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Articles 271 - 300 of 314

Full-Text Articles in Cardiology

Mobilization Studies In Mice Deficient In Sphingosine Kinase 2 Support A Crucial Role Of The Plasma Level Of Sphingosine-1-Phosphate In The Egress Of Hematopoietic Stem Progenitor Cells, Mateusz Adamiak, Lakshman Chelvarajan, Kevin R. Lynch, Webster L. Santos, Ahmed Abdel-Latif, Mariusz Z. Ratajczak Jul 2017

Mobilization Studies In Mice Deficient In Sphingosine Kinase 2 Support A Crucial Role Of The Plasma Level Of Sphingosine-1-Phosphate In The Egress Of Hematopoietic Stem Progenitor Cells, Mateusz Adamiak, Lakshman Chelvarajan, Kevin R. Lynch, Webster L. Santos, Ahmed Abdel-Latif, Mariusz Z. Ratajczak

Gill Heart & Vascular Institute Faculty Publications

Sphingosine-1-phosphate (S1P) is a bioactive lipid involved in cell signaling and, if released from cells, also plays a crucial role in regulating the trafficking of lympho-hematopoietic cells, including primitive hematopoietic stem/progenitor cells (HSPCs). It has been demonstrated that S1P chemoattracts HSPCs, and its level in peripheral blood creates a gradient directing egress of these cells during mobilization. In this paper we analyzed hematopoiesis in mice deficient in sphingosine kinase 2 (Sphk2-KO mice) and studied the effect of this mutation on plasma S1P levels. We found that Sphk2-KO mice have normal hematopoiesis, and, in contrast to Sphk1-KO mice, the circulating S1P …


Is Biological Repair Of Heart On The Horizon?, H R. Ahmad, Satwat Hashmi Jul 2017

Is Biological Repair Of Heart On The Horizon?, H R. Ahmad, Satwat Hashmi

Department of Biological & Biomedical Sciences

The stem cells keep us young by endogenously repairing us upon need. They do so bysmartly one step forward towards differentiation while another step backward to nurturethe undifferentiated stem cells. They are building blocks for every organ witha differential rate of repair of worn out tissues. Since stem cells can be cultured with a normal karyo type, they could be the ideal source for heart repair after myocardial infarction. As opposed to lower vertebrates and neonatal mice, cardiac regeneration in adult mammalian heart seems to be difficult to assess with a solid evidence of cytokinesis. It becomes more difficult to …


Optimal Nutrition For Endurance Exercise: A Systematic Review, Sarah E. Andrus Ms, Bruce W. Andrus Md Ms May 2017

Optimal Nutrition For Endurance Exercise: A Systematic Review, Sarah E. Andrus Ms, Bruce W. Andrus Md Ms

Dartmouth Scholarship

Introduction

As fatigue in endurance events correlates with depletion of muscle glycogen, the traditional approach to nutritional support has been carbohydrate loading. However, there has been recent interest in improving athletic endurance performance by novel diets in the days to weeks prior to endurance events, the pre-event meal, and during exercise.

Methods

We searched PubMed and SCOPUS for randomized trials published from 1992-2017 with a primary endpoint of endurance performance. We identified 407 citations which were examined against our inclusion criteria of randomization or crossover allocation to diet and for which a primary outcome was endurance performance.

Results

Twenty full …


Enhancing Cell Therapy For Ischemic Cardiomyopathy., Michael J. Book May 2017

Enhancing Cell Therapy For Ischemic Cardiomyopathy., Michael J. Book

Electronic Theses and Dissertations

Cardiac cell therapy using cardiac mesenchymal cells (CMC) significantly reduces ventricular dysfunction in patients with ischemic cardiomyopathy. Despite the improvement in function, a modest number of CMCs survive in the heart post-transplantation. In this study, we sought to improve the survival and retention of transplanted CMCs to prolong the therapeutic benefits afforded by cardiac cell therapy. To do this, we targeted the enzyme telomerase (TERT), known to be active in some highly proliferating cells (e.g. germ, stem). TERT is responsible for preventing telomere attrition, thereby allowing continued proliferation. TERT has also been shown to be protective, improve cell migration and …


Qt Prolongation Is Associated With Increased Mortality In End Stage Liver Disease, Sun Moon Kim, Bennet George, Diego Alcivar-Franco, Charles L. Campbell, Richard Charnigo, Brian P. Delisle, Jonathan Hundley, Yousef Darrat, Gustavo Morales, Samy-Claude Elayi, Alison L. Bailey Apr 2017

