Physiology Commons^™

Is Mitochondrial Development Impaired In Hyperoxic Rats And Does This Underpin The Blunting Of The Acute Hypoxic Ventilatory Response?, Tariq Hasan Fayyad

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Carotid body (CB) responses to hypoxia are low at birth and increase over time to mature responses. Using an in vitro rat CB-carotid sinus nerve (CSN) preparation, Kholwadwala and Donnelly (1992) demonstrated that the CSN activity in response to hypoxia increased from low levels to robust adult responses after two weeks. This time course of maturation was paralleled by an increase in TASK channel sensitivity to hypoxia in the O2-sensing Type I cells (Kim et al, 2011). Previous studies have indicated that a fall in Type I cell mitochondrial volume and an increase in the rate of oxidative phosphorylation may …

Measuring The Effects Of High-Fat Diet On Breathing And Oxygen-Sensitivity Of The Carotid Body Type I Cell, Ryan J. Rakoczy

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The carotid bodies (CB), the primary peripheral chemoreceptors, respond to changes in blood gases with neurotransmitter release, thereby increasing carotid sinus nerve firing frequency and ultimately correcting the pattern of breathing. It has previously been demonstrated that acute application of the adipokine leptin caused perturbations of intracellular calcium and membrane ion movement in isolated CB Type I cells (Pye et al, 2015) and augmented the response of the intact CB to hypoxia (Pye et al, 2016). This study's aim was to examine, in-vivo, if elevated leptin modulated CB function and breathing. Rats were fed high-fat chow or control chow for …

Investigating The Role Of An Sk Channel Activator On Survival And Motor Function In The Sod1-G93a, Als Mouse Model, Matthew Thomas Dancy

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Amyotrophic Lateral Sclerosis (ALS) is a fatal, adult-onset progressive degenerative motor neuron disease that is characterized by muscle atrophy and weakness due to the loss of upper and lower motor neurons. Average survival time for individuals diagnosed with the disease is three to five years; currently there is no cure and only one drug approved by the Food and Administration (FDA). Scientists have proposed various theories in order to solve the mystery which surrounds ALS. One of these theories hypothesizes how hyperexcitability and excitotoxicity leads to the death of motor neurons. In this study, we will address ways of combatting …

Po2 Dependence Of Oxygen Consumption In Skeletal Muscle Of Hypertensive And Normotensive Rats, Habiba Shah

Theses and Dissertations

Human essential hypertension affects over 75 million people in the United States, and can lead to death due to its several serious health complications such as hypertension-related cardiovascular disease. The purpose of this research was to understand how hypertension could cause physiological changes to the microcirculation, specifically the PO₂ dependence of oxygen consumption (VO₂) in skeletal muscle of normotensive and hypertensive rats. The Spontaneously Hypertensive Rat (SHR) strain was used as the diseased model, and Wistar-Kyoto (WKY) rats were used as controls to conduct this study. The SHR strain develops hypertension between 5-6 weeks after birth with …

Profiling The Action Of Acetylcholine In The Drosophila Melanogaster Larval Model: Heart, Behavior, And The Development And Maintenance Of Sensorimotor Circuits, Cole A. Malloy

Theses and Dissertations--Biology

Understanding the role of various chemical messengers in altering behaviors and physiological processes is a common goal for scientists across multiple disciplines. The main focus of this dissertation is on characterizing the action of an important neurotransmitter, acetylcholine (ACh), modulating larval Drosophila melanogaster neural circuits and heart. In this dissertation, I provide important insights into the mechanisms by which ACh influences the formation and performance of select neural circuits, while also revealing significant details regarding its role in additional physiological functions, including cardiac pace making. In Chapter 1, I provide a general overview of ACh action in mammals and flies …

The Effect Of Cold On The Physiology Of Drosophila Larva Heart And On Synaptic Transmission At Crayfish Neuromuscular Junctions, Yuechen Zhu

Theses and Dissertations--Biology

Ectothermic animals are susceptible to temperature changes such as cold shock with seasons. To survive through a cold shock, ectotherms have developed unique strategies. My interest is focusing on the physiological function of during cold shock and prolonged cold exposure in the fruit fly (Drosophila melanogaster) and crayfish (Procambarus clarkii). I used Drosophila melanogaster as a model system to investigate cardiac function in response to modulators (serotonin, acetylcholine, octopamine, dopamine and a cocktail of modulators) in acute cold shock and chronic cold shock conditions as possible mechanism to regulate heart rate in the cold. To examine if the dampened heart …

Using Exogenous Hormone Application To Suppress Axillary Shoot Development In Tobacco, W. Jesse Carmack

