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https://www.readbyqxmd.com/read/28776165/prolongation-of-the-qtc-interval-in-hiv-infected-individuals-compared-to-the-general-population
#1
Nico Reinsch, Marina Arendt, Marie Henrike Geisel, Christina Schulze, Volker Holzendorf, Anna Warnke, Till Neumann, Norbert H Brockmeyer, Dirk Schadendorf, Lewin Eisele, Raimund Erbel, Susanne Moebus, Karl-Heinz Jöckel, Stefan Esser
OBJECTIVES: Prolonged QT interval is associated with arrhythmias and sudden death. An increased prevalence of QT interval prolongation in human immunodeficiency virus-infected (HIV) subjects was previously described. The impact of different medications and HIV infection itself on the QT interval is rarely investigated in large HIV+ cohorts. METHODS: We compared QT interval measurement in 496 HIV(+) patients of the HIV-HEART study (HIVH) and 992 sex- and age-matched controls of the population-based German Heinz Nixdorf Recall study (HNR)...
August 3, 2017: Infection
https://www.readbyqxmd.com/read/28746337/genome-wide-analysis-of-ivermectin-response-by-onchocerca-volvulus-reveals-that-genetic-drift-and-soft-selective-sweeps-contribute-to-loss-of-drug-sensitivity
#2
Stephen R Doyle, Catherine Bourguinat, Hugues C Nana-Djeunga, Jonas A Kengne-Ouafo, Sébastien D S Pion, Jean Bopda, Joseph Kamgno, Samuel Wanji, Hua Che, Annette C Kuesel, Martin Walker, Maria-Gloria Basáñez, Daniel A Boakye, Mike Y Osei-Atweneboana, Michel Boussinesq, Roger K Prichard, Warwick N Grant
BACKGROUND: Treatment of onchocerciasis using mass ivermectin administration has reduced morbidity and transmission throughout Africa and Central/South America. Mass drug administration is likely to exert selection pressure on parasites, and phenotypic and genetic changes in several Onchocerca volvulus populations from Cameroon and Ghana-exposed to more than a decade of regular ivermectin treatment-have raised concern that sub-optimal responses to ivermectin's anti-fecundity effect are becoming more frequent and may spread...
July 2017: PLoS Neglected Tropical Diseases
https://www.readbyqxmd.com/read/28705431/-effect-of-intermittent-variable-intensity-exercise-on-qt-variation-and-risk-of-sudden-cardiac-death-among-cameroonian-school-adolescents
#3
E C Bika Lele, M N Pepouomi, A Temfemo, J Mekoulou, P Assomo Ndemba, S H Mandengue
INTRODUCTION: Several cases of sudden deaths are observed among students practicing sport and physical activity (SPA). Just few studies have been carried out on the variation of the QT (interval) and risk of sudden death during sporting exercises. AIM: To determine the effect of variable intermittent stress intensity on the variation of QT and the risk of sudden cardiac death. PATIENTS AND METHODS: Form 4, lower sixth and upper sixth students were recruited from a high school in Douala (Cameroon)...
July 10, 2017: Annales de Cardiologie et D'angéiologie
https://www.readbyqxmd.com/read/28699261/npq-t-a-chlorophyll-fluorescence-parameter-for-rapid-estimation-and-imaging-of-non-photochemical-quenching-of-excitons-in-photosystem-ii-associated-antenna-complexes
#4
Stefanie Tietz, Christopher C Hall, Jeffrey A Cruz, David M Kramer
In photosynthesis, light energy is absorbed by light-harvesting complexes and used to drive photochemistry. However, a fraction of absorbed light is lost to non-photochemical quenching (NPQ) that reflects several important photosynthetic processes to dissipate excess energy. Currently, estimates of NPQ and its individual components (qE , qI , qZ and qT ) are measured from pulse-amplitude-modulation (PAM) measurements of chlorophyll fluorescence yield and require measurements of the maximal yield of fluorescence in fully dark-adapted material (Fm ), when NPQ is assumed to be negligible...
August 2017: Plant, Cell & Environment
https://www.readbyqxmd.com/read/28673509/discovery-of-a-new-mexiletine-derived-agonist-of-the-herg-k-channel
#5
Roberta Gualdani, Maria Maddalena Cavalluzzi, Francesco Tadini-Buoninsegni, Giovanni Lentini
The human Ether-a-go-go Related Gene (hERG) potassium channel plays a central role in the rapid component (IKr) of cardiac action potential repolarization phase. A large number of structurally different compounds block hERG and cause a high risk of arrhythmias. Among the drugs that block hERG channel, a few compounds have been identified as hERG channel activators. Such compounds may be useful, at least in theory, for the treatment of long term QT syndrome. Here we describe a new activator of hERG channel, named MC450...
