Standardization of an ash (Fraxinus excelsior) pollen allergen extract

BACKGROUND: Ash tree (Fraxinus excelsior) is the main representative of the Oleaceae family in temperate zones. Diagnosis of ash pollen allergy is made difficult due to (1) an overlapping pollinization period with Betulaceae, (2) non-inclusion in current diagnostic assays, and (3) some cross- reactivity with minor allergens from Betulaceae. The aim of this study was to calibrate an ash pollen in-house reference preparation (IHRP) in allergic patients in order to produce standardized products for diagnosis and immunotherapy purposes. METHODS: Ash pollen IHRP was extracted, ultrafiltered and freeze dried. Allergens in the extract were detected after 2-dimensional PAGE using specific sera and a monoclonal antibody. The Fra e 1 content of IHRP was evaluated by quantitative immunoprint. Forty-eight subjects from the North-East of France exhibiting clinical symptoms, a positive skin test and specific IgE levels > or =class 2 to ash pollen were recruited. IgE immunoprints were performed to select patients sensitized to the ash Fra e 1 allergen as opposed to cross-reacting allergens. Serial 10-fold dilutions of the IHRP were tested by skin prick tests in order to determine the concentration inducing a geometrical mean wheal diameter of 7 mm, said to correspond to an index of reactivity (IR) of 100 per millilitre. RESULTS: IgE-reactive molecules in IHRP comprise Fra e 1, Fra e 2, a 9-kDa molecule (presumably Fra e 3), as well as a doublet at 15 kDa and high molecular weight allergens. The 100 IR concentration of IHRP inducing a geometrical mean wheal diameter of 7 mm in 22 patients sensitized to Fra e 1 corresponds to the 1/126 (w/v) extraction ratio (i.e. 259 microg/ml of protein by Bradford) and contains 17 microg/ml of Fra e 1. The variability in total activity of 5 batches of standardized extracts was found to be significantly reduced when compared with 7 non-standardized extracts. CONCLUSION: An ash pollen IHRP was defined and molecularly characterized. Its successful standardization at 100 IR/ml in patients specifically sensitized to Fra e 1 allowed a skin reactivity-based calibration in properly diagnosed patients. Such a standardized ash pollen extract is a reliable tool to support immunotherapy of ash pollen allergy.     

Venous leg ulcer patients: a review of the literature on lifestyle and pain-related interventions

Background. Having a leg ulcer has a major impact on daily life. Lifestyle is mentioned in most leg ulcer guidelines but mostly without much emphasis on the subject. Aims and objectives. Evidence for the effect of nutrition, leg elevation and exercise on the healing of leg ulcers was reconsidered. Furthermore, the evidence for effective pain‐related interventions was investigated. Design. Systematic literature review. Methods. Medline, Cinahl, Psychinfo and Cochrane were searched for studies on pain related interventions, and the effectiveness of leg elevation, leg exercise and nutritional interventions in patients with venous leg ulceration. Results. Some evidence was found to support a positive effect of leg exercises on the endurance and power of the calf muscle and on the haemodynamic status of the limb. There is also evidence for a positive effect of leg elevation during bed rest without compression. No hard evidence was found concerning the effect of enriched or altered nutrition on wound healing. However, there is some evidence of nutritional deficits in this patient group. The use of eutectic mixture of local anaesthetic cream is effective for reducing pain in wound debridement, but pain relief in daily life is insufficiently treated. Conclusion. There is no real evidence of effectiveness of the investigated lifestyle interventions but there are indications that lifestyle interventions might contribute to healing or prevention of venous leg ulceration. Relevance to clinical practice. Although there is no hard evidence, it can be expected that interventions such as nutritional monitoring, guided exercise and leg elevation will have a substantial impact on wound healing in patients with venous leg ulceration. The use of eutectic mixture of local anaesthetic cream can be advised for pain relief with wound debridement. The current lack of effective pain treatment with venous leg ulceration emphasizes the need for effective pain treatment.     

