keyword
MENU ▼
Read by QxMD icon Read
search

Sodium channelopathies

keyword
https://www.readbyqxmd.com/read/28325641/spectrum-of-nondystrophic-skeletal-muscle-channelopathies-in-children
#1
Fouad Al-Ghamdi, Basil T Darras, Partha S Ghosh
BACKGROUND: The nondystrophic skeletal muscle channelopathies are a group of disorders caused by mutations of various voltage-gated ion channel genes, including nondystrophic myotonia and periodic paralysis. METHODS: We identified patients with a diagnosis of muscle channelopathy from our neuromuscular database in a tertiary care pediatric center from 2005 to 2015. We then performed a retrospective review of their medical records for demographic characteristics, clinical features, investigations, treatment, and follow-up...
February 16, 2017: Pediatric Neurology
https://www.readbyqxmd.com/read/28290897/-the-brugada-syndrome-as-a-cause-of-sudden-death-diagnostics-and-clinical-manifestations-in-children
#2
I M Miklashevich, M A Shkolnikova
The Brugada syndrome is a hereditary potentially arrhythmogenic disease related to the category of channelopathies. It is manifested as syncopal states and sudden death in young people in the absence of structural cardiac disease. The basis of the disease is genetically determined abnormality of function of ionic channels of cardiomyocytes (sodium, potassium, calcium) phenotypically manifesting as sustained or transitory segment-ST elevation and high risk of polymorphic ventricular tachycardia, fibrillation, and sudden death...
October 2016: Kardiologiia
https://www.readbyqxmd.com/read/28286482/restoration-of-epithelial-sodium-channel-function-by-synthetic-peptides-in-pseudohypoaldosteronism-type-1b-mutants
#3
Anita Willam, Mohammed Aufy, Susan Tzotzos, Heinrich Evanzin, Sabine Chytracek, Sabrina Geppert, Bernhard Fischer, Hendrik Fischer, Helmut Pietschmann, Istvan Czikora, Rudolf Lucas, Rosa Lemmens-Gruber, Waheed Shabbir
The synthetically produced cyclic peptides solnatide (a.k.a. TIP or AP301) and its congener AP318, whose molecular structures mimic the lectin-like domain of human tumor necrosis factor (TNF), have been shown to activate the epithelial sodium channel (ENaC) in various cell- and animal-based studies. Loss-of-ENaC-function leads to a rare, life-threatening, salt-wasting syndrome, pseudohypoaldosteronism type 1B (PHA1B), which presents with failure to thrive, dehydration, low blood pressure, anorexia and vomiting; hyperkalemia, hyponatremia and metabolic acidosis suggest hypoaldosteronism, but plasma aldosterone and renin activity are high...
2017: Frontiers in Pharmacology
https://www.readbyqxmd.com/read/28185290/computational-analysis-of-the-human-sinus-node-action-potential-model-development-and-effects-of-mutations
#4
Alan Fabbri, Matteo Fantini, Ronald Wilders, Stefano Severi
The sinoatrial node (SAN) is the normal pacemaker of the mammalian heart.  Over several decades, a large amount of data on the ionic mechanisms underlying the spontaneous electrical activity of SAN pacemaker cells has been obtained, mostly in experiments on single cells isolated from rabbit SAN. This wealth of data has allowed the development of mathematical models of the electrical activity of rabbit SAN pacemaker cells. Our aim was to construct a more comprehensive model of the electrical activity of a human SAN pacemaker cell, using recently obtained electrophysiological data from human SAN pacemaker cells...
February 9, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/28183995/structure-of-a-eukaryotic-voltage-gated-sodium-channel-at-near-atomic-resolution
#5
Huaizong Shen, Qiang Zhou, Xiaojing Pan, Zhangqiang Li, Jianping Wu, Nieng Yan
Voltage-gated sodium (Nav) channels are responsible for the initiation and propagation of action potentials. They are associated with a variety of channelopathies and are targeted by multiple pharmaceutical drugs and natural toxins. Here, we report the cryo-EM structure of a putative Nav channel from American cockroach (designated NavPaS) at 3.8-Å resolution. The voltage sensing domains (VSDs) of the four repeats exhibit distinct conformations. The entrance to the asymmetric selectivity filter vestibule is guarded by heavily glycosylated and disulfide bond-stabilized extracellular loops...
