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https://www.readbyqxmd.com/read/29105899/left-ventricular-geometry-as-a-major-determinant-of-left-ventricular-ejection-fraction-physiological-considerations-and-clinical-implications
#1
REVIEW
Filippos Triposkiadis, Gregory Giamouzis, Konstantinos Dean Boudoulas, Georgios Karagiannis, John Skoularigis, Harisios Boudoulas, John Parissis
The limited myocardial fibre thickening and shortening alone cannot explain the marked left ventricular (LV) volume reduction during LV ejection. This can only be achieved with LV helical (spiral) orientation of myocardial fibres, which is determined by the non-contractile LV myocardial components (intrasarcomeric and extrasarcomeric cytoskeleton, extracellular matrix). Preservation of LV ejection fraction (LVEF) in heart failure (HF) is due to the presence of normal ellipsoid LV configuration and spiral myocardial fibre orientation...
November 6, 2017: European Journal of Heart Failure
https://www.readbyqxmd.com/read/29093491/dosimetric-comparison-of-the-helical-tomotherapy-volumetric-modulated-arc-therapy-and-fixed-field-intensity-modulated-radiotherapy-for-stage-iib-iiib-non-small-cell-lung-cancer
#2
Yujin Xu, Weiye Deng, Shuangyan Yang, Pu Li, Yue Kong, Ye Tian, Zhongxing Liao, Ming Chen
The study aimed to compare the dosimetric parameters to target dose coverage and the critical structures in the treatment planning of helical tomotherapy (TOMO), volumetric-modulated arc therapy (VMAT), and fixed-field intensity-modulated radiotherapy (IMRT) for NSCLC delivering conventionally fractionated radiotherapy. Thirty patients with pathologically confirmed NSCLC were included. Three radiation treatment plans were designed for each patient. All patients received the uniform prescription dose of 60 Gy to the planning target volume...
November 1, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29059653/blood-motion-turbulent-or-laminar
#3
Alla P Stepanchuk
INTRODUCTION: The issue on the mode of blood motion in the bloodstream, where the arterial and venous flow is significantly different, has been of greater concern recently. However, the conclusions are largely based on the analysis of the geometric orientation in the wall of arteries of smooth muscle elements. The aim of our study was to examine the characteristics of the prominent configuration of cardial cavities and arterial vessels. MATERIALS AND METHODS: The material for study were specimens of human heart, rabbit aorta and arterial microvessels of rat salivary glands, examined by injection and corrosive methods, scanning and transmission electron microscopy...
2017: Wiadomości Lekarskie: Organ Polskiego Towarzystwa Lekarskiego
https://www.readbyqxmd.com/read/28986446/the-seca-protein-deeply-penetrates-into-the-secyeg-channel-during-insertion-contacting-most-channel-transmembrane-helices-and-periplasmic-regions
#4
Tithi Banerjee, Zeliang Zheng, Jane Abolafia, Shelby Harper, Donald B Oliver
The bacterial Sec-dependent system is the major protein-biogenic pathway for protein secretion across the cytoplasmic membrane or insertion of integral membrane proteins into the phospholipid bilayer. The mechanism of SecA-driven protein transport across the SecYEG channel complex has remained controversial with conflicting claims from biochemical and structural studies regarding the depth and extent of SecA insertion into SecYEG during ongoing protein transport. Here we utilized site-specific in vivo photo-crosslinking to thoroughly map SecY regions that are in contact with SecA during its insertion cycle...
October 6, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28972185/calmodulin-regulates-cav3-t-type-channels-at-their-gating-brake
#5
Jean Chemin, Valentina Taiakina, Arnaud Monteil, Michael Piazza, Wendy Guan, Robert F Stephens, Ashraf Kitmitto, Zhiping P Pang, Annette C Dolphin, Edward Perez-Reyes, Thorsten Dieckmann, Joseph Guy Guillemette, J David Spafford
Calcium (Cav1 and Cav2) and sodium channels possess homologous CaM-binding motifs, known as IQ motifs in their C-termini, which associate with calmodulin (CaM), a universal calcium sensor. Cav3 T-type channels, which serve as pacemakers of the mammalian brain and heart, lack a C-terminal IQ motif. We illustrate that T-type channels associate with CaM using co-immunoprecipitation experiments and single particle cryo-electron microscopy. We demonstrate that protostome invertebrate (LCav3) and human Cav3.1, Cav3...
