Medical Physiology Commons^™

Critically Ill Covid-19 Patients Exhibit Anti-Sars-Cov-2 Serological Responses, Mark Daley, Douglas D. Fraser, Gediminas Cepinskas, Marat Slessarev, Claudio M. Martin, Maitray A. Patel, Michael Miller, Eric K. Patterson, David B. O’Gorman, Sean E. Gill, Ian Higgins, Julius P. John, Christopher Melo, Lylia Nini, Xiaoqin Wang, Johannes Zeidler, Jorge A. Cruz-Aguado

Physiology and Pharmacology Publications

Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2, is a global health care emergency. Anti-SARS-CoV-2 serological profiling of critically ill COVID-19 patients was performed to determine their humoral response. Blood was collected from critically ill ICU patients, either COVID-19 positive (+) or COVID-19 negative (−), to measure anti-SARS-CoV-2 immunoglobulins: IgM; IgA; IgG; and Total Ig (combined IgM/IgA/IgG). Cohorts were similar, with the exception that COVID-19+ patients had a greater body mass indexes, developed bilateral pneumonias more frequently and suffered increased hypoxia when compared to COVID-19-patients (p < 0.05). The mortality rate for COVID-19+ patients was 50%. COVID-19 status could be determined by anti-SARS-CoV-2 serological responses with excellent classification accuracies on ICU day 1 (89%); ICU day 3 (96%); and ICU days 7 and 10 (100%). The importance of each Ig isotype for determining COVID-19 status on combined ICU days 1 and 3 was: Total Ig, 43%; IgM, 27%; IgA, 24% and IgG, 6%. Peak serological responses for each Ig isotype occurred on different ICU days (IgM day 13 > IgA day 17 > IgG persistently increased), with the Total Ig peaking at approximately ICU day …

Myeloid Arginase 1 Insufficiency Exacerbates Amyloid-Β Associated Neurodegenerative Pathways And Glial Signatures In A Mouse Model Of Alzheimer’S Disease: A Targeted Transcriptome Analysis, Chao Ma, Jerry B. Hunt, Andrii Kovalenko, Huimin Liang, Maj-Linda B. Selenica, Michael B. Orr, Bei Zhang, John C. Gensel, David J. Feola, Marcia N. Gordon, Dave Morgan, Paula C. Bickford, Daniel C. Lee

Sanders-Brown Center on Aging Faculty Publications

Brain myeloid cells, include infiltrating macrophages and resident microglia, play an essential role in responding to and inducing neurodegenerative diseases, such as Alzheimer’s disease (AD). Genome-wide association studies (GWAS) implicate many AD casual and risk genes enriched in brain myeloid cells. Coordinated arginine metabolism through arginase 1 (Arg1) is critical for brain myeloid cells to perform biological functions, whereas dysregulated arginine metabolism disrupts them. Altered arginine metabolism is proposed as a new biomarker pathway for AD. We previously reported Arg1 deficiency in myeloid biased cells using lysozyme M (LysM) promoter-driven deletion worsened amyloidosis-related neuropathology and behavioral impairment. However, …

Water Exchange Rate Across The Blood-Brain Barrier Is Associated With Csf Amyloid-Β 42 In Healthy Older Adults, Brian T. Gold, Xingfeng Shao, Tiffany L. Sudduth, Gregory A. Jicha, Donna M. Wilcock, Elayna R. Seago, Danny J. J. Wang

Sanders-Brown Center on Aging Faculty Publications

INTRODUCTION: We tested if water exchange across the blood-brain barrier (BBB), estimated with a noninvasive magnetic resonance imaging (MRI) technique, is associated with cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD) and neuropsychological function.

METHODS: Forty cognitively normal older adults (67–86 years old) were scanned with diffusion‐prepared, arterial spin labeling (DP‐ASL), which estimates water exchange rate across the BBB (k_w). Participants also underwent CSF draw and neuropsychological testing. Multiple linear regression models were run with kw as a predictor of CSF concentrations and neuropsychological scores.

