Changes in microbial and soil properties following amendment with treated and untreated olive mill wastewater

We investigated the effect of untreated and biologically treated olive mill wastewater (OMW) spreading on the soil characteristics and the microbial communities. The water holding capacity, the salinity and the content of total organic carbon, humus, total nitrogen, phosphate and potassium increased when the spread amounts of the treated or untreated OMW increased. The OMW treated soil exhibited significantly higher respiration compared to the control soil. However, the C-CO2/C(tot) ratio decreased from 1.7 in the control soil to 0.5 in the soil amended with 100 m3 ha(-1) of untreated OMW. However, it slightly decreased to 1.15 in the soil amended with 400 m3 ha(-1) of treated OMW. The treated OMW increased the total mesophylic number while the number of fungi and nitrifiers decreased. Actinomycetes and spore-forming bacteria were neither sensitive to treated nor to untreated OMW. The total coliforms increased with higher doses of treated and untreated OMW. A toxic effect of the untreated OMW appeared from 100 m3 ha(-1). This toxicity was more significant with 200 m3 ha(-1), where microflora of total mesophilic, yeasts and moulds, actinomycetes, and nitrifiers were seriously inhibited except for total coliforms and spore-forming bacteria.     

An inhibitory role for FAK in regulating proliferation: a link between limited adhesion and RhoA-ROCK signaling

Focal adhesion kinase (FAK) transduces cell adhesion to the extracellular matrix into proliferative signals. We show that FAK overexpression induced proliferation in endothelial cells, which are normally growth arrested by limited adhesion. Interestingly, displacement of FAK from adhesions by using a FAK−/− cell line or by expressing the C-terminal fragment FRNK also caused an escape of adhesion-regulated growth arrest, suggesting dual positive and negative roles for FAK in growth regulation. Expressing kinase-dead FAK-Y397F in FAK−/− cells prevented uncontrolled growth, demonstrating the antiproliferative function of inactive FAK. Unlike FAK overexpression–induced growth, loss of growth control in FAK−/− or FRNK-expressing cells increased RhoA activity, cytoskeletal tension, and focal adhesion formation. ROCK inhibition rescued adhesion-dependent growth control in these cells, and expression of constitutively active RhoA or ROCK dysregulated growth. These findings demonstrate the ability of FAK to suppress and promote growth, and underscore the importance of multiple mechanisms, even from one molecule, to control cell proliferation.     

The microRNAs (miRs) overexpressing mesenchymal stem cells (MSCs) therapy in neurological disorders; hope or hype

Altered expression of multiple miRNAs was found to be extensively involved in the pathogenesis of different neurological disorders including Alzheimer's disease, Parkinson's disease, stroke, epilepsy, multiple sclerosis, amyotrophic lateral sclerosis, and Huntington's disease. One of the biggest concerns within gene-based therapy is the delivery of the therapeutic microRNAs to the intended place, which is obligated to surpass the biological barriers without undergoing degradation in the bloodstream or renal excretion. Hence, the delivery of modified and unmodified miRNA molecules using excellent vehicles is required. In this light, mesenchymal stem cells (MSCs) have attracted increasing attention. The MSCs can be genetically modified to express or overexpress a particular microRNA aimed with promote neurogenesis and neuroprotection. The current review has focused on the therapeutic capabilities of microRNAs-overexpressing MSCs to ameliorate functional deficits in neurological conditions.     

