine Lig3 results in early embryonic lethality. Here we report that Lig3 is essential for mtDNA integrity but dispensable for nuclear DNA repair. Inactivation of Lig3 in the mouse nervous system resulted in mtDNA loss leading to profound mitochondrial dysfunction, disruption of cellular homeostasis and incapacitating ataxia. Similarly, inactivation of Lig3 in cardiac muscle resulted in mitochondrial dysfunction and defective heart-pump function leading to heart failure. However, Lig3 inactivation did not result in nuclear DNA repair deficiency, indicating essential DNA repair functions of Xrcc1 can occur in the absence of Lig3. Instead, we found that Lig1 was critical for DNA repair, but acted in a cooperative manner with Lig3. Additionally, Lig3 deficiency did not recapitulate the hallmark features of neural Xrcc1 inactivation such as DNA damage-induced cerebellar interneuron loss, further underscoring functional separation of these DNA repair factors. Therefore, our data reveal that the critical biological role of Lig3 is to maintain mtDNA integrity and not Xrcc1-dependent DNA repair.
Assuntos
Núcleo Celular/genética , DNA Ligases/metabolismo , Reparo do DNA , DNA Mitocondrial/metabolismo , Proteínas de Ligação a DNA/metabolismo , Animais , Ataxia/patologia , Ataxia/fisiopatologia , Biocatálise , Sobrevivência Celular , Células Cultivadas , Dano ao DNA , DNA Ligase Dependente de ATP , DNA Ligases/deficiência , DNA Ligases/genética , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/genética , Genes Essenciais , Coração/fisiologia , Coração/fisiopatologia , Interneurônios/enzimologia , Interneurônios/patologia , Camundongos , Mitocôndrias/enzimologia , Mitocôndrias/genética , Mitocôndrias/patologia , Músculo Esquelético/enzimologia , Músculo Esquelético/patologia , Miocárdio/enzimologia , Miocárdio/patologia , Sistema Nervoso/enzimologia , Sistema Nervoso/patologia , Fenótipo , Proteínas de Ligação a Poli-ADP-Ribose , Proteína 1 Complementadora Cruzada de Reparo de Raio-X , Proteínas de XenopusRESUMO
Mammalian cells have three ATP-dependent DNA ligases, which are required for DNA replication and repair. Homologues of ligase I (Lig1) and ligase IV (Lig4) are ubiquitous in Eukarya, whereas ligase III (Lig3), which has nuclear and mitochondrial forms, appears to be restricted to vertebrates. Lig3 is implicated in various DNA repair pathways with its partner protein Xrcc1 (ref. 1). Deletion of Lig3 results in early embryonic lethality in mice, as well as apparent cellular lethality, which has precluded definitive characterization of Lig3 function. Here we used pre-emptive complementation to determine the viability requirement for Lig3 in mammalian cells and its requirement in DNA repair. Various forms of Lig3 were introduced stably into mouse embryonic stem (mES) cells containing a conditional allele of Lig3 that could be deleted with Cre recombinase. With this approach, we find that the mitochondrial, but not nuclear, Lig3 is required for cellular viability. Although the catalytic function of Lig3 is required, the zinc finger (ZnF) and BRCA1 carboxy (C)-terminal-related (BRCT) domains of Lig3 are not. Remarkably, the viability requirement for Lig3 can be circumvented by targeting Lig1 to the mitochondria or expressing Chlorella virus DNA ligase, the minimal eukaryal nick-sealing enzyme, or Escherichia coli LigA, an NAD(+)-dependent ligase. Lig3-null cells are not sensitive to several DNA-damaging agents that sensitize Xrcc1-deficient cells. Our results establish a role for Lig3 in mitochondria, but distinguish it from its interacting protein Xrcc1.
