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  • Proton irradiation and characterization of additively manufactured 304L stainless steels
    J. Nucl. Mater. (IF 2.547) Pub Date : 2020-01-21
    B.P. Eftink; J.S. Weaver; J.A. Valdez; V. Livescu; D. Chen; Y. Wang; C. Knapp; N.A. Mara; S.A. Maloy; G.T. Gray

    Irradiations were performed with 1.5 MeV protons to 0.6 dpa at 40–150 °C on additively manufactured (AM) 304L stainless steel and the changes in microstructure and mechanical behavior after irradiation were compared to wrought 304L stainless steel. All microstructural and hardness results after irradiation suggest the samples evolve toward a similar state, despite significant differences in the unirradiated microstructures and hardness values. A TEM and nanoindentation-based investigation of before and after proton irradiation at 40–150 °C is presented. Results are interpreted in terms of initial dislocation content, dislocation structures, and microstructural and chemical homogeneity.

    更新日期:2020-01-21
  • Comparison of the radial effects of burnup on fast reactor MOX fuel microstructure and solid fission products
    J. Nucl. Mater. (IF 2.547) Pub Date : 2020-01-20
    Riley J. Parrish; Fabiola Cappia; Assel Aitkaliyeva

    This work presents a comparison between the microstructural evolution of three annular fast-reactor mixed-oxide (MOX) fuel pellets irradiated to varying burnups at the Fast Flux Test Facility (FFTF). Fuel pellets irradiated to 3.4%, 13.7%, and 21.3% fissions per initial metal atom (FIMA) were examined using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) techniques. The cross-section of the low burnup pellet displayed minor structural changes, but the central annulus of the pellets at 13.7% and 21.3% FIMA shrank from their starting size. The high burnup fuel pellet featured streaking and porosity migration associated with columnar grain growth. The radial fission product distribution in each of the pellets had a higher number density of metallic particles >5 μm in diameter near the fuel centerline. Solid fission products in the fuel-cladding gap were observed in the low and intermediate burnup pellets. The low burnup sample showed minor accumulation of Ba in the gap, while the volatile Cs was primarily observed at the pellet surface. The intermediate burnup pellet displayed a porous mixture of fission products, consistent with the joint-oxide gain (JOG) that has been previously observed in fast-reactor MOX fuel pellets.

    更新日期:2020-01-21
  • Radiation damage tolerance of a novel metastable refractory high entropy alloy V2.5Cr1.2WMoCo0.04
    J. Nucl. Mater. (IF 2.547) Pub Date : 2020-01-18
    Dhinisa Patel; Mark D. Richardson; Bethany Jim; Shavkat Akhmadaliev; Russell Goodall; Amy S. Gandy

    A novel multicomponent alloy, V2.5Cr1.2WMoCo0.04, produced from elements expected to favour a BCC crystal structure, and to be suitable for high temperature environments, was fabricated by arc melting and found to exhibit a multiphase dendritic microstructure with W-rich dendrites and V–Cr segregated to the inter-dendritic cores. The as-cast alloy displayed an apparent single-phase XRD pattern. Following heat treatment at 1187 °C for 500 h the alloy transformed into three different distinct phases - BCC, orthorhombic, and tetragonal in crystal structure. This attests to the BCC crystal structure observed in the as-cast state being metastable. The radiation damage response was investigated through room temperature 5 MeV Au+ ion irradiation studies. Metastable as-cast V2.5Cr1.2WMoCo0.04 shows good resistance to radiation induced damage up to 40 displacements per atom (dpa). 96 wt% of the as-cast single-phase BCC crystal structure remained intact, as exhibited by grazing incidence X-ray diffraction (GI-XRD) patterns, whilst the remainder of the alloy transformed into an additional BCC crystal structure with a similar lattice parameter. The exceptional phase stability seen here is attributed to a combination of self-healing processes and the BCC structure, rather than a high configurational entropy, as has been suggested for some of these multicomponent “High Entropy Alloy” types. The importance of the stability of metastable high entropy alloy phases for behaviour under irradiation is for the first time highlighted and the findings thus challenge the current understanding of phase stability after irradiation of systems like the HEAs.

    更新日期:2020-01-21
  • Solubility and precipitation investigations of UO2 in LiF–BeF2 molten salt
    J. Nucl. Mater. (IF 2.547) Pub Date : 2020-01-18
    Hao Peng; Wei Huang; Leidong Xie; Qingnuan Li

    The solubility of UO2 in molten LiF–BeF2 (2:1 mol) (FLiBe) eutectic salt at 600 °C was studied by chemical and electrochemical methods. The results of dissolution experiment showed that the saturated solubility of UO2 in this melt was 2.37 × 10−3 mol/kg and its corresponding apparent solubility product (Ksp') was approximately 1.67 × 10−5 mol3/kg3. When more Li2O were added to the FLiBe–UF4 system, the cathodic peak current of U(IV) in the electrochemical cyclic voltammetry (CV) curve accordingly decreased because of precipitate formation. The precipitate corresponded to UO2 as determined by stoichiometric ratio (concentration variation of U4+ and O2−) and X-ray diffraction (XRD) analysis. Compared to the chemical analysis method, the CV technique was confirmed to be more feasible for accurate determination of concentration of U(IV). Meanwhile, the Ksp' value was also obtained to be 1.33 × 10−5 mol3/kg3 during the whole oxide titration procedure, which was highly consistent with that from the dissolution experiment. With the value of Ksp', the allowable amount of dissolved oxide ions (oxide tolerance) can be theoretically estimated in the FLiBe–UF4 system.

    更新日期:2020-01-21
  • Accelerated Monte Carlo method for calculation of sink strengths of absorbing surfaces for 3-D migrating particles in crystals of the cubic system
    J. Nucl. Mater. (IF 2.547) Pub Date : 2020-01-18
    A.B. Sivak; P.A. Sivak; V.M. Chernov

    An accelerated (compared to the standard “residence-time” Algorithm) Monte Carlo method for the calculation of the sink strengths of absorbing surfaces for particles in crystals of the cubic system has been suggested. On its basis, several algorithms have been developed which allow one to calculate the sink strengths either without any systematic inaccuracy or with its low and controlled magnitude. These algorithms have been tested by calculating the sink strengths of absorbing surfaces of different geometry (spherical, toroidal, cylindrical and planar) for particles (self-interstitial atoms, vacancies) in a crystal with BCC lattice. The use of the developed algorithms accelerates the calculations for low volume fractions of absorbers by orders of magnitude.

    更新日期:2020-01-21
  • Behaviour of (U,Am)O2 in oxidizing conditions: A high-temperature XRD study
    J. Nucl. Mater. (IF 2.547) Pub Date : 2020-01-17
    E. Epifano; R. Vauchy; F. Lebreton; A. Joly; C. Guèneau; Ch Valot; P.M. Martin

    Uranium–Americium oxides U1−yAmyO2±x are currently investigated as possible transmutation targets for next generation nuclear reactors. In the context of a comprehensive investigation of the thermodynamic and thermal properties of these materials, their behaviour in oxidizing conditions is here investigated for the first time. The results of high-temperature X-ray diffraction measurements in air are here presented. A wide composition domain of the solid solution has been investigated, measuring U1−yAmyO2±x oxides with Am/(Am + U) ratios ranging from 0.10 to 0.67. This allowed determining the effect of the americium content on the oxidation kinetics in air. Specifically, it will be shown that americium hinders the formation of the M4O9 and M3O8 phases.

    更新日期:2020-01-21
  • Corrosion of commercial alloys in FLiNaK molten salt containing EuF3 and simulant fission product additives
    J. Nucl. Mater. (IF 2.547) Pub Date : 2020-01-17
    Samuel W. McAlpine; Natasha Skowronski; Weiyue Zhou; Guiqiu Zheng; Michael P. Short

    In liquid–fuel molten salt reactor designs, salt–facing materials will be exposed to a molten salt containing a multitude of fission products and other corrosive species. Currently, little work has been done to understand the unique corrosion characteristics of materials in liquid–fuel systems. In this study, we conducted corrosion experiments up to 150 h in duration which exposed four commercial alloys (Hastelloy N, Incoloy 800H, 316L stainless steel, and Ni–201) to 3 molten salt compositions in order to better understand corrosion in liquid–fuel systems and inform reactor design going forward. It was found that the presence of simulant fission product species in a highly corrosive FLiNaK + EuF3 molten salt does not lead to any detectable increase in the extent of corrosion at reactor–relevant conditions. No penetration of simulant fission product species into the samples was detected. The unique corrosion morphology of each of the alloys tested in this work is discussed. In particular, Ni–201 was found to be an ideal salt–facing material in molten fluoride systems and is essentially immune to corrosion.

    更新日期:2020-01-21
  • Microstructure and morphology evolution of high-Z/low-Z gradient coatings on PAMS microspheres
    Mater. Lett. (IF 3.019) Pub Date : 2020-01-21
    Chao Huang; Yansong Liu; Lei Liu; Yajun Fu; Zhibing He; Kai Du; Linhong Cao
    更新日期:2020-01-21
  • An investigation by EXAFS of local atomic structure in an Mg-Nd alloy after processing by high-pressure torsion and ageing
    Mater. Lett. (IF 3.019) Pub Date : 2020-01-20
    Yousf Islem Bourezg; Hiba Azzeddine; Messaoud Harfouche; Dominique Thiaudiere; Cristian Mocuta; Yi Huang; Djamel Bradai; Terence G. Langdon

    The local atomic structure of an Mg-1.44Nd (wt.%) alloy was investigated after solution annealing, high-pressure torsion (HPT) processing up to1 and 10 turns and ageing at 250 °C for 5 h using X-ray absorption fine structure (XAFS) measurements at the Nd LIII-edge. The results show that HPT processing has no effect on the atomic structure around Nd atoms compared to the unprocessed state, whereas ageing at 250 °C for 5 h induces a significant modification in the coordination number and interatomic distances around the Nd atoms. These variations are analyzed based on the correlations between precipitation, defects and atomic mobility of the chemical species.

