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https://www.readbyqxmd.com/read/29677208/modeling-the-dynamics-and-kinetics-of-hiv-1-gag-during-viral-assembly
#1
Michael D Tomasini, Daniel S Johnson, Joshua S Mincer, Sanford M Simon
We report a computational model for the assembly of HIV-1 Gag into immature viral particles at the plasma membrane. To reproduce experimental structural and kinetic properties of assembly, a process occurring on the order of minutes, a coarse-grained representation consisting of a single particle per Gag molecule is developed. The model uses information relating the functional interfaces implicated in Gag assembly, results from cryo electron-tomography, and biophysical measurements from fluorescence microscopy, such as the dynamics of Gag assembly at single virions...
2018: PloS One
https://www.readbyqxmd.com/read/29676283/a-combined-positron-emission-tomography-pet-electron-paramagnetic-resonance-imaging-epri-system-initial-evaluation-of-a-prototype-scanner
#2
Mark Tseytlin, Alexander V Stolin, Priyaankadevi Guggilapu, Andrey A Bobko, Valery V Khramtsov, Oxana Tseytlin, Raymond R Raylman
The advent of hybrid scanners, combining complementary modalities, has revolutionized imaging; enhancing clinical practice and biomedical research. In this project, we investigated the melding of two complementary, functional imaging methods: positron emission tomography (PET) and electron paramagnetic resonance imaging (EPRI). The PET radiotracers can provide important information about cellular parameters, such as glucose metabolism. While EPR probes can provide assessment of tissue microenvironment, measuring parameters such as oxygenation and pH, for example...
April 20, 2018: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29673018/combining-high-pressure-freezing-with-pre-embedding-immunogold-electron-microscopy-and-tomography
#3
Michael W Hess, Georg F Vogel, Teodor E Yordanov, Barbara Witting, Karin Gutleben, Hannes L Ebner, Mariana E G de Araujo, Przemyslaw Filipek, Lukas A Huber
Immunogold labeling of permeabilized whole-mount cells or thin-sectioned material is widely used for the subcellular localization of biomolecules at the high spatial resolution of electron microscopy (EM). Those approaches are well compatible with either three-dimensional (3D) reconstruction of organelle morphology and antigen distribution or with rapid cryofixation - but not easily with both at once. We describe here a specimen preparation and labeling protocol for animal cell cultures, which represents a novel blend of specifically adapted versions of established techniques...
April 19, 2018: Traffic
https://www.readbyqxmd.com/read/29672573/transgenic-expression-of-dentin-phosphoprotein-dpp-partially-rescued-the-dentin-defects-of-dspp-null-mice
#4
Hua Zhang, Xiaohua Xie, Peihong Liu, Tian Liang, Yongbo Lu, Chunlin Qin
Mutations in the dentin sialophosphoprotein (DSPP) gene cause dentinogenesis imperfecta. After synthesis, DSPP is proteolytically processed into NH2- and COOH-terminal fragments. The NH2-terminal fragment of DSPP is highly glycosylated but not phosphorylated, whereas the COOH-terminal fragment (named "dentin phosphoprotein" or "DPP") is highly phosphorylated but not glycosylated. These two fragments are believed to perform distinct roles in dentin formation. To analyze the functions of DPP in dentinogenesis, we created "Dspp-/-;DPP Tg mice", which expressed transgenic DPP driven by a Type I collagen promoter but lacked the endogenous Dspp gene...
2018: PloS One
https://www.readbyqxmd.com/read/29672176/prevalence-and-risk-factors-for-vascular-calcification-in-chinese-patients-receiving-dialysis-baseline-results-from-a-prospective-cohort-study
#5
Zhi-Hong Liu, Xue-Qing Yu, Jun-Wei Yang, Ai-Li Jiang, Bi-Cheng Liu, Chang-Ying Xing, Ji-Zhuang Lou, Mei Wang, Hong Cheng, Jun Liu, Jun-Zhou Fu, Ai-Hua Zhang, Miao Zhang, Qiao-Ling Zhou, Chen Yu, Rong Wang, Li Wang, Yu-Qing Chen, Tian-Jun Guan, Ai Peng, Chen Nan, Chuan-Ming Hao, Xu-Yang Cheng
OBJECTIVE: With limited data available on calcification prevalence in chronic kidney disease (CKD) patients on dialysis, the China Dialysis Calcification Study (CDCS) determined the prevalence of vascular/valvular calcification (VC) and association of risk factors in Chinese patients with prevalent hemodialysis (HD) or peritoneal dialysis (PD). METHODS: CKD patients undergoing HD/PD for ≥6 months were enrolled. Prevalence data for calcification and medical history were documented at baseline...
