626
|
Liu H, Wu Y, Yang W, Hsu Y. SU-EE-A4-02: Modeling Contrast Agent Extravasation in Dynamic Susceptibility Contrast MRI of Very Leaky Brain Tumors. Med Phys 2008. [DOI: 10.1118/1.2961393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
627
|
Li H, Yang W, Mendes F, Amaral M, Sheppard D. Renal cyst formation as tool for CFTR research. J Cyst Fibros 2008. [DOI: 10.1016/s1569-1993(08)60066-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
628
|
Yang J, Bogni A, Cheng C, Bleibel WK, Cai X, Fan Y, Yang W, Rocha JCC, Pei D, Liu W, Dolan ME, Pui CH, Relling MV. Etoposide sensitivity does not predict MLL rearrangements or risk of therapy-related acute myeloid leukemia. Clin Pharmacol Ther 2008; 84:691-7. [PMID: 18509329 DOI: 10.1038/clpt.2008.86] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Therapy-related acute myeloid leukemia (t-AML) caused by MLL rearrangements (rMLL) can arise from topoisomerase II agents. However, whether rMLL-related leukemogenesis is inextricably linked to drug cytotoxicity remains controversial. We therefore compared (i) rMLL in children with acute lymphoblastic leukemia (ALL) who developed t-AML and those who did not, (ii) epipodophyllotoxin toxicity in patients with t-AML and in controls, and (iii) rMLL in cells sensitive to etoposide and in those resistant to etoposide. In children with ALL, rMLL appeared to be more frequent in children who developed t-AML than in those who did not (seven pairs, P = 0.04), although independent of the cumulative etoposide dose (P = 0.5). Similarly, the frequency of epipodophyllotoxin-related toxicities did not differ between patients with t-AML and controls (26 pairs, P > 0.17). Moreover, in 25 cell lines, etoposide-induced MLL fusions did not differ in sensitive vs. resistant lines at equitoxic concentrations (P = 0.65). Together, these results indicate that epipodophyllotoxin-mediated leukemogenesis is not directly linked to drug cytotoxicity.
Collapse
|
629
|
Chen M, Yang W, Yan K, Dai Y, Wu W, Wu J. Imaging instructed standardized treatment for hepatocellular carcinoma with radiofrequency ablation. J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.15534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
630
|
Rathkopf DE, Wong BY, Ross RW, George DJ, Picus J, Tanaka E, Chen Y, Atadja P, Yang W, Culver KW, Scher HI. A phase I study of oral panobinostat (LBH589) alone and in combination with docetaxel (Doc) and prednisone in castration-resistant prostate cancer (CRPC). J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.5152] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
631
|
Yang W, Sahin AA, Wong H, Tsimelzon A, Hess K, Karadag N, Cairo M, Meric F, Arun B, Chang JC. Molecular portraits of mammographic breast density in normal breast tissue. J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.22227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
632
|
Inthavong K, Tian ZF, Tu JY, Yang W, Xue C. Optimising nasal spray parameters for efficient drug delivery using computational fluid dynamics. Comput Biol Med 2008; 38:713-26. [PMID: 18468593 DOI: 10.1016/j.compbiomed.2008.03.008] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2007] [Revised: 01/17/2008] [Accepted: 03/24/2008] [Indexed: 11/25/2022]
Abstract
Experimental images from particle/droplet image analyser (PDIA) and particle image velocimetry (PIV) imaging techniques of particle formation from a nasal spray device were taken to determine critical parameters for the study and design of effective nasal drug delivery devices. The critical parameters found were particle size, diameter of spray cone at a break-up length and a spray cone angle. A range of values for each of the parameters were ascertained through imaging analysis which were then transposed into initial particle boundary conditions for particle flow simulation within the nasal cavity by using Computational Fluid Dynamics software. An Eulerian-Lagrangian scheme was utilised to track mono-dispersed particles (10 and 20 microm) at a breathing rate of 10 L/min. The results from this qualitative study aim to assist the pharmaceutical industry to improve and help guide the design of nasal spray devices.
