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Texture features of T2w magnetic resonance imaging mirror tissue changes in Parkinson's disease models.
No full textInternational audienceAfter successful applications in the oncology field to provide new in vivo diagnosis and prognosis imaging features, texture analysis and more generally radiomics were also reported as having the potential to provide markers of different neurodegenerative processes. Indeed, in neurodegenerative diseases such as Parkinson’s disease (PD), there is a need for neuroprotective therapies, the development of which will be fundamentally aided by imaging biomarkers capable of inferring tissue changes such as loss of neurons in the nigro-striatal pathway or alpha synuclein aggregates that characterize PD. In this study, we therefore sought to decipher the relationship between signal changes measured using brain MRI texture features and histological changes in preclinical models of this disease.Three rodent models were used: two toxin-based models, one involving 6-hydroxydopamine injection and the other using methyl-phenyl-tetrahydropyridine, and a third model based on alpha-synuclein overexpression. Animals had MR imaging with a T2w sequence evaluation and were sacrificed for histological analyses of the brains. Texture features were measured in different brain structures. The association analyses revealed significant correlations between the imaging features measured in the substantia nigra and the striatum with dopaminergic degeneration, as well as significant correlations between texture features in key structures (substantia nigra, striatum, thalamus, hippocampus and associative and cingulate cortices), and alpha-synuclein quantified in these regions.These preliminary results suggest that MR signal changes captured using texture features reflect the underlying tissue changes occurring in the brain such as neuronal death and proteins accumulation
Cerebrospinal fluid from patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) with rapid evolution affects mitochondrial DNA transcription and network in human glioblastoma cell lines
No full textHuman T-lymphotropic virus 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a progressive neurodegenerative disease that affects motor and sensory functions. While alterations in the cerebrospinal fluid (CSF) have been used to identify biomarkers for this disease, the effects of such modified CSF on neural cells remain unexplored. This study aimed to compare the effects of cerebrospinal fluid (CSF) from HTLV-1 asymptomatic carriers (HAC) with that from patients diagnosed with HAM/TSP on a glioblastoma cell line, U87-MG, which is often used to study neurodegenerative diseases. CSF samples were obtained from HTLV-1 asymptomatic carriers (HAC), and HAM/TSP patients categorized according to the speed of disease progression: very slow (HAMvs), typical (HAMt), and rapid (HAMr). RNA sequencing of U87-MG cells treated with CSF from HAMr patients revealed notable changes in gene expression with a significant downregulation of mitochondrial DNA transcripts. Confocal microscopy showed phenotypical changes in the mitochondrial network: glioblastoma cells exposed to HAMr CSF exhibited a less complex mitochondrial network compared to CSF from other patient groups, with longer mitochondrial branches, fewer junctions per branch length, and a slight increase in branch diameter. Despite these changes, U87-MG cells treated with the CSF from HTLV-1-infected donors with distinct neurological outcomes presented with similar mitochondrial metabolism. In conclusion, our findings suggest that CSF from HTLV-1-infected individuals induces mitochondrial alterations in glioblastoma cells, potentially helping to compensate for the cellular stress induced by CSF exposure. As mitochondrial alterations play an important role in other neurodegenerative diseases, we speculate that such alterations may participate in HAM/TSP pathogenesis
Vaccination au Niger : Enjeux de perception, de gouvernance et de réponse à la pandémie de COVID-19
