Quelles pratiques infirmières permettent de répondre aux besoins des mères lors de la période de transition à la naissance afin de limiter le risque d'épuisement postnatal ?: travail de Bachelor

Contexte : Le risque d’épuisement ou de dépression durant la période postnatale est un sujet encore peu étudié; les femmes, souvent, ne parlent pas des difficultés rencontrées durant cette période par peur d’être jugées sous le poids des représentations sociétales. But : Conçu sous forme de revue de la littérature, ce travail de Bachelor consiste à identifier les besoins principaux des mères lors de la période de transition à la naissance, ainsi que les pratiques infirmières permettant de prévenir ou de dépister le risque d’épuisement. Méthode : La recherche est réalisée sur la base de données CINAHL, à l’aide de mots clés préalablement définis. Les articles ont été sélectionnés par la pertinence de leur titre puis par la lecture des abstracts et la concordance avec les thématiques principales traitées. Finalement, douze études qualitatives, quantitatives ou revues systématiques ont été analysées. Résultats : Les besoins principaux des mères en cette période de transition sont le soutien social et professionnel, le repos, et la confiance en elles et en leurs capacités à prendre soin de leur bébé. Les pratiques soignantes auprès des mères consistent principalement en un soutien émotionnel et informatif basé sur leurs propres besoins et ceux du nouveau-né et renforçant leurs compétences. Conclusion : Cette revue de la littérature permet de sensibiliser les futurs parents et les professionnels de santé sur les risques engendrés par la période de transition à la naissance. Elle met également en évidence le rôle infirmier dans la prévention et le dépistage d’un épuisement postnatal

Up-Regulation of Intestinal Vascular Endothelial Growth Factor by Afa/Dr Diffusely Adhering Escherichia coli

BACKGROUND: Angiogenesis has been recently described as a novel component of inflammatory bowel disease pathogenesis. The level of vascular endothelial growth factor (VEGF) has been found increased in Crohn's disease and ulcerative colitis mucosa. To question whether a pro-inflammatory Escherichia coli could regulate the expression of VEGF in human intestinal epithelial cells, we examine the response of cultured human colonic T84 cells to infection by E. coli strain C1845 that belongs to the typical Afa/Dr diffusely adhering E. coli family (Afa/Dr DAEC). METHODOLOGY: VEGF mRNA expression was examined by Northern blotting and q-PCR. VEGF protein levels were assayed by ELISA and its bioactivity was analysed in endothelial cells. The bacterial factor involved in VEGF induction was identified using recombinant E. coli expressing Dr adhesin, purified Dr adhesin and lipopolysaccharide. The signaling pathway activated for the up-regulation of VEGF was identified using a blocking monoclonal anti-DAF antibody, Western blot analysis and specific pharmacological inhibitors. PRINCIPAL FINDINGS: C1845 bacteria induce the production of VEGF protein which is bioactive. VEGF is induced by adhering C1845 in both a time- and bacteria concentration-dependent manner. This phenomenon is not cell line dependent since we reproduced this observation in intestinal LS174, Caco2/TC7 and INT407 cells. Up-regulation of VEGF production requires: (1) the interaction of the bacterial F1845 adhesin with the brush border-associated decay accelerating factor (DAF, CD55) acting as a bacterial receptor, and (2) the activation of a Src protein kinase upstream of the activation of the Erk and Akt signaling pathways. CONCLUSIONS: Results demonstrate that a Afa/Dr DAEC strain induces an adhesin-dependent activation of DAF signaling that leads to the up-regulation of bioactive VEGF in cultured human intestinal cells. Thus, these results suggest a link between an entero-adherent, pro-inflammatory E. coli strain and angiogenesis which appeared recently as a novel component of IBD pathogenesis

Infection bactérienne, inflammation et carcinogenèse (événements moléculaires associés à l'activation d'HIF-1 en réponse à l'infection des cellules épithéliales intestinales par les "Diffusely Adhering Afa/Dr E. coli" (Afa/Dr DAEC))

