Cholesteatome Congenital De L’oreille Moyenne A Propos De Deux Cas

But :Le cholesteatome congenital de l’oreille moyenne est une entite rare. L’objectif de ce travail est de discuter les particularites cliniques et therapeutiques de cette pathologie a travers deux observations de malades presentant un cholesteatome congenital operes et suivis au service d’ORL et de chirurgie cervico-faciale Fattouma Bourguiba Monastir, entre 2002 et 2008. Résultats : Il s’agissait de deux garcons, ages de 5 et 7 ans. La symptomatologie etait dominee par l’apparition d’une hypoacousie et l’examen otologique a revele un tympan complet dans les deux cas. La TDM des rochers a permis d’evoquer le diagnostic du cholesteatome congenital et d’apprecier les extensions locales des lesions. Les deux malades ont eu une tympanoplastie en technique fermee. Conclusion : L’evolution du cholesteatome congenital est insidieuse et le diagnostic est souvent tardif. Le traitement est chirurgical, domine par la tympanoplastie en technique fermee. Mots clès : Chlolesteatome congenital, hypoacousie, tympan complet, tympanoplastie en technique fermee, technique ouverte

Myxome Du Maxillaire A Propos D\'un Cas

Les myxomes des maxillaires sont des tumeurs bénignes rares dont la pathogénie reste encore controversée. Leur indolence et la pauvreté des manifestations qui les accompagnent rendent leur diagnostic souvent tardif et leur prise en charge difficile. Nous présentons un cas de myxome du maxillaire chez un nourrisson âgé de 12 mois suivi d\'une revue de la littérature permettant de synthétiser les données cliniques ainsi que la stratégie thérapeutique à adopter.Maxillary myxoma are rare benign tumours whose pathogenesis remains extremely discussed. The poor clinical picture and the absence of pain makes the diagnosis difficult. We report a pediatric case of maxillary myxoma of a 12- monthold infant and review the clinical features, radiographic evaluation and the appropriate treatment Keywords:Myxoma - maxillary - benign tumor. Journal Tunisien d\'ORL et de chirurgie cervico-faciale Vol. 18 2007: pp. 43-4

Tumeur Germinale De L\'espace Para Pharynge : A Propos D\'un Cas

Les tumeurs germinales à localisation cervico-faciale sont rares. Nous rapportons l\'observation d\'une une fillette de 7 ans porteuse d\'une tumeur maligne à cellules germinales de l\'espace para-pharyngé droit traité par chimiothérapie. Les particularités étiopathogéniques, thérapeutiques, et pronostiques de cette tumeur sont rappelées après une revue des données de la littérature.Extragonadal germ cell tumors of the head and neck are very rare. We report the case of a 7-year-old girl with malignant germ cell tumor of the right parapharyngeal space treated by chemotherapy. Etiopathogenic, therapeutic, and prognostic characteristics of this tumour are recalled after a review of the literature data. Keywords: Extragonadal germ cell tumors, parapharyngeal tumors. Journal Tunisien d\'ORL et de chirurgie cervico-faciale Vol. 18 2007: pp. 61-6

Adenome pleomorphe a localisation extra-parotidienne

Objectives : Pleormorphic adenoma is a benign tumor of salivary gland. It mainly occurs in the parotid gland. The submandibular and minor salivary glands are rarely sites of occurrence. We describe the features of pleomorphic adenoma occurring at these sites.Material and methods: Between 2000 and 2009, 15 cases of pleomorphic adenoma occurring externly to the parotid have been collected.Results: Tumors were seen in the submandibular gland in 40 % of cases, in the hard palate in 33 % of cases, in the upper lip in 20 % of cases and in the parapharyngeal space in 7 % of cases. The mean age of patients was 48 years. The majority of cases were female. All patients were operated. We didn't report recurrence or malignants tumors after one year follow-up.Conclusion: After the parotid gland, the most common site of a pleomorphic adenoma is the submandibular gland followedby minor salivary gland of palate and lips. Each localisation has his clinical and therapeutic particularities.Key words : pleomorphic adenoma, submandibular gland, minor salivary glan

The actin-binding ERM protein Moesin binds to and stabilizes microtubules at the cell cortex

Ezrin, Radixin, and Moesin (ERM) proteins play important roles in many cellular processes including cell division. Recent studies have highlighted the implications of their metastatic potential in cancers. ERM’s role in these processes is largely attributed to their ability to link actin filaments to the plasma membrane. In this paper, we show that the ERM protein Moesin directly binds to microtubules in vitro and stabilizes microtubules at the cell cortex in vivo. We identified two evolutionarily conserved residues in the FERM (4.1 protein and ERM) domains of ERMs that mediated the association with microtubules. This ERM–microtubule interaction was required for regulating spindle organization in metaphase and cell shape transformation after anaphase onset but was dispensable for bridging actin filaments to the metaphase cortex. These findings provide a molecular framework for understanding the complex functional interplay between the microtubule and actin cytoskeletons mediated by ERM proteins in mitosis and have broad implications in both physiological and pathological processes that require ERMs

