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https://www.readbyqxmd.com/read/28728086/nanostructured-lipid-systems-modified-with-waste-material-of-propolis-for-wound-healing-design-in-vitro-and-in-vivo-evaluation
#1
Hélen Cássia Rosseto, Lucas de Alcântara Sica de Toledo, Lizziane Maria Belloto de Francisco, Elisabetta Esposito, Yunsook Lim, Giuseppe Valacchi, Rita Cortesi, Marcos Luciano Bruschi
Propolis, a natural compound that can accelerate the wound healing process, is mainly used as ethanolic extract. The extractive solution may also be obtained from the propolis by-product (BP), transforming this waste material into a pharmaceutical active ingredient. Even if propolis does not show toxicity, when used as an extract over harmed skin or mucosa, the present ethanol content may be harmful to the tissue recovering, besides hindering the drug release. This study describes the development of solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) as topical propolis delivery systems and the investigation of their in vitro and in vivo activities...
July 10, 2017: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/28726904/vesicle-aggregates-as-a-model-for-primitive-cellular-assemblies
#2
Tereza Pereira de Souza, Guilherme Volpe Bossa, Pasquale Stano, Frank Steiniger, Sylvio May, Pier Luigi Luisi, Alfred Fahr
Primitive cell models help to understand the role that compartmentalization plays in origin of life scenarios. Here we present a combined experimental and modeling approach towards the construction of simple model systems for primitive cellular assemblies. Charged lipid vesicles aggregate in the presence of oppositely charged biopolymers, such as nucleic acids or polypeptides. Based on zeta potential measurements, dynamic light scattering and cryo-transmission electron-microscopy, we have characterized the behavior of empty and ferritin-filled large unilamellar POPC vesicles, doped with different amounts of cationic (DDAB, CTAB) and anionic (sodium oleate) surfactants, and their aggregation upon the addition of anionic (tRNA, poly-l-glutamic acid) and cationic (poly-l-arginine) biopolymers, respectively...
July 20, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28726246/cryo-electron-tomography-the-cell-biology-that-came-in-from-the-cold
#3
REVIEW
Jonathan Wagner, Miroslava Schaffer, Rubén Fernández-Busnadiego
Cryo-electron tomography (cryo-ET) provides high resolution 3D views into cells pristinely preserved by vitrification. Recent technical advances such as direct electron detectors, the Volta phase plate and cryo-focused ion beam milling have dramatically pushed image quality and expanded the range of cryo-ET applications. Cryo-ET not only allows mapping the positions and interactions of macromolecules within their intact cellular context, but can also reveal their in situ structure at increasing resolution. Here, we review how recent work using cutting-edge cryo-ET technologies is starting to provide fresh views into different aspects of cellular biology at an unprecedented level of detail...
July 20, 2017: FEBS Letters
https://www.readbyqxmd.com/read/28725003/distribution-of-salicifoline-in-freeze-fixed-stems-of-magnolia-kobus-as-observed-by-cryo-tof-sims
#4
Wakaba Okumura, Dan Aoki, Yasuyuki Matsushita, Masato Yoshida, Kazuhiko Fukushima
Alkaloids are basic nitrogen-containing chemicals that have important physiological and pharmacological characteristics. Many vascular plant species contain alkaloids, and their roles in planta are of interest. However, the detailed distribution of alkaloids remains unclear because of their low water solubility and low concentrations in plants. In this study, we visualized the distribution of salicifoline, a water-soluble quaternary ammonium alkaloid, in the freeze-fixed stems of Magnolia kobus by cryo time-of-flight secondary ion mass spectrometry...
July 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28724762/stability-of-cucumber-necrosis-virus-at-the-quasi-six-fold-axis-affects-zoospore-transmission
#5
Michael B Sherman, Kishore Kakani, D'Ann Rochon, Wen Jiang, Neil R Voss, Thomas J Smith
Cucumber necrosis virus (CNV) is a member of the genus Tombusvirus and has a monopartite positive-sense RNA genome. CNV is transmitted in nature via zoospores of the fungus, Olpidium bornovanus As with other members of the Tombusvirus genus, the CNV capsid swells when exposed to alkaline pH and EDTA. We previously demonstrated that a P73G mutation blocks the virus from zoospore transmission while not significantly affecting replication in plants (1). P73 lies immediately adjacent to a putative zinc binding site (2) that is formed by three icosahedrally related His residues in the N-termini of the C subunit at the quasi 6-fold axes...
