keyword
MENU ▼
Read by QxMD icon Read
search

O6

keyword
https://www.readbyqxmd.com/read/28429715/mapping-clinicopathological-entities-within-colorectal-mucinous-adenocarcinomas-a-hierarchical-clustering-approach
#1
Charly Liddell, Laure Droy-Dupré, Sylvie Métairie, Fabrice Airaud, Christelle Volteau, Stéphane Bezieau, Christian L Laboisse, Jean-François Mosnier
The aim of this study was to interrogate the heterogeneity of colorectal mucinous adenocarcinomas. This study is based on hierarchical clustering approach combining clinicopathological and molecular patterns known to be relevant to oncogenesis and therapeutic management of patients with colorectal carcinoma, ie, microsatellite instability, O6-methylguanine-DNA methyltransferase (MGMT) status, KRAS, and BRAF mutations and wnt signaling pathway activation. Comparison of the study group of 60 mucinous adenocarcinomas defined according to World Health Organization classification with control group of 136 colorectal adenocarcinomas successively removed shows higher frequency of BRAF and KRAS mutations and microsatellite instability-high status and lower frequency of wnt signaling pathway activation in mucinous adenocarcinomas...
April 21, 2017: Modern Pathology: An Official Journal of the United States and Canadian Academy of Pathology, Inc
https://www.readbyqxmd.com/read/28427986/prognostic-implications-of-extent-of-resection-in-glioblastoma-analysis-from-a-large-database
#2
Daniel M Trifiletti, Clayton Alonso, Surbhi Grover, Camilo E Fadul, Jason P Sheehan, Timothy N Showalter
OBJECTIVE: To analyze the predictors for and clinical impact of gross total resection (GTR) in patients with glioblastoma (GBM). METHODS AND MATERIALS: The National Cancer Database was queried for patients with GBM diagnosed from 2004-2013 with known survival and extent of resection. Patients were grouped based on extent of resection into biopsy alone, subtotal resection (STR), and GTR. Univariable and multivariable (MVA) analyses were performed to investigate factors associated with the likelihood of GTR and overall survival (OS) following diagnosis...
April 17, 2017: World Neurosurgery
https://www.readbyqxmd.com/read/28427088/a-phase-2-study-of-temozolomide-in-pretreated-metastatic-colorectal-cancer-with-mgmt-promoter-methylation
#3
M A Calegari, A Inno, S Monterisi, A Orlandi, D Santini, M Basso, A Cassano, M Martini, T Cenci, I de Pascalis, F Camarda, B Barbaro, L M Larocca, S Gori, G Tonini, C Barone
BACKGROUND: Presently, few options are available for refractory colorectal cancer (CRC). O6-methyl-guanine-DNA-methyltransferase (MGMT) promoter methylation is a frequent and early event in CRC tumourigenesis. This epigenetic silencing is a predictor of response to the alkylating drug temozolomide in glioblastoma. Preclinical evidences and some case reports showed temozolomide activity in CRC with MGMT silencing, but the available data from clinical trials are inconsistent. METHODS: This was a multicentre, phase 2 trial, planned according to a two-stage Simon's optimal design to investigate activity and safety of temozolomide in refractory CRC harbouring MGMT promoter methylation...
April 20, 2017: British Journal of Cancer
https://www.readbyqxmd.com/read/28415741/enhancement-of-radiosensitivity-by-the-novel-anticancer-quinolone-derivative-vosaroxin-in-preclinical-glioblastoma-models
#4
Giovanni Luca Gravina, Andrea Mancini, Claudia Mattei, Flora Vitale, Francesco Marampon, Alessandro Colapietro, Giulia Rossi, Luca Ventura, Antonella Vetuschi, Ernesto Di Cesare, Judith A Fox, Claudio Festuccia
PURPOSE: Glioblastoma multiforme (GBM) is the most aggressive brain tumor. The activity of vosaroxin, a first-in-class anticancer quinolone derivative that intercalates DNA and inhibits topoisomerase II, was investigated in GBM preclinical models as a single agent and combined with radiotherapy (RT). RESULTS: Vosaroxin showed antitumor activity in clonogenic survival assays, with IC50 of 10-100 nM, and demonstrated radiosensitization. Combined treatments exhibited significantly higher γH2Ax levels compared with controls...
