{"title":"A C-GAN denoising algorithm in Projection Domain for Micro-CT","authors":"Lujie Chen, Liang Zheng, Maosen Lian, Shouhua Luo","doi":"10.32604/mcb.2019.07386","DOIUrl":"https://doi.org/10.32604/mcb.2019.07386","url":null,"abstract":"Micro-CT provides a high-resolution 3D imaging of micro-architecture in a non-invasive way, which becomes a significant tool in biomedical research and preclinical applications. Due to the limited power of micro-focus X-ray tube, photon starving occurs and noise is inevitable for the projection images, resulting in the degradation of spatial resolution, contrast and image details. In this paper, we propose a C-GAN (Conditional Generative Adversarial Nets) denoising algorithm in projection domain for Micro-CT imaging. The noise statistic property is utilized directly and a novel variance loss is developed to suppress the blurry effects during denoising procedure. Conditional Generative Adversarial Networks (C-GAN) is employed as a framework to implement the denoising task. To guarantee the pixelwised accuracy, fully convolutional network is served as the generator structure. During the alternative training of the generator and the discriminator, the network is able to learn noise distribution automatically. Moreover, residual learning and skip connection architecture are applied for faster network training and further feature fusion. To evaluate the denoising performance, mouse lung, milkvetch root and bamboo stick are imaged by micro-CT in the experiments. Compared with BM3D, CNN-MSE and CNN-VGG, the proposed method can suppress noise effectively and recover image details without introducing any artifacts or blurry effect. The result proves that our method is feasible, efficient and practical.","PeriodicalId":48719,"journal":{"name":"Molecular & Cellular Biomechanics","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90909942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zahra Alimanesh, Zeynab Alimanesh, F. Davari, S. - Shadmehri, M. Ahmadi, S. Hosseini, S. Dolati, Alemeh Hariri Far
{"title":"The Effect of Continued Training with Crocin on Apoptosis Markers in Liver Tissue of High Fat Diet Induced Diabetic Rats","authors":"Zahra Alimanesh, Zeynab Alimanesh, F. Davari, S. - Shadmehri, M. Ahmadi, S. Hosseini, S. Dolati, Alemeh Hariri Far","doi":"10.32604/mcb.2020.011532","DOIUrl":"https://doi.org/10.32604/mcb.2020.011532","url":null,"abstract":": Diabetes mellitus (DM) disease can affect process of apoptosis by increasing oxidative stress, nevertheless exercise and crocin can improve apoptosis; therefore present study aimed to investigate the effect of continued training with crocin on apoptosis markers in liver tissue of diabetic rats. In this experimental study 32 diabetic rats based on fasting glucose divided into four groups of eight rats including: 1) sham, 2) training, 3) crocin, and 4) training with crocin also for investigate the effect of DM induction on apoptosis markers, eight healthy rats assigned in healthy control group. During eight weeks groups 2 and 4 ran 60 minutes on treadmill with intensity of 50 – 55% maximum speed for three sessions per week and groups 3 and 4 received 25 mg/kg/day crocin peritoneally. Shapiro ’ post-hot statistical analysis of data (P ≤ 0.05) . DM induction signi fi cantly increased Bcl-2 as well as decreased Bax and P52 (P ≤ 0.05) nevertheless training and training with crocin signi fi cantly decreased Bcl-2 and increased Bax and P53 (P ≤ 0.05) ; crocin signi fi cantly decreased Bcl-2 and increased P53 (P ≤ 0.05) and training with crocin had higher effect on increase of Bax and P53 compare to training (P ≤ 0.05) also increase of Bax compare to crocin. Although training and crocin alone can improve apoptotic markers in diabetic rats, nevertheless training simultaneously with crocin have better effects than training alone.","PeriodicalId":48719,"journal":{"name":"Molecular & Cellular Biomechanics","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76292710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Liang Wang, H. Jia, Luping He, R. Lv, Xiaoya Guo, Chun Yang, D. Giddens, H. Samady, A. Maehara, G. Mintz, D. Tang