Collapse
|
633
|
Gao H, Xiao W, Wang C, Zhang J, Yang Y, Yang J, Yang W, Hong T. The metabolic effects of once daily extended-release metformin in patients with type 2 diabetes: a multicentre study. Int J Clin Pract 2008; 62:695-700. [PMID: 18412932 DOI: 10.1111/j.1742-1241.2008.01733.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
AIM To investigate the effects of extended-release metformin (MXR) compared with immediate-release metformin (MIR) on post-prandial glycaemic excursion, chronic glycaemia, lipid profiles, insulin resistance and islet function in type 2 diabetes. METHODS A randomised, open-labelled, positive-controlled multicentre study was conducted on 150 Chinese patients with type 2 diabetes. After 2 weeks of run-in period with MIR, 150 subjects were randomised into MXR group and MIR group. The patients in MXR group were assigned to take MXR 1500 mg once daily after dinner, while the patients in MIR group were assigned to continue MIR 500 mg thrice daily after meals for 12 weeks. Standard meal tests were carried out at baseline and at the end of this study. Plasma glucose, serum insulin, HbA1c and lipid profiles were measured. Homeostasis model assessment (HOMA) was used to evaluate insulin resistance index (HOMA-IR) and islet beta-cell function index (HOMA-B). RESULTS Either MIR or MXR modestly, but significantly decreased HbA1c levels and body mass index (BMI) after 12 weeks of treatment. However, there were no significant differences between two groups. The post-prandial glycaemia at 120 min after a standard meal in MXR group was higher than in MIR group (11.02 +/- 3.08 mmol/l vs. 9.74 +/- 2.61 mmol/l, p < 0.05). Moreover, no differences in the areas under curve of insulin release response, HOMA-B, HOMA-IR and lipid profiles were found within or between groups after 12 weeks of treatment. CONCLUSION The effects of once daily MXR on chronic glycaemia, BMI, lipid profiles, insulin resistance and islet function are comparable with that of thrice daily MIR in oriental population.
Collapse
|
634
|
Rababah TM, Ereifej KI, Al-Mahasneh MA, Ismaeal K, Hidar AG, Yang W. Total Phenolics, Antioxidant Activities, and Anthocyanins of Different Grape Seed Cultivars Grown in Jordan. INTERNATIONAL JOURNAL OF FOOD PROPERTIES 2008. [DOI: 10.1080/10942910701567521] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
635
|
Sun M, Ma F, Zeng X, Liu Q, Zhao XL, Wu FX, Wu GP, Zhang ZF, Gu B, Zhao YF, Tian SH, Lin B, Kong XY, Zhang XL, Yang W, Lo WHY, Zhang X. Triphalangeal thumb-polysyndactyly syndrome and syndactyly type IV are caused by genomic duplications involving the long range, limb-specific SHH enhancer. J Med Genet 2008; 45:589-95. [PMID: 18417549 DOI: 10.1136/jmg.2008.057646] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
BACKGROUND The Sonic hedgehog (SHH) protein produced in the zone of polarising activity (ZPA) is a major determinant of the identity and numbers of digits in early limb development. Preaxial polydactyly types II (PPD2) and III (PPD3) have been mapped to a critical region at 7q36, and subsequently shown to be caused by point mutations in the ZPA regulatory sequence (ZRS), a long range cis-regulator for the SHH gene. Triphalangeal thumb-polysyndactyly syndrome (TPTPS) and syndactyly type IV (SD4) were also mapped to the 7q36 region but pathogenic mutations in ZRS have not yet been affirmed. METHODS AND RESULTS We performed linkage and haplotype analysis in six Han Chinese families with TPTPS and/or SD4, and refined the disease locus to an interval of 646 kb containing ZRS. In all families, the affected individuals heterozygous at rs10254391 (a single nucleotide polymorphism within ZRS) revealed a remarkable allele imbalance on sequence chromatogram. Using real-time quantitative polymerase chain reaction (qPCR), we identified duplication of ZRS and found that this duplication segregated with the limb phenotypes in all families but was not detected in unaffected family members or in unrelated control individuals. The duplication was also confirmed by interphase fluorescence in situ hybridisation (FISH) in an affected individual. We designed 17 additional qPCR assays and defined the minimum duplications in all six families, ranging from 131kb to 398kb. CONCLUSION Both TPTPS and SD4 are due to duplications involving ZRS, the limb specific SHH enhancer. Point mutations in the ZRS and duplications encompassing the ZRS cause distinctive limb phenotypes.
