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https://www.readbyqxmd.com/read/29227935/hematite-%C3%AE-fe2o3-a-potential-ce4-carrier-in-red-mud
#1
Ralph M Bolanz, Stefan Kiefer, Jörg Göttlicher, Ralph Steininger
Cerium is the most abundant rare earth element (REE) within the waste product of alumina production (red mud), but its speciation in this complex material is still barely understood. Previous studies showed evidence for a correlation between Ce and the main constituent of red mud, iron oxides, which led us to investigate the most abundant iron oxide in red mud, hematite, as possible carrier phase for Ce. Synthetic hematite can incorporate up to 1.70±0.01wt% Ce, which leads to a systematical increase of all unit cell parameters...
December 7, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/29225516/hedgehog-gli1-signaling-pathway-regulates-mgmt-expression-and-chemoresistance-to-temozolomide-in-human-glioblastoma
#2
Ke Wang, Dongjiang Chen, Zhouqi Qian, Daming Cui, Liang Gao, Meiqing Lou
Background: Chemoresistance of glioblastoma (GBM) is a feature of this devastating disease. This study is to determine the relationship between Hedgehog (HH)/Gli1 signaling pathway and chemoresistance to temozolomide (TMZ) in human GBM. Methods: We analyzed Gli1 nuclear staining and O6-methylguanine DNA methyltransferase (MGMT) expression in 48 cases of primary GBM tissues by immunohistochemistry. Quantitative PCR, western blot, methylation-specific PCR, cell proliferation and apoptosis assay were used to investigate changes of MGMT expression and chemosensitivity to TMZ after manipulating HH/Gli1 signaling activity in A172 and U251 GBM cell lines...
2017: Cancer Cell International
https://www.readbyqxmd.com/read/29220701/molecular-criteria-for-mutagenesis-by-dna-methylation-some-computational-elucidations
#3
Tejeshwori Salam, S Premila Devi, R H Duncan Lyngdoh
Alkylating agents and N-nitroso compounds are well-known mutagens and carcinogens which act by alkylating DNA at the nucleobase moieties. Criteria for mutagenicity through DNA alkylation include (a) absence of the Watson-Crick (N1-guanine and N3-thymine) protons, (b) rotation of the alkyl group away from the H-bonding zone, (c) configuration of the alkylated base pair close to the Watson-Crick type. This computational study brings together these three molecular criteria for the first time. Three methylated DNA bases-N7-methylguanine, O6-methylguanine and O4-methylthymine-are studied using computational chemical methods...
November 10, 2017: Mutation Research
https://www.readbyqxmd.com/read/29218894/mri-to-mgmt-predicting-methylation-status-in-glioblastoma-patients-using-convolutional-recurrent-neural-networks
#4
Lichy Han, Maulik R Kamdar
Glioblastoma Multiforme (GBM), a malignant brain tumor, is among the most lethal of all cancers. Temozolomide is the primary chemotherapy treatment for patients diagnosed with GBM. The methylation status of the promoter or the enhancer regions of the O6-methylguanine methyltransferase (MGMT) gene may impact the efficacy and sensitivity of temozolomide, and hence may affect overall patient survival. Microscopic genetic changes may manifest as macroscopic morphological changes in the brain tumors that can be detected using magnetic resonance imaging (MRI), which can serve as noninvasive biomarkers for determining methylation of MGMT regulatory regions...
2018: Pacific Symposium on Biocomputing
https://www.readbyqxmd.com/read/29198811/preparation-of-pegylated-liposomes-incorporating-lipophilic-lomeguatrib-derivatives-for-the-sensitization-of-chemo-resistant-gliomas
#5
Rea D Signorell, Alexandros Papachristodoulou, Jiawen Xiao, Bianca Arpagaus, Tommaso Casalini, Joanes Grandjean, Jana Thamm, Frank Steiniger, Paola Luciani, Davide Brambilla, Beat Werner, Ernst Martin, Michael Weller, Patrick Roth, Jean-Christophe Leroux
Liposomal delivery is a well-established approach to increase the therapeutic index of drugs, mainly in the field of cancer chemotherapy. Here, we report the preparation and characterization of a new liposomal formulation of a derivative of lomeguatrib, a potent O6-methylguanine-DNA methyltransferase (MGMT) inactivator. The drug had been tested in clinical trials to revert chemoresistance, but was associated with a low therapeutic index. A series of lomeguatrib conjugates with distinct alkyl chain lengths - i...
