Potential of EPR spin-trapping to investigate in situ free radicals generation from skin allergens in reconstructed human epidermis: cumene hydroperoxide as proof of concept

The first step in the development of skin sensitisation to a chemical, and in the elicitation offurther allergic contact dermatitis (ACD), is the binding of the allergen to skin proteins after pene-trating into the epidermis. The so-formed antigenic adduct is then recognised by the immunesystem as foreign to the body. Sensitising organic hydroperoxides derived from autoxidation ofnatural terpenes are believed to form antigens through radical-mediated mechanisms, althoughthis has not yet been established. So far,in vitroinvestigations on reactive radical intermediatesderived from these skin sensitisers have been conducted in solution, yet with experimental condi-tions being far away from real-life sensitisation. Herein, we report for the first time, the potentialuse of EPR spin-trapping to study thein situgeneration of free radicals derived from cumenehydroperoxide CumOOH in a 3D reconstructed human epidermis (RHE) model, thus much closerto what may happenin vivo. Among the undesirable effects associated with dermal exposure toCumOOH, it is described to cause allergic and irritant dermatitis, being reported as a significantsensitiser. We considered exploiting the usage of spin-trap DEPMPO as an extensive view of allsort of radicals derived from CumOOH were observed all at once in solution. We showed that inthe EpiskinTMRHE model, both by incubating in the assay medium and by topical application,carbon radicals are mainly formed by redox reactions suggesting the key role of CumOOH-derived carbon radicals in the antigen formation process

Development and implementation of a highly-multiplexed SNP array for genetic mapping in maritime pine and comparative mapping with loblolly pine

<p>Abstract</p> <p>Background</p> <p>Single nucleotide polymorphisms (SNPs) are the most abundant source of genetic variation among individuals of a species. New genotyping technologies allow examining hundreds to thousands of SNPs in a single reaction for a wide range of applications such as genetic diversity analysis, linkage mapping, fine QTL mapping, association studies, marker-assisted or genome-wide selection. In this paper, we evaluated the potential of highly-multiplexed SNP genotyping for genetic mapping in maritime pine (<it>Pinus pinaster </it>Ait.), the main conifer used for commercial plantation in southwestern Europe.</p> <p>Results</p> <p>We designed a custom GoldenGate assay for 1,536 SNPs detected through the resequencing of gene fragments (707 <it>in vitro </it>SNPs/Indels) and from Sanger-derived Expressed Sequenced Tags assembled into a unigene set (829 <it>in silico </it>SNPs/Indels). Offspring from three-generation outbred (G2) and inbred (F2) pedigrees were genotyped. The success rate of the assay was 63.6% and 74.8% for <it>in silico </it>and <it>in vitro </it>SNPs, respectively. A genotyping error rate of 0.4% was further estimated from segregating data of SNPs belonging to the same gene. Overall, 394 SNPs were available for mapping. A total of 287 SNPs were integrated with previously mapped markers in the G2 parental maps, while 179 SNPs were localized on the map generated from the analysis of the F2 progeny. Based on 98 markers segregating in both pedigrees, we were able to generate a consensus map comprising 357 SNPs from 292 different loci. Finally, the analysis of sequence homology between mapped markers and their orthologs in a <it>Pinus taeda </it>linkage map, made it possible to align the 12 linkage groups of both species.</p> <p>Conclusions</p> <p>Our results show that the GoldenGate assay can be used successfully for high-throughput SNP genotyping in maritime pine, a conifer species that has a genome seven times the size of the human genome. This SNP-array will be extended thanks to recent sequencing effort using new generation sequencing technologies and will include SNPs from comparative orthologous sequences that were identified in the present study, providing a wider collection of anchor points for comparative genomics among the conifers.</p

In Situ Alkylation of Reconstructed Human Epidermis by Methyl Methanesulfonate: A Quantitative HRMAS NMR Chemical Reactivity Mapping

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Produits du tabac, produits connexes et arômes - Analyse des cas enregistrés par les centres antipoison (de janvier 2017 à décembre 2022): Rapport d’étude de toxicovigilance

