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https://www.readbyqxmd.com/read/28737890/a-difluoroboron-%C3%AE-diketonate-probe-shows-turn-on-near-infrared-fluorescence-specific-for-tau-fibrils
#1
Kwang-Su Park, Mi Kyoung Kim, Yujin Seo, Taewoong Ha, Kyeongha Yoo, Seung Jae Hyeon, Yu Jin Hwang, Junghee Lee, Hoon Ryu, Hyunah Choo, Youhoon Chong
Tau aggregation in neuronal cells has recently received significant attention as a robust predictor of the progression of Alzheimer's disease (AD) because of its proven correlation with the degree of cognitive impairment in AD patients. Accordingly, non-invasive imaging of tau aggregates has been highlighted as a promising diagnostic tool for AD. We have previously identified a tau-specific "turn-on" near-infrared fluorescent (NIRF) probe (1) and, in this study, structural modification was performed to optimize its physicochemical as well as fluorescence properties...
July 24, 2017: ACS Chemical Neuroscience
https://www.readbyqxmd.com/read/28736366/-lactic-acid-inhibits-the-formation-of-semen-derived-amyloid-fibrils
#2
Jin-Qing Li, Ya-Li Song, Tian-Rong Xun, Sui-Yi Tan, Shu-Wen Liu
OBJECTIVE: To investigate the inhibitory effect of lactic acid on semen-derived amyloid (SEVI) fibril formation. METHODS: PAP248-286 (2 mg/mL) was incubated with 4.0, 2.0, 1.0, 0.5, 0.25, and 0.125 mg/mL of lactic acid. After incubation for different times, aliquots were drawn from each sample for Thioflavin T (ThT) and Congo red staining to monitor semen-derived amyloid fibril formation. The β sheet structure formation of PAP248-286 was measured by circular dichroism spectrum, and the morphology of amyloid fibrils incubated with or without lactic acid was observed with transmission electron microscopy (TEM)...
July 20, 2017: Nan Fang Yi Ke da Xue Xue Bao, Journal of Southern Medical University
https://www.readbyqxmd.com/read/28735892/clinical-and-echocardiographic-correlates-of-left-atrial-function-index-the-framingham-offspring-study
#3
Mayank Sardana, Gregory Nah, Connie W Tsao, Adedotun A Ogunsua, Eric Vittinghoff, Randell C Thomas, Susan Cheng, Aditya Vaze, Jayashri R Aragam, Gary F Mitchell, Emelia J Benjamin, Ramachandran S Vasan, Gerard P Aurigemma, Nelson B Schiller, David D McManus, Nisha I Parikh
BACKGROUND: Left atrial (LA) remodeling is a predictor of cardiovascular disease (CVD). We performed measurement of the LA function index (LAFI), a composite measure of LA structure and function, in a community-based cohort and here report the distribution and cross-sectional correlates of LAFI. METHODS: In 1,719 Framingham Offspring Study participants (54% women, mean age 66 ± 9 years), we derived LAFI from the LA emptying fraction, left ventricular (LV) outflow tract velocity time integral, and indexed maximal LA volume...
July 20, 2017: Journal of the American Society of Echocardiography
https://www.readbyqxmd.com/read/28733782/catheter-ablation-of-atrial-fibrillation-an-overview-for-clinicians
#4
REVIEW
Nebojša Mujović, Milan Marinković, Radoslaw Lenarczyk, Roland Tilz, Tatjana S Potpara
Catheter ablation (CA) of atrial fibrillation (AF) is currently one of the most commonly performed electrophysiology procedures. Ablation of paroxysmal AF is based on the elimination of triggers by pulmonary vein isolation (PVI), while different strategies for additional AF substrate modification on top of PVI have been proposed for ablation of persistent AF. Nowadays, various technologies for AF ablation are available. The radiofrequency point-by-point ablation navigated by electro-anatomical mapping system and cryo-balloon technology are comparable in terms of the efficacy and safety of the PVI procedure...
July 21, 2017: Advances in Therapy
https://www.readbyqxmd.com/read/28733641/influence-of-c-terminal-truncation-of-murine-serum-amyloid-a-on-fibril-structure
#5
Matthies Rennegarbe, Inga Lenter, Angelika Schierhorn, Romy Sawilla, Christian Haupt
Amyloid A (AA) amyloidosis is a systemic protein misfolding disease affecting humans and other vertebrates. While the protein precursor in humans and mice is the acute-phase reactant serum amyloid A (SAA) 1.1, the deposited fibrils consist mainly of C-terminally truncated SAA fragments, termed AA proteins. For yet unknown reasons, phenotypic variations in the AA amyloid distribution pattern are clearly associated with specific AA proteins. Here we describe a bacterial expression system and chromatographic strategies to obtain significant amounts of C-terminally truncated fragments of murine SAA1...
