Gastric Cancer: Advances in Carcinogenesis Research and New Therapeutic Strategies

Gastric cancer’s bad incidence, prognosis, cellular and molecular heterogeneity amongst others make this disease a major health issue worldwide. Understanding this affliction is a priority for proper patients’ management and for the development of efficient therapeutical strategies. This review gives an overview of major scientific advances, made during the past 5-years, to improve the comprehension of gastric adenocarcinoma. A focus was made on the different actors of gastric carcinogenesis, including, Helicobacter pylori cancer stem cells, tumour microenvironment and microbiota. New and recent potential biomarkers were assessed as well as emerging therapeutical strategies involving cancer stem cells targeting as well as immunotherapy. Finally, recent experimental models to study this highly complex disease were discussed, highlighting the importance of gastric cancer understanding in the hard-fought struggle against cancer relapse, metastasis and bad prognosis.     

The distribution of lithium intercalated in V2O5 thin films studied by XPS and ToF-SIMS

The distribution of lithium in V₂O₅/V lower oxide duplex thin films prepared by thermal oxidation of V metal was analysed by XPS and ToF-SIMS after intercalation at 2.8 V versus Li/Li⁺ and de-intercalation at 3.8 V following cycling between 3.8 and 2.8 V in 1 M LiClO₄-PC. XPS analysis of the intercalated thin film evidenced a partial reduction (43 at.% V⁴⁺) of the V₂O₅ surface, the modification of its electronic structure and the presence of Li, consistent with the formation of the δ-Li_xV₂O₅ (0.9 ≤ x ≤ 1) phase. The Li in-depth distribution measured by ToF-SIMS shows a maximum in the outer layer of V₂O₅, but Li is also found at the oxide film/metal substrate interface indicating its diffusion across the inner layer of V lower oxides. The analyses performed after de-intercalation on the samples cycled 12, 120 and 300 times reveal the effect of aging on the trapping of lithium. A significant reduction (17-22 at.% V⁴⁺) of the V₂O₅ surface was measured after 300 cycles. The Li in-depth distribution shows a maximum at the interface between the outer layer of V₂O₅ and the inner layer of lower oxides. Aging favours the accumulation of lithium at this interface with a resulting enlarged distribution enriching the sub-surface of the outer layer of V₂O₅ and the inner layer of lower oxides after 300 cycles. Lithium is also found, but in smaller quantities, at the oxide film/metal substrate interface. Measurements performed in the non-electrochemically treated surface areas of the de-intercalated samples revealed the same type of modifications, evidencing the diffusion of lithium along the interfaces where it is trapped.     

Use of a new natural clay to produce poly(methyl methacrylate)‐based nanocomposites

Nanocomposites of poly(methyl methacrylate) (PMMA) filled with 3 wt% of modified natural Algerian clay (AC; montmorillonite type) were prepared by either in situ polymerization of methyl methacrylate initiated by 2,2′‐azobisisobutyronitrile or a melt‐mixing process with preformed PMMA via twin‐screw extrusion. The organo‐modification of the AC montmorillonite was achieved by ion exchange of Na⁺ with octadecyldimethylhydroxyethylammonium bromide. Up to now, this AC montmorillonite has found applications only in the petroleum industry as a rheological additive for drilling muds and in water purification processes; its use as reinforcement in polymer matrices has not been reported yet. The modified clay was characterized using X‐ray diffraction (XRD), which showed an important shift of the interlayer spacing after organo‐modification. The degree of dispersion of the clay in the polymer matrix and the resulting morphology of nanocomposites were evaluated using XRD and transmission electron microscopy. The resulting intercalated PMMA nanocomposites were analysed using thermogravimetric analysis and differential scanning calorimetry. The glass transition temperature of the nanocomposites was not significantly influenced by the presence of the modified clay while the thermal stability was considerably improved compared to unfilled PMMA. This Algerian natural montmorillonite can serve as reinforcing nanofiller for polymer matrices and is of real interest for the fabrication of nanocomposite materials with improved properties. Copyright © 2009 Society of Chemical Industry     

