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1.
Cell ; 186(10): 2193-2207.e19, 2023 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-37098343

RESUMO

Somatic hypermutation (SHM), initiated by activation-induced cytidine deaminase (AID), generates mutations in the antibody-coding sequence to allow affinity maturation. Why these mutations intrinsically focus on the three nonconsecutive complementarity-determining regions (CDRs) remains enigmatic. Here, we found that predisposition mutagenesis depends on the single-strand (ss) DNA substrate flexibility determined by the mesoscale sequence surrounding AID deaminase motifs. Mesoscale DNA sequences containing flexible pyrimidine-pyrimidine bases bind effectively to the positively charged surface patches of AID, resulting in preferential deamination activities. The CDR hypermutability is mimicable in in vitro deaminase assays and is evolutionarily conserved among species using SHM as a major diversification strategy. We demonstrated that mesoscale sequence alterations tune the in vivo mutability and promote mutations in an otherwise cold region in mice. Our results show a non-coding role of antibody-coding sequence in directing hypermutation, paving the way for the synthetic design of humanized animal models for optimal antibody discovery and explaining the AID mutagenesis pattern in lymphoma.


Assuntos
Citidina Desaminase , Hipermutação Somática de Imunoglobulina , Animais , Camundongos , Anticorpos/genética , Citidina Desaminase/genética , Citidina Desaminase/metabolismo , DNA/genética , DNA de Cadeia Simples , Mutação , Evolução Molecular , Regiões Determinantes de Complementaridade/genética , Motivos de Nucleotídeos
2.
Brief Bioinform ; 24(2)2023 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-36790856

RESUMO

Potential miRNA-disease associations (MDA) play an important role in the discovery of complex human disease etiology. Therefore, MDA prediction is an attractive research topic in the field of biomedical machine learning. Recently, several models have been proposed for this task, but their performance limited by over-reliance on relevant network information with noisy graph structure connections. However, the application of self-supervised graph structure learning to MDA tasks remains unexplored. Our study is the first to use multi-view self-supervised contrastive learning (MSGCL) for MDA prediction. Specifically, we generated a learner view without association labels of miRNAs and diseases as input, and utilized the known association network to generate an anchor view that provides guiding signals for the learner view. The graph structure was optimized by designing a contrastive loss to maximize the consistency between the anchor and learner views. Our model is similar to a pre-trained model that continuously optimizes upstream tasks for high-quality association graph topology, thereby enhancing the latent representation of association predictions. The experimental results show that our proposed method outperforms state-of-the-art methods by 2.79$\%$ and 3.20$\%$ in area under the receiver operating characteristic curve (AUC) and area under the precision/recall curve (AUPR), respectively.


Assuntos
Aprendizado de Máquina , MicroRNAs , Humanos , Área Sob a Curva , MicroRNAs/genética , Curva ROC
3.
Hepatology ; 79(2): 307-322, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-37140231

RESUMO

BACKGROUND AIMS: Cholangiocarcinoma (CCA) is a highly lethal malignancy originating from the biliary ducts. Current CCA diagnostic and prognostic assessments cannot satisfy the clinical requirement. Bile detection is rarely performed, and herein, we aim to estimate the clinical significance of bile liquid biopsy by assessing bile exosomal concentrations and components. APPROACH RESULTS: Exosomes in bile and sera from CCA, pancreatic cancer, and common bile duct stone were identified and quantified by transmission electronmicroscopy, nanoparticle tracking analysis, and nanoFCM. Exosomal components were assessed by liquid chromatography with tandem mass spectrometry and microRNA sequencing (miRNA-seq). Bile exosomal concentration in different diseases had no significant difference, but miR-182-5p and miR-183-5p were ectopically upregulated in CCA bile exosomes. High miR-182/183-5p in both CCA tissues and bile indicates a poor prognosis. Bile exosomal miR-182/183-5p is secreted by CCA cells and can be absorbed by biliary epithelium or CCA cells. With xenografts in humanized mice, we showed that bile exosomal miR-182/183-5p promotes CCA proliferation, invasion, and epithelial-mesenchymal transition (EMT) by targeting hydroxyprostaglandin dehydrogenase in CCA cells and mast cells (MCs), and increasing prostaglandin E2 generation, which stimulates PTGER1 and increases CCA stemness. In single-cell mRNA-seq, hydroxyprostaglandin dehydrogenase is predominantly expressed in MCs. miR-182/183-5p prompts MC to release VEGF-A release from MC by increasing VEGF-A expression, which facilitates angiogenesis. CONCLUSIONS: CCA cells secret exosomal miR-182/183-5p into bile, which targets hydroxyprostaglandin dehydrogenase in CCA cells and MCs and increases prostaglandin E2 and VEGF-A release. Prostaglandin E2 promotes stemness by activating PTGER1. Our results reveal a type of CCA self-driven progression dependent on bile exosomal miR-182/183-5p and MCs, which is a new interplay pattern of CCA and bile.


