274 results on '"Dong Feng Chen"'
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2. A Study on the Effect of Experience Value and Trust of Hotel Services on Hotel Revisit Intention: Focused on Chinese Hotels
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Mao-Bin Ding, Bing-Sen Zhao, Ni Bi-Yuan, Dong-Feng Chen, Young-Ha Kim, and Hyun-Jee Park
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- 2022
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3. A Study on Service Quality, Emotional Service Value, and Revisit Intention of Chinese Rural Tourism
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Bing-Sen Zhao, Mao-Bin Ding, Dong-Feng Chen, Bi-Yuan Ni, Young-Ha Kim, and Hyun-Jee Park
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- 2022
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4. Berberine blocks inflammasome activation and alleviates diabetic cardiomyopathy via the miR‑18a‑3p/Gsdmd pathway
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Lin Yang, Chun-Feng Cheng, Zhi-Fang Li, Xiao-Jing Huang, Shao-Qing Cai, Shan-Yu Ye, Li-Jun Zhao, Yi Xiong, Dong-Feng Chen, He-Lu Liu, Zhen-Xing Ren, and Hong-Cheng Fang
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Genetics ,General Medicine - Published
- 2023
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5. Aberrant RNA m6A modification in gastrointestinal malignancies: versatile regulators of cancer hallmarks and novel therapeutic opportunities
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Li-Ting Shen, Lin-Rong Che, Zongsheng He, Qian Lu, Dong-Feng Chen, Zhong-yi Qin, and Bin Wang
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Cancer Research ,Cellular and Molecular Neuroscience ,Immunology ,Cell Biology - Abstract
Gastrointestinal (GI) cancer is one of the most common malignancies, and a leading cause of cancer-related death worldwide. However, molecular targeted therapies are still lacking, leading to poor treatment efficacies. As an important layer of epigenetic regulation, RNA N6-Methyladenosine (m6A) modification is recently linked to various biological hallmarks of cancer by orchestrating RNA metabolism, including RNA splicing, export, translation, and decay, which is partially involved in a novel biological process termed phase separation. Through these regulatory mechanisms, m6A dictates gene expression in a dynamic and reversible manner and may play oncogenic, tumor suppressive or context-dependent roles in GI tumorigenesis. Therefore, regulators and effectors of m6A, as well as their modified substrates, represent a novel class of molecular targets for cancer treatments. In this review, we comprehensively summarize recent advances in this field and highlight research findings that documented key roles of RNA m6A modification in governing hallmarks of GI cancers. From a historical perspective, milestone findings in m6A machinery are integrated with a timeline of developing m6A targeting compounds. These available chemical compounds, as well as other approaches that target core components of the RNA m6A pathway hold promises for clinical translational to treat human GI cancers. Further investigation on several outstanding issues, e.g. how oncogenic insults may disrupt m6A homeostasis, and how m6A modification impacts on the tumor microenvironment, may dissect novel mechanisms underlying human tumorigenesis and identifies next-generation anti-cancer therapeutics. more...
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- 2023
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6. Analysis of the Relationship Between Experiential Tourism Motive, Tourism Satisfaction, and Revisit Intention of Visitors to Sichuan Panda National Park: Using Prior Knowledge as a Moderating Variable
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Mao-Bin Ding, Dong-Feng Chen, Bi-Yuan Ni, Bing-Sen Zhao, and Youngha Kim
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- 2022
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7. Investigation of Interfacial Microstructures of TiN/AlN Multilayers by Neutron Reflectometry
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Rong Deng Liu, Yun Tao Liu, Tian Fu Li, Li Zhang, Zi Jun Wang, Kai Sun, and Dong Feng Chen
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Mechanics of Materials ,Mechanical Engineering ,General Materials Science ,Condensed Matter Physics - Abstract
Three alternate TiN/AlN nanostructured multilayers with the TiN layer thicknesses of 60, 70, and 120 Å and the AlN layer thickness of 10 Å were fabricated using dc reactive magnetron sputtering. Microstructural characterizations of the three nano-scale films were performed using nonpolarized specular neutron reflectometry. The results showed that the three TiN/AlN multilayer thin films were typical superlattice films and the thicknesses of the TiN layer and AlN layer in the multilayers were consistent with the design thickness nearly. The interface roughness was asymmetric in all the samples. The interface of AlN growing on TiN was much sharper than that of TiN growing on AlN and the latter was the diffusion interface in the TiN/AlN multilayer films. more...
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- 2022
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8. The Prevalence of Autoimmune Diseases in Patients with Primary Open-Angle Glaucoma Undergoing Ophthalmic Surgeries
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Kin-Sang Cho, Lucy Q. Shen, Dong Feng Chen, Eleftherios I. Paschalis, Rafaella Nascimento e Silva, Julia Devlin, David Sola-Del Valle, Milica A. Margeta, Maltish M. Lorenzo, Roberto Pineda, Louis R. Pasquale, Sherleen H. Chen, Joseph B. Ciolino, Courtney L. Ondeck, Chhavi Saini, and James Chodosh more...
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Intraocular pressure ,medicine.medical_specialty ,genetic structures ,business.industry ,medicine.medical_treatment ,Glaucoma ,Subgroup analysis ,General Medicine ,Odds ratio ,Cup-to-disc ratio ,Cataract surgery ,medicine.disease ,eye diseases ,Internal medicine ,Normal tension glaucoma ,Medicine ,sense organs ,business ,Body mass index - Abstract
Purpose To assess the prevalence of autoimmune disease (AiD) in patients with primary open-angle glaucoma (POAG) undergoing ophthalmic surgery. Design Retrospective, cross-sectional study. Participants Patients with POAG undergoing any ophthalmic surgery and control subjects undergoing cataract surgery at the Massachusetts Eye and Ear from March 2019 to April 2020. Methods All available medical records with patient demographics, ocular, and medical conditions were reviewed. Differences in AiD prevalence were assessed and adjusted for covariates using multiple logistic regression. Additionally, a subgroup analysis comparing the POAG patients with and without AiD was performed. Main Outcome Measures To assess the prevalence of AiD based on the American Autoimmune Related Diseases Association list. Results A total of 172 patients with POAG and 179 controls were included. The overall prevalence of AiD was 17.4% in the POAG group and 10.1% in the controls (P = 0.044); 6.4% of POAG patients and 3.4% of controls had more than 1 AiD (P = 0.18). The most prevalent AiDs in POAG group were rheumatoid arthritis (4.6%) and psoriasis (4.1%), which were also the most common in controls (2.8% each). In a fully adjusted multiple logistic regression analysis accounting for steroid use, having an AiD was associated with 2.62-fold increased odds of POAG relative to controls (95% confidence interval, 1.27–5.36, P = 0.009); other risk factors for POAG derived from the analysis included age (odds ratio [OR], 1.04, P = 0.006), diabetes mellitus (OR, 2.31, P = 0.008), and non-White ethnicity (OR, 4.75, P 0.13, for both). Conclusions A higher prevalence of AiD was found in POAG patients compared with control patients undergoing ophthalmic surgery. The presence of AiD was associated with increased risk for POAG after adjusting for covariates. Additional factors may have prevented a difference in RNFL thickness in POAG patients with and without AiD. Autoimmunity should be explored further in the pathogenesis of POAG. more...
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- 2022
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9. Proteomic profiling identifies CLEC4C expression as a novel biomarker of primary graft dysfunction after heart transplantation
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Carmelo A. Milano, Chetan B. Patel, Christopher L. Holley, Dawn E. Bowles, Lydia Coulter Kwee, Richa Agarwal, Dong-Feng Chen, Adam D. DeVore, Lauren K. Truby, Jacob N. Schroder, Svati H. Shah, and Elizabeth Grass more...
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Male ,Proteomics ,Pulmonary and Respiratory Medicine ,Oncology ,medicine.medical_specialty ,medicine.medical_treatment ,Primary Graft Dysfunction ,Sensitivity and Specificity ,Article ,chemistry.chemical_compound ,Postoperative Complications ,Internal medicine ,Humans ,Medicine ,Lectins, C-Type ,Receptors, Immunologic ,Aged ,Aged, 80 and over ,Heart transplantation ,Transplantation ,Creatinine ,Membrane Glycoproteins ,business.industry ,Middle Aged ,Pathophysiology ,chemistry ,Heart Transplantation ,Biomarker (medicine) ,Population study ,Female ,Surgery ,Cardiomyopathies ,Cardiology and Cardiovascular Medicine ,Complication ,business ,Biomarkers - Abstract
PURPOSE: Clinical models to identify patients at high risk of primary graft dysfunction (PGD) after heart transplantation (HT) are limited, and the underlying pathophysiology of this common post-transplant complication remains poorly understood. We sought to identify whether pre-transplant levels of circulating proteins reporting on immune activation and inflammation are associated with incident PGD. METHODS: The study population consisted of 219 adult heart transplant recipients identified between 2016 and 2020 at Duke University Medical Center, randomly divided into derivation (n = 131) and validation (n = 88) sets. PGD was defined using modified ISHLT criteria. Proteomic profiling was performed using Olink panels (n = 354 proteins) with serum samples collected immediately prior to transplantation. Association between normalized relative protein expression and PGD was tested using univariate and multivariable (recipient age, creatinine, mechanical circulatory support, and sex; donor age; ischemic time) models. Significant proteins identified in the derivation set (p < 0.05 in univariate models), were then tested in the validation set. Pathway enrichment analysis was used to test candidate biological processes. The predictive performance of proteins was compared to that of the RADIAL score. RESULTS: Nine proteins were associated with PGD in univariate models in the derivation set. Of these, only CLEC4C remained associated with PGD in the validation set after Bonferroni correction (OR [95% CI] = 3.04 [1.74,5.82], p = 2.8×10(−4)). Patterns of association were consistent for CLEC4C in analyses stratified by biventricular/left ventricular and isolated right ventricular PGD. Pathway analysis identified interferon-alpha response and C-type lectin signaling as significantly enriched biologic processes. The RADIAL score was a poor predictor of PGD (AUC = 0.55). CLEC4C alone (AUC = 0.66, p = 0.048) and in combination with the clinical covariates from the multivariable model (AUC = 0.69, p = 0.018) improved discrimination for the primary outcome. CONCLUSIONS: Pre-transplantation circulating levels of CLEC4C, a protein marker of plasmacytoid dendritic cells (pDCs), may identify HT recipients at risk for PGD. Further studies are needed to better understand the potential role pDCs and the innate immune response in PGD. more...