February 9, 2017: Science
https://www.readbyqxmd.com/read/28150151/structure-based-assessment-of-disease-related-mutations-in-human-voltage-gated-sodium-channels
#6
REVIEW
Weiyun Huang, Minhao Liu, S Frank Yan, Nieng Yan
Voltage-gated sodium (Nav) channels are essential for the rapid upstroke of action potentials and the propagation of electrical signals in nerves and muscles. Defects of Nav channels are associated with a variety of channelopathies. More than 1000 disease-related mutations have been identified in Nav channels, with Nav1.1 and Nav1.5 each harboring more than 400 mutations. Nav channels represent major targets for a wide array of neurotoxins and drugs. Atomic structures of Nav channels are required to understand their function and disease mechanisms...
February 1, 2017: Protein & Cell
https://www.readbyqxmd.com/read/28090678/the-epileptic-and-nonepileptic-spectrum-of-paroxysmal-dyskinesias-channelopathies-synaptopathies-and-transportopathies
#7
REVIEW
Roberto Erro, Kailash P Bhatia, Alberto J Espay, Pasquale Striano
Historically, the syndrome of primary paroxysmal dyskinesias was considered a group of disorders as a result of ion channel dysfunction. This proposition was primarily based on the discovery of mutations in ion channels, which caused other episodic neurological disorders such as epilepsy and migraine and also supported by the frequent association between paroxysmal dyskinesias and epilepsy. However, the discovery of the genes responsible for the 3 classic forms of paroxysmal dyskinesias disproved this ion channel theory...
March 2017: Movement Disorders: Official Journal of the Movement Disorder Society
https://www.readbyqxmd.com/read/28024841/a-novel-ile1455thr-variant-in-the-skeletal-muscle-sodium-channel-alpha-subunit-in-a-patient-with-a-severe-adult-onset-proximal-myopathy-with-electrical-myotonia-and-a-patient-with-mild-paramyotonia-phenotype
#8
Marcin Bednarz, Bas C Stunnenberg, Benno Kusters, Erik-Jan Kamsteeg, Christiaan G Saris, James Groome, Vern Winston, Giovanni Meola, Karin Jurkat-Rott, Nicol C Voermans
In sodium channelopathies, a severe fixed myopathy caused by a dominant mutation is rare. We describe two unrelated patients with a novel variant, p.Ile1455Thr, with phenotypes of paramyotonia in one case and fixed proximal myopathy with latent myotonia in another. In-vitro whole cell patch-clamp studies show that the mutation slows inactivation and accelerates recovery, in line with other paramyotonia variants with destabilized fast inactivation as pathomechanism. Additionally, p.IleI1455 causes a loss-of-function by reduced membrane insertion, right-shift of activation, and slowed kinetics...
October 19, 2016: Neuromuscular Disorders: NMD
https://www.readbyqxmd.com/read/28008953/glycosuria-and-renal-outcomes-in-patients-with-nondiabetic-advanced-chronic-kidney-disease
#9
Chi-Chih Hung, Hugo You-Hsien Lin, Jia-Jung Lee, Lee Moay Lim, Yi-Wen Chiu, Heng-Pin Chiang, Shang-Jyh Hwang, Hung-Chun Chen
Sodium glucose cotransporter 2 inhibitors have shown a potential for renoprotection beyond blood glucose lowering. Glycosuria in nondiabetic patients with chronic kidney disease (CKD) is sometimes noted. Whether glycosuria in CKD implies a channelopathy or proximal tubulopathy is not known. The consequence of glycosuria in CKD is also not studied. We performed a cross-sectional study for the association between glycosuria and urine electrolyte excretion in 208 nondiabetic patients. Fractional excretion (FE) of glucose >4% was 3...
December 23, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27922499/the-dystrophic-and-nondystrophic-myotonias
#10
Valeria A Sansone
PURPOSE OF REVIEW: This article describes clinical and electrical myotonia and provides an update on the classification, diagnosis, and management of myotonic disorders. RECENT FINDINGS: In the myotonic dystrophies, antisense oligonucleotides provide a general strategy to correct RNA gain of function and modulate the expression of CTG expanded repeats; they are currently being tested in a phase 1-2 randomized controlled trial in patients with adult-onset myotonic dystrophy type 1...
