Circulatory and Respiratory Physiology Commons^™

Tobramycin-Treated Pseudomonas Aeruginosa Pa14 Enhances Streptococcus Constellatus 7155 Biofilm Formation In A Cystic Fibrosis Model System, Katherine E. E. Price, Amanda A. Naimie, Edward F. Griffin, Charles Bay, George A. O'Toole

Dartmouth Scholarship

Cystic fibrosis (CF) is a human genetic disorder which results in a lung environment that is highly conducive to chronic microbial infection. Over the past decade, deep-sequencing studies have demonstrated that the CF lung can harbor a highly diverse polymicrobial community. We expanded our existing in vitro model of Pseudomonas aeruginosa biofilm formation on CF-derived airway cells to include this broader set of CF airway colonizers to investigate their contributions to CF lung disease, particularly as they relate to the antibiotic response of the population. Using this system, we identified an interspecies interaction between P. aeruginosa, a bacterium associated with …

Effects Of Adipocyte Aryl Hydrocarbon Receptor Deficiency On Pcb-Induced Disruption Of Glucose Homeostasis In Lean And Obese Mice, Nicki A. Baker, Robin Shoemaker, Victoria English, Nika Larian, Manjula Sunkara, Andrew J. Morris, Mary Walker, Frederique Yiannikouris, Lisa A. Cassis

Saha Cardiovascular Research Center Faculty Publications

BACKGROUND: Coplanar polychlorinated biphenyls (PCBs) promote adipocyte inflammation and impair glucose homeostasis in lean mice. The diabetes-promoting effects of lipophilic PCBs have been observed only during weight loss in obese mice. The molecular mechanisms linking PCB exposures to impaired glucose metabolism are unclear.

OBJECTIVES: In this study we tested the hypothesis that coplanar PCBs act at adipocyte aryl hydrocarbon receptors (AhRs) to promote adipose inflammation and impair glucose homeostasis in lean mice and in obese mice during weight loss.

METHODS AND RESULTS: PCB-77 administration impaired glucose and insulin tolerance in LF (low fat diet)-fed control (AhR^fl/fl) mice …

Lipin1 Regulates Skeletal Muscle Differentiation Through Extracellular Signal-Regulated Kinase (Erk) Activation And Cyclin D Complex-Regulated Cell Cycle Withdrawal, Weihua Jiang, Jing Zhu, Xun Zhuang, Xiping Zhang, Tao Luo, Karyn Esser, Hongmei Ren

Saha Cardiovascular Research Center Faculty Publications

Lipin1, an intracellular protein, plays critical roles in controlling lipid synthesis and energy metabolism through its enzymatic activity and nuclear transcriptional functions. Several mouse models of skeletal muscle wasting are associated with lipin1 mutation or altered expression. Recent human studies have suggested that children with homozygous null mutations in the LPIN1 gene suffer from rhabdomyolysis. However, the underlying pathophysiologic mechanism is still poorly understood. In the present study we examined whether lipin1 contributes to regulating muscle regeneration. We characterized the time course of skeletal muscle regeneration in lipin1-deficient fld mice after injury. We found that fld mice exhibited smaller regenerated …

Left Ventricular Mechanical Dysfunction In Diet-Induced Obese Mice Is Exacerbated During Inotropic Stress: A Cine Dense Cardiovascular Magnetic Resonance Study, Christopher M. Haggerty, Andrea C. Mattingly, Sage P. Kramer, Cassi M. Binkley, Linyuan Jing, Jonathan D. Suever, David K. Powell, Richard J. Charnigo, Frederick H. Epstein, Brandon K. Fornwalt

Saha Cardiovascular Research Center Faculty Publications

BACKGROUND: Obesity is a risk factor for cardiovascular disease. There is evidence of impaired left ventricular (LV) function associated with obesity, which may relate to cardiovascular mortality, but some studies have reported no dysfunction. Ventricular function data are generally acquired under resting conditions, which could mask subtle differences and potentially contribute to these contradictory findings. Furthermore, abnormal ventricular mechanics (strains, strain rates, and torsion) may manifest prior to global changes in cardiac function (i.e., ejection fraction) and may therefore represent more sensitive markers of cardiovascular disease. This study evaluated LV mechanics under both resting and stress conditions with the hypothesis …

Vascular Medicine: A ‘Primary’ Specialty, Mark W. Mewissen

Journal of Patient-Centered Research and Reviews

N/A

Ankyrin-B And Mtor Complex 1 In The Regulation Of Electrical Activities In The Heart, Henry C. Wu, Henry C. Wu

