Modélisation de la distribution géographique de deux scolytes, Tomicus destruens et Tomicus piniperda, en Europe et dans la région méditerranéenne

Article publié suite à l'événement : MEDINSECT 3 ; Hammamet-Tunis (Tunisie) - (2012-05-08 - 2012-05-11).Preliminary note – Data and results presented in that paper come from the original article: Horn A., Kerdelhué C., Lieutier F., Rossi J.P., 2012. Predicting the distribution of the two bark beetles Tomicus destruens and Tomicus piniperda in Europe and the Mediterranean region. Agricultural and Forest Entomology, 14, 358-366.Various factors such as climate and resource availability influence the geographical distributions of organisms. Species that are susceptible to small temperature variations are known to experience rapid distribution shifts as a result of current global warming, sometimes leading to new threats to agriculture and forests. Tomicus destruens and Tomicus piniperda (Coleoptera, Curculionidae, Scolytinae) cause economic damage to pines in Europe and around the Mediterranean Basin. However, their respective potential distributions have not yet been studied at a large scale, mostly because these two species have long been misidentified. The present study aimed to investigate the influence of climatic factors on the geographical distributions of both Tomicus species in Europe and around the Mediterranean Sea, and to establish maps of suitable areas. We used occurrence data from 114 published localities where the presence or absence of both species was unambiguously recorded and confirmed by molecular data, and we gathered WorldClim meteorological records to link the occurrence of insects and climatic data and to build potential distribution maps. The two studied Tomicus species presented parapatric distributions and opposite climate requirements. T. destruens occurs in locations with warmer temperatures, whereas T. piniperda occurs under colder, continental climates. Amongst the investigated climatic variables, temperature appeared to be most correlated with both species distributions. We further extended our approach to explore potential geographical distributions under climate change scenarios. This showed that the distribution of both species is expected to exhibit strong alteration in the near future (2080) corresponding to a marked expansion of T. destruens towards northern Europe and a retractation and fragmentation of the distribution of T. piniperda.Résumé - Différents facteurs, tels que le climat ou la disponibilité de certaines ressources, affectent la distribution géographique des organismes. Aujourd’hui, les espèces sensibles à de faibles variations de température connaissent des modifications de leur aire de distribution sous l’effet du changement climatique, avec parfois de nouveaux risques pour l’agriculture et les forêts. Tomicus destruens et Tomicus piniperda (Coleoptera, Curculionidae, Scolytinae) causent des dégâts importants aux pins en Europe et sur le pourtour méditerranéen mais leur aire de distribution potentielle à une large échelle est encore mal connue, en particulier parce que ces deux espèces ont longtemps été confondues. L’étude présentée ici a pour objectif de mieux comprendre l’impact des variables climatiques sur la distribution géographique des deux espèces et d’établir des cartes de distribution potentielle, actuelles et futures. Nous avons utilisé 114 données d’occurrence publiées pour lesquelles la présence et l’absence des deux espèces sont avérées par des diagnostiques moléculaires. Nous avons utilisé les données climatiques disponibles dans la base « WorldClim » afin d’ajuster des modèles linéaires généralisés pour modéliser les relations climat – occurrences de T. destruens et T. piniperda. Les résultats obtenus montrent que les deux espèces ont des distributions parapatriques et des préférences climatiques différentes. T. destruens est présent dans les zones les plus chaudes tandis que T. piniperda occupe les régions les plus froides ayant probablement des saisons marquées. Nous avons utilisé les modèles précédents pour réaliser une projection permettant d’estimer la distribution potentielle de chaque espèce dans le cadre du scénario de changement climatique IPCC 4 du CIAT (modèle CCCM avec un scénario d’émission a2a). Les résultats indiquent que les distributions des deux espèces devraient connaître d’importants changements à court terme (2080). Ainsi, T. destruens remonterait vers le nord de l’Europe tandis que l’aire de distribution de T. piniperda serait à la fois réduite et très fragmentée