September 25, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28958005/the-end-of-the-unique-myocardial-band-part-i-anatomical-considerations
#6
David H MacIver, Robert S Stephenson, Bjarke Jensen, Peter Agger, Damián Sánchez-Quintana, Jonathan C Jarvis, John B Partridge, Robert H Anderson
The concept of the 'unique myocardial band', which proposes that the ventricular myocardial cone is arranged like skeletal muscle, provides an attractive framework for understanding haemodynamics. The original idea was developed by Francisco Torrent-Guasp. Using boiled hearts and blunt dissection, Torrent-Guasp created a single band of ventricular myocardium extending from the pulmonary trunk to the aortic root, with the band thus constructed encircling both ventricular cavities. Cooked hearts can, however, be dissected in many ways...
August 24, 2017: European Journal of Cardio-thoracic Surgery
https://www.readbyqxmd.com/read/28947768/ventricular-myocardium-development-and-the-role-of-connexins-in-the-human-fetal-heart
#7
Eleftheria Pervolaraki, James Dachtler, Richard A Anderson, Arun V Holden
The developmental timeline of the human heart remains elusive. The heart takes on its characteristic four chambered appearance by ~56 days gestational age (DGA). However, owing to the complexities (both technical and logistical) of exploring development in utero, we understand little of how the ventricular walls develop. To address this, we employed diffusion tensor magnetic resonance imaging to explore the architecture and tissue organization of the developing heart aged 95-143 DGA. We show that fractional anisotropy increases (from ~0...
September 25, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28836502/inhibition-of-pde4-by-low-doses-of-rolipram-induces-changes-in-lipid-and-protein-components-of-mice-heart
#8
Sevgi Türker-Kaya, İpek Komsuoğlu Celikyurt, Umut Celikyurt, Aygül Kına
There is significant increasing interest in phosphodiesterase-4 (PDE4) inhibition in treatment of cardiovascular diseases. Related with this, research has focused on cellular, biochemical, molecular and structural changes in heart tissue induced by PDE4s inhibitors. However, for their clinical applicability additional studies are still needed. Fourier transform infrared spectroscopy offers promising approach to contribute such issue due to its ability in detection the changes in biomolecules. By utilizing this method, we examined the effects of PDE4 inhibition by rolipram at 0...
August 24, 2017: General Physiology and Biophysics
https://www.readbyqxmd.com/read/28758063/acquired-systemic-to-pulmonary-venous-shunt-or-persistent-left-superior-vena-cava-a-rare-right-to-left-shunt-case-based-discussion
#9
Alexandre Gamet, Pascale Raud-Raynier, Thomas Kerforne, Stéphane Velasco, Luc Christiaens
Cardiac shunts are often described in congenital or pediatric populations, but systemic-to-pulmonary venous shunts in adult patients are reported in literature in isolated case reports. We present the case of a 70-year-old female with a left superior vena cava (SVC) draining into the left atrium by the left superior pulmonary vein, with a complete right-to-left shunt of the superior venous circulation caused by a former catheter thrombosis in the right SVC. Diagnosis was suspected after a contrast echocardiography showing an exclusive perfusion of left heart after intravenous injection and confirmed by helical computed tomography with three-dimensional reconstruction...
July 2017: Journal of Cardiovascular Echography
https://www.readbyqxmd.com/read/28691076/self-assembling-cyclic-d-l-%C3%AE-peptides-as-modulators-of-plasma-hdl-function-a-supramolecular-approach-toward-antiatherosclerotic-agents
#10
Yannan Zhao, Luke J Leman, Debra J Search, Ricardo A Garcia, David A Gordon, Bruce E Maryanoff, M Reza Ghadiri
There is great interest in developing new modes of therapy for atherosclerosis to treat coronary heart disease and stroke, particularly ones that involve modulation of high-density lipoproteins (HDLs). Here, we describe a new supramolecular chemotype for altering HDL morphology and function. Guided by rational design and SAR-driven peptide sequence enumerations, we have synthesized and determined the HDL remodeling activities of over 80 cyclic d,l-α-peptides. We have identified a few distinct sequence motifs that are effective in vitro in remodeling human and mouse plasma HDLs to increase the concentration of lipid-poor pre-beta HDLs, which are key initial acceptors of cholesterol in the reverse cholesterol transport (RCT) process, and concomitantly promote cholesterol efflux from macrophage cells...