Assuntos
DNA Ligases/metabolismo , Reparo do DNA , DNA Mitocondrial/metabolismo , Proteínas de Ligação a DNA/metabolismo , Mitocôndrias/enzimologia , Mitocôndrias/genética , Animais , Biocatálise , Sobrevivência Celular , Dano ao DNA , DNA Ligase Dependente de ATP , DNA Ligases/química , DNA Ligases/deficiência , DNA Ligases/genética , Células-Tronco Embrionárias/metabolismo , Genes Essenciais , Teste de Complementação Genética , Humanos , Camundongos , Mitocôndrias/patologia , Proteínas de Ligação a Poli-ADP-Ribose , Estrutura Terciária de Proteína , Troca de Cromátide Irmã/efeitos dos fármacos , Proteína 1 Complementadora Cruzada de Reparo de Raio-X , Proteínas de XenopusRESUMO
A novel molecularly imprinted polymer (MIP) was synthesized by precipitation polymerization with baicalein (BAI) as the template and used as solid-phase extraction (SPE) adsorbent, aiming at the affinity isolation and selective knockout of BAI from Scutellaria baicalensis Georgi (SB). We used computational simulation to predict the optimal functional monomer, polymerization solvent and molar ratio of template to functional monomer. Characterization and performance tests revealed that MIP exhibited uniform spherical morphology, rapid binding kinetics, and higher adsorption capacity for BAI compared with nonimprinted polymer (NIP). The application of MIP in SPE coupled with high-performance liquid chromatography to extract BAI from SB showed excellent recovery (94.3%) and purity (97.0%). Not only the single BAI compound, but also the BAI-removed SB extract was obtained by one-step process. This new method is useful for isolation and knockout of key bioactive compounds from herbal medicines.
Assuntos
Flavanonas/isolamento & purificação , Impressão Molecular/métodos , Scutellaria baicalensis/química , Extração em Fase Sólida/métodos , Simulação por Computador , Flavanonas/análise , Flavanonas/química , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos TestesRESUMO
Highly selective molecularly imprinted mesoporous silica polymer (SBA-15@MIP) for baicalein (BAI) extraction was synthesized using a surface molecular imprinting technique on the SBA-15 supporter. Computational simulation was used to predict the optimal functional monomer for the rational design of SBA-15@MIP. Meanwhile, high adsorption capacity was obtained when a suitable yield of molecularly imprinted polymers (MIPs) layer was grafted onto the surface of SBA-15. Characterization and performance tests of the obtained polymer revealed that SBA-15@MIP possessed a highly ordered mesoporous structure, reached saturated adsorption within 60 min, and exhibited higher sorption capacity to the target molecule BAI compared with non-imprinted mesoporous silica polymer (SBA-15@NIP) and SBA-15. Finally, SBA-15@MIP was successfully applied to solid-phase extraction (SPE) coupled with high-performance liquid chromatography and ultraviolet detection (HPLC-UV) for the determination of trace BAI in plasma samples. Mean recoveries of BAI through the molecularly imprinted solid-phase extraction (MISPE) sorbent, non-imprinted solid-phase extraction (NISPE) sorbent, and SBA-15 solid-phase extraction (SBA-15-SPE) sorbent were 94.4, 22.7, and 10.7 %, respectively, and the relative standard deviations were 2.9, 2.6, and 3.6 %, respectively. These results reveal that SBA-15@MIP as a SPE sorbent has good applicability to selectively separate and enrich trace BAI from complex samples.
Assuntos
Flavanonas/sangue , Flavanonas/isolamento & purificação , Impressão Molecular/métodos , Dióxido de Silício/química , Extração em Fase Sólida/métodos , Adsorção , Animais , Cromatografia Líquida de Alta Pressão/métodos , Humanos , Microscopia Eletrônica de Varredura , Polímeros/síntese química , Polímeros/química , Ratos , Reprodutibilidade dos Testes , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria , Raios UltravioletaRESUMO
Taking mesoporous molecular sieve MCM-41 as a substrate, baicalin (BA) as template, acrylamide (AM) as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as a cross-linking agent, ethanol as solvent, under thermal polymerization initiator of azobis isobutyronitrilo (AIBN) , a kind of selective recognition of baicalin surface molecularly imprinted polymer was synthesized. The surface morphologies and characteristics of the MIPs were characterized by infrared spectroscopy (IR) and transmission electron microscope (TEM). The adsorption properties of polymer microsphere for the template were tested by the dynamic adsorption equilibrium experiments and static adsorption equilibrium experiments. The experiment showed that the imprinting process was successfully and the well-ordered one-dimensional pore structure of MCM-41 was still preserved. Furthermore, molecularly imprinted polymers had higher selective ability for BA, then provided a new method for the efficient separation and enrichment of baicalin active ingredients from medicinal plants Scutellaria baicalensis.
