2376
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Tan A, Aucejo F, Liu X, Lopez R, Kim RD. Prognostic role of serum vascular endothelial growth factor level in hepatocellular carcinoma. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.e14662] [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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2377
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Liu X, Wang W, Li J, Tang C, Yu F. Sunitinib in treatment of advanced non-small cell lung cancer after failure of multiregimens of chemotherapy and EGFR-TKI. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.e18139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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2378
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Markovic S, Suman V, Trieu VN, Liu X, Yeh W, Hwang L, Treece T, Motamed K, Pramanik P, Desai N. Tumor SPARC microenvironment signature (SMS) and plasma levels in a phase II trial of unresectable stage IV melanoma treated with nab-paclitaxel and carboplatin: A translational study of NCCTG trial N057E. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.8578] [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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2379
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Singh S, Liu X, Lee T, Kirkland R, Kuller A, Ohrmund L, Lin F, Hanna M, Kim P, Ybarrondo B. Analysis of truncated HER2 expression and activation in breast cancer. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.1099] [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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2380
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Liu X, Gomez-Pinillos A, Ferrari AC. Simultaneous targeting of the androgen receptor and PI3K/mTOR pathway in androgen-dependent and androgen-independent prostate cancer cells. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.e15049] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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2381
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Kim P, Wu Y, Liu X, Vargas-Quesada EA, Gomez-Moreno HL, Shin P, Lee T, Leesman G, Singh S, Lowder JN. Characterization of HER2 functional profiling in fine needle aspirates (FNA) in patients with metastatic breast cancer (MBC). J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.e21029] [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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2382
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Zhou C, Wu Y, Chen G, Feng J, Liu X, Wang C, Zhang S, Wang J, Zhou S, Ren S. Preliminary results of randomized phase III study comparing efficacy and safety of first-line erlotinib versus carboplatin (CBDCA) plus gemcitabine (GEM) in Chinese advanced non-small cell lung cancer (NSCLC) patients (pts) with EGFR-activating mutations (OPTIMAL). J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.7575] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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2383
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Xu G, Liu X, Zheng L, Fang X, Yin Q. Successful Recanalization of a Chronic In-stent Occlusion at the Vertebral Artery Ostium. A Case Report. Interv Neuroradiol 2010; 15:462-5. [PMID: 20465887 DOI: 10.1177/159101990901500416] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Accepted: 10/11/2009] [Indexed: 11/16/2022] Open
Abstract
SUMMARY In-stent restenosis or occlusion has been frequently reported as a complication after angioplasty and stenting in vertebral arteries. Reopening chronic in-stent occlusion in cervical arteries with endovascular techniques has not been reported. Here we describe a case with stent implantation in the origin of right vertebral artery. The stent was occluded one year after the procedure. The patient demonstrated concurrent ischemic symptoms which were relieved after the in-stent occlusion being recanalized successfully with re-angioplasty.
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2384
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Peluso JJ, Liu X, Gawkowska A, Lodde V, Wu CA. Progesterone inhibits apoptosis in part by PGRMC1-regulated gene expression. Mol Cell Endocrinol 2010; 320:153-61. [PMID: 20144686 PMCID: PMC2844455 DOI: 10.1016/j.mce.2010.02.005] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Revised: 01/27/2010] [Accepted: 02/01/2010] [Indexed: 11/25/2022]
Abstract
Progesterone receptor membrane component-1 (PGRMC1) is present in both the cytoplasm and nucleus of spontaneously immortalized granulosa cells (SIGCs). PGRMC1 is detected as a monomer in the cytoplasm and a DTT-resistant PGRMC1 dimer in the nucleus. Transfected PGRMC1-GFP localizes mainly to the cytoplasm and does not form a DTT-resistant dimer. Moreover, forced expression of PGRMC1-GFP increases the sensitivity of the SIGCs to progesterone (P4)'s anti-apoptotic action, indicating that the PGRMC1 monomer is functional. However, when endogenous PGRMC1 is depleted by siRNA treatment and replaced with PGRMC1-GFP, P4 responsiveness is not enhanced, although overall levels of PGRMC1 are increased. P4's anti-apoptotic action is also attenuated by actinomycin D, an inhibitor of RNA synthesis, and P4 activation of PGRMC1 suppresses Bad and increases Bcl2a1d expression. Taken together, the present studies suggest a genomic component to PGRMC1's anti-apoptotic mechanism of action, which requires the presence of the PGRMC1 dimer.
