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1.
Immunity ; 55(4): 671-685.e10, 2022 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-35417675

RESUMO

Interferon-gamma (IFN-γ) has pleiotropic effects on cancer immune checkpoint blockade (ICB), including roles in ICB resistance. We analyzed gene expression in ICB-sensitive versus ICB-resistant tumor cells and identified a strong association between interferon-mediated resistance and expression of Ripk1, a regulator of tumor necrosis factor (TNF) superfamily receptors. Genetic interaction screening revealed that in cancer cells, RIPK1 diverted TNF signaling through NF-κB and away from its role in cell death. This promoted an immunosuppressive chemokine program by cancer cells, enhanced cancer cell survival, and decreased infiltration of T and NK cells expressing TNF superfamily ligands. Deletion of RIPK1 in cancer cells compromised chemokine secretion, decreased ARG1+ suppressive myeloid cells linked to ICB failure in mice and humans, and improved ICB response driven by CASP8-killing and dependent on T and NK cells. RIPK1-mediated resistance required its ubiquitin scaffolding but not kinase function. Thus, cancer cells co-opt RIPK1 to promote cell-intrinsic and cell-extrinsic resistance to immunotherapy.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Inibidores de Checkpoint Imunológico , Interferons , Neoplasias , Proteína Serina-Treonina Quinases de Interação com Receptores , Animais , Imunoterapia , Interferon gama/metabolismo , Interferons/metabolismo , Camundongos , NF-kappa B/metabolismo , Neoplasias/genética , Proteína Serina-Treonina Quinases de Interação com Receptores/genética , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo
2.
Mol Cell ; 78(1): 70-84.e6, 2020 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-32017897

RESUMO

Post-transcriptional mechanisms regulate the stability and, hence, expression of coding and noncoding RNAs. Sequence-specific features within the 3' untranslated region (3' UTR) often direct mRNAs for decay. Here, we characterize a genome-wide RNA decay pathway that reduces the half-lives of mRNAs based on overall 3' UTR structure formed by base pairing. The decay pathway is independent of specific single-stranded sequences, as regulation is maintained in both the original and reverse complement orientation. Regulation can be compromised by reducing the overall structure by fusing the 3' UTR with an unstructured sequence. Mutating base-paired RNA regions can also compromise this structure-mediated regulation, which can be restored by re-introducing base-paired structures of different sequences. The decay pathway requires the RNA-binding protein UPF1 and its associated protein G3BP1. Depletion of either protein increased steady-state levels of mRNAs with highly structured 3' UTRs as well as highly structured circular RNAs. This structure-dependent mechanism therefore enables cells to selectively regulate coding and noncoding RNAs.


Assuntos
Regiões 3' não Traduzidas , DNA Helicases/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , RNA Helicases/metabolismo , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Estabilidade de RNA , RNA Mensageiro/metabolismo , Transativadores/metabolismo , Pareamento de Bases , Linhagem Celular , Regulação da Expressão Gênica , Humanos , RNA Circular/química , RNA Circular/metabolismo
3.
Nature ; 573(7774): 421-425, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31511693

RESUMO

Early human embryonic development involves extensive lineage diversification, cell-fate specification and tissue patterning1. Despite its basic and clinical importance, early human embryonic development remains relatively unexplained owing to interspecies divergence2,3 and limited accessibility to human embryo samples. Here we report that human pluripotent stem cells (hPSCs) in a microfluidic device recapitulate, in a highly controllable and scalable fashion, landmarks of the development of the epiblast and amniotic ectoderm parts of the conceptus, including lumenogenesis of the epiblast and the resultant pro-amniotic cavity, formation of a bipolar embryonic sac, and specification of primordial germ cells and primitive streak cells. We further show that amniotic ectoderm-like cells function as a signalling centre to trigger the onset of gastrulation-like events in hPSCs. Given its controllability and scalability, the microfluidic model provides a powerful experimental system to advance knowledge of human embryology and reproduction. This model could assist in the rational design of differentiation protocols of hPSCs for disease modelling and cell therapy, and in high-throughput drug and toxicity screens to prevent pregnancy failure and birth defects.


