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Luo JH, Chen W, Sun JJ, Xie D, Mo JC, Zhou L, Lu J. Laparoscopic Management of Mullerian Duct Remnants: Four Case Reports and Review of the Literature. ACTA ACUST UNITED AC 2008; 29:638-42. [DOI: 10.2164/jandrol.108.005496] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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102
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Cao J, Liu W, Wang Z, Xie D, Jia L, Chen Y. Green and Blue Monochromatic Lights Promote Growth and Development of Broilers Via Stimulating Testosterone Secretion and Myofiber Growth. J APPL POULTRY RES 2008. [DOI: 10.3382/japr.2007-00043] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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103
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Xie D, Zhao J, Yang Y, Park J, Chu TM, Zhang JT. Preparation and evaluation of a high-strength biocompatible glass-ionomer cement for improved dental restoratives. Biomed Mater 2008; 3:025012. [DOI: 10.1088/1748-6041/3/2/025012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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104
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Tang S, Chen JM, Zhu Q, Li X, Chen M, Sun R, Zhou Y, Deng F, Xie D. LAI inversion algorithm based on directional reflectance kernels. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2007; 85:638-48. [PMID: 17129659 DOI: 10.1016/j.jenvman.2006.08.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2004] [Revised: 12/06/2005] [Accepted: 08/23/2006] [Indexed: 05/12/2023]
Abstract
Leaf area index (LAI) is an important ecological and environmental parameter. A new LAI algorithm is developed using the principles of ground LAI measurements based on canopy gap fraction. First, the relationship between LAI and gap fraction at various zenith angles is derived from the definition of LAI. Then, the directional gap fraction is acquired from a remote sensing bidirectional reflectance distribution function (BRDF) product. This acquisition is obtained by using a kernel driven model and a large-scale directional gap fraction algorithm. The algorithm has been applied to estimate a LAI distribution in China in mid-July 2002. The ground data acquired from two field experiments in Changbai Mountain and Qilian Mountain were used to validate the algorithm. To resolve the scale discrepancy between high resolution ground observations and low resolution remote sensing data, two TM images with a resolution approaching the size of ground plots were used to relate the coarse resolution LAI map to ground measurements. First, an empirical relationship between the measured LAI and a vegetation index was established. Next, a high resolution LAI map was generated using the relationship. The LAI value of a low resolution pixel was calculated from the area-weighted sum of high resolution LAIs composing the low resolution pixel. The results of this comparison showed that the inversion algorithm has an accuracy of 82%. Factors that may influence the accuracy are also discussed in this paper.
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105
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Feng JX, Hou FF, Liang M, Wang GB, Zhang X, Li HY, Xie D, Tian JW, Liu ZQ. Restricted intake of dietary advanced glycation end products retards renal progression in the remnant kidney model. Kidney Int 2007; 71:901-11. [PMID: 17342181 DOI: 10.1038/sj.ki.5002162] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Diet-derived advanced glycation end products (AGEs) contribute significantly to accumulation of AGEs in renal insufficiency. To test whether modulation of dietary AGEs would impact on progression of chronic renal disease, 5/6 nephrectomy rats were randomly placed on three diets that differed only in AGEs content (low AGEs diet (LAD), high AGEs diet (HAD), and standard rodent diet (SRD)) for 5-13 weeks. Compared with SRD- or HAD-fed rats, LAD-treated animals showed decreased proteinuria and retarded decline of creatinine clearance without alteration of blood pressure. Glomerular volume was reduced by 23% compared with HAD-fed rats at week 13 (P<0.001). Renal fibrosis progressed with time in the remnant kidneys from HAD-fed rats. However, LAD-fed animals presented a better-preserved structure of the kidneys. LAD-fed rats demonstrated significantly decreased serum and renal AGEs concentration (P<0.01 and P<0.01). This was associated with marked decrease of intrarenal advanced oxidation protein products and thiobarbituric acid reactive substances, as well as increase of glutathione peroxidase activity. LAD treatment also downregulated expression of monocyte chemoattractant protein-1 and transforming growth factor-1 and ameliorated macrophage infiltration in the remnant kidney. These results demonstrated that restriction of dietary AGEs intake retards progression of renal fibrosis and dysfunction in the remnant kidney model.
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Widlowski JL, Taberner M, Pinty B, Bruniquel-Pinel V, Disney M, Fernandes R, Gastellu-Etchegorry JP, Gobron N, Kuusk A, Lavergne T, Leblanc S, Lewis PE, Martin E, Mõttus M, North PRJ, Qin W, Robustelli M, Rochdi N, Ruiloba R, Soler C, Thompson R, Verhoef W, Verstraete MM, Xie D. Third Radiation Transfer Model Intercomparison (RAMI) exercise: Documenting progress in canopy reflectance models. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jd007821] [Citation(s) in RCA: 160] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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107
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Wang G, Culbertson BM, Xie D, Seghi RR. PHYSICAL PROPERTY EVALUATIONS OF PERFLUOROTRIETHYLENE GLYCOL DIMETHACRYLATE AS A POTENTIAL REACTIVE DILUENT IN DENTAL COMPOSITE RESINS. JOURNAL OF MACROMOLECULAR SCIENCE PART A-PURE AND APPLIED CHEMISTRY 2007. [DOI: 10.1081/ma-100101527] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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108
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Kelley SK, Gelzleichter T, Xie D, Lee WP, Darbonne WC, Qureshi F, Kissler K, Oflazoglu E, Grewal IS. Preclinical pharmacokinetics, pharmacodynamics and activity of a humanized anti-CD40 antibody (SGN-40) in rodents and non-human primates. Br J Pharmacol 2007. [DOI: 10.1038/sj.bjp.0707129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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109
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Zhang YW, Xie D, Chen YX, Zhang HY, Xia ZX. Protective Effect of Gui Qi Mixture on the Progression of Diabetic Nephropathy in Rats. Exp Clin Endocrinol Diabetes 2006; 114:563-8. [PMID: 17177138 DOI: 10.1055/s-2006-948307] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Huang Qi (root of Astragalus membranaceus) and Dang Gui ( Angelica sinensis), two of the most widely used herbs in traditional Chinese medicine, have been proven to be effective in the treatment of diabetes mellitus (DM) although the underlying molecular mechanisms are not fully elucidated. This study was designed to investigate the protective effect of Dang Gui and Huang Qi mixture (GQM) on the development of diabetic nephropathy in rats with streptozotocin (STZ)-induced DM and the possible underlying molecular mechanism. The diabetic animal model was made by a single intraperitoneal injection of STZ and then treated with GQM or benazepril. Blood glucose, triglyceride (TG), cholesterol (CHO), high density lipoprotein (HDL), serum creatinine (Scr), creatinine clearance rate (Ccr), blood urea nitrogen (BUN), urine beta (2)-microglobin (beta (2)-MG), kidney/body weight (K/B) ratio, glomerular area (GA), renal transforming growth factor-beta (1) (TGF-beta (1)) mRNA expression and blood and renal angiotensin II (AngII) expression were determined 8 weeks after the treatment. The blood glucose, CHO and TG levels, BUN, SCr, Ccr. K/B ratio, GA, the excretion of beta (2)-MG, renal TGF-beta (1) mRNA expression and blood and renal AngII expression were significantly increased while the HDL level was decreased 8 week after STZ injection. The changes in blood glucose, TG, CHO and HDL were reversed by GQM, not by benazepril, whereas the changes in other variables were reversed by both GQM and benazepril. Our results suggest that GQM alleviates the disorder in blood glucose and lipids, protects against the progression of renal nephropathy in diabetic rats, probably by inhibiting the expression of AngII and TGF-beta (1) mRNA.
