50 research outputs found
New protective coatings against lampenflora growing in the Pommery Champagne cellar
Phototrophic microorganisms such as cyanobacteria and microalgae can proliferate readily in underground heritage sites where the introduction of artificial illumination equipment has significantly altered previously stable environmental conditions. The extended lampenflora biofilm growth on the bas-reliefs carved in the underground Pommery Champagne cellar in Reims (France) represents a recurring biocolonisation problem which requires periodic cleaning. The aim of this work was to limit the growth of lampenflora on chalk substrates using preventative biocidal treatments based on polyoxometalate ionic liquids (POM-ILs). Biocidal assays carried out in laboratory showed how two different colourless POM-IL coatings were more effective than commercial Preventol RI80 against two algal strains isolated from the Pommery bas reliefs, Pseudostichococcus monallantoides and Chromochloris zofingiensis. However, only one POM-IL variant was capable of sustained prevention of biofilm growth when applied to wet chalk, which replicates the more drastic natural environmental conditions of the cellar and can limit the performance of the biocidal coatings. Crucially, coating concentration studies demonstrate how POM-IL-coated slabs from previous experiments retain their biocidal activity and can prevent subsequent recolonisation following the re-inoculation of coated slabs with algae and cyanobacteria. Consequently, POM-ILs represent excellent candidates to eliminate lampenflora growth on the chalk bas-reliefs in the unique subterranean environment of the Pommery Champagne cellar. © 2022 The Author
Cellular Adhesion Gene SELP Is Associated with Rheumatoid Arthritis and Displays Differential Allelic Expression.
In rheumatoid arthritis (RA), a key event is infiltration of inflammatory immune cells into the synovial lining, possibly aggravated by dysregulation of cellular adhesion molecules. Therefore, single nucleotide polymorphisms of 14 genes involved in cellular adhesion processes (CAST, ITGA4, ITGB1, ITGB2, PECAM1, PTEN, PTPN11, PTPRC, PXN, SELE, SELP, SRC, TYK2, and VCAM1) were analyzed for association with RA. Association analysis was performed consecutively in three European RA family sample groups (Nfamilies = 407). Additionally, we investigated differential allelic expression, a possible functional consequence of genetic variants. SELP (selectin P, CD62P) SNP-allele rs6136-T was associated with risk for RA in two RA family sample groups as well as in global analysis of all three groups (ptotal = 0.003). This allele was also expressed preferentially (p<10-6) with a two- fold average increase in regulated samples. Differential expression is supported by data from Genevar MuTHER (p1 = 0.004; p2 = 0.0177). Evidence for influence of rs6136 on transcription factor binding was also found in silico and in public datasets reporting in vitro data. In summary, we found SELP rs6136-T to be associated with RA and with increased expression of SELP mRNA. SELP is located on the surface of endothelial cells and crucial for recruitment, adhesion, and migration of inflammatory cells into the joint. Genetically determined increased SELP expression levels might thus be a novel additional risk factor for RA
Brazing techniques for the fabrication of biocompatible carbon-based electronic devices
Deformulation of metalworking lubricants: Organic phosphorus additives characterization by H, C and P NMR
The analysis of two phosphate ester additives found in the formulation of metalworking fluids is reported. These are isopropylated triarylphosphates which are used as extreme pressure additives and polyethoxylated phosphates with emulgating properties. The additives are first analyzed as raw materials; then within a typical lubricant where they are identified and quantified. The methodology makes use of chromatography (TLC, HPLC, SPE) and NMR spectroscopy (H, C, P). The valuable contribution of P NMR to the deformulation of such products is particularly emphasized
Lack of association between signaling lymphocytic activation molecule family member 1 gene and rheumatoid arthritis in the French and Tunisian populations
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Electron spin resonance detection of oxygen radicals released by UVA-irradiated human fibroblasts
This work reports the electron spin resonance (ESR) detection of oxygenated radicals (OR) released by cultured human fibroblasts after UVA (365 nm) exposure.
