Prognostic factors of liver metastases from uveal melanoma

Objectives: This study was designed to assess survival and identify prognostic factors for liver metastases diagnosed by systematic screening in uveal melanoma patients. Methods: Among 602 consecutive patients treated over 10 years for uveal melanoma and followed by systematic semi-annual hepatic screening (abdominal ultrasonography), 63 (10.5%) developed liver metastases; these patients form the basis of this study. Factors including patient demographics, characteristics of the uveal tumor, metastasis-free interval, severity of liver metastatic involvement, and treatments of metastases were studied retrospectively regarding their prognostic value, using univariate (Kaplan-Meier method) and multivariate (Cox model) analyses. Results: Thirty-five patients (55.6% of the metastatic population) received systemic chemotherapy or best supportive care only; 14 patients (22.2% of the metastatic population) diagnosed with diffuse liver involvement had cytoreductive surgery and intra-arterial chemotherapy; 14 (22.2% of the metastatic population) had complete surgical removal of liver metastases followed by postoperative intra-arterial chemotherapy. No significant surgical complications were experienced. The median overall survival after diagnosis of liver metastases was 15 months. It reached 25 months for selected patients with complete resection (P=0.0002). In this cohort of 63 patients, ten or fewer preoperatively diagnosed metastases and primary uveal melanoma not involving the ciliary body were independently associated with better prognosis. Conclusions: This study suggests that selected patients with screened liver metastases from uveal melanoma may benefit from aggressive treatment, including surgery. The two independent favorable prognostic factors are fewer than ten metastases at screening and the absence of ciliary body involvemen

Complémentarité diffraction électronique et imagerie pour la résolution structurale d’oxydes et d’hydroxydes

International audienc

Low-dose electron diffraction tomography (LD-EDT)

International audienc

La tomographie en diffraction électronique en low-dose

International audienc

Étude de l'adhérence et de la formation des biofilms à staphylococcus epidermidis sur des implants intraoculaires de biomatériaux différents dans des conditions expérimentales dynamiques

Postoperative endophthalmitis remains a serious sight threatening complication of intraocular surgery. Staphylococcus epidermidis is currently recognized as an important etiological agent of endophthalmitis after cataract surgery. It is characterised by its ability to adhere to polymer surfaces such as intraocular lenses (IOLs). The binding of bacteria is the first step in IOL colonization. It is followed by bacterial accumulation in multilayered cell clusters embedded in an exopolysaccharide matrix leading to the formation of a confluent structured biofilm. Biofilm formation on polymer surfaces is a complex process that depends on bacterial cell surface characteristics, on the nature of the polymer material and on environmental factors. Numerous studies have tried to investigate the interactions between bacteria and different types of IOLs so as to determine which biomaterial would be more permissive to bacterial adherence. But large discrepancies were found between the data. Moreover, the lack of similarity between the selected experimental conditions and intraocular physiological ones made it difficult to extrapolate the in vitro results to the clinical situation. To overcome these problems, we designed an in vitro model that more closely resembled intraocular conditions. Our developed model allowed the study of Staphylococcus epidermidis biofilm formation (from the primary attachment phase to the biofilm maturation phase) on intraocular lenses. It also showed significant differences in bacterial adhesion among IOL materials. Adherence was weakest on the hydrophilic acrylic polymer and strongest on the silicone polymer, more hydrophobic. Bacterial adhesion and biofilm development on the implant surface must therefore depend on biomaterial characteristics particularly on its hydrophobic or hydrophilic natureLYON1-BU.Sciences (692662101) / SudocSudocFranceF

Endophtalmie post-chirurgie de la cataracte et implant intraoculaire (étude clinique et recherche fondamentale)

LYON1-BU Santé (693882101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Periodic mesoporous organosilica nanoparticles: Morphology control and sorption properties

International audienceThe synthesis of various periodic mesoporous organosilica nanoparticles (nanoPMOs) from the corresponding organo-bridged bis(triethoxy)silanes is described. A strong influence of the sodium hydroxide concentration is observed, leading to various sizes or morphologies depending on the precursor. In particular, in the case of the ethenylene linker, the morphology evolves from small flakes to elongated particles, while in the case of the phenylene precursor, small well-organized arms start to form at high base concentration. A mechanistic study shows that in all cases the nanoparticles nucleate before the condensation reaction commences and at very low conversions of the hydrolysis reaction of ethoxysilanes. The resulting hybrid nanoPMOs were compared for their adsorption properties towards rhodamine B (RB), which highlights large differences between the nanoPMOs with different linkers, and evidences a very strong affinity of the phenylene PMO with the poly-aromatic dye. Similarly, the sorption of cyclohexane and water revealed a much higher lipophilicity of the phenylene-bridged nanoPMO compared to the other studied linkers, despite a similar hydrophilicity. These results should help to better design nanoPMOs as nanovectors for drugs

Synthesis of high-quality garnet-type Gd3Sc2Al3O12:Ce3+ nanocrystals

SPIE OPTO 2018, San Francisco, California, United StatesInternational audienc

Low-Dose Electron Crystallography: Structure Solution and Refinement

International audienceThere is a wealth of materials that are beam sensitive and only exist in nanometric crystals, because the growth of bigger crystals is either impossible or so complicated that it is not reasonable to spend enough time and resources to grow big crystals before knowing their potential for research or applications. This difficulty is encountered in minerals, zeolites, metal-organic frameworks or molecular crystals, including pharmaceuticals and biological crystals. In order to study these crystals a structure determination method for beam sensitive crystals of nanometric size is needed. The nanometric size makes them destined for electron diffraction, since electrons interact much more strongly with matter than X-rays or neutrons. In addition, for the same amount of beam damage, electron diffraction yields more information than X-rays. The recently developed low-dose electron diffraction tomography (LD-EDT) not only combines the advantages inherent in electron diffraction, but is also optimized for minimizing the electron dose used for the data collection. The data quality is high, allowing not only the solution of complex unknown structures, but also their refinement taking into account the dynamical diffraction effects. Here we present several examples of crystals solved and refined by this method. The range of the crystals presented includes two synthetic oxides, Sr5CuGe9O24 and (Na2/3Mn1/3)3Ge5O12, a natural mineral (bulachite), and a metal organic framework (Mn-formiate). The dynamical refinement can be successfully performed on data sets that needed less than 0.1 e−/Å2 for the entire data set