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https://www.readbyqxmd.com/read/28640605/high-pressure-synthesis-crystal-structure-and-magnetic-and-transport-properties-of-a-six-layered-srrho3
#1
Yan Li, Jinguang Cheng, José Antonio Alonso, John B Goodenough, Jianshi Zhou
A SrRhO3 polytype with six-layered (6M) structure was synthesized under high pressure and high temperature. The crystal structure was obtained by refining X-ray powder diffraction with the monoclinic space group C2/c with lattice parameters a = 5.5650(1) Å, b = 9.5967(2) Å, c = 14.0224(4) Å, and β = 92.846(2)°. It is isostructural with SrIrO3 synthesized under ambient pressure and consists of dimers of the face-shared Rh(2)O6 octahedra connected by their vertices to the corner-shared Rh(1)O6 octahedra along the c axis with a stacking of SrO3 layers in the sequence of CCHCCH, where C and H denote cubic and hexagonal closed packing, respectively...
June 22, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28632960/snap-tag-based-subcellular-proteins-labeling-and-fluorescent-imaging-with-naphthalimides
#2
Chao Wang, Xinbo Song, Yi Xiao
Genetically encoded technologies provide methods for specific labeling and imaging of proteins, which is essential for the understanding of their subcellular localization and function. Herein, we employ naphthalimide, an efficient two-photon fluorophore, to develop O6-benzylguanine (BG) derivatives for specific labeling of subcellular proteins and fluorescent imaging through the SNAP-tag. The three naphthalimide-BG derivatives, TNI-BG, QNI-BG and ONI-BG are conveniently synthesized through modular "click chemistry" with high yields...
June 20, 2017: Chembiochem: a European Journal of Chemical Biology
https://www.readbyqxmd.com/read/28631925/anticancer-activity-of-polyoxometalate-bisphosphonate-complexes-synthesis-characterization-in-vitro-and-in-vivo-results
#3
Amandine Boulmier, Xinxin Feng, Olivier Oms, Pierre Mialane, Eric Rivière, Christopher J Shin, Jiaqi Yao, Tadahiko Kubo, Taisuke Furuta, Eric Oldfield, Anne Dolbecq
We synthesized a series of polyoxometalate-bisphosphonate complexes containing Mo(VI)O6 octahedra, zoledronate, or an N-alkyl (n-C6 or n-C8) zoledronate analogue, and in two cases, Mn as a heterometal. Mo6L2 (L = Zol, ZolC6, ZolC8) and Mo4L2Mn (L = Zol, ZolC8) were characterized by using single-crystal X-ray crystallography and/or IR spectroscopy, elemental and energy dispersive X-ray analysis and (31)P NMR. We found promising activity against human nonsmall cell lung cancer (NCI-H460) cells with IC50 values for growth inhibition of ∼5 μM per bisphosphonate ligand...
June 20, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28609363/o6-methylguanine-dna-methyltransferase-status-does-not-predict-response-or-resistance-to-alkylating-agents-in-well-differentiated-pancreatic-neuroendocrine-tumors
#4
Nitya Raj, David S Klimstra, Natally Horvat, Liying Zhang, Joanne F Chou, Marinela Capanu, Olca Basturk, Richard Kinh Gian Do, Peter J Allen, Diane Reidy-Lagunes
OBJECTIVES: Alkylating agents have activity in well-differentiated pancreatic neuroendocrine tumors (WD panNETs). In glioblastoma multiforme, decreased activity of O-methylguanine DNA methyltransferase (MGMT) predicts response; in panNETs, MGMT relevance is unknown. METHODS: We identified patients with WD panNETs treated with alkylating agents, determined best overall response by Response Evaluation Criteria In Solid Tumors (RECIST) 1.1, and performed MGMT activity testing...
July 2017: Pancreas
https://www.readbyqxmd.com/read/28602885/high-expression-of-glypican-1-predicts-dissemination-and-poor-prognosis-in-glioblastomas
#5
Taiichi Saito, Kazuhiko Sugiyama, Seiji Hama, Fumiyuki Yamasaki, Takeshi Takayasu, Ryo Nosaka, Shumpei Onishi, Yoshihiro Muragaki, Takakazu Kawamata, Kaoru Kurisu
OBJECTIVE: Glioblastoma (GBM) relapses locally or in a disseminated pattern, and is highly resistant to chemo-radiotherapy. Although dissemination is associated with poor prognosis for GBM patients, the clinico-pathological factors that promote dissemination have not been elucidated. Glypican-1 (GPC-1) is a heparin sulfate proteoglycan that is attached to the extracytoplasmic surface of the cell membrane and regulates cell motility. The aim of this study was to determine whether GPC-1 expression correlated with GBM dissemination and patient prognosis...