November 30, 2017: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/29191871/mr-imaging-characteristics-associate-with-tumor-associated-macrophages-in-glioblastoma-and-provide-an-improved-signature-for-survival-prognostication
#6
J Zhou, M V Reddy, B K J Wilson, D A Blair, A Taha, C M Frampton, R A Eiholzer, P Y C Gan, F Ziad, Z Thotathil, S Kirs, N A Hung, J A Royds, T L Slatter
BACKGROUND AND PURPOSE: In glioblastoma, tumor-associated macrophages have tumor-promoting properties. This study determined whether routine MR imaging features could predict molecular subtypes of glioblastoma that differ in the content of tumor-associated macrophages. MATERIALS AND METHODS: Seven internally derived MR imaging features were assessed in 180 patients, and 25 features from the Visually AcceSAble Rembrandt Images feature set were assessed in 164 patients...
November 30, 2017: AJNR. American Journal of Neuroradiology
https://www.readbyqxmd.com/read/29174509/tlr8-activation-and-inhibition-by-guanosine-analogs-in-rna-importance-of-functional-groups-and-chain-length
#7
Tiannan Hu, Scott R Suter, Madeline M Mumbleau, Peter A Beal
Toll-like receptor 8 (TLR8) is an important component of the human innate immune system that recognizes single stranded RNA (ssRNA). Recent X-ray crystal structures of TLR8 bound to ssRNA revealed a previously unrecognized binding site for a 5'-UpG-3' dinucleotide. Here we use an atomic mutagenesis strategy coupled with a cellular TLR8 activation assay to probe the importance of specific functional groups present on the guanine base in RNA-mediated receptor agonism and antagonism. Results from RNA analogs containing 7-deazaguanosine, 2-aminopurine and inosine confirm the importance of guanine N7, O6 and N2, respectively, in TLR8 activation...
November 11, 2017: Bioorganic & Medicinal Chemistry
https://www.readbyqxmd.com/read/29165638/feasibility-of-real-time-molecular-profiling-for-patients-with-newly-diagnosed-glioblastoma-without-mgmt-promoter-hypermethylation-the-nct-neuro-master-match-n2m2-pilot-study
#8
Elke Pfaff, Tobias Kessler, Gnana Prakash Balasubramanian, Anne Berberich, Daniel Schrimpf, Antje Wick, Jürgen Debus, Andreas Unterberg, Martin Bendszus, Christel Herold-Mende, David Capper, Irini Schenkel, Andreas Eisenmenger, Susan Dettmer, Benedikt Brors, Michael Platten, Stefan M Pfister, Andreas von Deimling, David T W Jones, Wolfgang Wick, Felix Sahm
Introduction: O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status is a predictive biomarker in glioblastoma patients. Glioblastoma without hypermethylated MGMT promoter are largely resistant to treatment with temozolomide. These patients are in particular need of new treatment approaches, which are offered by biomarker-driven clinical trials with targeted drugs based on molecular characterization of individual tumors. Methods: In preparation for an upcoming clinical study, a comprehensive molecular profiling approach was undertaken on tissues from 43 glioblastoma patients harboring an unmethylated MGMT promoter at diagnosis...
November 18, 2017: Neuro-oncology
https://www.readbyqxmd.com/read/29162646/nkg2d-dependent-anti-tumor-effects-of-chemotherapy-and-radiotherapy-against-glioblastoma
#9
Tobias Weiss, Hannah Schneider, Manuela Silginer, Alexander Steinle, Martin N Pruschy, Bojan Polic, Michael Weller, Patrick Roth
PURPOSE: NKG2D is a potent activating immune cell receptor and glioma cells express the cognate ligands (NKG2DL). These ligands are inducible by cellular stress and temozolomide (TMZ) or irradiation (IR), the standard treatment of glioblastoma, could affect their expression. However, a role of NKG2DL for the efficacy of TMZ and IR has never been addressed. EXPERIMENTAL DESIGN: We assessed the effect of TMZ and IR on NKG2DL in vitro and in vivo in a variety of murine and human glioblastoma models including glioma-initiating cells and a cohort of paired glioblastoma samples from patients before and after therapy...
November 21, 2017: Clinical Cancer Research: An Official Journal of the American Association for Cancer Research
https://www.readbyqxmd.com/read/29151909/bkm120-sensitizes-c6-glioma-cells-to-temozolomide-via-suppression-of-the-pi3k-akt-nf-%C3%AE%C2%BAb-mgmt-signaling-pathway
#10
Mao Li, Ruo Fei Liang, Xiang Wang, Qing Mao, Yan Hui Liu
Glioblastoma is the most common type of malignant intracranial tumor in adults. Temozolomide (TMZ), as the first-line chemotherapy agent used in patients with glioblastoma, has demonstrated different effects in patients due to the expression of O6-methylguanine-DNA methyltransferase (MGMT) which is able to repair the DNA lesions induced by TMZ. The phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway is over-activated in glioblastoma and has been revealed to be potentially implicated in resistance to TMZ...