July 19, 2017: Journal of Virology
https://www.readbyqxmd.com/read/28723304/the-quest-for-durable-lesions-in-catheter-ablation-of-atrial-fibrillation-technological-advances-in-radiofrequency-catheters-and-balloon-devices
#6
Tilman Maurer, Karl-Heinz Kuck
Atrial fibrillation is the most common cardiac arrhythmia and represents a growing clinical, social and economic challenge. Catheter ablation for symptomatic atrial fibrillation has evolved from an experimental procedure into a widespread therapy and offers a safe and effective treatment option. A prerequisite for durable PVI are transmural and contiguous circumferential lesions around the pulmonary veins. However, electrical reconnection of initially isolated pulmonary veins remains a primary concern and is a dominant factor for arrhythmia recurrence during long-term follow up...
July 19, 2017: Expert Review of Medical Devices
https://www.readbyqxmd.com/read/28716906/virus-found-in-a-boreal-lake-links-ssdna-and-dsdna-viruses
#7
Elina Laanto, Sari Mäntynen, Luigi De Colibus, Jenni Marjakangas, Ashley Gillum, David I Stuart, Janne J Ravantti, Juha T Huiskonen, Lotta-Riina Sundberg
Viruses have impacted the biosphere in numerous ways since the dawn of life. However, the evolution, genetic, structural, and taxonomic diversity of viruses remain poorly understood, in part because sparse sampling of the virosphere has concentrated mostly on exploring the abundance and diversity of dsDNA viruses. Furthermore, viral genomes are highly diverse, and using only the current sequence-based methods for classifying viruses and studying their phylogeny is complicated. Here we describe a virus, FLiP (Flavobacterium-infecting, lipid-containing phage), with a circular ssDNA genome and an internal lipid membrane enclosed in the icosahedral capsid...
July 17, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28716758/oral-delivery-of-vancomycin-by-tetraether-lipid-liposomes
#8
Philipp Uhl, Silvia Pantze, Philip Storck, Johannes Parmentier, Dominik Witzigmann, Götz Hofhaus, Jörg Huwyler, Walter Mier, Gert Fricker
Despite the outstanding progress in modern medicine, the oral delivery of peptide drugs is limited until today due to their instability in the gastrointestinal tract and low mucosa penetration. To overcome these hurdles, liposomes containing the specific tetraether lipid GCTE (glycerylcaldityltetraether lipid) were examined. For this purpose, the glycopeptide antibiotic vancomycin was used as model substance and liposomes were prepared by DAC (dual assymetric centrifugation). These liposomes showed a size and polydispersity index comparable to standard liposomes...
July 14, 2017: European Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28714467/cryo-em-structures-of-the-atp-bound-vps4-e233q-hexamer-and-its-complex-with-vta1-at-near-atomic-resolution
#9
Shan Sun, Lin Li, Fan Yang, Xiaojing Wang, Fenghui Fan, Mengyi Yang, Chunlai Chen, Xueming Li, Hong-Wei Wang, Sen-Fang Sui
The cellular ESCRT-III (endosomal sorting complex required for transport-III) and Vps4 (vacuolar protein sorting 4) comprise a common machinery that mediates a variety of membrane remodelling events. Vps4 is essential for the machinery function by using the energy from ATP hydrolysis to disassemble the ESCRT-III polymer into individual proteins. Here, we report the structures of the ATP-bound Vps4(E233Q) hexamer and its complex with the cofactor Vta1 (vps twenty associated 1) at resolutions of 3.9 and 4.2 Å, respectively, determined by electron cryo-microscopy...
July 17, 2017: Nature Communications
https://www.readbyqxmd.com/read/28712809/near-atomic-resolution-structure-of-a-plant-geminivirus-determined-by-electron-cryomicroscopy
#10
Katharina Hipp, Clemens Grimm, Holger Jeske, Bettina Böttcher
African cassava mosaic virus is a whitefly-transmitted geminivirus which forms unique twin particles of incomplete icosahedra that are joined at five-fold vertices, building an unusual waist. How its 22 capsomers interact within a half-capsid or across the waist is unknown thus far. Using electron cryo-microscopy and image processing, we determined the virion structure with a resolution of 4.2 Å and built an atomic model for its capsid protein. The inter-capsomer contacts mediated by the flexible N termini and loop regions differed within the half-capsids and at the waist, explaining partly the unusual twin structure...
