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https://www.readbyqxmd.com/read/28100834/soft-robotic-sleeve-supports-heart-function
#1
Ellen T Roche, Markus A Horvath, Isaac Wamala, Ali Alazmani, Sang-Eun Song, William Whyte, Zurab Machaidze, Christopher J Payne, James C Weaver, Gregory Fishbein, Joseph Kuebler, Nikolay V Vasilyev, David J Mooney, Frank A Pigula, Conor J Walsh
There is much interest in form-fitting, low-modulus, implantable devices or soft robots that can mimic or assist in complex biological functions such as the contraction of heart muscle. We present a soft robotic sleeve that is implanted around the heart and actively compresses and twists to act as a cardiac ventricular assist device. The sleeve does not contact blood, obviating the need for anticoagulation therapy or blood thinners, and reduces complications with current ventricular assist devices, such as clotting and infection...
January 18, 2017: Science Translational Medicine
https://www.readbyqxmd.com/read/28057907/molecular-cloning-and-characterization-of-the-porcine-ribosomal-protein-l21
#2
Wu-Sheng Sun, Ju-Lan Chun, Dong-Hwan Kim, Jin-Seop Ahn, Min-Kyu Kim, In-Sul Hwang, Dae-Jin Kwon, Seong-Soo Hwang, Jeong-Woong Lee
Ribosomal protein L21 (RPL21) is a structural component of the 60S subunit of the eukaryotic ribosome. This protein plays an important role in protein synthesis and the occurrence of hereditary diseases. Pig is a common laboratory model, however, to the best of our knowledge, its RPL21 gene has not been cloned to date. In this study, we cloned and identified the full-length sequence of the pig RPL21 gene for the first time. Then we studied its expression pattern and function by overexpression or knockdown approach...
January 4, 2017: Journal of Veterinary Science
https://www.readbyqxmd.com/read/28047037/su-f-t-435-helical-tomotherapy-for-craniospinal-irradiation-what-we-have-learned-from-a-multi-institutional-study
#3
D Du, C Han, J Chen, A Perez-Andujar, B Lee, T Kaprealian, D Low, X Qi
PURPOSE: To report cranio-spinal irradiation (CSI) planning experience, compare dosimetric quality and delivery efficiency with Tomotherapy from different institutions, and to investigate effect of planning parameters on plan quality and treatment time. METHODS: Clinical helical tomotherapy IMRT plans for thirty-nine CSI cases from three academic institutions were retrospectively evaluated. The planning parameters: field width (FW), pitch, modulation factor (MF), and achieved dosimetric endpoints were cross-compared...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28000164/respiratory-average-ct-for-attenuation-correction-in-myocardial-perfusion-spect-ct
#4
Duo Zhang, Bang-Hung Yang, Nien Yun Wu, Greta Seng Peng Mok
OBJECTIVE: Cine average CT (CACT) and interpolated average CT (IACT) have been proposed to improve attenuation correction (AC) for PET/CT in oncologic and cardiac studies. This study aims to evaluate their effectiveness on myocardial perfusion SPECT/CT using computer simulation and physical phantom experiments. METHODS: We first simulated normal male with (99m)Tc-sestamibi distribution using digital XCAT phantom with respiratory motion amplitudes of 2, 3, and 4 cm...
December 20, 2016: Annals of Nuclear Medicine
https://www.readbyqxmd.com/read/27984146/deciphering-the-interaction-of-bovine-heart-cystatin-with-zno-nanoparticles-spectroscopic-and-thermodynamic-approach
#5
Aamir Sohail, Mohd Faraz, Hussain Arif, Sheraz Ahmad Bhat, Azad Alam Siddiqui, Bilqees Bano
ZnO-NPs have been widely used in biomedical fields such as therapeutics, cellular imaging, and drug delivery. However, the risk of exposure of nanoparticles to the biological system is not well understood. Nanoparticle-protein interaction is pivotal to understand their biological behavior and predict nanoparticle toxicity that is crucial for its safer applications. In the present study zinc oxide nanoparticles (ZnO-NPs) were synthesized and subjected to interact with buffalo heart cystatin (BHC), purified from buffalo heart, to assess the effect(s) of ZnO-NPs on the structure and function of BHC...
