186 results on '"Guo HC"'
Search Results
52. Low-temperature thermal reduction of suspended graphene oxide film for electrical sensing of DNA-hybridization.
- Author
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Wang T, Guo HC, Chen XY, and Lu M
- Subjects
- Biosensing Techniques, Cold Temperature, Electrodes, Gases chemistry, Immobilized Nucleic Acids chemistry, Limit of Detection, Microscopy, Atomic Force, Nucleic Acid Hybridization, Oxidation-Reduction, Oxides chemistry, DNA analysis, Electrochemical Techniques instrumentation, Graphite chemistry
- Abstract
A reduced graphene oxide (RGO) based capacitive real time bio-sensor was presented. Suspended graphene oxide (GO) film was assembled electrophoretically between the source and drain electrodes of a transistor and then reduced by annealing in hydrogen/nitrogen forming gas to optimize the surface functional groups and conductivity. The resonance frequency of the transmission coefficient (S
21 ) of the transistor was observed to shift with deoxyribonucleic acid (DNA)-hybridization, with a detecting limit of ~5nM. The advantages of the bio-sensing approach include low-noise frequency output, solution based real time detection and capable of on-chip integration., (Copyright © 2016 Elsevier B.V. All rights reserved.)- Published
- 2017
- Full Text
- View/download PDF
53. Recent progress of atomic layer deposition on polymeric materials.
- Author
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Guo HC, Ye E, Li Z, Han MY, and Loh XJ
- Subjects
- Electricity, Models, Theoretical, Surface Properties, Materials Testing methods, Polymers chemistry
- Abstract
As a very promising surface coating technology, atomic layer deposition (ALD) can be used to modify the surfaces of polymeric materials for improving their functions and expanding their application areas. Polymeric materials vary in surface functional groups (number and type), surface morphology and internal structure, and thus ALD deposition conditions that typically work on a normal solid surface, usually do not work on a polymeric material surface. To date, a large variety of research has been carried out to investigate ALD deposition on various polymeric materials. This paper aims to provide an in-depth review of ALD deposition on polymeric materials and its applications. Through this review, we will provide a better understanding of surface chemistry and reaction mechanism for controlled surface modification of polymeric materials by ALD. The integrated knowledge can aid in devising an improved way in the reaction between reactant precursors and polymer functional groups/polymer backbones, which will in turn open new opportunities in processing ALD materials for better inorganic/organic film integration and potential applications., (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
54. Crystal structure of a polypeptide's C-terminus in complex with the regulatory domain of ER aminopeptidase 1.
- Author
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Sui L, Gandhi A, and Guo HC
- Subjects
- Aminopeptidases metabolism, Animals, Crystallography, X-Ray, Humans, Minor Histocompatibility Antigens metabolism, Peptides metabolism, Protein Conformation, Aminopeptidases chemistry, Antigen Presentation physiology, Minor Histocompatibility Antigens chemistry, Peptides chemistry
- Abstract
Endoplasmic reticulum aminopeptidase 1 (ERAP1) is involved in the final processing of peptide precursors to generate the N-termini of MHC class I-restricted epitopes. ERAP1 thus influences immunodominance and cytotoxic immune responses by controlling the peptide repertoire available for cell surface presentation by MHC molecules. To enable this critical role in antigen processing, ERAP1 trims peptides by a unique molecular ruler mechanism that turns on/off hydrolysis activity in a peptide-length and -sequence dependent manner. Thus unlike other aminopeptidases, ERAP1 could recognize both the N- and C-termini of peptides in order to read the substrate's length. To exemplify and validate this molecular ruler mechanism, we have carried out crystallographic studies on molecular recognition of antigenic peptide's C-terminus by ERAP1. In this report, we have determined a 2.8Å-resolution crystal structure of an intermolecular complex between the ERAP1 regulatory domain and a natural epitope's C-terminus displayed in a fusion protein. It reveals the structural details of peptide's C-termini recognition by ERAP1. ERAP1 uses specificity pockets on the regulatory domain to bind the peptide's carboxyl end and side chain of the C-terminal anchoring residue. At the same time, flexibility in length and sequence at the middle of peptides is accommodated by a kink with minimal interactions with ERAP1., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
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55. Characterization of chemical constituents and rats metabolites of an alkaloidal extract of Alstonia scholaris leaves by liquid chromatography coupled with mass spectrometry.
- Author
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Cao J, Shen HM, Wang Q, Qian Y, Guo HC, Li K, Qiao X, Guo DA, Luo XD, and Ye M
- Subjects
- Animals, Male, Rats, Rats, Sprague-Dawley, Alkaloids chemistry, Alstonia chemistry, Chromatography, Liquid methods, Mass Spectrometry methods, Plant Extracts analysis, Plant Leaves chemistry
- Abstract
Alstonia scholaris has been used in "Dai" ethnic medicine to treat chronic respiratory diseases for a long history, and the major bioactive constituents are alkaloids. An alkaloidal extract of A. scholaris leaves (AAS) has been developed into an investigational new drug, and has been approved for phase I/II clinical trials by China Food and Drug Administration. However, little is known on the chemical composition and in vivo metabolism of AAS, thus far. In this study, an ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC/qTOF-MS) method was established to characterize the chemical constituents of AAS. Samples were separated on an ACQUITY UPLC CSH column (2.1×100mm, 1.7μm) with acetonitrile and water containing 0.3% formic acid as the mobile phase. On the basis of high-accuracy mass spectral analysis, a total of 35 alkaloids were characterized from AAS, including 11 scholaricine-type, 9 vallesamine-type, 12 picrinine-type, and 3 tubotaiwine-type alkaloids. Furthermore, the metabolic pathways of 4 representative alkaloids in rats were studied. They mainly undertook hydroxylation and glucuronidation reactions. Based on the above metabolic pathways, the metabolism of AAS (10mg/kg) in rats after oral administration was studied by LC/MS. A total of 33 compounds in plasma, 40 compounds in urine, and 38 compounds in feces were characterized. The results indicated that scholaricine-type alkaloids could get into circulation more readily than the other types. This is the first systematic study on chemical profiling and metabolites identification of AAS., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2016
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56. Biological function of Foot-and-mouth disease virus non-structural proteins and non-coding elements.
- Author
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Gao Y, Sun SQ, and Guo HC
- Subjects
- 3' Untranslated Regions, 5' Untranslated Regions, Animals, Foot-and-Mouth Disease Virus genetics, Gene Expression Regulation, Viral, Open Reading Frames, Viral Nonstructural Proteins genetics, Foot-and-Mouth Disease virology, Foot-and-Mouth Disease Virus metabolism, Viral Nonstructural Proteins metabolism
- Abstract
Foot-and-mouth disease virus (FMDV) represses host translation machinery, blocks protein secretion, and cleaves cellular proteins associated with signal transduction and the innate immune response to infection. Non-structural proteins (NSPs) and non-coding elements (NCEs) of FMDV play a critical role in these biological processes. The FMDV virion consists of capsid and nucleic acid. The virus genome is a positive single stranded RNA and encodes a single long open reading frame (ORF) flanked by a long structured 5'-untranslated region (5'-UTR) and a short 3'-UTR. The ORF is translated into a polypeptide chain and processed into four structural proteins (VP1, VP2, VP3, and VP4), 10 NSPs (L(pro), 2A, 2B, 2C, 3A, 3B1-3, 3C(pro), and 3D(pol)), and some cleavage intermediates. In the past decade, an increasing number of studies have begun to focus on the molecular pathogenesis of FMDV NSPs and NCEs. This review collected recent research progress on the biological functions of these NSPs and NCEs on the replication and host cellular regulation of FMDV to understand the molecular mechanism of host-FMDV interactions and provide perspectives for antiviral strategy and development of novel vaccines.
- Published
- 2016
- Full Text
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57. RNAi Reveals Phase-Specific Global Regulators of Human Somatic Cell Reprogramming.
- Author
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Toh CX, Chan JW, Chong ZS, Wang HF, Guo HC, Satapathy S, Ma D, Goh GY, Khattar E, Yang L, Tergaonkar V, Chang YT, Collins JJ, Daley GQ, Wee KB, Farran CA, Li H, Lim YP, Bard FA, and Loh YH
- Subjects
- Cells, Cultured, Gene Knockdown Techniques, Genetic Testing, Genome, Human, Humans, Kinetics, Microtubule-Associated Proteins genetics, Microtubule-Associated Proteins metabolism, RNA Splicing genetics, RNA, Messenger genetics, RNA, Messenger metabolism, RNA, Small Interfering metabolism, Repressor Proteins metabolism, Serine-Arginine Splicing Factors metabolism, Cellular Reprogramming genetics, RNA Interference
- Abstract
Incomplete knowledge of the mechanisms at work continues to hamper efforts to maximize reprogramming efficiency. Here, we present a systematic genome-wide RNAi screen to determine the global regulators during the early stages of human reprogramming. Our screen identifies functional repressors and effectors that act to impede or promote the reprogramming process. Repressors and effectors form close interacting networks in pathways, including RNA processing, G protein signaling, protein ubiquitination, and chromatin modification. Combinatorial knockdown of five repressors (SMAD3, ZMYM2, SFRS11, SAE1, and ESET) synergistically resulted in ∼85% TRA-1-60-positive cells. Removal of the novel splicing factor SFRS11 during reprogramming is accompanied by rapid acquisition of pluripotency-specific spliced forms. Mechanistically, SFRS11 regulates exon skipping and mutually exclusive splicing of transcripts in genes involved in cell differentiation, mRNA splicing, and chromatin modification. Our study provides insights into the reprogramming process, which comprises comprehensive and multi-layered transcriptional, splicing, and epigenetic machineries., (Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2016
- Full Text
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58. Identification of cranial nerves around trigeminal schwannomas using diffusion tensor tractography: a technical note and report of 3 cases.
- Author
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Wei PH, Qi ZG, Chen G, Li MC, Liang JT, Guo HC, Bao YH, and Hao Q
- Subjects
- Adult, Cranial Nerve Neoplasms pathology, Female, Humans, Male, Middle Aged, Neurilemmoma pathology, Trigeminal Nerve pathology, Cranial Nerve Neoplasms surgery, Diffusion Tensor Imaging methods, Neurilemmoma surgery, Trigeminal Nerve surgery
- Abstract
Background: There are no large series studies identifying the locations of cranial nerves (CNs) around trigeminal schwannomas (TSs); however, surgically induced cranial neuropathies are commonly observed after surgeries to remove TSs. In this study, we preoperatively identified the location of CNs near TSs using diffusion tensor tractography (DTT)., Methods: An observational study of the DTT results and intraoperative findings was performed. We preoperatively completed tractography from images of patients with TSs who received surgical therapy. The result was later validated during tumorectomy., Results: A total of three consecutive patients were involved in this study. The locations of CNs V-VIII in relation to the tumor was clearly revealed in all cases, except for CN VI in case 3.The predicted fiber tracts were in agreement with intraoperative observations., Conclusions: In this study, preoperative DTT accurately predicted the location of the majority of the nerves of interest. This technique can be applied by surgeons to preoperatively visualize nerve arrangements.
- Published
- 2016
- Full Text
- View/download PDF
59. Quantitative Detection of the Foot-And-Mouth Disease Virus Serotype O 146S Antigen for Vaccine Production Using a Double-Antibody Sandwich ELISA and Nonlinear Standard Curves.