Collapse
|
636
|
Pan C, Yang W, Barona JP, Wang Y, Niggli M, Mohideen P, Wang Y, Foley JE. Comparison of vildagliptin and acarbose monotherapy in patients with Type 2 diabetes: a 24-week, double-blind, randomized trial. Diabet Med 2008; 25:435-41. [PMID: 18341596 DOI: 10.1111/j.1464-5491.2008.02391.x] [Citation(s) in RCA: 128] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
AIMS To compare the efficacy and tolerability of the dipeptidyl peptidase-4 inhibitor, vildagliptin, with the alpha glucosidase inhibitor, acarbose, in drug-naive patients with Type 2 diabetes. METHODS This multi-centre, randomized, double-blind, parallel-arm study compared the efficacy and tolerability of vildagliptin (100 mg daily, given as 50 mg twice daily, n = 441) and acarbose (up to 300 mg daily, given as three equally divided doses, n = 220) during 24-week treatment in drug-naive patients with Type 2 diabetes. RESULTS Monotherapy with vildagliptin or acarbose decreased glycated haemoglobin (HbA(1c)) (baseline approximately 8.6%) to a similar extent during 24-week treatment. The adjusted mean change from baseline to end-point (AMDelta) in HbA(1c) was -1.4 +/- 0.1% and -1.3 +/- 0.1% in patients receiving vildagliptin and acarbose, respectively, meeting the statistical criterion for non-inferiority (upper limit of 95% confidence interval for between-treatment difference < or = 0.4%). The decrease in fasting plasma glucose was similar with acarbose (-1.5 +/- 0.2 mmol/l) and vildagliptin (-1.2 +/- 0.1 mmol/l). Body weight did not change in vildagliptin-treated patients (-0.4 +/- 0.1 kg) but decreased in acarbose-treated patients (-1.7 +/- 0.2 kg, P < 0.001 vs. vildagliptin). The proportion of patients experiencing any adverse event (AE) was 35% vs. 51% in patients receiving vildagliptin or acarbose, respectively; gastrointestinal AEs were significantly more frequent with acarbose (25.5%) than vildagliptin (12.3%, P < 0.001). No hypoglycaemia was reported for either group. CONCLUSIONS Vildagliptin is effective and well tolerated in patients with Type 2 diabetes, demonstrating similar glycaemic reductions to acarbose, but with better tolerability.
Collapse
|
637
|
Wang Z, Lv M, Li D, Zhou Z, Zhang L, Yang W. High-performance liquid chromatographic analysis of iodoamino acids produced by hydrolysis of iodinated casein with barium hydroxide. ACTA CHROMATOGR 2008. [DOI: 10.1556/achrom.20.2008.1.5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
638
|
Yang W, Chen MH, Yan K, Wu W, Dai Y, Zhang H. Differential diagnosis of nonfunctional islet cell tumor and pancreatic carcinoma with sonography. Clin Imaging 2008. [DOI: 10.1016/j.clinimag.2008.01.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
639
|
Jia W, Yang W, Lei A, Gao Z, Yang C, Hua J, Huang W, Ma X, Wang H, Dou Z. A caprine chimera produced by injection of embryonic germ cells into a blastocyst. Theriogenology 2008; 69:340-8. [DOI: 10.1016/j.theriogenology.2007.08.037] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2007] [Revised: 10/01/2007] [Accepted: 08/02/2007] [Indexed: 11/30/2022]
|
640
|
Cui J, Mao L, Yang W, Xu X, Chen D, Xiu W. Thermoelectric properties of Cu-doped n-type (Bi2Te3)0.9–(Bi2−xCuxSe3)0.1(x=0–0.2) alloys. J SOLID STATE CHEM 2007. [DOI: 10.1016/j.jssc.2007.10.013] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
641
|
Qing T, Liu H, Wei W, Ye X, Shen W, Zhang D, Song Z, Yang W, Ding M, Deng H. Mature oocytes derived from purified mouse fetal germ cells. Hum Reprod 2007; 23:54-61. [DOI: 10.1093/humrep/dem334] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
642
|
Nemani D, Yang W, Mitra N, Lin L. Prognostic Factors and Adjuvant Therapy in Patients With Uterine Carcinosarcoma. Int J Radiat Oncol Biol Phys 2007. [DOI: 10.1016/j.ijrobp.2007.07.221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
643
|