{"title":"Impact of Plaque Erosion on Stress/Strain and Flow Shear Stress Calculation: An OCT-Based FSI Modeling Study","authors":"Liang Wang, H. Jia, Luping He, R. Lv, Xiaoya Guo, Chun Yang, D. Giddens, H. Samady, A. Maehara, G. Mintz, D. Tang","doi":"10.32604/mcb.2019.07522","DOIUrl":"https://doi.org/10.32604/mcb.2019.07522","url":null,"abstract":"Plaque erosion, one of the primary causes for coronary thrombosis, is responsible for about one third of the patients with acute coronary syndrome (ACS) [1]. Histological studies characterized the eroded plaque as a plaque with following morphological features: 1) plaque intima having direct contact with intraluminal thrombus due to the absence of endothelium or endothelial injury; 2) without rupture in the fibrous cap; 3) abundance of proteoglycans and smooth muscle cells on the luminal surface under the thrombus [2]. These characteristics has been applied in in vivo diagnosis of plaque erosion using optical coherence tomography (OCT) image technology and specific treatment strategy has also been developed for plaque erosion related ACS [3]. However, The pathogenesis mechanisms that cause plaque erosion are not fully understood [2]. It is postulated that plaque erosion has close association with biomechanical conditions in the coronary vessel [2]. In this work, a patient-specific OCT-based modeling approach was develop 3D fluid-structure interaction (FSI) models to investigate the biomechanical conditions in eroded plaque and investigate the impact of erosion-induced inflammation on plaque stress/strain conditions. \u0000Patient-specific OCT data of eroded coronary plaque were acquired from one male patient (age: 64) with frequency-domain OCT C7XR system and the Dragon Fly catheter (Lightlab Imaging/St. Jude Medical). Erosion sites were identified as the luminal surface having direct contact with intraluminal thrombus on the OCT images. Biplane X-ray angiographic data (Allura Xper FD10 System, Philips, Bothel, WA) were also acquired with the information of the location of the coronary artery stenosis and vessel curvature. OCT images were segmented manually with external elastic membrane (EEM) contour assumed to have positive remodeling ratio 1.1 for this plaque. The trailing edge of the lipid-rich necrotic core (lipid) was also assumed since it cannot be seen on the OCT images. Co-registration of OCT and angiographic data were performed to reconstruct the 3D coronary geometry. Our FSI modeling procedures with pre-shrink–stretch process and anisotropic material properties were previously developed. Blood flow was assumed to be laminar, Newtonian and incompressible, with arbitrary Lagrangian–Eulerian formulation of the Navier–Stokes equations used as the governing equations. The governing equations of the structure models included equations of motion, the nonlinear Cauchy–Green strain–displacement relation and Mooney–Rivlin material properties. To reflect tissue weakening caused by erosion-induced inflammation, the material stiffness of plaque intima at the erosion site was adjust to one tenth of un-eroded fibrous plaque tissue [2]. Three FSI models were constructed to investigate the impacts of erosion-induced inflammation and lipid component on plaque stress/strain conditions: M1, without erosion (this means plaque intima at the erosion sites were","PeriodicalId":48719,"journal":{"name":"Molecular & Cellular Biomechanics","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72660607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Epigenetic Modulations Induction Using DSCR1 Ectopic Expression in Breast Cancer Cells","authors":"Z. N. Boroujeni, Atefeh Shirkavand, A. Aleyasin","doi":"10.32604/MCB.2019.04366","DOIUrl":"https://doi.org/10.32604/MCB.2019.04366","url":null,"abstract":"Today, prognosis, diagnosis and treatment of cancers are progressing with non-invasive methods, including investigation and modification of the DNA methylation profile in cancer cells. One of the effective factors in regulating gene expression in mammals is DNA methylation. Methylation alterations of genes by external factors can change the expression of genes and inhibit the cancer. In the present study, we investigated the effect of down syndrome critical region 1 gene (DSCR1) ectopic expression on the methylation status of the BCL-XL, ITGA6, TCF3, RASSF1A, DOK7, VIM and CXCR4 genes in breast cancer cell lines. \u0000The effect of DSCR1 ectopic expression on cell viability in MCF7, MDA-MB-468, MDA-MB-231 and MCF10A cell lines was evaluated using MTT assay after the cells treated by lentivirus vectors harboring DSCR1 for 72 hrs. Methylation status of BCL-XL, ITGA6, TCF3, RASSF1A, DOK7, VIM and CXCR4 genes in breast cancer cell lines was assessed by Restriction Enzyme PCR (REP) method. Also, methylation changes of these genes in breast cancer cell lines after treatment by lentivirus vectors harboring DSCR1 for 7 days were analyzed by REP method. To confirm the effect of DSCR1 on methylation of genes, Real-time PCR was performed. \u0000The MTT assay results indicated that DSCR1 ectopic expression reduced cell viability in all three human breast cancer cell lines. Our results showed that DSCR1 ectopic expression after 6 days reversed the hypomethylation status of the BCL-XL, ITGA6, TCF3, VIM and CXCR4 genes and hypermethylation of RASSF1A and DOK7 genes. The expression levels of BCL-XL, ITGA6, TCF3, VIM and CXCR4 mRNA significantly reduced (P<0.05) and the expression levels of RASSF1A and DOK7 mRNA significantly increased (P<0.05). \u0000Our findings reveal for the first time the impact of DSCR1 ectopic expression on the methylation status of breast cancer cells and identify a novel agent for epigenetic therapy.","PeriodicalId":48719,"journal":{"name":"Molecular & Cellular Biomechanics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90045068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Baba, Ayano Shinmura, S. Tada, T. Amo, A. Tsukamoto