- Author
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Feng X, Ma JW, Sun SQ, Guo HC, Yang YM, Jin Y, Zhou GQ, He JJ, Guo JH, Qi SY, Lin M, Cai H, and Liu XT
- Subjects
- Animals, Antigens, Viral immunology, Foot-and-Mouth Disease immunology, Limit of Detection, Vaccines, Inactivated analysis, Vaccines, Inactivated immunology, Viral Vaccines immunology, Antigens, Viral analysis, Enzyme-Linked Immunosorbent Assay methods, Foot-and-Mouth Disease virology, Foot-and-Mouth Disease Virus immunology, Viral Vaccines analysis
- Abstract
The efficacy of an inactivated foot-and-mouth disease (FMD) vaccine is mainly dependent on the integrity of the foot-and-mouth disease virus (FMDV) particles. At present, the standard method to quantify the active component, the 146S antigen, of FMD vaccines is sucrose density gradient (SDG) analysis. However, this method is highly operator dependent and difficult to automate. In contrast, the enzyme-linked immunosorbent assay (ELISA) is a time-saving technique that provides greater simplicity and sensitivity. To establish a valid method to detect and quantify the 146S antigen of a serotype O FMD vaccine, a double-antibody sandwich (DAS) ELISA was compared with an SDG analysis. The DAS ELISA was highly correlated with the SDG method (R2 = 0.9215, P<0.01). In contrast to the SDG method, the DAS ELISA was rapid, robust, repeatable and highly sensitive, with a minimum quantification limit of 0.06 μg/mL. This method can be used to determine the effective antigen yields in inactivated vaccines and thus represents an alternative for assessing the potency of FMD vaccines in vitro. But it still needs to be prospectively validated by analyzing a new vaccine preparation and determining the proper protective dose followed by an in vivo vaccination-challenge study to confirm the ELISA findings.
- Published
- 2016
- Full Text
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60. Choledochojejunostomy with an innovative magnetic compressive anastomosis: How to determine optimal pressure?
- Author
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Xue F, Guo HC, Li JP, Lu JW, Wang HH, Ma F, Liu YX, and Lv Y
- Subjects
- Anastomotic Leak blood, Anastomotic Leak etiology, Animals, Bilirubin blood, Biomarkers blood, Choledochostomy adverse effects, Choledochostomy methods, Cholestasis blood, Disease Models, Animal, Dogs, Equipment Design, Feasibility Studies, Male, Pressure, Suture Techniques, Time Factors, Choledochostomy instrumentation, Cholestasis surgery, Magnetics instrumentation, Magnets adverse effects
- Abstract
Aim: To investigate the optimal magnetic pressure and provide a theoretical basis for choledochojejunostomy magnetic compressive anastomosis (magnamosis)., Methods: Four groups of neodymium-iron-boron magnets with different magnetic pressures of 0.1, 0.2, 0.3 and 0.4 MPa were used to complete the choledochojejunostomy magnamosis. Twenty-six young mongrel dogs were randomly divided into five groups: four groups with different magnetic pressures and 1 group with a hand-suture anastomosis. Serum bilirubin levels were measured in all groups before and 1 wk, 2 wk, 3 wk, 1 mo and 3 mo after surgery. Daily abdominal X-ray fluoroscopy was carried out postoperatively to detect the path and the excretion of the magnet. The animals were euthanized at 1 or 3 mo after the operation, the burst pressure was detected in each anastomosis, and the gross appearance and histology were compared according to the observation., Results: The surgical procedures were all successfully performed in animals. However, animals of group D (magnetic pressure of 0.4 MPa) all experienced complications with bile leakage (4/4), whereas half of animals in group A (magnetic pressure of 0.1 MPa) experienced complications (3/6), 1 animal in the manual group E developed anastomotic stenosis, and animals in group B and group C (magnetic pressure of 0.2 MPa and 0.3 MPa, respectively) all healed well without complications. These results also suggested that the time required to form the stoma was inversely proportional to the magnetic pressure; however, the burst pressure of group A was smaller than those of the other groups at 1 mo (187.5 ± 17.7 vs 290 ± 10/296.7 ± 5.7/287.5 ± 3.5, P < 0.05); the remaining groups did not differ significantly. A histologic examination demonstrated obvious differences between the magnamosis groups and the hand-sewn group., Conclusion: We proved that the optimal range for choledochojejunostomy magnamosis is 0.2 MPa to 0.3 MPa, which will help to improve the clinical application of this technique in the future.
- Published
- 2016
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61. Productive Entry of Foot-and-Mouth Disease Virus via Macropinocytosis Independent of Phosphatidylinositol 3-Kinase.
- Author
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Han SC, Guo HC, Sun SQ, Jin Y, Wei YQ, Feng X, Yao XP, Cao SZ, Xiang Liu D, and Liu XT
- Subjects
- Actins metabolism, Animals, Caveolins metabolism, Cell Line, Cholesterol metabolism, Membrane Lipids metabolism, Receptor Protein-Tyrosine Kinases metabolism, Virus Replication, Foot-and-Mouth Disease Virus physiology, Phosphatidylinositol 3-Kinases metabolism, Pinocytosis, Virus Internalization
- Abstract
Virus entry is an attractive target for therapeutic intervention. Here, using a combination of electron microscopy, immunofluorescence assay, siRNA interference, specific pharmacological inhibitors, and dominant negative mutation, we demonstrated that the entry of foot-and-mouth disease virus (FMDV) triggered a substantial amount of plasma membrane ruffling. We also found that the internalization of FMDV induced a robust increase in fluid-phase uptake, and virions internalized within macropinosomes colocalized with phase uptake marker dextran. During this stage, the Rac1-Pak1 signaling pathway was activated. After specific inhibition on actin, Na(+)/H(+) exchanger, receptor tyrosine kinase, Rac1, Pak1, myosin II, and protein kinase C, the entry and infection of FMDV significantly decreased. However, inhibition of phosphatidylinositol 3-kinase (PI3K) did not reduce FMDV internalization but increased the viral entry and infection to a certain extent, implying that FMDV entry did not require PI3K activity. Results showed that internalization of FMDV exhibited the main hallmarks of macropinocytosis. Moreover, intracellular trafficking of FMDV involves EEA1/Rab5-positive vesicles. The present study demonstrated macropinocytosis as another endocytic pathway apart from the clathrin-mediated pathway. The findings greatly expand our understanding of the molecular mechanisms of FMDV entry into cells, as well as provide potential insights into the entry mechanisms of other picornaviruses.
- Published
- 2016
- Full Text
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62. The application of virus-like particles as vaccines and biological vehicles.
- Author
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Yan D, Wei YQ, Guo HC, and Sun SQ
- Subjects
- Drug Carriers isolation & purification, Vaccines, Virus-Like Particle administration & dosage, Vaccines, Virus-Like Particle isolation & purification, Virosomes isolation & purification, Drug Carriers metabolism, Drug Delivery Systems, Vaccines, Virus-Like Particle immunology, Virosomes metabolism
- Abstract
Virus-like particles (VLPs) can be spontaneously self-assembled by viral structural proteins under appropriate conditions in vitro while excluding the genetic material and potential replication probability. In addition, VLPs possess several features including can be rapidly produced in large quantities through existing expression systems, highly resembling native viruses in terms of conformation and appearance, and displaying repeated cluster of epitopes. Their capsids can be modified via genetic insertion or chemical conjugation which facilitating the multivalent display of a homologous or heterogeneous epitope antigen. Therefore, VLPs are considered as a safe and effective candidate of prophylactic and therapeutic vaccines. VLPs, with a diameter of approximately 20 to 150 nm, also have the characteristics of nanometer materials, such as large surface area, surface-accessible amino acids with reactive moieties (e.g., lysine and glutamic acid residues), inerratic spatial structure, and good biocompatibility. Therefore, assembled VLPs have great potential as a delivery system for specifically carrying a variety of materials. This review summarized recent researches on VLP development as vaccines and biological vehicles, which demonstrated the advantages and potential of VLPs in disease control and prevention and diagnosis. Then, the prospect of VLP biology application in the future is discussed as well.
- Published
- 2015
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63. A long-lasting protective immunity against chronic toxoplasmosis in mice induced by recombinant rhoptry proteins encapsulated in poly (lactide-co-glycolide) microparticles.
- Author
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Xu Y, Zhang NZ, Wang M, Dong H, Feng SY, Guo HC, and Zhu XQ
- Subjects
- Animals, Antibodies, Protozoan blood, Drug Carriers administration & dosage, Female, Humans, Immunization, Mice, Models, Animal, Polyesters administration & dosage, Protozoan Proteins immunology, Recombinant Proteins, Toxoplasmosis, Animal prevention & control, Antigens, Protozoan administration & dosage, Antigens, Protozoan immunology, Protozoan Proteins administration & dosage, Protozoan Vaccines immunology, Toxoplasma immunology, Toxoplasmosis, Animal immunology
- Abstract
Toxoplasma gondii infection in humans and animals is a worldwide zoonosis. Prevention and control of toxoplasmosis based on vaccination is one of the promising strategies. In the present study, recombinant T. gondii rhoptry proteins 38 and 18 (TgROP38 and TgROP18) were encapsulated into poly (lactide-co-glycolide) (PLG) (1:1), respectively, to obtain the stable water-in-oil-in-water double emulsion. Female Kunming mice were then immunized with the protein vaccines twice at a 2-week interval. Eight weeks after the second immunization, 10 mice from each group were challenged with T. gondii PRU strain (genotype II). The entrapment rates of PLG-rROP38 and PLG-rROP18 ranged from 65.5 to 77.7% and 58.1 to 72.3%, respectively. Immunization of mice with rROP38 and rROP18 proteins encapsulated into PLG microparticles elicited strongly humoral and cell-mediated responses against T. gondii, associated with relatively high levels of total IgG, IgG2a isotype, and IFN-γ, as well as the mixed Th1/Th2 immunity responses. Immunization with various protein vaccines induced significant reduction of the brain cysts after chronic infection with the T. gondii PRU strain, and the most effective protection was achieved in the PLG-rROP38-rROP18-immunized mice, with a cyst reduction of 81.3%. The findings of the present study indicated that recombinant rhoptry antigens encapsulated in PLG could maintain the protein immunogenicity in an extended period and elicit effective protection against chronic T. gondii infection, which has implications for the development of long-lasting vaccines against chronic toxoplasmosis in animals.
- Published
- 2015
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64. Tert-butylhydroquinone ameliorates doxorubicin-induced cardiotoxicity by activating Nrf2 and inducing the expression of its target genes.
- Author
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Wang LF, Su SW, Wang L, Zhang GQ, Zhang R, Niu YJ, Guo YS, Li CY, Jiang WB, Liu Y, and Guo HC
- Abstract
Oxidative stress plays an important role in doxorubicin (DOX)-induced cardiotoxicity. Nuclear factor E2-related factor-2 (Nrf2) is a transcription factor that orchestrates the antioxidant and cytoprotective responses to oxidative stress. In the present study, we tested whether tert-butylhydroquinone (tBHQ) could protect against DOX-induced cardiotoxicity in vivo and, if so, whether the protection was associated with the up-regulation of the Nrf2 pathway. The results showed that treatment with tBHQ significantly decreased the DOX-induced cardiac injury in wild-type mice. Moreover, tBHQ ameliorated the DOX-induced oxidative stress and apoptosis. Further studies suggested that tBHQ increased the nuclear accumulation of Nrf2 and the Nrf2-regulated gene expression, including heme oxygenase-1 (HO-1) and, Nad(p)h: quinone oxido-reductase-1 (NQO-1) expression. Knocking out Nrf2 in mice abolished the protective effect of tBHQ on the DOX-induced cardiotoxicity. These results indicate that tBHQ has a beneficial effect on DOX-induced cardiotoxicity, and this effect was associated with the enhanced expression of Nrf2 and its downstream antioxidant genes, HO-1 and NQO-1.
