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[Reversible inner ear hearing loss in middle ear tuberculosis].

Middle ear tuberculosis in a female teacher aged 29 is reported. White necrotic areas were found on the skin of the remaining tympanic membrane and the auditory meatus, that stood out clearly against the healthy skin of the auditory meatus. The patient also had inner ear deafness. The function of the inner ear returned to normal after antituberculous therapy: a comparable course of this disease could not be found in the literature.

Antitubercular Agents↗

Multifrequency tympanometry: effects of ear canal volume compensation on middle ear resonance.

Sweep frequency tympanograms compensating for ear canal volume at 200 and -400 daPa were obtained on 106 ears of 53 subjects during four different sessions. Resonance frequencies were obtained and analyzed to determine normative data, resonance differences between the compensation methods, and the interaction effect of running consecutive tympanograms. There were no gender or interaural differences for either compensation method. Although statistically significant, the compensation method by order interaction found between the first and second runs of tympanograms was not clinically significant. Compensation at 200 daPa was recommended when using sweep frequency tympanometry. Mean resonance frequency difference of the two compensation methods was 400 Hz. Large intersubject variability emphasized the need for audiologists to use proper compensation norms when examining middle ear resonance.

Acoustic Impedance Tests↗

Middle ear mucosa and chronic ear disease. III. Enzyme studies of thick noncholesteatomous epithelium.

Thick mucosa removed from the promontory in cases with chronic otitis media showed prominent PAS-positive glands and epithelial secretory cells. Alcian blue positivity was less pronounced, contrary to the mucosa from glue ears. Enzyme activity in the epithelium and propria was comparable to that in glue ears, with some increase in alkaline phosphatase and some decrease in proprial lactate dehydrogenase and malate dehydrogenase activity. Removal of thick, permanently altered mucoas is recommended even in the absence of squamous epithelium. Steps should be taken to allow regrowth of thin, normal middle ear epithelium on the promontory.

Acid Phosphatase↗

Inner ear fine structures of the hamster in frozen sections used for immunohistochemical assays for inner ear diseases.

Frozen sections of the inner ear of the hamster enable detailed investigations of the fine structures in immunofluorescence assays. At high magnification single mitochondria can be identified by their reactions with an antiserum containing antibodies against mitochondria. In the positive reaction with an antiserum against nuclei, the typical green fluorescence is restricted to the nuclei, which are mostly separated by the surrounding cytoplasm. The method of immunohistochemical assay using frozen sections from the non-decalcified inner ear is very time-consuming and cannot be recommended for the routine diagnosis of inner ear diseases, although it may be useful in research and for studying critical clinical cases.

Animals↗

Making and breaking the innervation of the ear: neurotrophic support during ear development and its clinical implications.

Analyses of single and double mutants of members of the neurotrophin family and their receptors are reviewed. These data demonstrate that the two neurotrophins, brain-derived neurotrophic factor (BDNF) and neurotrophin 3 (NT-3), and their high-affinity receptors trkB and trkC, are the sole support for the developing afferent innervation of the ear. Neurotrophins are first expressed in the otocyst around the time afferent sensory neurons become postmitotic. They are crucial for the survival of certain topologically distinct populations of sensory neurons. BDNF supports all sensory neurons to the semicircular canals, most sensory neurons to the saccule and utricle, and many sensory neurons to the apex and middle turn of the cochlea. In contrast, NT-3 supports few sensory neurons to the utricle and saccule, all sensory neurons to the basal turn of the cochlea and most sensory neurons to the middle and apical turn. Some topologically restricted effects reflect the pattern of neurotrophin distribution as revealed by in situ hybridization (e.g., loss of all innervation to the semicircular canal sensory epithelia in BDNF or trkB mutants). However, other topologically restricted effects cannot be explained on the basis of current knowledge of neurotrophin or neurotrophin receptor distribution. Data on mutants also support the notion that BDNF may play a role in neonatal plastic reorganization of the pattern of innervation in the ear and possibly the brainstem. In contrast, data obtained thus far on the ability of neurotrophins to rescue adult sensory neuron after insults to cochlear hair cells are less compelling. The ear is a model system to test the interactions of the two neurotrophins, BDNF and NT-3, with their two high-affinity receptors, trkB and trkC.