Nam RK, Sugar L, Yang W, Srivastava S, Klotz LH, Yang LY, Stanimirovic A, Encioiu E, Neill M, Loblaw DA, Trachtenberg J, Narod SA, Seth A. Expression of the TMPRSS2:ERG fusion gene predicts cancer recurrence after surgery for localised prostate cancer. Br J Cancer 2007; 97:1690-5. [PMID: 17971772 PMCID: PMC2360284 DOI: 10.1038/sj.bjc.6604054] [Citation(s) in RCA: 207] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The prostate-specific gene, TMPRSS2 is fused with the gene for the transcription factor ERG in a large proportion of human prostate cancers. The prognostic significance of the presence of the TMPRSS2:ERG gene fusion product remains controversial. We examined prostate cancer specimens from 165 patients who underwent surgery for clinically localised prostate cancer between 1998 and 2006. We tested for the presence of TMPRSS2:ERG gene fusion product, using RT–PCR and direct sequencing. We conducted a survival analysis to determine the prognostic significance of the presence of the TMPRSS2:ERG fusion gene on the risk of prostate cancer recurrence, adjusting for the established prognostic factors. We discovered that the fusion gene was expressed within the prostate cancer cells in 81 of 165 (49.1%) patients. Of the 165 patients, 43 (26.1%) developed prostate-specific antigen (PSA) relapse after a mean follow-up of 28 months. The subgroup of patients with the fusion protein had a significantly higher risk of recurrence (58.4% at 5 years) than did patients who lacked the fusion protein (8.1%, P<0.0001). In a multivariable analysis, the presence of gene fusion was the single most important prognostic factor; the adjusted hazard ratio for disease recurrence for patients with the fusion protein was 8.6 (95% CI=3.6–20.6, P<0.0001) compared to patients without the fusion protein. Among prostate cancer patients treated with surgery, the expression of TMPRSS2:ERG fusion gene is a strong prognostic factor and is independent of grade, stage and PSA level.
Collapse
|
644
|
Dodge J, Treleaven C, Yang W, Clarke J, Martin H, Handy C, Hester M, Taksir T, Griffiths D, Cheng S, Kaspar B, Shihabuddin L. G.P.11.07 AAV mediated gene transfer of IGF-1 and VEGF to the ventricular system provides significant therapeutic benefit in a mouse model of amyotrophic lateral sclerosis. Neuromuscul Disord 2007. [DOI: 10.1016/j.nmd.2007.06.214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
645
|
Harris SE, Gluhak-Heinrich J, Harris MA, Yang W, Bonewald LF, Riha D, Rowe PSN, Robling AG, Turner CH, Feng JQ, McKee MD, Nicollela D. DMP1 and MEPE expression are elevated in osteocytes after mechanical loading in vivo: theoretical role in controlling mineral quality in the perilacunar matrix. JOURNAL OF MUSCULOSKELETAL & NEURONAL INTERACTIONS 2007; 7:313-315. [PMID: 18094489 PMCID: PMC3357082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
|
646
|
Orsat V, Yang W, Changrue V, Raghavan G. Microwave-Assisted Drying of Biomaterials. FOOD AND BIOPRODUCTS PROCESSING 2007. [DOI: 10.1205/fbp07019] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
647
|
Suck D, Biertuempfel C, Yang W. Crystal structure of a phage T4 endonuclease VII – Holliday junction complex. Acta Crystallogr A 2007. [DOI: 10.1107/s0108767307099631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
648
|
Hartford C, Yang W, Cheng C, Fan Y, Liu W, Treviño L, Pounds S, Neale G, Raimondi SC, Bogni A, Dolan ME, Pui CH, Relling MV. Genome scan implicates adhesion biological pathways in secondary leukemia. Leukemia 2007; 21:2128-36. [PMID: 17673902 DOI: 10.1038/sj.leu.2404885] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The genetic risk factors for etoposide-induced leukemia with MLL translocations remain largely unknown. To identify genetic risk factors for and novel characteristics of secondary leukemia, we profiled 116,204 single nucleotide polymorphisms (SNPs) in germline and paired leukemic cell DNA from 13 secondary leukemia/myelodysplasia cases and germline DNA from 13 matched and 156 unmatched controls, all with acute lymphoblastic leukemia treated with etoposide. We analyzed global gene expression from a partially overlapping cohort. No single locus was altered in most cases. We discovered 81 regions of loss of heterozygosity (LOH) in leukemic blasts and 309 SNPs whose allele frequencies differed in cases vs controls. Candidate genes were prioritized on the basis of genes whose SNPs or expression differentiated cases from controls or showed LOH or copy number change in germline vs paired blast DNA from the 13 cases. Three biological pathways were altered: adhesion, Wnt signaling and regulation of actin. Validation experiments using a genome scan for etoposide-induced leukemogenic MLL chimeric fusions in 15 HapMap cell lines also implicated genes involved in adhesion, a process linked to de novo leukemogenesis. Independent clinical epidemiologic and in vitro genome-wide approaches converged to identify novel pathways that may contribute to therapy-induced leukemia.
