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Differential impact of porcine reproductive and respiratory virus and swine Influenza A virus infections on respiratory Lymph Nodes B cells and macrophages
No full textInternational audiencePorcine Reproductive and Respiratory Syndrome Virus (PRRSV) has a profound impact on the swine industry due to its ability to persist in infected animals. The PRRSV family exhibits considerable genetic variability, with PRRSV-1 and PRRSV-2 now classified as two distinct species (Betaarterivirus suid 1 and 2). Interestingly, both species – and their corresponding attenuated vaccine strains – can persist for months, in part by delaying the appearance of neutralizing antibodies. Leveraging recently developed tools for in-depth analysis of the previously poorly characterized porcine inverted lymph node (LN), we investigated early events in LN B cell maturation during PRRSV-1 infection and compared them to those induced by acute swine influenza A virus infection. We highlighted PRRSV-specific mechanisms, including PD-L1 upregulation in efferent macrophages, the presence of extrafollicular centrocytes, and the influx of inflammatory monocytes/macrophages. These findings are consistent with previous observations in PRRSV-2 infections and may therefore reflect conserved immune evasion mechanisms across PRRSV strains
The impact of medical status on the choice of dental procedures under general anesthesia—a retrospective study
No full textInternational audienceBackground: The purpose of this study was to assess the type of dental procedures performed on children under General Anesthesia (GA) and to determine if the pattern differs between healthy children and those with special healthcare needs. Methods: In this retrospective study, data were reviewed from the dental records of pediatric patients who underwent dental treatment under GA from 2015 to 2020 at Nantes University Hospital. Patients with mental or physical disabilities were categorized as Disabled (D), while healthy children were assigned to the Healthy group (H). Records from patients with Systemic Diseases were also analyzed with (D + SD) or without (SD) Disabilities. Results: The mean age of each group was evaluated and compared to the others. The number and type of dental treatments were compared between each group for both primary and permanent teeth. A total of 655 patients were treated under GA. Patients in groups H and SD were significantly younger than those in the disabled group (p < 0.001). Primary teeth were more frequently treated in groups H and SD than in groups D and SD + D, while the opposite was true for permanent teeth. There were more extractions of primary teeth than restorative treatments performed in children with disabilities (p = 0.0005). Conclusions: The findings of this study suggest that the health conditions of young patients could impact their dental procedures when undergoing GA. Children with systemic diseases don’t seem to differ from healthy patients in the acts performed, but patients with disabilities do
Tripartite ER-Mitochondria-Lipid Droplets contact sites control adipocyte metabolic flexibility
No full textInternational audienceAbstract Obesity is a major risk factor for cardiometabolic diseases, with adipocyte dysfunction playing a central role. In individuals living with obesity, adipose tissue (AT) enters a state of metabolic inertia, reducing its capacity to store excess lipids and promoting ectopic lipid accumulation in non-adipose tissues—thereby contributing to cardiometabolic complications. Understanding the mechanisms that regulate lipid storage and mobilization in adipocytes—and how these are disrupted in obesity—is critical for addressing these complications. Generalized lipodystrophy, the most severe form of primary adipocyte dysfunction, is caused in approximately 50% of cases by mutations in the BSCL2 gene encoding Seipin, an endoplasmic reticulum (ER) protein essential for lipid droplet (LD) biogenesis and maintenance. Seipin also localizes to ER/mitochondria contact sites (MAM), where it regulates calcium exchange and mitochondrial function. This study aimed to determine whether Seipin’s recruitment to MAM and ER/LD contact sites overlaps and to assess the consequences of Seipin dysfunction on membrane contact site (MCS) dynamics and adipocyte metabolism. Using in situ proximity ligation assays (PLA) and transmission electron microscopy (TEM), we observed altered MCS involving the ER, LDs, and mitochondria in Seipin-deficient models. Functional assays revealed that Seipin knockdown impairs triglyceride transfer to LDs, an effect that was rescued by the MAM-reinforcing synthetic peptide, the Linker-ER-Mi. Further, we investigated how MCS remodeling influences adipocyte metabolic flexibility. Using TEM and PLA in both mouse AT and 3T3-L1 adipocytes, here, we show that lipid loading increases contacts involving the lipid droplet (LD), specifically ER/LD and mitochondria/LD (Mi/LD) contacts. However, lipid loading exerts opposite effects on MAM subtypes: oleic acid increases the MAM involving mitochondria in close contact with the LD, the MAM-LD, while decreasing the MAM involving cytosolic mitochondria, the “classical” MAM-CM contacts. Notably, this adaptive MCS remodeling was blunted in the AT of diet-induced obese mice. Genetic disruption of MCS in 3T3-L1 adipocytes led to altered lipid flux, impaired lipolysis, and reduced insulin signaling. Collectively, our findings demonstrate that MAM-LD contacts are central to adipocyte metabolic flexibility and lipid handling, and that their dysregulation in obesity may underlie the metabolic inflexibility characteristic of this condition
Inactivation of non-proteolytic Clostridium botulinum spores in refrigerated plant-based food