Assuntos
Neoplasias dos Ductos Biliares , Colangiocarcinoma , MicroRNAs , Humanos , Animais , Camundongos , Dinoprostona , MicroRNAs/genética , Bile/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Neoplasias dos Ductos Biliares/patologia , Linhagem Celular Tumoral , Colangiocarcinoma/patologia , Ductos Biliares Intra-Hepáticos/patologia , Hidroxiprostaglandina Desidrogenases/genética , Proliferação de Células , Regulação Neoplásica da Expressão Gênica
4.
Hepatology ; 79(4): 798-812, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37505213

RESUMO

ABSTRACT AND AIM: Cholangiocarcinoma (CCA) is a highly aggressive and lethal cancer that originates from the biliary epithelium. Systemic treatment options for CCA are currently limited, and the first targeted drug of CCA, pemigatinib, emerged in 2020 for CCA treatment by inhibiting FGFR2 phosphorylation. However, the regulatory mechanism of FGFR2 phosphorylation is not fully elucidated. APPROACH AND RESULTS: Here we screened the FGFR2-interacting proteins and showed that protein tyrosine phosphatase (PTP) N9 interacts with FGFR2 and negatively regulates FGFR2 pY656/657 . Using phosphatase activity assays and modeling the FGFR2-PTPN9 complex structure, we identified FGFR2 pY656/657 as a substrate of PTPN9, and found that sec. 14p domain of PTPN9 interacts with FGFR2 through ACAP1 mediation. Coexpression of PTPN9 and ACAP1 indicates a favorable prognosis for CCA. In addition, we identified key amino acids and motifs involved in the sec. 14p-APCP1-FGFR2 interaction, including the "YRETRRKE" motif of sec. 14p, Y471 of PTPN9, as well as the PH and Arf-GAP domain of ACAP1. Moreover, we discovered that the FGFR2 I654V substitution can decrease PTPN9-FGFR2 interaction and thereby reduce the effectiveness of pemigatinib treatment. Using a series of in vitro and in vivo experiments including patient-derived xenografts (PDX), we showed that PTPN9 synergistically enhances pemigatinib effectiveness and suppresses CCA proliferation, migration, and invasion by inhibiting FGFR2 pY656/657 . CONCLUSIONS: Our study identifies PTPN9 as a negative regulator of FGFR2 phosphorylation and a synergistic factor for pemigatinib treatment. The molecular mechanism, oncogenic function, and clinical significance of the PTPN9-ACAP1-FGFR2 complex are revealed, providing more evidence for CCA precision treatment.


Assuntos
Neoplasias dos Ductos Biliares , Colangiocarcinoma , Morfolinas , Pirimidinas , Pirróis , Humanos , Colangiocarcinoma/tratamento farmacológico , Epitélio , Neoplasias dos Ductos Biliares/tratamento farmacológico , Ductos Biliares Intra-Hepáticos , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos , Proteínas Ativadoras de GTPase
5.
Small ; 20(22): e2309589, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38105589

RESUMO

Achieving ultrabright fluorogens is a key issue for fluorescence-guided surgery (FGS). Fluorogens with aggregation-induced emission (AIEgens) are potential agents for FGS on the benefit of the bright fluorescence in physiological conditions. Herein, the fluorescence brightness of AIEgen is further improved by preparing the nanoparticle using a polystyrene-based matrix and utilizing it for tumor FGS with a high signal-to-background ratio. After encapsulating AIEgen into polystyrene-poly (ethylene glycol) (PS-PEG), the fluorescence intensity of the prepared AIE@PS-PEG nanoparticles is multiple times that of nanoparticles in 1, 2-distearoyl-sn-glycero-3-phosphoethanolamine-poly (ethylene glycol) (DSPE-PEG), a commonly used polymer matrix for nanoparticle preparation. Molecular dynamics simulations suggest that higher free energy is required for the outer rings of AIEgen to rotate in polystyrene than in the DSPE, indicating that the benzene rings in polystyrene can restrict the intramolecular motions of AIEgen better than the alkyl chain in DSPE-PEG. Fluorescence correlation microscopy detections suggest that the triplet excited state of AIEgens is less in PS-PEG than in DSPE-PEG. The restricted intramolecular motions and suppressed triplet excited state result in ultrabright AIE@PS-PEG nanoparticles, which are more conducive to illuminating tumor tissues in the intestine for FGS. The illumination of metastatic tumors in lungs by AIE@PS-PEG nanoparticles is also tried.