Assuntos
Âmnio/embriologia , Camadas Germinativas/embriologia , Modelos Biológicos , Células-Tronco Pluripotentes/citologia , Âmnio/citologia , Diferenciação Celular , Embrião de Mamíferos/citologia , Embrião de Mamíferos/embriologia , Feminino , Camadas Germinativas/citologia , Humanos , Gravidez , Linha Primitiva/citologia
4.
J Neurosci ; 43(13): 2305-2325, 2023 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-36813575

RESUMO

Cholecystokinin (CCK) enables excitatory circuit long-term potentiation (LTP). Here, we investigated its involvement in the enhancement of inhibitory synapses. Activation of GABA neurons suppressed neuronal responses in the neocortex to a forthcoming auditory stimulus in mice of both sexes. High-frequency laser stimulation (HFLS) of GABAergic neurons potentiated this suppression. HFLS of CCK interneurons could induce the LTP of their inhibition toward pyramidal neurons. This potentiation was abolished in CCK knock-out mice but intact in mice with both CCK1R and 2R knockout of both sexes. Next, we combined bioinformatics analysis, multiple unbiased cell-based assays, and histology examinations to identify a novel CCK receptor, GPR173. We propose GPR173 as CCK3R, which mediates the relationship between cortical CCK interneuron signaling and inhibitory LTP in the mice of either sex. Thus, GPR173 might represent a promising therapeutic target for brain disorders related to excitation and inhibition imbalance in the cortex.SIGNIFICANCE STATEMENT CCK, the most abundant and widely distributed neuropeptide in the CNS, colocalizes with many neurotransmitters and modulators. GABA is one of the important inhibitory neurotransmitters, and much evidence shows that CCK may be involved in modulating GABA signaling in many brain areas. However, the role of CCK-GABA neurons in the cortical microcircuits is still unclear. We identified a novel CCK receptor, GPR173, localized in the CCK-GABA synapses and mediated the enhancement of the GABA inhibition effect, which might represent a promising therapeutic target for brain disorders related to excitation and inhibition imbalance in the cortex.


Assuntos
GABAérgicos , Receptores da Colecistocinina , Masculino , Feminino , Camundongos , Animais , GABAérgicos/farmacologia , Células Piramidais/fisiologia , Sinapses/fisiologia , Neurônios GABAérgicos/fisiologia , Camundongos Knockout , Interneurônios , Colecistocinina , Ácido gama-Aminobutírico/fisiologia , Potenciação de Longa Duração/fisiologia , Receptores Acoplados a Proteínas G/genética
5.
Small ; 20(4): e2302404, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37735983

RESUMO

Strain gradients widely exist in development and physiological activities. The directional movement of cells is essential for proper cell localization, and directional cell migration in responses to gradients of chemicals, rigidity, density, and topography of extracellular matrices have been well-established. However; it is unclear whether strain gradients imposed on cells are sufficient to drive directional cell migration. In this work, a programmable uniaxial cell stretch device is developed that creates controllable strain gradients without changing substrate stiffness or ligand distributions. It is demonstrated that over 60% of the single rat embryonic fibroblasts migrate toward the lower strain side in static and the 0.1 Hz cyclic stretch conditions at ≈4% per mm strain gradients. It is confirmed that such responses are distinct from durotaxis or haptotaxis. Focal adhesion analysis confirms higher rates of contact area and protrusion formation on the lower strain side of the cell. A 2D extended motor-clutch model is developed to demonstrate that the strain-introduced traction force determines integrin fibronectin pairs' catch-release dynamics, which drives such directional migration. Together, these results establish strain gradient as a novel cue to regulate directional cell migration and may provide new insights in development and tissue repairs.