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- 2021
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10. High-dose dual therapy
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Zhe, Zhao, Pei-Ying, Zou, Na-Yun, Su, Yan, Guo, Xing-Wei, Wang, Jing-Tao, Zhao, Hao, Mei, Qing, Shi, Bin, Wang, Dong-Feng, Chen, and Chun-Hui, Lan
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Although the Maastricht VI/Florence consensus report recommended high-dose proton pump inhibitor-amoxicillin dual therapy as possible rescue therapy forTo compare the efficacy, safety, patient compliance, and cost between high-dose dual therapy (HDDT) and culture-based susceptibility-guided therapy (CB-SGT) as a rescue regimen forA single-center, open-label, randomized controlled clinical trial.In all, 146 patients with a history of eradication failure were enrolled and randomly assigned to receive HDDT or CB-SGT. HDDT consisted of esomeprazole 20 mg and amoxicillin 750 mg, both given four times per day (qid). CB-SGT consisted of esomeprazole 20 mg twice daily (bid), amoxicillin 1000 mg bid plus clarithromycin 500 mg bid, metronidazole 400 mg bid, or levofloxacin 500 mg daily (qd) for sensitive patients, in that order. For patients with triple resistance, a bismuth-containing regimen with a high dose of metronidazole was chosen, including esomeprazole 20 mg bid, bismuth 220 mg bid, amoxicillin 1000 mg bid, and metronidazole 400 mg qid. All regimens were given for 14 days.The eradicationHDDT can reach an eradication rate of 85% in treatment-experienced patients ofThis clinical trial was registered at the Chinese Clinical Trail Registry (trail registration number: ChiCTR1900025044). more...
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- 2022
11. Association between HSP-Specific T-Cell Counts and Retinal Nerve Fiber Layer Thickness in Patients with Primary Open-Angle Glaucoma
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Chhavi Saini, Shuhong Jiang, Julia Devlin, Li Pan, Yizhen Tang, Jing Tang, Jessica A. Sun, Maltish M. Lorenzo, Qingyi Wang, Louis R. Pasquale, Kin-Sang Cho, Dong Feng Chen, and Lucy Q. Shen
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General Medicine - Published
- 2023
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12. Epigenetic Regulation of Optic Nerve Development, Protection, and Repair
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Ajay Ashok, Sarita Pooranawattanakul, Wai Lydia Tai, Kin-Sang Cho, Tor P. Utheim, Dean M. Cestari, and Dong Feng Chen
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Organic Chemistry ,Optic Nerve ,General Medicine ,Catalysis ,Axons ,Computer Science Applications ,Epigenesis, Genetic ,Nerve Regeneration ,Inorganic Chemistry ,Oligodendroglia ,Physical and Theoretical Chemistry ,Molecular Biology ,Spectroscopy ,Myelin Sheath - Abstract
Epigenetic factors are known to influence tissue development, functionality, and their response to pathophysiology. This review will focus on different types of epigenetic regulators and their associated molecular apparatus that affect the optic nerve. A comprehensive understanding of epigenetic regulation in optic nerve development and homeostasis will help us unravel novel molecular pathways and pave the way to design blueprints for effective therapeutics to address optic nerve protection, repair, and regeneration. more...
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- 2022
13. Analysis on the Relationships among Characteristics of Choosing Tourism Destination, Image of Tourist Destination, Tourism Satisfaction and Revisit Intention: Focused on Domestic Tourists in China
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Dong-Feng Chen and HyunJee Park
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Business ,Marketing ,Destination image ,China ,Tourism - Published
- 2021
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14. Metabolomics in Primary Open Angle Glaucoma: A Systematic Review and Meta-Analysis
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Yizhen Tang, Simran Shah, Kin-Sang Cho, Xinghuai Sun, and Dong Feng Chen
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General Neuroscience - Abstract
Glaucoma is a leading cause of blindness worldwide. It is suggested that primary open angle glaucoma (POAG), the most common form of glaucoma, may be associated with significant metabolic alternations, but the systemic literature review and meta-analysis in the area have been missing. Altered metabolomic profiles in the aqueous humor and plasma may serve as possible biomarkers for early detection or treatment targets. In this article, we performed a systematic meta-analysis of the current literature surrounding the metabolomics of patients with POAG and metabolites associated with the disease. Results suggest several metabolites found to be specifically altered in patients with POAG, suggesting broad generalizability and pathways for future research. more...
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- 2022
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15. Relationship Analysis of Tourism Social Media Marketing Attributes on Tourism Commitment, Tourism Image, Tourism Satisfaction, Reuse Intention: Targeting Chinese Visitors to Korea
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Dong-Feng Chen and HyunJee Park
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Relationship analysis ,Business ,Reuse ,Marketing ,Tourism ,Social media marketing - Published
- 2020
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16. Increased Calculated Panel Reactive Antigen Is Associated With Increased Waitlist Time and Mortality in Lung Transplantation
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Dong-Feng Chen, Jacob A. Klapper, Mani A. Daneshmand, Michael S. Mulvihill, Matthew G. Hartwig, Yaron D. Barac, Basil S. Nasir, Carmelo A. Milano, Oliver K. Jawitz, and John C. Haney
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Pulmonary and Respiratory Medicine ,United Network for Organ Sharing ,medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,Hazard ratio ,030204 cardiovascular system & hematology ,Confidence interval ,Organ transplantation ,Transplantation ,03 medical and health sciences ,Organ procurement ,0302 clinical medicine ,030228 respiratory system ,Antigen ,Internal medicine ,Medicine ,Lung transplantation ,Surgery ,Cardiology and Cardiovascular Medicine ,business - Abstract
Background Sensitized candidates with unacceptable antigens are a group that demands special attention in organ transplantation. Calculated panel reactive antigen (cPRA) is not used to modify allocation priorities in lung transplantation. The impact of cPRA on waiting list time and mortality is unknown. Methods We performed a retrospective review of candidates for lung transplantation listed from May 2005 to 2018. Data from the Organ Procurement and Transplantation Network/United Network for Organ Sharing STAR (Standard Analysis and Research) dataset was paired with additional unacceptable human leukocyte antigen (UA-HLA) data, which were used to calculate the listing cPRA. Candidates were stratified based on the lack of UA-HLAs or cPRA level for candidates with unacceptable antigens reported. Unadjusted competing risks and adjusted subdistribution hazard models were fit. Results A total of 29,085 candidates met inclusion criteria for analysis. Of these, 23,562 (81%) with no UA-HLAs, 3472 (11.9%) with a cPRA less than 50, and 2051 with a cPRA greater than or equal to 50 (7.1%). On adjusted analysis, a cPRA greater than or equal to 50 was independently associated with increased waitlist mortality at 1 year (hazard ratio, 1.71; 95% confidence interval, 1.55-1.88; P Conclusions Further evaluation of organ allocation with consideration of a candidate's cPRA may be warranted in order to optimize equity in access to transplants. more...
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- 2020
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17. CD4+ T-Cell Responses Mediate Progressive Neurodegeneration in Experimental Ischemic Retinopathy
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Eric F. Thee, Li Pan, Nan Wu, Martine J. Jager, Elisa Arlotti, Thi Hong Khanh Vu, Djoeke Doesburg, Huihui Chen, Kin-Sang Cho, and Dong Feng Chen
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0301 basic medicine ,Retina ,Pathology ,medicine.medical_specialty ,business.industry ,Central nervous system ,Ischemia ,Retinal ,medicine.disease ,Pathology and Forensic Medicine ,Pathogenesis ,Optic neuropathy ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,0302 clinical medicine ,medicine.anatomical_structure ,Retinal ganglion cell ,chemistry ,medicine ,Neuron ,business ,030217 neurology & neurosurgery - Abstract
Retinal ischemic events, which result from occlusion of the ocular vasculature share similar causes as those for central nervous system stroke and are among the most common cause of acute and irreversible vision loss in elderly patients. Currently, there is no established treatment, and the condition often leaves patients with seriously impaired vision or blindness. The immune system, particularly T-cell- mediated responses, is thought to be intricately involved, but the exact roles remain elusive. We found that acute ischemia-reperfusion injury to the retina induced a prolonged phase of retinal ganglion cell loss that continued to progress during 8 weeks after the procedure. This phase was accompanied by microglial activation and CD4+ T-cell infiltration into the retina. Adoptive transfer of CD4+ T cells isolated from diseased mice exacerbated retinal ganglion cell loss in mice with retinal reperfusion damage. On the other hand, T-cell deficiency or administration of T-cell or interferon-gamma-neutralizing antibody attenuated retinal ganglion cell degeneration and retinal function loss after injury. These findings demonstrate a crucial role for T-cell-mediated responses in the pathogenesis of neural ischemia. These findings point to novel therapeutic targets of limiting or preventing neuron and function loss for currently untreatable conditions of optic neuropathy and/or central nervous system ischemic stroke. more...
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- 2020
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18. Apolipoprotein E4 impairs the response of neurodegenerative retinal microglia and prevents neuronal loss in glaucoma
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Milica A. Margeta, Zhuoran Yin, Charlotte Madore, Kristen M. Pitts, Sophia M. Letcher, Jing Tang, Shuhong Jiang, Christian D. Gauthier, Sebastian R. Silveira, Caitlin M. Schroeder, Eleonora M. Lad, Alan D. Proia, Rudolph E. Tanzi, David M. Holtzman, Susanne Krasemann, Dong Feng Chen, and Oleg Butovsky more...