April 19, 2018: Current Medical Research and Opinion
https://www.readbyqxmd.com/read/29671071/synthesis-of-highly-stable-and-biocompatible-gold-nanoparticles-for-use-as-a-new-x-ray-contrast-agent
#6
Pooya Iranpour, Maral Ajamian, Afsaneh Safavi, Nasser Iranpoor, Abdolkarim Abbaspour, Sanaz Javanmardi
This work reports a novel reduction procedure for the synthesis of Gum Arabic (GA) capped-gold nanoparticles (AuNPs) in glucosammonium formate as a new ionic liquid. The GA coated AuNPs show good stability in physiological media. The synthesized AuNPs were characterized by UV-Vis spectroscopy, transmission electron microscopy, dynamic light scattering and X-ray diffraction analysis. These stable AuNPs are introduced as a new contrast agent for X-ray Computed Tomography (X-ray CT). These nanoparticles have higher contrasting properties than the commercial contrast agent, Visipaque...
April 18, 2018: Journal of Materials Science. Materials in Medicine
https://www.readbyqxmd.com/read/29666899/altered-mitochondrial-bioenergetics-and-ultrastructure-in-the-skeletal-muscle-of-young-adults-with-type-1-diabetes
#7
Cynthia M F Monaco, Meghan C Hughes, Sofhia V Ramos, Nina E Varah, Christian Lamberz, Fasih A Rahman, Chris McGlory, Mark A Tarnopolsky, Matthew P Krause, Robert Laham, Thomas J Hawke, Christopher G R Perry
AIMS/HYPOTHESIS: A comprehensive assessment of skeletal muscle ultrastructure and mitochondrial bioenergetics has not been undertaken in individuals with type 1 diabetes. This study aimed to systematically assess skeletal muscle mitochondrial phenotype in young adults with type 1 diabetes. METHODS: Physically active, young adults (men and women) with type 1 diabetes (HbA1c 63.0 ± 16.0 mmol/mol [7.9% ± 1.5%]) and without type 1 diabetes (control), matched for sex, age, BMI and level of physical activity, were recruited (n = 12/group) to undergo vastus lateralis muscle microbiopsies...
April 18, 2018: Diabetologia
https://www.readbyqxmd.com/read/29666871/harmonic-analysis-of-surface-instability-patterns-on-colloidal-particles
#8
Tero Kämäräinen, Mariko Ago, Jani Seitsonen, Janne Raula, Esko I Kauppinen, Janne Ruokolainen, Orlando J Rojas
Wrinkling of colloidal particles alter a wide variety of interfacial properties but quantitative topographical descriptions have been explored experimentally to a very limited extent. In this study, we present a harmonic analysis of surface wrinkles and folds on submicron colloidal particles, obtained using an aerosol flow route, with small radius (<300 nm) and high crust thickness-to-radius ratio (>0.1). The particle surface coordinates were mapped in their entirety using cryo-electron tomography and subsequently reconstructed using spherical harmonics, allowing a spectral topographical description of the instability patterns and the identification of their surface modes by lateral wavelength...
April 18, 2018: Soft Matter
https://www.readbyqxmd.com/read/29666283/the-origin-dynamic-morphology-and-pi4p-independent-formation-of-encephalomyocarditis-virus-replication-organelles
#9
C E Melia, H M van der Schaar, A W M de Jong, H R Lyoo, E J Snijder, A J Koster, F J M van Kuppeveld, M Bárcena
Picornaviruses induce dramatic rearrangements of endomembranes in the cells that they infect to produce dedicated platforms for viral replication. These structures, termed replication organelles (ROs), have been well characterized for the Enterovirus genus of the Picornaviridae However, it is unknown whether the diverse RO morphologies associated with enterovirus infection are conserved among other picornaviruses. Here, we use serial electron tomography at different stages of infection to assess the three-dimensional architecture of ROs induced by encephalomyocarditis virus (EMCV), a member of the Cardiovirus genus of the family of picornaviruses that is distantly related...
April 17, 2018: MBio
https://www.readbyqxmd.com/read/29665086/severely-impaired-bone-material-quality-in-chihuahua-zebrafish-resembles-classical-dominant-human-osteogenesis-imperfecta
#10
Imke A K Fiedler, Felix N Schmidt, Eva M Wölfel, Christine Plumeyer, Petar Milovanovic, Roberta Gioia, Francesca Tonelli, Hrishikesh A Bale, Katharina Jähn, Roberta Besio, Antonella Forlino, Björn Busse
Excessive skeletal deformations and brittle fractures in the vast majority of patients suffering from osteogenesis imperfecta (OI) are a result of substantially reduced bone quality. Since the mechanical competence of bone is dependent on the tissue characteristics at small length scales, it is of crucial importance to assess how osteogenesis imperfecta manifests at the micro- and nanoscale of bone. In this context, the Chihuahua (Chi/ +) zebrafish, carrying a heterozygous glycine substitution in the α1 chain of collagen type I, has recently been proposed as suitable animal model of classical dominant OI, showing skeletal deformities, altered mineralization patterns and a smaller body size...