Assuntos
Quimiotaxia , Matriz Extracelular , Ratos , Animais , Movimento Celular , Adesões Focais , Adesão Celular
6.
Arterioscler Thromb Vasc Biol ; 43(10): 1900-1920, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37589142

RESUMO

BACKGROUND: Thoracic aortic dissection (TAD) is a life-threatening aortic disease without effective medical treatment. Increasing evidence has suggested a role for NE (neutrophil elastase) in vascular diseases. In this study, we aimed at investigating a causal role for NE in TAD and exploring the molecular mechanisms involved. METHODS: ß-aminopropionitrile monofumarate was administrated in mice to induce TAD. NE deficiency mice, pharmacological inhibitor GW311616A, and adeno-associated virus-2-mediated in vivo gene transfer were applied to explore a causal role for NE and associated target gene in TAD formation. Multiple functional assays and biochemical analyses were conducted to unravel the underlying cellular and molecular mechanisms of NE in TAD. RESULTS: NE aortic gene expression and plasma activity was significantly increased during ß-aminopropionitrile monofumarate-induced TAD and in patients with acute TAD. NE deficiency prevents ß-aminopropionitrile monofumarate-induced TAD onset/development, and GW311616A administration ameliorated TAD formation/progression. Decreased levels of neutrophil extracellular traps, inflammatory cells, and MMP (matrix metalloproteinase)-2/9 were observed in NE-deficient mice. TBL1x (F-box-like/WD repeat-containing protein TBL1x) has been identified as a novel substrate and functional downstream target of NE in TAD. Loss-of-function studies revealed that NE mediated inflammatory cell transendothelial migration by modulating TBL1x-LTA4H (leukotriene A4 hydrolase) signaling and that NE regulated smooth muscle cell phenotype modulation under TAD pathological condition by regulating TBL1x-MECP2 (methyl CpG-binding protein 2) signal axis. Further mechanistic studies showed that TBL1x inhibition decreased the binding of TBL1x and HDAC3 (histone deacetylase 3) to MECP2 and LTA4H gene promoters, respectively. Finally, adeno-associated virus-2-mediated Tbl1x gene knockdown in aortic smooth muscle cells confirmed a regulatory role for TBL1x in NE-mediated TAD formation. CONCLUSIONS: We unravel a critical role of NE and its target TBL1x in regulating inflammatory cell migration and smooth muscle cell phenotype modulation in the context of TAD. Our findings suggest that the NE-TBL1x signal axis represents a valuable therapeutic for treating high-risk TAD patients.


Assuntos
Aneurisma da Aorta Torácica , Dissecção Aórtica , Dissecção da Aorta Torácica , Animais , Humanos , Camundongos , Aminopropionitrilo/toxicidade , Aneurisma da Aorta Torácica/induzido quimicamente , Aneurisma da Aorta Torácica/genética , Aneurisma da Aorta Torácica/metabolismo , Dissecção Aórtica/induzido quimicamente , Dissecção Aórtica/genética , Elastase de Leucócito/genética , Elastase de Leucócito/efeitos adversos
7.
BMC Public Health ; 24(1): 1452, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38816823

RESUMO

BACKGROUND: This study analyzes the correlation between oxidative balance score (OBS), cardiometabolic risk factors (CMRFs), and mortality in individuals with CMRFs. METHODS: Data were chosen from the National Health and Nutrition Examination Survey. The survey-weighted multivariable logistic regression models were implemented to explore the relationship between OBS and the risk of CMRFs. Then, Cox proportional hazard models were employed to estimate the impact of OBS on mortality in individuals with CMRFs. RESULTS: Following multivariate adjustment, the subjects in the highest quartile exhibited a 46% reduction in the risk of CMRFs, a 33% reduction in the risk of diabetes, a 31% reduction in the risk of hypertension, and a 36% reduction in the risk of hyperlipidemia, compared with those in the lowest quartile. Furthermore, each 1-unit increase in OBS was remarkably negatively correlated with the prevalence of CMRFs, diabetes, hypertension, and hyperlipidemia. The correlation between OBS and CMFRs was found to be mediated by serum γ-glutamyltransferase (GGT) and white blood cells (WBC), and the mediation effect of GGT levels and WBC, accounting for 6.90% and 11.51%, respectively. Lastly, the multivariate Cox regression model revealed that elevated OBS, irrespective of whether it was treated as a categorical or continuous variable, exhibited a significant association with decreased mortality from all causes, cardiovascular disease, and cancer. CONCLUSIONS: An increased OBS might reflect a lower risk of CMRFs and a favorable prognosis for individuals with CMRFs. Moreover, WBC and GGT may play a potential mediating role between OBS and CMRFs.