December 2017: Oncology Letters
https://www.readbyqxmd.com/read/29150792/correlation-between-mgmt-promoter-methylation-and-response-to-temozolomide-based-therapy-in-neuroendocrine-neoplasms-an-observational-retrospective-multicenter-study
#11
Davide Campana, Thomas Walter, Sara Pusceddu, Fabio Gelsomino, Emmanuelle Graillot, Natalie Prinzi, Andrea Spallanzani, Michelangelo Fiorentino, Marc Barritault, Filippo Dall'Olio, Nicole Brighi, Guido Biasco
PURPOSE: Temozolomide (TEM) based therapy has been reported being effective in the treatment of metastatic neuroendocrine neoplasms (NEN), with response rates ranging from 30 to 70%. Among patients affected by advanced glioblastoma or melanoma and treated with TEM, loss of tumoral O6-methylguanine DNA methyltransferase (MGMT) is correlated with improved survival. In NEN patients, the role of MGMT deficiency in predicting clinical outcomes of TEM treatment is still under debate. METHODS: In this study we evaluated 95 patients with advanced NENs undergoing treatment with TEM-based therapy...
November 17, 2017: Endocrine
https://www.readbyqxmd.com/read/29136645/a-4-mirna-signature-to-predict-survival-in-glioblastomas
#12
Simon K Hermansen, Mia D Sørensen, Anker Hansen, Steen Knudsen, Alvaro G Alvarado, Justin D Lathia, Bjarne W Kristensen
Glioblastomas are among the most lethal cancers; however, recent advances in survival have increased the need for better prognostic markers. microRNAs (miRNAs) hold great prognostic potential being deregulated in glioblastomas and highly stable in stored tissue specimens. Moreover, miRNAs control multiple genes representing an additional level of gene regulation possibly more prognostically powerful than a single gene. The aim of the study was to identify a novel miRNA signature with the ability to separate patients into prognostic subgroups...
2017: PloS One
https://www.readbyqxmd.com/read/29121933/biochemical-analysis-and-the-preliminary-crystallographic-characterization-of-d-tagatose-3-epimerase-from-rhodobacter-sphaeroides
#13
Zhengliang Qi, Zhangliang Zhu, Jian-Wen Wang, Songtao Li, Qianqian Guo, Panpan Xu, Fuping Lu, Hui-Min Qin
BACKGROUND: D-Tagatose 3-epimerase epimerizes D-fructose to yield D-psicose, which is a rare sugar that exists in small quantities in nature and is difficult to synthesize chemically. We aim to explore potential industrial biocatalysts for commercial-scale manufacture of this rare sugar. A D-tagatose 3-epimerase from Rhodobacter sphaeroides (RsDTE) has recently been identified as a D-tagatose 3-epimerase that can epimerize D-fructose to yield D-psicose with a high conversion rate. RESULTS: The purified RsDTE by Ni-affinity chromatography, ionic exchange chromatography and gel filtration forms a tetramer in solution...
November 9, 2017: Microbial Cell Factories
https://www.readbyqxmd.com/read/29119180/organically-templated-inorganic-organic-hybrid-metal-zn-and-cd-sulfite-oxalates-with-layered-and-three-dimensional-structures
#14
Ranjay K Tiwari, Jitendra Kumar, J N Behera
We report single crystal X-ray investigations of three d(10) metal based oxalate-sulfite inorganic-organic hybrid open framework materials, namely [Zn2(SO3)2(C2O4)0.5(C6N2H13)]·(H2O)2, 1, [C4N2H12]0.5[Zn2(SO3)2(C2O4)0.5(H2O)2], 2 and [C4N2H12][Cd2(SO3)2(C2O4)(H2O)]·H2O, 3 which show layered and three dimensional structures with different organic templates. These materials were synthesized under hydrothermal conditions and characterized by techniques such as single crystal X-ray diffraction, dipole moment calculations, FTIR, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC)...
November 21, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/29116782/inner-sphere-coordination-of-divalent-metal-ion-with-nucleobase-in-catalytic-rna
#15
Xin Liu, Yu Chen, Carol A Fierke
Identification of the function of metal ions and the RNA moieties, particularly nucleobases, that bind metal ions are important questions in RNA catalysis. Here we combine single-atom and abasic substitutions to probe functions of conserved nucleobases in ribonuclease P (RNase P). Structural and biophysical studies of bacterial RNase P propose direct coordination of metal ions by the nucleobases of conserved uridine and guanosine in helix P4 of the RNA subunit (P RNA). To biochemically probe the function of metal ion interactions, we substituted the universally conserved bulged uridine (U51) in the P4 helix of circularly permuted Bacillus subtilis P RNA with 4-thiouridine, 4-deoxyuridine and abasic modifications and G378/379 with 2-aminopurine, N7-deazaguanosine, and 6-thioguanosine...
