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https://www.readbyqxmd.com/read/28213506/role-of-apamin-sensitive-calcium-activated-small-conductance-potassium-currents-on-the-mechanisms-of-ventricular-fibrillation-in-pacing-induced-failing-rabbit-hearts
#1
Dechun Yin, Yu-Cheng Hsieh, Wei-Chung Tsai, Adonis Zhi-Yang Wu, Zhaolei Jiang, Yi-Hsin Chan, Dongzhu Xu, Na Yang, Changyu Shen, Zhenhui Chen, Shien-Fong Lin, Peng-Sheng Chen, Thomas H Everett
BACKGROUND: Ventricular fibrillation (VF) during heart failure is characterized by stable reentrant spiral waves (rotors). Apamin-sensitive small-conductance calcium-activated potassium currents (IKAS) are heterogeneously upregulated in failing hearts. We hypothesized that IKAS influences the location and stability of rotors during VF. METHODS AND RESULTS: Optical mapping was performed on 9 rabbit hearts with pacing-induced heart failure. The epicardial right ventricular and left ventricular surfaces were simultaneously mapped in a Langendorff preparation...
February 2017: Circulation. Arrhythmia and Electrophysiology
https://www.readbyqxmd.com/read/28209766/glycosylated-chromogranin-a-in-heart-failure-implications-for-processing-and-cardiomyocyte-calcium-homeostasis
#2
Anett Hellebø Ottesen, Cathrine R Carlson, William E Louch, Mai Britt Dahl, Ragnhild A Sandbu, Rune Forstrøm Johansen, Hilde Jarstadmarken, Magnar Bjørås, Arne Didrik Høiseth, Jon Brynildsen, Ivar Sjaastad, Mats Stridsberg, Torbjørn Omland, Geir Christensen, Helge Røsjø
BACKGROUND: Chromogranin A (CgA) levels have previously been found to predict mortality in heart failure (HF), but currently no information is available regarding CgA processing in HF and whether the CgA fragment catestatin (CST) may directly influence cardiomyocyte function. METHODS AND RESULTS: CgA processing was characterized in postinfarction HF mice and in patients with acute HF, and the functional role of CST was explored in experimental models. Myocardial biopsies from HF, but not sham-operated mice, demonstrated high molecular weight CgA bands...
February 2017: Circulation. Heart Failure
https://www.readbyqxmd.com/read/28209241/st-elevation-due-to-hypercalcemia-case-report-and-review-of-the-literature
#3
Edward Durant, Amandeep Singh
Characteristic ECG changes with hypercalcemia include shortening of the QoT, QaT, and QeT intervals which are measured from the beginning of the QRS complex to the origin (O), apex (A), and end (E) of the T wave respectively. At very high serum calcium levels ECG changes include slight prolongation of the PR and QRS intervals, T wave flattening or inversion, and the appearance of a J wave at the end of the QRS complex. We present a case of a 22year-old male, who had been bedbound for 5months following a severe motor vehicle collision, presenting with shortening of the QoT and QaT intervals leading to anterior ST elevation mimicking acute myocardial infarction...
February 6, 2017: American Journal of Emergency Medicine
https://www.readbyqxmd.com/read/28193459/epileptiform-activity-and-behavioral-arrests-in-mice-overexpressing-the-calcium-channel-subunit-%C3%AE-2%C3%AE-1
#4
Leonardo C Faria, Feng Gu, Isabel Parada, Ben Barres, Z David Luo, David A Prince
: The alpha2delta-1 subunit (α2δ-1) of voltage-gated calcium channels is a receptor for astrocyte-secreted thrombospondins that promote developmental synaptogenesis.Alpha2delta-1 receptors are upregulated in models of injury-induced peripheral pain and epileptogenic neocortical trauma associated with an enhancement of excitatory synaptic connectivity. These results lead to the hypothesis that overexpression of α2δ-1 alone in neocortex of uninjured transgenic (TG) mice might result in increased excitatory connectivity and consequent cortical hyperexcitability and epileptiform activity...