    更新日期:2020-01-21
  • Deformation behavior and microstructure evolution of rare earth magnesium alloy during rotary extrusion
    Mater. Lett. (IF 3.019) Pub Date : 2020-01-20
    Jianmin Yu; Zhimin Zhang; Ping Xu; Yingze Meng; Mo Meng; Beibei Dong; Huiling Liu

    Rotary extrusion is a technique to produce workpieces with a very large strain and a weak texture. In this work, deformation behavior and microstructure evolution of magnesium alloys via rotary extrusion were investigated. The results show that the flow stress of the rotary extrusion is significantly lower than that of the direct backward extrusion. The equivalent stress decreases upon the increase of the rotations number. The cup-shaped parts formed via rotary extrusion exhibits a typical gradient structure, which expands from its center to the borders. The basal texture of the sample is smaller than that produced by direct backward extrusion. Moreover, it further decreases upon the increase of the rotation number.

    更新日期:2020-01-21
  • Preparation of SnS/reduced graphene oxide@Cu nanocomposite with high reversible lithium storage
    Mater. Lett. (IF 3.019) Pub Date : 2020-01-20
    Junsheng Zhu; Zhaoqi Zhang; Xiaobo Ding; Guangzhou Hu

    SnS/reduced graphene [email protected] nanocomposite has been fabricated via a two–step synthetic strategy. In the composite material, most of SnS nanoplates are embedded in reduced graphene oxide. Partial SnS nanoplates exposed on the surface of reduced graphene oxide, have been largely coated with Cu nanoparticles. As a result, the nanocomposite has demonstrated high reversible lithium storage. After 640 cycles at 100 mA g-1, the composite remains a reversible capacity of 710 mAh g-1. The results from the electrochemical impedance spectroscopy suggest that the introduction of Cu can reduce the transfer resistance of the electrode and the enhanced lithium storage properties can be attributed to the synergistic effect of SnS, reduced graphene oxide and Cu.

    更新日期:2020-01-21
  • Hydrothermal synthesis of hierarchical WO3/NiO porous microsphere with enhanced gas sensing performances
    Mater. Lett. (IF 3.019) Pub Date : 2020-01-20
    Zhijie Wei; Qu Zhou; Jingxuan Wang; Wen Zeng

    Two novel hierarchical WO3/NiO microspheres with porous and rough surface have been prepared through a simple one-stop hydrothermal method. Interestingly, it is a surprise that the introduction of different amounts of WO3 plays a critical role in the growth and self-assembly of nanosheets and then the morphology of microsphere. Further gas sensing experiment demonstrates that the sensor based on porous microsphere possesses prominent performance towards 100 ppm ethanol at the optimal working temperature of 300 °C compared with that of rough microsphere. It is believed that the enhanced gas sensing properties benefit from the porous structure on the surface with abundant active sites and gas passages for sufficient gas adsorption and diffusion.

    更新日期:2020-01-21
  • Kinking in a refractory TiZrHfNb0.7 medium-entropy alloy
    Mater. Lett. (IF 3.019) Pub Date : 2020-01-18
    Shubin Wang; Mingxu Wu; Da Shu; Baode Sun
    更新日期:2020-01-21
  • Template-assisted freeze casting of macroporous Ti6Al4V scaffolds with long-range order lamellar structure
    Mater. Lett. (IF 3.019) Pub Date : 2020-01-18
    Zhuyin Chen; Xinli Liu; Ting Shen; Chuanzong Wu; Lei Zhang

    A modified water-based freeze casting to fabricate long-range order lamellar Ti6Al4V scaffolds with macropores and high porosity has been developed by using the pre-frozen WS2 substrate as the template. Pores morphologies of the scaffolds relied on the previous ice crystal which had formed in templates and thus could be adjusted by altering the template structure. The decrease of gelatin in WS2 slurry transformed the bottom template from cell pore structure into the lamellar structure followed by improvement of lamellar orientation of the top Ti6Al4V scaffold. The pore widths of the scaffolds were in the range of 84-217 μm which were difficult to realize without the assisted template. The scaffolds also exhibited mechanical compatibility with bone tissues, indicating that the template-assisted freeze casting is a promising approach to fabricate macroporous Ti6Al4V implants.

    更新日期:2020-01-21
  • Fabrication of three-dimensional connected W-Cu10Sn composites by selective laser melting
    Mater. Lett. (IF 3.019) Pub Date : 2020-01-18
    Zhenlu Zhou; Zhen Tan; Dingyong He; Zheng Zhou; Li Cui; Yiming Wang; Wei Shao; Guohong Wang
    更新日期:2020-01-21
  • Influences of blocky retained austenite on the heat-affected zone softening of dual-phase steels
    Mater. Lett. (IF 3.019) Pub Date : 2020-01-18
    D.C. Saha; E. Biro; A.P. Gerlich; Y. Zhou

    The purpose of the present study is to mitigate the effect of heat-affected zone (HAZ) softening on laser welded dual-phase (DP) steel by modifying the steel microstructure. It was shown that DP steels composed of ferrite, martensite, and blocky retained austenite provide enhanced joint toughness, which could match that of the un-welded base metal. Conversely, a DP steel containing only ferrite and martensite phases exhibited severe reduction in ductility due to HAZ softening. The underlining mechanism relates to the presence of retained austenite to maintain high joint strength and ductility was revealed by investigating the work hardening behaviour under tensile deformation and microhardness distributions across the welds as well as by examining the microstructure using scanning and transmission electron microscopy.

    更新日期:2020-01-21
  • Synthesis of Porous Gadolinium Oxide Nanosheets for Cancer Therapy and Magnetic Resonance Imaging
    Mater. Lett. (IF 3.019) Pub Date : 2020-01-18
    Meng Luo; Lingling Xu; Jiale Xia; Hongyang Zhao; Yaping Du; Bo Lei

    Porous nanomaterials have great potential in biomedical applications due to their unique structure and properties. Herein, we demonstrated the synthesis of porous gadolinium oxide nanosheets (Gd2O3 NSs) with a colloidal synthesis method. The porous Gd2O3 NSs exhibited a promising pH-responsive drug release behavior for cancer chemotherapy and can be used as an efficient contrast agent for magnetic resonance (MR) imaging.

    更新日期:2020-01-21
  • Quantitative evaluation of hidden hierarchical pores in laser additive manufactured bulk metallic glasses via computed tomography
    Mater. Lett. (IF 3.019) Pub Date : 2020-01-18
    Linlin Zhai; Yunzhuo Lu; Lu Wang; Xing Lu

    Laser additive manufacturing (LAM) technology presents a great chance to break through the size limitation and realize the wide applications of bulk metallic glasses (BMGs). However, one of the inherent problems associated with this technical route is the unavoidable hidden pore defects, which is detrimental to the mechanical properties of the BMGs. In the present study, a comprehensive investigation of hidden pore defects in a typical model BMG Zr51Ti5Cu25Ni10Al9 fabricated by LAM is performed by using the computed tomography (CT) technology. The overall porosity of the LAMed BMG samples is found to be increased with increasing laser power. However, the variation trends of the proportions for different-size pores are not the same. Specifically, the proportions of larger pores are increased with the consumption of small ones as the laser power increasing. This opposite evolution trends of pores with the increasing laser power is analyzed from the Marangoni effect in the molten pool flow.

    更新日期:2020-01-21
  • Fe3+ stabilized 3D cross-linked glycine-melamine formaldehyde networks as precursor for highly efficient oxygen reduction catalyst in alkaline media
    Mater. Lett. (IF 3.019) Pub Date : 2020-01-17
    K. Shijina; Rajith Illathvalappil; S. Nisa; G.S. Sailaja; A. Peer Mohamed; Balagopal N. Nair; Gopinathan M. Anilkumar; Sreekumar Kurungot; Takeo Yamaguchi; U.S. Hareesh
    更新日期:2020-01-21
  • Enhanced thermoelectric properties in Polypyrrole composites with silicide fillers
    Mater. Lett. (IF 3.019) Pub Date : 2020-01-17
    Marco Longhin; Mahmoud Khalil; Linda Abbassi; Mickael Beaudhuin; Philippe Papet; Romain Viennois

    We report the design and the thermoelectric properties of organic/inorganic composites made of Poly-pyrrole (PPy) and of two silicides (Co0.85Fe0.15Si and CrSi2). For both composites, we find a significant enhancement of the thermoelectric properties of the PPy with increasing content of the inorganic filler. The maximum power factor of the composites were up to 0.8 µW/m.K2 for ϕi = 50% and of 2 µW/m.K2 for ϕi = 90% for Co0.85Fe0.15Si and up to 3.37 µW/m.K2 for ϕi = 50% and of 9.7 µW/m.K2 for ϕi = 90% for CrSi2, more than two orders of magnitude higher than in pure PPy. This study proposed a novel and effective way to improve the thermoelectric performances of the thermoelectric polymer PPy.

    更新日期:2020-01-21
  • Facile synthesis of TiO2/PbS heterojunction with Au doped for photoelectrocatalytic degradation
    Mater. Lett. (IF 3.019) Pub Date : 2020-01-17
    Huixia Guo; Ce Su; Yurong Zhang; Dongmei Yu; Liangliang Li; Ziye Liu

    TiO2/PbS heterojunction with Au doped photoelectrode was fabricated by simple hydrothermal, Chemical bath deposition (CBD) and successive ionic layer adsorption and reaction (SILAR) methods. The photoelectrochemical (PEC) characterizations showed the TiO2/PbS heterojunction with Au doped photoanodes had better PEC performance than TiO2 and certain photoelectrocatalytic degradation ability of RhB. The photocurrent density achieved 4.753 mA/cm2 and the degradation efficiency of RhB could be degraded to 47.4 %. The improvement of properties was due to the formation of heterojunction and doped element facilitated the separation and mobility of the photoinduced electrons and holes in photoanode. The photoelectrode may be a good candidate for photoelectrocatalytic degradation.

    更新日期:2020-01-21
  • Structure and mechanical properties of an in-situ refractory Al20Cr10Nb15Ti20V25Zr10 high entropy alloy composite
    Mater. Lett. (IF 3.019) Pub Date : 2020-01-17
    N. Yurchenko; E. Panina; M. Tikhonovsky; G. Salishchev; S. Zherebtsov; N. Stepanov

    Structure, deformation behavior, and mechanical properties of a refractory Al20Cr10Nb15Ti20V25Zr10 high entropy alloy are reported. In the as-cast state, the alloy had a composite-like hypoeutectic microstructure comprised of a softer primary B2 phase and a harder eutectic mixture consisting of a C14 Laves and the B2 phases. Annealing at 1200°C retained the composite-like constitution and led to the formation of a small amount of a Zr5Al3-type phase. The annealing also had a positive effect on strength and ductility of the alloy at 22 and 800°C; compatibility of plastic deformation at 800°C can be ascribed to the relative softness of the B2 phase. Reasonable agreement was found between the experimental structures and the results of thermodynamic modeling.