Virioplankton Community Structure in Tunisian Solar Salterns

The microbial community inhabiting Sfax solar salterns on the east coast of Tunisia has been studied by means of different molecular and culture-dependent tools that have unveiled the presence of novel microbial groups as well as a community structure different from that of other coastal hypersaline environments. We have focused on the study of the viral assemblages of these salterns and their changes along the salinity gradient and over time. Viruses from three ponds (C4, M1, and TS) encompassing salinities from moderately hypersaline to saturated (around 14, 19, and 35%, respectively) were sampled in May and October 2009 and analyzed by transmission electron microscopy (TEM) and pulsed-field gel electrophoresis (PFGE). Additionally, for all three October samples and the May TS sample, viral metagenomic DNA was cloned in fosmids, end sequenced, and analyzed. Viral concentration, as well as virus-to-cell ratios, increased along the salinity gradient, with around 10¹⁰ virus-like particles (VLPs)/ml in close-to-saturation ponds, which represents the highest viral concentration reported so far for aquatic systems. Four distinct morphologies could be observed with TEM (spherical, tailed, spindled, and filamentous) but with various proportions in the different samples. Metagenomic analyses indicated that every pond harbored a distinct viral assemblage whose G+C content could be roughly correlated with that of the active part of the microbial community that may have constituted the putative hosts. As previously reported for hypersaline metaviromes, most sequences did not have matches in the databases, although some were conserved among the Sfax metaviromes. BLASTx, BLASTp, and dinucleotide frequency analyses indicated that (i) factors additional to salinity could be structuring viral communities and (ii) every metavirome had unique gene contents and dinucleotide frequencies. Comparison with hypersaline metaviromes available in the databases indicated that the viral assemblages present in close-to-saturation environments located thousands of kilometers apart presented some common traits among them in spite of their differences regarding the putative hosts. A small core metavirome for close-to-saturation systems was found that contained 7 sequences of around 100 nucleotides (nt) whose function was not hinted at by in silico search results, although it most likely represents properties essential for hyperhalophilic viruses.     

Sweet block copolymer nanoparticles: preparation and self-assembly of fully oligosaccharide-based amphiphile

The preparation of biocompatible nanocarriers that have potential applications in the cosmetic and health industries is highly desired. The self-assembly of amphiphilic block copolymers displaying biosourced polysaccharides at the surface is one of the most promising approaches. In the continuity of our works related to the preparation of "hybrid" amphiphilic oligosaccharide-based block copolymers, we present here the design of a new generation of self-assembled nanoparticles composed entirely of oligosaccharide-based amphiphilic block co-oligomers (BCO). These systems are defined by a covalent linkage of the two saccharidic blocks through their reducing end units, resulting in a sweet "head-to-head" connection. As an example, we have prepared and studied a BCO in which the hydrophilic part is composed of a free maltoheptaosyl derivative clicked to a hydrophobic part composed of a peracetylated maltoheptaosyl derivative. This amphiphilic BCO self-assembles to form spherical micelles in water with an average diameter of 30 nm. The efficient enzymatic hydrolysis of the maltoheptaose that constitutes the shell of the micelles was followed by light scattering and colorimetric methods.     

The effect of monosodium glutamate on the cerebellar cortex of male albino rats and the protective role of vitamin C (histological and immunohistochemical study)

Monosodium glutamate (MSG) is a natural constituent of many foods and was reported to have neurotoxic effects. The aim of this study was to investigate the possible toxic effect of MSG on histological and glial fibrillary acidic protein (GFAP) immunohistochemical features of cerebellar cortex of albino rats and to evaluate the possible protective role of vitamin C against this effect. Thirty rats were divided into 3 equal groups. Group I, control; Group II, treated with 3 g/kg/day of MSG and Group III, received 100 mg/kg/day of vitamin C simultaneously with MSG. After 14 days, cerebellar tissues were obtained and processed to prepare sections stained with H&E, toluidine blue. The GFAP was detected immunohistochemically. Histological examination of group II showed degenerative changes as pyknotic Purkinje and granule cells with areas of degeneration surrounded by inflammatory cells in granular layer. However, group III showed more preserved histological structure of cerebellar cortex. Statistical analysis of area percent of the GFAP immunoreaction among studied groups showed significant increase in group III when compared with group I and group II. However, a non significant increase was detected in group II when compared with group I. In conclusion, MSG has neurotoxic effect leading to degenerative changes in neurons and astrocytes in cerebellar cortex of albino rats and vitamin C supplementation could protect from these changes. Getting more attention to the constituents of food products is recommended and vitamin C could be advised to protect people from food oxidants additives.     

