The heterogeneous plane acoustic wave in a thermoviscous fluid

The linearized equations of perturbation in a thermoviscous fluid have three independent solutions as heterogeneous plane waves: the acoustic wave, the rotational and the entropic one . The first wave is detailed. Particular cases are showned: the evanescent wave in a perfect fluid, and the Alais' heterogeneous mode in a viscous fluid when the attenuation vector is very small .Les équations de perturbations linéarisées d'un fluide thermovisqueux possèdent comme solutions trois modes plans hétérogènes indépendants : les modes acoustique, de rotation et d'entropie . Le premier mode est décrit en détail. Des cas particuliers de ce mode sont présentés : l'onde plane évanescente classique dans un fluide parfait, et le mode hétérogène de Alais dans un fluide visqueux quand le vecteur d'atténuation est très petit

REPRESENTATIONS LAGRANGIENNE ET EULERIENNE DE L'ACOUSTIQUE NON LINÉAIRE

A partir des équations de la mécanique des fluides écrites en variables de Lagrange (resp. en variables d'Euler), nous obtenons par petites perturbations, les équations du second ordre vérifiées par le champ acoustique lagrangien (resp. eulérien) dans le cas suivant : fluide parfait, initialement au repos, illimité, à caractéristiques C∞, en présence d'une force extérieure. Après avoir relié champ acoustique lagrangien et champ acoustique eulérien, nous montrons l'équivalence entre les deux représentations en dehors des sources acoustiques.From the equations of fluid mechanics written in Lagrange variables (resp. Euler variables) we get by small perturbations the second order equations for the lagrangian (resp. eulerian) acoustic field in the following case : perfect fluid, initially at rest, unlimited, endowed with C∞ characteristics, in the presence of an external force. We establish the correspondence between the lagrangian and eulerian acoustic fields and we deduce the equivalence between the two representations outside the acoustic sources

O-267 Uterine volume is dramatically decreased in Stem Cell Hematopoietic Transplantation childhood survivors whatever the conditioning regimen. A case-control MRI study in the L.E.A cohort

International audienceStudy question: Could a hydrogel with similar mechanical properties of reproductive age ovarian cortex support the growth of human preantral follicles? Summary answer: Yes, our optimized PEGylated fibrin hydrogel with tailored mechanical strength provides a suitable substrate for follicle survival and growth. What is known already: The most challenging part of assembling an engineered ovary is developing an appropriate scaffold that can maintain follicle spatial architecture and allow them to have radial growth and development 1-3. Fibrin is a promising biomaterial due to its biocompatibility and bioactivity. Although fibrin has been used as a scaffold in fabricating different tissues such as the ovary, it has a fast degradation rate resulting in loss of physical support for the isolated follicles 4-6. Therefore, various approaches such as physical or chemical modifications have been investigated to overcome the fibrin limitation 7-10. Study design, size, duration: PEGylation as a chemical reaction was used to control fibrin degradation. Moreover, to create an appropriate scaffold for encapsulating human preantral follicles, the Response Surface Methodology was used to find a hydrogel formulation with similar mechanical properties to the reproductive-age ovarian cortex. The chosen hydrogel was used to in vitro culture isolated human preantral follicles for 7 days. Participants/materials, setting, methods: Design-Expert V R software was employed to optimize PEGylated fibrin formulation to match mechanical properties of human ovarian tissues. Preantral follicles isolated from reproductive age patients were embedded in the hydrogel and in vitro cultured for 7 days. Follicle viability and diameter were evaluated on days 1 and 7. Moreover, confocal microscopy analysis was performed on whole follicles to confirm their growth by Ki67 staining of granulosa cells. Main results and the role of chance: In this study, the biomechanically optimized PEGylated fibrin formulation was obtained by mathematical modeling. The hydrogel formulation was established by setting the specific goal of targeting 3178 § 245 Pa, Young's modulus of ovarian tissue fragments in reproductive-age women 11 , in order to obtain the optimized concentration of PEGylated fibrinogen and thrombin. Our results showed that the optimum condition with the desirability of 97.5% occurred by the PEGylated fibrin hydrogel containing 39.06 mg/ml of PEGylated fibrinogen and 50.36 IU/ml of thrombin with Young's modulus of 3512.31 §656.97 pa. Isolated follicles cultured in our hydrogel significantly increased in their diameter from 48.5 §10.8mm (day 1) to 222.5 §84.5mm (day 7), indicating the suitability of the optimized PEGylated fibrin formulation to support radial follicle growth. Moreover, follicles survival on days 1 and 7 did not significantly differ (86.9 §8.9% and 83.4 §6.4%, respectively). Follicle growth was confirmed by the presence of Ki67-positive granulosa cells from follicles at day 7. Limitations, reasons for caution: In this study, the optimized hydrogel was first evaluated only in vitro, which is different from the actual physiological condition. Therefore, it is essential to perform a study analyzing the follicles after their encapsulation in the optimized hydrogel and transplantation, which will be the next step of our study. Wider implications of the findings: Our results introduced an appropriate biomaterial, which resembles Young's modulus of ovarian tissues in reproductive age, for encapsulating human preantral follicles. The optimal concentration of PEGylated fibrin allowed follicles to maintain their viability and have radial growth. Moreover, PEGylation enhanced the fibrin stability and physical support of follicles. Trial registration number: not applicable Abstract citation ID: deac106.049 O-267 Uterine volume is dramatically decreased in Stem Cell Hematopoietic Transplantation childhood survivors whatever the conditioning regimen. A case-control MRI study in the L.E.A cohor