- Published
- 2015
65. Systematic identification of factors for provirus silencing in embryonic stem cells.
- Author
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Yang BX, El Farran CA, Guo HC, Yu T, Fang HT, Wang HF, Schlesinger S, Seah YF, Goh GY, Neo SP, Li Y, Lorincz MC, Tergaonkar V, Lim TM, Chen L, Gunaratne J, Collins JJ, Goff SP, Daley GQ, Li H, Bard FA, and Loh YH
- Subjects
- Animals, Chromatin Assembly Factor-1 genetics, Chromatin Assembly Factor-1 metabolism, Embryonal Carcinoma Stem Cells virology, Epigenesis, Genetic, Mice, Small Ubiquitin-Related Modifier Proteins metabolism, Embryonic Stem Cells virology, Endogenous Retroviruses genetics, Proviruses genetics
- Abstract
Embryonic stem cells (ESCs) repress the expression of exogenous proviruses and endogenous retroviruses (ERVs). Here, we systematically dissected the cellular factors involved in provirus repression in embryonic carcinomas (ECs) and ESCs by a genome-wide siRNA screen. Histone chaperones (Chaf1a/b), sumoylation factors (Sumo2/Ube2i/Sae1/Uba2/Senp6), and chromatin modifiers (Trim28/Eset/Atf7ip) are key determinants that establish provirus silencing. RNA-seq analysis uncovered the roles of Chaf1a/b and sumoylation modifiers in the repression of ERVs. ChIP-seq analysis demonstrates direct recruitment of Chaf1a and Sumo2 to ERVs. Chaf1a reinforces transcriptional repression via its interaction with members of the NuRD complex (Kdm1a, Hdac1/2) and Eset, while Sumo2 orchestrates the provirus repressive function of the canonical Zfp809/Trim28/Eset machinery by sumoylation of Trim28. Our study reports a genome-wide atlas of functional nodes that mediate proviral silencing in ESCs and illuminates the comprehensive, interconnected, and multi-layered genetic and epigenetic mechanisms by which ESCs repress retroviruses within the genome., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2015
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66. Quantitative Proteomic Analysis of BHK-21 Cells Infected with Foot-and-Mouth Disease Virus Serotype Asia 1.
- Author
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Guo HC, Jin Y, Han SC, Sun SQ, Wei YQ, Liu XJ, Feng X, Liu DX, and Liu XT
- Subjects
- Animals, Blotting, Western, Cell Line, Chromatography, Liquid, Computational Biology, Down-Regulation, Foot-and-Mouth Disease Virus genetics, Gene Knockdown Techniques, Genes, Viral, Immunoblotting, Isotope Labeling, Mass Spectrometry, Metabolic Networks and Pathways, Proteome metabolism, RNA Interference, RNA, Small Interfering metabolism, Reproducibility of Results, Subcellular Fractions metabolism, Time Factors, Transfection, Up-Regulation, Viral Proteins metabolism, Foot-and-Mouth Disease virology, Foot-and-Mouth Disease Virus physiology, Proteomics methods
- Abstract
Stable isotope labeling with amino acids in cell culture (SILAC) was used to quantitatively study the host cell gene expression profile, in order to achieve an unbiased overview of the protein expression changes in BHK-21 cells infected with FMDV serotype Asia 1. The SILAC-based approach identified overall 2,141 proteins, 153 of which showed significant alteration in the expression level 6 h post FMDV infection (57 up-regulated and 96 down-regulated). Among these proteins, six cellular proteins, including three down-regulated (VPS28, PKR, EVI5) and three up-regulated (LYPLA1, SEC62 and DARs), were selected according to the significance of the changes and/or the relationship with PKR. The expression level and pattern of the selected proteins were validated by immunoblotting and confocal microscopy. Furthermore, the functions of these cellular proteins were assessed by small interfering RNA-mediated depletion, and their functional importance in the replication of FMDV was demonstrated by western blot, reverse transcript PCR (RT-PCR) and 50% Tissue Culture Infective Dose (TCID50). The results suggest that FMDV infection may have effects on the expression of specific cellular proteins to create more favorable conditions for FMDV infection. This study provides novel data that can be utilized to understand the interactions between FMDV and the host cell.
- Published
- 2015
- Full Text
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67. Identification of cranial nerves near large vestibular schwannomas using superselective diffusion tensor tractography: experience with 23 cases.
- Author
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Wei PH, Qi ZG, Chen G, Hu P, Li MC, Liang JT, Guo HC, Ling F, and Bao YH
- Subjects
- Adult, Cochlear Nerve physiology, Facial Nerve physiology, Female, Humans, Male, Middle Aged, Neuroma, Acoustic pathology, Trigeminal Nerve physiology, Cochlear Nerve anatomy & histology, Diffusion Tensor Imaging methods, Facial Nerve anatomy & histology, Monitoring, Intraoperative methods, Neuroma, Acoustic surgery, Trigeminal Nerve anatomy & histology
- Abstract
Background: The preservation of the facial nerve (FN) and acoustic function in large vestibular schwannoma (VS) surgery is challenging because of nerve course uncertainties and morphological deviations. Preoperative diffusion tensor tractography (DTT) has been proposed to predict the FN location. This study was conducted to evaluate the effectiveness of this technique for identifying the FN, cochlear nerve (CN) and trigeminal nerve (TN) in large VSs., Methods: The study included 23 consecutive patients with VS of Hannover classification T3b to T4b from November 2013 through May 2014. Diffusion tensor images and anatomical images were acquired. The DTT images of the cranial nerves were extracted before surgery for each patient to determine the relationships of these nerves with the tumor. The results were then validated during the tumorectomy., Results: In 21 (91.30%) patients, the location of the FN on the DTT images agreed with the intraoperative findings, including in 2 patients in whom the FN passed through the interface between the parenchyma and the cystic changes and in 3 patients with a membranoid FN. The CN or fibers of unclear function were observed on DTT images in four patients with functional hearing. One penetrating fiber of unknown function was effectively constructed. The TN was accurately detected on the DTT images for all patients., Conclusions: DTT effectively revealed the location of the FN, including cases in which the FN was membranoid or passed through the interface between an area exhibiting cystic changes and the tumor nodule. Fibers aside from the FN and the TN were revealed by DTT in patients who retained functional hearing. Penetrating fibers were also found using DTT. This technique can be useful during VS resection.
- Published
- 2015
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68. NLRP3 Inflammasome Activation by Viroporins of Animal Viruses.
- Author
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Guo HC, Jin Y, Zhi XY, Yan D, and Sun SQ
- Subjects
- Animals, Carrier Proteins genetics, Humans, Inflammasomes genetics, Viral Proteins genetics, Virus Diseases genetics, Virus Diseases virology, Viruses genetics, Carrier Proteins immunology, Inflammasomes immunology, Viral Proteins immunology, Virus Diseases immunology, Viruses immunology
- Abstract
Viroporins are a group of low-molecular-weight proteins containing about 50-120 amino acid residues, which are encoded by animal viruses. Viroporins are involved in several stages of the viral life cycle, including viral gene replication and assembly, as well as viral particle entry and release. Viroporins also play an important role in the regulation of antiviral innate immune responses, especially in inflammasome formation and activation, to ensure the completion of the viral life cycle. By reviewing the research progress made in recent years on the regulation of the NLRP3 inflammasome by viroporins of animal viruses, we aim to understand the importance of viroporins in viral infection and to provide a reference for further research and development of novel antiviral drugs.
- Published
- 2015
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69. Viroporin Activity of the Foot-and-Mouth Disease Virus Non-Structural 2B Protein.
- Author
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Ao D, Guo HC, Sun SQ, Sun DH, Fung TS, Wei YQ, Han SC, Yao XP, Cao SZ, Liu DX, and Liu XT
- Subjects
- Amantadine pharmacology, Animals, Calcium metabolism, Cell Line, Cell Membrane Permeability, Cricetinae, Endoplasmic Reticulum virology, Escherichia coli virology, Foot-and-Mouth Disease Virus genetics, Humans, Protein Structure, Tertiary, Virus Release drug effects, Virus Replication physiology, Autophagy genetics, Cell Membrane metabolism, Foot-and-Mouth Disease Virus metabolism, Viral Nonstructural Proteins antagonists & inhibitors, Viral Regulatory and Accessory Proteins antagonists & inhibitors
- Abstract
Viroporins are a family of low-molecular-weight hydrophobic transmembrane proteins that are encoded by various animal viruses. Viroporins form transmembrane pores in host cells via oligomerization, thereby destroying cellular homeostasis and inducing cytopathy for virus replication and virion release. Among the Picornaviridae family of viruses, the 2B protein encoded by enteroviruses is well understood, whereas the viroporin activity of the 2B protein encoded by the foot-and-mouth disease virus (FMDV) has not yet been described. An analysis of the FMDV 2B protein domains by computer-aided programs conducted in this study revealed that this protein may contain two transmembrane regions. Further biochemical, biophysical and functional studies revealed that the protein possesses a number of features typical of a viroporin when it is overexpressed in bacterial and mammalian cells as well as in FMDV-infected cells. The protein was found to be mainly localized in the endoplasmic reticulum (ER), with both the N- and C-terminal domains stretched into the cytosol. It exhibited cytotoxicity in Escherichia coli, which attenuated 2B protein expression. The release of virions from cells infected with FMDV was inhibited by amantadine, a viroporin inhibitor. The 2B protein monomers interacted with each other to form both intracellular and extracellular oligomers. The Ca(2+) concentration in the cells increased, and the integrity of the cytoplasmic membrane was disrupted in cells that expressed the 2B protein. Moreover, the 2B protein induced intense autophagy in host cells. All of the results of this study demonstrate that the FMDV 2B protein has properties that are also found in other viroporins and may be involved in the infection mechanism of FMDV.
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- 2015
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70. Full-length genomic characterizations of two canine parvoviruses prevalent in Northwest China.
- Author
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Han SC, Guo HC, Sun SQ, Shu L, Wei YQ, Sun DH, Cao SZ, Peng GN, and Liu XT
- Subjects
- Animals, Base Sequence, China, Dogs, Genetic Variation, Genome genetics, Molecular Sequence Data, Parvoviridae Infections virology, Phylogeny, Prevalence, Sequence Alignment, Sequence Analysis, Sequence Analysis, DNA, Capsid Proteins genetics, Dog Diseases virology, Parvoviridae Infections veterinary, Parvovirus, Canine genetics, Viral Nonstructural Proteins genetics
- Abstract
Canine parvovirus (CPV) can cause acute hemorrhagic diarrhea and fatal myocarditis in young dogs. Currently, most studies have focused on the evolution of the VP2 gene, whereas the full-length genome of CPV has been rarely reported. In this study, the whole genomes of CPV-LZ1 and CPV-LZ2 strains prevalent in Northwest China were determined and analyzed in comparison with those of the reference CPVs. The genome sequences of both LZ strains consisted of 5053 nucleotides. CPV-LZ1 and CPV-LZ2 strains were designated as new CPV-2a and CPV-2b, respectively. Sequence alignment analysis results revealed that these two new strains underwent specific unique variations during the process of local adaption. The left non-translated regions of these strains formed a Y-shaped hairpin structure, whereas the right non-translated regions lacked the reiteration of DNA sequence. A phylogenetic tree constructed from 33 whole coding regions of CPVs showed a strong spatial clustering, and these two strains belonged to the Chinese strain cluster lineage. This study provides a method to obtain the full-length genome of CPV. The isolation and characterization of these viruses adds incrementally to the knowledge of the full-length genome of CPV. The results from this study also provide insight into the molecular epidemiology and genetic diversity of the CPV field isolates from Northwest China and can be useful in preventing and controlling CPV infection in this region.
