Relationships Linking Amplification Level to Gene Over-Expression in Gliomas

Background: Gene amplification is thought to promote over-expression of genes favouring tumour development. Because amplified regions are usually megabase-long, amplification often concerns numerous syntenic or non-syntenic genes, among which only a subset is over-expressed. The rationale for these differences remains poorly understood. Methodology/Principal Finding: To address this question, we used quantitative RT-PCR to determine the expression level of a series of co-amplified genes in five xenografted and one fresh human gliomas. These gliomas were chosen because we have previously characterised in detail the genetic content of their amplicons. In all the cases, the amplified sequences lie on extra-chromosomal DNA molecules, as commonly observed in gliomas. We show here that genes transcribed in nonamplified gliomas are over-expressed when amplified, roughly in proportion to their copy number, while non-expressed genes remain inactive. When specific antibodies were available, we also compared protein expression in amplified and nonamplified tumours. We found that protein accumulation barely correlates with the level of mRNA expression in some of these tumours. Conclusions/Significance: Here we show that the tissue-specific pattern of gene expression is maintained upon amplification in gliomas. Our study relies on a single type of tumour and a limited number of cases. However, it strongly suggests that, even when amplified, genes that are normally silent in a given cell type play no role in tumour progression

Les aspects réglementaires et organisationnels d'une banque de tumeur ou tumorothèque (application au Centre régional de lutte contre le cancer Alexis Vautrin)

NANCY1-SCD Pharmacie-Odontologie (543952101) / SudocNANCY1-Bib. numérique (543959902) / SudocSudocFranceF

Interindividual functional mapping: a nonlinear local approach.

International audienceWithin the scope of three-dimensional brain imaging, we propose an interindividual fusion scheme to register functional activations according to anatomical cortical structures, the sulci. This paper is based on the assumption that an important part of functional intersubject variability is encoded in anatomical variability. The aim of this paper is therefore to propose a generic framework to register functional activations according to the relevant anatomical landmarks. Compared to "classical" interindividual fusion schemes, this approach is local. It relies on a statistical sulci shape model accounting for the interindividual variability of a population of subjects and providing deformation modes relative to a reference shape (a mean sulcus). The deformation field obtained between a given sulcus and the reference sulcus is extended to a neighborhood of the given sulcus by using the thin-plate spline interpolation. It is then applied to functional activations located in the vicinity of this sulcus. This approach is compared with rigid and nonrigid registration methods. In this paper, we present results on MEG somatosensory data acquired on 18 subjects. We show that the nonlinear local fusion scheme significantly reduces the observed functional variability

A Local Approach for Inter-individual Functional Registration

Within the scope of three-dimensional brain imaging, we propose an inter-indiv- idual fusion scheme to register functional activations according to anatomical cortical structures, the sulci. This paper is based on the assumption that an important part of the functional inter-subject variability is encoded in the anatomical variability. Therefore, we aim in this paper at proposing a generic framework to register functional activations according to relevant anatomical landmarks. Compared to «classical» inter-individual fusion schemes, this approach is local. It relies on a statistical sulci shape model accounting for the inter-individual variability of a population of subjects, and providing deformation modes relatively to a reference shape (a mean sulcus). The deformation field obtained between a given sulcus and the reference sulcus is extended to a neighborhood of the given sulcus by using the thin-plate spline interpolation. It is then applied to functional activations located in the vicinity of this sulcus. This approach is compared with rigid and non rigid registration methods. We present in this paper results on MEG somatosensory data acquired on 18 subjects. We show that the non-linear local fusion scheme significantly reduces the functional variability after registration

Synthesis of S-nitrosoglutathione-alginate for prolonged delivery of nitric oxide in intestines

International audienceS-nitrosothiols are a class of NO-donors currently under investigation for the treatment of various diseases. In this study, we developed a novel NO-donor (S-nitrosoglutathione-alginate, SNA) by cross-linking alginate with S-nitrosothiols, which can deliver NO in a sustained manner. This compound can be further evaluated for oral delivery to treat Crohn’s disease. This new compound was prepared using a two-step procedure involving (I) linkage of reduced glutathione to alginate and (II) post-nitrosation with sodium nitrite (NaNO2). The amount of linked thiol moieties for the possible nitrosation was calculated using Ellman’s method, and the amount of NO abducted on the polymer was calculated using the Griess–Saville method. An ex vivo model (i.e. Ussing chamber) was used to investigate the permeation of this new NO-donor across the rat intestinal barrier. We obtained polymers with different numbers of abducted NOs (174 ± 21 μmol/g for SNA F1 and 468 ± 23 μmol/g for SNA F2) depending on the procedure used for nitrosation. In the ex vivo studies in the Ussing chamber, SNA F2 exhibited a sustained release for at least 10 h. The effect of pH on the stability of the new compound was also investigated, and the new compound was more stable at a mildly basic pH of 8.4 where 73% remained after 1 week. However, only 50% remained after 1 week at an acidic pH of 1.2. In the cytotoxicity studies (Caco2), this compound was nontoxic at concentrations of less than 200 μM

Melarsoprol-cyclodextrins inclusion complexes.

