Blood lead, cadmium and mercury among children from urban, industrial and rural areas of Fez Boulemane Region (Morocco): Relevant factors and early renal effects

Objectives: To describe blood lead (Pb-B), cadmium (Cd-B) and mercury (Hg-B) levels in children living in urban, industrial and rural areas in Fez city (north of Morocco) and to identify the determinants and some renal effects of exposure. Material and Methods: The study was conducted from June 2007 to January 2008 in 209 school children (113 girls, 96 boys), aged 6-12 years, from urban, industrial and rural areas in Fez city. Interview and questionnaires data were obtained. Blood and urinary samples were analyzed. Results: The mean of blood lead levels (Pb-B) in our population was 55.53 μg/l (range: 7.5-231.1 μg/l). Children from the urban area had higher blood lead levels (BLLs) mean (82.36 μg/l) than children from industrial and rural areas (48.23 and 35.99 μg/l, respectively); with no significant difference between boys and girls. BLLs were associated with traffic intensity, passive smoking and infancy in the urban area. The mean of blood cadmium levels (BCLs) was 0.22 μg/l (range: 0.06-0.68 μg/l), with no difference between various areas. Rural boys had higher BCLs mean than rural girls, but no gender influence was noticed in the other areas. BCLs were associated with the number of cigarettes smoked at children's homes. The blood mercury levels (BMLs) mean was 0.49 μg/l (range: 0.01-5.31 μg/l). The BMLs mean was higher in urban and industrial areas than in the rural area with no gender-related difference. BMLs were associated with amalgam fillings and infancy in the urban area. About 8% of the children had BLLs ≥ 100 μg/l particularly in the urban area, microalbuminuria and a decrease in height were noticed in girls from the inner city of Fez and that can be related to high BLLs (89.45 μg/l). Conclusions: There is a need to control and regulate potential sources of contamination by these trace elements in children; particularly for lead

Technico-Economic Study of a Photovoltaic Pumping System Using a Variable-Frequency Drive Converter

This paper presents a technical-economic study of a photovoltaic pumping system using an inverter with a Variable Frequency Drive (VFD) to improve system efficiency. We propose a comparative study between two pumping station projects located in places very close to each other, in order to consider that they are exposed to the same meteorological data. One of the projects has the maximum power tracking technique (MPPT), while the other project does not have this technique. The study will compare the various experimental surveys carried out in the field with modeling results using Matlab Simulink

Effect of Ferromagnetic Material on the Reduction of Parasitic Emission in Near Field

International audienceIn this article the results of measurement in near-field concerning a 16-bit microcontroller from Freescale are reported, with and without a film of ferromagnetic material (Permalloy) plated against the surface of its package. This material improves near-field electromagnetic compatibility performances by reducing, in good proportion, the parasitic emission

Atteinte cardiaque au cours de la dystrophie myotonique de Steinert: Expérience marocaine, à propos de 18 cas

La maladie de Steinert ou dystrophie myotonique de type 1 (DM1) est une maladie génétique à transmission autosomique dominante caractériséepar une myotonie et une atteinte de plusieurs organes dont le coeur. L'atteinte cardiaque est la plus grave des atteintes systémiques puisqu'elleconditionne le pronostic vital. Ce travail a pour but de déterminer les anomalies cardiaques rencontrées au cours de la DM1 et de mettre enexergue l'intérêt d'un examen cardiaque rigoureux et régulier,  indépendamment de la sévérité de l'atteinte neuromusculaire, ainsi que l'apport des examens cardiaques complémentaires et notamment l'exploration électrophysiologique. 18 patients atteints de DM1 ont  bénéficiés d'une exploration cardiaque systématique. Il s'agit de 9 hommes et de 9 femmes, d'âge moyen de 41,8 +/- 16,2 ans. 66 p.100 des patients sont symptomatiques sur le plan cardiovasculaire. Les  anomalies électrocardiographiques sont dominées par un trouble de la conduction intraventriculaire dans 16 p.100 des cas et un BAV de 1er degré dans 16 p.100 des cas. L'Holter ECG objective une hyperexcitabilité à l'étage atrial et/ou ventriculaire dans 50p.100 des cas. L'ETT est normale chez 95 p.100 des patients. L'exploration électrophysiologique, réalisée chez 4 patients symptomatiques, a objectivé un bloc tronculaire dans un cas ayant conduit à l'implantation d'un PM double chambre. Un seul patient est décédé suite à une détresse respiratoire. Enfin, on n'a pas noté de corrélation entre l'atteinte cardiaque et neuromusculaire. Une exploration cardiaque est indispensable chez tout patient atteint de DM1, en dépit de l'absence de symptômes, et un bilan annuel minimal s'impose pour guetter un éventuel trouble rythmique et/ou conductif, fatal en l'absence de traitement adéquat