    更新日期:2020-01-21
  • The Influence of Lung Microbiota on Lung Carcinogenesis, Immunity, and Immunotherapy
    Trends Cancer (IF 8.884) Pub Date : 2020-01-18
    Ariel G. Ramírez-Labrada; Dolores Isla; Angel Artal; Maykel Arias; Antonio Rezusta; Julián Pardo; Eva M. Gálvez

    Microbiota have emerged as key modulators of both the carcinogenic process and the immune response against cancer cells, and, thus, it seems to influence the efficacy of immunotherapy. While most studies have focused on analyzing the influence of gut microbiota, its composition substantially differs from that in the lung. Here, we describe how microbial life in the lungs is associated with host immune status in the lungs and, thus, how the identification of the microbial populations in the lower respiratory tract rather than in the gut might be key to understanding the lung carcinogenic process and to predict the efficacy of different treatments. Understanding the influence of lung microbiota on host immunity may identify new therapeutic targets and help to design new immunotherapy approaches to treat lung cancer.

    更新日期:2020-01-21
  • Targeting the Tumor Microenvironment in Colorectal Peritoneal Metastases
    Trends Cancer (IF 8.884) Pub Date : 2020-01-16
    Wim Ceelen; Robert G. Ramsay; Vignesh Narasimhan; Alexander G. Heriot; Olivier De Wever

    Peritoneal metastasis (PM) occurs in approximately one in four colorectal cancer (CRC) patients. The pathophysiology of colorectal PM remains poorly characterized. Also, the efficacy of current treatment modalities, including surgery and intraperitoneal (IP) delivery of chemotherapy, is limited. Increasingly, therefore, efforts are being developed to unravel the PM cascade and at understanding the PM-associated tumor microenvironment (TME) and peritoneal ecosystem as potential therapeutic targets. Here, we review recent insights in the structure and components of the TME in colorectal PM, and discuss how these may translate into novel therapeutic approaches aimed at re-engineering the metastasis-promoting activity of the stroma.

    更新日期:2020-01-21
  • Suprachoroidal and subretinal injections of AAV using transscleral microneedles for retinal gene delivery in nonhuman primates
    Mol. Ther. Methods Clin. Dev. (IF 4.875) Pub Date : 2020-01-21
    Glenn Yiu; Sook Hyun Chung; Iris N. Mollhoff; Uyen Tu Nguyen; Sara M. Thomasy; Jesse Yoo; Donna Taraborelli; Glenn Noronha

    Retinal gene therapy using adeno-associated viruses (AAV) is constrained by the mode of viral vector delivery. Intravitreal AAV injections are impeded by the internal limiting membrane barrier, while subretinal injections require invasive surgery and produces a limited region of therapeutic effect. In this study, we introduce a novel mode of ocular gene delivery in rhesus macaques using transscleral microneedles to inject AAV8 into the subretinal or suprachoroidal space – a potential space between the choroid and scleral wall of the eye. Using in vivo imaging, we found that suprachoroidal AAV8 produces diffuse, peripheral expression in retinal pigment epithelial (RPE) cells, but elicited local infiltration of inflammatory cells. Transscleral subretinal injection of AAV8 using microneedles leads to focal gene expression with transduction of RPE and photoreceptors, and minimal intraocular inflammation. In comparison, intravitreal AAV8 shows minimal transduction of retinal cells, but elicits greater systemic humoral immune responses. Our study introduces a novel mode of transscleral viral delivery that can be performed without vitreoretinal surgery, with focal or diffuse transgene expression patterns suitable for different applications. The decoupling of local and systemic immune responses reveals important insights into the immunological consequences of AAV delivery to different ocular compartments surrounding the blood-retinal barrier.

    更新日期:2020-01-21
  • Successful Transduction with AAV Vectors After Selective Depletion of Anti-AAV Antibodies by Immunoadsorption.
    Mol. Ther. Methods Clin. Dev. (IF 4.875) Pub Date : 2020-01-21
    Alejandro Orlowski; Michael G. Katz; Sarah M. Gubara; Anthony S. Fargnoli; Kenneth M. Fish; Thomas Weber

    Gene Therapy with adeno-associated virus (AAV) based vectors shows great promise for the gene therapeutic treatment of a broad array of diseases. In fact, the treatment of genetic diseases with AAV vectors is currently the only in vivo gene therapy approach that is approved by the U.S. Food and Drug Administration (FDA). Unfortunately, pre-existing antibodies against AAV severely limit the patient population that can potentially benefit from AAV gene therapy, especially if the vector is delivered by intravenous injection. Here, we demonstrate that we can selectively deplete anti-AAV antibodies by hemapheresis combined with AAV9 particles coupled to Sepharose beads. In rats that underwent hemapheresis and immunoadsorption luciferase expression was dramatically increased in the hearts and fully restored in the livers of these rats. Importantly, our method can be readily adapted for the use in clinical AAV gene therapy.

    更新日期:2020-01-21
  • Chromosome transplantation: a possible approach to treat human X-linked disorders.
    Mol. Ther. Methods Clin. Dev. (IF 4.875) Pub Date : 2020-01-21
    Marianna Paulis; Lucia Susani; Alessandra Castelli; Teruhiko Suzuki; Takahiko Hara; Letizia Straniero; Stefano Duga; Dario Strina; Stefano Mantero; Elena Caldana; Lucia Sergi Sergi; Anna Villa; Paolo Vezzoni
    更新日期:2020-01-21
  • CAR T cell generation by piggyBac transposition from linear doggybone™ DNA vectors requires transposon DNA flanking regions.
    Mol. Ther. Methods Clin. Dev. (IF 4.875) Pub Date : 2020-01-16
    David C. Bishop; Lisa Caproni; Kavitha Gowrishankar; Michal Legiewicz; Kinga Karbowniczek; John Tite; David J. Gottlieb; Kenneth P. Micklethwaite

    CD19-specific chimeric antigen receptor (CAR19) T cells generated using viral vectors are an efficacious but costly treatment for B cell malignancies. The non-viral piggyBac transposon system provides a simple and inexpensive alternative for CAR19 T cell production. Until now, piggyBac has been plasmid-based, facilitating economical vector amplification in bacteria. However, amplified plasmids have several undesirable qualities for clinical translation, including bacterial genetic elements, antibiotic resistance genes, and the requirement for purification to remove endotoxin. Doggybones (dbDNA™) are linear, covalently closed, minimal DNA vectors that can be inexpensively produced enzymatically in vitro at large scale. Importantly, they lack the undesirable features of plasmids. We used dbDNA incorporating piggyBac to generate CAR19 T cells. Initially, expression of functional transposase was evident, but stable CAR expression did not occur. After excluding other causes, additional random DNA flanking the transposon within the dbDNA was introduced, promoting stable CAR expression comparable to that using plasmid components. Our findings demonstrate that dbDNA incorporating piggyBac can be used to generate CAR T cells, and indicate that there is a requirement for DNA flanking the piggyBac transposon to enable effective transposition. dbDNA may further reduce the cost and improve the safety of CAR T cell production with transposon systems.

    更新日期:2020-01-21
  • GENE SILENCING OF TRANSFERRIN-1 RECEPTOR AS A POTENTIAL THERAPEUTICAL TARGET FOR HUMAN FOLLICULAR AND ANAPLASTIC THYROID CANCER
    Mol. Ther. Oncolytics (IF 5.710) Pub Date : 2020-01-21
    Agata Campisi; Roberta Bonfanti; Giuseppina Raciti; Gabriele Bonaventura; Laura Legnani; Gaetano Magro; Marzio Pennisi; Giulia Russo; Maria Assunta Chiacchio; Francesco Pappalardo; Rosalba Parenti

    Herein, we assessed the gene expression changes activated in thyroid tumors through a computational approach, using MapReduce algorithm. Through this predictive analysis, we identified the TfR1 gene as a critical mediator of thyroid tumor progression. Then, we investigated the effect of TfR1 gene silencing through siRNA in the expression of Erk1/2 pathway and c-Myc in human differentiated follicular and undifferentiated anaplastic thyroid cancer. The expression levels of cyclin D1, p53, and p27, proteins involved in cell cycle progression, were also evaluated. The effect of TfR1 gene silencing through siRNA on the apoptotic pathway activation was tested, too. Computational prediction and in vitro studies demonstrate that TfR1 plays a key role in thyroid cancer and that its down-regulation was able to inhibit ERK pathway, reducing also c-Myc expression, which blocks the cell cycle and activates the apoptotic pathway. We demonstrate that TfR1 plays a crucial role for a rapid and transient activation of the ERK signaling pathway, which induces a deregulation of genes involved in the aberrant accumulation of intracellular free iron and in drug resistance. We also suggest that TfR1 might represent an important target for thyroid cancer therapy.

    更新日期:2020-01-21
  • microRNA modification of Coxsackievirus B3 decreases its toxicity, while retaining oncolytic potency against lung cancer
    Mol. Ther. Oncolytics (IF 5.710) Pub Date : 2020-01-21
    Huitao Liu; YuanChao Xue; Haoyu Deng; Yasir Mohamud; ChenSeng Ng; Axel Chu; Chinten James Lim; William W. Lockwood; William W.G. Jia; Honglin Luo

    We recently discovered that coxsackievirus B3 (CVB3) is a potent oncolytic virus against KRAS-mutant lung adenocarcinoma. Nevertheless, the evident toxicity restricts the use of wild-type (WT)-CVB3 for cancer therapy. The current study aims to engineer the CVB3 to decrease its toxicity and to extend our previous research to determine its safety and efficacy in treating TP53/RB1-mutant small cell lung cancer (SCLC). A microRNA-modified CVB3 (miR-CVB3) was generated via inserting multiple copies of tumor-suppressive miR-145/miR-143 target sequences into the viral genome. In vitro experiments revealed that miR-CVB3 retained the ability to infect and lyse KRAS-mutant lung adenocarcinoma and TP53/RB1-mutant SCLC cells, but with a markedly reduced cytotoxicity towards cardiomyocytes. In vivo study using a TP53/RB1-mutant SCLC xenograft model demonstrated that a single dose of miR-CVB3 via systemic administration resulted in a significant tumor regression. Most strikingly, mice treated with miR-CVB3 exhibited greatly attenuated cardiotoxicities and decreased viral titers compared to WT-CVB3-treated mice. Collectively, we generated a recombinant CVB3 that is powerful in destroying both KRAS-mutant lung adenocarcinoma and TP53/RB1-mutant SCLC, with a negligible toxicity towards normal tissues. Future investigation is needed to address the issue of genome instability of miR-CVB3, which was observed in ∼40% of mice after a prolonged treatment.