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- 2015
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71. Enhanced N input to Lake Dianchi Basin from 1980 to 2010: drivers and consequences.
- Author
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Gao W, Howarth RW, Swaney DP, Hong B, and Guo HC
- Subjects
- China, Eutrophication, Fertilizers analysis, Human Activities, Phosphorus analysis, Environmental Monitoring, Lakes chemistry, Nitrogen analysis, Water Pollutants, Chemical analysis
- Abstract
Due to a rapid increase in human population and development of neighborhood economy over the last few decades, nitrogen (N) and other nutrient inputs in Lake Dianchi drainage basin have increased dramatically, changing the lake's trophic classification from oligotrophic to eutrophic. Although human activities are considered as main causes for the degradation of water quality in the lake, a numerical analysis of the share of the effect of different anthropogenic factors is still largely unexplored. We use the net anthropogenic N input (NANI) method to estimate human-induced N inputs to the drainage basin from 1980 to 2010, which covers the period of dramatic socioeconomic and environmental changes. For the last three decades, NANI increased linearly by a factor of three, from 4700 kg km(-2)year(-1) in 1980 to 12,600 kg km(-2)year(-1) in 2010. The main reason for the rise of NANI was due to fertilizer N application as well as human food and animal feed imports. From the perspective of direct effects of food consumption on N inputs, contributions of drivers were estimated in terms of human population and human diet using the Logarithmic Mean Divisia Index (LMDI) factor decomposition method. Although human population density is highly correlated to NANI with a linear correlation coefficient of 0.999, human diet rather than human population is found to be the single largest driver of NANI change, accounting for 47% of total alteration, which illustrates that the role of population density in the change of NANI may be overestimated through simple relational analysis. The strong linear relationships (p<0.01) between NANI and total N concentrations in the lakes over time may indicate that N level in the lake is able to respond significantly to N inputs to the drainage basin., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2015
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72. Phylogenetic analysis of canine parvovirus isolates from Sichuan and Gansu provinces of China in 2011.
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Xu J, Guo HC, Wei YQ, Shu L, Wang J, Li JS, Cao SZ, and Sun SQ
- Subjects
- Amino Acid Sequence, Animals, Base Sequence, Capsid Proteins genetics, China, Dogs, Genetic Variation, Molecular Sequence Data, Parvoviridae Infections epidemiology, Parvovirus, Canine genetics, Phylogeny, Sequence Analysis, DNA veterinary, Sequence Homology, Dog Diseases epidemiology, Dog Diseases virology, Parvoviridae Infections veterinary, Parvovirus, Canine classification
- Abstract
Canine parvovirus causes serious disease in dogs. Study of the genetic variation in emerging CPV strains is important for disease control strategy. The antigenic property of CPV is connected with specific amino acid changes, mainly in the capsid protein VP2. This study was carried out to characterize VP2 gene of CPV viruses from two provinces of China in 2011. The complete VP2 genes of the CPV-positive samples were amplified and sequenced. Genetic analysis based on the VP2 genes of CPV was conducted. All of the isolates screened and sequenced in this study were typed as CPV-2a except GS-K11 strain, which was typed as CPV-2b. Sequence comparison showed nucleotide identities of 98.8-100% among CPV strains, whereas the Aa similarities were 99.6-100%. Compared with the reference strains, there are three distinctive amino acid changes at VP2 gene residue 267, 324 and 440 of the strains isolated in this study. Of the 27 strains, fourteen (51.85%) had the 267 (Phe-Tyr) and 440 (Thr-Ala) substitution, all the 27 (100%) had 324 (Tyr-Ile) substitution. Phylogenetically, all of the strains isolated in this study formed a major monophyletic cluster together with one South Korean isolate, two Thailand isolates and four Chinese former isolates., (© 2013 Blackwell Verlag GmbH.)
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- 2015
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73. Three-dimensional structure of foot-and-mouth disease virus and its biological functions.
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Han SC, Guo HC, and Sun SQ
- Subjects
- Animals, Models, Molecular, Protein Conformation, Virus Assembly, Foot-and-Mouth Disease Virus physiology, Foot-and-Mouth Disease Virus ultrastructure, Viral Structural Proteins chemistry, Viral Structural Proteins metabolism
- Abstract
Foot-and-mouth disease (FMD), an acute, violent, infectious disease of cloven-hoofed animals, remains widespread in most parts of the world. It can lead to a major plague of livestock and an economical catastrophe. Structural studies of FMD virus (FMDV) have greatly contributed to our understanding of the virus life cycle and provided new horizons for the control and eradication of FMDV. To examine host-FMDV interactions and viral pathogenesis from a structural perspective, the structures of viral structural and non-structural proteins are reviewed in the context of their relevance for virus assembly and dissociation, formation of capsid-like particles and virus-receptor complexes, and viral penetration and uncoating. Moreover, possibilities for devising novel antiviral treatments are discussed.
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- 2015
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74. Three new sativene sesquiterpenoids from cultures of endophytic fungus Bipolaris eleusines.
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Ai HL, Yang MS, Zi SH, and Guo HC
- Subjects
- Antineoplastic Agents chemistry, Ascomycota, Drug Screening Assays, Antitumor, Female, Humans, Inhibitory Concentration 50, Molecular Structure, Nuclear Magnetic Resonance, Biomolecular, Sesquiterpenes chemistry, Sesquiterpenes pharmacology, Antineoplastic Agents isolation & purification, Antineoplastic Agents pharmacology, Sesquiterpenes isolation & purification
- Abstract
Three new sativene sesquiterpenoids, bipolenins A-C (1-3), together with two known analogs (4 and 5), were obtained from cultures of endophytic fungus Bipolaris eleusines. The structures of new compounds were elucidated on the basis of extensive spectroscopic analyses. Compound 2 showed weak inhibitory activities against lung cancer A-549 and breast cancer MCF-7 with IC50 values of 33.2 and 19.1 μmol, respectively.
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- 2015
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75. Structural basis of a point mutation that causes the genetic disease aspartylglucosaminuria.
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Sui L, Lakshminarasimhan D, Pande S, and Guo HC
- Subjects
- Crystallography, X-Ray, Humans, Models, Molecular, Aspartylglucosaminuria genetics, Aspartylglucosylaminase genetics, Point Mutation
- Abstract
Aspartylglucosaminuria (AGU) is a lysosomal storage disease caused by a metabolic disorder of lysosomes to digest Asn-linked glycoproteins. The specific enzyme linked to AGU is a lysosomal hydrolase called glycosylasparaginase. Crystallographic studies revealed that a surface loop blocks the catalytic center of the mature hydrolase. Autoproteolysis is therefore required to remove this P loop and open up the hydrolase center. Nonetheless, AGU mutations result in misprocessing of their precursors and are deficient in hydrolyzing glycoasparagines. To understand the catalytic and structural consequences of AGU mutations, we have characterized two AGU models, one corresponding to a Finnish allele and the other found in a Canadian family. We also report a 2.1 Å resolution structure of the latter AGU model. The current crystallographic study provides a high-resolution structure of an AGU mutant. It reveals substantial conformation changes at the defective autocleavage site of the AGU mutant, which is trapped as an inactive precursor., (Copyright © 2014 Elsevier Ltd. All rights reserved.)
- Published
- 2014
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76. Near-infrared upconversion nanoparticles for bio-applications.
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Dou QQ, Guo HC, and Ye E
- Subjects
- Animals, Drug Carriers chemistry, Humans, Infrared Rays, Lasers, Neoplasms diagnosis, Neoplasms drug therapy, Photochemotherapy, Photosensitizing Agents chemistry, Photosensitizing Agents therapeutic use, RNA Interference, RNA, Small Interfering chemistry, RNA, Small Interfering metabolism, Nanoparticles chemistry
- Abstract
Upconversion nanoparticles (UCNs) attract intensive attentions in biomedical applications. They have shown great potential in bioimaging, biomolecule detection, drug delivery, photodynamic therapy and cellular molecules interactions. Due to the anti-Stokes optical property and NIR excitation, UCNs overcome the drawbacks encountered in conventional luminescent biomarkers. High signal to noise ratio, low cytotoxicity and stable high throughput results are obtained using UCNs as luminescent labels or light triggers in biomedical applications. In this review article, the reason for choosing UCNs as biomedical agents, the progress of the UCNs development and case studies of their biomedical applications will be discussed., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2014
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77. [Rescue of the recombinant infectious bronchitis virus with the ectodomain region of H120 spike glycoprotein].
- Author
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Wei YQ, Guo HC, Wang HM, Sun DH, Han SC, and Sun SQ
- Subjects
- Animals, Chick Embryo, Chickens, Chlorocebus aethiops, Coronavirus Infections virology, Infectious bronchitis virus chemistry, Infectious bronchitis virus genetics, Infectious bronchitis virus growth & development, Protein Structure, Tertiary, Spike Glycoprotein, Coronavirus genetics, Transfection, Vero Cells, Coronavirus Infections veterinary, Infectious bronchitis virus metabolism, Poultry Diseases virology, Spike Glycoprotein, Coronavirus chemistry, Spike Glycoprotein, Coronavirus metabolism
- Abstract
To explore the expression potential of heterogeneous genes using the backbone of infectious bronchitis virus (IBV) Beaudette strain, the ectodomain region of the Spike gene (1,302 bp) of IBV H120 strain was amplified by RT-PCR and replaced into the corresponding location of the IBV Beaudette strain full-length cDNA. This recombinant was designated as BeauR-H120(S1). BeauR-H120(S1) was directly used as the DNA template for the transcription of viral genomic RNA in vitro. Then, the transcription product was transfected into Vero cells by electroporation. At 48 h post-transfection, the transfected Vero cells were harvested, and passaging continued. A syncytium was not observed until the recombinant virus had passed through four passages. The presence of rBeau-H120(S1) was verified by the detection of the replaced ectodomain region of the H120 Spike gene using RT-PCR. Western blot analysis of rBeau-H120 (S1)-infected Vero cell lysates demonstrated that the nucleocapsid (N) protein was expressed, which implied that rBeau-H120(S1) could propagate in Vero cells. The TCIDs0 and EIDs0 data demonstrated that the titer levels of rBeau-H120(S1) reached 10(590+/-0.22)TCID50/mL and 10(6.13+/-0.23)EID50/mL in Vero cells and 9-day-old SPF chicken embryos, respectively. Protection studies showed that the percentage of antibody-positive chickens, which were vaccinated with rBeau-H120(S1) at 7 days after hatching, rose to 90% at 21 days post-inoculation. Inoculation provided an 85% rate of immune protection against a challenge of the virulent IBV M41 strain (103EID50/chicken). This recombinant virus constructed using reverse genetic techniques could be further developed as a novel genetic engineering vaccine against infectious bronchitis.