February 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/27983818/structural-and-functional-effects-of-cardiomyopathy-causing-mutations-in-the-troponin-t-binding-region-of-cardiac-tropomyosin
#6
Alexander M Matyushenko, Daniil V Shchepkin, Galina V Kopylova, Katerina E Popruga, Natalya V Artemova, Anastasia V Pivovarova, Sergey Y Bershitsky, Dmitrii I Levitsky
Hypertrophic cardiomyopathy (HCM) is a severe heart disease caused by missense mutations in genes encoding sarcomeric proteins of cardiac muscle. Many of these mutations are identified in the gene encoding the cardiac isoform of tropomyosin (Tpm), an α-helical coiled-coil actin-binding protein that plays a key role in Ca(2+)-regulated contraction of cardiac muscle. We employed various methods to characterize structural and functional features of recombinant human Tpm species carrying HCM mutations that lie either within the troponin T-binding region in the C-terminal part of Tpm (E180G, E180V, and L185R) or near this region (I172T)...
December 16, 2016: Biochemistry
https://www.readbyqxmd.com/read/27886501/fate-of-alpha-dynamos-at-large-rm
#7
Alexandre Cameron, Alexandros Alexakis
At the heart of today's solar magnetic field evolution models lies the alpha dynamo description. In this work, we investigate the fate of alpha dynamos as the magnetic Reynolds number Rm is increased. Using Floquet theory, we are able to precisely quantify mean-field effects like the alpha and beta effect (i) by rigorously distinguishing dynamo modes that involve large-scale components from the ones that only involve small scales, and by (ii) providing a way to investigate arbitrary large-scale separations with minimal computational cost...
November 11, 2016: Physical Review Letters
https://www.readbyqxmd.com/read/27856252/the-interchain-disulfide-cross-linking-of-tropomyosin-alters-its-regulatory-properties-and-interaction-with-actin-filament
#8
Alexander M Matyushenko, Natalia V Artemova, Daniil V Shchepkin, Galina V Kopylova, Salavat R Nabiev, Larisa V Nikitina, Dmitrii I Levitsky, Sergey Y Bershitsky
Tropomyosin (Tpm) is an α-helical coiled-coil actin-binding protein that plays a key role in the Ca(2+)-regulated contraction of striated muscles. Two chains of Tpm can be cross-linked by formation of a disulfide bond between Cys-190 residues. Normally, the SH-groups of these residues in cardiac muscle are in reduced state but in heart pathologies the interchain cross-linking of Tpm was shown to occur. Previous studies have shown that this cross-linking increases the thermal stability of the C-terminal part of the Tpm molecule...
January 8, 2017: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/27801552/th17-responses-to-collagen-type-v-k%C3%AE-1-tubulin-and-vimentin-are-present-early-in-human-development-and-persist-throughout-life
#9
J A Sullivan, E Jankowska-Gan, S Hegde, M A Pestrak, V V Agashe, A C Park, M E Brown, J F Kernien, D S Wilkes, D B Kaufman, D S Greenspan, W J Burlingham
T helper 17 (Th17)-dependent autoimmune responses can develop after heart or lung transplantation and are associated with fibro-obliterative forms of chronic rejection; however, the specific self-antigens involved are typically different from those associated with autoimmune disease. To investigate the basis of these responses, we investigated whether removal of regulatory T cells or blockade of function reveals a similar autoantigen bias. We found that Th17 cells specific for collagen type V (Col V), kα1-tubulin, and vimentin were present in healthy adult peripheral blood mononuclear cells, cord blood, and fetal thymus...
November 1, 2016: American Journal of Transplantation
https://www.readbyqxmd.com/read/27791164/structural-basis-for-dynamic-regulation-of-the-human-26s-proteasome
#10
Shuobing Chen, Jiayi Wu, Ying Lu, Yong-Bei Ma, Byung-Hoon Lee, Zhou Yu, Qi Ouyang, Daniel J Finley, Marc W Kirschner, Youdong Mao
The proteasome is the major engine of protein degradation in all eukaryotic cells. At the heart of this machine is a heterohexameric ring of AAA (ATPases associated with diverse cellular activities) proteins that unfolds ubiquitylated target proteins that are concurrently translocated into a proteolytic chamber and degraded into peptides. Using cryoelectron microscopy, we determined a near-atomic-resolution structure of the 2.5-MDa human proteasome in its ground state, as well as subnanometer-resolution structures of the holoenzyme in three alternative conformational states...
November 15, 2016: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/27764526/an-in-vitro-investigation-to-assess-procedure-parameters-for-injecting-therapeutic-hydrogels-into-the-myocardium
#11
Clive J Curley, Eimear B Dolan, Brenton Cavanagh, Janice O'Sullivan, Garry P Duffy, Bruce P Murphy
Localized delivery of stem cells is potentially a promising therapeutic strategy for regenerating damaged myocardium. Many studies focus on limiting the biologic component of cell loss, but few address the contribution of mechanical factors. This study investigates optimal parameters for retaining the largest volume of cell loaded hydrogels post intramyocardial injection, without compromising cell viability. In vitro, hydrogel was injected into porcine hearts using various needle designs. Hydrogel retention and distribution pattern was then determined...