June 19, 2017: Biophysical Chemistry
https://www.readbyqxmd.com/read/28624887/voriconazole-induced-qt-prolongation-among-hemato-oncologic-patients-clinical-characteristics-and-risk-factors
#6
I Gueta, R Loebstein, N Markovits, Y Kamari, H Halkin, G Livni, H Yarden-Bilavsky
PURPOSE: The purpose of this study is to determine the rate of QTcP and associated risk factors in patients treated with voriconazole. METHODS: We conducted a retrospective chart review of all patients treated with voriconazole in a large tertiary center between 2009 and 2015, using paired comparison of QTc intervals on and off voriconazole treatment, adjusted for comorbidities, electrolyte abnormalities, and concurrent medications. RESULTS: Fifty-four patients were included, of whom 53 were diagnosed with oncologic/hemato-oncologic disease...
September 2017: European Journal of Clinical Pharmacology
https://www.readbyqxmd.com/read/28610624/normal-limits-of-the-electrocardiogram-derived-from-a-large-database-of-brazilian-primary-care-patients
#7
Daniel M F Palhares, Milena S Marcolino, Thales M M Santos, José L P da Silva, Paulo R Gomes, Leonardo B Ribeiro, Peter W Macfarlane, Antonio L P Ribeiro
BACKGROUND: Knowledge of the normal limits of the electrocardiogram (ECG) is mandatory for establishing which patients have abnormal ECGs. No studies have assessed the reference standards for a Latin American population. Our aim was to establish the normal ranges of the ECG for pediatric and adult Brazilian primary care patients. METHODS: This retrospective observational study assessed all the consecutive 12-lead digital electrocardiograms of primary care patients at least 1 year old in Minas Gerais state, Brazil, recorded between 2010 and 2015...
June 13, 2017: BMC Cardiovascular Disorders
https://www.readbyqxmd.com/read/28608915/abc-om-pediatrisk-ekg-tolkning
#8
Caroline Fransson, Stefan Johansson, Cecilia Halvorsen
The ABC of paediatric ECG interpretation In paediatric patients, ECG is used as a tool for investigation of arrhythmias, chest pain, syncope, intoxications and congenital heart abnormalities. Paediatric ECGs differ significantly from adult ECGs, and change gradually during childhood, largely because of the changes that start with the transition of foetal circulation at birth. This evolution is most prominent during the first year of life, but it is not until the late adolescent years that the ECG corresponds to that of adults...
June 9, 2017: Läkartidningen
https://www.readbyqxmd.com/read/28590366/effect-of-gwas-identified-genetic-variants-on-maximum-qt-interval-in-patients-with-schizophrenia-receiving-antipsychotic-agents-a-24-hour-holter-ecg-study
#9
Junzo Watanabe, Naoki Fukui, Yutaro Suzuki, Takuro Sugai, Shin Ono, Nobuto Tsuneyama, Mami Saito, Misuzu Tajiri, Toshiyuki Someya
BACKGROUND: Users of antipsychotics (APs) have a risk of sudden cardiac death (SCD). Sudden cardiac death in such patients is thought to be largely due to drug-induced QT prolongation. It has been reported that many subjects with drug-induced torsades de pointes (TdP) have risk alleles associated with subclinical congenital long QT syndrome. METHODS: We investigated the effects of the risk alleles associated with long QT on the QT interval in patients receiving APs using 24-hour Holter electrocardiograms to take into account the circadian fluctuation of QT intervals...
August 2017: Journal of Clinical Psychopharmacology
https://www.readbyqxmd.com/read/28542844/the-inward-rectifier-current-inhibitor-pa-6-terminates-atrial-fibrillation-and-does-not-cause-ventricular-arrhythmias-in-goat-and-dog-models
#10
Yuan Ji, Rosanne Varkevisser, Dragan Opacic, Alexandre Bossu, Marion Kuiper, Jet D M Beekman, Sihyung Yang, Azinwi Phina Khan, Dobromir Dobrev, Niels Voigt, Michael Zhuo Wang, Sander Verheule, Marc A Vos, Marcel A G van der Heyden
BACKGROUND AND PURPOSE: The density of the inward rectifier current (IK1 ) increases in atrial fibrillation (AF), shortening effective refractory period and thus promoting atrial re-entry. The synthetic compound pentamidine analogue 6 (PA-6) is a selective and potent IK1 inhibitor. We tested PA-6 for anti-AF efficacy and potential proarrhythmia, using established models in large animals. EXPERIMENTAL APPROACH: PA-6 was applied i.v. in anaesthetized goats with rapid pacing-induced AF and anaesthetized dogs with chronic atrio-ventricular (AV) block...
