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1.
EMBO J ; 42(4): e111883, 2023 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-36546550

RESUMO

Proper stamen filament elongation is essential for pollination and plant reproduction. Plant hormones are extensively involved in every stage of stamen development; however, the cellular mechanisms by which phytohormone signals couple with microtubule dynamics to control filament elongation remain unclear. Here, we screened a series of Arabidopsis thaliana mutants showing different microtubule defects and revealed that only those unable to sever microtubules, lue1 and ktn80.1234, displayed differential floral organ elongation with less elongated stamen filaments. Prompted by short stamen filaments and severe decrease in KTN1 and KTN80s expression in qui-2 lacking five BZR1-family transcription factors (BFTFs), we investigated the crosstalk between microtubule severing and brassinosteroid (BR) signaling. The BFTFs transcriptionally activate katanin-encoding genes, and the microtubule-severing frequency was severely reduced in qui-2. Taken together, our findings reveal how BRs can regulate cytoskeletal dynamics to coordinate the proper development of reproductive organs.


Assuntos
Brassinosteroides , Katanina , Microtúbulos , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Brassinosteroides/metabolismo , Katanina/genética , Katanina/metabolismo , Microtúbulos/metabolismo , Reguladores de Crescimento de Plantas/metabolismo
2.
Plant Physiol ; 193(2): 1561-1579, 2023 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-37467431

RESUMO

An apical hook is a special structure formed during skotomorphogenesis in dicotyledonous plant species. It is critical for protecting the shoot apical meristem from mechanical damage during seed germination and hypocotyl elongation in soil. Brassinosteroid (BR) and jasmonate (JA) phytohormones antagonistically regulate apical hook formation. However, the interrelationship between BRs and JAs in this process has not been well elucidated. Here, we reveal that JAs repress BRs to regulate apical hook development in Arabidopsis (Arabidopsis thaliana). Exogenous application of methyl jasmonate (MeJA) repressed the expression of the rate-limiting BR biosynthetic gene DWARF4 (DWF4) in a process relying on 3 key JA-dependent transcription factors, MYC2, MYC3, and MYC4. We demonstrated that MYC2 interacts with the critical BR-activated transcription factor BRASSINAZOLE RESISTANT 1 (BZR1), disrupting the association of BZR1 with its partner transcription factors, such as those of the PHYTOCHROME INTERACTING FACTOR (PIF) family and downregulating the expression of their target genes, such as WAVY ROOT GROWTH 2 (WAG2), encoding a protein kinase essential for apical hook development. Our results indicate that JAs not only repress the expression of BR biosynthetic gene DWF4 but, more importantly, attenuate BR signaling by inhibiting the transcriptional activation of BZR1 by MYC2 during apical hook development.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Proteínas de Arabidopsis/metabolismo , Brassinosteroides/metabolismo , Arabidopsis/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Regulação da Expressão Gênica de Plantas
3.
BMC Cancer ; 24(1): 418, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38580939

RESUMO

BACKGROUND: This study aimed to develop and validate a machine learning (ML)-based fusion model to preoperatively predict Ki-67 expression levels in patients with head and neck squamous cell carcinoma (HNSCC) using multiparametric magnetic resonance imaging (MRI). METHODS: A total of 351 patients with pathologically proven HNSCC from two medical centers were retrospectively enrolled in the study and divided into training (n = 196), internal validation (n = 84), and external validation (n = 71) cohorts. Radiomics features were extracted from T2-weighted images and contrast-enhanced T1-weighted images and screened. Seven ML classifiers, including k-nearest neighbors (KNN), support vector machine (SVM), logistic regression (LR), random forest (RF), linear discriminant analysis (LDA), naive Bayes (NB), and eXtreme Gradient Boosting (XGBoost) were trained. The best classifier was used to calculate radiomics (Rad)-scores and combine clinical factors to construct a fusion model. Performance was evaluated based on calibration, discrimination, reclassification, and clinical utility. RESULTS: Thirteen features combining multiparametric MRI were finally selected. The SVM classifier showed the best performance, with the highest average area under the curve (AUC) of 0.851 in the validation cohorts. The fusion model incorporating SVM-based Rad-scores with clinical T stage and MR-reported lymph node status achieved encouraging predictive performance in the training (AUC = 0.916), internal validation (AUC = 0.903), and external validation (AUC = 0.885) cohorts. Furthermore, the fusion model showed better clinical benefit and higher classification accuracy than the clinical model. CONCLUSIONS: The ML-based fusion model based on multiparametric MRI exhibited promise for predicting Ki-67 expression levels in HNSCC patients, which might be helpful for prognosis evaluation and clinical decision-making.