October 20, 2016: Journal of Biomedical Materials Research. Part B, Applied Biomaterials
https://www.readbyqxmd.com/read/27733623/nebulette-is-a-powerful-cytolinker-organizing-desmin-and-actin-in-mouse-hearts
#12
Daniel A Hernandez, Christina M Bennett, Lyubov Dunina-Barkovskaya, Tatjana Wedig, Yassemi Capetanaki, Harald Herrmann, Gloria M Conover
In the hearts of patients bearing nebulette mutations, a severe general disorganization in cardiomyocytes of the extrasarcomeric desmin intermediate filament system is frequently observed. However, the molecular and functional relationship between the desmin cytoskeleton and nebulette-containing sarcomeres is still unclear. Here we report a high-affinity in vitro interaction between nebulette and desmin filaments. A major interaction site has been mapped to the desmin α-helical rod domain, indicating that the filament core is directly involved in the binding of nebulette...
December 1, 2016: Molecular Biology of the Cell
https://www.readbyqxmd.com/read/27708056/structural-basis-for-the-gating-mechanism-of-the-type-2-ryanodine-receptor-ryr2
#13
Wei Peng, Huaizong Shen, Jianping Wu, Wenting Guo, Xiaojing Pan, Ruiwu Wang, S R Wayne Chen, Nieng Yan
RyR2 is a high-conductance intracellular calcium (Ca(2+)) channel that controls the release of Ca(2+) from the sarco(endo)plasmic reticulum of a variety of cells. Here, we report the structures of RyR2 from porcine heart in both the open and closed states at near-atomic resolutions determined using single-particle electron cryomicroscopy. Structural comparison reveals a breathing motion of the overall cytoplasmic region resulted from the interdomain movements of amino-terminal domains (NTDs), Helical domains, and Handle domains, whereas almost no intradomain shifts are observed in these armadillo repeats-containing domains...
October 21, 2016: Science
https://www.readbyqxmd.com/read/27685129/comprehensive-dosimetric-planning-comparison-for-early-stage-non-small-cell-lung-cancer-with-sabr-fixed-beam-imrt-versus-vmat-versus-tomotherapy
#14
Ilma Xhaferllari, Omar El-Sherif, Stewart Gaede
Volumetric-modulated arc therapy (VMAT) is emerging as a leading technology in treating early-stage, non-small cell lung cancer (NSCLC) with stereotactic ablative radiotherapy (SABR). However, two other modalities capable of deliver-ing intensity-modulated radiation therapy (IMRT) include fixed-beam and helical TomoTherapy (HT). This study aims to provide an extensive dosimetric compari-son among these various IMRT techniques for treating early-stage NSCLC with SABR. Ten early-stage NSCLC patients were retrospectively optimized using three fixed-beam techniques via nine to eleven beams (high and low modulation step-and-shoot (SS), and sliding window (SW)), two VMAT techniques via two partial arcs (SmartArc (SA) and RapidArc (RA)), and three HT techniques via three different fan beam widths (1 cm, 2...
September 8, 2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/27648167/helical-tomotherapy-and-volumetric-modulated-arc-therapy-new-therapeutic-arms-in-the-breast-cancer-radiotherapy
#15
Olivier Lauche, Youlia M Kirova, Pascal Fenoglietto, Emilie Costa, Claire Lemanski, Celine Bourgier, Olivier Riou, David Tiberi, Francois Campana, Alain Fourquet, David Azria
AIM: To analyse clinical and dosimetric results of helical tomotherapy (HT) and volumetric modulated arc therapy (VMAT) in complex adjuvant breast and nodes irradiation. METHODS: Seventy-three patients were included (31 HT and 42 VMAT). Dose were 63.8 Gy (HT) and 63.2 Gy (VMAT) in the tumour bed, 52.2 Gy in the breast, 50.4 Gy in supraclavicular nodes (SCN) and internal mammary chain (IMC) with HT and 52.2 Gy and 49.3 Gy in IMC and SCN with VMAT in 29 fractions...
