Efficacy of HI-6 dimethanesulfonate in Russian-VX (VR)-intoxicated cynomolgus monkeys

In the French armed forces, the emergency treatment against nerve agent poisoning is the oxime pralidoxime methylsulfate (Contrathion®), included in a bicompartment autoinjector (AIBC, Ineurope ®), combined with atropine sulphate and avizafone chlorhydrate. However, the reactivating potency of pralidoxime methylsulfate is weak against specific nerve agents such as Russian VX (VR). To assess whether the oxime HI-6 dimethylsulfonate (HI-6-DMS) could replace pralidoxime methylsulfate, we tested the efficacy of the combined treatment including HI-6-DMS against increasing doses of VR. Given the strong inter-species variability in the efficacy of oximes, the French regulatory agency (Agence nationale de sécurité du medicament) requested data obtained in non-human primates. The cynomolgus monkey strain was selected since background data from previous studies were available. A better efficacy of HI-6-DMS AIBC was clearly evidenced: up to 5 LD50 of VR, HI-6-DMS administered shortly after the onset of clinical signs allowed the survival of intoxicated animals who recovered faster than those treated with pralidoxime methylsulfate.Dans les armées françaises, le traitement d’urgence des intoxications par les neurotoxiques organophosphorés est l’oxime méthylsulfate de pralidoxime (Contrathion®) associée, dans un autoinjecteur bicompartimenté (AIBC, Ineurope ®), au sulfate d’atropine et au chlorhydrate d’avizafone. Le méthylsulfatede pralidoxime ne permet pas la réactivation des cholinestérases inhibées par certains agents neurotoxiques tel que le VX Russe (VR). Nous avons donc évalué l’efficacité d’une autre oxime, le diméthane sulfonate d’HI-6 (HI-6-DMS), face à des doses croissantes de VR. L’utilisation de primates non humains ayant été demandée par l’Agence nationale de sécurité du médicament en raison de la forte variabilité inter-espèces de l'efficacité des oximes, nous avons choisi le cynomolgus pour lequel des données expérimentales étaient déjà disponibles. Une meilleure efficacité de l’AIBC contenant l’HI-6-DMS a été clairement mise en évidence : jusqu'à au moins 5 DL50 de VR, l’HI-6-DMS administré rapidement après l'apparition des signes cliniques a permis d'éviter le décès et d’améliorer la récupération des animaux intoxiqués

Altimetry for the future: Building on 25 years of progress

In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the ‘‘Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

Altimetry for the future: building on 25 years of progress

In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the “Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

PREVENTION ET TRAITEMENT DES LESIONS CEREBRALES INDUITES PAR LE SOMAN (MOYENS ACTUELS ET NOUVELLES APPROCHES.)

LYON1-BU Santé (693882101) / SudocSudocFranceF

Evénements moléculaires et cellulaires associés à l'épileptogenèse dans deux modèles murins d'injection intrahippocampique de toxiques (implication des mécanismes neuro-inflammatoires)