Estimation of 3D shape, internal density and mechanics of proximal femur by combining bone mineral density images with shape and density templates

Measurement of bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA) alone is only a moderate predictor of fracture risk. Finite element analysis (FEA) of bone mechanics, based on DXA images, may improve the prediction of fracture risk. We developed a method to estimate the 3D shape and density distribution of the proximal femur, using a 2D BMD image and a femur shape template. Proximal femurs of eighteen human cadavers were imaged using computed tomography and divided into two sets (N = 9 + 9). The template was created from the samples in first set by using 3D generalized Procrustes analysis and thin-plate splines. Subsequently, the template and 2D BMD image were utilized to estimate the shape and internal density distribution of the femurs in the second set. Finally, FEA was conducted based on the original and the estimated bone models to evaluate the effect of geometrical and density distributional errors on the mechanical strength. The volumetric errors induced by the estimation itself were low (<1.4%). In the estimation of bones in the second set, the mean distance difference between the estimated and the original bone surfaces was 0.80 ± 0.19 mm, suggesting feasible estimation of the femoral shape. The mean absolute error in voxel-by-voxel BMD was 120±8 mg cm?3. In FEA, the stiffness of the proximal femur differed by -7±16% between the original and estimated bones. The present method, in comparison with methods used in previous studies, improved the prediction of the geometry, the BMD distribution and the mechanical characteristics of the proximal femur. Potentially, the proposed method could ultimately improve the determination of bone fracture risk.     

Development and application of a miniaturized gel electrophoresis device for protein analysis

The present article describes a miniaturized polyacrylamide slab gel electrophoresis-chip (PASGE-Chip) that can rapidly separate a set of predefined samples as well as cell lysate samples for clinical diagnosis. The chip consists of a polymethyl methacrylate (PMMA) upper unit (25 x 30 x 10 mm, width x length x depth) with integrated buffer chambers, running electrodes and loading wells and a bottom unit comprising a silicon dioxide-coated silicon plate with embossed gel chamber (11 x 15 x 0.37 mm). This miniaturized device was designed to be fast, easy to use and cheap to produce. The polyacrylamide slab gel electrophoresis can be performed in less than 10 min with low voltage. The gel-to-gel repeatability is around 3.8%. The limit of detection is approx. 10 ng as determined by Coomassie staining of selected standard proteins, and corresponds to a 10-fold increase in sensitivity as compared with a common size PAGE analysis device (e.g. 10 x 7 cm). The device was successfully applied to peptide mass fingerprint analysis, protein sequencing and ultra-sensitive immunodetection, and the performance was compared to a commonly used regular PAGE device.     

Evaluation of bone plate with low-stiffness material in terms of stress distribution

The aim of this study is to evaluate a newly developed bone plate with low-stiffness material in terms of stress distribution. In this numerical study, 3D finite element models of the bone plate with low-stiffness material and traditional bone plates made of stainless steel and Ti alloy have been developed by using the ANSYS software. Stress analyses have been carried out for all three models under the same loading and boundary conditions. Compressive stresses occurring in the intact portion of the bone (tibia) and at the fractured interface at different stages of bone healing have been investigated for all three types of bone-plate systems. The results obtained have been compared and presented in graphs. It has been seen that the bone plate with low-stiffness material offers less stress-shielding to the bone, providing a higher compressive stress at the fractured interface to induce accelerated healing in comparison with Ti alloy and stainless-steel bone plate. In addition, the effects of low-stiffness materials with different Young's modulus on stress distribution at the fractured interface have been investigated in the newly developed bone-plate system. The results showed that when a certain value of Young's modulus of low-stiffness material is exceeded, increase in stiffness of the bone plate does not occur to a large extent and stress distributions and micro-motions at the fractured interface do not change considerably.