March 13, 2017: Oncotarget
https://www.readbyqxmd.com/read/28405827/mgmt-promoter-methylation-status-in-merkel-cell-carcinoma-in-vitro-versus-invivo
#5
Giuseppina Improta, Cathrin Ritter, Angela Pettinato, Valeria Vasta, David Schrama, Filippo Fraggetta, Jürgen C Becker
PURPOSE: Expression of O6-methylguanine-DNA methyltransferase (MGMT) in Merkel cell carcinoma (MCC) is very variable; thus, we tested whether this may be due to differential methylation of the MGMT gene promoter. METHODS: Quantitative analysis of MGMT mRNA and protein expression, as well as MGMT promoter methylation status, was performed in a series of tissue samples of MCC tumors, representing both primary and metastatic lesions, as well as in six MCC cell lines...
April 12, 2017: Journal of Cancer Research and Clinical Oncology
https://www.readbyqxmd.com/read/28395138/formation-of-s-2-n-6-deoxyadenosinyl-ethyl-glutathione-in-dna-and-replication-past-the-adduct-by-translesion-dna-polymerases
#6
Carl A Sedgeman, Yan Su, F Peter Guengerich
1,2-Dibromoethane (DBE, ethylene dibromide) is a potent carcinogen due at least in part to its DNA cross-linking effects. DBE cross-links glutathione (GSH) to DNA, notably to sites on 2'-deoxyadenosine and 2'-deoxyguanosine ( Cmarik , J. L. , et al. ( 1991 ) J. Biol. Chem. 267 , 6672 - 6679 ). Adduction at the N6 position of 2'-deoxyadenosine (dA) had not been detected, but this is a site for the linkage of O(6)-alkylguanine DNA alkyltransferase ( Chowdhury , G. , et al. ( 2013 ) Angew. Chem. Int. Ed. 52 , 12879 - 12882 )...
April 14, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/28389881/influence-of-incidental-radiation-dose-in-the-subventricular-zone-on-survival-in-patients-with-glioblastoma-multiforme-treated-with-surgery-radiotherapy-and-temozolomide
#7
P Foro Arnalot, O Pera, N Rodriguez, X Sanz, A Reig, I Membrive, A Ortiz, R Granados, M Algara
PURPOSE: To determine if there is an association between the incidental radiation dose to the subventricular zone and survival in patients with glioblastoma multiforme treated with surgery, radiotherapy and temozolomide. METHODS AND MATERIALS: Sixty-five patients, treated between 2006 and 2015, were included in this retrospective study. The doses (75th percentile; p75) administered to the ipsilateral, contralateral and bilateral subventricular zone were compared to overall survival and progression-free survival using Cox proportional hazards models...
April 7, 2017: Clinical & Translational Oncology
https://www.readbyqxmd.com/read/28367443/electrostatic-switch-function-in-the-mechanism-of-protein-kinase-a-i%C3%AE-activation-results-of-the-molecular-dynamics-simulation
#8
Olga N Rogacheva, Boris F Shchegolev, Elena A Vershinina, Alexander A Tokmakov, Vasiliy E Stefanov
We used molecular dynamics to find the average path of the A-domain H → B conformational transition in protein kinase A Iα. We obtained thirteen productive trajectories and processed them sequentially using factor and cross-correlation analyses. The conformational transition is presented as partly deterministic sequence of six events. Event B represents H → B transition of the phosphate binding cassette. Main participants of this event form electrostatic switch cAMP(O6)-A202(N-H)-G199(C=O). Through this switch, cAMP transmits information about its binding to hydrophobic switch L203-Y229 and thus triggers conformational transition of A-domain...
