Medical Physiology Commons^™

The Beta-1-Receptor Blocker Nebivolol Elicits Dilation Of Cerebral Arteries By Reducing Smooth Muscle [Ca2+]I, Peter Cseplo, Zoltan Vamos, Ivan Ivic, Orsolya Torok, Attila Toth, Akos Koller

NYMC Faculty Publications

RATIONALE: Nebivolol is known to have beta-1 blocker activity, but it was also suggested that it elicits relaxation of the peripheral arteries in part via release of nitric oxide (NO). However, the effect of nebivolol on the vasomotor tone of cerebral arteries is still unclear.

OBJECTIVE: To assess the effects of nebivolol on the diameter of isolated rat basilar arteries (BA) in control, in the presence of inhibitors of vasomotor signaling pathways of know action and hemolysed blood.

METHODS AND RESULTS: Vasomotor responses were measured by videomicroscopy and the intracellular Ca2+ by the Fura-2 AM ratiometric method. Under control conditions, …

Maternal Nutrient Restriction With Fetal Growth Restriction In Guinea Pigs Impacts Brain Development And Neuroimaging Correlates In Neonatal Offspring, Catherine Nevin

Electronic Thesis and Dissertation Repository

Aberrant brain development in utero accompanied by fetal growth restriction (FGR) increases the risk of neurodevelopmental disorders in later life. However there are limited non-invasive biomarkers in the brain for the early identification of said neurodevelopmental disorders in an animal model of FGR. Guinea pig sows were fed either ad libitum (Control) or 70% of the control diet pre-pregnancy, increasing to 90% at mid-pregnancy (MNR) creating appropriately grown (AGA) Control and FGR-MNR neonates, respectively. Three to four weeks corrected post-natal age, neonates were imaged using magnetic resonance imaging (MRI) and spectroscopy (MRS) techniques, and were killed 48-72 hours later for …

An Excitatory Cortical Feedback Loop Gates Retinal Wave Transmission In Rodent Thalamus, Yasunobu Murata, Matthew T. Colonnese

Pharmacology and Physiology Faculty Publications

Spontaneous retinal waves are critical for the development of receptive fields in visual thalamus (LGN) and cortex (VC). Despite a detailed understanding of the circuit specializations in retina that generate waves, whether central circuit specializations also exist to control their propagation through visual pathways of the brain is unknown. Here we identify a developmentally transient, corticothalamic amplification of retinal drive to thalamus as a mechanism for retinal wave transmission in the infant rat brain. During the period of retinal waves, corticothalamic connections excite LGN, rather than driving feedforward inhibition as observed in the adult. This creates an excitatory feedback loop …

Reduced Motor Neuron Excitability Is An Important Contributor To Weakness In A Rat Model Of Sepsis, Paul Nardelli, Jacob A. Vincent, Randall K. Powers, Timothy C. Cope, Mark M. Rich

Neuroscience, Cell Biology & Physiology Faculty Publications

The mechanisms by which sepsis triggers intensive care unit acquired weakness (ICUAW) remain unclear. We previously identified difficulty with motor unit recruitment in patients as a novel contributor to ICUAW. To study the mechanism underlying poor recruitment of motor units we used the rat cecal ligation and puncture model of sepsis. We identified striking dysfunction of alpha motor neurons during repetitive firing. Firing was more erratic, and often intermittent. Our data raised the possibility that reduced excitability of motor neurons was a significant contributor to weakness induced by sepsis. In this study we quantified the contribution of reduced motor neuron …

Toll-Like Receptor 4 Mutation Suppresses Hyperhomocysteinemia-Mediated Hypertension., Anastasia Familtseva

Electronic Theses and Dissertations

Background: Hyperhomocysteinemia (HHcy) has been observed to promote hypertension, but the mechanisms are unclear. Toll-like receptor 4 (TLR-4) is a cellular membrane protein that is ubiquitously expressed in all cell types of the vasculature. TLR-4 activation has been shown to promote inflammation that has been associated with pathogenesis of hypertension. In this study, we hypothesize that HHcy induces hypertension by TLR-4 activation that promotes inflammatory cytokine up-regulation (IL-1β, IL-6, TNF-α) and initiation of mitochondrial dysfunction leading to cell death and chronic vascular inflammation. Methods: To test this hypothesis, we used C57BL/6J mice (WT); Cystathionine-β-synthase deficient mice (CBS+/-) with genetic mild …

