Accumulation and transport of microbial-size particles in a pressure protected model burn unit: CFD simulations and experimental evidence

<p>Abstract</p> <p>Background</p> <p>Controlling airborne contamination is of major importance in burn units because of the high susceptibility of burned patients to infections and the unique environmental conditions that can accentuate the infection risk. In particular the required elevated temperatures in the patient room can create thermal convection flows which can transport airborne contaminates throughout the unit. In order to estimate this risk and optimize the design of an intensive care room intended to host severely burned patients, we have relied on a computational fluid dynamic methodology (CFD).</p> <p>Methods</p> <p>The study was carried out in 4 steps: i) patient room design, ii) CFD simulations of patient room design to model air flows throughout the patient room, adjacent anterooms and the corridor, iii) construction of a prototype room and subsequent experimental studies to characterize its performance iv) qualitative comparison of the tendencies between CFD prediction and experimental results. The Electricité De France (EDF) open-source software <it>Code_Saturne</it>^®(<url>http://www.code-saturne.org</url>) was used and CFD simulations were conducted with an hexahedral mesh containing about 300 000 computational cells. The computational domain included the treatment room and two anterooms including equipment, staff and patient. Experiments with inert aerosol particles followed by time-resolved particle counting were conducted in the prototype room for comparison with the CFD observations.</p> <p>Results</p> <p>We found that thermal convection can create contaminated zones near the ceiling of the room, which can subsequently lead to contaminate transfer in adjacent rooms. Experimental confirmation of these phenomena agreed well with CFD predictions and showed that particles greater than one micron (i.e. bacterial or fungal spore sizes) can be influenced by these thermally induced flows. When the temperature difference between rooms was 7°C, a significant contamination transfer was observed to enter into the positive pressure room when the access door was opened, while 2°C had little effect. Based on these findings the constructed burn unit was outfitted with supplemental air exhaust ducts over the doors to compensate for the thermal convective flows.</p> <p>Conclusions</p> <p>CFD simulations proved to be a particularly useful tool for the design and optimization of a burn unit treatment room. Our results, which have been confirmed qualitatively by experimental investigation, stressed that airborne transfer of microbial size particles via thermal convection flows are able to bypass the protective overpressure in the patient room, which can represent a potential risk of cross contamination between rooms in protected environments.</p

Higher placental anti-inflammatory IL-10 cytokine expression in HIV-1 infected women receiving longer zidovudine prophylaxis associated with nevirapine

Placental cytokine balance may be critical for the control of mother-to-child transmission (MTCT) of HIV. We assessed whether the type and duration of antiretrovirals used for prevention of HIV-1-MTCT modified the inflammatory cytokine profile. We investigated the levels of cytokine expression in the placentas of 61 HIV-1-infected women who received zidovudine (ZDV) plus single dose nevirapine (SD-NVP) or ZDV only for prevention of MTCT. Placentas of 38 HIV-1-uninfected women were included as controls. All placentas were obtained after vaginal delivery. Levels of mRNA and cytokine expression were quantified using real-time PCR and ELISA, respectively, in placental explants and 24-hour culture supernatants and analyzed in relation to the women's characteristics and the type and duration of antiretroviral prophylaxis. HIV-1-infected and uninfected women did not show any differences in the expression of placental cytokine secretion except for a trend toward lower TNF-10 mRNA levels in HIV-1-infected women. Within the HIV-1-infected group, women who were exposed to a long duration of ZDV (>72 days) or received SD-NVP less than 5h prior to delivery, more frequently expressed detectable levels of IL-10 in their placentas (32% versus 7% (p = 0.01) and 32% versus 5% (p = 0.02), respectively). No infant was found to be HIV-1-infected. Our results showed a normalization of the placental cytokine balance in HIV-1-infected women receiving antiretroviral prophylaxis. Furthermore, the type and duration of antiretroviral prophylaxis have an impact on the placental anti-inflammatory IL-10 expression level, which may contribute to controlling HIV replication at the placental level, thus reducing MTCT of HIV-1.Fil: Pornprasert, Sakorn. Chiang Mai University; TailandiaFil: Mary, Jean-Yves. Université Paris Diderot - Paris 7; FranciaFil: Faye, Albert. Institut National de la Santé et de la Recherche Médicale; FranciaFil: Leechanachai, Pannee. Chiang Mai University; TailandiaFil: Limtrakul, Aram. Health Promotion Center Region; TailandiaFil: Rugpao, Sungwal. Chiang Mai University; TailandiaFil: Sirivatanapa, Pannee. Chiang Mai University; TailandiaFil: Gomuthbutra, Vorapin. Nakornping Hospital; TailandiaFil: Matanasaravoot, Wanmanee. Lamphun Hospital; TailandiaFil: Le Coer, Sophie. Institut National d’Etudes Démographiques; FranciaFil: Lallemant, Marc. Centre National de la Recherche Scientifique. Institut de Recherche pour le Développement; FranciaFil: Barré-Sinoussi, Françoise. Instituto Pasteur; FranciaFil: Menu, Elisabeth. Instituto Pasteur; FranciaFil: Ngo Giang Huong, Nicole. Centre National de la Recherche Scientifique. Institut de Recherche pour le Développement; FranciaFil: Ayouba, Ahidjo. Instituto Pasteur; FranciaFil: Chailert, Sanupong. Chiang Mai University; Tailandia. Instituto Pasteur; FranciaFil: Chaouat, Gérard. Institut National de la Santé et de la Recherche Médicale; FranciaFil: Derrien, Muriel. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Dolcini, Guillermina Laura. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Departamento de Sanidad Animal y Medicina Preventiva. Laboratorio de Virología; Argentina. Instituto Pasteur; Francia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Eteki, Nicole. Hôpital Central de Yaoundé. Maternité Principale; CamerúnFil: Kfutwah, Anfumbom Jude. Instituto Pasteur; FranciaFil: Kouo, Odette. Instituto Pasteur; FranciaFil: Lemen, Brigitte. Instituto Pasteur; FranciaFil: Abal, Facundo Juan Pablo. Instituto Pasteur; FranciaFil: Nerrienet, Eric. Instituto Pasteur; FranciaFil: Njinku, Bernadette. Instituto Pasteur; FranciaFil: Scarlatti, Gabriella. Suan Dok Hospital; TailandiaFil: Tejiokem, Mathurin. Centre Pasteur du Cameroun; CamerúnFil: Téné, Gilbert. No especifíca

