Genotype at the P554L Variant of the Hexose-6 Phosphate Dehydrogenase Gene Is Associated with Carotid Intima-Medial Thickness

Objective: The combined thickness of the intima and media of the carotid artery (carotid intima-medial thickness, CIMT) is associated with cardiovascular disease and stroke. Previous studies indicate that carotid intima-medial thickness is a significantly heritable phenotype, but the responsible genes are largely unknown. Hexose-6 phosphate dehydrogenase (H6PDH) is a microsomal enzyme whose activity regulates corticosteroid metabolism in the liver and adipose tissue; variability in measures of corticosteroid metabolism within the normal range have been associated with risk factors for cardiovascular disease. We performed a genetic association study in 854 members of 224 families to assess the relationship between polymorphisms in the gene coding for hexose-6 phosphate dehydrogenase (H6PD) and carotid intima-medial thickness. Methods: Families were ascertained via a hypertensive proband. CIMT was measured using B-mode ultrasound. Single nucleotide polymorphisms (SNPs) tagging common variation in the H6PD gene were genotyped. Association was assessed following adjustment for significant covariates including "classical" cardiovascular risk factors. Functional studies to determine the effect of particular SNPs on H6PDH were performed. Results: There was evidence of association between the single nucleotide polymorphism rs17368528 in exon five of the H6PD gene, which encodes an amino-acid change from proline to leucine in the H6PDH protein, and mean carotid intima-medial thickness (p = 0.00065). Genotype was associated with a 5% (or 0.04 mm) higher mean carotid intima-medial thickness measurement per allele, and determined 2% of the population variability in the phenotype. Conclusions: Our results suggest a novel role for the H6PD gene in atherosclerosis susceptibility

Selective 13C labeling of nucleotides for large RNA NMR spectroscopy using an E. coli strain disabled in the TCA cycle

Escherichia coli (E. coli) is an ideal organism to tailor-make labeled nucleotides for biophysical studies of RNA. Recently, we showed that adding labeled formate enhanced the isotopic enrichment at protonated carbon sites in nucleotides. In this paper, we show that growth of a mutant E. coli strain DL323 (lacking succinate and malate dehydrogenases) on 13C-2-glycerol and 13C-1,3-glycerol enables selective labeling at many useful sites for RNA NMR spectroscopy. For DL323 E. coli grown in 13C-2-glycerol without labeled formate, all the ribose carbon atoms are labeled except the C3′ and C5′ carbon positions. Consequently the C1′, C2′ and C4′ positions remain singlet. In addition, only the pyrimidine base C6 atoms are substantially labeled to ~96% whereas the C2 and C8 atoms of purine are labeled to ~5%. Supplementing the growth media with 13C-formate increases the labeling at C8 to ~88%, but not C2. Not unexpectedly, addition of exogenous formate is unnecessary for attaining the high enrichment levels of ~88% for the C2 and C8 purine positions in a 13C-1,3-glycerol based growth. Furthermore, the ribose ring is labeled in all but the C4′ carbon position, such that the C2′ and C3′ positions suffer from multiplet splitting but the C5′ position remains singlet and the C1′ position shows a small amount of residual C1′–C2′ coupling. As expected, all the protonated base atoms, except C6, are labeled to ~90%. In addition, labeling with 13C-1,3-glycerol affords an isolated methylene ribose with high enrichment at the C5′ position (~90%) that makes it particularly attractive for NMR applications involving CH2-TROSY modules without the need for decoupling the C4′ carbon. To simulate the tumbling of large RNA molecules, perdeuterated glycerol was added to a mixture of the four nucleotides, and the methylene TROSY experiment recorded at various temperatures. Even under conditions of slow tumbling, all the expected carbon correlations were observed, which indicates this approach of using nucleotides obtained from DL323 E. coli will be applicable to high molecular weight RNA systems

Asymmetry of 13C labeled 3-pyruvate affords improved site specific labeling of RNA for NMR spectroscopy