The Role Of O-Glcnacase During Heart Failure., Sujith Dassanayaka

Electronic Theses and Dissertations

Global augmentation of protein O-GlcNAcylation occurs in response to a myriad of stressors and confers a survival advantage at the cellular level. This protective phenomenon has been demonstrated to mediate cardioprotection through various in vitro and in vivo studies during ischemia-reperfusion, myocardial infarction, and oxidative stress; however, relatively little is known of the regulation of protein O-GlcNAcylation. Protein O-GlcNAcylation is regulated by two antagonistic enzymes, namely, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). Ablation of cardiomyocyte OGT, the enzyme that catalyzes the addition of O-GlcNAc to proteins, exacerbates cardiac dysfunction during infarct-induced heart failure (HF). However, little is known of the …

Ovarian Tumour Growth Is Characterized By Mevalonate Pathway Gene Signature In An Orthotopic, Syngeneic Model Of Epithelial Ovarian Cancer., James B Greenaway, Carl Virtanen, Kata Osz, Tamas Revay, Daniel Hardy, Trevor Shepherd, Gabriel Dimattia, Jim Petrik

Physiology and Pharmacology Publications

Epithelial ovarian cancer (EOC) is the most lethal gynecological cancer and often is not detected until late stages when cancer cells transcoelomically metastasize to the abdomen and typically become resistant to therapy resulting in very low survival rates. We utilize an orthotopic, syngeneic mouse model to study late stage disease and have discovered that the tumor cells within the abdominal ascites are irreversibly re-programmed, with an increased tumorigenicity and resistance to apoptosis. The goal of this study was to characterize the reprogramming that occurred in the aggressive ascites-derived cells (28-2 cells) compared to the original cell line used for tumor …

Malignant Hyperthermia, Aaron Roth

Nursing Student Class Projects (Formerly MSN)

Malignant hyperthermia is a rare disease trait and can take place in a variety of settings. If not treated in a timely manner, the consequences will be dire. It is recommended that nurses and other healthcare personnel be properly educated on MH crises. By detecting the signs and symptoms associated with the disease, providers can efficiently remedy the crisis and save patient lives (Seifert, 2014). Since the discovery of dantrolene in 1975 and the advancement of genetics regarding MH, death rates dropped from about 80% to about 5% (Schneiderbanger et al., 2014). Today there is a MH group called the …

Complex Regional Pain Syndrome, Maria A. Hendrix

Nursing Student Class Projects (Formerly MSN)

Complex regional pain syndrome (CRPS) is a chronic and often disabling condition that is seen in many patients seeking pain management. The condition leaves patients in excruciating pain that is disproportionate to the inciting injury. In addition, patients with this pain disorder experience abnormal sensations such as cold and heat allodynia, hyperalgesia, edema, abnormal sudomotor activity and trophic changes (D. Lee et al., 2015). CRPS disproportionally affects four times as many women as men (Alexander, Peterlin, Perreault, Grothusen, & Schwartzman, 2012). There are two types of CRPS: type 1, often referred to as reflex sympathetic dystrophy (RSD), is not evident …

Associative Spike Timing-Dependent Potentiation Of The Basal Dendritic Excitatory Synapses In The Hippocampus In Vivo., Thomas K Fung, Clayton S Law, L Stan Leung

Physiology and Pharmacology Publications

Spike timing-dependent plasticity in the hippocampus has rarely been studied in vivo. Using extracellular potential and current source density analysis in urethane-anesthetized adult rats, we studied synaptic plasticity at the basal dendritic excitatory synapse in CA1 after excitation-spike (ES) pairing; E was a weak basal dendritic excitation evoked by stratum oriens stimulation, and S was a population spike evoked by stratum radiatum apical dendritic excitation. We hypothesize that positive ES pairing-generating synaptic excitation before a spike-results in long-term potentiation (LTP) while negative ES pairing results in long-term depression (LTD). Pairing (50 pairs at 5 Hz) at ES intervals of -10 …

Mechanisms Of Post-Hemorrhagic Hydrocephalus After Germinal Matrix Hemorrhage, Damon William Klebe

Loma Linda University Electronic Theses, Dissertations & Projects

The inherently fragile vasculature of the germinal matrix is susceptible to rupture, possibly as a result of hemodynamic and cardiorespiratory instability associated with prematurity. Germinal matrix hemorrhage is a leading cause of morbidity and mortality in preterm and/or very low birthweight infants, and post-hemorrhagic hydrocephalus is major consequence of severe grade hemorrhages. Chronic post-hemorrhagic hydrocephalus treatment involves surgical insertion of shunts, which are costly and prone to complications. Thus, a safe non-invasive therapeutic approach towards post-hemorrhagic hydrocephalus clinical management would significantly improve the quality of life for this patient population. Thrombin, cerebroventricular blood clots, and iron have been identified as …

Mechanism Of Chimeric Vaccine Mediated Immune Suppression Of Human Dendritic Cells, Jacques Christian Mbongue