Qt Prolongation Is Associated With Increased Mortality In End Stage Liver Disease, Sun Moon Kim, Bennet George, Diego Alcivar-Franco, Charles L. Campbell, Richard Charnigo, Brian P. Delisle, Jonathan Hundley, Yousef Darrat, Gustavo Morales, Samy-Claude Elayi, Alison L. Bailey

Internal Medicine Faculty Publications

AIM

To determine the prevalence of QT prolongation in a large series of end stage liver disease (ESLD) patients and its association to clinical variables and mortality.

METHODS

The QT interval was measured and corrected for heart rate for each patient, with a prolonged QT cutoff defined as QT > 450 ms for males and QT > 470 ms for females. Multiple clinical variables were evaluated including sex, age, serum sodium, international normalized ratio, creatinine, total bilirubin, beta-blocker use, Model for End-Stage Liver Disease (MELD), MELD-Na, and etiology of liver disease.

RESULTS

Among 406 ESLD patients analyzed, 207 (51.0%) had QT prolongation. …


Vestibular Activation Habituates The Vasovagal Response In The Rat, Bernard Cohen, Giorgio P. Martinelli, Yongqing Xiang, Theodore Raphan, Sergei B. Yakushin Mar 2017

Vestibular Activation Habituates The Vasovagal Response In The Rat, Bernard Cohen, Giorgio P. Martinelli, Yongqing Xiang, Theodore Raphan, Sergei B. Yakushin

Publications and Research

Vasovagal syncope is a significant medical problem without effective therapy, postulated to be related to a collapse of baroreflex function. While some studies have shown that repeated static tilts can block vasovagal syncope, this was not found in other studies. Using anesthetized, male Long–Evans rats that were highly susceptible to generation of vasovagal responses, we found that repeated activation of the vestibulosympathetic reflex (VSR) with ±2 and ±3 mA, 0.025 Hz sinusoidal galvanic vestibular stimulation (sGVS) caused incremental changes in blood pressure (BP) and heart rate (HR) that blocked further generation of vasovagal responses. Initially, BP and HR fell ≈20–50 …


Diastolic Dysfunction In Coronary Artery Disease, Sarwat Hashmi, H R. Ahmad, Hasanat Sharif, Syedah Saira Bokhari Mar 2017

Diastolic Dysfunction In Coronary Artery Disease, Sarwat Hashmi, H R. Ahmad, Hasanat Sharif, Syedah Saira Bokhari

Department of Biological & Biomedical Sciences

No abstract provided.


Myocardial Relaxation Is Accelerated By Fast Stretch, Not Reduced Afterload, Charles S. Chung, Charles W. Hoopes, Kenneth S. Campbell Feb 2017

Myocardial Relaxation Is Accelerated By Fast Stretch, Not Reduced Afterload, Charles S. Chung, Charles W. Hoopes, Kenneth S. Campbell

Physiology Faculty Publications

Fast relaxation of cross-bridge generated force in the myocardium facilitates efficient diastolic function. Recently published research studying mechanisms that modulate the relaxation rate has focused on molecular factors. Mechanical factors have received less attention since the 1980s when seminal work established the theory that reducing afterload accelerates the relaxation rate. Clinical trials using afterload reducing drugs, partially based on this theory, have thus far failed to improve outcomes for patients with diastolic dysfunction. Therefore, we reevaluated the protocols that suggest reducing afterload accelerates the relaxation rate and identified that myocardial relengthening was a potential confounding factor. We hypothesized that the …


Cerebellar Tdcs: A Novel Approach To Augment Language Treatment Post-Stroke, Rajani Sebastian, Sadhvi Saxena, Kyrana Tsapkini, Andreia V. Faria, Charltien Long, Amy Wright, Cameron Davis, Donna C. Tippett, Antonios P. Mourdoukoutas, Marom Bikson, Pablo Celnik, Argye E. Hillis Jan 2017

Cerebellar Tdcs: A Novel Approach To Augment Language Treatment Post-Stroke, Rajani Sebastian, Sadhvi Saxena, Kyrana Tsapkini, Andreia V. Faria, Charltien Long, Amy Wright, Cameron Davis, Donna C. Tippett, Antonios P. Mourdoukoutas, Marom Bikson, Pablo Celnik, Argye E. Hillis