Dissertations and Theses (Open Access)

The mammalian target of rapamycin complex 1 (mTORC1) activity is paramount in the regulation of electrical activities in the brain and the heart. In the brain, the tumor suppressor gene TSC2 encodes the protein product tuberin that interacts with hamartin to form a heterodimer Tuberous Sclerosis Complex (TSC) that regulates mTORC1. When TSC2 is disrupted, mTORC1 activity becomes dysregulated resulting in abnormal electrical activities in the brain manifesting in the form of epileptic seizures. In the heart, mTORC1 activity is triggered by a sustained increase in hemodynamic pressure causing the heart to electrically remodel. A likely candidate serving as the …

Exogenous 17-Β Estradiol Administration Blunts Progression Of Established Angiotensin Ii-Induced Abdominal Aortic Aneurysms In Female Ovariectomized Mice, Sean E. Thatcher, Xuan Zhang, Shannon Woody, Yu Wang, Yasir Alsiraj, Richard Charnigo, Alan Daugherty, Lisa A. Cassis

Saha Cardiovascular Research Center Faculty Publications

BACKGROUND: Abdominal aortic aneurysms (AAAs) occur predominately in males. However, AAAs in females have rapid growth rates and rupture at smaller sizes. Mechanisms contributing to AAA progression in females are undefined. We defined effects of ovariectomy, with and without 17-β estradiol (E2), on progression of established angiotensin II (AngII)-induced AAAs in female mice.

METHODS: We used neonatal testosterone exposures at 1 day of age to promote susceptibility to AngII-induced AAAs in adult female Ldlr^-/- mice. Females were infused with AngII for 28 days to induce AAAs, and then stratified into groups that were sham, ovariectomized (Ovx, vehicle), or Ovx …

Telemetric Blood Pressure Assessment In Angiotensin Ii-Infused Apoe-/- Mice: 28 Day Natural History And Comparison To Tail-Cuff Measurements, Christopher M. Haggerty, Andrea C. Mattingly, Ming C. Gong, Wen Su, Alan Daugherty, Brandon K. Fornwalt

Saha Cardiovascular Research Center Faculty Publications

Abdominal aortic aneurysm (AAA) is a disease of the aortic wall, which can progress to catastrophic rupture. Assessment of mechanical characteristics of AAA, such as aortic distensibility, may provide important insights to help identify at-risk patients and understand disease progression. While the majority of studies on this topic have focused on retrospective patient data, recent studies have used mouse models of AAA to prospectively evaluate the evolution of aortic mechanics. Quantification of aortic distensibility requires accurate measurement of arterial blood pressure, particularly pulse pressure, which is challenging to perform accurately in murine models. We hypothesized that volume/pressure tail-cuff measurements of …

Role Of Ataxia Telangiectasia Mutated Kinase In The Healing Process Of The Heart Following Myocardial Infarction, Laura L. Daniel

Electronic Theses and Dissertations

Ataxia telangiectasia (AT), caused by mutations in the gene encoding ataxia telangiectasia mutated kinase (ATM), is a rare autosomal recessive disorder. AT individuals exhibit neuronal degeneration and are predisposed to cancer. Carriers of this disorder are predisposed to cancer and ischemic heart disease. Heart disease, mostly due to myocardial infarction (MI), is a leading cause of death in the US. Following MI, release of catecholamines in the heart stimulates β- adrenergic receptors (β-AR). Our lab has shown that β-AR stimulation increases ATM expression in the heart and myocytes, and ATM plays an important role in β-AR-stimulated myocardial remodeling with effects …

Validation Of In Vivo 2d Displacements From Spiral Cine Dense At 3t, Gregory J. Wehner, Jonathan D. Suever, Christopher M. Haggerty, Linyuan Jing, David K. Powell, Sean M. Hamlet, Jonathan D. Grabau, Walter Dimitri Mojsejenko, Xiaodong Zhong, Frederick H. Epstein, Brandon K. Fornwalt

Saha Cardiovascular Research Center Faculty Publications

BACKGROUND: Displacement Encoding with Stimulated Echoes (DENSE) encodes displacement into the phase of the magnetic resonance signal. Due to the stimulated echo, the signal is inherently low and fades through the cardiac cycle. To compensate, a spiral acquisition has been used at 1.5T. This spiral sequence has not been validated at 3T, where the increased signal would be valuable, but field inhomogeneities may result in measurement errors. We hypothesized that spiral cine DENSE is valid at 3T and tested this hypothesis by measuring displacement errors at both 1.5T and 3T in vivo.

