L’image de l’enfant dans la stratégie de communication de l’Unicef

The image of childhood is a fundamental element of Unicef communication. The purpose of the article is to examine whether Unicef is adopting a differentiated representation of childhood in its campaigns for poor children over time and across countries. Several results stand out. Certainly, this representation evolves over time. In fact, the professionalization of Unicef communication has resulted in a greater emphasis on the emotional dimension of the communications being deployed. Admittedly, Unicef has also decided to concentrate its communication efforts more strongly in the northern countries than in the Southern countries. However, the comparison between countries shows that the arguments used by the organization does not depending on the countries. Contrary to the original hypothesis, the empirical study has shown that, with respect to the arguments used (hope versus guilt, mobilization versus compassion), Unicef does not change its visual argumentation according to the target audience. Thus, and it is a contribution of this study to researchs on humanitarian communication, the new emphasis on the emotional dimension of humanitarian communications does not imply – in the case of Unicef – to search different reactions on the part of the publics (encouraging or guilty). And this, despite the different situations and living standards of the target populations

Spiralyde A, an Antikinetoplastid Dolabellane from the Brown Alga <i>Dictyota spiralis</i>

Bioassay-guided fractionation of the antikinetoplastid extract of the brown alga Dictyota spiralis has led to the isolation of spiralyde A (1), a new dolabellane aldehyde, along with other five known related diterpenes (2&#8211;6). Their structures were determined by HRESIMS, 1D and 2D NMR spectroscopy, and comparison with data reported in the literature. The antiparasitic activity of all compounds was evaluated. Spiralyde A (1) and the known compound 3,4-epoxy-7,18-dolabelladiene (2) were the most active compounds against Leishmania amazonensis and Trypanosoma cruzi. Spiralyde A (1) was the most potent compound, comparable to benznidazole, the reference drug for trypanocidal activity

Programmed cell death in Acanthamoeba castellanii Neff induced by several molecules present in olive leaf extracts.

Therapy against Acanthamoeba infections such as Granulomatous Amoebic Encephalitis (GAE) and Acanthamoeba Keratitis (AK), remains as an issue to be solved due to the existence of a cyst stage which is highly resistant to most chemical and physical agents. Recently, the activity of Olive Leaf Extracts (OLE) was demonstrated against Acanthamoeba species. However, the molecules involved in this activity were not identified and/or evaluated. Therefore, the aim of this study was to evaluate the activity of the main molecules which are present in OLE and secondly to study their mechanism of action in Acanthamoeba. Among the tested molecules, the observed activities ranged from an IC50 of 6.59 in the case of apigenine to an IC50 > 100 μg/ml for other molecules. After that, elucidation of the mechanism of action of these molecules was evaluated by the detection of changes in the phosphatidylserine (PS) exposure, the permeability of the plasma membrane, the mitochondrial membrane potential and the ATP levels in the treated cells. Vanillic, syringic and ursolic acids induced the higher permeabilization of the plasma membrane. Nevertheless, the mitochondrial membrane was altered by all tested molecules which were also able to decrease the ATP levels to less than 50% in IC90 treated cells after 24 h. Therefore, all the molecules tested in this study could be considered as a future therapeutic alternative against Acanthamoeba spp. Further studies are needed in order to establish the true potential of these molecules against these emerging opportunistic pathogenic protozoa

In Vitro Activity of Statins against Naegleria fowleri

Naegleria fowleri causes a deadly disease called primary amoebic meningoencephalitis (PAM). Even though PAM is still considered a rare disease, the number of reported cases worldwide has been increasing each year. Among the factors to be considered for this, awareness about this disease, and also global warming, as these amoebae thrive in warm water bodies, seem to be the key factors. Until present, no fully effective drugs have been developed to treat PAM, and the current options are amphotericin B and miltefosine, which present side effects such as liver and kidney toxicity. Statins are able to inhibit the 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, which is a key enzyme for the synthesis of ergosterol of the cell membrane of these amoebae. Therefore, the in vitro activity of a group of statins was tested in this study against two types of strains of Naegleria fowleri. The obtained results showed that fluvastatin was the most effective statin tested in this study and was able to eliminate these amoebae at concentrations of 0.179 &plusmn; 0.078 to 1.682 &plusmn; 0.775 &micro;M depending on the tested strain of N. fowleri. Therefore, fluvastatin could be a potential novel therapeutic agent against this emerging pathogen

The effect of ursolic acid on the mitochondrial potential, JC-1 dye accumulates in the mitochondria of healthy cells as aggregates (red fluorescing) (Negative controle A); in cells treated with the IC₉₀ of the ursolic acid for 24 h, due to collapse of mitochondrial potential, the JC-1 dye remained in the cytoplasm in its monomeric form, which fluoresced green.