Assuntos
Poliestirenos , Poliestirenos/química , Fluorescência , Polietilenoglicóis/química , Humanos , Nanopartículas/química , Cirurgia Assistida por Computador/métodos , Simulação de Dinâmica Molecular , Animais , Corantes Fluorescentes/química
6.
Nat Chem Biol ; 18(11): 1196-1203, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35982227

RESUMO

Adhesion G protein-coupled receptors are elusive in terms of their structural information and ligands. Here, we solved the cryogenic-electron microscopy (cryo-EM) structure of apo-ADGRG2, an essential membrane receptor for maintaining male fertility, in complex with a Gs trimer. Whereas the formations of two kinks were determinants of the active state, identification of a potential ligand-binding pocket in ADGRG2 facilitated the screening and identification of dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate and deoxycorticosterone as potential ligands of ADGRG2. The cryo-EM structures of DHEA-ADGRG2-Gs provided interaction details for DHEA within the seven transmembrane domains of ADGRG2. Collectively, our data provide a structural basis for the activation and signaling of ADGRG2, as well as characterization of steroid hormones as ADGRG2 ligands, which might be used as useful tools for further functional studies of the orphan ADGRG2.


Assuntos
Receptores Acoplados a Proteínas G , Transdução de Sinais , Humanos , Masculino , Microscopia Crioeletrônica , Sulfato de Desidroepiandrosterona , Desoxicorticosterona , Ligantes , Receptores Acoplados a Proteínas G/química
7.
Hum Brain Mapp ; 44(12): 4590-4604, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37347619

RESUMO

Anatomical and functional heterogeneous substantia nigra (SN) has been extensively studied in humans and animals like rhesus monkeys given its crucial role in modulating a broad range of behaviors. Increasingly important cross-species research of SN may require connectionally homogeneous and homologous subregions of SN as objective and stable starting points from which the evolutionary characteristics of brain could be inspected. However, existing atlases of SN were all inaccurate mappings as a cross-species connectome atlas due to inadequate homology constraint during their constructions, and arbitrary paired use of these atlases might cause unreliable findings. In this study, a reliable blind-source cross-species parcellation of SN was developed based on the following rationale: striatonigrostriatal circuits form major structure of nigral connectivity; different nigral components have unique striatonigrostriatal connectivity; and inter-species corresponding human and macaque nigral components have similar striatonigrostriatal connectivity. Specifically, all voxels in human and macaque SN were grouped together and then classified based on inter-species identically characterized striatonigrostriatal connectivity attributes. Our results delineated a pars compacta-pars reticulate-like parcellation and further demonstrated its reliability by illustrating best-matched whole-brain structural and functional connectivity profiles of inter-species corresponding nigral subregions. Detailed inter-species and inter-regional differences in multi-aspect connectivities of these nigral subregions were inspected. It is expected that this cross-species connectome atlas of SN can offer biologically reliable cornerstones and important information to facilitate future cross-species research.


Assuntos
Conectoma , Imageamento por Ressonância Magnética , Animais , Humanos , Imageamento por Ressonância Magnética/métodos , Reprodutibilidade dos Testes , Substância Negra/diagnóstico por imagem , Conectoma/métodos , Macaca mulatta
8.
Phytother Res ; 37(9): 4117-4132, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37246830

