Membrane Retraction Research Articles

Gastroesophageal Reflux Disease in Patients with Eustachian Tube Catarrh

ABSTRACT Background Eustachian tube catarrh could be due to laryngopharyngeal reflux besides other causes. Objectives To assess gastroesophageal reflux disease (GERD) in patients with Eustachian tube catarrh and the effect of proton pump inhibitors on symptoms of Eustachian tube disease. Methodology A total of 50 patients were selected with symptoms of Eustachian tube catarrh and evaluated prospectively in the ENT Outpatient Department of the Pondicherry Institute of Medical Sciences, Puducherry. Results The group consisted of 15 (30%) males and 35 (70%) females. The largest group was of the age of 45 years and above (44%). The most common symptom of Eustachian tube catarrh was itching (84%), followed by otalgia (76%) and popping sensation on swallowing (74%). On otoscopic examination, the commonest grade of tympanic membrane retraction was grade I (57%), on tympanometry 90% of cases had middle ear pressure in range −100 to +100. The middle compliance ranged from 0.5 to 1.75 (normal) in 86% of the cases. The tympanomeric curve was type A (normal) in 78% of the cases and type C in 8% of the cases. At the end of 4 and 8 weeks, the response of treatment to proton pump inhibitors was significantly higher (z = 3.53, p < 0.05) in the studied group. Conclusion Laryngopharyngeal reflux (LPR) could be an important etiological factor in Eustachian tube catarrh. The treatment, with proton pump inhibitors, of Eustachian tube catarrh with no local identifiable cause, could be very useful to this subsect of patients. How to cite this article Bhargava A, Cherian M, Cherian TA, Gupta S. Gastroesophageal Reflux Disease in Patients with Eustachian Tube Catarrh. Int J Phonosurg Laryngol 2015;5(2): 61-66.

Carotid Artery Prolapse and Myringocarotidopexy in Osteogenesis Imperfecta

Osteogenesis Imperfecta is a rare genetic disorder of connective tissue that is caused by an error in collagen formation. The disease is characterized by abnormal bone fragility, osteopenia, blue discoloration of the sclerae and hearing loss. Chronic non-suppurative otitis media is frequent in Osteogenesis Imperfecta patients and usually attributed to Eustachian tube dysfunction due to cranial molding and deformities. In some cases of severe Osteogenesis Imperfecta, the fragile bone of the petrous carotid canal can be broken down by the pulsations of the carotid artery, this may result in prolapse of the carotid artery into the protympanum with resultant Eustachian tube obstruction and tympanic membrane retraction with adhesion to prolapsed carotid artery, a condition called myringocarotidopexy.

A comparison of induced and developmental cell death morphologies in lace plant (Aponogeton madagascariensis) leaves.

BackgroundProgrammed cell death (PCD) is an important process for the development and maintenance of multicellular eukaryotes. In animals, there are three morphologically distinct cell death types: apoptosis, autophagic cell death, and necrosis. The search for an all-encompassing classification system based on plant cell death morphology continues. The lace plant is a model system for studying PCD as leaf perforations form predictably via this process during development. This study induced death in cells that do not undergo developmental PCD using various degrees and types of stress (heat, salt, acid and base). Cell death was observed via live cell imaging and compared to the developmental PCD pathway.ResultsMorphological similarities between developmental and induced PCD included: disappearance of anthocyanin from the vacuole, increase in vesicle formation, nuclear condensation, and fusing of vesicles containing organelles to the vacuole prior to tonoplast collapse. Plasma membrane retraction was a key feature of developmental PCD but did not occur in all induced modes of cell death.ConclusionsRegardless of the causal agent in cell death, the vacuole appeared to play a central role in dying cells. The results indicated that within a single system, various types and intensities of stress will influence cell death morphology. In order to establish a plant cell death classification system, future research should combine morphological data with biochemical and molecular data.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-014-0389-x) contains supplementary material, which is available to authorized users.

