Publications by authors named "Yi Qun Xiao"

Edwardsiella anguillarum is one of the common bacterial pathogens for the cultivated eels in China. The aim of this study was to reveal the cause of E. anguillarum pathogenic to European eel (Anguilla anguilla) from the perspective of the transcriptome.

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In cultivated European eels, Aeromonas hydrophila, Edwardsiella anguillarum and Vibrio vulnificus are three important bacterial pathogens. In this study, an expressed recombinant Outer membrane proteinⅡ (rOmpⅡ) from A. hydrophila was intraperitoneally injected into European eels (Angullia angullia).

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The 12th GCC Closed Forum was held in Philadelphia, PA, USA, on 9 April 2018. Representatives from international bioanalytical Contract Research Organizations were in attendance in order to discuss scientific and regulatory issues specific to bioanalysis. The issues discussed at the meeting included: critical reagents; oligonucleotides; certificates of analysis; method transfer; high resolution mass spectrometry; flow cytometry; recent regulatory findings and case studies involving stability and nonclinical immunogenicity.

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Over the last decade, the use of biomarker data has become integral to drug development. Biomarkers are not only utilized for internal decision-making by sponsors; they are increasingly utilized to make critical decisions for drug safety and efficacy. As the regulatory agencies are routinely making decisions based on biomarker data, there has been significant scrutiny on the validation of biomarker methods.

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The 11th Global CRO Council Closed Forum was held in Universal City, CA, USA on 3 April 2017. Representatives from international CRO members offering bioanalytical services were in attendance in order to discuss scientific and regulatory issues specific to bioanalysis. The second CRO-Pharma Scientific Interchange Meeting was held on 7 April 2017, which included Pharma representatives' sharing perspectives on the topics discussed earlier in the week with the CRO members.

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The 9th GCCClosed Forum was held just prior to the 2015 Workshop on Recent Issues in Bioanalysis (WRIB) in Miami, FL, USA on 13 April 2015. In attendance were 58 senior-level participants, from eight countries, representing 38 CRO companies offering bioanalytical services. The objective of this meeting was for CRO bioanalytical representatives to meet and discuss scientific and regulatory issues specific to bioanalysis.

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Phagocytosis plays a pivotal and essential role in host immune defense, both as a focal constituent of the innate immune response and a bridging element linking innate and adaptive immunity. Phagocytosis has been demonstrated to be critical in development, tissue remodeling, wound healing and resolution of inflammation through clearance of foreign organisms, apoptotic cells and the production of anti-inflammatory mediators. During pre-clinical investigations, therapeutic drug candidates may alter host resistance to infectious agents by modulating the immune system.

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Rural sewage treatment is now paid more and more attention in China. Vermifiltration technology could be one of the practical options under the review of previous studies. It showed good removal rates of contaminants on small to pilot scales for short-term tests.

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Cystic fibrosis (CF) is caused by mutated CF transmembrane conductance regulator (CFTR) and is characterized by robust airway inflammation and accumulation of apoptotic cells. Phagocytosis of apoptotic cells (efferocytosis) is a pivotal regulator of inflammation, because it prevents postapoptotic necrosis and actively suppresses release of a variety of proinflammatory mediators, including IL-8. Because CF is associated with accumulation of apoptotic cells, inappropriate levels of IL-8, and robust inflammation, we sought to determine whether CFTR deficiency specifically impairs efferocytosis and its regulation of inflammatory mediator release.

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Rationale: Cigarette smoke (CS) is the primary cause of chronic obstructive pulmonary disease (COPD), an effect that is, in part, due to intense oxidant stress. Clearance of apoptotic cells (efferocytosis) is a critical regulator of lung homeostasis, which is defective in smokers and in patients with COPD, suggesting a role in disease pathogenesis.

Objectives: We hypothesized that CS would impair efferocytosis through oxidant-dependent activation of RhoA, a known inhibitor of this process.

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Interaction between apoptotic cells and phagocytes through phosphatidylserine recognition structures results in the production of TGF-beta, which has been shown to play pivotal roles in the anti-inflammatory and anti-immunogenic responses to apoptotic cell clearance. Using 3T3-TbetaRII and RAWTbetaRII cells in which a truncated dominant-negative TGF-beta receptor II was stably transfected to avoid autofeedback induction of TGF-beta, we investigate the mechanisms by which TGF-beta was produced through PSRS engagement. We show, in the present study, that TGF-beta was regulated at both transcriptional and translational steps.