International audienceMelarsoprol, a water-insoluble drug, is mainly used in the treatment of trypanosomiasis and has demonstrated an in vitro activity on myeloid and lymphoid leukemia derived cell lines. It is marketed as a very poorly tolerated non-aqueous solution (Arsobal). The aim of our work was to develop melarsoprol-cyclodextrin complexes in order to improve the tolerability and the bioavailability of melarsoprol. Phase-solubility analysis showed A(L)-type diagrams with beta-cyclodextrin (betaCD), randomly methylated beta-cyclodextrin (RAMEbetaCD) and hydroxypropyl-beta-cyclodextrin (HPbetaCD), which suggested the formation of 1:1 inclusion complexes. The solubility enhancement factor of melarsoprol (solubility in 250 mM of cyclodextrin/solubility in water) was about 7.2x10(3) with both beta-cyclodextrin derivatives. The 1:1 stoichiometry was confirmed in the aqueous solutions by the UV spectrophotometer using Job's plot method. The apparent stability constants K(1:1), calculated from mole-ratio titration plots, were 57 143+/-4 425M(-1) for RAMEbetaCD and 50 761+/-5 070 M(-1) for HPbetaCD. Data from 1H-NMR and ROESY experiments provided a clear evidence of inclusion complexation of melarsoprol with its dithiaarsane extremity inserted into the wide rim of the cyclodextrin torus. Moreover, RAMEbetaCD had a pronounced effect on the drug hydrolysis and the dissolution rate of melarsoprol. However, the cytotoxic properties of melarsoprol on K562 and U937 human leukemia cell lines was not modified by complexation

Automatic Selection of Clinical Trials Based on A Semantic Web Approach

International audienceRecruitment of patients in clinical trials is nowadays preoccupying, as the inclusion rate is particularly low. The main identified factors are the multiplicity of open clinical trials, the high number and complexity of eligibility criteria, and the additional workload that a systematic search of the clinical trials a patient could be enrolled in for a physician. The principal objective of the ASTEC project is to automate the prescreening phase during multidisciplinary meetings (MDM). This paper presents the evaluation of a computerized recruitment support systems (CRSS) based on semantic web approach. The evaluation of the system was based on data collected retrospectively from a 6 month period of MDM in Urology and on 4 clinical trials of prostate cancer. The classification performance of the ASTEC system had a precision of 21%, recall of 93%, and an error rate equal to 37%. Missing data was the main issue encountered. The system was designed to be both scalable to other clinical domains and usable during MDM proces

Predicting hERG repolarization power at 37°C from recordings at room temperature

International audienceDear Editor, Loss-of-function and gain-of-function mutations in the KCNH2 gene cause long and short-QT syndromes (LQTS or SQTS), respectively, predisposing to life-threatening F I G U R E 1 Repolarization power of wild-type (WT) hERG as a function of temperature. A simplified and optimized action potential was applied (AP-clamp) by an automated patch clamp system in 384-well plates on HEK293 cells stably expressing hERG. (A) Mean (± SEM) current recordings during AP-clamp at various temperatures (in pA, n = 194, 211, 114 and 172 cells at 22-37 • C, respectively). Dashed line: AP time course (voltage scale: right Y axis). (B) Mean (± SEM) current recordings during AP-clamp at 27 • C for AP of various durations (see inset for APs; for currents: n = 168−254 for Time x 0.5 to x 5). The small inward current observed in (A) and (B), when the AP is returning to resting values, is attributed to contamination of the intracellular solution by the extracellular Tyrode solution, intrinsic to the cell catch process in the automated patch clamp (see supplementary information). (C) Mean (± SEM) time integral of the recorded currents: repolarization power, at various temperatures versus time factor (n = 155−232, 168−254, 79−133 and 144−173 at 22-37 • C, respectively). Horizontal dashed line: repolarization power at 37 • C: 22.3 pA.s. (D) As in (B), at 27 • C, after time and current corrections using various factors from 1.5 to 3 on the respective recordings. For example, for the recordings obtained during the AP of 2 x duration, the time was divided by 2 and the current multiplied by 2. Note the overlap of the current corrected by the factor of 2 at 27 • C (black) with the reference current obtained during the standard AP at 37 • C (red)

West Syndrome Is an Exceptional Presentation of Pyridoxine- and Pyridoxal Phosphate-Dependent Epilepsy: Data From a French Cohort and Review of the Literature

International audienceObjective: To characterize the electro-clinical presentation of patients with pyridoxine-dependent epilepsy (PDE) and pyridoxal phosphate (PLP)-dependent epilepsy in order to determine whether some of them could be diagnosed as de novo West syndrome, i. e., West syndrome that starts after the age of 2 months without other types of seizures (focal seizures for instance) before the onset of epileptic spasms. Methods: We analyzed data from an unpublished cohort of 28 genetically confirmed cases of PDE with antiquitine (ATQ) deficiency and performed a review of the literature looking for description of West syndrome in patients with either PDE with ATQ deficiency or PLP-dependent epilepsy with Pyridox(am)ine phosphate oxidase (PNPO) deficiency. Results: Of the 28 cases from the ATQ deficiency French cohort, 5 had spasms. In four cases, spasms were associated with other types of seizures (myoclonus, focal seizures). In the last case, seizures started on the day of birth. None of these cases corresponded to de novo West syndrome. The review of the literature found only one case of PNPO deficiency presenting as de novo West syndrome and no case of ATQ deficiency. Significance: The presentation of PDE- and PLP-dependent epilepsy as de novo West syndrome is so exceptional that it probably does not justify a systematic trial of pyridoxine or PLP. We propose considering a therapeutic trial with these vitamins in West syndrome if spasms are associated with other seizure types or start before the age of 2 months