RESULTS: In multiple brain regions, BBB kw was positively associated with CSF amyloid …

The Role Of Nutrition And Hormone Signaling In Extended Larval Development And Obesity In Starvation-Selected Drosophila Melanogaster, Jennifer M. Clark

UNLV Theses, Dissertations, Professional Papers, and Capstones

Brief periods of starvation are a common stressor that most animals encounter in the wild and must be able to survive in order to maximize their fitness. Starvation resistance of the adult fruit fly, Drosophila melanogaster, is thought to be primarily conferred by adult fat stores, body size, metabolic rate, behavior, and activity levels. Additionally, flies selected for starvation resistance also often show delayed pupariation, which is usually indicative of altered hormone signaling. How starvation selection extends development and if it contributes to adult starvation resistance remains incompletely studied. Identifying the targets of starvation selection that cause extended development and …

The Mechanism Underlying Transient Weakness In Myotonia Congenita, Jessica H. Myers, Kirsten Denman, Chris Dupont, Ahmed A. Hawash, Kevin R. Novak, Andrew Koesters, Manfred Grabner, Anamika Dayal, Andrew A. Voss, Mark M. Rich

Neuroscience, Cell Biology & Physiology Faculty Publications

In addition to the hallmark muscle stiffness, patients with recessive myotonia congenita (Becker disease) experience debilitating bouts of transient weakness that remain poorly understood despite years of study. We performed intracellular recordings from muscle of both genetic and pharmacologic mouse models of Becker disease to identify the mechanism underlying transient weakness. Our recordings reveal transient depolarizations (plateau potentials) of the membrane potential to -25 to -35 mV in the genetic and pharmacologic models of Becker disease. Both Na + and Ca 2+ currents contribute to plateau potentials. Na + persistent inward current (NaPIC) through Na V 1.4 channels is the …

Vitamin D Promotes Skeletal Muscle Regeneration And Mitochondrial Health, Christine M. Latham, Camille R. Brightwell, Alexander R. Keeble, Brooke D. Munson, Nicholas T. Thomas, Alyaa M. Zagzoog, Christopher S. Fry, Jean L. Fry

Athletic Training and Clinical Nutrition Faculty Publications

Vitamin D is an essential nutrient for the maintenance of skeletal muscle and bone health. The vitamin D receptor (VDR) is present in muscle, as is CYP27B1, the enzyme that hydroxylates 25(OH)D to its active form, 1,25(OH)D. Furthermore, mounting evidence suggests that vitamin D may play an important role during muscle damage and regeneration. Muscle damage is characterized by compromised muscle fiber architecture, disruption of contractile protein integrity, and mitochondrial dysfunction. Muscle regeneration is a complex process that involves restoration of mitochondrial function and activation of satellite cells (SC), the resident skeletal muscle stem cells. VDR expression is strongly upregulated …

The Crosstalk Between Insulin Resistance, Systemic Inflammation, Redox Imbalance And The Thyroid In Subjects With Obesity, Nicoleta Răcătăianu, Nicoleta Valentina Leach, Sorana D. Bolboacă, Maria Loredana Soran, Mirela Flonta, Ana Valea, Andrada-Luciana Lazăr, Cristina Ghervan

Journal of Mind and Medical Sciences

We aimed at assessing the interaction between visceral adipose tissue (VAT), insulin resistance (IR), circulating levels of monocyte chemoattractant protein-1 (MCP-1) and malondialdehyde (MDA) and the thyroid parameters in obese subjects. Methods. Obese subjects without thyroid pathologies or diseases associated with systemic inflammation and OS were recruited. Insulinemia, visceral fat thickness, metabolic and thyroid parameters were assayed. Circulating levels of MCP-1 and MDA were used to quantify inflammation and OS. Results. A number of 160 obese subjects were included. The MCP-1 level increased with the degree of obesity and HOMA-IR. MCP 1 was positively associated with antithyroperoxidase antibody (TPOab) levels …

A Mouse Model Of Huntington’S Disease Shows Altered Ultrastructure Of Transverse Tubules In Skeletal Muscle Fibers, Shannon H. Romer, Sabrina Metzger, Kristiana Peraza, Matthew C. Wright, D. Scott Jobe, Long-Sheng Song, Mark M. Rich, Brent D. Foy, Robert J. Talmadge, Andrew A. Voss

