Laboratoire Dimmunologie Et Of Microbiologie

Witry-lès-Reims, France

Laboratoire Dimmunologie Et Of Microbiologie

Witry-lès-Reims, France
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Acebey-Castellon I.L.,CNRS Institute of Molecular Chemistry - Reims | Voutquenne-Nazabadioko L.,CNRS Institute of Molecular Chemistry - Reims | Doan Thi Mai H.,CNRS Institute of Chemistry | Roseau N.,CNRS Institute of Molecular Chemistry - Reims | And 8 more authors.
Journal of Natural Products | Year: 2011

Three new bidesmosidic saponins (1-3) and a new ursane triterpenoid, 2α,3β,11α,23-tetrahydroxyurs-12-en-28-oic acid (4), along with seven known compounds, were isolated from a methanolic extract of the leaves of Symplocos lancifolia. The bidesmosidic saponins were found to possess the same sugar unit part, composed of two β-d-glucose moieties and one α-l-rhamnose moiety, linked to maslinic acid, arjunolic acid, and asiatic acid, respectively. Their structures were elucidated by interpretation of their 1D and 2D NMR spectra and completed by analysis of the HRESIMS data. The antibacterial activity of the isolated triterpenoids was evaluated against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa, and several showed activity against Gram-positive bacteria. © 2011 The American Chemical Society and American Society of Pharmacognosy.

Bourrous M.,Sina | Drais G.,Sina | Amine M.,Laboratoire dEpidemiolosie | Adabbous A.,Sina | And 2 more authors.
Journal de Pediatrie et de Puericulture | Year: 2010

Introduction. - The viral hepatitis A infection represents a real public health problem in Morocco, always stated with other countries of Africa as an endemic country. Objectives. - To assess prevalence of the viral hepatitis A infection in febrile icteric children and to examine the main risk factors of transmission. Patients and methods.- A cross-sectional study was conducted in a sample of 129 acute infantile febrile icteric cases between October 2006 and September 2008 in the paediatric department of the University Hospital of Marrakech. Baseline data included demographic and socio-economic information, conditions of living, dietary habits and conditions of hygiene. The serology of the viral hepatitis A (anti-VHA IgM) used the standard test ELISA immunocapture. Results. - From the 129 cases of acute icteric hepatitis, 118 (91.5%) were positive for IgM anti-VHA. Among positive children, age ranged from one to 15 years, with an average of 6.1 ±3.1 years, and a middle age of 5.5 years. The prevalence was highest (51.7%) among children aged less than six years and declined progressively thereafter. The sex-ratio M/F was of 1.4. Most cases was diagnosed between July and October, had a low socioeconomic level (60.2%), were living in the urban area (72%) and had a crowding households (51.7%). Conclusion. - This study points out the high prevalence of hepatitis A in Marrakech; it suggests that this infection is still endemic in this region. More studies are required to establish the epidemiological profile of hepatitis A in this context in order to appreciate the most appropriate preventive approach © 2009 Elsevier Masson SAS. All rights reserved.

Al Alam D.,Laboratoire Dimmunologie Et Of Microbiologie | Al Alam D.,Saban Research Institute | Deslee G.,Reims University Hospital Center | Deslee G.,French Institute of Health and Medical Research | And 8 more authors.
American Journal of Respiratory Cell and Molecular Biology | Year: 2010

Staphylococcus aureus is frequently isolated from lungs of patients with cystic fibrosis (CF). Upon lung infection with S. aureus, airway epithelial cells (AEC) produce high levels of chemokines that enhance T-cell chemotaxis. Although the number of lymphocytes is increased in the airways and bronchoalveolar lavage fluid of patients with CF, the mechanisms responsible for their accumulation and the role of S. aureus in this process are largely unknown. This study investigated early S. aureus impact on chemokine secretion by CF epithelial cells and chemotaxis of CF T cells. CF and non-CF AEC were grown in a cell culture model and apically stimulated with S. aureus. Supernatants were quantified for chemokine secretions and assayed for T-cell chemotaxis. CF AEC secreted constitutively larger amounts of IL-8, GROα, MIG, MIP-3β, and MCP-1 than non-CF epithelial cells. S. aureus interaction with epithelial cells increased chemokine production by non-CF cells but had no effect on CF cells. Chemotaxis of T cells derived from patients with CF was greater than that of T cells from subjects without CF. Moreover, there were more CF T cells expressing CXCR1 as compared with non-CF T cells. Under our experimental conditions, inhibition of IL-8 or its receptor CXCR1 resulted in a considerable decrease in T-cell chemotaxis (up to 80%). These data suggest that IL-8 and its receptor CXCR1 are key players in the chemotaxis of CF T cells and could be used as targets to develop therapies for CF.

Rusciani A.,University of Reims Champagne Ardenne | Duca L.,University of Reims Champagne Ardenne | Sartelet H.,University of Reims Champagne Ardenne | Chatron-Colliet A.,University of Reims Champagne Ardenne | And 6 more authors.
PLoS ONE | Year: 2010

The sialidase activity of neuraminidase-1 (Neu-1) is responsible for ERK 1/2 pathway activation following binding of elastin peptide on the elastin receptor complex. In this work, we demonstrate that the receptor and lipid rafts colocalize at the plasma membrane. We also show that the disruption of these microdomains as well as their depletion in glycolipids blocks the receptor signaling. Following elastin peptide treatment, the cellular GM3 level decreases while lactosylceramide (LacCer) content increases consistently with a GM3/LacCer conversion. The use of lactose or Neu-1 siRNA blocks this process suggesting that the elastin receptor complex is responsible for this lipid conversion. Flow cytometry analysis confirms this elastin peptide-driven LacCer generation. Further, the use of a monoclonal anti-GM3 blocking antibody shows that GM3 is required for signaling. In conclusion, our data strongly suggest that Neu-1-dependent GM3/LacCer conversion is the key event leading to signaling by the elastin receptor complex. As a consequence, we propose that LacCer is an early messenger for this receptor. © 2010 Rusciani et al.

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