Disposable potentiometric sensors for monitoring cholinesterase activity.

A highly sensitive disposable screen-printed butyrylcholine (BuCh) potentiometric sensor, based on heptakis (2,3,6-tri-o-methyl)-ß-cyclodextrin (ß-CD) as ionophore, was developed for butyrylcholinesterase (BuChE) activity monitoring. The proposed sensors have been characterized and optimized according to the constituents of homemade printing carbon ink including ß-CD, anionic sites, and plasticizer. The fabricated sensor showed Nernstian responses from 10(-6) to 10(-2)mol L(-1) with detection limit of 8 × 10(-7)mol L(-1), fast response time (1.6s) and adequate shelf-life (6 months). Improved selectivity towards BuCh with minimal interference from choline (Ch) was achieved and the sensor was used for determination of 0.06-1.25 U mL(-1) BuChE. The developed disposable sensors have been successfully applied for real-time intoxication monitoring through assaying cholinesterases (ChEs) activity in human serum. Determination of organophosphate pesticide was conducted by measuring their inhibition of BuChE with successful assaying of malathion in insecticide samples with high accuracy and precision.

Elastokine-mediated up-regulation of MT1-MMP is triggered by nitric oxide in endothelial cells.

Membrane-type I matrix metalloproteinase (MT1-MMP) has been previously reported to be up-regulated in human microvascular endothelial cell-1 line (HMEC) by elastin-derived peptides (elastokines). The aim of the present study was to identify the signaling pathways responsible for this effect. We showed that elastokines such as (VGVAPG)(3) peptide and kappa elastin induced nitric oxide (NO) production in a time-, concentration- and receptor-dependent manner as it could be abolished by lactose and a receptor-derived competitive peptide. As evidenced by the use of NO synthase inhibitors, elastokine-mediated up-regulation of MT1-MMP and pseudotube formation on Matrigel required NO production through activation of the PI(3)-kinase/Akt/NO synthase and NO/cGMP/Erk1/2 pathways. Elastokines induced both PI(3)-kinase p110gamma sub-unit, Akt and Erk1/2 activation, as shown by a transient increase in phospho-Akt and phospho-Erk1/2, reaching a maximum after 5 and 15 min incubation, respectively. Inhibitors of PI(3)-kinase and MEK1/2 suppressed elastokine-mediated MT1-MMP expression at both the mRNA and protein levels, and decreased the ability of elastokines to accelerate pseudotube formation. Besides, elastokines mediated a time- and concentration-dependent increase of cGMP, suggesting a link between NO and MT1-MMP expression. This was validated by the use of a guanylyl cyclase inhibitor, a NO donor and a cGMP analog. The guanylyl cyclase inhibitor abolished the stimulatory effect of elastokines on MT1-MMP expression. Inversely, the cGMP analog, mimicked the effect of both elastokines and NO donor in a concentration- and time-dependent manner. Overall, our results demonstrated that such elastokine properties through NO and MT1-MMP may be of importance in the context of tumour progression.

Phenology of Phlebotomus papatasi (Diptera: Psychodidae) relative to the seasonal prevalence of zoonotic cutaneous leishmaniasis in central Tunisia.

The population density of Phlebotomus papatasi Scopoli (Diptera: Psychodidae), vector of Leishmania major Yakimoff & Schokhor (Kinetoplastida: Trypanosomatidae), the etiologic agent of zoonotic cutaneous leishmaniasis (ZCL), was assessed May-November 2005 in central Tunisia by using sticky traps. The densities of P. papatasi were found to peak in early spring and again in the autumn. The lowest densities were observed in August. Prevalence of ZCL in the governorate of Sidi Bouzid peaks in December, 3 to 3.5 mo after the fall sand fly population peak, suggesting a close temporal association with the abundance of P. papatasi.

[Migration phenomena and urbanization as an object lesson: Mauritania]. / Les phenomenes migratoires et l'urbanisation comme objet d'enseignement: la Mauritanie.

PIP: Mauritania had been a country of nomads traveling long distances to water holes, cemeteries, and oases. A teacher was responsible for teaching young children about the Koran. The best students attended a traveling university to receive personalized teaching at a higher level. Between 1965 and 1988, the spatial distribution of the population changed considerably (nomads, 78% vs. 12%; settled rural dwellers, 15% vs. 41% [45% in 1977]; urban dwellers, 8% vs. 47%). The leading reasons for a settled life, especially in 1965-1980, were desertification and aridity and their effects on water sources and grazing lands. Other contributing factors included iron and copper mining, creation of new states after the war in the Western Sahara, birth of new towns (e.g., the capital Nouakchott), and suppression of slavery. Urbanization grew 10%/year (20%/year for Nouakchott between 1962-1977) after independence. The new towns were mining and industrial centers. Spatial redistribution of the population is a vast and fruitful subject to include in teaching curricula at all levels (primary, secondary, and postsecondary) and for almost all disciplines (e.g., geography, history, civics, and mathematics). The author has provided a model curriculum for grades 1 through 6 of primary school. For example, contents for 6th grade history and geography include causes for the shift from a nomadic lifestyle to a sedentary lifestyle and urbanization, impact on the family and the environment, international migrations, and case study of a town. The author also lists comprehensive knowledge, proficiency, and behavior objectives. Behavior objectives are: participant in manual activities and agricultural work; help uprooted classmates better integrate themselves in a new welcoming milieu; support rural development efforts; and preserve or strengthen links between the city and rural areas through exchange visits and correspondence. Using arrows on a map to show the flow of nomads from departure zones to arrival zones helps visually demonstrate the migrations.^ieng