- Published
- 2014
78. Topology and biological function of enterovirus non-structural protein 2B as a member of the viroporin family.
- Author
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Ao D, Sun SQ, and Guo HC
- Subjects
- Membrane Proteins metabolism, Molecular Sequence Data, Picornaviridae metabolism, Picornaviridae Infections virology, Sequence Analysis, DNA veterinary, Viral Nonstructural Proteins metabolism, Picornaviridae genetics, Picornaviridae Infections veterinary, Viral Nonstructural Proteins genetics
- Abstract
Viroporins are a group of transmembrane proteins with low molecular weight that are encoded by many animal viruses. Generally, viroporins are composed of 50-120 amino acid residues and possess a minimum of one hydrophobic region that interacts with the lipid bilayer and leads to dispersion. Viroporins are involved in destroying the morphology of host cells and disturbing their biological functions to complete the life cycle of the virus. The 2B proteins encoded by enteroviruses, which belong to the family Picornaviridae, can form transmembrane pores by oligomerization, increase the permeability of plasma membranes, disturb the homeostasis of calcium in cells, induce apoptosis, and cause autophagy; these abilities are shared among viroporins. The present paper introduces the structure and biological characteristics of various 2B proteins encoded by enteroviruses of the family Picornaviridae and may provide a novel idea for developing antiviral drugs.
- Published
- 2014
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79. An integrated simulation and optimization approach for managing human health risks of atmospheric pollutants by coal-fired power plants.
- Author
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Dai C, Cai XH, Cai YP, Guo HC, Sun W, Tan Q, and Huang GH
- Subjects
- Air Pollutants adverse effects, China, Environmental Monitoring, Humans, Respiration Disorders etiology, Risk Factors, Software Design, Air Pollutants analysis, Coal, Computer Simulation, Health Status Indicators, Nonlinear Dynamics, Power Plants, Smoke analysis
- Abstract
Unlabelled: This research developed a simulation-aided nonlinear programming model (SNPM). This model incorporated the consideration of pollutant dispersion modeling, and the management of coal blending and the related human health risks within a general modeling framework In SNPM, the simulation effort (i.e., California puff [CALPUFF]) was used to forecast the fate of air pollutants for quantifying the health risk under various conditions, while the optimization studies were to identify the optimal coal blending strategies from a number of alternatives. To solve the model, a surrogate-based indirect search approach was proposed, where the support vector regression (SVR) was used to create a set of easy-to-use and rapid-response surrogates for identifying the function relationships between coal-blending operating conditions and health risks. Through replacing the CALPUFF and the corresponding hazard quotient equation with the surrogates, the computation efficiency could be improved. The developed SNPM was applied to minimize the human health risk associated with air pollutants discharged from Gaojing and Shijingshan power plants in the west of Beijing. Solution results indicated that it could be used for reducing the health risk of the public in the vicinity of the two power plants, identifying desired coal blending strategies for decision makers, and considering a proper balance between coal purchase cost and human health risk., Implications: A simulation-aided nonlinear programming model (SNPM) is developed. It integrates the advantages of CALPUFF and nonlinear programming model. To solve the model, a surrogate-based indirect search approach based on the combination of support vector regression and genetic algorithm is proposed. SNPM is applied to reduce the health risk caused by air pollutants discharged from Gaojing and Shijingshan power plants in the west of Beijing. Solution results indicate that it is useful for generating coal blending schemes, reducing the health risk of the public, reflecting the trade-offbetween coal purchase cost and health risk.
- Published
- 2014
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80. Virus-like particles in picornavirus vaccine development.
- Author
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Dong H, Guo HC, and Sun SQ
- Subjects
- Drug Discovery trends, Humans, Picornaviridae Infections immunology, Drug Discovery methods, Picornaviridae immunology, Picornaviridae Infections prevention & control, Vaccines, Virus-Like Particle immunology, Viral Vaccines immunology
- Abstract
Virus-like particles (VLP), which are similar to natural virus particles but do not contain viral genes, have brought about significant breakthroughs in many research fields because of their unique advantages. The ordered repeating epitopes of VLP can induce immunity responses similar to those prompted by natural viral infection; thus, VLP vaccines are regarded as candidate alternatives to whole-virus vaccines. As picornavirus has serious impacts on human and animal health, the development of efficient and safe vaccines is a key endeavor in preventing virus infections. The characteristics of picornavirus capsid proteins allow the development of VLP vaccines. This paper investigates research scenarios and progress on picornavirus VLP vaccines with the aim of providing a reference for researchers focusing on virology and vaccinology.
- Published
- 2014
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81. Self-assembly of virus-like particles of canine parvovirus capsid protein expressed from Escherichia coli and application as virus-like particle vaccine.
- Author
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Xu J, Guo HC, Wei YQ, Dong H, Han SC, Ao D, Sun DH, Wang HM, Cao SZ, and Sun SQ
- Subjects
- Animals, Antibodies, Viral blood, Capsid Proteins genetics, Cell Proliferation, Dog Diseases immunology, Dog Diseases virology, Dogs, Escherichia coli genetics, Gene Expression, Injections, Subcutaneous, Lymphocytes immunology, Mice, Parvoviridae Infections immunology, Parvoviridae Infections prevention & control, Parvoviridae Infections virology, Parvovirus, Canine genetics, Recombinant Proteins genetics, Recombinant Proteins metabolism, Vaccination methods, Vaccines, Synthetic administration & dosage, Vaccines, Synthetic genetics, Vaccines, Synthetic immunology, Vaccines, Synthetic isolation & purification, Vaccines, Virus-Like Particle administration & dosage, Vaccines, Virus-Like Particle genetics, Vaccines, Virus-Like Particle isolation & purification, Viral Vaccines administration & dosage, Viral Vaccines genetics, Viral Vaccines isolation & purification, Capsid Proteins metabolism, Dog Diseases prevention & control, Parvoviridae Infections veterinary, Parvovirus, Canine immunology, Protein Multimerization, Vaccines, Virus-Like Particle immunology, Viral Vaccines immunology
- Abstract
Canine parvovirus disease is an acute infectious disease caused by canine parvovirus (CPV). Current commercial vaccines are mainly attenuated and inactivated; as such, problems concerning safety may occur. To resolve this problem, researchers developed virus-like particles (VLPs) as biological nanoparticles resembling natural virions and showing high bio-safety. This property allows the use of VLPs for vaccine development and mechanism studies of viral infections. Tissue-specific drug delivery also employs VLPs as biological nanomaterials. Therefore, VLPs derived from CPV have a great potential in medicine and diagnostics. In this study, small ubiquitin-like modifier (SUMO) fusion motif was utilized to express a whole, naturalVP2 protein of CPV in Escherichia coli. After the cleavage of the fusion motif, the CPV VP2 protein has self-assembled into VLPs. The VLPs had a size and shape that resembled the authentic virus capsid. However, the self-assembly efficiency of VLPs can be affected by different pH levels and ionic strengths. The mice vaccinated subcutaneously with CPV VLPs and CPV-specific immune responses were compared with those immunized with the natural virus. This result showed that VLPs can effectively induce anti-CPV specific antibody and lymphocyte proliferation as a whole virus. This result further suggested that the antigen epitope of CPV was correctly present on VLPs, thereby showing the potential application of a VLP-based CPV vaccine.
- Published
- 2014
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82. New triterpene saponins from the roots of Glycyrrhiza yunnanensis and their rapid screening by LC/MS/MS.
- Author
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Ji S, Wang Q, Qiao X, Guo HC, Yang YF, Bo T, Xiang C, Guo DA, and Ye M
- Subjects
- China, Magnetic Resonance Spectroscopy, Medicine, Chinese Traditional, Plant Extracts analysis, Plant Extracts chemistry, Plant Roots, Saponins analysis, Saponins isolation & purification, Triterpenes analysis, Triterpenes isolation & purification, Chromatography, Liquid methods, Glycyrrhiza chemistry, Saponins chemistry, Tandem Mass Spectrometry methods, Triterpenes chemistry
- Abstract
The roots of Glycyrrhiza yunnanensis Cheng f. et L. K. Dai ex P. C. Li are used as licorice in traditional medicine of Southwest China. Triterpene saponins are the major chemical constituents. In this study, one new oleanane-type triterpenoid, glyyunnansapogenin I (I), seven new triterpene saponins, yunganosides E3 (II), L (III), M (IV), N1 (V), O (VI), P (VII) and N2 (VIII), together with four known saponins (IX-XII) were isolated from the roots of G. yunnanensis by preparative chromatography. Their structures were identified by spectroscopic analysis including NMR and HR-MS. Based on (-)-ESI-MS/MS fragmentation behaviors of these reference standards, an LC/MS/MS method using neutral loss scan and precursor ion scan on a triple quadrupole mass spectrometer was established to rapidly and comprehensively analyze triterpene saponins in G. yunnanensis. Combined with high-accuracy qTOF mass spectrometry analysis, a total of 50 saponins were detected, and their structures were identified or tentatively characterized. This is the first systematic study on triterpene saponins in G. yunnanensis., (Copyright © 2013. Published by Elsevier B.V.)
- Published
- 2014
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83. Mitochondrial permeability transition pore plays a role in the cardioprotection of CB2 receptor against ischemia-reperfusion injury.
- Author
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Li Q, Guo HC, Maslov LN, Qiao XW, Zhou JJ, and Zhang Y
- Subjects
- Animals, Cannabinoids pharmacology, Cytochromes c metabolism, MAP Kinase Signaling System physiology, Male, Mitochondria, Heart drug effects, Mitochondria, Heart metabolism, Mitochondrial Membrane Transport Proteins drug effects, Mitochondrial Permeability Transition Pore, Myocardial Infarction pathology, Myocardial Infarction prevention & control, Myocardial Reperfusion Injury physiopathology, Myocardial Reperfusion Injury prevention & control, Rats, Rats, Sprague-Dawley, Receptor, Cannabinoid, CB2 agonists, Mitochondrial Membrane Transport Proteins physiology, Myocardial Reperfusion Injury metabolism, Receptor, Cannabinoid, CB2 metabolism
- Abstract
The aim of this study was to investigate whether the mitochondrial permeability transition pore (MPTP) opening was involved in the protective effects of CB2 receptor against ischemia-reperfusion (I-R) injury. For this, isolated perfused rat hearts were subjected to 30 min global ischemia followed by 120 min reperfusion, and left ventricle function was recorded. At the end of reperfusion, the infarct size in the hearts was measured by staining with triphenyltetrazolium chloride. MPTP opening and the mitochondrial membrane potential (ΔΨ(m)) were measured by flow cytometry. Western blot analysis of cytochrome c in the mitochondrion and cytosol, as well as ERK1/2 and p-ERK1/2 were performed. Administration of CB2 receptor agonist JWH133 before ischemia significantly improved the recovery of cardiac ventricular function during reperfusion, increased coronary flow, reduced infarct size, prevented the loss of ΔΨ(m) and MPTP opening, reduced the release of cytochrome c from mitochondria, and increased levels of p-ERK1/2. These effects of JWH133 were abolished by pretreatment with CB2 receptor antagonist AM630, or ERK1/2 inhibitor PD98059. Furthermore, JWH133 reversed the MPTP opening induced by atractyloside. The protective effect of JWH133 on the heart against I-R injury may be through increased ERK1/2 phosphorylation, inhibiting MPTP opening.