METHODS: Two-dimensional spiral cine DENSE and tagged …

The Tmao-Generating Enzyme Flavin Monooxygenase 3 Is A Central Regulator Of Cholesterol Balance, Manya Warrier, Diana M. Shih, Amy C. Burrows, Daniel Ferguson, Anthony D. Gromovsky, Amanda L. Brown, Stephanie Marshall, Allison Mcdaniel, Rebecca C. Schugar, Zeneng Wang, Jessica Sacks, Xin Rong, Thomas De Aguiar Vallim, Jeff Chou, Pavlina T. Ivanova, David S. Myers, H. Alex Brown, Richard G. Lee, Rosanne M. Crooke, Mark J. Graham, Xiuli Liu, Paolo Parini, Peter Tontonoz, Aldon J. Lusis, Stanley L. Hazen, Ryan E. Temel, J. Mark Brown

Saha Cardiovascular Research Center Faculty Publications

Circulating levels of the gut microbe-derived metabolite trimethylamine-N-oxide (TMAO) have recently been linked to cardiovascular disease (CVD) risk. Here, we performed transcriptional profiling in mouse models of altered reverse cholesterol transport (RCT) and serendipitously identified the TMAO-generating enzyme flavin monooxygenase 3 (FMO3) as a powerful modifier of cholesterol metabolism and RCT. Knockdown of FMO3 in cholesterol-fed mice alters biliary lipid secretion, blunts intestinal cholesterol absorption, and limits the production of hepatic oxysterols and cholesteryl esters. Furthermore, FMO3 knockdown stimulates basal and liver X receptor (LXR)-stimulated macrophage RCT, thereby improving cholesterol balance. Conversely, FMO3 knockdown exacerbates hepatic endoplasmic reticulum (ER) stress …

Inverse Relationship Between Physical Activity, Adiposity And Arterial Stiffness In Healthy Middle-Aged Subjects, Oscar Mac Ananey, B Mc Loughlin, A Leonard, L Maher, P Gaffney, G Boran, V Maher

Articles

BACKGROUND:

Several obesity related factors are reported to exacerbate premature arterial stiffening, including inactivity and metabolic disarray. The aim of the present study was to investigate the relationship between physical activity, arterial stiffness and adiposity using objective methods. To further explore the role of adiposity in this complex process, obesity associated anthropometric and humoral biomarkers were measured.

METHODS:

Seventy-nine healthy, lifelong non-smoking, subjects were recruited. Habitual physical activity was measured using accelerometry. Arterial stiffness (augmentation index; AIx & pulse wave velocity; PWV), was measured using tonometry. Body composition was estimated using bioimpedence. Adipose associated biomarkers, leptin and adiponectin, were also …

Dysregulation Of Micrornas In Blood As Biomarkers For Diagnosing Prostate Cancer, Rhonda W. Daniel

Theses and Dissertations

Prostate cancer is the most common noncutaneous cancer among men, yet current diagnostic methods are insufficient and more reliable diagnostic markers need to be developed. The answer that can bridge this gap and enable more efficient diagnoses may lie in microRNAs. These small, single stranded RNA molecules impact protein expression at the translational level and regulate important cellular pathways. Dysregulation of these small RNA molecules can have tumorigenic effects on cells and lead to many types of cancers.

Currently the Prostate-Stimulating Antigen (PSA) is used as a diagnostic marker for prostate cancer. However, many factors can elevate PSA levels such …

Inhibition Of Mtor Signaling Protects Against Myocardial Reperfusion Injury, Acute Myocardial Infarction, Scott M. Filippone

Theses and Dissertations

Acute myocardial infarction (AMI) is the leading cause of death worldwide. Currently, the best method of treating cardiac ischemia is early reperfusion which, itself, induces myocardial damage. The mTOR complex is a key regulator of cardioprotection against cell stressors. We hypothesized that reperfusion therapy with Rapamycin, a potent mTOR inhibitor, would reduce infarct size in adult mouse hearts. Rapamycin was administered at the onset of reperfusion following 30 min in situ LAD ligation. After 24 hours of reperfusion, myocardial infarct size and apoptosis were significantly reduced in rapamycin-treated mice compared to control. Rapamycin inhibited pro-apoptotic protein Bax and phosphorylation of …

One Year Review Of High Flow Oxygen Delivery System Outcomes, Susan Carvin Rrt-Accs, Kenneth Miller Med, Rrt-Nps, Diane Horoski, Robert Leshko Bs,Rrt, Rita Pechulis Md, Fccp

Patient Care Services / Nursing

No abstract provided.

