Carbohydrate–Lectin Interaction on Graphene-Coated Surface Plasmon Resonance (SPR) Interfaces

The paper describes the detection of carbohydrate–lectin interaction on graphene-on-metal surface plasmon resonance (SPR) interfaces. Graphene-coated gold-based SPR interfaces were formed through the transfer of large-area graphene grown by chemical vapor deposition (CVD) on polycrystalline Cu foils. The method allowed successful transfer of single- and double-layered graphene sheets onto the SPR interfaces in a reproducible manner. Functionalization of the graphene interface with mannose was achieved by simple immersion into a mannose aqueous solution (100 mM), resulting in noncovalent interactions between the aromatic ring structure of graphene and mannose. The utility of the carbohydrate-modified graphene-on-gold interface for the selective and sensitive detection of carbohydrate–lectin interactions was demonstrated using model lectins from Lens culinaris (LC) and Triticum vulgaris (TV). While LC lectin binds specifically to mannopyranoside units, TV lectin has an affinity for N-acetyl glucosamine and sialic acid residues.     

Alginate Nanoparticles Enhance Anti-Clostridium perfringens Activity of the Leaderless Two-Peptide Enterocin DD14 and Affect Expression of Some Virulence Factors

Probiotics and Antimicrobial Proteins - Here, we report a novel approach to improve the anti-Clostridium perfringens activity of the leaderless two-peptide enterocin 14 (EntDD14), produced by...     

Emergence pattern,site selection,and seasonal regulation of Onychogomphus costae Selys, 1885 (Odonata: Gomphidae) in northeastern Algeria

Emergence and seasonal regulation of the dragonfly Onychogomphus costae Selys, 1885, were surveyed thoroughly during two consecutive years from two nearby stretches upstream the Seybouse River, northeastern Algeria. The emergence season started in mid-May and lasted 68 and 58 days showing a peak in late May and early June in 2011 and 2012, respectively. During the two years 2011 and 2012, 50% of annual emergence occurred after 25 and 22 days, respectively. Sex ratio was slightly but not significantly male biased. Female exuviae were recorded at higher height than males. Height of the exuviae fixation was positively correlated to support height and head width. Percentage mortality at emergence was mainly due to deformity and predation counting from 7.9% to 9.15% of the total emergent population. The species seasonal regulation is inferred and discussed based on the emergence temporal pattern and larval development.     

A new actinomycete strain SK4-6 producing secondary metabolite effective against methicillin-resistant Staphylococcus aureus

A new actinomycete strain designated SK4-6, was isolated. This organism exhibited strong activity against bacteria including methicillin-resistant Staphylococcus aureus and Micrococcus luteus, in addition to the causative agents of Candidiasis and Aspergillosis diseases, Candida albicans and Aspergillus species respectively. Morphological and chemical studies indicated that this organism belongs to the genus Streptomyces. Analysis of the 16S rRNA sequence of strain SK4-6 showed a high similarity, 99%, with S. qinlingensis. Optimization of cultural conditions was carried out using Plackett–Burman statistical design where seven variables were examined. Starch, pH and inoculum size showed a positive effect on the production of the active substances, however, sucrose, (NH₄)₂SO₄ and yeast extract repress the production.     

Acute Taxol nephrotoxicity: Histological and ultrastructural studies of mice kidney parenchyma

Taxol is a microtubule inhibitor drug widely used in treatment of many types of cancer. Nephrotoxicity is the most hazardous effect complicating chemotherapy in general and kidney functions must be monitored early during any chemotherapeutic course. The main objective of the present study was to investigate the effect of acute Taxol nephrotoxicity in mice. In the present study Taxol at different doses; MD, ID and MTD (0.6, 1.15 and 1.7 mg/kg), respectively, was given by intra-peritoneal route to 54 adult male mice with an average body weight of 20–25 g. Kidney samples was taken 6, 24, 48 h following administration, fixed in 10% neutral buffered formalin, paraffin sections 5 μm thick were stained by haematoxylin and eosin and PAS and then examined for histological changes. Samples from animals treated by the maximum dose (MTD = 1.7 mg/kg) for 48 h were fixed in 3% gluteraldehyde in phosphate buffer (pH 7.4) and processed for transmission electron microscope. Taxol given for short duration was found to produce marked degenerative changes in kidney parenchyma even in minimum tolerated dose (MD = 0.6 mg/kg). Individual variations were observed regarding the degree of nephrotoxicity. There was marked loss of renal tubules epithelial lining, damage of brush border and formation of hyaline casts within the damaged tubules. The alterations were in the form of both necrotic and apoptotic changes in the kidney tubules. Focal atrophy of glomerular tufts was also observed. Vascular congestion and degenerative changes in renal blood vessels were occasionally evident in some samples. Ultrastructure study revealed damage of glomerular membrane. Proximal tubule showed loss of basal infoldings, damage of brush border, mitochondrial degeneration and nuclear changes. Distal tubules also showed demarked degenerative changes. Increased frequency of micronuclei proved that Taxol had genotoxic effects in mice bone marrow cells. In conclusion Taxol had nephrotoxic effect on mice kidney that must be considered during its use as a chemotherapeutic agent in human.     