- Published
- 2014
- Full Text
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84. Development and characterization of a recombinant infectious bronchitis virus expressing the ectodomain region of S1 gene of H120 strain.
- Author
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Wei YQ, Guo HC, Dong H, Wang HM, Xu J, Sun DH, Fang SG, Cai XP, Liu DX, and Sun SQ
- Subjects
- Animals, Chickens, Coronavirus Infections immunology, Infectious bronchitis virus genetics, Poultry Diseases immunology, Viral Vaccines immunology, Infectious bronchitis virus immunology
- Abstract
Infectious bronchitis (IB), caused by infectious bronchitis virus (IBV), is a highly contagious chicken disease, and can lead to serious economic losses in poultry enterprises. The continual introduction of new IBV serotypes requires alternative strategies for the production of timely and safe vaccines against the emergence of variants. Modification of the IBV genome using reverse genetics is one way to generate recombinant IBVs as the candidates of new IBV vaccines. In this study, the recombinant IBV is developed by replacing the ectodomain region of the S1 gene of the IBV Beaudette strain with the corresponding fragment from H120 strain, designated as rBeau-H120(S1e). In Vero cells, the virus proliferates as its parental virus and can cause syncytium formation. The peak titer would reach 10(5.9) 50% (median) tissue culture infective dose/mL at 24 h post-infection. After inoculation of chickens with the recombinant virus, it demonstrated that rBeau-H120(S1e) remained nonpathogenic and was restricted in its replication in vivo. Protection studies showed that vaccination with rBeau-H120 (S1e) at 7-day after hatch provided 80% rate of immune protection against challenge with 10(3) 50% embryos infection dose of the virulent IBV M41 strain. These results indicate that rBeau-H120 (S1e) has the potential to be an alternative vaccine against IBV based on excellent propagation property and immunogenicity. This finding might help in providing further information that replacement of the ectodomain fragment of the IBV Beaudette S1 gene with that from a present field strain is promising for IBV vaccine development.
- Published
- 2014
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85. Mechanisms of isoform-specific Na/K pump regulation by short- and long-term adrenergic activation in rat ventricular myocytes.
- Author
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Yin J, Guo HC, Yu D, Wang HC, Li JX, and Wang YL
- Subjects
- Adrenergic Agents pharmacology, Animals, Blotting, Western, Cell Membrane metabolism, Cells, Cultured, Cyclic AMP-Dependent Protein Kinases metabolism, Endosomes metabolism, Gene Expression Regulation, Enzymologic drug effects, Isoenzymes genetics, Isoenzymes metabolism, Myocytes, Cardiac metabolism, Protein Kinase C metabolism, Protein Transport drug effects, Rats, Sprague-Dawley, Reverse Transcriptase Polymerase Chain Reaction, Sodium-Potassium-Exchanging ATPase genetics, Time Factors, Isoproterenol pharmacology, Myocytes, Cardiac drug effects, Norepinephrine pharmacology, Sodium-Potassium-Exchanging ATPase metabolism
- Abstract
Background: Many stressful conditions, including cardiovascular diseases, induce long-term elevations in circulating catecholamines, thereby leading to changes of the Na/K pump and thus affecting myocardial functions. However, only short-term adrenergic regulation of the Na/K pump has been reported. The present study is the first investigation of long-term adrenergic regulation of the Na/K pump and the potential mechanism., Methods: After acutely isolated Sprague-Dawley rat myocytes were incubated with noradrenaline or isoprenaline for 24 h, Na/K pump high- (IPH) and low-affinity current (IPL), α-isoform mRNA, and α-isoform protein were examined using patch-clamp, RT-PCR, and Western blotting techniques, respectively., Results: After the short-term incubation, isoprenaline reduced the IPL through a PKA-dependent pathway that involves α1-isoform translocation from the membrane to early endosomes, and noradrenaline increased the IPH through a PKC-dependent pathway that involves α2-isoform translocation from late endosomes to the membrane. After long-term incubation, isoprenaline increased the IPL, α1-isoform mRNA, and α1-isoform protein, and noradrenaline reduced the IPH, α2-isoform mRNA, and α1-isoform protein through a PKA-or PKC-dependent pathway, respectively., Conclusions: These results suggest that long-term adrenergic Na/K pump regulation is isoform-specific and negatively feeds back on the short-term response. Furthermore, long-term regulation involves transcription and translation of the respective α-isoform, whereas short-term regulation involves the translocation of the available α-isoform to the plasma membrane., (© 2014 S. Karger AG, Basel.)
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- 2014
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86. [Study on the stages of major sediments in Dianchi lake].
- Author
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Wang XY, Zhou F, Yi X, and Guo HC
- Subjects
- China, Environmental Monitoring, Geologic Sediments chemistry, Lakes chemistry, Metals, Heavy analysis, Water Pollutants, Chemical analysis
- Abstract
The statistical technique self-organizing maps (SOM) was applied for stages analysis of Lake Dianchi sediments, southwestern China. The dataset of nine pollutants, including Cd, Cr, Cu, Hg, Pb, Sn, Zn, TP and KN, was observed and collected for 10 monitoring sites from 1991 to 2010. The results show that the 20 years' study could be divided into 4 stages. In stage one (1991 to 1995) , concentrations of sediments are relativity low. In the second stage (1996 to 2001) , concentrations of most sediments are higher than the stage before and show increasing trends. In the following stage (2002 to 2006), majority of the observed sediments exhibit fluctuation characteristics. Nevertheless, different concentration patterns exist among different pollutants, the concentration climaxes of most pollutants have been observed during the year 1996 to 1999 and 2005 to 2007. According to the relevant information gathering from yearly lake pollution load, the national survey of pollution sources etc., the reason for the above stages and concentration patterns of observed sediments are analyzed. The result shows that sediment concentration is sensitive to human activities in the basin, such as pollution emission as well as controlling.
- Published
- 2014
87. Four new C18-diterpenoid alkaloids with analgesic activity from Aconitum weixiense.
- Author
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Zhao DK, Ai HL, Zi SH, Zhang LM, Yang SC, Guo HC, Shen Y, Chen YP, and Chen JJ
- Subjects
- Acetic Acid, Aconitine chemistry, Aconitine isolation & purification, Aconitine pharmacology, Aconitine therapeutic use, Analgesics chemistry, Analgesics isolation & purification, Analgesics pharmacology, Animals, Drugs, Chinese Herbal isolation & purification, Drugs, Chinese Herbal pharmacology, Drugs, Chinese Herbal therapeutic use, Mice, Mice, Inbred Strains, Molecular Structure, Pain chemically induced, Phytotherapy, Aconitine analogs & derivatives, Aconitum chemistry, Analgesics therapeutic use, Pain drug therapy
- Abstract
Four new C18-diterpenoid alkaloids, weisaconitines A-D (1-4), were isolated from Aconitum weixiense. Based on extensive UV, IR, MS, 1D and 2D NMR analyses, their structures were elucidated as 8-O-ethyldolaconine (1), 4-demethylgenicunine B (2), 14-oxoaconosine (3), and 8-O-ethylaconosine (4). The analgesic activity of compound 4 was studied with CH3COOH-induced writhing model in mice. Compound 4 showed writhing inhibitions of 24% (50 mg/kg), 26% (100 mg/kg) and 34% (200 mg/kg), respectively, as compared to the reference drug aspirin (63%) at a dose of 200 mg/kg., (© 2013.)
- Published
- 2013
- Full Text
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88. The protective effect of grape seed procyanidin extract against cadmium-induced renal oxidative damage in mice.
- Author
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Chen Q, Zhang R, Li WM, Niu YJ, Guo HC, Liu XH, Hou YC, and Zhao LJ
- Subjects
- Animals, Antioxidants chemistry, Apoptosis drug effects, Biflavonoids chemistry, Blotting, Western, Body Weight drug effects, Cadmium Poisoning pathology, Catechin chemistry, Flow Cytometry, Glutathione Peroxidase metabolism, Immunohistochemistry, Kidney Diseases chemically induced, Kidney Diseases prevention & control, Malondialdehyde metabolism, Mice, Organ Size drug effects, Oxidative Stress drug effects, Proanthocyanidins chemistry, Proto-Oncogene Proteins c-bcl-2 biosynthesis, Seeds chemistry, Superoxide Dismutase metabolism, bcl-2-Associated X Protein biosynthesis, Antioxidants pharmacology, Biflavonoids pharmacology, Cadmium Poisoning prevention & control, Catechin pharmacology, Kidney pathology, Kidney Diseases pathology, Plant Extracts pharmacology, Proanthocyanidins pharmacology, Vitis chemistry
- Abstract
As an important environmental pollutant, cadmium (Cd) can lead to serious renal damage. Grape seed procyanidins extract (GSPE), a biological active component of grape seed, has been shown to possess antioxidative effects. Here, we assessed the protective effect of GSPE on Cd-induced renal damage using animal experiment. After 30 days, the oxidative damage of kidney was evaluated through measurement of superoxide dismutase (SOD), glutathione peroxidation (GSH-Px) and malondialdehyde (MDA). Since, oxidative stress could lead to apoptosis, the renal apoptosis was measured using flow cytometer. Moreover, the expression of apoptosis-related protein Bax and Bcl-2 was analyzed by immunohistochemistry and Western blot. The results showed that Cd led to the decrease of SOD and GSH-Px activities, and the increase of MDA level, induced renal apoptosis. However, the coadministration of GSPE attenuated Cd-induced lipid peroxidation, and antagonized renal apoptosis, probably associated with the expression of Bax and Bcl-2. These data suggested that GSPE has protective effect against renal oxidative damage induced by Cd, which provide a potential natural chemopreventive agent against Cd-poisoning., (Copyright © 2013 Elsevier B.V. All rights reserved.)
- Published
- 2013
- Full Text
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89. [Early experience of resection of meningiomas in anterior skull base with intra-extracranial extension via a pure endoscopic endonasal approach].
- Author
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Wang ZL, Zhang QH, Guo HC, Kong F, Chen G, Bao YH, and Ling F
- Subjects
- Adult, Aged, Endoscopy methods, Female, Humans, Male, Middle Aged, Nose surgery, Skull Base surgery, Treatment Outcome, Meningeal Neoplasms surgery, Meningioma surgery, Skull Base Neoplasms surgery
- Abstract
Objective: The early experience of treating anterior skull base meningiomas with intra-extracranial extension via pure endoscopic endonasal approach (EEA) was presented, the safety, feasibility and preliminary treatment outcomes were investigated., Methods: Eight patients with intra-extradural meningiomas who were admitted from October 2006 to October 2010 were operated on via EEA in one stage in Xuanwu hospital. In this study, the operative technique was described, the degree of resection, complications and the early clinical outcomes were discussed., Results: The complete resection of meningiomas with intra-extracranial extension was achieved in all patients using EEA in one stage. Preoperative visual symptoms were improved or resolved in all cases who presented with preoperative visual complaints. No patient in our series experienced a new neurological deficit after surgery or recurrence and death related meningiomas in the follow-up period (33-75 months). One patient experienced postoperative cerebrospinal fluid leak, delayed meningitis and secondary hydrocephalus which responded to therapy. After treatment, the patient was cure., Conclusion: Our limited experience indicates that EEA is feasible and safe for the complete resection of anterior skull base meningiomas with intra- and extracranial extension in one stage in selected cases.