Assuntos
Medicamentos de Ervas Chinesas/isolamento & purificação , Flavonoides/química , Flavonoides/isolamento & purificação , Polímeros/síntese química , Scutellaria baicalensis/química , Adsorção , Medicamentos de Ervas Chinesas/química , Impressão Molecular , Polimerização , Polímeros/química , PorosidadeRESUMO
A novel molecular imprinted sensor based on CdTe@SiO2 quantum dots (QDs) was developed for norepinephrine (NE) recognition. The molecularly imprinted polymer (MIP) on the surface of CdTe@SiO2 QDs (CdTe@SiO2@MIP) was characterized by Fourier transform infrared spectroscopy, transmission electron microscopy and fluorescence spectroscopy. The synthesized nanosensor had a distinguished selectivity and high binding affinity to NE. Under optimal conditions, the relative fluorescence intensity of CdTe@SiO2@MIP linearly decreased with increase of the concentration of NE in the range of 0.04-10 µM. The limit of detection was 8 nM (3σ/K). The proposed method was applied to the analysis of NE in rat plasma, and the result obtained by the method was in good agreement with that assayed by the fluorescence derivatization method. The method developed is simple, fast, and can be applied to the determination of NE in biological samples.
Assuntos
Compostos de Cádmio/química , Corantes Fluorescentes/química , Impressão Molecular , Norepinefrina/análise , Polímeros/química , Pontos Quânticos , Dióxido de Silício/química , Telúrio/química , Limite de Detecção , Microscopia Eletrônica de Transmissão , Espectrometria de Fluorescência , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
Nonhomologous end-joining (NHEJ) is the primary DNA repair pathway thought to underlie chromosomal translocations and other genomic rearrangements in somatic cells. The canonical NHEJ pathway, including DNA ligase IV (Lig4), suppresses genomic instability and chromosomal translocations, leading to the notion that a poorly defined, alternative NHEJ (alt-NHEJ) pathway generates these rearrangements. Here, we investigate the DNA ligase requirement of chromosomal translocation formation in mouse cells. Mammals have two other DNA ligases, Lig1 and Lig3, in addition to Lig4. As deletion of Lig3 results in cellular lethality due to its requirement in mitochondria, we used recently developed cell lines deficient in nuclear Lig3 but rescued for mitochondrial DNA ligase activity. Further, zinc finger endonucleases were used to generate DNA breaks at endogenous loci to induce translocations. Unlike with Lig4 deficiency, which causes an increase in translocation frequency, translocations are reduced in frequency in the absence of Lig3. Residual translocations in Lig3-deficient cells do not show a bias toward use of pre-existing microhomology at the breakpoint junctions, unlike either wild-type or Lig4-deficient cells, consistent with the notion that alt-NHEJ is impaired with Lig3 loss. By contrast, Lig1 depletion in otherwise wild-type cells does not reduce translocations or affect microhomology use. However, translocations are further reduced in Lig3-deficient cells upon Lig1 knockdown, suggesting the existence of two alt-NHEJ pathways, one that is biased toward microhomology use and requires Lig3 and a back-up pathway which does not depend on microhomology and utilizes Lig1.
Assuntos
DNA Ligases/metabolismo , Translocação Genética , Animais , Sequência de Bases , Núcleo Celular/metabolismo , DNA Ligase Dependente de ATP , DNA Ligases/genética , Reparo do DNA , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Camundongos , Modelos Genéticos , Dados de Sequência Molecular , Proteínas de Ligação a Poli-ADP-Ribose , Transfecção , Proteínas de XenopusRESUMO
Breast cancer has emerged as the most common cancer globally, with a significant reduction in overall survival rate after metastasis. Compared with other types of breast cancer, triple-negative breast cancer (TNBC) is more prone to metastasize, presenting substantial treatment challenges due to the lack of effective therapies. LGR4, which is highly expressed in breast cancer, has been shown to promote the proliferation and invasion of breast cancer cells. However, its specific role in TNBC remains unclear. In this study, we applied a multi-omics approach to explore the regulatory mechanism of LGR4 in TNBC metastasis. Our findings showed that LGR4 could regulate actin cytoskeletal through EGFR and curtail EGFR activation-induced TNBC metastasis by inhibiting MGP expression. These insights provide new perspectives on the role of LGR4 in breast cancer metastasis.
