-
International Journal of Molecular... Oct 2017Otitis media (OM) refers to inflammatory diseases of the middle ear (ME), regardless of cause or pathological mechanism. Among the molecular biological studies assessing... (Review)
Review
Otitis media (OM) refers to inflammatory diseases of the middle ear (ME), regardless of cause or pathological mechanism. Among the molecular biological studies assessing the pathology of OM are investigations of the expression of aquaporins (AQPs) in the ME and Eustachian tube (ET). To date, fifteen studies have evaluated AQPs expression in the ME and ET. Although the expression of individual AQPs varies by species and model, eleven types of AQP, AQP1 to AQP11, were found to be expressed in mammalian ME and ET. The review showed that: (1) various types of AQPs are expressed in the ME and ET; (2) AQP expression may vary by species; and (3) the distribution and levels of expression of AQPs may depend on the presence or absence of inflammation, with variations even in the same species and same tissue. Fluid accumulation in the ME and ET is a common pathological mechanism for all types of OM, causing edema in the tissue and inducing inflammation, thereby possibly involving various AQPs. The expression patterns of several AQPs, especially AQP1, 4 and 5, were found to be altered in response to inflammatory stimuli, including lipopolysaccharide (LPS), suggesting that AQPs may have immunological functions in OM.
Topics: Animals; Aquaporins; Cell Membrane Permeability; Ear, Middle; Eustachian Tube; Gene Expression Regulation; Humans; Multigene Family; Otitis Media
PubMed: 29039751
DOI: 10.3390/ijms18102164 -
The Journal of Experimental Biology Nov 2022In most anuran amphibians, acoustic communication is of prime importance for mate localization and selection. The tympanic middle ear increases auditory sensitivity and...
In most anuran amphibians, acoustic communication is of prime importance for mate localization and selection. The tympanic middle ear increases auditory sensitivity and directionality and is therefore expected to be favoured by natural selection. However, especially within the family of true toads (Bufonidae) there is a tendency for species to lose parts of the middle ear apparatus and consequently have a reduced sensitivity to high-frequency sounds (above 1 kHz). Part of the explanation for this may be that development of the middle ear is especially slow in bufonids, and thus the middle ear would be more likely to be lost or non-functional in paedomorphic species. However, a timeline of development of the middle ear has not been established previously. The goal of the present study was to investigate middle ear development in a toad species that has a well-known natural history and acoustic communication behaviour. We made a detailed study of anatomy and biophysics of the middle ear with measurements of auditory sensitivity across age in post-metamorphic natterjack toads (Epidalea calamita). The tadpoles and toadlets were raised in the laboratory, so their exact age was known, their auditory sensitivity was measured using auditory brainstem responses, and middle ear development and function were assessed by anatomical studies and laser vibrometry. We found that the developmental stage of the middle ear depends on the size of the toad rather than its age. The middle ear was functional at the earliest at a snout-vent length of 40 mm, which for these toads was around 500 days post-metamorphosis, close to the time of first reproduction. The functional, adult-like middle ear was shown to have 30 dB increased sensitivity to the dominant frequency of the mating call compared with sensitivities measured in newly metamorphosed individuals.
Topics: Humans; Animals; Bufonidae; Ear, Middle; Tympanic Membrane; Larva; Metamorphosis, Biological
PubMed: 36268787
DOI: 10.1242/jeb.244759 -
Journal of Comparative Physiology. A,... Sep 2020The sheep middle ear has been used in training to prepare physicians to perform surgeries and to test new ways of surgical access. This study aimed to (1) collect... (Comparative Study)
Comparative Study
The sheep middle ear has been used in training to prepare physicians to perform surgeries and to test new ways of surgical access. This study aimed to (1) collect anatomical data and inertial properties of the sheep middle-ear ossicles and (2) explore effects of these features on sound transmission, in comparison to those of the human. Characteristic dimensions and inertial properties of the middle-ear ossicles of White-Alpine sheep (n = 11) were measured from high-resolution micro-CT data, and were assessed in comparison with the corresponding values of the human middle ear. The sheep middle-ear ossicles differed from those of human in several ways: anteroinferior orientation of the malleus handle, relatively small size of the incus with a relatively short distance to the lenticular process, a large area of the articular surfaces at the incudostapedial joint, and a relatively small moment of inertia along the anterior-posterior axis. Analysis in this study suggests that structure and orientation of the middle-ear ossicles in the sheep are conducive to an increase in the hinge-like ossicular-lever-action around the anterior-posterior axis. Considering the substantial anatomical differences, outcomes of middle-ear surgeries would presumably be difficult to assess from experiments using the sheep middle ear.
Topics: Animals; Ear Ossicles; Ear, Middle; Hearing; Humans; Incus; Malleus; Sheep
PubMed: 32564138
DOI: 10.1007/s00359-020-01430-w -
The Journal of the Acoustical Society... Nov 2022For evoked otoacoustic emissions (OAEs), the stimulus and emission signals traverse the middle ear (ME) in forward and reverse directions, respectively. In this study, a...
