Coopération ou résistances : qu'apprend-on quand on s'engage comme bénévole dans le monde associatif ?

International audienceAssociations are important places for volunteers with regard to their sociability and to the acquisition of knowledge and skills other than relational ones. One could imagine, given the egalitarian ethos of associations, that cooperative processes should be given a pivotal status. What does one learn in the confrontation with other volunteers? How can we define participation in associations, and how does participating allow taking responsibilities? What are the other factors that determine access to responsibilities?Based on data collected through a participatory approach involving volunteers and employees of associations, we will show how women and young people who wish to get involved in associations sometimes encounter resistance. Facilitators of their involvement will also be explored.Les associations sont pour les bénévoles des lieux importants de sociabilité et d'acquisition de savoirs et de savoir-faire autres que relationnels. On pourrait imaginer, vu l'éthos égalitaire du monde associatif, que les processus coopératifs y tiennent une place centrale. Qu'apprend-on dans la confrontation avec les autres bénévoles ? Qu'est-ce que la participation dans l'association, et comment permet-elle de prendre des responsabilités ? Quels autres facteurs déterminent l'accès à ces dernières ? À partir des données recueillies grâce à une démarche participative impliquant des bénévoles et des salariés du monde associatif, nous montrons comment femmes et jeunes qui souhaitent s'impliquer dans les associations se confrontent parfois à des résistances. Les facilitateurs de leur implication sont également explorés. Mots-clefs

La relation entre l'insomnie, le fonctionnement immunitaire et l'occurrence d'infections chez des patients atteints de cancer

La présente thèse visait à évaluer la relation entre l’insomnie, le fonctionnement immunitaire et l’occurrence d’épisodes infectieux chez des patients atteints de cancer. Dans la première étude, le but consistait à évaluer la relation entre l’insomnie et l’occurrence d’épisodes infectieux chez près de 1000 patients atteints de divers types de cancer ayant participé à une étude épidémiologique plus large réalisée par notre équipe de recherche. Dans cette étude, les patients ont complété des mesures lors de la période péri-opératoire ainsi que 2, 6, 10, 14 et 18 mois plus tard. Les résultats ont indiqué que les patients souffrant d’un syndrome d’insomnie avaient un risque accru de développer un épisode d’infection au temps de mesure subséquent, comparativement aux bons dormeurs. Ce risque était également plus élevé, quoique de moindre importance, chez des patients rapportant des symptômes d’insomnie, comparativement aux bons dormeurs. Une fois l’anxiété et la dépression incluses comme covariables dans le modèle statistique, seule la présence d’un syndrome d’insomnie demeurait significativement associée à l’accroissement du risque infectieux. Quant à la deuxième étude, menée chez des patientes traitées en chimiothérapie pour un cancer du sein ou gynécologique, son but était de documenter l’évolution du sommeil avant, pendant et après des traitements de chimiothérapie, et d’évaluer la relation entre l’insomnie, le fonctionnement immunitaire et l’occurrence d’épisodes infectieux. Pour ce faire, un échantillon de 52 patientes a été recruté. Celles-ci ont complété des mesures avant l’initiation des traitements de chimiothérapie, à 4 moments en cours de traitement (phases d’immunosuppression et de récupération pour les deux premiers cycles de chimiothérapie), après la fin des traitements et lors de deux suivis 3 et 6 mois plus tard. Les résultats ont indiqué que l’ensemble des participantes, sans égard à leur statut d’insomnie au niveau de base, présentaient un accroissement des difficultés de sommeil pendant la chimiothérapie, suivi d’un retour progressif vers la qualité de sommeil initiale suite à la fin des traitements. Concernant la relation entre l’insomnie, le fonctionnement immunitaire et l’occurrence d’infections, il est ressorti que les patientes souffrant d’un syndrome d’insomnie au niveau de base présentaient significativement plus d’altérations immunitaires que les deux autres groupes à différents moments, notamment lors de la période suivant la fin des traitements. Les résultats ont également suggéré que les participantes ayant un syndrome d’insomnie au niveau de base étaient plus à risque de rapporter des symptômes infectieux en cours de chimiothérapie. Les résultats de la présente thèse suggèrent ainsi que le fait de souffrir de difficultés de sommeil, en particulier d’un syndrome d’insomnie, caractérisé par des difficultés plus sévères et plus persistantes, pourrait accroître le risque de vivre des altérations immunitaires et de rapporter des infections pendant la trajectoire de soins oncologiques. Bien que ces résultats nécessitent d’être répliqués, ils témoignent de la nécessité de détecter et traiter les difficultés de sommeil chez les patients atteints de cancer, considérant l’impact éventuel de ces dernières sur leur qualité de vie et leur santé