July 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28733070/spatial-relationship-of-sites-for-atrial-fibrillation-drivers-and-atrial-tachycardia-in-patients-with-both-arrhythmias
#6
Tina Baykaner, Junaid A B Zaman, Albert J Rogers, Rachita Navara, Mahmood AlHusseini, Ryan T Borne, Shirley Park, Paul J Wang, David E Krummen, William H Sauer, Sanjiv M Narayan
INTRODUCTION: Atrial fibrillation (AF) often converts to and from atrial tachycardia (AT), but it is undefined if these rhythms are mechanistically related in such patients. We tested the hypothesis that critical sites for AT may be related to regional AF sources in patients with both rhythms, by mapping their locations and response to ablation on transitions to and from AF. METHODS: From 219 patients undergoing spatial mapping of AF prior to ablation at 3 centers, we enrolled 26 patients in whom AF converted to AT by ablation (n=19) or spontaneously (n=7; left atrial size 42±6cm, 38% persistent AF)...
July 14, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/28731438/evidence-that-the-human-innate-immune-peptide-ll-37-may-be-a-binding-partner-of%C3%A2-amyloid-%C3%AE-and-inhibitor-of%C3%A2-fibril-assembly
#7
Ersilia De Lorenzi, Marcella Chiari, Raffaella Colombo, Marina Cretich, Laura Sola, Renzo Vanna, Paola Gagni, Federica Bisceglia, Carlo Morasso, Jennifer S Lin, Moonhee Lee, Patrick L McGeer, Annelise E Barron
BACKGROUND: Identifying physiologically relevant binding partners of amyloid-β (Aβ) that modulate in vivo fibril formation may yield new insights into Alzheimer's disease (AD) etiology. Human cathelicidin peptide, LL-37, is an innate immune effector and modulator, ubiquitous in human tissues and expressed in myriad cell types. OBJECTIVE: We present in vitro experimental evidence and discuss findings supporting a novel hypothesis that LL-37 binds to Aβ42 and can modulate Aβ fibril formation...
July 18, 2017: Journal of Alzheimer's Disease: JAD
https://www.readbyqxmd.com/read/28731126/mir%C3%A2-132-in-atrial-fibrillation-directly-targets-connective-tissue-growth-factor
#8
Gang Qiao, Dongsheng Xia, Zhaoyun Cheng, Guobao Zhang
Atrial fibrillation (AF) is the most frequently occurring, persistent cardiac arrhythmia, and the hallmark of AF‑dependent structural remodeling is atrial fibrosis. Connective tissue growth factor (CTGF) is important in the process of fibrosis. The association between miRNA and CTGF in AF‑dependent fibrosis remains to be elucidated. The present study aimed to determine if microRNA (miR)‑132 was able to regulate CTGF with an anti‑fibrotic effect in AF. A total of ten dogs or patients were assigned to control (n=4) and AF groups (n=6)...
July 21, 2017: Molecular Medicine Reports
https://www.readbyqxmd.com/read/28727450/carbon-nanotube-reinforced-polymer-stabilized-liquid-crystal-device-lowered-and-thermally-invariant-threshold-with-accelerated-dynamics
#9
Subbarao Krishna Prasad, Marlin Baral, Adhigan Murali, Sellamuthu N Jaisankar
Polymer stabilized liquid crystal (PSLC) devices comprise a polymer matrix in an otherwise continuous phase of liquid crystal. The fibrils of the polymer provide, even in the bulk, virtual surfaces with finite anchoring energy resulting in attractive electro-optic properties. Here we describe a novel variation of the PSLC device fabricated by reinforcing the polymer matrix with polymer-capped single-walled carbon nanotubes (CNTs). The most important outcome of this strengthening of the polymer strands is that the threshold voltage associated with the electro-optic switching becomes essentially temperature independent in marked contrast to the significant thermal variation seen in the absence of the nanotubes...
July 20, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28727202/influence-of-the-left-atrial-contact-areas-on-fixed-low-voltage-zones-during-atrial-fibrillation-and-sinus-rhythm-in-persistent-atrial-fibrillation
#10
Shiro Nakahara, Yuichi Hori, Naoki Nishiyama, Yasuo Okumura, Reiko Fukuda, Sayuki Kobayashi, Takaaki Komatsu, Yoshihiko Sakai, Isao Taguchi
BACKGROUND: Atrial low-voltage zones (LVZ) are suggested as important factors for maintaining persistent atrial fibrillation (PsAF). The relationship between LVZs and left atrial (LA) contact areas (CoAs) is still unclear. OBJECTIVE: To assess whether CoA regions were involved in atrial substrate properties maintaining PsAF. METHODS: A total of 50 patients with PsAF (36 long-lasting) were analyzed. Three representative CoA detection areas (ascending aorta-anterior-LA, descending aorta-left pulmonary vein antrum, and vertebrae-posterior-LA) were registered on the mapping geometry...
