Physiology Commons^™

Post-Acquisition Processing Confounds In Brain Volumetric Quantification Of White Matter Hyperintensities, Ahmed A. Bahrani, Omar M. Al-Janabi, Erin L. Abner, Shoshana H. Bardach, Richard J. Kryscio, Donna M. Wilcock, Charles D. Smith, Gregory A. Jicha

Neurology Faculty Publications

BACKGROUND: Disparate research sites using identical or near-identical magnetic resonance imaging (MRI) acquisition techniques often produce results that demonstrate significant variability regarding volumetric quantification of white matter hyperintensities (WMH) in the aging population. The sources of such variability have not previously been fully explored.

NEW METHOD: 3D FLAIR sequences from a group of randomly selected aged subjects were analyzed to identify sources-of-variability in post-acquisition processing that can be problematic when comparing WMH volumetric data across disparate sites. The methods developed focused on standardizing post-acquisition protocol processing methods to develop a protocol with less than 0.5% inter-rater variance.

RESULTS: A series …

A Comparison Of Lung Function Values Among A Scuba Diver Population And In Comparison To A Non-Diver Population, Gabriel C. Hutson, Jeremy D. Rentsch, Erin M. Eaton

Journal of the South Carolina Academy of Science

The purpose of this study was to investigate possible correlations between lung function values (PEF, IRV, ERV, and FVC) among a diver population, as well as in comparison to a non-diver population. Independent variables for both populations were biological sex, age, and weekly physical activity. Independent variables for the diver population were dive tenure, number of logged dives, certification level, and gas mixture used. A spirometry test was conducted to collect lung function values of both populations. Data from this study suggest a statistically significant relationship between diver and non-diver sex and FVC, diver age and ERV, diver sex and …

Evaluation Of Kidney Injury Molecule-1 As A Disease Progression Biomarker In Diabetic Nephropathy, Fatima Abid Khan, Syeda Sadia Fatima, Ghulam Mustafa Khan, Sana Shahid

Department of Biological & Biomedical Sciences

Background & Objective: Kidney Injury Molecule-1 (KIM-1) is a peptide whose release into circulation is specific to tubular injury. This study aimed to estimate levels of kidney injury molecule-1 in diabetic patients with and without kidney disease. And evaluate the role of KIM-1 as an early screening marker of progressive kidney injury.
Methods: This follow-up study included n=85 subjects from the diabetic clinic of Jinnah Post Graduate Medical Center (JPMC) in collaboration with Aga Khan University from November 2016 till September 2017. They were divided as: i) Group A1 (n=30) participants with diabetes for <5 years without microalbuminuria ii) Group A2 (n= 30) subjects with diabetes for 6-10 years with microalbuminuria; iii) Group B (n=25) subjects as healthy control group. All study participants were followed for 6 months and their blood glucose, urea, creatinine, electrolytes, albuminuria and serum KIM-1 were assayed.
Results: High KIM-1 at baseline was …

Rising Rural Body-Mass Index Is The Main Driver Of The Global Obesity Epidemic In Adults, Con Burns, Tara Coppinger, Janette Walton, Et Al

Publications

Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities1,2. This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity3,4,5,6. Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to …

Development Of A Sonically Powered Biodegradable Nanogenerator For Bone Regeneration, Avi Patel

Honors Scholar Theses

Background: Reconstruction of bone fractures and defects remains a big challenge in orthopedic surgery. While regenerative engineering has advanced the field greatly using a combination of biomaterial scaffolds and stem cells, one matter of difficulty is inducing osteogenesis in these cells. Recent works have shown electricity’s ability to promote osteogenesis in stem cell lines when seeded in bone scaffolds; however, typical electrical stimulators are either (a) externally housed and require overcomplex percutaneous wires be connected to the implanted scaffold or (b) implanted non-degradable devices which contain toxic batteries and require invasive removal surgeries.

