Eosinophilic Esophagitis in Patients with Refractory Gastroesophageal Reflux Disease

Background Eosinophilic esophagitis is among the causes of refractory reflux disease. Biopsy of esophagus is the gold standard for diagnosis. In this study we determined the frequency of eosinophilic esophagitis (EE) in refractory reflux cases referred to Motility Department of Shahid Beheshti Research Center of Gastroenterology and Liver Disease, Tehran, Iran. Methods In this cross-sectional study, 68 cases with refractory reflux disease underwent endoscopy and had biopsies taken. Specimens were stained by hematoxylin and eosin and two independent pathologists confirmed the diagnosis of eosinophilic esophagitis. Results Mean (standard deviation, SD) age at diagnosis was 41.8 (10.94) years. All had allergy or atopy, and unknown dysphagia was noted for 66%. Endoscopic findings were as follows: esophagitis (33.3%), rings (33.3%), and whitish plaques (33.3%). Prevalence of eosinophilic esophagitis was 8.8% (N = 6; one man and five women). No statistical difference in demographic variables was found between eosinophilic esophagitis cases and others, except for history of atopy, food impaction, and endoscopic features (P value <0.005). Conclusion Eosinophilic esophagitis should be considered in the differential diagnosis of any cases with refractory reflux who complain of chronic unexplained dysphagia, with history of recurrent food impaction, and atopy or abnormal endoscopic features.     

The cannabinoid WIN 55,212‐2‐mediated protection of dentate gyrus granule cells is driven by CB1 receptors and modulated by TRPA1 and Cav2.2 channels

Cannabinoids regulate numerous physiological and pathological events like inflammation or neurodegeneration via CB₁ and CB₂ receptors. The mechanisms behind cannabinoid effects show a high variability and may also involve transient receptor potential channels (TRP) and N‐type voltage‐gated Ca²⁺ channels (Ca_v2.2). In the present study we investigated the neuroprotective effects of the synthetic cannabinoid WIN 55,212–2 (WIN) on dentate gyrus (DG) granule cells and elucidated the involvement of TRP and Ca_v2.2 that are shown to participate in inflammatory processes. Organotypic hippocampal slice cultures were excitotoxically lesioned using NMDA and subsequently incubated with different WIN concentrations (0.001–10 μM). WIN showed neuroprotective properties in an inverse concentration‐dependent manner, most effectively at 0.01 μM. The CB₁ receptor antagonist AM251 blocked neuroprotection mediated by WIN whereas the CB₂ receptor antagonist AM630 showed no effects. Application of the TRPA1 blocker HC‐030031 enhanced the neuroprotective efficacy of high (10 μM) WIN concentrations and the number of degenerating neurons became equal to that seen after application of the most effective WIN dose (0.01 μM). In contrast, the application of TRPA1 agonist icilin or allyl isothiocyanate (AITC) led to a stronger neurodegeneration. The use of TRPV1 blocker 6‐iodo‐nordihydrocapsaicin did not affect WIN‐mediated neuroprotection. The selective Ca_v2.2 blocker ω‐conotoxin (GVIA) completely blocked neuroprotection shown by 10 μM WIN. GVIA and HC‐030031 exerted no effects at WIN concentrations lower than 10 μM. Our data show that WIN protects dentate gyrus granule cells in a concentration dependent manner by acting upon CB₁ receptors. At high (10 μM) concentrations WIN additionally activates TRPA1 and Ca_v2.2 within the hippocampal formation that both interfere with CB₁ receptor‐mediated neuroprotection. This leads to the conclusion that physiological and pharmacological effects of cannabinoids strongly depend on their concentration and the neuroprotective efficacy of cannabinoids may be determined by interaction of activated CB₁ receptor, TRPA1, and Ca_v2.2. © 2010 Wiley‐Liss, Inc.     

Myringoplasty using rotation flap of canal skin for total tympanic membrane perforation

Objective

To evaluate the efficacy of a novel technique of using rotation flap of canal skin in patients with total or subtotal tympanic membrane (TM) perforation with no anterior residual tympanic membrane.

Methods

A retrospective study of 50 patients with total or subtotal perforation repaired with rotation flap of canal skin. Clinical and audiometric data were recorded.