Le processus d'épileptogenèse, qui conduit à la production de décharges électro-encéphalographiques spontanées caractéristiques de la maladie épileptique, implique des mécanismes inconnus pour la plupart et probablement divers. Des études récentes soulignent le rôle potentiel de l'inflammation cérébrale dans les mécanismes précoces de l'épileptogenèse. Le syndrome d'épilepsie de la face mésiale du lobe temporal (EMLT) est souvent associé à une perte neuronale unilatérale et sélective dans l'hippocampe, suggérant que cette structure est particulièrement sensible. Notre travail a donc été consacré à l'étude de l'épileptogenèse faisant suite à l'injection intrahippocampique de toxiques chimiques capables d'entraîner des modifications tissulaires et cellulaires locales chez la souris C57BL/6. Le rôle potentiel de la neuro-inflammation a été plus particulièrement recherché. Dans notre premier modèle, un déséquilibre cholinergique est induit par l'injection de soman, un puissant inhibiteur des cholinestérases. Il est capable d'induire un processus d'épileptogenèse sans état de mal initial, associé à un déficit de la réponse émotionnelle conditionnée contextuelle mais en l'absence de remaniements tissulaires majeurs (neurodégénérescence, œdème et neuro-inflammation). En revanche, dans le modèle d'EMLT obtenu par l'injection de kaïnate, une forte activation microgliale est détectée précocement dans les zones de neurodégénérescence. Une astrogliose est également observée. Grâce à la technique quantitative de transcription inverse suivie de polymérisation en chaîne (RT-qPCR), nous avons également pu mettre en évidence que certains médiateurs moléculaires de l'inflammation sont également liés dans le temps et dans l'espace (particulièrement la transcription d'IL-1b) aux événements neurodégénératifs. Pour s'assurer de la fiabilité des données analytiques de RT-qPCR dans les régions cérébrales touchées par ces modifications, le choix des gènes de référence doit faire l'objet d'études spécifiques. Nous avons pu montrer qu'un ensemble de cinq gènes (Hprt1, Ppia, Tbp, Actb et Arbp) avait une forte stabilité dans la structure hippocampique dans ce modèle murin d'EMLT et pouvait être utilisé pour normaliser les données brutes de RT-qPCR dans ce modèle. Nos résultats indiquent que, chez la souris, des altérations neurochimiques sont capables d'initier l'épileptogenèse même en l'absence de lésions tissulaires notables et qu'une réponse neuro-inflammatoire massive n'est pas une condition sine qua non. Déterminer le caractère bénéfique ou délétère de la neuro-inflammation reste un enjeu majeur pour la découverte de nouvelles thérapeutiques anti-épileptogènes.Epileptogenesis, which leads to the occurrence of sponteanous electroencephalographic fits that are a key feature of epilepsy, arises from mostly unknown and probably diverse mechanisms. Recent studies stress that cerebral inflammation may be involved in the early events of epileptogenesis. The mesiotemporal lobe epilepsy (MTLE) syndrome is often associated to a unilateral hippocampal neuronal loss stressing that hippocampus is a particularly sensitive region of the brain. Our work focused on epileptogenesis that follows the intrahippocampal injection of chemical toxicants that are able to induce local tissular and cellular modifications in C57BL/6 mice. The potential role of neuro-inflammation was of particular interest. In our first model, a cholinergic imbalance was created by the injection of soman, a potent cholinesterase inhibitor. It was able to induce epileptogenesis without an initial status epilepticus and a deficit in the contextual fear conditioning test. Interestingly no major tissular changes (neuronal damage, edema and neuro-inflammation) could be observed. Conversely, in the murine MLTE model obtained with the injection of kainate, a strong microglial reaction could quickly be observed in the areas showing neuronal damage. Astrogliosis was also present. Thanks to reverse transcription quantitative polymerase chain reaction (RT-qPCR), we could show that changes in mRNA levels of some neuroinflammatory mediators (especially d'IL-1b) were related to the time course of neuronal degenerescence in areas showing damage. For the RT-qPCR data, from samples obtained from these regions, to be reliably considered, appropriate sets of reference genese have to be determined. We showed that a group of five genes (Hprt1, Ppia, Tbp, Actb et Arbp) were highly stable in the hippocampus of mice experiencing MTLE and could be used to normalize raw data from RT-qPCR in this model. All in all, ours results stress the fact that, in mice, neurochemical modifications are able to induce epileptogenesis even when no tissular lesions could be noticed and that massive neuro-inflammation is not a sine qua non condition. To determine if neuro-inflammation is beneficial or deleterious is still a major research thrust as this may lead to the discovery of new antiepileptogenic drugs.GRENOBLE1-BU Sciences (384212103) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

Etude de la réaction inflammatoire cérébrale au cours de l'épileptogenèse dans un modèle murin d'épilepsie mésio-temporale

DIJON-BU Médecine Pharmacie (212312103) / SudocSudocFranceF

Caractérisation des brûlures cutanées induites par la Lewisite chez la souris SKH-1 par des approches non invasives, cellulaires et moléculaires