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Wu J, Feng Y, Xie D, Li X, Xiao W, Tao D, Qin J, Hu J, Gardner K, Judge SIV, Li QQ, Gong J. Unscheduled CDK1 activity in G1 phase of the cell cycle triggers apoptosis in X-irradiated lymphocytic leukemia cells. Cell Mol Life Sci 2006; 63:2538-45. [PMID: 17013563 DOI: 10.1007/s00018-006-6138-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cyclin-dependent kinase 1 (CDK1) is a major component of the cell cycle progression engine. Recently, several investigations provided evidence demonstrating that unscheduled CDK1 activation may also be involved in apoptosis in cancerous cells. In this article, we demonstrate that X-ray irradiation induced G1 arrest in MOLT-4 lymphocytic leukemia cells, the arrest being accompanied by reduction in the activity of CDK2, but increased CDK1 activity and cell apoptosis in the G1 phase. Interestingly, this increase in CDK1 and apoptosis by ionizing radiation was prevented by pretreatment with the CDK1 inhibitor, roscovitine, suggesting that CDK1 kinase activity is required for radiation-induced apoptotic cell death in this model system. Furthermore, cyclin B1 and CDK1 were detected co-localizing and associating in G1 phase MOLT-4 cells, with the cellular lysates from these cells revealing a genotoxic stress-induced increase in CDK1 phosphorylation (Thr-161) and dephosphorylation (Tyr-15), as analyzed by postsorting immunoprecipitation and immunoblotting. Finally, X-irradiation was found to increase Bcl-2 phosphorylation in G1 phase cells. Taken together, these novel findings suggest that CDK1 is activated by unscheduled accumulation of cyclin B1 in G1 phase cells exposed to X-ray, and that CDK1 activation, at the wrong time and in the wrong phase, may directly or indirectly trigger a Bcl-2-dependent signaling pathway leading to apoptotic cell death in MOLT-4 cells.
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111
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Yin D, Xie D, Sakajiri S, Miller CW, Zhu H, Popoviciu ML, Said JW, Black KL, Koeffler HP. DLK1: increased expression in gliomas and associated with oncogenic activities. Oncogene 2006; 25:1852-61. [PMID: 16288219 DOI: 10.1038/sj.onc.1209219] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
DLK1 (delta-like) is a transmembrane and secreted protein in the epidermal growth factor-like homeotic family. Although expressed widely during embryonic development, only a few tissues retain the expression in adults. Neuroendocrine tumors often highly express this protein; therefore, we hypothesized that brain tumors might also express it. This study found that the expression of DLK1 in gliomas was higher than that in normal brain (P < 0.05). After stable transfection of a DLK1 cDNA expression vector into GBM cell lines, their proliferation was increased. Furthermore, they lost contact inhibition, had enhanced anchorage-independent growth in soft agar, and had significantly greater capacity to migrate. Western blot studies showed that expression of cyclin D1, CDK2, and E2F4 were increased, and Rb levels were decreased in these cells. DLK1 was found on the cell surface and secreted in the medium from the transfected GBM cells. DLK1-enriched condition medium stimulated the growth of glioblastoma multiforme cell lines and explants. DLK1 antibody blocked cell growth stimulated by DLK1. In summary, these results suggest that DLK1 may play a role in the formation or progression of gliomas.
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Lau SH, Sham JST, Xie D, Tzang CH, Tang D, Ma N, Hu L, Wang Y, Wen JM, Xiao G, Zhang WM, Lau GKK, Yang M, Guan XY. Clusterin plays an important role in hepatocellular carcinoma metastasis. Oncogene 2006; 25:1242-50. [PMID: 16247463 DOI: 10.1038/sj.onc.1209141] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
To identify genes associated with tumor metastasis in hepatocellular carcinoma (HCC), gene expression profiles between a pair of primary HCC (H2-P) and their matched metastatic HCC (H2-M) were compared. Overexpression of clusterin (CLU) was found in H2-M cells. To determine the roles CLU played in HCC metastasis, CLU was transfected into H2-P cells. Overexpression of CLU in H2-P cells increased cell migration by twofold in vitro and formation of metastatic tumor nodules in liver by eightfold in vivo. To evaluate the correlation of CLU expression with HCC metastasis, the expression levels of CLU in HCCs were investigated using a tissue microarray (TMA) containing 104 pairs of primary HCCs and their matched metastases. The frequency of CLU overexpression increased significantly in metastatic HCCs (59.1%) compared with that in primary tumors (32.6%, P<0.001). To gain additional insight into the function of CLU, the expression profile of H2P-CLU was compared with vector-transfected H2-P cells by cDNA microarray. A total of 35 upregulated and 14 downregulated genes were detected in H2P-CLU. One of the upregulated genes known as YKL-40, which is implicated in matrix-remodeling and metastasis, was further studied using TMA. A significant correlation (P<0.001) between the expression levels of YKL-40 and CLU was observed, implying that the CLU-YKL-40 pathway may play an important role in HCC metastasis.
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113
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Xie D, Zeng YX, Wang HJ, Wen JM, Tao Y, Sham JST, Guan XY. Expression of cytoplasmic and nuclear Survivin in primary and secondary human glioblastoma. Br J Cancer 2006; 94:108-14. [PMID: 16404364 PMCID: PMC2361075 DOI: 10.1038/sj.bjc.6602904] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Clinically, human glioblastoma (GBM) may develop de novo or from a low-grade glioma (secondary GBM), and molecular alterations in the two pathways may differ. This study examined the status of Survivin expression and apoptosis in 30 primary and 26 secondary GBMs. Our results show that cytoplasmic Survivin positivity was significantly (P<0.001) more frequent in primary GBMs (83%) than that in secondary GBMs (46%). In addition, an inverse correlation of cytoplasmc Survivin positivity with GBM apoptotic index, and a positive association between cytoplasmic Survivin and size of the tumours were observed. These results suggest that cytoplasmic Survivin, via its antiapoptotic function, may be involved in the tumorigenesis of many primary GBMs, but only in a small fraction of secondary GBMs. Furthermore, the overall progression times from low-grade precursor lesions to secondary GBMs were significantly shorter (P<0.05) in cytoplasmic Survivin-positive cases (mean, 15.6 months) than those in Survivin-negative cases (mean, 23.8 moths), and the positive expression level of Survivin in cytoplasm was upregulated in most secondary GBMs when compared to matched pre-existing low-graded lesions. These results suggest that the increased accumulation of Survivin in the cytoplasm of more malignant glioma cells may prove to be a selective advantage, thus accelerating progression to a more aggressive phenotype.
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Xie D, Chen L, Liu C, Liu K. The inhibitory effects of oxytocin on distal colonic contractile activity in rabbits are enhanced by ovarian steroids. Acta Physiol (Oxf) 2006; 186:141-9. [PMID: 16497191 DOI: 10.1111/j.1365-201x.2005.01506.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
AIMS To study the effects of oxytocin on isolated rabbit distal colon and the regulation of ovarian steroids by its action. METHODS Muscle strips parallel to either the circular or the longitudinal fibres were excised and suspended in tissue chambers containing 5 mL Krebs solution (37 degrees C) and bubbled continuously with 95% O(2) and 5% CO(2). The effects of oxytocin on isometric spontaneous contractile responses were recorded. The effects of atosiban, tetrodotoxin, Mg(2+), progesterone and oestradiol on the oxytocin-induced response were also examined. RESULTS Oxytocin (1, 10 and 100 nmol L(-1)) dose dependently decreased the area under the contraction curve of distal colonic smooth muscle strips. The oxytocin receptor antagonist atosiban blocked the oxytocin (10 nmol L(-1))-caused responses in a dose-dependent manner. Tetrodotoxin (10 micromol L(-1)) had no effect on the oxytocin-induced response. Mg(2+)-free Krebs solution attenuated the oxytocin-induced response, but oestradiol (0.1 micromol L(-1)) or progesterone (0.1 micromol L(-1)) increased the oxytocin-induced response. CONCLUSION These results suggest that oxytocin inhibits the contractile motility of the distal colon, which is regulated by Mg(2+) and ovarian steroids.