Objective: Here, we establish a biodegradable, piezoelectric …

Deciphering The Consequences Of Yolk Testosterone Metabolism In Birds, Nicole A. Campbell

Theses and Dissertations

Maternal steroids transferred to eggs can elicit permanent effects on various aspects of offspring phenotype. Although, testosterone was thought to be a key mediator of maternal effects in birds, we now know that vertebrate embryos actively regulate their exposure to maternal testosterone through steroid metabolism, suggesting testosterone metabolites may elicit the observed phenotypic effects. To address the role steroid metabolism plays in mediating yolk testosterone effects, we used European starling (Sturnus vulgaris) eggs to characterize the timing of testosterone metabolism and determine whether etiocholanolone, a prominent testosterone metabolite in avian embryos, is capable of influencing early embryonic development. Tritiated testosterone …

Dennd5b Regulates Intestinal Triglyceride Absorption And Body Mass, Scott M. Gordon, Edward B. Neufeld, Zhihong Yang, Milton Pryor, Lita A. Freeman, Xiao Fan, Iftikhar J. Kullo, Leslie G. Biesecker, Alan T. Remaley

Saha Cardiovascular Research Center Faculty Publications

Regulation of lipid absorption by enterocytes can influence metabolic status in humans and contribute to obesity and related complications. The intracellular steps of chylomicron biogenesis and transport from the Endoplasmic Reticulum (ER) to the Golgi complex have been described, but the mechanisms for post-Golgi transport and secretion of chylomicrons have not been identified. Using a newly generated Dennd5b^−/− mouse, we demonstrate an essential role for this gene in Golgi to plasma membrane transport of chylomicron secretory vesicles. In mice, loss of Dennd5b results in resistance to western diet induced obesity, changes in plasma lipids, and reduced aortic atherosclerosis. In …

Antisense Oligonucleotides Targeting Angiotensinogen: Insights From Animal Studies, Chia-Hua Wu, Ya Wang, Murong Ma, Adam E. Mullick, Rosanne M. Crooke, Mark J. Graham, Alan Daugherty, Hong S. Lu

Saha Cardiovascular Research Center Faculty Publications

Angiotensinogen (AGT) is the unique substrate of all angiotensin peptides. We review the recent preclinical research of AGT antisense oligonucleotides (ASOs), a rapidly evolving therapeutic approach. The scope of the research findings not only opens doors for potentially new therapeutics of hypertension and many other diseases, but also provides insights into understanding critical physiological and pathophysiological roles mediated by AGT.

Enhancing Cognitive Engagement Of Pre-Clinical Undergraduate Medical Students Via Video Cases And Interactive Quizzes In Problem-Based Learning, Syeda Sadia Fatima, Kulsoom Ghias, Kauser Jabeen, Saniya Sabzwari

Department of Biological & Biomedical Sciences

Background: Problem-based learning (PBL) is one of the main pedagogical approaches utilized in the undergraduate medical education (UGME) program at a private medical college in Karachi, Pakistan. Video-enhanced cases and formative assessments were introduced at the end of PBL sessions to evaluate their effectiveness in enhancing student engagement.
Methods: A mixed methods study was conducted with Year 2 medical students (n=102; divided into 11 groups) and faculty (n=11) facilitating the PBL process. Of the 10 PBL cases, five were converted to video-enhanced cases and five were kept as paper-based, “traditional” cases. “Micro” videos were used to introduce clinical scenarios, augmented …

The Effect Of Dorsal Rhizotomy On Renal Sodium Excretion Following Dorsal Spinal Stimulation, Tanko Tijani Ahmed

All Graduate Theses, Dissertations, and Other Capstone Projects

Hypertension is one of the most common risk factors in the development of heart disease, stroke and end stage renal failure. Sympathetic overactivity is believed to be one of the main mechanism behind resistant hypertension. Renal denervation has been used to treat resistant hypertension, although this procedure is an invasive one. Spinal cord stimulation (SCS) is a known modality to treat ischemic pain, angina pectoris, and peripheral vascular diseases. In previous studies in this laboratory, unilateral spinal cord stimulation in spontaneously hypertensive rat (SHR) at 67% of the motor threshold increased urinary sodium and water excretion significantly, without affecting mean …

Associations Between Income, Acculturation, Country Of Origin, And Type Ii Diabetes Among African Immigrants To Ontario, Canada, Girma Aman Goshe

Walden Dissertations and Doctoral Studies

Diabetes has become a longstanding public health challenge around the world. Over the last 3 decades, the number of people with Type II diabetes (T2DM) has grown to an epidemic level in Canada. Prior research indicated African immigrants residing in Ontario, Canada experienced a 2-4 times higher prevalence of T2DM than Canadian-born individuals. The social determinants of health theoretical framework guided this study assessing the relationship of the risk factors with T2DM. A quantitative, cross-sectional design was employed using the 2007-2014 Canadian Community Health Survey data. The random sample included 1,526 African immigrants residing in Ontario, Canada. Descriptive, bivariate, and …