A nanoparticle ink allowing the high precision visualization of tissue engineered scaffolds by MRI

Hydrogels are widely used as cell scaffolds in several biomedical applications. Once implanted in vivo, cell scaffolds must often be visualized, and monitored overtime. However, cell scaffolds appear poorly contrasted in most biomedical imaging modalities such as magnetic resonance imaging (MRI). MRI is the imaging technique of choice for high-resolution visualization of low-density, water-rich tissues. Attempts to enhance hydrogel contrast in MRI are performed with “negative” contrast agents that produce several image artifacts impeding the delineation of the implant’s contours. In this study, a magnetic ink based on ultra-small iron oxide nanoparticles (USPIONs; <5 nm diameter cores) is developed and integrated into biocompatible alginate hydrogel used in cell scaffolding applications. Relaxometric properties of the magnetic hydrogel are measured, as well as biocompatibility and MR-visibility (T1-weighted mode; in vitro and in vivo). A 2-week MR follow-up study is performed in the mouse model, demonstrating no image artifacts, and the retention of “positive” contrast overtime, which allows very precise delineation of tissue grafts with MRI. Finally, a 3D-contouring procedure developed to facilitate graft delineation and geometrical conformity assessment is applied on an inverted template alginate pore network. This proof-of-concept establishes the possibility to reveal precisely engineered hydrogel structures using this USPIONs ink high-visibility approach

In silico Hierarchical Clustering of Neuronal Populations in the Rat Ventral Tegmental Area Based on Extracellular Electrophysiological Properties.

The ventral tegmental area (VTA) is a heterogeneous brain region, containing different neuronal populations. During recordings, electrophysiological characteristics are classically used to distinguish the different populations. However, the VTA is also considered as a region harboring neurons with heterogeneous properties. In the present study, we aimed to classify VTA neurons using approaches, in an attempt to determine if homogeneous populations could be extracted. Thus, we recorded 291 VTA neurons during extracellular recordings in anesthetized rats. Initially, 22 neurons with high firing rates (>10 Hz) and short-lasting action potentials (AP) were considered as a separate subpopulation, in light of previous studies. To segregate the remaining 269 neurons, presumably dopaminergic (DA), we performed analyses, using a combination of different electrophysiological parameters. These parameters included: (1) firing rate; (2) firing rate coefficient of variation (CV); (3) percentage of spikes in a burst; (4) AP duration; (5) Δt duration (i.e., time from initiation of depolarization until end of repolarization); and (6) presence of a notched AP waveform. Unsupervised hierarchical clustering revealed two neuronal populations that differed in their bursting activities. The largest population presented low bursting activities (17.5%). Within non-high-firing neurons, a large heterogeneity was noted concerning AP characteristics. In conclusion, this analysis based on conventional electrophysiological criteria clustered two subpopulations of putative DA VTA neurons that are distinguishable by their firing patterns (firing rates and bursting activities) but not their AP properties

Familial hypercholesterolaemia in children and adolescents from 48 countries: a cross-sectional study