June 5, 2017: World Neurosurgery
https://www.readbyqxmd.com/read/28602417/survival-outcomes-with-short-course-radiation-therapy-in-elderly-patients-with-glioblastoma-data-from-a-randomized-phase-3-trial
#6
Douglas Guedes de Castro, Juliana Matiello, Wilson Roa, Sunita Ghosh, Lucyna Kepka, Narendra Kumar, Valery Sinaika, Darejan Lomidze, Dalenda Hentati, Eduardo Rosenblatt, Elena Fidarova
PURPOSE: To perform a subset analysis of survival outcomes in elderly patients with glioblastoma from a randomized phase 3 trial comparing 2 short-course radiation therapy (RT) regimens in elderly and/or frail patients. METHODS AND MATERIALS: The original trial population included elderly and/or frail patients with a diagnosis of glioblastoma. Patients joined the phase 3, randomized, multicenter, prospective, noninferiority trial; were assigned to 1 of 2 groups in a 1:1 ratio, either short-course RT (25 Gy in 5 fractions, arm 1) or commonly used RT (40 Gy in 15 fractions, arm 2); and were stratified by age (<65 years and ≥65 years), Karnofsky Performance Status (KPS), and extent of surgery...
July 15, 2017: International Journal of Radiation Oncology, Biology, Physics
https://www.readbyqxmd.com/read/28594901/detection-of-human-cytomegalovirus-in-glioblastoma-among-taiwanese-subjects
#7
Ching-Fen Yang, Hsiang-Ling Ho, Shih-Chieh Lin, Chih-Yi Hsu, Donald Ming-Tak Ho
The relationship between human cytomegalovirus (HCMV) and glioblastoma (GBM) has been debated for more than a decade. We investigated the presence of HCMV genes, RNA and protein in GBMs and their relationships with tumor progression. Results of quantitative PCR for HCMV UL73, nested PCR for HCMV UL144, in situ hybridization (ISH) for RNA transcript, and immunohistochemistry (IHC) for protein expression and their relationship to the prognosis of 116 patients with GBM were evaluated. Nine (7.8%) cases revealed a low concentration of HCMV UL73, and only 2 of the 9 (1...
2017: PloS One
https://www.readbyqxmd.com/read/28594893/pandemic-extra-intestinal-pathogenic-escherichia-coli-expec-clonal-group-o6-b2-st73-as-a-cause-of-avian-colibacillosis-in-brazil
#8
Marcos Paulo Vieira Cunha, Andre Becker Saidenberg, Andrea Micke Moreno, Antonio José Piantino Ferreira, Mônica Aparecida Midolli Vieira, Tânia Aparecida Tardelli Gomes, Terezinha Knöbl
Extra-intestinal pathogenic Escherichia coli (ExPEC) represent an emerging pathogen, with pandemic strains increasingly involved in cases of urinary tract infections (UTIs), bacteremia, and meningitis. In addition to affecting humans, the avian pathotype of ExPEC, avian pathogenic E. coli (APEC), causes severe economic losses to the poultry industry. Several studies have revealed overlapping characteristics between APEC and human ExPEC, leading to the hypothesis of a zoonotic potential of poultry strains. However, the description of certain important pandemic clones, such as Sequence Type 73 (ST73), has not been reported in food sources...
2017: PloS One
https://www.readbyqxmd.com/read/28591780/position-dependent-effects-of-regioisomeric-methylated-adenine-and-guanine-ribonucleosides-on-translation
#9
Changjun You, Xiaoxia Dai, Yinsheng Wang
Reversible methylation of the N6 or N1 position of adenine in RNA has recently been shown to play significant roles in regulating the functions of RNA. RNA can also be alkylated upon exposure to endogenous and exogenous alkylating agents. Here we examined how regio-specific methylation at the hydrogen bonding edge of adenine and guanine in mRNA affects translation. When situated at the third codon position, the methylated nucleosides did not compromise the speed or accuracy of translation under most circumstances...
June 7, 2017: Nucleic Acids Research
https://www.readbyqxmd.com/read/28590111/synthesis-of-water-dispersible-single-layer-coal-carbonate-layered-double-hydroxide
#10
Haiping Li, Thanh-Nhan Tran, Byong-Jun Lee, Chunfei Zhang, Jong-Deok Park, Tong-Hyun Kang, Jong-Sung Yu
Despite extensive study on single-layer layered double hydroxides (SL-LDHs) with NO3(-) counterions, SL-LDHs with CO3(2-) counterions (CO3(2-) SL-LDHs) have never been prepared before. Herein, a CoAl-CO3(2-) SL-LDH which stays stable in water and powdery state is first synthesized using ethylene glycol as a reaction medium. The SL-LDH, with thickness of ∼0.85 nm, is composed of one Co(Al)O6 layer sandwiched between two CO3(2-) layers. The SL-LDH powder shows high specific surface area (∼289 m(2)/g) and excellent electrocatalytic oxygen evolution efficiency...
