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Qian D, Zhang Z, He J, Zhang P, Ou X, Li T, Niu L, Nan Q, Niu Y, He W, An L, Jiang K, Xiang Y. Arabidopsis ADF5 promotes stomatal closure by regulating actin cytoskeleton remodeling in response to ABA and drought stress. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:435-446. [PMID: 30476276 PMCID: PMC6322581 DOI: 10.1093/jxb/ery385] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 10/01/2018] [Indexed: 05/20/2023]
Abstract
Stomatal movement plays an essential role in plant responses to drought stress, and the actin cytoskeleton and abscisic acid (ABA) are two important components of this process. Little is known about the mechanism underlying actin cytoskeleton remodeling and the dynamic changes occurring during stomatal movement in response to drought stress/ABA signaling. Actin-depolymerizing factors (ADFs) are conserved actin severing/depolymerizing proteins in eukaryotes, and in angiosperms ADFs have evolved actin-bundling activity. Here, we reveal that the transcriptional expression of neofunctionalized Arabidopsis ADF5 was induced by drought stress and ABA treatment. Furthermore, we demonstrated that ADF5 loss-of-function mutations increased water loss from detached leaves, reduced plant survival rates after drought stress, and delayed stomatal closure by regulating actin cytoskeleton remodeling via its F-actin-bundling activity. Biochemical assays revealed that an ABF/AREB transcription factor, DPBF3, could bind to the ADF5 promoter and activate its transcription via the ABA-responsive element core motif ACGT/C. Taken together, our findings indicate that ADF5 participates in drought stress by regulating stomatal closure, and may also serve as a potential downstream target of the drought stress/ABA signaling pathway via members of the ABF/AREB transcription factors family.
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Deoni SC, Adams SH, Li X, Badger TM, Pivik RT, Glasier CM, Ramakrishnaiah RH, Rowell AC, Ou X. Cesarean Delivery Impacts Infant Brain Development. AJNR Am J Neuroradiol 2019; 40:169-177. [PMID: 30467219 DOI: 10.3174/ajnr.a5887] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 10/06/2018] [Indexed: 12/18/2022]
Abstract
BACKGROUND AND PURPOSE The cesarean delivery rate has increased globally in the past few decades. Neurodevelopmental outcomes associated with cesarean delivery are still unclear. This study investigated whether cesarean delivery has any effect on the brain development of offspring. MATERIALS AND METHODS A total of 306 healthy children were studied retrospectively. We included 3 cohorts: 2-week-old neonates (cohort 1, n = 32/11 for vaginal delivery/cesarean delivery) and 8-year-old children (cohort 2, n = 37/23 for vaginal delivery/cesarean delivery) studied at Arkansas Children's Hospital, and a longitudinal cohort of 3-month to 5-year-old children (cohort 3, n = 164/39 for vaginal delivery/cesarean delivery) studied independently at Brown University. Diffusion tensor imaging, myelin water fraction imaging, voxel-based morphometry, and/or resting-state fMRI data were analyzed to evaluate white matter integrity, myelination, gray matter volume, and/or functional connectivity, respectively. RESULTS While not all MR imaging techniques were shared across the institutions/cohorts, post hoc analyses showed similar results of potential effects of cesarean delivery. The cesarean delivery group in cohort 1 showed significantly lower white matter development in widespread brain regions and significantly lower functional connectivity in the brain default mode network, controlled for a number of potential confounders. No group differences were found in cohort 2 in white matter integrity or gray matter volume. Cohort 3 had significantly different trajectories of white matter myelination between groups, with those born by cesarean delivery having reduced myelin in infancy but normalizing with age. CONCLUSIONS Cesarean delivery may influence infant brain development. The impact may be transient because similar effects were not observed in older children. Further prospective and longitudinal studies may be needed to confirm these novel findings.