Mouse Macrophages Completely Lacking Rho Subfamily GTPases (RhoA, RhoB, and RhoC) Have Severe Lamellipodial Retraction Defects, but Robust Chemotactic Navigation and Altered Motility

RhoA is thought to be essential for coordination of the membrane protrusions and retractions required for immune cell motility and directed migration. Whether the subfamily of Rho (Ras homolog) GTPases (RhoA, RhoB, and RhoC) is actually required for the directed migration of primary cells is difficult to predict. Macrophages isolated from myeloid-restricted RhoA/RhoB (conditional) double knock-out (dKO) mice did not express RhoC and were essentially "pan-Rho"-deficient. Using real-time chemotaxis assays, we found that retraction of the trailing edge was dissociated from the advance of the cell body in dKO cells, which developed extremely elongated tails. Surprisingly, velocity (of the cell body) was increased, whereas chemotactic efficiency was preserved, when compared with WT macrophages. Randomly migrating RhoA/RhoB dKO macrophages exhibited multiple small protrusions and developed large "branches" due to impaired lamellipodial retraction. A mouse model of peritonitis indicated that monocyte/macrophage recruitment was, surprisingly, more rapid in RhoA/RhoB dKO mice than in WT mice. In comparison with dKO cells, the phenotypes of single RhoA- or RhoB-deficient macrophages were mild due to mutual compensation. Furthermore, genetic deletion of RhoB partially reversed the motility defect of macrophages lacking the RhoGAP (Rho GTPase-activating protein) myosin IXb (Myo9b). In conclusion, the Rho subfamily is not required for "front end" functions (motility and chemotaxis), although both RhoA and RhoB are involved in pulling up the "back end" and resorbing lamellipodial membrane protrusions. Macrophages lacking Rho proteins migrate faster in vitro, which, in the case of the peritoneum, translates to more rapid in vivo monocyte/macrophage recruitment.

Minimally Invasive Repair of Posterior‐Superior Retraction Pockets in Children with Lysis of Middle Ear Adhesions

Objectives: (1) Treat adhesive tympanic membrane (TM) retractions in children by lysis of middle ear adhesions during insertion of tympanostomy tubes (TT). (2) Analyze the ability to improve conductive hearing loss and to prevent progression of retraction pockets, incus erosion, and avoid future tympanoplasty. Methods: A retrospective review from 2005 to 2013 was performed in 22 ears of 18 patients who were candidates for cartilage tympanoplasty to correct a progressive posterior-superior retraction pocket, with or without incus erosion. Lysis of middle ear adhesions using angled picks was performed through the myringotomy before insertion of a TT. The hypothesis was that the released redundant TM, wrapped around the barrel of the TT to maintain it under tension, could allow regeneration of a healthy tympanic membrane in children. Results: TM retractions were elevated and adhesions lysed in 22 ears. Mean age was 11.3 years (range, 4-22 years). Follow-up ranged from 3 to 72 months (mean, 23.2 months). Preoperatively, there were 15 Sade grade III and 7 grade IV atelectatic TMs. Postoperatively, there were 14 without retraction, 6 grade I, 1 grade III, and 1 grade IV TMs. Grade I and nonretracted TMs healed without dimers. Mean AB gap improved from 19.94 to 3.88 dB. Two ears required a revision procedure and a third ear developed a cholesteatoma. Conclusions: Lysis of middle ear adhesions through a myringotomy at the time of TT insertion allows for healing of the tympanic membrane, improved hearing, and can be effective in preventing progression of atelectasis and incus erosion in children.

Cholesteatoma in Children: An Overview

Objectives: Describe in children: (1) cholesteatoma growth patterns; (2) conductive hearing loss severity; (3) contralateral ear (CLE) findings. Methods: Cross-sectional study. Videotoscopies of 129 pediatric patients at a tertiary care hospital were analyzed for cholesteatoma growth patterns, air-bone gap, and CLE otoscopic findings. Data were compared with the chi-squared test and analyzed using SPSS. Results: The mean patient age was 12.4 ± 4.36 years. The cholesteatoma growth patterns were anterior epitympanic cholesteatomas (5.4%), posterior epitympanic (21.7%), posterior mesotympanic (43.4%), 2 routes pattern (17.1%), and undetermined (12.4%). The pure tone average air-bone gap (PTA-ABG) was ≤20 dB in 8.7% of patients, between 20 to 40 dB in 43.4% of patients, and ≥40 dB in 47.9%. The CLE was normal in 34.9% of patients and had moderate or severe tympanic membrane (TM) retractions in 46.5%, TM perforation in 7.8%, and cholesteatoma in 10.9% of patients. The CLE disease prevalence was similar between the groups, except in anterior epitympanic group, which had normal CLE ( P = .004). Conclusions: Posterior mesotympanic cholesteatomas were the most prevalent in the study population. Most patients had a PTA-ABG greater than 20 dB, and the most prevalent CLE abnormalities were moderate or severe TM retraction and cholesteatoma. The CLE of patients diagnosed with anterior epitympanic cholesteatoma were normal, suggesting a probable congenital origin.