Background: Approximately 450 000 children are born with familial hypercholesterolaemia worldwide every year, yet only 2·1% of adults with familial hypercholesterolaemia were diagnosed before age 18 years via current diagnostic approaches, which are derived from observations in adults. We aimed to characterise children and adolescents with heterozygous familial hypercholesterolaemia (HeFH) and understand current approaches to the identification and management of familial hypercholesterolaemia to inform future public health strategies. Methods: For this cross-sectional study, we assessed children and adolescents younger than 18 years with a clinical or genetic diagnosis of HeFH at the time of entry into the Familial Hypercholesterolaemia Studies Collaboration (FHSC) registry between Oct 1, 2015, and Jan 31, 2021. Data in the registry were collected from 55 regional or national registries in 48 countries. Diagnoses relying on self-reported history of familial hypercholesterolaemia and suspected secondary hypercholesterolaemia were excluded from the registry; people with untreated LDL cholesterol (LDL-C) of at least 13·0 mmol/L were excluded from this study. Data were assessed overall and by WHO region, World Bank country income status, age, diagnostic criteria, and index-case status. The main outcome of this study was to assess current identification and management of children and adolescents with familial hypercholesterolaemia. Findings: Of 63 093 individuals in the FHSC registry, 11 848 (18·8%) were children or adolescents younger than 18 years with HeFH and were included in this study; 5756 (50·2%) of 11 476 included individuals were female and 5720 (49·8%) were male. Sex data were missing for 372 (3·1%) of 11 848 individuals. Median age at registry entry was 9·6 years (IQR 5·8-13·2). 10 099 (89·9%) of 11 235 included individuals had a final genetically confirmed diagnosis of familial hypercholesterolaemia and 1136 (10·1%) had a clinical diagnosis. Genetically confirmed diagnosis data or clinical diagnosis data were missing for 613 (5·2%) of 11 848 individuals. Genetic diagnosis was more common in children and adolescents from high-income countries (9427 [92·4%] of 10 202) than in children and adolescents from non-high-income countries (199 [48·0%] of 415). 3414 (31·6%) of 10 804 children or adolescents were index cases. Familial-hypercholesterolaemia-related physical signs, cardiovascular risk factors, and cardiovascular disease were uncommon, but were more common in non-high-income countries. 7557 (72·4%) of 10 428 included children or adolescents were not taking lipid-lowering medication (LLM) and had a median LDL-C of 5·00 mmol/L (IQR 4·05-6·08). Compared with genetic diagnosis, the use of unadapted clinical criteria intended for use in adults and reliant on more extreme phenotypes could result in 50-75% of children and adolescents with familial hypercholesterolaemia not being identified. Interpretation: Clinical characteristics observed in adults with familial hypercholesterolaemia are uncommon in children and adolescents with familial hypercholesterolaemia, hence detection in this age group relies on measurement of LDL-C and genetic confirmation. Where genetic testing is unavailable, increased availability and use of LDL-C measurements in the first few years of life could help reduce the current gap between prevalence and detection, enabling increased use of combination LLM to reach recommended LDL-C targets early in life

Environmental enteric dysfunction and child stunting

In 2017, an estimated 1 in every 4 (23%) children aged < 5 years were stunted worldwide. With slow progress in stunting reduction in many regions and the realization that a large proportion of stunting is not due to insufficient diet or diarrhea alone, it remains that other factors must explain continued growth faltering. Environmental enteric dysfunction (EED), a subclinical state of intestinal inflammation, can occur in infants across the developing world and is proposed as an immediate causal factor connecting poor sanitation and stunting. A result of chronic pathogen exposure, EED presents multiple causal pathways, and as such the scope and sensitivity of traditional water, sanitation, and hygiene (WASH) interventions have possibly been unsubstantial. Although the definite pathogenesis of EED and the mechanism by which stunting occurs are yet to be defined, this paper reviews the existing literature surrounding the proposed pathology and transmission of EED in infants and considerations for nutrition and WASH interventions to improve linear growth worldwide