Novel Allelic Variants in the Canine Cyclooxgenase-2 (Cox-2) Promoter Are Associated with Renal Dysplasia in Dogs

Renal dysplasia (RD) in dogs is a complex disease with a highly variable phenotype and mode of inheritance that does not follow a simple Mendelian pattern. Cox-2 (Cyclooxgenase-2) deficient mice have renal abnormalities and a pathology that has striking similarities to RD in dogs suggesting to us that mutations in the Cox-2 gene could be the cause of RD in dogs. Our data supports this hypothesis. Sequencing of the canine Cox-2 gene was done from clinically affected and normal dogs. Although no changes were detected in the Cox-2 coding region, small insertions and deletions of GC boxes just upstream of the ATG translation start site were found. These sequences are putative SP1 transcription factor binding sites that may represent important cis-acting DNA regulatory elements that govern the expression of Cox-2. A pedigree study of a family of Lhasa apsos revealed an important statistical correlation of these mutant alleles with the disease. We examined an additional 22 clinical cases from various breeds. Regardless of the breed or severity of disease, all of these had one or two copies of the Cox-2 allelic variants. We suggest that the unusual inheritance pattern of RD is due to these alleles, either by changing the pattern of expression of Cox-2 or making Cox-2 levels susceptible to influences of other genes or environmental factors that play an unknown but important role in the development of RD in dogs

Structural Insight into Transition Metal Oxide containing glasses by Molecular Dynamic Simulations

In the last years, glass research focused particular attention on transition metal oxide containing systems for semi-conductive applications, for instance glasses for solid-state devices and secondary batteries. In glass matrices, transition metal ions show multiple oxidation states that lead to peculiar structures and to highly complex systems, which produce interesting optical, electrical and magnetic properties. Computational methods have been largely employed as complementary tool to experimental techniques, in order to improve the knowledge on the materials and their performances. In this work, Molecular Dynamic (MD) simulations have been performed on a series of alkali vanado-phosphate glasses in order to gain deep comprehension of the glass structure. The short and medium range order of the V4+ and the V5+ sites in terms of coordination, pair distribution function, V\u2013O\u2013V linkages, bridging and non-bridging oxygen distributions were calculated and discussed. Finally, the comparison between MD and experimental results shows a very good agreement allowing the validation of the computational models and highlights the correlations between the structure and the conduction mechanism in these glasses. This allows enriching the know-how on these glass systems that result still ambiguous until now

Neutron and X-Ray Diffraction of Glass

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P-31 MAS refocused INADEQUATE spin-echo (REINE) NMR spectroscopy : revealing J coupling and chemical shift two-dimensional correlations in disordered solids

Two-dimensional (2D) variations in (2)J(P1,P1), (2)J(P1,P2), and (2)J(P2,P2) are obtained-using the REINE (REfocused INADEQUATE spin-Echo) pulse sequence presented by Cadars et al. (Phys. Chem. Chem. Phys. 2007, 9, 92-103)-from pixel-by-pixel fittings of the spin-echo modulation for the 2D correlation peaks due to linked phosphate tetrahedra (P-1-P-1, P-1-P-2, P-2-P-1, and P-2-P-2) in a P-31 refocused INADEQUATE solid-state MAS NMR spectrum of a cadmium phosphate glass, 0.575CdO-0.425P(2)O(5). In particular, separate variations for each 2D P-31 REINE peak are obtained which reveal correlations between the J couplings and the P-31 chemical shifts of the coupled nuclei that are much clearer than those evident in previously presented 2D z-filtered P-31 spin-echo spectra. Notably, such correlations between the J couplings and the P-31 chemical shifts are observed even though the conditional probability distributions extracted using the protocol of Cadars et al. (J. Am. Chem. Soc. 2005, 127, 4466-4476) indicate that theme is no marked correlation between the P-31 chemical shifts of neighboring phosphate tetrahedra. For 2D peaks at the P-2 P-31 chemical shift in the direct dimension, there can be contributions from chains of three units (P-1-P-2-P-1), chains of four units (P-1-P-2-P-2-P-1), or longer chains or rings (-P-2-P-2-P-2-): for the representative glass considered here, best fits are obtained assuming a glass comprised predominantly of chains of four units. The following variations are found: (2)J(P1,P1) = 13.4 +/- 0.3 to 14.8 +/- 0.5 Hz, (2)J(P1,P2) = 15.0 +/- 0.3 to 18.2 +/- 0.3 Hz, and (2)J(P2,P2) = 5.9 +/- 0.6 to 9.1 +/- 0.9 Hz from the fits to the P-1-P-1, P-1-P-2, and P-2-P-2 peaks, respectively. The correlation of a particular J coupling with the P-31 chemical shifts of the considered nucleus and the coupled nucleus is quantified by the coefficients C-F2 and C-F1 that correspond to the average pixel-by-pixel change in the J coupling with respect to the chemical shift of the observed (F-2) and neighboring (F-1) P-31 nuclei, respectively

Tools for the discovery of hyperaccumulator plant species and understanding their ecophysiology

Globally the discovery of hyperaccumulator plants has been hindered by systematic screening of plant species, and is highly biased towards Ni hyperaccumulators. This is mainly due to the existence of a reagent paper test that is only specific to nickel (based on dimethylglyoxime) such that more than 400 of the approximately 500 known hyperaccumulators species are for Ni. New technical advances now permit massive screening of herbarium specimens using non-destructive, portable X-Ray Fluorescence Spectroscopy (XRF), an approach that has already led to the discovery of numerous hyperaccumulator species new to science. The elemental distribution in selected hyperaccumulator plant tissues can then be further studied using techniques such as desktop or synchrotron micro-XRF, nuclear microprobe (PIXE), scanning/transmission electron microscopy with energy-dispersive spectroscopy (SEM/TEM-EDS), secondary ion mass spectrometry (SIMS) or laser ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS). The use of histochemical dyes combined with light microscopy further aids in the identification of anatomical and structural features of the studied plant tissues