February 10, 2017: Neurobiology of Disease
https://www.readbyqxmd.com/read/28169003/increased-calcium-leak-associated-with-reduced-calsequestrin-expression-in-hyperthyroid-cardiomyocytes
#5
David R de Alba-Aguayo, Natalia Pavón, Martha Mercado-Morales, Miyamin Miranda-Saturnino, Mavil López-Casamichana, Agustin Guerrero-Hernández, Angelica Rueda
INTRODUCTION: Calcium (Ca(2+)) leak during cardiac diastole is chiefly mediated by intracellular Ca(2+) channel/Ryanodine Receptors. Increased diastolic Ca(2+) leak has been proposed as the mechanism underlying the appearance of hereditary arrhythmias. However, little is known about alterations in diastolic Ca(2+) leak and the specific roles played by key intracellular Ca(2+)-handling proteins in hyperthyroidism, a known arrhythmogenic condition. AIM: We sought to determine whether there were modifications in diastolic Ca(2+) leak, based on the recording of Ca(2+) sparks and Ca(2+) waves; we also investigated changes in the expression and activity of key Ca(2+) handling proteins, including ryanodine receptors, Sarco-Endoplasmic Reticulum Ca(2+) ATPase pump and calsequestrin in isolated left-ventricular cardiomyocytes isolated from hyperthyroid rats...
January 23, 2017: Cell Calcium
https://www.readbyqxmd.com/read/28165545/nf-%C3%AE%C2%BAb-p65-signaling-pathway-a-potential-therapeutic-target-in-postoperative-cognitive-dysfunction-after-sevoflurane-anesthesia
#6
J-W Zheng, B Meng, X-Y Li, B Lu, G-R Wu, J-P Chen
OBJECTIVE: This study aimed to explore the role of NF-κB/P65 signaling pathway in postoperative cognitive dysfunction (POCD) after sevoflurane anesthesia. MATERIALS AND METHODS: A total of 120 male Sprague-Dawley (SD) rats were selected and assigned into five groups (24 rats in each group): the control, sevoflurane, sevoflurane + splenectomy, pyrrolidine dithiocarbamate (PDTC, a specific inhibitor of NF-κB), and sevoflurane + splenectomy + PDTC groups. Electrocardiogram (ECoG) and behavior changes of rats were monitored before and after anesthesia/operation...
2017: European Review for Medical and Pharmacological Sciences
https://www.readbyqxmd.com/read/28164461/flexible-polygon-mirror-based-laser-scanning-microscope-platform-for-multiphoton-in-vivo-imaging
#7
Y X Li, V Gautam, A Brüstle, I A Cockburn, V R Daria, C Gillespie, K Gaus, C Alt, W M Lee
Commercial microscopy systems make use of tandem scanning i.e. either slow or fast scanning. We constructed, for the first time, an advanced control system capable of delivering a dynamic line scanning speed ranging from 2.7 kHz to 27 kHz and achieve variable frame rates from 5 Hz to 50 Hz (512 × 512). The dynamic scanning ability is digitally controlled by a new customized open-source software named PScan1.0. This permits manipulation of scanning rates either to gain higher fluorescence signal at slow frame rate without increasing laser power or increase frame rates to capture high speed events...
February 6, 2017: Journal of Biophotonics
https://www.readbyqxmd.com/read/28155854/prenatal-thalamic-waves-regulate-cortical-area-size-prior-to-sensory-processing
#8
Verónica Moreno-Juan, Anton Filipchuk, Noelia Antón-Bolaños, Cecilia Mezzera, Henrik Gezelius, Belen Andrés, Luis Rodríguez-Malmierca, Rafael Susín, Olivier Schaad, Takuji Iwasato, Roland Schüle, Michael Rutlin, Sacha Nelson, Sebastien Ducret, Miguel Valdeolmillos, Filippo M Rijli, Guillermina López-Bendito
The cerebral cortex is organized into specialized sensory areas, whose initial territory is determined by intracortical molecular determinants. Yet, sensory cortical area size appears to be fine tuned during development to respond to functional adaptations. Here we demonstrate the existence of a prenatal sub-cortical mechanism that regulates the cortical areas size in mice. This mechanism is mediated by spontaneous thalamic calcium waves that propagate among sensory-modality thalamic nuclei up to the cortex and that provide a means of communication among sensory systems...
