651
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Ye P, Yang W, Wu SM, Sheng L. Effect of pioglitazone on the expression of inflammatory cytokines in attenuating rat cardiomyocyte hypertrophy. ACTA ACUST UNITED AC 2007; 28:691-6. [PMID: 17235413 DOI: 10.1358/mf.2006.28.10.1037500] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Pioglitazone, one of the synthetic peroxisome proliferator-activated receptor (PPARgamma) agonists, has been found to inhibit inflammatory response. However, it is not known yet whether the preventive effect of pioglitazone on cardiac hypertrophy is related to its antiinflammatory function. The objective of this study was to investigate the role of pioglitazone in attenuation of cardiac hypertrophy and its relation to the inhibitory effect on the inflammatory cytokine expression in cultured neonatal rat cardiomyocytes. The mRNA expression of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), interleukin (IL)-1beta, IL-6, and PPARgamma was measured by using RT-PCR. Cardiomyocyte hypertrophy was induced by stimulating angiotensin II (Ang II) and evaluated both by measuring surface area of cardiac myocyte and 3H-leucine incorporation. The expressions of IL-1beta, IL-6, ANP, and BNP were significantly enhanced, whereas that of PPARgamma was significantly reduced in Ang II-induced hypertrophic cardiomyocytes. Pioglitazone decreased cardiac myocyte surface area and inhibited 3H-leucine incorporation into cardiomyocytes. Furthermore, pioglitazone upregulated the suppressed expression of PPARgamma and attenuated the increased IL-1beta and IL-6 expression. The effect of pioglitazone might be associated with PPARgamma activation and the consequent antiinflammatory function in prevention and treatment of cardiac hypertrophy.
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652
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Kuan B, Yang W, Schwarz M. Dilute gas–solid two-phase flows in a curved90∘duct bend: CFD simulation with experimental validation. Chem Eng Sci 2007. [DOI: 10.1016/j.ces.2006.12.054] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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653
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Jones TS, Yang W, Evans WE, Relling MV. Using HapMap Tools in Pharmacogenomic Discovery: The Thiopurine Methyltransferase Polymorphism. Clin Pharmacol Ther 2007; 81:729-34. [PMID: 17329987 DOI: 10.1038/sj.clpt.6100135] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
One purpose of the International HapMap Project is to provide a genome-wide resource to discover pharmacogenetic determinants of drug response. The thiopurine methyltransferase (TPMT) 719A>G single-nucleotide polymorphism (SNP) causes decreased TPMT activity, increased intracellular thiopurines, and drug toxicities. Using HapMap cell lines and 3.3 million SNPs, we tested whether the TPMT 719A>G SNP could be identified as predicting TPMT phenotype. Assuming TPMT was a candidate gene, five SNPs and four haplotypes predicted TPMT phenotype, two of which were in complete linkage disequilibrium with the functional 719A>G SNP. We also used a genome-wide approach to rank all 17,542 genes as predictors of TPMT activity. A TPMT haplotype, HAP1, significantly predicted TPMT phenotype; however, haplotypes of 96 genes ranked higher than TPMT. Our findings show that HapMap resources are useful for pharmacogenetic discovery when the candidate gene is known, but challenges remain for definitive gene identification when a genome-wide agnostic approach is employed.
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654
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Yang W, Fung TC, Chian KS, Chong CK. 3D Mechanical properties of the layered esophagus: experiment and constitutive model. J Biomech Eng 2007; 128:899-908. [PMID: 17154692 DOI: 10.1115/1.2354206] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The identification of a three dimensional constitutive model is useful for describing the complex mechanical behavior of a nonlinear and anisotropic biological tissue such as the esophagus. The inflation tests at the fixed axial extension of 1, 1.125, and 1.25 were conducted on the muscle and mucosa layer of a porcine esophagus separately and the pressure-radius-axial force was recorded. The experimental data were fitted with the constitutive model to obtain the structure-related parameters, including the collagen amount and fiber orientation. Results showed that a bilinear strain energy function (SEF) with four parameters could fit the inflation data at an individual extension very well while a six-parameter model had to be used to capture the inflation behaviors at all three extensions simultaneously. It was found that the collagen distribution was axial preferred in both layers and the mucosa contained more collagen, which were in agreement with the findings through a pair of uniaxial tensile test in our previous study. The model was expected to be used for the prediction of stress distribution within the esophageal wall under the physiological state and provide some useful information in the clinical studies of the esophageal diseases.