Neuroscience, Cell Biology & Physiology Faculty Publications

Huntington’s disease (HD) is a fatal and progressive condition with severe debilitating motor defects and muscle weakness. Although classically recognized as a neurodegenerative disorder, there is increasing evidence of cell autonomous toxicity in skeletal muscle. We recently demonstrated that skeletal muscle fibers from the R6/2 model mouse of HD have a decrease in specific membrane capacitance, suggesting a loss of transverse tubule (t-tubule) membrane in R6/2 muscle. A previous report also indicated that Cav1.1 current was reduced in R6/2 skeletal muscle, suggesting defects in excitation–contraction (EC) coupling. Thus, we hypothesized that a loss and/or disruption of the skeletal muscle t-tubule …

Neurophysiology Of Space Medicine: A Literature Review, Jose R. Velasquez

MEDI 9331 Scholarly Activities Clinical Years

Space medicine is becoming an essential and expanding clinical discipline. Acquiring a deeper and complete picture understanding of the multi-systemic response due to space on human health and function is essential to ensure the success of future space exploration. A comprehensive review of the literature was performed using PubMed and focused on the current neurophysiologic findings of the central nervous system’s response to space. Ground-based analogues, which mimic the effects of microgravity, and actual spaceflight studies have been used to analyze these physiologic adaptations to space. Overall, cerebellar, sensorimotor and vestibular brain regions seem to be affected the most. Through …

Alcohol Use Is Associated With Intestinal Dysbiosis And Dysfunctional Cd8+T-Cell Phenotypes In Persons With Human Immunodeficiency Virus, Vincent J. Maffei, Robert W. Siggins, Meng Luo, Meghan M. Brashear, Donald E. Mercante, Christopher M. Taylor, Patricia Molina, David A. Welsh

School of Medicine Faculty Publications

Background: Inflammation persists among persons with human immunodeficiency virus (PWH) despite effective antiretroviral therapy and may contribute to T-cell dysfunction. Alcohol use is prevalent among PWH and promotes intestinal leak, dysbiosis, and a proinflammatory milieu. Whether alcohol use is associated with T-cell late differentiation remains to be investigated. Methods: Data and samples from PWH (Nâ...=â...359 of 365) enrolled in the New Orleans Alcohol Use in HIV Study were used. Alcohol use was assessed by self-report (Alcohol Use Disorders Identification Test; lifetime alcohol exposure; 30-day Alcohol Timeline Followback) and phosphatidylethanol (PEth) quantitation. In a subset of participants, fecal bacterial content was …

Methamphetamine Associated Cardiomyopathy In Pregnancy: The Distinctions And The Implications, Ashan Hatharasinghe, Hossein Akhondi

HCA Healthcare Journal of Medicine

Introduction

Methamphetamine associated cardiomyopathy (MAC) and peripartum cardiomyopathy (PPCM) are both rare obstetric conditions. Literature regarding methamphetamine associated cardiomyopathy in the obstetric population is limited, and it can be difficult to make the distinction between the two given the similarities in clinical presentation. However similar, there are significant distinctions in the pathophysiology of these two that can help clinicians with the management process.

Clinical Findings and Outcomes

This case involves a 35-year-old Hispanic G6P5005 at 37 weeks gestation presenting with acute respiratory failure secondary to acute decompensated heart failure with reduced ejection fraction and superimposed preeclampsia leading to urgent cesarean …

CertL Reduces C16 Ceramide, Amyloid-Β Levels, And Inflammation In A Model Of Alzheimer’S Disease, Simone M. Crivelli, Qian Luo, Jo A. A. Stevens, Caterina Giovagnoni, Daan Van Kruining, Gerard Bode, Sandra Den Hoedt, Barbara Hobo, Anna-Lena Scheithauer, Jochen Walter, Monique T. Mulder, Christopher Exley, Matthew Mold, Michelle M. Mielke, Helga E. De Vries, Kristiaan Wouters, Daniel L. A. Van Den Hove, Dusan Berkes, María Dolores Ledesma, Joost Verhaagen, Mario Losen, Erhard Bieberich, Pilar Martinez-Martinez

Physiology Faculty Publications

BACKGROUND: Dysregulation of ceramide and sphingomyelin levels have been suggested to contribute to the pathogenesis of Alzheimer's disease (AD). Ceramide transfer proteins (CERTs) are ceramide carriers which are crucial for ceramide and sphingomyelin balance in cells. Extracellular forms of CERTs co-localize with amyloid-β (Aβ) plaques in AD brains. To date, the significance of these observations for the pathophysiology of AD remains uncertain.