Assuntos
Neoplasias de Cabeça e Pescoço , Imageamento por Ressonância Magnética Multiparamétrica , Humanos , Teorema de Bayes , Antígeno Ki-67/genética , Radiômica , Estudos Retrospectivos , Carcinoma de Células Escamosas de Cabeça e Pescoço/diagnóstico por imagem , Aprendizado de Máquina , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem
4.
FASEB J ; 37(3): e22791, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36723768

RESUMO

Atherosclerosis (As) is a chronic vascular inflammatory disease. Macrophages are the most important immune cells in atherosclerotic plaques, and the phenotype of plaque macrophages shifts dynamically to adapt to changes in the plaque microenvironment. The aerobic microenvironment of early atherosclerotic plaques promotes the transformation of M2/alternatively activated macrophages mainly through oxidative phosphorylation; the anoxic microenvironment of advanced atherosclerotic plaques mainly promotes the formation of M1/classically activated macrophages through anaerobic glycolysis; and the adventitia angiogenesis of aged atherosclerotic plaques leads to an increase in the proportion of M2/M1 macrophages. Therefore, this review deeply elucidates the dynamic change mechanism of plaque macrophages and the regulation of plaque oxygen content and immune metabolism to find new targets for the treatment of As.


Assuntos
Aterosclerose , Placa Aterosclerótica , Humanos , Placa Aterosclerótica/metabolismo , Oxigênio/metabolismo , Aterosclerose/metabolismo , Macrófagos/metabolismo , Fenótipo
5.
Eur Radiol ; 2024 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-39414655

RESUMO

OBJECTIVES: We evaluated the value of dual-energy computed tomography (DECT) parameters derived from pancreatic ductal adenocarcinoma (PDAC) to discriminate between high- and low-grade tumors and predict overall survival (OS) in patients. METHODS: Data were retrospectively collected from 169 consecutive patients with pathologically confirmed PDAC who underwent third-generation dual-source DECT enhanced dual-phase scanning before surgery between January 2017 and March 2023. Patients with prior treatments, other malignancies, small tumors, or poor-quality scans were excluded. Two radiologists evaluated three clinical and seven radiological features and measured sixteen DECT-derived parameters. Univariate and multivariate analyses were applied to select independent predictors. A prediction model and a corresponding nomogram were developed, and the area under the curve (AUC), calibration, and clinical applicability were assessed. The correlations between factors and OS were evaluated using Kaplan-Meier survival and Cox regression analyses. RESULTS: One hundred sixty-nine patients were randomly divided into training (n = 118) and validation (n = 51) cohorts, among which 43 (36.4%) and 19 (37.3%) had high-grade PDAC confirmed by pathology, respectively. The vascular invasion, normalized iodine concentration in the venous phase, and effective atomic number in the venous phase were independent predictors for histological grading. A nomogram was constructed to predict the risk of high-grade tumors in PDAC, with AUCs of 0.887 and 0.844 in the training and validation cohorts, respectively. The nomogram exhibited good calibration and was more beneficial than a single parameter in both cohorts. Pathological- and nomoscore-predicted high-grade PDACs were associated with poor OS (all p < 0.05). CONCLUSIONS: The nomogram, which combines DECT parameters and radiological features, can predict the histological grade and OS in patients with PDAC before surgery. KEY POINTS: Question Preoperative determination of histological grade in PDAC is crucial for guiding treatment, yet current methods are invasive and limited. Findings A DECT-based nomogram combining vascular invasion, normalized iodine concentration, and effective atomic number accurately predicts histological grade and OS in PDAC patients. Clinical relevance The DECT-based nomogram is a reliable, non-invasive tool for predicting histological grade and OS in PDAC. It provides essential information to guide personalized treatment strategies, potentially improving patient management and outcomes.

