Hydrochimie des eaux de surface de la région d’Adiaké (sud-est côtier de la Côte d’Ivoire)

Objectif : Évaluer la qualité physicochimique des eaux de surface de la région d’Adiaké (sud-est côtier de la Côte d’Ivoire) et expliquer les phénomènes à l’origine de la minéralisation de ces eaux.Méthodologie and résultats : Dix-sept paramètres physico-chimiques sont déterminés pour chacun des 7 échantillons d’eaux. Les résultats sont traités à l’aide de méthodes hydrochimiques (diagramme de Piper) pour l’étude de la typologie des eaux et des techniques d’analyse statistique multivariée. L’Analyse en Composantes Principales Normées (ACPN) et l’analyse en Classification Hiérarchique Ascendante (CHA) sont utilisées pour mettre en évidence respectivement les phénomènes à l’origine de la minéralisation des eaux et les liens entre ces eaux. Les eaux étudiées sont acides (5,09 pH 7,43) et très faiblement minéralisées (CE100 JScm-1). Les teneurs des paramètres chimiques sont inférieurs aux normes OMS ; excepté, la silice (15,8 mg/L à 56,8 mg/L) et les éléments métalliques en traces : le fer (0,31 à 3,82 mg/L), le manganèse (0,019 à 0,264 mg/L) et l’aluminium (0,02 à 0,232 mg/L). Les eaux sont dans la majorité chlorurées sodi-potassiques. Trois phénomènes sont à l’origine de la minéralisation des eaux : les apports des activités anthropogéniques, le pluviolessivage des sols et le contact eau-roche (principal mécanisme de production d’ions). Trois groupes d’eaux sont obtenus. La Bia se distingue des autres eaux par son importante composition chimique.Conclusion et applications : Cette étude révèle que 43% des eaux de surface de la région d’Adiaké subissent une pollution anthropique importante. En dehors de la contamination bactérienne non traitée, cette étude montre que les eaux du Toumanguié, de l’Ehania et de la lagune Ehy peuvent représenter d’importantes réserves pour l’approvisionnement en eau potable de la région.Mots-clés : Eaux de surface, Paramètres physico-chimique, Éléments Métalliques en Traces, région d’Adiaké, Côte d’Ivoire

Test d’efficacité d’un herbicide en culture d’ananas, à la station d’expérimentation et de production d’Anguédédou en Côte d’Ivoire

Objectif : Un produit à base de glyphosate (Dominator 360) est testé en vue d’évaluer son efficacité sur les adventices des cultures d’ananas. Ceci pour élargir la gamme des produits dans cette culture et de minimiser les coûts de traitement en jouant sur les doses tout en veillant à leur efficacité.Méthodologie et résultats : Le Dominator 360 est comparé à des herbicides de référence en usage sur la culture d’ananas dans la station expérimentale d’Anguédédou. Ces herbicides sont le Kalach, également à base de glyphosate et le Special 30 à base de diuron + bromacile. L’essai a été conduit suivant un bloc de Fisher randomisé, dont le dispositif est celui des témoins adjacents. Le Dominator 360 est expérimenté à trois doses : 2, 3 et 4 l/ha et les deux témoins à une seule dose : 4 l/ha pour le Kalach et 4 kg/ha pour le Special 30.Les efficacités observées sont différentes selon les doses utilisées. Le Dominator, les témoins Kalach et le Spécial 30 se sont montrés efficaces pratiquement au même titre aux doses maximales utilisées (4 l/ha et 4 kg/ha). La dose de 3 l/ha du Dominator est apparue la plus faible dose expérimentée qui présente une bonne efficacité.Conclusion et application : La dose de 3 l/ha du Dominator 360 constitue la faible dose du produit, comparée aux deux témoins utilisés dans cette étude, qui présente une bonne efficacité dans la lutte contre les adventices en cultures d’ananas. Ceci en rapport avec la baisse des doses efficaces, recommandées, pour minimiser les coûts d’achat des herbicides. Cette dose de 3 l/ha du Dominator 360 est ainsi la dose par excellence à vulgariser.Mots clefs : Herbicide, glyphosate, Dominator, efficacité, anana

Stochastic Modeling of B Lymphocyte Terminal Differentiation and Its Suppression by Dioxin