Assuntos
Fatores de Risco Cardiometabólico , Inquéritos Nutricionais , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Estudos Transversais , Adulto , Idoso , Estresse Oxidativo , Doenças Cardiovasculares/mortalidade , Modelos de Riscos Proporcionais , Hipertensão
8.
Int J Cancer ; 153(5): 1096-1107, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37232006

RESUMO

Non-diagnostic findings are common in transbronchial lung biopsy (TBLB) and endobronchial ultrasound-guided transbronchial lung biopsy (EBUS-TBLB). One of the challenges is to improve the detection of lung cancer using these techniques. To address this issue, we utilized an 850 K methylation chip to identify methylation sites that distinguish malignant from benign lung nodules. Our study found that a combination of HOXA7, SHOX2 and SCT methylation analysis has the best diagnostic yield in bronchial washing (sensitivity: 74.1%; AUC: 0.851) and brushing samples (sensitivity: 86.1%; AUC: 0.915). We developed a kit comprising these three genes and validated it in 329 unique bronchial washing samples, 397 unique brushing samples and 179 unique patients with both washing and brushing samples. The panel's accuracy in lung cancer diagnosis was 86.9%, 91.2% and 95% in bronchial washing, brushing and washing + brushing samples, respectively. When combined with cytology, rapid on-site evaluation (ROSE), and histology, the panel's sensitivity in lung cancer diagnosis was 90.8% and 95.8% in bronchial washing and brushing samples, respectively, and 100% in washing + brushing samples. Our findings suggest that quantitative analysis of the three-gene panel can improve the diagnosis of lung cancer using bronchoscopy.


Assuntos
Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Pulmão/patologia , Biópsia/métodos , Broncoscopia , DNA
9.
Biochem Biophys Res Commun ; 681: 225-231, 2023 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-37783121

RESUMO

The commitment of mesenchymal stem cells (MSCs) to preadipocytes and the termination of differentiation to adipocytes are critical for maintaining systemic energy homeostasis. However, our knowledge of the molecular mechanisms governing the commitment of MSCs to preadipocytes and the subsequent termination of their differentiation into adipocytes remain limited. Additionally, the role of Sox6 sex-determining region Y (SRY)-box6 (Sox6), a transcription factor that regulates gene transcription, is reportedly involved in various cellular processes, including adipogenesis; however, its function in regulating preadipocyte development and the factors involved in the termination of adipogenic differentiation remain unexplored. Therefore, we investigated the role of Sox6 in regulating the differentiation of adipocytes by monitoring the effects of its overexpression in C3H10T1/2 cells (in vitro) and C57BL/6J mouse (in vivo) models of adipogenesis. We observed lower Sox6 expression in the adipose tissue of obese mice than that in control mice. Sox6 overexpression inhibited the differentiation of MSC by directly binding to the lysyl oxidase (Lox) and preadipocyte factor 1 (Pref1) promoters, which was potentiated by histone deacetylase-1(HDAC1). Our findings suggest that Sox6 is a key regulator of MSC commitment to adipocytes; therefore, targeting the Sox6-mediated regulation of this process could offer potential therapeutic avenues for addressing obesity and related metabolic disorders.


Assuntos
Adipogenia , Células-Tronco Mesenquimais , Animais , Camundongos , Adipogenia/genética , Diferenciação Celular/genética , Camundongos Endogâmicos C57BL , Proteína-Lisina 6-Oxidase/genética , Proteína-Lisina 6-Oxidase/metabolismo , Fatores de Transcrição SOXD/genética , Fatores de Transcrição SOXD/metabolismo
10.
Ann Surg Oncol ; 30(3): 1366-1378, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36273058