June 28, 2017: ACS Central Science
https://www.readbyqxmd.com/read/28675658/spectroscopic-study-of-the-interaction-between-horse-heart-myoglobin-and-zirconium-iv-substituted-polyoxometalates-as-artificial-proteases
#11
Hong Giang T Ly, Tatjana N Parac-Vogt
A recent study [Angew. Chem. Int. Ed. 2015, 54, 7391-7394] has shown that horse heart myoglobin (HHM) is selectively hydrolyzed by a range of zirconium(IV)-substituted polyoxometalates (POMs) under mild conditions. In this study, the molecular interactions between the Zr-POM catalysts and HHM are investigated by using a range of complementary techniques, including circular dichroism (CD), UV/Vis spectroscopy, tryptophan fluorescence spectroscopy, and (1) H and (31) P NMR spectroscopy. A tryptophan fluorescence quenching study reveals that, among all examined Zr-POMs, the most reactive POM, 2:2 Zr(IV) -Keggin, exhibits the strongest interaction with HHM...
July 4, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
https://www.readbyqxmd.com/read/28663827/heart-structural-remodeling-in-a-mouse-model-of-duchenne-cardiomyopathy-revealed-using-optical-polarization-tractography-invited
#12
Y Wang, K Zhang, D Duan, G Yao
We investigated the heart structural remodeling in the mdx4cv mouse model of Duchenne cardiomyopathy using optical polarization tractography. Whole heart tractography was obtained in freshly dissected hearts from six mdx4cv mice. Six hearts from C57BL/6J mice were also imaged as the normal control. The mdx4cv hearts were significantly larger than the control hearts and had significantly higher between-subject variations in myofiber organization. While both strains showed classic cross-helical fiber organization in the left ventricle, the rate of the myocardial fiber orientation change across the heart wall was significantly altered in the right ventricle of the mdx4cv heart...
March 1, 2017: Biomedical Optics Express
https://www.readbyqxmd.com/read/28594468/application-of-an-advanced-maximum-likelihood-estimation-restoration-method-for-enhanced-resolution-and-contrast-in-second-harmonic-generation-microscopy
#13
Mayandi Sivaguru, Mohammad M Kabir, Manas Ranjan Gartia, David S C Biggs, Barghav S Sivaguru, Vignesh A Sivaguru, Glenn A Fried, Gang Logan Liu, Sakthivel Sadayappan, Kimani C Toussaint
Second-harmonic generation (SHG) microscopy has gained popularity because of its ability to perform submicron, label-free imaging of noncentrosymmetric biological structures, such as fibrillar collagen in the extracellular matrix environment of various organs with high contrast and specificity. Because SHG is a two-photon coherent scattering process, it is difficult to define a point spread function (PSF) for this modality. Hence, compared to incoherent two-photon processes like two-photon fluorescence, it is challenging to apply the various PSF-engineering methods to improve the spatial resolution to be close to the diffraction limit...
September 2017: Journal of Microscopy
https://www.readbyqxmd.com/read/28593869/a-mock-heart-engineered-with-helical-aramid-fibers-for-in-vitro-cardiovascular-device-testing
#14
So-Hyun Jansen-Park, Po-Lin Hsu, Indra Müller, Ulrich Steinseifer, Dirk Abel, Rüdiger Autschbach, Rolf Rossaint, Thomas Schmitz-Rode
Mock heart circulation loops (MHCLs) serve as in-vitro platforms to investigate the physiological interaction between circulatory systems and cardiovascular devices. A mock heart (MH) engineered with silicone walls and helical aramid fibers, to mimic the complex contraction of a natural heart, has been developed to advance the MHCL previously developed in our group. A mock aorta with an anatomical shape enables the evaluation of a cannulation method for ventricular assist devices (VADs) and investigation of the usage of clinical measurement systems like pressure-volume catheters...
April 4, 2017: Biomedizinische Technik. Biomedical Engineering
https://www.readbyqxmd.com/read/28539564/improvement-of-local-cell-delivery-using-helix-transendocardial-delivery-catheter-in-a-porcine-heart
#15
Yoshiaki Mitsutake, Wook Bum Pyun, Didier Rouy, Cheryl Wong Po Foo, Simon H Stertzer, Peter Altman, Fumiaki Ikeno
Cardiac regeneration strategies using stem cells have shown variable and inconsistent results with respect to patient cardiac function and clinical outcomes. There has been increasing consensus that improving the efficiency of delivery may improve results. The Helix transendocardial delivery system (BioCardia Inc.) has been developed to enable percutaneous transendocardial biotherapeutic delivery. Therefore, we evaluated cell retention using this unique system compared with direct transepicardial injection and intracoronary infusion in an animal model...