April 17, 2018: Journal of Bone and Mineral Research: the Official Journal of the American Society for Bone and Mineral Research
https://www.readbyqxmd.com/read/29661070/scaphoid-cysts-literature-review-of-etiology-treatment-and-prognosis
#11
Tyler Safran, Jessica Hazan, Becher Al-Halabi, Hassan Al-Naeem, Sabrina Cugno
BACKGROUND: Cystic lesions of the carpal bones are rare entities that are infrequently reported in the literature. Scaphoid intraosseous cystic lesions represent a rare subset of carpal bone cysts. This review aims to summarize the available evidence on the evaluation and treatment of scaphoid cystic lesions to help guide clinical management. METHODS: Systematic electronic searches were performed using PubMed, Ovid, and Embase databases. Studies included were graded for their risk of bias...
April 1, 2018: Hand: Official Journal of the American Association for Hand Surgery
https://www.readbyqxmd.com/read/29658792/scandium-and-terbium-radionuclides-for-radiotheranostics-current-state-of-development-towards-clinical-application
#12
Cristina Müeller, Katharina A Domnanich, Christoph A Umbricht, Nicholas P van der Meulen
Currently, different radiometals are in use for imaging and therapy in nuclear medicine: 68 Ga and 111 In are examples of nuclides for positron emission tomography (PET) and single photon emission computed tomography (SPECT), respectively, while 177 Lu and 225 Ac are used for β- - and α-radionuclide therapy. The application of diagnostic and therapeutic radionuclides of the same element (radioisotopes) would utilize chemically-identical radiopharmaceuticals for imaging and subsequent treatment, thereby enabling the radiotheranostic concept...
April 16, 2018: British Journal of Radiology
https://www.readbyqxmd.com/read/29658023/biodistribution-studies-of-ultrasmall-silicon-nanoparticles-and-carbon-dots-in-experimental-rats-and-tumor-mice
#13
Nadia Licciardello, Sebastian Hunoldt, Ralf Bergmann, Garima Singh, Constantin Mamat, Angélique Faramus, John L Z Ddungu, Simone Silvestrini, Michele Maggini, Luisa De Cola, Holger Stephan
Ultrasmall clearable nanoparticles possess enormous potential as cancer imaging agents. In particular, biocompatible silicon nanoparticles (Si NPs) and carbon quantum dots (CQDs) hold great potential in this regard. Their facile surface functionalization easily allows the introduction of different labels for in vivo imaging. However, to date, a thorough biodistribution study by in vivo positron emission tomography (PET) and a comparative study of Si vs. C particles of similar size are missing. In this contribution, ultrasmall (size <5 nm) Si NPs and CQDs were synthesized and characterized by high-resolution transmission electron microscopy (HR-TEM), Fourier-transform infrared (FTIR), absorption and steady-state emission spectroscopy...
April 16, 2018: Nanoscale
https://www.readbyqxmd.com/read/29656089/microbiology-catches-the-cryo-em-bug
#14
REVIEW
Lesley A Earl, Veronica Falconieri, Sriram Subramaniam
Over the past few years, the advances in technology and methods that have revolutionized cryo-EM are allowing for key insights in a variety of areas in biology, and microbiology is no exception. A wide range of important macromolecular assemblies in prokaryotic and eukaryotic cells, as well as intact viruses, have now become accessible to investigation by new methods in 3D electron microscopy. We focus here on selected examples that illustrate this breadth, and review the application of methods in single particle cryo-EM and cryo-electron tomography to progress in the structural biology of CRISPR systems, visualization of small molecule drugs in membrane proteins, in situ visualization of bacterial nanomachines, and the analysis of antigen-antibody interactions to drive vaccine design...
April 12, 2018: Current Opinion in Microbiology
https://www.readbyqxmd.com/read/29642566/in-vitro-and-in-vivo-osteogenic-activity-of-titanium-implants-coated-by-pulsed-laser-deposition-with-a-thin-film-of-fluoridated-hydroxyapatite
#15
Luyuan Chen, Satoshi Komasa, Yoshiya Hashimoto, Shigeki Hontsu, Joji Okazaki
To enhance biocompatibility, osteogenesis, and osseointegration, we coated titanium implants, by krypton fluoride (KrF) pulsed laser deposition, with a thin film of fluoridated hydroxyapatite (FHA). Coating was confirmed by scanning electron microscopy (SEM) and scanning probe microscopy (SPM), while physicochemical properties were evaluated by attenuated reflectance Fourier transform infrared spectroscopy (ATR-FTIR). Calcium deposition, osteocalcin production, and expression of osteoblast genes were significantly higher in rat bone marrow mesenchymal stem cells seeded on FHA-coated titanium than in cells seeded on uncoated titanium...
