317 research outputs found

    Les complications chirurgicales de la transplantation rénale à partir du donneur vivant: expérience du CHU Ibn Sina de Rabat

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    Introduction: La transplantation rénale (TR) est actuellement considérée comme un traitement de choix de l’insuffisance rénale chronique terminale (IRCT). Ses résultats se sont améliorés au cours des dernières années. Cependant, les complications chirurgicales demeurent graves car elles touchent un rein unique et surviennent sur un terrain fragilisé par l’insuffisance rénale et l’immunosuppression. L’objectif de ce travail est d’évaluer la fréquence des complications chirurgicales lors de l’activité de TR au CHU Ibn Sina de Rabat, et de dégager les facteurs ayant influé l’apparition de ces complications. Méthodes : Étude rétrospective des patients transplantés rénaux à partir de donneurs vivants apparentés (DVA) de Juin 1999 à Décembre 2008 dans notre centre hospitalo-universitaire. Nous avons recensé les caractéristiques propres au receveur, au prélèvement, au donneur ainsi qu’au greffon. Les complications chirurgicales ont été colligées ainsi que leur prise en charge et évolution. Résultats: Soixante sept dossiers ont été analysés avec un suivi moyen de 55 +/- 28 mois. 38 complications chirurgicales ont été recensées : sténose des artères rénales (38,7%), lymphocèle (21%), hématome (12,7%), thrombose vasculaire (7,8%), reflux vésico-urétéral (4,8%), rupture du greffon (3,2%), calcul (1 cas), éventration (1 cas), L’analyse statistique de notre série n’a pas mis en évidence de facteurs de risque significatifs semblant influer sur l’incidence des complications chirurgicales. Conclusion: La morbidité liée aux complications chirurgicales de la TR reste élevée nécessitant un diagnostic et un traitement adéquat afin d’éviter les répercussions sur la survie des patients et des greffons

    The reliability of the anterior pelvic plane for computer navigated acetabular component placement during total hip arthroplasty: Prospective study with the EOS imaging system

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    Introduction Computer navigated total hip arthroplasty is mostly based on the use of the anterior pelvic plane (APP) as a reference. EOS is a new imaging system that provides three-dimensional analysis of the pelvis in a functional position with a low dose of radiation. The aim of this study was to evaluate the reliability of the APP for placement of the cup during computer navigated THA using EOS. Hypothesis The reliability of the APP is limited for the placement of the acetabular cup during computer navigated THA. Materials and methods This was a prospective monocentric study using the EOS imaging system evaluating 44 patients in the standing position three months after computer navigated THA (Orthopilot™). Reproducibility of EOS measurements were analyzed using SterEOS software and the reliability of the navigation data for the position of the cup were assessed. Results Intra and interobserver reproducibility of the measurements of the orientation of the cup by EOS were good with correlation coefficients above 93% and 95% and confidence intervals of less than ± 5°. Mean cup inclination and anteversion were 41.3° and 20.9° and 44.3° and 29.5° respectively in operatively and post-operatively. The differences between measurements of operative cup inclination using computer assisted navigation and the post-operative EOS measurements were significant (P < 0.05) with a correlation coefficient of less than 40%. Discussion Our study confirms the lack of precision of the APP as a reference for positioning of the acetabular component, especially in relation to anteversion. Although for many years the APP was considered to be a global reference, in fact, it is subject to significant inter-individual variations and variations during changes in position. These factors, associated with the difficulty of determining the preoperative APP, explain the lack of reliability of this reference. Preoperative evaluation of the orientation of APP by EOS and its integration into the navigation system could help the operator position these components

    Evaluation of a patient-specific finite-element model to simulate conservative treatment in adolescent idiopathic scoliosis

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    PublishedJournal ArticleAuthor's accepted manuscript.Study design: Retrospective validation study. Objectives: To propose a method to evaluate, from a clinical standpoint, the ability of a finite-element model (FEM) of the trunk to simulate orthotic correction of spinal deformity and to apply it to validate a previously described FEM. Summary of background data: Several FEMs of the scoliotic spine have been described in the literature. These models can prove useful in understanding the mechanisms of scoliosis progression and in optimizing its treatment, but their validation has often been lacking or incomplete. Methods: Three-dimensional (3D) geometries of 10 patients before and during conservative treatment were reconstructed from biplanar radiographs. The effect of bracing was simulated by modeling displacements induced by the brace pads. Simulated clinical indices (Cobb angle, T1-T12 and T4-T12 kyphosis, L1-L5 lordosis, apical vertebral rotation, torsion, rib hump) and vertebral orientations and positions were compared to those measured in the patients' 3D geometries. Results: Errors in clinical indices were of the same order of magnitude as the uncertainties due to 3D reconstruction; for instance, Cobb angle was simulated with a root mean square error of 5.7°, and rib hump error was 5.6°. Vertebral orientation was simulated with a root mean square error of 4.8° and vertebral position with an error of 2.5 mm. Conclusions: The methodology proposed here allowed in-depth evaluation of subject-specific simulations, confirming that FEMs of the trunk have the potential to accurately simulate brace action. These promising results provide a basis for ongoing 3D model development, toward the design of more efficient orthoses.ParisTech BiomecAM chair programProteorParisTechYves Cotrel Foundation

