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https://www.readbyqxmd.com/read/29664141/circadian-rhythms-are-associated-with-variation-in-photosystem-ii-function-and-photoprotective-mechanisms
#1
Yulia Yarkhunova, Carmela R Guadagno, Matthew J Rubin, Seth J Davis, Brent E Ewers, Cynthia Weinig
The circadian clock regulates many aspects of leaf gas supply and biochemical demand for CO2 , and is hypothesized to improve plant performance. Yet the extent to which the clock may regulate the efficiency of photosystem II (PSII) and photoprotective mechanisms such as heat dissipation is less explored. Based on measurements of chlorophyll a fluorescence, we estimated the maximum efficiency of photosystem II in light (Fv'/Fm') and heat dissipation by non-photochemical quenching (NPQ). We further dissected total NPQ into its main components, qE (pH-dependent quenching), qT (state-transition quenching) and qI (quenching related to photoinhibition), in clock mutant genotypes of Arabidopsis thaliana, the cognate wild-type genotypes, and a panel of recombinant inbred lines (RILs) expressing quantitative variation in clock period...
April 17, 2018: Plant, Cell & Environment
https://www.readbyqxmd.com/read/29663449/mild-hypothermia-33%C3%A2-c-increases-the-inducibility-of-atrial-fibrillation-an-in-vivo-large-animal-model-study
#2
Martin Manninger, Alessio Alogna, David Zweiker, Birgit Zirngast, Stefan Reiter, Viktoria Herbst, Heinrich Maechler, Burkert M Pieske, Frank R Heinzel, Helmut Brussee, Heiner Post, Daniel Scherr
OBJECTIVE: Application of therapeutic mild hypothermia in patients after resuscitation, often accompanied by myocardial infarction, cardiogenic shock and systemic inflammation may impact on cardiac rhythm. We therefore tested susceptibility to atrial arrhythmias during hyperthermia (HT, 40.5°C), normothermia (NT, 38.0°C) and mild hypothermia (MH, 33.0°C). METHODS: Nine healthy, anesthetized closed-chest landrace pigs were instrumented with a quadripolar stimulation catheter in the high right atrium and a decapolar catheter in the coronary sinus...
April 16, 2018: Pacing and Clinical Electrophysiology: PACE
https://www.readbyqxmd.com/read/29661707/the-genetic-architecture-of-long-qt-syndrome-a-critical-reappraisal
#3
REVIEW
John R Giudicessi, Arthur A M Wilde, Michael J Ackerman
Collectively, the completion of the Human Genome Project and subsequent development of high-throughput next-generation sequencing methodologies have revolutionized genomic research. However, the rapid sequencing and analysis of thousands upon thousands of human exomes and genomes has taught us that most genes, including those known to cause heritable cardiovascular disorders such as long QT syndrome, harbor an unexpected background rate of rare, and presumably innocuous, non-synonymous genetic variation. In this Review, we aim to reappraise the genetic architecture underlying both the acquired and congenital forms of long QT syndrome by examining how the clinical phenotype associated with and background genetic variation in long QT syndrome-susceptibility genes impacts the clinical validity of existing gene-disease associations and the variant classification and reporting strategies that serve as the foundation for diagnostic long QT syndrome genetic testing...
March 30, 2018: Trends in Cardiovascular Medicine
https://www.readbyqxmd.com/read/29660035/the-preventable-burden-of-work-related-ill-health
#4
P Cocco, R Agius
Background: The fraction of ill-health overall attributable to occupational conditions has not been extensively evaluated, thus contributing to the perception of a lesser relevance of education and research in occupational health in respect to other fields of medical research and practice. Aims: To assess the relevance of work-related conditions on the aetiology of human ill-health in different health domains. Methods: We extracted the risk estimates associated with heritability and with occupational risk factors for chronic lymphocytic leukaemia (CLL), major depressive disorder (MDD) and long QT syndrome (LQTS) from 13 published international reports...
April 12, 2018: Occupational Medicine
https://www.readbyqxmd.com/read/29659201/evaluation-of-eluxadoline-effect-on-cardiac-repolarization
#5
Laura Bonifacio, Thomas L Hunt, Gail McIntyre, Leonard S Dove, Paul S Covington
This study evaluated the effects of eluxadoline, a mixed μ-opioid receptor (OR) and κ-OR agonist and δ-OR antagonist, on cardiac repolarization. This evaluator-blinded, placebo- and positive-controlled, 4-period crossover study randomized healthy men and women to single oral doses of eluxadoline (therapeutic dose 100 mg or supratherapeutic dose 1000 mg), moxifloxacin 400 mg, or placebo. QT data were corrected using individual custom correction (QTcI). The primary endpoint was the change from baseline in QTcI intervals (ΔQTcI) between eluxadoline and placebo (ΔΔQTcI)...