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655
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Gluhak-Heinrich J, Pavlin D, Yang W, MacDougall M, Harris SE. MEPE expression in osteocytes during orthodontic tooth movement. Arch Oral Biol 2007; 52:684-90. [PMID: 17270144 PMCID: PMC1868431 DOI: 10.1016/j.archoralbio.2006.12.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2006] [Revised: 11/28/2006] [Accepted: 12/06/2006] [Indexed: 10/23/2022]
Abstract
UNLABELLED MEPE and DMP1 may play a role in mineralisation and demineralisation within the osteocyte microenvironment. Our earlier studies showed that DMP1 is mechanically responsive [Gluhak-Heinrich J, Ye L, Bonewald LF, Feng JQ, MacDougall M, Harris SE, et al. Mechanical loading stimulates dentin matrix protein 1 (DMP1) in osteocytes in vivo. J Bone Min Res 2003;18(5):807-17]. OBJECTIVES To examine the effect of mechanical loading on the expression of MEPE using mouse tooth movement model, and compare this effect to that on DMP1. METHODS In situ hybridisation and immunohistochemistry was performed on 38 treated and 38 control bone sites loaded 6-72 h. ImageJ was used for quantification of mRNA expression in osteocytes. RESULTS Alveolar osteocytes showed high basal level of MEPE that decreased during the first day of loading, followed by 2.8-fold stimulation at day 3, and returning to a control level by day 7. CONCLUSION The osteocyte specific mechanical stimulation of MEPE was delayed and different, compared to that of DMP1. This suggests a distinct role of MEPE and DMP1 in the response of osteocytes to mechanical loading in vivo.
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656
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Yang W, Fung TC, Chian KS, Chong CK. Instability of the two-layered thick-walled esophageal model under the external pressure and circular outer boundary condition. J Biomech 2007; 40:481-90. [PMID: 16677658 DOI: 10.1016/j.jbiomech.2006.02.020] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2005] [Accepted: 02/27/2006] [Indexed: 10/24/2022]
Abstract
The mucosal folding is a phenomenon observed for some biological tissues, including the pulmonary airway and gastrointestinal tract. In order to understand the mechanism of the formation of mucosal folding, a thick-walled two-layered cylindrical mathematical model was developed to investigate the buckling behavior under the external pressure and circular outer boundary condition. With the finite element method, the validity and accuracy of the proposed model was verified. The results showed that the fold number was in the range of 4-6, which was agreed with the experimental observation for the mucosal folding of a porcine esophagus. The fold number was found to decrease with the increase in the ratio of the inner to outer material stiffness. The increase in the thickness of inner layer also caused a slight declination of the fold number. Since the effects of both the material and geometrical nonlinearities have been accounted for, this model is more general to be used for the prediction of the buckling behavior of the layered structure with a wide range of thickness ratios and/or stiffness ratios.
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657
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Watt F, Watanabe R, Yang W, Agren N, Arvidsson Y, Funa K. A novel MASH1 enhancer with N-myc and CREB-binding sites is active in neuroblastoma. Cancer Gene Ther 2006; 14:287-96. [PMID: 17124508 DOI: 10.1038/sj.cgt.7701012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Neuroblastoma is one of the most common solid tumors in childhood. With the aim of developing a targeting vector for neuroblastoma, we cloned and characterized an enhancer in the 5'-flanking regions of the MASH1 gene by a random-trap method from a 36 kb cosmid DNA. The enhancer-containing clone was identified by the expression of GFP when transfected into neuroblastoma cell lines. The enhancer-luciferase activity is higher in neuroblastoma cell lines, IMR32, BE2 and SH-SY5Y, compared with those in non-neuroblastoma cell lines, U1242 glioma, N417 small cell lung cancer and EOMA hemangioma. The core enhancer was determined within a 0.2 kb fragment, yielding three- to fourfold higher activity than that of the MASH1 promoter alone in IMR32 and BE2. This area possesses GATA- and CREB-binding sites, as well as the E-box. EMSA on this area demonstrated that CREB/ATF could bind the DNA. Chromatin immunoprecipitation assay revealed that N-myc, CREB, and co-activators CBP and PCAF, but not HDAC1, are bound to the core enhancer at the same time as the co-activators and N-myc bind to the promoter. This supports the idea that the commonly overexpressed genes HASH1 and N-myc are regulated in concert, confirming their importance as prognostic markers or targets for therapy.