La lewisite est une arsine organique de la catégorie des vésicants dont l'antidote est le British Anti-Lewisite. Cet agent chimique de guerre dont la menace d'utilisation reste d'actualité, provoque après contact cutané, des lésions allant de l'érythème à la vésication plus ou moins étendue selon la dose reçue. Les données de toxicité, en particulier humaines, sont restreintes et parfois contradictoires, ce qui limite la pertinence d'une description précise des symptômes et de leur chronologie d'apparition. Les traitements actuels des brûlures cutanées sont peu spécifiques, uniquement symptomatiques, et s'inspirent généralement des approches utilisées dans le cas des brûlures thermiques. Dans ce contexte, il nous a semblé important de mieux comprendre les mécanismes lésionnels associés à une exposition cutanée à la lewisite. Ces étapes de compréhension physiopathologiques permettent d'identifier des cibles potentielles pour des interventions pharmacologiques et sont également nécessaires et préalables à l'établissement de nouvelles stratégies curatives. C'est dans ce cadre que s'est inscrit notre travail de recherche. En privilégiant une approche expérimentale chez l'animal, la souris sans poils SKH-1, le travail a consisté dans un premier temps à décrire l'évolution temporelle des lésions cutanées induites par une exposition de la peau du dos de la souris à des vapeurs saturantes de lewisite. Le processus lésionnel a été suivi pendant les 3 premières semaines après l'exposition permettant ainsi de couvrir les différentes phases de la cicatrisation cutanée. Un suivi à plus long terme sur 27 semaines a été également réalisé. L'utilisation de différentes méthodes d'exploration fonctionnelle a permis d'étudier la couleur de la peau, d'évaluer l'intégrité de la fonction barrière ainsi que les propriétés biomécaniques de la peau. Ces études ont été complétées par des analyses microscopiques des tissus lésés. Dans un deuxième temps, des cibles clés de la toxicité cutanée de la lewisite ont été identifiées par des approches génomiques et biochimiques. Sur une cinétique courte de 7 jours après l'exposition, les transcrits de gènes cibles ont été quantifiés par RT-qPCR. Ces données ont été complétées par une analyse protéique faisant intervenir différentes méthodes d'analyse complémentaires de puce à protéines, de western blot et de zymographie sur une cinétique plus longue de 14 jours. Pour terminer, l'intérêt de la détersion hydrochirurgicale associée à une thérapie matricielle a été envisagé pour traiter les lésions cutanées induites par la lewisite.Lewisite is an organic arsenical compound ranked among the vesicating agents whose antidote is the British Anti-Lewisite. This chemical warfare agent remains a current threat and generates damage ranging from erythema to vesication, larger or smaller depending on the dose received after skin contact. Only few data are available regarding the toxicity on human and are sometimes contradictory. Therefore, the relevance of the description of the symptoms and their chronology of apparition are limited. Current treatments of skin burns are not specific, only symptomatic and are closed to those used to treat thermal burns. In such context, we consider it important to gain better understanding of the injury mechanisms associated with skin exposure to lewisite. These understanding stages of the physiopathology aim at identifying potential targets for pharmacological interventions and are necessary and prerequisites for the establishment of new curative strategies. It is within this framework that our investigations are based on. An appropriate experimental approach was conducted using the SKH-1 hairless mouse. In the first place, the aim was to describe the time course of skin lesions development induced by exposure to saturating vapors of lewisite on the dorsal skin of the mouse. The injury process was monitored throughout the first 3 weeks after exposure in order to cover the different phases of wound healing. A long term monitoring throughout 27 weeks was also performed. The use of several methods of functional exploration has enabled the study of the skin color, the evaluation of the integrity of the barrier function and the biomechanical properties of the skin. These studies were completed by microscopic analyses of the injured tissues. In a second step, key targets of the lewisite skin toxicity were identified by genomic and biochemical approaches. The transcripts of the target genes were quantified by RT-qPCR in a 7-day kinetic after exposure. Data were completed by protein analyses involving complementary analytical methods (antibody array, western blot, gel zymography in a 14-day kinetic. Lastly, a combination of hydrosurgical debridement and matrix therapy was assessed and considered in order to treat skin lesions induced by lewisite.SAVOIE-SCD - Bib.électronique (730659901) / SudocGRENOBLE1/INP-Bib.électronique (384210012) / SudocGRENOBLE2/3-Bib.électronique (384219901) / SudocSudocFranceF

Selection of reference genes for real-time quantitative reverse transcription-polymerase chain reaction in hippocampal structure in a murine model of temporal lobe epilepsy with focal seizures.