July 20, 2017: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/28722339/structured-pain-management-reduces-patient-discomfort-after-catheter-ablation-and-rhythm-device-surgery
#11
M Dörschner, A Bollmann, B Dinov, S Richter, M Döring, A Arya, A Müssigbrodt, S Kircher, N Dagres, P Sommer, G Hindricks, K Bode
BACKGROUND: The goal was to test the effectiveness of a structured pain management programme after invasive electrophysiological interventions in cardiology including ablation of atrial fibrillation (AF) or ventricular tachycardia (VT) and implantation, or explantation, of pacemakers or implantable cardioverter defibrillators. METHODS: This was a prospective study with a pre-/post-design where a post-intervention group (116 consecutive patients) was compared to a pre-intervention group (102 consecutive patients) after implementation of a structured pain-management programme using the numeric rating scale (NRS 0-10) and classified as moderate-to-severe if NRS > 3...
July 18, 2017: European Journal of Pain: EJP
https://www.readbyqxmd.com/read/28722055/the-amyloid-architecture-provides-a-scaffold-for-enzyme-like-catalysts
#12
Z S Al-Garawi, B A McIntosh, D Neill-Hall, A A Hatimy, S M Sweet, M C Bagley, L C Serpell
Natural biological enzymes possess catalytic sites that are generally surrounded by a large three-dimensional scaffold. However, the proportion of the protein molecule that participates in the catalytic reaction is relatively small. The generation of artificial or miniature enzymes has long been a focus of research because enzyme mimetics can be produced with high activity at low cost. These enzymes aim to mimic the active sites without the additional architecture contributed by the protein chain. Previous work has shown that amyloidogenic peptides are able to self-assemble to create an active site that is capable of binding zinc and catalysing an esterase reaction...
July 19, 2017: Nanoscale
https://www.readbyqxmd.com/read/28721830/redox-state-in-atrial-fibrillation-pathogenesis-and-relevant-therapeutic-approaches
#13
Alexios S Antonopoulos, Athina Goliopoulou, Evangelos Oikonomou, Sotiris Tsalamandris, Georgios-Angelos Papamikroulis, George Lazaros, Eleftherios Tsiamis, George Latsios, Stella Brili, Spyridon Papaioannou, Vasiliki Gennimata, Dimitris Tousoulis
Myocardial redox state is a critical determinant of myocardial biology, regulating cardiomyocytes' apoptosis, hypertrophy, ion channels function and cardiac contractility and relaxation. Data from animal models have shown that altered myocardial nitroso-redox balance and NADPH oxidases activity are pivotally involved in the pathogenesis of atrial fibrillation. Similarly experimental animal data have demonstrated that increased reactive oxygen / nitrogen species formation in the atrial tissue is associated with altered electrophysiological properties of atrial myocytes and electrical remodeling...
July 18, 2017: Current Medicinal Chemistry
https://www.readbyqxmd.com/read/28721223/atrial-fibrillation-in-a-preterm-newborn-with-structurally-normal-heart
#14
Pier Paolo Bassareo, Andrea Raffaele Marras, Mariangela Marras, Silvia Marras, Giuseppe Mercuro
Atrial fibrillation (AF) is a really uncommon arrhythmia in newborns. Here, we report the case of a 1-day-old infant who was recovered in Neonatal Intensive Care Unit for a twin-to-twin transfusion. The appearance of an unexpected AF was registered at his continuous electrocardiographic monitoring. Both chest X-ray and echocardiographic examination revealed the anomalous insertion of the tip of a central venous catheter (CVC) into the heart ('umbilical artery → inferior vena cava → right atrium → patent foramen ovale → left atrium')...
March 2017: Oxford Medical Case Reports
https://www.readbyqxmd.com/read/28716747/cysteine-as-a-potential-anti-amyloidogenic-agent-with-protective-ability-against-amyloid-induced-cytotoxicity
#15
Masihuz Zaman, Syed Mohammad Zakariya, Saima Nusrat, Tajalli Ilm Chandel, Syed Musthapa Meeran, Mohammad Rehan Ajmal, Parvez Alam, Wahiduzzaman, Rizwan Hasan Khan
Protein aggregation and misfolding have been allied with numerous human disorders and thus inhibition of such occurrence has been center for intense research efforts against these diseases. Here, we investigated anti-fibrillation activity of cysteine and its effect on kinetics of stem bromelain amyloid fibril formation. We established the anti-fibrillation and anti aggregation activities of cysteine by using multiple approaches like turbidity measurements, dye binding assays (ThT and ANS) and structural changes were monitored by circular dichroism (CD) followed by electron microscopy...