April 10, 2018: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/29629868/computed-tomography-identified-factors-that-preclude-living-kidney-donation
#16
Katerina Mastrocostas, Christina M Chingkoe, Kenneth T Pace, Joseph J Barfett, Anish Kirpalani, Gevork N Mnatzakanian, Paraskevi A Vlachou, Errol Colak
INTRODUCTION: The purpose of this study was to determine the variety and prevalence of renal and non-renal abnormalities detected on multi-detector computed tomography (MDCT) that precluded patients from donating a kidney. METHODS: Institutional review board approval was obtained and the requirement for informed consent was waived. A retrospective, single-centre review of 701 patients (444 female, 257 male; age range 18-86 years; mean age 43.2±11.9 years) that underwent renal donor protocol MDCT was conducted...
April 6, 2018: Canadian Urological Association Journal, Journal de L'Association des Urologues du Canada
https://www.readbyqxmd.com/read/29624708/accuracy-of-electron-density-effective-atomic-number-and-iodine-concentration-determination-with-a-dual-layer-dual-energy-computed-tomography-system
#17
Chia-Ho Hua, Nadav Shapira, Thomas E Merchant, Paul Klahr, Yoad Yagil
PURPOSE: This study aimed to quantify the accuracy of the determination of electron density (ED), effective atomic number (Zeff ), and iodine concentration, directed for more accurate radiation therapy planning, with a new dual-layer dual-energy computed tomography (DL-DECT) system. The dependence of the accuracy of these values on the scan and reconstruction parameters, as well as on the phantom size, was also examined. METHODS: Measurements were performed on a commercial DECT system with a DL detector (IQon Spectral CT, Philips Healthcare), using phantoms with various tissue-equivalent inserts as well as iodine and calcium inserts of different concentrations...
April 6, 2018: Medical Physics
https://www.readbyqxmd.com/read/29621189/nanoscale-origins-of-the-size-effect-in-the-compression-response-of-single-crystal-ni-base-superalloy-micro-pillars
#18
Siqi Ying, Lifeng Ma, Tan Sui, Chrysanthi Papadaki, Enrico Salvati, Leon Romano Brandt, Hongjia Zhang, Alexander M Korsunsky
Nickel superalloys play a pivotal role in enabling power-generation devices on land, sea, and in the air. They derive their strength from coherent cuboidal precipitates of the ordered γ' phase that is different from the γ matrix in composition, structure and properties. In order to reveal the correlation between elemental distribution, dislocation glide and the plastic deformation of micro- and nano-sized volumes of a nickel superalloy, a combined in situ nanoindentation compression study was carried out with a scanning electron microscope (SEM) on micro- and nano-pillars fabricated by focused ion beam (FIB) milling of Ni-base superalloy CMSX4...
April 5, 2018: Materials
https://www.readbyqxmd.com/read/29616690/atomically-resolved-calcium-phosphate-coating-on-a-gold-substrate
#19
Noah Metoki, Sung-Il Baik, Dieter Isheim, Daniel Mandler, David N Seidman, Noam Eliaz
Some articles have revealed that the electrodeposition of calcium phosphate (CaP) coatings entails a precursor phase, similarly to biomineralization in vivo. The chemical composition of the initial layer and its thickness are, however, still arguable, to the best of our knowledge. Moreover, while CaP and electrodeposition of metal coatings have been studied utilizing atom-probe tomography (APT), the electrodeposition of CaP ceramics has not been heretofore studied. Herein, we present an investigation of the CaP deposition on a gold substrate...
April 4, 2018: Nanoscale
https://www.readbyqxmd.com/read/29608574/healing-potentials-of-polymethylmethacrylate-bone-cement-combined-with-platelet-gel-in-the-critical-sized-radial-bone-defect-of-rats
#20
Ahmad Oryan, Soodeh Alidadi, Amin Bigham-Sadegh, Ali Moshiri
Polymethylmethacrylate (PMMA) is the most commonly used filler material that lacks biological properties and osteoconductivity or osteoinductivity. Platelet gel (PG) is a typical source of growth factors, cytokines and molecules efficient for bone formation and remodeling. The aim of this study was to evaluate bone healing and regeneration of bone defect in rat model by combining PMMA with PG. A total of 50 defects were created in the diaphysis of the radii of 25 male Sprague-Dawley rats. These defects were randomly divided into five groups (n = 10 defects for each group) and treated by autograft, plain PMMA, PG and PMMA-PG or left untreated...
2018: PloS One
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