Manganese-Enhanced Magnetic Resonance Imaging: Overview And Central Nervous System Applications With A Focus On Neurodegeneration, Ryan A. Cloyd, Shon A. Koren, Jose F. Abisambra

Physiology Faculty Publications

Manganese-enhanced magnetic resonance imaging (MEMRI) rose to prominence in the 1990s as a sensitive approach to high contrast imaging. Following the discovery of manganese conductance through calcium-permeable channels, MEMRI applications expanded to include functional imaging in the central nervous system (CNS) and other body systems. MEMRI has since been employed in the investigation of physiology in many animal models and in humans. Here, we review historical perspectives that follow the evolution of applied MRI research into MEMRI with particular focus on its potential toxicity. Furthermore, we discuss the more current in vivo investigative uses of MEMRI in CNS investigations and …

Hdl In Endocrine Carcinomas: Biomarker, Drug Carrier, And Potential Therapeutic, Emily E. Morin, Xiang-An Li, Anna Schwendeman

Physiology Faculty Publications

High-density lipoprotein (HDL) have long been studied for their protective role against cardiovascular diseases, however recently relationship between HDL and cancer came into focus. Several epidemiological studies have shown an inverse correlation between HDL-cholesterol (HDL-C) and cancer risk, and some have even implied that HDL-C can be used as a predictive measure for survival prognosis in for specific sub-population of certain types of cancer. HDL itself is an endogenous nanoparticle capable of removing excess cholesterol from the periphery and returning it to the liver for excretion. One of the main receptors for HDL, scavenger receptor type B-I (SR-BI), is highly …

Macrophage-Derived Netrin-1 Promotes Abdominal Aortic Aneurysm Formation By Activating Mmp3 In Vascular Smooth Muscle Cells, Tarik Hadi, Ludovic Boytard, Michele Silvestro, Dornazsadat Alebrahim, Samson Jacob, Jordyn Feinstein, Krista Barone, Wes Spiro, Susan Hutchison, Russell Simon, Debra L. Rateri, Florence Pinet, David Fenyo, Mark Adelman, Kathryn J. Moore, Holger K. Eltzschig, Alan Daugherty, Bhama Ramkhelawon

Physiology Faculty Publications

Abdominal aortic aneurysms (AAA) are characterized by extensive extracellular matrix (ECM) fragmentation and inflammation. However, the mechanisms by which these events are coupled thereby fueling focal vascular damage are undefined. Here we report through single-cell RNA-sequencing of diseased aorta that the neuronal guidance cue netrin-1 can act at the interface of macrophage-driven injury and ECM degradation. Netrin-1 expression peaks in human and murine aneurysmal macrophages. Targeted deletion of netrin-1 in macrophages protects mice from developing AAA. Through its receptor neogenin-1, netrin-1 induces a robust intracellular calcium flux necessary for the transcriptional regulation and persistent catalytic activation of matrix metalloproteinase-3 (MMP3) …

Hyperhomocysteinemia As A Risk Factor For Vascular Contributions To Cognitive Impairment And Dementia, Brittani R. Price, Donna M. Wilcock, Erica M. Weekman

Physiology Faculty Publications

Behind only Alzheimer’s disease, vascular contributions to cognitive impairment and dementia (VCID) is the second most common cause of dementia, affecting roughly 10–40% of dementia patients. While there is no cure for VCID, several risk factors for VCID, such as diabetes, hypertension, and stroke, have been identified. Elevated plasma levels of homocysteine, termed hyperhomocysteinemia (HHcy), are a major, yet underrecognized, risk factor for VCID. B vitamin deficiency, which is the most common cause of HHcy, is common in the elderly. With B vitamin supplementation being a relatively safe and inexpensive therapeutic, the treatment of HHcy-induced VCID would seem straightforward; however, …

Myocardial Ischemia Reperfusion Injury: Apoptotic, Inflammatory And Oxidative Stress Role Of Galectin-3, Suhail Al-Salam, Satwat Hashmi

Department of Biological & Biomedical Sciences

Background/aims: Myocardial reperfusion has the potential to salvage the ischemic myocardium after a period of coronary occlusion. Reperfusion, however, can cause a wide spectrum of deleterious effects. Galectin-3 (GAL-3), a beta galactoside binding lectin, is closely associated with myocardial infarction (MI), myocardial fibrosis and heart failure. In our study, we investigated its role in ischemia-reperfusion injuries (IR) as this phenomenon is extremely relevant to the early intervention after acute MI.
Methods: C57B6/J wild type (WT) mice and GAL-3 knockout (KO) mice were used for murine model of IR injury in the heart where a period of 30 minutes ischemia was …

