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Guo Q, Cheng J, Zhang J, Su B, Bian C, Lin S, Zhong C. Delayed post-injury administration of C5a improves regeneration and functional recovery after spinal cord injury in mice. Clin Exp Immunol 2013; 174:318-25. [PMID: 23855891 DOI: 10.1111/cei.12175] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/09/2013] [Indexed: 12/13/2022] Open
Abstract
The activation of a complement system can aggravate the secondary injury after spinal cord injury (SCI). However, it was reported recently that the activation of a complement could have both a secondary injury and a neuroprotective effect, in which C5a is the most important factor, but there is no direct evidence for this dual effect of C5a after SCI. In order to investigate the potential neuroprotective effect of C5a after SCI, in this study ectogenic C5a was injected intraperitoneally before/after SCI in vivo, or administrated to mechanically injured neurones in vitro; following this, neurone apoptosis, neurite outgrowth, axonal regeneration and functional recovery were investigated. The in-vivo experiments indicated that, following treatment with C5a 24 h before or immediately after injury, locomotor function was impaired significantly. However, when treatment with C5a took place 24 h after injury, locomotor function improved significantly. In-vitro experiments indicated that a certain concentration of C5a (50-100 nM) could inhibit caspase-3-mediated neurone apoptosis by binding to its receptor CD88, and that it could even promote the neurite outgrowth of uninjured neurones. In conclusion, delayed post-injury administration of C5a within a certain concentration could exert its neuroprotective effect through inhibiting caspase-3-mediated neurone apoptosis and promoting neurite outgrowth of uninjured neurones as well. These data suggest that C5a may have opposite functions in a time- and concentration-dependent manner after SCI. The dual roles of C5a have to be taken into account when measures are taken to inhibit complement activation in order to promote regeneration after SCI.
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Tong L, Cai M, Huang Y, Zhang H, Su B, Li Z, Dong H. Activation of K(2)P channel-TREK1 mediates the neuroprotection induced by sevoflurane preconditioning. Br J Anaesth 2013; 113:157-67. [PMID: 24154701 PMCID: PMC4062297 DOI: 10.1093/bja/aet338] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Background Preconditioning with volatile anaesthetic agents induces tolerance to focal cerebral ischaemia, although the underlying mechanisms have not been clearly defined. The present study analyses whether TREK-1, a two-pore domain K+ channel and target for volatile anaesthetics, plays a role in mediating neuroprotection by sevoflurane. Methods Differentiated SH-SY5Y cells were preconditioning with sevoflurane and challenged by oxygen–glucose deprivation (OGD). Cell viability and expression of caspase-3 and TREK-1 were evaluated. Rats that were preconditioned with sevoflurane were subjected to middle cerebral artery occlusion (MCAO), and the expression of TREK-1 protein and mRNA was analysed. Neurological scores were evaluated and infarction volume was examined. Results Sevoflurane preconditioning reduced cell death in differentiated SH-SY5Y cells challenged by OGD. Sevoflurane preconditioning reduced infarct volume and improved neurological outcome in rats subjected to MCAO. Sevoflurane preconditioning increased levels of TREK-1 mRNA and protein. Knockdown of TREK-1 significantly attenuated sevoflurane preconditioning-induced neuroprotective effects in vitro and in vivo. Conclusions Sevoflurane preconditioning-induced neuroprotective effects against transient cerebral ischaemic injuries involve TREK-1 channels. These results suggest a novel mechanism for sevoflurane preconditioning-induced tolerance to focal cerebral ischaemia.
