Le FORUM, Vol. 35 No. 4

https://digitalcommons.library.umaine.edu/francoamericain_forum/1032/thumbnail.jp

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

Meeting abstrac

Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.

RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Chapitre VII. Sur quelques caractères de la faune des milieux niolins

Some results of surveys and observations made by several authors are reported (J. Frochot, P.R. Carle, G. Dusaussoy and C. Geri) as well as the studies on the Orthoptera of the valley made by J. Bonfils. These results explain how the animal population are depending on the plant deeply altered by changes related to human activities. The existing bird fauna of the Niolu is strongly insular. It is heavily influenced by the altitude of the valley, and conditionned by man. The specific composition is rather poor and common in the former agricultural lands. On the contrary, the chestsnut grove is characterized by a great species richness and a high density. The pine avian fauna is less rich. Numerous species live in both environments. In the Niolu, as well as in most other mountain forests of Corsica, and in spite of high population levels the xylophagous insects do not damage severely the trees, in forests where silvicultural technics are maintained. The most important species are Ips sexdentatus, Blastophagus piniperda and B. minor. Their appearance is related to lack of management and exploitation of the forest. Their role is limited in the state high forests, but may become important in the natural reforestation process of fallows and pastures. As to the Orthoptera fauna, the Niolu valley does not present any difference with the other mountainous areas of Corsica. The number and diversity of species is highly reduced above 1 000 m. The left bank of the Golo river, bare and sunny, has the most various and abundant populations. The arboreal species live only on hardwood stands and the pine woods shelter mostly litter forms (species). The highest species diversity is observed on shrubs in the upper mediterranean and supra-mediterranean levels but there are also numerous and various Orhoptera in the meadows. In the past, in the Niolu, heavy outbreaks of Acridian occured due to Dociostaurus marocanus (moroccan locust) and to Caliptamus italicus (italian locust) ; they were favoured by a biocenotic factor : the heavy pressure of the agricultural and grazing activities on the slope. The decline of cultivated lands has resulted in the acridian increase particularly during periods of overgrazing because of the increasing sheep and goat flocks. The cattle decline and the colonization of the forest in the present days result in changes of the environment favorable to the extinction of locusts, and in qualitative changes in the fauna. In the past, the larvae of Euproctis chrysorrhea caused every 8-10 years severe defoliation on chestnut trees in the Niolu. The observations made recently show some stability of populations and no outbreak since 1965. The Berberis aetnensis Roem et Schult, an endemic plant frequently growing in around the sheep fold was found as host of the insect. These changes in the development of the insect populations is perhaps related also to the changes of the Niolu environment (the cattle becoming scarce, the chestnut grove becoming old and unmanaged).Un certain nombre d’enquêtes et d’observations faites par différents auteurs (J. Frochot, P.R. Carie, G. Dusaussoy et C. Géri) sont rapportées dans ce chapitre ainsi que les travaux réalisés par J. Bonfils sur les Orthoptères de cette vallée. Les résultats obtenus montrent comment les populations animales dépendent de la composition et de la structure végétale de la vallée et peuvent être profondément modifiées par les transformations qu’elles subissent en fonction des activités humaines. La faune actuelle des oiseaux du Niolu présente un caractère d’insularité marqué. Elle est fortement influencée par la situation élevée de la vallée et conditionnée par l’action de l’homme. Le peuplement d’oiseaux est relativement banal et pauvre dans les anciennes terres agricoles. La châtaigneraie est au contraire caractérisée par une grande richesse spécifique et une très forte densité. L’avifaune des pinèdes est moins riche. De nombreuses espèces sont communes aux deux milieux. Les insectes xylophages, dans le Niolu, comme dans la plupart des autres forêts d’altitude de la Corse, ne provoquent pas malgré des niveaux de populations élevés, de dégâts graves dans le contexte actuel de la gestion sylvicole de ces milieux. Les espèces les plus importantes sont Ips sexdentatus ainsi que Blastophagus piniperda et B. minor. Leur intervention est liée aux défauts d’entretien et d’exploitation de la forêt. Leur rôle, limité dans les futaies de la forêt domaniale, peut être important dans le processus de reforestation naturelle des jachères et pâtures. Du point de vue de la faune des Orthoptères, le bassin du Niolu ne présente pas de grandes différences par rapport aux autres régions montagneuses de la Corse. L’importance numérique et la diversité des espèces est très réduite au-dessus de 1 000 m. La rive gauche du Golo, dénudée et ensoleillée, est la plus abondamment et la plus diversement peuplée. Les espèces arboricoles sont limitées aux peuplements de feuillus et la pinède comprend essentiellement des formes inféodées aux litières. La diversité spécifique maximum est observée sur les formations arbustives des étages méditerranéen supérieur et supra-méditerranéen mais les Orthoptères sont également très variés et abondants dans les pelouses herbeuses. Autrefois, la Niolu subissait épisodiquement de fortes pullulations acridiennes, dues à Dociostaurus marocanus (Criquet marocain) et à Calliptamus italicus (Criquet italien), dont le facteur biocoenotique favorisant était la forte pression des activités agro-pastorales sur le saltus de pente. La régression des cultures a favorisé la multiplication des sauteriaux surtout durant les périodes de surpâturage dues à l’accroissement des troupeaux ovins-caprins. La régression du cheptel et l’emprise actuelle de la forêt colonisante, se traduident par une transformation du milieu favorable à l’extinction des sauteriaux, et par des modifications qualitatives des faunes considérés. Pour le Bombyx-cul-brun, Euproctis chrysorrhea, dont les chenilles causaient autrefois avec une périodicité de 8-10 ans des défoliaisons extrêmement graves sur les châtaigniers du Niolu, les observations effectuées montrent une ralative stabilité des populations dans la vallée et l’absence de pullulations depuis 1965, elles mettent en évidence l’importance de l’Épine-Vinette de l’Etna, plante endémique fréquente autour des bergeries comme hôte de cet insecte. Cette modification du développement des populations du Bombyx est peut-être également liée aux modifications du milieu niolin (raréfaction des troupeaux, vieillissement et manque d’entretien de la châtaigneraie).Géri Claude, Frochot Bernard, Carle Pierre, Bonfils Jacques, Dusaussoy G., Santini Q. Chapitre VII. Sur quelques caractères de la faune des milieux niolins. In: Ecologia mediterranea, tome 6,1980. Études écologiques et ethnologiques dans le Niolu. pp. 135-149