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658
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Selkirk JV, Nottebaum LM, Lee J, Yang W, Foster AC, Lechner SM. Identification of differential melanocortin 4 receptor agonist profiles at natively expressed receptors in rat cortical astrocytes and recombinantly expressed receptors in human embryonic kidney cells. Neuropharmacology 2006; 52:459-66. [PMID: 17095023 DOI: 10.1016/j.neuropharm.2006.08.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2006] [Revised: 08/01/2006] [Accepted: 08/02/2006] [Indexed: 11/25/2022]
Abstract
Using cAMP accumulation as a functional readout, we pharmacologically characterized the response of native melanocortin receptors in cultured rat astrocytes, and found this response to be mediated by the melanocortin 4 receptor (MC4R). Melancortin agonists stimulate cAMP in a concentration-dependent manner in both astrocytes and human embryonic kidney cells recombinantly expressing rat MC4R (HEK-rMC4R), however, the relative potency and intrinsic activity of both small molecule and peptide agonists are reduced in the native system. As such, the small molecules THIQ, NBI-702 and MB243 display 43, 30 and 18% of the maximal response elicited by alpha-MSH in astrocytes. Likewise, the peptides MTII and ACTH display 55 and 72% of the maximal response elicited by alpha-MSH in these cells. In contrast, all of these compounds elicit full agonist responses with similar intrinsic activity to alpha-MSH in HEK-rMC4R cells. MC4R mRNA was detected in astrocytes, however radioligand binding experiments failed to detect measurable MC4R in astrocyte membranes, in contrast to membranes from HEK-rMC4R cells that display a binding site density of 18.1+/-1.5 fmol/mg. We propose that the divergent observations in functional activity between the cell types reflect differences in receptor expression and that caution should be exercised when interpreting agonist activity in over-expression systems for the purposes of drug discovery.
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MESH Headings
- Animals
- Animals, Newborn
- Astrocytes
- Binding Sites/drug effects
- Cells, Cultured
- Cerebral Cortex/cytology
- Cyclic AMP/metabolism
- Cyclic AMP Response Element-Binding Protein/metabolism
- Dose-Response Relationship, Drug
- Embryo, Mammalian
- Gene Expression Regulation/drug effects
- Gene Expression Regulation/physiology
- Hormones/pharmacology
- Humans
- Inhibitory Concentration 50
- Kidney
- Protein Binding/drug effects
- Rats
- Receptor, Melanocortin, Type 4/agonists
- Receptor, Melanocortin, Type 4/genetics
- Receptor, Melanocortin, Type 4/metabolism
- Time Factors
- alpha-MSH/pharmacology
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659
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Wang L, Wang X, Jiang H, Ji W, Zhao L, Zhu X, Zhang L, Yang W. 2496. Int J Radiat Oncol Biol Phys 2006. [DOI: 10.1016/j.ijrobp.2006.07.908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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660
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Jian P, Yahui H, Yang W, Linlin L. Preparation of polysulfone–Fe3O4 composite ultrafiltration membrane and its behavior in magnetic field. J Memb Sci 2006. [DOI: 10.1016/j.memsci.2006.07.052] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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661
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Liu H, Yang W. 222 POSTER Study of in vitro tumor invasion and metastasis: the application of an innovative three dimensional tumor model. EJC Suppl 2006. [DOI: 10.1016/s1359-6349(06)70227-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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662
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Huang W, Yang W, Wang Y, Zhao Q, Gu D, Chen R. Association study of angiotensin-converting enzyme 2 gene (ACE2) polymorphisms and essential hypertension in northern Han Chinese. J Hum Hypertens 2006; 20:968-71. [PMID: 17024138 DOI: 10.1038/sj.jhh.1002090] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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663
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Khan AN, Yang W, Seifalian AM, Winslet MC. HER2 (ErbB2) receptors, a potential therapeutic target in squamous cell carcinoma of oesophagus. Br J Cancer 2006; 94:1213-4; author reply 1214-5. [PMID: 16622443 PMCID: PMC2361248 DOI: 10.1038/sj.bjc.6603080] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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664
