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  • Open Access

    ABSTRACT

    Computational Modeling of Human Bicuspid Pulmonary Valve Dynamic Deformation in Patients with Tetralogy of Fallot

    Caili Li1,§, Christopher Baird2, Jing Yao3, Chun Yang4, Liang Wang5, Han Yu5, Tal Geva6, Dalin Tang5,*,7,§

    Molecular & Cellular Biomechanics, Vol.16, Suppl.2, pp. 59-59, 2019, DOI:10.32604/mcb.2019.06872

    Abstract Pulmonary valve stenosis (PVS) is one common right ventricular outflow tract obstruction problem in patients with tetralogy of Fallot (TOF). Congenital bicuspid pulmonary valve (BPV) is a condition of valvular stenosis, and the occurrence of congenital BPV is often associated with TOF. Dynamic computational models of normal pulmonary root (PR) with tri-leaflet and PR with BPV in patients with TOF were developed to investigate the effect of geometric structure of BPV on valve stress and strain distributions. The pulmonary root geometry included valvular leaflets, sinuses, interleaflet triangles and annulus. Mechanical properties of pulmonary valve leaflet were obtained from biaxial testing… More >

  • Open Access

    ABSTRACT

    Computational Biomechanical Right Ventricle Modeling with Contracting Bands to Improve Ventricle Cardiac Function for Patient with Repaired Tetralogy of Fallot

    Han Yu1, Tal Geva2, Rahul H. Rathod2, Alexander Tang2, Chun Yang3, Zheyang Wu3, Kristen L. Billiar4, Xueying Huang5, Dalin Tang1,*,3

    Molecular & Cellular Biomechanics, Vol.16, Suppl.2, pp. 56-57, 2019, DOI:10.32604/mcb.2019.07257

    Abstract Computational biomechanical models are widely used in cardiovascular research for better understanding of mechanisms governing disease development, quantitative diagnostic strategies and improved surgical designs with better outcome. Patients with repaired tetralogy of Fallot (TOF) account for the majority of cases with late onset right ventricle (RV) failure. The current surgical approach, which includes pulmonary valve replacement/insertion (PVR), has yielded mixed results. An innovative PVR surgical approach was proposed using active contracting bands to help ventricle to contract and improve RV function measured by ejection fraction [1]. Muscle active contraction caused by sarcomere shortening leads to change of zero-load configurations. In… More >

  • Open Access

    ABSTRACT

    Papillary Muscle Related Biomechanical Properties of Mitral Valve Chordae Tendineae

    Shengda Chen1,2, Candra Ratna Sari1, Patrick Segers2, Guixue Wang1, Xingshuang Ma1,*

    Molecular & Cellular Biomechanics, Vol.16, Suppl.1, pp. 69-70, 2019, DOI:10.32604/mcb.2019.05740

    Abstract This article has no abstract. More >

  • Open Access

    ARTICLE

    Nitric oxide metabolism in heart mitochondria

    Tamara ZAOBORNYJ, Darío E. IGLESIAS, Silvina S. BOMBICINO, Alberto BOVERIS, Laura B. VALDEZ*

    BIOCELL, Vol.40, No.1, pp. 55-58, 2016, DOI:10.32604/biocell.2016.40.055

    Abstract Normal cardiac function is accomplished through a continuous energy supply provided by mitochondria. Heart mitochondria are the major source of reactive oxygen and nitrogen species: superoxide anion (O2-) and nitric oxide (NO). NO production by mitochondrial NOS (mtNOS) is modified by metabolic state and shows an exponential dependence on Δψ. The interaction between mtNOS and complexes I and IV might be a mechanism involved in the regulation of mitochondrial NO production. NO exerts a high affinity, reversible and physiological inhibition of cytochrome c oxidase activity. A second effect of NO on the respiratory chain is accomplished through its interaction with… More >

  • Open Access

    ARTICLE

    The role of mitochondria in inflammatory syndromes

    Virginia VANASCO, Timoteo MARCHINI, Natalia MAGNANI, Tamara VICO, Mariana GARCES, Lourdes CACERES, Alejandro GUAGLIANONE, Pablo EVELSON, Silvia ALVAREZ.*

    BIOCELL, Vol.40, No.1, pp. 47-50, 2016, DOI:10.32604/biocell.2016.40.047

    Abstract Several authors have addressed the importance of mitochondrial function in inflammatory syndromes, as it may play a role in the genesis of tissue injury. Sepsis and exposition to environmental particles are examples of inflammatory conditions. Sepsis occurs with an exacerbated inflammatory response that damages tissue mitochondria and impairs bioenergetic processes. One of the current hypotheses for the molecular mechanisms underlying the complex condition of sepsis is that enhanced NO production and oxidative stress lead to mitochondrial dysfunction, bioenergetic derangement and organ failure. The mechanism of particulate matter-health effects are believed to involve inflammation and oxidative stress. Components in particles that… More >

  • Open Access

    ARTICLE

    Computational Modeling of Human Bicuspid Pulmonary Valve Dynamic Deformation in Patients with Tetralogy of Fallot

    Caili Li1, §, Christopher Baird2, Jing Yao3, Chun Yang4, Liang Wang5, Han Yu5, Tal Geva6, Dalin Tang5*, 7, §

    CMES-Computer Modeling in Engineering & Sciences, Vol.119, No.1, pp. 227-244, 2019, DOI:10.32604/cmes.2019.06036

