G protein-coupled receptor 40 expression in human melanoma - correlation with tumour thickness, AJCC stage and survival.

BACKGROUND: In melanoma, preclinical data suggest a possible role of polyunsaturated fatty acids inhibiting cell growth. A new target molecule for free fatty acids, the G protein-coupled receptor GPR40, was identified in melanoma cells. OBJECTIVES: The aim of this study was to investigate GPR40 expression in human melanocytic tissues and to evaluate its potential as a prognostic marker. METHODS AND RESULTS: A total of 114 tissue sections of naevi, primary melanoma and melanoma metastasis were immunohistochemically stained with anti-GPR40. The staining was evaluated, using the immunoreactivity scoring system. Compared to naevi, primary melanoma and melanoma metastasis showed significantly higher levels of GPR40 (P < 0.05). In primary melanoma, GPR40 expression positively correlated with tumour thickness (P = 0.044) and AJCC level (P = 0.017) and in melanoma metastasis with AJCC level (P = 0.035). Primary melanoma patients with high levels of GPR40 had a significantly poorer overall survival (P = 0.004) and shorter disease-free survival (0.040). CONCLUSION: The present study identified GPR40 as a novel target molecule in melanoma. First evidence for a potential role of the receptor in tumour progression and metastases was found, and it could be demonstrated that GPR40 expression is negatively correlated with patient's survival.

Polarization mechanisms of dielectric materials at a binary liquid interface: impacts on electrowetting actuation.

We explored polarization mechanisms at the interface between a dielectric material (an electrolyte) and an insulating liquid, during electrowetting actuation. Native surface charge density due to hydrophobic coating has been measured as an offset voltage for which the contact angle is at its minimum. Surface charge densities as low as 0.023 mC m-2 have been measured using this method, demonstrating that electrowetting can be used as a probe to measure native surface charge density. This effect strongly differs depending on the kind of polarization and is at the origin of major discrepancies between alternative and direct polarization during electrowetting actuation. A new model describing electrowetting actuation is also proposed, leading to a more predictive description as well as useful recommendations on materials to obtain a stable actuation under DC polarization.

Nanoscale flow on a bubble mattress: effect of surface elasticity.

We present an experimental study of the elastic properties of a superhydrophobic surface in the Cassie regime, due to the gas bubbles trapped at the liquid-solid interface. We use a surface force apparatus to measure the force response to an oscillating drainage flow between a sphere and the surface. We show that the force response allows to determine the surface elasticity without contact, using the liquid film as a probe. The elasticity of the bubble mattress is dominated by the meniscii stiffness, and its determination enables us to probe the shape of these meniscii. Another effect of surface elasticity is to decrease the viscous friction. We show that this effect can be wrongly attributed to rate dependant boundary slippage if elastohydrodynamics is not taken into account.

Electrophoresis PDMS/glass chips with continuous on-chip derivatization and analysis of amino acids using naphthalene-2,3-dicarboxaldehyde as fluorogenic agent.

In this work, we developed a PDMS electrophoresis device able to carry out on-chip derivatization and quantification of amino acids (AAs) using naphthalene-2,3-dicarboxaldehyde (NDA) as a fluorogenic agent. A chemical modification of the PDMS surface was found compulsory to achieve the derivatization of AAs with NDA and a limit of detection (LOD) of 40nM was reached for glycine. Finally, we suggested the applicability of this microdevice for the analysis of real biological samples such as a rat hippocampus microdialysate.

[The gracilis muscle as musculocutaneous flap. Evaluation of 20 cases]. / Le lambeau musculo-cutané de droit interne. Bilan de 20 cas.

The use of gracilis as muscular or myocutaneous flap is very well-known. The authors report 20 cases of gracilis flap including 13 reconstructions of the vaginal cavity following extended abdomino-perineal resection. Some technical points concerning the localization of the cutaneous part of the flap and the pedicle dissection are discussed. The use of gracilis flap is still limited in surgical teams following extended abdomino-perineal resection, nevertheless it is a very useful flap because of its low morbidity, the shortening of patient hospitalization and the very satisfying aesthetic result of the neo-vaginal cavity.