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https://read.qxmd.com/read/30772665/single-trial-estimation-of-quasi-static-emg-to-joint-mechanical-impedance-relationship-over-a-range-of-joint-torques
#1
Chenyun Dai, Stephane Martel, Francois Martel, Denis Rancourt, Edward A Clancy
Joint mechanical impedance is commonly measured by applying dynamic perturbations about a joint at a fixed operating point/background torque, and quantifying torque change vs. angle change. Impedance characterization in functional tasks, therefore, requires multiple experimental trials over a range of operating points-a cumbersome, invasive, time-consuming and impractical task. As an alternative, studies have related EMG to impedance, after which EMG can estimate impedance without applying joint perturbations...
February 8, 2019: Journal of Electromyography and Kinesiology
https://read.qxmd.com/read/30772484/the-expression-pattern-of-calcium-signaling-related-genes-during-smoltification-of-salmo-salar-in-productive-conditions
#2
F J Domínguez, J P Pontigo, R Oyarzún, C Vargas-Lagos, F J Morera, L Vargas-Chacoff
Variations in the mRNA expression of hepatic and muscle genes that are related to calcium signaling were analyzed by real-time qPCR in farmed Atlantic salmon (Salmo salar L. 1758) to determine changes in expression between parr and smolt stages. These organs were selected due to their close relationship with calcium signaling and metabolism (e.g., glycolysis, oxidative phosphorylation, muscle contraction). Differential expression between smolt and parr specimens and between organs was observed. Compared to parr specimens, smolts exhibited upregulated expression of the calcitonin receptor precursor, calcitonin receptor, calcitonin isoform, parathyroid hormone, and calmodulin in the liver...
February 14, 2019: Comparative Biochemistry and Physiology. Part B, Biochemistry & Molecular Biology
https://read.qxmd.com/read/30772229/global-longitudinal-strain-as-a-predictor-of-first-and-subsequent-arrhythmic-events-in-remotely-monitored-icd-patients-with-structural-heart-disease
#3
Federico Guerra, Alessandro Malagoli, Daniele Contadini, Erika Baiocco, Alessio Menditto, Paolo Bonelli, Luca Rossi, Concetta Sticozzi, Alessia Zanni, Jianwen Cai, Poulami Maitra, Giovanni Q Villani, Alessandro Capucci
OBJECTIVES: This study sought to assess speckle-tracking-derived parameters as predictors of first and subsequent ventricular events in patients with structural heart disease and implantable cardioverter-defibrillators (ICD). BACKGROUND: Left ventricular ejection fraction (LVEF), the current primary parameter of risk stratification for ventricular arrhythmias (VAs) in structural heart diseases is burdened by many limitations. METHODS: In this retrospective, observational study, all consecutive patients with structural heart disease were admitted for ICD implantation...
February 11, 2019: JACC. Cardiovascular Imaging
https://read.qxmd.com/read/30772011/the-inhibitory-subunit-of-cardiac-troponin-ctni-is-modified-by-arginine-methylation-in-the-human-heart
#4
Donatus O Onwuli, Sabrina Francesca Samuel, Pagona Sfyri, Kevin Welham, Martin Goddard, Yasir Abu-Omar, Mahmoud Loubani, Francisco Rivero, Antonios Matsakas, David M Benoit, Mark Wade, John Greenman, Pedro Beltran-Alvarez
BACKGROUND: The inhibitory subunit of cardiac troponin (cTnI) is a gold standard cardiac biomarker and also an essential protein in cardiomyocyte excitation-contraction coupling. The interactions of cTnI with other proteins are fine-tuned by post-translational modification of cTnI. Mutations in cTnI can lead to hypertrophic cardiomyopathy. METHODS AND RESULTS: Here we report, for the first time, that cTnI is modified by arginine methylation in human myocardium. Using Western blot, we observed reduced levels of cTnI arginine methylation in human hypertrophic cardiomyopathy compared to dilated cardiomyopathy biopsies...
