30 research outputs found
NO resistance in angiotensin II–induced hypertension is associated with S-nitrosation of soluble guanylyl cyclase
Effets des pratiques biopesticides sur l’entomofaune et la production de tomate (Solanum lycopersicum) dans la station expérimentale de l’ISAE (Dakar-Sénégal)
In Senegal, the tomato represents 22.5% of the overall vegetable production estimated at 70,000 tons and is the second most important vegetable crop. However, its production is exposed to many constraints, including the threat of insects. To face the problems posed by these pests, it is necessary to implement effective control methods, capable of reducing the pest population to a tolerable economic threshold. For this reason, this study was conducted in the experimental field of application and incubator of ISAE at UCAD in 2021 in order to test the effectiveness of biological controls on insect pests and tomato yield. A Fisher experimental set-up consisting of three (3) blocks divided into nine (9) plots was installed. The results of this study show that the number of insects is significantly higher (14.7) in untreated plants. On the other hand, the incidence of insects is significantly lower (8.08) with plants treated with Capscicum annum than with plants treated with Azadirachta indica (8.5).
Key words: Azadirachta indica, Capscicum annum, incidence, Production, pest, TomatoAu Sénégal, la tomate représente 22,5 % de la production globale de légumes estimée à 710 000 tonnes et occupe la deuxième place des cultures maraichères. Cependant, sa production est exposée à de nombreuses contraintes dont la menace des insectes. Pour faire face aux problèmes posés par ces déprédateurs, il est nécessaire de mettre en œuvre des méthodes de lutte efficaces, capables de réduire la population des ravageurs à un seuil économique tolérable. C’est pour cela que cette étude a été réalisée dans le champ d’expérimentation d’application et incubateur de l’ISAE à l’UCAD en 2021 dans le but de tester l’efficacité des luttes biologiques sur les insectes ravageurs et sur le rendement de la tomate. Un dispositif expérimental de Fisher constitué en trois (3) blocs repartis en neuf (9) placettes a été installé. Les résultats de cette étude montrent que le nombre d’insectes est significativement plus élevé (14,7) sur les plantes non traitées. Par contre, l’incidence des insectes est significativement plus faible (8,08) avec les plantes traitées avec le Capscicum annum qu’avec les plantes traitées à l’Azadirachta indica (8,5).
Mots clés : Azadirachta indica, Capscicum annum, incidence, Production, ravageur, Tomat
Overall and Gender-Specific Effects of Intermittent Preventive Treatment of Malaria with Artemisinin-Based Combination Therapies among Schoolchildren in Mali: A Three-Group Open Label Randomized Controlled Trial.
Intermittent preventive treatment of malaria among schoolchildren (IPTsc) reduces clinical malaria, asymptomatic parasitemia, and anemia. The effects of IPTsc by gender have not been studied longitudinally. We investigated overall IPTsc efficacy and conducted a secondary analysis to explore gender-specific differences. We enrolled schoolchildren aged 6-13 years in an open-label, rolling-cohort randomized controlled trial between September 2007 and February 2013 in Kolle, Mali. Annually, schoolchildren received two full-treatment courses of sulfadoxine-pyrimethamine (SP) plus artesunate, or amodiaquine (AQ) plus artesunate, or no malaria treatment as control. We used mixed-effects generalized linear models to estimate differences in treatment outcomes across groups with interaction terms to explore gender-specific differences associated with Plasmodium falciparum infection, hemoglobin, and grade point averages (GPA) based on standardized testing. Overall, 305 students contributed 4,564 observations. Compared with the control, SP plus artesunate and AQ plus artesunate reduced the odds of P. falciparum infection (odds ratio [OR]: 0.33, 95% CI: 0.26-0.43; OR: 0.46, 95% CI: 0.36-0.59). We found strong evidence of increased mean hemoglobin concentrations (g/dL) in the SP plus artesunate group versus control (difference +0.37, 95% CI: 0.13-0.58). Collectively, schoolchildren given AQ plus artesunate had higher mean GPA (difference +0.36, 95% CI: 0.02-0.69) relative to control. Schoolgirls, compared with schoolboys, given SP plus artesunate had greater improvement in GPA (+0.50, 95% CI: -0.02 to 1.02 versus -0.27, 95% CI: -0.71 to 0.16); interaction P = 0.048, respectively. The IPTsc decreases P. falciparum infections in schoolchildren. Treatment regimens that include longer-acting drugs may be more effective at decreasing malaria-related anemia and improving educational outcomes as observed among girls in this setting
The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance
INTRODUCTION
Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic.