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Kaur D, Hollins F, Woodman L, Yang W, Monk P, May R, Bradding P, Brightling CE. Mast cells express IL-13R alpha 1: IL-13 promotes human lung mast cell proliferation and Fc epsilon RI expression. Allergy 2006; 61:1047-53. [PMID: 16918506 DOI: 10.1111/j.1398-9995.2006.01139.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND The Th2 cytokine interleukin (IL)-13 is implicated in the development of various allergic diseases including asthma. The IL-13 receptor, IL-13Ralpha1, is expressed on most leukocytes, except T-cells. Evidence to support IL-13Ralpha1 expression on mast cells is limited. METHODS We investigated: (i) IL-13Ralpha1 expression by human lung mast cells (HLMC); (ii) the number of IL-13Ralpha1+ bronchial submucosal mast cells in subjects with asthma and normal controls and (iii) the effect of IL-13 priming on HLMC expression of high-affinity IgE receptor (FcepsilonRI), stem cell factor receptor (CD117), histamine release, proliferation, and survival. RESULTS Human lung mast cell expressed IL-13Ralpha1 mRNA. IL-13Ralpha1 was highly expressed on the surface HLMC (82+/-9%). Bronchial submucosal mast cell IL-13Ralpha1 expression was higher in asthmatics (86+/-2%) than normal controls (78+/-2%; P=0.015). IL-13 priming for 30 min did not increase HLMC histamine release, in the presence or absence of SCF or in response to IgE/anti-IgE activation. IL-13 priming for 5 days upregulated HLMC FcepsilonRI expression (22% increase in fluorescent intensity; P=0.003), increased histamine release following IgE/anti-IgE activation by 56% (P=0.03) and increased proliferation by 50% (P=0.003) without affecting cell survival or CD117 expression. The IL-13 specific neutralizing antibody CAT-354 inhibited all IL-13 mediated effects. CONCLUSION Human lung mast cell express IL-13Ralpha1 and activation by IL-13 for 5 days increased FcepsilonRI expression and proliferation. Histamine release was not affected by short-term priming with IL-13, but was upregulated by priming for 5 days suggesting that this effect was mediated by the increased FcepsilonRI expression. These data support the view that targeting IL-13 may be beneficial in the treatment of asthma.
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665
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Yang W, Briggs P. Towards data management for PX structure determination with CCP4. Acta Crystallogr A 2006. [DOI: 10.1107/s0108767306097376] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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666
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Yang W, Fung TC, Chian KS, Chong CK. Directional, regional, and layer variations of mechanical properties of esophageal tissue and its interpretation using a structure-based constitutive model. J Biomech Eng 2006; 128:409-18. [PMID: 16706590 DOI: 10.1115/1.2187033] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The esophagus, like other soft tissues, exhibits nonlinear and anisotropic mechanical properties. As a composite structure, the properties of the outer muscle and inner mucosal layer are different. It is expected that the complex mechanical properties will induce nonhomogeneous stress distributions in the wall and nonuniform tissue remodeling. Both are important factors which influence the function of mechanosensitive receptor located in various layers of the wall. Hence, the characterization of the mechanical properties is essential to understand the neuromuscular motion of the esophagus. In this study, the uniaxial tensile tests were conducted along two mutually orthogonal directions of porcine esophageal tissue to identify the directional (circumferential and axial), regional (abdominal, thoracic, and cervical), and layer (muscle and mucosa) variations of the mechanical properties. A structure-based constitutive model, which took the architectures of the tissue's microstructures into account, was applied to describe the mechanical behavior of the esophagus. Results showed that the constitutive model successfully described the mechanical behavior and provided robust estimates of the material parameters. In conclusion, the model was demonstrated to be a good descriptor of the mechanical properties of the esophagus and it was able to facilitate the directional, layer, and regional comparisons of the mechanical properties in terms of the associated material parameters.