    更新日期:2020-01-21
  • The PERK inhibitor GSK2606414 enhances reovirus infection in head and neck squamous cell carcinoma via an ATF4-dependent mechanism
    Mol. Ther. Oncolytics (IF 5.710) Pub Date : 2020-01-17
    M. McLaughlin; M. Pedersen; V. Roulstone; K.F. Bergerhoff; H.G. Smith; H. Whittock; J. Kyula; M.T. Dillon; H. Pandha; R. Vile; A. Melcher; K.J. Harrington

    Reovirus type 3 Dearing (reovirus) is a tumour-selective oncolytic virus currently under evaluation in clinical trials. Here, we report that the therapeutic efficacy of reovirus in head and neck squamous cell cancer can be enhanced by targeting the unfolded protein response (UPR) kinase, PERK. PERK inhibition by GSK2606414 increased reovirus efficacy in both 2D and 3D models in vitro, while perturbing the normal host cell response to reovirus-induced ER stress. UPR reporter constructs were used for live cell 3D spheroid imaging. Profiling of eIF2a-ATF4, IRE1a-XBP1 and ATF6 pathway activity revealed a context-dependent increase in eIF2a-ATF4 signaling due to GSK2606414. GSK2606414 blocked eIF2a-ATF4 signaling due to the canonical ER stress agent thapsigargin. In the context of reovirus infection, GSK2606414 induced eIF2a-ATF4 signaling. Knockdown of eIF2a kinases PERK, GCN2 and PKR revealed eIF2a-ATF4 reporter activity was dependent on either PERK or GCN2. Knockdown of ATF4 abrogated the GSK2606414 induced increase in reovirus protein levels, confirming eIF2a-ATF signaling as key to the observed phenotype. Our work identifies a novel approach to enhance the efficacy and replication of reovirus in a therapeutic setting.

    更新日期:2020-01-21
  • Specific IgA and CLA+ T-cell IL-17 response to Streptococcus pyogenes in psoriasis
    J. Invest. Dermatol. (IF 6.290) Pub Date : 2020-01-21
    Carmen De Jesús-Gil; Lidia Sans-de San Nicolás; Ester Ruiz-Romeu; Marta Ferran; Laura Soria-Martinez; Anca Chiriac; Antonio Celada; Ramon M. Pujol; Luis F. Santamaria-Babí

    Streptococcus pyogenes tonsillar infection is well-known to trigger and exacerbate psoriasis lesions in both guttate and plaque forms of the disease. Although mucosal and cutaneous tissues are closely involved in psoriasis pathology, the interaction between their specific immune responses has not been deeply explored. This work aims to address and characterize the presence of humoral responses against Streptococcus pyogenes in psoriasis patients and its putative association with cytokine responses detected in vitro in our psoriasis ex vivo model, based on the coculture of CLA+/- T cells with autologous epidermal cells. Psoriasis patients presented increased IgA response to S. pyogenes when compared to control subjects. Surprisingly, in plaque psoriasis patients, despite being negative for anti-streptolysin O antibody titer, IgA plasma levels against S. pyogenes correlated with CLA+ T cell dependent IL-17F response in vitro. Not association is observed for IgG levels in plaque psoriasis. Similar association is observed for IgA anti-SE and IL-17A in guttate psoriasis patients. We propose S. pyogenes specific IgA as a potential new perspective for better understanding the role of S. pyogenes in psoriasis development.

    更新日期:2020-01-21
  • Molecular and Cellular Responses to the TYK2/JAK1 Inhibitor, PF 06700841, Reveal Reduction of Skin Inflammation in Plaque Psoriasis
    J. Invest. Dermatol. (IF 6.290) Pub Date : 2020-01-21
    Karen M. Page; Mayte Suarez-Farinas; Maria Suprun; Weidong Zhang; Sandra Garcet; Judilyn Fuentes-Duculan; Xuan Li; Matthew Scaramozza; Elizabeth Kieras; Christopher Banfield; James D. Clark; Andrew Fensome; James G. Krueger; Elena Peeva

    The interleukin (IL)-23/T-helper type 17 cell axis is a target for psoriasis. The tyrosine kinase 2 (TYK2)/Janus kinase 1 (JAK1) inhibitor, PF-06700841, will directly suppress TYK2-dependent IL-12 and IL-23 signaling and JAK1-dependent signaling in cells expressing these signaling molecules, including T cells and keratinocytes. This clinical study sought to define the inflammatory gene and cellular pathways through which PF-06700841 improves the clinical manifestations of psoriasis. Patients (n=30) with moderate-to-severe psoriasis were randomized to once-daily 30 mg (n=14) or 100 mg (n=7) PF-06700841, or placebo (n=9) for 28 days. Biopsies were taken from non-lesional and lesional skin at baseline, weeks 2 and 4. Changes in the psoriasis transcriptome and genes induced by IL-17 in keratinocytes were evaluated with microarray profiling and RT-PCR. Reductions in IL-17A, IL-17F, and IL-12B mRNA were observed as early as 2 weeks and ∼70% normalization of lesional gene expression after 4 weeks. Immunohistochemistry showed significant decreases in markers of keratinocyte activation, epidermal thickness, KRT16 and Ki-67 expression, and immune cell infiltrates CD3+/CD8+ (T cells) and CD11c (dendritic cells) after 2 weeks of treatment, corresponding with improvement in histologic score. PF-06700841 improves clinical symptoms of chronic plaque psoriasis by inhibition of pro-inflammatory cytokines that require TYK2 and JAK1 for signal transduction.

    更新日期:2020-01-21
  • The phosphatase regulator NIPP1 restrains chemokine-driven skin inflammation
    J. Invest. Dermatol. (IF 6.290) Pub Date : 2020-01-21
    Iris Verbinnen; Marloes Jonkhout; Kifayathullah Liakath-Ali; Kathelijne Szekér; Mónica Ferreira; Shannah Boens; Raphael Rouget; Margareta Nikolic; Susan Schlenner; Aleyde Van Eynde; Mathieu Bollen

    NIPP1 is a ubiquitously expressed nuclear protein that regulates functions of protein Ser/Thr phosphatase-1 in cell proliferation and lineage specification. The role of NIPP1 in tissue homeostasis is not fully understood. Here we show that the selective deletion of NIPP1 in mouse epidermis resulted in epidermal hyperproliferation, a reduced adherence of basal keratinocytes and a gradual decrease in the stemness of hair follicle stem cells, culminating in hair loss. This complex phenotype was associated with chronic sterile skin inflammation and could be partially rescued by dexamethasone treatment. NIPP1-deficient keratinocytes massively expressed pro-inflammatory chemokines and immunomodulatory proteins in a cell-autonomous manner. Chemokines subsequently induced the recruitment and activation of immune cells, in particular conventional dendritic cells and Langerhans cells, accounting for the chronic inflammation phenotype. Our data identify NIPP1 as a key regulator of epidermal homeostasis and as a potential target for the treatment of inflammatory skin diseases.

    更新日期:2020-01-21
  • Activated Hgf-Met signaling cooperates with oncogenic Braf to drive primary cutaneous melanomas and angiotropic lung metastases in mice
    J. Invest. Dermatol. (IF 6.290) Pub Date : 2020-01-20
    Andreas Dominik Braun; Miriam Mengoni; Susanne Bonifatius; Thomas Tüting; Evelyn Gaffal

    Oncogenic mutations in the Braf-kinase gene represent the most frequent genomic driver in acquired melanocytic nevi and in cutaneous melanomas. It is currently thought that oncogene-induced senescence and cell cycle arrest limit the ability of oncogenic Braf to promote melanocyte proliferation in benign nevi. The molecular and cellular mechanisms that allow an oncogenic Braf mutation to fully transform melanocytes into invasively growing melanoma cells that are able to metastasize systemically are only partially understood. Here we show in a genetic mouse model that constitutively enhanced Hgf-Met signaling cooperates with oncogenic Braf to drive tumor development and metastatic spread. Activation of oncogenic Braf in mice with transgenic Hgf overexpression and an oncogenic Cdk4 germline mutation accelerated and increased the development of primary cutaneous melanomas. Primary melanomas showed considerable phenotypic heterogeneity with frequent signs of dedifferentiation. Braf activation in Hgf-Cdk4 mice also increased the number of lung metastases. Intriguingly, melanoma cells showed a pronounced angiotropic growth pattern both at the invasive front in primary tumors and in metastatic lesions of the lung. Taken together, our work supports the notion that activated Hgf-Met signaling and oncogenic Braf can cooperate in melanoma pathogenesis.

    更新日期:2020-01-21
  • Uniting Discovery and Care: The Role of Pharmaceutical Companies in Research, Clinical Studies and Patient Care
    J. Invest. Dermatol. (IF 6.290) Pub Date : 2020-01-20
    Chenyun Tan; James M. McGill; Lotus Mallbris

    In an era of increased complexity of clinical research, a demand for personalized medicine, an increasing value of diversity, a focus on digital health, and a call for patient-centricity, the discovery and development of new medicines, more than ever, is dependent on collaboration between multiple stakeholders (Figure 1).

    更新日期:2020-01-21
  • IL-17E (IL-25) and IL-17A differentially affect the functions of human keratinocytes
    J. Invest. Dermatol. (IF 6.290) Pub Date : 2020-01-18
    Julia Borowczyk; Claudia Buerger; Neschaat Tadjrischi; Justyna Drukala; Michal Wolnicki; Dawid Wnuk; Ali Modarressi; Wolf-Henning Boehncke; Nicolò Costantino Brembilla

    Our group has recently shown that keratinocyte-derived IL-17E (IL-25), one of six members of the IL-17 family, is overexpressed in lesional psoriatic skin and is involved in its pathophysiology. We show here that IL-22 enhances IL-17E production in human keratinocytes and that these cells display a complete IL-17E receptor at their surface, which expression is further induced by IL-17A, indicating a potential autocrine effect of IL-17E. Therefore, we addressed the impact of IL-17E on the function of human primary keratinocytes. IL-17E promoted the proliferation of keratinocytes in 2D and 3D cultures and caused the concomitant up-regulation of differentiation-associated gene transcripts (e.g keratin 10), while their expression was either inhibited or not changed by IL-17A. Contrary to IL-17A, IL-17E was not involved in the induction of antimicrobial proteins. Time-lapse analysis of cell movement showed that IL-17E influences cell motility increasing both cell speed and displacement. This was associated with specific changes in the actin cytoskeleton organization and the cell-substrate adhesion. No such effects were observed upon IL-17A stimulation. In summary, we identified to our knowledge previously unreported effects of IL-17E clearly distinct from IL-17A, pointing towards an important role of IL-17E in the physiology and pathophysiology of the epidermis.