Loma Linda University Electronic Theses, Dissertations & Projects

Type 1 diabetes mellitus is a chronic inflammatory disease in which insulin producing β-cells of the pancreatic islets are killed by autoreactive cells of the immune system in response to a loss of tolerance. Dendritic cells (DC) interact predominantly with naïve T cells to regulate the delicate balance between immunity and tolerance required to maintain immunological homeostasis. In this dissertation, immature human dendritic cells (iDC) were inoculated with a chimeric fusion protein vaccine containing the pancreatic β-cell auto-antigen proinsulin linked to a mucosal adjuvant the cholera toxin B subunit (CTB-INS). Proteomic analysis of vaccine inoculated DCs revealed strong up-regulation of …

There Is Relief For Constipated Patients Taking Opioids., Ahmad Mohammadieh, James Choi, Md, Chelsea Gonzalez, Do, Diyanah Elyaman, Md

Clinical Research in Practice: The Journal of Team Hippocrates

A critical appraisal and clinical application of Tack J, Lappalainen J, Diva U, Tummala R, Sostek M. Efficacy and safety of naloxegol in patients with opioid-induced constipation and laxative-inadequate response. United European Gastroenterol J. 2015 Oct;3(5):471-80. doi: 10.1177/2050640615604543

Synapse Formation In Monosynaptic Sensory–Motor Connections Is Regulated By Presynaptic Rho Gtpase Cdc42, Fumiyasu Imai, David R. Ladle, Jennifer R. Leslie, Xin Duan, Tilat A. Rizvi, Georgianne M. Ciraolo, Yi Zheng, Yutaka Yoshida

Neuroscience, Cell Biology & Physiology Faculty Publications

Spinal reflex circuit development requires the precise regulation of axon trajectories, synaptic specificity, and synapse formation. Of these three crucial steps, the molecular mechanisms underlying synapse formation between group Ia proprioceptive sensory neurons and motor neurons is the least understood. Here, we show that the Rho GTPase Cdc42 controls synapse formation in monosynaptic sensory–motor connections in presynaptic, but not postsynaptic, neurons. In mice lacking Cdc42 in presynaptic sensory neurons, proprioceptive sensory axons appropriately reach the ventral spinal cord, but significantly fewer synapses are formed with motor neurons compared with wild-type mice. Concordantly, electrophysiological analyses show diminished EPSP amplitudes in monosynaptic …

White Blood Cell Count Versus Temperature As Predictors Of Pediatric Bacteremia, Ashley Ashby, Loren Moscinski

Physician Assistant Capstones, 2016 to 2019

Introduction: Although the prevalence of bacteremia has largely declined with the development of the Haemophilus Influenza Type b (Hib) and pneumococcal vaccines, it continues to be a leading cause of morbidity and mortality in children. Thus, it is crucial to differentiate bacteremia from other illnesses via the clinical picture and laboratory test results. Objective: The purpose of this research was to determine whether there is a clinically significant difference between temperature and white blood cell (WBC) count as determinants of bacteremia in the pediatric population. Methods: A PubMed search was conducted utilizing the following terms and filters: temperature, WBC, pediatrics, …

Role Of Chemokine Rantes In The Regulation Of Perivascular Inflammation, T-Cell Accumulation, And Vascular Dysfunction In Hypertension., Tomasz P Mikolajczyk, Ryszard Nosalski, Piotr Szczepaniak, Klaudia Budzyn, Grzegorz Osmenda, Paul J. Marvar, +10 Additional Authors