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Disease Models, Animal ,Mice ,Infectious Diseases ,Apolipoproteins E ,Galectin 3 ,Immunology ,Apolipoprotein E4 ,Immunology and Allergy ,Animals ,Humans ,Glaucoma ,Microglia - Abstract
The apolipoprotein E4 (APOE4) allele is associated with an increased risk of Alzheimer disease and a decreased risk of glaucoma, but the underlying mechanisms remain poorly understood. Here, we found that in two mouse glaucoma models, microglia transitioned to a neurodegenerative phenotype characterized by upregulation of Apoe and Lgals3 (Galectin-3), which were also upregulated in human glaucomatous retinas. Mice with targeted deletion of Apoe in microglia or carrying the human APOE4 allele were protected from retinal ganglion cell (RGC) loss, despite elevated intraocular pressure (IOP). Similarly to Apoe more...
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- 2021
19. Layered Co/Ni-free Mn-rich oxide P2-Na2/3Mn0.8Fe0.1Mg0.1O2 as high-performance cathode material for sodium-ion batteries
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Liu Xiaolong, Kai Sun, Dong-Feng Chen, Li Yuqing, Li Meijuan, Wu Meimei, Han Songbai, Linfeng He, Zheng-Yao Li, and Yun-Tao Liu
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Diffraction ,Materials science ,Ionic radius ,General Chemical Engineering ,Sodium ,Doping ,General Engineering ,Oxide ,General Physics and Astronomy ,chemistry.chemical_element ,02 engineering and technology ,Crystal structure ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,Energy storage ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,General Materials Science ,0210 nano-technology - Abstract
In this work, the Co/Ni-free Na2/3Mn0.8Fe0.1Mg0.1O2 has been synthesized and investigated as low-cost and high–Mn content layered oxide cathode material for sodium-ion batteries by x-ray diffraction and electrochemical techniques. Due to a larger ionic size of Mg2+ than of Fe3+, the lattice parameters a and c both increase and the Mg2+ doping results in an expanded space for sodium-ion diffusion with the improved diffusion coefficient of sodium ion compared with Na2/3Mn0.8Fe0.2O2. Na2/3Mn0.8Fe0.1Mg0.1O2 delivers a high initial discharge capacity of 168 mAh g−1, and great rate capabilities of 102, 80, and 55 mAh g−1 at high rates of 2 C, 5 C, and 10 C. Mg2+ doping also can alleviate the Jahn-Teller effect by Mn3+ and stabilize the crystal structure, thus enhancing the cyclic stability of Na2/3Mn0.8Fe0.1Ti0.1O2 with about 90% capacity retention at 0.1 C. Electrochemical inactive and low-cost Mg-ion doping is an effective approach to improve the layered oxide cathode materials for sodium-ion batteries. more...
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- 2019
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20. Daratumumab in Sensitized Kidney Transplantation: Potentials and Limitations of Experimental and Clinical Use
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Thibault Damy, Karim Belhadj, Brian Ezekian, Chantal Gautreau, Jaeberm Park, Vincent Audard, David Kheav, Jean Kwun, Marie Matignon, Bradley H. Collins, John S. Yi, Stuart J. Knechtle, Diane Bodez, Janghoon Yoon, Dong-Feng Chen, Alton B. Farris, Elsa Poullot, Philippe Grimbert, Mark D. Stegall, Miriam Manook, Laureline Faivre, Alyssa M. Bilewski, Dehbia Menouch, and Soulef Guendouz more...
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Adult ,Graft Rejection ,Male ,0301 basic medicine ,Benzylamines ,medicine.medical_specialty ,medicine.drug_class ,Urology ,030230 surgery ,Plasma cell ,CD38 ,Cyclams ,Monoclonal antibody ,T-Lymphocytes, Regulatory ,03 medical and health sciences ,0302 clinical medicine ,HLA Antigens ,Heterocyclic Compounds ,Isoantibodies ,Animals ,Humans ,Medicine ,Kidney transplantation ,biology ,business.industry ,Plerixafor ,Antibody-Dependent Cell Cytotoxicity ,Antibodies, Monoclonal ,Daratumumab ,General Medicine ,medicine.disease ,ADP-ribosyl Cyclase 1 ,Kidney Transplantation ,Macaca mulatta ,Transplantation ,Basic Research ,030104 developmental biology ,medicine.anatomical_structure ,Nephrology ,biology.protein ,Antibody ,business ,medicine.drug - Abstract
BACKGROUND: Donor-specific antibodies are associated with increased risk of antibody-mediated rejection and decreased allograft survival. Therefore, reducing the risk of these antibodies remains a clinical need in transplantation. Plasma cells are a logical target of therapy given their critical role in antibody production. METHODS: To target plasma cells, we treated sensitized rhesus macaques with daratumumab (anti-CD38 mAb). Before transplant, we sensitized eight macaques with two sequential skin grafts from MHC-mismatched donors; four of them were also desensitized with daratumumab and plerixafor (anti-CXCR4). We also treated two patients with daratumumab in the context of transplant. RESULTS: The animals treated with daratumumab had significantly reduced donor-specific antibody levels compared with untreated controls (57.9% versus 13% reduction; P more...
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- 2019
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21. Analysis of Dimer Impurity in Polyamidoamine Dendrimer Solutions by Small-angle Neutron Scattering
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Han Wenze, Liu Rongdeng, Chunming Yang, Daniel Clemens, Dong-Feng Chen, Uwe Keiderling, Yiyun Cheng, Hui Wang, Wang Zijun, Charl J. Jafta, Yu Wang, Yun-Tao Liu, Tian-Fu Li, and Li Zhang
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Quantitative Biology::Biomolecules ,010407 polymers ,Materials science ,Polymers and Plastics ,Scattering ,General Chemical Engineering ,Dimer ,Organic Chemistry ,Neutron scattering ,01 natural sciences ,Small-angle neutron scattering ,0104 chemical sciences ,Condensed Matter::Soft Condensed Matter ,chemistry.chemical_compound ,Monomer ,chemistry ,Impurity ,Dendrimer ,Indirect Fourier transform ,Physical chemistry ,Condensed Matter::Strongly Correlated Electrons - Abstract
Dimer impurity in the solution of a generation five (G5) polyamidoamine (PAMAM) dendrimer has been investigated by small-angle neutron scattering (SANS). The existence of dimer impurity in dendrimer solution was evidenced by indirect Fourier transform (IFT) analysis of the SANS data, in which the maximum dimension of particles in solution was found to be about twice the diameter of G5 dendrimer. We then developed an analytical model which accounts for the scattering contribution from both dendrimer monomer and dimer. The experimental data were well fitted by using the established model. The results showed that the amount of dimer impurities is significant for the measured three batches of G5 PAMAM dendrimers. more...
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- 2019
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22. Non-invasive electrical stimulation as a potential treatment for retinal degenerative diseases
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Sam Enayati, Dong Feng Chen, Tor Paaske Utheim, Karen Chang, and Kin-Sang Cho
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Pathology ,medicine.medical_specialty ,business.industry ,Non invasive ,Retinal ,Stimulation ,lcsh:RC346-429 ,chemistry.chemical_compound ,Developmental Neuroscience ,chemistry ,Perspective ,medicine ,business ,lcsh:Neurology. Diseases of the nervous system - Published
- 2021
23. Pilot Allocation Scheme Based on Machine Learning Algorithm and Users’ Angle of Arrival in Massive MIMO System
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Si Yuan Li, Dong Feng Chen, and Min Yu
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Scheme (programming language) ,Computer science ,business.industry ,05 social sciences ,MIMO ,k-means clustering ,050801 communication & media studies ,Machine learning ,computer.software_genre ,0508 media and communications ,System capacity ,Angle of arrival ,0502 economics and business ,Overhead (computing) ,050211 marketing ,Artificial intelligence ,Antenna (radio) ,business ,computer ,Algorithm ,computer.programming_language - Abstract
Massive MIMO system has attracted attention due to it’s significant improvement in system capacity and spectrum utilization. Pilot pollution greatly limited the performance of Massive MIMO system. To optimize the pilot pollution in Massive MIMO system. In this paper, a pilot allocation scheme based on machine learning algorithm and users’ angle of arrival is proposed. The scheme firstly classified all users according to whether the users’ angle of arrival overlaps with each other. It randomly assigned pilot sequences to users whose angle of arrival do not overlap with each other. Secondly, it used machine learning algorithm to classify users whose angle of arrival overlap with each other into interfering group and non-interfering groups based on users’ location information. We assign orthogonal pilots to users in the interfering group and randomly assign pilot sequences to users in the non-interfering group. Simulation results show that when the number of antenna reached 300, the pilot efficiency can be increased by about 11.67%. The pilot allocation scheme proposed in this paper can effectively suppress the impact of pilot pollution on the performance of Massive MIMO system, improve pilot efficiency and reduce pilot overhead. more...
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- 2021
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24. Study on Bulk Texture and Mechanical Properties of As-Extruded Wide Mg-Al-Zn Alloy Sheets with Different Al Addition
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Yu-Qing Li, Da-Ye Xu, Min Zha, Dong-Feng Chen, Yun-Tao Liu, Mei-Juan Li, Kai Sun, Gui-Jie Zhu, Si-Qing Wang, Tong Wang, Jian-Bo Gao, and Xiao-Long Liu
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wide magnesium alloy sheets ,extrusion ,microstructure ,bulk texture ,mechanical properties ,General Materials Science - Abstract
The wide Mg alloy sheets produced by hot extrusion usually can easily form an inhomogeneous texture, resulting in anisotropic mechanical properties and poor formability. However, few studies have been carried out on the bulk texture investigation at different areas of as-extruded Mg alloy sheets, especially the Mg alloys with different alloying elements. In this work, the effect of Al on the bulk texture and mechanical properties at different areas for three wide Mg-Al-Zn alloy sheets with different Al contents (Mg-3Al-0.5Zn, Mg-8Al-0.5Zn and Mg-9Al-0.5Zn) are mainly investigated by neutron diffraction. The results showed that a strong and uneven basal texture was formed in the Mg-3Al-0.5Zn sheet. Meanwhile, the intensity of the basal texture was significantly weakened due to the numerous fine precipitates of Mg17Al12 particles, with the Al content increasing, which hinder the grain growth during extrusion, while fine recrystallized grains have a more random orientation. The enhanced tensile properties in Mg-8Al-0.5Zn and Mg-9Al-0.5Zn alloy sheets are ascribed to the cooperation effect of a refined microstructure, precipitates and weakened basal texture. Among the three Mg alloy sheets, the Mg-8Al-0.5Zn alloy sheet has a yield strength of about 270 MPa, an ultimate tensile strength of about 330 MPa and ultimate elongation of about 16% in the extrusion direction, which possesses the most excellent comprehensive mechanical properties. more...
