Emergence of New Concepts in Skin Physiopathology through the Use of in vitro Human Skin Explants Models

Background: This review summarizes uses and new applications for dermatological research of in vitro culture models of human skin explants (HSEs). In the last decade, many innovations have appeared in the literature and an exponential number of studies have been recorded in various fields of application such as process culture engineering, stem cell extractions methodology, or cell-to-cell interaction studies under physiological and pathological conditions, wound-healing, and inflammation. Most studies also concerned pharmacology, cosmetology, and photobiology. However, these topics will not be considered in our review. Summary: A better understanding of the mechanisms driving intercellular relationships, at work in the maintenance of 3D tissue architectures has led to the improvement of cell culture techniques. Many papers have focused on the physiological ways that govern in vitro tissue maintenance of HSEs. The analysis of the necessary mechanical stress, intercellular and cell-matrix interactions, allows the maintenance and prolonged use of HSEs in culture for up to 15 days, regardless of the great variability of study protocols from one laboratory to another and in accordance with the objectives set. Because of their close similarities to fresh skin, HSEs are increasingly used to study skin barrier repair and wound healing physiology. Easy to use in co-culture, this model allows a better understanding of the connections and interactions between the peripheral nervous system, the skin and the immune system. The development of the concept of an integrated neuro-immuno-cutaneous system at work in skin physiology and pathology highlighted by this article represents one of the new technical challenges in the field of in vitro culture of HSE. This review of the literature also reveals the importance of using such models in pathology. As sources of stem cells, HSEs are the basis for the development of new tissue engineering models such as organoids or optical clearing tissues technology. This study identifies the main advances and cross-cutting issues in the use of HSE

Dysmenorrhea among 12-year-old teenagers from different socioeconomic backgrounds

International audienceBackground: The age of menarche has been gradually declining since the end of the 20th century. Few studies have been carried out about dysmenorrhea in Europe and they mainly included girls over the age of 15 years.Methods: We conducted an observational study among sixth-grade schoolgirls (usually 11-12 years) during the 2020 academic year in 72 randomly selected public schools in a French region (approval number #20.94).Results: Among 1712 girls interviewed, 257 (23 %) had reached menarche. Overall, 83 % of these teenagers had dysmenorrhea. Symptoms were reported to occur since the first periods in 59 % of the girls. School absenteeism was positively correlated with severe abdominal pain (p = 0.001). Median age at menarche was 11 years (10.7-11.5). Periods lasted less than 3 days, 3-8 days, and more than 8 days in, respectively, 18 %, 70 %, and 7 % of the girls. Symptoms were significantly more frequent and more severe in the urban group than the rural group (p = 0.005). Symptoms were abdominal pain (70 %), fatigue (48 %), difficulty in concentrating (26 %), headache (25 %), digestive disorders (16 %), and breast discomfort (11 %). Of the girls with dysmenorrhea, 61 % took painkillers; 10 % were uncomfortable despite taking painkillers. Sport exemption was more frequent in the urban group (p = 0.003) and among girls with severe abdominal pain (p = 0.001).Conclusions: The duration of the menstrual cycle was similar between the various socioeconomic groups, but symptoms and ways of coping were significantly different. Dysmenorrhea is definitely an issue that has to be raised with teenagers as soon as menarche occurs or even before that. Easy access to skilled health practitioners should be widespread

Different fecal microbiota in Hirschsprung's patients with and without associated enterocolitis

International audienceBackground and Objectives. Patients with Hirschsprung's disease are at risk of developing Hirschsprung-associated enterocolitis, especially in the first 2 years of life. The pathophysiology of this inflammatory disease remains unclear, and intestinal dysbiosis has been proposed in the last decade. The primary objective of this study was to evaluate in a large cohort if Hirschsprung-associated enterocolitis was associated with alterations of fecal bacterial composition compared with HD without enterocolitis in different age groups. Methods. We analyzed the fecal microbiota structure of 103 Hirschsprung patients from 3 months to 16 years of age, all of whom had completed definitive surgery for rectosigmoid Hirschsprung. 16S rRNA gene sequencing allowed us to compare the microbiota composition between Hirschsprung's disease patients with (HAEC group) or without enterocolitis (HD group) in different age groups (0–2, 2–6, 6–12, and 12–16 years). Results. Richness and diversity increased with age group but did not differ between HD and HAEC patients, irrespective of the age group. Relative abundance of Actinobacteria was lower in HAEC than in HD patients under 2 years of age (−66%, P = 0.045). Multivariate analysis by linear models (MaAsLin) considering sex, medications, birth mode, breast-feeding, and the Bristol stool scale, as well as surgery parameters, highlighted Flavonifractor plautii and Eggerthella lenta , as well as Ruminococcus gnavus group, as positively associated with Hirschsprung-associated enterocolitis in the 0–2 years age group. Conclusion Hirschsprung-associated enterocolitis was associated with features of intestinal dysbiosis in infants (0–2 years) but not in older patients. This could explain the highest rate of enterocolitis in this age group