Systems and Integrative Physiology Commons^™

The Role Of E-Liquid Constituents In E-Cigarette-Induced Cardiac Arrhythmia And Autonomic Imbalance., Cory Kucera

Electronic Theses and Dissertations

Introduction. Accumulating evidence indicates that exposure to electronic cigarettes (e-cigs) promotes sympathetic dominance and electrophysiologic instability in the heart, potentially culminating in arrhythmogenesis. E-liquids contain various formulations of nicotine and flavorings, but the effects of specific e-liquid constituents and their concentrations on e-cig-induced autonomic imbalance and electrical dysfunction are unresolved. To that end, we tested the hypothesis that e-cigs modify cardiac autonomic balance and ventricular arrhythmogenesis in mice dependent on e-liquid constituent type and concentration. Methods. Using a crossover design and a serial exposure regimen, ECG-telemetered male C57BL/6J mice underwent whole-body exposure to e-cig aerosols generated from e-liquids containing different …

Effects Of Intertidal Position On The Response To Oxygen And Desiccation Stress In The Common Acorn Barnacle, Balanus Glandula, Megan M. Dotterweich

Master's Theses

Sessile invertebrates in the rocky intertidal experience intermittent periods of air exposure due to tidal flux, presenting risks of temperature extremes, hypoxia, nutrient limitation, and most dangerously, desiccation. Microscale variation in severity and frequency of these risks is widely dependent on vertical position within the intertidal zone. Common acorn barnacles (Balanus glandula) have a wide vertical distribution in the intertidal, creating large differences in microhabitat between the highest and lowest individuals in the population. This study set out to explore whether tidal position dependent differences exist in the response to oxygen and desiccation stress in B. glandula. …

Multichannel Modulation Of Depolarizing And Repolarizing Ion Currents Increases The Positive Rate-Dependent Action Potential Prolongation, Candido Cabo

Publications and Research

Prolongation of the action potential duration (APD) could prevent reentrant arrhythmias if prolongation occurs at the fast excitation rates of tachycardia with minimal prolongation at slow excitation rates (i.e., if prolongation is positive rate-dependent). APD prolongation by current anti-arrhythmic agents is either reverse (larger APD prolongation at slow rates than at fast rates) or neutral (similar APD prolongation at slow and fast rates), which may not result in an effective anti-arrhythmic action. In this report we show that, in computer models of the human ventricular action potential, the combined modulation of both depolarizing and repolarizing ion currents results in a …

A Proof Of Concept For Detection Of Palato-Lingual Contact Without Intraoral Electrodes In A Human Participant, Amitava Biswas

Master's Theses

The author of this thesis conceived and investigated an unexpected electrical signal that may not be noticed during regular electroglottography (EGG) when electrodes are conventionally placed on the anterior surface of the throat. It appears that there is a measurable electrical signal from the EGG equipment when electrodes are placed over the frontal cheek (belly of zygomatic muscle), and the tongue is elevated to contact the hard palate, or the tongue is lowered to break the contact. Therefore, this phenomenon is designated as unconventional electroglottography (UEGG, Dr. Steven Cloud, private communication, July 17, 2022).

Two distinctive patterns of waveforms were …

Review Of Biomedical Applications Of Cardiovascular Tissue Engineering, Natalie M. Howard

Honors College Theses

Tissue engineering can be defined as processes that aim to generate three-dimensional functional tissues in vitrothat have been favorably altered according to the structural, biochemical, electrophysiological, and biomechanical properties of the desired tissue before implantation into the human body. In relation to cardiac tissues, these properties would include the ability to conduct action potentials, withstand systolic pressure, permit sufficient O₂ and CO₂penetration, sufficient vascularization to supply nutrients for cellular activity, surface topology that enables cellular communication, and more. As heart diseases and instances of myocardial infarction continue to rise worldwide, there is an increasing need for …

Effects Of Equine Interaction On Mutual Autonomic Nervous System Responses And Interoception In A Learning Program For Older Adults, Ann L. Baldwin, Lisa Walters, Barbara K. Rector, Ann C. Alden