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Zhang YW, Xie D, Xia B, Zhen RT, Liu IM, Cheng JT. Suppression of transforming growth factor-beta1 gene expression by Danggui buxue tang, a traditional Chinese herbal preparation, in retarding the progress of renal damage in streptozotocin-induced diabetic rats. Horm Metab Res 2006; 38:82-8. [PMID: 16523407 DOI: 10.1055/s-2006-925118] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Danggui buxue tang (DBT), a preparation containing Angelica sinensis (danggui) and Astragalus membranaceus (huangqi) at a ratio of 1 : 5, is used widely in China for stimulating red blood cell production and enhancing cardiovascular function. The present study was undertaken to characterize the effects of this preparation on diabetic nephropathy using streptozotocin-diabetic rats as a model. Streptozotocin-dependent alterations in renal weight/body weight ratio, urinary albumin and beta (2)-microglobulin concentrations, urinary albumin excretion rate, and creatinine clearance were ameliorated after eight weeks of treatment with either DBT or the angiotensin-converting enzyme inhibitor, benazepril. DBT, but not benazepril, partially attenuated the increases in blood glucose, triglycerides and cholesterol in STZ-diabetic rats. Additionally, the increased expression of transforming growth factor-beta (1) mRNA in the renal cortex due to streptozotocin-induced diabetes was modestly attenuated by these treatments. However, eight weeks of treatment with DBT failed to modify the concentration of angiotensin II in plasma or kidney, indicating that the ability of the preparation to retard the progression of kidney disease was not attributable to inhibition of the renin-angiotensin system. We propose that DBT alleviates renal alterations in diabetes and slows the progression of diabetic nephropathy by suppressing transforming growth factor-beta (1) mRNA expression. The preparation may therefore be useful as an adjuvant therapy for controlling diabetes and its complications.
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Qiao GB, Wu YL, Yang XN, Zhong WZ, Xie D, Guan XY, Fischer D, Kolberg HC, Kruger S, Stuerzbecher HW. High-level expression of Rad51 is an independent prognostic marker of survival in non-small-cell lung cancer patients. Br J Cancer 2005; 93:137-43. [PMID: 15956972 PMCID: PMC2361489 DOI: 10.1038/sj.bjc.6602665] [Citation(s) in RCA: 137] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
High-level expression of Rad51, a key factor in homologous recombination, has been observed in a variety of human malignancies. This study was aimed to evaluate Rad51 expression to serve as prognostic marker in non-small-cell lung cancer (NSCLC). A total of 383 non-small-cell lung tumours were analysed immunohistochemically on NSCLC tissue microarrays. High-level Rad51 expression was observed in 29.4% (100 out of 340) of cases. Patients whose tumours displayed high-level Rad51 expression showed a significantly shorter median survival time of 19 vs 68 months (P<0.0001, log-rank test). Similarly T status, N status, M status, clinical stage and histological tumour grade were significant prognostic markers in univariate Cox survival analysis. Importantly, Rad51 expression (P<0.0001) together with tumour differentiation (P<0.009), clinical stage (P=0.004) and N status (P=0.0001) proved to be independent prognostic parameters in multivariate analysis. Rad51 expression predicted the outcome of squamous cell cancer as well as adenocarcinoma of the lung. Our results suggest that Rad51 expression provides additional prognostic information for surgically treated NSCLC patients. We hypothesise that the decreased survival of NSCLC patients with high-level expression of Rad51 is related to an enhanced propensity of tumour cells for survival, antiapoptosis and chemo-/radioresistance.
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Zhong W, Qiao G, Xie D, Guan X, Ou W, Yang X, Lin J, Henning W, Stuerzbecher H, Wu Y. P-142 Prognostic role of e-cadherin in resected non-small-cell lungcancer detected by immunohistochemistry on high-throughput tissue microarray. Lung Cancer 2005. [DOI: 10.1016/s0169-5002(05)80636-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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118
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Qiao G, Wu Y, Yang X, Zhong W, Xie D, Guan X, Stuerzbecher H. O-131 High level expression of Rad51 is an independent prognosticmarker of survival in non-small cell lung cancer patients. Lung Cancer 2005. [DOI: 10.1016/s0169-5002(05)80265-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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119
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Hamrick MW, Pennington C, Newton D, Xie D, Isales C. Leptin deficiency produces contrasting phenotypes in bones of the limb and spine. Bone 2004; 34:376-83. [PMID: 15003785 DOI: 10.1016/j.bone.2003.11.020] [Citation(s) in RCA: 266] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2003] [Revised: 10/06/2003] [Accepted: 11/04/2003] [Indexed: 11/28/2022]
Abstract
Leptin is a hormone secreted by adipocytes that can regulate bone mass through a central, neuroendocrine signaling pathway. We tested the hypothesis that the response of bone tissue to altered leptin signaling is not uniform throughout the skeleton, but may vary between different skeletal regions and between cortical and trabecular moieties. We investigated the effects of leptin deficiency on muscle mass and bone architecture in obese, leptin-deficient (ob/ob) mice, and in lean controls. Results indicate that the obese mice weigh approximately twice as much as the lean mice, but the quadriceps muscles of the ob/ob mice are 40% smaller than those of controls. Leptin-deficient mice have significantly shorter femora, lower femoral bone mineral content (BMC), bone mineral density (BMD), cortical thickness, and trabecular bone volume compared to lean mice. Marrow tissue from the femora of ob/ob mice also shows a marked increase in adipocyte number compared to that of normal mice. In contrast to the pattern observed in the femur, ob/ob mice have significantly increased vertebral length, lumbar BMC, lumbar BMD, and trabecular bone volume compared to lean controls. Few adipocytes are observed in bone marrow from lumbar vertebrae of ob/ob mice, despite being numerous in marrow of the femur. However, like the femur, significant cortical thinning is also observed in the spine. These results indicate that the effects of altered leptin signaling on bone differ significantly between axial and appendicular regions, and may be mediated in part by muscle mass. The muscle hypoplasia, increased marrow adipogenesis, and decreased bone mass observed in the hindlimbs of ob/ob mice are also observed with aging in humans, suggesting that the ob/ob mouse may be a new and useful animal model for studying the relationship between bone marrow adipogenesis and osteopenia.
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120
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Xie D, Hao F, Xie G, Wang L. LMI approach to L2-gain analysis and control synthesis of uncertain switched systems. ACTA ACUST UNITED AC 2004. [DOI: 10.1049/ip-cta:20040010] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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121
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Brouard M, Burak I, Marinakis S, Minayev D, O'Keeffe P, Vallance C, Aoiz FJ, Bañares L, Castillo JF, Zhang DH, Xie D, Yang M, Lee SY, Collins MA. Cross section for the H+H2O abstraction reaction: experiment and theory. PHYSICAL REVIEW LETTERS 2003; 90:093201. [PMID: 12689220 DOI: 10.1103/physrevlett.90.093201] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2002] [Indexed: 05/24/2023]
Abstract
The absolute value of the cross section for the abstraction reaction between fast H atoms and H2O has been determined experimentally at a mean collision energy of 2.46 eV. The OH population distribution at the same mean energy has also been determined. The new measurements are compared with state-of-the-art quantum mechanical and quasiclassical scattering calculations on the most recently developed potential energy surface.