    更新日期:2020-01-21
  • Thermal unmixing based downscaling for fine resolution diurnal land surface temperature analysis
    ISPRS J. Photogramm. Remote Sens. (IF 6.942) Pub Date : 2020-01-16
    Jiong Wang; Oliver Schmitz; Meng Lu; Derek Karssenberg

    Due to the limitation in the availability of airborne imagery data that are high in both spatial and temporal resolution, land surface temperature (LST) dense in both space and time can only be obtained through downscaling of frequently acquired LST with coarse resolution. Many conventional downscaling techniques are only feasible in an ideal situation, where land surface factors as LST predictors are continuously available for downscaling the LST. These techniques are also applied only at large scales ignoring sub-regional variations. Based upon unmixing based approaches, this study presents an LST downscaling workflow, where only the coarse resolution of 1 km LST image at the prediction time is required. The conceptual backbone of the study is assuming that the LST patterns are governed by thermal behaviors of a fixed set of temperature sensitive land surface components. In operation, the study focuses on central Netherlands covering an area of 90 × 90 km. The MODIS and Landsat imagery acquired simultaneously are used as a coarse-fine resolution pair to derive downscaling mechanism which is then applied to coarse imagery at a time with missing fine resolution imagery. First, an optimal number of thermal components are extracted at fine resolution through the application of the non-negative matrix factorization (NMF). These components are assumed to possess unique temperature change patterns caused by combined effects of land cover change, radiance change, or both. Given the LST change and thermal components at coarse resolution, the LST change load of each component can then be obtained at the coarse resolution by solving a system of linear equations encoding thermal component-LST relationship. Such LST change load of thermal components is further unmixed to fine resolution and linearly weighted by the component distribution at fine resolution to obtain the fine resolution LST change. During the process, the coarse LST data is used directly without any resampling practice as shown in previous studies. Thus the technique is less time consuming even with a large downscaling factor of 30. The downscaled fine resolution LST represents an R-squared of over 0.7 outperforming classic downscaling techniques. The downscaled LST differentiates temperature over major land types and captures both seasonal and diurnal LST dynamics.

    更新日期:2020-01-21
  • Examining earliest identifiable timing of crops using all available Sentinel 1/2 imagery and Google Earth Engine
    ISPRS J. Photogramm. Remote Sens. (IF 6.942) Pub Date : 2020-01-20
    Nanshan You; Jinwei Dong

    Timely and accurate information on crop planting areas is critical for estimating crop production, and earlier crop mapping can benefit decision-making related to crop insurance, land rental, supply-chain logistics, and food market. Previous efforts generally produce crop planting area maps after harvest and early season cropping information is rarely available. New opportunities emerge with rapid increase in satellite data acquisition and cloud computing platform such as Google Earth Engine (GEE) which can access and process a vast volume of multi-sensor images. Here we aimed to examine earliest identifiable timing (EIT) of major crops (rice, soybean, and corn) and generate early season crop maps independent of within-year field surveys in the Heilongjiang province, one most important province of grain production in China. The Random Forest classifiers were trained based on early season images and field samples in 2017, then were transferred (applied) to corresponding images in 2018 to obtain resultant maps. Six scenarios with different temporal intervals (10d, 15d, 20d, and 30d) and data integration (Sentinel-2 and Sentinel-1, a total of 16, 450 images) were compared to get the optimal crop maps. The results showed that the Sentinel-2 time series and 10-day composite outperformed in obtaining EITs and crop maps. We found various EITs for the three grain staples. Specifically, rice could be identified in the late transplanting stage (four months before harvest) with F1 score of 0.93, following by corn recognizable in the early heading stage (two months before harvest, with F1 score of 0.92) and soybean in the early pod setting stage (50 days before harvest, with F1 score of 0.91). The crop maps in the EITs based on the classifier transfer approach have comparable accuracies (overall accuracy = 0.91) comparing to the traditional post-season mapping approach based on current year’s all available images and samples (overall accuracy = 0.95). This study suggests the potential of growing fine resolution observations for timely monitoring of crop planting area within season, which provides valuable and timely information for different stakeholders and decision makers.

    更新日期:2020-01-21
  • Noise-robust transparent visualization of large-scale point clouds acquired by laser scanning
    ISPRS J. Photogramm. Remote Sens. (IF 6.942) Pub Date : 2020-01-21
    Tomomasa Uchida; Kyoko Hasegawa; Liang Li; Motoaki Adachi; Hiroshi Yamaguchi; Fadjar I. Thufail; Sugeng Riyanto; Atsushi Okamoto; Satoshi Tanaka

    We propose a high-quality transparent visualization method suitable for large-scale laser-scanned point clouds. We call the method “stochastic point-based rendering (SPBR),” which is based on a novel stochastic algorithm. SPBR enables us to clearly observe the deep interior of laser-scanned 3D objects with the correct feeling of depth. The high quality of SPBR originates from the effect of “stochastic noise transparentization,” which is an effect to make the measurement noise transparent and invisible in the created images. We mathematically prove that this effect also makes the created transparent images coincide with the results of the conventional methods based on the alpha blending, which is time-consuming and impractical for large-scale laser-scanned point clouds. We also demonstrate the effectiveness of SPBR by applying it to modern buildings, cultural heritage objects, forests, and a factory. For all of the cases, the method works quite well, realizing clear and correct 3D see-through imaging of the laser-scanned objects.

    更新日期:2020-01-21
  • miR-25 promotes cardiomyocyte proliferation by targeting FBXW7
    Mol. Ther. Nucl. Acids (IF 5.919) Pub Date : 2020-01-21
    Bei Wang; Mengting Xu; Miaomiao Li; Fujian Wu; Shijun Hu; Xiangbo Chen; Liqun Zhao; Zheyong Huang; Feng Lan; Dong Liu; Yongming Wang

    Induction of endogenous cardiomyocyte (CM) proliferation is one of the key strategies for heart regeneration. Increasing evidence points to the potential role of microRNAs (miRNAs) in the regulation of CM proliferation. Here, we used human embryonic stem cell (hESC)-derived CMs (hESC-CMs) as a tool to identify miRNAs that promotes CM proliferation. We profiled miRNA expression at early stage of CM differentiation and identified a list of highly expressed miRNAs. Among these miRNAs, miR-25 was enriched in early-stage hESC-CMs, but its expression decreased over time. Overexpression of miR-25 promoted CM proliferation. RNA-seq analysis revealed that genes related to cell cycle signal were strongly influenced by miR-25 overexpression. We further showed that miR-25 promoted CM proliferation by targeting FBXW7. Finally, the function of miR-25 in the regulation of CM proliferation was demonstrated in zebrafish. Our study suggested that miR-25 is a promising molecule for heart regeneration.

    更新日期:2020-01-21
  • Allele-selective knockdown of MYH7 using antisense oligonucleotides
    Mol. Ther. Nucl. Acids (IF 5.919) Pub Date : 2020-01-21
    Brian R. Anderson; Marianne L. Jensen; Peter H. Hagedorn; Sean C. Little; Richard E. Olson; Ron Ammar; Bernadette Kienzle; John Thompson; Ivar McDonald; Stephen Mercer; Jonas Vikesaa; Bettina Nordbo; Larry Iben; Yang Cao; Joanne Natale; Greg Dalton-Kay; Angela Cacace; Bo R. Hansen; Linda J. Bristow

    Hundreds of dominant negative myosin mutations have been identified that lead to hypertrophic cardiomyopathy, and the biomechanical link between mutation and disease is heterogeneous across this patient population. To increase the therapeutic feasibility of treating this diverse genetic population, we investigated the ability of locked nucleic acid (LNA)-modified antisense oligonucleotides (ASOs) to selectively knockdown mutant myosin transcripts by targeting single nucleotide polymorphisms (SNPs) that were found to be common in the myosin heavy chain 7 (MYH7) gene. We identified three SNPs in MYH7 and designed ASO libraries to selectively target either the reference or alternate MYH7 sequence. We identified ASOs that selectively knocked down either the reference or alternate allele at all three SNP regions. We also show allele selective knockdown in a mouse model that was humanized on one allele. These results suggest that SNP-targeting ASOs are a promising therapeutic modality for treating cardiac pathology.

    更新日期:2020-01-21
  • Mbd2 mediates retinal cell apoptosis by targeting the lncRNA Mbd2-AL1/miR-188-3p/Traf3 axis in ischemia/reperfusion injury
    Mol. Ther. Nucl. Acids (IF 5.919) Pub Date : 2020-01-18
    Yanni Ge; Ran Zhang; Yuqing Feng; Huiling Li

    Recent studies reported that DNA methylation was involved in retinal cell death. Methyl-CpG binding domain protein 2 (Mbd2) is one of DNA methylation readers. Its role and mechanism of regulation remain unclear. The ischemia/reperfusion (I/R) model in mice primary culture retinal ganglion cells and Mbd2 knock-out (Mbd2-KO) mice were used in the current study. We demonstrated that Mbd2 mediates RGCs apoptosis caused by I/R injury. Mechanistically, the data suggested that Mbd2 upregulated Mbd2-associated long non-coding RNA 1 (Mbd2-AL1) via demethylation of its promoter. Furthermore, Mbd2-AL1 sponged miR-188-3p, thus preventing TNF receptor associated factor 3 (Traf3) downregulation and inducing RGCs apoptosis. This was further demonstrated by the fact that inhibition of miR-188-3p diminished the anti-apoptosis role of Mbd2-AL1 siRNA. Finally, it showed that the apoptosis of retinal cells was attenuated and the visual function was preserved in Mbd2-KO mice which was associated with the Mbd2-AL1/miR-188-3p/Traf3 axis. Our present study revealed the role of Mbd2 in RGCs apoptosis which may provide a novel therapeutic strategy for retinal ischemic diseases.