Citation suggérée : Anses. 2023. Produits du tabac, produits connexes et arômes. Bilan des cas rapportés aux centres antipoison du 1er janvier 2017 au 31 décembre 2022. Autosaisine 2023-AUTO-0121. Anses, Maisons-Alfort, 37 p.Le marché des produits du tabac, des produits connexes (ne contenant pas de tabac mais de la nicotine), et des arômes pour les parfumer ne cesse de se diversifier. Parmi eux, cinq types font l’objet d’appels aux Centres antipoison (CAP) mais à ce jour, aucun bilan n’en avait été dressé. Il s’agit du tabac à chauffer (bâtonnets de tabac chauffés), du tabac à mâcher (encore appelé tabac à chiquer), du snus (sachets de tabac à usage oral, à placer entre la lèvre et la gencive), plus récemment des sachets de nicotine (sans tabac à usage oral, à placer également entre la lèvre et la gencive),et des billes aromatiques (à insérer dans le filtre de cigarettes).Le bilan de ces appels aux CAP entre le 1 er janvier 2017 et le 31 décembre 2022 a recensé 295 cas : 12 cas pour le tabac à chauffer, 98 pour le tabac à mâcher, 47 pour le snus et sachets de nicotine et 138 cas pour les billes aromatiques. Hormis pour le tabac à chauffer et à mâcher dont le nombre d’appels évoluait peu dans le temps, le nombre de cas n’a cessé d’augmenter depuis 2020 pour le snus, les sachets de nicotine et les billes aromatiques. L’étude a montré que les jeunes enfants étaient les plus concernés par des ingestions accidentelles de bâtonnets de tabac à chauffer et detabac à mâcher (âge médian : 1 an) ou de billes aromatiques (âge médian : 3 ans). Les adolescents étaient davantage concernés par une consommation intentionnelle de snus ou de sachets de nicotine (âge médian : 14 ans). Les adultes étaient plus rarement concernés par de ces deux types de produits ou par l’ingestion accidentelle de billes aromatiques au moment de leur utilisation dans des cigarettes. Dans 54,6 % des cas, les personnes présentaient des symptômes dont 82,6% étaient de gravité faible. Les cas de gravité moyenne correspondaient à un syndrome nicotinique plus sévère(vomissements prolongés avec risque de déshydratation, convulsions, troubles de la conscience, hypotension ayant nécessité un remplissage vasculaire), chez des enfants ayant ingéré accidentellement du tabac à chauffer (un enfant d’un an) et du tabac à mâcher (15 enfants de 6 mois à 7 ans), et chez dix adolescents ayant consommé du snus ou des sachets de nicotine dont huit d’entre eux en milieu scolaire. Concernant les billes aromatiques, après ingestion, un enfant de 3 ans avait présenté des symptômes de gravité moyenne (vomissements persistants). Quatorze cas correspondaient à des projections oculaires de gravité faible à l’origine de douleurs et de rougeurs oculaires.Le nombre des cas est probablement sous-estimé. Une attention particulière doit être portée aux sachets de nicotine qui n’entrent pas dans un cadre règlementaire spécifique en France, ni même harmonisé en Europe. Ces produits, par leurprésentation, peuvent être confondus avec du snus. La vente de ces deux types de produits est fortement promue sur les réseaux sociaux et s’adresse à une population jeune, sous-estimant les risques d’intoxication aiguë ou à moyen et long terme, de dépendance. Il est important de sensibiliser la communauté éducative, les professionnels de santé et l’entourage à ces risques liés à l’exposition à la nicotine

Patch testing with a new fragrance mix detects additional patients sensitive to perfumes and missed by the current fragrance mix

The currently used 8% fragrance mix (FM I) does not identify all patients with a positive history of adverse reactions to fragrances. A new FM II with 6 frequently used chemicals was evaluated in 1701 consecutive patients patch tested in 6 dermatological centres in Europe. FM II was tested in 3 concentrations - 28% FM II contained 5% hydroxyisohexyl 3-cyclohexene carboxaldehyde (Lyral((R))), 2% citral, 5% farnesol, 5% coumarin, 1% citronellol and 10%alpha-hexyl-cinnamic aldehyde; in 14% FM II, the single constituents' concentration was lowered to 50% and in 2.8% FM II to 10%. Each patient was classified regarding a history of adverse reactions to fragrances: certain, probable, questionable, none. Positive reactions to FM I occurred in 6.5% of the patients. Positive reactions to FM II were dose-dependent and increased from 1.3% (2.8% FM II), through 2.9% (14% FM II) to 4.1% (28% FM II). Reactions classified as doubtful or irritant varied considerably between the 6 centres, with a mean value of 7.2% for FM I and means ranging from 1.8% to 10.6% for FM II. 8.7% of the tested patients had a certain fragrance history. Of these, 25.2% were positive to FM I; reactivity to FM II was again dose-dependent and ranged from 8.1% to 17.6% in this subgroup. Comparing 2 groups of history - certain and none - values for sensitivity and specificity were calculated: sensitivity: FM I, 25.2%; 2.8% FM II, 8.1%; 14% FM II, 13.5%; 28% FM II, 17.6%; specificity: FM I, 96.5%; 2.8% FM II, 99.5%; 14% FM II, 98.8%; 28% FM II, 98.1%. 31/70 patients (44.3%) positive to 28% FM II were negative to FM I, with 14% FM II this proportion being 16/50 (32%). In the group of patients with a certain history, a total of 7 patients were found reacting to FM II only. Conversely, in the group of patients without any fragrance history, there were significantly more positive reactions to FM I than to any concentration of FM II. In conclusion, the new FM II detects additional patients sensitive to fragrances missed by FM I; the number of false-positive reactions is lower with FM II than with FM I. Considering sensitivity, specificity and the frequency of doubtful reactions, the medium concentration, 14% FM II, seems to be the most appropriate diagnostic screening tool