April 16, 2018: Clinical Pharmacology in Drug Development
https://www.readbyqxmd.com/read/29657083/the-course-of-awake-breathing-disturbances-across-the-lifespan-in-rett-syndrome
#6
Daniel C Tarquinio, Wei Hou, Jeffrey L Neul, Gamze Kilic Berkmen, Jana Drummond, Elizabeth Aronoff, Jennifer Harris, Jane B Lane, Walter E Kaufmann, Kathleen J Motil, Daniel G Glaze, Steven A Skinner, Alan K Percy
Rett syndrome (RTT), an X-linked dominant neurodevelopmental disorder caused by mutations in MECP2, is associated with a peculiar breathing disturbance exclusively during wakefulness that is distressing, and can even prompt emergency resuscitation. Through the RTT Natural History Study, we characterized cross sectional and longitudinal characteristics of awake breathing abnormalities in RTT and identified associated clinical features. Participants were recruited from 2006 to 2015, and cumulative lifetime prevalence of breathing dysfunction was determined using the Kaplan-Meier estimator...
April 12, 2018: Brain & Development
https://www.readbyqxmd.com/read/29652656/electrocardiogram-abnormalities-related-to-anti-malarials-in-systemic-lupus-erythematosus
#7
Taneisha K McGhie, Paula Harvey, Jiandong Su, Nicole Anderson, George Tomlinson, Zahi Touma
OBJECTIVES: Cardiotoxicity with potential conduction/structural abnormalities on electrocardiogram (ECG) have been reported with anti-malarial (AM). We aimed to study whether cumulative AM is associated with ECG abnormalities. METHODS: A standard resting supine ECG was performed on consecutive patients attending the Lupus Clinic since 2012. ECG abnormalities were grouped into structural [left ventricular hypertrophy or atrial enlargement] and conduction abnormalities [prolonged corrected QT interval (QTc), short PR interval, left bundle branch block (LBBB), right bundle branch block (RBBB) and atrioventricular block (AVB), bradycardia, tachycardia, premature atrial complex, ectopic atrial rhythm, atrial fibrillation, premature ventricular complex and ventricular bigeminy]...
April 13, 2018: Clinical and Experimental Rheumatology
https://www.readbyqxmd.com/read/29651961/the-benefit-of-prescribing-vitamin-d-as-add-on-therapy-on-the-electrocardiographic-changes-in-epileptic-patients
#8
Marwan S M Al-Nimer
BACKGROUND: Epileptic children and adolescent have a significantly low serum level of vitamin D due to the effect of antiepileptic drugs on the vitamin D metabolism. Those patients are at risk of cardiovascular events. OBJECTIVE: This study aimed to show that epileptic patients who treated with antiepileptic drugs supplemented with vitamin D are free from the electrocardiograph changes compared with those treated with antiepileptic drugs. METHOD: This cross-sectional study included, 121 epileptic patients aged < 18 years of both genders with a history of idiopathic generalized tonic clonic seizure...
April 12, 2018: Current Clinical Pharmacology
https://www.readbyqxmd.com/read/29651591/importance-of-qt-rr-hysteresis-correction-in-studies-of-drug-induced-qtc-interval-changes
#9
Marek Malik, Christine Garnett, Katerina Hnatkova, Lars Johannesen, Jose Vicente, Norman Stockbridge
QT/RR hysteresis and QT/RR adaptation are interlinked but separate physiological processes signifying how quickly and how much QT interval changes when heart rate changes, respectively. While QT interval duration is, as a rule, corrected for heart rate in terms of the QT/RR adaptation, the correction for QT/RR hysteresis is frequently omitted in studies of drug-induced QTc changes. This study used data from previously conducted thorough QT studies to investigate the extent of QTc errors caused by omitting the correction for QT/RR hysteresis, particularly in small clinical investigations...
April 12, 2018: Journal of Pharmacokinetics and Pharmacodynamics
https://www.readbyqxmd.com/read/29650124/phenotypic-landscape-and-risk-management-in-long-qt-syndrome-nudging-forward
#10
EDITORIAL
Andrew A Grace, Gareth D K Matthews
No abstract text is available yet for this article.