L angiogenèse participe au processus inflammatoire de type chronique, notamment dans les maladies inflammatoires chroniques intestinales (MICI). L origine de ces maladies est encore mal connue, mais il existe de nombreux arguments incriminant les microorganismes intestinaux. Plusieurs études suggèrent que des E. coli opportunistes présentant des caractéristiques pro-inflammatoires participent à l établissement des MICI. Nous avons émis l hypothèse que ces souches de bactéries pourraient moduler la réponse angiogénique de cellules épithéliales intestinales humaines. L infection de ces cellules par la souche E. coli Afa/Dr DAEC C1845 induit une augmentation de l expression de gènes angiogéniques et inflammatoires dont le Vascular Endothélial Growth Factor et l Interleukine-8. Le VEGF produit est biologiquement actif sur des cellules endothéliales en culture. Le facteur HIF-1 rend compte de la production de VEGF mais aussi de kl IL-8. Contrairement à l hypoxie qui stabilise la protéine HIF-1alpha par inhibition de l activité des prolyl hydroxylases, les bactéries C1845 induisent un macanisme traductionnel conduisant à l activation de la protéine S6 par l intermédiaire des voies MEK/ERK et PI-3K/AKT. La stimulation de HIF 1alpha en réponse aux bactéries requiert la liaison de l adhésine F1845 au récepteur membranaire DAF. Le niveau d expression et l activité du facteur HIF-1 est de plus en plus étudié dans le cadre d inflammations intestinales, dont les MICI, HIF-1 pourraient représenter un élément clé dans la chronicité et l évolution des MICI de part son rôle au cours de l inflammation, de l angiogenèse et dans le maintien de l intégrité de l épithélium intestinal.Angiogenesis is involved in chronic inflammatory processes, including Inflammatory Bowel Disease (IBD). The origin of IBD is not known yet, but there are a lot of arguments incriminating intestinal microorganisms. Some opportunistic E. coli shows inflammatory characteristics in sensitive people. Several studies suggest that bacteria are involved in IBD. We have proposed the hypothesis that bacterial strain might modulate the angiogenic response of human intestinal epithelial cells. The infection of these cells with an inflammatory strain of E. coli Afa/Dr DAEC C1845 induced the expression of inflammatory and angiogenic genes like the Vascular Endothelial Growth Factor (VEGF) and the Interleukin-8 (IL-8). The VEGF product by infected cells is biologically active on endothelial cells in culture. The factor HIF-1 reports the production of VEGF and IL-8. Unlike hypoxia which stabilised HIF-1alpha protein by inhibition of the prolyl hydroxylases activity, C1845 bacteria induced a translational mechanism leading to the activation of the ribosomal protein S6 mediated by the MEK/ERK and PI-3K/AKT pathways. Moreover, the activation of HIF-1alpha in response to the infection requires the binding of the F1845 adhesin to the DAF/CD55 membrane receptor. The level of expression and the activity of HIF-1 are more and more analysed in intestinal inflammations like IBD. HIF-1 could be a key factor in the chronicity if the inflammation and in thhe evolution of IBD thanks to its effect on inflammation, angiogenesis and intestinal epithelium integrity.NICE-BU Sciences (060882101) / SudocSudocFranceF

Wild-type C1845-induced gene expression

<p>Cells were infected for four hours with Afa/Dr DAEC wild-type strain C1845 and total RNA extracted. Selected gene expression was assayed by q-PCR. The oligonucleotides used in this study were designed by Applied Biosystems, the manufacturer's references are given in brackets. Abbreviations are as follows: VEGF: Vascular Endothelial Growth Factor, IL8: interleukin 8, PlGF: Placental growth factor, TGFβ R2: Transforming growth factor Receptor 2, EGF R1: Epithelial growth factor Receptor 1. Results (means±SD) are representative of independent experiments (where n represents the number of experiments). *, p<0.001 versus non infected cells.</p

Increase in VEGF mRNA by wild-type C1845 bacteria requires binding to brush border-associated DAF.

<p>In A, binding to DAF is necessary for the C1845-induced increase in VEGF mRNA expression. Confluent serum-starved T84 cells infected were with wild-type C1845 at 5×10⁷ CFU/ml, which represents a multiplicity of infection of 20 bacteria per epithelial cell, for two hours. When indicated, cells were treated for 30 minutes prior to infection with the anti-DAF blocking IH4 monoclonal antibody. VEGF mRNA expression was assayed by q-PCR. *, p = 0,03 (n = 7). In B, wild-type C1845-induced VEGF mRNA increase is blocked by transcription inhibitor. Confluent serum-starved T84 cells were pre-treated for 30 minutes with 25 µg/ml of the reversible transcription inhibitor, 5,6-dichloro-1-beta-D-ribobenzimidazole (DRB). Cells were then infected with 5×10⁷ CFU/ml wild-type C1845 for four hours and total RNA prepared. The relative quantity of VEGF mRNA was measured by q-PCR. Quantification of the results from three independent experiments (means±SD) is shown. *, p<0,01.</p

A Src protein is involved in wild-type C1845-induced Akt and Erk activation.

