Search results for "HeLa"
showing 10 items of 738 documents
DOTAGA-anhydride: a valuable building block for the preparation of DOTA-like chelating agents.
2012
International audience; A DOTA derivative that contains an anhydride group was readily synthesized by reacting DOTAGA with acetic anhydride and its reactivity was investigated. Opening the anhydride with propylamine led to the selective formation of one of two possible regioisomers. The structure of the obtained isomer was unambiguously determined by 1D and 2D NMR experiments, including COSY, HMBC, and NOESY techniques. This bifunctional chelating agent offers a convenient and attractive approach for labeling biomolecules and, more generally, for the synthesis of a large range of DOTA derivatives. The scope of the reaction was extended to prepare DOTA-like compounds that contained various f…
A top-down synthesis route to ultrasmall multifunctional Gd-based Silica nanoparticles for theranostic applications
2013
International audience; New, ultrasmall nanoparticles with sizes below 5 nm have been obtained. These small rigid platforms (SRP) are composed of a polysiloxane matrix with DOTAGA (1,4,7,10-tetraazacyclododecane-1-glutaric anhydride-4,7,10-triacetic acid)-Gd3+ chelates on their surface. They have been synthesised by an original top-down process: 1) formation of a gadolinium oxide Gd2O3 core, 2) encapsulation in a polysiloxane shell grafted with DOTAGA ligands, 3) dissolution of the gadolinium oxide core due to chelation of Gd3+ by DOTAGA ligands and 4) polysiloxane fragmentation. These nanoparticles have been fully characterised using photon correlation spectroscopy (PCS), transmission elec…
Metal complexes of phenobarbituric acid. Chelating behavior of the phenobarbiturate ring. Anticonvulsant properties of the K2[Cu(N-methylphenobarbitu…
1992
Abstract Na2Ni(phenobarbiturato)4·3H2O, Na2Ni3(phenobarbiturato)2(OH)6·4H2O, and NaZn(phenobarbiturato)2(OH)·H2O derivatives were prepared from Ni(II) and Zn(II) and phenobarbital. The Na2Ni(phenobarbiturato)4·3H2O complex is diamagnetic and isostructural with the complex previously reported, Na2Cu(phenobarbiturato)4, suggesting a square-planar environment around the Ni(II) ion. The DMF solutions of this complex show the existence of two species. The EPR spectra of the Cu(II) doped complex show the hyperfine and superhyperfine structures. The covalence parameters α2, β2, and δ2 show a strong bonding in the equatorial plane and suggests the formation of a [CuN4] chromophore. The anticonvulsa…
Coordination Complexes of a Neutral 1,2,4-Benzotriazinyl Radical Ligand: Synthesis, Molecular and Electronic Structures, andMagnetic Properties
2015
A series of d-block metal complexes of the recently reported coordinating neutral radical ligand 1-phenyl-3-(pyrid-2-yl)-1,4-dihydro-1,2,4-benzotriazin-4-yl (1) was synthesized. The investigated systems contain the benzotriazinyl radical 1 coordinated to a divalent metal cation, MnII, FeII, CoII, or NiII, with 1,1,1,5,5,5-hexafluoroacetylacetonato (hfac) as the auxiliary ligand of choice. The synthesized complexes were fully characterized by single-crystal X-ray diffraction, magnetic susceptibility measurements, and electronic structure calculations. The complexes [Mn(1)(hfac)2] and [Fe(1)(hfac)2] displayed antiferromagnetic coupling between the unpaired electrons of the ligand and the meta…
Presence of Genital Spines in a Male Corynosoma cetaceum Johnston and Best, 1942 (Acanthocephala)
2002
We collected 83 females and 80 males of Corynosoma cetaceum from 2 common dolphins, Delphinus delphis, collected in northern Patagonia (Argentina). Worms were most similar to specimens collected in other South American localities. However, 1 male had 2 spines adjacent to the genital pore and isolated from the rest of body spines. This finding confirms the recent reassignment of C. cetaceum to Corynosoma. Absence of genital spines is suggested to be avoided as the sole criterion to exclude specimens from Corynosoma or Andracantha. Aznar Avendaño, Francisco Javier, Francisco.Aznar@uv.es ; Raga Esteve, Juan Antonio, Toni.Raga@uv.es