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- 2022
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25. NF-κB activation in retinal microglia is involved in the inflammatory and neovascularization signaling in laser-induced choroidal neovascularization in mice
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Anton Lennikov, Fumihito Hikage, Hu Huang, Tor Paaske Utheim, Dong Feng Chen, Anthony Mukwaya, Yosuke Ida, Hiroshi Ohguro, and Mieszko Lachota
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0301 basic medicine ,Angiogenesis ,Biology ,Retina ,Article ,Neovascularization ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,In vivo ,medicine ,Animals ,education ,Inflammation ,education.field_of_study ,Lasers ,NF-kappa B ,Cell Biology ,Molecular biology ,eye diseases ,Choroidal Neovascularization ,Vascular endothelial growth factor ,Mice, Inbred C57BL ,Microglial cell migration ,Disease Models, Animal ,030104 developmental biology ,Choroidal neovascularization ,chemistry ,Gene Expression Regulation ,030220 oncology & carcinogenesis ,Allograft inflammatory factor 1 ,I-kappa B Proteins ,sense organs ,Microglia ,medicine.symptom ,Ex vivo - Abstract
Purpose To evaluate Nuclear Factor NF-κB (NF-κB) signaling on microglia activation, migration, and angiogenesis in laser-induced choroidal neovascularization (CNV). Methods Nine-week-old C57BL/6 male mice were randomly assigned to IMD-0354 treated or untreated groups (5 mice, 10 eyes per group). CNV was induced with a 532-nm laser. Laser spots (power 250 mW, spot size 100 μm, time of exposure 50 ms) were created in each eye using a slit-lamp delivery system. Selective inhibitor of nuclear factor kappa-B kinase subunit beta (IKK2) inhibitor IMD-0354 (10 μg) was delivered subconjunctivally; vehicle-treated mice were the control. The treatment effect on CNV development was assessed at five days post-CNV induction in vivo in C57BL/6 and Cx3cr1gfp/wt mice by fluorescent angiography, fundus imaging, and ex vivo by retinal flatmounts immunostaining and Western blot analysis of RPE/Choroidal/Scleral complexes (RCSC) lysates. In vitro evaluations of IMD-0354 effects were performed in the BV-2 microglial cell line using lipopolysaccharide (LPS) stimulation. Results IMD-0354 caused a significant reduction in the fluorescein leakage and size of the laser spot, as well as a reduction in microglial cell migration and suppression of phospho-IκBα, Vascular endothelial growth factor (VEGF-A), and Prostaglandin-endoperoxide synthase 2 (COX-2). In vivo and ex vivo observations demonstrated reduced lesion size in mice, CD68, and Allograft inflammatory factor 1 (IBA-1) positive microglia cells migration to the laser injury site in IMD-0354 treated eyes. The data further corroborate with GFP-positive cells infiltration of the CNV site in Cx3cr1wt/gfp mice. In vitro IMD-0354 (10–25 ng/ml) treatment reduced NF-κB activation, expression of COX-2, caused decreased Actin-F presence and organization, resulting in reduced BV-2 cells migration capacity. Conclusion The present data indicate that NF-κB activation in microglia and it's migration capacity is involved in the development of laser CNV in mice. Its suppression by NF-κB inhibition might be a promising therapeutic strategy for wet AMD. more...
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- 2020
26. The role of commensal microflora-induced T cell responses in glaucoma neurodegeneration
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Jing, Tang, Yizhen, Tang, Irvin, Yi, and Dong Feng, Chen
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T-Lymphocytes ,Blood-Retinal Barrier ,Nerve Degeneration ,Animals ,Humans ,Glaucoma ,Heat-Shock Proteins ,Retina ,Gastrointestinal Microbiome - Abstract
Over the last decade, new evidence has become increasingly more compelling that commensal microflora profoundly influences the maturation and function of resident immune cells in host physiology. The concept of gut-retina axis is actively being explored. Studies have revealed a critical role of commensal microbes linked with neuronal stress, immune responses, and neurodegeneration in the retina. Microbial dysbiosis changes the blood-retina barrier permeability and modulates T cell-mediated autoimmunity to contribute to the pathogenesis of retinal diseases, such as glaucoma. Heat shock proteins (HSPs), which are evolutionarily conserved, are thought to function both as neuroprotectant and pathogenic antigens of T cells contributing to cell protection and tissue damage, respectively. Activated microglia recruit and interact with T cells during this process. Glaucoma, characterized by the progressive loss of retinal ganglion cells, is the leading cause of irreversible blindness. With nearly 70 million people suffering glaucoma worldwide, which doubles the number of patients with Alzheimer's disease, it represents the most frequent neurodegenerative disease of the central nervous system (CNS). Thus, understanding the mechanism of neurodegeneration in glaucoma and its association with the function of commensal microflora may help unveil the secrets of many neurodegenerative disorders in the CNS and develop novel therapeutic interventions. more...
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- 2020
27. Author response: Mouse retinal cell behaviour in space and time using light sheet fluorescence microscopy
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Lena Claesson-Welsh, Lakshmi Venkaraman, Karen Chang, Kyle Harrington, Claudio A. Franco, Kin-Sang Cho, Mark Richards, Ana M. Figueiredo, Douglas S. Richardson, Parham Ashrafzadeh, Thomas Mead, Dong Feng Chen, Andreia Pena, Marie Ouarné, Ana Martins Russo, Claudia Prahst, and Katie Bentley more...
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Materials science ,Light sheet fluorescence microscopy ,Biophysics ,Retinal cell - Published
- 2020
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28. Primary Synchronization Signal Low Complexity Sliding Correlation Method
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Juan Li, Huahua Wang, and Dong Feng Chen
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Signal processing ,Computer science ,Computation ,05 social sciences ,Real-time computing ,Fast Fourier transform ,050801 communication & media studies ,Synchronization signal ,Synchronization ,Low complexity ,0508 media and communications ,0502 economics and business ,Baseband ,050211 marketing ,Correlation method - Abstract
With the development of technology, the mobile communication system has the characteristics of high rate and low delay. How to deal with the signal quickly and accurately has become a research hotspot. As the first step of the mobile communication system, the efficiency and performance of synchronization directly determine the follow-up signal Processing. In the mobile communication system, the terminal needs to synchronize the frequency and time of the received signal, that is, the synchronization signal is captured and processed. Frequency synchronization mainly carries on the digital down-conversion operation to the signal, the time synchronization is mainly through sliding the baseband signal with the locally generated synchronization sequence to determine the starting position of the synchronization signal, so as to achieve the time synchronization. Therefore, in this paper, taking LTE-A (Long Term Evolution Advanced) system as an example, a low-complexity sliding correlation method based on Fast Fourier Transform (FFT) is proposed in this paper, which can significantly reduce the computations in the synchronization process the complexity. more...
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- 2020
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29. The role of commensal microflora-induced T cell responses in glaucoma neurodegeneration
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Yizhen Tang, Dong Feng Chen, Irvin Yi, and Jing Tang
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Retina ,Microglia ,T cell ,Neurodegeneration ,Biology ,medicine.disease ,medicine.disease_cause ,Retinal ganglion ,Autoimmunity ,03 medical and health sciences ,0302 clinical medicine ,medicine.anatomical_structure ,Immune system ,Heat shock protein ,Immunology ,medicine ,sense organs ,030217 neurology & neurosurgery - Abstract
Over the last decade, new evidence has become increasingly more compelling that commensal microflora profoundly influences the maturation and function of resident immune cells in host physiology. The concept of gut-retina axis is actively being explored. Studies have revealed a critical role of commensal microbes linked with neuronal stress, immune responses, and neurodegeneration in the retina. Microbial dysbiosis changes the blood-retina barrier permeability and modulates T cell-mediated autoimmunity to contribute to the pathogenesis of retinal diseases, such as glaucoma. Heat shock proteins (HSPs), which are evolutionarily conserved, are thought to function both as neuroprotectant and pathogenic antigens of T cells contributing to cell protection and tissue damage, respectively. Activated microglia recruit and interact with T cells during this process. Glaucoma, characterized by the progressive loss of retinal ganglion cells, is the leading cause of irreversible blindness. With nearly 70 million people suffering glaucoma worldwide, which doubles the number of patients with Alzheimer's disease, it represents the most frequent neurodegenerative disease of the central nervous system (CNS). Thus, understanding the mechanism of neurodegeneration in glaucoma and its association with the function of commensal microflora may help unveil the secrets of many neurodegenerative disorders in the CNS and develop novel therapeutic interventions. more...