6.
Exp Cell Res ; 425(1): 113525, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-36841324

RESUMO

Gastric cancer is a serious malignant tumor in the world, accounting for the third cause of cancer death worldwide. The pathogenesis of gastric cancer is very complex, in which epigenetic inheritance plays an important role. In our study, we found that DZIP3 was significantly up-regulated in gastric cancer tissues as compared to adjacent normal tissue, which suggested it may be play a crucial part in gastric cancer. To clarify the mechanism of it, we further analyzed the interacting proteome and transcriptome of DZIP3. An association between DZIP3 and some epigenetic regulators, such as CUL4B complex, was verified. We also present the first proteomic characterization of the protein-protein interaction (PPI) network of DZIP3. Then, the transcriptome analysis of DZIP3 demonstrated that knockdown DZIP3 increased a cohort of genes, including SETD7 and ZBTB4, which have essential role in tumors. We also revealed that DZIP3 promotes proliferation and metastasis of gastric cancer cells. And the higher expression of DZIP3 is positively associated with the poor prognosis of several cancers. In summary, our study revealed a mechanistic role of DZIP3 in promoting proliferation and metastasis in gastric cancer, supporting the pursuit of DZIP3 as a potential target for gastric cancer therapy.


Assuntos
Neoplasias Gástricas , Humanos , Neoplasias Gástricas/patologia , Proteômica , Proliferação de Células/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Movimento Celular/genética , Metástase Neoplásica , Histona-Lisina N-Metiltransferase/genética , Proteínas de Ligação a RNA/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Proteínas Culina/metabolismo
7.
Hepatobiliary Pancreat Dis Int ; 21(6): 559-568, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35643910

RESUMO

BACKGROUND: Current surveillance strategies for hepatocellular carcinoma (HCC) among patients with nonalcoholic fatty liver disease (NAFLD) are insufficient. This study aimed to investigate the diagnostic performance of alpha-fetoprotein (AFP), protein induced by vitamin K absence or antagonist-II (PIVKA-II), lens culinaris agglutinin-reactive fraction of AFP (AFP-L3), and their combinations in HCC underlying NAFLD patients. METHODS: Serologic AFP, AFP-L3, and PIVKA-II levels in NAFLD patients with and without HCC were measured. By receiver operating characteristic (ROC) analyses, the area under the curve (AUC), sensitivity, and specificity were obtained to evaluate the diagnostic accuracy of each biomarker and their combinations. RESULTS: This study was conducted on 139 patients with NAFLD-HCC and 345 NAFLD controls. The elevation of these three biomarkers was observed in patients with NAFLD-HCC compared to those in NAFLD controls (all P < 0.001). When they were analyzed individually, PIVKA-II showed the best performance in diagnosing any-stage HCC with an AUC of 0.869, followed by AFP (0.763; vs. PIVKA-II, P < 0.001) and AFP-L3 (0.689; vs. PIVKA-II, P < 0.001). When they were analyzed in combination, AFP + PIVKA-II yielded the highest AUC (0.906), followed by AFP + PIVKA-II + AFP-L3 (0.904; vs. AFP + PIVKA-II, P = 0.086), PIVKA-II + AFP-L3 (0.881; vs. AFP + PIVKA-II, P < 0.001), and AFP + AFP-L3 (0.759; vs. AFP + PIVKA-II, P < 0.001). Similar findings were obtained in the subgroup with early-stage NAFLD-HCC, as well as the non-cirrhotic subgroup. CONCLUSIONS: These data validated the better diagnostic ability of PIVKA-II than AFP or AFP-L3 alone for diagnosing any-stage HCC among patients with NAFLD, and the combination of AFP + PIVKA-II significantly improved the diagnostic accuracy of NAFLD-HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Hepatopatia Gordurosa não Alcoólica , Humanos , alfa-Fetoproteínas/metabolismo , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/patologia , Hepatopatia Gordurosa não Alcoólica/complicações , Hepatopatia Gordurosa não Alcoólica/diagnóstico , Neoplasias Hepáticas/diagnóstico , Protrombina/análise , Protrombina/metabolismo , Precursores de Proteínas , Biomarcadores , Vitamina K , Biomarcadores Tumorais
8.
J Integr Plant Biol ; 64(8): 1502-1513, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35587568

RESUMO

Receptor-like kinases (RLKs) play key roles in regulating various physiological aspects in plant growth and development. In Arabidopsis thaliana, there are at least 223 leucine-rich repeat (LRR) RLKs. The functions of the majority of RLKs in the LRR XI subfamily were previously revealed. Only three RLKs were not characterized. Here we report that two independent triple mutants of these RLKs, named ROOT ELONGATION RECEPTOR KINASES (REKs), exhibit increased cell numbers in the root apical meristem and enhanced cell size in the elongation and maturation zones. The promoter activities of a number of Quiescent Center marker genes are significantly up-regulated in the triple mutant. However, the promoter activities of several marker genes known to control root stem cell niche activities are not altered. RNA-seq analysis revealed that a number of cell wall remodeling genes are significantly up-regulated in the triple mutant. Our results suggest that these REKs play key roles in regulating root development likely via negatively regulating the expression of a number of key cell wall remodeling genes.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Parede Celular/metabolismo , Expressão Gênica , Regulação da Expressão Gênica de Plantas/genética , Raízes de Plantas/metabolismo , Proteínas Serina-Treonina Quinases
9.
Eur Radiol ; 31(10): 7500-7511, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33860832