The nucleotide excision repair protein XPC is essential for bulky DNA adducts to promote interleukin-6 expression via the activation of p38-SAPK
2016
Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants, and many are potent carcinogens. Benzo[a]pyrene (B[a]P), one of the best-studied PAHs, is metabolized ultimately to the genotoxin anti-B[a]P-7,8-dihydrodiol-9,10-epoxide (BPDE). BPDE triggers stress responses linked to gene expression, cell death and survival. So far, the underlying mechanisms that initiate these signal transduction cascades are unknown. Here we show that BPDE-induced DNA damage is recognized by DNA damage sensor proteins to induce activation of the stress-activated protein kinase (SAPK) p38. Surprisingly, the classical DNA damage response, which involves the kinases ATM and ATR, is not involved in p38-SA…
An approach to the evaluation of the activity of the DNA repair enzyme O6-methylguanine-DNA-methyl-transferase in tumor tissue in vivo: syntheses of …
2002
Abstract The resistance of tumor cells to the cytostatic activity of methylating and chloroethylating anticancer drugs is determined by the level of expression of the DNA repair protein O 6 -methylguanine-DNA-methyl-transferase (MGMT). The synthesis of labelled 6-benzyloxy-9H-purin-2-ylamine derivatives should hence allow a quantification of the MGMT status of tumor and non-target tissue in vivo. 6-benzyloxy-9-(2-fluoroethyl)-9H-purin-2-yl-amine and 6-benzyloxy-7-(2-fluoroethyl)-7H-purin-2-yl-amine were synthesized and evaluated in vitro, both showing an affinity of 1.8 μM. 6-benzyloxy-9-(2-[ 18 F]fluoroethyl)-9H-purin-2-yl-amine and 6-benzyloxy-7-(2-[ 18 F]fluoroethyl)-7H-purin-2-yl-amine …
Fluorovinylsulfones and -Sulfonates as Potent Covalent Reversible Inhibitors of the Trypanosomal Cysteine Protease Rhodesain: Structure–Activity Rela…
2021
Rhodesain is a major cysteine protease of Trypanosoma brucei rhodesiense, a pathogen causing Human African Trypanosomiasis, and a validated drug target. Recently, we reported the development of α-halovinylsulfones as a new class of covalent reversible cysteine protease inhibitors. Here, α-fluorovinylsulfones/-sulfonates were optimized for rhodesain based on molecular modeling approaches. 2d, the most potent and selective inhibitor in the series, shows a single-digit nanomolar affinity and high selectivity toward mammalian cathepsins B and L. Enzymatic dilution assays and MS experiments indicate that 2d is a slow-tight binder (Ki = 3 nM). Furthermore, the nonfluorinated 2d-(H) shows favorabl…
Bone marrow cell transcripts from Fanconi anaemia patients revealin vivoalterations in mitochondrial, redox and DNA repair pathways
2013
Fanconi anaemia (FA) is a genetic cancer predisposition disorder associated with cytogenetic instability, bone marrow failure and a pleiotropic cellular phenotype, including low thresholds of responses to oxidative stress, cross-linking agents and selected cytokines. This study was aimed at defining the scope of abnormalities in gene expression using the publicly available FA Transcriptome Consortium (FTC) database (Gene Expression Omnibus, 2009 and publicly available as GSE16334). We evaluated the data set that included transcriptomal analyses on RNA obtained from low-density bone marrow cells (BMC) from 20 patients with FA and 11 healthy volunteers, by seeking to identify changes in expre…
''Effect of stroke on arginase expression and localization in the rat brain''
2013
Quirie, Aurore | Demougeot, C. Eline | Bertrand, Nathalie | Mossiat, Claude | Garnier, Philippe | Marie, Christine | Prigent-Tessier, Anne; International audience; ''Because arginase and nitric oxide (NO) synthases (NOS) compete to degrade l-arginine, arginase plays a crucial role in the modulation of NO production. Moreover, the arginase 1 isoform is a marker of M2 phenotype macrophages that play a key role in tissue remodeling and resolution of inflammation. While NO has been extensively investigated in ischemic stroke, the effect of stroke on the arginase pathway is unknown. The present study focuses on arginase expression/activity and localization before and after (1, 8, 15 and 30days) …