RESUMO
OBJECTIVE: To demonstrate the value of using 50 keV virtual monochromatic images with deep learning image reconstruction (DLIR) in low-dose dual-energy CT enterography (CTE). METHODS: In this prospective study, 114 participants (62 % M; 41.9 ± 16 years) underwent dual-energy CTE. The early-enteric phase was performed using standard-dose (noise index (NI): 8) and images were reconstructed at 70 keV and 50 keV with 40 % strength ASIR-V (ASIR-V40%). The late-enteric phase used low-dose (NI: 12) and images were reconstructed at 50 keV with ASIR-V40%, and DLIR at medium (DLIR-M) and high strength (DLIR-H). Image standard deviation (SD), signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), edge-rise-slope (ERS) were computed. The quantitative comb sign score was calculated for the 27 patients with Crohn's disease. The subjective noise, image contrast, display of rectus artery were scored using a 5-point scale by two radiologists blindly. RESULTS: Effective dose was reduced by 50 % (P < 0.001) in the late-enteric phase to 3.26 mSv. The lower-dose 50 keV-DLIR-H images (SD:17.7 ± 0.5HU) had similar image noise (P = 0.97) as the standard-dose 70 keV-ASIR-V40% images (SD:17.7 ± 0.73HU), but with higher (P < 0.001) SNR, CNR, ERS and quantitative comb sign score (5.7 ± 0.17, 1.8 ± 0.12, 156.04 ± 5.21 and 5.05 ± 0.73, respectively). Furthermore, the lower-dose 50 keV-DLIR-H images obtained the highest score in the rectus artery visibility (4.27 ± 0.6). CONCLUSIONS: The 50 keV images in dual-energy CTE with DLIR provides high-quality images, with a 50 % reduction in radiation dose. Images with high contrast and density resolutions significantly enhance the diagnostic confidence of Crohn's disease and are essential for the clinical development of individualized treatment plans.
Assuntos
Aprendizado Profundo , Doses de Radiação , Interpretação de Imagem Radiográfica Assistida por Computador , Imagem Radiográfica a Partir de Emissão de Duplo Fóton , Tomografia Computadorizada por Raios X , Humanos , Feminino , Masculino , Adulto , Estudos Prospectivos , Tomografia Computadorizada por Raios X/métodos , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/métodos , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Pessoa de Meia-Idade , Razão Sinal-Ruído , Idoso , Doença de Crohn/diagnóstico por imagemRESUMO
OBJECTIVE: To demonstrate the clinical advantages of a deep-learning image reconstruction (DLIR) in low-dose dual-energy computed tomography enterography (DECTE) by comparing images with standard-dose adaptive iterative reconstruction-Veo (ASIR-V) images. METHODS: In this Institutional review board approved prospective study, 86 participants who underwent DECTE were enrolled. The early-enteric phase scan was performed using standard-dose (noise index: 8) and images were reconstructed at 5 mm and 1.25 mm slice thickness with ASIR-V at a level of 40% (ASIR-V40%). The late-enteric phase scan used low-dose (noise index: 12) and images were reconstructed at 1.25 mm slice thickness with ASIR-V40%, and DLIR at medium (DLIR-M) and high (DLIR-H). The 70 keV monochromatic images were used for image comparison and analysis. For objective assessment, image noise, artifact index, SNR and CNR were measured. For subjective assessment, subjective noise, image contrast, bowel wall sharpness, mesenteric vessel clarity, and small structure visibility were scored by two radiologists blindly. Radiation dose was compared between the early- and late-enteric phases. RESULTS: Radiation dose was reduced by 50% in the late-enteric phase [(6.31 ± 1.67) mSv] compared with the early-enteric phase [(3.01 ± 1.09) mSv]. For the 1.25 mm images, DLIR-M and DLIR-H significantly improved both objective and subjective image quality compared to those with ASIR-V40%. The low-dose 1.25 mm DLIR-H images had similar image noise, SNR, CNR values as the standard-dose 5 mm ASIR-V40% images, but significantly higher scores in image contrast [5(5-5), P < 0.05], bowel wall sharpness [5(5-5), P < 0.05], mesenteric vessel clarity [5(5-5), P < 0.05] and small structure visibility [5(5-5), P < 0.05]. CONCLUSIONS: DLIR significantly reduces image noise at the same slice thickness, but significantly improves spatial resolution and lesion conspicuity with thinner slice thickness in DECTE, compared to conventional ASIR-V40% 5 mm images, all while providing 50% radiation dose reduction.