    更新日期:2020-01-21
  • LncRNA RMST Suppressed GBM Cells Mitophagy through Enhancing FUS SUMOylation
    Mol. Ther. Nucl. Acids (IF 5.919) Pub Date : 2020-01-18
    Changhong Liu; Zixuan Peng; Peiyao Li; Haijuan Fu; Jianbo Feng; Yan Zhang; Tao Liu; Yang Liu; Qing Liu; Qiang Liu; Di Li; Minghua Wu

    Background Long non-coding RNAs (lncRNAs) play significant role in post-translational modifications of proteins, yet the importance of lncRNAs for sumoylation is unknown. Methods RMST expression in glioma tissues and normal brain tissues was measured by RT-qPCR and in situ hybridization.The functional roles of RMST in astrocytomas were demonstrated by a series of in vitro experiments. The potentialmechanisms of RMST for sumoylation was investigatedby RNA immunoprecipitation,RNA pull-down,western blotting and co-immunoprecipitation assays. Findings We first demonstrated the oncogenic activity of lncRNA RMST by inhibiting glioma cells mitophagy. We also first determined that RMST is an enhancer of FUS SUMOylation, especially boosting SUMO1 modification at K333. SUMOylation induced by RMST contributes to the interaction between FUS and hnRNPD and stabilized their expression and cells mitophagy. Importantly, LncRNA RMST could serve as a promising prognostic factor for glioma patients. Interpretation our results demonstrated a previously unknown function of lncRNAs worked as an enhancer in FUS SUMOylation, and RMST will be a significant guide for the development of medications targeting gliomas.

    更新日期:2020-01-21
  • Identification of the regulatory role of lncRNA SNHG16 in myasthenia gravis by constructing a competing endogenous RNA network
    Mol. Ther. Nucl. Acids (IF 5.919) Pub Date : 2020-01-18
    Jianjian Wang; Yuze Cao; Xiaoyu Lu; Xiaolong Wang; Xiaotong Kong; Chunrui Bo; Shuang Li; Ming Bai; Yang Jiao; Hongyu Gao; Xiuhua Yao; Shangwei Ning; Lihua Wang; Huixue Zhang

    Myasthenia gravis (MG) is an autoimmune disorder resulting from antibodies against the proteins at the neuromuscular junction. Emerging evidence indicates that lncRNAs, acting as competing endogenous RNAs (ceRNAs), are involved in various diseases. However, the regulatory mechanisms of ceRNA underlying MG remain largely unknown. In this study, we constructed a lncRNA-mediated ceRNA network involved in MG using a multi-step computational strategy. Functional annotation analysis suggests that these lncRNAs may play crucial roles in the immunological mechanism underlying MG. Importantly, through manual literature-mining, we found that lncRNA SNHG16, acting as a ceRNA, plays important roles in the immune processes. Further experiments showed that SNHG16 expression was up-regulated in peripheral blood mononuclear cells (PBMCs) from MG patients compared to healthy controls. Luciferase reporter assays confirmed that SNHG16 is a target of the miRNA let-7c-5p. Subsequent experiments indicated that SNHG16 regulates the expression of the key MG gene IL-10 by sponging let-7c-5p in a ceRNA manner. Furthermore, functional assays showed that SNHG16 inhibits Jurkat cell apoptosis and promotes cell proliferation by sponging let-7c-5p. Our study will contribute to a deeper understanding of the regulatory mechanism of MG and will potentially provide new therapeutic targets for MG patients.

    更新日期:2020-01-21
  • Transplantation of human mesenchymal stem cells genome-edited with LEF1 improves cardio-protective effects in myocardial infarction
    Mol. Ther. Nucl. Acids (IF 5.919) Pub Date : 2020-01-18
    Hyun-Min Cho; Kang-Hoon Lee; Yi-ming Shen; Tae-Jin Shin; Pan-Dong Ryu; Min-Cheol Choi; Kyung-Sun Kang; Je-Yoel Cho

    Stem cell-based therapy is one of the most attractive approaches to ischemic heart diseases such as myocardial infarction (MI). We evaluated the cardio-protective effects of the hUCB-MSCs stably expressing LEF1 (LEF1/hUCB-MSCs) in a rat model of MI. LEF1 overexpression in hUCB-MSCs promoted cell proliferation and anti-apoptotic effects in hypoxic conditions. For the application of its therapeutic effects in vivo, the LEF1 gene was introduced into an AAVS1 locus known as a safe harbor site on chromosome 19 by CRISPR/Cas9-mediated gene integration in hUCB-MSCs. Transplantation of LEF1/hUCB-MSCs onto the infarction region in the rat model significantly improved overall survival. The cardio-protective effect of LEF1/hUCB-MSCs was proved by echocardiogram parameters including greatly improved left ventricle ejection fraction (EF) and fractional shortening (FS). Moreover, histology and immunohistochemistry successfully presented reduced MI region and fibrosis by LEF1/hUCB-MSCs. We found that this overall positive effects of LEF1/hUCB-MSCs are attributed by increased proliferation and survival of stem cells in oxidative stress conditions and by the secretion of various growth factors by LEF1. In conclusion, this study suggests that the stem cell-based therapy conjugated with genome editing of transcription factor LEF1, which promotes cell survival, could be an effective therapeutic strategy for cardiovascular disease.

    更新日期:2020-01-21
  • Long non-coding RNA NEAT1 binds to microRNA-339-5p to increase HOXA1 and alleviate ischemic brain damage in neonatal mice
    Mol. Ther. Nucl. Acids (IF 5.919) Pub Date : 2020-01-17
    Jing Zhao; Ling He; Lingling Yin

    Hypoxic-ischemic brain damage (HIBD) is a major cause of fatality and morbidity in neonates. However, current treatment approaches to alleviate HIBD are not effective. Various studies have highlighted the role of microRNAs (miRNAs) in various biological functions in multiple diseases. This study investigated the role of miR-339-5p in HIBD progression. Neonatal HIBD mouse model was induced by ligation of the right common carotid artery. Neuronal cell model exposed to oxygen-glucose deprivation (OGD) was also established. The miR-339-5p expression in mouse brain tissues and neuronal cells was quantified and the effects of miR-339-5p on neuronal cell activity and apoptosis induced by hypoxia-ischemia were explored. The overexpression or knockdown of long non-coding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1) in hippocampal neurons was used to determine the effect of lncRNA NEAT1 on the expression of miR-339-5p and homeobox A1 (HOXA1) and apoptosis. Short hairpin RNA targeting lncRNA NEAT1 and miR-339-5p antagomir were used in neonatal HIBD mice to identify their roles in HIBD. Our results revealed that miR-339-5p was downregulated in neonatal HIBD mice and neuronal cells exposed to OGD. Downregulated miR-339-5p promoted neuronal cell viability and suppressed apoptosis during hypoxia-ischemia. Moreover, lncRNA NEAT1 competitively bind to miR-339-5p to increase HOXA1 expression and inhibited neuronal cell apoptosis under hypoxic-ischemic conditions. The key observations of the current study present evidence demonstrating that lncRNA NEAT1 upregulated HOXA1 to alleviate HIBD in mice by binding to miR-339-5p.

    更新日期:2020-01-21
  • MiRNA-31 improves cognition and abolishes amyloid-β pathology by targeting APP and BACE1 in an animal model of Alzheimer’s disease
    Mol. Ther. Nucl. Acids (IF 5.919) Pub Date : 2020-01-17
    Ana Teresa Barros-Viegas; Vítor Carmona; Elisabete Ferreiro; Joana Guedes; Pedro Cunha; Luís Pereira de Almeida; Catarina Resende de Oliveira; João Pedro de Magalhães; João Peça; Ana Luísa Cardoso
    更新日期:2020-01-21
  • LncRNA CCAT1 acts as a microRNA-218 sponge to increase gefitinib resistance in NSCLC by targeting HOXA1
    Mol. Ther. Nucl. Acids (IF 5.919) Pub Date : 2020-01-17
    Xiang Jin; Xiuhua Liu; Zhen Zhang; Yinghui Guan

    Long non-coding RNA (lncRNA) colon cancer associated transcript-1 (CCAT1) has been reported to play important roles in the development and progression of multiple human malignancies. However, the functional role and molecular mechanism of CCAT1 on gefitinib resistance in non-small-cell lung cancer (NSCLC) are largely unclear. The aim of this study is to explore the roles of CCAT1 on gefitinib resistance in NSCLC and explore the underlying mechanisms. The qRT-PCR analysis was to investigate the expression pattern of CCAT1 in gefitinib resistant NSCLC patient tissues and cell lines. Then, the effects of CCAT1 on gefitinib resistance of NSCLC in vitro and in vivo. Furthermore, bioinformatics online programs predicted and luciferase reporter assay were used to validate the association of CCAT1 and miR-218 in NSCLC cells. In this study, CCAT1 was observed to be upregulated in gefitinib resistant patient tissues and cell lines. In vitro and in vivo experiments demonstrated that CCAT1 knockdown impaired cell proliferation and promoted the gefitinib-induced cell apoptosis. Furthermore, we demonstrated that CCAT1 acts as a sponge for miR-218 and verified that HOXA1 is a novel target of miR-218. These results suggest that CCAT1 may serve as a promising therapeutic target for the treatment of EGFR+ NSCLC patients.

    更新日期:2020-01-21
  • Strong immune responses induced by direct local injections of modified mRNA-lipid nanocomplex
    Mol. Ther. Nucl. Acids (IF 5.919) Pub Date : 2020-01-16
    Smriti Arya; Qiubin Lin; Nan Zhou; Xiang Gao; Jian-Dong Huang

    In vitro transcribed mRNAs hold the promises of many medical applications in disease prevention and treatment, such as replacement or supplement of missing or inadequately expressed endogenous proteins and as preventive vaccines against infectious diseases, therapeutic vaccines or other protein-based biopharmaceutics for cancer therapy. A safe and efficient delivery system for mRNA is crucial to the success of mRNA therapeutic applications. In this study, we report that InstantFECT, a liposome-based transfection reagent, can pack pseudouridine incorporated mRNA into nanocomplex that are highly efficient in mediating in vivo transfection in multiple organs after local delivery. High levels of expression of EGFP and luciferase reporters after intra-tumoral and intramuscular injections were observed, which lasted for up to 96 hrs. Immunogenicity of antigens encoded by mRNA, delivered with nanocomplex was investigated by subcutaneous delivery of modified mRNAs encoding Staphylococcus aureus adenosine synthase A (AdsA) and a model tumor-associated antigen ovalbumin (OVA). Strong T cell responses were provoked by both mRNAs delivered. Therapeutic and protective treatment with OVA mRNA-liposome nanocomplex significantly inhibited B16-OVA tumor progression and increased mice survival. There was no sign of obvious toxicity related to the treatment both in tissue culture and in mice. An intravenous injection of the same dosage of the modified mRNA-lipid nanocomplex showed minimal transfection in major organs, indicating an excellent safety feature as the gene transfer occurred only at the injection sites, whereas i.v. injection with the same amount of mRNA complexed with a commercial transfection reagent Trans-IT showed luciferase expression in the spleen. In summary, InstantFECT cationic liposomes provide a safe and efficient in vivo locoregional delivery of mRNA and could be a useful tool for basic research and for the development of mRNA-based therapies.