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2385
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Rodenburg C, Liu X, Jepson MAE, Zhou Z, Rainforth WM, Rodenburg JM. The role of helium ion microscopy in the characterisation of complex three-dimensional nanostructures. Ultramicroscopy 2010; 110:1178-84. [PMID: 20452124 DOI: 10.1016/j.ultramic.2010.04.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Revised: 04/04/2010] [Accepted: 04/20/2010] [Indexed: 10/19/2022]
Abstract
This work addresses two major issues relating to Helium Ion Microscopy (HeIM). First we show that HeIM is capable of solving the interpretation difficulties that arise when complex three-dimensional structures are imaged using traditional high lateral resolution techniques which are transmission based, such as scanning transmission electron microscopy (STEM). Secondly we use a nano-composite coating consisting of amorphous carbon embedded in chromium rich matrix to estimate the mean escape depth for amorphous carbon for secondary electrons generated by helium ion impact as a measure of HeIM depth resolution.
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2386
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Zhao Z, Zhao S, Xu N, Yu C, Guan S, Liu X, Huang L, Liao W, Jia W. Lovastatin improves neurological outcome after nucleus basalis magnocellularis lesion in rats. Neuroscience 2010; 167:954-63. [DOI: 10.1016/j.neuroscience.2010.02.054] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2009] [Revised: 02/13/2010] [Accepted: 02/19/2010] [Indexed: 12/15/2022]
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2387
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Zaĭtseva IV, Voloshina PV, Liu X, Ovadis MI, Berg G, Chernin LS, Khmel' IA. [Involvement of the global regulators GrrS, RpoS, and SplIR in formation of biofilms in Serratia plymuthica]. GENETIKA 2010; 46:616-621. [PMID: 20583596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Most bacteria exist in the natural environment as biofilms, multicellular communities attached to hard surfaces. Biofilms have a characteristic architecture and are enclosed in the exopolymer matrix. Bacterial cells in biofilms are extremely resistant to antibacterial factors. It was shown in this work that the GrrA/GrrS system of global regulators of gene expression and the sigma S subunit of RNA polymerase (RpoS) play a significant role in positive regulation of biofilm formation in the rhizospheric bacterium Serratia plymuthica IC1270. Inactivation of grrS and rpoS genes resulted in an up to six-to-sevenfold and four-to-fivefold reduction in biofilm formation, respectively. Mutations in the grrS gene decreased the capacity of the bacterium for swarming motility. The splIR Quorum Sensing (QS) system was shown to negatively influence the biofilm formation. Transfer of the recombinant plasmid containing cloned genes splI/splR of S. plymuthica HRO-C48 into S. plymuthica IC1270 cells led to a twofold decrease of their ability to form biofilms. Inactivation of the splI gene coding for the synthase of N-acyl-homoserine lactones in S. plymuthica HRO-C48 resulted in a 2-2.5-fold increase in the level of biofilm formation, whereas the inclusion of plasmid carrying the cloned splI/splR genes into these mutant cells restored the biofilm formation to the normal level. The results obtained demonstrate that the formation of biofilms in S. plymuthica is positively regulated by the GrrA/GrrS and RpoS global regulators and is negatively regulated by the SplIR QS system.