RESUMO

OBJECTIVES: To develop and validate a pre-transcatheter arterial chemoembolization (TACE) MRI-based radiomics model for predicting tumor response in intermediate-advanced hepatocellular carcinoma (HCC) patients. MATERIALS: Ninety-nine intermediate-advanced HCC patients (69 for training, 30 for validation) treated with TACE were enrolled. MRI examinations were performed before TACE, and the efficacy was evaluated according to the mRECIST criterion 3 months after TACE. A total of 396 radiomics features were extracted from T2-weighted pre-TACE images, and least absolute shrinkage and selection operator (LASSO) regression was applied to feature selection and model construction. The performance of the model was evaluated by receiver operating characteristic (ROC) curves, calibration curves, and decision curves. RESULTS: The AFP value, Child-Pugh score, and BCLC stage showed a significant difference between the TACE response (TR) and non-TACE response (nTR) patients. Six radiomics features were selected by LASSO and the radiomics score (Rad-score) was calculated as the sum of each feature multiplied by the non-zero coefficient from LASSO. The AUCs of the ROC curve based on Rad-score were 0.812 and 0.866 in the training and validation cohorts, respectively. To improve the diagnostic efficiency, the Rad-score was further integrated with the above clinical indicators to form a novel predictive nomogram. Results suggested that the AUC increased to 0.861 and 0.884 in the training and validation cohorts, respectively. Decision curve analysis showed that the radiomics nomogram was clinically useful. CONCLUSION: The radiomics and clinical indicator-based predictive nomogram can well predict TR in intermediate-advanced HCC and can further be applied for auxiliary diagnosis of clinical prognosis. KEY POINTS: • The therapeutic outcome of TACE varies greatly even for patients with the same clinicopathologic features. • Radiomics showed excellent performance in predicting the TACE response. • Decision curves demonstrated that the novel predictive model based on the radiomics signature and clinical indicators has great clinical utility.


Assuntos
Carcinoma Hepatocelular , Quimioembolização Terapêutica , Neoplasias Hepáticas , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/terapia , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/terapia , Imageamento por Ressonância Magnética , Nomogramas , Estudos Retrospectivos
10.
Nano Lett ; 17(1): 143-149, 2017 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-28073262

RESUMO

The characterization of the aggregation kinetics of protein amyloids and the structural properties of the ensuing aggregates are vital in the study of the pathogenesis of many neurodegenerative diseases and the discovery of therapeutic targets. In this article, we show that the fluorescence lifetime of synthetic dyes covalently attached to amyloid proteins informs on the structural properties of amyloid clusters formed both in vitro and in cells. We demonstrate that the mechanism behind such a "lifetime sensor" of protein aggregation is based on fluorescence self-quenching and that it offers a good dynamic range to report on various stages of aggregation without significantly perturbing the process under investigation. We show that the sensor informs on the structural density of amyloid clusters in a high-throughput and quantitative manner and in these aspects the sensor outperforms super-resolution imaging techniques. We demonstrate the power and speed of the method, offering capabilities, for example, in therapeutic screenings that monitor biological self-assembly. We investigate the mechanism and advantages of the lifetime sensor in studies of the K18 protein fragment of the Alzheimer's disease related protein tau and its amyloid aggregates formed in vitro. Finally, we demonstrate the sensor in the study of aggregates of polyglutamine protein, a model used in studies related to Huntington's disease, by performing correlative fluorescence lifetime imaging microscopy and structured-illumination microscopy experiments in cells.