2017: BioMed Research International
https://www.readbyqxmd.com/read/28355483/gas-phase-conformations-and-n-glycosidic-bond-stabilities-of-sodium-cationized-2-deoxyguanosine-and-guanosine-sodium-cations-preferentially-bind-to-the-guanine-residue
#9
Y Zhu, L A Hamlow, C C He, J K Lee, J Gao, G Berden, J Oomens, M T Rodgers
2'-Deoxyguanosine (dGuo) and guanosine (Guo) are fundamental building blocks of DNA and RNA nucleic acids. In order to understand the effects of sodium cationization on the gas-phase conformations and stabilities of dGuo and Guo, infrared multiple photon dissociation (IRMPD) action spectroscopy experiments and complementary electronic structure calculations are performed. The measured IRMPD spectra of [dGuo+Na](+) and [Guo+Na](+) are compared to calculated IR spectra predicted for the stable low-energy structures computed for these species to determine the most favorable sodium cation binding sites, identify the structures populated in the experiments, and elucidate the influence of the 2'-hydroxyl substituent on the structures and IRMPD spectral features...
April 11, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28339723/leveraging-molecular-datasets-for-biomarker-based-clinical-trial-design-in-glioblastoma
#10
Shyam K Tanguturi, Lorenzo Trippa, Shakti H Ramkissoon, Kristine Pelton, David Knoff, David Sandak, Neal I Lindeman, Azra H Ligon, Rameen Beroukhim, Giovanni Parmigiani, Patrick Y Wen, Keith L Ligon, Brian M Alexander
Background.: Biomarkers can improve clinical trial efficiency, but designing and interpreting biomarker-driven trials require knowledge of relationships among biomarkers, clinical covariates, and endpoints. We investigated these relationships across genomic subgroups of glioblastoma (GBM) within our institution (DF/BWCC), validated results in The Cancer Genome Atlas (TCGA), and demonstrated potential impacts on clinical trial design and interpretation. Methods.: We identified genotyped patients at DF/BWCC, and clinical associations across 4 common GBM genomic biomarker groups were compared along with overall survival (OS), progression-free survival (PFS), and survival post-progression (SPP)...
February 20, 2017: Neuro-oncology
https://www.readbyqxmd.com/read/28338623/a-study-of-intramolecular-hydrogen-bonding-in-levoglucosan-derivatives
#11
Lucas Quiquempoix, Elena Bogdan, Neil J Wells, Jean-Yves Le Questel, Jérôme Graton, Bruno Linclau
Organofluorine is a weak hydrogen-bond (HB) acceptor. Bernet et al. have demonstrated its capability to perturb OH···O intramolecular hydrogen bonds (IMHBs), using conformationally rigid carbohydrate scaffolds including levoglucosan derivatives. These investigations are supplemented here by experimental and theoretical studies involving six new levoglucosan derivatives, and complement the findings of Bernet et al. However, it is shown that conformational analysis is instrumental in interpreting the experimental data, due to the occurrence of non-intramolecular hydrogen-bonded populations which, although minor, cannot be neglected and appears surprisingly significant...
March 24, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28328619/evaluation-of-o6-methylguanine-dna-methyltransferase-as-a-predicting-factor-of-response-to-temozolomide-based-chemotherapy-in-well-differentiated-metastatic-pancreatic-neuroendocrine-tumors
#12
Paul Girot, Clotilde Dumars, Jean-François Mosnier, Léa Muzellec, Hélène Senellart, Fanny Foubert, François-Xavier Caroli-Bosc, Estelle Cauchin, Nicolas Regenet, Tamara Matysiak-Budnik, Yann Touchefeu
OBJECTIVE: Temozolomide (TMZ) is an alkylating agent frequently used in well-differentiated metastatic pancreatic neuroendocrine tumors (PNETs) with very variable responses. O-methylguanine-DNA methyltransferase (MGMT) is a DNA repair enzyme whose loss of expression has been suggested to be predictive of response to TMZ in various human tumors. We evaluated the predictive value of MGMT status, assessed by immunohistochemistry (IHC) and methylation-specific PCR (MS-PCR), in well-differentiated metastatic PNETs treated by a TMZ-based chemotherapy...