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2388
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Shah AJ, Liu X, Jadidi AS, Haïssaguerre M. Early management of atrial fibrillation: from imaging to drugs to ablation. Nat Rev Cardiol 2010; 7:345-54. [PMID: 20421888 DOI: 10.1038/nrcardio.2010.49] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Atrial fibrillation (AF) is the most common cardiac arrhythmia, and is responsible for the highest number of rhythm-related disorders and cardioembolic strokes worldwide. Early management of this condition will lower the risk of AF-associated morbidity and mortality. Targeted drug therapy has an important role in preventing the progression of AF through modification of the substrate. Discovery of the role of pulmonary veins as a trigger has been an important breakthrough, leading to the development of pulmonary vein ablation-an established curative therapy for drug-resistant AF. Identifying the underlying reasons for the abnormal firing of venous cardiomyocytes and the widespread progressive alterations of atrial tissue found in persistent AF are challenges for the future. Novel imaging techniques may help to determine the right time for intervention, provide specific targets for ablation, and judge the efficacy of treatment. If new developments can successfully address these issues, the knowledge acquired as a result will have a vital role in preclinical and early management of AF.
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2389
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Yang L, Zhang Y, Dong R, Peng L, Liu X, Wang Y, Cheng X. Effects of adenoviral-mediated coexpression of bone morphogenetic protein-7 and insulin-like growth factor-1 on human periodontal ligament cells. J Periodontal Res 2010; 45:532-40. [PMID: 20412417 DOI: 10.1111/j.1600-0765.2009.01268.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND AND OBJECTIVE Bone morphogenetic protein-7 (BMP-7) and insulin-like growth factor-1 (IGF-1) are important in periodontal reconstruction. However, their synergistic effect in periodontal regeneration by gene delivery has not been reported. In this study, gene delivery of these two growth factors to human periodontal ligament cells (hPDLCs) was examined for its effects on cell proliferation and differentiation. MATERIAL AND METHODS Recombinant adenoviruses containing both human BMP-7 and IGF-1 cDNA created by introducing the internal ribosome entry site (IRES) sequence were used to transfer the genes into hPDLCs. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and cell cycle analysis were used to observe their effects on cell proliferation, while alkaline phosphatase activity measurement, RT-PCR and in vivo tests were conducted to investigate their effects on cell differentiation. RESULTS The proliferation of hPDLCs transduced by adenoviruses coexpressing BMP-7 and IGF-1 was suppressed while their differentiation ability was enhanced. There was a synergism of BMP-7 and IGF-1 in up-regulating alkaline phosphatase activity and mRNA levels of collagen type I and Runx2. Implantation in vivo with scaffolds illustrated that the transduced cells exhibited osteogenic differentiation and formed bone-like structures. CONCLUSION The combined delivery of BMP-7 and IGF-1 genes using an IRES-based strategy synergistically enhanced differentiation of hPDLCs. It is suggested that this could be a new potential method in gene therapy for periodontal reconstruction.
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2390
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Liu X, Fang W, Liu L, Yu T, Lou B, Zheng X. Biological control of postharvest sour rot of citrus by two antagonistic yeasts. Lett Appl Microbiol 2010; 51:30-5. [PMID: 20477956 DOI: 10.1111/j.1472-765x.2010.02851.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIMS To investigate antifungal effects of two antagonistic yeasts on postharvest sour rot caused by Geotrichum citri-aurantii in citrus and evaluate possible mechanisms. METHODS AND RESULTS Cell suspension of Cryptococcus laurentii at 10(8) to 10(9) cells per ml effectively reduced sour rot incidence from 55.6% among untreated control fruit to 29.9-20.7% after 5 days of incubation at 26 degrees C. Application of cell-free culture filtrate of C. laurentii was effective in reducing the sour rot, but the effectiveness was lower than that of the cell suspension (1 x 10(8) cells per ml). In addition, C. laurentii multiplied more rapidly than Rhodosporidium paludigenum at 26 degrees C. The fruit inoculated with the two yeasts demonstrated changes in peroxidase and superoxide dismutase activity. Cryptococcus laurentii, in particular, was capable of inducing a striking response in treated citrus fruits. CONCLUSIONS The antifungal ability of C. laurentii can be attributed to the competitions of nutrients and space, defensive responses and possible secretion of antibiotic compounds. SIGNIFICANCE AND IMPACT OF THE STUDY The use of such antagonists may constitute an important alternative to synthetic fungicides for controlling postharvest sour rot in citrus.