Diagnostic contribution of positron emission tomography with [18F]fluorodeoxyglucose for invasive fungal infections

Presented in part at the 46th Interscience Conference on Antimicrobial Agents and Chemotherapy; 27–30 September 2006, San Francisco, CA, USA, Abstract M-1307International audienceOptimal staging and evaluation of residual lesions of invasive fungal infections (IFIs) are major challenges in the immunocompromised host. Preliminary data have suggested that [ 18 F]fluorodeoxyglucose ([ 18 F]FDG) uptake may be observed in the course of active inva-sive fungal infections. The aim of this study was to assess the role of positron emission tomography with [ 18 F]FDG ([ 18 F]FDG-PET) in the diagnosis and staging of IFI. A prospective monocentric study evaluating [ 18 F]FDG-PET in 30 consecutive adults and children with European Organization for Research and Treatment of Cancer/Mycoses Study Group probable or proven IFI was performed. Twenty males and ten females (median age, 45 years (range 6-75 years)) were enrolled. Twenty-six were immunocompromised, as follows: haematological malignancy (18) with allogeneic stem cell transplantation (16/18), solid tumour (three), solid organ transplanta-tion (two), diabetes mellitus (two) and cystic fibrosis (one). IFIs were acute invasive aspergillosis (ten), chronic disseminated candidia-sis (ten), zygomycosis (two), black grains eumycetoma (two), pulmonary Histoplasma capsulatum var. capsulatum histoplasmosis (two), and Phomopsis sp. osteoarthritis, Scedosporium apiospermum and Candida krusei spondylodiscitis, and acute pulmonary coccidioidomyco-sis in one case each. An increased uptake of [ 18 F]FDG was observed in all areas previously identified by computed tomography and/ or magnetic resonance imaging to be involved by IFI. In 4/10 chronic disseminated candidiasis cases, [ 18 F]FDG-PET revealed small splenic abscesses that were unapparent on the corresponding computed tomography scan. [ 18 F]FDG uptake disappeared after 6 months of antifungal therapy in three patients with chronic disseminated candidiasis for whom the [ 18 F]FDG-PET was performed to assess the evolution of the disease. [ 18 F]FDG-PET could potentially be useful for the initial diagnosis and staging of IFI. Whether or not [ 18 F]FDG-PET might be useful for assessing the optimal duration of IFI therapy should now be assessed in a specific prospective study

Late effects in survivors of infantile acute leukemia: a study of the L.E.A program

International audienc

Spectrum of Pulmonary Aspergillosis in Hyper-IgE Syndrome with Autosomal-Dominant STAT3 Deficiency

International audienceBackground: Autosomal-dominant signal transducer and activator of transcription 3 (STAT3) deficiency predisposes to recurrent bacterial pneumonia, complicated by bronchiectasis and cavitations. Aspergillosis is a major cause of morbidity in these patients. However, its diagnosis, classification, and treatment are challenging.Objective: We aimed to assess the prevalence and describe the clinical, mycological, and radiological presentation and related therapy and outcome of Aspergillus infections of the respiratory tract in the STAT3-deficient patients of the National French cohort.Methods: We performed a retrospective study of all pulmonary aspergillosis cases in STAT3-deficient patients (n = 74). Clinical and mycological data were collected up to October 2015 and imaging was centralized.Results: Twenty-one episodes of pulmonary aspergillosis in 13 (17.5%) STAT3-deficient patients were identified. The median age at first episode was 13 years (interquartile range, 10-26 years). Ninety percent of patients had previous bronchiectasis or cavitations. Infections were classified as follows: 5 single aspergilloma, 9 chronic cavity pulmonary aspergillosis, 5 allergic bronchopulmonary aspergillosis-like disease, and 2 mixed forms of concomitant allergic bronchopulmonary aspergillosis-like disease and chronic cavity pulmonary aspergillosis. No invasive aspergillosis cases were identified. Aspergillus species were isolated in 71% of episodes and anti-Aspergillus antibodies in 93%. Eleven episodes were breakthrough infections. Antifungal treatment was prolonged, with a median of 13 months, and 6 patients (7 episodes) required surgery, with a high rate of postsurgical complications. One patient died and 6 had a relapse.Conclusions: Chronic and allergic forms of aspergillosis occurred in 17.5% of STAT3-deficient patients, mostly in lung cavities. Almost half had recurrences, despite prolonged antifungal treatment and/or surgery