June 21, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28575445/quaternary-interactions-and-supercoiling-modulate-the-cooperative-dna-binding-of-agt
#11
Manana Melikishvili, Michael G Fried
Human O6-alkylguanine-DNA alkyltransferase (AGT) repairs mutagenic O6-alkylguanine and O4-alkylthymine adducts in single-stranded and duplex DNAs. The search for these lesions, through a vast excess of competing, unmodified genomic DNA, is a mechanistic challenge that may limit the repair rate in vivo. Here, we examine influences of DNA secondary structure and twist on protein-protein interactions in cooperative AGT complexes formed on lesion-free DNAs that model the unmodified parts of the genome. We used a new approach to resolve nearest neighbor (nn) and long-range (lr) components from the ensemble-average cooperativity, ωave...
May 27, 2017: Nucleic Acids Research
https://www.readbyqxmd.com/read/28556666/field-assisted-slow-magnetic-relaxation-in-a-six-coordinate-co-ii-co-iii-complex-with-large-negative-anisotropy
#12
Elena A Buvaylo, Vladimir N Kokozay, Olga Yu Vassilyeva, Brian W Skelton, Andrew Ozarowski, Ján Titiš, Beáta Vranovičová, Roman Boča
The reaction of Co(CH3COO)2·4H2O with the Schiff base ligand LH4 derived from o-vanillin and tris(hydroxymethyl)aminomethane produces the dinuclear mixed-valence complex [Co(II)Co(III)(LH2)2(CH3COO)(H2O)](H2O)3 (1), which has been investigated using IR spectroscopy, X-ray crystallography, temperature-dependent magnetic susceptibility, magnetization, HFEPR spectroscopy, and ac susceptibility measurements at various frequencies, temperatures, and external magnetic fields. The structure of 1 consists of neutral molecules in which two cobalt ions with distorted octahedral geometries, Co(II)O6 and Co(III)N2O4, are bridged by two deprotonated -CH2O(-) groups of the two LH2(2-) ligands...
May 30, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28531304/replication-studies-of-carboxymethylated-dna-lesions-in-human-cells
#13
Jun Wu, Pengcheng Wang, Lin Li, Nicole L Williams, Debin Ji, Walter J Zahurancik, Changjun You, Jianshuang Wang, Zucai Suo, Yinsheng Wang
Metabolic activation of some N-nitroso compounds (NOCs), an important class of DNA damaging agents, can induce the carboxymethylation of nucleobases in DNA. Very little was previously known about how the carboxymethylated DNA lesions perturb DNA replication in human cells. Here, we investigated the effects of five carboxymethylated DNA lesions, i.e. O6-CMdG, N6-CMdA, N4-CMdC, N3-CMdT and O4-CMdT on the efficiency and fidelity of DNA replication in HEK293T human embryonic kidney cells. We found that, while neither N6-CMdA nor N4-CMdC blocked DNA replication or induced mutations, N3-CMdT, O4-CMdT and O6-CMdG moderately blocked DNA replication and induced substantial frequencies of T→A (81%), T→C (68%) and G→A (6...
May 22, 2017: Nucleic Acids Research
https://www.readbyqxmd.com/read/28530384/divalent-metal-ion-activation-of-a-guanine-general-base-in-the-hammerhead-ribozyme-insights-from-molecular-simulations
#14
Haoyuan Chen, Timothy J Giese, Barbara L Golden, Darrin M York
The hammerhead ribozyme is a well-studied nucleolytic ribozyme that catalyzes the self-cleavage of the RNA phosphodiester backbone. Despite experimental and theoretical efforts, key questions remain about details of the mechanism with regard to the activation of the nucleophile by the putative general base guanine (G12). Straightforward interpretation of the measured activity-pH data implies the pKa value of the N1 position in the G12 nucleobase is significantly shifted by the ribozyme environment. Recent crystallographic and biochemical work has identified pH-dependent divalent metal ion binding at the N7/O6 position of G12, leading to the hypothesis that this binding mode could induce a pKa shift of G12 toward neutrality...
June 12, 2017: Biochemistry
https://www.readbyqxmd.com/read/28529799/new-m-m-3-arsenates-the-framework-structures-of-agm-3-haso4-2-m-3-al-ga-and-m-gaas2o7-m-na-ag
#15
Karolina Schwendtner, Uwe Kolitsch
The crystal structures of hydro-thermally synthesized silver(I) aluminium bis-[hydrogen arsenate(V)], AgAl(HAsO4)2, silver(I) gallium bis-[hydrogen arsenate(V)], AgGa(HAsO4)2, silver gallium diarsenate(V), AgGaAs2O7, and sodium gallium diarsenate(V), NaGaAs2O7, were determined from single-crystal X-ray diffraction data collected at room temperature. The first two compounds are representatives of the MCV-3 structure type known for KSc(HAsO4)2, which is characterized by a three-dimensional anionic framework of corner-sharing alternating M(3+)O6 octa-hedra (M = Al, Ga) and singly protonated AsO4 tetra-hedra...
