IgE Ratio in Tears: A Predictive Tool of Ocular Allergic Inflammation.

PURPOSE: To demonstrate the tear IgE (measured/exuded) ratio (R) as a useful biological marker of ocular allergy in order to distinguish severe from less severe inflammatory status. METHODS: Tear samples and sera from 78 ocular allergy patients and 19 control subjects were analyzed. Total IgE and albumin were measured for calculating the tear IgE-R defining two subgroups (SG) of samples: R ≥ 4-SG and R < 4-SG. Eosinophil cationic protein, Th1 and Th2 cytokines (IFN-γ, IL-4, -5, -6, -8 and -10) and protein electrophoretic profiles were also investigated in tears. RESULTS: The R < 4-SG compared to the R ≥ 4-SG shows higher levels of tear albumin, eosinophil cationic protein, and Th1 and Th2 cytokines. Moreover, each subgroup presents a specific protein profile. CONCLUSION: This study showed that an IgE-R lower than four must be carefully interpreted as a warning sign of a severe inflammatory context and should be also associated with an exploration of immunological profile.

Use of functionalized nanosilica to improve thermo-mechanical properties of epoxy adhesive joint bonding aluminium substrates.

The present work is concerned with the improvement of thermal properties and mechanical strength of adhesive joints consisting of an epoxy adhesive layer bonding aluminium substrates by grafted nanosilica. Epoxy resin/silica nanocomposites were prepared by using functionalized silica. Silica was functionalized by amine group (SiO2-NH2). It was identified by Raman and Fourier Transform Infrared (FTIR). Effects of silica on viscoelastic properties for epoxy resin and its assemblies with aluminium substrates were studied by Dynamical Mechanical Analysis (DMA). Particles distribution was characterized by Scanning Electron Microscope (SEM). Our experimental results showed that functionalized silica presents a better distribution in the matrix than the pure silica. Our results also showed that grafting of functionalized silica improves the glass transition temperature (Tg) and the ultimate strength of aluminium/epoxy/aluminium assembly.

[Measurement of total IgE in tears : the adaptation of an immunoenzyme technique and the value of investigating locally produced IgE in the diagnosis of chronic conjunctivitis]. / Dosage des IgE totales dans les larmes: adaptation d'une technique immuno-enzymatique et intéret de la recherce d'une syntheèse locale d'IgE dans l'exploration des conjonctivites chroniques.

The measurement of total IgE in tears could be useful to confirm the diagnosis of allergic conjunctivitis, particularly in chronic forms when the etiology is difficult to determine solely on clinical criteria and allergologic anamnesis. Since the level of IgE is normally very low in tears, the adaptation of a fluorescent enzyme immunoassay of total IgE (Unicap, Pharmacia-Upjohn) reduces the detection limit from 0.35 to 0.15 kU/l. Satisfactory results are obtained for accuracy, within-run precision (CV < 5%) and between-run precision (CV < or =11%). During allergic reactions, the local synthesis of IgE is evaluated by the ratio between the measured lacrimal IgE and the lacrimal IgE that have been filtered through the hemato-lacrimal barrier. The serum and tear albumin allows to quantify the permeability of the barrier and thus the amount of filtered tear IgE.