August 2017: British Journal of Pharmacology
https://www.readbyqxmd.com/read/28515853/qt-prolongation-is-associated-with-increased-mortality-in-end-stage-liver-disease
#11
Sun Moon Kim, Bennet George, Diego Alcivar-Franco, Charles L Campbell, Richard Charnigo, Brian Delisle, Jonathan Hundley, Yousef Darrat, Gustavo Morales, Samy-Claude Elayi, Alison L Bailey
AIM: To determine the prevalence of QT prolongation in a large series of end stage liver disease (ESLD) patients and its association to clinical variables and mortality. METHODS: The QT interval was measured and corrected for heart rate for each patient, with a prolonged QT cutoff defined as QT > 450 ms for males and QT > 470 ms for females. Multiple clinical variables were evaluated including sex, age, serum sodium, international normalized ratio, creatinine, total bilirubin, beta-blocker use, Model for End-Stage Liver Disease (MELD), MELD-Na, and etiology of liver disease...
April 26, 2017: World Journal of Cardiology
https://www.readbyqxmd.com/read/28509723/determinants-of-retinal-microvascular-features-and-their-relationships-in-two-european-populations
#12
Mirna Kirin, Reka Nagy, Thomas J MacGillivray, Ozren Polašek, Caroline Hayward, Igor Rudan, Harry Campbell, Sarah Wild, Alan F Wright, James F Wilson, Veronique Vitart
OBJECTIVES: To examine factors influencing retinal vasculature in two environmentally contrasted, cross-sectional studies of adult participants of European descent and to estimate the extent and specificity of genetic contributions to each retinal vasculature feature. METHODS: Retinal images from 1088 participants in the Orkney Complex Disease Study and 387 in the CROATIA-Korčula study, taken using the same nonmydriatic camera system and graded by the same person, were evaluated...
August 2017: Journal of Hypertension
https://www.readbyqxmd.com/read/28500657/modulation-of-kv-11-1-herg-channels-by-5-1h-indazol-5-yl-oxy-methyl-n-4-trifluoromethoxy-phenyl-pyrimidin-2-amine-itp-2-a-novel-small-molecule-activator
#13
Harinath Sale, Samrat Roy, Jayakumar Warrier, Srinivasan Thangathirupathy, Yoganand Vadari, Shruthi K Gopal, Prasad Krishnamurthy, Manjunath Ramarao
BACKGROUND AND PURPOSE: Activators of Kv 11.1 (hERG) channels have potential utility in the treatment of acquired and congenital long QT (LQT) syndrome. Here, we describe a new hERG channel activator, 5-(((1H-indazol-5-yl)oxy)methyl)-N-(4-(trifluoromethoxy)phenyl)pyrimidin-2-amine (ITP-2), with a chemical structure distinct from previously reported compounds. EXPERIMENTAL APPROACH: Conventional electrophysiological methods were used to assess the effects of ITP-2 on hERG1a and hERG1a/1b channels expressed heterologously in HEK-293 cells...
August 2017: British Journal of Pharmacology
https://www.readbyqxmd.com/read/28499268/first-universal-pharmacophore-model-for-herg1-k-channel-activators-acther
#14
Serdar Durdagi, Ismail Erol, Ramin Ekhteiari Salmas, Matthew Patterson, Sergei Y Noskov
The intra-cavitary drug blockade of hERG1 channel has been extensively studied, both experimentally and theoretically. Structurally diverse ligands inadvertently block the hERG1 K(+) channel currents lead to drug induced Long QT Syndrome (LQTS). Accordingly, designing either hERG1 channel openers or current activators, with the potential to target other binding pockets of the channel, has been introduced as a viable approach in modern anti-arrhythmia drug development. However, reports and investigations on the molecular mechanisms underlying activators binding to the hERG1 channel remain sparse and the overall molecular design principles are largely unknown...
April 5, 2017: Journal of Molecular Graphics & Modelling
https://www.readbyqxmd.com/read/28486916/are-markers-of-cardiac-dysfunction-useful-in-the-assessment-of-cardiovascular-risk-in-dialysis-patients
#15
Beata Franczyk, Anna Gluba-Brzózka, Piotr Bartnicki, Maciej Banach, Jacek Rysz
Cardiovascular morbidity and mortality of dialysis patients is a major problem in this group. The purpose of this study was also to evaluate whether any of studied markers are better than troponin in early detection of the occurrence of ventricular arrhythmias and prolongation of QT interval. This study included 45 patients undergoing haemodialysis. ECG Holter and echocardiographic examination were performed before and after dialysis. The concentration of markers: copeptin, GDF-15, HFABP and troponin were measured with the use of ELISA tests...