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Xu QH, Shi JY, Zhang J, Sun YF, Chang AH, Zhao YM, Cai WJ, Liu D, Zhou CC, Fan LH, Su B. Comparison of tumor neovasculature-targeted paramagnetic nanoliposomes for MRI in mice xenograft models. Clin Transl Oncol 2013; 16:395-401. [DOI: 10.1007/s12094-013-1091-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 07/17/2013] [Indexed: 01/30/2023]
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Guo Q, Cheng J, Zhang H, Zhang J, Su B, Bian C, Lin S. Expressions of C5a and its receptor CD88 after spinal cord injury in C3-deficient mice. Scand J Immunol 2013; 77:224-9. [PMID: 23033813 DOI: 10.1111/sji.12001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Accepted: 09/20/2012] [Indexed: 12/13/2022]
Abstract
The activation of complement system can aggravate the secondary injury after spinal cord injury (SCI). Our previous study indicates that the interception of complement activation by C3 deficiency can reduce the secondary injury and improve the regeneration and functional recovery after SCI. However, recently, it was reported that C5a which was generated during the complement activation pathways also had a protective effect on neurons, but whether it has the similar effect after SCI is unknown. To investigate the possibility and mechanism of the protective effect of C5a on neurons, it is necessary to study the expression profiles of C5a and its receptor CD88 after SCI and the influence on their expression when C3 was knocked out. By immunohistochemistry and Western blot, we found that in wild-type (WT) mice, both the expression of C5a and its receptor CD88 increased significantly, and there were two peaks during their expression after SCI. However, in C3-deficient mice, the expression of C5a still increased after SCI, although it was lower than that in WT group at every time points after SCI, and the expression of CD88 remained stable. Our study suggests that the expressions of C5a and CD88 can be inhibited in different degrees after SCI when the activation of complement system is blocked through C3 deficiency, which can reduce the secondary injury caused by C5a after SCI on one hand but deprive neurons of the possible protective effect from C5a on the other hand.
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Singer J, Katz P, Dean M, Chen J, Su B, Kern R, Leard L, Hays S, Kukreja J, Blanc P. Frailty Is Common in Lung Transplant Candidates and Associated with Poorer Health-Related Quality of Life. J Heart Lung Transplant 2013. [DOI: 10.1016/j.healun.2013.01.912] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Li R, Zhang XM, Campana MG, Huang JP, Chang ZH, Qi XB, Shi H, Su B, Zhang RF, Lan XY, Chen H, Lei CZ. Paternal origins of Chinese cattle. Anim Genet 2013; 44:446-9. [DOI: 10.1111/age.12022] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/28/2012] [Indexed: 11/28/2022]
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Zhang X, Su B, Li J, Li Y, Lu D, Zhu K, Pei H, Zhao M. Analysis by RP-HPLC of Mangiferin Component Correlation between Medicinal Loranthus and their Mango Host Trees. J Chromatogr Sci 2012; 52:1-4. [DOI: 10.1093/chromsci/bms196] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Su B, Biedma ME, Lederle A, Lambotin M, Moog C. Modulation of HIV-1 replication in primary dendritic cells in contact with autologous CD4 T-lymphocytes. Retrovirology 2012. [PMCID: PMC3441910 DOI: 10.1186/1742-4690-9-s2-p182] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Su B, Gao L, Meng F, Guo LW, Rothschild J, Gelman IH. Adhesion-mediated cytoskeletal remodeling is controlled by the direct scaffolding of Src from FAK complexes to lipid rafts by SSeCKS/AKAP12. Oncogene 2012; 32:2016-26. [PMID: 22710722 PMCID: PMC3449054 DOI: 10.1038/onc.2012.218] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Metastatic cell migration and invasion are regulated by altered adhesion-mediated signaling to the actin-based cytoskeleton via activated Src-FAK complexes. SSeCKS (the rodent orthologue of human Gravin/AKAP12), whose expression is downregulated by oncogenic Src and in many human cancers, antagonizes oncogenic Src pathways including those driving neovascularization at metastatic sites, metastatic cell motility and invasiveness. This is likely manifested through its function as a scaffolder of F-actin and signaling proteins such as cyclins, calmodulin, protein kinase (PK) C and PKA. Here, we show that in contrast to its ability to inhibit haptotaxis, SSeCKS increased prostate cancer cell adhesion to fibronectin (FN) and type I collagen in a FAK-dependent manner, correlating with a relative increase in FAKpoY397 levels. In contrast, SSeCKS suppressed adhesion-induced Src activation (SrcpoY416) and phosphorylation of FAK at Y925, a known Src substrate site. SSeCKS also induced increased cell spreading, cell flattening, integrin β1 clustering and formation of mature focal adhesion plaques. An in silico analysis identified a Src-binding domain on SSeCKS (a.a.153–166) that is homologous to the Src binding domain of Caveolin-1, and this region is required for SSeCKS-Src interaction, for SSeCKS-enhanced Src activity and sequestration to lipid rafts, and for SSeCKS-enhanced adhesion of MAT-LyLu and CWR22Rv1 prostate cancer cells. Our data suggest a model in which SSeCKS suppresses oncogenic motility by sequestering Src to caveolin-rich lipid rafts, thereby disengaging Src from FAK-associated adhesion and signaling complexes.