5,5-dimethyl-pyrroline-N-oxide (DMPO) was used as spin trap. After a UVA irradiation of one hour, followed by a latent period of at least 45 min., and an incubation time of 30 min. in a trapping
medium containing DMPO, glucose, Na+, K+ and Ca2+ an ESR signal was recorded. By contrast, an ESR signal was produced after only 15 min. incubation when calcium ionophore A23187 was
used. Although the ESR signal was characteristic of the hydroxyl adduct DMPO-OH, the use of catalase and superoxide dismutase (SOD) revealed that UVA stimulated fibroblasts released the
superoxide anion O in the medium. SOD, vitamin C and (+)-catechin inhibited the release of superoxide generated by human fibroblasts stimulated with A23187 calcium ionophore at 5 units/ml,
10-5 M and M, respectively
A family-based study shows no association between rheumatoid arthritis and the PADI4 gene in a French caucasian population
Background: Autoantibodies to citrullinated proteins (ACPA) are considered a specific marker for
rheumatoid arthritis. Peptidylarginine deiminase (PAD) is the enzyme that converts arginyl into citrullyl
residues; different isoforms of the enzyme are expressed in mammals. It has been suggested that the PADI4
gene may contribute to genetic susceptibility to rheumatoid arthritis, but conflicting results have been
obtained in different populations.
Objective: To test the hypothesis that the PADI4 gene may confer susceptibility to rheumatoid arthritis in a
white French population, using powerful and highly reliable family based association tests.
Methods: DNA samples were analysed from 100 families where one member was affected by rheumatoid
arthritis and both parents were available for sampling. Five single nucleotide polymorphisms, located
within the PADI4 gene and in its close proximity, were genotyped by restriction fragment length
polymorphism, and haplotypes were constructed. The analysis involved use of the transmission
disequilibrium test and genotype relative risk. ACPA were detected by ELISA on cyclic citrullinated
peptides and on human deiminated fibrinogen.
Results: No single SNP or haplotype was associated with the disease, or was preferentially transmitted. No
association was found when patients were partitioned according to ACPA positivity.
Conclusions: No PADI4 haplotype is associated with rheumatoid arthritis in a white French population.
The role of genes encoding the other PAD isoforms, or modulating tissue expression or enzyme activity,
remains to be elucidated
Cenerimod, a selective S1P receptor modulator, improves organ-specific disease outcomes in animal models of Sjögren's syndrome.
BACKGROUND
Sjögren's syndrome is a systemic autoimmune disease characterized by immune cells predominantly infiltrating the exocrine glands and frequently forming ectopic lymphoid structures. These structures drive a local functional immune response culminating in autoantibody production and tissue damage, associated with severe dryness of mucosal surfaces and salivary gland hypofunction. Cenerimod, a potent, selective and orally active sphingosine-1-phosphate receptor 1 modulator, inhibits the egress of lymphocytes into the circulation. Based on the mechanism of action of cenerimod, its efficacy was evaluated in two mouse models of Sjögren's syndrome.
METHODS
Cenerimod was administered in two established models of Sjögren's syndrome; firstly, in an inducible acute viral sialadenitis model in C57BL/6 mice, and, secondly, in the spontaneous chronic sialadenitis MRL/lpr mouse model. The effects of cenerimod treatment were then evaluated by flow cytometry, immunohistochemistry, histopathology and immunoassays. Comparisons between groups were made using a Mann-Whitney test.
RESULTS
In the viral sialadenitis model, cenerimod treatment reduced salivary gland immune infiltrates, leading to the disaggregation of ectopic lymphoid structures, reduced salivary gland inflammation and preserved organ function. In the MRL/lpr mouse model, cenerimod treatment decreased salivary gland inflammation and reduced T cells and proliferating plasma cells within salivary gland ectopic lymphoid structures, resulting in diminished disease-relevant autoantibodies within the salivary glands.
CONCLUSIONS
Taken together, these results suggest that cenerimod can reduce the overall autoimmune response and improve clinical parameters in the salivary glands in models of Sjögren's syndrome and consequently may reduce histological and clinical parameters associated with the disease in patients