Theses and Dissertations--Plant and Soil Sciences

The variability in the number of basal axillary shoots (ground suckers) among all tobacco (Nicotiana tabacum L.) varieties, has increased since the hydroponic transplant production system became the standard. The larger root ball of hydroponically produced transplants compared to traditionally produced transplants potentially generates a difference in the ratio of auxin (inhibits axillary shoot formation) to cytokinin (promotes lateral branching), that induces basal axillary shoot development. Starting in 2014, studies were conducted to investigate whether the addition of synthetic auxins or cytokinins to hydroponic transplant production could prevent ground sucker formation. Different tobacco cultivars, with high or low ground sucker …

Vitamin D Status And Bone Mineral Density In Female Collegiate Dancers And Cheerleaders, Tara Sue Kenny, Damon Mccune, Laura J. Kruskall, James Navalta, John C. Young

Kinesiology and Nutrition Sciences Faculty Research

Bone mineral density reflects an athlete’s cumulative history of energy availability, physical activity, and menstrual status, as well as nutritional and environmental factors. Although sports with high-impact loading are associated with higher bone mineral density than low-impact or non-impact sports, confounding variables are differences in the athletes’ body size and sport-specific training. The purpose of this study was to determine if bone mineral density (BMD) and vitamin D status are different between two groups of female collegiate athletes who have comparable body size/weight requirements, but who engage in qualitatively different training regimens. Full body, spine and dual femur BMD was …

Effects Of 17Β Estradiol In The Metabolism And Morphology Of Bluegill Sunfish (Lepomis Macrochirus), Neeta Parajulee Karki

Masters Theses

Fish natural habitats are increasingly contaminated with various estrogenic compounds, including 17β estradiol (E2). This compound causes adverse effects on the reproductive system of male fish; however, the effects of E2 on other aspects of fish metabolism, morphology and histopathological changes in internal organs are not well known. The objective of this study is to evaluate the effects of E2 exposure on the basal and stressed metabolic rate, morphological changes in body shapes, and histological changes in the liver tissues of sunfish species. Fish were held individually in ten gallon tanks under two treatments of 40 and 80 ng/L and …

The Role Of Creg1 As A Master Regulator Of Liver Function, Abdulrahman Siran Aldaghmi

Masters Theses

The liver is known as the chemical factory of the body because it performs a wide range of biochemical functions required for life. Since the liver has such an important role in regulation of normal physiological processes, liver diseases cause a high rate of morbidity and mortality. Therefore, understanding the mechanisms of liver development will shed light on the causes of liver disease. In this study, a cell line model that utilizes rat hepatoma cells (Fg14) and hepatoma variant cells (H11) was used to identify master regulators of liver gene expression. Whole genome expression studies identified the gene CREG1 (Cellular …

The Influence Of Different Pre-Exercise Routines On Sprint Performance, Rok Mravljak

Masters Theses

Sprint performance can be enhanced by interventions for short-term (acute) purposes and/or long-term purposes. Acute neuromuscular responses are usually achieved by using different pre-exercise routines at the end of the warm-up period. Recently, there have been several studies examining the effects of various pre-exercise routines on sprint performance, yet there has not been a research study designed that compared the three most commonly used pre-exercise routines in professional and recreational sports (static stretching, dynamic stretching and foam-rolling). Therefore, this study investigated and compared the results of static stretching, dynamic stretching, self-myofascial release and the control group, in order to provide …

The Effect Of Repeated Sprint Training In Hypoxia And Beta-Alanine Supplementation On Exercise Performance, Ran Wang

Electronic Theses and Dissertations

The primary objective of this study was to evaluate the synergistic effects of repeated sprint training in hypoxia (RSH) and beta-alanine supplementation on performance in recreationally active men. Participants were randomly assigned to one of the following groups: hypoxia + beta-alanine (HB, n = 10), hypoxia + placebo (HP, n = 9), normoxia + beta-alanine (NB, n = 11) and normoxia + placebo (NP, n = 8). All participants completed a total of 8 training sessions (each consisting of 3 sets of 5 × 10-s sprints at a resistance of 7.5% of body mass, with 20-s rest intervals between sprints) …

Remote Preconditioning: Evaluating The Efficacy Of Cardioprotection In Type-2 Diabetes And Exploring The Mechanistic Role Of Exosomes, Joseph Michael Wider

Wayne State University Dissertations

Remote preconditioning is a promising and robust treatment for myocardial

ischemia/reperfusion injury that evokes cardioprotection through endogenous neural

and/or humoral signaling. A recent study has reported that protective signaling is

mediated by exosomes through the circulation; however this concept is supported by

limited and inconsistent evidence. Despite overwhelming success in preclinical studies,

the efficacy of remote preconditioning in human studies is inconclusive. Importantly, the

majority of remote preconditioning studies use healthy animal models despite growing

evidence that comorbidities, such as type-2 diabetes, may negatively influence

outcomes. Nonetheless, the efficacy of remote preconditioning in the setting of type-2

diabetes has not …

Estimating The Variables Of The Nonlinear Dynamical Theory Of Acute Cell Injury, Fika Tri Anggraini

