Treatment and seroconversion in a cohort of children suffering from recent chronic Chagas infection in Yoro, Honduras

Between 1999-2002, Médécins Sans Frontières-Spain implemented a project seeking to determine the efficacy and safety of benznidazole in the treatment of recent chronic Chagas disease in a cohort of seropositive children in the Yoro Department, Honduras. A total of 24,471 children were screened for Trypanosoma cruzi IgG antibodies through conventional enzyme-linked immunosorbent assays (ELISA) on filter paper. Recombinant ELISA (0.93% seroprevalence) showed 256 initially reactive cases, including 232 confirmed positive cases. Of these, 231 individuals were treated with benznidazole (7.5 mg/kg/day) for 60 days and were followed with a strict weekly medical control and follow-up protocol. At the end of the project, 229 patients were examined by the Honduras Secretariat of Health for post-treatment serological assessments; 88.2% seroconverted after 18 months and 93.9% seroconverted after three years. No differences were found in the seroconversion rates according to age or sex. Most of the side effects of the treatment were minor. These results support the argument that in areas where T. cruzi I is predominant and in areas affected by T. cruzi II, when vector transmission has been interrupted, Chagas disease diagnosis and treatment are feasible, necessary and ethically indisputable

Behaviour of the clay cover of a site for storing nuclear waste of verylow activity submitted to differential settlement of underlying waste:laboratory and field bending tests

International audienceThe behaviour of the cover barrier of a site for storing nuclear waste of very low activity isstudied. The risk of a bending of the clay layer in case of differential settlements within underlying waste isparticularly studied. Laboratory and field bending tests are performed. Influence of the water content on themechanical behaviour of the clay is examined. Initialization and propagation of cracks are studied. The limitvalue of the extension strain of the clay layer without cracking is characterized. Results of field and laboratorybending tests are presented. The main aim is to optimize the use of clay as landfill cover, in terms ofconditions of implementation (water content, compaction energy)

Cerium negatively impacts the nutritional status in rapeseed

Cerium (Ce) has been reported to be both beneficial and harmful to plants. This contradiction deserves explanation in the light of increased anthropogenic release of Ce in the environment. Ce tolerance and accumulation were evaluated in hydroponically cultivated Brassica napus L. (rapeseed). Ce and other nutrient concentrations were measured with increasing Ce concentration in the nutrient solution. Moreover, Ce and calcium(Ca) accumulationwere evaluated at different Ca and Ce concentrations in nutrient solution and a Michaelis-Menten type inhibition model considering Ce and Ca competition was tested. Plants were also sprayed with Ce solution in Ca-deficient media. Ce decreased the growth and root function,which affected shoot nutritional status. Calciumwas the most severely inhibited nutrient in both roots and shoots. High Ca concentrations in the nutrient solution inhibited Ce accumulation in a non-competitive way. Moreover, phosphorus (P) precipitated Ce inside root cells. Ce spraying did not alleviate Ca deficiency symptoms and the results were critically compared to the available literature

Changes in Physiological and Agronomical Parameters of Barley (Hordeum vulgare) Exposed to Cerium and Titanium Dioxide Nanoparticles

The aims of our experiment were to evaluate the uptake and translocation of cerium and titaniumoxide nanoparticles and to verify their effects on the growth cycle of barley (Hordeum vulgare L.). Barley plants were grown to physiological maturity in soil enriched with either 0, 500 or 1000 mg kg1 cerium oxide nanoparticles (nCeO2) or titanium oxide nanoparticles (nTiO2) and their combination. The growth cycle of nCeO2 and nTiO2 treated plants was about 10 days longer than the controls. In nCeO2 treated plants the number of tillers, leaf area and the number of spikes per plant were reduced respectively by 35.5%, 28.3% and 30% (p \ua4 0.05). nTiO2 stimulated plant growth and compensated for the adverse effects of nCeO2. Concentrations of Ce and Ti in aboveground plant fractions were minute. The fate of nanomaterials within the plant tissues was different. Crystalline nTiO2 aggregates were detected within the leaf tissues of barley, whereas nCeO2 was not present in the form of nanoclusters

Nanotechnology in Agriculture: New Opportunities and Perspectives

The prediction that in 2050 our planet will be populated by over 9 billion people is quite reliable. This will pose serious problems with food, water and energy supply, particularly in less-developed countries. Considering that the human pressure over natural resources has already reached critical levels, international agencies such as the World Bank and UN Food and Agriculture Organization (FAO) are soliciting scientific research in order to identify innovative solutions to support the primary sector. Nanotechnology is a rapidly evolving field with the potential to take forward the agriculture and food industry with new tools which promise to increase food production in a sustainable manner and to protect crops from pests. Such expectations are coupled with some uncertainties about the fate of nanomaterials in the agro-environment. However, the field application of engineered nanomaterials (ENMs) has not been properly investigated yet, and many aspects have only been considered theoretically or with models, which make it difficult to properly assess the usefulness of ENMs for plant fertilization and protection