Assuntos
Amiloide/química , Amiloide/metabolismo , Agregados Proteicos , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/metabolismo , Fluorescência , Corantes Fluorescentes/química , Células HEK293 , Humanos , Doença de Huntington/diagnóstico por imagem , Doença de Huntington/metabolismo , Cinética , Imagem Óptica , Peptídeos/química , Peptídeos/metabolismo , Conformação Proteica
11.
BMC Biol ; 13: 2, 2015 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-25575667

RESUMO

BACKGROUND: Endoplasmic reticulum (ER) lumenal protein thiol redox balance resists dramatic variation in unfolded protein load imposed by diverse physiological challenges including compromise in the key upstream oxidases. Lumenal calcium depletion, incurred during normal cell signaling, stands out as a notable exception to this resilience, promoting a rapid and reversible shift towards a more reducing poise. Calcium depletion induced ER redox alterations are relevant to physiological conditions associated with calcium signaling, such as the response of pancreatic cells to secretagogues and neuronal activity. The core components of the ER redox machinery are well characterized; however, the molecular basis for the calcium-depletion induced shift in redox balance is presently obscure. RESULTS: In vitro, the core machinery for generating disulfides, consisting of ERO1 and the oxidizing protein disulfide isomerase, PDI1A, was indifferent to variation in calcium concentration within the physiological range. However, ER calcium depletion in vivo led to a selective 2.5-fold decline in PDI1A mobility, whereas the mobility of the reducing PDI family member, ERdj5 was unaffected. In vivo, fluorescence resonance energy transfer measurements revealed that declining PDI1A mobility correlated with formation of a complex with the abundant ER chaperone calreticulin, whose mobility was also inhibited by calcium depletion and the calcium depletion-mediated reductive shift was attenuated in cells lacking calreticulin. Measurements with purified proteins confirmed that the PDI1A-calreticulin complex dissociated as Ca(2+) concentrations approached those normally found in the ER lumen ([Ca(2+)]K(0.5max) = 190 µM). CONCLUSIONS: Our findings suggest that selective sequestration of PDI1A in a calcium depletion-mediated complex with the abundant chaperone calreticulin attenuates the effective concentration of this major lumenal thiol oxidant, providing a plausible and simple mechanism for the observed shift in ER lumenal redox poise upon physiological calcium depletion.


Assuntos
Cálcio/deficiência , Difusão , Retículo Endoplasmático/metabolismo , Isomerases de Dissulfetos de Proteínas/metabolismo , Animais , Células COS , Cálcio/metabolismo , Calreticulina/metabolismo , Chlorocebus aethiops , Dissulfetos/metabolismo , Células HEK293 , Proteínas de Choque Térmico HSP40/metabolismo , Humanos , Camundongos , Chaperonas Moleculares/metabolismo , Oxirredução , Ligação Proteica
12.
Biophys J ; 108(5): 999-1002, 2015 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-25762312

RESUMO

FRET is widely used for the study of protein-protein interactions in biological samples. However, it is difficult to quantify both the FRET efficiency (E) and the affinity (Kd) of the molecular interaction from intermolecular FRET signals in samples of unknown stoichiometry. Here, we present a method for the simultaneous quantification of the complete set of interaction parameters, including fractions of bound donors and acceptors, local protein concentrations, and dissociation constants, in each image pixel. The method makes use of fluorescence lifetime information from both donor and acceptor molecules and takes advantage of the linear properties of the phasor plot approach. We demonstrate the capability of our method in vitro in a microfluidic device and also in cells, via the determination of the binding affinity between tagged versions of glutathione and glutathione S-transferase, and via the determination of competitor concentration. The potential of the method is explored with simulations.


Assuntos
Transferência Ressonante de Energia de Fluorescência/métodos , Microfluídica/métodos , Células HEK293 , Humanos , Proteínas Luminescentes/metabolismo
13.
Curr Biol ; 2024 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-39476837

RESUMO

Precise regulation of cell division is essential for proper tissue patterning in multicellular organisms. In Arabidopsis, the ground tissue (GT) comprises cortex and endodermis in the early stages of root development. During GT maturation, additional periclinal cell divisions (PCDs) occasionally occur of the endodermis, generating a middle cortex (MC) layer between the cortex and endodermis. Although several regulatory proteins and phytohormones were identified to mediate GT patterning, such as SHORT-ROOT (SHR), SCARECROW (SCR), CYCLIND6;1 (CYCD6;1), and gibberellins (GAs), the interrelationship among these factors is not elucidated. Here, we report that three closely related receptor-like kinases (RLKs), ARH1, FEI1, and FEI2, play crucial roles in mediating a signal transduction pathway from the SHR-SCR module to GA to regulate GT patterning. Two independent triple mutants of these RLKs (tri-1 and tri-2) exhibit increased MC formation compared with wild type. Genetic analysis indicated that all three RLKs regulate MC formation mainly in a cell-autonomous manner. The transcription levels of these RLKs are negatively controlled by SHR and SCR. The altered GT patterns in shr and scr can be partially complemented by tri-1. GA biosynthesis is significantly reduced in the roots of tri-1. The excessive MC formation in tri-1 can be greatly suppressed by the exogenous application of GA3 or by the mutation of CYCD6;1. Our results demonstrate a signaling pathway involving SHR/SCR-ARH1/FEI1/FEI2-GA-CYCD6;1 to govern GT patterning in Arabidopsis thaliana.