Adult↗

EMLA cream on the ears--is it effective? A prospective, randomised controlled trial of the efficacy of topical anaesthetic cream in reducing the pain of local anaesthetic infiltration for prominent ear correction.

A prospective, randomised, double blind trial was carried out to test whether or not the application of topical anaesthetic cream (EMLA cream) before infiltration of local anaesthetic would decrease the discomfort of correction of prominent ears under local anaesthetic. 23 patients were entered into the trial. They acted as their own controls, one ear having EMLA cream applied approximately 2 h prior to surgery, and the other Aqueous cream. Immediately after surgery, the patients were asked to complete two scales describing the amount of pain they had felt in each ear, both at the time of injection of local anaesthetic and during the surgery. They were also asked whether they thought the inconvenience associated with the use of the EMLA cream was worth any improvement they felt. The results showed that, compared to the placebo cream, EMLA cream significantly decreased the pain felt both at the time of injection (p < 0.005) and during the surgery (p < 0.01). However, only 62% of patients asked felt that the inconvenience associated with the use of EMLA cream was worth the benefits that it conveyed.

Administration, Topical↗

On the physics of the infant feeding bottle and middle ear sequela: ear disease in infants can be associated with bottle feeding.

BACKGROUND: When using conventional feeding bottles, negative pressure is generated in the oral cavity, as well as, in the bottle when fluid is removed by sucking. The negative pressure inside the bottle causes the infant to suck excessively and the intraoral negative pressure may subsequently be transmitted to the middle ear via the eustachian tube. METHODS: in seven infants, simultaneous pressure recordings were performed in the feeding vessel and the middle ear using three types of feeding bottles. RESULTS: with conventional non-ventilated and under-ventilated bottles a negative pressure formed while the infant sucked and negative intratympanic pressure was frequently generated. CONCLUSIONS: it is suggested that this sequence of events may lead to secretory otitis and it's accompanying consequences. In contrast, a fully ventilated bottle showed positive pressure throughout the feeding procedure, which is similar to normal breast-feeding, and negative pressure changes were not recorded in the middle ear.

Bottle Feeding↗

Development of the ear and of connections between the ear and the brain: is there a role for gravity?

This paper outlines the development of the gravistatic sensory system of the ear. First, evidence is presented that a genetic program, for which major transcription factors have already been identified using gene expression studies and targeted mutagenesis, governs the initial development of this system. Second, the formation of sensory neurons and their connections to the brain is described as revealed by tracing studies and genetic manipulations. It is concluded that the initial development of the connections of sensory neurons with mechanosensory transducers of the ear (the hair cells) and the targets in the brainstem (vestibular nuclei) is also dependent on fairly rigid genetic programs. During late embryonic and early postnatal development, however, sensory input appears to be used to fine-tune connections of these sensory neurons with the hair cells in the ear as well as with second order vestibular neurons in the brainstem. This phase is proposed to be critical for a proper calibration of the gravistatic information processing in the brain.

Animals↗

Surface morphology of middle ear epithelium in chronic ear disease.

The ultrastructural details of normal middle ear mucosa have been reported in detail in the literature. This study was aimed at investigating the superficial structure of middle ear epithelium with the scanning electron microscope in patients with persistent otitis media with effusion (OME) and chronic suppurative otitis media (CSOM), especially in the light of the authors' recent findings regarding decreased ciliary beat frequency (CBF) in patients exposed to tobacco smoke. Mucosal biopsies were taken from the anterior mesotympanum in four patients with OME and another four patients with CSOM. There was no significant abnormality of cellular surface structure in patients with chronic middle ear disease. Furthermore, no significant difference was observed between smoke exposed and nonsmoke exposed patients. It is concluded that the effect of tobacco smoke on CBF is functional and not related to any anatomical abnormality observed by scanning electron microscopy (SEM).