Publications and Research

People with post-stroke aphasia may have some degree of chronic deficit for which current rehabilitative treatments are variably effective. Accumulating evidence suggests that transcranial direct current stimulation (tDCS) may be useful for enhancing the effects of behavioral aphasia treatment. However, it remains unclear which brain regions should be stimulated to optimize effects on language recovery. Here, we report on the therapeutic potential of right cerebellar tDCS in augmenting language recovery in SMY, who sustained bilateral MCA infarct resulting in aphasia and anarthria. We investigated the effects of 15 sessions of anodal cerebellar tDCS coupled with spelling therapy using a randomized, …


Omecamtiv Mecarbil Enhances The Duty Ratio Of Human Β-Cardiac Myosin Resulting In Increased Calcium Sensitivity And Slowed Force Development In Cardiac Muscle, Anja M. Swenson, Wanjian Tang, Cheavar A. Blair, Christopher M. Fetrow, William C. Unrath, Michael J. Previs, Kenneth S. Campbell, Christopher M. Yengo Jan 2017

Omecamtiv Mecarbil Enhances The Duty Ratio Of Human Β-Cardiac Myosin Resulting In Increased Calcium Sensitivity And Slowed Force Development In Cardiac Muscle, Anja M. Swenson, Wanjian Tang, Cheavar A. Blair, Christopher M. Fetrow, William C. Unrath, Michael J. Previs, Kenneth S. Campbell, Christopher M. Yengo

Physiology Faculty Publications

The small molecule drug omecamtiv mecarbil (OM) specifically targets cardiac muscle myosin and is known to enhance cardiac muscle performance, yet its impact on human cardiac myosin motor function is unclear. We expressed and purified human β-cardiac myosin subfragment 1 (M2β-S1) containing a C-terminal Avi tag. We demonstrate that the maximum actin-activated ATPase activity of M2β-S1 is slowed more than 4-fold in the presence of OM, whereas the actin concentration required for half-maximal ATPase was reduced dramatically (30-fold). We find OM does not change the overall actin affinity. Transient kinetic experiments suggest that there are …


Myofilament Calcium Sensitivity: Consequences Of The Effective Concentration Of Troponin I, Jalal K. Siddiqui, Svetlana B. Tikunova, Shane D. Walton, Bin Liu, Meredith Meyer, Pieter P. De Tombe, Nathan Neilson, Peter M. Kekenes-Huskey, Hussam E. Salhi, Paul M.L. Janssen, Brandon J. Biesiadecki, Jonathan P. Davis Dec 2016

Myofilament Calcium Sensitivity: Consequences Of The Effective Concentration Of Troponin I, Jalal K. Siddiqui, Svetlana B. Tikunova, Shane D. Walton, Bin Liu, Meredith Meyer, Pieter P. De Tombe, Nathan Neilson, Peter M. Kekenes-Huskey, Hussam E. Salhi, Paul M.L. Janssen, Brandon J. Biesiadecki, Jonathan P. Davis

Chemistry Faculty Publications

Control of calcium binding to and dissociation from cardiac troponin C (TnC) is essential to healthy cardiac muscle contraction/relaxation. There are numerous aberrant post-translational modifications and mutations within a plethora of contractile, and even non-contractile, proteins that appear to imbalance this delicate relationship. The direction and extent of the resulting change in calcium sensitivity is thought to drive the heart toward one type of disease or another. There are a number of molecular mechanisms that may be responsible for the altered calcium binding properties of TnC, potentially the most significant being the ability of the regulatory domain of TnC to …


Dna Methylation Signatures Of Chronic Low-Grade Inflammation Are Associated With Complex Diseases, Symen Ligthart, Carola Marzi, Stella Aslibekyan, Michael M. Mendelson, Karen N. Conneely, Toshiko Tanaka, Elena Colicino, Lindsay L. Waite, Roby Joehanes, Weihua Guan, Jennifer A. Brody, Cathy Elks, Riccardo Marioni, Min A. Jhun, Golareh Agha, Jan Bressler, Cavin K. Ward-Caviness, Brian H. Chen, Tianxiao Huan, Kelly Bakulski, Elias L. Salfati, Whi-Empc Investigators, Giovanni Fiorito, Charge Epigenetics Of Coronary Heart Disease, Simone Wahl, Katharina Schramm, Jin Sha, Dena G. Hernandez, Allan C. Just, Jennifer A. Smith, Donna K. Arnett Dec 2016

