Analogues of the epoxy resin monomer diglycidyl ether of bisphenol F: Effects on contact allergenic potency and cytotoxicity

Diglycidyl ethers of bisphenol A (DGEBA) and bisphenol F (DGEBF) are widely used as components in epoxy resin thermosetting products. They are known to cause occupational and non-occupational allergic contact dermatitis. The aim of this study is to investigate analogues of DGEBF with regard to contact allergy and cytotoxicity. A comprehensive knowledge of the structural features that contribute to the allergenic and cytotoxic effects of DGEBF will guide the development of future novel epoxy resin systems with reduced health hazards for those coming into contact with them. It was found that the allergenic effects of DGEBF were dependent on its terminal epoxide groups. In contrast, it was found that the cytotoxicity in monolayer cell culture was not only dependent on the presence of epoxide groups, but also on other structural features

Epoxy Resin Monomers with Reduced Skin Sensitizing Potency

Epoxy resin monomers (ERMs), especially diglycidyl ethers of bisphenol A and F (DGEBA and DGEBF), are extensively used as building blocks for thermosetting polymers. However, they are known to commonly cause skin allergy. This research describes a number of alternative ERMs, designed with the aim of reducing the skin sensitizing potency while maintaining the ability to form thermosetting polymers. The compounds were designed, synthesized, and assessed for sensitizing potency using the in vivo murine local lymph node assay (LLNA). All six epoxy resin monomers had decreased sensitizing potencies compared to those of DGEBA and DGEBF. With respect to the LLNA EC3 value, the best of the alternative monomers had a value approximately 2.5 times higher than those of DGEBA and DGEBF. The diepoxides were reacted with triethylenetetramine, and the polymers formed were tested for technical applicability using thermogravimetric analysis and differential scanning calorimetry. Four out of the six alternative ERMs gave polymers with a thermal stability comparable to that obtained with DGEBA and DGEBF. The use of improved epoxy resin monomers with less skin sensitizing effects is a direct way to tackle the problem of contact allergy to epoxy resin systems, particularly in occupational settings, resulting in a reduction in the incidence of allergic contact dermatitis

Chemical compounds and mechanisms involved in the formation and stabilization of foam in sparkling wines

The visual properties of sparkling wine including foam and bubbles are an indicator of sparkling wine quality. Foam properties, particularly foam height (FH) and foam stability (TS), are significantly influenced by the chemical composition of the wine. This review investigates our current knowledge of specific chemical compounds and, the mechanisms by which they influence the foam properties of sparkling wines. Grape and yeast proteins, amino acids, polysaccharides, phenolic compounds, organic acids, fatty acids, ethanol and sugar are examined with respect to their contribution to foam characteristics in sparkling wines made with the Traditional, Transfer, and Charmat and carbonation methods. Contradictory results have been identified that appear to be due to the analytical methods used to measure and quantify compounds and foam. Biopolymer complexes are discussed and absent knowledge with regards to thaumatin-like proteins (TLPs), polysaccharides, amino acids, oak-derived phenolic compounds and organic acids are identified. Future research is also likely to concentrate on visual analysis of sparkling wines by in-depth imaging analysis and specific sensory analysis techniques

Antiseptics and Disinfectants

Antiseptics and disinfectants (see definitions) share common skin side effects, i.e., irritation, allergic contact dermatitis, and eventually immunological contact urticaria. Some antiseptics fall into disuse, due to their lack of efficacy (dyes) or their strong allergic properties (mercurials), except thiomersal, the indications of which remain important. Current antiseptics (i.e., povidone-iodine or chlorhexidine) are of great importance, due to the emergence of MRSA and CA-MRSA, leading to a decrease in the use of topical antibiotics to which Gram-positive and Gram-negative bacteria are more and more resistant. Silver-based wound and burn dressings may lead to new cases of allergic contact dermatitis, mainly related to the incorporation of new antiseptics, such as octenidine or PHMB. Disinfectants are a common source of occupational irritant and/or allergic contact dermatitis. Aldehydes are widely used as disinfectants. Formaldehyde, glutaraldehyde, and glyoxal are responsible for many cases of allergic contact dermatitis. Quaternary ammonium compounds, and particularly benzalkonium chloride, are disinfectants provoking irritant and/or allergic contact dermatitis. The interpretation of patch tests is difficult, and the use of ROATs is advised