    Detecting cadmium(II) by using coal extracted from argan oilcake waste (Argania spinosa) as modifier of carbon paste electrode.

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    The detection of Cd2+ ions was studied by cyclic voltammetry (CV) and Square Wave Voltammetry (SWV). This method is mainly based on the accumulation of Cd2+ ions on the surface of a carbon paste electrode modified by coal extract from argan oilcake waste (AC-CPE). To evaluate the detection  performance of AC-CPE against Cd2+ ions, an optimization  study was carried out to determine the following optimal conditions, pH=5, preconcentration time of 120s, and deposition potential of 1.2V. Under these optimal conditions, a linear relationship between current peak intensity and concentration has been defined  over a concentration range from 5.10-4 to 5.10-7M; with detection limit (DL, 3 б) of 3.04x10-6M. An analytical application of the electrode in a real matrix, tap water, was performed and revealed good detection performance of AC-CPE. These results show that the AC-CPE can be used as an excellent detector of Cd2+ ions in aqueous solutio

    A mathematical model for fibro-proliferative wound healing disorders

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    The normal process of dermal wound healing fails in some cases, due to fibro-proliferative disorders such as keloid and hypertrophic scars. These types of abnormal healing may be regarded as pathologically excessive responses to wounding in terms of fibroblastic cell profiles and their inflammatory growth-factor mediators. Biologically, these conditions are poorly understood and current medical treatments are thus unreliable. In this paper, the authors apply an existing deterministic mathematical model for fibroplasia and wound contraction in adult mammalian dermis (Olsenet al., J. theor. Biol. 177, 113–128, 1995) to investigate key clinical problems concerning these healing disorders. A caricature model is proposed which retains the fundamental cellular and chemical components of the full model, in order to analyse the spatiotemporal dynamics of the initiation, progression, cessation and regression of fibro-contractive diseases in relation to normal healing. This model accounts for fibroblastic cell migration, proliferation and death and growth-factor diffusion, production by cells and tissue removal/decay. Explicit results are obtained in terms of the model processes and parameters. The rate of cellular production of the chemical is shown to be critical to the development of a stable pathological state. Further, cessation and/or regression of the disease depend on appropriate spatiotemporally varying forms for this production rate, which can be understood in terms of the bistability of the normal dermal and pathological steady states—a central property of the model, which is evident from stability and bifurcation analyses. The work predicts novel, biologically realistic and testable pathogenic and control mechanisms, the understanding of which will lead toward more effective strategies for clinical therapy of fibro-proliferative disorders

    Lower-limb lengths and angles in children older than six years: Reliability and reference values by EOS® stereoradiography

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    Lower-limb alignment in children is classically assessed clinically or based on conventional radiography, which is associated with projection bias. Low-dose biplanar radiography was described recently as an alternative to conventional imaging. The primary objective of this study was to assess the reliability of length and angle values inferred from 3D reconstructions in children seen in everyday practice. The secondary objective was to obtain reference values for goniometry parameters in children. The paediatric reliability study was done in 18 volunteers who were divided into three groups based on whether they were typically developing (TD) children, had skeletal development abnormalities, or had cerebral palsy. The reference data were obtained in 129 TD children. Each study participant underwent biplanar radiography with 3D reconstruction performed by experts and radiology technicians. Goniometry parameters were computed automatically. Reproducibility was assessed based on the intra-class coefficient (ICC) and the ISO 5725 standard (standard deviation of reproducibility, SDR). For length parameters, the ICCs ranged from 0.94 to 1.00 and the SDR from 2.1 to 3.5 mm. For angle parameters, the ICC and SDR ranges were 0.60–0.95 and 0.9°–4.6°, respectively. No significant differences were found across experts or radiology technicians. Age-specific reference data are reported. These findings confirm the reliability of low-dose biplanar radiography for assessing lower-limb parameters in children seen in clinical practice. In addition, the study provides reference data for commonly measured parameters