METHODS: A plasmid expressing CERT_L, the long isoform of CERTs, was used to study the interaction of CERT_L with amyloid precursor protein (APP) by co-immunoprecipitation and immunofluorescence in HEK cells. The recombinant CERT_L protein …

Novel Influences Of Sex And Apoe Genotype On Spinal Plasticity And Recovery Of Function After Spinal Cord Injury, Lydia E. Strattan, Daimen R. Britsch, Chris M. Calulot, Rachel S. J. Maggard, Erin L. Abner, Lance A. Johnson, Warren J. Alilain

Sanders-Brown Center on Aging Faculty Publications

Spinal cord injuries can abolish both motor and sensory function throughout the body. Spontaneous recovery after injury is limited and can vary substantially between individuals. Despite an abundance of therapeutic approaches that have shown promise in preclinical models, there is currently a lack of effective treatment strategies that have been translated to restore function after SCI in the human population. We hypothesized that sex and genetic background of injured individuals could impact how they respond to treatment strategies, presenting a barrier to translating therapies that are not tailored to the individual. One gene of particular interest is APOE, which has …

The Role Of Panx3 In Age-Associated And Injury-Induced Intervertebral Disc Degeneration, Meaghan Serjeant, Paxton M. Moon, Diana Quinonez, Silvia Penuela, Frank Beier, Cheryle A. Séguin

Physiology and Pharmacology Publications

© 2021 by the authors. Licensee MDPI, Basel, Switzerland. Pannexin 3 (Panx3) is a mechanosensitive, channel-forming glycoprotein implicated in the progression of post-traumatic osteoarthritis. Despite evidence for Panx3 expression in the intervertebral disc (IVD), its function in this cartilaginous joint structure remained unknown. Using Panx3 knockout mice, this study investigated the role of Panx3 in age-associated IVD degeneration and degeneration induced by annulus fibrosus (AF) needle puncture. Loss of Panx3 did not significantly impact the progression of age-associated histopathological IVD degeneration; however, loss of Panx3 was associated with decreased gene expression of Acan, Col1a1, Mmp13 and Runx2 and altered localization …

Macrophage-Engineered Vesicles For Therapeutic Delivery And Bidirectional Reprogramming Of Immune Cell Polarization, Khaga R. Neupane, J. Robert Mccorkle, Timothy J. Kopper, Jourdan E. Lakes, Surya P. Aryal, Masud Abdullah, Aaron A. Snell, John C. Gensel, Jill M. Kolesar, Christopher I. Richards

Spinal Cord and Brain Injury Research Center Faculty Publications

Macrophages, one of the most important phagocytic cells of the immune system, are highly plastic and are known to exhibit diverse roles under different pathological conditions. The ability to repolarize macrophages from pro-inflammatory (M1) to anti-inflammatory (M2) or vice versa offers a promising therapeutic approach for treating various diseases such as traumatic injury and cancer. Herein, it is demonstrated that macrophage-engineered vesicles (MEVs) generated by disruption of macrophage cellular membranes can be used as nanocarriers capable of reprogramming macrophages and microglia toward either pro- or anti-inflammatory phenotypes. MEVs can be produced at high yields and easily loaded with diagnostic molecules …

The Association Of Circulating Amylin With Β-Amyloid In Familial Alzheimer's Disease, Han Gia Ly, Nirmal Verma, Savita Sharma, Deepak Kotiya, Sanda Despa, Erin L. Abner, Peter T. Nelson, Gregory A. Jicha, Donna M. Wilcock, Larry B. Goldstein, Rita Guerreiro, José Brás, Angela J. Hanson, Suzanne Craft, Andrew J. Murray, Geert Jan Biessels, Claire Troakes, Henrik Zetterberg, John Hardy, Tammaryn Lashley, Alzheimer’S Disease Exome Sequencing Group, Florin Despa

Pharmacology and Nutritional Sciences Faculty Publications

Introduction

This study assessed the hypothesis that circulating human amylin (amyloid‐forming) cross‐seeds with amyloid beta (Aβ) in early Alzheimer's disease (AD).