Collapse
|
649
|
Yang W, Beaudoin EL, Lu L, Du Pasquier RA, Kuroda MJ, Willemsen RA, Koralnik IJ, Junghans RP. Chimeric immune receptors (CIRs) specific to JC virus for immunotherapy in progressive multifocal leukoencephalopathy (PML). Int Immunol 2007; 19:1083-93. [PMID: 17660502 DOI: 10.1093/intimm/dxm076] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Progressive multifocal leukoencephalopathy (PML) is a deadly brain disease caused by the polyomavirus JC (JCV). The aim of this study is to develop 'designer T cells' armed with anti-JCV TCR-based chimeric immune receptors (CIRs) by gene modification for PML immunotherapy. Two T cell lines specific to two dominant CTL epitopes derived from JCV VP1 protein (termed p36 and p100) from an HLA-A0201+ PML survivor were generated for TCR cloning. Two distinct dominant TCR alpha chains (Valpha6 and Valpha12) and a unique TCR beta chain (Vbeta5.1) were cloned from the p36-specific cell line, while only one alpha (Valpha8.6) and one beta (Vbeta2) chains were dominant in the p100-specific line. Retroviral constructs encoding CIRs were created with the extracellular domains of TCR alpha and beta chains fused to the transmembrane and cytoplasmic portions of CD3zeta (ValphaCalphaCD3zeta or VbetaCbetaCD3zeta). Cellular expression and screening for binding specific peptide-HLA-A0201 tetramer confirmed the reactivity of the p100 TCRalphabeta and of one of the two pairs of p36 TCRalphabeta (Valpha12 and Vbeta5.1). Functional tests confirmed CIR-expressing T cells secreted cytokines and expressed potent cytotoxicity on contact with A0201+ B-lymphoblastoid line loaded with peptides and/or with HLA-A0201+ cells expressing native JCV VP1 protein. In conclusion, anti-JCV designer T cells were generated.
Collapse
|
650
|
Yang W, Fung TC, Chian KS, Chong CK. Three-dimensional finite element model of the two-layered oesophagus, including the effects of residual strains and buckling of mucosa. Proc Inst Mech Eng H 2007; 221:417-26. [PMID: 17605399 DOI: 10.1243/09544119jeim47] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This study was carried out to develop a two-layered finite element model of the oesophagus. The outer muscle and inner mucosal layer were constructed individually with different mechanical properties and zero-stress opening angles. With the model, two simulations were performed. First, the distention of oesophageal wall under the pressurized state was investigated, from which the effects of residual strains on the stress distribution were evaluated. Second, the buckling modes were determined using a linear eigenvalue analysis. The self-contact capability in ABAQUS was applied to simulate the folding of mucosa under the muscle contraction. The first simulation indicated that, by taking the residual strains into account, the mucosa undertook a very small portion of stress and the luminal pressure almost transmitted completely to the outer muscle layer. On the other hand, the folding of mucosa was shown to be able to reduce the contractile force of circular muscle to maintain the lumen closure. In conclusion, the preliminary study demonstrated the feasibility of simulating the oesophageal peristaltic transport using finite element analysis.
Collapse
|