{"title":"Mitochondrial Remodeling in Endothelial Cells under Cyclic Stretch is Independent of Drp1 Activation","authors":"M. Baba, Ayano Shinmura, S. Tada, T. Amo, A. Tsukamoto","doi":"10.32604/MCB.2019.05199","DOIUrl":"https://doi.org/10.32604/MCB.2019.05199","url":null,"abstract":"Mitochondria in endothelial cells remodel morphologically when supraphysiological cyclic stretch is exerted on the cells. During remodeling, mitochondria become shorter, but how they do so remains elusive. Drp1 is a regulator of mitochondrial morphologies. It shortens mitochondria by shifting the balance from mitochondrial fusion to fission. In this study, we hypothesized that Drp1 activation is involved in mitochondrial remodeling under supraphysiological cyclic stretch. To verify the involvement of Drp1, its activation was first quantified with Western blotting, but Drp1 was not significantly activated in endothelial cells under supraphysiological cyclic stretch. Next, Drp1 activation was inhibited with Mdivi-1, but this did not inhibit mitochondrial remodeling. Intracellular Ca2+ increase activates Drp1 through calcineurin. First, we inhibited the intracellular Ca2+ increase with Gd3+ and thapsigargin, but this did not inhibit mitochondrial remodeling. Next, we inhibited calcineurin with cyclosporin A, but this also did not inhibit mitochondrial remodeling. These results indicate that mitochondrial remodeling under supraphysiological cyclic stretch is independent of Drp1 activation. In endothelial cells under supraphysiological cyclic stretch, reactive oxygen species (ROS) are generated. Mitochondrial morphologies are remodeled by ROS generation. When ROS was eliminated with N-acetyl-L-cysteine, mitochondrial remodeling was inhibited. Furthermore, when the polymerization of the actin cytoskeleton was inhibited with cytochalasin D, mitochondrial remodeling was also inhibited. These results suggest that ROS and actin cytoskeleton are rather involved in mitochondrial remodeling. In conclusion, the present results suggest that mitochondrial remodeling in endothelial cells under supraphysiological cyclic stretch is induced by ROS in association with actin cytoskeleton rather than through Drp1 activation.","PeriodicalId":48719,"journal":{"name":"Molecular & Cellular Biomechanics","volume":"438 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75672902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shaoxiong Yang, Ying‐Xin Qi, Zong-Lai Jiang, X. Gong
{"title":"Characterizing the Mechanical Variations of Human Femoropopliteal Artery During Aging Process","authors":"Shaoxiong Yang, Ying‐Xin Qi, Zong-Lai Jiang, X. Gong","doi":"10.32604/MCB.2019.06096","DOIUrl":"https://doi.org/10.32604/MCB.2019.06096","url":null,"abstract":"Vascular diseases during aging process are closely correlated to the age-related changes of mechanical stimuli for resident cells. Characterizing the variations of mechanical environments in vessel walls with advancing age is crucial for a better understanding of vascular remodeling and pathological changes. In this study, the mechanical stress, strain, and wall stiffness of the FPAs were compared among four different age groups from adolescent to young, middle-aged, and aged subjects. The material parameters and geometries adopted in the FPA models were obtained from published experimental results. It is found that high mechanical stress appears at different layers in young and old FPA walls respectively. The characteristics of the middle-aged FPA wall suggests that it is the most capable of resisting high blood pressures and maintaining a mechanical homeostasis during the entire life span. It is demonstrated that the variations of stress and strain rather than that of wall stiffness can be used as an indicator to illustrate the profile of FPA aging. Our results could serve as an age-specific mechanical reference for vascular mechanobiological studies, and allow further exploration of cellular dysfunctions in vessel walls during aging process.","PeriodicalId":48719,"journal":{"name":"Molecular & Cellular Biomechanics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79806150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wenjia Wang, Xiuqing Qian, Qi Li, Gong Zhang, Huangxuan Zhao, Tan Li, Yang Yu, Hongfang Song, Zhicheng Liu