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Ou X, Glasier CM, Ramakrishnaiah RH, Kanfi A, Rowell AC, Pivik RT, Andres A, Cleves MA, Badger TM. Gestational Age at Birth and Brain White Matter Development in Term-Born Infants and Children. AJNR Am J Neuroradiol 2017; 38:2373-2379. [PMID: 29025726 DOI: 10.3174/ajnr.a5408] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 07/22/2017] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Studies on infants and children born preterm have shown that adequate gestational length is critical for brain white matter development. Less is known regarding how variations in gestational age at birth in term infants and children affect white matter development, which was evaluated in this study. MATERIALS AND METHODS Using DTI tract-based spatial statistics methods, we evaluated white matter microstructures in 2 groups of term-born (≥37 weeks of gestation) healthy subjects: 2-week-old infants (n = 44) and 8-year-old children (n = 63). DTI parameters including fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity were calculated by voxelwise and ROI methods and were correlated with gestational age at birth, with potential confounding factors such as postnatal age and sex controlled. RESULTS Fractional anisotropy values, which are markers for white matter microstructural integrity, positively correlated (P < .05, corrected) with gestational age at birth in most major white matter tracts/regions for the term infants. Mean diffusivity values, which are measures of water diffusivities in the brain, and axial and radial diffusivity values, which are markers for axonal growth and myelination, respectively, negatively correlated (P < .05, corrected) with gestational age at birth in all major white matter tracts/regions excluding the body and splenium of the corpus callosum for the term infants. No significant correlations with gestational age were observed for any tracts/regions for the term-born 8-year-old children. CONCLUSIONS Our results indicate that longer gestation during the normal term period is associated with significantly greater infant white matter development (as reflected by higher fractional anisotropy and lower mean diffusivity, axial diffusivity, and radial diffusivity values); however, similar associations were not observable in later childhood.
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Miao Y, Ou X, Wang J, Wang X, He X, Shen C, Ying H, Hu W, Hu C. Development and Validation of a Model for Temporal Lobe Necrosis Based on 749 Nasopharyngeal Carcinoma Patients Following IMRT. Int J Radiat Oncol Biol Phys 2017. [DOI: 10.1016/j.ijrobp.2017.06.381] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Ou X, Miao Y, Hu C. The Feasibility of Selectively Omission of Radiation to Level IB Lymph Nodes in Low-Risk Nasopharyngeal Carcinoma. Int J Radiat Oncol Biol Phys 2017. [DOI: 10.1016/j.ijrobp.2017.06.581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Isner JC, Xu Z, Costa JM, Monnet F, Batstone T, Ou X, Deeks MJ, Genty B, Jiang K, Hetherington AM. Actin filament reorganisation controlled by the SCAR/WAVE complex mediates stomatal response to darkness. THE NEW PHYTOLOGIST 2017; 215:1059-1067. [PMID: 28636198 PMCID: PMC5519931 DOI: 10.1111/nph.14655] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 04/25/2017] [Indexed: 05/20/2023]
Abstract
Stomata respond to darkness by closing to prevent excessive water loss during the night. Although the reorganisation of actin filaments during stomatal closure is documented, the underlying mechanisms responsible for dark-induced cytoskeletal arrangement remain largely unknown. We used genetic, physiological and cell biological approaches to show that reorganisation of the actin cytoskeleton is required for dark-induced stomatal closure. The opal5 mutant does not close in response to darkness but exhibits wild-type (WT) behaviour when exposed to abscisic acid (ABA) or CaCl2 . The mutation was mapped to At5g18410, encoding the PIR/SRA1/KLK subunit of the ArabidopsisSCAR/WAVE complex. Stomata of an independent allele of the PIR gene (Atpir-1) showed reduced sensitivity to darkness and F1 progenies of the cross between opal5 and Atpir-1 displayed distorted leaf trichomes, suggesting that the two mutants are allelic. Darkness induced changes in the extent of actin filament bundling in WT. These were abolished in opal5. Disruption of filamentous actin using latrunculin B or cytochalasin D restored wild-type stomatal sensitivity to darkness in opal5. Our findings suggest that the stomatal response to darkness is mediated by reorganisation of guard cell actin filaments, a process that is finely tuned by the conserved SCAR/WAVE-Arp2/3 actin regulatory module.