<p>Abstract</p> <p>Background</p> <p>Upon antigen encounter, naïve B lymphocytes differentiate into antibody-secreting plasma cells. This humoral immune response is suppressed by the environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and other dioxin-like compounds, which belong to the family of aryl hydrocarbon receptor (AhR) agonists.</p> <p>Results</p> <p>To achieve a better understanding of the immunotoxicity of AhR agonists and their associated health risks, we have used computer simulations to study the behavior of the gene regulatory network underlying B cell terminal differentiation. The core of this network consists of two coupled double-negative feedback loops involving transcriptional repressors Bcl-6, Blimp-1, and Pax5. Bifurcation analysis indicates that the feedback network can constitute a bistable system with two mutually exclusive transcriptional profiles corresponding to naïve B cells and plasma cells. Although individual B cells switch to the plasma cell state in an all-or-none fashion when stimulated by the polyclonal activator lipopolysaccharide (LPS), stochastic fluctuations in gene expression make the switching event probabilistic, leading to heterogeneous differentiation response among individual B cells. Moreover, stochastic gene expression renders the dose-response behavior of a population of B cells substantially graded, a result that is consistent with experimental observations. The steepness of the dose response curve for the number of plasma cells formed vs. LPS dose, as evaluated by the apparent Hill coefficient, is found to be inversely correlated to the noise level in Blimp-1 gene expression. Simulations illustrate how, through AhR-mediated repression of the AP-1 protein, TCDD reduces the probability of LPS-stimulated B cell differentiation. Interestingly, stochastic simulations predict that TCDD may destabilize the plasma cell state, possibly leading to a reversal to the B cell phenotype.</p> <p>Conclusion</p> <p>Our results suggest that stochasticity in gene expression, which renders a graded response at the cell population level, may have been exploited by the immune system to launch humoral immune response of a magnitude appropriately tuned to the antigen dose. In addition to suppressing the initiation of the humoral immune response, dioxin-like compounds may also disrupt the maintenance of the acquired immunity.</p

Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease

Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.

Parasitisme des loranthaceae dans les plantations de legumineuses arborescentes en zone forestiere de la C&#244 d'Ivoire

Leguminous trees provide edible fruits, wood, forage and the main nitrogen in ecosystems. They are increasingly used in agroforestry systems as shade for trees and for soil reclamation. However, leguminous trees are often hosts of Mistletoes, vascular parasites that destroy foliages, depreciate wood quality and cause the death of their hosts. In this study on Leguminous trees, in a forest area of Côte d'Ivoire, infestation rates and intensities of Mistletoes were assessed at the Centre National de Recherche Agronomique (CNRA) station in the district of Oumé. Results show a high sensitivity of exotic species (Acacia mangium, Acacia auriculaeformis, Albizia guachapele and Albizia lebbeck) to Mistletoes, while native species (Albizia adianthifolia and Albizia zygia) were less infested. Infestation rates seemed to be related to the position at the exploitation border, the weediness of plots and the proximity of crop land that attract Mistletoes scattering birds. The most infested leguminous tree is Albizia lebbeck and the plentiful parasitic was Tapinanthus bangwensis. Les Légumineuses arborescentes produisent des fruits comestibles, du bois, du fourrage et fournissent l'essentiel du flux d'azote dans les écosystèmes. Elles sont utilisées dans les systèmes agroforestiers pourl’ombrage et la restauration de la fertilité. Cependant, ces Légumineuses arborescentes sont parasitées par les Loranthaceae, qui détruisent le feuillage, déprécient la qualité du bois et provoquent la mort de leurshôtes. La présente étude, réalisée sur des Légumineuses arborescentes, plantées dans la zone forestière de la Côte d'Ivoire, a permis d'évaluer le taux et l'intensité d'infestation des Loranthaceae sur la station deOumé, Centre National de Recherche Agronomique (CNRA). Les résultats montrent une forte sensibilité, aux Loranthaceae, des Légumineuses arborescentes exotiques (Acacia mangium, Acacia auriculaeformis,Albizia guachapele et Albizia lebbeck), tandis que les espèces locales (Albizia adianthifolia et Albizia zygia) ont été moins infestées. Les taux d'infestation des parcelles ont semblé être liés à l'emplacementen bordure d'exploitation, au degré d'enherbement et à la proximité des espaces agricoles fréquentés par les disséminateurs des Loranthaceae (oiseaux frugivores). La Légumineuse arborescente la plus infestéea été Albizia lebbeck et la Loranthaceae la plus infestante Tapinanthus bangwensis

Outcome of undiagnosed traumatic diaphragmatic injuries: A review of our management

The authors relate on the outcomes of traumatic diaphragmatic injuries unknown early. The files of three patients have been reviewed retrospectively. All of them presented early undiagnosed injuries. The first patient had a left diaphragmatic injury consecutive to a stab wound to the left hypochondrium. The diagnosis was made 18 days later. He died 2 days after operation because of septicaemia. The second patient presented a colonic strangulation through a left diaphragmatic rupture consecutive to a stab wound three years before. A resection and anastomosis to the colon was performed. The patient left the hospital with a definitive pachypleuritis. The third patient was admitted for blunt trauma to the chest with dyspnoea. The chest X-ray showed the diaphragmatic rupture. The peri- operative exploration showed an old rupture with fibrosis banks. The lesion had been respected. The outcomes of early missed traumatic diaphragmatic rupture are various. Their treatment is sometime difficult and dangerous