Introduction: Innate immunity is crucial to reducing parasite burden and contributing to survival in severe malaria. Monocytes are key actors in the innate response and, like macrophages, are plastic cells whose function and phenotype are regulated by the signals from the microenvironment. In the context of cerebral malaria (CM), monocyte response constitutes an important issue to understand.
View Article and Find Full Text PDFThe composition of essential oils varies according to culture conditions and climate, which induces a need for simple and inexpensive characterization methods close to the place of extraction. This appears particularly important for developing countries. Herein, we develop an analytical strategy to determine the thymol content in Ocimum Gratissimum, a medicinal plant from Benin.
View Article and Find Full Text PDFCerebral malaria (CM) is one of the most severe forms of malaria and is a neuropathology that can lead to death. Monocytes have been shown to accumulate in the brain microvasculature at the onset of neurological symptoms during CM. Monocytes have a remarkable ability to adapt their function to their microenvironment from pro-inflammatory to resolving activities.
View Article and Find Full Text PDFThis work presents 4 open source potentiostat solutions for performing accurate measurements in cyclic voltammetry and square wave voltammetry at a low price. A very simple and easy to reproduce analogic board (c.a.
View Article and Find Full Text PDFExposure to pesticides through eyes, skin, ingestion and inhalation may affects human health by interfering with immune cells, such as macrophages. We evaluated, in vitro, the effect of six pesticides widely used in apple arboriculture on the functions of human monocyte-derived macrophages (hMDMs). hMDMs were cultured for 4 or 24 h with or without pesticides (0.
View Article and Find Full Text PDFBackground: While malaria morbidity and mortality have declined since 2000, viral central nervous system infections appear to be an important, underestimated cause of coma in malaria-endemic Eastern Africa. We aimed to describe the etiology of non-traumatic comas in young children in Benin, as well as their management and early outcomes, and to identify factors associated with death.
Methods: From March to November 2018, we enrolled all HIV-negative children aged between 2 and 6 years, with a Blantyre Coma Score ≤ 2, in this prospective observational study.
Cerebral malaria (CM) is the severest form of Plasmodium falciparum infection. Children under 5 years old are those most vulnerable to CM, and they consequently have the highest risk of malaria-related death. Parasite-associated factors leading to CM are not yet fully elucidated.
View Article and Find Full Text PDFBackground: The disparity of harvesting locations can influence the chemical composition of a plant species, which could affect its quality and bioactivity. Terminalia albida is widely used in traditional Guinean medicine whose activity against malaria has been validated in vitro and in murine models. The present work investigated the antimalarial properties and chemical composition of two samples of T.
View Article and Find Full Text PDFPfEMP1 is the major antigen involved in -infected erythrocyte sequestration in cerebrovascular endothelium. While some PfEMP1 domains have been associated with clinical phenotypes of malaria, formal associations between the expression of a specific domain and the adhesion properties of clinical isolates are limited. In this context, 73 cerebral malaria (CM) and 98 uncomplicated malaria (UM) Beninese children were recruited.
View Article and Find Full Text PDFZiram, a zinc dithiocarbamate is widely used worldwide as a fungicide in agriculture. In order to investigate ziram-induced changes in macrophage functions and polarization, human monocytes-derived macrophages in culture were treated with ziram at 0.01-10 μmol.
View Article and Find Full Text PDFColonic macrophages are considered to be major effectors of inflammatory bowel diseases (IBDs) and the control of gut inflammation through C-type lectin receptors is an emerging concept. We show that during colitis, the loss of dectin-1 on myeloid cells prevents intestinal inflammation, while the lack of mannose receptor (MR) exacerbates it. A marked increase in dectin-1 expression in dextran sulfate sodium (DSS)-exposed MR-deficient mice supports the critical contribution of dectin-1 to colitis outcome.
View Article and Find Full Text PDFBackground: The development of Plasmodium resistance to the last effective anti-malarial drugs necessitates the urgent development of new anti-malarial therapeutic strategies. To this end, plants are an important source of new molecules. The objective of this study was to evaluate the anti-malarial effects of Terminalia albida, a plant used in Guinean traditional medicine, as well as its anti-inflammatory and antioxidant properties, which may be useful in treating cases of severe malaria.
View Article and Find Full Text PDFMonocytes are plastic heterogeneous immune cells involved in host-parasite interactions critical for malaria pathogenesis. Human monocytes have been subdivided into three populations based on surface expression of CD14 and CD16. We hypothesised that proportions and phenotypes of circulating monocyte subsets can be markers of severity or fatality in children with malaria.