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667
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Jones T, Yang W, Evans W, Relling M. Using hapmap tools to predict oncology-related phenotypes: TPMT activity vs hapmap SNPs. J Clin Oncol 2006. [DOI: 10.1200/jco.2006.24.18_suppl.13035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
13035 Background: Thiopurine S-methyltransferase (TPMT) is a cytosolic enzyme responsible for the S-methylation of thiopurines. There are several functional genetic polymorphisms in TPMT activity, which can lead to drug toxicities; however, among individuals with high TPMT activity, a substantial portion of enzymatic variability remains unexplained. B-lymphoblastoid CEPH cell lines have been genotyped at over 2 million single nucleotide polymorphisms (SNPs) as part of the International HapMap project. Therefore, extensive phenotype-genotype association studies can be conducted in these cell lines by systematic determination of cancer-related phenotypes. Methods: We measured the phenotype of TPMT activity in 82 CEPH cell lines. Of these, 53 had expression data available on over 8000 genes from Affymetrix Focus Array technology. We evaluated whether TPMT activity was associated with HapMap SNPs in TPMT (cis SNPs), genome-wide HapMap SNPs (trans SNPs), and level of gene expression using Kruskal-Wallis test and Spearmans rank correlation. Results: We found associations of TPMT activity with four SNPs (p < 0.05) in TPMT (± 100K bp), one of which (rs1142345, p = 0.009) is a known functional SNP responsible for TPMT deficiency. Two other significant SNPs are in linkage disequilibrium with rs1142345. Associations were also found with 1598 trans SNPs across the genome (p < 0.001). TPMT activity was associated with the expression of eight genes (p < 0.0001, FDR <20%). The only overlapping trans gene is PACSIN2, whose expression most significantly correlated with TPMT activity and also contains two significantly predictive trans SNPs. Conclusions: The CEPH cell lines were useful in that a known functional variant, rs1142345, (serving as a positive control) was associated with TPMT activity, and that additional polymorphisms in TPMT and in potentially important trans-acting factors have been identified as possible additional genomic determinants of TPMT activity. Similar experiments with other phenotypes can likewise capitalize on this publicly available resource. With further validation, these studies may lead to discovery of additional candidate polymorphisms that can lead to further optimization of thiopurine therapy in the clinic. No significant financial relationships to disclose.
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668
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Strong MJ, Yang W, Strong WL, Leystra-Lantz C, Jaffe H, Pant HC. Tau protein hyperphosphorylation in sporadic ALS with cognitive impairment. Neurology 2006; 66:1770-1. [PMID: 16769962 DOI: 10.1212/01.wnl.0000218161.15834.db] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The authors have characterized frontal cortical tau protein in cognitively intact (4) and cognitively impaired (ALSci, 4) ALS patients and compared it with control (2) or Alzheimer disease (AD, 1)- derived tau. The authors observed expression of both 3R and 4R tau isoforms; increased insoluble tau protein; phosphatase resistance; and hyperphosphorylation at T175, S208, and S210. Soluble tau from both AD and ALSci was also phosphorylated at S237. Tau hyperphosphorylation is associated with ALS.
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669
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Yang W, Fung TC, Chian KS, Chong CK. Viscoelasticity of Esophageal Tissue and Application of a QLV Model. J Biomech Eng 2006; 128:909-16. [PMID: 17154693 DOI: 10.1115/1.2372473] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The time-dependent mechanical properties of the porcine esophagus were investigated experimentally and theoretically. It was hypothesized that the viscoelasticity was quasilinear, i.e., the time and strain effects were independent. In order to verify the separability of time and strain effects, the stress-relaxation test was conducted at various strains and the data were fitted with the Fung’s quasilinear viscoelastic (QLV) model. By using the material parameters obtained from the stress relaxation test, the cyclic peak stress and hysteresis were predicted. Results showed that the stress relaxed by 20–30% of the peak stress within the first 10s and stabilized at ∼50% at the time of 300s. The relative stress relaxation R2 (i.e., the difference of stress at a particular time to the final equilibrium stress normalized by the total difference of the peak and final stress) was not different significantly for various strains. It was also found that, by using the stress-time data during both the ramp and relaxation phases, the correlation between parameters was substantially reduced. The model could also predict the cyclic peak stress and hysteresis except for the underestimate of valley stress. We conclude that the QLV model could be used as the material characterization of the esophageal tissue.
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670
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Bujalski J, Yang W, Nikolov J, Solnordal C, Schwarz M. Measurement and CFD simulation of single-phase flow in solvent extraction pulsed column. Chem Eng Sci 2006. [DOI: 10.1016/j.ces.2005.10.057] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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671
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Abstract
BACKGROUND Human lung mast cells (HLMC) lie in close proximity to the bronchial epithelium in asthma and adhere with high affinity to bronchial epithelial monolayers in vitro. We investigated the consequences of this adhesive interaction on HLMC activation in response to Fc epsilon RI cross-linking. METHODS Human lung mast cells were cultured with the bronchial epithelial cell line BEAS-2B or plastic control for either 30 min or 16 h and then activated with anti-IgE. Histamine was measured by radioenzymatic assay. RESULTS After co-culture for 30 min, IgE-dependent histamine release from HLMC was identical on both BEAS-2B and plastic. After 16 h of co-culture, there was a marked decrease in constitutive and IgE-dependent histamine release from HLMC cultured on BEAS-2B compared with those cultured on plastic or fibronectin. In contrast, the Ca(2+)/ATPase inhibitor thapsigargin produced concentration-dependent histamine release that was significantly increased on BEAS-2B compared with plastic. IgE-dependent degranulation was not significantly affected by BEAS-2B-conditioned medium. CONCLUSIONS BEAS-2B bronchial epithelial cells attenuate IgE-dependent but not thapsigargin-induced histamine release from HLMC. The differential effect with anti-IgE compared with thapsigargin suggests that the mechanism includes interference with the proximal Fc epsilon RI signalling pathway.