July 5, 2017: Structure
https://www.readbyqxmd.com/read/28711156/towards-a-structural-view-of-drug-binding-to-herg-k-channels
#11
REVIEW
Jamie I Vandenberg, Eduardo Perozo, Toby W Allen
The human ether-a-go-go-related gene (hERG) K(+) channel is of great medical and pharmaceutical relevance. Inherited mutations in hERG result in congenital long-QT syndrome which is associated with a markedly increased risk of cardiac arrhythmia and sudden death. hERG K(+) channels are also remarkably susceptible to block by a wide range of drugs, which in turn can cause drug-induced long-QT syndrome and an increased risk of sudden death. The recent determination of the near-atomic resolution structure of the hERG K(+) channel, using single-particle cryo-electron microscopy (cryo-EM), provides tremendous insights into how these channels work...
July 12, 2017: Trends in Pharmacological Sciences
https://www.readbyqxmd.com/read/28710447/cryo-em-reconstruction-of-the-cafeteria-roenbergensis-virus-capsid-suggests-novel-assembly-pathway-for-giant-viruses
#12
Chuan Xiao, Matthias G Fischer, Duer M Bolotaulo, Nancy Ulloa-Rondeau, Gustavo A Avila, Curtis A Suttle
Whereas the protein composition and overall shape of several giant virus capsids have been described, the mechanism by which these large capsids assemble remains enigmatic. Here, we present a reconstruction of the capsid of Cafeteria roenbergensis virus (CroV), one of the largest viruses analyzed by cryo-electron microscopy (cryo-EM) to date. The CroV capsid has a diameter of 3,000 Å and a Triangulation number of 499. Unlike related mimiviruses, the CroV capsid is not decorated with glycosylated surface fibers, but features 30 Å-long surface protrusions that are formed by loops of the major capsid protein...
July 14, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28710336/subunit-conformational-variation-within-individual-groel-oligomers-resolved-by-cryo-em
#13
Soung-Hun Roh, Corey F Hryc, Hyun-Hwan Jeong, Xue Fei, Joanita Jakana, George H Lorimer, Wah Chiu
Single-particle electron cryo-microscopy (cryo-EM) is an emerging tool for resolving structures of conformationally heterogeneous particles; however, each structure is derived from an average of many particles with presumed identical conformations. We used a 3.5-Å cryo-EM reconstruction with imposed D7 symmetry to further analyze structural heterogeneity among chemically identical subunits in each GroEL oligomer. Focused classification of the 14 subunits in each oligomer revealed three dominant classes of subunit conformations...
July 14, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28709083/the-peculiar-extra-acrosomal-structure-of-the-collembola-hexapoda-spermatozoa
#14
P P Fanciulli, C Mencarelli, D Mercati, R Dallai, P Lupetti
The springtail Collembola are characterized by having rolled spermatozoa, with a long cylindrical extracellular structure adhering to the acrosome. This structure is produced by the secretory activity of the testes epithelial cells at almost the end of spermiogenesis. At the beginning of its formation, it is a thin extension with a helical wall and a dense axial region. Later the cylindrical structure shows an inner organization which is different in the several species examined: species of Entomobryidae contain material with a paracrystalline structure, whilst some of Symphypleona contain ovoid structures...
June 29, 2017: Micron: the International Research and Review Journal for Microscopy
https://www.readbyqxmd.com/read/28707880/pinpoint-chemical-modification-of-the-quinone-access-channel-of-mitochondrial-complex-i-via-a-two-step-conjugation-reaction
#15
Takahiro Masuya, Masatoshi Murai, Takeshi Ito, Shunsuke Aburaya, Wataru Aoki, Hideto Miyoshi
We previously showed that a bulky ring-strained cycloalkyne possessing a rhodamine fluorophore directly reacts (via strain-promoted click chemistry) with the azido group incorporated (via ligand-directed tosyl chemistry) into Asp160 in the 49 kDa subunit of complex I in bovine heart submitochondrial particles [Masuya et al. (2014) Biochemistry 53, 7816-7823]. This two-step conjugation may be a promising technique for specific chemical modifications of the quinone-access channel in complex I by various molecular probes, which would lead to new methodologies for studying the enzyme...
