Gastrokine 1 regulates NF‐κB signaling pathway and cytokine expression in gastric cancers

Gastrokine 1 (GKN1) plays an important role in the gastric mucosal defense mechanism and also acts as a functional gastric tumor suppressor. In this study, we examined the effect of GKN1 on the expression of inflammatory mediators, including NF‐κB, COX‐2, and cytokines in GKN1‐transfected AGS cells and shGKN1‐transfected HFE‐145 cells. Lymphocyte migration and cell viability were also analyzed after treatment with GKN1 and inflammatory cytokines in AGS cells by transwell chemotaxis and an MTT assay, respectively. In GKN1‐transfected AGS cells, we observed inactivation and reduced expression of NF‐κB and COX‐2, whereas shGKN1‐transfected HFE‐145 cells showed activation and increased expression of NF‐κB and COX‐2. GKN1 expression induced production of inflammatory cytokines including IL‐8 and ‐17A, but decreased expression of IL‐6 and ‐10. We also found IL‐17A expression in 9 (13.6%) out of 166 gastric cancer tissues and its expression was closely associated with GKN1 expression. GKN1 also acted as a chemoattractant for the migration of Jurkat T cells and peripheral B lymphocytes in the transwell assay. In addition, GKN1 significantly reduced cell viability in both AGS and HFE‐145 cells. These data suggest that the GKN1 gene may inhibit progression of gastric epithelial cells to cancer cells by regulating NF‐κB signaling pathway and cytokine expression. J. Cell. Biochem. 114: 1800–1809, 2013. © 2013 Wiley Periodicals, Inc.     

Structural characterization of MG and pre-MG states of proteins by MD simulations,NMR, and other techniques

Almost all proteins fold via a number of partially structured intermediates such as molten globule (MG) and pre-molten globule states. Understanding the structure of these intermediates at atomic level is often a challenge, as these states are observed under extreme conditions of pH, temperature, and chemical denaturants. Furthermore, several other processes such as chemical modification, site-directed mutagenesis (or point mutation), and cleavage of covalent bond of natural proteins often lead to MG like partially unfolded conformation. However, the dynamic nature of proteins in these states makes them unsuitable for most structure determination at atomic level. Intermediate states studied so far have been characterized mostly by circular dichroism, fluorescence, viscosity, dynamic light scattering measurements, dye binding, infrared techniques, molecular dynamics simulations, etc. There is a limited amount of structural data available on these intermediate states by nuclear magnetic resonance (NMR) and hence there is a need to characterize these states at the molecular level. In this review, we present characterization of equilibrium intermediates by biophysical techniques with special reference to NMR.     

Role of phytoestrogenic oils in alleviating osteoporosis associated with ovariectomy in rats

The objective of this study was to elucidate the effect of soybean oil (SbO) and sesame oil (SO) supplemented diets on bone biomarkers changes in OVX (ovariectomized) rats. The current data exhibited significant decrease in BMD (bone mineral density), accompanied with marked depletion in the level of Ca, P and Mg in both serum and bone of OVX rats. Also, serum estrogen, total protein, HDL-C (high density lipoprotein cholesterol), bone NO levels were decreased in OVX rats. However, a significant increase in the level of serum TL (total lipids), TC (total cholesterol), TG (triglycerides), LDL-C (low density lipoprotein cholesterol), VLDL-C (very low density lipoprotein cholesterol), urine minerals (Ca, P, Mg), as well as serum, bone and urine ALP (alkaline phosphatase) and ACP (acid phosphatase) activity were recorded in OVX rats. Further changes were also detected by the increased level of urine hydroxyproline, serum parathyroid hormone and osteocalcin, as well as urea and creatinine level in both serum and urine. On the other hand, when OVX rats were fed on SbO (soy bean oil) (15 % w/w) or SO (sesame oil) (10 % w/w) supplemented diets, the data recorded a significant improvement in all the above mentioned parameters. So, it can be concluded that consumption of SbO or SO supplemented diets might be considered as a functional food for retarding risks of osteoporosis associated with estrogen deficiency in OVX states.     

Chiral Separation of the Clinically Important Compounds Fucose and Pipecolic Acid Using CE: Determination of the Most Effective Chiral Selector

In this study, simple electrophoretic methods were developed for the chiral separation of the clinically important compounds fucose and pipecolic acid. In recent years, these analytes, and particularly their individual enantiomers, have attracted considerable attention due to their role in biological functions and disorders. The detectability and sensitivity of pipecolic acid and fucose were improved by reacting them with fluorenylmethyloxycarbonyl chloride (FMOC‐Cl) and 5‐amino‐2‐naphthalene‐sulfonic acid (ANSA), respectively. The enantioseparation conditions were optimized by initially investigating the type of the chiral selector. Different chiral selectors, such as polymeric surfactants and cyclodextrins, were used and the most effective ones were determined with regard to resolution and analysis time. A 10‐mM β‐cyclodextrin was able to separate the enantiomers of ANSA‐DL‐fucose and the polymeric surfactant poly(sodium N‐undecanoyl‐LL‐leucine‐valinate) was able to separate the enantiomers of FMOC‐DL‐pipecolic acid, with resolution values of 3.45 and 2.78, respectively. Additional parameters, such as the concentration and the pH of the background electrolyte (BGE), the concentration of the chiral selector, and the addition of modifiers were examined in order to optimize the separations. The addition of the chiral ionic liquid D‐alanine tert‐butyl ester lactate into the BGE was also investigated, for the first time, in order to improve resolution of the enantiomers. Chirality 25:556–560, 2013. © 2013 Wiley Periodicals, Inc.     