Dna Methylation Signatures Of Chronic Low-Grade Inflammation Are Associated With Complex Diseases, Symen Ligthart, Carola Marzi, Stella Aslibekyan, Michael M. Mendelson, Karen N. Conneely, Toshiko Tanaka, Elena Colicino, Lindsay L. Waite, Roby Joehanes, Weihua Guan, Jennifer A. Brody, Cathy Elks, Riccardo Marioni, Min A. Jhun, Golareh Agha, Jan Bressler, Cavin K. Ward-Caviness, Brian H. Chen, Tianxiao Huan, Kelly Bakulski, Elias L. Salfati, Whi-Empc Investigators, Giovanni Fiorito, Charge Epigenetics Of Coronary Heart Disease, Simone Wahl, Katharina Schramm, Jin Sha, Dena G. Hernandez, Allan C. Just, Jennifer A. Smith, Donna K. Arnett

Epidemiology and Environmental Health Faculty Publications

Background: Chronic low-grade inflammation reflects a subclinical immune response implicated in the pathogenesis of complex diseases. Identifying genetic loci where DNA methylation is associated with chronic low-grade inflammation may reveal novel pathways or therapeutic targets for inflammation.

Results: We performed a meta-analysis of epigenome-wide association studies (EWAS) of serum C-reactive protein (CRP), which is a sensitive marker of low-grade inflammation, in a large European population (n = 8863) and trans-ethnic replication in African Americans (n = 4111). We found differential methylation at 218 CpG sites to be associated with CRP (P < 1.15 × 10–7) in the discovery panel …


Unusual Presentation Of A Young Man With Disseminated Tuberculosis And Right Ventricular Mass, Shahrukh Hashmani, Fateh Ali Tipoo Sultan, Muhammad Qamar Masood Oct 2016

Unusual Presentation Of A Young Man With Disseminated Tuberculosis And Right Ventricular Mass, Shahrukh Hashmani, Fateh Ali Tipoo Sultan, Muhammad Qamar Masood

Section of Cardiology

We report a 22-year-old man who presented to the emergency department with worsening shortness of breath and chronic fever for 2 months. Physical examination was unremarkable except for raised jugular venous pressure and palpable liver. Echocardiogram showed a large right ventricular mass causing obstruction at tricuspid valve. A subsequent chest CT scan confirmed the presence of a large mass in the right ventricle. There were multiple enlarged lymph nodes and consolidation in the right upper lobe. Diagnosis of disseminated tuberculosis(TB) was made and later confirmed by histopathology of lymph node biopsy along with positive sputum culture for acid-fast bacilli. Remarkable …


Attenuation Of Na/K-Atpase Mediated Oxidant Amplification With Pnaktide Ameliorates Experimental Uremic Cardiomyopathy, Jiang Liu, Jiang Tian, Muhammad Chaudhry, Nader G. Abraham, Joseph Shapiro Oct 2016

Attenuation Of Na/K-Atpase Mediated Oxidant Amplification With Pnaktide Ameliorates Experimental Uremic Cardiomyopathy, Jiang Liu, Jiang Tian, Muhammad Chaudhry, Nader G. Abraham, Joseph Shapiro

NYMC Faculty Publications

We have previously reported that the sodium potassium adenosine triphosphatase (Na/K-ATPase) can effect the amplification of reactive oxygen species. In this study, we examined whether attenuation of oxidant stress by antagonism of Na/K-ATPase oxidant amplification might ameliorate experimental uremic cardiomyopathy induced by partial nephrectomy (PNx). PNx induced the development of cardiac morphological and biochemical changes consistent with human uremic cardiomyopathy. Both inhibition of Na/K-ATPase oxidant amplification with pNaKtide and induction of heme oxygenase-1 (HO-1) with cobalt protoporphyrin (CoPP) markedly attenuated the development of phenotypical features of uremic cardiomyopathy. In a reversal study, administration of pNaKtide after the induction of uremic …


Vitamin K2 (Menaquinone) Supplementation And Its Benefits In Cardiovascular Disease, Osteoporosis, And Cancer, Grant S. Buchanan, Md, Thomas Melvin, Brandon Merritt, Charles Bishop, Md, Franklin D. Shuler, Md, Phd Jul 2016