Regulation of cell surface transferrin receptor-2 by iron-dependent cleavage and release of a soluble form

Transferrin receptor-2 is a transmembrane protein whose expression is restricted to hepatocytes and erythroid cells. Transferrin receptor-2 has a regulatory function in iron homeostasis, since its inactivation causes systemic iron overload. Hepatic transferrin receptor-2 participates in iron sensing and is involved in hepcidin activation, although the mechanism remains unclear. Erythroid transferrin receptor-2 associates with and stabilizes erythropoietin receptors on the erythroblast surface and is essential to control erythrocyte production in iron deficiency. We identified a soluble form of transferrin receptor-2 in the media of transfected cells and showed that cultured human erythroid cells release an endogenous soluble form. Soluble transferrin receptor-2 originates from a cleavage of the cell surface protein, which is inhibited by diferric transferrin in a dose-dependent manner. Accordingly, the shedding of the transferrin receptor-2 variant G679A, mutated in the Arginine-Glycine-Aspartic acid motif and unable to bind diferric transferrin, is not modulated by the ligand. This observation links the process of transferrin receptor-2 removal from the plasma membrane to iron homeostasis. Soluble transferrin receptor-2 does not affect the binding of erythropoietin to erythropoietin receptor or the consequent signaling and partially inhibits hepcidin promoter activation only in vitro. Whether it is a component of the signals released by erythropoiesis in iron deficiency remains to be investigated. Our results indicate that membrane transferrin receptor-2, a sensor of circulating iron, is released from the cell membrane in iron deficiency.     

Dual-scale TiO2 and SiO2 particles in combination with a fluoroalkylsilane and polydimethylsiloxane superhydrophobic/superoleophilic coating for efficient solvent–water separation

Surfaces that have unique wettabilities and are simultaneously superhydrophobic with water contact angles > 150°, and superoleophilic with oil contact angles < 5°, are of critical importance in the oil/solvent–water separation field. This work details the facile preparation of highly efficient oil–water separation devices that successfully combine hierarchical surface roughening particles and low surface energy components with porous substrates. Coatings were generated using TiO₂ and hydrophobic-SiO₂ micro/nanoparticle loadings which were then embedded within polydimethylsiloxane, commercially known as Sylgard® 184, and 1H,1H,2H,2H-perfluorooctyltriethoxysilane (FAS) polymer mixtures. The resulting slurries were dip coated onto copper meshes with varying pore diameters (30, 60 and 100 meshes had 595, 250 and 149 μm pore dimensions respectively). Functional testing proved that mesh substrates coated in the lowest Sylgard® 184 : FAS polymer ratio formulations displayed heightened water repellency and retained their superoleophilic properties upon repeat testing. The largest average water contact angle of 145 ± 1°, was recorded on a copper 30 mesh substrate with a coating comprising H-SiO₂ microparticles and TiO₂ nanoparticles in a 1 : 9 polymer mixture of Sylgard® and FAS. The coating''s extreme oil affinity was supported by high solvent–water separation efficiencies (≥99%) which withstood numerous testing/washing cycles.

Surfaces that have unique wettabilities and are simultaneously superhydrophobic with water contact angles > 150°, and superoleophilic with oil contact angles < 5°, are of critical importance in the oil/solvent–water separation field.     

Prospective, Multicenter, 3-Year Trial of Laparoscopic Adjustable Gastric Banding with the MIDBAND?

Background

Although laparoscopic adjustable gastric banding (LAGB) is a popular metabolic/bariatric procedure, few prospective studies have assessed its outcomes. This study aimed to prospectively assess LAGB safety and effectiveness outcomes using the MIDBAND? (MID, Dardilly, France).

Methods

Between May 2005 and September 2006, 262 morbidly obese patients underwent primary gastric banding with pars flaccida technique in 13 French medical centers. Excess weight loss and change in body mass index (BMI, kilogram per square meter), percentage of patients with comorbidities, and obesity-related complications were recorded. Patients were followed at 6-month intervals for 3?years. A multivariable individual growth model was used to analyze weight change over time and determine potential predictors of weight loss.

Results

The majority of patients were female (n?=?233, 89%), with mean age of 36.4?±?9.7?years. At 3?years, LAGB with MIDBAND resulted in significant decrease in mean BMI from 41.8?±?4.2 to 30.7?±?5.8 (p?p?Conclusion Prospective outcomes demonstrate the safety and efficacy of gastric banding over time using the MIDBAND. Individual growth modeling demonstrated that postoperative weight loss is strongly related to the frequency and consistency of follow-up visits.