Postpartum Depression: Prevention And Multimodal Therapy, Anca Daniela Stanescu, Denisa Oana Balalau, Liana Ples, Stana Paunica, Cristian Balalau

Journal of Mind and Medical Sciences

A woman goes through many biological (hormonal, physical), psychological (emotional), and socio-cultural changes during pregnancy. Furthermore, changes also occur in the mother's familial and interpersonal world after childbirth. While some mothers have positive emotions at birth, such as joy and pleasure, others complain of negative experiences varying from sadness and depression to psychosis. Thus, the risk of depression is higher for women during the postpartum period, having a tendency to decrease in most cases over the first 2 weeks after delivery. Unfortunately, this favorable evolution does not happen in about 1 in 4-7 women, who develops postpartum depression. Postpartum depression …

Association Between Bone-Specific Physical Activity Scores And Pqct-Derived Measures Of Bone Strength And Geometry In Healthy Young And Middle-Aged Premenopausal Women., Sojung Kim, Breanne S Baker, Pragya Sharma-Ghimire, Debra A Bemben, Michael G Bemben

College of Science & Mathematics Departmental Research

The aim of this study was to determine if bone-specific physical activity questionnaire (BPAQ) scores were positively related to bone health in healthy young and middle-aged premenopausal women. The total BPAQ was a stronger predictor of bone strength and bone mineral density of hip in young women as compared to middle-aged premenopausal women.

PURPOSE: The purpose of this study was to determine whether the BPAQ scores were predictive indices of volumetric BMD (vBMD), bone strength, and bone geometry in young and middle-aged premenopausal women.

METHODS: Healthy young (n = 60) and middle-aged premenopausal women (n = 54) between the ages …

Returners Exhibit Greater Jumping Performance Improvements During A Peaking Phase Compared With New Players On A Volleyball Team, Caleb D. Bazyler, Satoshi Mizuguchi, Ashley A. Kavanaugh, John J. Mcmahon, Paul Comfort, Michael H. Stone

ETSU Faculty Works

Purpose: To determine if jumping-performance changes during a peaking phase differed among returners and new players on a female collegiate volleyball team and to determine which variables best explained the variation in performance changes.

Methods: Fourteen volleyball players were divided into 2 groups—returners (n = 7) and new players (n = 7)—who completed a 5-wk peaking phase prior to conference championships. Players were tested at baseline before the preseason on measures of the vastus lateralis cross-sectional area using ultrasonography, estimated back-squat 1-repetition maximum, countermovement jump height (JH), and relative peak power on a force platform. Jumping performance, rating of perceived …

The Effect Of Cellular Dehydration On Glucose Regulation In Lean And Obese Females, Chunbo Yang

Graduate Theses and Dissertations

A chronically elevated vasopressin level has been associated with an impaired glucose regulation system in humans. A recent study in patients with diabetes suggested that low water intake is associated with impaired glucose regulation. The aim of this study was to examine the effect of hypertonic saline infusion on glucose regulation in healthy females. Thirty healthy, non-diabetic females performed a 2-h infusion followed by a 4-h oral glucose tolerance test (OGTT). Every subject participated in two trials separated by one month, in a counterbalanced order. Two trials were identical in the procedure, differing in the concentration of saline infusion, with …

Out Of The Shell: Exploring The Phagocytic Capabilities Of The B Cell And Isolated Lymphoid Follicle-Lie Structures In The Red-Eared Slider, Trachemys Scripta, Marc A. Ashford Jr.

Theses and Dissertations

Management of immunity is crucial for survival in all living organisms. While there is a large amount of research for established model organisms, such as the mouse model, much less is known about reptiles. When compared to immunity in mammals, we discover many differences such as susceptibility to certain pathogens, alteration of immune processes due to environmental temperature, the total absence of certain lymphoid organs contained in mammals, among many others. Despite this, the reptile has shown in many studies that they are worthy systems to study immunity in an evolutionary perspective and recent studies may show that they may …

Markers Of Cardiometabolic Risk And Thyroid Dysfunction In U.S. Adolescents: Nhanes Iii, Jonathan Austin

