Évaluation d’un programme de périnatalité, région de Québec

S’étant vu confier par le Ministère des Affaires sociales la responsabilité de mettre sur pied un programme de périnatalité, quatre (4) Départements de santé communautaire de la région immédiate de Québec ont uni leurs efforts en vue de réaliser les objectifs fixés. A l’heure actuelle, la partie information du public est, à toute fin pratique, la seule qui soit vraiment en voie de réalisation. Dans le but d’évaluer dans quelle mesure le programme a su rejoindre les clientèles jugées prioritaires et aussi pour connaître le niveau d’impact de ces cours, un projet pilote impliquant le Ministère des Affaires sociales, les quatre (4) Départements de santé communautaire concernés et cinq (5) hôpitaux avec département d’obstétrique a permis de rejoindre 1 933 femmes ayant accouché dans ces centres hospitaliers. Sur la base d’une comparaison entre celles qui avaient ou non suivi les cours prénatals, il a été possible de dégager des renseignements intéressants sur les deux aspects : atteinte des clientèles cibles et impact des cours. Après avoir fait état des résultats observés, on émet quelques commentaires sur certains éléments de la problématique des cours prénatals

Dehydrated pork manure by-product: effect of a chitosan amendment on bacterial community and common scab incidence

Chitosan amendment modified the composition of a microbial community associated with dehydrated pork manure by-product. The amended product (biosolid PC) contained a lower number of anaerobic bacteria than the non-amended product (biosolid P). Chitosan also significantly reduced the fungal population. A 16S rRNA gene bank constructed from DNA extracted from the bacterial community associated with both P and PC biosolids revealed that bacterial orders Xanthomonodales, Pseudomonadales, Enterobacteriales, Burkholderiales, Actinomycetales, Bacillales, Clostridiales and Lactobacillales were found in both biosolids. Bacteria from the Stenotrophomonas genus were abundant in both biosolids. However, the addition of chitosan appeared to induce changes in the population of some bacterial genera. For example, clones carrying a 16S rRNA gene corresponding to the Bacillus genus were doubled in biosolid PC. In field trials carried out to test their effect on common scab incidence, biosolids P and PC were applied as potato seed treatment. Biosolid P increased disease incidence by a factor of 1.33 and 2.85 in two independent experiments. However, when chitosan was added to the seed treatment, the stimulating effect of biosolid P on common scab was cancelled out.Un amendement en chitosane a modifié la composition de la communauté microbienne associée à un sous-produit déshydraté de fumier de porc. Le produit amendé (biosolide PC) contenait un nombre de bactéries anaérobies inférieur à celui du produit non amendé (biosolide P). Le chitosane a aussi réduit de façon significative la population fongique. Une banque de gènes de l’ARNr 16S construite à partir de l’ADN extrait de la communauté bactérienne associée aux biosolides P et PC a révélé que les ordres bactériens Xanthomonodales, Pseudomonadales, Enterobacteriales, Burkholderiales, Actinomycetales, Bacillales, Clostridiales et Lactobacillales se trouvaient dans les deux types de biosolides. Les bactéries du genre Stenotrophomonas étaient les plus abondantes dans les deux types de biosolides. L’addition de chitosane a toutefois induit des changements dans la population de quelques genres de bactéries. Par exemple, les clones transportant un gène d’ARNr 16S correspondant au genre Bacillus doublaient dans le biosolide PC. Dans des essais en champs entrepris dans le but de tester leur effet sur l’incidence de la gale commune, les biosolides P et PC ont été appliqués comme traitement des semences de pomme de terre. Le biosolide P a augmenté l’incidence de la maladie par un facteur de 1,33 et de 2,85 dans deux expériences indépendantes. Toutefois, quand le chitosane était ajouté au traitement de semences, l’effet stimulant du biosolide P sur la gale commune était aboli

Why Is Aging a Risk Factor for Cognitive Impairment in Parkinson's Disease?—A Resting State fMRI Study

Using resting-state functional MRI (rsfMRI) data of younger and older healthy volunteers and patients with Parkinson's disease (PD) with and without mild cognitive impairment (MCI) and applying two different analytic approaches, we investigated the effects of age, pathology, and cognition on brain connectivity. When comparing rsfMRI connectivity strength of PD patients and older healthy volunteers, reduction between multiple brain regions in PD patients with MCI (PD-MCI) compared with PD patients without MCI (PD-non-MCI) was observed. This group difference was not affected by the number and location of clusters but was reduced when age was included as a covariate. Next, we applied a graph-theory method with a cost-threshold approach to the rsfMRI data from patients with PD with and without MCI as well as groups of younger and older healthy volunteers. We observed decreased hub function (measured by degree and betweenness centrality) mainly in the medial prefrontal cortex (mPFC) in older healthy volunteers compared with younger healthy volunteers. We also found increased hub function in the posterior medial structure (precuneus and the cingulate cortex) in PD-non-MCI patients compared with older healthy volunteers and PD-MCI patients. Hub function in these posterior medial structures was positively correlated with cognitive function in all PD patients. Together these data suggest that overlapping patterns of hub modifications could mediate the effect of age as a risk factor for cognitive decline in PD, including age-related reduction of hub function in the mPFC, and recruitment availability of the posterior medial structure, possibly to compensate for impaired basal ganglia function

Unprecedented tunability of riboswitch structure and regulatory function by sub-millimolar variations in physiological Mg2+

Riboswitches are cis-acting regulatory RNA biosensors that rival the efficiency of those found in proteins. At the heart of their regulatory function is the formation of a highly specific aptamer–ligand complex. Understanding how these RNAs recognize the ligand to regulate gene expression at physiological concentrations of Mg2+ ions and ligand is critical given their broad impact on bacterial gene expression and their potential as antibiotic targets. In this work, we used single-molecule FRET and biochemical techniques to demonstrate that Mg2+ ions act as fine-tuning elements of the amino acid-sensing lysC aptamer's ligand-free structure in the mesophile Bacillus subtilis. Mg2+ interactions with the aptamer produce encounter complexes with strikingly different sensitivities to the ligand in different, yet equally accessible, physiological ionic conditions. Our results demonstrate that the aptamer adapts its structure and folding landscape on a Mg2+-tunable scale to efficiently respond to changes in intracellular lysine of more than two orders of magnitude. The remarkable tunability of the lysC aptamer by sub-millimolar variations in the physiological concentration of Mg2+ ions suggests that some single-aptamer riboswitches have exploited the coupling of cellular levels of ligand and divalent metal ions to tightly control gene expression.Publisher PDFPeer reviewe

A novel structural rearrangement of hepatitis delta virus antigenomic ribozyme

A bioinformatic covariation analysis of a collection of 119 novel variants of the antigenomic, self-cleaving hepatitis delta virus (HDV) RNA motif supported the formation of all of the Watson–Crick base pairs (bp) of the catalytic centre except the C19–G81 pair located at the bottom of the P2 stem. In fact, a novel Watson–Crick bp between C19 and G80 is suggested by the data. Both chemical and enzymatic probing demonstrated that initially the C19–G81 pair is formed in the ribozyme (Rz), but upon substrate (S) binding and the formation of the P1.1 pseudoknot C19 switches its base-pairing partner from G81 to G80. As a result of this finding, the secondary structure of this ribozyme has been redrawn. The formation of the C19–G80 bp results in a J4/2 junction composed of four nucleotides, similar to that seen in the genomic counterpart, thereby increasing the similarities between these two catalytic RNAs. Additional mutagenesis, cleavage activity and probing experiments yield an original characterization of the structural features involving the residues of the J4/2 junction