Can nurses exclude middle-ear effusion without otoscopy in young asymptomatic children in primary care?

Objective. Scandinavian guidelines recommend controlling middle-ear effusion (MEE) after acute otitis media. The study aim was to determine whether nurses without otoscopic experience can reliably exclude MEE with tympanometry or spectral gradient acoustic reflectometry (SG-AR) at asymptomatic visits. Design. Three nurses were taught to perform examinations with tympanometry and SG-AR. Pneumatic otoscopy by the study physician served as the diagnostic standard. Setting. Study clinic at primary health care level. Patients. A total of 156 children aged 6–35 months. Main outcome measures. Predictive values (with 95% confidence interval) for tympanometry and SG-AR, and the clinical usefulness, i.e. the proportion of visits where nurses obtained the exclusive test result from both ears of the child. Results. At 196 visits, the negative predictive value of type A and C1 tympanograms (tympanometric peak pressure > −200 daPa) was 95% (91–97%). Based on type A and C1 tympanograms, the nurse could exclude MEE at 81/196 (41%) of visits. The negative predictive value of SG-AR level 1 result was 86% (79–91%). Based on SG-AR level 1 results, the nurse could exclude MEE at 29/196 (15%) of visits. Conclusion. Tympanograms with tympanometric peak pressure > −200 daPa (types A and C1) obtained by nurses are reliable test results in excluding MEE. However, these test results were obtained at less than half of the asymptomatic visits and, thus, the usefulness of excluding MEE by nurses depends on the clinical setting.     

Role of p19ink4d in the pathogenesis of hearing loss

This study aimed to investigate the p19 expression in cisplatin-treated rats and the role of p19 in the degeneration of inner ear cells. It also searched for p19 gene alterations in patients with profound sensorineural deafness. P19ink4d is essential for the postmitotic maintenance of hair cells. It is presumed that a mutation in the functional homolog of p19 or a disturbance in its regulated expression can be the underlying cause of hearing loss. Experiments were conducted on male and female Sprague-Dawley rats (aged 6-7 weeks, 280-320 g) with thresholds of auditory brainstem responses <30 dB in the sound pressure level, and signs of middle ear infection were used for the experiment. For clinical evaluation, 400 children (age less than 13 years) from unrelated families with severe or profound sensorineural hearing loss (SNHL) were recruited at the second Xiangya Hospital of Central South University between 2005 and 2013, and genomic DNA for deafness gene analysis was obtained from peripheral blood samples of the patients and their lineal relatives. It was found that the p19 expression increased over time in the inner ear cells after cisplatin administration, but the p19 mRNA and protein levels significantly decreased in rats with manifested hearing loss induced by cisplatin. However, no mutation existed within the coding exons of p19 in the patients with profound sensorineural deafness. To conclude, the results support the concept that p19 may play an important role in the ototoxic effects of cisplatin and is probably involved in the pathogenesis of hearing loss.     

Excitatory actions of GABA in developing chick vestibular afferents: Effects on resting electrical activity

The aim of this study was to characterize the effect of γ-aminobutyric acid (GABA) in the resting multiunit activity of the vestibular afferents during development using the isolated inner ear of embryonic and postnatal chickens (E15-E21 and P5). GABA (10⁻³ to 10⁻⁵ M; n = 133) and muscimol (10⁻³M) elicited an increase in the frequency of the basal discharge of the vestibular afferents. We found that GABA action was dose-dependent and inversely related to animal age. Thus, the largest effect was observed in embryonic ages such as E15 and E17 and decreases in E21 and P5. The GABA_A receptor antagonists, bicuculline (10⁻⁵M; n = 10) and picrotoxin (10⁻⁴M; n = 10), significantly decreased the excitatory action of GABA and muscimol (10⁻³M). Additionally, CNQX 10⁻⁶M, MCPG 10⁻⁵M and 7ClKyn 10⁻⁵M (n = 5) were co-applied by bath substitution (n = 5). Both the basal discharge and the GABA action significantly decreased in these experimental conditions. The chloride channel blocker 9-AC 0.5 mM produced an important reduction in the effect of GABA 10⁻³ (n = 5) and 10⁻⁴M (n = 5). Thus, our results suggest an excitatory role of GABA in the resting activity of the vestibular afferents that can be explained by changes in the gradient of concentration of Cl⁻ during development. We show for the first time that the magnitude of this GABA effect decreases at later stages of embryonic and early postnatal development. Taking into account the results with glutamatergic antagonists, we conclude that GABA has a presynaptic action but is not the neurotransmitter in the vestibular afferent synapses, although it could act as a facilitator of the spontaneous activity and may regulate glutamate release. Synapse 67:374–381, 2013. © 2013 Wiley Periodicals, Inc.     

