38 research outputs found
Characterization of Plant Carotenoid Cyclases as Members of the Flavoprotein Family Functioning with No Net Redox Change
Prevalence and clinical impact of endoscopic pseudomembranes in patients with inflammatory bowel disease and Clostridium difficile infection
Background and aim: Limited data suggests that pseudomembranes are uncommon in patients with inflammatory bowel disease (IBD) and C. difficile associated disease (CDAD), but the reason for this is unknown.
We aimed to evaluate the rate of pseudomembranes in this population, identify predictive factors for pseudomembranes' presence and assess its clinical impact.
Methods: This was a sub-study of a retrospective European Crohn's & Colitis Organization (ECCO) multi-center study on the outcome of hospitalized IBD patients with C. difficile. The present study included only patients who underwent lower endoscopy during hospitalization, and compared
demographic and clinical parameters in the group of patients with discernable pseudomembranes versus those without.
Results: Out of 155 patients in the original cohort, 93 patients underwent lower endoscopy and constituted the study population. Endoscopic pseudomembranes were found in 12 (13%) of these patients. Patients with pseudomembranes presented more commonly with fever (p=0.02) compared to patients without pseudomembranes. No difference between the two groups was found with respect to the use of immunosuppressant drugs, background demographics or disease
characteristics. Neither was there a difference between the group with or without pseudomembranes in the frequency of severe adverse clinical outcome or in the duration of hospitalization. On multi-variate analysis the presence of fever remained independently associated with the finding of
pseudomembranes (OR 6, 95% CI 1.2â32, p=0.03).
Conclusions: This study documents that hospitalized IBD patients with CDAD have low rate of endoscopic pseudomembranes, which is not accounted for by the use of immunosuppressant drugs. IBD patients with CDAD and discernable pseudomembranes more commonly present with
fever, but their clinical outcome is similar to patients without pseudomembranes.
© 2009 Published by Elsevier B.V. on behalf of European Crohn's and Colitis Organisation
Philippe Hanus et Rémi Korman (dir.), Prendre le maquis. Traces, histoires, mémoires
DĂšs avant la fin de la Seconde Guerre mondiale, la RĂ©sistance a fait lâobjet dâune abondante littĂ©rature, souvent Ă©logieuse et parfois critique lorsquâelle nâĂ©tait pas scientifique. Elle reste lâun des sujets incontournables de ce conflit, explorĂ© par de nombreux historiens depuis plus de septante ans. Les maquis, « regroupement[s] dâhommes rassemblĂ©s illĂ©galement dans un massif forestier ou un village isolé » (p. 17), constituent lâun des piliers de ce thĂšme. Si la mĂ©moire collective nâen a ..
BiosynthÚse des stérols (Biochimie et analyse moléculaire des stérol-4a-méthyl-oxydases de plantes)
Les stérols, vitaux aux eucaryotes supérieurs, ne sont fonctionnels qu'aprÚs élimination des méthyles en position C4. La déméthylation en C4 des précurseurs stéroliques est effectuée par un complexe multienzymatique au sein duquel les stérol-4a-méthyl-oxydases (SMO) réalisent la premiÚre étape de ce processus. Chez les plantes, deux familles de gÚnes candidats, SMO1 et SMO2, faisant partie de la famille des oxygénases membranaires à fer non-hémique, ont été isolées in silico. L'expression hétérologue des gÚnes candidats d'Arabidopsis thaliana dans un mutant de Saccharomyces cerevisiae déficient en SMO, montre que seuls les gÚnes de la famille SMO2 permettent de rétablir la synthÚse d'ergostérol dans celui-ci et sa croissance en absence d'ergostérol dans la milieu. La réduction d'expression des gÚnes SMO1, chez Nicotiana benthamiana, via la technique de virus-induced gene silencing (VIGS), provoque une accumulation spécifique de 4,4-diméthyl-cyclopropyl-stérols, alors que celle de SMO2 induit une augmentation spécifique de 4a-méthyl-D7-stérols. Les données obtenues ont permis d'identifier et de caractériser fonctionnellement, pour la premiÚre fois, deux familles de SMO végétales distinctes, régulant respectivement le taux des précurseurs 4,4-diméthyl- et 4a-méthyl-stérols. Les plantes se distinguent donc nettement des animaux et des levures, qui ne possÚdent qu'une seule enzyme catalysant l'oxydation successive des deux méthyles en position 4 des précurseurs 4,4-diméthyl-stérols.Sterols are ubiquitous and essential membrane components of eukaryotic cells. In plants, the conversion of cycloartenol to functional phytosterols requires the removal of two methyl-groups at C4 position by an enzymatic complex including a sterol-4a-methyl-oxidase (SMO). We have identified in silico candidate genes for two distinct families of SMO in Arabidopsis thaliana which belong to the small family of membrane-bound non-heme iron oxygenases involved in lipid oxidation. Heterologous expression of plants AtSMO1 in a yeast mutant lacking SMO activity can restore neither SMO activity nor endogenous ergosterol biosynthesis in contrast to AtSMO2 which can functionally complement this mutant strain. In order to decrease the level of plant SMO expression in Nicotiana benthamiana, we have used a virus-induced gene silencing (VIGS) approach. The silencing of SMO1 genes generates a substantial and specific accumulation of 4,4-dimethyl-cyclopropyl-sterols whereas in SMO2 silenced plants there is an accumulation of 4a-methyl-D7-sterols. These distinct biochemical phenotypes demonstrate that in photosynthetic eukaryotes, contrary to animals and fungi, SMO1 and SMO2 families are respectively controlling the levels of 4,4-dimethyl- and 4a-methylsterol precursors.STRASBOURG-Sc. et Techniques (674822102) / SudocSudocFranceF