The Surgical Management of Tympanic Membrane Retraction Pockets Using Cartilage Tympanoplasty.

Evaluate the surgical treatment of tympanic membrane (TM) retractions with modified cartilage augmentation tympanoplasty. Retrospective review of subjects with Charachon stage II and III TM retractions who underwent modified cartilage augmentation tympanoplasty following excision of the retracted TM segment. Pre and postoperative symptoms and air-bone gaps were recorded. Forty two ears were included in the study. Twenty six ears were of stage II and 16 were stage III retractions. 35 (83%) ears had ossicular erosion and cholesteatoma was found in 13 (31%) ears, all in stage III retractions. Follow-up ranged 12-102months. The air-bone gap (ABG) improved in 29 (76%) and worsened in seven (19%). Ears without cholesteatoma had a greater improvement in ABG. The results of our modified cartilage tympanoplasty technique are comparable to the published literature and should provide a safe and acceptable result. The high rate of cholesteatoma found preoperatively in stage III retractions advocates early surgical intervention.

Proline-rich region of non-muscle myosin light chain kinase modulates kinase activity and endothelial cytoskeletal dynamics

Disruption of the pulmonary endothelial barrier and subsequent vascular leak is a hallmark of acute lung injury. Dynamic rearrangements in the endothelial cell (EC) peripheral membrane and underlying cytoskeleton are critical determinants of barrier function. The cytoskeletal effector protein non-muscle myosin light chain kinase (nmMLCK) and the actin-binding regulatory protein cortactin are important regulators of the endothelial barrier. In the present study we functionally characterize a proline-rich region of nmMLCK previously identified as the possible site of interaction between nmMLCK and cortactin. A mutant nmMLCK construct deficient in proline residues at the putative sites of cortactin binding (amino acids 973, 976, 1019, 1022) was generated. Co-immunoprecipitation studies in human lung EC transfected with wild-type or mutant nmMLCK demonstrated similar levels of cortactin interaction at baseline and after stimulation with the barrier-enhancing agonist, sphingosine 1-phosphate (S1P). In contrast, binding studies utilizing recombinant nmMLCK fragments containing the wild-type or proline-deficient sequence demonstrated a two-fold increase in cortactin binding (p<0.01) to the mutant construct. Immunofluorescent microscopy revealed an increased stress fiber density in ECs expressing GFP-labeled mutant nmMLCK at baseline (p=0.02) and after thrombin (p=0.01) or S1P (p=0.02) when compared to wild-type. Mutant nmMLCK demonstrated an increase in kinase activity in response to thrombin (p<0.01). Kymographic analysis demonstrated an increased EC membrane retraction distance and velocity (p<0.01) in response to the barrier disrupting agent thrombin in cells expressing the mutant vs. the wild-type nmMLCK construct. These results provide evidence that critical prolines within nmMLCK (amino acids 973, 976, 1019, 1022) regulate cytoskeletal and membrane events associated with pulmonary endothelial barrier function.

Quantitative assessment of the relationship between cellular morphodynamics and signaling events by stochastic analysis of fluorescent images.

Cell motility involves a number of strategies that cells use in order to seek nutrients, escape danger, and fulfill morphogenetic roles. Here we present a methodology to quantify morphological changes and their relationship with signaling events from time-lapse imaging microscopy experiments, in order to characterize physiological and pathological processes. To this aim, the stationary spatial pattern of signaling events is determined through an intracellular fluorescent probe, and it is related with the frequency and entity of morphodynamic events, which are in turn quantified through a stochastic approach: two pseudoimages are obtained from a time series of moving cells that describe the probability that a pixel belongs to the cell, and the probability that a pixel is subject to a dynamic event. The simultaneous construction of these maps permits visualization of hot spots of dynamic events, i.e., zones of formation of membrane protrusions and retractions and their relationship with the signaling events reported by the specific probe employed. The method is tested on spontaneous movement of cells, trasfected with redox-sensitive yellow fluorescent protein, in which the distribution of the hot spots and its change upon expression of constitutively active Rac (V12-Rac), is related to the distribution of oxidized spots.