Polar growth in pollen tubes is associated with spatially confined dynamic changes in cell mechanical properties

Cellular morphogenesis involves changes to cellular size and shape which in the case of walled cells implies the mechanical deformation of the extracellular matrix. So far, technical challenges have made quantitative mechanical measurements of this process at subcellular scale impossible. We used micro-indentation to investigate the dynamic changes in the cellular mechanical properties during the onset of spatially confined growth activities in plant cells. Pollen tubes are cellular protuberances that have a strictly unidirectional growth pattern. Micro-indentation of these cells revealed that the initial formation of a cylindrical protuberance is preceded by a local reduction in cellular stiffness. Similar cellular softening was observed before the onset of a rapid growth phase in cells with oscillating growth pattern. These findings provide the first quantitative cytomechanical data that confirm the important role of the mechanical properties of the cell wall for local cellular growth processes. They are consistent with a conceptual model that explains pollen tube oscillatory growth based on the relationship between turgor pressure and tensile resistance in the apical cell wall. To further confirm the significance of cell mechanics, we artificially manipulated the mechanical cell wall properties as well as the turgor pressure. We observed that these changes affected the oscillation profile and were able to induce oscillatory behavior in steadily growing tubes.     

Masitinib treatment in patients with progressive multiple sclerosis: a randomized pilot study

ABSTRACT: BACKGROUND: Treatment options for patients suffering from progressive forms of multiple sclerosis (MS) remain inadequate. Mast cells actively participate in the pathogenesis of MS, in part because they release large amounts of various mediators that sustain the inflammatory network. Masitinib, a selective oral tyrosine kinase inhibitor, effectively inhibits the survival, migration and activity of mast cells. This exploratory study assessed the safety and clinical benefit of masitinib in the treatment of primary progressive MS (PPMS) or relapse-free secondary progressive MS (rfSPMS). METHODS: Multicenter, randomized, placebo-controlled, proof-of-concept trial. Masitinib was administered orally at 3 to 6 mg/kg/day for at least 12 months, with dose adjustment permitted in event of insufficient response with no toxicity. The primary response endpoint was the change relative to baseline in the multiple sclerosis functional composite score (MSFC). Clinical response was defined as an increase in MSFC score relative to baseline of > 100%. RESULTS: Thirty-five patients were randomized to receive masitinib (N = 27) or placebo (N = 8). Masitinib was relatively well tolerated with the most common adverse events being asthenia, rash, nausea, edema, and diarrhea. The overall frequency of adverse events was similar to the placebo group, however, a higher incidence of severe and serious events was associated with masitinib treatment. Masitinib appeared to have a positive effect on MS-related impairment for PPMS and rfSPMS patients, as evidenced by an improvement in MSFC scores relative to baseline, compared with a worsening MSFC score in patients receiving placebo; +103% +/- 189 versus -60% +/- 190 at month-12, respectively. This positive albeit non-statistically significant response was observed as early as month-3 and sustained through to month-18, with similar trends seen in the PPMS and rfSPMS subpopulations. A total of 7/17 (41%) assessable masitinib patients reported clinical response following 12 months of treatment (according to the modified intent-to-treat population, observed cases) compared with none in the placebo group. The Expanded Disability Status Scale remained stable for both treatment groups. CONCLUSION: These data suggest that masitinib is of therapeutic benefit to PPMS and rfSPMS patients and could therefore represent an innovative avenue of treatment for this disease. This exploratory trial provides evidence that may support a larger placebo-controlled investigation.