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Tsai C, Lin Y, Su B, Yang L, Chiu W. Masseter muscle fibre changes following reduction of masticatory function. Int J Oral Maxillofac Surg 2012; 41:394-9. [DOI: 10.1016/j.ijom.2011.10.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Revised: 07/11/2011] [Accepted: 10/18/2011] [Indexed: 10/15/2022]
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Ke Y, Su B, Xiao J, Chen H, Huang W, Chen Z, Chu J, Tan J, Jin L, Lu D. Y-chromosome haplotype distribution in Han Chinese populations and modern human origin in East Asians. ACTA ACUST UNITED AC 2011; 44:225-32. [PMID: 18726402 DOI: 10.1007/bf02879329] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2000] [Indexed: 10/22/2022]
Abstract
We investigated the distribution of Y-chromosome haplotype using 19 Y-SNPs in Han Chinese populations from 22 provinces of China. Our data indicate distinctive patterns of Y chromosome between southern and northern Han Chinese populations. The southern populations are much more polymorphic than northern populations. The latter has only a subset of the southern haplotypes. This result confirms the genetic difference observed between southern and northern ethnic populations in East Asia. It supports the hypothesis that the first settlement of modern humans of African origin occurred in the southern part of East Asia during the last Ice Age, and a northward migration led to the peopling of northern China.
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Hsu CC, Lin YA, Su B, Li JH, Huang HY, Hsu MCP. NO EFFECT OF CORDYCEPS SINENSIS SUPPLEMENTATION ON TESTOSTERONE LEVEL AND MUSCLE STRENGTH IN HEALTHY YOUNG ADULTS FOR RESISTANCE TRAINING. Biol Sport 2011. [DOI: 10.5604/942739] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Becker W, Su B, Holub O, Weisshart K. FLIM and FCS detection in laser-scanning microscopes: increased efficiency by GaAsP hybrid detectors. Microsc Res Tech 2010; 74:804-11. [PMID: 23939667 DOI: 10.1002/jemt.20959] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Accepted: 09/29/2010] [Indexed: 11/06/2022]
Abstract
Photon counting detectors currently used in fluorescence lifetime microscopy have a number of deficiencies that result in less-than-ideal signal-to-noise ratio of the lifetimes obtained: either the quantum efficiency is unsatisfactory or the active area is too small, and afterpulsing or tails in the temporal response contribute to overall timing inaccuracy. We have therefore developed a new FLIM detector based on a GaAsP hybrid photomultiplier. Compared with conventional PMTs and SPADs, GaAsP hybrid detectors have a number of advantages: The detection quantum efficiency reaches or surpasses the efficiency of fast SPADs, and the active area is on the order of 5 mm², compared with 2.5 10⁻³ mm² for a SPAD. The TCSPC response is clean, without the bumps and the diffusion tails typical for PMTs and SPADs. Most important, the hybrid detector is intrinsically free of afterpulsing. FLIM results are therefore free of signal-dependent background, and FCS curves are free of the known afterpulsing peak. We demonstrate the performance of the new detector for multiphoton NDD FLIM and for FCS.