Potencial evocado auditivo de estado estável por via aérea e via óssea em crianças de zero a seis meses sem e com comprometimento condutivo

Objetivo verificar a viabilidade de pesquisar os níveis mínimos de resposta do Potencial Evocado Auditivo de Estado Estável por via aérea e via óssea em crianças do nascimento aos seis meses e mensurar o “gap” aéreo-ósseo de crianças com comprometimento condutivo. Métodos avaliadas 60 crianças, 30 com comprometimento condutivo e 30 sem, distribuídas em grupo controle e estudo. Foram realizadas medidas de imitância acústica, avaliação otorrinolaringológica e Potencial Evocado Auditivo de Estado Estável por via aérea e via óssea. O Potencial Evocado Auditivo de Estado Estável foi realizado por via aérea com fones de inserção e por via óssea com vibrador ósseo. Por via aérea as respostas foram pesquisadas em ambas as orelhas e por via óssea captadas somente da orelha esquerda. Resultados no grupo controle, houve predominância de curva do tipo “A”. No grupo estudo, de curvas tipo “B” e tipo “C”. Na avaliação otorrinolaringológica do grupo controle evidenciou-se normalidade da membrana timpanica. No grupo estudo, opacidade e retração. No Potencial Evocado Auditivo de Estado Estável do grupo controle por via aérea as respostas foram em torno de 17,2; 26,2; 22, 7 e 19,8dBNA nas frequências 500 a 4KHz e para via óssea entre 18,8 a 20dBNA. No grupo estudo por via aérea as respostas foram de 53; 56; 50,2 e 48dBNA e por via óssea de 25; 25; 20 e 20dBNA. Conclusão foi possível realizar a avaliação dos Potenciais Evocados Auditivos de Estado Estável por via aérea e via óssea em crianças até os seis meses e o “gap” aéreo-ósseo foi em torno de 20dB nas crianças com comprometimento condutivo.

Cholesteatoma has a high prevalence in Turner syndrome, highlighting the need for earlier diagnosis and the potential benefits of otoscopy training for paediatricians

Girls with Turner syndrome are prone to cholesteatoma, a serious suppurative middle ear disease. We aimed to confirm its high prevalence in Turner syndrome, identify risk factors and suggest possible strategies for earlier detection. We reviewed 179 girls with Turner syndrome between 1989 and 2012 to identify cases of cholesteatoma. Seven girls (3.9%) had cholesteatoma (index girls) and each was compared with three age-matched girls without cholesteatoma (comparison girls). All the index girls had either the 45,X or 45,X/46X,i(Xq) karyotypes. Nine ears were initially affected, with three recurrences in two girls. Median age at first cholesteatoma presentation was 11.9 years (range: 7.5-15.2), with otorrhoea for three (range: one to seven) months in all 12 affected ears. Index girls had a significantly higher proportion of previous recurrent acute (p = 0.007) and chronic otitis media (p = 0.008), chronic perforation (p = 0.038) aural polyps (p < 0.0001) and tympanic membrane retraction (p = 0.0001) than comparison girls. Cholesteatoma has a high prevalence in Turner syndrome. Risk factors include 45,X and 46,XiXq karyotypes; a history of chronic otitis media, tympanic membrane retraction and persistent otorrhoea; and older age. Earlier recognition of ear disease is needed and otoscopy training for paediatricians caring for Turner syndrome patients may be beneficial.