March 21, 2017: European Journal of Gastroenterology & Hepatology
https://www.readbyqxmd.com/read/28322566/o6-corona-6-arenes-with-expanded-cavities-for-specific-complexation-with-c70
#13
Yao Lu, Zhan-Da Fu, Qing-Hui Guo, Mei-Xiang Wang
O6-Corona[3]arene[3]tetrazines with expanded cavities were synthesized by one-pot SNAr reaction between 3,6-dichlorotetrazine and aromatic diols. The macrocycle-to-macrocycle transformation involving IEDDA of tetrazine moieties with an enamine followed by denitrogenative aromatization afforded O6-corona[3]arene[3]pyridazines. O6-Corona[6]arenes adopted coronary conformations yielding hexagonal cavities of varied sizes. While O6-corona[3]arene[3]pyridazines complexed both C60 and C70 in a virtually nonselective manner, O6-corona[3]arene[3]tetrazines behaved as selective receptors to complex C70 with K1:1 values up to (3...
April 7, 2017: Organic Letters
https://www.readbyqxmd.com/read/28321994/detection-and-imaging-of-chrome-yellow-lead-chromate-in-latent-prints-solid-residues-and-minerals-by-laser-desorption-ionization-mass-spectrometry-ldi-ms
#14
Zhaoyu Zheng, Julius Pavlov, Athula B Attygalle
In the past, Chrome Yellow (lead chromate, PbCrO4 ), a bright orange-red substance, has been widely used as an inorganic pigment in the production of paints, coatings, and plastics. Herein, we demonstrate that laser desorption/ionization mass spectrometry (LDI-MS) is a powerful tool for the detection of lead chromate in solid residues. In fact, lead chromate in trace amounts is easily detectable by LDI-MS even from residues left as latent prints. For example, a latent print obtained by stamping the exposed laterally cut surface of a pencil over 50 years old on an acetonitrile-moistened paper, was successfully imaged for both lead and chromate using a Synapt G2 HDMS mass spectrometer...
March 21, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28316806/crystal-structure-of-the-solid-solution-ba8-35pb0-65-b3o6-6
#15
Wenwu Zhao
Single crystals of lead barium borate, Ba8.35Pb0.65(B3O6)6, octabarium lead(II) hexa-kis-(triborate), have been obtained by spontaneous nucleation from a high-temperature melt. Its three-dimensional structure is constructed on the basis of a BaO9 polyhedron, a (Pb/Ba)O6 octa-hedron (occupancy ratio Pb:Ba = 0.216:0.784) and a condensed B3O6 ring anion. In the crystal, the planar B3O6 anions are stacked in an alternating fashion with Ba and (Pb/Ba) atoms along [001]. A comparison is made with the structures of related solid solutions in the system Ba/Pb/B/O...
March 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/28316805/new-mixed-aluminium-chromium-diarsenate
#16
Mohamad Alem Bouhassine, Habib Boughzala
Potassium chromium aluminium diarsenate, KCr1/4Al3/4As2O7, was prepared by solid-state reaction. The structure consists of (Cr1/4/Al3/4)O6 octa-hedra and As2O7 diarsenate groups sharing corners to build up a three-dimensional anionic framework. The potassium cations are located in wide channels running along the c-axis direction. The crystal structure is isostructural with the triclinic A(I)M(III)X2O7 (A(I) = alkali metal; M(III) = Al, Cr, Fe; X = As, P) compounds. However, the M(III) octa-hedrally coordinated site is 25% partially occupied by chromium and 75% by aluminium...