February 3, 2017: Nature Communications
https://www.readbyqxmd.com/read/28146127/association-between-obesity-and-serum-25-oh-d-concentrations-in-older-mexican-adults
#9
Victoria G Rontoyanni, Jaqueline C Avila, Sapna Kaul, Rebeca Wong, Sreenivas P Veeranki
BACKGROUND: Vitamin D is essential for maintaining bone mineralization and calcium homeostasis, and prevents falls and fractures in older adults. Mexico is undergoing an epidemiologic and demographic transition with increasing obesity rates. The study's aim was to determine the association of obesity with serum 25-hydroxyvitamin D [25(OH)D] concentrations in older Mexican adults. METHODS: Data from 1772 Mexicans, aged ≥50 years, enrolled in a sub-sample of the 3rd wave of the Mexican Health and Aging Study, were included...
January 31, 2017: Nutrients
https://www.readbyqxmd.com/read/28130256/ca2-calmodulin-dependent-protein-kinase-ii%C3%AE-and-ii%C3%AE-mediate-tgf%C3%AE-induced-transduction-of-fibronectin-and-collagen-in-human-pulmonary-fibroblasts
#10
Subhendu Mukherjee, Wei Sheng, Rui Sun, Luke J Janssen
It is now clear that in addition to activating several complex kinase pathways (Smad, MAP kinase, PI3 kinase), TGFβ also acts by elevating [Ca2+] within the cytosol of human pulmonary fibroblasts. Ca2+/calmodulin-dependent protein kinase II (CamK II) is also known to regulate gene expression in fibroblasts. In this study, we examined the interactions between calcium signaling, activation of CamK and other kinases, and extracellular matrix (ECM) gene expression. Human pulmonary fibroblasts were cultured and stimulated with artificially-generated Ca2+-pulses in the absence of TGFβ, or with TGFβ (1 nM) or vehicle in the presence of various blockers of Ca2+ signaling...
January 27, 2017: American Journal of Physiology. Lung Cellular and Molecular Physiology
https://www.readbyqxmd.com/read/28128211/glia-derived-atp-inversely-regulates-excitability-of-pyramidal-and-cck-positive-neurons
#11
Zhibing Tan, Yu Liu, Wang Xi, Hui-Fang Lou, Liya Zhu, Zhifei Guo, Lin Mei, Shumin Duan
Astrocyte responds to neuronal activity with calcium waves and modulates synaptic transmission through the release of gliotransmitters. However, little is known about the direct effect of gliotransmitters on the excitability of neuronal networks beyond synapses. Here we show that selective stimulation of astrocytes expressing channelrhodopsin-2 in the CA1 area specifically increases the firing frequency of CCK-positive but not parvalbumin-positive interneurons and decreases the firing rate of pyramidal neurons, phenomena mimicked by exogenously applied ATP...
January 27, 2017: Nature Communications
https://www.readbyqxmd.com/read/28119152/component-resolved-bleaching-study-in-natural-calcium-fluoride-using-cw-osl-lm-osl-and-residual-tl-glow-curves-after-bleaching
#12
Vasiliki Angeli, George S Polymeris, Ioanna K Sfampa, Nestor C Tsirliganis, George Kitis
Natural calcium fluoride has been commonly used as thermoluminescence (TL) dosimeter due to its high luminescence intensity. The aim of this work includes attempting a correlation between specific TL glow curves after bleaching and components of linearly modulated optically stimulated luminescence (LM-OSL) as well as continuous wave OSL (CW-OSL). A component resolved analysis was applied to both integrated intensity of the RTL glow curves and all OSL decay curves, by using a Computerized Glow-Curve De-convolution (CGCD) procedure...
