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https://www.readbyqxmd.com/read/28430456/the-microstructure-of-%C3%AE-sitosterol-%C3%AE-oryzanol-edible-organogels
#1
Andrew Barclay Matheson, Vasileios Koutsos, Georgios A Dalkas, Stephen Robert Euston, Paul S Clegg
Rheology and atomic force microscopy (AFM) were employed to examine the microstructure of β-sitosterol : γ-oryzanol organogels in sunflower oil. Using time resolved rheology we followed gel formation, paying specific attention to the fibril aggregation process, which had not been studied in detail previously for this system. Using AFM we observed gel structures directly, and obtained detailed information of the gel structure, far exceeding previous studies. Our analysis suggests that though gels are formed by the self-assembly and aggregation of one-dimensional fibrils, the manner in which these fibrils aggregate into ribbons results in complex structures of higher dimensionality...
April 21, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28429276/enhancing-thermal-stability-of-a-highly-concentrated-insulin-formulation-with-pluronic-f-127-for-long-term-use-in-microfabricated-implantable-devices
#2
Jason Li, Michael K Chu, Brian Lu, Sako Mirzaie, Kuan Chen, Claudia R Gordijo, Oliver Plettenburg, Adria Giacca, Xiao Yu Wu
Development of highly concentrated formulations of protein and peptide drugs is a major challenge due to increased susceptibility to aggregation and precipitation. Numerous drug delivery systems including implantable and wearable controlled-release devices require thermally stable formulations with high concentrations due to limited device sizes and long-term use. Herein we report a highly concentrated insulin gel formulation (up to 80 mg/mL, corresponding to 2200 IU/mL), stabilized with a non-ionic amphiphilic triblock copolymer (i...
April 20, 2017: Drug Delivery and Translational Research
https://www.readbyqxmd.com/read/28427941/elongation-affinity-activation-barrier-and-stability-of-a%C3%AE-42-oligomers-fibrils-in-physiological-saline
#3
Roberto A Rodriguez, Liao Y Chen, Germán Plascencia-Villa, George Perry
Amyloid-beta (Aβ) peptides, Aβ40 and the more neurotoxic Aβ42, have been the subject of many research efforts for Alzheimer's disease. In two recent independent investigations, the atomistic structure of Aβ42 fibril has been clearly established in the S-shaped conformation consisting of three β-sheets stabilized by salt bridges formed between the Lys28 sidechain and the C-terminus of Ala42. This structure distinctively differs from the long-known structure of Aβ40 in the β-hairpin shaped conformation consisting of two β-sheets...
April 17, 2017: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/28427903/atrial-fibrillation-is-associated-with-hypermethylation-in-human-left-atrium-and-treatment-with-decitabine-reduces-atrial-tachyarrhythmias-in-spontaneously-hypertensive-rats
#4
R Doñate Puertas, E Meugnier, C Romestaing, C Rey, E Morel, J Lachuer, N Gadot, A Scridon, C Julien, F Tronc, B Chapuis, C Valla, A Janin, L Pirola, A Méjat, S Rome, P Chevalier
Atrial fibrillation (AF) is the most common cardiac arrhythmia. As the molecular mechanisms underlying the pathology are largely unknown, this cardiac arrhythmia remains difficult to treat. To identify specific molecular actors involved in AF, we have performed a transcriptomic analysis on left atrium (LA) from patients with valvular heart disease with or without AF. We showed that 1627 genes had altered basal expression level in LA tissue of AF patients compared with the control group. The significantly enriched gene ontology biological process "anatomical structure morphogenesis" contained the highest number of genes in line with changes in structure that occur when the human heart remodels following AF development (ie, LA dilatation and interstitial fibrosis)...
March 30, 2017: Translational Research: the Journal of Laboratory and Clinical Medicine
https://www.readbyqxmd.com/read/28427851/circulating-ceruloplasmin-ceruloplasmin-associated-genes-and-the-incidence-of-atrial-fibrillation-in-the-atherosclerosis-risk-in-communities-study
#5
Antonio P Arenas de Larriva, Faye L Norby, Lin Y Chen, Elsayed Z Soliman, Ron C Hoogeveen, Dan E Arking, Laura R Loehr, Alvaro Alonso
BACKGROUND: Ceruloplasmin (CP) may promote structural changes in the atrium making it more arrhythmogenic. We assessed the associations between CP, CP-associated genetic variants, and incident atrial fibrillation (AF) in the Atherosclerosis Risk in Communities (ARIC) study. METHODS AND RESULTS: We studied 10,059 men and women without prevalent AF aged 53 to 75years in 1996-1998 and followed through 2012. Circulating CP was measured in stored blood samples obtained in 1996-1998...