Analysis Of Drug Interactions With Lipoproteins By High Performance Affinity Chromatography, Matthew R. Sobansky

Department of Chemistry: Dissertations, Theses, and Student Research

High density lipoprotein (HDL), low density lipoprotein (LDL), and very low density lipoprotein (VLDL) are lipoproteins previously shown to bind many basic and neutral hydrophobic drugs in serum. These interactions impact the distribution, delivery, metabolism, and excretion of drugs and are important in determining drug activity, pharmacokinetics, and toxicity in the human body. Information about drug-lipoprotein interactions and the strength of these interactions can be useful in determining the distribution of drugs following administration.

The research presented in this dissertation uses high performance affinity chromatography (HPAC) and packed columns to study binding of the drug propranolol to immobilized lipoproteins such …

Simplified Post Processing Of Cine Dense Cardiovascular Magnetic Resonance For Quantification Of Cardiac Mechanics, Jonathan D. Suever, Gregory J. Wehner, Christopher M. Haggerty, Linyuan Jing, Sean M. Hamlet, Cassi M. Binkley, Sage P. Kramer, Andrea C. Mattingly, David K. Powell, Kenneth C. Bilchick, Frederick H. Epstein, Brandon K. Fornwalt

Saha Cardiovascular Research Center Faculty Publications

BACKGROUND: Cardiovascular magnetic resonance using displacement encoding with stimulated echoes (DENSE) is capable of assessing advanced measures of cardiac mechanics such as strain and torsion. A potential hurdle to widespread clinical adoption of DENSE is the time required to manually segment the myocardium during post-processing of the images. To overcome this hurdle, we proposed a radical approach in which only three contours per image slice are required for post-processing (instead of the typical 30-40 contours per image slice). We hypothesized that peak left ventricular circumferential, longitudinal and radial strains and torsion could be accurately quantified using this simplified analysis.

METHODS …

Implementation And Validation Of Aortic Remodeling In Hypertensive Rats, Shijia Zhao, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

A computational framework was implemented and validated to better understand the hypertensive artery remodeling in both geometric dimensions and material properties. Integrating the stress-modulated remodeling equations into commercial finite element codes allows a better control and visualization of local mechanical parameters. Both arterial thickening and stiffening effects were captured and visualized. An adaptive material remodeling strategy combined with the element birth and death techniques for the geometrical growth were implemented. The numerically predicted remodeling results in terms of the wall thickness, inner diameter, and the ratio of elastin to collagen content of the artery were compared with and fine-tuned by …

Acute Sterol O-Acyltransferase 2 (Soat2) Knockdown Rapidly Mobilizes Hepatic Cholesterol For Fecal Excretion, Stephanie M. Marshall, Anthony D Gromovsky, Kathryn L. Kelley, Matthew A. Davis, Martha D. Wilson, Richard G. Lee, Rosanne M. Crooke, Mark J. Graham, Lawrence L. Rudel, J. Mark Brown, Ryan E. Temel

Saha Cardiovascular Research Center Faculty Publications

The primary risk factor for atherosclerotic cardiovascular disease is LDL cholesterol, which can be reduced by increasing cholesterol excretion from the body. Fecal cholesterol excretion can be driven by a hepatobiliary as well as a non-biliary pathway known as transintestinal cholesterol efflux (TICE). We previously showed that chronic knockdown of the hepatic cholesterol esterifying enzyme sterol O-acyltransferase 2 (SOAT2) increased fecal cholesterol loss via TICE. To elucidate the initial events that stimulate TICE, C57Bl/6 mice were fed a high cholesterol diet to induce hepatic cholesterol accumulation and were then treated for 1 or 2 weeks with an antisense oligonucleotide targeting …

Assessing The Relationship Between The Blood-Air Partition Coefficient And Fractional Uptake Of Inspired Halothane, Acetone, And Ethanol Vapors In The Airways Of The C57bl/6j Mouse, Joshua Baruch Baldino

Honors Scholar Theses

The following series of studies investigates the elimination and uptake trends of halothane, acetone, and ethanol vapors in the airways of C57BL/6J mice. These vapors were chosen because they span a wide range of solubilities, as indicated by their blood-air partition coefficients, and are not associated with any significant airway metabolism or reactivity with tissue substrates in vivo. Mice were exposed to a homogeneous vapor mixture containing a 1:1:1 ratio of halothane, acetone, and ethanol at relative concentrations of approximately 10 ppm. Exposure studies were performed with mice in two states, conscious and deceased, in order to provide control …