RESUMO

OBJECTIVE: The aim of this study was to compare the short- and long-term outcomes of laparoscopic surgery (LS) and open surgery (OP) for perihilar cholangiocarcinoma (PHC) using a large real-world dataset in China. METHODS: Data of patients with PHC who underwent LS and OP from January 2013 to October 2018, across 10 centers in China, were extracted from medical records. A comparative analysis was performed before and after propensity score matching (PSM) in the LS and OP groups and within the study subgroups. The Cox proportional hazards mixed-effects model was applied to estimate the risk factors for mortality, with center and year of operation as random effects. RESULTS: A total of 467 patients with PHC were included, of whom 161 underwent LS and 306 underwent OP. Postoperative morbidity, such as hemorrhage, biliary fistula, abdominal abscess, and hepatic insufficiency, was similar between the LS and OP groups. The median overall survival (OS) was longer in the LS group than in the OP group (NA vs. 22 months; hazard ratio [HR] 1.19, 95% confidence interval [CI] 1.02-1.39, p = 0.024). Among the matched datasets, OS was comparable between the LS and OP groups (NA vs. 35 months; HR 0.99, 95% CI 0.77-1.26, p = 0.915). The mixed-effect model identified that the surgical method was not associated with long-term outcomes and that LS and OP provided similar oncological outcomes. CONCLUSIONS: Considering the comparable long-term prognosis and short-term outcomes of LS and OP, LS could be a technically feasible surgical method for PHC patients with all Bismuth-Corlett types of PHC.


Assuntos
Neoplasias dos Ductos Biliares , Colangiocarcinoma , Tumor de Klatskin , Laparoscopia , Humanos , Tumor de Klatskin/cirurgia , Estudos Retrospectivos , Laparoscopia/métodos , Prognóstico , Neoplasias dos Ductos Biliares/patologia , Resultado do Tratamento , Colangiocarcinoma/cirurgia
11.
BMC Cancer ; 23(1): 394, 2023 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-37138243

RESUMO

BACKGROUND: Laparoscopic surgery (LS) has been increasingly applied in perihilar cholangiocarcinoma (pCCA). In this study, we intend to compare the short-term outcomes of LS versus open operation (OP) for pCCA in a multicentric practice in China. METHODS: This real-world analysis included 645 pCCA patients receiving LS and OP at 11 participating centers in China between January 2013 and January 2019. A comparative analysis was performed before and after propensity score matching (PSM) in LS and OP groups, and within Bismuth subgroups. Univariate and multivariate models were performed to identify significant prognostic factors of adverse surgical outcomes and postoperative length of stay (LOS). RESULTS: Among 645 pCCAs, 256 received LS and 389 received OP. Reduced hepaticojejunostomy (30.89% vs 51.40%, P = 0.006), biliary plasty requirement (19.51% vs 40.16%, P = 0.001), shorter LOS (mean 14.32 vs 17.95 d, P < 0.001), and lower severe complication (CD ≥ III) (12.11% vs. 22.88%, P = 0.006) were observed in the LS group compared with the OP group. Major postoperative complications such as hemorrhage, biliary fistula, abdominal abscess, and hepatic insufficiency were similar between LS and OP (P > 0.05 for all). After PSM, the short-term outcomes of two surgical methods were similar, except for shorter LOS in LS compared with OP (mean 15.19 vs 18.48 d, P = 0.0007). A series subgroup analysis demonstrated that LS was safe and had advantages in shorting LOS. CONCLUSION: Although the complex surgical procedures, LS generally seems to be safe and feasible for experienced surgeons. TRIAL REGISTRATION: NCT05402618 (date of first registration: 02/06/2022).


Assuntos
Neoplasias dos Ductos Biliares , Tumor de Klatskin , Laparoscopia , Humanos , Estudos Retrospectivos , Tumor de Klatskin/cirurgia , Pontuação de Propensão , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Laparoscopia/efeitos adversos , Laparoscopia/métodos , Tempo de Internação , Neoplasias dos Ductos Biliares/complicações , Resultado do Tratamento
12.
BMC Cardiovasc Disord ; 23(1): 75, 2023 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-36755239