January 31, 2019: International Journal of Cardiology
https://read.qxmd.com/read/30771756/validation-of-a-methodology-for-neuro-urological-and-lumbosacral-stimulation-studies-in-domestic-pigs-a-humanlike-animal-model
#5
Thomas Guiho, Christine Azevedo-Coste, David Guiraud, Claire Delleci, Grégoire Capon, Natalia Delgado-Piccoli, Luc Bauchet, Jean-Rodolphe Vignes
OBJECTIVESpinal cord injuries (SCIs) result in loss of movement and sensory feedback, but also organ dysfunction. Nearly all patients with complete SCI lose bladder control and are prone to kidney failure if intermittent catheterization is not performed. Electrical stimulation of sacral spinal roots was initially considered to be a promising approach for restoring continence and micturition control, but many patients are discouraged by the need for surgical deafferentation as it could lead to a loss of sensory functions and reflexes...
February 15, 2019: Journal of Neurosurgery. Spine
https://read.qxmd.com/read/30771688/dynamic-histological-events-and-molecular-changes-in-excisional-wound-healing-of-diabetic-db-db-mice
#6
Xiao Tian Wang, Claire C McKeever, Peter Vonu, Charles Patterson, Paul Y Liu
BACKGROUND: Wound contraction and re-epithelialization over the entire healing process had never been histologically examined daily in diabetic mouse wounds. Correlating morphological characters with molecular changes may be essential to understand the potential mechanism of impeded diabetic wound healing. MATERIALS AND METHODS: In 99 db/db and 63 db/m mice, dorsal-paired 8 mm-diameter wounds were created. Wound contraction and re-epithelialization were histologically analyzed daily-six wounds per group each day...
February 13, 2019: Journal of Surgical Research
https://read.qxmd.com/read/30771349/pomolic-acid-reduces-contractility-and-modulates-excitation-contraction-coupling-in-rat-cardiomyocytes
#7
Rubén López, Pura Bolaños, Alis Guillén, Marbely C Fernández, Magaly Ramos, Sergio Granados, Andrés F Milán, Carlo Caputo, Claudia Alvarado-Castillo, Omar Estrada, Juan C Calderón
Pomolic acid (PA) isolated from Licania pittieri has hypotensive effects in rats, inhibits human platelet aggregation and elicits endothelium-dependent relaxation in rat aortic rings. The present study was designed to investigate the effects of PA on cardiomyocytes. Trabeculae and enzymatically isolated cardiomyocytes from rats were used to evaluate the concentration-dependent effects of PA on cardiac muscle tension and excitation-contraction coupling (ECC) by recording Ca2+ transients reported with Fluo-3 and Fura-2, as well as L-type Ca2+ currents (LTCC)...
February 13, 2019: European Journal of Pharmacology
https://read.qxmd.com/read/30771310/luteolin-induced-coronary-arterial-relaxation-involves-activation-of-the-myocyte-voltage-gated-k-channels-and-inward-rectifier-k-channels
#8
Weiping Li, Miaomiao Dong, Pengmei Guo, Yu Liu, Yixin Jing, Rui Chen, Mingsheng Zhang
AIMS: Luteolin has been shown to be beneficial to cardiovascular tissues and organs. We aimed to study its vasospasmolytic effects against various vasoconstrictors in the isolated rat coronary arteries (RCAs) and its electrophysiological effects on K+ currents via voltage-gated potassium (Kv) channels and inward rectifier potassium (Kir) channels in freshly isolated rat coronary arterial smooth muscle cells (RCASMCs). MAIN METHODS: The vascular tone of the endothelium-denuded RCAs was recorded by a wire myograph...
February 13, 2019: Life Sciences
https://read.qxmd.com/read/30771259/placental-growth-factor-blunts-uterine-artery-responses-to-angiotensin-ii
#9
Jimmy Espinoza, Ancizar Betancourt, Michael A Belfort, Alireza A Shamshirsaz, Karin A Fox, Chandrasekhar Yallampalli
OBJECTIVE: Changes in maternal serum concentration of placental growth factor (PlGF) and vascular response to intravascular infusion of Angiotensin II (Ang II) follow a bell-shaped curve pattern during gestation. This study evaluates the effects of PlGF and soluble vascular endothelial growth factor receptor-1 (sFlt-1) on responses of human uterine arteries (UA) to Ang II. DESIGN: Experimental. SETTING: Baylor College of Medicine and Texas Children's Hospital-Pavilion for Women...