Impaired neural development in a zebrafish model for Lowe syndrome

Lowe syndrome, which is characterized by defects in the central nervous system, eyes and kidneys, is caused by mutation of the phosphoinositide 5-phosphatase OCRL1. The mechanisms by which loss of OCRL1 leads to the phenotypic manifestations of Lowe syndrome are currently unclear, in part, owing to the lack of an animal model that recapitulates the disease phenotype. Here, we describe a zebrafish model for Lowe syndrome using stable and transient suppression of OCRL1 expression. Deficiency of OCRL1, which is enriched in the brain, leads to neurological defects similar to those reported in Lowe syndrome patients, namely increased susceptibility to heat-induced seizures and cystic brain lesions. In OCRL1-deficient embryos, Akt signalling is reduced and there is both increased apoptosis and reduced proliferation, most strikingly in the neural tissue. Rescue experiments indicate that catalytic activity and binding to the vesicle coat protein clathrin are essential for OCRL1 function in these processes. Our results indicate a novel role for OCRL1 in neural development, and support a model whereby dysregulation of phosphoinositide metabolism and clathrin-mediated membrane traffic leads to the neurological symptoms of Lowe syndrome

Molecular networks linked by Moesin drive remodeling of the cell cortex during mitosis

During mitosis, cortical Moesin activity is restricted to promote cell elongation and cytokinesis, but localized Moesin recruitment is necessary for polar bleb retraction and cortical relaxation

Lowe Syndrome Protein OCRL1 Supports Maturation of Polarized Epithelial Cells

Mutations in the inositol polyphosphate 5-phosphatase OCRL1 cause Lowe Syndrome, leading to cataracts, mental retardation and renal failure. We noted that cell types affected in Lowe Syndrome are highly polarized, and therefore we studied OCRL1 in epithelial cells as they mature from isolated individual cells into polarized sheets and cysts with extensive communication between neighbouring cells. We show that a proportion of OCRL1 targets intercellular junctions at the early stages of their formation, co-localizing both with adherens junctional components and with tight junctional components. Correlating with this distribution, OCRL1 forms complexes with junctional components α-catenin and zonula occludens (ZO)-1/2/3. Depletion of OCRL1 in epithelial cells growing as a sheet inhibits maturation; cells remain flat, fail to polarize apical markers and also show reduced proliferation. The effect on shape is reverted by re-expressed OCRL1 and requires the 5′-phosphatase domain, indicating that down-regulation of 5-phosphorylated inositides is necessary for epithelial development. The effect of OCRL1 in epithelial maturation is seen more strongly in 3-dimensional cultures, where epithelial cells lacking OCRL1 not only fail to form a central lumen, but also do not have the correct intracellular distribution of ZO-1, suggesting that OCRL1 functions early in the maturation of intercellular junctions when cells grow as cysts. A role of OCRL1 in junctions of polarized cells may explain the pattern of organs affected in Lowe Syndrome

dOCRL maintains immune cell quiescence in Drosophila by regulating endosomal traffic

Lowe Syndrome is a developmental disorder characterized by eye, kidney, and neurological pathologies, and is caused by mutations in the phosphatidylinositol-5-phosphatase OCRL. OCRL plays diverse roles in endocytic and endolysosomal trafficking, cytokinesis, and ciliogenesis, but it is unclear which of these cellular functions underlie specific patient symptoms. Here, we show that mutation of Drosophila OCRL causes cell-autonomous activation of hemocytes, which are macrophage-like cells of the innate immune system. Among many cell biological defects that we identified in docrl mutant hemocytes, we pinpointed the cause of innate immune cell activation to reduced Rab11-dependent recycling traffic and concomitantly increased Rab7-dependent late endosome traffic. Loss of docrl amplifies multiple immune-relevant signals, including Toll, Jun kinase, and STAT, and leads to Rab11-sensitive mis-sorting and excessive secretion of the Toll ligand Spåtzle. Thus, docrl regulation of endosomal traffic maintains hemocytes in a poised, but quiescent state, suggesting mechanisms by which endosomal misregulation of signaling may contribute to symptoms of Lowe syndrome

Wide Nematogenic Azomethine/Ester Liquid Crystals Based on New Biphenyl Derivatives: Mesomorphic and Computational Studies

The thermal stability and mesomorphic behavior of a new biphenyl azomethine liquid crystal homologues series, (E)-4-(([1,1′-biphenyl]-4-ylmethylene)amino)phenyl 4-(alkoxy)benzoate, In, were investigated. The chemical structures of the synthesized compounds were characterized using FT-IR, NMR, and elemental analyses. Differential scanning calorimetry (DSC) and polarized optical microscopy were employed to evaluate the mesomorphic characteristics of the designed homologues. The examined homologues possessed high thermal stability and broad nematogenic temperature ranges. Furthermore, the homologues were covered by enantiotropic nematic phases. The experimental measurements of the mesomorphic behavior were substantiated by computational studies using the density functional theory (DFT) approach. The reactivity parameters, dipole moments, and polarizability of the studied molecules are discussed. The theoretical calculations demonstrated that as the chain length increased, the polarizability of the studied series increased; while it did not significantly affect the HOMO–LUMO energy gap and other reactivity descriptors, the biphenyl moiety had an essential impact on the stability of the possible geometries and their thermal as well as physical parameters