For evoked otoacoustic emissions (OAEs), the stimulus and emission signals traverse the middle ear (ME) in forward and reverse directions, respectively. In this study, a fully coupled three-dimensional finite-element model of the mouse ear canal (EC), ME, and cochlea was used to calculate ME pressure gains, impedances, and reflectances at the EC-entrance and stapes-footplate-cochlear-fluid interfaces. The cochlear model incorporates a series of interdigitated Y-shaped structures sandwiched between the basilar membrane and reticular lamina, each comprised of a Deiters' cell, its phalangeal-process extension, and an outer hair cell (OHC). By introducing random perturbations to the OHC gains, stimulation-frequency otoacoustic emissions (SFOAEs) were generated. Raising the perturbation magnitude from 10% to 80% increased the SFOAE magnitude by up to 24 dB in the 10-30 kHz frequency range. Increasing or decreasing the stiffness of the stapes annular ligament and eardrum by a factor of 8 changed the SFOAEs by up to 30 dB, but the round-trip ME gain as measured could not account for this. A modified round-trip ME gain, with reflections removed at the EC-entrance and stapes-cochlea boundaries, eliminated a ±10 dB discrepancy and allowed ME changes to be quantitatively associated with changes in measured OAEs.
Topics: Mice; Animals; Otoacoustic Emissions, Spontaneous; Cochlea; Ear, Middle; Stapes; Hair Cells, Auditory, Outer; Disease Models, Animal
PubMed: 36456266
DOI: 10.1121/10.0014901 -
Radiologia 2021The radiological evaluation of the postsurgical middle ear is complex due to the intricate anatomy of this region and the wide variety of procedures and materials used...
OBJECTIVE
The radiological evaluation of the postsurgical middle ear is complex due to the intricate anatomy of this region and the wide variety of procedures and materials used iin middle ear surgery. Knowledge of these factors will enable normal postsurgical changes to be differentiated from complications. This article describes the most common surgical procedures in the middle ear, their indications, and the normal radiological appearance after these procedures. It reviews the most common causes of failure in stapes surgery, in surgery for chronic otitis media, and in surgery for cholesteatoma, suggesting the best imaging method to assess the middle ear in each case.
CONCLUSION
Computed tomography enables the evaluation of prostheses and the aeration of the cavities, whereas magnetic resonance imaging makes it possible to characterize the possible occupation of the cavities and is the technique of choice for the follow-up of closed mastoidectomy for cholesteatomas.
Topics: Cholesteatoma, Middle Ear; Ear, Middle; Humans; Mastoid; Mastoidectomy; Treatment Outcome
PubMed: 34625199
DOI: 10.1016/j.rxeng.2021.04.006 -
International Journal of Molecular... Apr 2023The aim of this comprehensive review was to present the current knowledge on the role of microRNAs (miRNAs) in acute, recurrent, and chronic forms of otitis media.... (Review)
Review
The aim of this comprehensive review was to present the current knowledge on the role of microRNAs (miRNAs) in acute, recurrent, and chronic forms of otitis media. Special attention was focused on cholesteatoma of the middle ear. MicroRNAs modulate gene expression, which, in turn, influences the development and likelihood of the recurrence of acute and aggressive chronic middle ear inflammatory processes. Moreover, this study discusses the modulating role of a specific subgroup of noncoding RNA, circular RNA (circRNA). Recognizing the precise potential pathways and the mechanisms of their function may contribute to a better understanding of the molecular bases of middle ear diseases and identifying novel methods for treating this demanding pathology. Articles published between 2009 and 2022 were used in this analysis. In this review, we provide a complete overview of the latest progress in identifying the role and mechanisms of particular miRNAs and circRNAs in acute, recurrent and chronic forms of otitis media.
Topics: Humans; MicroRNAs; RNA, Circular; Otitis Media; Ear, Middle
PubMed: 37047725
DOI: 10.3390/ijms24076752 -
Scientific Reports Oct 2022Human temporal bone specimens are used in experiments measuring the sound transfer of the middle ear, which is the standard method used in the development of active and...
Human temporal bone specimens are used in experiments measuring the sound transfer of the middle ear, which is the standard method used in the development of active and passive middle ear implants. Statistical analyses of these experiments usually require that the TB samples are representative of the population of non-pathological middle ears. Specifically, this means that the specimens must be mechanically well-characterized. We present an in-depth statistical analysis of 478 data sets of middle ear transfer functions (METFs) from different laboratories. The data sets are preprocessed and various contributions to the variance of the data are evaluated. We then derive a statistical range as a reference against which individual METF measurements may be validated. The range is calculated as the two-sided 95% tolerance interval at audiological frequencies. In addition, the mean and 95% confidence interval of the mean are given as references for assessing the validity of a sample group. Finally, we provide a suggested procedure for measuring METFs using the methods described herein.