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Cui HY, Zhang Q, Su B, Li W, Tang SJ. Differential Levels of Cytokines and Soluble Fas Ligand between Tuberculous and Malignant Effusions. J Int Med Res 2010; 38:2063-9. [PMID: 21227011 DOI: 10.1177/147323001003800621] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Tuberculous pleurisy, which is characterized by an extensive inflammatory exudate in the pleural space, is a common manifestation of extrapulmonary tuberculosis caused by Mycobacterium tuberculosis infection but is difficult to diagnose. This study compared concentrations of three cytokines (interferon-γ and interleukin [IL]−2 and −4) and soluble Fas ligand in serum and pleural effusions from 36 patients with tuberculous pleurisy, 30 with malignant pleurisy and 30 healthy volunteers. Interferon-γ concentration was significantly higher in serum and pleural effusions, and the concentration of soluble Fas ligand was significantly higher in pleural effusion, from patients with tuberculous pleurisy than in those with malignant pleurisy. Levels of IL-2 and IL-4 were also raised in serum, but failed to reach statistical significance. Interferon-γ and soluble Fas ligand levels were significantly higher in pleural effusion than in serum. Pleural soluble Fas ligand concentrations correlated linearly with those of interferon-γ in patients with tuberculous pleurisy. These findings suggest a predominant T-helper-1 response to M. tuberculosis infection.
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Curtis A, West N, Su B. Synthesis of nanobioglass and formation of apatite rods to occlude exposed dentine tubules and eliminate hypersensitivity. Acta Biomater 2010; 6:3740-6. [PMID: 20206307 DOI: 10.1016/j.actbio.2010.02.045] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Revised: 02/22/2010] [Accepted: 02/24/2010] [Indexed: 10/19/2022]
Abstract
The occlusion of patent dentine tubules may reduce or eliminate hypersensitivity by restricting dentinal fluid movement. The efficacy of a novel sol-gel nanobioglass and a melt-derived bioglass to occlude tubules and promote apatite formation was tested by mechanically brushing a slurry of bioglass powder and human saliva onto dentine possessing exposed tubules. Scanning electron microscopy, focused ion beam and energy-dispersive X-ray spectroscopy were used to characterize the powders and assess tubule occlusion. Melt-derived bioglass possessed an irregular particle morphology and had a mean size of 3.30 +/- 0.42 microm. The sol-gel bioglass particles were spherical, with a mean size of 0.65 +/- 0.19 microm. Dentine treated with melt-derived bioglass exhibited a tightly adherent continuous apatite layer. Treatment with nanobioglass resulted in particle deposition within tubules and formation of apatite rods which were tightly adherent to tubule walls and continuous to a measured depth of 270 microm.
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Goldman VJ, Su B. Resonant tunneling in the quantum Hall regime: measurement of fractional charge. Science 2010; 267:1010-2. [PMID: 17811442 DOI: 10.1126/science.267.5200.1010] [Citation(s) in RCA: 248] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
In experiments on resonant tunneling through a "quantum antidot" (a potential hill) in the quantum Hall (QH) regime, periodic conductance peaks were observed as a function of both magnetic field and back gate voltage. A combination of the two periods constitutes a measurement of the charge of the tunneling particles and implies that charge deficiency on the antidot is quantized in units of the charge of quasi-particles of the surrounding QH condensate. The experimentally determined value of the electron charge e is 1.57 x 10(-19) coulomb = (0.98 +/- 0.03) e for the states v = 1 and v = 2 of the integer QH effect, and the quasi-particle charge is 5.20 x 10(-20) coulomb = (0.325 +/- 0.01)e for the state v = (1/3) of the fractional QH effect.