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Ou X, Shen C, Wang X, Ying H, He X, Hu C. Residual Disease at the Late Course of Intensity Modulated Radiation Therapy in Nasopharyngeal Carcinoma: An Adverse Prognostic Factor and Potential Role of Boost Irradiation and Adjuvant Chemotherapy. Int J Radiat Oncol Biol Phys 2016. [DOI: 10.1016/j.ijrobp.2016.06.1524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Ou X, Zhou X, Shi Q, Xing X, Yang Y, Jiang W, Hu C. Does an Adequate Dose of Cisplatin Need to Achieve Better Disease Control and Overall Survival in Locally Advanced Nasopharyngeal Carcinoma? Int J Radiat Oncol Biol Phys 2016. [DOI: 10.1016/j.ijrobp.2016.06.1483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Metcalfe AWS, MacIntosh BJ, Scavone A, Ou X, Korczak D, Goldstein BI. Effects of acute aerobic exercise on neural correlates of attention and inhibition in adolescents with bipolar disorder. Transl Psychiatry 2016; 6:e814. [PMID: 27187236 PMCID: PMC5070058 DOI: 10.1038/tp.2016.85] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 03/29/2016] [Accepted: 03/31/2016] [Indexed: 12/15/2022] Open
Abstract
Executive dysfunction is common during and between mood episodes in bipolar disorder (BD), causing social and functional impairment. This study investigated the effect of acute exercise on adolescents with BD and healthy control subjects (HC) to test for positive or negative consequences on neural response during an executive task. Fifty adolescents (mean age 16.54±1.47 years, 56% female, 30 with BD) completed an attention and response inhibition task before and after 20 min of recumbent cycling at ~70% of age-predicted maximum heart rate. 3 T functional magnetic resonance imaging data were analyzed in a whole brain voxel-wise analysis and as regions of interest (ROI), examining Go and NoGo response events. In the whole brain analysis of Go trials, exercise had larger effect in BD vs HC throughout ventral prefrontal cortex, amygdala and hippocampus; the profile of these effects was of greater disengagement after exercise. Pre-exercise ROI analysis confirmed this 'deficit in deactivation' for BDs in rostral ACC and found an activation deficit on NoGo errors in accumbens. Pre-exercise accumbens NoGo error activity correlated with depression symptoms and Go activity with mania symptoms; no correlations were present after exercise. Performance was matched to controls and results survived a series of covariate analyses. This study provides evidence that acute aerobic exercise transiently changes neural response during an executive task among adolescents with BD, and that pre-exercise relationships between symptoms and neural response are absent after exercise. Acute aerobic exercise constitutes a biological probe that may provide insights regarding pathophysiology and treatment of BD.
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Ou X, Pan W, Zhang X, Xiao P. Skin image retrieval using Gabor wavelet texture feature. Int J Cosmet Sci 2016; 38:607-614. [PMID: 27068932 DOI: 10.1111/ics.12332] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 03/12/2016] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Skin imaging plays a key role in many clinical studies. We have used many skin imaging techniques, including the recently developed capacitive contact skin imaging based on fingerprint sensors. The aim of this study was to develop an effective skin image retrieval technique using Gabor wavelet transform, which can be used on different types of skin images, but with a special focus on skin capacitive contact images. METHODS Content-based image retrieval (CBIR) is a useful technology to retrieve stored images from database by supplying query images. In a typical CBIR, images are retrieved based on colour, shape, texture, etc. In this study, texture feature is used for retrieving skin images, and Gabor wavelet transform is used for texture feature description and extraction. RESULTS The results show that the Gabor wavelet texture features can work efficiently on different types of skin images. Although Gabor wavelet transform is slower compared with other image retrieval techniques, such as principal component analysis (PCA) and grey-level co-occurrence matrix (GLCM), Gabor wavelet transform is the best for retrieving skin capacitive contact images and facial images with different orientations. Gabor wavelet transform can also work well on facial images with different expressions and skin cancer/disease images. CONCLUSION We have developed an effective skin image retrieval method based on Gabor wavelet transform, that it is useful for retrieving different types of images, namely digital colour face images, digital colour skin cancer and skin disease images, and particularly greyscale skin capacitive contact images. Gabor wavelet transform can also be potentially useful for face recognition (with different orientation and expressions) and skin cancer/disease diagnosis.