Vitamin K2 (Menaquinone) Supplementation And Its Benefits In Cardiovascular Disease, Osteoporosis, And Cancer, Grant S. Buchanan, Md, Thomas Melvin, Brandon Merritt, Charles Bishop, Md, Franklin D. Shuler, Md, Phd

Marshall Journal of Medicine

Vitamin K is known to play an essential role in the coagulation cascade; however, a growing body of research has found that a subtype of this vitamin, vitamin K2 (menaquinone) may have a beneficial effect in osteoporosis, cardiovascular disease, and cancer. This purpose of this article is to provide a comprehensive review of recent literature regarding menaquinone and its role in human health. This review discusses the physiology of menaquinone, its clinical benefits in cardiovascular disease, osteoporosis, and cancer, and how it may interact with certain medications. The authors conclude that menaquinone supplementation has been shown to improve carboxylation …


Cardiac Remodeling And Dysfunction In Childhood Obesity: A Cardiovascular Magnetic Resonance Study, Linyuan Jing, Cassi M. Binkley, Jonathan D. Suever, Nivedita Umasankar, Christopher M. Haggerty, Jennifer Rich, Christopher D. Nevius, Gregory J. Wehner, Sean M. Hamlet, David K. Powell, Aurelia Radulescu, H. Lester Kirchner, Frederick H. Epstein, Brandon K. Fornwalt May 2016

Cardiac Remodeling And Dysfunction In Childhood Obesity: A Cardiovascular Magnetic Resonance Study, Linyuan Jing, Cassi M. Binkley, Jonathan D. Suever, Nivedita Umasankar, Christopher M. Haggerty, Jennifer Rich, Christopher D. Nevius, Gregory J. Wehner, Sean M. Hamlet, David K. Powell, Aurelia Radulescu, H. Lester Kirchner, Frederick H. Epstein, Brandon K. Fornwalt

Pediatrics Faculty Publications

Background: Obesity affects nearly one in five children and is associated with increased risk of premature death. Obesity-related heart disease contributes to premature death. We aimed to use cardiovascular magnetic resonance (CMR) to comprehensively characterize the changes in cardiac geometry and function in obese children.

Methods and results: Forty-one obese/overweight (age 12 ± 3 years, 56 % female) and 29 healthy weight children (age 14 ± 3 years, 41 % female) underwent CMR, including both standard cine imaging and displacement encoded imaging, for a complete assessment of left ventricular (LV) structure and function. After adjusting for age, LV mass index …


Programming Heart Disease: Does Poor Maternal Nutrition Alter Expression Of Cardiac Markers Of Proliferation, Hypertrophy, And Fibrosis In Offspring?, Cathy Chun May 2016

Programming Heart Disease: Does Poor Maternal Nutrition Alter Expression Of Cardiac Markers Of Proliferation, Hypertrophy, And Fibrosis In Offspring?, Cathy Chun

Honors Scholar Theses

Maternal malnutrition can affect fetal organogenesis, metabolic processes, and factors involved in developmental regulation. Of the many physiological effects poor maternal nutrition can induce in offspring, one of the most important organs affected is the heart. Cardiovascular disease has been associated with poor maternal diet. It also been suggested that hypertension can originate during impaired intrauterine growth and development. Hypertension can trigger hypertensive heart disease and is associated with numerous heart complications. We hypothesized that poor maternal nutrition would alter critical growth factors associated with normal heart development, specifically, insulin-like growth factor (IGF)-1, IGF-2, transforming growth factor (TGF)β, and connective …


Steroid Binding To Autotaxin Links Bile Salts And Lysophosphatidic Acid Signalling, Willem-Jan Keune, Jens Hausmann, Ruth Bolier, Dagmar Tolenaars, Andreas Kremer, Tatjana Heidebrecht, Robbie P. Joosten, Manjula Sunkara, Andrew J. Morris, Elisa Matas-Rico, Wouter H. Moolenaar, Ronald P. Oude Elferink, Anastassis Perrakis Apr 2016

Steroid Binding To Autotaxin Links Bile Salts And Lysophosphatidic Acid Signalling, Willem-Jan Keune, Jens Hausmann, Ruth Bolier, Dagmar Tolenaars, Andreas Kremer, Tatjana Heidebrecht, Robbie P. Joosten, Manjula Sunkara, Andrew J. Morris, Elisa Matas-Rico, Wouter H. Moolenaar, Ronald P. Oude Elferink, Anastassis Perrakis