Effect of otitis media with effusion and its clinical intervention on the development of mastoid in children

Conclusion: Otitis media with effusion (OME) can affect the development of mastoid in children. For younger children (<12 years old), surgical intervention may promote the development of mastoid. It is highly recommended that patients with severe tympanic membrane retraction have tympanostomy tubes to improve the circulation in the middle ear as early as possible. Objective: To investigate the effect of OME and its clinical intervention on the development of mastoid in children. Methods: A total of 46 children with OME were divided into 2 groups according to their ages. In group 1, 26 cases (0–6 years old) were treated for approximately 2 months, while in group 2, 20 cases (7–15 years old) were treated for 10 months. The treatments included tympanic effusion incision or catheterization, and adenoidectomy and/or bilateral tonsillectomy. Before and 6 months after treatments, patients were examined by bilateral temporal bone CT scanning, pure-tone audiometry, and tympanometry. 3-D volumetric reconstruction was then performed to determine the morphological properties of each patient's mastoid. Results: After a 2-month comprehensive treatment, the volume of mastoid was close to that in normal children, indicating that it could return to normal level if the treatment was completed within 2 months. In group 2, the results suggested that if the treatment lasted more than 6 months, the development of mastoid would be stalled.

Phosphatidylinositol Patches in a Reconstituted Lipid Membrane and its Dynamics

Amoeboid locomotion is one of the fundamental modes of cell motion that accompanies dynamic deformation of plasma membrane. From yeast to human cell, localized activation of small GTPase and phosphatidylinositol signaling initiates breaking of intracellular symmetry and are thought to play critical roles in generating polarized membrane extension and retraction. Although it is generally believed that some forms of reaction-diffusion driven mechanisms underlie these “symmetry breaking” events, the physicochemical basis of its onset, i.e. autonomous nucleation events of the localized signaling patches and actin polymerization remains unclear. Here, we report on the behavior observed in our “two-dimensional reconstituted-system” consisting of a cytosolic extract and a solid-supported lipid membrane. We tested whether the solid-supported lipid membrane in a microchamber containing cytosol extracted by Dictyostelium discoideum provides an appropriate microenvironment for localized signaling by observing translocation of PH-domain protein and PTEN which were tagged with RFP and GFP respectively. Signal intensities were analyzed by a confocal laser scanning fluorescence and bright field microscopy. We found that both the PH-domain protein and PTEN attached to the membrane composed of both lipid extract and 2- or 3- component lipid mixture. In the case of lipid extract membrane, inhomogeneous domain formation of micrometer scale was observed. We examined the effect of several inhibitors related phosphatidylinositol signaling and found different patterning of the lipid membranes. We will discuss how the current system may be employed to address the origin of self-organized PIP2/PIP3 patches during amoeboid deformation.

Balloon dilatation of the Eustachian tube: an evidence‐based review of case series for those considering its use

Eustachian tube dysfunction is common and implicated in persistent middle ear disease. Recent studies suggest the promise of balloon dilatation of the Eustachian tube to modify local anatomy and physiology, restoring normal function. A literature review of the outcomes of balloon dilatation of the Eustachian tube was conducted, assessing four criteria (tympanometry, otoscopy findings, Valsalva and subjective symptoms). Outcomes were divided into short term (≤ 6 months) and long term (>6 months). Rates and severity of complications were documented. We also assessed cost, learning curve and requisite training. Medline via PubMed was consulted with the following search request: 'eustachian tube' OR 'auditory tube' AND 'balloon'. No restrictions were placed on study date, type or language. Non-clinical studies, published abstracts and very small studies (<10 procedures) were excluded. Our search yielded 24 results and six case series, five of which met the inclusion criteria. Balloon dilatation has been performed on 375 Eustachian tubes (235 patients) and demonstrates clear short-term (<6 month) benefits across all recorded outcome measures in a majority of cases. 69 of 89 (78%) tympanogram profiles recorded preoperatively as abnormal (Type B/C/open) resolved to type A profiles postoperatively. 40 of 46 (87%) otoscopy findings preoperatively reported as abnormal (tympanic membrane retraction, perforation or otitis media with effusion) normalised postoperatively. The ability to perform a consistently positive Valsalva manoeuvre improved from 15 of 139 (11%) to 89 of 139 (64%) cases following dilatation. The two largest studies reported on 210 and 100 procedures and described symptom improvement in 67% of cases at 2 months and 71% at 26.3 weeks, respectively. An overall complication rate of ≈ 3% was observed, and no major adverse events are reported (0%). Cost and learning curve of the procedure were both deemed to be acceptable. Balloon dilatation of the Eustachian tube appears to be safe, effective and affordable. Like many newly introduced techniques, the evidence remains limited to non-controlled case series, with heterogeneous data collection methods and lacking long-term outcomes. However, short-term data provides promising, consistent results based on objective measures, and when used selectively in patients refractive to maximal existing therapy, balloon dilatation presents a potentially significant advance.