Osteoclast Cytomorphometry and Scanning Electron Microscopy of Bone Eroded Surfaces During Leukemic Disorders

Tartrate resistant acid phosphatase (TRAP) is a reliable histochemical marker of osteoclasts when used on tissue sections of undecalcified bone. This paper presents an original morphometric analysis which can be done after histochemical identification of osteoclasts. These bone resorbing cells were demonstrated on undecalcified bone biopsies from control subjects and patients presenting a malignant disease of the lymphocyte B lineage. Computerized analysis of the osteoclastic population revealed that: (1) all TRAP positive cells along bone trabeculae belong to a osteoclastic population; (2) that B cell malignancies had an increased bone resorption. At the scanning electron microscopic level small resorption bays (about 10 μm in diameter) were observed either associated or separated from eroded surfaces presenting a normal appearance; TRAP staining of histological sections of undecalcified bone, coupled with morphometric studies, may help in the understanding of bone disease pathobiology

Effects of earthworms on soil organic matter and nutrient dynamics at a landscape scale over decades

International audienceThis chapter synthesizes information on the effects of earthworms on soil systems at scales longer than 1 year, and earthworm behavior that may affect these processes is detaile

Optimisation of anti-interleukin-6 therapy: Precision medicine through mathematical modelling

BackgroundDysregulated interleukin (IL)-6 production can be characterised by the levels present, the kinetics of its rise and its inappropriate location. Rapid, excessive IL-6 production can exacerbate tissue damage in vital organs. In this situation, therapy with an anti-IL-6 or anti-IL-6 receptor (IL-6R) monoclonal antibody, if inappropriately dosed, may be insufficient to fully block IL-6 signalling and normalise the immune response.MethodsWe analysed inhibition of C-reactive protein (CRP) – a biomarker for IL-6 activity – in patients with COVID-19 or idiopathic multicentric Castleman disease (iMCD) treated with tocilizumab (anti-IL-6R) or siltuximab (anti-IL-6), respectively. We used mathematical modelling to analyse how to optimise anti-IL-6 or anti-IL-6R blockade for the high levels of IL-6 observed in these diseases.ResultsIL-6 signalling was insufficiently inhibited in patients with COVID-19 or iMCD treated with standard doses of anti-IL-6 therapy. Patients whose disease worsened throughout therapy had only partial inhibition of CRP production. Our model demonstrated that, in a scenario representative of iMCD with persistent high IL-6 production not controlled by a single dose of anti-IL-6 therapy, repeated administration more effectively inhibited IL-6 activity. In a situation with rapid, high, dysregulated IL-6 production, such as severe COVID-19 or a cytokine storm, repeated daily administration of an anti-IL-6/anti-IL-6R agent, or alternating daily doses of anti-IL-6 and anti-IL-6R therapies, could neutralise IL-6 activity.ConclusionIn clinical practice, IL-6 inhibition should be individualised based on pathophysiology to achieve full blockade of CRP production.FundingEUSA Pharma funded medical writing assistance and provided access to the phase II clinical data of siltuximab for analysis

Systemic AA amyloidosis caused by inflammatory hepatocellular adenoma

To the Editor: Amyloid A (AA) systemic amyloidosis is a complication of chronic inflammatory diseases that is caused by the deposition of insoluble aggregates of cleaved N-terminal fragments of serum amyloid A (SAA) protein in tissues and organs throughout the body. Under physiologic conditions, SAA protein is produced by hepatocytes during the acute inflammatory phase in response to various cytokines such as interleukin-6. SAA is also overexpressed by neoplastic hepatocytes in inflammatory hepatocellular adenomas, a specific molecular subtype of benign liver tumors

Non-Invasive Detection of Coronary Artery Disease in Patients With Left Bundle Branch Block Using 64-Slice Computed Tomography