People and Animals: The International Journal of Research and Practice

Equine-assisted learning (EAL) may improve the health of older adults, but scientific data are sparse. This study investigated whether people aged 55 and older show increased heart rate variability (HRV) during EAL and awareness of bodily sensations that are overall pleasant. Subjects (n = 24) participated in mindful grooming during which they slowed their breathing and brushed a horse while noticing sensations in their body and watching the horse’s reactions. The subject’s and horse’s HRV were recorded simultaneously before, during, and after mindful grooming. For control, the same subjects performed mindful grooming with a plush simulation horse. During exit …

Endothelial Cell Nrf2-Ko Attenuates Endothelial Function And Skeletal Muscle Antioxidant Capacity, Elizabeth J. Pekas, Cody P. Anderson, Michael F. Allen, Kollyn B. Jallen, Dong Gun Jin, Andres Benitez-Albiter, Christian D. Sanchez Tato, Lie Gao, Neha Dhyani, Tara L. Rudebush, Irving H. Zucker, Song-Young Park

UNO Student Research and Creative Activity Fair

INTRODUCTION: Endothelial cells line the inner surface of blood vessels and play a major role in modulating blood flow and gas exchange. Endothelial dysfunction is thought to be a contributor to cardiovascular disease development, and it is well-accepted that excessive reactive oxygen species (harmful molecules) likely contribute to endothelial dysfunction. The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) is considered the master regulator of cellular protection in response to elevated reactive oxygen species. Therefore, Nrf2 may be a potential therapeutic target to protect against endothelial dysfunction. However, the roles of endothelial cell-specific Nrf2 on endothelial function are not …

Repeated Social Defeat Stress Leads To Immunometabolic Shifts In Innate Immune Cells Of The Spleen, Mandakh Bekhbat, John Drake, Emily C. Reed, Tatlock H. Lauten, Tamara Natour, Vladimir I. Vladimirov, Adam J. Case

Journal Articles: Cellular & Integrative Physiology

Psychosocial stress has been shown to prime peripheral innate immune cells, which take on hyper-inflammatory phenotypes and are implicated in depressive-like behavior in mouse models. However, the impact of stress on cellular metabolic states that are thought to fuel inflammatory phenotypes in immune cells are unknown. Using single cell RNA-sequencing, we investigated mRNA enrichment of immunometabolic pathways in innate immune cells of the spleen in mice subjected to repeated social defeat stress (RSDS) or no stress (NS). RSDS mice displayed a significant increase in the number of splenic macrophages and granulocytes (p < 0.05) compared to NS littermates. RSDS-upregulated genes in macrophages, monocytes, and granulocytes significantly enriched immunometabolic pathways thought to play a role in myeloid-driven inflammation (glycolysis, HIF-1 signaling, MTORC1 signaling) as well as pathways related to oxidative phosphorylation (OXPHOS) and oxidative stress (p < 0.05 and FDR<0.1). These results suggest that the metabolic enhancement reflected by upregulation of glycolytic and OXPHOS pathways may be important for cellular proliferation of splenic macrophages and granulocytes following repeated stress exposure. A better understanding of these intracellular metabolic mechanisms may ultimately help develop novel strategies to reverse the impact of stress and associated peripheral immune changes on the brain and behavior.

Defining The Nuanced Nature Of Redox Biology In Post-Traumatic Stress Disorder, Emily C. Reed, Adam J. Case

Journal Articles: Cellular & Integrative Physiology

Post-traumatic stress disorder (PTSD) is a mental health disorder that arises after experiencing or witnessing a traumatic event. Despite affecting around 7% of the population, there are currently no definitive biological signatures or biomarkers used in the diagnosis of PTSD. Thus, the search for clinically relevant and reproducible biomarkers has been a major focus of the field. With significant advances of large-scale multi-omic studies that include genomic, proteomic, and metabolomic data, promising findings have been made, but the field still has fallen short. Amongst the possible biomarkers examined, one area is often overlooked, understudied, or inappropriately investigated: the field of …

Potential Of Synthetic And Natural Compounds As Novel Histone Deacetylase Inhibitors For The Treatment Of Hematological Malignancies, Dilipkumar Pal, Khushboo Raj, Shyam Sundar Nandi, Surajit Sinha, Abhishek Mishra, Arijit Mondal, Ricardo Lagoa, Jack T. Burcher, Anupam Bishayee