Motility efficiency and spatiotemporal synchronization in non-metastatic vs. metastatic breast cancer cells.

Metastatic breast cancer cells move not only more rapidly and persistently than their non-metastatic variants but in doing so use the mechanical work of the cytoskeleton more efficiently. The efficiency of the cell motions is defined for entire cells (rather than parts of the cell membrane) and is related to the work expended in forming membrane protrusions and retractions. This work, in turn, is estimated by integrating the protruded and retracted areas along the entire cell perimeter and is standardized with respect to the net translocation of the cell. A combination of cross-correlation, Granger causality, and morphodynamic profiling analyses is then used to relate the efficiency to the cell membrane dynamics. In metastatic cells, the protrusions and retractions are highly "synchronized" both in space and in time and these cells move efficiently. In contrast, protrusions and retractions formed by non-metastatic cells are not "synchronized" corresponding to low motility efficiencies. Our work provides a link between the kinematics of cell motions and their energetics. It also suggests that spatiotemporal synchronization might be one of the hallmarks of invasiveness of cancerous cells.

Abstract A34: A regulatory role of beta-PIX in epidermal growth factor-induced cancer cell migration

Abstract Expression of epidermal growth factor receptor (EGFR) in non–small cell lung cancer (NSCLC) tumors correlates with poor prognosis. EGFR signaling is Src dependent. Activation of EGFR leads to cycles of membrane protrusion, cell adhesion, contraction, and retraction, therefore promoting cell migration. Here, we show a novel role of beta-PIX (Pak-interactive exchange factor) in EGFR-mediated NSCLC cell migration. EGFR signals through Src, which phosphorylates beta-PIX sequentially at two specific tyrosine residues, 442 and 595. Phosphorylation of beta-PIX at tyrosine 442 leads to activation of small GTPase Rac1, which promotes membrane protrusion and cell adhesion assembly around 5 min after EGF stimulation. After another 20 minutes, tyrosine 442 is dephosphorylated, while tyrosine 595 of beta-PIX is phosphorylated. Phosphorylation of tyrosine 595 results in activation of small GTPase RhoA, contraction generation, adhesion disassembly, and cell retraction. These data suggest that the phosphorylation-dephosphorylation cycle of beta-PIX at tyrosine 442 and 595 serves as a regulatory signal downstream of EGFR to control migration and invasion of NSCLC cells. Note: This abstract was not presented at the conference. Citation Format: Jean-Cheng Kuo. A regulatory role of beta-PIX in epidermal growth factor-induced cancer cell migration. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr A34.

Relationship between tympanic membrane retraction and habitual sniffing in patients with cholesteatoma

Conclusion: Habitual sniffing affects the pathogenicity and recurrence of cholesteatoma. Postoperative instructions requesting patients to cease sniffing may reduce the retraction and recurrence of cholesteatoma. Objective: To examine the relationship between tympanic membrane retraction and habitual sniffing in patients with cholesteatoma. Methods: We recruited 98 patients (102 ears) who were surgically treated for cholesteatoma by canal wall-down tympanoplasty (22 ears) or canal wall-down tympanoplasty with reconstruction methods (80 ears). We classified these patients into two groups on the basis of their preoperative habitual sniffing: habitual and non-habitual sniffers. The findings of the contralateral tympanic membrane were examined in each group and were classified according to the Tos classifications. Next, we evaluated the incidence of 1-year postoperative tympanic membrane retraction treated by the canal-down tympanoplasty with reconstruction method in the following three groups: non-habitual sniffing group, sniffing cessation group, and continual sniffing group. Results: In habitual sniffers, the Tos classifications of contralateral tympanic membrane were normal in 7% (3/41). In contrast, for non-habitual sniffers, the findings were normal in 39% (21/54). These results indicate that sniffing causes tympanic membrane retraction. The tympanic membranes of patients in the sniffing cessation group were largely normal after surgery. However, more than 50% of the patients who continued to sniff after surgery showed retraction or recurrent cholesteatoma.