14.
Br J Radiol ; 97(1154): 439-450, 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-38308028

RESUMO

OBJECTIVES: Accurate axillary evaluation plays an important role in prognosis and treatment planning for breast cancer. This study aimed to develop and validate a dynamic contrast-enhanced (DCE)-MRI-based radiomics model for preoperative evaluation of axillary lymph node (ALN) status in early-stage breast cancer. METHODS: A total of 410 patients with pathologically confirmed early-stage invasive breast cancer (training cohort, N = 286; validation cohort, N = 124) from June 2018 to August 2022 were retrospectively recruited. Radiomics features were derived from the second phase of DCE-MRI images for each patient. ALN status-related features were obtained, and a radiomics signature was constructed using SelectKBest and least absolute shrinkage and selection operator regression. Logistic regression was applied to build a combined model and corresponding nomogram incorporating the radiomics score (Rad-score) with clinical predictors. The predictive performance of the nomogram was evaluated using receiver operator characteristic (ROC) curve analysis and calibration curves. RESULTS: Fourteen radiomic features were selected to construct the radiomics signature. The Rad-score, MRI-reported ALN status, BI-RADS category, and tumour size were independent predictors of ALN status and were incorporated into the combined model. The nomogram showed good calibration and favourable performance for discriminating metastatic ALNs (N + (≥1)) from non-metastatic ALNs (N0) and metastatic ALNs with heavy burden (N + (≥3)) from low burden (N + (1-2)), with the area under the ROC curve values of 0.877 and 0.879 in the training cohort and 0.859 and 0.881 in the validation cohort, respectively. CONCLUSIONS: The DCE-MRI-based radiomics nomogram could serve as a potential non-invasive technique for accurate preoperative evaluation of ALN burden, thereby assisting physicians in the personalized axillary treatment for early-stage breast cancer patients. ADVANCES IN KNOWLEDGE: This study developed a potential surrogate of preoperative accurate evaluation of ALN status, which is non-invasive and easy-to-use.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/patologia , Estudos Retrospectivos , Metástase Linfática/diagnóstico por imagem , Metástase Linfática/patologia , Estudos de Viabilidade , Radiômica , Linfonodos/diagnóstico por imagem , Linfonodos/patologia , Nomogramas , Imageamento por Ressonância Magnética/métodos
15.
Acad Radiol ; 31(1): 142-156, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37280128

RESUMO

RATIONALE AND OBJECTIVES: This study aimed to develop and validate a dual-energy CT (DECT)-based model for preoperative prediction of the number of central lymph node metastases (CLNMs) in clinically node-negative (cN0) papillary thyroid carcinoma (PTC) patients. MATERIALS AND METHODS: Between January 2016 and January 2021, 490 patients who underwent lobectomy or thyroidectomy, CLN dissection, and preoperative DECT examinations were enrolled and randomly allocated into the training (N = 345) and validation cohorts (N = 145). The patients' clinical characteristics and quantitative DECT parameters obtained on primary tumors were collected. Independent predictors of> 5 CLNMs were identified and integrated to construct a DECT-based prediction model, for which the area under the curve (AUC), calibration, and clinical usefulness were assessed. Risk group stratification was performed to distinguish patients with different recurrence risks. RESULTS: More than 5 CLNMs were found in 75 (15.3%) cN0 PTC patients. Age, tumor size, normalized iodine concentration (NIC), normalized effective atomic number (nZeff) and the slope of the spectral Hounsfield unit curve (λHu) in the arterial phase were independently associated with> 5 CLNMs. The DECT-based nomogram that incorporated predictors demonstrated favorable performance in both cohorts (AUC: 0.842 and 0.848) and significantly outperformed the clinical model (AUC: 0.688 and 0.694). The nomogram showed good calibration and added clinical benefit for predicting> 5 CLNMs. The KaplanMeier curves for recurrence-free survival showed that the high- and low-risk groups stratified by the nomogram were significantly different. CONCLUSION: The nomogram based on DECT parameters and clinical factors could facilitate preoperative prediction of the number of CLNMs in cN0 PTC patients.