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Yang X, Lu Y, Xie D. [Protective effect of Radix Salvia Miltiorrhizae on radiation damage of the cochlea]. HUNAN YI KE DA XUE XUE BAO = HUNAN YIKE DAXUE XUEBAO = BULLETIN OF HUNAN MEDICAL UNIVERSITY 2002; 24:465-7. [PMID: 12080686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
In order to evaluate the preventive and therapeutic effects of Radix Salvia Miltiorrhizae on radiation damage of the cochlea, guinea pigs were divided into 3 groups. Group 1 was treated by radiation added with Radix Salvia Miltiorrhizae. Group 2 was radiated alone, and Group 3 was control. Group 1 and Group 2 were radiated with a single dose of gamma radiation(60 Gy). Morphological and functional observation of the cochleae was performed in two weeks after radiation. The result showed that the changes of complex action potential(CAP) and the cochlear structure were slight in Group 1, but obvious changes were found in Group 2. There was a significant difference in CAP response threshold and incidence of the cochlear hair cell loss between Group 1 and Group 2 (P < 0.01). These results suggest that Radix Salvia Miltiorrhiza may prevent radiation-induced cochlea damage. Its protective mechanisms may be cleaning free radicals, blocking calcium channel and improving microcirculation of the cochlea.
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Wu W, Xie D. [The effects of muscarinic and nicotinic receptor antagonists on compound action potentials in the cochleae of gerbils]. HUNAN YI KE DA XUE XUE BAO = HUNAN YIKE DAXUE XUEBAO = BULLETIN OF HUNAN MEDICAL UNIVERSITY 2002; 24:407-10. [PMID: 12080668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
To explore the mechanism of the medial olivocochlear(MOC) efferents and their neurotransmitter acetylcholine in regulating the cochlear mechanics and the auditory afferent activities, the effects of contralateral noise(CLN) and muscarinic(M) and nicotinic(N) receptor antagonist on the compound action potential(CAP) of the cochleae of gerbils were observed in our studies. The results showed that the CAP was significantly inhibited by CLN, and the suppressive effect of CLN on CAP was eliminated either by atropine or by gentamycin. These results support that MOC efferents play their physiological effect via both M and N receptors.
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Tian BL, Wen JM, Zhang M, Xie D, Xu RB, Luo CJ. The expression of ADAM12 (meltrin alpha) in human giant cell tumours of bone. Mol Pathol 2002; 55:394-7. [PMID: 12456779 PMCID: PMC1187278 DOI: 10.1136/mp.55.6.394] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIMS To examine the expression of ADAM12 (meltrin alpha), a member of the disintegrin and metalloprotease (ADAM) family, in human giant cell tumours of the bone, skeletal muscle tissue from human embryos, and human adult skeletal muscle tissue. METHODS ADAM12 mRNA was detected by reverse transcription polymerase chain reaction and in situ hybridisation. RESULTS ADAM12 mRNA was detected in 14 of the 20 giant cell tumours of bone and in three of the six tumour cell cultures. The expression of ADAM12 in cells cultured from the tumour was linked to the presence of multinucleated giant cells. ADAM12 mRNA could not be detected in the five adult skeletal muscle tissue samples, although it was found in the two embryonic skeletal muscle tissue samples. ADAM12 mRNA was localised to the cytoplasm of multinucleated giant cells and some mononuclear stromal cells. CONCLUSIONS These results indicate that multinucleated giant cells are formed by the cell fusion of mononuclear stromal cells in giant cell tumours of bone and that ADAM12 is involved in the cell fusion process.
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125
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Shen YX, Xie D, Gibson HW. Polyrotaxanes based on polyurethane backbones and crown ether cyclics. 1. Synthesis. J Am Chem Soc 2002. [DOI: 10.1021/ja00081a014] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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126
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Yang J, Xie D, Yelon WB, Newsam JM. Aluminum-gallium substitution in zeolite Li-A(BW). ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100323a052] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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127
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Xie D, Nakachi K, Wang H, Elashoff R, Koeffler HP. Elevated levels of connective tissue growth factor, WISP-1, and CYR61 in primary breast cancers associated with more advanced features. Cancer Res 2001; 61:8917-23. [PMID: 11751417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
To gain insight into the role of the CCN genes in human breast carcinomas, we quantified connective tissue growth factor (CTGF), WISP-1, CYR61, and human NOV (NOVH) mRNA expression levels in samples from 44 primary breast tumors and seven normal breasts using quantitative real-time PCR assay. Overexpression of CTGF, WISP-1, CYR61, and NOVH was found in 55 (24 of 44), 46 (20 of 44), 39 (17 of 44), and 11% (5 of 44) primary breast tumors, respectively. Statistical univariate analysis was performed to explore the links between expression of the CCN genes and clinical and pathological parameters. Interestingly, significant associations were found between CTGF expression versus stage, tumor size, lymph node status, and age at diagnosis; WISP-1 mRNA levels versus stage, tumor size, lymph node, and HER-2/neu overexpression; and CYR61 expression with stage, tumor size, lymph node, age, and estrogen receptor expression. In contrast to CTGF, WISP-1, and CYR61, no significant correlation was found between NOVH expression and any of the clinical and pathological factors. Furthermore, multivariate classification tree model analysis showed that stage and lymph node involvement were important for predicting CTGF expression in breast cancers; the stage, age, and HER-2/neu status were key factors for WISP-1 expression; and the stage, age, and estrogen receptor were valuable predictors for CYR61 expression. In summary, these results suggest that CTGF, WISP-1, and CYR61 may play a role in the progression of breast cancer and might serve as a valuable tool for monitoring tumor status of breast cancer patients.
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Tong X, Xie D, O'Kelly J, Miller CW, Muller-Tidow C, Koeffler HP. Cyr61, a member of CCN family, is a tumor suppressor in non-small cell lung cancer. J Biol Chem 2001; 276:47709-14. [PMID: 11598125 DOI: 10.1074/jbc.m107878200] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Cysteine-rich protein 61 (Cyr61) is a member of a family of growth factor-inducible immediate-early genes. It regulates cell adhesion, migration, proliferation, and differentiation and is involved in tumor growth. In our experiments, the role of Cyr61 in non-small cell lung cancer (NSCLC) was examined. Expression of Cyr61 mRNA was decreased markedly in four of five human lung tumor samples compared with their normal matched lung samples. NSCLC cell lines NCI-H520 and H460, which have no endogenous Cyr61, formed 60-90% fewer colonies after being transfected with a Cyr61 cDNA expression vector than cells transfected with the same amount of empty vector. After stable transfection of a Cyr61 cDNA expression vector, proliferation of both H520-Cyr61 and H460-Cyr61 sublines decreased remarkably compared with the cells stably transfected with empty vector. The addition of antibody against Cyr61 partially rescued the growth suppression of both H520-Cyr61 and H460-Cyr61 cells. Cell cycle analysis revealed that both H520-Cyr61 and H460-Cyr61 cells developed G(1) arrest, prominently up-regulated expression of p53 and p21(WAF1), and had decreased activity of cyclin-dependent kinase 2. The increase of pocket protein pRB2/p130 was also detected in these cells. Notably, both of the Cyr61-stably transfected lung cancer cell lines developed smaller tumors than those formed by the wild-type cells in nude mice. Taken together, we conclude that Cyr61 may play a role as a tumor suppressor in NSCLC.