April 6, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/28425516/mechanical-and-vibrational-characterization-of-amyloid-like-het-s-nanosheets-based-on-the-skewed-plate-theory
#6
Hyun Joon Chang, Myeongsang Lee, Jae In Kim, Gwonchan Yoon, Sungsoo Na
Pathological amyloidogenic prion proteins have a toxic effect on functional cells in the human cerebrum because of poor degradability and the tendency to accumulate in an uncontrolled manner under physiological conditions. HET-s, a fungal prion protein, is known to undergo conformational variations from fibrillar to nanosheet structures during a change from low to high pH conditions. It has been said that this conformational change can lead to self-propagation by nucleating on the lateral surface of singlet fibrils...
April 20, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28422654/novel-mri-technique-enables-non-invasive-measurement-of-atrial-wall-thickness
#7
Marta Varela, Ross Morgan, Adeline Theron, Desmond Dillon-Murphy, Henry Chubb, John Whitaker, Markus Henningsson, Paul Aljabar, Tobias Schaeffter, Christoph Kolbitsch, Oleg V Aslanidi
Knowledge of atrial wall thickness (AWT) has the potential to provide important information for patient stratification and the planning of interventions in atrial arrhythmias. To date, information about AWT has only been acquired in post-mortem or poor-contrast CT studies, providing limited coverage and highly variable estimates of AWT. We present a novel contrast agent-free MRI sequence for imaging AWT and use it to create personalized AWT maps and a biatrial atlas. A novel black-blood phase-sensitive inversion recovery protocol was used to image 10 volunteers and 2 atrial fibrillation patients, as proof of concept...
April 13, 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28422428/identification-of-novel-transthyretin-fibril-formation-inhibitors-using-structure-based-virtual-screening
#8
Gabriella Ortore, Adriano Martinelli
Transthyretin (TTR) is the primary carrier for thyroxine (T4) in cerebrospinal fluid and a secondary carrier in blood. TTR is a stable homotetramer, but certain factors, genetic or environmental, could promote its degradation to form amyloid fibrils. A docking study in the wild-type TTR crystal structures was planned; our aim was to design new ligands able to inhibit TTR fibril formation. The computational protocol was thought to overcome the multiple binding modes of the ligands induced by the specularity of the TTR binding site and by the pseudosymmetry of the site pockets, which generally weaken such structure-based studies...
April 19, 2017: ChemMedChem
https://www.readbyqxmd.com/read/28422368/safety-and-efficacy-of-pulmonary-vein-isolation-using-a-surround-flow-catheter-with-contact-force-measurement-capabilities-a-multicenter-registry
#9
Giuseppe Stabile, Paolo Di Donna, Vincenzo Schillaci, Antonio Di Monaco, Assunta Iuliano, Domenico Caponi, Francesco Urraro, Francesco Solimene, Massimo Grimaldi, Marco Scaglione
INTRODUCTION: Pulmonary vein (PV) isolation is the cornerstone of catheter ablation in patients with atrial fibrillation (AF). Surround flow and contact force (CF) measurement capabilities might enhance procedure efficacy and safety. We report on the safety and mid-term efficacy of a novel ablation catheter for PV isolation in patients with AF. METHODS AND RESULTS: Two hundred thirty-three consecutive patients (57±11 years, 76% males, 51% with structural heart disease) referred for paroxysmal (157) or persistent (76) AF, underwent PV isolation by a surround flow catheter with CF measurement capability in 4 centers...
April 19, 2017: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/28421621/presence-of-ganglia-and-telocytes-in-proximity-to-myocardial-sleeve-tissue-in-the-porcine-pulmonary-veins-wall
#10
T Vandecasteele, P Cornillie, K Vandevelde, A Logothetidou, L Couck, G van Loon, W Van den Broeck
Ganglia and telocytes were identified inside the porcine pulmonary veins wall near myocardial sleeve tissue at the atriopulmonary junction. These structures are reported to play a role in the initiation of pulses from outside the heart, which potentially can cause cardiac conduction disorders such as atrial fibrillation. In-depth knowledge on the fine structure of the pulmonary vein wall is a pre-requisite to better understand the underlying pathophysiology of atrial fibrillation and the origin and conduction of ectopic pulses...