Assuntos
Neoplasias da Glândula Tireoide , Humanos , Câncer Papilífero da Tireoide/diagnóstico por imagem , Câncer Papilífero da Tireoide/cirurgia , Câncer Papilífero da Tireoide/patologia , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/cirurgia , Neoplasias da Glândula Tireoide/patologia , Metástase Linfática/diagnóstico por imagem , Metástase Linfática/patologia , Tireoidectomia , Nomogramas , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Linfonodos/patologia
16.
Heliyon ; 10(16): e35528, 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-39229502

RESUMO

Rationale and objectives: We constructed a dual-energy computed tomography (DECT)-based model to assess cervical lymph node metastasis (LNM) in patients with laryngeal squamous cell carcinoma (LSCC). Materials and methods: We retrospectively analysed 164 patients with LSCC who underwent preoperative DECT from May 2019 to May 2023. The patients were randomly divided into training (n = 115) and validation (n = 49) cohorts. Quantitative DECT parameters of the primary tumours and their clinical characteristics were collected. A logistic regression model was used to determine independent predictors of LNM, and a nomogram was constructed along with a corresponding online model. Model performance was assessed using the area under the curve (AUC) and the calibration curve, and the clinical value was evaluated using decision curve analysis (DCA). Results: In total, 64/164 (39.0 %) patients with LSCC had cervical LNM. Independent predictors of LNM included normalized iodine concentration in the arterial phase (odds ratio [OR]: 8.332, 95 % confidence interval [CI]: 2.813-24.678, P < 0.001), normalized effective atomic number in the arterial phase (OR: 5.518, 95 % CI: 1.095-27.818, P = 0.002), clinical T3-4 stage (OR: 5.684, 95 % CI: 1.701-18.989, P = 0.005), and poor histological grade (OR: 5.011, 95 % CI: 1.003-25.026, P = 0.049). These predictors were incorporated into the DECT-based nomogram and the corresponding online model, showing good calibration and favourable performance (training AUC: 0.910, validation AUC: 0.918). The DCA indicated a significant clinical benefit of the nomogram for estimating LNM. Conclusions: DECT parameters may be useful independent predictors of LNM in patients with LSCC, and a DECT-based nomogram may be helpful in clinical decision-making.

17.
Acad Radiol ; 31(8): 3081-3095, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38490840

RESUMO

RATIONALE AND OBJECTIVES: This study aimed to construct a machine learning radiomics-based model using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) images to evaluate non-sentinel lymph node (NSLN) metastasis in Chinese breast cancer (BC) patients who underwent total mastectomy (TM) and had 1-2 positive sentinel lymph nodes (SLNs). MATERIALS AND METHODS: In total, 494 patients were retrospectively enrolled from two hospitals, and were divided into the training (n = 286), internal validation (n = 122), and external validation (n = 86) cohorts. Features were extracted from DCE-MRI images for each patient and screened. Six ML classifies were trained and the best classifier was evaluated to calculate radiomics (Rad)-scores. A combined model was developed based on Rad-scores and clinical risk factors, then the calibration, discrimination, reclassification, and clinical usefulness were evaluated. RESULTS: 14 radiomics features were ultimately selected. The random forest (RF) classifier showed the best performance, with the highest average area under the curve (AUC) of 0.833 in the validation cohorts. The combined model incorporating RF-based Rad-scores, tumor size, lymphovascular invasion, and proportion of positive SLNs resulted in the best discrimination ability, with AUCs of 0.903, 0.890, and 0.836 in the training, internal validation, and external validation cohorts, respectively. Furthermore, the combined model significantly improved the classification accuracy and clinical benefit for NSLN metastasis prediction. CONCLUSION: A RF-based combined model using DCE-MRI images exhibited a promising performance for predicting NSLN metastasis in Chinese BC patients who underwent TM and had 1-2 positive SLNs, thereby aiding in individualized clinical treatment decisions.


Assuntos
Neoplasias da Mama , Metástase Linfática , Aprendizado de Máquina , Imageamento por Ressonância Magnética , Linfonodo Sentinela , Humanos , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Feminino , Metástase Linfática/diagnóstico por imagem , Pessoa de Meia-Idade , Imageamento por Ressonância Magnética/métodos , Estudos Retrospectivos , Linfonodo Sentinela/diagnóstico por imagem , Linfonodo Sentinela/patologia , Adulto , China , Meios de Contraste , Idoso , Biópsia de Linfonodo Sentinela , Linfonodos/diagnóstico por imagem , Linfonodos/patologia , Mastectomia , Radiômica , População do Leste Asiático
18.
Front Plant Sci ; 15: 1347842, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38328701