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- 2020
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30. High-dose dual therapy versus culture-based susceptibility-guided therapy as a rescue regimen for Helicobacter pylori infection: a randomized controlled trial
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Zhe Zhao, Pei-Ying Zou, Na-Yun Su, Yan Guo, Xing-Wei Wang, Jing-Tao Zhao, Hao Mei, Qing Shi, Bin Wang, Dong-Feng Chen, and Chun-Hui Lan
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Gastroenterology - Abstract
Background: Although the Maastricht VI/Florence consensus report recommended high-dose proton pump inhibitor–amoxicillin dual therapy as possible rescue therapy for Helicobacter pylori infection, clinical evidence of its efficacy was lacking. Objectives: To compare the efficacy, safety, patient compliance, and cost between high-dose dual therapy (HDDT) and culture-based susceptibility-guided therapy (CB-SGT) as a rescue regimen for H. pylori infection. Design: A single-center, open-label, randomized controlled clinical trial. Methods: In all, 146 patients with a history of eradication failure were enrolled and randomly assigned to receive HDDT or CB-SGT. HDDT consisted of esomeprazole 20 mg and amoxicillin 750 mg, both given four times per day (qid). CB-SGT consisted of esomeprazole 20 mg twice daily (bid), amoxicillin 1000 mg bid plus clarithromycin 500 mg bid, metronidazole 400 mg bid, or levofloxacin 500 mg daily (qd) for sensitive patients, in that order. For patients with triple resistance, a bismuth-containing regimen with a high dose of metronidazole was chosen, including esomeprazole 20 mg bid, bismuth 220 mg bid, amoxicillin 1000 mg bid, and metronidazole 400 mg qid. All regimens were given for 14 days. Results: The eradication H. pylori rates achieved with HDDT in the intention-to-treat (ITT), per-protocol, and modified ITT analyses were all 84.9% [62/73, 95% confidence interval (CI): 76.5–93.9%], compared with 83.6% (61/73, 95% CI: 74.9–92.3%), 84.7% (61/72, 95% CI: 76.2–93.2%), and 84.7% (61/72, 95% CI: 76.2–93.2%) with CB-SGT, respectively. For patients with CYP2C19 polymorphisms of intermediate/poor metabolizers, the eradication rates of HDDT and CB-SGT were 90.70% (39/43, 95% CI: 77.86–97.41%) and 84.21% (32/38, 95% CI: 68.75–93.98%), respectively. The difference between groups was 6.49% (95% CI: −8.00% to 20.97%), and the non-inferiority p value was 0.0128. For patients with a treatment interval of more than 3 months, the eradication rates of the two regimens reached 88.71% (95% CI: 78.11–95.34%) and 71.97% (95% CI: 70.02–90.64%). The difference between groups was 6.74% (95% CI: −5.71% to 19.20%), with a non-inferiority p value of 0.0042. Patient adherence was high in both groups. The HDDT had a lower cost and rate of side effects ( p Conclusions: HDDT can reach an eradication rate of 85% in treatment-experienced patients of H. pylori infection and 91% in patients with CYP2C19 polymorphisms of intermediate/poor metabolizers, with good compliance, lower side effects and costs, and less use of antibiotics. In conclusion, HDDT offers an effective rescue regimen for H. pylori infection. Registration: This clinical trial was registered at the Chinese Clinical Trail Registry (trail registration number: ChiCTR1900025044) more...
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- 2022
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31. De novo belatacept in clinical vascularized composite allotransplantation
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Guy G. Potter, Maria Angelica Selim, Mingqing Song, Gregory Ruskin, Linda C. Cendales, Dong-Feng Chen, Joshua Dooley, Daniel Dore, Adela R. Cardones, David S. Ruch, Allan D. Kirk, and Jonah P. Orr
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Graft Rejection ,Male ,0301 basic medicine ,medicine.medical_specialty ,medicine.medical_treatment ,Hand Transplantation ,Urology ,030230 surgery ,Belatacept ,Vascularized Composite Allotransplantation ,Abatacept ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,Immunology and Allergy ,Pharmacology (medical) ,Kidney transplantation ,Transplantation ,business.industry ,Graft Survival ,Immunosuppression ,Middle Aged ,medicine.disease ,Clinical trial ,Calcineurin ,Regimen ,030104 developmental biology ,business ,Immunosuppressive Agents ,Hand transplantation ,medicine.drug - Abstract
Most immunosuppressive regimens used in clinical vascularized composite allotransplantation (VCA) have been calcineurin inhibitor (CNI)-based. As such, most recipients have experienced CNI-related side effects. Costimulation blockade, specifically CD28/B7 inhibition with belatacept, has emerged as a clinical replacement for CNI-based immunosuppression in kidney transplantation. We have previously shown that belatacept can be used as a centerpiece immunosuppressant for VCA in nonhuman primates, and subsequently reported successful conversion from a CNI-based regimen to a belatacept-based regimen after clinical hand transplantation. We now report on the case of a hand transplant recipient, whom we have successfully treated with a de novo belatacept-based regimen, transitioned to a CNI-free regimen. This case demonstrates that belatacept can provide sufficient prophylaxis from rejection without chronic CNI-associated side effects, a particularly important goal in nonlifesaving solid organ transplants such as VCA. more...
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- 2018
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32. Neuroinflammation and microglia in glaucoma: time for a paradigm shift
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Dong Feng Chen, Kin-Sang Cho, Eric F. Thee, Xin Wei, and Martine J. Jager
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0301 basic medicine ,medicine.medical_specialty ,genetic structures ,Glaucoma ,Cell Communication ,Neuroprotection ,Article ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,0302 clinical medicine ,Normal tension glaucoma ,Ophthalmology ,medicine ,Animals ,Humans ,Neuroinflammation ,Inflammation ,Microglia ,business.industry ,Retinal Degeneration ,Neurodegeneration ,neurodegeneration ,medicine.disease ,eye diseases ,Disease Models, Animal ,030104 developmental biology ,medicine.anatomical_structure ,Retinal ganglion cell ,Astrocytes ,Nerve Degeneration ,Optic nerve ,sense organs ,business ,030217 neurology & neurosurgery ,Signal Transduction - Abstract
Glaucoma is a complex neurodegenerative disease with many clinical subtypes. Some of its rare forms include pigmentary glaucoma, uveitic glaucoma and congenital glaucoma. While they all share common features of progressive retinal ganglion cell (RGC) loss, optic nerve damage and corresponding visual field loss, the exact mechanisms underlying glaucomatous neuron loss are not clear. This has largely hindered the development of a real cure for this disease. Elevated intraocular pressure (IOP) is a known major risk factor of glaucoma; however, progressive degeneration of RGCs and axons can also be found in patients with a normal IOP, i.e., normal tension glaucoma (NTG). Interestingly, patients who carry the gain-of-function mutation of the pro-inflammatory gene TBK1 - tumor necrosis factor (TNF) receptor associated factor NF-κB activator (TANK) binding kinase 1 - are at increased risk to develop NTG. This finding suggests a causal link between neuroinflammatory processes and glaucoma. Various studies have reported the presence of neuroinflammatory responses by microglia, astrocytes and other blood-born immune cells in the optic nerve head (ONH) at early stages of experimental glaucoma. Inhibition of certain pro-inflammatory pathways, particularly those associated with microglial activation, appears to be neuroprotective. In this review, we will focus on the inflammatory responses, in particular the proposed roles of microglia, in the pathogenesis of glaucoma. more...
- Published
- 2018
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33. (+)-Cholesten-3-One Promotes Proliferation of Hair Follicle Stem Cells via Wnt/β-Catenin Pathway
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Xiang-Jun Li, Fengxue Zhang, Ai-Jun Liu, Dong-Feng Chen, Yuqiong Wu, Sai-Xia Zhang, Yi Tang, Jian-Hong Zhou, and Chun Li
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0301 basic medicine ,03 medical and health sciences ,030104 developmental biology ,Chemistry ,Catenin ,Biomedical Engineering ,Wnt signaling pathway ,Medicine (miscellaneous) ,Bioengineering ,Biotechnology ,Hair follicle stem ,Cell biology - Published
- 2018
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34. Rare cause of severe hematemesis due to IgG4-related gastric ulcer
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Dong-Feng Chen, Yu-Qin He, and Xin Fu
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medicine.medical_specialty ,Text mining ,business.industry ,Gastroenterology ,MEDLINE ,Medicine ,business ,Letter to the Editor ,Dermatology - Published
- 2019
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35. Human Leukocyte Antigen Sensitization in Solid Organ Transplantation: A Primer on Terminology, Testing, and Clinical Significance for the Apheresis Practitioner
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Laurie D. Snyder, Gowthami M. Arepally, Matthew J. Ellis, Dong-Feng Chen, Tereza Martinu, Alice L. Gray, Sarah Abbes, Oluwatoyosi A. Onwuemene, and Ara Metjian
- Subjects
Kidney ,education.field_of_study ,business.industry ,Population ,030232 urology & nephrology ,Context (language use) ,Human Leukocyte Antigen Sensitization ,Hematology ,Human leukocyte antigen ,030230 surgery ,Transplantation ,03 medical and health sciences ,surgical procedures, operative ,0302 clinical medicine ,medicine.anatomical_structure ,Apheresis ,Nephrology ,Immunology ,medicine ,Clinical significance ,education ,business - Abstract
The human leukocyte antigen (HLA) system is an important immunologic barrier that must be considered for successful solid organ transplantation. Formation of donor-specific HLA antibodies in solid organ transplantation is an important cause of allograft injury and may contribute to recipient morbidity and mortality. Therapeutic plasma exchange is often requested to lower HLA antibody levels prior to or after transplantation and for management of HLA antibodies in the context of organ rejection. In this review, we summarize the current terminology, laboratory testing, and clinical significance of HLA sensitization in the solid organ transplant population. Furthermore, to illustrate applications of HLA testing in clinical practice, we summarize our own lung and kidney institutional protocols for managing HLA antibodies in the peri-transplant setting. more...