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Ou X, Andres A, Pivik RT, Cleves MA, Snow JH, Ding Z, Badger TM. Voxel-Based Morphometry and fMRI Revealed Differences in Brain Gray Matter in Breastfed and Milk Formula-Fed Children. AJNR Am J Neuroradiol 2015; 37:713-9. [PMID: 26585259 DOI: 10.3174/ajnr.a4593] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 09/10/2015] [Indexed: 02/04/2023]
Abstract
BACKGROUND AND PURPOSE Infant diets may have significant impact on brain development in children. The aim of this study was to evaluate brain gray matter structure and function in 8-year-old children who were predominantly breastfed or fed cow's milk formula as infants. MATERIALS AND METHODS Forty-two healthy children (breastfed: n = 22, 10 boys and 12 girls; cow's milk formula: n = 20, 10 boys and 10 girls) were studied by using structural MR imaging (3D T1-weighted imaging) and blood oxygen level-dependent fMRI (while performing tasks involving visual perception and language functions). They were also administered standardized tests evaluating intelligence (Reynolds Intellectual Assessment Scales) and language skills (Clinical Evaluation of Language Fundamentals). RESULTS Total brain gray matter volume did not differ between the breastfed and cow's milk formula groups. However, breastfed children had significantly higher (P < .05, corrected) regional gray matter volume measured by voxel-based morphometry in the left inferior temporal lobe and left superior parietal lobe compared with cow's milk formula-fed children. Breastfed children showed significantly more brain activation in the right frontal and left/right temporal lobes on fMRI when processing the perception task and in the left temporal/occipital lobe when processing the visual language task than cow's milk formula-fed children. The imaging findings were associated with significantly better performance for breastfed than cow's milk formula-fed children on both tasks. CONCLUSIONS Our findings indicated greater regional gray matter development and better regional gray matter function in breastfed than cow's milk formula-fed children at 8 years of age and suggested that infant diets may have long-term influences on brain development in children.
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Ou X, Han Q, Wang CH. Molecular dynamics analysis on tensile properties of carbon nanotubes with different cracks. MOLECULAR SIMULATION 2015. [DOI: 10.1080/08927022.2015.1089993] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Ou X, Glasier CM, Ramakrishnaiah RH, Mulkey SB, Ding Z, Angtuaco TL, Andres A, Kaiser JR. Impaired white matter development in extremely low-birth-weight infants with previous brain hemorrhage. AJNR Am J Neuroradiol 2014; 35:1983-9. [PMID: 24874534 DOI: 10.3174/ajnr.a3988] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND AND PURPOSE Brain hemorrhage is common in premature infants. The purpose of the study is to evaluate white matter development in extremely low-birth-weight infants with or without previous brain hemorrhage. MATERIALS AND METHODS Thirty-three extremely low-birth-weight infants were prospectively enrolled and included in this institutional review board-approved study. Another 10 healthy term infants were included as controls. The medical records of the extremely low-birth-weight infants were reviewed for sonography diagnosis of intraventricular hemorrhage. All infants had an MR imaging examination at term-equivalent age for detection of previous hemorrhage, and their white matter was scored and compared among different groups. DTI measured fractional anisotropy values were also compared voxelwise by tract-based spatial statistics. RESULTS Compared with controls, the white matter score was not significantly different in extremely low-birth-weight infants without blood deposition on MR imaging (P = .17), but was significantly worse in extremely low-birth-weight infants with blood deposition on MR imaging but no intraventricular hemorrhage diagnosis by sonography (P = .02), in extremely low-birth-weight infants with grade 1 or 2 intraventricular hemorrhage on sonography (P = .003), and in extremely low-birth-weight infants with grade 3 or 4 intraventricular hemorrhage on sonography (P = .0001). Extremely low-birth-weight infants without blood deposition on MR imaging did not show any white matter regions with significantly lower fractional anisotropy values than controls. Extremely low-birth-weight infants with blood deposition on MR imaging, but no intraventricular hemorrhage diagnosis, did show white matter regions with significantly lower fractional anisotropy values, and extremely low-birth-weight infants with intraventricular hemorrhage diagnosis had widespread white matter regions with lower fractional anisotropy values. CONCLUSIONS Previous brain hemorrhage is associated with abnormal white matter in extremely low-birth-weight infants at term-equivalent age, and sonography is not sensitive to minor hemorrhages that are sufficient to cause white matter injury.