RATIONALE
We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs).
RESULTS
Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants.
CONCLUSION
Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century
Ontologies combining design semantics and semantics used in operation and maintenance: Feedback from EDF power plants case studies
http://ceur-ws.org/Vol-2900/WS4Paper3.pdfInternational audienceUsual langage pratices of industrial maintenance are rather different from those used during the power plants design. Maintenance is part of O&M (Operation & Maintenance) whose concepts are more “operational” than the ones of design phases. As co-researches in this work, we instigated these practices for a better understandability between semantic fields, as this inquiry offers food for thought, the theoretical as well as the practical. Also, the role of ontologies are questioned while the real case study are from the EDF (Electricity of France) power plants
Percutaneous pelvic osteotomy in cerebral palsy patients: Surgical technique and indications
To describe the surgical technique of and indications for percutaneous pelvic osteotomy in patients with severe cerebral palsy
F-18 FDG PET/CT Findings in Pulmonary Necrotizing Sarcoid Granulomatosis.
Necrotizing sarcoid granulomatosis (NSG) is a rare systemic disease that was described by Liebow in 1973. Dyspnea and chest pain may be present, as in our first patient; however, 25% of patients are asymptomatic, as our second patient. The typical radiographic findings are nonspecific: single or multiple lung opacities, with common involvement of the pleura. To the best of our knowledge, fluorodeoxyglucose (FDG) PET has only been reported in one case of NSG, which was atypical as it occurred in an adolescent. We report 2 cases, confirming that the lesions of NSG are FDG positive, showing a typical pattern of multiple bilateral lung nodules (imaged with PET/CT in 1 case). FDG imaging has a potential role when this distribution is observed on CT, to guide the surgical biopsy and show the actual extent of the disease
Phylogeny of nodulation genes and symbiotic diversity of <em>Acacia senegal</em> (L.) Willd. and <em>A-seyal</em> (Del.) mesorhizobium strains from different regions of Senegal
International audienceAcacia senegal and Acacia seyal are small, deciduous legume trees, most highly valued for nitrogen fixation and for the production of gum arabic, a commodity of international trade since ancient times. Symbiotic nitrogen fixation by legumes represents the main natural input of atmospheric N-2 into ecosystems which may ultimately benefit all organisms. We analyzed the nod and nif symbiotic genes and symbiotic properties of root-nodulating bacteria isolated from A. senegal and A. seyal in Senegal. The symbiotic genes of rhizobial strains from the two Acacia species were closed to those of Mesorhizobium plurifarium and grouped separately in the phylogenetic trees. Phylogeny of rhizobial nitrogen fixation gene nifH was similar to those of nodulation genes (nodA and nodC). All A. senegal rhizobial strains showed identical nodA, nodC, and nifH gene sequences. By contrast, A. seyal rhizobial strains exhibited different symbiotic gene sequences. Efficiency tests demonstrated that inoculation of both Acacia species significantly affected nodulation, total dry weight, acetylene reduction activity (ARA), and specific acetylene reduction activity (SARA) of plants. However, these cross-inoculation tests did not show any specificity of Mesorhizobium strains toward a given Acacia host species in terms of infectivity and efficiency as stated by principal component analysis (PCA). This study demonstrates that large-scale inoculation of A. senegal and A. seyal in the framework of reafforestation programs requires a preliminary step of rhizobial strain selection for both Acacia species
Soluble guanylyl cyclase is a target of angiotensin II-induced nitrosative stress in a hypertensive rat model