{"title":"Experimental Study of Aqueous Humor Flow in a Transparent Anterior Segment Phantom by Using PIV Technique","authors":"Wenjia Wang, Xiuqing Qian, Qi Li, Gong Zhang, Huangxuan Zhao, Tan Li, Yang Yu, Hongfang Song, Zhicheng Liu","doi":"10.32604/MCB.2019.06393","DOIUrl":"https://doi.org/10.32604/MCB.2019.06393","url":null,"abstract":"Pupillary block is considered as an important cause of primary angle-closure glaucoma (PACG). In order to investigate the effect of pupillary block on the hydrodynamics of aqueous humor (AH) in anterior chamber (AC) and potential risks, a 3D printed eye model was developed to mimic the AH flow driven by fluid generation, the differential pressure between AC and posterior chambers (PC) and pupillary block. Particle image velocimetry technology was applied to visualize flow distribution. The results demonstrated obvious differences in AH flow with and without pupillary block. Under the normal condition (without pupillary block), the flow filed of AH was nearly symmetric in the AC. The highest flow velocity located at the central of AC when the differential pressure between AC and PC was under 5.83 Pa, while it appeared near the cornea and iris surface when the differential pressure was greater than 33.6 Pa. Once pupillary block occurred, two asymmetric vortices with different sizes were observed and the shear stress in the paracentral cornea and iris epithelium increased greatly. It can be concluded that the pupillary block and the elevated differential pressure between AC and PC could change the flow distribution and thus increase the risk of corneal endothelial cells detachment. This study could make a further understanding of the pathogenesis of PACG.","PeriodicalId":48719,"journal":{"name":"Molecular & Cellular Biomechanics","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89299155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Traction Force Measurements of Human Aortic Smooth Muscle Cells Reveal a Motor-Clutch Behavior","authors":"C. Petit, A. Guignandon, S. Avril","doi":"10.32604/mcb.2019.06415","DOIUrl":"https://doi.org/10.32604/mcb.2019.06415","url":null,"abstract":"The contractile behavior of smooth muscle cells (SMCs) in the aorta is an important determinant of growth, remodeling, and homeostasis. However, quantitative values of SMC basal tone have never been characterized precisely on individual SMCs. Therefore, to address this lack, we developed an in vitro technique based on Traction Force Microscopy (TFM). Aortic SMCs from a human lineage at low passages (4-7) were cultured 2 days in conditions promoting the development of their contractile apparatus and seeded on hydrogels of varying elastic modulus (1, 4, 12 and 25 kPa) with embedded fluorescent microspheres. After complete adhesion, SMCs were artificially detached from the gel by trypsin treatment. The microbeads movement was tracked and the deformation fields were processed with a mechanical model, assuming linear elasticity, isotropic material, plane strain, to extract the traction forces formerly applied by individual SMCs on the gel. Two major interesting and original observations about SMC traction forces were deduced from the obtained results: 1. they are variable but driven by cell dynamics and show an exponential distribution, with 40% to 80% of traction forces in the range 0-10 µN. 2. They depend on the substrate stiffness: the fraction of adhesion forces below 10 µN tend to decrease when the substrate stiffness increases, whereas the fraction of higher adhesion forces increases. As these two aspects of cell adhesion (variability and stiffness dependence) and the distribution of their traction forces can be predicted by the probabilistic motor-clutch model, we conclude that this model could be applied to SMCs. Further studies will consider stimulated contractility and primary culture of cells extracted from aneurysmal human aortic tissue.","PeriodicalId":48719,"journal":{"name":"Molecular & Cellular Biomechanics","volume":"61 2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82158192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Echo-Based FSI Models to Simulate Ventricular Electrical Signal Conduction in Pig Pacemaker Models","authors":"Longling Fan, Jing Yao, Chun Yang, Di Xu, D. Tang","doi":"10.32604/MCB.2019.05720","DOIUrl":"https://doi.org/10.32604/MCB.2019.05720","url":null,"abstract":"Cardiac pacing has been an effective treatment in the management of patients with arrhythmia. Different pacemaker location may have different impact on pacemaker effectiveness. A novel image-based ventricle animal modeling approach was proposed to integrate echocardiography images, propagating dynamic electric potential on ventricle surface to perform myocardial