January 18, 2017: Applied Radiation and Isotopes
https://www.readbyqxmd.com/read/28119009/real-time-imaging-of-human-epidermal-calcium-dynamics-in-response-to-point-laser-stimulation
#13
Junichi Kumamoto, Makiko Goto, Masaharu Nagayama, Mitsuhiro Denda
BACKGROUND: Changes of epidermal calcium ion concentration are involved in regulation of barrier homeostasis and keratinocyte differentiation. Moreover, intracellular calcium dynamics might play a role in skin sensation. But, although calcium dynamics of cultured keratinocytes in response to mechanical stresses has been well studied, calcium propagation in stimulated human epidermis is still poorly understood. OBJECTIVE: The aim of this study was to demonstrate a novel method for real-time measurement of calcium dynamics in response to point stimulation of human epidermis at the single-cell level...
January 6, 2017: Journal of Dermatological Science
https://www.readbyqxmd.com/read/28115483/gap-junction-mediated-signaling-from-motor-neurons-regulates-motor-generation-in-the-central-circuits-of-larval-drosophila
#14
Teruyuki Matsunaga, Hiroshi Kohsaka, Akinao Nose
: In this study, we used the peristaltic crawling of Drosophila larvae as a model to study how motor patterns are regulated by central circuits. We built an experimental system that allows simultaneous application of optogenetics and calcium imaging to the isolated ventral nerve cord (VNC). We then investigated the effects of manipulating local activity of motor neurons (MNs) on fictive locomotion observed as waves of MN activity propagating along neuromeres. Optical inhibition of MNs with halorhodopsin3 (NpHR3) in a middle segment (A4, A5 or A6), but not other segments, dramatically decreased the frequency of the motor waves...
January 23, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28098180/an-aposymbiotic-primary-coral-polyp-counteracts-acidification-by-active-ph-regulation
#15
Yoshikazu Ohno, Akira Iguchi, Chuya Shinzato, Mayuri Inoue, Atsushi Suzuki, Kazuhiko Sakai, Takashi Nakamura
Corals build their skeletons using extracellular calcifying fluid located in the tissue-skeleton interface. However, the mechanism by which corals control the transport of calcium and other ions from seawater and the mechanism of constant alkalization of calcifying fluid are largely unknown. To address these questions, we performed direct pH imaging at calcification sites (subcalicoblastic medium, SCM) to visualize active pH upregulation in live aposymbiotic primary coral polyps treated with HCl-acidified seawater...
January 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28087911/-aortic-stiffness-and-its-influencing-factors-in-patients-with-chronic-kidney-disease
#16
Binxian Ye, Li Zhao, Wei Shen, Yan Ren, Bo Lin, Maosheng Chen, Junda Tang, Xinxin Jiang, Yiwen Li, Qiang He
Objective: To investigate the changes of aortic stiffness and its influencing factors in patients with chronic kidney diseases (CKD). Methods: Eightyfour patients with CKD from Department of Nephrology, Zhejiang Provincial People's Hospital were divided into the dialysis group (CKD stage 5, n=48) and non-dialysis group (CKD stage 3-5, n=36). Clinical data, biochemical parameters and echocardiography findings were collected. SphygmoCor pulse wave analysis system was used to obtain pulse wave analysis (PWA) parameters including central aortic systolic blood pressure (CSP), central pulse pressure (CPP), augmented pressure (AP), augmentation index (AIX), and heart rate 75-adjusted augmentation index (HR75AIX)...