April 17, 2018: Journal of the American College of Cardiology
https://www.readbyqxmd.com/read/29650123/interplay-between-genetic-substrate-qtc-duration-and-arrhythmia-risk-in-patients-with-long-qt-syndrome
#11
Andrea Mazzanti, Riccardo Maragna, Gaetano Vacanti, Nicola Monteforte, Raffaella Bloise, Maira Marino, Lorenzo Braghieri, Patrick Gambelli, Mirella Memmi, Eleonora Pagan, Massimo Morini, Alberto Malovini, Martin Ortiz, Luciana Sacilotto, Riccardo Bellazzi, Lorenzo Monserrat, Carlo Napolitano, Vincenzo Bagnardi, Silvia G Priori
BACKGROUND: Long QT syndrome (LQTS) is a common inheritable arrhythmogenic disorder, often secondary to mutations in the KCNQ1, KCNH2, and SCN5A genes. The disease is characterized by a prolonged ventricular repolarization (QTc interval) that confers susceptibility to life-threatening arrhythmic events (LAEs). OBJECTIVES: This study sought to create an evidence-based risk stratification scheme to personalize the quantification of the arrhythmic risk in patients with LQTS...
April 17, 2018: Journal of the American College of Cardiology
https://www.readbyqxmd.com/read/29648903/cardiotoxicity-of-anthracycline-ant-treatment-in-children-with-malignant-tumors
#12
Huimin Hu, Weiling Zhang, Dongsheng Huang, Qingmiao Yang, Jing Li, Yanan Gao
OBJECTIVE: To investigate the cardiotoxicity indexes in children with malignant tumors after the administration of anthracycline (ANT) chemotherapy. MATERIALS AND METHODS: Data from 131 children with malignant tumors who were treated using ANT chemotherapy at our hospital from January 2011 to December 2015 were collected to analyze the serologic indexes (such as N-terminal pro-brain natriuretic peptide [NT-proBNP] and isoenzyme of creatine kinase [CK-MB]) and changes in corrected QT interval(QT-c) and left ventricular ejection fraction (LVEF) before and after treatment with different ANT cumulative doses...
April 12, 2018: Pediatric Hematology and Oncology
https://www.readbyqxmd.com/read/29648704/abnormal-ventricular-repolarization-in-long-qt-syndrome-carriers-is-related-to-short-left-ventricular-filling-time-and-attenuated-stroke-volume-response-during-exercise
#13
Dafni Charisopoulou, George Koulaouzidis, Annika Rydberg, Michael Y Henein
BACKGROUND: Long QT syndrome (LQTS) carriers are characterized by abnormal ventricular repolarization, prolonged systole, and mechanical dispersion. Prolonged left ventricular (LV) systole has been shown to result in disproportionate shortening of LV filling in other conditions. The aim of this study was to assess LV filling, diastolic function, and stroke volume (SV) response to dynamic exercise, in a group of LQTS carriers. METHODS: Forty-seven LQTS carriers (45 ± 15 years, 20 symptomatic) and 35 healthy individuals underwent bicycle stress echocardiogram...
April 12, 2018: Echocardiography
https://www.readbyqxmd.com/read/29643708/evidence-based-review-and-appraisal-of-the-use-of-droperidol-in-the-emergency-department
#14
REVIEW
Pei-Chun Lai, Yen-Ta Huang
Droperidol is a short-acting, potent dopamine D2 antagonist that can pass through the blood-brain barrier. A black box warning was issued for droperidol by the United States Food and Drug Administration in 2001 because of a risk of development of torsades de pointes induced by QT prolongation. Many experts feel that the incidence of arrhythmia is overestimated, and low-dose droperidol is almost always used by anesthesiologists for postoperative nausea and vomiting. In this review, we used evidence-based analysis to appraise high-quality studies with a low risk of bias published after 2001 on the use of droperidol in the emergency department (ED)...
January 2018: Ci Ji Yi Xue za Zhi, Tzu-chi Medical Journal
https://www.readbyqxmd.com/read/29642718/psychotropic-pharmacotherapy-associated-with-qt-prolongation-among-veterans-with-posttraumatic-stress-disorder
#15
Eileen M Stock, John E Zeber, Catherine J McNeal, Javier E Banchs, Laurel A Copeland
BACKGROUND: In 2012, the Food and Drug Administration issued Drug Safety Communications on several drugs associated with QT prolongation and fatal ventricular arrhythmias. Among these was citalopram, a selective serotonin reuptake inhibitor (SSRI) approved for depression and commonly used for posttraumatic stress disorder (PTSD). Evaluation of the risk for QT prolongation among other psychotropic drugs for individuals with PTSD remains limited. OBJECTIVE: Explore psychotropic drugs associated with QT prolongation among veterans with PTSD...