- Published
- 2013
90. Genetic typing of classical swine fever virus isolates from China.
- Author
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Sun SQ, Yin SH, Guo HC, Jin Y, Shang YJ, and Liu XT
- Subjects
- Animals, China epidemiology, Classical Swine Fever epidemiology, Classical Swine Fever Virus isolation & purification, Phylogeny, RNA, Messenger genetics, Real-Time Polymerase Chain Reaction, Reverse Transcriptase Polymerase Chain Reaction, Swine, Viral Envelope Proteins genetics, Classical Swine Fever virology, Classical Swine Fever Virus classification, Classical Swine Fever Virus genetics, Disease Outbreaks veterinary, RNA, Viral genetics
- Abstract
The E2 genes of 73 classical swine fever virus (CSFV) originated from CSF suspected cases in different regions of China were genetically characterized and compared with reference CSF viruses. All Chinese viruses that characterized were segregated into two major groups and subdivided into four subgroups. Most of isolates (61.6%) belonged to group 2 and were further divided into three subgroups: subgroup 2.1, 2.2 and 2.3. Subgroup 2.1 was the largest subgroup which contained 46.6% of isolates, while subgroup 2.3 was the smallest subgroup which contained only one isolate (1.4%). The remaining 38.4% of isolates were classified into subgroup 1.1 within group 1. However, no group 3 and subgroups 1.2 and 1.3 viruses were found in this study. This study has provided epidemiological information useful for assessing the virus origin and establishing a national prevention and control strategy against the disease., (© 2012 Blackwell Verlag GmbH.)
- Published
- 2013
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91. Foot-and-mouth disease virus-like particles produced by a SUMO fusion protein system in Escherichia coli induce potent protective immune responses in guinea pigs, swine and cattle.
- Author
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Guo HC, Sun SQ, Jin Y, Yang SL, Wei YQ, Sun DH, Yin SH, Ma JW, Liu ZX, Guo JH, Luo JX, Yin H, Liu XT, and Liu DX
- Subjects
- Animals, Capsid Proteins immunology, Escherichia coli, Escherichia coli Proteins metabolism, Foot-and-Mouth Disease virology, SUMO-1 Protein metabolism, Vaccines, Virus-Like Particle administration & dosage, Viral Vaccines administration & dosage, Cattle immunology, Foot-and-Mouth Disease immunology, Foot-and-Mouth Disease Virus immunology, Guinea Pigs immunology, Swine immunology, Vaccines, Virus-Like Particle immunology, Viral Vaccines immunology
- Abstract
Foot-and-mouth disease virus (FMDV) causes a highly contagious infection in cloven-hoofed animals. The format of FMD virus-like particles (VLP) as a non-replicating particulate vaccine candidate is a promising alternative to conventional inactivated FMDV vaccines. In this study, we explored a prokaryotic system to express and assemble the FMD VLP and validated the potential of VLP as an FMDV vaccine candidate. VLP composed entirely of FMDV (Asia1/Jiangsu/China/2005) capsid proteins (VP0, VP1 and VP3) were simultaneously produced as SUMO fusion proteins by an improved SUMO fusion protein system in E. coli. Proteolytic removal of the SUMO moiety from the fusion proteins resulted in the assembly of VLP with size and shape resembling the authentic FMDV. Immunization of guinea pigs, swine and cattle with FMD VLP by intramuscular inoculation stimulated the FMDV-specific antibody response, neutralizing antibody response, T-cell proliferation response and secretion of cytokine IFN-γ. In addition, immunization with one dose of the VLP resulted in complete protection of these animals from homologous FMDV challenge. The 50% protection dose (PD50) of FMD VLP in cattle is up to 6.34. These results suggest that FMD VLP expressed in E. coli are an effective vaccine in guinea pigs, swine and cattle and support further development of these VLP as a vaccine candidate for protection against FMDV.
- Published
- 2013
- Full Text
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92. Viroporin activity and membrane topology of classic swine fever virus p7 protein.
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Guo HC, Sun SQ, Sun DH, Wei YQ, Xu J, Huang M, Liu XT, Liu ZX, Luo JX, Yin H, and Liu DX
- Subjects
- Amino Acid Sequence, Animals, Anti-Bacterial Agents, Cell Line, Cell Membrane metabolism, Hygromycin B, Membrane Proteins metabolism, Sequence Analysis, Protein, Swine, Virus Release, Virus Replication, Cell Membrane Permeability, Classical Swine Fever Virus metabolism, Nucleocapsid Proteins metabolism, Viral Regulatory and Accessory Proteins metabolism
- Abstract
Viroporins are a group of viral proteins that participate in viral replication cycles, including modification of membrane permeability and promotion of viral release. Although biological data have been accumulated on viroporion-like proteins of other viruses belonging to family Flaviviridae, the viroporin activity and membrane topology of p7 protein from classical swine fever virus (CSFV), a member of the genus Pestivirus of the family Flaviviridae, are largely unknown. In this study, sequence analysis of the primary structure of p7 polypeptide demonstrates that p7 contains two putative transmembrane regions connected by a short hydrophilic segment. Expression of p7 protein in Escherichia coli leads to the permeabilization of bacterial cells to small molecules. The p7 protein also enhances the permeability of mammalian cells, increasing the intracellular Ca(2+) concentration and the permeability of cells to the translation inhibitor Hygromycin B. This protein is an integral membrane protein and can form homo-oligomers. It mainly localizes to the ER at the early stage of the expression and can be transferred to the plasma membrane at the late stage of the expression. Detergent permeabilization assays confirmed that the p7 protein is a 2-pass transmembrane protein and its N and C termini are exposed to the ER lumen. Deletion analysis showed that amino acid residues 41-63 may be essential for the viroporin activity of the protein. Our studies demonstrate that CSFV p7 possesses properties commonly associated with viroporins, which could be a potential target for the development of a therapeutic intervention for classic swine fever virus infection., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
- Full Text
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93. [First flush effects of storm events of Baoxiang River in Lake Dianchi Watershed].
- Author
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Guo HC, Xiang N, Zhou F, Wang YH, Li FR, Zhu X, Mao GZ, Yu SX, Li N, Sheng H, Yang YH, He CJ, and Wang CY
- Subjects
- China, Eutrophication, Lakes, Environmental Monitoring, Rain, Rivers, Water Movements, Water Pollutants, Chemical analysis
- Abstract
To understand riverine process of non-point source effectively, first flush effects of storm events were investigated at Baoxiang River of Lake Dianchi Watershed. Three sampling stations were selected along Baoxiang River for observing the flow rate and pollutant concentrations of the first three storm events from June 2009 to August 2009. Net discharged volume, net discharged loading, and net event mean concentration (EMC(n)) were proposed with their calculation methods. According to the analysis of three storm events at three stations, the following results colcd be extracted: (1) the larger the percent of impervious land and population density were, the higher EMC(n) of TSS, TN, TP, permanganate index and their cumulative curves [M(V)] were along the river; (2) TSS, TP loadings as well as their M (V) were positively correlated to the storm intensity, while TN and permanganate index loadings were consistent with the total rainfall of each storm event, where the percent of NO3(-) -N in total nitrogen decreased gradually when the number of storm events increased; (3) compared to tradition EMC, EMC(n) was proven to be a better indicator to accurately uncover and magnify the differences in first flush effects of storm events among different stations or storm events.
- Published
- 2013
94. [An object-oriented intelligent engineering design approach for lake pollution control].
- Author
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Zou R, Zhou J, Liu Y, Zhu X, Zhao L, Yang PJ, and Guo HC
- Subjects
- China, Fresh Water analysis, Eutrophication, Lakes, Water Pollutants, Chemical analysis, Water Pollution prevention & control, Water Quality
- Abstract
Regarding the shortage and deficiency of traditional lake pollution control engineering techniques, a new lake pollution control engineering approach was proposed in this study, based on object-oriented intelligent design (OOID) from the perspective of intelligence. It can provide a new methodology and framework for effectively controlling lake pollution and improving water quality. The differences between the traditional engineering techniques and the OOID approach were compared. The key points for OOID were described as object perspective, cause and effect foundation, set points into surface, and temporal and spatial optimization. The blue algae control in lake was taken as an example in this study. The effect of algae control and water quality improvement were analyzed in details from the perspective of object-oriented intelligent design based on two engineering techniques (vertical hydrodynamic mixer and pumping algaecide recharge). The modeling results showed that the traditional engineering design paradigm cannot provide scientific and effective guidance for engineering design and decision-making regarding lake pollution. Intelligent design approach is based on the object perspective and quantitative causal analysis in this case. This approach identified that the efficiency of mixers was much higher than pumps in achieving the goal of low to moderate water quality improvement. However, when the objective of water quality exceeded a certain value (such as the control objective of peak Chla concentration exceeded 100 microg x L(-1) in this experimental water), the mixer cannot achieve this goal. The pump technique can achieve the goal but with higher cost. The efficiency of combining the two techniques was higher than using one of the two techniques alone. Moreover, the quantitative scale control of the two engineering techniques has a significant impact on the actual project benefits and costs.
- Published
- 2013
95. Emodin induces Panc-1 cell apoptosis via declining the mitochondrial membrane potential.
- Author
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Liu JX, Zhang JH, Li HH, Lai FJ, Chen KJ, Chen H, Luo J, Guo HC, Wang ZH, and Lin SZ
- Subjects
- Animals, Cell Line, Tumor, Cell Proliferation drug effects, Drugs, Chinese Herbal administration & dosage, Drugs, Chinese Herbal pharmacology, Drugs, Chinese Herbal therapeutic use, Eating, Emodin administration & dosage, Emodin therapeutic use, Humans, Male, Mice, Mice, Inbred BALB C, Mice, Nude, Pancreatic Neoplasms pathology, Pancreatic Neoplasms physiopathology, Protein Kinase Inhibitors administration & dosage, Protein Kinase Inhibitors pharmacology, Protein Kinase Inhibitors therapeutic use, Apoptosis drug effects, Emodin pharmacology, Membrane Potential, Mitochondrial drug effects, Pancreatic Neoplasms drug therapy
- Abstract
In this study, we investigated the apoptotic effect of emodin on human pancreatic cancer cell line Panc-1 in vitro and in vivo as well as the possible mechanisms involved. In vitro, human pancreatic cancer cell line Panc-1 was exposed to varying concentrations of emodin (0, 10, 20, 40 or 80 µmol/l). Then the mitochondrial membrane potential (MMP) was analyzed by JC-1 staining, cell apoptosis was analyzed by flow cytometry (FCM) and cell proliferation was analyzed by MTT. In vivo, nude mice orthotopically implanted were randomly divided into five groups to receive treatments by different doses of emodin: control group (normal saline 0.2 ml), E10 group (emodin 10 mg/kg), E20 group (emodin 20 mg/kg), E40 group (emodin 40 mg/kg) and E80 group (emodin 80 mg/kg). Each mouse was treated 5 times by intraperitoneal injection of emodin every 3 days. During the treatment, the feeding stuff was recorded. One week after the last treatment, we recorded the body weight and the maximum diameter of tumor in each group before the mice were sacrificed. Then the cell apoptosis of the tumor was tested by TUNEL assay. The results in vitro showed that the MMP of the cells declined and the apoptosis rate increased with the emodin concentration increasing and the cell proliferation of each group was inhibited in a dose- and time-dependent manner by emodin. The feeding stuff curve did not decline significantly in E40 group and the apoptosis rate of the tumor cells in this group was higher than the lower-dose groups. Taken together, our results demonstrate that emodin may induce the pancreatic cancer cell apoptosis via declining the MMP and a moderate dose of emodin improved the living state of the model mice.