Gill Heart & Vascular Institute Faculty Publications

Autotaxin (ATX) generates the lipid mediator lysophosphatidic acid (LPA). ATX-LPA signalling is involved in multiple biological and pathophysiological processes, including vasculogenesis, fibrosis, cholestatic pruritus and tumour progression. ATX has a tripartite active site, combining a hydrophilic groove, a hydrophobic lipid-binding pocket and a tunnel of unclear function. We present crystal structures of rat ATX bound to 7α-hydroxycholesterol and the bile salt tauroursodeoxycholate (TUDCA), showing how the tunnel selectively binds steroids. A structure of ATX simultaneously harbouring TUDCA in the tunnel and LPA in the pocket, together with kinetic analysis, reveals that bile salts act as partial non-competitive inhibitors …


A Model Of Blood Pressure, Heart Rate, And Vaso-Vagal Responses Produced By Vestibulo-Sympathetic Activation, Theodore Raphan, Bernard Cohen, Yongqing Xiang, Sergei B. Yakushin Mar 2016

A Model Of Blood Pressure, Heart Rate, And Vaso-Vagal Responses Produced By Vestibulo-Sympathetic Activation, Theodore Raphan, Bernard Cohen, Yongqing Xiang, Sergei B. Yakushin

Publications and Research

Blood Pressure (BP), comprised of recurrent systoles and diastoles, is controlled by central mechanisms to maintain blood flow. Periodic behavior of BP was modeled to study how peak amplitudes and frequencies of the systoles are modulated by vestibular activation. The model was implemented as a relaxation oscillator, driven by a central signal related to Desired BP. Relaxation oscillations were maintained by a second order system comprising two integrators and a threshold element in the feedback loop. The output signal related to BP was generated as a nonlinear function of the derivative of the first state variable, which is a summation …


'Refractory Epilepsy': What Lies Beneath?, Syedah Saira Bokhari, Satwat Hashmi Mar 2016

'Refractory Epilepsy': What Lies Beneath?, Syedah Saira Bokhari, Satwat Hashmi

Section of Internal Medicine

A 30-year-old woman presented to the emergency room with recurrent seizures for 5 days. She had been diagnosed with epilepsy 2 years previously but stopped treatment due to the side effects of her medications. She was now experiencing episodes every 15-30 min. While undergoing a brain MRI to investigate for structural central nervous system pathology, she experienced another episode, preceded by prodromal symptoms. Polymorphic ventricular tachycardia was noted during the event. Further investigation revealed a normal QT interval, normal electrolyte panel, normal coronaries and severe left ventricular systolic dysfunction. Cardiac MRI revealed non-ischaemic cardiomyopathy. The patient was managed with heart …


The Role Of Notch Signaling On Heart Rate And Atrial Conduction, Somya Bhatnagar Jan 2016

The Role Of Notch Signaling On Heart Rate And Atrial Conduction, Somya Bhatnagar

Undergraduate Research Symposium Posters

Heart disease is the leading cause of death worldwide and can result in arrhythmias, or dysregulation in the electrical activation of the heart. Sick Sinus Syndrome (SSS) is characterized by sinus bradycardia (slowed heart rate, HR), slowed conduction through atrial myocardium, and can predispose to the development of atrial fibrillation. A developmental signaling pathway, Notch, regulates cellular identity through differentiation of cardiomyocytes (CMs) into cardiac conduction system-like cells. Previous data show that Notch electrically remodels the right atrium, causing slowed conduction velocity (CV) and hallmarks of SSS including sinus pauses, sinus bradycardia and a predisposition to atrial fibrillation. However, the …


Effect Of Twisted Fiber Anisotropy In Cardiac Tissue On Ablation With Pulsed Electric Fields, Fei Xie, Christian W. Zemlin Jan 2016

Effect Of Twisted Fiber Anisotropy In Cardiac Tissue On Ablation With Pulsed Electric Fields, Fei Xie, Christian W. Zemlin

Bioelectrics Publications

Background: Ablation of cardiac tissue with pulsed electric fields is a promising alternative to current thermal ablation methods, and it critically depends on the electric field distribution in the heart.