RESUMO

FHY3 and its homologous protein FAR1 are the founding members of FRS family. They exhibited diverse and powerful physiological functions during evolution, and participated in the response to multiple abiotic stresses. FRF genes are considered to be truncated FRS family proteins. They competed with FRS for DNA binding sites to regulate gene expression. However, only few studies are available on FRF genes in plants participating in the regulation of abiotic stress. With wide adaptability and high stress-resistance, barley is an excellent candidate for the identification of stress-resistance-related genes. In this study, 22 HvFRFs were detected in barley using bioinformatic analysis from whole genome. According to evolution and conserved motif analysis, the 22 HvFRFs could be divided into subfamilies I and II. Most promoters of subfamily I members contained abscisic acid and methyl jasmonate response elements; however, a large number promoters of subfamily II contained gibberellin and salicylic acid response elements. HvFRF9, one of the members of subfamily II, exhibited a expression advantage in different tissues, and it was most significantly upregulated under drought stress. In-situ PCR revealed that HvFRF9 is mainly expressed in the root epidermal cells, as well as xylem and phloem of roots and leaves, indicating that HvFRF9 may be related to absorption and transportation of water and nutrients. The results of subcellular localization indicated that HvFRF9 was mainly expressed in the nuclei of tobacco epidermal cells and protoplast of arabidopsis. Further, transgenic arabidopsis plants with HvFRF9 overexpression were generated to verify the role of HvFRF9 in drought resistance. Under drought stress, leaf chlorosis and wilting, MDA and O2 - contents were significantly lower, meanwhile, fresh weight, root length, PRO content, and SOD, CAT and POD activities were significantly higher in HvFRF9-overexpressing arabidopsis plants than in wild-type plants. Therefore, overexpression of HvFRF9 could significantly enhance the drought resistance in arabidopsis. These results suggested that HvFRF9 may play a key role in drought resistance in barley by increasing the absorption and transportation of water and the activity of antioxidant enzymes. This study provided a theoretical basis for drought resistance in barley and provided new genes for drought resistance breeding.

19.
Artigo em Inglês | MEDLINE | ID: mdl-38862429

RESUMO

DNA sequencers have become increasingly important research and diagnostic tools over the past 20 years. In this study, we developed a single-molecule desktop sequencer, GenoCare 1600 (GenoCare), which utilizes amplification-free library preparation and two-color sequencing-by-synthesis chemistry, making it more user-friendly compared with previous single-molecule sequencing platforms for clinical use. Using the GenoCare platform, we sequenced an Escherichia coli standard sample and achieved a consensus accuracy exceeding 99.99%. We also evaluated the sequencing performance of this platform in microbial mixtures and coronavirus disease 2019 (COVID-19) samples from throat swabs. Our findings indicate that the GenoCare platform allows for microbial quantitation, sensitive identification of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, and accurate detection of virus mutations, as confirmed by Sanger sequencing, demonstrating its remarkable potential in clinical application.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/virologia , COVID-19/diagnóstico , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Análise de Sequência de DNA/métodos , Escherichia coli/genética , Mutação
20.
Insights Imaging ; 14(1): 38, 2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36854872

RESUMO

OBJECTIVES: This study compared the accuracy of predicting transarterial chemoembolization (TACE) outcomes for hepatocellular carcinoma (HCC) patients in the four different classifiers, and comprehensive models were constructed to improve predictive performance. METHODS: The subjects recruited for this study were HCC patients who had received TACE treatment from April 2016 to June 2021. All participants underwent enhanced MRI scans before and after intervention, and pertinent clinical information was collected. Registry data for the 144 patients were randomly assigned to training and test datasets. The robustness of the trained models was verified by another independent external validation set of 28 HCC patients. The following classifiers were employed in the radiomics experiment: machine learning classifiers k-nearest neighbor (KNN), support vector machine (SVM), the least absolute shrinkage and selection operator (Lasso), and deep learning classifier deep neural network (DNN). RESULTS: DNN and Lasso models were comparable in the training set, while DNN performed better in the test set and the external validation set. The CD model (Clinical & DNN merged model) achieved an AUC of 0.974 (95% CI: 0.951-0.998) in the training set, superior to other models whose AUCs varied from 0.637 to 0.943 (p < 0.05). The CD model generalized well on the test set (AUC = 0.831) and external validation set (AUC = 0.735). CONCLUSIONS: DNN model performs better than other classifiers in predicting TACE response. Integrating with clinically significant factors, the CD model may be valuable in pre-treatment counseling of HCC patients who may benefit the most from TACE intervention.

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