- Published
- 2012
- Full Text
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96. Oridonin enhances antitumor activity of gemcitabine in pancreatic cancer through MAPK-p38 signaling pathway.
- Author
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Bu HQ, Luo J, Chen H, Zhang JH, Li HH, Guo HC, Wang ZH, and Lin SZ
- Subjects
- Animals, Antimetabolites, Antineoplastic pharmacology, Antineoplastic Combined Chemotherapy Protocols pharmacology, Apoptosis drug effects, Cell Cycle Checkpoints drug effects, Cell Line, Tumor, Cell Proliferation drug effects, Deoxycytidine pharmacology, Drug Resistance, Neoplasm, Drug Synergism, Female, Humans, Mice, Mice, Inbred BALB C, Mice, Nude, Pancreatic Neoplasms metabolism, Random Allocation, Tumor Suppressor Protein p53 biosynthesis, Tumor Suppressor Protein p53 metabolism, Xenograft Model Antitumor Assays, p38 Mitogen-Activated Protein Kinases biosynthesis, Gemcitabine, Deoxycytidine analogs & derivatives, Diterpenes, Kaurane pharmacology, MAP Kinase Signaling System, Pancreatic Neoplasms drug therapy, p38 Mitogen-Activated Protein Kinases metabolism
- Abstract
Gemcitabine is currently the best treatment available for pancreatic cancer (PaCa); however, patients with the disease develop resistance to the drug over time. Agents that can either enhance the effects of gemcitabine or overcome chemoresistance to the drug are required for the treatment of PaCa. Oridonin is one such agent which is safe and multitargeted, and has been linked with the suppression of survival, proliferation, invasion and angiogenesis of cancer. In this study, we investigated whether oridonin could sensitize PaCa to gemcitabine in vitro and in vivo. In vitro, oridonin inhibited the proliferation of the PaCa cell line, BxPC-3, potentiated the apoptosis induced by gemcitabine, induced G1 cell cycle arrest and activated p38 and p53; these results were significant when oridonin was combined with gemcitabine. In vivo, we found that oridonin significantly suppressed tumor growth and this effect was further enhanced by gemcitabine (P<0.05). Tumors from nude mice injected with BxPC-3 PaCa cells and treated with a combination of oridonin and gemcitabine showed a significant upregulation in p38 and p53 activation (P<0.05 vs. control, P<0.05 vs. gemcitabine or oridonin alone). Taken together, our results demonstrate that oridonin can potentiate the effects of gemcitabine in PaCa through the mitogen-activated protein kinase (MAPK)-p38 signaling pathway, which is dependent on p53 activation.
- Published
- 2012
- Full Text
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97. Highly enantioselective addition of 1,3-diynes to aldehydes catalyzed by a zinc-amino alcohol complex.
- Author
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Zheng B, Li SN, Mao JY, Wang B, Bian QH, Liu SZ, Zhong JC, Guo HC, and Wang M
- Subjects
- Catalysis, Molecular Structure, Stereoisomerism, Aldehydes chemistry, Amino Alcohols chemistry, Diynes chemistry, Organometallic Compounds chemistry, Zinc chemistry
- Abstract
Asymmetric catalysis: A highly enantioselective and efficient procedure for the amino alcohol-zinc-catalyzed addition of 1,3-diynes to various aromatic, α,β-unsaturated, and aliphatic aldehydes has been developed. The present catalytic system was successfully applied in the concise synthesis of natural products such as (S)-strongylodiols A and B (see scheme)., (Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2012
- Full Text
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98. The H₁-H₂ domain of the α₁ isoform of Na+-K+-ATPase is involved in ouabain toxicity in rat ventricular myocytes.
- Author
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Xiong C, Li JX, Guo HC, Zhang LN, Guo W, Meng J, and Wang YL
- Subjects
- Animals, Antibodies immunology, Antibody Specificity, Binding Sites, Blotting, Western, Calcium metabolism, Cardiac Glycosides administration & dosage, Cardiotonic Agents administration & dosage, Cardiotonic Agents toxicity, Dose-Response Relationship, Drug, Enzyme-Linked Immunosorbent Assay, Heart Ventricles cytology, Heart Ventricles pathology, Isoenzymes, Male, Membrane Potential, Mitochondrial drug effects, Myocytes, Cardiac pathology, Ouabain administration & dosage, Rats, Rats, Sprague-Dawley, Sodium-Potassium-Exchanging ATPase metabolism, Cardiac Glycosides toxicity, Heart Ventricles drug effects, Myocytes, Cardiac drug effects, Ouabain toxicity, Sodium-Potassium-Exchanging ATPase drug effects
- Abstract
The composition of different isoforms of Na+-K+-ATPase (NKA, Na/K pump) in ventricular myocytes is an important factor in determining the therapeutic effect and toxicity of cardiac glycosides (CGs) on heart failure. The mechanism whereby CGs cause these effects is still not completely clear. In the present study, we prepared two site-specific antibodies (SSA78 and WJS) against the H₁-H₂ domain of α₁ and α₂ isoforms of NKA in rat heart, respectively, and compared their influences on the effect of ouabain (OUA) in isolated rat ventricular myocytes. SSA78 or WJS, which can specifically bind with the α₁ or α₂ isoform, were assessed with enzyme linked immunosorbent assay (ELISA), Western blot and immunofluorescent staining methods. Preincubation of myocytes with SSA78 inhibited low OUA affinity pump current but not high OUA affinity pump current, reduced the rise in cytosolic calcium concentration ([Ca²⁺](i)), attenuated mitochondrial Ca²⁺ overload, restored mitochondrial membrane potential reduction, and delayed the decrease of the myocardial contractile force as well as the occurrence of arrhythmic contraction induced by high concentrations (1 mM) but not low concentrations (1 μM) of OUA. Similarly, preincubation of myocytes with WJS inhibited high OUA affinity pump current, reduced the increase of [Ca²⁺](i) and the contractility induced by 1 μM but not that induced by 1 mM OUA. These results indicate that the H₁-H₂ domain of the NKA α₁ isoform mediates OUA-induced cardiac toxicity in rat ventricular myocytes, and inhibitors for this binding site may be used as an adjunct to CGs treatment for cardiovascular disease., (Copyright © 2012 Elsevier Inc. All rights reserved.)
- Published
- 2012
- Full Text
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99. Immunization of mice by hollow mesoporous silica nanoparticles as carriers of porcine circovirus type 2 ORF2 protein.
- Author
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Guo HC, Feng XM, Sun SQ, Wei YQ, Sun DH, Liu XT, Liu ZX, Luo JX, and Yin H
- Subjects
- Animals, Antibodies, Viral blood, CD4-Positive T-Lymphocytes immunology, CD8-Positive T-Lymphocytes immunology, Cell Proliferation, Interferon-gamma metabolism, Mice, Spleen immunology, Viral Vaccines administration & dosage, Circovirus immunology, Drug Carriers administration & dosage, Nanoparticles administration & dosage, Silicon Dioxide administration & dosage, Vaccination methods, Viral Proteins immunology, Viral Vaccines immunology
- Abstract
Background: Porcine circovirus type 2 (PCV2) is a primary etiological agent of post-weaning multi-systemic wasting syndrome (PMWS), which is a disease of increasing importance to the pig industry worldwide. Hollow mesoporous silica nanoparticles (HMSNs) have gained increasing interest for use in vaccines., Methods: To study the potential of HMSNs for use as a protein delivery system or vaccine carriers. HMSNs were synthesized by a sol-gel/emulsion(oil-in-water/ethanol) method, purified PCV2 GST-ORF2-E protein was loaded into HMSNs, and the resulting HMSN/protein mixture was injected into mice. The uptake and release profiles of protein by HMSNs in vitro were investigated. PCV2 GST-ORF2-E specific antibodies and secretion of IFN-γ were detected by enzyme-linked immunosorbent assays, spleen lymphocyte proliferation was measured by the MTS method, and the percentage of CD4+ and CD8+ were determined by flow cytometry., Results: HMSNs were found to yield better binding capacities and delivery profiles of proteins; the specific immune response induced by PCV2 GST-ORF2-E was maintained for a relatively long period of time after immunization with the HMSN/protein complex., Conclusion: The findings suggest that HMSNs are good protein carriers and have high potential for use in future applications in therapeutic drug delivery.
- Published
- 2012
- Full Text
- View/download PDF
100. Emodin potentiates the antitumor effects of gemcitabine in PANC-1 pancreatic cancer xenograft model in vivo via inhibition of inhibitors of apoptosis.
- Author
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Guo HC, Bu HQ, Luo J, Wei WT, Liu DL, Chen H, Tong HF, Wang ZH, Wu HY, Li HH, Zuo MM, Li W, and Lin SZ
- Subjects
- Animals, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Caspases metabolism, Cell Line, Tumor, Deoxycytidine administration & dosage, Deoxycytidine analogs & derivatives, Down-Regulation, Drug Synergism, Emodin administration & dosage, Humans, Inhibitor of Apoptosis Proteins genetics, Inhibitor of Apoptosis Proteins metabolism, Ki-67 Antigen metabolism, Male, Mice, Mice, Inbred BALB C, Mice, Nude, NF-kappa B antagonists & inhibitors, NF-kappa B metabolism, Pancreatic Neoplasms pathology, Survivin, Tumor Burden drug effects, X-Linked Inhibitor of Apoptosis Protein genetics, X-Linked Inhibitor of Apoptosis Protein metabolism, Xenograft Model Antitumor Assays, Gemcitabine, Antineoplastic Combined Chemotherapy Protocols pharmacology, Apoptosis drug effects, Apoptosis Regulatory Proteins antagonists & inhibitors, Pancreatic Neoplasms drug therapy
- Abstract
Pancreatic cancer is a highly aggressive malignant disease. Gemcitabine is currently the standard first-line chemotherapeutic agent for pancreatic cancer. As members of apoptosis inhibitors, Survivin and XIAP play an important role in chemotherapy resistance in pancreatic cancer. Emodin has therapeutic potential against cancers. This study was designed to investigate whether combination therapy with gemcitabine and emodin enhanced antitumor efficacy in pancreatic cancer. The application of the combination therapy triggered significantly higher frequency of pancreatic cancer cell apoptosis. Our research demonstrated that the combination of emodin and gemcitabine resulted in significantly reduced tumor volumes compared to gemcitabine or emodin treatment alone. Immunohistochemistry and western immunoblot analyses showed that Survivin and XIAP expression were downregulated in emodin and the combination groups compared to the other two groups. Reverse transcriptase polymerase chain reaction analyses showed that Survivin and XIAP mRNA expression in emodin and the combination groups were downregulated significantly compared to the other two groups. Furthermore, the expression of the nuclear transcription factor κB (NF-κB) protein and NF-κB mRNA were downregulated in the emodin and the combination groups. DNA-binding activity of NF-κB was inhibited in emodin and combination groups compared to the other groups. This study suggests that emodin potentiates the antitumor effects of gemcitabine in PANC-1 cell xenografts via promotion of apoptosis and IAP suppression.
- Published
- 2012
- Full Text
- View/download PDF
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