April 19, 2017: Anatomia, Histologia, Embryologia
https://www.readbyqxmd.com/read/28421394/waveform-integrity-in-atrial-fibrillation-the-forgotten-issue-of-cardiac-electrophysiology
#11
Miguel Martínez-Iniesta, Juan Ródenas, Raúl Alcaraz, José J Rieta
Atrial fibrillation (AF) is the most common arrhythmia in clinical practice with an increasing prevalence of about 15% in the elderly. Despite other alternatives, catheter ablation is currently considered as the first-line therapy for the treatment of AF. This strategy relies on cardiac electrophysiology systems, which use intracardiac electrograms (EGM) as the basis to determine the cardiac structures contributing to sustain the arrhythmia. However, the noise-free acquisition of these recordings is impossible and they are often contaminated by different perturbations...
April 18, 2017: Annals of Biomedical Engineering
https://www.readbyqxmd.com/read/28419230/structuring-right-atrial-fibrillation-location-matters
#12
Uwe Lendeckel, Carmen Wolke
No abstract text is available yet for this article.
April 13, 2017: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/28416818/large-scale-analyses-of-common-and-rare-variants-identify-12-new-loci-associated-with-atrial-fibrillation
#13
(no author information available yet)
Atrial fibrillation affects more than 33 million people worldwide and increases the risk of stroke, heart failure, and death. Fourteen genetic loci have been associated with atrial fibrillation in European and Asian ancestry groups. To further define the genetic basis of atrial fibrillation, we performed large-scale, trans-ancestry meta-analyses of common and rare variant association studies. The genome-wide association studies (GWAS) included 17,931 individuals with atrial fibrillation and 115,142 referents; the exome-wide association studies (ExWAS) and rare variant association studies (RVAS) involved 22,346 cases and 132,086 referents...
April 17, 2017: Nature Genetics
https://www.readbyqxmd.com/read/28416467/early-repolarization-is-associated-with-significantly-increased-risk-for-ventricular-arrhythmias-and-sudden-cardiac-death-in-patients-with-structural-heart-diseases
#14
Yun-Jiu Cheng, Zhu-Yu Li, Feng-Juan Yao, Xiong-Jun Xu, Cheng-Cheng Ji, Xu-Miao Chen, Li-Juan Liu, Xiao-Xiong Lin, Hao Yao, Su-Hua Wu
BACKGROUND: Early repolarization pattern (ERP) has been proved to increase risk of arrhythmia death in the general population, but its prognostic significance in subjects with structural heart disease (SHD) is controversial. OBJECTIVE: To conduct a meta-analysis of studies assessing the association between ERP and risk of ventricular arrhythmias (VTAs) and sudden cardiac death (SCD) in patients with SHD. METHODS: We performed a literature search using MEDLINE (January 1, 1966 to September25, 2016) and EMBASE (January 1, 1980 to September25, 2016) with no restrictions...
April 14, 2017: Heart Rhythm: the Official Journal of the Heart Rhythm Society
https://www.readbyqxmd.com/read/28415526/effect-of-variable-aminoalkyl-chains-on-chemical-grafting-of-cellulose-nanofiber-and-their-antimicrobial-activity
#15
Seema Saini, Mohamed Naceur Belgacem, Julien Bras
Recent focus on the preparation of antimicrobial surfaces using cellulose nanofibers (CNF) has gained considerable attention. In this work, functionalization of CNF films in 100% aqueous solution with three different aminosilanes, including 3-aminopropyl trimethoxysilane (APMS), 2-aminoethyl 3-aminopropyl trimethoxysilane (DAMS)and 3-2-(2-aminoethylamino) ethylamino propyl-trimethoxysilane (TAMS) is reported for the fabrication of contact active antimicrobial materials. Grafted CNF films were comprehensively characterized by FTIR, TGA, contact angle, elemental analysis, solid-state (29)Si NMR, FEG-SEM and SEM-EDX...
June 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28413881/molecular-mechanism-on-stabilizing-huntingtin-n17-helical-structure-in-micelle-environment
#16
Leili Zhang, Hongsuk Kang, Francisco X Vázquez, Leticia Marisel Toledo-Sherman, Binquan Luan, Ruhong Zhou
Huntington's disease is a deadly neurodegenerative disease caused by the fibrilization of huntingtin (HTT) exon-1 protein mutants. Despite extensive efforts over the past decade, much remains unknown about the structures of (mutant) HTT exon-1 and their enigmatic roles in aggregation. Particularly, whether the first 17 residues in the N-terminal (HTT-N17) adopt a helical or a coiled structure remains unclear. Here, with the rigorous study of molecular dynamics simulations, we explored the most possible structures of HTT-N17 in both dodecylphosphocholine (DPC) micelles and aqueous solution, using three commonly applied force fields (OPLS-AA/L, CHARMM36 and AMBER99sb*-ILDNP) to examine the underlying molecular mechanism and rule out the potential artifacts...
