Glycophenotypic Alterations Induced by Pteridium aquilinum in Mice Gastric Mucosa: Synergistic Effect with Helicobacter pylori Infection

The bracken fern Pteridium aquilinum is a plant known to be carcinogenic to animals. Epidemiological studies have shown an association between bracken fern exposure and gastric cancer development in humans. The biological effects of exposure to this plant within the gastric carcinogenesis process are not fully understood. In the present work, effects in the gastric mucosa of mice treated with Pteridium aquilinum were evaluated, as well as molecular mechanisms underlying the synergistic role with Helicobacter pylori infection. Our results showed that exposure to Pteridium aquilinum induces histomorphological modifications including increased expression of acidic glycoconjugates in the gastric mucosa. The transcriptome analysis of gastric mucosa showed that upon exposure to Pteridium aquilinum several glycosyltransferase genes were differently expressed, including Galntl4, C1galt1 and St3gal2, that are mainly involved in the biosynthesis of simple mucin-type carbohydrate antigens. Concomitant treatment with Pteridium aquilinum and infection with Helicobacter pylori also resulted in differently expressed glycosyltransferase genes underlying the biosynthesis of terminal sialylated Lewis antigens, including Sialyl-Lewisx. These results disclose the molecular basis for the altered pattern of glycan structures observed in the mice gastric mucosa. The gene transcription alterations and the induced glycophenotypic changes observed in the gastric mucosa contribute for the understanding of the molecular mechanisms underlying the role of Pteridium aquilinum in the gastric carcinogenesis process

Nanostructure Study of Ti/TiN Multilayers: Effect of the Deposition Temperature

International audienc

Epitaxially induced anisotropy in thin films of Laves phase compounds

Thin films of $\rm DyFe_2$ and $\rm ErFe_2$ have been epitaxially grown along the [110] direction. At 4.2 K, the easy magnetization axis in the films, determined by Mössbauer spectroscopy, is the same as in bulk compounds (i.e. $\langle100\rangle$ for $\rm DyFe_2$ and $\langle111\rangle$ for ${\rm ErFe_2}$). At 300 K, the magnetic moments, which remain in the same direction as at 4.2 K in bulk compounds, rotate towards $\langle110\rangle$ directions in thin films: they are close to the in-plane $[1\overline10]$ direction in $\rm DyFe_2$ films, and close to the perpendicular-to-the-plane [110] direction in $\rm ErFe_2$ films. These modifications of the magnetic anisotropy are related to the epitaxial strains, and to the sign and the relative importance of the anisotropy and magnetoelastic constants of the compound

Structure, magnetism and thermal stability of Fe/Al2O3 multilayers

International audienc

Magnetism of Mn ultra-thin films grown on (001) bcc Fe studied by X-ray magnetic circular dichroism

International audienc

Magnetism of Mn ultra-thin films grown on (001) bcc Fe studied by X-ray magnetic circular dichroism

The magnetic properties of Mn ultra-thin films epitaxially grown on (001) bcc Fe are studied by soft–X-ray magnetic circular dichroism. At room temperature, the Mn growth is two-dimensional without interdiffusion in Fe, as checked by RHEED and Auger spectroscopy. A net Mn magnetic moment is observed in the Mn thickness range up to 2 monolayers. We find that the Mn/Fe interfacial coupling is definitely ferromagnetic. In this range, the magnetic moment carried per Mn atom is found to be about $1.7\;\mu_{\rm B}$, which is much smaller than the value of $3\;\mu_{\rm B}$ predicted for ferromagnetic Mn ultra-thin films

Neutron and X-Ray Diffraction of Glass

International audienc