RESUMO

Hepatocellular carcinoma (HCC) is a common malignancy affecting many people worldwide. Baicalin is a flavonoid extracted from the dried root of Scutellaria baicalensis Georgi. It can effectively inhibit the occurrence and development of HCC. Nonetheless, the mechanism through which Baicalin inhibits HCC growth and metastasis remain unknown. This work discovered that Baicalin inhibited HCC cell proliferation, invasion, metastasis while inducing cell cycle arrest at the G0/G1 phase and apoptosis. In vivo HCC xenograft results indicated that Baicalin inhibited HCC growth. Western blotting analysis indicated that Baicalin suppressed the expressions of ROCK1, p-GSK-3ß, and ß-catenin, whereas it up-regulated the expressions of GSK-3ß and p-ß-catenin. Baicalin also reduced the expressions of Bcl-2, C-myc, Cyclin D1, MMP-9, and VEGFA, while increasing the expression of Bax. Molecular docking revealed that Baicalin docked in the binding site of the ROCK1 agonist, with a binding energy of -9 kcal/mol between the two. In addition, lentivirus-mediated suppression of ROCK1 expression improved the inhibitory effect of Baicalin on the proliferation, invasion, and metastasis of HCC and the expression of proteins associated with ROCK1/GSK-3ß/ß-catenin signaling pathway. Moreover, restoring ROCK1 expression decreased the anti-HCC efficacy of Baicalin. These findings suggest that Baicalin may decrease HCC proliferation and metastasis by suppressing ROCK1/GSK-3ß/ß-catenin signaling.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , beta Catenina/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Linhagem Celular Tumoral , Simulação de Acoplamento Molecular , Transdução de Sinais , Flavonoides/farmacologia , Proliferação de Células , Quinases Associadas a rho
9.
Eur Arch Otorhinolaryngol ; 280(3): 1455-1465, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36348098

RESUMO

PURPOSE: We aimed to explore the clinicodemographic characteristics and prognosis of grey zone squamous cell cancer (GZSCC) located in the overlapping or ambiguous area of oral cavity and oropharynx and to identify valuable factors that would improve its differential diagnosis and prognosis. METHODS: Information of GZSCC patients in the Surveillance, Epidemiology, and End Results (SEER) database were compared to patients with oral cavity (OCSCC) and oropharyngeal (OPSCC) squamous cell carcinomas with corresponding HPV status, respectively. Kaplan-Meier method with log-rank test and multivariate Cox regression analysis were applied to assess associations between clinical characteristics and overall survival (OS). A predictive model integrating age, gender, marital status, HPV status and staging variables was conducted to classify GZSCC patients into three risk groups and verified internally by tenfold cross validation. RESULTS: A total of 3318 GZSCC, 10792 OPSCC and 6656 OCSCC patients were identified. HPV-positive GZSCC patients had the best 5-year OS as HPV-positive OPSCC (81% vs. 82%). However, the 5-year OS of HPV-negative/unknown GZSCC (43%/42%) were the worst among all groups, indicating that HPV status and the overlapping nature of tumors were valuable prognostic predictors in GZSCC patients. Compared with the strategy of dividing GZSCC into two groups by HPV status, the predictive model integrating more variables could additionally identify a unique high-risk GZSCC group with the lowest OS rate. CONCLUSIONS: GZSCC patients had distinct clinical characteristics and prognosis compared with OPSCC and OCSCC, integrating HPV status and other clinical factors could help distinguish GZSCC and predict their prognosis.


Assuntos
Carcinoma de Células Escamosas , Neoplasias Orofaríngeas , Infecções por Papillomavirus , Humanos , Neoplasias Orofaríngeas/patologia , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/epidemiologia , Carcinoma de Células Escamosas/patologia , Prognóstico , Boca/patologia
10.
Dig Endosc ; 35(7): 857-865, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36905288

RESUMO

OBJECTIVES: The disposable esophagogastroduodenoscopy (EGD) system is a novel endoscopic device which is highly portable and is designed to eliminate the risk of cross-infection caused by reusable EGD. This study aimed to investigate the feasibility and safety of disposable EGD in emergency, bedside, and intraoperative settings. METHODS: This was a prospective, single-center, noncomparative study. Disposable EGD was used for emergency, bedside, and intraoperative endoscopies in 30 patients. The primary end-point was the technical success rate of the disposable EGD. Secondary end-points included technical performance indicators including clinical operability, image quality score, procedure time, the incidence of device malfunction and/or failure, and the incidence of adverse events. RESULTS: A total of 30 patients underwent diagnosis and/or treatment with disposable EGD. Therapeutic EGD was performed on 13/30 patients, including hemostasis (n = 3), foreign body retrieval (n = 6), nasoenteric tube placement (n = 3), and percutaneous endoscopic gastrostomy (n = 1). The technical success rate was 100%: all procedures and indicated interventions were completed without changing to a conventional upper endoscope. The mean image quality score obtained immediately after procedure completion was 3.72 ± 0.56. The mean (± SD) procedure time was 7.4 (± 7.6) min. There were no device malfunctions or failures, device-related adverse events, or overall adverse events. CONCLUSION: The disposable EGD may be a feasible alternative to the traditional EGD in emergency, bedside, and intraoperative settings. Preliminary data show that it is a safe and effective tool for diagnosis and treatment in emergency and bedside upper gastrointestinal cases. TRIAL REGISTRATION: Chinese Clinical Trial Registry (Trial ID: ChiCTR2100051452, https://www.chictr.org.cn/showprojen.aspx?proj=134284).