Methods: We developed a model that incorporates the twisted anisotropy of cardiac tissue and computed the electric field distribution in the tissue. We also performed experiments in rabbit ventricles to validate our model. We find that the model agrees well with the experimentally determined ablation volume if we assume that all tissue that is exposed to a field greater than 3 kV/cm is ablated. In our numerical analysis, we considered …


Development And Application Of Gadolinium Free Cardiac Magnetic Resonance Fibrosis Imaging For Multiscale Study Of Heart Failure In Patients With End Stage Renal Disease, Tori A. Stromp Jan 2016

Development And Application Of Gadolinium Free Cardiac Magnetic Resonance Fibrosis Imaging For Multiscale Study Of Heart Failure In Patients With End Stage Renal Disease, Tori A. Stromp

Theses and Dissertations--Physiology

Cardiac magnetic resonance (CMR) is a powerful tool to noninvasively image ventricular fibrosis. Late gadolinium enhancement (LGE) CMR identifies focal and, with T1 mapping, diffuse fibrosis. Despite prevalent cardiac fibrosis and heart failure, patients with end stage renal disease (ESRD) are excluded from LGE. Absence of a suitable diagnostic has limited the understanding of heart failure and obstructed development of therapies in the setting of ESRD. A quantitative, gadolinium free fibrosis detection method could overcome this critical barrier, propelling the advancement of diagnostic, monitoring, and therapy options. This project describes the development of a gadolinium free CMR technique and application …


Background Differences In Baseline And Stimulated Mmp Levels Influence Abdominal Aortic Aneurysm Susceptibility, Matthew A. Dale, Melissa K. Suh, Shijia Zhao, Trevor Meisinger, Linxia Gu, Vicki J. Swier, Devendra K. Agrawal, Timothy Greiner, Jeffrey S. Carson, B. Timothy Baxter, Wanfen Xiong Dec 2015

Background Differences In Baseline And Stimulated Mmp Levels Influence Abdominal Aortic Aneurysm Susceptibility, Matthew A. Dale, Melissa K. Suh, Shijia Zhao, Trevor Meisinger, Linxia Gu, Vicki J. Swier, Devendra K. Agrawal, Timothy Greiner, Jeffrey S. Carson, B. Timothy Baxter, Wanfen Xiong

Department of Mechanical and Materials Engineering: Faculty Publications

Objective: Evidence has demonstrated profound influence of genetic background on cardiovascular phenotypes. Murine models in Marfan syndrome (MFS) have shown that genetic background-related variations affect thoracic aortic aneurysm formation, rupture, and lifespan of mice. MFS mice with C57Bl/6 genetic background are less susceptible to aneurysm formation compared to the 129/SvEv genetic background. In this study, we hypothesize that susceptibility to abdominal aortic aneurysm (AAA) will be increased in 129/SvEv mice versus C57Bl/6 mice. We tested this hypothesis by assessing differences in aneurysm size, tissue properties, immune response, and MMP expression.

Methods: Mice of C57Bl/6 or 129/SvEv background underwent AAA induction …


Acute Myocardial Infarction And Myocardial Ischemia-Reperfusion Injury: A Comparison, Satwat Hashmi, Suhail Al-Salam Aug 2015

Acute Myocardial Infarction And Myocardial Ischemia-Reperfusion Injury: A Comparison, Satwat Hashmi, Suhail Al-Salam

Department of Biological & Biomedical Sciences

Myocardial infarction (MI) denotes the death of cardiac myocytes due to extended ischemia. Myocardial reperfusion is the restoration of coronary blood flow after a period of coronary occlusion. Reperfusion has the potential to salvage ischemic myocardium but paradoxically can cause injury, a phenomenon called as 'reperfusion injury' (IR). Standard histologic, immunohistochemical and Elisa techniques were used to study the histopathologic, oxidative, apoptotic and inflammatory changes in MI and IR. The IL-6 levels in the LV of the MI group were significantly raised as compared to the IR group (P=0.0008). Plasma IL-6 was also significantly increased in the MI group as …


Galectin-1: A Biomarker Of Surgical Stress In Murine Model Of Cardiac Surgery, Satwat Hashmi, Suhail Al-Salam Jun 2015

Galectin-1: A Biomarker Of Surgical Stress In Murine Model Of Cardiac Surgery, Satwat Hashmi, Suhail Al-Salam