Topics: Ear, Middle; Humans; Ossicular Prosthesis; Sound; Temporal Bone
PubMed: 36241675
DOI: 10.1038/s41598-022-21245-w -
Journal of Anatomy Feb 2016Here we present a brief, historical review of research into the mammalian middle ear structures. Most of their essential homologies were established by embryologists,... (Review)
Review
Here we present a brief, historical review of research into the mammalian middle ear structures. Most of their essential homologies were established by embryologists, notably including Reichert, during the 19th century. The evolutionary dimension was confirmed by finds of fossil synapsids, mainly from the Karroo of South Africa. In 1913, Ernst Gaupp was the first to present a synthesis of the available embryological and paleontological data, but a number of morphological details remained to be solved, such as the origin of the tympanic membrane. Gaupp favoured an independent origin of the eardrum in anurans, sauropsids, and mammals; we support most of his ideas. The present review emphasizes the problem of how the mammalian middle ear structures that developed at the angle of the lower jaw were transferred to the basicranium; the ontogenesis of extant marsupials provides important information on this question.
Topics: Animals; Biological Evolution; Biomedical Research; Developmental Biology; Ear, Middle; History, 19th Century; History, 20th Century; History, 21st Century; Mammals; Phylogeny
PubMed: 26397963
DOI: 10.1111/joa.12379 -
The South African Journal of... Jul 2022The coronavirus disease 2019 (COVID-19) pandemic is the latest public health emergency that has presented challenges globally. Limited evidence exists on the... (Review)
Review
BACKGROUND
The coronavirus disease 2019 (COVID-19) pandemic is the latest public health emergency that has presented challenges globally. Limited evidence exists on the association between COVID-19 and middle ear pathologies, regardless of the respiratory nature of some of the core symptoms.
OBJECTIVE
This scoping review aimed at exploring evidence on the effects of COVID-19 on middle ear functioning as part of symptom mapping and preventive planning for ear and hearing care.
METHOD
Electronic bibliographic databases, including Medline, ProQuest, PubMed, Science Direct, ERIC and Scopus, were searched to identify peer reviewed publications, published in English, between December 2019 and January 2022, related to the effects of COVID-19 on middle ear functioning. The keywords used as MeSH terms included 'middle ear pathology', 'middle ear disorder', 'otitis media', 'hearing loss', 'hearing impairment', 'audiology' and 'COVID-19' or 'coronavirus'.
RESULTS
From eight studies that met the inclusion criteria, the findings revealed that middle ear pathologies occur in this population, with the occurrence ranging from 1.15% to 75%. Tympanic membrane structural changes, otitis media and conductive hearing loss (CHL) were commonly reported. The current findings must be interpreted with caution given that most of the studies reviewed had extremely small sample sizes or were case studies or series, thus limiting generalisability.
CONCLUSION
The findings highlight the value of strategic research planning to collate data during pandemics, ensuring that future studies use appropriate and well-designed methodologies. Trends and patterns of middle ear pathologies in this population must also be established to determine the need for periodic monitoring.
Topics: Audiology; COVID-19; Ear, Middle; Hearing Loss; Hearing Tests; Humans; Otitis Media
PubMed: 35924607
DOI: 10.4102/sajcd.v69i2.910 -
Acta Otorhinolaryngologica Italica :... Apr 2022To evaluate the safety, speech performance in noise and subjective satisfaction of patients with congenital aural atresia (CAA) implanted with the active middle ear...
OBJECTIVES
To evaluate the safety, speech performance in noise and subjective satisfaction of patients with congenital aural atresia (CAA) implanted with the active middle ear implant.
METHODS
This retrospective study included 13 patients (15 ears) implanted with middle ear implants with different methods of floating mass transducer attachment. In 6 ears, the floating mass transducer (FMT) was coupled with the short process of incus; in 8 ears, a clip coupler was used; and in one ear, a round window coupler was used. Patients were assessed preoperatively, and at one, three, and six months postoperatively. The assessment included Pure Tone Average (PTA4), Speech Reception Threshold (SRT) and Speech Discrimination Score (SDS). The Speech Spatial and Qualities of Hearing scale (SSQ12) was also used to evaluate levels of satisfaction.
RESULTS
The mean aided PTA4 using Vibrant Sound Bridge (VSB) was 26.44 4.03 dB HL compared to 61.88 ±1.53 dB HL unaided. The SDS improved significantly (p = 0.002) from 51% (± 9.17%) to 94.60% (± 4.43%). Furthermore, there was a significant improvement in SDS in noise (p = 0.008) and SSQ12 responses (p < 0.0001).
CONCLUSIONS
Patients with hearing loss due to CAA can substantially benefit from VSB, with highly satisfactory subjective results and a negligible rate of complications.
Topics: Congenital Abnormalities; Ear; Ear, Middle; Hearing Loss, Conductive; Humans; Ossicular Prosthesis; Personal Satisfaction; Retrospective Studies; Speech; Speech Perception; Treatment Outcome
PubMed: 35612511
DOI: 10.14639/0392-100X-N1668