Results

The overall perforation closure rate was 96%. A statistically significant shortened healing time was observed.

Conclusion

The rotation flap of canal skin could be an effective and safe technique for perforations with no anterior residual TM.     

Congenital aural atresia surgery: Transmastoid approach,complications and outcomes

Repair of complete congenital aural atresia (CAA) could be a challenging procedure due to complications reported with CAA surgery such as facial nerve palsy, canal stenosis, graft lateralization, sensorineural hearing loss or the difficulty involved in the surgical technique. From 2006 to 2009, we used a one stage-modified transmastoid approach for surgical repair of 33 ears with complete CAA via a non-randomized controlled clinical trial. Some modifications in the technique of mastoidectomy, ossiculoplasty, fascia and skin grafting and meatoplasty have been described. Patients were followed up for 12 months to assess audiometric results and post-operative complications. Changes in air-bone gap and need for revision surgery or hearing aids were assessed at follow-up. There were no cases of facial weakness, dead ear or bony canal stenosis. Hearing success in 2 months follow-up was achieved in 72.7% of all patients. Success rate increased to 92.3% in patients with Jahrsdoefer’s scores of 8 and above. Overall success rate decreased to 63.6% at 12 months follow-up. There were no significant difference in Jahrsdoerfer score of patients with successful first surgical attempt and those who needed revision surgery (P value >0.056). Also patients of lower age (less than 5-years-old) did not have more need for revision surgery when compared with older patients (P value >0.36). However, being a syndromic patient did increase the need for revision surgery (P value <0.04). Age was not a predictor of meatal/canal stenosis and patients with lower Jahrsdoerfer scores could also achieve good results.     

Rescue of sarcoglycan mutations by inhibition of endoplasmic reticulum quality control is associated with minimal structural modifications

Sarcoglycanopathies (SGP) are a group of autosomal recessive muscle disorders caused by primary mutations in one of the four sarcoglycan genes. The sarcoglycans (α-, β-, γ-, and δ-sarcoglycan) form a tetrameric complex at the muscle membrane that is part of the dystrophin-glycoprotein complex and plays an essential role for membrane integrity during muscle contractions. We previously showed that the most frequent missense mutation in α-sarcoglycan (p.R77C) leads to the absence of the protein at the cell membrane due to its blockade by the endoplasmic reticulum (ER) quality control. Moreover, we demonstrated that inhibition of the ER α-mannosidase I activity using kifunensine could rescue the mutant protein localization at the cell membrane. Here, we investigate 25 additional disease-causing missense mutations in the sarcoglycan genes with respect to intracellular fate and localization rescue of the mutated proteins by kifunensine. Our studies demonstrate that, similarly to p.R77C, 22 of 25 of the selected mutations lead to defective intracellular trafficking of the SGs proteins. Six of these were saved from ER retention upon kifunensine treatment. The trafficking of SGs mutants rescued by kifunensine was associated with mutations that have moderate structural impact on the protein.     

A new efficient protocol for directed differentiation of retinal pigmented epithelial cells from normal and retinal disease induced pluripotent stem cells

We describe a new, efficient protocol that involves the serial addition of noggin, basic fibroblast growth factor (bFGF), retinoic acid, and sonic hedgehog (Shh) for the differentiation of human induced pluripotent stem cells (hiPSC) to retinal pigmented epithelium (RPE) in a serum- and feeder-free adherent condition. hiPSC-RPE cells exhibited RPE morphology and specific molecular markers. Additionally, several hiPSC lines were generated from retinal-specific patients with Leber's congenital amaurosis, Usher syndrome, two patients with retinitis pigmentosa, and a patient with Leber's hereditary optic neuropathy. The RPE cells generated from these disease-specific hiPSCs expressed specific markers by the same RPE lineage-directed differentiation protocol. These findings indicate a new short-term, simple, and efficient protocol for differentiation of hiPSCs to RPE cells. Such specific retinal disease-specific hiPSCs offer an unprecedented opportunity to recapitulate normal and pathologic formation of human retinal cells in vitro, thereby enabling pharmaceutical screening, and potentially autologous cell replacement therapies for retinal diseases.