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129
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Gilbertson SR, Xie D, Fu Z. Proline-based P, N ligands in asymmetric allylation and the Heck reaction. J Org Chem 2001; 66:7240-6. [PMID: 11681933 DOI: 10.1021/jo0158231] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A series of phosphine-oxazoline ligands based on proline are reported. These ligands are synthesized from commercially available trans-4-hydroxy-L-proline in four steps. The ability of this type of ligand to catalyze allylic alkylation in an asymmetric fashion as well as the asymmetric Heck reaction is reported. The best of these ligands gave a palladium complex, which catalyzed the addition of dimethylmalonate to cyclopentenyl acetate in excellent yield and up to 96% ee. This same system catalyzed the Heck reaction between dihydrofuran and cyclohexene in up to 86% ee. These ligands appear to differ from the traditional phosphine-oxazoline ligands in that the stereochemistry of the stereogenic carbon next to the oxazoline is not necessarily the dominant chiral center in the induction of selectivity.
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Wu TR, Xie D. [Central Hospital of Yan'an during the period of anti-Japanese War] (Chi). ZHONGHUA YI SHI ZA ZHI (BEIJING, CHINA : 1980) 2001; 22:166-8. [PMID: 11612987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
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131
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Tian B, Wen J, Zhang M, Li Q, Xie D. [Expression of ADAM12 (Meltrin-alpha) gene in giant cell tumor of bone]. ZHONGHUA BING LI XUE ZA ZHI = CHINESE JOURNAL OF PATHOLOGY 2001; 30:350-2. [PMID: 11769731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To detect expression and location of ADAM12 (meltrin-alpha) gene in giant cell tumor of bone and to study its effect on the formation of multinucleated giant cells in the tumor. METHODS ADAM12 mRNA was detected by RT-PCR and RNA in situ hybridization in 18 cases of giant cell tumors, 6 cases of cultured tumor cells, 2 specimens of embryonic muscle tissue and 5 specimens of adult muscle tissue. RESULTS RT-PCR showed that 12/18 (67%) cases of giant cell tumor of bone expressed ADAM12 mRNA. RNA in situ hybridization demonstrated positive ADAM12 mRNA in 12 cases of the detected tumors. The ADAM 12 mRNA positive signal was localized in the cytoplasm of almost all multinucleated giant cells and mononuclear stromal cells. However, the expression of ADAM12 mRNA decreased gradually, and eventually lost with increased passages of tumor cells and the disappearance of multinucleated giant cells in the culture. CONCLUSION Multinucleated giant cells probably originated from the fusion of mononuclear stromal cells and ADAM12 may participate in the fusion process.
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Hofmann WK, Takeuchi S, Xie D, Miller CW, Hoelzer D, Koeffler HP. Frequent loss of heterozygosity in the region of D1S450 at 1p36.2 in myelodysplastic syndromes. Leuk Res 2001; 25:855-8. [PMID: 11532517 DOI: 10.1016/s0145-2126(01)00037-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
To understand the underlying mechanisms in myelodysplastic syndromes (MDS) by identifying target tumor suppressor genes, we performed a detailed deletional mapping of the short arm of chromosome 1 in 38 paired samples of bone marrow and peripheral blood obtained from individuals with MDS by PCR amplification of a total of 23 highly informative microsatellite sequences. We identified the commonly deleted region between D1S508 and D1S244. LOH of this region was found in five patients (13%). In addition, LOH at 1p was associated with a poor clinical outcome, suggesting that the deletion of a gene in this region may be involved in the course of this disease. By analyzing the chromosomal map of this region, we found TNFRSF12 as a candidate tumor suppressor gene. However, our search for mutations in this gene did not identify somatic mutations in MDS. Our findings are consistent with the possible existence of an as-yet unknown tumor suppressor gene in this region that is altered in MDS.
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133
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Kelley SK, Harris LA, Xie D, Deforge L, Totpal K, Bussiere J, Fox JA. Preclinical studies to predict the disposition of Apo2L/tumor necrosis factor-related apoptosis-inducing ligand in humans: characterization of in vivo efficacy, pharmacokinetics, and safety. J Pharmacol Exp Ther 2001; 299:31-8. [PMID: 11561060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
Apo2L/TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) is a member of the tumor necrosis factor gene family known to induce apoptosis in a number of cancer cell lines and may have broad-spectrum activity against human malignancies. These studies have evaluated the potency of recombinant soluble human Apo2L/TRAIL in a mouse xenograft model and the disposition and safety of Apo2L/TRAIL in rodents and nonhuman primates. Mice with established COLO205 tumors were given daily i.v. injections of Apo2L/TRAIL (30-120 mg/kg/day). Control tumors doubled in size every 2 to 3 days, while time to tumor doubling in the treatment groups was significantly longer and related to dose (14-21 days). For pharmacokinetic studies, Apo2L/TRAIL was given as an i.v. bolus to mice (10 mg/kg), rats (10 mg/kg), cynomolgus monkeys (1, 5, and 50 mg/kg), and chimpanzees (1 and 5 mg/kg). Apo2L/TRAIL was rapidly eliminated from the serum of all species studied. Half-lives were approximately 3 to 5 min in rodents and approximately 23 to 31 min in nonhuman primates. Allometric scaling provided estimates of Apo2L/TRAIL kinetics in humans, suggesting that on a milligram per kilogram basis, doses significantly lower than those used in xenograft studies could be effective in humans. Apo2L/TRAIL clearance was highly correlated with glomerular filtration rate across species, indicating that the kidneys play a critical role in the elimination of this molecule. Safety evaluations in cynomolgus monkeys and chimpanzees revealed no abnormalities associated with Apo2L/TRAIL exposure. In conclusion, these studies have characterized the disposition of Apo2L/TRAIL in rodents and primates and provide information that will be used to predict the pharmacokinetics of Apo2L/TRAIL in humans.
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Kim JA, Hedrick CC, Xie D, Fisher MJ. Adenoviral-mediated transfer of tissue plasminogen activator gene into brain capillary endothelial cells in vitro. Angiology 2001; 52:627-34. [PMID: 11570662 DOI: 10.1177/000331970105200907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Tissue plasminogen activator (tPA) has a critical role in fibrinolysis, converting plasminogen into active protease plasmin. Because intravenous tPA has only limited effectiveness as acute stroke therapy, enhancement of endogenous tPA represents a potential alternative to stroke treatment. Adenoviral-mediated gene transfer was used to enhance production of tPA in bovine brain capillary endothelial cells (BEC). Antigen and activity levels of tPA and plasminogen activator inhibitor-1 (PAI-1) in media from BEC infected with AdCMVtPA were analyzed. Conditioned media were analyzed for thrombomodulin, the integral membrane antithrombotic molecule that co-activates protein C. BEC infected with AdCMVtPA demonstrated enhanced expression of tPA antigen (40.2 +/- 0.4 ng/mL vs 1.1 +/- 1.5 ng/mL [p<0.001] and 0.3 +/- 0.5 ng/mL [p<0.0001], respectively) and increased tPA enzymatic activity (27.4 +/- 5.7 IU/mL vs 8.3 +/- 1.7 IU/mL [p<0.05] and 13.3 +/- 3.2 IU/mL [p<0.05], respectively) compared to BEC infected with the control adenovirus (Adl327) or uninfected BEC. There was a moderate increase in PAI-1 protein 4 days after transfection with AdCMVtPA, and the integral membrane protein thrombomodulin was released into media by transfected BEC. These results demonstrate that adenoviral-mediated delivery in vitro of the human tPA gene resulted in high levels of expression of tPA in BEC. Transient overexpression of tPA by gene transfer might be a useful strategy to protect against thrombotic occlusion during the period of risk of acute stroke.