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Deng Q, Zhou S, Su B, Zhao Y, Zhou C. β1 integrin mediated acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitor in non-small lung cancer cells. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.e13651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Su B, Wang X, Nunomura A, Moreira PI, Lee HG, Perry G, Smith MA, Zhu X. Oxidative stress signaling in Alzheimer's disease. Curr Alzheimer Res 2009; 5:525-32. [PMID: 19075578 DOI: 10.2174/156720508786898451] [Citation(s) in RCA: 196] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Multiple lines of evidence demonstrate that oxidative stress is an early event in Alzheimer's disease (AD), occurring prior to cytopathology, and therefore may play a key pathogenic role in AD. Oxidative stress not only temporally precedes the pathological lesions of the disease but also activates cell signaling pathways, which, in turn, contribute to lesion formation and, at the same time, provoke cellular responses such as compensatory upregulation of antioxidant enzymes found in vulnerable neurons in AD. In this review, we provide an overview of the evidence of oxidative stress and compensatory responses that occur in AD, particularly focused on potential sources of oxidative stress and the roles and mechanism of activation of stress-activated protein kinase pathways.
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Su B, Zhou W, Dorman KS, Jones DE. Mathematical Modelling of Immune Response in Tissues. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2009. [DOI: 10.1080/17486700801982713] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
We have developed a spatial–temporal mathematical model (PDE) to capture fundamental aspects of the immune response to antigen. We have considered terms that broadly describe intercellular communication, cell movement, and effector function (activation or inhibition). The PDE model is robust to variation in antigen load and it can account for (1) antigen recognition, (2) an innate immune response, (3) an adaptive immune response, (4) the elimination of antigen and subsequent resolution of the immune response or (5) equilibrium of the immune response to the presence of persistent antigen (chronic infection) and the formation of a granuloma.
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Yang J, Chen X, Su B, Zhao S, Qiang L. A new grossing knife with two parallel blades for preparing uniform thickness gross tissue sections. J Clin Pathol 2008; 61:1069-70. [PMID: 18755729 DOI: 10.1136/jcp.2008.057786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Luo XJ, Diao HB, Wang JK, Zhang H, Zhao ZM, Su B. Association of haplotypes spanning PDZ-GEF2, LOC728637 and ACSL6 with schizophrenia in Han Chinese. J Med Genet 2008; 45:818-26. [PMID: 18718982 DOI: 10.1136/jmg.2008.060657] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Schizophrenia is a complex genetic disorder caused by multiple genetic and environmental factors. Several lines of linkage and association studies have repeatedly suggested that the chromosome 5q22-33 region is implicated in the aetiology of schizophrenia. However, most of the previous studies on the linkage of 5q22-33 with schizophrenia were from European populations, and it was not well characterised in other populations. METHODS We analysed eight single nucleotide polymorphisms (SNPs) located in the 5q23.3 region in a cohort of 506 schizophrenia patients and 672 control subjects from south western China. Single marker association, haplotypic association, sex-specific association and molecular evolutionary analysis were performed. RESULTS Single marker analysis indicated that SNP5 (rs1355095) in LOC728637 is associated with schizophrenia. When males and females were analysed separately, SNP4 (rs31251) in PDZ-GEF2 is associated with schizophrenia in females. Further analysis using haplotypes demonstrated that a haplotype block spanning PDZ-GEF2, LOC728637 and ACSL6 is highly associated with schizophrenia and several haplotypes in this haploblock have about twofold to 10-fold increase in the affected subjects. In addition, molecular evolutionary analysis suggests that PDZ-GEF2 has undergone adaptive evolution due to Darwinian positive selection in the human lineage. CONCLUSION Our data provide evidence of the association of 5q22-33 with schizophrenia in Han Chinese. This chromosomal region is likely responsible for genetic susceptibility to schizophrenia, supporting previous data from European patients. In addition, our evolutionary analysis is consistent with the hypothesis that genes contributing to schizophrenia are likely under positive selection during human evolution.