Selective isotopic labeling provides an unparalleled window within which to study the structure and dynamics of RNAs by high resolution NMR spectroscopy. Unlike commonly used carbon sources, the asymmetry of 13C-labeled pyruvate provides selective labeling in both the ribose and base moieties of nucleotides using E. coli variants, that until now were not feasible. Here we show that an E. coli mutant strain that lacks succinate and malate dehydrogenases (DL323) and grown on [3-13C]-pyruvate affords ribonucleotides with site specific labeling at C5′ (~95%) and C1′ (~42%) and minimal enrichment elsewhere in the ribose ring. Enrichment is also achieved at purine C2 and C8 (~95%) and pyrimidine C5 (~100%) positions with minimal labeling at pyrimidine C6 and purine C5 positions. These labeling patterns contrast with those obtained with DL323 E. coli grown on [1, 3-13C]-glycerol for which the ribose ring is labeled in all but the C4′ carbon position, leading to multiplet splitting of the C1′, C2′ and C3′ carbon atoms. The usefulness of these labeling patterns is demonstrated with a 27-nt RNA fragment derived from the 30S ribosomal subunit. Removal of the strong magnetic coupling within the ribose and base leads to increased sensitivity, substantial simplification of NMR spectra, and more precise and accurate dynamic parameters derived from NMR relaxation measurements. Thus these new labels offer valuable probes for characterizing the structure and dynamics of RNA that were previously limited by the constraint of uniformly labeled nucleotides

Procédé de mesure de la répartition d'épandage pour épandeurs de particules

Dispositif rotatif de mesure de la distribution d'engrais réalisée par un distributeur centrifuge d'engrais minéraux

Epandeur

Procédé de régulation volumique et massique d'un épandeur de fumier par automatisation d'un suivi de contour

Procédé de mesure de la répartition d'épandage pour épandeur de particules à épandre

Dispositif rotatif de mesure de la distribution d'engrais réalisée par un distributeur centrifuge d'engrais minéraux

Agriculture raisonnée - un outil pour cartographier les nappes d'engrais

AutresTo limit excessive use of mineral fertilisers, it is important to know their real distribution on the ground. In Montoldre, a team has developed a new testing facility, the CEMIB (Cemagref mineral bench). In just one to two minutes, this tool, unique in Europe, creates a map of the spread pattern.Pour limiter les apports excessifs d'engrais minéraux, il est important de connaître la répartition réelle de l'engrais au sol. A Montoldre, une équipe a mis au point un nouveau dispositif de test, le Cemib (Cemagref mineral bench). En une à deux minutes, cet outil unique en Europe établit une image spatiale de la nappe d'épandage

Développements technologiques récents en épandage d'engrais minéraux

International audienceRevue détaillée des avancées scientifiques et techniques en technologies d'épandage des engrais minéraux

Centrifugal fertiliser spreaders : a new method for their evaluation and testing

Mineral fertiliser spreading is mainly carried out by centrifugal spreaders, which are simple and efficient. Making prototypes, developing and working out setting tables, etc. are operations that rely on transverse bench tests. The distribution cuve obtained in this way shows the quantities spread in relation to the distance to the spreader's axis of work. This is a curve simplifying real spreading conditions, which only represents the final result of spreading when it is carried out in ideal conditions, in a straight line and with optimum overlapping between runs. The size of the test bench to be used is also extremely important and therefore requires a hall in which climate conditions are controlled. The area of this facility increases expoentially with the working width of appliances to be tested. So, a new test device has been devises with the prime objective of providing characteristic spatial values of spreading. The configuration and operating method of this bench help cut down the size of the hall needed. Investment, maintenance and air conditioning costs are therefore greatly reduced

What is the Search Space of the Regular Inference?

This paper revisits the theory of regular inference, in particular by extending the definition of structural completeness of a positive sample and by demonstrating two basic theorems. This framework enables to state the regular inference problem as a search through a boolean lattice built from the positive sample. Several properties of the search space are studied and generalization criteria are discussed. In this framework, the concept of border set is introduced, that is the set of the most general solutions excluding a negative sample. Finally, the complexity of regular language identification from both a theoritical and a practical point of view is discussed. 1 Introduction Regular inference is the process of learning a regular language from a set of examples, consisting of a positive sample, i.e. a finite subset of a regular language. A negative sample, i.e. a finite set of strings not belonging to this language, may also be available. This problem has been studied as early as th..