University of Rennes

About: University of Rennes is a education organization based out in Rennes, France. It is known for research contribution in the topics: Population & Catalysis. The organization has 18404 authors who have published 40374 publications receiving 995327 citations.

Improved and General Manganese‐Catalyzed N‐Methylation of Aromatic Amines Using Methanol

Abstract: A novel lutidine-based manganese PNP-pincer complex has been synthesized for the selective N-methylation of aromatic amines with methanol. Using borrowing hydrogen methodology, a selection of differently functionalized aniline derivatives is selectively methylated in good yields.

C-reactive protein is an informative predictor of renal cell carcinoma-specific mortality: a European study of 313 patients.

Abstract: BACKGROUND. C-reactive protein (CRP) represents a promising prognostic variable in patients with sporadic renal cell carcinoma (RCC). It was hypothesized that CRP can improve the prognostic ability of standard RCC-specific mortality (RCC-SM) predictors in patients treated with nephrectomy for all stages of RCC. METHODS. Radical nephrectomy was performed in 314 patients from 2 European centers. Life table, Kaplan-Meier, and Cox regression analyses addressed RCC-SM. Covariates included age, gender, TNM stage, tumor size, Fuhrman grade, and histologic subtype. RESULTS. The median survival of the cohort was 19.9 years. Age ranged from 10 to 77 years. Most patients were male (69%). T-stages were distributed as follows: T1-121 (38.7%), T2-45 (14.4%), T3-140 (44.7%), T4-7 (2.2%). CRP values ranged from 1.0 to 358.0 mg/L (mean 40.9, median 11.0 mg/L). In multivariable analyses, CRP was an independent predictor of RCC-SM (P = .003). The consideration of CRP in the multivariable model increased the predictive accuracy by 3.7% (P < .001). Moreover, the model with CRP performed 2.4% and 4.6% better than the UCLA Integrated Staging System (UISS) at, respectively, 2 and 5 years. CONCLUSIONS. CRP represents an informative predictor of RCC-SM. Its routine use could allow better risk stratification and risk-adjusted follow-up of RCC patients. Cancer 2007. © 2007 American Cancer Society.

Drosophila S2 Cells Secrete Wingless on Exosome-Like Vesicles but the Wingless Gradient Forms Independently of Exosomes

Abstract: Wingless acts as a morphogen in Drosophila wing discs, where it specifies cell fates and controls growth several cell diameters away from its site of expression. Thus, despite being acylated and membrane associated, Wingless spreads in the extracellular space. Recent studies have focussed on identifying the route that Wingless follows in the secretory pathway and determining how it is packaged for release. We have found that, in medium conditioned by Wingless-expressing Drosophila S2 cells, Wingless is present on exosome-like vesicles and that this fraction activates signal transduction. Proteomic analysis shows that Wingless-containing exosome-like structures contain many Drosophila proteins that are homologous to mammalian exosome proteins. In addition, Evi, a multipass transmembrane protein, is also present on exosome-like vesicles. Using these exosome markers and a cell-based RNAi assay, we found that the small GTPase Rab11 contributes significantly to exosome production. This finding allows us to conclude from in vivo Rab11 knockdown experiments, that exosomes are unlikely to contribute to Wingless secretion and gradient formation in wing discs. Consistent with this conclusion, extracellularly tagged Evi expressed from a Bacterial Artificial Chromosome is not released from imaginal disc Wingless-expressing cells.