Structure of the (E)-4-hydroxy-3-methyl-but-2-enyl-diphosphate reductase from Plasmodium falciparum

Terpenoid precursor biosynthesis occurs in human and many pathogenic organisms via the mevalonate and 2-C-methyl-d-erythritol-4-phosphate (MEP) pathways, respectively. We determined the X-ray structure of the Fe/S containing (E)-4-hydroxy-3-methyl-but-2-enyl-diphosphate reductase (LytB) of the pathogenic protozoa Plasmodium falciparum which catalyzes the terminal step of the MEP pathway. The cloverleaf fold and the active site of P. falciparum LytB corresponds to those of the Aquifex aeolicus and Escherichia coli enzymes. Its distinct electron donor [2Fe–2S] ferredoxin was modeled to its binding site by docking calculations. The presented structural data provide a platform for a rational search of anti-malarian drugs.     

Effect of meteorological parameters on Poaceae pollen in the atmosphere of Tetouan (NW Morocco)

Poaceae pollen is one of the most prevalent aeroallergens causing allergenic reactions. The aim of this study was to characterise the grass pollen season in Tetouan during the years 2008–2010, to analyse the effect of some meteorological parameters on the incidence of the airborne Poaceae pollen, and to establish forecasting variables for daily pollen concentrations. Aerobiological sampling was undertaken over three seasons using the volumetric method. The pollen season started in April and showed the highest pollen index in May and June, when the maximum temperature ranged from 23 to 27 °C, respectively. The annual pollen score recorded varied from year to year between 2,588 and 5,404. The main pollen season lasted 114–173 days, with peak days occurring mainly in May; the highest concentration reached 308 pollen grains/m³. Air temperature was the most important meteorological parameter and correlated positively to daily pollen concentration increase. An increase in relative humidity and precipitation was usually related to a decrease in airborne pollen content. External validation of the models performed using data from 2011 showed that Poaceae pollen concentration can be highly predicted (64.2–78.6 %) from the maximum temperature, its mean concentration for the same day in other years, and its concentration recorded on the previous day. Sensitive patients suffering allergy to Poaceae pollen are at moderate to highest risk of manifesting allergic symptoms to grass pollen over 33–42 days. The results obtained provide new information on the quantitative contribution of the Poaceae pollen to the airborne pollen of Tetouan and on its temporal distribution. Airborne pollen can be surveyed and forecast in order to warn the atopic population.     

Effect of decimation on the classification rate of non-linear analysis methods applied to uterine EMG signals

Recently, much attention has been paid to the use of non-linear analysis techniques for the characterization of biological signals. Several measures have been proposed to detect non-linear characteristics in time series. The effect of sampling frequency on the performance of these non-linear methods has rarely been evaluated. In this paper, we present a preliminary study of this effect for four methods that are widely used in non-linearity detection: Time reversibility, Sample Entropy, Lyapunov Exponents and Delay Vector Variance. These methods have been applied to real uterine EMG signals with the aim of distinguishing between pregnancy and labor contractions. The signals were used to classify contractions before and after decimating them by a factor 10. The results show that decimation improves the performance for sample entropy. It reduces it considerably for Delay Vector Variance and only slightly for Time reversibility and Lyapunov exponents. Time reversibility still gives the highest classification rate. The methods were much less computationally expensive after down sampling.     

Chemical speciation and competitive cationic partitioning on a sandy aquifer material

Abstract

Coupled geochemical speciation/transport models are being developed to assess potential transport of metal contaminants in the subsurface environment. In a test of the geochemical speciation portion of the effort, MINTEQA2 model predictions are compared with laboratory data concerning the pH dependent partitioning behavior of eight cationic contaminants (Ba, Be, Cd, Cu, Ni, Pb, Tl and Zn) on a sandy aquifer material in an oxidized environment. MINTEQA2 contains provisions for describing potential attenuation due to both mineral phase precipitation processes and adsorption processes resulting from amorphous iron oxides in aquifer materials (MIT Diffuse Layer Model). In the comparison, several trends were discerned. (1) Adsorptive processes tend to better describe the pH-dependent partitioning behavior of transition metals (especially Pb, Zn and Ni). (2) Cd behavior is better described by precipitation as a cadmium carbonate phase. (3) Cu behavior is not reasonably described by the model. (4) Ba and Be comparisons are poor (although presumably their partitioning behavior results from adsorptive and/or pH sensitive solid solution processes). (5) unlike the other elements, the behavior of Tl is relatively insensitive to pH.