April 17, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28412645/a-hidden-structural-vulnerability-in-the-thrombospondin-2-deficient-aorta-increases-the-propensity-to-intramural-delamination
#17
C Bellini, N J Kristofik, M R Bersi, T R Kyriakides, J D Humphrey
Mice lacking thrombospondin-2 (TSP2) represent an animal model of impaired collagen fibrillogenesis. Collagen constitutes ~1/3 of the wall of the normal murine descending thoracic aorta (DTA) and is thought to confer mechanical strength at high pressures. Microstructural analysis of the DTA from TSP2-null mice revealed irregular and disorganized collagen fibrils in the adventitia and at the interface between the media and adventitia. Yet, biaxial mechanical tests performed under physiologic loading conditions showed that most mechanical metrics, including stress and stiffness, were not different between mutant and control DTAs at 20- and 40-weeks of age, thus suggesting that the absence of TSP2 is well compensated under normal conditions...
March 9, 2017: Journal of the Mechanical Behavior of Biomedical Materials
https://www.readbyqxmd.com/read/28411451/anisotropic-tough-double-network-hydrogel-from-fish-collagen-and-its-spontaneous-in%C3%A2-vivo-bonding-to-bone
#18
Md Tariful Islam Mredha, Nobuto Kitamura, Takayuki Nonoyama, Susumu Wada, Keiko Goto, Xi Zhang, Tasuku Nakajima, Takayuki Kurokawa, Yasuaki Takagi, Kazunori Yasuda, Jian Ping Gong
Soft supporting tissues in the human body, such as cartilages and ligaments, are tough materials and firmly fixed to bones. These soft tissues, once injured, cannot regenerate spontaneously invivo. Developing tough and biocompatible hydrogels as artificial soft supporting tissues would substantially improve outcomes after soft tissue injury. Collagen is the main rigid component in soft connective tissues which is organized in various hierarchical arrays. We have successfully developed a novel class of collagen fibril-based tough hydrogels based on the double network (DN) concept using swim bladder collagen (SBC) extracted from Bester sturgeon fish...
April 5, 2017: Biomaterials
https://www.readbyqxmd.com/read/28410407/bacterial-amyloid-curli-acts-as-a-carrier-for-dna-to-elicit-an-autoimmune-response-via-tlr2-and-tlr9
#19
Sarah A Tursi, Ernest Y Lee, Nicole J Medeiros, Michael H Lee, Lauren K Nicastro, Bettina Buttaro, Stefania Gallucci, Ronald Paul Wilson, Gerard C L Wong, Çagla Tükel
Bacterial biofilms are associated with numerous human infections. The predominant protein expressed in enteric biofilms is the amyloid curli, which forms highly immunogenic complexes with DNA. Infection with curli-expressing bacteria or systemic exposure to purified curli-DNA complexes triggers autoimmunity via the generation of type I interferons (IFNs) and anti-double-stranded DNA antibodies. Here, we show that DNA complexed with amyloid curli powerfully stimulates Toll-like receptor 9 (TLR9) through a two-step mechanism...
April 14, 2017: PLoS Pathogens
https://www.readbyqxmd.com/read/28406293/n-terminus-binding-preference-for-either-tanshinone-or-analogue-in-both-inhibition-of-amyloid-aggregation-and-disaggregation-of-preformed-amyloid-fibrils-toward-introducing-a-kind-of-novel-anti-alzheimer-compounds
#20
Mingyan Dong, Wei Zhao, Dingkun Hu, Hongqi Ai, Baotao Kang
Amyloid-β (Aβ40/Aβ42) peptide with length of 40 or 42 residues is naturally secreted as cleavage product of the amyloid precursor protein, and formation of Aβ aggregates in patient's brain is a hallmark of Alzheimer's disease (AD). Therefore disaggregation and disruption provide potential therapeutic approaches to reduce, inhibit, and even reverse Aβ aggregation. The disaggregation/inhibition effect of the inhibitors applies generally to both Aβ40 and Aβ42 aggregations. Here we capture the atomic-level details of the interaction between Aβ40/Aβ42 and either natural tanshinone compound TS1 or its derivative TS0, and observe novel results by using molecular dynamics simulations...
April 13, 2017: ACS Chemical Neuroscience
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