Targeting CD226/DNAX accessory molecule-1 (DNAM-1) in collagen-induced arthritis mouse models

International audienceBackground: Genetic studies have pointed out that CD226 variants, encoding DNAM-1, could be associated with susceptibility to rheumatoid arthritis. Therefore, we aimed to determine the influence of DNAM-1 on the development of arthritis using the collagen-induced arthritis (CIA) mouse model. Methods: CIA was induced in mice on a DBA/1 background, treated in parallel with a DNAM-1 neutralizing monoclonal antibody, a control IgG and PBS, respectively. CIA was also induced in mice deficient for DNAM-1(dnam1−/−) and control dnam-1+/+ mice on a C57/BL6 background. Mice were monitored for clinical and ultrasound signs of arthritis. Histological analysis was performed to search for inflammatory infiltrates and erosions. The Mann–Whitney U test for non-related samples was used for statistical analysis. Results: There was a non-significant trend for a less arthritic phenotype in mice receiving anti-DNAM-1 mAb at both clinical, ultrasound and histological assessments. But, we did not observe any difference between dnam1+/+ and dnam1−/− mice for incidence nor severity of clinical arthritis. Histological analysis revealed inflammatory scores similar in both groups, without evidence of erosion. Collagen antibodies levels were similar in all mice, confirming immunization with collagen. Conclusion: Despite some clues suggesting a role of DNAM-1 in arthritis, these complementary approaches demonstrate no contribution of CD226/DNAM-1 in the arthritic phenotype. These results contrast with previous studies showing a role in vivo of DNAM-1 in some autoimmune disorders

Decreased peripheral health service utilisation during an outbreak of Marburg haemorrhagic fever, Uíge, Angola, 2005.

In 2005, a Marburg haemorrhagic fever (MHF) outbreak occurred in Uíge province, Angola, which had its epicentre in Uíge municipality. Concurrently, a health facility located a considerable distance from the outbreak's epicentre reported a drastic reduction in attendance, possibly due to a remote effect of the ongoing MHF outbreak. Health officials should devise strategies to ensure that communities far from a filovirus haemorrhagic fever epicentre are not adversely affected by interventions at the epicentre and, to the greatest extent possible, ensure that these peripheral communities receive essential medical care during an epidemic

Application of Nanotechnology in Agriculture: Assessment of TiO2 Nanoparticle Effects on Barley

Many aspects associated with the application of nanotechnology to agricultural activities are still unknown. In particular, there is not enough information on nanotoxicology in crops and we do not know the fate of nanoparticles in crops. Multiple experiments were carried out to study the effects of titanium oxide nanoparticles (nTiO2) on barley (Hordeum vulgare). Germinating seeds were exposed to 0, 500, 1000, and 2000 mg l−1nTiO2. Seed germination percentage, mitotic index, root elongation, and Ti concentration in seedlings were observed. In a greenhouse experiment, plants of barley were grown to physiological maturity in control soil and soil enriched with 500 and 1000 mg nTiO2 mg kg−1, respectively. The duration of the growth cycle and the plant biomass was influenced by nTiO2 compared to control plants. Concentrations of Ti were not very high with the exception of roots. However, the nTiO2 soil amendment had an impact on composition and nutritional quality of barley grains. Concentrations of Ca, Mn, and Zn in kernels were increased by nTiO2 treatments. Concentration of amino acids was affected by the treatments as well. nTiO2 treatments have the potential to influence the food chain and processing and economics of barley

High-protein-low-carbohydrate diet: deleterious metabolic and cardiovascular effects depend on age

High-protein-low-carbohydrate (HP-LC) diets have become widespread. Yet their deleterious consequences, especially on glucose metabolism and arteries, have already been underlined. Our previous study (2) has already shown glucose intolerance with major arterial dysfunction in very old mice subjected to an HP-LC diet. The hypothesis of this work was that this diet had an age-dependent deleterious metabolic and cardiovascular outcome. Two groups of mice, young and adult (3 and 6 mo old), were subjected for 12 wk to a standard or to an HP-LC diet. Glucose and lipid metabolism was studied. The cardiovascular system was explored from the functional stage with Doppler-echography to the molecular stage (arterial reactivity, mRNA, immunohistochemistry). Young mice did not exhibit any significant metabolic modification, whereas adult mice presented marked glucose intolerance associated with an increase in resistin and triglyceride levels. These metabolic disturbances were responsible for cardiovascular damages only in adult mice, with decreased aortic distensibility and left ventricle dysfunction. These seemed to be the consequence of arterial dysfunctions. Mesenteric arteries were the worst affected with a major oxidative stress, whereas aorta function seemed to be maintained with an appreciable role of cyclooxygenase-2 to preserve endothelial function. This study highlights for the first time the age-dependent deleterious effects of an HP-LC diet on metabolism, with glucose intolerance and lipid disorders and vascular (especially microvessels) and cardiac functions. This work shows that HP-LC lead to equivalent cardiovascular alterations, as observed in very old age, and underlines the danger of such diet