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672
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Yang W, Wang J. Charge-discharge behavior of K2FeO4 electrodes in concentrated KOH solutions. RUSS J ELECTROCHEM+ 2006. [DOI: 10.1134/s1023193506040045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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673
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Xi L, Chen G, Zhou J, Xu G, Wang S, Wu P, Zhu T, Zhang A, Yang W, Xu Q, Lu Y, Ma D. Inhibition of telomerase enhances apoptosis induced by sodium butyrate via mitochondrial pathway. Apoptosis 2006; 11:789-98. [PMID: 16554963 DOI: 10.1007/s10495-006-5701-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Telomerase activation represents an early step in carcinogenesis. Increased telomerase activity in cervical cancer suggests a potential target for the development of novel therapeutic drugs. The aim of this study is to investigate the impact of telomerase activity on the biological features of HeLa cells and the possible mechanisms of enhanced apoptosis rate induced by sodium butyrate after telomerase inhibition. We introduced vectors encoding dominate negative (DN)-hTERT, wild-type (WT)-hTERT, or a control vector expressing only a drug-resistance marker into HeLa cells. Thus we assessed the biological effects of telomerase activity on telomere length, cell proliferation, chemosensitivity and radiosensitivity. In order to understand the mechanisms in which DN-hTERT enhances the apoptosis induced by sodium butyrate, we detected the release status of cytochrome c and apoptosis inducing factor (AIF) from mitochondria. Ectopic expression of DN-hTERT resulted in inhibition of telomerase activity, reduction of telomere length, decreased colony formation ability, and loss of tumorigenicity in nude mice. Moreover, DN-hTERT transfected HeLa cells with shortened telomeres were more susceptible to multiple chemotherapeutic agents and radiation. WT-hTERT transfected HeLa cells with longer telomeres exhibited resistance to radiation and chemotherapeutic agents. Our data demonstrate that elevated release level of cytochrome c and AIF from mitochondria might contribute to the enhanced apoptosis in DN-hTERT transfected HeLa cells after treatment with sodium butyrate. Inhibition of telomerase might serve as a promising adjunctive therapy combined with conventional therapy in cervical cancer.
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674
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Noda T, Maki K, Takeuchi T, Suzuki H, Araki H, Yang W. Induced activity and damage of superconducting materials for a fusion reactor. FUSION ENGINEERING AND DESIGN 2006. [DOI: 10.1016/j.fusengdes.2005.06.371] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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675
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Gan J, Bondarenko S, Ernst F, Yang W, Ries SB, Sedlak DL. Leaching of N-nitrosodimethylamine (NDMA) in turfgrass soils during wastewater irrigation. JOURNAL OF ENVIRONMENTAL QUALITY 2006; 35:277-84. [PMID: 16397103 DOI: 10.2134/jeq2005.0264] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
N-nitrosodimethylamine (NDMA) is a carcinogenic by-product of chlorination that is frequently found in municipal wastewater effluent. NDMA is miscible in water and negligibly adsorbed to soil, and therefore may pose a threat to ground water when treated wastewater is used for landscape irrigation. A field study was performed in the summer months under arid Southern California weather conditions to evaluate the leaching potential of NDMA in turfgrass soils during wastewater irrigation. Wastewater was used to irrigate multiple turfgrass plots at 110 to 160% evapotranspiration rate for about 4 mo, and leachate was continuously collected and analyzed for NDMA. The treated wastewater contained relatively high levels of NDMA (114-1820 ng L(-1); mean 930 ng L(-1)). NDMA was detected infrequently in the leachate regardless of the soil type or irrigation schedule. At a method detection limit of 2 ng L(-1), NDMA was only detected in 9 out of 400 leachate samples and when it was detected, the NDMA concentration was less than 5 ng L(-1). NDMA was relatively persistent in the turfgrass soils during laboratory incubation, indicating that mechanisms other than biotransformation, likely volatilization and/or plant uptake, contributed to the rapid dissipation. Under conditions typical of turfgrass irrigation with wastewater effluent it is unlikely that NDMA will contaminate ground water.
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