December 2016: Continuum: Lifelong Learning in Neurology
https://www.readbyqxmd.com/read/27882075/in-silico-evaluation-of-the-potential-antiarrhythmic-effect-of-epigallocatechin-3-gallate-on-cardiac-channelopathies
#11
Maroua Boukhabza, Jaouad El Hilaly, Nourdine Attiya, Ahmed El-Haidani, Younes Filali-Zegzouti, Driss Mazouzi, Mohamed-Yassine Amarouch
Ion channels are transmembrane proteins that allow the passage of ions according to the direction of their electrochemical gradients. Mutations in more than 30 genes encoding ion channels have been associated with an increasingly wide range of inherited cardiac arrhythmias. In this line, ion channels become one of the most important molecular targets for several classes of drugs, including antiarrhythmics. Nevertheless, antiarrhythmic drugs are usually accompanied by some serious side effects. Thus, developing new approaches could offer added values to prevent and treat the episodes of arrhythmia...
2016: Computational and Mathematical Methods in Medicine
https://www.readbyqxmd.com/read/27867041/infantile-epileptic-encephalopathy-associated-with-scn2a-mutation-responsive-to-oral-mexiletine
#12
Laura A Foster, Maria R Johnson, John T MacDonald, Peter I Karachunski, Thomas R Henry, David R Nascene, Brian P Moran, Gerald V Raymond
BACKGROUND: Genetic alterations are significant causes of epilepsy syndromes; especially early-onset epileptic encephalopathies and voltage-gated sodium channelopathies are among the best described. Mutations in the SCN2A subunit of voltage-gated sodium channels have been associated with benign familial neonatal-infantile seizures, generalized epilepsy febrile seizures plus, and an early-onset infantile epileptic encephalopathy. METHOD: We describe two infants with medically refractory seizures due to a de novo SCN2A mutation...
January 2017: Pediatric Neurology
https://www.readbyqxmd.com/read/27688678/all-that-looks-like-brugada-is-not-brugada-case-series-of-brugada-phenocopy-caused-by-hyponatremia
#13
Yashwant Agrawal, Sourabh Aggarwal, Jagadeesh K Kalavakunta, Vishal Gupta
Brugada syndrome (BS), a life-threatening channelopathy associated with reduced inward sodium current due to dysfunctional sodium channels, is characterized by ST-segment elevation with downsloping "coved type" (type 1) or "saddle back" (type 2) pattern in V1-V3 precordial chest leads (1, 2). Brugada phenocopy, a term describing conditions inducing Brugada-like pattern of electrocardiogram (EKG) manifestations in patients without true BS, is an emerging condition (3). We describe a case series of Brugada phenocopy with hyponatremia...
October 2016: Journal of the Saudi Heart Association
https://www.readbyqxmd.com/read/27595042/scn2a-related-early-onset-epileptic-encephalopathy-responsive-to-phenobarbital
#14
Fiona M Baumer, Jurriaan M Peters, Christelle M El Achkar, Phillip L Pearl
Voltage-gated sodium channels (Nav) are critical regulators of neuronal excitability. Genes for the α-subunits of three sodium channel subtypes-SCN1A, SCN2A, and SCN3A-are all located on chromosome 2q24. A full-term boy with an unremarkable birth history presented at 1 month of age with unusual movements that had started on day of life 2. Exam was notable for lack of visual attention, hypotonia, and hyperreflexia. Electroencephalogram (EEG) showed an invariant burst suppression with multifocal spikes, ictal episodes with bicycling movements associated with buildups of rhythmic activity, and epileptic spasms...
March 2016: Journal of Pediatric Epilepsy
https://www.readbyqxmd.com/read/27586295/nav-channels-in-damaged-membranes
#15
C E Morris, B Joos
Sick excitable cells (ie, Nav channel-expressing cells injured by trauma, ischemia, inflammatory, and other conditions) typically exhibit "acquired sodium channelopathies" which, we argue, reflect bleb-damaged membranes rendering their Nav channels "leaky." The situation is excitotoxic because untreated Nav leak exacerbates bleb damage. Fast Nav inactivation (a voltage-independent process) is so tightly coupled, kinetically speaking, to the inherently voltage-dependent process of fast activation that when bleb damage accelerates and thus left-shifts macroscopic fast activation, fast inactivation accelerates to the same extent...