RESUMO

BACKGROUND: Thoracic acute aortic dissection (TAAD), one of the most fatal cardiovascular diseases, leads to sudden death, however, its mechanism remains unclear. METHODS: Three Gene Expression Omnibus datasets were employed to detect differentially expressed genes (DEGs). A similar function and co-expression network was identified by weighted gene co-expression network analysis. The least absolute shrinkage and selection operator, random forest, and support vector machines-recursive feature elimination were utilized to filter diagnostic TAAD markers, and then screened markers were validated by quantitative real-time PCR and another independent dataset. CIBERSORT was deployed to analyze and evaluate immune cell infiltration in TAAD tissues. RESULTS: Twenty-five DEGs were identified and narrowed down to three after screening. Finally, two genes, SLC11A1 and FGL2, were verified by another dataset and qRT-PCR. Function analysis revealed that SLC11A1 and FGL2 play significant roles in immune-inflammatory responses. CONCLUSION: SLC11A1 and FGL2 are differently expressed in aortic dissection and may be involved in immune-inflammatory responses.


Assuntos
Dissecção Aórtica , Humanos , Dissecção Aórtica/genética , Biomarcadores , Biologia Computacional , Fibrinogênio , Reação em Cadeia da Polimerase em Tempo Real
13.
Clin Exp Dermatol ; 48(10): 1128-1137, 2023 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-37171787

RESUMO

BACKGROUND: The various types of ionizing radiation and altered gravity in the space environment present a risk to humans during space missions. Changes in the space environment lead to skin diseases, affecting the status of the aviators to fly. Therefore, it is important to explore the molecular-level changes in the skin during space missions. OBJECTIVES: Bioinformatics analysis of gene arrays from hair follicle tissue of 10 astronauts was performed to explore changes in gene expression before, during and after space missions. METHODS: First, STEM (Short Time-series Expression Miner) software was used to identify the expression patterns of hair follicle genes of astronauts pre-, in- and postflight. Gene Ontology Enrichment Analysis was then performed to explore the gene functions within the module. Protein-protein interaction network analysis was performed on skin-related genes. The transcriptional regulatory network within the module was constructed using the TRRUST database. The circadian rhythm-related genes within the module were screened using the MSigDB (Molecular Signatures Database). RESULTS: Based on differential expression analysis between the two groups, there were 327 differentially expressed genes after the astronauts entered space compared with preflight, and only 54 differentially expressed genes after returning to Earth. This outcome suggests that the expression of most genes can be recovered on return to the ground, but there are a small number of genes whose expression cannot be recovered in a short period of time. Based on time series analysis, 311 genes showed increased expression on entry into space and decreased expression on return to Earth. The genes of this expression pattern were associated with skin development, keratinocyte differentiation and cornification. Ten hub genes were identified as skin-related genes within the module, as well as nine transcription factors and three circadian genes. One hundred and seventy-nine genes decreased in expression after entry into space and increased on return to Earth. By reviewing the literature, we found that four of the genes, CSCD2, HP, CXCR1 and SSTR4, are associated with skin diseases. CONCLUSIONS: Through bioinformatics analysis, we found that the space environment affects skin keratinocyte differentiation, leading to skin barrier damage and inflammatory responses, and that this effect was decreased after return to Earth.


Assuntos
Dermatopatias , Voo Espacial , Humanos , Astronautas , Pele , Expressão Gênica
14.
Phys Rev Lett ; 129(12): 128101, 2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-36179209

RESUMO

Growing axons are one-dimensional active structures that are important for wiring the brain and repairing nerves. However, the biophysical mechanisms underlying the complex kinetics of growing axons remain elusive. Here, we develop a theoretical framework to recapitulate force-regulated states and their transitions in growing axons. We demonstrate a unique negative feedback mechanism that defines four distinct kinetic states in a growing axon, whose transitional boundaries depend on the interplay between cytoskeletal dynamics and axon-substrate adhesion. A phase diagram for axonal growth is formulated based on two dimensionless numbers.


