Intestinal parasitism among waste pickers in Mato Grosso do Sul, Midwest Brazil

ABSTRACT The purpose of this study was to estimate the prevalence of intestinal parasites in both cooperative-affiliated and independent waste pickers operating at the municipal sanitary landfill in Campo Grande, Mato Grosso do Sul, Brazil, and associate these findings with hemoglobin, eosinophils, vitamin A and C levels and interleukin 5 and 10 (IL-5 and IL-10) production. Biological samples were collected, in addition to clinical, epidemiological, and sociodemographic data. Stool analyzes were based on sedimentation by centrifugation and on spontaneous sedimentation. High-performance liquid chromatography was used to determine vitamin A and C levels. ELISA was employed to quantify interleukins. Intestinal parasites were found in 29 of the 66 subjects assessed (43.9%). Endolimax nana (22.7%), Entamoeba coli (21.1%), Giardia lamblia (6.1%), Entamoeba histolytica/E. dispar (4.5%), and Ascaris lumbricoides (4.5%) were the most prevalent species. Pathogenic parasites were detected in 11 individuals (16.7%). Hypovitaminoses A and C were detected in 19.6% (13/66) and 98.4% (65/66) of subjects, respectively. IL-5 and IL-10 production was observed in 21 (31.8%) and 32 (48.4%) subjects, respectively. Infection with pathogenic intestinal parasites was not a cause of vitamin A and C deficiency or IL-5 and IL-10 production among these workers

Diamond biosensors

International audienceDiamond is wide band gap semiconductor presenting many extreme properties. It is notably known as the most stable material with the highest chemical inertness, the highest mechanical hardness and the highest thermal conductivity. Since the mid 1970s it has been possible to grow synthetic diamond by several methods. High Pressure High Temperature techniques that mimic the diamond formation in the earth's crust were first developed. Then Chemical Vapour Deposition (CVD) methods enable diamond growth at laboratory scale as well as the control the P-type and N-type doping of diamond. Besides, it is possible to tune the diamond electrical properties form very resistive to metallic thanks to the P-type doping with boron. Current achievements have enabled the development of diamond sensors that can operate in extreme conditions. After being used for its mechanical and thermal properties, diamond was considered for chemical sensing. In fact the chemical stability and the close-to-metallic conductivity of diamond make it a powerful tool for electrochemical detection in various environment. Furthermore, the diamond is an ideal substrate for surface functionalization thanks to the wide and very known carbon based chemistry. Such a feature combined to the outstanding electrochemical properties of the diamond electrodes have enable the production of very efficient biosensors and biochips. Diamond is also an interesting sensor for medical imaging. Its carbon nature, well tolerated by living tissues, are actually very useful for its use as a biosensor capable of working in contact with bio-environments as well as real neuronal interfaces. Both those topics will be discussed in details in the following pages. In a first part an overview on electrochemical based biosensors and their performance is described. Then in a second half of the chapter, novel applications where diamond is directly used as an electrode for neural tissue interfacing is presented in details