Adolescent↗

Ear protection as a treatment for disruptive snoring: do ear plugs really work?

BACKGROUND: In the absence of surgical treatments with demonstrable long-term efficacy, conservative treatments for snoring remain appropriate. Only limited evidence evaluating the use of ear protection by partners has been published. METHODS: Eligible couples were invited to participate in a two-month trial, with each partner using custom-moulded ear plugs. Five questionnaires were completed by patients and their partners, at baseline and after two months: the snoring outcomes survey (SOS) or the spouse/bed partners survey (SBPS), the Epworth sleepiness scale (ESS), the general health questionnaire-12 (GHQ-12), the Nottingham health profile (NHP) and the Golombok-Rust inventory of marital status (GRIMS). RESULTS: After two months, there was a significant improvement in the SOS score for patients (p = 0.005), the SBPS score for partners (p = 0.001) and the ESS for partners (p = 0.004). CONCLUSIONS: For selected couples, ear plugs represent an effective short-term treatment for some of the social effects of disruptive snoring, as determined by the SOS, SBPS and ESS questionnaires.

Ear Protective Devices↗

Morphologic changes in the inner ear of Chinchilla laniger after middle ear administration of gentamicin in a sustained-release vehicle.

The use of transtympanic gentamicin has become a popular method of treating Meniere's disease; nevertheless, many questions still remain regarding this therapy. Until investigators can control the exact amount of medicine that is administered to the ear and have an understanding of the kinetics of gentamicin, therapy will continue to rely on empirical data. Previously we described the use of a fibrin-based sustained-release vehicle impregnated with gentamicin in the middle ears of chinchillas. With this model a kinetics curve of gentamicin was defined. The inner ears of these animals were submitted for immunohistochemical and histologic analysis. We discuss the ultrastructural changes seen and correlate this to our kinetics data. We also examine measurement of hair cell damage with heat shock protein levels. By better understanding the actions of gentamicin in this animal model, we hope to facilitate safer use of intratympanic medicines in our patient population.

Animals↗

Transient receptor potential channels in the inner ear: presence of transient receptor potential channel subfamily 1 and 4 in the guinea pig inner ear.

CONCLUSION: The results of this study indicate that transient receptor potential subfamily 1 (TRPV1) may play a functional role in sensory cell physiology and that TRPV4 may be important for fluid homeostasis in the inner ear. OBJECTIVE: To analyze the expression of TRPV1 and -4 in the normal guinea pig inner ear. MATERIAL AND METHODS: Albino guinea pigs were used. The location of TRPV1 and -4 in the inner ear, i.e. cochlea, vestibular end organs and endolymphatic sac, was investigated by means of immunohistochemistry. RESULTS: Immunohistochemistry revealed the presence of TRPV1 in the hair cells and supporting cells of the organ of Corti, in spiral ganglion cells, sensory cells of the vestibular end organs and vestibular ganglion cells. TRPV4 was found in the hair cells and supporting cells of the organ of Corti, in marginal cells of the stria vascularis, spiral ganglion cells, sensory cells, transitional cells, dark cells in the vestibular end organs, vestibular ganglion cells and epithelial cells of the endolymphatic sac.

Animals↗

The influence of endotoxin upon middle ear fibroblasts cultured in normal middle ear gas and atmospheric air.

Otitis media represents a continuum of inflammatory stages frequently in association with bacteria and/or endotoxin. Furthermore, the disease is often treated with insertion of ventilation tubes, which causes hyperoxia relative to the physiological state in the tympanic cavity. The present study was undertaken to quantitate the interaction between endotoxin and relative hyperoxia in cultures of rabbit middle ear fibroblasts incubated in normal middle ear gas and atmospheric air, respectively. Growth was monitored by determination of DNA, cell protein and cell division. The synthetic activity was estimated by collagen production. The antioxidant defense was determined by measuring the intra-and extracellular concentrations of superoxide dismutase (SOD). The results demonstrated that hyperoxia significantly impaired the growth of middle ear fibroblasts, which was compensated for by addition of endotoxin stimulating the growth. The collagen synthesis increased significantly in atmospheric air with a synergistic effect of endotoxin. Hyperoxia induced intracellular SOD formation, while endotoxin tended to reduce the synthesis. Finally, exposure to atmospheric air caused significantly larger amounts of reducing agents extracellularly in cultures without endotoxin compared to endotoxin incubated cultures. It is suggested that endotoxin possess both synergistic and antagonistic potential as regards the effects of relative hyperoxia, and that the interaction between endotoxin and hyperoxia may be an important factor in otitis media.