Contrast-ultrasound dispersion imaging of cancer neovascularization by mutual-information analysis

Being an established marker for cancer growth, neovascularization is probed by several approaches with the aim of cancer imaging. Recently, analysis of the dispersion kinetics of ultrasound contrast agents (UCAs) has been proposed as a promising approach for localizing neovascularization in prostate cancer. Determined by multipath trajectories through the microvasculature, dispersion enables characterization of the microvascular architecture and, therefore, localization of cancer neovascularization. Analysis of the spatiotemporal similarity among indicator dilution curves (IDCs) measured at each pixel by dynamic contrast-enhanced ultrasound imaging has been proposed to assess the local dispersion kinetics of UCAs. Only linear similarity measures, such as temporal correlation or spectral coherence, have been used up until now. Here we investigate the use of nonlinear similarity measures by estimation of the statistical dependency between IDCs. In particular, dispersion maps are generated by estimation of the mutual information between IDCs. The method is tested for prostate cancer localization and the results compared with the histology results in 15 patients referred for radical prostatectomy because of biopsy-proven prostate cancer. With sensitivity and specificity equal to 84% and 85%, respectively, and receiver operating characteristic curve area equal to 0.92, our results outperformed those obtained by any other parameter, motivating further validation with a larger dataset and with other types of cancer

Contrast-enhanced ultrasound Angiogenesis imaging by mutual information analysis for Prostate Cancer localization

OBJECTIVE: The role of angiogenesis in cancer growth has stimulated research aimed at non-invasive cancer detection by blood perfusion imaging. Recently, contrast ultrasound dispersion imaging was proposed as an alternative method for angiogenesis imaging. After the intravenous injection of an ultrasoundcontrast- agent bolus, dispersion can be indirectly estimated from the local similarity between neighboring time-intensity curves (TICs) measured by ultrasound imaging. Up until now, only linear similarity measures have been investigated. Motivated by the promising results of this approach in prostate cancer (PCa), we developed a novel dispersion estimation method based on mutual information, thus including nonlinear similarity, to further improve its ability to localize PCa. METHODS: First, a simulation study was performed to establish the theoretical link between dispersion and mutual information. Next, the method's ability to localize PCa was validated in vivo in 23 patients (58 datasets) referred for radical prostatectomy by comparison with histology. RESULTS: A monotonic relationship between dispersion and mutual information was demonstrated. The in-vivo study resulted in a receiver operating characteristic (ROC) curve area equal to 0.77, which was superior (p=0.21-0.24) to that obtained by linear similarity measures (0.74-0.75) and (p<0.05) to that by conventional perfusion parameters (0.70). CONCLUSION: Mutual information between neighboring TICs can be used to indirectly estimate contrast dispersion and can lead to more accurate PCa localization. SIGNIFICANCE: An improved PCa localization method can possibly lead to better grading and staging of tumors, and support focal-treatment guidance. Moreover, future employment of the method in other types of angiogenic cancer can be considered