Theses and Dissertations

The global prevalence of metabolic syndrome (MetS) and its associated components (high fasting glucose, waist circumference, blood pressure, triglycerides, and low HDL) have increased over the past few decades. In addition, abnormal thyroid hormone levels have been found to manifest in a cascade of metabolic dysfunction, which may be linked to MetS in youth. PURPOSE: The purpose of the study is to investigate the association between MetS, its components, and markers of thyroid function in a nationally-representative sample of adolescents. METHODS: The National Health and Nutrition Examination Survey III (1988-1994) collected data on the components of metabolic syndrome and thyroid …

The Relationship Between The Metabolic Responsiveness To A High-Fat Meal And An Acute Bout Of Moderateintensity Exercise Among Postpartum Women, Apoorva Tadakaluru

Masters Theses & Specialist Projects

Background: There has been very little research regarding the metabolic health of women during the postpartum period. Metabolic flexibility is the physiological ability to alter substrate oxidation in response to substrate availability and is a good indicator of overall metabolic health. Metabolic flexibility can be assessed by placing metabolic demands on the body and observing metabolic responsiveness- two examples of such metabolic stressors are lipid oxidation rates in response to a high-fat meal and as well as exercise. However, it is unknown whether postpartum women will respond similarly to these two different types of metabolic stressors. This information will allow …

Apolipoprotein-Defined Lipoprotein Subclasses, Serum Apolipoproteins, And Carotid Intima-Media Thickness In T1d, Arpita Basu, Alicia J. Jenkins, Julie A. Stoner, Ying Zhang, Richrd L. Klein

Kinesiology and Nutrition Sciences Faculty Research

Circulating apolipoprotein-defined lipoprotein subclasses (ADLS) and apolipoproteins predict vascular events in the general and type 2 diabetes populations, but data in T1D are limited. We examined associations of ADLS, serum apolipoproteins, and conventional lipids with carotid intima-media thickness (IMT) measured contemporaneously and 6 years later in 417 T1D participants [men: n = 269, age 42 +/- 6 y (mean +/- SD); women: n = 148, age 39 +/- 8 y] in the Epidemiology of Diabetes Interventions and Complications study, the follow-up of the Diabetes Control and Complications Trial (DCCT). Date were analyzed by multiple linear regression stratified by sex, and …

Rad Gtpase Deletion Atenuates Post-Ischemic Cardiac Dysfunction And Remodeling, Janet R. Manning, Lakshman Chelvarajan, Bryana R. Levitan, Catherine Nicole Kaminski Withers, Prabhakara R. Nagareddy, Christopher M. Haggerty, Brandon K. Fornwalt, Erhe Gao, Himi Tripathi, Ahmed Abdel-Latif, Douglas A. Andres, Jonathan Satin

Physiology Faculty Publications

The protein Rad interacts with the L-type calcium channel complex to modulate trigger Ca²⁺ and hence to govern contractility. Reducing Rad levels increases cardiac output. Ablation of Rad also attenuated the inflammatory response following acute myocardial infarction. Future studies to target deletion of Rad in the heart could be conducted to establish a novel treatment paradigm whereby pathologically stressed hearts would be given safe, stable positive inotropic support without arrhythmias and without pathological structural remodeling. Future investigations will also focus on establishing inhibitors of Rad and testing the efficacy of Rad deletion in cardioprotection relative to the time of …

Resting Hormone Alterations And Injuries: Block Vs. Dup Weight-Training Among D-1 Track And Field Athletes, Keith B. Painter, G. Gregory Haff, N. Travis Triplett, Charles Stuart, Guy Hornsby, Mike W. Ramsey, Caleb D. Bazyler, Michael H. Stone

ETSU Faculty Works

Daily undulating periodization (DUP), using daily alterations in repetitions, has been advocated as a superior method of resistance training, while traditional forms of programming for periodization (Block) have been questioned. Nineteen Division I track and field athletes were assigned to either a 10-week Block or DUP training group. Year and event were controlled. Over the course of the study, there were four testing sessions, which were used to evaluate a variety of strength characteristics, including maximum isometric strength, rate of force development, and one repetition maximum (1RM). Although, performance trends favored the Block group for strength and rate of force …

Reduction Of Endothelial Nitric Oxide Increases The Adhesiveness Of Constitutive Endothelial Membrane Icam-1 Through Src-Mediated Phosphorylation, Feng Gao, Brandon P. Lucke-Wold, Xiang Li, Aric F. Logsdon, Li-Chong Xu, Sulei Xu, Kyle B. Lapenna, Huaqi Wang, M.A. Hassan Talukder, Christopher A. Siedlecki, Jason D. Huber, Charles L. Rosen, Pingnian He