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135
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Xie D, Liu D, Zhu H, Liu T. Multipulse feed strategy for glycerol fed-batch fermentation: a steady-state nonlinear optimization approach. Appl Biochem Biotechnol 2001; 95:103-12. [PMID: 11694060 DOI: 10.1385/abab:95:2:103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2000] [Revised: 01/08/2001] [Accepted: 01/12/2001] [Indexed: 11/11/2022]
Abstract
During glycerol fed-batch fermentation, the process could be divided into multiple equal subintervals, and the feed operation was performed in pulse form at the start of each subinterval. Based on the macrokinetic models, the multipulse feed strategy for both glucose and corn steep slurry was determined by a general nonlinear optimization approach to maximize the final glycerol productivity and still control the residual glucose at a low concentration. The experimental results in a 600-mL Airlift Loop Reactor showed that the tested data with this strategy agreed well with the corresponding model prediction, and that the feed mode with nonlinear optimization could improve the glycerol productivity significantly compared with those determined just by limited experimental optimization in previous studies.
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136
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Xie D, Miller CW, O'Kelly J, Nakachi K, Sakashita A, Said JW, Gornbein J, Koeffler HP. Breast cancer. Cyr61 is overexpressed, estrogen-inducible, and associated with more advanced disease. J Biol Chem 2001; 276:14187-94. [PMID: 11297518 DOI: 10.1074/jbc.m009755200] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
To identify genes involved in breast cancer, polymerase chain reaction-selected cDNA subtraction was utilized to construct a breast cancer-subtracted library. Differential screening of the library isolated the growth factor-inducible immediate-early gene Cyr61, a secreted, cysteine-rich, heparin binding protein that promotes endothelial cell adhesion, migration, and neovascularization. Northern analysis revealed that Cyr61 was expressed highly in the invasive breast cancer cell lines MDA-MB-231, T47D, and MDA-MB-157; very low levels were found in the less tumorigenic MCF-7 and BT-20 breast cancer cells and barely detectable amounts were expressed in the normal breast cells, MCF-12A. Univariate analysis showed a significant or borderline significant association between Cyr61 expression and stage, tumor size, lymph node positivity, age, and estrogen receptor levels. Interestingly, expression of Cyr61 mRNA increased 8- to 12-fold in MCF-12A and 3- to 5-fold in MCF-7 cells after 24- and 48-h exposure to estrogen, respectively. Induction of Cyr61 mRNA was blocked by tamoxifen and ICI182,780, inhibitors of the estrogen receptor. Stable expression of Cyr61 cDNA under the regulation of a constitutive promoter in MCF-7 cells enhanced anchorage-independent cell growth in soft agar and significantly increased tumorigenicity and vascularization of these tumors in nude mice. Moreover, overexpression of Cyr61 in MCF-12A normal breast cells induced their tumor formation and vascularization in nude mice. In summary, these results suggest that Cyr61 may play a role in the progression of breast cancer and may be involved in estrogen-mediated tumor development.
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MESH Headings
- Adult
- Age Factors
- Aged
- Aged, 80 and over
- Animals
- Antineoplastic Agents, Hormonal/pharmacology
- Blotting, Northern
- Breast Neoplasms/blood supply
- Breast Neoplasms/drug therapy
- Breast Neoplasms/metabolism
- Carcinoma, Ductal, Breast/metabolism
- Carcinoma, Ductal, Breast/pathology
- Cell Movement
- Cells, Cultured
- Cysteine-Rich Protein 61
- DNA, Complementary/metabolism
- Disease Progression
- Estradiol/analogs & derivatives
- Estradiol/pharmacology
- Estrogen Antagonists/pharmacology
- Estrogens/metabolism
- Female
- Fulvestrant
- Gene Library
- Growth Substances/biosynthesis
- Humans
- Immediate-Early Proteins/biosynthesis
- Intercellular Signaling Peptides and Proteins
- Mice
- Mice, Nude
- Middle Aged
- Multivariate Analysis
- Neoplasm Transplantation
- Promoter Regions, Genetic
- Protein Binding
- Receptors, Estrogen/biosynthesis
- Recombinant Proteins/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Tamoxifen/pharmacology
- Time Factors
- Transfection
- Tumor Cells, Cultured
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Xu L, Liu F, Wang Z, Peng W, Huang R, Huang D, Xie D. An Arabidopsis mutant cex1 exhibits constant accumulation of jasmonate-regulated AtVSP, Thi2.1 and PDF1.2. FEBS Lett 2001; 494:161-4. [PMID: 11311233 DOI: 10.1016/s0014-5793(01)02331-6] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Jasmonates (JA) act as a regulator in plant growth as well as a signal in plant defense. The Arabidopsis vegetative storage protein (AtVSP) and plant defense-related proteins thionin (Thi2.1) and defensin (PDF1.2) have previously been shown to accumulate in response to JA induction. In this report, we isolated and characterized a novel recessive mutant, cex1, conferring constitutive JA-responsive phenotypes including JA-inhibitory growth and constitutive expression of JA-regulated AtVSP, Thi2.1 and PDF1.2. The plant morphology and the gene expression pattern of the cex1 mutant could be phenocopied by treatment of wild-type plants with exogenous JA, indicating that CEX1 might be a negative regulator of the JA response pathway.
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138
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Zheng W, Kataoka N, Xie D, Young SR. RESPONSE: Re: Population-Based, Case-Control Study of HER2 Genetic Polymorphism and Breast Cancer Risk. J Natl Cancer Inst 2001. [DOI: 10.1093/jnci/93.7.558] [Citation(s) in RCA: 13] [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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139
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Shields RL, Namenuk AK, Hong K, Meng YG, Rae J, Briggs J, Xie D, Lai J, Stadlen A, Li B, Fox JA, Presta LG. High resolution mapping of the binding site on human IgG1 for Fc gamma RI, Fc gamma RII, Fc gamma RIII, and FcRn and design of IgG1 variants with improved binding to the Fc gamma R. J Biol Chem 2001; 276:6591-604. [PMID: 11096108 DOI: 10.1074/jbc.m009483200] [Citation(s) in RCA: 852] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Immunoglobulin G (IgG) Fc receptors play a critical role in linking IgG antibody-mediated immune responses with cellular effector functions. A high resolution map of the binding site on human IgG1 for human Fc gamma RI, Fc gamma RIIA, Fc gamma RIIB, Fc gamma RIIIA, and FcRn receptors has been determined. A common set of IgG1 residues is involved in binding to all Fc gamma R; Fc gamma RII and Fc gamma RIII also utilize residues outside this common set. In addition to residues which, when altered, abrogated binding to one or more of the receptors, several residues were found that improved binding only to specific receptors or simultaneously improved binding to one type of receptor and reduced binding to another type. Select IgG1 variants with improved binding to Fc gamma RIIIA exhibited up to 100% enhancement in antibody-dependent cell cytotoxicity using human effector cells; these variants included changes at residues not found at the binding interface in the IgG/Fc gamma RIIIA co-crystal structure (Sondermann, P., Huber, R., Oosthuizen, V., and Jacob, U. (2000) Nature 406, 267-273). These engineered antibodies may have important implications for improving antibody therapeutic efficacy.