Pharmacology and Physiology Faculty Publications

Recent studies have emphasized the role of perivascular inflammation in cardiovascular disease. We studied mechanisms of perivascular leukocyte infiltration in angiotensin II (Ang II)-induced hypertension and their links to vascular dysfunction. Chronic Ang II infusion in mice increased immune cell content of T cells (255 ± 130 to 1664 ± 349 cells/mg; P < 0.01), M1 and M2 macrophages, and dendritic cells in perivascular adipose tissue. In particular, the content of T lymphocytes bearing CC chemokine receptor (CCR) 1, CCR3, and CCR5 receptors for RANTES chemokine was increased by Ang II (CCR1, 15.6 ± 1.5% vs. 31 ± 5%; P < 0.01). Hypertension was associated with an increase in perivascular adipose tissue expression of the chemokine RANTES (relative quantification, 1.2 ± 0.2 vs. 3.5 ± 1.1; P < 0.05), which induced T-cell chemotaxis and vascular accumulation of T cells expressing the chemokine receptors CCR1, CCR3, and CCR5. Mechanistically, RANTES(-/-) knockout protected against vascular leukocyte, and in particular T lymphocyte infiltration (26 ± 5% in wild type Ang II vs. 15 ± 4% in RANTES(-/-)), which was associated with protection from endothelial dysfunction induced by Ang II. This effect was linked with diminished infiltration of IFN-γ-producing CD8(+) and double-negative CD3(+)CD4(-)CD8(-) T cells in perivascular space and reduced vascular oxidative stress while FoxP3(+) T-regulatory cells were unaltered. IFN-γ ex vivo caused significant endothelial dysfunction, which was reduced by superoxide anion scavenging. In a human cohort, a significant inverse correlation was observed between circulating RANTES levels as a biomarker and vascular function measured as flow-mediated dilatation (R = -0.3, P < 0.01) or endothelial injury marker von Willebrand factor (R = +0.3; P < 0.01). Thus, chemokine RANTES is important in the regulation of vascular dysfunction through modulation of perivascular inflammation.-Mikolajczyk, T. P., Nosalski, R., Szczepaniak, P., Budzyn, K., Osmenda, G., Skiba, D., Sagan, A., Wu, J., Vinh, A., Marvar, P. J., Guzik, B., Podolec, J., Drummond, G., Lob, H. E., Harrison, D. G., Guzik, T. J. Role of chemokine RANTES in the regulation of perivascular inflammation, T-cell accumulation, and vascular dysfunction in hypertension.

The Influence Of Mir-99a On Mtor Signaling Regulation In Colorectal Cancer Cell Lines., Jonathan Rice

Electronic Theses and Dissertations

Colorectal cancer (CRC) is the third most common cancer worldwide and the fourth most common cause of death. These are staggering statistics for a disease that can essentially be cured if caught early and the pathology is favorable to therapeutic intervention. There is currently a drastic decrease in five year survival as the cancer stage increases from locally confined disease to metastatic disease. These statistics suggest that although some strides have been made with colon cancer screening and early intervention, there is still much room for improvement in both screening and treatment of CRC. One of the pathways that have …

Na/K-Atpase Amplification Of Oxidant Stress; A Universal But Unrecognized Clinical Target?, Zijian Xie, Phd, Joseph I. Shapiro, Md

Joseph I Shapiro MD

The Na/K-ATPase has a signaling function which appears to be separate from its ion pumping function. This signaling function refers to the transduction of conformational changes in the Na/K-ATPase alpha1 subunit into activating Src’s tyrosine kinase activity, triggering a cascade which generates reactive oxygen species (ROS), modulates other signaling pathways, and causes many physiological and pathophysiological effects. We have recently observed that ROS themselves as well as cardiotonic steroids can actually initiate the signal by directly inducing conformational changes in alpha1. It therefore appears that the Na/K-ATPase signal cascade can serve as a feed forward amplification for ROS with circulating …

Na/K-Atpase Amplification Of Oxidant Stress; A Universal But Unrecognized Clinical Target?, Zijian Xie, Phd, Joseph I. Shapiro, Md

Marshall Journal of Medicine

The Na/K-ATPase has a signaling function which appears to be separate from its ion pumping function. This signaling function refers to the transduction of conformational changes in the Na/K-ATPase alpha1 subunit into activating Src’s tyrosine kinase activity, triggering a cascade which generates reactive oxygen species (ROS), modulates other signaling pathways, and causes many physiological and pathophysiological effects. We have recently observed that ROS themselves as well as cardiotonic steroids can actually initiate the signal by directly inducing conformational changes in alpha1. It therefore appears that the Na/K-ATPase signal cascade can serve as a feed forward amplification for ROS with circulating …

Ablation Of Matrix Metalloproteinase-9 Prevents Cardiomyocytes Contractile Dysfunction In Diabetics., Priyanka Prathipati, Naira Metreveli, Shyam Sundar Nandi, Suresh C. Tyagi, Paras K. Mishra

Journal Articles: Cellular & Integrative Physiology

Elevated expression and activity of matrix metalloproteinase-9 (MMP9) and decreased contractility of cardiomyocytes are documented in diabetic hearts. However, it is unclear whether MMP is involved in the regulation of contractility of cardiomyocytes in diabetic hearts. In the present study, we tested the hypothesis that MMP9 regulates contractility of cardiomyocytes in diabetic hearts, and ablation of MMP9 prevents impaired contractility of cardiomyocytes in diabetic hearts. To determine the specific role of MMP9 in cardiomyocyte contractility, we used 12-14 week male WT (normoglycemic sibling of Akita), Akita, and Ins(2+∕-)/MMP9(-∕-) (DKO) mice. DKO mice were generated by cross-breeding male Ins2(+∕-) Akita (T1D) …