Wayne State University Dissertations

This Dissertation is the first to estimate the variables D and S of the nonlinear theory of acute cell injury in hippocampal regions CA1 and CA3 using a rat model of global brain ischemia and reperfusion (I/R). D was estimated by quantifying protein aggregates using ubiquitin Western blotting. S was estimated by quantifying changes in polysomal mRNAs as measured by microarray chips. D and S time courses were sampled at 0.5, 8, 16, 24, 48, and 72 hrs of reperfusion after 10 min brain ischemia. CA1 dies and CA3 survives. The theory predicts D will be larger in CA1 and …

Circadian Modulation Of Breathing Stability And Respiratory Plasticity, Mohamad El Chami

Wayne State University Dissertations

Purpose: Our project was designed to determine the effect of time of day on multiple mechanisms influencing breathing stability and respiratory plasticity. We investigated if the number and duration of breathing events coupled to upper airway collapsibility, as well as the carbon dioxide reserve, chemoreflex sensitivity and arousal threshold during non-rapid eye movement (NREM) sleep were affected by the time of day. In addition, we examined if mild intermittent hypoxia (IH) initiates long-term facilitation of upper airway muscle activity leading to a reduction in the therapeutic continuous positive airway pressure required to eliminate breathing events.

Methods: Male participants with obstructive …

Burnout And The Hypothalamic-Pituitary-Thyroid Axis: A Methodological Comment, Renzo Bianchi, Irvin Sam Schonfeld, Eric Laurent

Publications and Research

Because (a) burnout overlaps with depression and (b) depression has been associated with altered functioning of the hypothalamic-pituitary-thyroid axis changes in the activity of the HPT axis can be expected in burnout. Most probably, Guo et al.’s (2017) results are flawed by a severe form of the “healthy worker effect.”

Deletion Of Cardiac Mir-17-92 Cluster Increases Ischemia/ Reperfusion Injury Via Pten Upregulation, Meeta B. Prakash

Theses and Dissertations

The miR-17- 92 cluster is necessary for cell proliferation and development of the cardiovascular system. Deletion of this cluster leads to death in neonatal mice. The role of this cluster still needs to be defined following ischemia and reperfusion. Methods and Results: Adult male mice were injected with Tamoxifen- was to induce inducible cardiac-specific miR-17- 92-deficient (miR-17- 92-def: MCM:TG:miR-17- 92 flox/flox ) and wild type (WT: MCM:NTG:miR-17-92 flox/flox ) mice were subjected to 30 minutes of myocardial ischemia via left anterior descending coronary artery ligation followed by reperfusion for 24 hours. Post I/R survival (48%) and ejection fraction were reduced, …

The Role Of Human Msc Derived Exosomes In The Treatment Of Periodontal Diseases, Sonia S. Talegaonkar

Theses and Dissertations

Periodontal disease affects 47% of Americans over 30. Characterized by microbial dysbiosis and unregulated inflammation, severe periodontitis causes degradation of bone and soft tissue around teeth. Current treatments have limited regenerative outcomes and frequent reinfection by harmful bacteria. Human mesenchymal stem cells (hMSCs) have been shown to promote wound healing and tissue regeneration. Many therapeutic benefits of hMSCs are due to their secretome products, like exosomes. Our long-term goal is to develop periodontal therapies with hMSC exosomes. The objectives of this study were to determine the effect of hMSC-derived exosomes on cellular activity of hMSCs and investigate whether hMSC exosome …

The Effects Of Female Genital Mutilation On Women Of Sierra Leone, Nenneh Kalokoh Kalokoh

Walden Dissertations and Doctoral Studies

Female genital mutilation or cutting (FGM/C), a common practice among Sierra Leonean women, carries significant psychological and physical risks. Prior to this study, a substantial need existed for inquiry of the experiences and belief systems within this cultural group to better understand the effects of FGM/C on women and girls. Guided by feminist theory and the theory of cultural relativism, the goal of this phenomenological study was to review the cultural perspectives and experiences of Sierra Leonean women who underwent FGM/C to investigate their concerns about safety and their perceptions of the practices. In addition, this study explored concerns among …

Functional Studies Of Novel Mosquito Stage-Specific Genes In The Malaria Parasite, Plasmodium Berghei., Kaitlyn Kiernan

Master's Theses

The development and survival of the malaria parasite Plasmodium within its mosquito vector is not very well understood. When the parasite is taken up by an Anopheles mosquito, it is exposed to digestive enzymes, reactive oxygen species, increasing pH, decreasing temperature, and a diverse microbial flora. Our lab is studying the adaptive mechanisms underlying parasite survival in this hostile environment, one of which is movement out of the midgut. In order to escape the midgut, the parasite develops into an elongated, motile form called the ookinete. I am investigating two genes, thioredoxin-like protein 1 (trxl-1) and subpellicular microtubule protein 1 …