Journal Articles: Cellular & Integrative Physiology

Histone deacetylases (HDACs) and histone acetyltransferases (HATs) are enzymes that remove or add acetyl groups to lysine residues of histones, respectively. Histone deacetylation causes DNA to more snugly encircle histones and decreases gene expression, whereas acetylation has the opposite effect. Through these small alterations in chemical structure, HATs and HDACs regulate DNA expression. Recent research indicates histone deacetylase inhibitors (HDACis) may be used to treat malignancies, including leukemia, B-cell lymphoma, virus-associated tumors, and multiple myeloma. These data suggest that HDACis may boost the production of immune-related molecules, resulting in the growth of CD8-positive T-cells and the recognition of nonreactive tumor …

Repeated Social Defeat Stress Induces An Inflammatory Gut Milieu By Altering The Mucosal Barrier Integrity And Gut Microbiota Homeostasis, Santosh K. Yadav, Rizwan Ahmad, Cassandra M. Moshfegh, Jagadesan Sankarasubramanian, Vineet A. Joshi, Safwan K. Elkhatib, Yashpal S. Chhonker, Goeffrey A. Talmon, Chittibabu Guda, Adam Case, Amar B. Singh

Journal Articles: Cellular & Integrative Physiology

Background

Posttraumatic stress disorder (PTSD) is a mental health condition triggered by exposure to traumatic events in an individual’s life. Patients with PTSD are also at a higher risk for comorbidities. However, it is not well understood how PTSD affects human health and/or promotes the risk for comorbidities. Nevertheless, patients with PTSD harbor a proinflammatory milieu and dysbiotic gut microbiota. Gut barrier integrity helps to maintain normal gut homeostasis and its dysregulation promotes gut dysbiosis and inflammation.

Methods

We used a mouse model of repeated social defeat stress (RSDS), a preclinical model of PTSD. Behavioral studies, metagenomics analysis of the …

Enhanced Central Sympathetic Tone Induces Heart Failure With Preserved Ejection Fraction (Hfpef) In Rats, Shyam S. Nandi, Kenichi Katsurada, Michael J. Moulton, Hong Zheng, Kaushik K. Patel

Journal Articles: Cellular & Integrative Physiology

Heart failure with preserved ejection fraction (HFpEF) is a heterogenous clinical syndrome characterized by diastolic dysfunction, concentric cardiac left ventricular (LV) hypertrophy, and myocardial fibrosis with preserved systolic function. However, the underlying mechanisms of HFpEF are not clear. We hypothesize that an enhanced central sympathetic drive is sufficient to induce LV dysfunction and HFpEF in rats. Male Sprague-Dawley rats were subjected to central infusion of either saline controls (saline) or angiotensin II (Ang II, 20 ng/min, i.c.v) via osmotic mini-pumps for 14 days to elicit enhanced sympathetic drive. Echocardiography and invasive cardiac catheterization were used to measure systolic and diastolic …

A Critical Role For Staphylococcal Nitric Oxide Synthase In Controlling Flavohemoglobin Toxicity, Ryan M. Singh, Sujata S. Chaudhari, Sasmita Panda, Elizabeth H. Hutfless, Cortney E. Heim, Dhananjay Shinde, Abdulelah A. Alqarzaee, Margaret F. Sladek, Vineet Kumar, Matthew C. Zimmerman, Paul D. Fey, Tammy Kielian, Vinai Chittezham Thomas

Journal Articles: Cellular & Integrative Physiology

Most coagulase-negative staphylococcal species, including the opportunistic pathogen Staphylococcus epidermidis, struggle to maintain redox homeostasis and grow under nitrosative stress. Under these conditions, growth can only resume once nitric oxide (NO) is detoxified by the flavohemoglobin Hmp. Paradoxically, S. epidermidis produces endogenous NO through its genetically encoded nitric oxide synthase (seNOS) and heavily relies on its activity for growth. In this study, we investigate the basis of the growth advantage attributed to seNOS activity. Our findings reveal that seNOS supports growth by countering Hmp toxicity. S. epidermidis relies on Hmp activity for its survival in the host under NO stress. …

Elevated Crp And Tnf-Α Levels Are Associated With Blunted Neural Oscillations Serving Fluid Intelligence, Sarah M. Dietz, Mikki Schantell, Rachel K. Spooner, Megan E. Sandal, Amirsalar Mansouri, Yasra Arif, Hannah J. Okelberry, Jason A. John, Ryan Glesinger, Pamela E. May, Elizabeth Heinrichs-Graham, Adam J. Case, Matthew C. Zimmerman, Tony W. Wilson

Journal Articles: Cellular & Integrative Physiology

INTRODUCTION: Inflammatory processes help protect the body from potential threats such as bacterial or viral invasions. However, when such inflammatory processes become chronically engaged, synaptic impairments and neuronal cell death may occur. In particular, persistently high levels of C-reactive protein (CRP) and tumor necrosis factor-alpha (TNF-α) have been linked to deficits in cognition and several psychiatric disorders. Higher-order cognitive processes such as fluid intelligence (Gf) are thought to be particularly vulnerable to persistent inflammation. Herein, we investigated the relationship between elevated CRP and TNF-α and the neural oscillatory dynamics serving Gf.