International audienceReference genes are often used to normalize expression of data from real-time quantitative reverse transcription-polymerase chain reaction (RT-qPCR), and only a validation of their stability during a given experimental paradigm leads to reliable interpretations. The present study was thus designed to validate potential reference genes in a mouse model of mesiotemporal lobe epilepsy (MTLE) with focal seizures after unilateral intrahippocampal injection of kainate (KA). Ipsilateral and contralateral hippocampi were removed during nonconvulsive status epilepticus (5 hr), epileptogenesis (7 days), and the chronic period of recurrent focal seizures (21 days). Naive animals were equally studied. The stability of eight potential reference genes (hypoxanthine phosphoribosyltransferase, Hprt1; peptidylprolyl isomerase A, Ppia; TATA box binding protein, Tbp; beta-actin, Actb; acidic ribosomal phosphoprotein P0, Arbp; glyceraldehyde-3-phosphate dehydrogenase, Gapdh; ribosomal RNA 18S, 18S rRNA; and glucuronidase beta, Gusb) were determined using geNorm and NormFinder software. The first five (Hprt1, Ppia, Tbp, Actb, and Arbp) were found to be stable across the different phases of the disease and appeared adequate for normalizing RT-qPCR data in this model. This was in contrast to the other three (18S rRNA, Gapdh, and Gusb), which showed unstable expressions and should be avoided. The analysis of KA-induced changes in the expression of glial fibrillary acidic protein (Gfap) gene resulted in various relative expressions or even a completely different pattern when unstable reference genes were used. These results highlight the absolute need to validate the reference genes for a correct interpretation of mRNA quantification

Exposure to organophosphorus compounds : best practice in managing timely, effective emergency responses

© 2023 The Author(s). Published by Wolters Kluwer Health, Inc. This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBYNC-ND).Increasing indications, reports and studies demonstrate that threats from the deliberate use of chemical weapons remain high and are evolving. One of the deadliest classes of chemical weapons are the organophosphorus nerve agents. It is now clear that both state and non-state actors have the ability to deploy and use these types of weapons against individuals and the wider civilian population posing a real and significant threat. The objective of this article is to provide an overview of the issues impacting on a timely critical response to the accidental or deliberate release of Organophosphorus Nerve Agents in order to enhance the understanding of their effects and provide guidance on how first responders might better treat themselves or victims of exposure through a discussion of available evidence and best practices for rapid skin decontamination. The article also examines use of the current nomenclature of 'wet' and 'dry' to describe different forms of decontamination. One of the key conclusions of this article is that adequate preparedness is essential to ensuring that responders are trained to understand the threat posed by Organophosphorus Nerve Agents as well as how to approach a contaminated environment. A key aspect to achieving this will be to ensure that generic medical countermeasures are forward-deployed and available, preferably within minutes of a contamination and that first responders know how to use them.Peer reviewe

Hyperosmolar treatment of soman-induced brain lesions in mice: evaluation of the effects through diffusion-weighted magnetic resonance imaging and through histology.

International audiencePURPOSE: A convulsive dose of soman induces seizure-related brain damage (SRBD), including cerebral edema (CE) and neuronal loss. In the present study on soman-intoxicated mice, we applied diffusion-weighted magnetic resonance imaging (DW-MRI) and quantitative histology, and we measured brain water content to investigate the antiedematous and neuroprotective efficacies of two hyperosmolar treatments: mannitol (Mann) and hypertonic saline (HTS). METHODS: Mice intoxicated with soman (172 microg/kg after a protective pretreatment) were administered 1 min and 5-h post-challenge an i.v. bolus of saline, of Mann or of HTS. 1 day later, mice were examined with DW-MRI and then sacrificed for brain histology. Additional animals were intoxicated and treated similarly for the measurement of the brain water content (dry/wet weight method). RESULTS: In intoxicated controls, a significant decrease of the apparent diffusion coefficient (ADC), numerous damaged (eosinophilic) cells, high edema scores, and a significant increase in brain water content were detected 24-h post-challenge in sensitive brain structures. These soman-induced changes were not significantly modified by treatment with Mann or HTS. CONCLUSIONS: Treatment with hyperosmolar solutions did not reduce the effects of soman on ADC, on cell damage and on CE. Therefore, despite similar treatment protocols, the prominent protection by Mann that was previously demonstrated by others in poisoned rats, was not reproduced in our murine model