Phytochemical and biological investigation of Hymenocallis littoralis SALISB

A phytochemical investigation of the bulbs and flowers of Hymenocallis littoralis SALISB., cultivated in Egypt, was carried out, which resulted in the isolation of four alkaloids, lycorine (1), hippeastrine (2), 11-hydroxyvittatine (3), and (+)-8-O-demethylmaritidine (4), and of two flavonoids, quercetin 3'-O-glucoside (5), and rutin (6). The volatile constituents of the plant flowers were analyzed for the first time by GC/MS, which led to the identification of 26 known compounds (Table 1). Finally, the antimicrobial activity of the petroleum ether extract of the flowers of H. littoralis was investigated.     

Leishmania major: effects of proteophosphoglycan on reactive oxygen species, IL-12, IFN-gamma and IL-10 production in healthy individuals

Protozoan parasites of the genus Leishmania secrete a range of proteophosphoglycans (PPG) known to be important for successful colonization of Leishmania in the sandfly and for virulence in the mammalian host. PPGs are a large family of extensively glycosylated proteins with some unusual and unique features. In this study we purified PPG from culture supernatant of Leishmania major metacyclic promastigotes. In discontinuous SDS-PAGE, PPG could not enter the resolving gel but after mild acid hydrolysis several bands resolved. Agarose gel electrophoresis and immunoblot analysis using monoclonal antibody (WIC 79.3) indicated that the PPG preparation consisted of heterogeneous molecules. Compositional analysis showed that the PPG preparation contained 67% glycan, 28% protein and 5% phosphate. Additionally, the effect of PPG on reactive oxygen species (ROS) production and induction of IL-10, IL-12 and IFN-γ secretion by human peripheral blood mononuclear cells (PBMCs) isolated from healthy individuals was investigated. The water-soluble secreted form of PPG at a concentration of 1 μg glycan/ml seems to be a potent inducer of ROS and IL-10 and to a lesser extent of IFN-γ and IL-12. Cytokines and ROS production was decreased in a dose-dependent manner as the concentration of PPG was increased to 100 μg glycan/ml.     

Survival of Vibrio fluvialis in seawater under starvation conditions

The viability of Vibrio fluvialis in seawater microcosms, with and without sediment was investigated. The strain survived as culturable bacteria for at least 1 year and the expression of its virulence factors was maintained. In microcosms containing sediment Vibrio fluvialis was more stable. Viable but nonculturable (VBNC) cells of Vibrio fluvialis were able to resuscitate to the culturable state up to 6 years of incubation in marine sediment. These cells recuperate their initial biochemical characteristics after 3 months of incubation in marine broth. Amplified 16S ribosomal DNA (rDNA) restriction analysis (ARDRA) was used to confirm that it is the same strain of Vibrio fluvialis which resists in all microcosms during a long period of time.     

New rapid validated HPTLC method for the determination of galanthamine in Amaryllidaceae plant extracts

The work reported in this paper aims at developing an accurate, specific, repeatable and robust HPTLC method for the determination of galanthamine in different Amaryllidaceae plant extracts.     

In-vitro anti-<Emphasis Type="Italic">Vibrio</Emphasis> spp. activity and chemical composition of some Tunisian aromatic plants

The chemical composition of five aromatic plants (Mentha longifolia, M. pulegium, Eugenia caryophyllata, Thymus vulgaris and Rosmarinus officinalis) frequently used in food preparation in Tunisia was analysed by GC-MS. The antimicrobial effect of the essential oils obtained from these plants was tested against Vibrio alginolyticus, Vibrio parahaemolyticus, Vibrio vulnificus and Vibrio fluvialis strains. Thyme oil exhibited a high level of antimicrobial activities against Vibrio spp. strains. The diameter of the zones of growth inhibition for V. parahaemolyticus species was interestingly high (ranging from 14.66 to 28 mm). The MIC and MBC values were interestingly low for thyme oil (MIC 0.078–0.156 mg/ml) and (MBC >0.31–1.25 mg/ml). These results showed that these plants especially thyme and clove, can be to be used for seafood preparation to protect against contamination by Vibrio spp. strains. An erratum to this article can be found at     

Dimeric transferrin inhibits phagocytosis of residual bodies by testicular rat Sertoli cells

Transferrin is well known as an iron transport glycoprotein. Dimeric or tetrameric transferrin forms have recently been reported to modulate phagocytosis by human leukocytes. It is mainly synthesized by the liver, and also by other sources, such as Sertoli cells of the testis. Sertoli cells show a strong phagocytic activity toward apoptotic germ cells and residual bodies. Here, we provide evidence that purified human dimeric transferrin from commercial sources decreased residual body phagocytosis, unlike monomeric transferrin. The presence of iron appeared essential for dimeric transferrin inhibitory activity. Importantly, dimeric transferrin could be visualized by immunoblotting in Sertoli cell lysates as well as in culture media, indicating that dimeric transferrin could be physiologically secreted by Sertoli cells. By siRNA-mediated knockdown, we show that endogenous transferrin significantly inhibited residual body ingestion by Sertoli cells. These results are the first to identify dimeric transferrin in Sertoli cells and to demonstrate its implication as a physiological modulator of residual body phagocytosis by Sertoli cells.     