May 25, 2016: Zhejiang da Xue Xue Bao. Yi Xue Ban, Journal of Zhejiang University. Medical Sciences
https://www.readbyqxmd.com/read/28073210/the-importance-of-citrates-in-treatment-and-prophylaxis-of-calcium-oxalate-urinary-stones
#17
Michele Barbera, Andreas Tsirgiotis, Mauro Barbera, Quintino Paola
About 10% of the people is the subject of an episode of kidney stones during their lifetime, about 70% of these people undergoes relapses. About 80% of the urinary stones contains calcium, of wich 80% is formed of calcium oxalate, in pure form or associated with calcium phosphate. Therefore we can saythat in most cases (about 65%) the urinary stones are composedof calcium oxalate. Use of supplements of potassium citrate and magnesium citrate can help in the prevention of kidney stones of calcium oxalate, but mostly they can be used in the days before a shockwaves lithotripsy treatment to make the stones more fragile to the effect of the shock waves...
December 30, 2016: Archivio Italiano di Urologia, Andrologia
https://www.readbyqxmd.com/read/28068560/effect-of-sarpogrelate-a-selective-5-ht2a-receptor-antagonist-on-characteristics-of-coronary-artery-disease-in-patients-with-type-2-diabetes
#18
Dong-Hwa Lee, Eun Ju Chun, Jee Hye Hur, Se Hee Min, Jie-Eun Lee, Tae Jung Oh, Kyoung Min Kim, Hak Chul Jang, Seung Jin Han, Doo Kyoung Kang, Hae Jin Kim, Soo Lim
BACKGROUND AND AIMS: Sarpogrelate, a 5-hydroxytryptamine type 2A antagonist, is a potential antiplatelet agent. We performed a randomized study to evaluate the effect of sarpogrelate on vascular health in Korean patients with diabetes. METHODS: Forty diabetic patients aged 58.6 ± 6.8 years with 10-75% coronary artery stenosis, as assessed by coronary computed tomography angiography, were randomly assigned to sarpogrelate 300 mg/day plus aspirin 100 mg/day (SPG + ASA group) or aspirin 100 mg/day alone (ASA group) for 6 months...
December 10, 2016: Atherosclerosis
https://www.readbyqxmd.com/read/28056168/conformational-changes-and-competitive-adsorption-between-serum-albumin-and-hemoglobin-on-bioceramic-substrate
#19
Cristina Gruian, Christian Rickert, Sascha Nicklisch, Emilia Vanea, Heinz-Jürgen Steinhoff, Simion Simon
Traditional methods to analyze interactions and conformational changes of proteins adsorbed onto biomaterials are limited by the protein's associations with the substrate material and the complexity of the surrounding media. We used EPR spectroscopy in combination with site directed spin labeling (SDSL) to investigate single protein and competitive adsorption kinetics of horse hemoglobin (Hgb) and bovine serum albumin (BSA) on a silica-calcium-phosphate bioceramic substrate. Combined continuous wave and pulsed (DEER) EPR techniques were employed to monitor local mobility/flexibility changes within the proteins and tertiary structure dynamics upon adsorption...
January 5, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
https://www.readbyqxmd.com/read/28056022/l-type-calcium-channel-inhibition-contributes-to-the-proarrhythmic-effects-of-aconitine-in-human-cardiomyocytes
#20
Jianjun Wu, Xiangchong Wang, Ying Ying Chung, Cai Hong Koh, Zhenfeng Liu, Huicai Guo, Qiang Yuan, Chuan Wang, Suwen Su, Heming Wei
Aconitine (ACO) is well-known for causing lethal ventricular tachyarrhythmias. While cardiac Na+ channel opening during repolarization has long been documented in animal cardiac myocytes, the cellular effects and mechanism of ACO in human remain unexplored. This study aimed to assess the proarrhythmic effects of ACO in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). ACO concentration-dependently (0.3 ~ 3.0 μM) shortened the action potentials (AP) durations (APD) in ventricular-like hiPSC-CMs by > 40% and induced delayed after-depolarization...
2017: PloS One
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