2016: Current Topics in Membranes
https://www.readbyqxmd.com/read/27586279/on-the-natural-and-unnatural-history-of-the-voltage-gated-na-channel
#16
E G Moczydlowski
This review glances at the voltage-gated sodium (Na(+)) channel (NaV) from the skewed perspective of natural history and the history of ideas. Beginning with the earliest natural philosophers, the objective of biological science and physiology was to understand the basis of life and discover its intimate secrets. The idea that the living state of matter differs from inanimate matter by an incorporeal spirit or mystical force was central to vitalism, a doctrine based on ancient beliefs that persisted until the last century...
2016: Current Topics in Membranes
https://www.readbyqxmd.com/read/27514480/ion-channelopathies-in-functional-gi-disorders
#17
REVIEW
Arthur Beyder, Gianrico Farrugia
In the gastrointestinal (GI) tract, abnormalities in secretion, absorption, motility, and sensation have been implicated in functional gastrointestinal disorders (FGIDs). Ion channels play important roles in all these GI functions. Disruptions of ion channels' ability to conduct ions can lead to diseases called ion channelopathies. Channelopathies can result from changes in ion channel biophysical function or expression due to mutations, posttranslational modification, and accessory protein malfunction. Channelopathies are strongly established in the fields of cardiology and neurology, but ion channelopathies are only beginning to be recognized in gastroenterology...
October 1, 2016: American Journal of Physiology. Gastrointestinal and Liver Physiology
https://www.readbyqxmd.com/read/27242528/therapeutic-approaches-to-genetic-ion-channelopathies-and-perspectives-in-drug-discovery
#18
REVIEW
Paola Imbrici, Antonella Liantonio, Giulia M Camerino, Michela De Bellis, Claudia Camerino, Antonietta Mele, Arcangela Giustino, Sabata Pierno, Annamaria De Luca, Domenico Tricarico, Jean-Francois Desaphy, Diana Conte
In the human genome more than 400 genes encode ion channels, which are transmembrane proteins mediating ion fluxes across membranes. Being expressed in all cell types, they are involved in almost all physiological processes, including sense perception, neurotransmission, muscle contraction, secretion, immune response, cell proliferation, and differentiation. Due to the widespread tissue distribution of ion channels and their physiological functions, mutations in genes encoding ion channel subunits, or their interacting proteins, are responsible for inherited ion channelopathies...
2016: Frontiers in Pharmacology
https://www.readbyqxmd.com/read/27214504/novel-mutations-in-the-nonselective-sodium-leak-channel-nalcn-lead-to-distal-arthrogryposis-with-increased-muscle-tone
#19
Mert Karakaya, Raoul Heller, Volkmar Kunde, Klaus-Peter Zimmer, Cho-Ming Chao, Peter Nürnberg, Sebahattin Cirak
Distal arthrogryposis (DA) is a feature in genetically and clinically heterogeneous groups of disorders. Mostly myopathic and neurogenic defects have been described, but many patients remain without genetic diagnosis. We are elaborating on the clinical presentation of neonatal cases with DA who carry novel mutations in the nonselective sodium leak channel (NALCN). Two patients reported herein were remarkable for central hypertonicity in addition to DA. By trio-whole exome sequencing, two undescribed de novo mutations in NALCN were revealed...
August 2016: Neuropediatrics
https://www.readbyqxmd.com/read/27212419/dramatic-response-after-lamotrigine-in-a-patient-with-epileptic-encephalopathy-and-a-de-novocacna1a-variant
#20
Heather M Byers, Christopher W Beatty, Si Houn Hahn, Sidney M Gospe
BACKGROUND: Channelopathies are a group of monogenic disorders that affect a single ion channel and can result in neurological disease. While a rare cause of epilepsy, channelopathies offer unique insight to the molecular basis of epilepsy and treatment opportunities. Calcium homeostasis is tightly regulated by a series of interacting subunits. CACNA1A encodes the principal pore-forming subunit of the voltage-gated P/Q-type calcium channel, alpha1. Patients with epileptic encephalopathy due to pathogenic variants in CACNA1A have been previously described and are challenging to treat...
July 2016: Pediatric Neurology
keyword
keyword
50416
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"