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- 2017
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36. TNFα drives the proliferation and inflammatory response, but not regenerative potential of Müller cells in the mouse retina
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Lianglaing Niu, Yuan Fang, Xiaoqian Yao, Yi Zhang, Jihong Wu, Dong Feng Chen, and Xinghuai Sun
- Abstract
Background Mouse Müller cells, considered dormant retinal progenitors, respond to retinal injury by undergoing reactive gliosis rather than displaying regenerative responses. Tumor necrosis factor alpha (TNFα) is a key cytokine induced after injury, and implicated in mediating inflammatory and regenerative responses. However, the molecular events driving reactive gliosis and regenerative responses in Müller cells, and the role of TNFα in these processes, remain unclear. In this study, we investigated the effects of TNFα on Müller cell responses following injury. Methods To investigate the involvement of TNFα in retinal injury, adult C57BL/6J mice were subjected to treatment with light (5,000 lux) for 14 consecutive days; induction of TNFα was confirmed by quantitative polymerase chain reaction (qPCR). TNFα effects on Müller-cell proliferation were evaluated via 5-ethynyl-2’-deoxyuridine (EdU) incorporation in culture. TNFα-mediated gene profile changes were examined using Affymetrix microarray, and gene ontology analysis was carried out to define the molecular pathways involved. Gene- and protein-expression changes were further verified by qPCR, western blot, and enzyme linked immunosorbent assay (ELISA). Results We showed that TNFα induced Müller cell proliferation and the expression of inflammatory and proliferation-related genes, including NFKBIA, Leukemia inhibitory factor, Interleukin-6, Janus kinase (Jak) 1, Jak2, Signal transducer and activator of transcription (Stat) 1, Stat2, Mitogen-Activated Protein Kinase (MAPK) 7, and MAP4K4. Blockade of Jak/Stat and MAPK pathways attenuated TNFα-induced Müller cell proliferation. Moreover, we detected TNFα drove A1 phenotype-reactive gliosis, while Wnt attenuated TNFα-mediated induction of A1 phenotype and promoted an A2-like phenotype. Conclusion In Müller cells, TNFα triggered primarily inflammatory and reactive gliosis by activating Jak/Stat and MAPK-pathways without inducing progenitor cell/regeneration-related genes. Wnt signaling suppressed inflammation, and induced proliferation and expression of progenitor-cell genes in Müller cells. These results suggest that reactive gliosis and regenerative responses in Müller cells are regulated by independent mechanisms. Our study provides new insights into regulation of inflammatory and regenerative responses of Müller cells in the injured retina more...
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- 2019
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37. A comparison of the use of adipose-derived and bone marrow-derived stem cells for peripheral nerve regeneration in vitro and in vivo
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Li Na Zhou, Jia Chuan Wang, Prince Last Mudenda Zilundu, Ya Qiong Wang, Wen Ping Guo, Sai Xia Zhang, Hui Luo, Jian Hong Zhou, Ru Dong Deng, and Dong Feng Chen
- Subjects
Adipose-derived stem cells ,Pathology ,medicine.medical_specialty ,Peripheral nerve repair ,Medicine (miscellaneous) ,Adipose tissue ,Biochemistry, Genetics and Molecular Biology (miscellaneous) ,lcsh:Biochemistry ,Rats, Sprague-Dawley ,Bone Marrow ,medicine ,Animals ,lcsh:QD415-436 ,Schwann cells ,Chemically extracted acellular nerve allograft ,Cells, Cultured ,Bone marrow-derived stem cells ,lcsh:R5-920 ,Nerve allograft ,business.industry ,Regeneration (biology) ,Stem Cells ,Research ,Mesenchymal stem cell ,Cell Biology ,Sciatic nerve injury ,medicine.disease ,Sciatic Nerve ,Axons ,Nerve Regeneration ,Rats ,medicine.anatomical_structure ,Adipose Tissue ,Molecular Medicine ,Bone marrow ,Sciatic nerve ,Stem cell ,Co-culture ,lcsh:Medicine (General) ,business - Abstract
Background To date, it has repeatedly been demonstrated that infusing bone marrow-derived stem cells (BMSCs) into acellular nerve scaffolds can promote and support axon regeneration through a peripheral nerve defect. However, harvesting BMSCs is an invasive and painful process fraught with a low cellular yield. Methods In pursuit of alternative stem cell sources, we isolated stem cells from the inguinal subcutaneous adipose tissue of adult Sprague–Dawley rats (adipose-derived stem cells, ADSCs). We used a co-culture system that allows isolated adult mesenchymal stem cells (MSCs) and Schwann cells (SCs) to grow in the same culture medium but without direct cellular contact. We verified SC phenotype in vitro by cell marker analysis and used red fluorescent protein-tagged ADSCs to detect their fate after being injected into a chemically extracted acellular nerve allograft (CEANA). To compare the regenerative effects of CEANA containing either BMSCs or ADSCs with an autograft and CEANA only on the sciatic nerve defect in vivo, we performed histological and functional assessments up to 16 weeks after grafting. Results In vitro, we observed reciprocal beneficial effects of ADSCs and SCs in the ADSC–SC co-culture system. Moreover, ADSCs were able to survive in CEANA for 5 days after in vitro implantation. Sixteen weeks after grafting, all results consistently showed that CEANA infused with BMSCs or ADSCs enhanced injured sciatic nerve repair compared to the acellular CEANA-only treatment. Furthermore, their beneficial effects on sciatic injury regeneration were comparable as histological and functional parameters evaluated showed no statistically significant differences. However, the autograft group was roundly superior to both the BMSC- or ADSC-loaded CEANA groups. Conclusion The results of the present study show that ADSCs are a viable alternative stem cell source for treating sciatic nerve injury in lieu of BMSCs. more...
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- 2019
38. Small intestinal bacterial overgrowth is associated with Diarrhea-predominant irritable bowel syndrome by increasing mainly
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Kang-Qi, Wu, Wen-Jing, Sun, Ning, Li, Yu-Qin, Chen, Yan-Ling, Wei, and Dong-Feng, Chen
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Adult ,Diarrhea ,Male ,China ,Prevotella ,Irritable Bowel Syndrome ,Feces ,Breath Tests ,Intestine, Small ,Bacteroidaceae Infections ,Prevalence ,Dysbiosis ,Humans ,Female ,Correlation of Data - Published
- 2019
39. Integrin alpha 7 correlates with poor clinical outcomes, and it regulates cell proliferation, apoptosis and stemness via PTK2-PI3K-Akt signaling pathway in hepatocellular carcinoma
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Jun-Chen Ge, Zhi-Biao Chen, Dong-Feng Chen, and Yu-Xi Wang
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0301 basic medicine ,Male ,Carcinoma, Hepatocellular ,Cell ,Apoptosis ,Biology ,03 medical and health sciences ,Phosphatidylinositol 3-Kinases ,0302 clinical medicine ,Antigens, CD ,Cell Line, Tumor ,medicine ,Biomarkers, Tumor ,Humans ,Protein kinase B ,PI3K/AKT/mTOR pathway ,Aged ,Cell Proliferation ,Cell growth ,CD44 ,Liver Neoplasms ,Cell Biology ,Middle Aged ,Hep G2 ,Gene Expression Regulation, Neoplastic ,030104 developmental biology ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,Focal Adhesion Kinase 1 ,biology.protein ,Cancer research ,Female ,Signal transduction ,Integrin alpha Chains ,Proto-Oncogene Proteins c-akt ,Signal Transduction - Abstract
This study aimed to evaluate the correlation of integrin alpha 7 (ITGA7) with clinical outcomes and its effect on cell activities as well as stemness in hepatocellular carcinoma (HCC). HCC tumor tissues and paired adjacent tissues from 90 HCC patients were obtained and ITGA7 expression was detected using immunohistochemistry assay. Cellular experiments were conducted to examine the effect of ITGA7 on cell activities, astemness via ITGA7 ShRNA transfection, and compensation experiments were further performed to test whether ITGA7 functioned via regulating PTK2-PI3K-AKT signaling pathway. ITGA7 was overexpressed in tumor tissues compared with paired adjacent tissues and its high expression was correlated with larger tumor size, vein invasion and advanced Barcelona Clinic Liver Cancer stage, and it also independently predicted worse overall survival in HCC patients. In cellular experiments, ITGA7 was upregulated in SMMC-7721, Hep G2, HuH-7 and BEL-7404 cell lines compared with normal human liver cells HL-7702. ITGA7 knockdown suppressed cell proliferation but promoted apoptosis, and it also downregulated CSCs markers (CD44, CD133 and OCT-4) as well as PTK2, PI3K and AKT expressions in SMMC-7721 and Hep G2 cell lines. ITGA7 overexpression promoted cell proliferation but inhibited apoptosis, and it also upregulated CSCs markers in HL-7702 cells. Further compensation experiments verified that ITGA7 regulated cell proliferation, apoptosis and CSCs markers via PTK2-PI3K-Akt signaling pathway. ITGA7 negatively associates with clinical outcomes in HCC patients, and it regulates cell proliferation, apoptosis and CSCs markers via PTK2-PI3K-Akt signaling pathway. more...
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- 2019
40. CD4
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Thi Hong, Khanh Vu, Huihui, Chen, Li, Pan, Kin-Sang, Cho, Djoeke, Doesburg, Eric F, Thee, Nan, Wu, Elisa, Arlotti, Martine J, Jager, and Dong Feng, Chen
- Subjects
CD4-Positive T-Lymphocytes ,Retinal Ganglion Cells ,Disease Models, Animal ,Mice ,Retinal Diseases ,Ischemia ,Retinal Degeneration ,Disease Progression ,Animals ,Retinal Vessels ,Adoptive Transfer ,Retina ,Article - Abstract
Retinal ischemic events, which result from occlusion of the ocular vasculature share similar causes as those for central nervous system stroke and are among the most common cause of acute and irreversible vision loss in elderly patients. Currently, there is no established treatment, and the condition often leaves patients with seriously impaired vision or blindness. The immune system, particularly T-cell–mediated responses, is thought to be intricately involved, but the exact roles remain elusive. We found that acute ischemia-reperfusion injury to the retina induced a prolonged phase of retinal ganglion cell loss that continued to progress during 8 weeks after the procedure. This phase was accompanied by microglial activation and CD4(+) T-cell infiltration into the retina. Adoptive transfer of CD4(+) T cells isolated from diseased mice exacerbated retinal ganglion cell loss in mice with retinal reperfusion damage. On the other hand, T-cell deficiency or administration of T-cell or interferon-γ–neutralizing antibody attenuated retinal ganglion cell degeneration and retinal function loss after injury. These findings demonstrate a crucial role for T-cell–mediated responses in the pathogenesis of neural ischemia. These findings point to novel therapeutic targets of limiting or preventing neuron and function loss for currently untreatable conditions of optic neuropathy and/or central nervous system ischemic stroke. more...