Assuntos
Endoscopia do Sistema Digestório , Endoscopia , Humanos , Projetos Piloto , Estudos Prospectivos , Endoscopia do Sistema Digestório/métodos , Intubação Gastrointestinal
11.
Angew Chem Int Ed Engl ; 62(48): e202311224, 2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-37840434

RESUMO

Fluorescent materials with high brightness play a crucial role in the advancement of various technologies such as bioimaging, photonics, and OLEDs. While significant efforts are dedicated to designing new organic dyes with improved performance, enhancing the brightness of existing dyes holds equal importance. In this study, we present a simple supramolecular strategy to develop ultrabright cyanine-based fluorescent materials by addressing long-standing challenges associated with cyanine dyes, including undesired cis-trans photoisomerization and aggregation-caused quenching. Supra-cyanines are obtained by incorporating cyanine moieties in a cyclic peptide-based supramolecular scaffold, and exhibit high fluorescence quantum yields (up to 50 %) in both solution and in the solid state. These findings offer a versatile approach for constructing highly emissive cyanine-based supramolecular materials.

12.
Am J Gastroenterol ; 117(12): 1982-1989, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36455222

RESUMO

INTRODUCTION: Although recent guidelines recommend endoscopic resection of rectal neuroendocrine tumors (NET) ≤10 mm, there is no consensus on which endoscopic modality should be performed. We aimed to compare the safety and efficacy of modified cap-assisted endoscopic mucosal resection (mEMR-C) and endoscopic submucosal dissection (ESD) methods for the treatment of rectal NET ≤10 mm. METHODS: A randomized noninferiority trial comparing mEMR-C and ESD was conducted. The primary outcome was the histological complete resection rate; the secondary outcomes included en bloc resection rate, operation time, complications, and so on. Subgroup analyses and follow-up were also performed. RESULTS: Ninety patients were enrolled, and 79 patients with pathologically confirmed rectal NET were finally analyzed, including 38 cases of mEMR-C and 41 cases of ESD. Histological complete resection rate was 97.4% in the mEMR-C group and 92.7% in the ESD group. The noninferiority of mEMR-C compared with that of ESD was confirmed because the absolute difference was 4.7% (2-sided 90% confidence interval, -3.3% to 12.2%; P = 0.616). En bloc resection and successful removal of rectal NET were achieved in all patients. Advantages of mEMR-C over ESD included shorter operation time (8.89 ± 4.58 vs 24.8 ± 9.14 minutes, P < 0.05) and lower hospitalization cost ($2,233.76 ± $717.70 vs $2,987.27 ± $871.81, P < 0.05). Postoperative complications were recorded in 4 patients who received mEMR-C and 2 patients in the ESD group (11.5% vs 4.9%, P = 0.509), which were all well managed using endoscopy. Similar findings were observed when subgroup analysis was performed. DISCUSSION: mEMR-C is noninferior to ESD with a similar complete resection rate. In addition, mEMR-C had shorter procedure duration time and lower hospitalization costs. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03982264.


Assuntos
Ressecção Endoscópica de Mucosa , Tumores Neuroendócrinos , Neoplasias Retais , Humanos , Tumores Neuroendócrinos/cirurgia , Neoplasias Retais/cirurgia , Duração da Cirurgia , Complicações Pós-Operatórias/epidemiologia
13.
Eur Arch Otorhinolaryngol ; 279(4): 2157-2166, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35041065

RESUMO

PURPOSE: The purpose of this study was to determine whether contralateral cervical lymph node dissection is needed in patients with oropharyngeal squamous cell carcinoma (OPSCC) with contralateral cervical cN0. METHODS: We searched the PubMed, Web of Science, Embase, Chinese Biomedical Literature Database (CBM) and Cochrane Library databases up to August 14, 2021 for studies examining the contralateral neck occult metastasis rate of patients with ipsilateral clinical neck-negative (cN0) OPSCC and the contralateral neck occult metastasis rate of patients with ipsilateral clinical neck-positive (cN1, cN2a, cN2b) OPSCC. This rate is used to determine whether patients with contralateral cN0 OPSCC need contralateral cervical lymph node dissection. RESULTS: A total of 14 articles, including 532 cases, were included in the analysis. When studying the rate of ipsilateral cervical occult metastasis in patients with ipsilateral cN0, 163 cases were included in 11 studies. The results showed that the rate of contralateral cervical occult lymph node metastasis in patients with ipsilateral cN0 was 0.6816% (95% CI 0.0000-4.4880 (P = 0.3005)). In the study of ipsilateral cN+ (cN1, cN2a, cN2b), a total of 369 cases of 10 articles were included in the analysis. The results showed that the rate of contralateral cervical occult lymph node metastasis in patients with ipsilateral cN+ was 11.4920% [95% CI 7.8944-15.5223 (P = 0.0000)]. CONCLUSION: For cancer treatment, the ultimate goal is to achieve the best control of cancer and the lowest complications. It seems unnecessary to intervene in the contralateral neck of patients with OPSCC with ipsilateral cN0. For OPSCC with ipsilateral cN+ , this index is a factor that cannot be ignored when making clinical decisions.