Neurologic outcome of VZV encephalitis one year after ICU admission: a multicenter cohort study

International audienceBACKGROUND: Varicella-zoster virus (VZV) is one of the main viruses responsible of acute encephalitis. However, data on the prognosis and neurologic outcome of critically ill patients with VZV encephalitis are limited. We aimed to describe the clinical features of VZV encephalitis in the ICU and to identify factors associated with a favorable neurologic outcome. We performed a multicenter cohort study of patients with VZV encephalitis admitted in 18 ICUs in France between 2000 and 2017. Factors associated with a favorable neurologic outcome, defined by a modified Rankin Score (mRS) of 0-2 1 year after ICU admission, were identified by multivariable regression analysis. RESULTS: Fifty-five patients (29 (53%) men, median age 53 (interquartile range 36-66)) were included, of whom 43 (78%) were immunocompromised. ICU admission occurred 1 (0-3) day after the onset of neurological symptoms. Median Glasgow Coma Score at ICU admission was 12 (7-14). Cerebrospinal fluid examination displayed a median leukocyte count of 68 (13-129)/mm(3), and a median protein level of 1.37 (0.77-3.67) g/L. CT scan and MRI revealed brain lesions in 30% and 66% of the cases, respectively. Invasive mechanical ventilation was implemented in 46 (84%) patients for a median duration of 13 (3-30) days. Fourteen (25%) patients died in the ICU. One year after ICU admission, 20 (36%) patients had a favorable neurologic outcome (mRS 0-2), 12 (22%) had significant disability (mRS 3-5), and 18 (33%) were deceased (lost to follow-up n = 5, 9%). On multivariable analysis, age (OR 0.92 per year, (0.88-0.97), p = 0.01), and invasive mechanical ventilation (OR 0.09 CI 95% (0.01-0.84), p = 0.03) reduced the likelihood of favorable neurologic outcome. CONCLUSION: One in every three critically ill patients with VZV encephalitis had a favorable neurologic outcome 1 year after ICU admission. Older age and invasive mechanical ventilation were associated with a higher risk of disability and death

Thyrotropin receptor trafficking relies on the hScrib–βPIX–GIT1–ARF6 pathway

G protein-coupled receptors are regulated by ligand stimulation, endocytosis, degradation of recycling to the cell surface. Little information is available on the molecular mechanisms underlying G protein-coupled receptors recycling. We have investigated recycling of the G protein-coupled thyroid stimulating hormone receptor (TSHR) and found that it relies on hScrib, a membrane-associated PDZ protein. hScrib directly binds to TSHR, inhibits basal receptor endocytosis and promotes recycling, and thus TSHR signalling, at the cell membrane. We previously demonstrated that hScrib is associated with a βPIX–GIT1 complex comprised of a guanine nucleotide exchange factor and a GTPase-activating protein for ADP ribosylation factors that is involved in vesicle trafficking. We used dominant-negative constructs and small interfering RNA to show that TSHR recycling is regulated by the interaction between hScrib and βPIX, and by the activity of GIT1. In addition, ARF6, a major target for GIT1, is activated during TSH stimulation of HEK293 and FRTL-5 thyroid cells, and plays a key role in TSHR recycling. Thus, we have uncovered an hScrib–βPIX–GIT1–ARF6 pathway devoted to TSHR trafficking and function

Insect – Tree Interactions in Thaumetopoea pityocampa

The pine processionary moth is, by far, the most important insect defoliator of pine forests in Southern Europe and North Africa, both in terms of its temporal occurrence, geographic range and socioeconomic impact. Monitoring and pest management actions are therefore required on a regular basis, to ensure the detection, evaluation and mitigation of potential risks to forest and public health. However, we still lack some of the basic knowledge required for relevant analyses of the risk posed by the pine processionary moth. Pest risk is defined as a combination of three components: (1) pest occurrence, which depends on the spatiotemporal dynamics of populations; (2) plant vulnerability to the pest, resulting in a certain amount of damage; and (3) the socioeconomic impact of damage, depending on the potential value of the plants damaged (Jactel et al. 2012). The population dynamics of the processionary moth has been extensively studied, in particular within the context of climate change (see Battisti et al. 2014, Chap. 2, this volume). Several studies have recently addressed the question of tree and forest vulnerability to pine processionary attacks but a comprehensive review of evidence was missing. This is the first objective of this chapter. In particular we were interested in a better understanding of the ecological mechanisms responsible for the host tree selection, at both the species and individual tree levels. In a second part we show that pine susceptibility to the pine processionary moth could be reduced by improving forest diversity at different spatial scales. In the last part of this chapter we provide quantitative estimate of the growth losses caused by defoliations of the pine processionary moth. Altogether this information paves the way for quantitative risk analyses on pine processionary moth infestations based on forest growth models