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- 2019
41. The impact of belatacept on third-party HLA alloantibodies in highly sensitized kidney transplant recipients
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Ronald F. Parsons, Hannah Decker, Howard M. Gebel, Harold C. Sullivan, Annette M. Jackson, Christian P. Larsen, Mandy L. Ford, Dong-Feng Chen, Shalini Bumb, Malek Kamoun, Arslan Zahid, Frances Eun-Hyung Lee, Matthew H. Levine, Thomas C. Pearson, Robert A. Bray, and Idelberto R. Badell more...
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Adult ,Male ,Human leukocyte antigen ,030230 surgery ,Belatacept ,Kidney transplant ,Article ,Abatacept ,03 medical and health sciences ,0302 clinical medicine ,Highly sensitized ,HLA Antigens ,Immunology and Allergy ,Medicine ,Humans ,Pharmacology (medical) ,Sensitization ,Immunosuppression Therapy ,Transplantation ,Third party ,biology ,business.industry ,Middle Aged ,Kidney Transplantation ,Transplant Recipients ,medicine.anatomical_structure ,Immunology ,biology.protein ,Female ,Antibody ,business ,Immunosuppressive Agents ,medicine.drug - Abstract
Recent evidence suggests that belatacept reduces the durability of preexisting antibodies to class I and class II human leukocyte antigens (HLAs). In this case series of 163 highly sensitized kidney transplant candidates whose calculated panel-reactive antibody (cPRA) activity was ≥98% to 100%, the impact of belatacept on preexisting HLA antibodies was assessed. Of the 163 candidates, 72 underwent transplantation between December 4, 2014 and April 15, 2017; 60 of these transplanted patients remained on belatacept consecutively for at least 6 months. We observed a decrease in the breadth and/or strength of HLA class I antibodies as assessed by FlowPRA in belatacept-treated patients compared to controls who did not receive belatacept. Specifically, significant HLA antibody reduction was evident for class I (P < .0009). Posttransplant belatacept-treated patients also had a clinically significant reduction in their cPRA compared to controls (P < .01). Collectively, these findings suggest belatacept can reduce HLA class I antibodies in a significant proportion of highly sensitized recipients and could be an option to improve pretransplant compatibility with organ donors. more...
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- 2019
42. Proteomic Profiling of Heart Transplant Recipients Identifies CLE4C Expression as a Novel Biomarker of Primary Graft Dysfunction
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Adam D. DeVore, Christopher L. Holley, Carmelo A. Milano, C.B. Patel, Joseph G. Rogers, Elizabeth Grass, Lydia Coulter Kwee, Svati H. Shah, Dong-Feng Chen, Richa Agarwal, Jacob N. Schroder, and Lauren K. Truby more...
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Pulmonary and Respiratory Medicine ,Oncology ,Heart transplantation ,Transplantation ,medicine.medical_specialty ,Creatinine ,Proteomic Profiling ,business.industry ,medicine.medical_treatment ,Primary Graft Dysfunction ,Inflammation ,respiratory system ,Logistic regression ,Pathophysiology ,chemistry.chemical_compound ,chemistry ,Internal medicine ,medicine ,Biomarker (medicine) ,lipids (amino acids, peptides, and proteins) ,Surgery ,medicine.symptom ,Cardiology and Cardiovascular Medicine ,business - Abstract
Purpose Models to identify those at high risk of primary graft dysfunction (PGD) after heart transplantation (HT) are lacking and the pathophysiology remains poorly understood. We sought to identify whether proteins reporting on immune activation and inflammation were associated with incident PGD. Methods Using the Olink platform, we performed proteomic profiling of pre-transplant serum samples from HT recipients. PGD was defined using modified ISHLT criteria. We tested the association between PGD and protein levels using logistic regression with adjustment for clinical covariates (recipient age, creatinine, MCS, and sex; donor age; ischemic time). Significant proteins (p Results The derivation cohort consisted of 157 adult HT recipients, among whom 47 had PGD. Eleven of 368 proteins were associated with PGD in unadjusted and adjusted models and were tested in a validation cohort of 62 patients. The strongest association in the derivation cohort was with CLEC4C (OR [95%CI] = 2.0 [1.4,3.1], p=5.4 × 10−4), which remained the most significant tested protein in the validation set (OR [95%CI] = 1.8 [0.9,3.8], p=0.10; p Conclusion CLEC4C, a marker of plasmacytoid dendritic cells (PDC) which play a pro-inflammatory role via IFN-α signaling, may identify HT recipients at the highest risk for PGD. Further studies are needed to better understand the potential role of PDCs in PGD. more...
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- 2021
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43. New pathway ameliorating ulcerative colitis: focus on Roseburia intestinalis and the gut–brain axis
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Yuting Tian, Liqin Fan, Guangcong Ruan, Yan-Ling Wei, Dong-Feng Chen, Yi Cheng, Zhifeng Xiao, and Fenghua Xu
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Nervous system ,biology ,business.industry ,Gut–brain axis ,Gastroenterology ,Gut flora ,biology.organism_classification ,medicine.disease ,Ulcerative colitis ,law.invention ,Probiotic ,medicine.anatomical_structure ,law ,Immunology ,Medicine ,Roseburia intestinalis ,business - Abstract
Background: The community of gut microbes is a key factor controlling the intestinal barrier that communicates with the nervous system through the gut–brain axis. Based on our clinical data showing that populations of Roseburia intestinalis are dramatically decreased in the gut of patients with ulcerative colitis, we studied the efficacy of a strain belonging to this species in the context of colitis and stress using animal models. Methods: Dextran sulfate sodium was used to induce colitis in rats, which then underwent an enema with R. intestinalis as a treatment. The disease activity index, fecal changes and body weight of rats were recorded to evaluate colitis, while histological and immunohistochemical analyses were carried out to examine colon function, and 16S rRNA sequencing was performed to evaluate the gut microbiota change. Behavioral assays and immunohistochemical staining of brain were performed to assess the effect of R. intestinalis on the gut–brain axis. Results: Colitis-related symptoms in rats were significantly relieved after R. intestinalis enema, and the stool traits and colon length of rats were significantly recovered after treatment. The gut epithelial integrity and intestinal barrier were restored in treated rats, as evidenced by the higher expression of Zo-1 in colon tissues, accompanied by the restoration of gut microbiota. Meanwhile, depressive-like behaviors of rats were reduced after treatment, and laboratory experiments on neuronal cells also showed that IL-6, IL-7 and 5-HT were downregulated by R. intestinalis treatment in both serum and brain tissue, while Iba-1 expression was reduced in treated rats. Conclusions: The administration of R. intestinalis contributes to restoration of the gut microbiota, promoting colon repair and the recovery of gastrointestinal function. These alterations are accompanied by the relief of depressive-like behaviors through a process modulated by the neuronal network and the regulation of inflammation by the gut–brain axis. more...
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- 2021
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44. TNFα activates MAPK and Jak-Stat pathways to promote mouse Müller cell proliferation
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Yuan Fang, Xinghuai Sun, Xiaoqian Yao, Yi Zhang, Dong Feng Chen, Jihong Wu, and Liangliang Niu
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0301 basic medicine ,MAPK/ERK pathway ,Blotting, Western ,Ependymoglial Cells ,Enzyme-Linked Immunosorbent Assay ,Biology ,stat ,Mice ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,0302 clinical medicine ,Animals ,STAT2 ,Cell Proliferation ,Tumor Necrosis Factor-alpha ,JAK-STAT signaling pathway ,Sensory Systems ,Cell biology ,Mice, Inbred C57BL ,Ophthalmology ,030104 developmental biology ,Gene Expression Regulation ,Models, Animal ,030221 ophthalmology & optometry ,STAT protein ,biology.protein ,RNA ,Tumor necrosis factor alpha ,sense organs ,Mitogen-Activated Protein Kinases ,Janus kinase ,Leukemia inhibitory factor ,Signal Transduction - Abstract
Mouse Müller cells, considered as dormant retinal progenitors, often respond to retinal injury by undergoing reactive gliosis rather than displaying neural regenerative responses. Tumor necrosis factor alpha (TNFα) is a key cytokines induced after injury and implicated in mediating inflammatory and neural regenerative responses in zebrafish. To investigate the involvement of TNFα in mouse retinal injury, adult C57BL/6J mice were subjected to light damage for 14 consecutive days. TNFα was elevated in the retina of mice exposed to light damage, which induced Müller cell proliferation in vitro. Affymetrix microarray showed that, in Müller cells, TNFα induces up-regulation of inflammatory and proliferation-related genes, including NFKB2, leukemia inhibitory factor, interleukin-6, janus kinase (Jak) 1, Jak2, signal transducer and activator of transcription (Stat) 1, Stat2, mitogen-activated protein kinase (MAPK) 7, and MAP4K4 but down-regulation of neuroprogenitor genes, including Sox9, Ascl1, Wnt2 and Hes1. Blocking the Jak/Stat and MAPK pathways attenuated TNFα-induced Müller cell proliferation. These results suggest that TNFα may drive the proliferation and inflammatory response, rather than the neural regenerative potential, of mouse Müller cells. more...