ObjectivesThe goal of this study was to evaluate the diagnostic accuracy of 64-slice computed tomography (CT) to identify coronary artery disease (CAD) in patients with complete left bundle branch block (LBBB).BackgroundLeft bundle branch block increases risk of cardiac mortality, and prognosis is primarily determined by the underlying coronary disease. Non-invasive stress tests have limited performance, and conventional coronary angiography (CCA) is usually required.MethodsSixty-six consecutive patients with complete LBBB and sinus rhythm admitted for CCA were enrolled. Computed tomography was performed 3 ± 3.9 days before CCA. The accuracy of 64-slice CT to detect significant stenosis (>50% lumen narrowing) was compared with quantitative coronary angiography. All segments were analyzed regardless of image quality from coronary calcification or motion artifacts. Results were analyzed by patient and by coronary segment (990) using the American Heart Association 15-segment model.ResultsLower heart rates were associated with improved image quality. Computed tomography correctly identified 35 of 37 (95%) patients without significant stenosis and 28 of 29 (97%) patients with significant stenosis on CCA. Computed tomography correctly assessed 68 of 94 (72%) significant stenosis. Overall, accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of 64-slice CT for identifying CAD by patient was 95%, 97%, 95%, 93%, and 97%, respectively, and by segment was 97%, 72%, 99%, 91%, and 97%, respectively.ConclusionsIn a routine clinical practice, 64-slice CT detects with excellent accuracy a significant CAD in patients with complete LBBB. A normal CT in this clinical setting is a robust tool to act as a filter and avoid invasive diagnostic procedures

Patent Foramen Ovale Closure or Anticoagulation vs. Antiplatelets after Stroke

BACKGROUND Trials of patent foramen ovale (PFO) closure to prevent recurrent stroke have been inconclusive. We investigated whether patients with cryptogenic stroke and echocardiographic features representing risk of stroke would benefit from PFO closure or anticoagulation, as compared with antiplatelet therapy. METHODS In a multicenter, randomized, open-label trial, we assigned, in a 1:1:1 ratio, patients 16 to 60 years of age who had had a recent stroke attributed to PFO, with an associated atrial septal aneurysm or large interatrial shunt, to transcatheter PFO closure plus long-term antiplatelet therapy (PFO closure group), antiplatelet therapy alone (antiplatelet-only group), or oral anticoagulation (anticoagulation group) (randomization group 1). Patients with contraindications to anticoagulants or to PFO closure were randomly assigned to the alternative noncontraindicated treatment or to antiplatelet therapy (randomization groups 2 and 3). The primary outcome was occurrence of stroke. The comparison of PFO closure plus antiplatelet therapy with antiplatelet therapy alone was performed with combined data from randomization groups 1 and 2, and the comparison of oral anticoagulation with antiplatelet therapy alone was performed with combined data from randomization groups 1 and 3. RESULTS A total of 663 patients underwent randomization and were followed for a mean (+/- SD) of 5.3 +/- 2.0 years. In the analysis of randomization groups 1 and 2, no stroke occurred among the 238 patients in the PFO closure group, whereas stroke occurred in 14 of the 235 patients in the antiplatelet-only group (hazard ratio, 0.03; 95% confidence interval, 0 to 0.26; P<0.001). Procedural complications from PFO closure occurred in 14 patients (5.9%). The rate of atrial fibrillation was higher in the PFO closure group than in the antiplatelet-only group (4.6% vs. 0.9%, P = 0.02). The number of serious adverse events did not differ significantly between the treatment groups (P = 0.56). In the analysis of randomization groups 1 and 3, stroke occurred in 3 of 187 patients assigned to oral anticoagulants and in 7 of 174 patients assigned to antiplatelet therapy alone. CONCLUSIONS Among patients who had had a recent cryptogenic stroke attributed to PFO with an associated atrial septal aneurysm or large interatrial shunt, the rate of stroke recurrence was lower among those assigned to PFO closure combined with antiplatelet therapy than among those assigned to antiplatelet therapy alone. PFO closure was associated with an increased risk of atrial fibrillation