Assuntos
Neoplasias de Cabeça e Pescoço , Esvaziamento Cervical , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Linfonodos/patologia , Linfonodos/cirurgia , Metástase Linfática/patologia , Esvaziamento Cervical/métodos , Estadiamento de Neoplasias , Estudos Retrospectivos , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia
14.
Sensors (Basel) ; 22(1)2021 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-35009793

RESUMO

With the rise of deep learning, using deep learning to segment lesions and assist in diagnosis has become an effective means to promote clinical medical analysis. However, the partial volume effect of organ tissues leads to unclear and blurred edges of ROI in medical images, making it challenging to achieve high-accuracy segmentation of lesions or organs. In this paper, we assume that the distance map obtained by performing distance transformation on the ROI edge can be used as a weight map to make the network pay more attention to the learning of the ROI edge region. To this end, we design a novel framework to flexibly embed the distance map into the two-stage network to improve left atrium MRI segmentation performance. Furthermore, a series of distance map generation methods are proposed and studied to reasonably explore how to express the weight of assisting network learning. We conduct thorough experiments to verify the effectiveness of the proposed segmentation framework, and experimental results demonstrate that our hypothesis is feasible.


Assuntos
Fenômenos Biológicos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética
15.
J Environ Manage ; 282: 111956, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33445139

RESUMO

Excessive fertilizer consumption, poor management, and intense pollution currently restrict sustainable agriculture in China. To address these problems, two 9-year experiments involving typical maize production systems in Northcentral China (summer maize) and Northeast China (spring maize) were conducted to evaluate the effectiveness of Nutrient Expert (NE) management, a Nutrient Decision Support System which combines 4 R nutrient management with improved varieties and optimized plant density, on reducing carbon (C) and nitrogen (N) footprints. The mean grain yields under NE were 7.4 and 11.5 tons ha-1, which were 3.9% and 6.9% higher than those of local farmers' practices (FP) in the summer and spring maize systems, respectively; the N-derived (affected by N fertilization) yield accounted for 21.7% and 73.5% of the total yield under NE, respectively. Compared with FP, NE achieved 21.8% and 16.0% lower reactive nitrogen (Nr) losses, 18.4% and 20.9% lower greenhouse gas (GHG) emissions, 24.8% and 21.4% smaller N footprints (9.1 and 2.3 kg N ton-1 grain), and 21.5% and 26.0% smaller C footprints (436 and 206 kg CO2 eq ton-1 grain) in summer and spring maize, respectively. NE reduced the N-derived N and C footprints by 30.3% and 27.2% in summer maize and 22.9% and 28.0% in spring maize, respectively, as a result of greater yields and optimal N management. Moreover, compared with summer maize, spring maize showed significantly smaller N-derived N (12.6-fold) and C (7.2-fold) footprints. The results demonstrated the ability of long-term NE management to sustain maize yields, reduce Nr losses and GHG emissions, and cut C and N footprints, indicating its potential suitability as an alternative management for sustainable agriculture. Moreover, the summer maize system still had considerable potential for environmental footprints reduction even when current NE management practices were adopted.