No full textInternational audienceThis booklet is the result of in-depth research conducted as part of the Alliance SHS Africa project between 2023 and 2025, aimed at exploring the social, political, and cultural dynamics surrounding vaccination in several African countries, including Niger. It brings together empirical data collected in the field, interviews with institutional and community stakeholders, and a multidisciplinary analysis combining contributions from sociology, anthropology, public health, and political science.The COVID-19 pandemic has highlighted both the limitations and the potential of health systems in Africa. It has revealed the tensions between global public health approaches and local realities, between biomedical medicine and indigenous knowledge, and between institutional communication and informal information networks. Niger, a Sahelian country marked by significant logistical constraints and disparities in access to healthcare, provides a unique perspective on vaccine governance and the forms of support or resistance expressed within it.This booklet is intended for a wide audience: researchers, healthcare professionals, policymakers, students, and, more broadly, anyone interested in public health issues in the Global South. It offers a reading grounded in field realities, attentive to the voices of local populations, and committed to contributing to concrete improvements in health policies.Ce livret est le fruit d’un travail de rechercheapprofondi menné dans le cadre du projet AllianceSHS Afrique entre 2023 et 2025, visant à explorerles dynamiques sociales, politiques et culturellesautour de la vaccination dans plusieurs pays afri-cains, dont le Niger. Il rassemble des donnéesempiriques collectées sur le terrain, des entretiensavec des acteurs institutionnels et communautaires,ainsi qu’une analyse multidisciplinaire croisant lesapports de la sociologie, de l’anthropologie, de lasanté publique et de la science politique.La pandémie de COVID-19 a mis en lumière leslimites mais aussi les potentialités des systèmes desanté en Afrique. Elle a révélé les tensions entre leslogiques globales de santé publique et les réalitéslocales, entre la médecine biomédicale et les savoirsendogènes, entre la communication institutionnelleet les réseaux informels d’information. Le Niger,pays sahélien marqué par de fortes contrainteslogistiques et des disparités d’accès aux soins,constitue un terrain d’observation privilégié pourinterroger la gouvernance vaccinale et les formesd’adhésion ou de résistance qui s’y expriment.Ce livret s’adresse à un public large : chercheurs,professionnels de santé, décideurs politiques, étu-diants, et plus largement toute personne intéresséepar les enjeux de santé publique dans les pays duSud. Il propose une lecture ancrée dans les réali-tés de terrain, attentive aux voix des populations,et soucieuse de contribuer à une améliorationconcrète des politiques de santé
Protocol for monitoring Yersinia pestis colonization of the proventriculus in the flea Xenopsylla cheopis using microscopy
No full textInternational audienceColonization of the flea proventriculus is essential for increasing the likelihood of Yersinia pestis transmission. Here, we present a protocol for visualizing Y. pestis colonization dynamics within the proventriculus of the flea Xenopsylla cheopis. We describe steps for quantifying the number of infected proventriculi, the percentage of the surface colonized by bacteria, and an estimation of the bacterial load. These metrics provide a tool for assessing the role of bacterial genes in establishing a transmissible infection
Redifferentiation of a RET-Fusion, Radioiodine-Refractory, Differentiated Thyroid Cancer with Selpercatinib: Flip-Flop Between [18F]FDG PET/CT and 131I Posttreatment Scanning
No full textInternational audienc
Infection pulmonaire à Mycobacterium avium complexe : évaluation physiopathologique des souris Scnn1b-Tg comme nouveau modèle murin.
No full textInternational audienceIntroductionL'incidence de l'infection pulmonaire à M. avium complexe (MAC) est en constante augmentation. Elle touche surtout des patients atteints de bronchectasies, BPCO et mucoviscidose. Actuellement, les recommandations internationales proposent une triple antibiothérapie basée sur un macrolide, de l'ethambutol et de la rifampicine pour une période de 12 mois à partir de la négativation des prélèvements. Etant donné la difficulté pour traiter les patients, il apparait essentiel de développer la recherche sur la physiopathologie mais aussi sur le traitement. L'objectif de notre étude était d'évaluer les souris Scnn1b-Tg, génétiquement modifiées pour développer des dilatations des bronches comme modèle d'infection pulmonaire à MAC.Matériels et méthodesCinquante-cinq souris ont été infectés (28 C57BL/6 et 27 Scnn1b-Tg) avec un aérosol de Mycobacterium avium. Un traitement par Clarithromycine, Rifampicine et Ethambutol a été mis en place un mois après l'infection pour 10 C57BL/6 et 10 Scnn1b-Tg. Nous avons étudié la réponse microbiologique, les différents profils des cytokines inflammatoires, les lésions histologiques retrouvées en anatomopathologie et la réponse aux