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Ou X, Gan Y, Chen P, Qiu M, Jiang K, Wang G. Stomata prioritize their responses to multiple biotic and abiotic signal inputs. PLoS One 2014; 9:e101587. [PMID: 25003527 PMCID: PMC4086820 DOI: 10.1371/journal.pone.0101587] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 06/06/2014] [Indexed: 11/27/2022] Open
Abstract
Stomata are microscopic pores in leaf epidermis that regulate gas exchange between plants and the environment. Being natural openings on the leaf surface, stomata also serve as ports for the invasion of foliar pathogenic bacteria. Each stomatal pore is enclosed by a pair of guard cells that are able to sense a wide spectrum of biotic and abiotic stresses and respond by precisely adjusting the pore width. However, it is not clear whether stomatal responses to simultaneously imposed biotic and abiotic signals are mutually dependent on each other. Here we show that a genetically engineered Escherichia coli strain DH5α could trigger stomatal closure in Vicia faba, an innate immune response that might depend on NADPH oxidase-mediated ROS burst. DH5α-induced stomatal closure could be abolished or disguised under certain environmental conditions like low [CO2], darkness, and drought, etc. Foliar spraying of high concentrations of ABA could reduce stomatal aperture in high humidity-treated faba bean plants. Consistently, the aggressive multiplication of DH5α bacteria in Vicia faba leaves under high humidity could be alleviated by exogenous application of ABA. Our data suggest that a successful colonization of bacteria on the leaf surface is correlated with stomatal aperture regulation by a specific set of environmental factors.
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Pivik R, Andres A, Snow J, Ou X, Casey P, Cleves M, Badger T. Semantic memory processing is enhanced in preadolescents breastfed compared to those formula‐fed as infants: An ERP N400 study of sentential semantic congruity (629.1). FASEB J 2014. [DOI: 10.1096/fasebj.28.1_supplement.629.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Wang B, Yang J, Xiao J, Liang B, Zhou HX, Su Z, Xu S, Chen H, Ma C, Deng J, Li D, Zhou H, Ou X, Feng Y. Association of XRCC5 polymorphisms with COPD and COPD-related phenotypes in the Han Chinese population: a case-control cohort study. GENETICS AND MOLECULAR RESEARCH 2014; 13:7070-8. [PMID: 24615081 DOI: 10.4238/2014.january.24.11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Genome-wide association studies (GWAS) and integrative genomic approaches have demonstrated significant associations between chronic obstructive pulmonary disease (COPD) and polymorphisms of the X-ray repair cross-complementing protein 5 gene (XRCC5) in non-Asian populations. We investigated whether XRCC5 polymorphisms might be associated with COPD susceptibility and COPD-related phenotypes in the Chinese Han population. Nine single nucleotide polymorphisms (SNPs) (rs3821104, rs12470053, rs207936, rs3770498, rs6704622, rs3770492, rs4674066, rs7573191, and rs207906) in the XRCC5 gene were genotyped in a case-control study including 680 COPD patients and 687 controls. To estimate the strength of association, odds ratios (ORs) were calculated and the effects of potentially confounding variables were tested by logistic regression analysis. The association between haplotypes and COPD outcome was also assessed. Our data identified that the SNP rs207936 was associated with COPD with an adjusted P value of 0.038, which was also found when analyzing only data of current smokers (P=0.046). No significant associations were found between any of the SNPs and pulmonary function. Eight SNPs (rs3821104, rs12470053, rs207936, rs3770498, rs6704622, rs3770492, rs4674066, and rs7573191) showed strong linkage disequilibrium (R2≥0.9). Two major haplotypes were observed and showed a significant difference between case and control groups (P=0.0054 and 0.0081, respectively). The present study showed that the XRCC5 locus might be a contributor to COPD susceptibility in the Chinese Han population.