Assuntos
Fertilizantes , Zea mays , Agricultura , China , Fertilizantes/análise , Nitrogênio/análise , Nutrientes , Solo
16.
Nano Lett ; 19(5): 3229-3237, 2019 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-30957499

RESUMO

To develop a highly efficient strategy against tumors, here, a nanocombination (PDC/P@HCuS) was designed and constructed to actualize chemo-phototherapy with the assistance of fluorescence (FL) and photoacoustic (PA) images. First, a type of organic-inorganic hybrid nanosystem (P@HCuS) was engineered by coupling the fluorescence-labeled amphiphilic fPEDC copolymer on the surface of hollow mesoporous copper sulfide nanoparticle (HCuS), in which HCuS was used as a photothermal and PA agent; fPEDC as a stabilizer, chromophore, and redox/pH-sensitive gatekeeper; and both of them as drug carriers. Then, a peptide-drug conjugate (cRGD-SMCC-DM1, PDC), as a molecular targeted maytansinoid, was loaded inside of P@HCuS to form PDC/P@HCuS. Next, the PDC/P@HCuS was investigated carefully with or without near-infrared (NIR) laser irradiation. In vitro, the nanocombination exhibited stimuli-responsive drug release, obvious cellular uptake, strong cytotoxicity to tumor cells, significant impact on cell cycle, and cytoskeleton and cellular proteomics as well as evident permeability into the tumor sphere, most of which could be boosted by NIR laser irradiation. In vivo, the nanocombinaiton exerted good FL/PA imaging features and photothermal efficiency, achieved the best antitumor efficacy in the presence of NIR laser irradiation, and showed excellent biosafety. Together, it demonstrated that the PDC/P@HCuS, representing a chemo-phototherapy based on a nanocombination associated with peptide-drug conjugate, could achieve the highly efficient antitumor effect.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Sistemas de Liberação de Medicamentos , Peptídeos/farmacologia , Técnicas Fotoacústicas , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Neoplasias da Mama/patologia , Corantes/química , Corantes/farmacologia , Cobre/química , Cobre/farmacologia , Doxorrubicina/química , Doxorrubicina/farmacologia , Liberação Controlada de Fármacos , Feminino , Humanos , Hipertermia Induzida , Células MCF-7 , Maitansina/química , Maitansina/farmacologia , Nanopartículas , Peptídeos/química , Fototerapia , Sulfetos/química , Sulfetos/farmacologia
17.
J Environ Manage ; 270: 110929, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32721354

RESUMO

Excessive synthetic nitrogen (N) applications, high mineral N accumulation and low N use efficiency (NUE) are current issues in intensively cultivated winter wheat production system impeding the sustainable development of agriculture in China. To solve these problems, soil accumulated N in the top 1 m of the soil profile before sowing (Nsoil), returned straw-N from the previous maize crop (Nstraw) and fertilizer N application (Nfertilizer) should be comprehensively considered N supply sources in N management. As such, the objective of this research was to determine the optimal total N supply (TNsupply) level needed to meet crop requirements while minimizing environmental impacts. A 9-year on-farm experiment was conducted in accordance with a split-plot design involving two different fertilizer management systems (main treatments) and three N application strategies (sub treatments). Extensive TNsupply levels (ranging from 61 kg ha-1 to 813 kg ha-1) were detected, and relative yield (RY), N input and N output in response to the TNsupply were measured. The relationships between TNsupply and RY, N input, and N output strongly fit linear-plateau, linear, and linear-plateau models, respectively. The minimum TNsupply levels needed to achieve the maximum RY and N output were 325 and 392 kg ha-1, respectively. On the basis of N supply capacity, the TNsupply was removed from the growing system by 61% (N input). As the N input increased past 209 kg ha-1, the NUE declined, at which point the TNsupply reached 433 kg ha-1. Therefore, the suitable TNsupply should range from 325 kg ha-1 (ensuring a total N supply for high yield and N uptake) to 433 kg ha-1 (obtaining a relatively higher NUE and less N loss to the environment). The TNsupply was highlighted to be an indicator for use in N management recommendations. Considering the average high N accumulation in winter wheat production systems, N management should essentially take into account the consumption of Nsoil, the levels of Nstraw and the minimum application of Nfertilizer to obtain high yields while minimizing environmental impacts under suitable TNsupply levels.


Assuntos
Nitrogênio/análise , Triticum , Agricultura , China , Fertilizantes , Solo
18.
Exp Eye Res ; 186: 107712, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31254514

RESUMO

Crystallins are structural proteins in the lens that last a lifetime with little turnover. Deviant in crystallins can cause rare but severe visual impairment, namely, congenital cataracts. It is reported that several mutations in the acidic ß-crystallin 4 (CRYBA4) are related to congenital cataracts. However, the pathogenesis of these mutants is not well understood at molecular level. Here we evaluate the biochemical properties of wild type CRYBA4 (CRYBA4WT) and a pathogenic G64W mutant (CRYBA4G64W) including protein folding, polymerization state and protein stability. Furthermore, we explore the differences in their interactions with α-crystallin A (CRYAA) and basic ß-crystallin 1 (CRYBB1) via yeast two-hybrid and pull-down assay in vitro, through which we find that G64W mutation leads to protein misfolding, decreases protein stability, blocks its interaction with CRYBB1 but maintains its interaction with CRYAA. Our results deepen our understanding of the pathogenesis of congenital cataracts.