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2391
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Shah AJ, Jadidi A, Liu X, Miyazaki S, Forclaz A, Nault I, Rivard L, Linton N, Xhaet O, Derval N, Sacher F, Bordachar P, Ritter P, Hocini M, Jais P, Haissaguerre M. Atrial tachycardias arising from ablation of atrial fibrillation: a proarrhythmic bump or an antiarrhythmic turn? Cardiol Res Pract 2010; 2010:950763. [PMID: 20379387 PMCID: PMC2850548 DOI: 10.4061/2010/950763] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Accepted: 02/02/2010] [Indexed: 11/20/2022] Open
Abstract
The occurrence of atrial tachycardias (AT) is a direct function of the volume of atrial tissue ablated in the patients with atrial fibrillation (AF). Thus, the incidence of AT is highest in persistent AF patients undergoing stepwise ablation using the strategic combination of pulmonary vein isolation, electrogram based ablation and left atrial linear ablation. Using deductive mapping strategy, AT can be divided into three clinical categories viz. the macroreentry, the focal and the newly described localized reentry all of which are amenable to catheter ablation with success rate of 95%. Perimitral, roof dependent and cavotricuspid isthmus dependent AT involve large reentrant circuits which can be successfully ablated at the left mitral isthmus, left atrial roof and tricuspid isthmus respectively. Complete bidirectional block across the sites of linear ablation is a necessary endpoint. Focal and localized reentrant AT commonly originate from but are not limited to the septum, posteroinferior left atrium, venous ostia, base of the left atrial appendage and left mitral isthmus and they respond quickly to focal ablation. AT not only represents ablation-induced proarrhythmia but also forms a bridge between AF and sinus rhythm in longstanding AF patients treated successfully with catheter ablation.
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2392
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de Oteyza D, Wakayama Y, Liu X, Yang W, Cook P, Himpsel F, Ortega J. Effect of fluorination on the molecule–substrate interactions of pentacene/Cu(100) interfaces. Chem Phys Lett 2010. [DOI: 10.1016/j.cplett.2010.03.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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2393
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Lu W, Yang C, Fang Z, Liu X, Zhu X, Wei D. Implementation of a novel interpolating method to epicardial potential mapping for atrial fibrillation study. Comput Biol Med 2010; 40:456-63. [DOI: 10.1016/j.compbiomed.2010.02.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2009] [Accepted: 02/25/2010] [Indexed: 11/28/2022]
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2394
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Curtis L, Datta P, Liu X, Bogdanova N, Heidelberger R, Janz R. Syntaxin 3B is essential for the exocytosis of synaptic vesicles in ribbon synapses of the retina. Neuroscience 2010; 166:832-41. [PMID: 20060037 PMCID: PMC2837114 DOI: 10.1016/j.neuroscience.2009.12.075] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Revised: 12/30/2009] [Accepted: 12/30/2009] [Indexed: 10/20/2022]
Abstract
Ribbon synapses of the vertebrate retina are specialized synapses that release neurotransmitter by synaptic vesicle exocytosis in a manner that is proportional to the level of depolarization of the cell. This release property is different from conventional neurons, in which the release of neurotransmitter occurs as a short-lived burst triggered by an action potential. Synaptic vesicle exocytosis is a calcium regulated process that is dependent on a set of interacting synaptic proteins that form the so-called SNARE (soluble N-ethylmaleimide sensitive factor attachment protein receptor) complex. Syntaxin 3B has been identified as a specialized SNARE molecule in ribbon synapses of the rodent retina. However, the best physiologically-characterized neuron that forms ribbon-style synapses is the rod-dominant or Mb1 bipolar cell of the goldfish retina. We report here the molecular characterization of syntaxin 3B from the goldfish retina. Using a combination of reverse transcription (RT) polymerase chain reaction (PCR) and immunostaining with a specific antibody, we show that syntaxin 3B is highly enriched in the plasma membrane of bipolar cell synaptic terminals of the goldfish retina. Using membrane capacitance measurements we demonstrate that a peptide derived from goldfish syntaxin 3B inhibits synaptic vesicle exocytosis. These experiments demonstrate that syntaxin 3B is an important factor for synaptic vesicle exocytosis in ribbon synapses of the vertebrate retina.