March 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/28290677/molecular-insights-into-the-translesion-synthesis-of-benzyl-guanine-from-molecular-dynamics-simulations-structural-evidence-of-mutagenic-and-nonmutagenic-replication
#17
Katie A Wilson, Stacey D Wetmore
DNA can be damaged by many compounds in our environment, and the resulting damaged DNA is commonly replicated by translesion synthesis (TLS) polymerases. Because the mechanism and efficiency of TLS are affected by the type of DNA damage, obtaining information for a variety of DNA adducts is critical. However, there is no structural information for the insertion of a dNTP opposite an O6-dG adduct, which is a particularly harmful class of DNA lesions. We used molecular dynamics (MD) simulations to investigate structural and energetic parameters that dictate preferred dNTP insertion opposite O6-benzyl-guanine (Bz-dG) by DNA polymerase IV, a prototypical TLS polymerase...
March 24, 2017: Biochemistry
https://www.readbyqxmd.com/read/28284130/adsorption-of-cd-ii-and-pb-ii-by-in-situ-oxidized-fe3o4-membrane-grafted-on-316l-porous-stainless-steel-filter-tube-and-its-potential-application-for-drinking-water-treatment
#18
Mengfei Zhu, Li Zhu, Jianlong Wang, Tianli Yue, Ronghua Li, Zhonghong Li
Removing heavy metal ions from aqueous solutions is one of the most challenging separations. In situ oxidized Fe3O4 membranes using 316L porous stainless steel filter tube have shown great potential for removing anion Cr(VI). Here we report the performances of the in situ oxidized Fe3O4 membranes for removing two toxic cations Cd(II) and Pb(II) commonly existing in water and their potential applications for drinking water purification. The membranes exhibited high removal efficiency: 97% at pH 9.0 for Cd(II) of 1...
March 8, 2017: Journal of Environmental Management
https://www.readbyqxmd.com/read/28278076/adenovirus-based-strategies-enhance-antitumor-capability-through-p53-mediated-downregulation-of-mgmt-in-uveal-melanoma
#19
Xun Li, Ling Yuan, Jianfeng Zhao, Hui Yang, Yunzhi Yang, Yanfei Zhang, Biyun Cun
Uveal melanoma (UM) is an intractable disease with a low survival rates, despite adequate local treatment, as a result of its metastatic characteristics. Thus, new therapeutic strategies, including combinations of novel gene therapy and traditional chemotherapy, are under investigation to improve long-term prognosis. Dacarbazine or DTIC, an alkylating agent which results in DNA methylation, is most commonly used to treat melanoma but the response is very limited. The O6-methylguanine DNA methyl transferase (MGMT), a DNA repair protein, is involved in chemoresistance in DTIC treatment...
March 4, 2017: Cancer Biology & Therapy
https://www.readbyqxmd.com/read/28266716/the-prognostic-value-of-mgmt-promoter-methylation-in-glioblastoma-a-meta-analysis-of-clinical-trials
#20
Maryam Moradi, Afsane Bahrami, Soodabeh ShahidSales, Marjan Joodi, Mona Joudi Mashhad, Seyed Mahdi Hassanian, Kazem Anvari, Amir Avan
The DNA repair protein O6-Methylguanine-DNA methyltransferase (MGMT) is suggested to be associated with resistance to alkylating agents such as Temozolomide which is being used in treatment of patients with glioblastoma (GBM). Therefore we evaluated the associations between MGMT promoter methylation and prognosis of patients with glioblastoma (GBM). Data were extracted from publications in Embase, PubMed, and the Cochrane Library. Data on overall survival (OS), progression-free survival (PFS), and MGMT methylation status were obtained and 4097 subjects were enrolled...
March 7, 2017: Journal of Cellular Physiology
keyword
keyword
5502
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"