<p>The effect of ursolic acid on the mitochondrial potential, JC-1 dye accumulates in the mitochondria of healthy cells as aggregates (red fluorescing) (Negative controle A); in cells treated with the IC₉₀ of the ursolic acid for 24 h, due to collapse of mitochondrial potential, the JC-1 dye remained in the cytoplasm in its monomeric form, which fluoresced green.</p

Permeation of the <i>Acanthamoeba</i> Neff to the vital dye SYTOX^® green caused by addition of IC₉₀ of the bioactive molecules.

<p>Molecules were added to cells (10⁵ cells/ml) in the presence of 1 μM SYTOX^® green in PBS + 20 mM d-glucose and the increase in fluorescence (<i>λ</i>_exc = 485 nm, <i>λ</i>_em = 520 nm) monitored. Negative Control cells: cells labeled with the Sytox green in presence of 0.5% Methanol. Positive control contained 2.5% Triton X-100 (A). Confocal microscopy of <i>Acanthamoeba castellanii</i> Neff labeled with SYTOX^® Green. Amoeba were plated as above and incubated for 3 h with IC₉₀ of the vanillin (B), vanillic acid (C) syringic acid (D) and ursolic acid (E), Negative control (F). Cells were observed in a Leica TSC SPE- confocal microscope equipped with inverted optics (<i>λ</i>_exc = 482 nm and <i>λ</i>_em = 519 nm).</p

Screening of 24 molecules against <i>Acanthamoeba spp</i> (IC₅₀ and IC₉₀ expressed in μg/ml).

<p>Screening of 24 molecules against <i>Acanthamoeba spp</i> (IC₅₀ and IC₉₀ expressed in μg/ml).</p

Effects of the bioactive molecules against cysts were evaluated by incubating 10⁴ cysts of <i>A</i>. <i>castellanii</i> Neff with the previously calculated IC₉₀ values of the selected drugs in PYG medium, and cells were counted with a Neubauer chamber at between 96 and 168 h.

<p>Troph: Number of Trophozoite emerged from the cyst in the PYC medium.</p

Silver Nanoparticles as a Novel Potential Preventive Agent against Acanthamoeba Keratitis

Free living, cosmopolitan amoebae from Acanthamoeba genus present a serious risk to human health. As facultative human parasites, these amoebae may cause Acanthamoeba keratitis (AK). Acanthamoeba keratitis is a severe, vision-threatening corneal infection with non-specific symptoms. The number of reported AK cases worldwide has been increasing every year. Moreover, 90% of Acanthamoeba keratitis cases are related to contact lens use. Wearing and storage contact lenses not in accordance with the physicians and manufacturers recommendations are the primary key risk factors of this disease. Amoebae can easily adhere to the contact lens surface and transmit to the corneal epithelium. Preventing amoebae adhesion to the contact lens surface could significantly decrease the number of AK infections. Until now, the effective therapy against AK is still under development. Currently proposed therapies are mainly limited to the chlorhexidine digluconate combined with propamidine isethionate or hexamidine applications, which are insufficient and very toxic to the eye. Due to lack of effective treatment, looking for new potential preventive agents is crucial to decrease the number of Acanthamoeba keratitis infections, especially among contact lens users. Nanoparticles have been already included in several novel therapies against bacteria, viruses, fungi, and protist. However, their anti-amoebic potential has not been fully tested yet. The aim of this study was to assess silver nanoparticles (AgNPs) and platinum nanoparticles (PtNPs) anti-amoebic activity and influence on the amoebae adhesion to the surface of four different groups of contact lenses&mdash;classified according to the Food and Drugs Administration (FDA) guidelines. The obtained results show that both tested nanoparticles were effective against Acanthamoeba trophozoites and decreased the amoebae adhesion to the contact lens surface. AgNPs showed better anti-amoebic activity to cytotoxicity dependence and reduced amoebae adhesion in a wider spectrum of the tested contact lenses. Our studies also confirmed that ionization next to hydration of the contact lens material is a crucial parameter influencing the Acanthamoeba adhesion to the contact lens surface. In conclusion, silver nanoparticles might be considered as a novel preventive agent against Acanthamoeba keratitis infection