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He X, Zhang YZ, Mansell JP, Su B. Zirconia toughened alumina ceramic foams for potential bone graft applications: fabrication, bioactivation, and cellular responses. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2008; 19:2743-2749. [PMID: 18305904 DOI: 10.1007/s10856-008-3401-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2007] [Accepted: 02/05/2008] [Indexed: 05/26/2023]
Abstract
Zirconia toughened alumina (ZTA) has been regarded as the next generation orthopedic graft material due to its excellent mechanical properties and biocompatibility. Porous ZTA ceramics with good interconnectivity can potentially be used as bone grafts for load-bearing applications. In this work, three-dimensional (3D) interconnected porous ZTA ceramics were fabricated using a direct foaming method with egg white protein as binder and foaming agent. The results showed that the porous ZTA ceramics possessed a bimodal pore size distribution. Their mechanical properties were comparable to those of cancellous bone. Due to the bio-inertness of alumina and zirconia ceramics, surface bioactivation of the ZTA foams was carried out in order to improve their bioactivity. A simple NaOH soaking method was employed to change the surface chemistry of ZTA through hydroxylation. Treated samples were tested by conducting osteoblast-like cell culture in vitro. Improvement on cells response was observed and the strength of porous ZTA has not been deteriorated after the NaOH treatment. The porous 'bioactivated' ZTA ceramics produced here could be potentially used as non-degradable bone grafts for load-bearing applications.
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Song YL, Wang CN, Fan MW, Su B, Bian Z. Dentin phosphoprotein frameshift mutations in hereditary dentin disorders and their variation patterns in normal human population. J Med Genet 2008; 45:457-64. [PMID: 18456718 DOI: 10.1136/jmg.2007.056911] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Dentin phosphoprotein (DPP) is the most abundant non-collagenous protein in dentin, which is highly phosphorylated and plays key roles in dentin biomineralization. The aetiology of isolated hereditary dentin disorders in most affected families is largely unknown and the association between DPP and dentin disorders has not been well established. This study aims to determine whether there are some involvements for DPP mutations in inherited dentin disorders and to clarify the sequence variation patterns of DPP in normal population. METHODS Genomic DNA was analysed in eight families with hereditary dentin disorders and 110 individuals in the normal population. The full coding sequence of DPP was amplified by polymerase chain reaction (PCR) and screened for mutations and variations by direct sequencing and TOPO TA-cloning sequencing. RESULTS Five frameshift mutations in DPP coding region were identified in five of the eight families. The mutations co-segregated with the disease phenotypes in affected families and were not found in 220 control chromosomes. In the normal population, we revealed 14 in-frame indels (insertion/deletion), six non-synonymous single nucleotide polymorphisms (SNPs), and five synonymous SNPs in the DPP coding region. These variants display extensive linkage disequilibrium and constitute a total of 15 haplotypes with three predominant haplotypes in the investigated normal population. CONCLUSIONS Our data provide the first evidence that DPP mutations can cause hereditary dentin disorders and suggest that in-frame length variations and missense SNPs in DPP have no obvious pathogenetic effects on dentin formation.
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Zhang R, Wang YQ, Su B. Molecular Evolution of a Primate-Specific microRNA Family. Mol Biol Evol 2008; 25:1493-502. [DOI: 10.1093/molbev/msn094] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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Zhang YZ, Su B, Ramakrishna S, Lim CT. Chitosan nanofibers from an easily electrospinnable UHMWPEO-doped chitosan solution system. Biomacromolecules 2007; 9:136-41. [PMID: 18078323 DOI: 10.1021/bm701130e] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Conversion of natural biopolymer chitosan into nanofibers through electrospinning has significant usefulness in various biomedical applications, in particular, for constructing a biomimetic and bioactive nanofibrous artificial extracellular matrix for engineering various tissues. Here, we show that introduction of an ultrahigh-molecular-weight poly(ethylene oxide) (UHMWPEO) into aqueous chitosan solutions remarkably enhances the formation of chitosan nanofibrous structure and leads to much lower loading of the water soluble fiber-forming aiding agent of PEO down to 5 wt % as compared to previous high PEO loadings in the electrospun chitosan nanofibers. The excellent electrospinnability of the current formulation renders electrospinning of natural biopolymer chitosan a robust process for large-scale production of practically applicable nanofibrous structures.
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