Lack of methylation changes in GJB2 and RB1 non-coding regions of cochlear implant patients with sensorineural hearing loss

Objective@#Recent advances in epigenetic studies continue to reveal novel mechanisms of gene regulation and control, however little is known on the role of epigenetics in sensorineural hearing loss (SNHL) in humans. We aimed to investigate the methylation patterns of two regions, one in RB1 and another in GJB2 in Filipino patients with SNHL compared to hearing control individuals. @*Methods@#We investigated an RB1 promoter region that was previously identified as differentially methylated in children with SNHL and lead exposure. Additionally, we investigated a sequence in an enhancer-like region within GJB2 that contains four CpGs in close proximity. Bisulfite conversion was performed on salivary DNA samples from 15 children with SNHL and 45 unrelated ethnically-matched individuals. We then performed methylation-specific real-time PCR analysis (qMSP) using TaqMan® probes to determine percentage methylation of the two regions. @*Results@#Using qMSP, both our cases and controls had zero methylation at the targeted GJB2 and RB1 regions. @*Conclusion@#Our study showed no changes in methylation at the selected CpG regions in RB1 and GJB2 in the two comparison groups with or without SNHL. This may be due to a lack of environmental exposures to these target regions. Other epigenetic marks may be present around these regions as well as those of other HL-associated genes.

Simulation platform for myringotomy with ventilation tube insertion in adult ears

@#<p style="text-align: justify;"><strong>OBJECTIVE: </strong>To develop a ventilation tube insertion simulator for training and evaluation of otorhinolaryngology residents in myringotomy with ventilating tube insertion.</p><p style="text-align: justify;"><strong>METHODS:</strong></p><p style="text-align: justify;"><strong>            DESIGN:            </strong>Cross - Sectional Study</p><p style="text-align: justify;"><strong>            SETTING:           </strong>Tertiary National University Hospital</p><p style="text-align: justify;"><strong>            PARTICIPANTS:   </strong>Otologists and otorhinolaryngology resident trainees</p><p style="text-align: justify;">A simulation tool for myringotomy with ventilation tube insertion was fabricated using silicone sealant, aluminum tube, rubber ball, plaster of paris and plastic sheet, and pretested by our expert panel. Residents were then evaluated using an objective structured clinical examination (OSCE) checklist while performing the procedure using the same model. Three trials were given, and OSCE scores were obtained, for each resident.</p><p style="text-align: justify;"><strong>RESULT: </strong>The pinna, ear canal, tympanic membrane, malleus handle were deemed realistic by the expert panel. Residents performed the procedure at an average of 87 seconds. Average OSCE score for all residents was 17.17, with senior residents having a higher average score (18.3) than junior residents (16.6). However, this was not statistically significant (2 tailed t-value, significance level 0.05 = -1.27, p = .227). The most common cause of trial failure was dropping of the tube in the middle ear, while the most common error made was using more than 2 attempts at performing the incision.</p><p style="text-align: justify;"><strong>CONCLUSION:  </strong>This simulation platform may be a valuable tool to use in educating and developing skills and proper technique of myringotomy with ventilation tube insertion. It is reproducible, affordable, realistic, sturdy and versatile in its applications. Residents who show adequate dexterity and consistency during simulation may eventually be allowed to perform the procedure on patients and provide feedback regarding the usefulness of the simulation.</p>

Congenital oval window aplasia: An unusual cause of conductive hearing loss in an adult

@#<p style="text-align: justify;"><strong>OBJECTIVES:</strong> To  report  a  case  of  congenital  oval  window  aplasia  (COWA)  in  a  Filipino  adult presenting   with      unilateral   maximal   conductive   hearing   loss   and   discuss   the   diagnostic considerations, pathophysiology and management.<br /><strong>METHODS:</strong><br /><strong>Design:</strong> Case Report<br /><strong>Setting:</strong> Tertiary Public Referral Center<br /><strong>Patient:</strong> One <br /><strong>RESULTS:</strong> Audiometric evaluation showed a maximal unilateral left conductive hearing loss. High resolution temporal bone CT showed absence of the oval window on the left along with facial and stapes  abnormalities.    Exploratory  tympanotomy  showed  an  aberrant  facial  nerve,  monopodal and  abnormally  located  stapes  and  absent  oval  window. Postoperative  hearing  gain  achieved after a neo-oval window and Schuknecht piston wire prosthesis remained stable over two years.<br /><strong>CONCLUSION:</strong> A congenital minor ear anomaly classified as Cremers Class 4a in which a congenital oval  window  aplasia  was  associated  with  an  aberrant  facial  nerve  anomaly  and  a  monopodal stapes is reported. Recent literature supported the view that congenital oval window aplasia can in selected cases be amenable to various surgical approaches and a stable postoperative hearing gain is achievable in the long term.</p>

The Philippine National Ear Institute: Patient and audilogic profiles

Background: The Philippine National Ear Institute (PNEI) was created to promote health of hearing and balance among Filipinos. Over the years, it has provided audiologic services to thousands of patients annually and has published relevant hearing and balance research. Objective: To describe the patients served by the PNEI in terms of age, region of origin, occupation, pretest diagnosis, and audiologic results. Methods: Study Design - Cross-sectional study Setting - National tertiary care center Population - All records of patients referred for audiologic testing at PNEI in 2006 were reviewed and encoded into analyzable format. Results: A total of 1,756 patients had audiologic records for review. Median age was 32.5 years, with the age distribution presented according to sex, type of tests done including common reasons for referral, and median threshold levels by frequency. Coverage was national in scope, with most patients coming from the National Capital Region and from Regions III and IVa. Occupation was indicated in 37.8 percent of the working age group, most of whom were unemployed. The most common pretest diagnosis was chronic otitis media (26.6 percent), followed by hearing loss of unknown etiology (13.0 percent) and tinnitus (9.3 percent). Severity of hearing impairment based on pure tone audiometry was variable, and was presented according to common diagnoses. About 39 percent of hearing impairment cases were sensorineural, 36 percent conductive and 25 percent due to mixed defect. Bilateral Type A ears were found in 45.4 percent of patients by tympanometry, while 29.3 percent were bilateral Type B. For otoacoustic emissions, 69.0 percent were labeled as "refer" in at least one ear. Conclusion: The PNEI is a major national referral center for audiology that holds much promise in developing programs for national surveillance of the hearing status of different sectors in Philippine society. (Author)