May 8, 2017: Current Pharmaceutical Design
https://www.readbyqxmd.com/read/28443483/aneurysm-size-and-the-windkessel-effect-an-analysis-of-contrast-intensity-in-digital-subtraction-angiography
#16
Ahmed E Hussein, Darian R Esfahani, Andreas Linninger, Fady T Charbel, Chih-Yang Hsu, Fady T Charbel, Ali Alaraj
Large cerebral aneurysms are considered more dangerous than their smaller counterparts, with higher risk of subarachnoid hemorrhage. Understanding the hemodynamics of large aneurysms has potential to predict their response to treatment. Digital subtraction angiography images for patients with intracranial aneurysms over a seven-year period were reviewed. Unruptured solitary aneurysms of the internal carotid artery (ICA) proximal to the terminus and posterior communicating artery were included. Contrast intensity over time was analyzed at the center of the M1 segment of the middle cerebral artery distal to the aneurysm and compared to the contralateral side...
January 1, 2017: Interventional Neuroradiology
https://www.readbyqxmd.com/read/28437484/ecg-view-ii-a-freely-accessible-electrocardiogram-database
#17
Young-Gun Kim, Dahye Shin, Man Young Park, Sukhoon Lee, Min Seok Jeon, Dukyong Yoon, Rae Woong Park
The Electrocardiogram Vigilance with Electronic data Warehouse II (ECG-ViEW II) is a large, single-center database comprising numeric parameter data of the surface electrocardiograms of all patients who underwent testing from 1 June 1994 to 31 July 2013. The electrocardiographic data include the test date, clinical department, RR interval, PR interval, QRS duration, QT interval, QTc interval, P axis, QRS axis, and T axis. These data are connected with patient age, sex, ethnicity, comorbidities, age-adjusted Charlson comorbidity index, prescribed drugs, and electrolyte levels...
2017: PloS One
https://www.readbyqxmd.com/read/28403766/controversies-in-diagnosis-and-management-of-community-acquired-pneumonia
#18
REVIEW
Sarah Sparham, Patrick Gp Charles
Community-acquired pneumonia (CAP) is a common condition; however, it appears to be overdiagnosed. Diagnosing CAP too frequently may be adding to the problems of overuse of antibiotics, such as bacterial resistance in the community and greater costs and complications in individuals. Data support that most patients with non-severe CAP can be treated for 3-5 days; however, most patients with CAP are receiving much longer courses of therapy. Macrolides such as azithromycin have the potential to prolong the QT interval, although large population studies show that this does not appear to result in excess cardiac mortality...
April 17, 2017: Medical Journal of Australia
https://www.readbyqxmd.com/read/28403196/validation-of-automatic-measurement-of-qt-interval-variability
#19
Peter R Rijnbeek, Marten E van den Berg, Gerard van Herpen, Henk J Ritsema van Eck, Jan A Kors
BACKGROUND: Increased variability of beat-to-beat QT-interval durations on the electrocardiogram (ECG) has been associated with increased risk for fatal and non-fatal cardiac events. However, techniques for the measurement of QT variability (QTV) have not been validated since a gold standard is not available. In this study, we propose a validation method and illustrate its use for the validation of two automatic QTV measurement techniques. METHODS: Our method generates artificial standard 12-lead ECGs based on the averaged P-QRS-T complexes from a variety of existing ECG signals, with simulated intrinsic (QT interval) and extrinsic (noise, baseline wander, signal length) variations...
2017: PloS One
https://www.readbyqxmd.com/read/28394409/evaluation-of-qtc-in-rett-syndrome-correlation-with-age-severity-and-genotype
#20
Jane Crosson, Siddharth Srivastava, Genila M Bibat, Siddharth Gupta, Aditi Kantipuly, Constance Smith-Hicks, Scott M Myers, Abanti Sanyal, Gayane Yenokyan, Joel Brenner, Sakkubai R Naidu
Rett syndrome (RTT) is caused by MECP2 mutations, resulting in various neurological symptoms. Prolonged corrected QT interval (QTc) is also reported and is a speculated cause of sudden death in RTT. The purpose of this study was to correlate QTc in RTT patients with age, clinical severity, and genotype. 100 RTT patients (98 females, 2 males) with MECP2 mutations underwent baseline neurological evaluation (KKI-RTT Severity Scale) and QTc measurement (standard 12 lead electrocardiogram) as part of our prospective natural history study...
June 2017: American Journal of Medical Genetics. Part A
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