Presence of cytomegalovirus in the perilymphatic fluid of patients with profound sensorineural hearing loss caused by congenital cytomegalovirus infection

Conclusion: Not all patients diagnosed with congenital infection using umbilical cord assay were found to be positive for CMV-DNA by perilymphatic fluid assay. In addition, a CMV-DNA-positive result was observed in one patient who had not been diagnosed with congenital infection. Sampling of perilymphatic fluid from a large population of patients with congenital SNHL caused by congenital CMV infection or of unknown etiology is required to determine the prevalence of CMV-related profound HL. Objectives: Sensorineural hearing loss (SNHL) is one of the most frequent manifestations in patients with congenital cytomegalovirus (CMV) infection. Using dried umbilical cord, a PCR-based assay was recently developed for the retrospective detection of congenital CMV infection. This study analyzed the presence of CMV in the perilymphatic fluid and evaluated differences in the effect of cochlear implantation between CMV-positive and -negative groups. Method: Perilymphatic fluid was collected from each patient at the time of cochlear implantation and analyzed for the presence of CMV using a PCR method. Results: The perilymphatic fluid in two of the five patients suffering from congenital CMV infection and in one of the 17 patients without congenital CMV infection was found to be positive for CMV.     

The effect of inlay butterfly cartilage tympanoplasty technique on compliance

Conclusion: IBCT technique should be preferred owing to its high graft survival rate and ABG gain. While no significant difference was found in middle ear pressures between ears that underwent IBCT and normal ears, compliance values were found to be decreased in patients undergoing IBCT. However, the lack of correlation between ABG gain and compliance values indicated that compliance increase had no effect on post-operative ABG results. Objective: The aim of the present study was to compare tympanometric and audiological parameters in patients undergoing inlay butterfly cartilage tympanoplasty (IBCT) with their normal ears and to determine their difference with normal ear tympanometric parameters. Methods: Overall, 25 patients that underwent an operation between August 2010–May 2014 were included in the present study. In 13 of these patients, the ear that did not undergo operation was normal. 0.5, 1, 2, 4?kHz pure sound average values, tympanometric measurements and compliance values of normal and operated ears were compared. Results: The graft survival rate in patients was found to be 92%. Mean pre-operative air–bone gap (ABG) was 16.4?±?5.4 in patients, while mean post-operative ABG was 10.9?±?5.8, with a statistically significant difference (p?=?0.001) While there was no significant difference between operated and normal ears of patients in terms of middle ear pressure (0.441), compliance values were significantly higher in normal ears than those in operated ears (0.032). When post-operative ABG gain was compared with compliance values, no significant correlation was found between ABG gain and compliance measurements (r?=??0.025 and p?=?0.936).     

Endolymphatic space size in patients with Meniere’s disease and healthy controls

Conclusions: The incident ratios of cochlear and/or vestibular endolymphatic hydrops (EH) were significantly higher in the affected ears of patients with Meniere’s disease (MD) than in the ears of healthy controls. There were no significant differences between controls and the contralateral ears of MDs. Objectives: The aim was to compare the incidence ratios of EH between unilateral/bilateral MD and controls using 3T magnetic resonance imaging (MRI) with intravenous gadolinium. Methods: A total of 41 patients were diagnosed with MD: 32 with unilateral MD (uMD) and nine with bilateral MD (bMD). Fifteen healthy volunteers were enrolled as controls. The patients underwent 3T MRI 4?h after intravenous injection of gadolinium. Results: Cochlear EH was present in 3.3% of 30 ears of 15 controls, 6.3% of 32 contralateral (contra) ears of 32 uMDs, 62.5% of 32 affected ears of 32 uMDs, and 55.6% of 18 affected ears of nine bMDs. Vestibular EH was observed in 6.7% of control ears, 3.1% of contra-uMD ears, 65.6% of affected uMD ears, and in 55.6% of affected bMD ears. Either cochlear or vestibular EH was present in 10.0% of control ears, 6.3% of contra-uMD ears, 81.3% of affected uMD ears, and 44.4% of affected bMD ears.     

Localization of histamine (H1, H2, H3 and H4) receptors in mouse inner ear

Conclusion The present findings show that all four types of histamine receptors (H1R, H2R, H3R, and H4R) are present in the inner ear, thus supporting the hypothesis that histamine plays a physiological role in the inner ear. Objective To analyse the presence of histamine receptors in the normal mouse inner ear. Methods CBA/J mice were used in this study. The localization of H1R, H2R, H3R, and H4R in the inner ear, i.e. cochlea, vestibular end organs, vestibular ganglion, and endolymphatic sac, was studied by real-time PCR and immunohistochemistry. Results The mRNA for each receptor sub-type was detected in the inner ear. In the immunohistochemical study, the organ of Corti, spiral ganglion, vestibular ganglion, vestibular sensory epithelium, and endolymphatic sac cells showed an immunofluorescent reaction to all histamine receptors.