Assuntos
Axônios , Encéfalo , Axônios/fisiologia
15.
Chem Rev ; 120(17): 9363-9419, 2020 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-32786418

RESUMO

Heteroatom-doped porous carbon materials (HPCMs) have found extensive applications in adsorption/separation, organic catalysis, sensing, and energy conversion/storage. The judicious choice of carbon precursors is crucial for the manufacture of HPCMs with specific usages and maximization of their functions. In this regard, polymers as precursors have demonstrated great promise because of their versatile molecular and nanoscale structures, modulatable chemical composition, and rich processing techniques to generate textures that, in combination with proper solid-state chemistry, can be maintained throughout carbonization. This Review comprehensively surveys the progress in polymer-derived functional HPCMs in terms of how to produce and control their porosities, heteroatom doping effects, and morphologies and their related use. First, we summarize and discuss synthetic approaches, including hard and soft templating methods as well as direct synthesis strategies employing polymers to control the pores and/or heteroatoms in HPCMs. Second, we summarize the heteroatom doping effects on the thermal stability, electronic and optical properties, and surface chemistry of HPCMs. Specifically, the heteroatom doping effect, which involves both single-type heteroatom doping and codoping of two or more types of heteroatoms into the carbon network, is discussed. Considering the significance of the morphologies of HPCMs in their application spectrum, potential choices of suitable polymeric precursors and strategies to precisely regulate the morphologies of HPCMs are presented. Finally, we provide our perspective on how to predefine the structures of HPCMs by using polymers to realize their potential applications in the current fields of energy generation/conversion and environmental remediation. We believe that these analyses and deductions are valuable for a systematic understanding of polymer-derived carbon materials and will serve as a source of inspiration for the design of future HPCMs.

16.
Macromol Rapid Commun ; 43(8): e2200016, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35218095

RESUMO

A zwitterionic polymeric hair-coated stainless steel mesh membrane is fabricated, which demonstrates efficient separation of oil/water mixtures and emulsions. The hairy coating of poly(divinylbenzene-co-vinylbenzene chloride) is generated by precipitation cationic polymerization, and subsequently grafting a zwitterionic polymer layer by atom transfer radical polymerization of sulfobetaine methacrylate. The microstructure of the hairy coating is tunable from an array of individual nanofibers to porous networks by interweaving of the hairs. The long-range attraction of zwitterionic polymers with water renders the coated mesh with excellent superhydrophilic and underwater superoleophobic performance. The coated mesh is highly antifouling to avoid the prehydration in conventional methods. Moreover, the microstructure is demonstrated to be responsible for the high separation efficiency of oil/water emulsion. Therefore, separation of oil/water mixtures and emulsions becomes easier by the coated mesh, which is promising in industrial oil field sewage treatment.

17.
BMC Cardiovasc Disord ; 22(1): 146, 2022 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-35366817

RESUMO

BACKGROUND: Eosinophils are pro-inflammatory cells involved in thrombosis and have been proposed as a prognosis marker in acute ischemic stroke and ST-elevation myocardial Infarction. Here, we sought to clarify the prognostic value of eosinophil percentage (EOS%) in patients with acute type A aortic dissection (AAAD). METHODS: We examined 183 consecutive AAAD patients. Based on the optimum cut-off value of EOS% determined by X-tile software, patients were classified into the low EOS% (EOS% ≤ 0.1) and high EOS% groups (EOS% > 0.1). We performed multivariate regression analysis and Kaplan-Meier (KM) survival curves to assess the association between EOS% and mortality. Eosinophil accumulation in aortic dissection intraluminal thrombus was confirmed using hematoxylin-eosin (H&E) staining. An external cohort from Medical Information Mart for Intensive Care IV was performed to validate the results. RESULTS: Relative to surviving patients, those who died during hospitalization had significantly lower EOS% (p = 0.001) but significantly higher WBC (p = 0.002) and neutrophil (p = 0.001) counts. Multivariate regression analysis identified EOS% as an independent predictor of in-hospital and 1-year mortality. KM curves revealed that 1-year cumulative mortality was significantly higher in the low EOS% group, although it was mainly attributed to the higher 30-day mortality. H&E staining revealed massive infiltration of eosinophils in all 20 thrombus specimens. The external validation confirmed that relative to survivors, patients with in-hospital mortality (p = 0.010) had significantly lower EOS%. Moreover, multivariate regression analyses identified that decreased EOS% was independently significantly associated with in-hospital mortality. CONCLUSIONS: Low EOS% is significantly related to increased mortality rates in AAAD patients.