November 8, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/29114400/an-untypeable-enterotoxigenic-escherichia-coli-represents-one-of-the-dominant-types-causing-human-disease
#16
Atsushi Iguchi, Astrid von Mentzer, Taisei Kikuchi, Nicholas R Thomson
Enterotoxigenic Escherichia coli (ETEC) is a major cause of diarrhoea in children below 5 years of age in endemic areas, and is a primary cause of diarrhoea in travellers visiting developing countries. Epidemiological analysis of E. coli pathovars is traditionally carried out based on the results of serotyping. However, genomic analysis of a global ETEC collection of 362 isolates taken from patients revealed nine novel O-antigen biosynthesis gene clusters that were previously unrecognized, and have collectively been called unclassified...
September 2017: Microbial Genomics
https://www.readbyqxmd.com/read/29111516/an-arsenate-with-the-%C3%AE-crpo4-structure-type-naca1-xni3-2xal2x-aso4-3-x-0-23-crystal-structure-charge-distribution-and-bond-valence-sum-analyses
#17
Ridha Ben Smail, Mohamed Faouzi Zid
Since the discovery of electrochemically active LiFePO4, materials with tunnel and layered structures built up of transition metals and polyanions have become the subject of much research. A new quaternary arsenate, sodium calcium trinickel aluminium triarsenate, NaCa1-xNi3-2xAl2x(AsO4)3 (x = 0.23), was synthesized using the flux method in air at 1023 K and its crystal structure was determined from single-crystal X-ray diffraction (XRD) data. This material was also characterized by qualitative energy-dispersive X-ray spectroscopy (EDS) analysis and IR spectroscopy...
November 1, 2017: Acta Crystallographica. Section C, Structural Chemistry
https://www.readbyqxmd.com/read/29100425/promoter-methylation-of-tumor-related-genes-as-a-potential-biomarker-using-blood-samples-for-gastric-cancer-detection
#18
Jinfeng Wen, Tuo Zheng, Kefeng Hu, Chunxia Zhu, Lihua Guo, Guoliang Ye
Gene promoter methylation has been reported in gastric cancer (GC). However, the potential applications of blood-based gene promoter methylation as a noninvasive biomarker for GC detection remain to be evaluated. Hence, we performed this analysis to determine whether promoter methylation of 11 tumor-related genes could become a promising biomarker in blood samples in GC. We found that the cyclin-dependent kinase inhibitor 2A (p16), E-cadherin (CDH1), runt-related transcription factor 3 (RUNX3), human mutL homolog 1 (MLH1), RAS association domain family protein 1A (RASSF1A), cyclin-dependent kinase inhibitor 2B (p15), adenomatous polyposis coli (APC), Glutathione S-transferase P1 (GSTP1), TP53 dependent G2 arrest mediator candidate (Reprimo), and O6-methylguanine-DNAmethyl-transferase (MGMT) promoter methylation was notably higher in blood samples of patients with GC compared with non-tumor controls...
September 29, 2017: Oncotarget
https://www.readbyqxmd.com/read/29099956/recycling-drug-screen-repurposes-hydroxyurea-as-a-sensitizer-of-glioblastomas-to-temozolomide-targeting-de-novo-dna-synthesis-irrespective-of-molecular-subtype
#19
Jian Teng, Seyedali Hejazi, Lotte Hiddingh, Litia Carvalho, Mark de Gooijer, Hiroaki Wakimoto, Marco Barazas, Marie Tannous, Andrew S Chi, David P Noske, Pieter Wesseling, Thomas Wurdinger, Tracy T Batchelor, Bakhos A Tannous
Background: Glioblastoma (GBM) is the most common and most aggressive primary malignant brain tumor. Standard-of-care treatment involves maximal surgical resection of the tumor followed by radiation and chemotherapy (temozolomide; TMZ). The five-year survival rate of patients with GBM is <10%, a colossal failure that has been partially attributed to intrinsic and/or acquired resistance to TMZ through MGMT (O6-methylguanine DNA methyltransferase) promoter methylation status in the tumor...
November 1, 2017: Neuro-oncology
https://www.readbyqxmd.com/read/29039945/structural-consequences-of-1-4-cyclohexanedicarboxylate-cis-trans-isomerism-in-uranyl-ion-complexes-from-molecular-species-to-2d-and-3d-entangled-nets
#20
Pierre Thuéry, Jack Harrowfield
trans-1,4-Cyclohexanedicarboxylic acid (t-1,4-chdcH2) or the commercially available mixture of the cis and trans isomers (c,t-1,4-chdcH2) has been used in the synthesis of a series of 14 uranyl ion complexes, all obtained under solvohydrothermal conditions, some in the presence of additional metal cations and/or 2,2'-bipyridine (bipy). With its two isomeric forms having very different shapes and its great sensitivity to the experimental conditions, 1,4-chdc(2-) appears to be suitable for the synthesis of uranyl ion complexes displaying a wide range of architectures...
November 6, 2017: Inorganic Chemistry
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