April 1, 2018: Annals of Pharmacotherapy
https://www.readbyqxmd.com/read/29642642/improvement-of-strength-toughness-hardness-balance-in-large-cross-section-718h-pre-hardened-mold-steel
#16
Hanghang Liu, Paixian Fu, Hongwei Liu, Dianzhong Li
The strength-toughness combination and hardness uniformity in large cross-section 718H pre-hardened mold steel from a 20 ton ingot were investigated with three different heat treatments for industrial applications. The different microstructures, including tempered martensite, lower bainite, and retained austenite, were obtained at equivalent hardness. The microstructures were characterized by using metallographic observations, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and electron back-scattered diffraction (EBSD)...
April 10, 2018: Materials
https://www.readbyqxmd.com/read/29628380/quadriceps-tendon-autograft-in-anterior-cruciate-ligament-reconstruction-a-systematic-review
#17
REVIEW
Eoghan T Hurley, Manuel Calvo-Gurry, Dan Withers, Shane K Farrington, Ray Moran, Cathal J Moran
PURPOSE: To systematically review the current evidence to ascertain whether quadriceps tendon autograft (QT) is a viable option in anterior cruciate ligament reconstruction. METHODS: A literature review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Cohort studies comparing QT with bone-patellar tendon-bone autograft (BPTB) or hamstring tendon autograft (HT) were included. Clinical outcomes were compared, with all statistical analyses performed using IBM SPSS Statistics for Windows, version 22...
April 5, 2018: Arthroscopy: the Journal of Arthroscopic & related Surgery
https://www.readbyqxmd.com/read/29628379/quadriceps-tendon-autograft-for-primary-anterior-cruciate-ligament-reconstruction-a-systematic-review-of-comparative-studies-with-minimum-two-year-follow-up
#18
REVIEW
John W Belk, Matthew J Kraeutler, Hayden A Marshall, Jesse A Goodrich, Eric C McCarty
PURPOSE: To systematically review the literature in an effort to compare outcomes of patients undergoing primary anterior cruciate ligament reconstruction (ACLR) with a quadriceps tendon (QT) autograft versus a bone-patellar tendon-bone (BPTB) or hamstring tendon (HT) autograft. METHODS: A systematic review was performed by searching PubMed, the Cochrane Library, and Embase to locate studies (Level of Evidence I-III) comparing the clinical outcomes of the QT autograft versus the BPTB or HT autograft in patients undergoing primary ACLR...
April 5, 2018: Arthroscopy: the Journal of Arthroscopic & related Surgery
https://www.readbyqxmd.com/read/29627768/mitochondrial-ca-2-influx-contributes-to-arrhythmic-risk-in-nonischemic-cardiomyopathy
#19
An Xie, Zhen Song, Hong Liu, Anyu Zhou, Guangbin Shi, Qiongying Wang, Lianzhi Gu, Man Liu, Lai-Hua Xie, Zhilin Qu, Samuel C Dudley
BACKGROUND: Heart failure (HF) is associated with increased arrhythmia risk and triggered activity. Abnormal Ca2+ handling is thought to underlie triggered activity, and mitochondria participate in Ca2+ homeostasis. METHODS AND RESULTS: A model of nonischemic HF was induced in C57BL/6 mice by hypertension. Computer simulations were performed using a mouse ventricular myocyte model of HF. Isoproterenol-induced premature ventricular contractions and ventricular fibrillation were more prevalent in nonischemic HF mice than sham controls...
April 7, 2018: Journal of the American Heart Association
https://www.readbyqxmd.com/read/29627227/effects-of-moxifloxacin-on-the-proarrhythmic-surrogate-markers-in-healthy-filipino-subjects-exposure-response-modeling-using-ecg-data-of-thorough-qt-qtc-study
#20
Suchitra Matsukura, Yuji Nakamura, Kiyotaka Hoshiai, Takashi Hayashi, Tadashi Koga, Ai Goto, Koki Chiba, Nur Jaharat Lubna, Mihoko Hagiwara-Nagasawa, Hiroko Izumi-Nakaseko, Kentaro Ando, Atsuhiko T Naito, Atsushi Sugiyama
Effects of moxifloxacin on QTc as well as proarrhythmic surrogate markers including J-Tpeak c, Tpeak -Tend and short-term variability (STV) of repolarization were examined by using both standard E14 time-based evaluation and exposure-response modeling. The study was conducted with a single-blind, randomized, single-dose, placebo-controlled and two-period cross-over design in healthy Filipino subjects. QT interval was corrected by Fridericia's formula (QTcF). In the E14 time-based evaluation of ECG data, the largest ΔΔQTcF with 90% confidence interval was 14...
March 27, 2018: Journal of Pharmacological Sciences
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