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Ou X, Cheng J, Zhang Y, Hu C. Preliminary Results of 18 F-FMISO PET in Evaluating Tumor Hypoxia and Predicting Response to Chemoradiation Therapy in Nasopharyngeal Carcinoma. Int J Radiat Oncol Biol Phys 2012. [DOI: 10.1016/j.ijrobp.2012.07.1289] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Ou X, Cakmak M. Influence of biaxial stretching mode on the crystalline texture in polylactic acid films. POLYMER 2008. [DOI: 10.1016/j.polymer.2008.09.053] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Ou X, Zhang B, Zhang L, Dong K, Liu C, Zhao G, Ding X. SarA influences the sporulation and secondary metabolism in Streptomyces coelicolor M145. Acta Biochim Biophys Sin (Shanghai) 2008. [DOI: 10.1093/abbs/40.10.877] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Cheung YF, Ou X, Wong SJ. Central and peripheral arterial stiffness in patients after surgical repair of tetralogy of Fallot: implications for aortic root dilatation. Heart 2006; 92:1827-30. [PMID: 16775086 PMCID: PMC1861289 DOI: 10.1136/hrt.2006.091199] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
OBJECTIVES To test the hypotheses that (1) the central conduit arteries stiffen preferentially over the peripheral conduit arteries in patients with repaired tetralogy of Fallot (ToF); and (2) central arterial stiffening is related to aortic root dilatation. DESIGN AND PATIENTS Heart-femoral pulse wave velocity (PWV), femoral-ankle PWV, carotid augmentation index and body surface area-adjusted aortic sinotubular dimension were determined in 31 children after ToF repair and compared with those in 31 age-matched controls after left-to-right shunt repair. In addition, the PWVs and augmentation index were related to the sinotubular junction dimension. SETTINGS Tertiary paediatric cardiac centre. RESULTS Compared with controls, patients had significantly greater heart-femoral PWV (mean 666 (SD 151) v 587 (81) cm/s, p = 0.021) and carotid augmentation index (-14.1 (17.0)% v -25.2 (14.6)%, p = 0.016), whereas the right (888 (202) v 845 (207) cm/s, p = 0.42) and left (918 (227) v 851 (215) cm/s, p = 0.25) femoral-ankle PWVs were similar between the two groups. The sinotubular junction z score of patients was significantly greater than that of controls (4.7 (1.5) v 1.1 (1.4), p < 0.001). Univariate analysis showed that the sinotubular junction z score correlated positively with heart-femoral PWV (r = 0.43, p = 0.001) and carotid augmentation index (r = 0.46, p = 0.001). Multiple linear regression similarly identified heart-femoral PWV (beta = 0.30, p = 0.04) and carotid augmentation index (beta = 0.31, p = 0.04) (model R(2) = 0.26) as significant determinants of sinotubular junction z score. CONCLUSIONS The aorta stiffens in patients with repaired ToF, which may contribute to progressive dilatation of the aortic root in the long term.
