Three of a Kind: Control of the Expression of Liver-Expressed Antimicrobial Peptide 2 (LEAP2) by the Endocannabinoidome and the Gut Microbiome

The endocannabinoidome (expanded endocannabinoid system, eCBome)-gut microbiome (mBIome) axis plays a fundamental role in the control of energy intake and processing. The liver-expressed antimicrobial peptide 2 (LEAP2) is a recently identified molecule acting as an antagonist of the ghrelin receptor and hence a potential effector of energy metabolism, also at the level of the gastrointestinal system. Here we investigated the role of the eCBome-gut mBIome axis in the control of the expression of LEAP2 in the liver and, particularly, the intestine. We confirm that the small intestine is a strong contributor to the circulating levels of LEAP2 in mice, and show that: (1) intestinal Leap2 expression is profoundly altered in the liver and small intestine of 13 week-old germ-free (GF) male mice, which also exhibit strong alterations in eCBome signaling; fecal microbiota transfer (FMT) from conventionally raised to GF mice completely restored normal Leap2 expression after 7 days from this procedure; in 13 week-old female GF mice no significant change was observed; (2) Leap2 expression in organoids prepared from the mouse duodenum is elevated by the endocannabinoid noladin ether, whereas in human Caco-2/15 epithelial intestinal cells it is elevated by PPARγ activation by rosiglitazone; (3) Leap2 expression is elevated in the ileum of mice with either high-fat diet—or genetic leptin signaling deficiency—(i.e., ob/ob and db/db mice) induced obesity. Based on these results, we propose that LEAP2 originating from the small intestine may represent a player in eCBome- and/or gut mBIome-mediated effects on food intake and energy metabolism.     

Silica-modified electrode for the selective detection of mercury

Pure silica particles were dispersed within carbon paste and the resulting modified electrode was applied to the selective voltammetric detection of mercury(II) species after their accumulation at open circuit. The remarkable selectivity observed between pH 4 and 7 was attributed to the intrinsic adsorption mechanism which involves a condensation reaction between mercury(II) hydroxide and hydroxyl groups on the silica surface, leading to the formation of an inner-sphere-type surface complex. After optimization with respect to the electrode composition, the detection medium, and the voltammetric scan mode, a linear response was obtained in the concentration range between 2 × 10⁻⁷ M to 1 × 10⁻⁵ M, by applying anodic stripping square wave voltammetry. Various silica samples were used and their sorption behavior was discussed in relation to their specific surface area and porosity. The effect of chloride and pH on the accumulation of mercury(II) on silica was also investigated. Received: 4 September 1999 / Accepted: 5 January 2000     

Polymorphism and luminescence properties of CMONS organic crystals: bulk crystals and nanocrystals confined in gel-glasses

In order to compare the polymorphism of 1-cyano-1-(4-nitrophenyl)-2-(4-methoxyphenyl)ethene CMONS crystallized in solutions to that of CMONS nanocrystals grown in the pores of dense sol-gel matrices, we have first studied the CMONS polymorphism in various solvents which were then used in the nanocrystallization processes. The different polymorphs were characterized by differential scanning calorimetry, X-ray diffraction and absorption as well as luminescence spectroscopies. The differences observed between CMONS powders and CMONS nanocrystals illustrate the role played by the silicate matrices on the polymorphism of CMONS. This matrix effect would be used to stabilize a particular polymorph of an organic phase and thus to adjust the optical properties of the nanocomposite hybrid organic–inorganic material.     

HDD Detector,a New Detection System for Emission Spectroscopy Combining High Dynamic,Fast Acquisition,Continuous Spectrum

Emission lines varie in intensity on a nine orders range of magnitude depending on.     

Modelling the active site of glyceraldehyde-3 phosphate dehydrogenase with the LSCF formalism

In the framework of a theoretical approach to the relationship between structure and reactivity of the catalytic centers of enzymes, glyceraldehyde-3 phosphate dehydrogenase (GAPDH) has been chosen as a model enzyme. In GAPDH, the proximity of His₁₇₆ increases the reactivity of Cys₁₄₉ at neutral pH; however, its presence alone is not sufficient to explain the reactivity of the catalytic Cys. In order to determine which other interactions play an important role, a study of the geometric and electronic structure of the catalytic site has been made using a hybrid quantum mechanics/molecular mechanics local self-consistent field method. This allows the computation of the electronic properties of amino acid residues in subsystems influenced by other parts of the macromolecule. The quantum subsystem was centered on the Cys₁₄₉ residue of GAPDH. The structures of GAPDH taken from the crystallographic database did not include hydrogen atoms and these had to be added taking into account the fact that, in the active site, His₁₇₆ has three tautomeric forms: δ-His protonated, ε-His protonated and His⁺. The results presented here suggest that the most stable His…Cys system in GAPDH is a strongly hydrogen-bonded Cys₁₄₉ ⁻/His₁₇₆ ⁺ ion pair. Received: 24 March 1998 / Accepted: 3 September 1998 / Published online: 23 November 1998     

Evolution equations associated with non-isothermal phase separation: Subdifferential approach

This paper is concerned with a non-isothermal phase separation model, for instance, describing component separation dynamics for a class of binary systems (solid-solid systems). Our model is a couple of nonlinear parabolicPDE's which are possibly degenerate and singular at the same time. It will be shown that our model can be reformulated as a nonlinear evolution equation governed by subdifferential operator in a Hilbert space, and its mathematically basic questions, such as existence and uniqueness, can be handled in the abstract theory of nonlinear evolution equations in Hilbert spaces. Entrata in Redazione il 15 luglio 1997 e, in versione riveduta, il 25 ottobre 1997.     

Cyclic Cohomology and Hopf Algebras

We associate canonically a cyclic module to any Hopf algebra endowed with a modular pair in involution, consisting of a group-like element and a character. This provides the key construction for allowing the extension of cyclic cohomology to Hopf algebras in the nonunimodular case and, further, to developing a theory of characteristic classes for actions of Hopf algebras compatible not only with traces but also with the modular theory of weights. This applies to both ribbon and coribbon algebras as well as to quantum groups and their duals.     

Urothermal Syntheses of Chiral Zincic Benzotriazole-5-carboxylate Frameworks for Iodine Uptake

So far,the synthesis of chiral framework with achiral organic ligand still faces great challenge.Herein,three new coordinated complexes[Zn(btca)Cl]·DMA·N(CH₃)₂(1),[Zn(btca)(Ac^-)]·N(CH₃)₂(2)and[Zn(btca)]·H₂O(3)(DMA=N,N-dimethylacetamide,btca=benzotriazole-5-carboxylate acid)were synthesized via different methods.Single-crystal X-ray diffraction analysis revealed that compounds 1 and 2 were isostructural and showed achiral layer network with fes topology,and 3 presented a chiral three-dimensional framework with eta topology.The result of this work has demonstrated that urothermal synthesis will be promising means of constructing chiral framework with achiral building block.Compound 3 also displayed an excellent property of iodine uptake.