May 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/28529131/the-structure-of-the-guanidine-ii-riboswitch
#16
Lin Huang, Jia Wang, David M J Lilley
The guanidine-II (mini-ykkC) riboswitch is the smallest of the guanidine-responsive riboswitches, comprising two stem loops of similar sequence. We have solved high-resolution crystal structures of both stem loops for the riboswitch from Gloeobacter violaceus. The stem loops have a strong propensity to dimerize by intimate loop-loop interaction. The dimerization creates specific binding pockets for two guanidine molecules, explaining their cooperative binding. Within the binding pockets the ligands are hydrogen bonded to a guanine at O6 and N7, and to successive backbone phosphates...
May 18, 2017: Cell Chemical Biology
https://www.readbyqxmd.com/read/28506525/how-does-mg-2-modulate-the-rna-folding-mechanism-a-case-study-of-the-g-c-w-w-trans-basepair
#17
Antarip Halder, Rohit Roy, Dhananjay Bhattacharyya, Abhijit Mitra
Reverse Watson-Crick G:C basepairs (G:C W:W Trans) occur frequently in different functional RNAs. This is one of the few basepairs whose gas-phase-optimized isolated geometry is inconsistent with the corresponding experimental geometry. Several earlier studies indicate that through post-transcriptional modification, direct protonation, or coordination with Mg(2+), accumulation of positive charge near N7 of guanine can stabilize the experimental geometry. Interestingly, recent studies reveal significant variation in the position of putatively bound Mg(2+)...
May 12, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/28481096/cuo-and-zno-nanoparticles-modify-interkingdom-cell-signaling-processes-relevant-to-crop-production-a-review
#18
Anne Anderson, Joan E McLean, Astrid Rosa Jacobson, David Britt
As the world population increases, strategies for sustainable agriculture are needed to fulfill the global need for plants for food and other commercial products. Nanoparticle formulations are likely to be part of the developing strategies. CuO and ZnO nanoparticles (NPs) offer potential as fertilizers, as they provide bioavailable essential metals, and as pesticides, because of dose-dependent toxicity. Effects of these metal oxide NPs on rhizosphere functions are the focus of this review. These NPs at doses of 10 mg metal/kg and above change production of key metabolites involved in plant protection in a root-associated microbe, Pseudomonas chlororaphis O6...
May 8, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28460122/transcriptional-mutagenesis-reduces-splicing-fidelity-in-mammalian-cells
#19
João A Paredes, Monika Ezerskyte, Matteo Bottai, Kristian Dreij
Splicing fidelity is essential to the maintenance of cellular functions and viability, and mutations or natural variations in pre-mRNA sequences and consequent alteration of splicing have been implicated in the etiology and progression of numerous diseases. The extent to which transcriptional errors or lesion-induced transcriptional mutagenesis (TM) influences splicing fidelity is not currently known. To investigate this, we employed site-specific DNA lesions on the transcribed strand of a minigene splicing reporter in normal mammalian cells...
April 29, 2017: Nucleic Acids Research
https://www.readbyqxmd.com/read/28453749/an-independently-validated-nomogram-for-individualized-estimation-of-survival-among-patients-with-newly-diagnosed-glioblastoma-nrg-oncology-rtog-0525-and-0825
#20
Haley Gittleman, Daniel Lim, Michael W Kattan, Arnab Chakravarti, Mark R Gilbert, Andrew B Lassman, Simon S Lo, Mitchell Machtay, Andrew E Sloan, Erik P Sulman, Devin Tian, Michael A Vogelbaum, Tony J C Wang, Marta Penas-Prado, Emad Youssef, Deborah T Blumenthal, Peixin Zhang, Minesh P Mehta, Jill S Barnholtz-Sloan
Background.: Glioblastoma (GBM) is the most common primary malignant brain tumor. Nomograms are often used for individualized estimation of prognosis. This study aimed to build and independently validate a nomogram to estimate individualized survival probabilities for patients with newly diagnosed GBM, using data from 2 independent NRG Oncology Radiation Therapy Oncology Group (RTOG) clinical trials. Methods.: This analysis included information on 799 (RTOG 0525) and 555 (RTOG 0825) eligible and randomized patients with newly diagnosed GBM and contained the following variables: age at diagnosis, race, gender, Karnofsky performance status (KPS), extent of resection, O6-methylguanine-DNA methyltransferase (MGMT) methylation status, and survival (in months)...
May 1, 2017: Neuro-oncology
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