Assuntos
Aprendizado Profundo , Doses de Radiação , Interpretação de Imagem Radiográfica Assistida por Computador , Imagem Radiográfica a Partir de Emissão de Duplo Fóton , Tomografia Computadorizada por Raios X , Humanos , Feminino , Estudos Prospectivos , Masculino , Tomografia Computadorizada por Raios X/métodos , Pessoa de Meia-Idade , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/métodos , Adulto , Idoso , Idoso de 80 Anos ou maisRESUMO
BACKGROUND AND PURPOSE: To develop a computed tomography (CT)-based deep learning model to predict overall survival (OS) among small-cell lung cancer (SCLC) patients and identify patients who could benefit from prophylactic cranial irradiation (PCI) based on OS signature risk stratification. MATERIALS AND METHODS: This study retrospectively included 556 SCLC patients from three medical centers. The training, internal validation, and external validation cohorts comprised 309, 133, and 114 patients, respectively. The OS signature was built using a unified fully connected neural network. A deep learning model was developed based on the OS signature. Clinical and combined models were developed and compared with a deep learning model. Additionally, the benefits of PCI were evaluated after stratification using an OS signature. RESULTS: Within the internal and external validation cohorts, the deep learning model (concordance index [C-index] 0.745, 0.733) was far superior to the clinical model (C-index: 0.635, 0.630) in predicting OS, but slightly worse than the combined model (C-index: 0.771, 0.770). Additionally, the deep learning model had excellent calibration, clinical usefulness, and improved accuracy in classifying survival outcomes. Remarkably, patients at high risk had a survival benefit from PCI in both the limited and extensive stages (all P < 0.05), whereas no significant association was observed in patients at low risk. CONCLUSIONS: The CT-based deep learning model exhibited promising performance in predicting the OS of SCLC patients. The OS signature may aid in individualized treatment planning to select patients who may benefit from PCI.
Assuntos
Irradiação Craniana , Aprendizado Profundo , Neoplasias Pulmonares , Carcinoma de Pequenas Células do Pulmão , Tomografia Computadorizada por Raios X , Humanos , Carcinoma de Pequenas Células do Pulmão/radioterapia , Carcinoma de Pequenas Células do Pulmão/mortalidade , Carcinoma de Pequenas Células do Pulmão/diagnóstico por imagem , Carcinoma de Pequenas Células do Pulmão/patologia , Neoplasias Pulmonares/radioterapia , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/diagnóstico por imagem , Estudos Retrospectivos , Masculino , Feminino , Tomografia Computadorizada por Raios X/métodos , Pessoa de Meia-Idade , Irradiação Craniana/métodos , Idoso , Taxa de SobrevidaRESUMO
BACKGROUND: As a popular social networking platform for sharing short videos, TikTok has been widely used for sharing e-cigarettes or vaping-related videos, especially among the youth. OBJECTIVE: This study aims to characterize e-cigarette or vaping-related videos and their user engagement on TikTok through descriptive analysis. METHODS: From TikTok, a total of 417 short videos, posted between October 4, 2018, and February 27, 2021, were collected using e-cigarette or vaping-related hashtags. Two human coders independently hand-coded the video category and the attitude toward vaping (provaping or antivaping) for each vaping-related video. The social media user engagement measures (eg, the comment count, like count, and share count) for each video category were compared within provaping and antivaping groups. The user accounts posting these videos were also characterized. RESULTS: Among 417 vaping-related TikTok videos, 387 (92.8%) were provaping, and 30 (7.2%) were antivaping videos. Among provaping TikTok videos, the most popular category is vaping tricks (n=107, 27.65%), followed by advertisement (n=85, 21.95%), customization (n=75, 19.38%), TikTok trend (n=70, 18.09%), others (n=44, 11.37%), and education (n=6, 1.55%). By comparison, videos showing the TikTok trend had significantly higher user engagement (like count per video) than other provaping videos. Antivaping videos included 15 (50%) videos with the TikTok trend, 10 (33.33%) videos on education, and 5 (16.67%) videos about others. Videos with education have a significantly lower number of likes than other antivaping videos. Most TikTok users posting vaping-related videos are personal accounts (119/203, 58.62%). CONCLUSIONS: Vaping-related TikTok videos are dominated by provaping videos focusing on vaping tricks, advertisement, customization, and TikTok trend. Videos with the TikTok trend have higher user engagement than other video categories. Our findings provide important information on vaping-related videos shared on TikTok and their user engagement levels, which might provide valuable guidance on future policy making, such as possible restrictions on provaping videos posted on TikTok, as well as how to effectively communicate with the public about the potential health risks of vaping.