Assuntos
Catarata , Cristalino/metabolismo , Dobramento de Proteína , Cadeia A de beta-Cristalina/genética , beta-Cristalinas/química , Catarata/congênito , Catarata/genética , Catarata/metabolismo , Humanos , Mutação
19.
Neuropathology ; 39(2): 85-96, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30834629

RESUMO

The aim of this study is to explore the macroscale neural mechanisms of the antidepressant effects of Xiaoyaosan, a traditional Chinese herbal formula. We analyzed blood oxygen level-dependent (BOLD) functional magnetic resonance imaging signals. To further minimize the hemodynamic variations of BOLD signals and analyze the intra-region neural activity or temporal coherence, we employed the newly developed regional homogeneity (ReHo) approach to determine aberrant functional connectivity using the chronic unpredictable mild stress (CUMS) mouse model of depression and to also explore the brain-region rescue effect of modified Xiaoyaosan (MXYS) in such mice. We found the aberrant ReHo in CUMS mice replicated previous discoveries in patients with depression. Intriguingly, MXYS only normalized several limbic regions, which suggests the essential roles of these regions in mediating the antidepressant effects of MXYS. Our results provide a reliable framework for the use of ReHo analysis with animal models of depression and further suggest a new perspective to elucidate the antidepressant effects of MXYS.


Assuntos
Antidepressivos/administração & dosagem , Encéfalo/efeitos dos fármacos , Encéfalo/fisiopatologia , Depressão/tratamento farmacológico , Depressão/fisiopatologia , Medicamentos de Ervas Chinesas/administração & dosagem , Animais , Mapeamento Encefálico , Modelos Animais de Doenças , Imageamento por Ressonância Magnética , Masculino , Camundongos Endogâmicos C57BL
20.
J Pharmacol Sci ; 138(1): 46-53, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30245287

RESUMO

Hepatic steatosis is the early stage of alcoholic liver disease (ALD), may progress to steatohepatitis, fibrosis even cirrhosis. Polydatin, the primary active component of Polygonum cuspidatum Sieb. et Zucc, has been recognized to possess hepatoprotective and anti-inflammatory properties. To investigate whether polydatin alleviates ethanol induced liver injury and to elucidate the underlying molecular mechanisms, zebrafish larvae at 4 days post-fertilization (dpf) were exposed to 350 mmol/L of ethanol for 32 h, then treated with polydatin for 48 h. Oil red O, Nile Red and H&E staining were used to analyze the pathological changes in liver. The mRNA levels were measured by quantitative PCR and the antioxidant capacity was detected using H2O2-specific fluorescent probe. Here, polydatin strongly alleviated hepatic steatosis and decreased the expression levels of alcohol and lipid metabolism-related genes, including CYP2Y3, CYP3A65, HMGCRa, HMGCRb and FASN. Additionally, polydatin inhibited oxidative stress in the liver according to fluorescent probe. Moreover, significantly up-regulated expression of DNA damage-related genes (CHOP, GADD45αa) revealed that polydatin attenuated hepatic apoptosis in larvae. In conclusion, polydatin may improve the liver function of zebrafish with acute alcoholic liver injury through attenuating hepatic fat accumulation, ameliorating lipid and ethanol metabolism and reducing oxidative stress and DNA damage.


Assuntos
Anti-Inflamatórios , Antioxidantes , Glucosídeos/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Hepatopatias Alcoólicas/tratamento farmacológico , Hepatopatias Alcoólicas/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fitoterapia , Estilbenos/farmacologia , Peixe-Zebra , Animais , Hidrocarboneto de Aril Hidroxilases/genética , Hidrocarboneto de Aril Hidroxilases/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Família 3 do Citocromo P450/genética , Família 3 do Citocromo P450/metabolismo , Dano ao DNA/genética , Fallopia japonica/química , Expressão Gênica/efeitos dos fármacos , Glucosídeos/isolamento & purificação , Glucosídeos/uso terapêutico , Metabolismo dos Lipídeos/genética , Hepatopatias Alcoólicas/genética , Hepatopatias Alcoólicas/patologia , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Oxirredutases N-Desmetilantes/genética , Oxirredutases N-Desmetilantes/metabolismo , Estilbenos/isolamento & purificação , Estilbenos/uso terapêutico , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
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