antibiotiques entre 1 et 4 mois après la nébulisation de MAC.RésultatsAucune souris n'est décédée pendant l'étude. En analyse macroscopique, des granulomes sont apparus chez les souris non traitées. Les souris Scnn1b-Tg ont une susceptibilité plus importante à l'infection par Mycobacterium avium en comparaison des souris C57BL/6 sur les résultats anatomopathologiques et cytokiniques. En effet, la réponse macrophagique et lymphocytaire était majoritaire dès le premier mois post infection et persistaient après la mise sous traitement pour les Scnn1b-Tg en comparaison des C57BL/6. De même avec les dosages de cytokines, la réponse inflammatoire était majoritaire chez les Scnn1b-Tg sur les voies de l'IFNγ, IL12p40 and IL-17A les deux premiers mois. Une réponse au traitement a été retrouvée dans les 2 groupes de souris avec une diminution nette du nombre de CFU, même si la différence entre souris traitées et non traitées est moins nette dans le groupe Scnn1b-Tg.ConclusionCette étude confirme que les souris Scnn1b-Tg sont un meilleur modèle pour mimer les infections à MAC chez les patients avec une pathologie pulmonaire chronique, notamment en tant que modèle physiopathologique
Optimized protocol for direct extraction of SARS-CoV-2 RNA from raw wastewater samples (ANRS 0160)
No full textInternational audienceThis study aimed to evaluate whether a nucleic acid extraction protocol specifically designed for raw wastewater (WW) provides a measurable advantage over protocols not originally intended for WW matrices. Three laboratories have independently compared two RNA extraction protocols, using paired WW samples. A common WW-designed protocol (Z), based on silica columns was tested across all labs. As comparators, three non-WW designed protocols were used: NS1 and NS2 both silica beads-based, with NS2 including an additional phenol-chloroform step; and SB a homemade protocol using also silica beads but differing in its formulation. As different samples were used across labs, direct statistical comparison was difficult; instead, paired comparisons within each lab were used to rank SARS-CoV-2 RNA detection and RT-qPCR inhibitor removal. NS1 yielded significantly higher SARS-CoV-2 RNA concentrations than Z (Logrank test, p ≤ 0.001), though with RT-qPCR inhibition in one sample. NS2 also showed higher SARS-CoV-2 RNA detection than Z (Wilcoxon test, p < 0.0001), with both protocols showing complete inhibitor removal. SB performed worse than Z for SARS-CoV-2 RNA detection (Logrank test, p ≤ 0.05), and showed inhibition in one sample. NS2 was the most effective option for both RNA detection and inhibitor removal
Seasonal dynamic of ticks infesting cattle (Bos indicus) farms in two provinces in Cambodia
No full textInternational audienceCattle tick infestations pose a significant threat to livestock health and productivity worldwide. These parasitic arthropods, feed on blood and may cause various diseases in cattle, such as anaplasmosis, babesiosis, ehrlichiosis, and theileriosis. The objective of this study is to understand the seasonal dynamic and distribution patterns of tick infesting cattle in Cambodia. A longitudinal tick survey was conducted from January to December 2023 in two cattle farms in the Takeo and Kampong Speu provinces. Ticks were collected directly from the animal hosts with fine-tip forceps or specialized tools such as tick twisters, and from the vegetation using a combination of dragging and flagging method. A total of 13,678 ticks were collected from 240 inspected cattle and 11,384 ticks were found from vegetation around the two farms. The most prevalent species was Rhipicephalus microplus complex (60.6%), while R. haemaphysaloides was recorded in small numbers (0.4%). Unidentified species represented 39% of the collected ticks, consisting of immature Rhipicephalus spp. In addition, one adult Rhipicephalus linnaei, 245 immatures of Haemaphysalis spp., and 11,138 larvae of Rhipicephalus spp. were collected using dragging and flagging methods. The results revealed significant seasonal differences in tick population dynamics across both provinces, with 60.24% in Kampong Speu and 57.09% in Takeo during the rainy season, compared to 39.76% and 42.91% during the dry season. Statistical analysis on questing activity showed no significant differences in tick density across different collection sites, times of the day and province. Our findings indicate a very high density of tick-borne pathogen vectors was observed on cattle in the two farms, which a poses potential risk to cattle productivity in Cambodia. Study sitesTwo cattle farms located in Kampong Speu and Takeo provinces (Fig 1 ) were selected as study sites. These locations are about 76 km apart and have substantially different environmental collection and analysis, decision to publish, or preparation of the manuscript.</div
