Publications by authors named "Arnaud O"

Introduction: Type 1 diabetes (T1D) is a chronic autoimmune disease, characterised by progressive destruction of the insulin-producing β cells of the pancreas. One immunosuppressive agent that has recently shown promise in the treatment of new-onset T1D subjects aged 12-45 years is antithymocyte globulin (ATG), Thymoglobuline, encouraging further exploration in lower age groups.

Methods And Analysis: Minimal effective low dose (MELD)-ATG is a phase 2, multicentre, randomised, double-blind, placebo-controlled, multiarm parallel-group trial in participants 5-25 years diagnosed with T1D within 3-9 weeks of planned treatment day 1.

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The development of complex methods in molecular biology is a laborious, costly, iterative and often intuition-bound process where optima are sought in a multidimensional parameter space through step-by-step optimizations. The difficulty of miniaturizing reactions under the microliter volumes usually handled in multiwell plates by robots, plus the cost of the experiments, limit the number of parameters and the dynamic ranges that can be explored. Nevertheless, because of non-linearities of the response of biochemical systems to their reagent concentrations, broad dynamic ranges are necessary.

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To activate or repress specific genes, chromatin is constantly modified by chromatin-remodeling complexes. Among these complexes, the SWItch/Sucrose Non-Fermenting (SWI/SNF) complex, also referred to as BRG1-Associated Factor (BAF) complex, moves the nucleosome along chromatin using energy provided by ATP hydrolysis. In mammalian organisms, the SWI/SNF complex is composed of 10-15 subunits, depending on cell type, and a defect in one of these subunits can have dramatic consequences.

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Transcripts in all eukaryotes are characterized by the 5'-end specific cap structure in mRNAs. Cap Analysis Gene Expression or CAGE makes use of these caps to specifically obtain cDNA fragments from the 5'-end of RNA and sequences those at high throughput for transcript identification and genome-wide mapping of transcription start sites for coding and noncoding genes. Here, we provide an improved version of our nanoCAGE protocol that has been developed for preparing CAGE libraries from as little as 50 ng of total RNA within three standard working days.

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In some recent studies, a view emerged that stochastic dynamics governing the switching of cells from one differentiation state to another could be characterized by a peak in gene expression variability at the point of fate commitment. We have tested this hypothesis at the single-cell level by analyzing primary chicken erythroid progenitors through their differentiation process and measuring the expression of selected genes at six sequential time-points after induction of differentiation. In contrast to population-based expression data, single-cell gene expression data revealed a high cell-to-cell variability, which was masked by averaging.

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Transcriptome studies based on quantitative sequencing can estimate levels of gene expression by measuring target RNA abundance in sequencing libraries. Sequencing costs are proportional to the total number of sequenced reads, and in order to cover rare RNAs, considerable quantities of abundant and identical reads are needed. This major limitation can be addressed by depleting a proportion of the most abundant sequences from the library.

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Background: Gene expression is an inherently stochastic process, owing to its dynamic molecular nature. Protein amount distributions, which can be acquired by cytometry using a reporter gene, can inform about the mechanisms of the underlying microscopic molecular system.

Results: By using different clones of chicken erythroid progenitor cells harboring different integration sites of a CMV-driven mCherry protein, we investigated the dynamical behavior of such distributions.

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Despite the stochastic noise that characterizes all cellular processes the cells are able to maintain and transmit to their daughter cells the stable level of gene expression. In order to better understand this phenomenon, we investigated the temporal dynamics of gene expression variation using a double reporter gene model. We compared cell clones with transgenes coding for highly stable mRNA and fluorescent proteins with clones expressing destabilized mRNA-s and proteins.

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Human P-glycoprotein (P-gp) controls drugs bioavailability by pumping structurally unrelated drugs out of cells. The X-ray structure of the mouse P-gp ortholog has been solved, with two SSS enantiomers or one RRR enantiomer of the selenohexapeptide inhibitor QZ59, found within the putative drug-binding pocket (Aller SG, Yu J, Ward A, Weng Y, Chittaboina S, Zhuo R, Harrell PM, Trinh YT, Zhang Q, Urbatsch IL et al. (2009).