    更新日期:2020-01-21
  • Upregulation of microRNA-101a suppresses chronic renal fibrosis by regulating histone demethylases KDM3A via blockade of the YAP-TGFβ-Smad signaling pathway
    Mol. Ther. Nucl. Acids (IF 5.919) Pub Date : 2020-01-16
    Hong Ding; Yanyan Xu; Nan Jiang

    Renal fibrosis denotes a common complication of diabetic nephropathy and is a predominant cause of end-stage renal disease. Despite the association between microRNAs (miRNAs or miRs) and renal fibrosis, miRNAs have been reported to play a vital role in the development of chronic renal fibrosis. Therefore, the aim of the present study was to investigate the possible function of miR-101a in chronic renal fibrosis. Initially, microarray-based gene expression profiling of renal fibrosis was employed to screen the differentially expressed genes. An in vivo mouse model of chronic renal fibrosis induced by a unilateral ureteral obstruction (UUO) and an in vitro cell model induced by aristolochic acid (AA) were constructed. miR-101a expression was examined using FISH assay and RT-qPCR. Then, the interaction between miR-101a and KDM3A was identified using an online website combined with dual-luciferase reporter assay. Finally, gain- and loss-of-function experiments were conducted to elucidate the effect of miR-101a on the expression of Col1a1, fibronectin, α-SMA, and YAP-TGFβ-Smad signaling pathway-related genes, as well as the degree of renal fibrosis. miR-101a was poorly expressed while KDM3A was robustly induced in chronic renal fibrosis tissues and cells. In addition, miR-101a could target and downregulate KDM3A expression, which led to elevated TGIF1, inhibited expression of Col1a1, fibronectin, α-SMA, YAP1, and TGFβ2 along with the extent of Smad2/3 phosphorylation, as well as delayed renal fibrosis degree. Besides, overexpressed YAP/TGFβ2 or inhibited TGIF1 partially restored the inhibitory effect of miR-101a on chronic renal fibrosis. Taken together, miR-101a could potentially slow down chronic renal fibrosis by the inactivation of the YAP-TGFβ-Smad signaling pathway via KDM3A, highlighting the potential of miR-101a as a therapeutic target for chronic renal fibrosis treatment.

    更新日期:2020-01-21
  • Novel Mouse MicroRNA Chr13_novelMiR7354-5p Improves Bone Marrow-Derived Mesenchymal Stem Cell Differentiation into Insulin-Producing Cells
    Mol. Ther. Nucl. Acids (IF 5.919) Pub Date : 2020-01-16
    Feng Zhao; Xiaoyu Liu; Zhe Wang; Hongxin Lang; Tao Zhang; Rui Wang; Xuewen Lin; Dan He; Ping Shi; Xining Pang

    MicroRNAs (miRNAs) that play key roles in generation of insulin-producing cells from stem cells provide a cell-based approach for insulin replacement therapy. Here, we used next-generation sequencing to detect the miRNA expression profile of normal mouse pancreatic β-cells, non-β-cells, bone marrow mesenchymal stem cells (BM-MSCs) and adipose-derived stem cells (ADSCs) and determined relative miRNA expression levels in mouse pancreatic β-cells. After the novel mouse miRNA candidates were identified using miRDeep 2.0, we found that Chr13_novelMiR7354-5p, a novel miRNA candidate, significantly promoted the differentiation of BM-MSCs into insulin-producing cells in vitro. Furthermore, Chr13_novelMiR7354-5p-transfected BM-MSCs reversed hyperglycaemia in STZ-treated diabetic mice. In addition, bioinformatics analyses, a luciferase reporter assay and Western blotting demonstrated that Chr13_novelMiR7354-5p targeted Notch1 and Rbpj. Our results provide compelling evidence of the existence of 65 novel mouse miRNA candidates and present a new treatment strategy to generate insulin-producing cells from stem cells.

    更新日期:2020-01-21
  • Development of a facile approach for generating chemically-modified CRISPR/Cas9 RNA
    Mol. Ther. Nucl. Acids (IF 5.919) Pub Date : 2020-01-16
    Tristan Scott; Citradewi Soemardy; Kevin V. Morris

    The RNA-guided, modified type II prokaryotic clustered regularly interspaced palindromic repeats with CRISPR-associated proteins (CRISPR/Cas9) system represents a simple gene editing platform with applications in biotechnology and also potentially as a therapeutic modality. The system requires a small guide RNA (sgRNA) and a catalytic Cas9 protein to induced non-homologous end joining (NHEJ) at break sites resulting in the formation of inactivating mutations, or through homology-directed repair (HDR) can engineer in specific sequence changes. Although CRISPR/Cas9 is a powerful technology, the effects can be limited as a result of nuclease-mediated degradation of the RNA components. Significant research has focused on the solid-phase synthesis of CRISPR RNA components with chemically modified bases, but this approach is technically challenging and expensive. Development of a simple, generic approach to generate chemically modified CRISPR RNAs may broaden applications that require nuclease-resistant CRISPR components. We report here the development of a novel, functional U-replaced tracrRNA that can be in vitro transcribed with chemically stabilizing 2'F-pyrimidines. These data represent a unique and facile approach to generating chemically stabilized CRISPR RNA.

    更新日期:2020-01-21
  • CircRNA-AKT1 sequesters miR-942-5p to upregulate AKT1 and promote cervical cancer progression
    Mol. Ther. Nucl. Acids (IF 5.919) Pub Date : 2020-01-16
    Rongying Ou; Laiming Mo; Huijing Tang; Shaolong Leng; Haiyan Zhu; Liang Zhao; Yi Ren; Yunsheng Xu

    Statistics show that the prognosis of cervical cancer (CC) is poor and the death rate of CC in advanced stage has been rising in recent years. Increasing evidences have demonstrated that circular RNAs serve as promising biomarkers in human cancers, including CC. Present study planned to find out the circRNA involved in CC and to explore its regulatory mechanism in CC. We discovered the new circRNA, circ-0033550, upregulated in CC. Its associated gene was AKT (also known as protein kinase B) serine/threonine kinase 1 (AKT1), so we renamed circ-0033550 as circ-AKT1. We confirmed the high expression of circ-AKT1 in CC samples and cell lines as well as circle structure of circ-AKT1. Functionally, gain- and loss-of-function experiments indicated that circ-AKT1 and AKT1 promoted CC cell proliferation and invasion. Moreover, circ-AKT1 and AKT1 were induced by TGF-β, and facilitated EMT (epithelial-mesenchymal transition) in CC. Mechanically, we illustrated that circ-AKT1 upregulated AKT1 by sponging miR-942-5p. Rescue assays confirmed the role of circ-AKT1/miR-942-5p/AKT1 axis in CC progression. In vivo assays validated that circ-AKT1 promoted tumor growth in CC. Overall, circRNA-AKT1 sequestered miR-942-5p to upregulate AKT1 and promote CC progression, which may offer a new molecular target for the treatment improvement of CC.

    更新日期:2020-01-21
  • High Psychopathology Subgroup in Young Children With Autism: Associations With Biological Sex and Amygdala Volume
    J. Am. Acad. Child Adolesc. Psychiatry (IF 6.391) Pub Date : 2020-01-20
    Christine Wu Nordahl; Ana-Maria Iosif; Gregory S. Young; Alexa Hechtman; Brianna Heath; Joshua K. Lee; Lauren Libero; Vanessa P. Reinhardt; Breanna Winder-Patel; David G. Amaral; Sally Rogers; Marjorie Solomon; Sally Ozonoff

    Objective 1) To identify a subset of children with autism spectrum disorder (ASD) and co-occurring symptoms of psychopathology. 2) To evaluate associations between this subgroup and biological sex and amygdala volume. Method Participants included 420 children (ASD: 91 girls, 209 boys; typically developing controls: 57 girls, 63 boys). Latent profile analysis was used to identify ASD subgroups based on symptoms of psychopathology, adaptive functioning, cognitive development, and autism severity. Sex differences in the proportion of girls and boys in each subgroup were evaluated. MRI scans were acquired (346 children); amygdala volumes were evaluated in relation to subgroups and problem behavior scores. Results Three ASD subgroups were identified; one was characterized by high levels of psychopathology and moderate impairment on other measures (High Psychopathology Moderate Impairments [HPMI], comprising 27% of the sample). The other two subgroups had lower symptoms of psychopathology but were differentiated by high and low levels of impairment on other measures. A higher proportion of girls were classified into the HPMI subgroup (40% of girls vs. 22% of boys). Relative to controls, amygdala volumes were enlarged only in the HPMI subgroup, other subgroups did not differ. There was a positive association between right amygdala volume and internalizing behaviors in girls but not boys with ASD. Conclusion A higher proportion of girls with ASD faced greater challenges with psychopathology, suggesting a need for closer evaluation and potentially earlier intervention to help improve outcomes. Amygdala enlargement was associated with co-occurring symptoms of psychopathology and sex-specific correlations with symptoms were observed.