Department of Biological & Biomedical Sciences

Galectin-1 (GAL-1) belongs to the family of β-galactoside-binding lectins. It regulates cell-cell and cell-matrix interactions, the immune response, apoptosis, cell cycle, RNA splicing and neoplastic transformation. We investigate the effect of heart manipulation secondary to cardiac surgery on the level of GAL-1 in murine heart and plasma. Male C57B6/J mice were used for adopted model of cardiac surgery. Heart samples were processed for immunohistochemical and immunofluorescent labeling, Enzyme linked immunosorbent assay and quantitative RT-PCR to identify GAL-1 levels in the heart and plasma during the first 24 hours following cardiac surgery. There is significant increase of GAL-1 in the LV …


The Effect Of Active Video Games On The Heart Rate Of Older Adults, Yeon Bai, Shahla M. Wunderlich, Diane M. Hanel Feb 2015

The Effect Of Active Video Games On The Heart Rate Of Older Adults, Yeon Bai, Shahla M. Wunderlich, Diane M. Hanel

Department of Nutrition and Food Studies Scholarship and Creative Works

Background: Heart rate is used as a health biomarker. This aim of this study was to investigate the effects of playing active video games on the heart rate of older adults, in comparison to the heart rate after common table recreational activity.

Methods: An experimental study with 40 participants was conducted: a control group (n=20) participated in common Pokeno® card games; an experimental group (n=20) played WiiTM bowling. The participants’ pre- and post-activity heart rates were measured and compared between and within groups using t-tests.

Results: The findings signified an 11.9% increase (p

Conclusions: The inclusion of active video games …


The Wetsuit Effect: Physiological Response To Wearing A Wetsuit, Aaron Prado Aug 2014

The Wetsuit Effect: Physiological Response To Wearing A Wetsuit, Aaron Prado

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to investigate the effects of wearing a wetsuit on resting cardiovascular parameters (mean arterial pressure (MAP), rate-pressure product (RPP), and heart rate variability (HRV)). Furthermore, the position (i.e., upright vs. prone) as well as the wetsuit size were explored as possible factors that influence the cardiovascular parameters. Twelve male participants (79.1±5.1 kg, 178.4±2.9 cm, 33.3±12.1 years) granted written consent and were assigned two wetsuits based on height, weight, and corresponding manufacturer recommendations. SWS signified the smallest possible wetsuit the subject could fit into according to recommendations, LWS signified the largest wetsuit the subject could …


Effect Of Fontan Fenestration On Regional Venous Oxygen Saturation During Exercise: Further Insights Into Fontan Fenestration Closure, Rohit S. Loomba, Michael E. Danduran, Jennifer E. Dixon, Rohit P. Rao Mar 2014

Effect Of Fontan Fenestration On Regional Venous Oxygen Saturation During Exercise: Further Insights Into Fontan Fenestration Closure, Rohit S. Loomba, Michael E. Danduran, Jennifer E. Dixon, Rohit P. Rao

Exercise Science Faculty Research and Publications

Fontan fenestration closure is a topic of great debate. The body of data regarding the risks and benefits of fenestration closure is limited yet growing. Previous studies have demonstrated that Fontan patients have less exercise capacity than those with normal cardiovascular anatomy. Differences also have been noted within various subgroups of Fontan patients such as whether Fontan is fenestrated or not. This study aimed to compare trends in regional oxygen saturations using near-infrared spectroscopy (NIRS) in patients with Fontan circulations during ramping exercise to further delineate differences between patients with and without a fenestration. It was hypothesized that Fontan patients …


Galectin-1 In Early Acute Myocardial Infarction, Suhail Al-Salam, Satwat Hashmi Jan 2014

Galectin-1 In Early Acute Myocardial Infarction, Suhail Al-Salam, Satwat Hashmi

Department of Biological & Biomedical Sciences

Myocardial infarction (MI) is the most serious manifestation of coronary artery disease and the cause of significant mortality and morbidity worldwide. Galectin-1(GAL-1), a divalent 14.5-kDa protein, is present both inside and outside cells, and has both intracellular and extracellular functions. Hypoxia inducible factor-1 alpha (HIF-1α) is a transcription factor mediating early and late responses to myocardial ischemia. Identification of the pattern of expression of GAL-1 and HIF-1α in the heart during the first 24 hours following acute MI will help in understanding early molecular changes in this event and may provide methods to overcome serious complications. Mouse model of MI …