    Abstract Pulmonary valve stenosis (PVS) is one common right ventricular outflow tract obstruction problem in patients with tetralogy of Fallot (TOF). Congenital bicuspid pulmonary valve (BPV) is a condition of valvular stenosis, and the occurrence of congenital BPV is often associated with TOF. Dynamic computational models of normal pulmonary root (PR) with tri-leaflet and PR with BPV in patients with TOF were developed to investigate the effect of geometric structure of BPV on valve stress and strain distributions. The pulmonary root geometry included valvular leaflets, sinuses, interleaflet triangles and annulus. Mechanical properties of pulmonary valve leaflet were obtained from biaxial testing… More >

  • Open Access

    ARTICLE

    Intramyocardial Injections to De-Stiffen the Heart: A Subject-Specific in Silico Approach

    Yaghoub Dabiri1,3, Kevin L. Sack1,2, Semion Shaul1, Gabriel Acevedo-Bolton1, Jenny S. Choy3, Ghassan S. Kassab3, Julius M. Guccione1,*

    Molecular & Cellular Biomechanics, Vol.16, No.3, pp. 185-197, 2019, DOI:10.32604/mcb.2019.07364

    Abstract We hypothesized that minimally invasive injections of a softening agent at strategic locations in stiff myocardium could de-stiffen the left ventricle (LV) globally. Physics-based finite element models of the LV were created from LV echocardiography images and pressures recorded during experiments in four swine. Results confirmed animal models of LV softening by systemic agents. Regional de-stiffening of myocardium led to global de-stiffening of LV. The mathematical set up was used to design LV global de-stiffening by regional softening of myocardium. At an end diastolic pressure of 23 mmHg, when 8 ml of the free wall was covered by intramyocardial injections,… More >

  • Open Access

    ARTICLE

    A Novel Atlas-Based Strategy for Understanding Cardiac Dysfunction in Patients with Congenital Heart Disease

    Sara Salehyar1, †, Nickolas Forsch1,†,*, Kathleen Gilbert2,3, Alistair A. Young3,4, James C. Perry5, Sanjeet Hegde5, Jeffrey H. Omens1,6, Andrew D. McCulloch1,6

    Molecular & Cellular Biomechanics, Vol.16, No.3, pp. 179-183, 2019, DOI:10.32604/mcb.2019.07384

    Abstract Tetralogy of Fallot (TOF) is the most common form of cyanotic congenital heart disease. Infants diagnosed with TOF require surgical interventions to survive into adulthood. However, as a result of postoperative structural malformations and long-term ventricular remodeling, further interventions are often required later in life. To help identify those at risk of disease progression, serial cardiac magnetic resonance (CMR) imaging is used to monitor these patients. However, most of the detailed information on cardiac shape and biomechanics contained in these large four-dimensional (4D) data sets goes unused in clinical practice for lack of efficient and comprehensive quantitative analysis tools. While… More >

  • Open Access

    ARTICLE

    Combining Smaller Patch, RV Remodeling and Tissue Regeneration in Pulmonary Valve Replacement Surgery Design May Lead to Better Post-Surgery RV Cardiac Function for Patients with Tetralogy of Fallot

    Zhedian Zhou1, Tal Geva2, Rahul H. Rathod2, Alexander Tang2, Chun Yang3, Kristen L. Billiar4, Dalin Tang1,*,3, Pedro del Nido5

    Molecular & Cellular Biomechanics, Vol.15, No.2, pp. 99-115, 2018, DOI: 10.3970/mcb.2018.00558

    Abstract Patients with repaired Tetralogy of Fallot (ToF), a congenital heart defect which includes a ventricular septal defect and severe right ventricular outflow obstruction, account for the majority of cases with late onset right ventricle (RV) failure. The current surgical approach, which includes pulmonary valve replacement/insertion (PVR), has yielded mixed results. A computational parametric study using 7 patient-specific RV/LV models based on cardiac magnetic resonance (CMR) data as "virtual surgery" was performed to investigate the impact of patch size, RV remodeling and tissue regeneration in PVR surgery design on RV cardiac functions. Two patch sizes, three degrees of scar trimming (RV… More >

  • Open Access

    ARTICLE

    Comparison of Right Ventricle Morphological and Mechanical Characteristics for Healthy and Patients with Tetralogy of Fallot: An In Vivo MRI-Based Modeling Study

    Dalin Tang1,*,2, Heng Zuo2,*, Chun Yang2, Zheyang Wu2, Xueying Huang3, Rahul H. Rathod4, Alexander Tang4, Kristen L. Billiar5, Tal Geva4

    Molecular & Cellular Biomechanics, Vol.14, No.3, pp. 137-151, 2017, DOI:10.3970/mcb.2017.014.137

    Abstract Patients with repaired tetralogy of Fallot (TOF) account for the majority of cases with late onset right ventricle failure. Comparing TOF patients with healthy people may provide information to address this challenge. Cardiac magnetic resonance (CMR) data were obtained from 16 TOF patients (patient group, PG) and 6 healthy volunteers (healthy group, HG). At begin-of-ejection, better patient group (n=5, BPG) stress was very close to HG stress (54.7±38.4 kPa vs. 51.2±55.7 kPa, p=0.6889) while worse patient group (n=11, WPG) stress was 84% higher than HG stress (p=0.0418). Stress may be used as an indicator to differentiate BPG patients from WPG… More >

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