<p>Confluent serum-starved T84 cells were pre-treated with 15 µM LY294002 (LY), 10 µM U0126 (U0), 5 µM GF109203X (GFX) or 5 µM PP2 for 30 minutes prior to infection or no infection with wild-type C1845 bacteria at 5×10⁷ CFU/ml for two hours. Cells were lyzed in SDS sample buffer and phospho-Akt and total Akt (in A) and phospho-Erk and total Erk1/2 (in B) assayed by Western blotting as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0001359#pone-0001359-g005" target="_blank">Figure 5</a>. These results are representative of at least three independent experiments.</p

F1845 adhesin but not LPS, activates Erk and increases VEGF expression.

<p>In A, confluent serum-starved T84 cells were non infected (NI), infected with 5×10⁷ CFU/ml wild-type C1845 bacteria, or treated for 2 hours with indicated concentration of LPS purified from non-pathogenic AAEC185 or C1845 strains. Phospho-Erk1/2 and total Erk1 were visualized by Western Blotting with respectively anti-phospho-Erk and anti-Erk1 antibodies. This experiment is representative of two independent experiments. In B, confluent serum-starved T84 cells were non-infected (NI), infected with increasing concentrations of AAEC185 or recombinant AAEC185-F1845 strains for 2 h. Phospho-Erk and total Erk-1 were assayed by Western blotting using respectively anti-phospho-Erk and anti-Erk1 antibodies. In C, coomassie-stained polyacrylamide-SDS gel of fimbriae purified from C1845 or AAEC185 bacteria. 1 µg of bovine serum albumine (BSA) are showed on the left of the gel. In D, confluent serum-starved T84 cells were non treated (NT) or incubated 2 h in the presence of extracts of C1845 bacteria (containing 2 µg of purified F1845 adhesin) or AAEC185 bacteria. These result are representative of three independent experiments. In E, confluent serum-starved T84 cells (5×10⁶ cells/well) were infected with AAEC185 bacteria or recombinant AAEC185-F1845 bacteria expressing the pSSS1 operon encoding the F1845 adhesin (5×10⁷ CFU/ml). Total RNA were extracted and analysed by q-PCR. These results are representative of at least two independent experiments (means±SD).</p

Wild-type C1845 bacteria induce Akt and Erk signaling pathways in T84 epithelial cells.

<p>Confluent serum-starved T84 cells were non-infected (NI) or infected with increasing concentrations of wild-type C1845 bacteria, for two hours. When indicated, cells were pre-treated with an anti-DAF blocking IH4 monoclonal antibody prior to or in the absence of infection. In A, phospho-Akt and total Akt were assayed by Western blotting using respectively anti-phospho-Akt and anti-Akt antibodies. In B, phospho-Erk1/2 and total Erk1/2 were visualized with respectively anti-phospho-Erk and anti-Erk antibodies. These results are representative of at least three independent experiments.</p

Wild-type C1845-induced VEGF expression is dependant on Src and Erk proteins.

<p>Confluent serum-starved T84 cells were pre-treated with 5 µM PP2, 10 µM U0126 or 15 µM LY294002 for 30 minutes. Cells were then infected with wild-type C1845 bacteria at 5×10⁷ CFU/ml for four hours. Total RNA was prepared and the relative quantity of VEGF mRNA was measured by q-PCR. Quantification of the results from four independent experiments (means±SD.) is shown. *, p<0.005 versus non infected cells.</p

C1845 bacteria increase VEGF expression in cultured intestinal epithelial cells.

<p>In A, increase in VEGF mRNA expression. Confluent serum-starved T84 cells (5×10⁶ cells/well) were infected with wild-type C1845 bacteria and total RNA was prepared as indicated in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0001359#s4" target="_blank">Materials and Methods</a> section. Results for non-infected (NI) or cells infected with 5×10⁷ CFU/ml C1845 bacteria for the indicated time are shown on the left panel. The dose response effect is presented on the right. Cells were infected for four hours with the indicated number of bacteria. Results of Northern blots are presented in the upper part of the Figure and q-PCR shown in the lower part. These results are representative of three independent experiments. In B, confluent serum-starved LS174, Caco-2/TC7 or INT407 cells were infected with 5×10⁷ CFU/ml wild-type C1845 bacteria for four hours. VEGF mRNA expression was assayed by q-PCR. The signal corresponding to VEGF and 36B4 transcripts was quantified using a phosphoImager. Under each condition the signal was normalized to the 36B4 probe. Results are expressed as arbitrary units corresponding to the fold stimulation of treated versus non-treated conditions. In C, increase in the VEGF protein in the culture medium of wild-type C1845-infected T84 cells. Cells were infected with 5×10⁷ CFU/ml wild-type C1845 bacteria for four hours and the supernatant were collected as indicated in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0001359#s4" target="_blank">Materials and Methods</a> section. The VEGF protein level was then quantified using an ELISA. Quantification of the results from two independent experiments (means±SD) is shown. *, p<0,01</p