Anopheles mosquitoes in Mondulkiri forest, Cambodia: abundance, distribution, seasonal patterns and Plasmodium prevalence
No full textInternational audienceBackground Mosquitoes are important drivers of infectious diseases transmission, with Anopheles mosquitoes being responsible of malaria transmission. In Cambodia, where malaria is prevalent in forested regions, understanding the ecology of these vectors is crucial. This study aimed to investigate the abundance, distribution, seasonal patterns, biting behaviour of Anopheles mosquitoes, and prevalence of Plasmodium, in Mondulkiri province, Northeastern Cambodia.Methods Conducted in 9 sites, seven in forested and two in neighbouring villages, over one year, the collection of Anopheles mosquitoes was made hourly for a 72-h period every month, using a human-baited double net trap. Each mosquito was collected using a mouth-aspirator and identified morphologically, and screened for the presence of Plasmodium.ResultsPrimary vectors, including Anopheles baimaii, Anopheles dirus, Anopheles maculatus, and Anopheles minimus, constituted 11.1% of all female mosquitoes, while 12 secondary vector species represented 29.4% of the overall collection. Anopheles species were more prevalent during the late rainy season (August to November), with year-round activity observed. Primary vectors were predominantly found in forest sites, while other vector species were found in both village and forest environments. Notably, primary vectors exhibited a preference for nocturnal biting, yet a significant proportion (19.2%) displayed daytime activity, highlighting a potential risk of daytime malaria transmission. Among 5,056 Anopheles specimens tested, only 36 Plasmodium spp.-infected samples were detected, mainly in forest sites (94%), and in specimens collected at night. This study provides essential insights into the ecology of Anopheles in Mondulkiri Forest.ConclusionsThe identification of primary and secondary vectors, their seasonal dynamics, and biting behaviour contribute to enhances our understanding of malaria transmission risks in these areas, guiding future strategie
EuPPollNet : a European database of Plant‐Pollinator Networks
No full textInternational audienceMotivation Pollinators play a crucial role in maintaining Earth's terrestrial biodiversity. However, rapid human‐induced environmental changes are compromising the long‐term persistence of plant‐pollinator interactions. Unfortunately, we lack robust, generalisable data capturing how plant‐pollinator communities are structured across space and time. Here, we present the EuPPollNet (European Plant‐Pollinator Networks) database, a fully open European‐level database containing harmonised taxonomic data on plant‐pollinator interactions referenced in both space and time, along with other ecological variables of interest. In addition, we evaluate the taxonomic and sampling coverage of EuPPollNet, and summarise key structural properties in plant‐pollinator networks. We believe EuPPollNet will stimulate research to address data gaps in plant‐pollinator interactions and guide future efforts in conservation planning. Main Types of Variables Included EuPPollNet contains 1,162,109 interactions between plants and pollinators from 1864 distinct networks, which belong to 52 different studies distributed across 23 European countries. Information about sampling methodology, habitat type, biogeographic region and additional taxonomic rank information (i.e. order, family, genus and species) is also provided. Spatial Location and Grain The database contains 1214 different sampling locations from 13 different natural and anthropogenic habitats that fall in 7 different biogeographic regions. All records are geo‐referenced and presented in the World Geodetic System 1984 (WGS84). Time Period and Grain Species interaction data was collected between 2004 and 2021. Major Taxa and Level of Measurement The database contains interaction data at the species level for 94% of the records, including a total of 1411 plant and 2223 pollinator species. The database includes data on 6% of the European species of flowering plants, 34% of bees, 26% of butterflies and 33% of syrphid species at the European level. Software Format The database was built with R and is stored in ‘.rds’ and ‘.csv’ formats. Its construction is fully reproducible and can be accessed at: https://doi.org/10.5281/zenodo.14747448