Nitric oxide (NO) by activating soluble guanylyl cyclase (sGC) is involved in vascular homeostasis via induction of smooth muscle relaxation. In cardiovascular diseases (CVDs), endothelial dysfunction with altered vascular reactivity is mostly attributed to decreased NO bioavailability via oxidative stress. However, in several studies, relaxation to NO is only partially restored by exogenous NO donors, suggesting sGC impairment. Conflicting results have been reported regarding the nature of this impairment, ranging from decreased expression of one or both subunits of sGC to heme oxidation. We showed that sGC activity is impaired by thiol S-nitrosation. Recently, angiotensin II (ANG II) chronic treatment, which induces hypertension, was shown to generate nitrosative stress in addition to oxidative stress. We hypothesized that S-nitrosation of sGC occurs in ANG II-induced hypertension, thereby leading to desensitization of sGC to NO hence vascular dysfunction. As expected, ANG II infusion increases blood pressure, aorta remodeling, and protein S-nitrosation. Intravital microscopy indicated that cremaster arterioles are resistant to NO-induced vasodilation in vivo in anesthetized ANG II-treated rats. Concomitantly, NO-induced cGMP production decreases, which correlated with S-nitrosation of sGC in hypertensive rats. This study suggests that S-nitrosation of sGC by ANG II contributes to vascular dysfunction. This was confirmed in vitro by using A7r5 smooth muscle cells infected with adenoviruses expressing sGC or cysteine mutants: ANG II decreases NO-stimulated activity in the wild-type but not in one mutant, C516A. This result indicates that cysteine 516 of sGC mediates ANG II-induced desensitization to NO in cells.
soluble guanylyl cyclase (sGC) is the main receptor for nitric oxide (NO) and the enzyme responsible for the conversion of GTP into cGMP. As such, the NO-receptor sGC is crucially involved in the physiology of the cardiovascular system by modulating vessel tone. Indeed, mice lacking this receptor are hypertensive (5). Oxidative stress is associated with cardiovascular diseases (CVDs) such as hypertension, atherosclerosis, and diabetes. Most oxidative CVDs are accompanied by endothelial dysfunction and impaired vascular reactivity with decreased NO bioavailability. Nonetheless, it should be pointed out that oxidative stress affects as well the smooth muscle cell (SMC) layers where sGC is expressed. It has been reported that reactive oxygen species (ROS) alter sGC expression and activity (19, 25, 29). We (21) have previously shown that in vitro and in vivo S-nitrosation of sGC impairs its ability to be activated by NO. In particular, we established that infusion of low therapeutic doses of nitroglycerin in rats for 3 days induces S-nitrosation of sGC and correlates with desensitization of sGC to NO stimulation. Importantly, the nitroglycerin treatment was associated with reduced relaxation of arterioles to exogenous NO donors, thus implicating directly sGC activity (22). Association between protein S-nitrosation and diseases such as diabetes (2, 30) has been reported but association with other CVDs such as hypertension has not been directly addressed. Angiotensin II (ANG II) is a peptide involved in blood pressure regulation and renovascular hypertension (11, 14, 18) and elevated levels of ANG II induce hypertension. ANG II infusion or treatment, which is clearly established as an inducer of oxidative stress via activation of NADPH oxidases in vivo (17) and in vascular smooth muscle cells such as A7r5 (31), was recently reported to generate global S-nitrosation (3).
Most studies have focused on endothelial dysfunction in ANG II-linked hypertension, yet a decreased NO responsiveness, e.g., NO resistance, has been observed and could be due to scavenging of NO by reactive oxygen species, to decreased sGC activity, or to a decreased sGC expression, as reported in overactive renin-angiotensin system of hypertensive TGR rats (7). Based on our finding that sGC is desensitized to NO by S-nitrosation leading to decreased relaxation in vivo and that ANG II generates nitrosative stress, we hypothesized that sGC activity could be impaired via S-nitrosation in ANG II-induced hypertension thereby contributing to decreased vascular reactivity. Thus we assayed in ANG II-induced hypertension rat model, the level of S-nitrosation of the sGC, whether sGC was desensitized to NO, and measured vascular NO resistance in vivo (so far studies by others on NO responsiveness and vascular reactivity have been done on isolated vessels in organ chamber). In parallel, we explored the molecular mechanism of sGC desensitization by ANG II in A7r5 SMC, which are depleted for endogenous sGC, by infecting the SMC with adenoviruses expressing wild-type (WT) sGC and Cys mutants of sGC and measuring NO-stimulated sGC activity in the infected cells treated or not with ANG II