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The ABCG2 multidrug transporter is known to confer cancer cell multidrug resistance by causing the efflux of anticancer drugs; therefore, selective inhibitors have the potential to improve chemotherapeutic treatments. Here, various methoxy derivatives of resveratrol are shown to be potent inhibitors of mitoxantrone efflux by ABCG2: among a series of 11 derivatives, compound 9 (3,5,3',4'-tetramethoxy trans-stilbene) had an IC(50) of 0.16 μM and showed a maximal inhibition of 75%, as measured by flow cytometry.

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This review describes the breast cancer resistance protein ABCG2 through its structure, functional roles and involvement in cell multidrug resistance, especially in cancer cells resistance to chemotherapeutics. The different types of known inhibitors are described, some being non-selective, since they also bind to other targets, and others being quite specific such as flavonoids. The different classes of active flavonoids and other polyphenols are described, some as plant natural compounds, but most of them being prepared and derivatized through medicinal chemistry.

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The breast cancer resistance protein ABCG2 confers cellular resistance to irinotecan (CPT-11) and its active metabolite SN-38. We utilised ABCG2-expressing xenografts as a model to evaluate the ability of a non-toxic ABCG2 inhibitor to increase intracellular drug accumulation. We assessed the activity of irinotecan in vivo in SCID mice: irinotecan completely inhibited the development of control pcDNA3.

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N(α)-Boc-l-Asp(OBn)-l-Lys(Z)-OtBu (reversin 121, 1), an inhibitor of the P-gp ABC transporter, was used to conceive compounds inhibiting the drug efflux occurring through the Hoechst 33342 and daunorubicin transport sites of P-gp, respectively H and R sites. Replacement of the aspartyl residue by trans-4-hydroxy-l-proline (4(R)Hyp) gave compounds 11 and 15 characterized by half-maximal inhibitory concentrations (IC(50)) of 0.6 and 0.

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ABCG2 is an ATP-binding cassette (ABC) transporter preferentially expressed by immature human hematopoietic progenitors. Due to its role in drug resistance, its expression has been correlated with a protection role against protoporhyrin IX (PPIX) accumulation in stem cells under hypoxic conditions. We show here that zinc mesoporphyrin, a validated fluorescent heme analog, is transported by ABCG2.

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ABCG2 is a human membrane ATP-binding cassette half-transporter that hydrolyzes ATP to efflux a large number of chemotherapeutic agents. Several oligomeric states of ABCG2 from homodimers to dodecamers have been reported depending on the overexpression systems and/or the protocols used for purification. Here, we compared the oligomeric state of His(6)-ABCG2 expressed in Sf9 insect cells and in human Flp-In-293/ABCG2 cells after solubilization in mild detergents.

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The isolation and characterisation of the largest genomic segment of infectious salmon anaemia virus (ISAV) is reported. Following identification of ISAV-specific clones from a cDNA library, a rapid amplification of cDNA ends-PCR strategy was designed to obtain the sequence of the full length mRNA transcript. The full length open reading frame (ORF) of this gene was shown to be 2169 nucleotides in length, encoding a putative protein of 722 aa.

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Clinical and neuroradiological findings of 8 patients with a spinal dural arteriovenous fistula are reviewed. Disturbance of micturition or defecation and weakness of the legs were always present and the most frequent initial symptom was a progressive spastic paraparesis. Duration of symptoms before diagnosis was 2 years.

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The effects of Benfluorex administration on glucose tolerance have been examined in young and old Sprague Dawley rats. The ageing rats were used as a model of insulin resistance. Chronic oral administration of Benfluorex decreased triglycerides levels and normalized glucose tolerance in ageing rats, independently of effects on body weight.

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The fenfluramine racemate belongs to a new therapeutic class of molecules acting on food intake, without psychostimulant or addictive potential. This molecule was extensively studied in the treatment of obesity and its action was better understood by studying the dextrogyre and levogyre enantiomers. New methods allowed to show that dexfenfluramine (the dextrogyre isomer) worked through a serotoninergic activity which was responsible for the effect on food intake and disorders of eating behavior.

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The authors present nine cases of giant aneurysm treated endovascularly by obliteration of the aneurysm lumen using platinum coils. Three aneurysms were located on the anterior circulation and six on the vertebrobasilar system. Presenting symptoms were mass effect in five cases and subarachnoid hemorrhage in four.

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