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Gestion des prélèvements sanguins, d'histologie, ... Comment bien faire la demande et gérer la conservation des prélèvements
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A generalized hybrid machine learning framework for predicting biohydrogen production via dark fermentation of organic wastes
No full textInternational audienceThe rising global demand for sustainable energy has directed significant attention towards biohydrogen production via dark fermentation of organic wastes. Accurate yield prediction is crucial for optimizing process conditions and enhancing overall process. This study aims to develop a robust and interpretable predictive framework that integrates kinetic modeling with a hybrid Bayesian Optimization-Artificial Neural Network (BO-ANN) approach for precise biohydrogen yield prediction. The core novelty lies in representing each substrate not as a simple category, but by its quantitative kinetic parameters from the Modified Gompertz equation, providing a biologically meaningful input. A comprehensive database compiled from the literature incorporates key process variables, including temperature, pH, residence time, and substrate concentration, along with kinetic parameters from the Modified Gompertz equation characterizing each substrate. The BO algorithm was employed to optimize the ANN architecture, and 5-fold cross-validation was used to evaluate model generalization ability. The proposed hybrid model achieved outstanding predictive performance (R² = 0.9980, RMSE = 0.0117, MAE = 0.0062), confirming its accuracy and robustness. Furthermore, SHAP analysis and correlation metrics provided interpretable insights into feature contributions, particularly the relevance of kinetic descriptors. Overall, the proposed BO-ANN framework offers a scalable, interpretable, and biologically grounded tool to improve predictive accuracy and support the design of more efficient and sustainable biohydrogen production systems
Enterococcus faecalis CIRM-BIA2928 induces gluten proteolysis and reduces gluten immunoreactivity during fermentation
No full textInternational audienceAbstract Wheat is a staple food for human consumption thanks to its nutritional and technological quality. Worldwide, around 8% of the population is affected by wheat-related disorders, such as wheat allergy, celiac disease or non-celiac gluten-sensitivity. Food processing can modify gluten protein structure and immunoreactivity. Bacterial fermentation by Lactic Acid Bacteria (LAB) is of particular interest, as fermentation can cause the hydrolysis of gluten proteins. Our study aimed to identify LAB capable of hydrolysing gluten and to establish optimal fermentation conditions. Fifteen bacterial strains were screened on a liquid medium containing gluten as the sole nitrogen source. The protein profile of all fermentation products was characterised by SDS-PAGE. Of selected strains, a detailed peptide analysis of hydrolysed fermentation products was performed using mass spectrometry. Protein immunoreactivity was assessed by competitive ELISA. Finally, the bacterial enzyme class responsible for gluten hydrolysis was identified. One strain of Enterococcus faecalis (CIRM-BIA2928) was capable of hydrolysing gluten during fermentation. Fermentation time and bacterial cell concentration were identified as two factors modulating proteolysis. Gluten proteolysis led to a clear reduction in the immunoreactivity of the R5 peptide, implicated in celiac disease. This proteolysis was caused by zinc metalloprotease enzymes. Enterococcus faecalis CIRM-BIA2928 has interesting characteristics for hydrolysing wheat proteins. Hydrolyzed gluten could be used for preventive purposes to induce oral tolerance or for therapeutic purposes in wheat-allergic patients to avoid triggering a reaction
Valorization of waste from fruit processing industry for hydrophobisation of cellulosic materials.
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Causes of Death and Screening for Toxicants and Hemopathogens of European Hedgehogs (Erinaceus europaeus) from a Wildlife Rehabilitation Center in Northern France
No full textInternational audienceTo understand the dynamics of a pathogen in an animal population, one must assess how the infection status of individuals changes over time. With wild animals, this can be very challenging because individuals can be difficult to trap and sample, even more so since they are tested with imperfect diagnostic techniques. Multi-event capture-recapture models allow analysing longitudinal capture data of individuals whose infection status is assessed using imperfect tests. In this study, we used a two-year dataset from a longitudinal field study of peridomestic wild bird populations in the United Arab Emirates during which thousands of birds from various species were captured, sampled and tested for Newcastle disease virus exposure using a serological test. We developed a multi-event capture-recapture model to estimate important demographic and epidemiological parameters of the disease. The modelling outputs provided important insights into the understanding of Newcastle disease dynamics in peridomestics birds, which varies according to ecological and epidemiological parameters, and useful information in terms of surveillance strategies. To our knowledge, this study is the first attempt to model the dynamics of Newcastle disease in wild bird populations by combining longitudinal capture data and serological test results. Overall, it showcased that multi-event capture-recapture models represent a suitable method to analyse imperfect capture data and make reliable inferences on infectious disease dynamics in wild populations