Wnt5a Directs Polarized Calcium Gradients by Recruiting Cortical Endoplasmic Reticulum to the Cell Trailing Edge

Wnt5a directs the assembly of the Wnt-receptor-actin-myosin-polarity (WRAMP) structure, which integrates cell-adhesion receptors with F-actin and myosin to form a microfilament array associated with multivesicular bodies (MVBs). The WRAMP structure is polarized to the cell posterior, where it directs tail-end membrane retraction, driving forward translocation of the cell body. Here we define constituents of the WRAMP proteome, including regulators of microfilament and microtubule dynamics, protein interactions, and enzymatic activity. IQGAP1, a scaffold for F-actin nucleation and crosslinking, is necessary for WRAMP structure formation, potentially bridging microfilaments and MVBs. Vesicle coat proteins, including coatomer-I subunits, localize to and are required for the WRAMP structure. Electron microscopy and live imaging demonstrate movement of the ER to the WRAMP structure and plasma membrane, followed by elevation of intracellular Ca2+. Thus, Wnt5a controls directional movement by recruiting cortical ER to mobilize a rear-directed, localized Ca2+ signal, activating actomyosin contraction and adhesion disassembly for membrane retraction.

Eustachian Tube Function in Children with Normal Middle Ear and with Tympanic Membrane Retraction

Objectives: Identify the variation in middle ear pressure (MEP) after tubal function tests performed in normal children and in ears with retraction disease. Variability over time was analyzed. Methods: Observational cross-sectional study. A total of 38 subjects were studied between March and November of 2012. Subjects were classified into three groups: group1-normal ears (36 ears); group2-mild tympanic membrane (TM) retractions (23 ears); group3-moderate/severe TM retractions (17 ears). All patients had Valsalva maneuver, sniff test and Toynbee maneuver done sequentially in both ears twice with 15 days interval. MEP was measured with an Interacoustics AT235h tympanometer before and after the maneuvers. For analysis, MEP mixed effects models was used. For evaluation over time, Bland and Altman and intra-class correlation (ICC) were used. Significance of the study was ± = 0.05. Results: The mean ± SD age was 11 ± 2.72 years (8-17 years). At first time of the Valsalva maneuver, there was a trend of increasing pressures in the three groups ( P = 0.012), and the mean pressures of the groups were different ( P &lt;0.001). For the sniff test and Toynbee there was no statistically significant difference between basal pressure and pressure after the maneuvers in three groups of ears ( P &gt;0.05) at the two times. We found a moderate degree of replicability over the two times of measurement. Conclusions: The average MEP increased in the Valsalva maneuver in the three groups. Pressure had more variability in ears with moderate/severe retraction.

Tympanic membrane retraction pocket staging: is it worthwhile?

Our objectives were to review all reported staging systems of tympanic membrane (TM) retraction pockets (RP) and to report their reliability and utility to our daily clinical practice in terms of follow-up and decision making in the management of RP. We aim to propose a new management algorithm of TMRPs. We conducted a thorough research on Ovid Medline, Pubmed and Cochrane databases for English and French languages studies published between 1963 and 2012 on the retraction pocket. Studies were excluded if it were a short comments, photo clinical cases, experimental studies or round table articles. Cholesteatoma was not included in keywords, since it is considered as an advanced pathological entity with different staging and management approaches. We included 60 of 756 articles that met our inclusion criteria. Sadé and Berco proposed the first staging system of RP in 1976, while the last one was described by Borgstein et al. in 2007. From 1976 to 2007, 12 different staging systems have been described for tympanic membrane retractions. There are three broad categories of TMRPs: localized retractions of the pars tensa, generalized retractions of the pars tensa (atelectasis) and retraction of the pars flaccida. Most of the described staging systems are useful for following up the evolution of retractions over time. However, no consensus was found concerning the decision making in its management. In conclusion, proper management of TMRPs requires a reproducible, easily applicable staging system with low inter- and intra-observer variability. We propose a management algorithm that considers the functional handicap of the patient rather than the topographic description of the TM.