The Neurotensin Receptor-1 Pathway Contributes to Human Ductal Breast Cancer Progression

BACKGROUND: The neurotensin (NTS) and its specific high affinity G protein coupled receptor, the NT1 receptor (NTSR1), are considered to be a good candidate for one of the factors implicated in neoplastic progression. In breast cancer cells, functionally expressed NT1 receptor coordinates a series of transforming functions including cellular migration and invasion. METHODS AND RESULTS: we investigated the expression of NTS and NTSR1 in normal human breast tissue and in invasive ductal breast carcinomas (IDCs) by immunohistochemistry and RT-PCR. NTS is expressed and up-regulated by estrogen in normal epithelial breast cells. NTS is also found expressed in the ductal and invasive components of IDCs. The high expression of NTSR1 is associated with the SBR grade, the size of the tumor, and the number of metastatic lymph nodes. Furthermore, the NTSR1 high expression is an independent factor of prognosis associated with the death of patients. CONCLUSION: these data support the activation of neurotensinergic deleterious pathways in breast cancer progression

Reconstruction par lambeau de Taylor après amputation abdomino-périnéale (étude rétrospective de 68 patients)

PARIS7-Xavier Bichat (751182101) / SudocSudocFranceF

Bio-ingénierie de vaisseaux de petit calibre à base d'hydrogel

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

Evaluation clinique, photographique et évolutive de la profondeur des brûlures (à propos de 1002 cas)

PARIS7-Xavier Bichat (751182101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Pariétectomies géantes - greffes dans les cancers étendus du sein (à propos de 26 patientes)

PARIS7-Xavier Bichat (751182101) / SudocSudocFranceF

Free-style puzzle flap as a cross-leg pedicled flap: the concept of re-using a flap in acute burns, a case report

Abstract Background In well-selected cases, flaps can play a pivotal role in optimizing outcomes in the acute phase of burns. A previous redundant flap could be reused or recycled as a donor site from which a new flap could be raised. Case presentation We report the case of a patient with full thickness burns on both legs, leading to the exposure of joints of the right ankle and the right foot and left patellar tendon. The right lower extremity was covered with a free musculo-cutaneous latissimus dorsi flap. Then, a musculo-cutaneous cross-leg flap pedicled on the anterior branch and centered on a perforator was harvested from the previous redundant flap to cover the controlateral knee. Conclusion Sequential flap coverage can be considered in cases of extensive soft tissue defects and particularly in burns. This case illustrates that re-using a redundant part of a previous flap to cover another defect is a safe and interesting alternative in the event of a lack of donor sites or to save donor sites for later reconstruction of contracted burn scars