Assuntos
Dissecção Aórtica , AVC Isquêmico , Dissecção Aórtica/diagnóstico por imagem , Eosinófilos , Humanos , Contagem de Leucócitos , Prognóstico
18.
Arch Insect Biochem Physiol ; 110(1): e21857, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34859483

RESUMO

Tomato yellow leaf curl virus (TYLCV), a plant DNA virus of the genus Begomovirus, is transmitted by whiteflies of the Bemisia tabaci species complex in a persistent manner. Our previous study indicated that activation of the apoptosis pathway in whiteflies could facilitate TYLCV accumulation and transmission. Considering that temperature change can influence the spread of insect-borne plant viruses, we focused on plant virus induced-apoptosis to investigate the underlying mechanism of temperature regulation on plant virus transmission via an insect vector. We found that heat stress (40°C) on whiteflies could facilitate TYLCV accumulation and increase transmission to tomato plants. Despite upregulation of caspase-1 and caspase-3 gene expression, heat stress failed to induce an increase in the activation of cleaved caspase-3 and DNA fragmentation in TYLCV-infected whiteflies. However, our data failed to determine the role of heat stress in apoptosis modulation of insect-plant virus interplay while still providing clues to understand insect vectors and their transmitted plant viruses.


Assuntos
Begomovirus , Hemípteros , Animais , Apoptose , Begomovirus/fisiologia , Caspase 3 , Resposta ao Choque Térmico , Hemípteros/genética
19.
Angew Chem Int Ed Engl ; 61(27): e202205183, 2022 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-35470952

RESUMO

We report the large-scale synthesis of photoluminescent single-chain nanoparticles (SCNPs) by electrostatic-mediated intramolecular crosslinking in a concentrated solution of 40 mg mL-1 by continuous addition of the free radical initiator. Poly(vinyl benzyl chloride) was charged by quaternization with vinyl-imidazolium for the intramolecular crosslinking by using 2,2-dimethoxy-2-phenylacetophenone (DMAP) as the radical initiator. Under the electrostatic repulsion thus interchain isolation, the intrachain crosslinking experiences the transition from coil through pearl-necklace to globular state. The SCNPs demonstrate strong photoluminescence in the visible range when the non-emissive units are confined thereby. Composition and microstructure of the SCNPs are tunable. The photoluminescent tadpole-like Janus SCNP can be used to selectively illuminate interfacial membranes while stabilizing the emulsions.

20.
Ann Surg ; 273(1): 145-153, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30672792

RESUMO

OBJECTIVE: The aim of the study was to analyze the outcomes of patients who have undergone laparoscopic pancreaticoduodenectomy (LPD) in China. SUMMARY BACKGROUND DATA: LPD is being increasingly used worldwide, but an extensive, detailed, systematic, multicenter analysis of the procedure has not been performed. METHODS: We retrospectively reviewed 1029 consecutive patients who had undergone LPD between January 2010 and August 2016 in China. Univariate and multivariate analyses of patient demographics, changes in outcome over time, technical learning curves, and the relationship between hospital or surgeon volume and patient outcomes were performed. RESULTS: Among the 1029 patients, 61 (5.93%) required conversion to laparotomy. The median operation time (OT) was 441.34 minutes, and the major complications occurred in 511 patients (49.66%). There were 21 deaths (2.43%) within 30 days, and a total of 61 (5.93%) within 90 days. Discounting the effects of the early learning phase, critical parameters improved significantly with surgeons' experience with the procedure. Univariate and multivariate analyses revealed that the pancreatic anastomosis technique, preoperative biliary drainage method, and total bilirubin were linked to several outcome measures, including OT, estimated intraoperative blood loss, and mortality. Multicenter analyses of the learning curve revealed 3 phases, with proficiency thresholds at 40 and 104 cases. Higher hospital, department, and surgeon volume, as well as surgeon experience with minimally invasive surgery, were associated with a lower risk of surgical failure. CONCLUSIONS: LPD is technically safe and feasible, with acceptable rates of morbidity and mortality. Nonetheless, long learning curves, low-volume hospitals, and surgical inexperience are associated with higher rates of complications and mortality.


Assuntos
Laparoscopia , Pancreaticoduodenectomia/métodos , Padrões de Prática Médica , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , China , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
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