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140
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An B, Li B, Xie D, Chen Q, Cheng Z. [The numerical simulation of the dynamic stress field from impacting head]. SHENG WU YI XUE GONG CHENG XUE ZA ZHI = JOURNAL OF BIOMEDICAL ENGINEERING = SHENGWU YIXUE GONGCHENGXUE ZAZHI 2001; 18:16-8. [PMID: 11332102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
In order to study the mechanism of impact injury to the head, we have simulated the development of the stress field by using the numerical simulation method. The process of the head having been impacted vertically by an impactor can be described as a 2D problem, and the reactions of the head subjected to impacted force can be simulated and analyzed by the method based on the finite difference method (FDM). The model is subjected to applied force by an impactor with the initial velocity of 25 m/s (90 km/h). The pre-processing for the model is done on the microcomputer software. Once imported to the software, the nodes and elements are generated and material characteristics are assigned. The results demonstrate that the high resolution computer graphics can provide the dynamic distribution of the stress field, which can clearly show how the stress is developed, and how many its value is. The results are helpful to understanding the mechanism of impact injury to head.
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141
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Zheng W, Xie D, Cerhan JR, Sellers TA, Wen W, Folsom AR. Sulfotransferase 1A1 polymorphism, endogenous estrogen exposure, well-done meat intake, and breast cancer risk. Cancer Epidemiol Biomarkers Prev 2001; 10:89-94. [PMID: 11219777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
Sulfotransferase (SULT) 1A1 is involved in the inactivation of estrogens and bioactivation of heterocyclic amines and polycyclic aromatic hydrocarbons. A G--->A transition at codon 213 (CGC/Arg to CAC/His) of the SULT1A1 gene was reported recently, and individuals homozygous for the His allele have a substantially lower activity of this enzyme than those with other genotypes. We hypothesized that the His allele may be a risk factor for breast cancer, particularly among women who had risk factors related to higher endogenous estrogen exposure. This hypothesis was investigated in a case-control study conducted in a cohort of postmenopausal Iowa women who completed a mailed questionnaire in 1986 on lifestyle factors including information on major breast cancer risk factors. DNA samples and information related to well-done meat intake were obtained from breast cancer cases diagnosed between 1992 and 1994 and a random sample of cancer-free cohort members. Multivariate analysis was performed on data from 156 cases and 332 controls who donated a blood sample. The frequency of the His allele was 41.6% in cases and 34.1% in controls (P = 0.03), and the risk of breast cancer was increased with the number of His alleles (P for trend = 0.02). Compared with women with the Arg/Arg genotype, an 80% elevated risk was observed among women homozygous for the His allele (95% confidence interval, 1.0-3.2; P = 0.04). This positive association was more pronounced among women who drank alcohol and had a high body mass index, early age at menarche, and late age at menopause, factors related to high endogenous estrogen exposure, than among those who did not have these risk factors. The risk of breast cancer was elevated with increasing doneness level of red meat intake among women with the Arg/Arg genotype (P for trend, 0.01) or the Arg/His genotype (P for trend, 0.10), whereas this association was not evident for women with the His/His genotype. The results from this study suggest that homozygosity for the SULT1A1 His213 allele may be a risk factor for breast cancer, and its effect may be modified by the exposure level of endogenous estrogens and heterocyclic amines.
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Walters JJ, Muhammad W, Fox KF, Fox A, Xie D, Creek KE, Pirisi L. Genotyping single nucleotide polymorphisms using intact polymerase chain reaction products by electrospray quadrupole mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2001; 15:1752-1759. [PMID: 11555877 DOI: 10.1002/rcm.435] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Both single nucleotide polymorphisms (SNPs) and mutations are commonly observed in the gene encoding the tumor suppressor protein, p53. SNPs occur at specific locations within genes whereas mutations may be distributed across large regions of genes. When determining nucleotide differences, mass spectrometry is the only method other than Sanger sequencing which offers direct structural information. Electrospray ionization (ESI) quadrupole mass spectrometry (MS) analysis of intact polymerase chain reaction (PCR) products was performed following a simple purification and on-line heating to limit ion adduction. The PCR products were amplified directly from genomic DNA rather than plasmids, as in our previous work. Two known polymorphisms of the p53 gene were genotyped. A cytosine (C) or guanine (G) transversion, designated C <--> G (G <--> C on the opposite strand), were each detected by a 40.0 Da change upon ESI quadrupole MS analysis. Using known PCR products as standards, the genotypes determined for 10 human samples corresponded with restriction fragment length polymorphism (RFLP) analysis. Cytosine/thymine (T) transitions, designated C <--> T (G <--> A on the opposite strand), were also genotyped by ESI-MS. This SNP is discriminated by a 15.0 Da change on one strand (C <--> T) and a 16.0 Da change on the other (G <--> A). Appropriate sample preparation and instrumental configuration (including heated sample inlet syringe and MS source), to limit adducts, are both vital for successful ESI quadrupole MS analysis of intact PCR products.
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143
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Xie D, Leung S, Zeng W, Zhang M, Chan A, Yuen S, Wen J. [The expression of DNA mismatch repair genes and detection of DNA ploidy in young patients with colorectal carcinoma]. ZHONGHUA BING LI XUE ZA ZHI = CHINESE JOURNAL OF PATHOLOGY 2000; 29:412-5. [PMID: 11866941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To investigate the clinicopathologic characters and carcinogentic pathways of young (age < 36) colorectal carcinomas (CRCs) in Guangzhou, China. METHODS Immunohistochemistry and flow cytometry methods were used to detect the expression of hMSH(2) and hMLH(1), status of DNA ploidy in 63 cases of young CRCs from Guangzhou, China, and analyze their correlations with patient's clinicopathological characters. RESULTS Of the 63 young CRCs studied, forty-four (69.8%) tumors were non-mucinous carcinomas, thirty-nine (61.9%) patients were in Dukes' C or D stage. Of the 59 CRCs which were successfully detected by immunohistochemistry and flow cytometry, ten (16.9%) CRCs lost either hMSH(2) or hMLH(1) and showed DNA diploid or near-diploid, while twenty-six (44.1%) had aneuploid DNA content and all with the normal expression of hMSH(2) and hMLH(1). In addition, there existed a significant percentage (23/59, 39%) of young CRCs showing no loss of either of these two mismatch repair proteins and having a diploid or near diploid DNA content. CONCLUSION The overall percentage of young CRCs in Guangzhou is significantly higher than those in Caucasian predominant countries and about seventy percent of young CRCs in Guangzhou are conventional carcinomas. 39% of young CRCs in Guangzhou showed no evidence of either chromosomal instability or microsatellite instability carcinogentic pathway, indicating that there must be at least a third pathway which triggers the CRCs in these special subgroups of young patients in Guangzhou, China.
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Wang X, Wu H, Xie D, Weng S, Wu J. [Effect of Al3+ on luminescence intensity of Tb in silica glasses]. GUANG PU XUE YU GUANG PU FEN XI = GUANG PU 2000; 20:803-806. [PMID: 12938474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The silica glasses doped with Tb3+ and Al3+ iones was synthesized through Sol-Gel process in this paper. The effect of Al3+ on luminescence properties of Tb3+ were studied. The results show that no obvious effect of Al3+ on the emission peak position of Tb3+, but the emission intensity of Tb3+ doped Al3+ by sol-gel process increased obviously for all samples. The emission intensity of 1% Al-99% SiO2 glass was 5 times larger than that of 100% SiO2 glass. We concluded that the relation between the energy levels of Tb3+ and the energy levels of Al3+ may be appropriate for the energy transfer, the function of Al3+ was to absorb efficiently energy and to transfer fully to Tb3+.