July 14, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28716216/1-4-times-increase-in-atrial-fibrillation-related-ischemic-stroke-and-tia-over-12years-in-a-stroke-center
#16
Qiong Yang, Leonid Churilov, Dongsheng Fan, Stephen Davis, Bernard Yan
BACKGROUND AND PURPOSE: Prevalence of atrial fibrillation (AF) has quadrupled in the past 50years in the general population. However, there is uncertainty regarding prevalence of AF over time in ischemic stroke patients given the aging population and enhanced surveillance of AF. We aimed to explore the changing prevalence of AF as well as other risk factors, stroke subtypes, investigations and pre-stroke medications among ischemic stroke and transient ischemic attack (TIA) patients. METHODS: We performed a retrospective analysis of data from a prospective database of consecutive patients with acute ischemic stroke and TIA from 2004 to 2015...
August 15, 2017: Journal of the Neurological Sciences
https://www.readbyqxmd.com/read/28714118/body-wall-structure-in-the-starfish-asterias-rubens
#17
Liisa M Blowes, Michaela Egertová, Yankai Liu, Graham R Davis, Nick J Terrill, Himadri S Gupta, Maurice R Elphick
The body wall of starfish is composed of magnesium calcite ossicles connected by collagenous tissue and muscles and it exhibits remarkable variability in stiffness, which is attributed to the mechanical mutability of the collagenous component. Using the common European starfish Asterias rubens as an experimental animal, here we have employed a variety of techniques to gain new insights into the structure of the starfish body wall. The structure and organisation of muscular and collagenous components of the body wall were analysed using trichrome staining...
July 16, 2017: Journal of Anatomy
https://www.readbyqxmd.com/read/28710791/origin-of-enhanced-vcd-in-amyloid-fibril-spectra-effect-of-deuteriation-and-ph
#18
Markéta Pazderková, Tomáš Pazderka, Maruda Shanmugasundaram, Rina K Dukor, Igor K Lednev, Laurence A Nafie
Supramolecular chirality of amyloid fibrils, protein aggregates related to many neurodegenerative diseases, is a remarkable property associated with fibril structure and polymorphism. Since its discovery almost 10 years ago there is still little understanding of this phenomenon, including the cause of the highly enhanced vibrational circular dichroism (VCD) intensity arising from fibril supramolecular chirality. In this study, VCD spectra, enhanced by filament supramolecular chirality, are presented for lysozyme and insulin fibrils above and below pH 2 and after deuterium exchange, above and below pD 2...
July 15, 2017: Chirality
https://www.readbyqxmd.com/read/28710429/the-a2v-mutation-as-a-new-tool-for-hindering-a%C3%AE-aggregation-a-neutron-and-x-ray-diffraction-study
#19
Laura Cantu', Laura Colombo, Tatiana Stoilova, Bruno Demé, Hideyo Inouye, Rachel Booth, Valeria Rondelli, Giuseppe Di Fede, Fabrizio Tagliavini, Elena Del Favero, Daniel A Kirschner, Mario Salmona
We have described a novel C-to-T mutation in the APP gene that corresponds to an alanine to valine substitution at position 673 in APP (A673V), or position 2 of the amyloid-β (Aβ) sequence. This mutation is associated with the early onset of AD-type dementia in homozygous individuals, whereas it has a protective effect in the heterozygous state. Correspondingly, we observed differences in the aggregation properties of the wild-type and mutated Aβ peptides and their mixture. We have carried out neutron diffraction (ND) and x-ray diffraction (XRD) experiments on magnetically-oriented fibers of Aβ1-28WT and its variant Aβ1-28A2V...
July 14, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28710275/a-ph-dependent-switch-promotes-%C3%AE-synuclein-fibril-formation-via-glutamate-residues
#20
Gina M Moriarty, Michael P Olson, Tamr B Atieh, Maria K Janowska, Sagar D Khare, Jean Baum
Alpha-synuclein (αS) is the primary protein associated with Parkinson's disease, and undergoes aggregation from its intrinsically disordered monomeric form to a cross-β fibrillar form. The closely related homolog beta-synuclein (βS) is essentially fibril resistant under cytoplasmic physiological conditions. Toxic gain of function by βS has been linked to dysfunction, but the aggregation behavior of βS under altered pH is not well understood. In this work, we compare fibril formation of αS and βS at pH 7...
July 14, 2017: Journal of Biological Chemistry
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