May 31, 2017: International Heart Journal
https://www.readbyqxmd.com/read/28536896/helical-distribution-of-hypertrophy-in-patients-with-hypertrophic-cardiomyopathy-prevalence-and-clinical-implications
#16
Dafne Viliani, Eduardo Pozo, Norma Aguirre, Alberto Cecconi, María J Olivera, Paloma Caballero, Luis J Jiménez-Borreguero, Fernando Alfonso
Recently a novel pattern of helical distribution of hypertrophy has been described in patients with hypertrophic cardiomyopathy (HCM). Our aim was to determine its prevalence and potential implications in an unselected cohort. One-hundred- and eight consecutive patients diagnosed with HCM by cardiac magnetic resonance (CMR) were included (median clinical follow up of 1718 days). All clinical and complementary test information was prospectively collected. The presence of a helical pattern was assessed by a simple measurement of the maximal left ventricle (LV) wall thickness (LVWT) for each of the 17 classical LV segments and it was classified in one of three types according to its extension...
November 2017: International Journal of Cardiovascular Imaging
https://www.readbyqxmd.com/read/28487672/the-g-protein-coupled-receptor-ut-of-the-neuropeptide-urotensin-ii-displays-structural-and-functional-chemokine-features
#17
REVIEW
Hélène Castel, Laurence Desrues, Jane-Eileen Joubert, Marie-Christine Tonon, Laurent Prézeau, Marie Chabbert, Fabrice Morin, Pierrick Gandolfo
The urotensinergic system was previously considered as being linked to numerous physiopathological states, including atherosclerosis, heart failure, hypertension, pre-eclampsia, diabetes, renal disease, as well as brain vascular lesions. Thus, it turns out that the actions of the urotensin II (UII)/G protein-coupled receptor UT system in animal models are currently not predictive enough in regard to their effects in human clinical trials and that UII analogs, established to target UT, were not as beneficial as expected in pathological situations...
2017: Frontiers in Endocrinology
https://www.readbyqxmd.com/read/28469512/does-motion-assessment-with-4-dimensional-computed-tomographic-imaging-for-non-small-cell-lung-cancer-radiotherapy-improve-target-volume-coverage
#18
Naseer Ahmed, Sankar Venkataraman, Kate Johnson, Keith Sutherland, Shaun K Loewen
INTRODUCTION: Modern radiotherapy with 4-dimensional computed tomographic (4D-CT) image acquisition for non-small cell lung cancer (NSCLC) captures respiratory-mediated tumor motion to provide more accurate target delineation. This study compares conventional 3-dimensional (3D) conformal radiotherapy (3DCRT) plans generated with standard helical free-breathing CT (FBCT) with plans generated on 4D-CT contoured volumes to determine whether target volume coverage is affected. MATERIALS AND METHODS: Fifteen patients with stage I to IV NSCLC were enrolled in the study...
2017: Clinical Medicine Insights. Oncology
https://www.readbyqxmd.com/read/28398210/out-of-field-doses-from-pediatric-craniospinal-irradiations-using-3d-crt-imrt-helical-tomotherapy-and-electron-based-therapy
#19
Marijke De Saint-Hubert, Dirk Verellen, Kenneth Poels, Wouter Crijns, Federica Magliona, Tom Depuydt, Filip Vanhavere, Lara Struelens
Medulloblastoma treatment involves irradiation of the entire central nervous system, i.e. craniospinal irradiation (CSI). This is associated with the significant exposure of large volumes of healthy tissue and there is growing concern regarding treatment-associated side effects. The current study compares out-of-field organ doses in children receiving CSI through 3D-conformal radiotherapy (3D-CRT), intensity modulated radiotherapy (IMRT), helical tomotherapy (HT) and an electron-based technique, and includes radiation doses resulting from imaging performed during treatment...
July 7, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28375841/a-mock-heart-engineered-with-helical-aramid-fibers-for-in-vitro-cardiovascular-device-testing
#20
So-Hyun Jansen-Park, Po-Lin Hsu, Indra Müller, Ulrich Steinseifer, Dirk Abel, Rüdiger Autschbach, Rolf Rossaint, Thomas Schmitz-Rode
Mock heart circulation loops (MHCLs) serve as in-vitro platforms to investigate the physiological interaction between circulatory systems and cardiovascular devices. A mock heart (MH) engineered with silicone walls and helical aramid fibers, to mimic the complex contraction of a natural heart, has been developed to advance the MHCL previously developed in our group. A mock aorta with an anatomical shape enables the evaluation of a cannulation method for ventricular assist devices (VADs) and investigation of the usage of clinical measurement systems like pressure-volume catheters...
April 1, 2017: Biomedizinische Technik. Biomedical Engineering
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