    更新日期:2020-01-21
  • Valuing Innovative Endoscopic Techniques: Prophylactic Clip Closure After Endoscopic Resection of Large Colon Polyps
    Gastrointest. Endosc. (IF 7.229) Pub Date : 2020-01-19
    Eric D. Shah; Heiko Pohl; Douglas K. Rex; Michael B. Wallace; Seth D. Crockett; Shannon J. Morales; Linda A. Feagins; Ryan Law

    Background And Aims Clip closure of the mucosal defect after resecting large (≥20 mm) nonpedunculated colorectal polyps reduces postprocedure bleeding and is cost-saving to payers. Clip costs are not reimbursed by payers, posing a major barrier to adoption of this technique in the community. We aimed to determine appropriate clip costs to support broader use of this procedure in practice. Methods We performed budget impact analysis using our recent decision analytic model, comparing prophylactic clip closure to no clip closure on national cost and outcomes data, to determine the maximum feasible clip price while maintaining cost-savings in practice. Sensitivity analyses were performed on important clinical factors. Results In the original model, the baseline postprocedure bleeding risk was 6.8%, increasing cost-of-care by $614.11 averaged among all patients undergoing large polyp resection without clip closure. Prophylactic clip closure of only large right-sided polyps reduced postprocedure bleeding risk by 70.7% but resulted in cost-saving only if price of clips was $100 or less. Comparatively, prophylactic clip closure of large left-sided polyps had no clinical benefit and was not cost-saving. Clip closure strategies focused on only extra-large polyps (≥40 mm), or patients taking antithrombotics regardless of polyp characteristics, were only minimally cost-saving. Cost-savings and maximum tolerated clip prices depended on medical comorbidity, which directly influences the costs-of-care to manage postprocedure bleeding. Conclusions Prophylactic clip closure after endoscopic resection of large colon polyps, particular those in the right colon segment, is cost-saving, but requires clip costs less than $100. Translating these findings into practice requires gastroenterology practices to obtain reimbursement from payers for improved clinical outcomes and to align commercial clip prices with this clinical indication.

    更新日期:2020-01-21
  • Outcomes of early endoscopic intervention for pancreatic necrotic collections: a matched case-control study
    Gastrointest. Endosc. (IF 7.229) Pub Date : 2020-01-18
    Nicholas Oblizajek; Naoki Takahashi; Sevda Agayeva; Fateh Bazerbachi; Vinay Chandrasekhara; Michael Levy; Andrew Storm; Todd Baron; Suresh Chari; Ferga C. Gleeson; Randall Pearson; Bret T. Petersen; Santhi Swaroop Vege; Ryan Lennon; Mark Topazian; Barham K. Abu Dayyeh

    Background and Aims Pancreatic necrosis (PN) may be categorized as an acute necrotic collection (ANC) or walled-off necrosis (WON) based on complete encapsulation by a wall and collection age (≤ or > 4 weeks). Endoscopic intervention of WON has become the standard of care, but little is known regarding the safety and efficacy of endoscopic intervention of PN ≤4 weeks from disease onset. Methods Retrospective review of medical records and imaging studies of all patients undergoing early endoscopic intervention of PN between 2008 and 2018 at one referral center. Patients who underwent previous interventional treatment were excluded. Control WON patients were matched to early intervention cases. Primary outcome was defined as resolution of the collection after endoscopic treatment, without surgery. Results Nineteen patients with early intervention were identified. The most common indication for intervention was infection. Median age of these collections at the time of initial endoscopic intervention was 23 days (range 15-27), and all collections had a partial or complete wall discernable on contrast-enhanced CT. Eleven patients underwent concurrent endoscopic necrosectomy. Primary outcome was achieved in all of the early intervention group. Total duration of therapy was longer for early intervention compared with controls (103 vs 69 days, p=0.042), with no mortality and similar adverse event rates compared with controls. Conclusions Endoscopic intervention of PN in the third and fourth weeks of illness appears effective and safe when a partial collection wall is present on cross-sectional imaging studies, with outcomes paralleling those reported for intervention of WON.

    更新日期:2020-01-21
  • Short-term outcomes of double pyloromyotomy versus single pyloromyotomy at peroral endoscopic pyloromyotomy in treatment of gastroparesis (with video)
    Gastrointest. Endosc. (IF 7.229) Pub Date : 2020-01-17
    Mohamed M. Abdelfatah; Baiwen Li; Neil Kapil; Alan Noll; Lianyong Li; Hui Luo; Huimin Chen; Liang Xia; Xiangbo Chen; Vailshali Patel; Parit Mekaroonkamol; Julia Massaad; Steven Keilin; Qiang Cai

    Background and Aims Gastroparesis (Gp) is a chronic debilitating disorder rising in prevalence and hospitalizations. Gastric peroral endoscopic pyloromyotomy (POP or GPOEM) is a novel technique in the treatment of refractory Gp. Despite the initial promising results of GPOEM, one-third of patients do not exhibit any clinical response. Furthermore, loss of clinical response was reported in several studies. No response or loss of response after GPOEM may be related to inadequate myotomy. The aim of our study is to examine whether double pyloromyotomy at GPOEM is superior to single pyloromyotomy. Method A retrospective case-controlled study of patients who underwent GPOEM for refractory Gp at our tertiary care institution between June 2015 and March 2018 was performed. Because the follow-up time for the single myotomy group was much longer than that of the double-myotomy group, we matched the length of follow-up for the single myotomy group to that of the double myotomy group. The outcomes were measured by the changes in Gp cardinal symptom index (GCSI) before and 3 to 6 months after the procedure. Adverse events and other procedural and clinical parameters were also compared. Results Ninety patients underwent GPOEM (55 single and 35 double pyloromyotomy) Mean age was 47 ±14 years old, mean duration of symptoms was 5.3 ± 4.4 years. Average GCSI was 3.8 before the GPOEM and the average GCSI 6 months after procedure was 1.8 37 out of 55 (67%) patients underwent single pyloromyotomy achieved clinical response compared with 30 out of 35 (86%) patients receiving double pyloromyotomy. There were no significant differences among procedure time, postoperative pain or length of hospital stay between the 2 groups. There was no difference in adverse events in the 2 pyloromyotomy groups. Conclusion Double pyloromyotomy is a safe and feasible technique during GPOEM. Clinical success was higher in patients undergoing double pyloromyotomy compared with single pyloromyotomy in this nonrandomized, short-term follow-up study. Long-term studies are needed to further confirm our results.

    更新日期:2020-01-21
  • Clinical outcomes of adults with eosinophilic esophagitis with severe stricture
    Gastrointest. Endosc. (IF 7.229) Pub Date : 2020-01-16
    Jooho P. Kim; Gabriel Weingart; Brent Hiramoto; Dyanna L. Gregory; Nirmala Gonsalves; Ikuo Hirano

    Background & Aims Eosinophilic esophagitis (EoE) is an inflammatory disease of the esophagus that has been steadily increasing in prevalence over the past three decades. The prognosis of EoE patients presenting with severe esophageal strictures is poorly understood. The aim of this study is to describe the clinical outcomes of EoE patients with severe stricture and identify factors associated with a greater likelihood of improvement in esophageal diameter. Methods This study is a retrospective chart review of patients with EoE with severe stricture, defined as an esophageal diameter of 10 millimeters (mm) or less at one point in their disease course. Each patient’s clinical course was followed during standard of care follow-up with medical or dietary therapy in conjunction with repeated esophageal dilations. Multivariate regression analysis was performed to determine which variables are associated with endoscopic response, defined by an improvement in esophageal diameter to 13 mm and to 15 mm. Results From a cohort of 1091 adults with EoE, severe strictures were identified in 66 patients (7%). Of the 66 patients, 59 (89%) achieved an esophageal diameter of ≥13 mm, and 43 (65%) to ≥15 mm. Initial diameter (OR, 1.58; 95% CI, 1.06-2.35; P=0.025) and histologic remission (OR, 34.97; 95% CI, 6.45-189.49; P<0.0001) were significantly associated with achieving a ≥15 mm diameter. Age at diagnosis, gender, and number of months to maximum esophageal diameter were not associated with achieving either diameter. Conclusions The majority of patients with EoE with severe stricture experienced improvement in esophageal diameter to ≥15 mm with treatment, suggesting that the currently available treatment options are effective for patients with severe strictures. The most significant factors associated with disease reversibility are initial esophageal diameter and histologic remission.

    更新日期:2020-01-21
  • Osimertinib overcomes alectinib resistance caused by amphiregulin in a leptomeningeal carcinomatosis model of ALK-rearranged lung cancer
    J. Thorac. Oncol. (IF 12.460) Pub Date : 2020-01-21
    Sachiko Arai; Shinji Takeuchi; Koji Fukuda; Hirokazu Taniguchi; Akihiro Nishiyama; Azusa Tanimoto; Miyako Satouchi; Kaname Yamashita; Koshiro Ohtsubo; Shigeki Nanjo; Toru Kumagai; Ryohei Katayama; Makoto Nishio; Mei-mei Zheng; Yi-Long Wu; Hiroshi Nishihara; Takushi Yamamoto; Mitsutoshi Nakada; Seiji Yano

    Introduction Leptomeningeal carcinomatosis (LMC) occurs frequently in anaplastic lymphoma kinase (ALK)-rearranged non-small-cell lung cancer (NSCLC) and develops acquired resistance to ALK tyrosine kinase inhibitors (ALK-TKIs). This study aimed to clarify the resistance mechanism to alectinib, a second generation ALK-TKI, in LMC and test a novel therapeutic strategy. Methods We induced alectinib-resistance in an LMC mouse model with ALK-rearranged NSCLC cell line, A925LPE3, by continuous oral alectinib treatment, established A925L/AR cells. Resistance mechanisms were analyzed using several assays, including western blot and receptor tyrosine kinase array. We also measured amphiregulin concentrations in cerebrospinal fluid (CSF) from ALK-rearranged NSCLC patients with alectinib-refractory LMC by ELISA. Results A925L/AR cells were moderately resistant to various ALK-TKIs, such as alectinib, crizotinib, ceritinib, and lorlatinib, compared with parental cells in vitro. A925L/AR cells acquired the resistance by epidermal growth factor receptor (EGFR) activation due to amphiregulin overexpression caused by decreased expression of microRNA-449a. EGFR-TKIs and anti-EGFR antibody re-sensitized A925L/AR cells to alectinib in vitro. In the LMC model with A925L/AR cells, combined treatment with alectinib and EGFR-TKIs, such as erlotinib and osimertinib, successfully controlled progression of LMC. Imaging mass spectrometry showed accumulation of the EGFR-TKIs in the tumor lesions. Moreover, notably higher amphiregulin levels were detected in CSF from alectinib-resistant ALK-rearranged NSCLC patients with LMC (N=4), compared with those in EGFR-mutated NSCLC patients with EGFR-TKI-resistant LMC (N=30) or patients without LMC (N=24). Conclusions These findings indicate the potential of novel therapies targeting both ALK and EGFR for the treatment of ALK-TKI-resistant LMC in ALK-rearranged NSCLC.

    更新日期:2020-01-21
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