Soil-to-plant transfer of naphthalene and its effects on seedlings pea (Pisum sativum L.) grown on contaminated soil.

The aim of this work was to determinate effect of naphthalene at different concentrations on morphological, physiological and some metabolic responses of pea seedlings. The quantification of naphthalene and its by-products were also recorded by Gas Chromatography/ Mass Spectrometry (GC / MS) in soil and in the different plant parts (roots, stems, leaves and fruit). In our controlled laboratory studies, plants exposed to naphthalene were able to efficiently grow and maintain their content of chlorophyll and carotenoids comparatively to the control plants. However, the pollutant slightly increased the amounts of fatty acid peroxides and strongly those of malonyldialdehyde, the product of lipid peroxidation. The glutathione S transferase activity was also increased for all concentrations used especially in leaves. Chromatograms showed that naphthalene has fallen sharply in the soil or even disappeared for the highest concentration from the second to third week. Furthermore, the removal ratio of 67% of the pollutant from the soil was distributed between two metabolites (ion 47 and ion 59) in the leaves for this same concentration in only three weeks of cultivation. In parallel, the amount of pollutant remained higher in unvegetated control soil. These results suggest that seedlings of pea (Pisum sativum L.) can remove naphthalene from contaminated soil and consequently have a high potential to be used as a promising candidate for the phytoremediation of naphthalene-contaminated soil.

Purification and detoxification of petroleum refinery wastewater by electrocoagulation process.

The treatment of synthetic oily wastewater having the characteristics of a typical petroleum refinery wastewater (PRW) by electrocoagulation (EC) using iron and aluminum electrodes was conducted in an electrolytic reactor equipped with fluid recirculation. During the treatment, the emulsion stability was followed by the measurement of Zeta potential and particle sizes. Effects of some operating conditions such as electrodes material, current density and electrolysis time on removal efficiencies of turbidity, and chemical oxygen demand (COD) were investigated in detail. The PRW purification by the EC process was found to be the most effective using aluminum as the anode and cathode, current density of 60 A/m(2) and 30 min of electrolysis time. Under these conditions, the process efficiencies were 83.52% and 99.94%, respectively, for COD and turbidity removals which correspond to final values of 96 mg O2/L and 0.5 NTU. A moderate energy consumption (0.341 kWh) was needed to treat 1 m(3) of PRW. Besides, the ecotoxicity test proved that toxic substances presented in the PRW, and those inhibiting the germination growth of whet, were eliminated by the EC technique.

[Potential importance of antileukotrienes in the treatment of asthma and other inflammatory diseases: apropos of a new pharmacological class]. / Intérêt potentiel des antileucotriènes dans le traitement de l'asthme et autres pathologies inflammatoires: à propos d'une nouvelle classe pharmacologique.

OBJECTIVES: Among the mediators involved in the asthma bronchoconstriction and inflammation mechanisms, there is now substantial evidence that the sulfidopeptide leukotrienes (LTs) are important. Antagonists of their receptors and inhibitors of their synthesis have been developed. IMPORTANT POINTS: Antagonists of LTs, as well as inhibitors of their synthesis, reduce the LTs actions: bronchoconstriction, bronchial hyperresponsiveness, hypersecretion and inflammation. They produce an acute bronchodilating effect in mild asthma, reduce the hyperresponsiveness responses due to allergens, aspirin and cold and dry air, and also cutaneous and gastrointestinal reactions. Oral administrations tested during 4 or 6 weeks diminish the use of the beta-agonists, decrease the asthma symptom scores and other inflammatory signs. PERSPECTIVES AND PROJECTS: More studies for longer periods, double blind trials and comparisons with classical treatments will be necessary to define the real place of LTs antagonists in the treatment of asthma. So their efficacy has to be confirmed as well as their good tolerance profile (particularly for hepatic functions). CONCLUSION: Antagonists of receptors and synthesis inhibitors of LTs have known a recent and important development. They constitute a new therapeutic class: further studies are needed to better define the place of these new drugs in the treatment of asthma and other inflammatory diseases.