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Rationale: Efficient removal of apoptotic cells is essential for the resolution of acute pulmonary inflammation. Alveolar macrophages ingest apoptotic cells less avidly than other professional phagocytes at rest but overcome this defect during acute inflammation. Surfactant protein (SP)-A and SP-D are potent modulators of macrophage function and may suppress clearance of apoptotic cells through activation of the transmembrane receptor signal inhibitory regulatory protein alpha (SIRP alpha).

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Apoptotic cells are rapidly engulfed by adjacent tissue cells or macrophages before they can release pro-inflammatory/proimmunogenic intracellular contents. In addition, recognition of the apoptotic cells is actively anti-inflammatory and anti-immunogenic with generation of anti-inflammatory mediators such as transforming growth factor-beta (TGF-beta) and anti-inflammatory eicosanoids. Here, we have investigated the role played by the induction of TGF-beta in the coordinate expression of anti-inflammatory eicosanoids or peroxisome proliferator-activated receptor-gamma and in the suppression of pro-inflammatory lipid mediators and nitric oxide (NO).

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Statins are potent, cholesterol-lowering agents with newly appreciated, broad anti-inflammatory properties, largely based upon their ability to block the prenylation of Rho GTPases, including RhoA. Because phagocytosis of apoptotic cells (efferocytosis) is a pivotal regulator of inflammation, which is inhibited by RhoA, we sought to determine whether statins enhanced efferocytosis. The effect of lovastatin on efferocytosis was investigated in primary human macrophages, in the murine lung, and in human alveolar macrophages taken from patients with chronic obstructive pulmonary disease.

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Although TGF-beta inhibits the production of proinflammatory mediators in vitro and in vivo, its anti-inflammatory activities may be ineffective in early or severe acute inflammatory circumstances. In this study, we suggest a role for oxidative stress on TGF-beta signaling, leading to prevention of its normal anti-inflammatory effects but leaving its Smad-driven effects on cellular differentiation or matrix production unaffected. Stimulation of the RAW 264.

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Normal spontaneous apoptosis in neutrophils is enhanced by "stress" stimuli such as tumor necrosis factor-alpha, Fas ligand, and oxidants, and this effect is inhibited by anti-apoptotic stimuli including granulocyte-macrophage colony-stimulating factor, lipopolysaccharide, and formylmethionine-leucine-phenylalanine. In this report we demonstrate that anti-apoptotic stimuli protect neutrophils from stress-induced apoptosis via activation of the ERK/MAPK pathway. The protection occurs downstream of mitochondrial alterations assessed as a decrease in membrane potential concomitant with enhanced cytochrome c release.

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Using rat peritoneal neutrophils, the complete nucleotide sequence of rat macrophage inflammatory protein-2 (MIP-2) mRNA including 5'untranslated region (UTR) and 3'UTR was determined (GenBank Accession number, AB060092). It was found that the MIP-2 mRNA has a 70 bp 5'UTR, a 303 bp coding region and a 728 bp 3'UTR which contains adenylate/uridylate (AU)-rich areas defined as AU-rich elements (AREs). Site-directed mutagenesis studies using the tetracycline-sensitive transactivator protein-expressing rat basophilic leukemia cells (RBL-2H3-TO cells) revealed that MIP-2 mRNA mutants which lack the 3'UTR are more stable than MIP-2-wild-type (wt) mRNA.

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Surfactant proteins A and D (SP-A and SP-D) are lung collectins composed of two regions, a globular head domain that binds PAMPs and a collagenous tail domain that initiates phagocytosis. We provide evidence that SP-A and SP-D act in a dual manner, to enhance or suppress inflammatory mediator production depending on binding orientation. SP-A and SP-D bind SIRPalpha through their globular heads to initiate a signaling pathway that blocks proinflammatory mediator production.

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Phagocytosis of apoptotic cells by macrophages results in the production of transforming growth factor-beta (TGF-beta), which plays an important role in induction of an anti-inflammatory phenotype and resolution of inflammation. In this study, we show that TGF-beta prevents pro-inflammatory cytokine production through inhibition of p38 mitogen-activated protein kinase (MAPK) and NF-kappaB. Blockade of extracellular signal-regulated kinase (ERK) signaling by the MEK-1/2 inhibitor PD 98059 reversed the inhibitory effects of TGF-beta, suggesting that cross-talk between MAPKs is essential for this response.

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