July 14, 2017: Biochemistry
https://www.readbyqxmd.com/read/28706995/disabling-cas9-by-an-anti-crispr-dna-mimic
#16
Jiyung Shin, Fuguo Jiang, Jun-Jie Liu, Nicolas L Bray, Benjamin J Rauch, Seung Hyun Baik, Eva Nogales, Joseph Bondy-Denomy, Jacob E Corn, Jennifer A Doudna
CRISPR (clustered regularly interspaced short palindromic repeats)-Cas9 gene editing technology is derived from a microbial adaptive immune system, where bacteriophages are often the intended target. Natural inhibitors of CRISPR-Cas9 enable phages to evade immunity and show promise in controlling Cas9-mediated gene editing in human cells. However, the mechanism of CRISPR-Cas9 inhibition is not known, and the potential applications for Cas9 inhibitor proteins in mammalian cells have not been fully established...
July 2017: Science Advances
https://www.readbyqxmd.com/read/28704670/cryo-conditioned-rocky-coast-systems-a-case-study-from-wilczekodden-svalbard
#17
M C Strzelecki, M Kasprzak, M Lim, Z M Swirad, M Jaskólski, Ł Pawłowski, P Modzel
This paper presents the results of an investigation into the processes controlling development of a cryo-conditioned rock coast system in Hornsund, Svalbard. A suite of nested geomorphological and geophysical methods have been applied to characterise the functioning of rock cliffs and shore platforms influenced by lithological control and geomorphic processes driven by polar coast environments. Electrical resistivity tomosgraphy (ERT) surveys have been used to investigate permafrost control on rock coast dynamics and reveal the strong interaction with marine processes in High Arctic coastal settings...
July 10, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28702979/use-of-platelet-rich-plasma-in-human-infertility
#18
G V L Colombo, V Fanton, D Sosa, E Criado Scholz, J Lotti, S E Aragona, T Lotti
Successful embryo implantation requires good quality embryo but also needs a receptive endometrium site. In our clinical practice, we daily verify that an adequate endometrial growth is reached for successful implantation. To understand whether platelet rich plasma (PRP) can improve endometrium thickness and performance, PRP treatment was carried out after at least three of the classic medical protocols currently in use had been unsuccessfully adopted. Eight patients with more than 3 cryo-transfers cancelled because of failure of endometrial growth, defined as endometrium less than 6 mm, with negative hysteroscopic screening for endometrial pathology, and with negative bacteriologic screening, before present and all previous treatment, were selected to undergo PRP treatment...
July 13, 2017: Journal of Biological Regulators and Homeostatic Agents
https://www.readbyqxmd.com/read/28702650/influence-of-calcium-induced-droplet-heteroaggregation-on-the-physicochemical-properties-of-oppositely-charged-lactoferrin-coated-lutein-droplets-and-whey-protein-isolate-coated-dha-droplets
#19
Xin Li, Xu Wang, Duoxia Xu, Yanping Cao, Shaojia Wang, Bei Wang, Chengtao Wang, Baoguo Sun
The influence of calcium-induced droplet heteroaggregation on the formation and physicochemical stability of mixed lutein and DHA emulsions was studied. Heteroaggregation was induced by mixing oppositely charged lactoferrin (LF)-coated lutein and whey protein isolate (WPI)-coated DHA emulsions with different CaCl2 concentrations at pH 6.0. The droplet size, zeta-potential, transmission-physical stability and microstructure behavior (CLSM and Cryo-SEM) of single-protein emulsions and mixed emulsions were measured as a function of different CaCl2 concentrations...
July 12, 2017: Food & Function
https://www.readbyqxmd.com/read/28701465/the-yeast-kinesin-5-cin8-interacts-with-the-microtubule-in-a-noncanonical-manner
#20
Kayla M Bell, Hyo Keun Cha, Charles V Sindelar, Jared C Cochran
Kinesin motors play central roles in establishing and maintaining the mitotic spindle during cell division. Unlike most other kinesins, Cin8, a kinesin-5 motor in Saccharomyces cerevisiae, can move bidirectionally along microtubules, switching directionality according to biochemical conditions, a behavior that remains largely unexplained. To this end, we used biochemical rate and equilibrium constant measurements as well as cryo-electron microscopy methodologies to investigate the microtubule interactions of the Cin8 motor domain...
July 12, 2017: Journal of Biological Chemistry
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