February 16, 2019: BJOG: An International Journal of Obstetrics and Gynaecology
https://read.qxmd.com/read/30771257/automated-pectoral-muscle-identification-on-mlo-view-mammograms-comparison-of-deep-neural-network-to-conventional-computer-vision
#10
Xiangyuan Ma, Jun Wei, Chuan Zhou, Mark A Helvie, Heang-Ping Chan, Lubomir M Hadjiiski, Yao Lu
OBJECTIVES: To develop a fully automated deep learning approach for identification of the pectoral muscle on mediolateral oblique (MLO) view mammograms and evaluate its performance in comparison to our previously developed texture-field orientation (TFO) method using conventional image feature analysis. Pectoral muscle segmentation is an important step for automated image analyses such as breast density or parenchymal pattern classification, lesion detection, and multi-view correlation...
February 16, 2019: Medical Physics
https://read.qxmd.com/read/30771202/a-new-twist-on-tropomyosin-binding-to-actin-filaments-perspectives-on-thin-filament-function-assembly-and-biomechanics
#11
William Lehman, Michael J Rynkiewicz, Jeffrey R Moore
Tropomyosin, best known for its role in the steric regulation of muscle contraction, polymerizes head-to-tail to form cables localized along the length of both muscle and non-muscle actin-based thin filaments. In skeletal and cardiac muscles, tropomyosin, under the control of troponin and myosin, moves in a cooperative manner between blocked, closed and open positions on filaments, thereby masking and exposing actin-binding sites necessary for myosin crossbridge head interactions. While the coiled-coil signature of tropomyosin appears to be simple, closer inspection reveals surprising structural complexity required to perform its role in steric regulation...
February 15, 2019: Journal of Muscle Research and Cell Motility
https://read.qxmd.com/read/30771103/visual-inspection-of-transvaginal-ultrasound-videos-to-characterize-uterine-peristalsis-an-inter-observer-agreement-study
#12
N P M Kuijsters, F Sammali, C Rabotti, Y Huang, M Mischi, B C Schoot
PURPOSE: Contractions in non-pregnant uterine can be assessed by visual inspection of transvaginal ultrasound (TVUS). Many authors have used this method to extract features like contraction frequency and direction. However, visual inspection is a subjective method and the outcome is dependent on the sonographers and video analysts. In this study, we wanted to see which uterine feature is reproducible enough, in terms of inter-observer agreement, to serve as a reliable control for future research...
February 15, 2019: Journal of Ultrasound
https://read.qxmd.com/read/30771058/motor-unit-action-potential-amplitudes-and-firing-rates-during-repetitive-muscle-actions-of-the-first-dorsal-interosseous-in-children-and-adults
#13
Jonathan D Miller, Adam J Sterczala, Michael A Trevino, Mandy E Wray, Hannah L Dimmick, Trent J Herda
PURPOSE: Previous research has indicated greater muscle activation is needed for children (CH) to match relative intensity submaximal contractions in comparison with adults (AD). However, no study has compared motor unit (MU) firing and recruitment patterns between children and adults. Therefore, MU action potential amplitudes (MUAPAMP ) and firing rates were examined during two repetitive submaximal contractions of the first dorsal interosseous in children and adults. METHODS: Twenty-two children (age 9...
February 15, 2019: European Journal of Applied Physiology
https://read.qxmd.com/read/30770548/the-actin-a-triad-s-role-in-contractile-regulation-in-health-and-disease
#14
William Schmidt, Anthony Cammarato
Striated muscle contraction is regulated by Ca2+ -dependent modulation of myosin cross-bridge binding to F-actin by the thin filament troponin (Tn)-tropomyosin (Tm) complex. In the absence of Ca2+ , Tn binds to actin and constrains Tm to an azimuthal location where it sterically occludes myosin binding sites along the thin filament surface. This limits force production and promotes muscle relaxation. In addition to Tn-actin interactions, inhibitory Tm positioning requires associations between other thin filament constituents...
February 15, 2019: Journal of Physiology
https://read.qxmd.com/read/30770485/provable-data-integrity-in-the-pharmaceutical-industry-based-on-version-control-systems-and-the-blockchain
#15
Valentin Steinwandter, Christoph Herwig
In the pharmaceutical industry, process validation tasks are based on the generated process raw and derived analytical results. Risks to fail in process validation, affect both, the patient's safety as well as the economic success of the manufacturing company. Hence, data integrity is highly critical in this area. Regulatory agencies, such as the FDA, reacted to past data integrity breaches, by publishing new guidelines on data integrity for the correct handling of data in the pharmaceutical context. In this contribution, we want to show how data integrity can be improved on a technological level, removing the need for trusted third parties and centralized systems for this task...