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2396
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Miyazaki S, Liu X, Nault I, Haïssaguerre M, Hocini M. Dissociated potential within superior vena cava: what is the origin? Heart Rhythm 2010; 8:946. [PMID: 20226274 DOI: 10.1016/j.hrthm.2010.03.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Indexed: 11/15/2022]
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2397
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An L, Wu ZH, Wu YF, Zhang XL, Liu X, Zhu YB, Cheng WM, Gao HM, Guo M, Tian JH. Fertility in Single-ovulating and Superovulated Dairy Heifers after Insemination with Low Dose Sex-sorted Sperm. Reprod Domest Anim 2010; 45:e344-50. [DOI: 10.1111/j.1439-0531.2009.01574.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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2398
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Liu P, Li J, Yang X, Shen Y, Zhu Y, Wang S, Wu Z, Liu X, An G, Ji W, Gao W, Yang X. Helminth infection inhibits airway allergic reaction and dendritic cells are involved in the modulation process. Parasite Immunol 2010; 32:57-66. [PMID: 20042008 DOI: 10.1111/j.1365-3024.2009.01161.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Several previous studies have demonstrated that some helminth infections can inhibit allergic reactions, but the examination on the effect of live Schistosoma japonicum (SJ) infection on allergic inflammation remains limited. The aim of this study was to examine the effect and mechanism of chronic SJ infection on airway allergic inflammation in a murine model. The data showed that chronic SJ infection suppressed airway eosinophilia, mucus production and antigen-specific IgE responses induced by ovalbumin (OVA) sensitization and challenge. Cytokine production analysis showed that chronic SJ infection reduced allergen-driven interleukin (IL)-4 and IL-5 production, but had no significant effect on IFN-gamma production. More importantly, we found that the adoptive transfer of dendritic cells (DCs) from SJ-infected mice dramatically decreased airway allergic inflammation in the recipients, which was associated with significant decrease of IL-4/IL-5 production and increase of IL-10 production. The results suggest that SJ infection may inhibit the development of allergy and that DCs may be involved in the process of helminth infection-mediated modulation of allergic inflammation.
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Peng C, Huang H, Ji X, Liu X, Ren L, Yu W, You J, Lu J. Effects of n-Hexadecane Concentration and a Two-Stage Oxygen Supply Control Strategy on Arachidonic Acid Production by Mortierella Alpina ME-1. Chem Eng Technol 2010. [DOI: 10.1002/ceat.200900413] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Liu X, Newton RC, Friedman SM, Scherle PA. Indoleamine 2,3-dioxygenase, an emerging target for anti-cancer therapy. Curr Cancer Drug Targets 2010; 9:938-52. [PMID: 20025603 DOI: 10.2174/156800909790192374] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The inability of the host immune system to control tumor growth appears to result from dominant mechanisms of immune suppression that prevent the immune system from effectively responding in a way that consistently results in tumor rejection. Among the many possible mediators of tumoral immune escape, the immunoregulatory enzyme, indoleamine 2,3-dioxygenase (IDO), has recently gained considerable attention. IDO is a heme-containing, monomeric oxidoreductase that catalyzes the first and rate-limiting step in the degradation of the essential amino acid tryptophan to N formyl-kynurenine. Tryptophan depletion as well as the accumulation of its metabolites results in a strongly inhibitory effect on the development of immune responses by blocking T cell activation, inducing T cell apoptosis and promoting the differentiation of naïve T cells into cells with a regulatory phenotype (T(regs)). Recent data obtained from preclinical tumor models demonstrate that IDO inhibition can significantly enhance the antitumor activity of various chemotherapeutic and immunotherapeutic agents. These results, coupled with data showing that increased IDO expression is an independent prognostic variable for reduced overall survival in cancer patients, suggest that IDO inhibition may represent an effective strategy to treat malignancies, either alone or in combination with chemotherapeutics or other immune based therapies. This review will focus on the role of IDO as a mediator of peripheral immune tolerance, evidence that IDO becomes dysregulated in human cancers, and the latest progress on the development of IDO inhibitors as a novel anti-cancer therapy.
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