Animals↗

The behavior of acoustic distortion products in the ear canals of chinchillas with normal or damaged ears.

Acoustic intermodulation distortion products were measured in 15 ear canals of chinchillas with normal or damaged ears. Pretreatment results showed that when two primary tones at frequencies f1 and f2, f1 less than f2, were presented at levels from 30 to 90 dB SPL, acoustic distortion products at 2f1-f2 and 2f2-f1 were 30 to 50 dB below primary-tone levels. Noise exposures that caused temporary or permanent hearing loss produced corresponding temporary or permanent reductions in distortion-product levels. Mechanical damage to the cochlea or middle ear reduced the distortion-product levels to below the noise floor of the measurement system. Comparisons of distortion-product level with behaviorally measured threshold shift and cochlear histopathology suggest that, in the absence of conductive impairment, the level of 2f1-f2 or 2f2-f1 can be used as a sensitive indicator of hearing sensitivity and the condition of the cochlea.

Animals↗

Middle ear specific proteins in glue ears.

Two rabbits were immunized with a pool of mocoid secretion from glue ears. The ear fluids formed up to three specific protein precipitation lines with the absorbed immune serum. One of these proteins was identified as containing acid and another as containing neutral glycoproteins, the third component remained unidentified. The data bring out new evidence of the active secretory capacity of the middle ear mucosa in secretory otitis media.

Albumins↗

Fluctuations of middle ear aeration in atelectatic ears.

This is a prospective study of 27 eardrums which were found to be in an atelectatic condition before night sleep. On awakening in the morning, 10 (37.0%) of these ears were found to be inflated. The atelectasis as well as the presentation of spontaneous disappearance of the atelectasis were observed with the operating microscope. After awakening, the original atelectatic state reappeared within 65.7 min (on average). Spontaneous autoinflation of atelectatic ears cannot be explained by nocturnal CO2 diffusion into the middle ear, as CO2 would rediffuse within one order of time quicker than found-i.e. 6 min. The phenomenon emphasizes the fluctuating nature of atelectatic conditions.

Adult↗

[Tissue culture of middle ear epithelium of the guinea pig--differences of the cellular growth activity in the middle ear cavity using collagen gel culture method].

Primary tissue culture system from the middle ear and the tracheal epithelium of the guinea pig was established using collagen gel method. The cultured epithelium was studied by phase-contrast microscopy, light and scanning electron microscopy. The outgrowth area of the epithelium was quantitatively measured for period of up to ten days. In the middle ear cavity, the mucosal explants were sampled from various sites in order to compare their differential and proliferative activities. The mucosal explants attached on collagen substrates were composed of ciliated, non-ciliated, goblet and basal cells. This basic structure was similar to the natural middle ear epithelium. The ciliated cells showed well organized cilia. Most of the outgrowth cells devoid of fibroblastic cells in the monolayer were polygonal shaped with numerous microvilli. The morphology of the outgrowth cells changed from columnar or cuboidal to squamous shapes in the area away from the explants. There was a correlation between the distribution of the ciliated cells in the outgrowths and these in the explants. The explants with columnar or cuboidal ciliated epithelia sampled from the opening of the eustachian tube or its neighborhood formed more than eightfold outgrowth sheets in vitro. This is comparable to tracheal epithelia. On the other hand, the explants with simple squamous epithelia sampled from the area distal to the eustachian tube showed about fourfold proliferative activity. We concluded that this culture system would be useful for the study of cellular multiplication and differentiation mechanisms of the respiratory tract epithelium.

Animals↗