View Article and Find Full Text PDFEthnopharmacological Relevance: Malaria is still a highly challenging public health issue in southern Lao PDR, with increasing cases of artemisinin resistance and Plasmodium vivax infections which are more complicated to treat. Traditional medicine has a long history of use in Laos, and is primarily practised by traditional village healers, who possess unique bodies of transmitted knowledge focused on herbal prescriptions, including those for the treatment of malaria. Villagers also use plants for healthcare in the home.
View Article and Find Full Text PDFBackground: PfEMP1 is the major protein from parasitic origin involved in the pathophysiology of severe malaria, and PfEMP1 domain subtypes are associated with the infection outcome. In addition, PfEMP1 variability is endless and current publicly available protein repositories do not reflect the high diversity of the sequences of PfEMP1 proteins. The identification of PfEMP1 protein sequences expressed with samples remains challenging.
View Article and Find Full Text PDFIntroduction: In 2016, an estimated 216 million cases and 445 000 deaths of malaria occurred worldwide, in 91 countries. In Benin, malaria causes 26.8% of consultation and hospitalisation motif in the general population and 20.
View Article and Find Full Text PDFBackground: Plasmodium falciparum malaria is still one of the most deadly pathology worldwide. Efficient treatment is jeopardized by parasite resistance to artemisinin and its derivatives, and by poor access to treatment in endemic regions. Anti-malarial traditional remedies still offer new tracks for identifying promising antiplasmodial molecules, and a way to ensure that all people have access to care.
View Article and Find Full Text PDFDespite the growing knowledge with regard to the immunomodulatory properties of host defense peptides, their impact on macrophage differentiation and on its associated microbicidal functions is still poorly understood. Here, we demonstrated that the P17, a new cationic antimicrobial peptide from ant venom, induces an alternative phenotype of human monocyte-derived macrophages (h-MDMs). This phenotype is characterized by a C-type lectin receptors (CLRs) signature composed of mannose receptor (MR) and Dectin-1 expression.
View Article and Find Full Text PDFBackground: Pregnancy-associated malaria (PAM) constitutes one of the most severe forms of malaria infection leading to fetal growth restriction and high risk of infant death. The severity of the pathology is largely attributed to the recruitment of monocytes and macrophages in the placenta which is evidenced by dysregulated inflammation found in placental blood. Importantly, CD36(+) monocytes/macrophages are also thought to participate in the tight control of the pro- and anti-inflammatory responses following Plasmodium detection through elimination of apoptotic cells and malaria-infected erythrocytes, internalization and recycling of oxidized forms of low-density lipoprotein and collaboration with TLR2 in pro-inflammatory response.
View Article and Find Full Text PDFThe mechanisms underlying the heterogeneity of clinical malaria remain largely unknown. We hypothesized that differential gene expression contributes to phenotypic variation of parasites which results in a specific interaction with the host, leading to different clinical features of malaria. In this study, we analyzed the transcriptomes of isolates obtained from asymptomatic carriers and patients with uncomplicated or cerebral malaria.
View Article and Find Full Text PDFPathogens, which have recently colonized a new host species or new populations of the same host, are interesting models for understanding how populations may evolve in response to novel environments. During its colonization of South America from Africa, Plasmodium falciparum, the main agent of malaria, has been exposed to new conditions in distinctive new human populations (Amerindian and populations of mixed origins) that likely exerted new selective pressures on the parasite's genome. Among the genes that might have experienced strong selective pressures in response to these environmental changes, the eba genes (erythrocyte-binding antigens genes), which are involved in the invasion of the human red blood cells, constitute good candidates.
View Article and Find Full Text PDFArtemisinin-based combination therapies (ACTs) are the main option to treat malaria, and their efficacy and susceptibility must be closely monitored to avoid resistance. We assessed the association of Plasmodium falciparum polymorphisms and ex vivo drug susceptibility with clinical effectiveness. Patients enrolled in an effectiveness trial comparing artemether-lumefantrine (n = 96), fixed-dose artesunate-amodiaquine (n = 96), and sulfadoxine-pyrimethamine (n = 48) for the treatment of uncomplicated malaria 2007 in Benin were assessed.
View Article and Find Full Text PDFAn alarming increase in microbial resistance to traditional drugs and classical pharmacophores has spurred the search for new antimicrobial compounds. Indolone-N-oxides (INODs) possess a redox pharmacophore with promising, recently established, antimalarial activities. In this study, the anti-infectious properties of a series of INODs were investigated.
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