Faculty & Staff Scholarship

Nitric oxide (NO) is a known anti-adhesive molecule that prevents platelet aggregation and leukocyte adhesion to endothelial cells (ECs). The mechanism has been attributed to its role in the regulation of adhesion molecules on leukocytes and the adhesive properties of platelets. Our previous study conducted in rat venules found that reduction of EC basal NO synthesis caused EC ICAM-1-mediated firm adhesion of leukocytes within 10–30min. This quick response occurred in the absence of alterations of adhesion molecules on leukocytes and also opposes the classical pattern of ICAM-1-mediated leukocyte adhesion that requires protein synthesis and occurs hours after stimulation. The objective …

Absolute Lymphocyte And Neutrophil Counts In Neonatal Ischemic Brain Injury, Jessica M. Povroznik, Elizabeth B. Engler-Chiurazzi, Tania Nanavati, Paola Pergami

Faculty & Staff Scholarship

Objectives: This study aimed to identify differences in absolute neutrophils, lymphocytes, and neutrophil-to-lymphocyte ratio between neonates with two forms of ischemic brain injury, hypoxic-ischemic encephalopathy, and acute ischemic stroke, compared to controls. We also aimed to determine whether this neutrophil/lymphocyte response pattern is associated with disease severity or is a consequence of the effects of total-body cooling, an approved treatment for moderate-to-severe hypoxic-ischemic encephalopathy. Methods: A retrospective chart review of 101 neonates with hypoxic-ischemic encephalopathy + total-body cooling (n = 26), hypoxic-ischemic encephalopathy (n=12), acute ischemic stroke (n=15), and transient tachypnea of the newborn (n=48) was conducted; transient tachypnea of …

Spontaneous Dna Damage To The Nuclear Genome Promotes Senescence, T Redox Imbalance And Aging, Andria R. Robinson, Matthew J. Yousefzadeh, Tania A. Rozgaja, Jin Wang, Xuesen Li, Jeremy S. Tilstra, Chelsea H. Feldman, Siobhan Q. Gregg, Caroline H. Johnson, Erin M. Skoda, Marie-Celine Frantz, Harris Bell-Temin, Hannah Pope-Varsalona, Aditi U. Gurkar, Luigi A. Nasto, Rena A.S. Robinson, Heike Fuhrmann-Stroissnigg, Jolanta Czerwinska, Sara J. Mcgowan, Nadiezhda Cantu-Madellin, Jamie B. Harris, Salony Maniar, Mark A. Ross, Christy E. Trussoni, Nicholas F. Larusso, Eugenia Cifuentes-Pagano, Patrick J. Pagano, Barbara Tudek, Nam V. Vo, Lora H. Rigatti, Patricia L. Opresko, Donna B. Stolz, Simon C. Watkins, Christin E. Burd, Claudette M. St, Croix, Gary Siuzdak, Nathan A. Yates, Paul D. Robbins, Yinsheng Wang, Peter Wipf, Eric E. Kelley, Laura J. Neidernhofer

Faculty & Staff Scholarship

Accumulation of senescent cells over time contributes to aging and age-related diseases. However, what drives senescence in vivo is not clear. Here we used a genetic approach to determine if spontaneous nuclear DNA damage is sufficient to initiate senescence in mammals. Ercc1-/Δ mice with reduced expression of ERCC1-XPF endonuclease have impaired capacity to repair the nuclear genome. Ercc1-/Δ mice accumulated spontaneous, oxidative DNA damage more rapidly than wild-type (WT) mice. As a consequence, senescent cells accumulated more rapidly in Ercc1-/Δ mice compared to repair-competent animals. However, the levels of DNA damage and senescent cells in Ercc1-/Δ mice never exceeded that …

Patient-Specific Quantification Of The Relationship Between The Left Atrium Pressure And The Ostial Diameter Of The Left Atrial Appendage, Sky Tianqi Gao

Electronic Theses and Dissertations

The left atrial appendage has been a historically understudied region of the heart until fairly recently with the new understanding of its role in the stroke pathway of patients with atrial fibrillation. The goal of this study is to take a look at the biomechanical behavior of the left atrium and left atrial appendage under normal physiological loading conditions using material properties taken from biaxial stretch tests. Several different options for material properties models were tested and biaxial stretch test data of cadaveric human tissue samples for the left atrium and appendage were fit to a Fung-type strain-energy function for …