METHODS: Seventy adults between the ages of 20-66 years …

Restoration Of Normal Blood Flow In Atherosclerotic Arteries Promotes Plaque Stabilization, Morgan A. Schake, Ian S. Mccue, Evan T. Curtis, Thomas J. Ripperda, Samuel Harvey, Bryan T. Hackfort, Anna Fitzwater, Yiannis S. Chatzizisis, Forrest M. Kievit, Ryan M. Pedrigi

Journal Articles: Cellular & Integrative Physiology

Blood flow is a key regulator of atherosclerosis. Disturbed blood flow promotes atherosclerotic plaque development, whereas normal blood flow protects against plaque development. We hypothesized that normal blood flow is also therapeutic, if it were able to be restored within atherosclerotic arteries. Apolipoprotein E-deficient (ApoE^−/−) mice were initially instrumented with a blood flow-modifying cuff to induce plaque development and then five weeks later the cuff was removed to allow restoration of normal blood flow. Plaques in decuffed mice exhibited compositional changes that indicated increased stability compared to plaques in mice with the cuff maintained. The therapeutic benefit of …

Commonalities And Differences In Carotid Body Dysfunction In Hypertension And Heart Failure, Igor S. A. Felippe, Rodrigo Del Río, Harold D. Schultz, Benedito H. Machado, Julian F R Paton

Journal Articles: Cellular & Integrative Physiology

Carotid body pathophysiology is associated with many cardiovascular-respiratory-metabolic diseases. This pathophysiology reflects both hyper-sensitivity and hyper-tonicity. From both animal models and human patients, evidence indicates that amelioration of this pathophysiological signalling improves disease states such as a lowering of blood pressure in hypertension, a reduction of breathing disturbances with improved cardiac function in heart failure (HF) and a re-balancing of autonomic activity with lowered sympathetic discharge. Given this, we have reviewed the mechanisms of carotid body hyper-sensitivity and hyper-tonicity across disease models asking whether there is uniqueness related to specific disease states. Our analysis indicates some commonalities and some potential …

Artificial Light At Night Disrupts Male Dominance Relationships And Reproductive Success In A Model Fish Species, Lauren E. Closs, Muhammad Rahmad Rayan, Amin Sayyari, Ian Mayer, Finn-Arne Weltzien, Dianne M. Baker, Romain Fontaine

Biological Sciences Research

Environmental light is perceived and anticipated by organisms to synchronize their biological cycles. Therefore, artificial light at night (ALAN) disrupts both diurnal and seasonal biological rhythms. Reproduction is a complex physiological process involving integration of environmental signals by the brain, and release of endocrine signals by the pituitary that regulate gametogenesis and spawning. In addition, males from many species form a dominance hierarchy that, through a combination of aggressive and protective behavior, influences their reproductive success. In this study, we investigated the effect of ALAN and continuous daylight on the behavior and fitness of male fish within a dominance hierarchy …

Sex Differences In Endothelial Function, Metabolism, And Sleep: Responses To Disrupted Circadian Rhythms, Olga Hecmarie Meléndez-Fernández

Graduate Theses, Dissertations, and Problem Reports (ETD)

Circadian rhythms are endogenous cycles that recur approximately every 24 h, and manifest in virtually every physiological and behavioral process among the vast majority of organisms. These rhythms, sustained by the central circadian clock, the suprachiasmatic nucleus (SCN) of the hypothalamus, allow for optimal timing of biological processes that ensure organisms’ homeostasis, and are entrained to precisely 24 h by daily exposure to light. Disruption of the molecular mechanisms that drive these rhythms have negative consequences on physiology and behavior that may impair survival. The molecular mechanisms that underlie these effects are widely studied and linked to multiple diseases and …