Phase Diagram, Short-Range Structure, and Amorphous Phases in the ZrO2-GeO2(-H2O) System

Gels of the ZrO₂-GeO₂(-H₂O) system have been prepared via the hydrolysis-polycondensation of zirconium and germanium isopropoxides. Phase relationships have been deduced from differential thermal analysis, thermogravimetric analysis, and shrinkage analysis and are discussed on the basis of X-ray diffractometry and Raman scattering studies. Emphasis has been given to understanding the short-range structure. A small glass-forming domain is observed in the temperature range of 600°−700°C for compositions of 30–40 mol% GeO₂.     

Organic contamination of settled house dust, a review for exposure assessment purposes

People spend a considerable amount of time indoors. As a result, exposure to indoor contaminants is of great concern, notably via settled dust ingestion in particular for infants and toddlers. This paper proposes a critical review on the organic contamination of settled house dust and human exposure over the past 10 years and focused on sources, contaminations and measurement methods (sampling, pretreatment, storage and analysis). As many compounds were identified, arises the question of which ones to consider. Sensitive and selective analytical methods for simultaneous determination of targeted substances should be developed and evaluated. Various methods were described for sampling and sample preparation. Harmonization and standardization are needed to enable comparison of results from similar studies. Finally, an integrated multipollutant and multicompartment (settled dust, suspended particles and air) approach appears essential in order to determine the extent of the threat to public health posed by indoor contaminants.     

Basis of predictive mycology

For over 20 years, predictive microbiology focused on food-pathogenic bacteria. Few studies concerned modelling fungal development. On one hand, most of food mycologists are not familiar with modelling techniques; on the other hand, people involved in modelling are developing tools dedicated to bacteria. Therefore, there is a tendency to extend the use of models that were developed for bacteria to moulds. However, some mould specificities should be taken into account. The use of specific models for predicting germination and growth of fungi was advocated previously []. This paper provides a short review of fungal modelling studies.     

Ginsenosides and phenolics in fresh and processed Korean ginseng (Panax ginseng C.A. Meyer): Effects of cultivation location,year, and storage period

This study reports the effects of cultivation location, cultivation year, and storage period on 13 ginsenosides and 30 phenolics in Korean fresh ginseng (FG) and its three processed ginsengs (white ginseng, WG; taeguek ginseng, TG; red ginseng, RG). Total ginsenosides content in FG was affected by cultivation year (P = 0.038) and storage period (P = 0.0021), not by cultivation location. In contrast, phenolics content in FG was affected by cultivation locations (P < 0.0001) and cultivation year (P = 0.0083), but not by storage period. Processed ginsengs, especially RG, contained larger amounts of ginsenosides and phenolics than those in FG. Thus, RG could be considered as the best ginseng type for human health benefits. The present study extended our knowledge about the change of ginsenosides and phenolics in ginsengs with respect to cultivation location, cultivation year, and the storage period.     

Binding Mode and Structure–Activity Relationships around Direct Inhibitors of the Nrf2–Keap1 Complex

An X‐ray crystal structure of Kelch‐like ECH‐associated protein (Keap1) co‐crystallised with (1S,2R)‐2‐[(1S)‐1‐[(1,3‐dioxo‐2,3‐dihydro‐1H‐isoindol‐2‐yl)methyl]‐1,2,3,4‐tetrahydroisoquinolin‐2‐carbonyl]cyclohexane‐1‐carboxylic acid (compound (S,R,S)‐ 1 a ) was obtained. This X‐ray crystal structure provides breakthrough experimental evidence for the true binding mode of the hit compound (S,R,S)‐ 1 a , as the ligand orientation was found to differ from that of the initial docking model, which was available at the start of the project. Crystallographic elucidation of this binding mode helped to focus and drive the drug design process more effectively and efficiently.