August 28, 2016: World Journal of Radiology
https://www.readbyqxmd.com/read/27471092/bench-and-initial-preclinical-results-of-a-novel-8-mm-diameter-double-opposed-helical-biodegradable-stent
#16
Carrie E Herbert, Surendranath Veeram Reddy, Tré R Welch, Jian Wang, James A Richardson, Joseph M Forbess, Alan W Nugent
BACKGROUND: Metallic endovascular stents are utilized off-label in congenital heart disease. Biodegradable stents (BDS) offer potential advantages in a growing child. We have previously reported double opposed helical (DH) BDS up to 6 mm diameter (DH-6). The objectives are to investigate the bench characteristics of larger 8 mm diameter BDS (DH-8) manufactured with increasing strut thicknesses and the inflammatory profile in a porcine model. METHODS: DH-8 were manufactured with strut thicknesses 0...
July 29, 2016: Catheterization and Cardiovascular Interventions
https://www.readbyqxmd.com/read/27414988/conformational-flexibility-of-becn1-essential-to-its-key-role-in-autophagy-and-beyond
#17
REVIEW
Yang Mei, Karen Glover, Minfei Su, Sangita C Sinha
BECN1 (Beclin 1), a highly conserved eukaryotic protein, is a key regulator of autophagy, a cellular homeostasis pathway, and also participates in vacuolar protein sorting, endocytic trafficking, and apoptosis. BECN1 is important for embryonic development, the innate immune response, tumor suppression, and protection against neurodegenerative disorders, diabetes, and heart disease. BECN1 mediates autophagy as a core component of the class III phosphatidylinositol 3-kinase complexes. However, the exact mechanism by which it regulates the activity of these complexes, or mediates its other diverse functions is unclear...
October 2016: Protein Science: a Publication of the Protein Society
https://www.readbyqxmd.com/read/27376658/investigating-the-effects-of-tropomyosin-mutations-on-its-flexibility-and-interactions-with-filamentous-actin-using-molecular-dynamics-simulation
#18
Wenjun Zheng, Sarah E Hitchcock-DeGregori, Bipasha Barua
Tropomyosin (Tpm) is a two-chained α-helical coiled-coil protein that binds to filamentous actin (F-actin), and regulates its interactions with myosin by occupying three average positions on F-actin (blocked, closed, and open). Mutations in the Tpm are linked to heart diseases including hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). To elucidate the molecular mechanisms of Tpm mutations (including DCM mutation E54K, HCM mutations E62Q, A63V, K70T, V95A, D175N, E180G, L185R, E192K, and a designed synthetic mutation D137L) in terms of their effects on Tpm flexibility and its interactions with F-actin, we conducted extensive molecular dynamics simulations for the wild-type and mutant Tpm in complex with F-actin (total simulation time 160 ns per mutant)...
July 4, 2016: Journal of Muscle Research and Cell Motility
https://www.readbyqxmd.com/read/27372384/dosimetric-evaluation-of-total-marrow-irradiation-using-2-different-planning-systems
#19
Adrian Nalichowski, Don G Eagle, Jay Burmeister
This study compared 2 different treatment planning systems (TPSs) for quality and efficiency of total marrow irradiation (TMI) plans. The TPSs used in this study were VOxel-Less Optimization (VoLO) (Accuray Inc, Sunnyvale, CA) using helical dose delivery on a Tomotherapy Hi-Art treatment unit and Eclipse (Varian Medical Systems Inc, Palo Alto, CA) using volumetric modulated arc therapy (VMAT) dose delivery on a Varian iX treatment unit. A total dose of 1200cGy was prescribed to cover 95% of the planning target volume (PTV)...
2016: Medical Dosimetry: Official Journal of the American Association of Medical Dosimetrists
https://www.readbyqxmd.com/read/27350922/the-choice-of-multi-beam-imrt-for-whole-breast-radiotherapy-in-early-stage-right-breast-cancer
#20
Emel Haciislamoglu, Fatma Colak, Emine Canyilmaz, Ahmet Yasar Zengin, Ahmet Hakan Yilmaz, Adnan Yoney, Zumrut Bahat
The aim of this study was to identify a rational strategy for the selection of multi-beam IMRT in patients with right breast cancer through the comparison of dosimetric parameters of the planning target volume (PTV) and organs at risk (OARs) using five different radiotherapy modalities. This was a retrospective study using computed tomography scans from ten patients with early-stage right breast cancer who had been treated previously. Three dimensional conformal radiotherapy (3DCRT), forward-planned IMRT (for-IMRT), inverse-planned IMRT (inv-IMRT), helical tomotherapy (HT), and volumetric-modulated arc therapy (VMAT) were planned for each patient...
2016: SpringerPlus
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