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Ou X, Tang C, Dai X, Yang J, Hao X, Cao D, Jiang Z, Wang Z, Yi G, Wang Z. Th-P15:3 Effect of liver X receptor agonist on Niemann-Pick C-1 expression and intracellular cholesterol transportation in lipid-loaded THP-1 macrophages. ATHEROSCLEROSIS SUPP 2006. [DOI: 10.1016/s1567-5688(06)81963-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Yang J, Tang C, Dai X, Ou X, Wang Z, Jiang Z, Cao D, Hao X, Yi G, Wang Z. Th-P15:229 Apolipoprotein A-I activates ABCA1 gene transcription and protein synthesis. ATHEROSCLEROSIS SUPP 2006. [DOI: 10.1016/s1567-5688(06)82188-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Tang C, Dai X, Ou X, Yang J, Cao D, Hao X, Yi G, Wang Z, Liu L, Yang Y. Th-P15:227 Alteration of ATP binding cassette transporter A1 on liver in atherosclerotic minipigs. ATHEROSCLEROSIS SUPP 2006. [DOI: 10.1016/s1567-5688(06)82186-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Wang J, Zheng H, Ou X, Albertson CM, Fink LM, Herbert JM, Hauer-Jensen M. Hirudin ameliorates intestinal radiation toxicity in the rat: support for thrombin inhibition as strategy to minimize side-effects after radiation therapy and as countermeasure against radiation exposure. J Thromb Haemost 2004; 2:2027-35. [PMID: 15550035 DOI: 10.1111/j.1538-7836.2004.00960.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND The small bowel is a dose-limiting normal tissue in radiation therapy of malignancies in the abdomen and pelvis, as well as an important determinant of survival after non-therapeutic radiation exposure. Irradiation of normal tissues, including intestine, causes loss of vascular thromboresistance and upregulation of thrombin receptors. Radiation-induced endothelial dysfunction is thought to be involved in both early and delayed radiation responses. Hence, thrombin may be a potential target for ameliorating normal tissue radiation toxicity. OBJECTIVE To assess direct thrombin inhibition as a protective strategy against small bowel radiation toxicity. METHODS Rat small intestine was exposed to localized orthovoltage X-radiation. Recombinant hirudin, a direct thrombin inhibitor, or vehicle was infused from 2 days before irradiation to 14 days after irradiation. Structural, cellular, and molecular aspects of intestinal radiation injury were assessed at 2 weeks (early toxicity) and 26 weeks (chronic toxicity) after irradiation. RESULTS Compared with unirradiated intestine, irradiated intestine showed increased expression of tissue factor, increased immunoreactivity for enzymatically active thrombin, and increased extravascular fibrin(ogen) deposition. Hirudin treatment significantly attenuated radiation-induced mucosal damage (P = 0.04), reactive intestinal wall thickening (P = 0.02), transforming growth factor-beta immunoreactivity levels (P = 0.0002), and collagen III deposition (P = 0.003). The differences between hirudin-treated and control rats were more pronounced at 2 weeks than at 26 weeks after irradiation. Hirudin treatment did not affect postradiation granulocyte infiltration. CONCLUSIONS Short-term thrombin inhibition attenuates important aspects of intestinal radiation toxicity. Thrombin is a promising target for minimizing normal tissue injury after radiation therapy of cancer, as well as for protecting normal tissues from the adverse effects of non-therapeutic radiation exposure.
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Ou X, Kuang A, Liang Z, Peng X, Zhong Y. [The binding characteristics of insulin-MTX to insulin receptor]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 2001; 32:538-40. [PMID: 12528542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE It has been reported that several kinds of tumors express increased insulin receptor and the molecules of insulin can be internalized in cells and may thence enter into the nuclei mediated by insulin receptor. In this study, we investigated the receptor binding characteristics of insulin-MTX for the possibility of using insulin as a carrier for carcinoma targeted therapy by receptor mediation. METHODS MTX(methotrexate) was covalently linked to insulin directly. The insulin-MTX conjugate was purified by polyacrylamine agarose gel electrophoresis and analysed by high performance liquid chromatography and SDS- polyacrylamine agarose gel electrophoresis. Histologically confirmed human hepatocellular carcinoma specimens were obtained from patients at surgery and immediately frozen under -80 degrees C. Cell membrane fractions were isolated by sucrose density gradient centrifugation. Competitive displacement of 125I-insulin with insulin and insulin-MTX binding to insulin receptor were carried out and the values of IC50 and Ki were calculated so as to observe the characteristics of insulin-MTX binding to insulin receptor. RESULTS Insulin-MTX competed as effectively as insulin with 125I-insulin for insulin receptor. The values of IC50 and Ki for insulin-MTX were 93.82 +/- 19.32 nmol/L and 91.88 +/- 16.86 nmol/L respectively, while the values of IC50 and Ki for insulin were 5.01 +/- 1.24 nmol/L and 4.85 +/- 1.12 nmol/L respectively. CONCLUSION Insulin-MTX could bind with insulin receptor with high affinity. The result demonstrates us that there is a possibility of using insulin as a carrier for carcinoma targeted therapy by receptor mediation.
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