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- 2021
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45. Electrical Stimulation as a Means for Improving Vision
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Dong Feng Chen, Kin-Sang Cho, Rima Maria Corraya, Shuai Guo, Tor Paaske Utheim, and Amer Sehic
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Pathology ,medicine.medical_specialty ,business.operation ,Electric Stimulation Therapy ,Stimulation ,Review ,Clinical success ,Retina ,Pathology and Forensic Medicine ,03 medical and health sciences ,0302 clinical medicine ,Retinal Diseases ,Optic Nerve Diseases ,Animals ,Humans ,Medicine ,Optic nerve diseases ,Vision, Ocular ,business.industry ,Research ,Optic Nerve ,Rats ,Disease Models, Animal ,medicine.anatomical_structure ,Blood circulation ,Cats ,030221 ophthalmology & optometry ,Optic nerve ,Rabbits ,Animal studies ,business ,Neuroscience ,Transorbital ,030217 neurology & neurosurgery - Abstract
Evolving research has provided evidence that noninvasive electrical stimulation (ES) of the eye may be a promising therapy for either preserving or restoring vision in several retinal and optic nerve diseases. In this review, we focus on minimally invasive strategies for the delivery of ES and accordingly summarize the current literature on transcorneal, transorbital, and transpalpebral ES in both animal experiments and clinical studies. Various mechanisms are believed to underlie the effects of ES, including increased production of neurotrophic agents, improved chorioretinal blood circulation, and inhibition of proinflammatory cytokines. Different animal models have demonstrated favorable effects of ES on both the retina and the optic nerve. Promising effects of ES have also been demonstrated in clinical studies; however, all current studies have a lack of randomization and/or a control group (sham). There is thus a pressing need for a deeper understanding of the underlying mechanisms that govern clinical success and optimization of stimulation parameters in animal studies. In addition, such research should be followed by large, prospective, clinical studies to explore the full potential of ES. Through this review, we aim to provide insight to guide future research on ES as a potential therapy for improving vision. more...
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- 2016
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46. Loureirin A Activates Wnt/β-Catenin Pathway to Promote Wound with Follicle Stem Cell-Seeded Tissue-Engineered Skin Healing
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Yi Tang, Ai-Jun Liu, Hua Yi, Sai-Xia Zhang, Dong-Feng Chen, Biao-yan Du, Jian-Hong Zhou, and Xiang-Jun Li
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0301 basic medicine ,Chemistry ,Biomedical Engineering ,Wnt signaling pathway ,Medicine (miscellaneous) ,Bioengineering ,Cell biology ,03 medical and health sciences ,Follicle ,030104 developmental biology ,Catenin ,Tissue engineered skin ,Stem cell ,Biotechnology - Published
- 2016
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47. Rescue of Glaucomatous Neurodegeneration by Differentially Modulating Neuronal Endoplasmic Reticulum Stress Molecules
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William H. Ridder, Weidong Xiao, Shaohua Li, Yang Hu, Qizhao Wang, Haoliang Huang, Lin Xu, Dong Feng Chen, Xiuyin Teng, Randal J. Kaufman, Linqing Miao, Liu Yang, Toby A. Ferguson, and Feisi Liang
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Male ,Retinal Ganglion Cells ,0301 basic medicine ,genetic structures ,Nerve Tissue Proteins ,Biology ,Neuroprotection ,Mice ,03 medical and health sciences ,medicine ,Animals ,Axon ,General Neuroscience ,Endoplasmic reticulum ,Retinal Degeneration ,Neurodegeneration ,Glaucoma ,Neurodegenerative Diseases ,Articles ,Endoplasmic Reticulum Stress ,medicine.disease ,eye diseases ,Mice, Inbred C57BL ,030104 developmental biology ,medicine.anatomical_structure ,nervous system ,Retinal ganglion cell ,Unfolded Protein Response ,Unfolded protein response ,Female ,Soma ,sense organs ,Neuron ,Neuroscience - Abstract
Axon injury is an early event in neurodegenerative diseases that often leads to retrograde neuronal cell death and progressive permanent loss of vital neuronal functions. The connection of these two obviously sequential degenerative events, however, is elusive. Deciphering the upstream signals that trigger the neurodegeneration cascades in both neuronal soma and axon would be a key step toward developing the effective neuroprotectants that are greatly needed in the clinic. We showed previously that optic nerve injury-induced neuronal endoplasmic reticulum (ER) stress plays an important role in retinal ganglion cell (RGC) death. Using twoin vivomouse models of optic neuropathies (traumatic optic nerve injury and glaucoma) and adeno-associated virus–mediated RGC-specific gene targeting, we now show that differential manipulation of unfolded protein response pathways in opposite directions—inhibition of eukaryotic translation initiation factor 2α-C/EBP homologous protein and activation of X-box binding protein 1—promotes both RGC axons and somata survival and preserves visual function. Our results indicate that axon injury-induced neuronal ER stress plays an important role in both axon degeneration and neuron soma death. Neuronal ER stress is therefore a promising therapeutic target for glaucoma and potentially other types of neurodegeneration.SIGNIFICANCE STATEMENTNeuron soma and axon degeneration have distinct molecular mechanisms although they are clearly connected after axon injury. We previously demonstrated that axon injury induces neuronal endoplasmic reticulum (ER) stress and that manipulation of ER stress molecules synergistically promotes neuron cell body survival. Here we investigated the possibility that ER stress also plays a role in axon degeneration and whether ER stress modulation preserves neuronal function in neurodegenerative diseases. Our results suggest that neuronal ER stress is a general mechanism of degeneration for both neuronal cell body and axon, and that therapeutic targeting of ER stress produces significant functional recovery. more...
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- 2016
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48. Design and Optimization of the Monochromator for the New Residual Stress Diffractometer
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Xiao Long Liu, Yun Tao Liu, Mei Juan Li, Yu Qing Li, Jian Bo Gao, Dong Feng Chen, Lin Feng Yang, and Song Bai Han
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Diffraction ,Materials science ,business.industry ,Mechanical Engineering ,Condensed Matter Physics ,Curvature ,law.invention ,Optics ,Mechanics of Materials ,law ,Residual stress ,Figure of merit ,General Materials Science ,Research reactor ,Wafer ,business ,Diffractometer ,Monochromator - Abstract
The monochromator for the new residual stress diffractometer at China Advanced Research Reactor (CARR) was simulated and optimized using SIMRES software. Objected the Fe (211) diffraction peak, the effect of horizontal and vertical curvature of Si (400) monochromator on Figure of Merit was studied to optimize the focusing parameters. With the optimal focusing condition, the influence of wafer thickness, number of wafers, packet height and gap of packets on performance of instrument was calculated consequently and the corresponding geometrical size was fixed. Finally, the design of the monochromator for the new residual stress diffractometer at CARR was completed. more...
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- 2016
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49. Structure of LaNi3.8AlMn0.2D3.2 Compound Studied by Neutron Powder Diffraction
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Wen Ze Han, Kai Sun, Hao Guo, Er Dong Wu, De Min Chen, Shi Liu, Dong Feng Chen, and Yun Tao Liu
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Neutron powder diffraction ,Materials science ,Hexagonal crystal system ,Mechanical Engineering ,Alloy ,Neutron diffraction ,Intermetallic ,Crystal structure ,engineering.material ,Condensed Matter Physics ,Crystallography ,Mechanics of Materials ,Group (periodic table) ,Interstitial defect ,engineering ,General Materials Science - Abstract
The intermetallic alloy LaNi3.8AlMn0.2 and its deuteride LaNi3.8AlMn0.2D3.2 were studied by neutron powder diffraction. The experimental results show that the crystal structure of LaNi3.8AlMn0.2 is CaCu5 type with the hexagonal P6/mmm space group, the substituted Al atoms occupy 2c and 3g sites, while Mn atoms are only located on the 3g sites. For the corresponding deuteride LaNi3.8AlMn0.2D3.2, the P6/mmm space group gives the best refinement, but D atoms enter two interstitial sites 6m and 12n. more...
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- 2016
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50. Noninvasive Electrical Stimulation Improves Photoreceptor Survival and Retinal Function in Mice with Inherited Photoreceptor Degeneration
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Katarina Zihlavnikova, Shelley I. Fried, Karen Chang, Tor Paaske Utheim, Kin-Sang Cho, Mays Talib, Seung Woo Lee, Dong Feng Chen, Hamida Achour, Sam Enayati, Jia Xie, and Honghua Yu
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Retinal Ganglion Cells ,Retinal degeneration ,Rhodopsin ,Cell Survival ,Ependymoglial Cells ,Electric Stimulation Therapy ,Stimulation ,Biology ,Retina ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,retinitis pigmentosa ,Electroretinography ,In Situ Nick-End Labeling ,medicine ,Animals ,Progenitor cell ,electrical stimulation ,Cells, Cultured ,photoreceptor degeneration ,Cell Proliferation ,Müller cells ,Mice, Knockout ,medicine.diagnostic_test ,Cell growth ,Regeneration (biology) ,Cell Cycle ,Retinal Degeneration ,Cell Differentiation ,Retinal ,medicine.disease ,Immunohistochemistry ,Cell biology ,Disease Models, Animal ,medicine.anatomical_structure ,chemistry ,030221 ophthalmology & optometry ,sense organs ,030217 neurology & neurosurgery ,Photoreceptor Cells, Vertebrate - Abstract
Purpose: Neurons carry electrical signals and communicate via electrical activities. The therapeutic potential of electrical stimulation (ES) for the nervous system, including the retina, through improvement of cell survival and function has been noted. Here we investigated the neuroprotective and regenerative potential of ES in a mouse model of inherited retinal degeneration. Methods: Rhodopsin-deficient (Rho−/−) mice received one or two sessions of transpalpebral ES or sham treatments for 7 consecutive days. Intraperitoneal injection of 5-ethynyl-2′-deoxyuridine was used to label proliferating cells. Weekly electroretinograms were performed to monitor retinal function. Retinal morphology, photoreceptor survival, and regeneration were evaluated in vivo using immunohistochemistry and genetic fate-mapping techniques. Müller cell (MC) cultures were employed to further define the optimal conditions of ES application. Results: Noninvasive transpalpebral ES in Rho−/− mice improved photoreceptor survival and electroretinography function in vivo. ES also triggered residential retinal progenitor-like cells such as MCs to reenter the cell cycle, possibly producing new photoreceptors, as shown by immunohistochemistry and genetic fate-mapping techniques. ES directly stimulated cell proliferation and the expression of progenitor cell markers in MC cultures, at least partially through bFGF signaling. Conclusions: Our study showed that transpalpebral ES improved photoreceptor survival and retinal function and induced the proliferation, probably photoreceptor regeneration, of MCs; this occurs via stimulation of the bFGF pathways. These results suggest the exciting possibility of applying noninvasive ES as a versatile tool for preventing photoreceptor loss and mobilizing endogenous progenitors for reversing vision loss in patients with photoreceptor degeneration. more...
- Published
- 2020
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