    Distribution of laminin and fibronectin isoforms in oral mucosa and oral squamous cell carcinoma

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    The expression of laminin and fibronectin isoforms varies with cellular maturation and differentiation and these differences may well influence cellular processes such as adhesion and motility. The basement membrane (BM) of fetal oral squamous epithelium contains the laminin chains, α2, α3, α5, β1, β2, β3, γ1 and γ2. The BM of adult normal oral squamous epithelium comprises the laminin chains, α3, α5, β1, β3, γ1 and γ2. A re-expression of the laminin α2 and β2 chains could be shown in adult hyperproliferative, dysplastic and carcinomatous lesions. In dysplasia and oral squamous cell carcinoma (OSCC), multifocal breaks of the BM are present as indicated by laminin chain antibodies. These breaks correlate to malignancy grade in their extent. Moreover, in the invasion front the α3 and γ2 chain of laminin-5 can immunohistochemically be found outside the BM within the cytoplasm of budding carcinoma cells and in the adjacent stroma. The correlation between the morphological pattern of invasive tumour clusters and a laminin-5 immunostaining in the adjacent stroma may suggest, first, that a laminin-5 deposition outside the BM is an immunohistochemical marker for invasion and second, that OSCC invasion is guided by the laminin-5 matrix. Expression of oncofetal fibronectins (IIICS de novo glycosylated fibronectin and ED-B fibronectin) could be demonstrated throughout the stromal compartment. However, the ED-B fibronectin synthesizing cells (RNA/RNA in situ hybridization) are confined to small stroma areas and to single stroma and inflammatory cells in the invasion front. A correlation of the number of ED-B fibronectin synthesizing cells to malignancy grade could not be seen. ED-B fibronectin mRNA-positive cells seem to be concentrated in areas of fibrous stroma recruitment with a linear alignment of stromal fibro-/myofibroblasts (desmoplasia). Double staining experiments (ED-B fibronectin in situ hybridization and α-smooth muscle actin immunohistochemistry) indicated that the stroma myofibroblasts are a preferential source of ED-B fibronectin. In conclusion, in OSCC, a fetal extracellular matrix conversion is demonstrable. Tumour cells (laminin α2 and β2 chain) and recruited stromal myofibroblasts (oncofetal ED-B fibronectin) contribute to the fetal extracellular matrix milieu. © 1999 Cancer Research Campaig

    Proteotypic classification of spontaneous and transgenic mammary neoplasms

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    INTRODUCTION: Mammary tumors in mice are categorized by using morphologic and architectural criteria. Immunolabeling for terminal differentiation markers was compared among a variety of mouse mammary neoplasms because expression of terminal differentiation markers, and especially of keratins, provides important information on the origin of neoplastic cells and their degree of differentiation. METHODS: Expression patterns for terminal differentiation markers were used to characterize tumor types and to study tumor progression in transgenic mouse models of mammary neoplasia (mice overexpressing Neu (Erbb2), Hras, Myc, Notch4, SV40-TAg, Tgfa, and Wnt1), in spontaneous mammary carcinomas, and in mammary neoplasms associated with infection by the mouse mammary tumor virus (MMTV). RESULTS: On the basis of the expression of terminal differentiation markers, three types of neoplasm were identified: first, simple carcinomas composed exclusively of cells with a luminal phenotype are characteristic of neoplasms arising in mice transgenic for Neu, Hras, Myc, Notch4, and SV40-TAg; second, 'complex carcinomas' displaying luminal and myoepithelial differentiation are characteristic of type P tumors arising in mice transgenic for Wnt1, neoplasms arising in mice infected by the MMTV, and spontaneous adenosquamous carcinomas; and third, 'carcinomas with epithelial to mesenchymal transition (EMT)' are a characteristic feature of tumor progression in Hras-, Myc-, and SV40-TAg-induced mammary neoplasms and PL/J and SJL/J mouse strains, and display de novo expression of myoepithelial and mesenchymal cell markers. In sharp contrast, EMT was not detected in papillary adenocarcinomas arising in BALB/cJ mice, spontaneous adenoacanthomas, neoplasms associated with MMTV-infection, or in neoplasms arising in mice transgenic for Neu and Wnt1. CONCLUSIONS: Immunohistochemical profiles of complex neoplasms are consistent with a stem cell origin, whereas simple carcinomas might originate from a cell committed to the luminal lineage. In addition, these results suggest that the initiating oncogenic events determine the morphologic features associated with cancer progression because EMT is observed only in certain types of neoplasm
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