February 15, 2019: PDA Journal of Pharmaceutical Science and Technology
https://read.qxmd.com/read/30770212/do-we-need-to-stabilize-and-treat-the-os-acromiale-when-performing-reverse-shoulder-arthroplasty
#16
Ali Erşen, Serkan Bayram, Ata Can Atalar, Mehmet Demirhan
INTRODUCTION: The purpose of this study is to investigate the incidence of os acromiale in patients who had reverse shoulder arthroplasty (RSA) for rotator cuff tear arthropathy and the effect of presence of os acromiale on the functional results. HYPOTHESIS: We hypothesize than in the presence of os acromiale, the contraction strength of the deltoid would decrease due to the dynamic downward depression of the bony fragment leading to less favorable clinical results...
February 12, 2019: Orthopaedics & Traumatology, Surgery & Research: OTSR
https://read.qxmd.com/read/30769854/communicating-risk-regarding-food-consumption-the-case-of-processed-meat
#17
Slavica Zec, Clara Minto, Carlo Agostoni, Carolina Fano, Honoria Ocagli, Giulia Lorenzoni, Dario Gregori
The present research combines real data and parameters found in recent literature that were used to design realistic scenarios demonstrating the potential effects (benefits and costs) of the World Health Organization (WHO)'s risk communication regarding the consumption of processed meat, which was proven to be associated with an increased risk of colorectal cancer (CRC) in an International Agency for Research on Cancer (IARC)/WHO report. The impact of the risk communication of processed meat consumption was simulated using Monte Carlo microsimulation models...
February 14, 2019: Nutrients
https://read.qxmd.com/read/30769149/retinal-capillary-perfusion-spatial-and-temporal-heterogeneity
#18
REVIEW
Dao-Yi Yu, Stephen J Cringle, Paula K Yu, Chandrakumar Balaratnasingam, Andrew Mehnert, Marinko V Sarunic, Dong An, Er-Ning Su
The central role of the cardiovascular system is to maintain adequate capillary perfusion. The spatially and temporally heterogeneous nature of capillary perfusion has been reported in some organs. However, such heterogeneous perfusion properties have not been sufficiently explored in the retina. Arguably, spatial and temporal heterogeneity of capillary perfusion could be more predominant in the retina than that in other organs. This is because the retina is one of the highest metabolic demand neural tissues yet it has a limited blood supply due to optical requirements...
February 12, 2019: Progress in Retinal and Eye Research
https://read.qxmd.com/read/30769143/exploring-the-involvement-of-tac2-in-the-mouse-hippocampal-stress-response-through-gene-networking
#19
Mike Hook, Fuyi Xu, Elena Terenina, Wenyuan Zhao, Athena Starlard-Davenport, Pierre Mormede, Byron C Jones, Megan K Mulligan, Lu Lu
Tac2 is expressed in a number of areas throughout the brain, including the hippocampus. However, knowledge about its function has been only well explored in the hypothalamus in the context of reproductive health. In this study, we identified and validated increased hippocampal Tac2 mRNA expression in response to chronic mild stress in mice. Expression quantitative trait locus (eQTL) analysis showed Tac2 is cis-regulated in the hippocampus. Using a systems genetics approach, we constructed a Tac2 co-expression network to better understand the relationship between Tac2 and the hippocampal stress response...
February 12, 2019: Gene
https://read.qxmd.com/read/30768980/%C3%AE-1d-adrenoceptor-involves-the-relaxation-effect-of-farrerol-in-rat-aortic-vascular-smooth-muscle-cells
#20
Xiaojiang Qin, Xiaomin Hou, Kun Zhang, Qingshan Li
The aim of this study was to investigate the relaxation effect of farrerol on rat aortic vascular smooth muscle cells (VSMCs) and its underlying mechanism. VSMCs were cultured primarily and were used to examine the relaxation effect of farrerol. Cells surface and length were measured by dynamic observation, or by rhodamine-phalloidin labeling and hematoxylin-eosin staining. Cells contractive activity were tested using collagen gel contraction assay. The [Ca2+ ]in was measured with molecular probe fluo-4-AM...
February 12, 2019: European Journal of Pharmacology
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