Methods

Evidence of amylin‐AD pathology interaction was tested in brains of 31 familial AD mutation carriers and 20 cognitively unaffected individuals, in cerebrospinal fluid (CSF) (98 diseased and 117 control samples) and in genetic databases. For functional testing, we genetically manipulated amylin secretion in APP/PS1 and non‐APP/PS1 rats.

Results

Amylin‐Aβ cross‐seeding was identified in AD brains. High CSF amylin levels were associated with decreased CSF Aβ42 concentrations. AD risk and amylin gene are not correlated. Suppressed amylin secretion protected …

Novel Mammalian Models For Understanding And Treating Spinal Cord Injury, Michael B. Orr

Theses and Dissertations--Physiology

Spinal cord injury (SCI) is devastating and often leaves the injured individual with persistent dysfunction. The injury persists because humans have poor wound repair and there are no pharmacologic treatments to induce wound repair after SCI. The continued efforts to discover therapeutic targets and develop treatments heavily relies on animal models. The purpose of this project is to develop and study novel mammalian models of SCI to provide insights for the development and effective implementation of SCI therapies.

Lab mice (Mus musculus) are a powerful tool for recapitulating the progression and persistent damage evident in human SCI, but …

Novel Mechanisms Of Neuronal And Hormonal Regulation Of Large Intestinal Electrolyte Transport, Andrew John Nickerson

Graduate Theses, Dissertations, and Problem Reports

The mammalian colon plays a vital role in maintaining overall electrolyte and fluid homeostasis in the body, and it possesses the ability to either secrete or absorb water depending upon the needs of the organism. Secretion or absorption of electrolyte ions, such as Na⁺, Cl^- and K⁺, drives the movement of water across the colonic epithelium – the inner gut lining where all transport takes place. Aberrant absorptive and/or secretory activity within the colonic epithelium is central to the pathogenesis of many gastrointestinal diseases, such as irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), constipation …

Neurogenic Hypertension Mediated Mitochondrial Abnormality Leads To Cardiomyopathy: Contribution Of Upr Mt And Norepinephrine-Mir- 18a-5p-Hif-1Α Axis, Shyam Sundar Nandi, Kenichi Katsurada, Sushil K. Mahata, Kaushik K. Patel

Journal Articles: Cellular & Integrative Physiology

Aims: Hypertension increases the risk of heart disease. Hallmark features of hypertensive heart disease is sympathoexcitation and cardiac mitochondrial abnormality. However, the molecular mechanisms for specifically neurally mediated mitochondrial abnormality and subsequent cardiac dysfunction are unclear. We hypothesized that enhanced sympatho-excitation to the heart elicits cardiac miR-18a-5p/HIF-1α and mitochondrial unfolded protein response (UPR^mt) signaling that lead to mitochondrial abnormalities and consequent pathological cardiac remodeling. Methods and Results: Using a model of neurogenic hypertension (NG-HTN), induced by intracerebroventricular (ICV) infusion of Ang II (NG-HTN; 20 ng/min, 14 days, 0.5 μl/h, or Saline; Control, 0.9%) through osmotic mini-pumps in Sprague-Dawley …

Physiological Measurements For Real-Time Fatigue Monitoring In Train Drivers: Review Of The State Of The Art And Reframing The Problem, Bojana Bjegojevic, Maria Chiara Leva, Nora Balfe, Sam D. Cromie, Luca Longo

Conference papers

The impact of fatigue on train drivers is one of the most important safety-critical issues in rail. It affects drivers’ performance, significantly contributing to railway incidents and accidents. To address the issue of real-time fatigue detection in drivers, most reliable and applicable psychophysiological indicators of fatigue need to be identified. Hence, this paper aims to examine and present the current state of the art in physiological measures for real-time fatigue monitoring that could be applied in the train driving context. Three groups of such measures are identified: EEG, eye-tracking and heart-rate measures. This is the first paper to provide the …