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145
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Qureshi SA, Ding V, Li Z, Szalkowski D, Biazzo-Ashnault DE, Xie D, Saperstein R, Brady E, Huskey S, Shen X, Liu K, Xu L, Salituro GM, Heck JV, Moller DE, Jones AB, Zhang BB. Activation of insulin signal transduction pathway and anti-diabetic activity of small molecule insulin receptor activators. J Biol Chem 2000; 275:36590-5. [PMID: 10967116 DOI: 10.1074/jbc.m006287200] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
We recently described the identification of a non-peptidyl fungal metabolite (l-783,281, compound 1), which induced activation of human insulin receptor (IR) tyrosine kinase and mediated insulin-like effects in cells, as well as decreased blood glucose levels in murine models of Type 2 diabetes (Zhang, B., Salituro, G., Szalkowski, D., Li, Z., Zhang, Y., Royo, I., Vilella, D., Diez, M. T. , Pelaez, F., Ruby, C., Kendall, R. L., Mao, X., Griffin, P., Calaycay, J., Zierath, J. R., Heck, J. V., Smith, R. G. & Moller, D. E. (1999) Science 284, 974-977). Here we report the characterization of an active analog (compound 2) with enhanced IR kinase activation potency and selectivity over related receptors (insulin-like growth factor I receptor, epidermal growth factor receptor, and platelet-derived growth factor receptor). The IR activators stimulated tyrosine kinase activity of partially purified native IR and recombinant IR tyrosine kinase domain. Administration of the IR activators to mice was associated with increased IR tyrosine kinase activity in liver. In vivo oral treatment with compound 2 resulted in significant glucose lowering in several rodent models of diabetes. In db/db mice, oral administration of compound 2 elicited significant correction of hyperglycemia. In a streptozotocin-induced diabetic mouse model, compound 2 potentiated the glucose-lowering effect of insulin. In normal rats, compound 2 improved oral glucose tolerance with significant reduction in insulin release following glucose challenge. A structurally related inactive analog (compound 3) was not effective on insulin receptor activation or glucose lowering in db/db mice. Thus, small molecule IR activators exert insulin mimetic and sensitizing effects in cells and in animal models of diabetes. These results have implications for the future development of new therapies for diabetes mellitus.
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146
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O'Keefe BR, Shenoy SR, Xie D, Zhang W, Muschik JM, Currens MJ, Chaiken I, Boyd MR. Analysis of the interaction between the HIV-inactivating protein cyanovirin-N and soluble forms of the envelope glycoproteins gp120 and gp41. Mol Pharmacol 2000; 58:982-92. [PMID: 11040045 DOI: 10.1124/mol.58.5.982] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The novel virucidal protein cyanovirin-N (CV-N) binds with equally high affinity to soluble forms of either H9 cell-produced or recombinant glycosylated HIV-1 gp120 (sgp120) or gp160 (sgp160). Fluorescence polarization studies showed that CV-N is also capable of binding to the glycosylated ectodomain of the HIV-envelope protein gp41 (sgp41) (as well as SIV glycoprotein 32), albeit with considerably lower affinity than the sgp120/CV-N interaction. Pretreatment of CV-N with either sgp120 or sgp41 abrogated the neutralizing activity of CV-N against intact, infectious HIV-1 virions. Isothermal calorimetry and optical biosensor binding studies showed that CV-N bound to recombinant sgp120 with a K(d) value ranging from 2 to 45 nM and to sgp41 with a K(d) value of 606 nM; furthermore, they indicated an approximate 5:1 stoichiometry for CV-N binding to sgp120 and a 1:1 stoichiometry for CV-N binding to sgp41. Circular dichroism studies additionally illuminated the binding of CV-N with both sgp120 and sgp41, providing the first direct evidence that conformational changes are a consequence of CV-N interactions with both HIV-1 envelope glycoproteins.
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147
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Deng Y, Tian F, Yang X, Xie D, Lu Y, Shao X, Chen Z. [Precise map of allelic loss on chromosome 3p14 in nasopharyngeal carcinoma]. ZHONGHUA ER BI YAN HOU KE ZA ZHI 2000; 35:391-3. [PMID: 12768747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
OBJECTIVE To determine the precise allelic loss on chromosome 3p14 and discuss the possible relations between loss of heterozygosity (LOH) and EBV infection, clinical stage and clinic-pathology of nasopharyngeal carcinoma (NPC). METHODS Six high dense microsatellite marker on chromosome 3p14 were selected to examine LOH in 32 cases of NPC. RESULTS 23 of 32 (71.9%) tumors were deleted for at least one locus of six loci. High frequencies of LOH (> 40%) were observed at loci D3S1300(50.0%), D3S1313(46.4%) and D3S1312(44.4%). 12 cases showed LOH in one contiguous and nonrandom region. The smallest common deletion region seems likely to lie between D3S1313 and D3S1312. Relations between LOH on 3p14 and clinical stage and EBV infection were observed. The frequency of LOH was 70.0% in 30 cases of poor-differentiated squamous cell carcinoma. 2 cases of vesicular nucleus cell carcinoma had LOH at two loci. CONCLUSION The high deletion rate on 3p14 in NPC indicates that there might be a putative tumor suppressor gene related to the development and progression of NPC.
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148
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Xue Y, Xu D, Xie D, Yan G. Density functional theory studies on tautomeric stability and infrared spectra of 2-chloroadenine. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2000; 56A:1929-1938. [PMID: 10989885 DOI: 10.1016/s1386-1425(00)00252-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The tautomeric stability and vibrational IR spectrum of 2-chloroadenine were studied using density functional theory (DFT) at B3LYP/6-31G* level. The amino N(9)H tautomer of 2-chloroadenine was predicted to be most stable. A scaled quantum mechanical (SQM) force field approach was used to calculate the vibrational frequencies of amino N(9)H form of 2-chloroadenine. The force constant scale factors were transferred from those of purine. The mean deviation between the predicted vibrational frequencies and the observed ones is 8.0 cm(-1). The results made it possible to give complete assignments of the IR spectrum of this molecule.
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149
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Xiao Z, Feng Y, Pan Q, Xie D, Shi X, Xia J. [Mutations in the connexin 26 gene in patients with nonsyndromic hearing impairment]. ZHONGHUA ER BI YAN HOU KE ZA ZHI 2000; 35:188-91. [PMID: 12768774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
OBJECTIVE To determine the prevalence and characteristics of deafness-causing mutations in Connexin 26(Cx26, GJB2) gene in Chinese with nonsyndromic hearing impairment(NSHI). METHODS Study subjects are all Chinese including 16 infants with sporadic congenital deaf-mutism, 39 patients with autosomal recessive hereditary hearing loss, 30 patients with autosomal dominant hereditary hearing loss and 100 normal adults. The subjects were screened for base variations by single-strand conformational polymorphism (SSCP) analysis of the amplified products of polymerase chain reaction (PCR). Those who were found have abnormal conformational band were sequenced. RESULTS Five kinds of polymorphism were found in 15 cases of controls and six kinds of polymorphism in 10 patients. No mutation was found in Cx26 gene in Chinese with autosomal recessive NSHI. Heterozygous deletion AT at position 299-300 of Cx26 cDNA, which results in premature chain termination, was found in a pedigree with autosomal dominant hereditary nonsyndromic hearing loss. CONCLUSION The prevalence of deafness-causing mutations in Cx26 gene in Chinese with autosomal recessive NSHI maybe is lower than that of other ethnic groups. Heterozygous deletion AT at position 299-300 of Cx26 cDNA can lead to autosomal dominant hereditary hearing loss (DFNA3).
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150
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Liao X, Hui Y, Xie D, Dai L. [Malignant melanoma of uterus]. Chin Med J (Engl) 2000; 113:571-3. [PMID: 11775884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
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