Effect of Environmental Conditions on Hydrophobicity of Marine Bacteria Adapted to Textile Effluent Treatment

Summary Bioflocculation of bacteria isolated from the marine biomass acclimatized to textile wastewater has been achieved. Pseudomonas was the main genus found in the marine biomass. This bacterium showed an important hydrophobicity but slightly weaker than that of pilot plant genera adapted to the conventional sewage. This hydrophobicity provided the bacteria with hydrophobic characters, especially those of the polymeric extracellular substances (ECS) released in the sewage. Whereas some factors such as the divalent cations, calcium and magnesium had an effect on this bacterial hydrophobicity, glucose concentration did not have any impact. Furthermore, the physiological state of the cells hatched in the sewage had an impact on the hydrophobicity. Indeed, during the logarithmic growth phase, cell hydrophobicity increase enhanced floc formation, thus improving wastewater treatment.     

The Cell Adhesion Molecule Necl-4/CADM4 Serves as a Novel Regulator for Contact Inhibition of Cell Movement and Proliferation

Contact inhibition of cell movement and proliferation is critical for proper organogenesis and tissue remodeling. We show here a novel regulatory mechanism for this contact inhibition using cultured vascular endothelial cells. When the cells were confluently cultured, Necl-4 was up-regulated and localized at cell–cell contact sites where it cis-interacted with the vascular endothelial growth factor (VEGF) receptor. This interaction inhibited the tyrosine-phosphorylation of the VEGF receptor through protein-tyrosine phosphatase, non-receptor type 13 (PTPN13), eventually reducing cell movement and proliferation. When the cells were sparsely cultured, Necl-4 was down-regulated but accumulated at leading edges where it inhibited the activation of Rho-associated protein kinase through PTPN13, eventually facilitating the VEGF-induced activation of Rac1 and enhancing cell movement. Necl-4 further facilitated the activation of extracellular signal-regulated kinase 1/2, eventually enhancing cell proliferation. Thus, Necl-4 serves as a novel regulator for contact inhibition of cell movement and proliferation cooperatively with the VEGF receptor and PTPN13.     

Electrostatic Solitary Pulses in a Dusty Electronegative Magnetoplasma

The nonlinear characteristics of dust-electron-acoustic (DEA) waves in a dusty electronegative magnetoplasma system consisting of nonextensive hot electrons, inertial cold electrons, positively charged static ions, and negatively charged immobile dust grains has been investigated. In this observation, the well-known reductive perturbation technique is employed to determine different types of nonlinear dynamical equations, namely, magnetized Korteweg–de Vries (KdV), magnetized modified KdV (mKdV), and magnetized Gardner equations. The stationary solitary wave and double layer solution of these three equations, which describe the characteristics of solitary waves and double layers of DEA waves, are obtained and numerically analyzed. It is noticed that various plasma parameters (viz., hot electron nonextensivity, positive ion-to-cold electron number density ratio, dust-to-cold electron number density ratio, etc.) significantly affect the basic properties of DEA solitary waves (DEASWs) and Gardner solitons (GSs). The prodigious results found from this theoretical investigation may be useful for researchers to investigate the nonlinear structures in various space and laboratory plasmas.     

Shining a light on cell signaling in leukemia through proteomics: relevance for the clinic

Introduction: Although cure rates for acute leukemia have steadily improved over the past decades, leukemia remains a deadly disease. Enhanced risk stratification and new therapies are needed to improve outcome. Extensive genetic analyses have identified many mutations that contribute to the development of leukemia. However, most mutations occur infrequently and most gene alterations have been difficult to target. Most patients have more than one driver mutation in combination with secondary mutations, that result in a leukemic transformation via the alteration of proteins. The proteomics of acute leukemia could more directly identify proteins to facilitate risk stratification, predict chemoresistance and aid selection of therapy.

Areas covered: This review discusses aberrantly expressed proteins identified by mass spectrometry and reverse phase protein arrays and their relationship to survival. In addition, we will discuss proteins in the context of functionally related protein groups.

Expert commentary: Proteomics is a powerful tool to analyze protein abundance and functional alterations simultaneously for large numbers of patients. In the forthcoming years, validation of tools to quickly assess protein levels to enable routine rapid profiling of proteins with differential abundance and functional activation may be used as adjuncts to aid in therapy selection and to provide additional prognostic insights.