function assessment. The models will be used to simulate ventricular electrical signal conduction and optimize pacemaker location for better cardiac outcome. One health female adult pig weight 42.5kg was used to make pacing animal model with different ventricle pacing locations. Pig health status was assessed before undergoing experimental procedures. Ventricle surface electric signal, blood pressure and echo image were acquired 15 minutes after the pacemaker was implanted. Echo-based left ventricle (LV) fluid-structure interaction (FSI) models were constructed to perform ventricle function analysis and investigate impact of pacemaker location on cardiac outcome. The nonlinear Mooney-Rivlin model was used for ventricle tissue material model. With the measured electric signal map from the pig associated with the actual pacemaker site, electric potential conduction of myocardium was modeled by material stiffening and softening in our model, with stiffening simulating contraction and softening simulating relaxation. Material stiffness parameters were adjusted in a cardiac cycle to match Echo-measured LV deformation and volume variations. Mapping between material stiffness and ventricle electric signal was quantified using data measured from the animal with different pacemaker locations. Ventricle model without pacemaker and three ventricle models with the following pacemaker locations were simulated: right ventricular apex (RVA), posterior interventricular septum (PIVS) and right ventricular outflow tract (RVOT). Data for ventricle volume change, ejection fraction, stress and strain, flow velocity and shear stress data were collected for comparisons. Our results demonstrating that PIVS pacing model had higher peak flow velocity and stress/strain. It indicated that PIVS pacemaker site may be the best location. This modeling approach could be used as “virtual surgery” to try various pacemaker locations and avoid risky and dangerous surgical experiments on real patients.","PeriodicalId":48719,"journal":{"name":"Molecular & Cellular Biomechanics","volume":"85 3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79423712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Caili Li, Jing Yao, Chun Yang, Di Xu, Liang Wang, D. Tang
{"title":"Biomechanical Implications of Bicuspid Pulmonary Valve Dynamic Deformation in Patients with Repaired Tetralogy of Fallot","authors":"Caili Li, Jing Yao, Chun Yang, Di Xu, Liang Wang, D. Tang","doi":"10.32604/MCB.2019.05745","DOIUrl":"https://doi.org/10.32604/MCB.2019.05745","url":null,"abstract":"Pulmonary valve stenosis (PVS) is one common post-operative problem in patients with tetralogy of Fallot (TOF) after repair. Congenital bicuspid pulmonary valve (BPV) is a condition of valvular stenosis, and the occurrence of congenital BPV is often associated with TOF. Compared with the biomechanical simulation model of the bicuspid aortic valve, the BPV is often neglected. In this study, we developed a dynamic biomechanical model of a simulated normal pulmonary root (PR) with tri-leaflet and a model of simulated PR with BPV in patients with repaired TOF in order to describe the effect of geometric structure with BPV on the stress and strain distribution. The geometry of PR included valvular leaflets, valsalva sinuses, inter leaflet triangle and annulus. Mechanical properties of PV leaflet were obtained from biaxial testing of human PV leaflet, and characterized by an anisotropic hyperelastic material model. Our model simulated complete cardiac cycles to observe valve leaflet dynamic stress/strain behaviors. Our results indicated that stress/strain distribution patterns of normal PV and the BPV were similar on pulmonary root and valve leaflets, but their values were different. When the valve was completely closed, maximum stresses were found leaflet attachment boundary, with their values at 17.1 kPa and 17.2 kPa respectively. When the valve was fully open, maximum stresses were found at the vicinity of commissures of sinus and leaflet, that is, near the annulus, with the values at 115.0 kPa and 143.0 kPa respectively. Compared with normal PR, the valve orifice area in the completely opened position in congenital BPV is significantly reduced. Our initial results demonstrated that geometrical variations with BPV may be a potential risk factor linked to occurrence of PVS in patients with repaired TOF. Computational models could be a useful tool in identifying possible linkage between valve disease development and biomechanical factors. Large-scale clinical studies are needed to validate these preliminary findings.","PeriodicalId":48719,"journal":{"name":"Molecular & Cellular Biomechanics","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76986117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}