No abstract available.
Humans*

No abstract available.

BACKGROUND: Evaluation of the quality of tinnitus is very useful for understanding of the nature of tinnitus by non-sufferers including physicians. But tinntus matching with pure tone is a limited access to qualify tinnitus and frequently it is difficult for sufferer to match and this may be an important cause of low test-retest reliability. OBJECTIVES: The aim of this study are to identify sounds mimicking tinnitus using generated and environmental sounds and its reliability on repeated tests. MATERIALS AND METHODS: 34 patients(M: 22, F: 12) who have suffered from continuous tinnitus were selected. Electronically generated sounds were pure tone, narrow band(1/3 octave band width) noise filtered from gaussian noise, random frequency band sine waves with center frequency. Twenty artificial and fourteen natural environmental sounds were recorded and calibrated. The most similar sound were selected by sufferer three times at the minimum time interval 2 weeks. The frequency spectrums of environmental sounds were analyzed. RESULTS: The most similar sounds mimicking tinnitus were pure tone(29.2%), frequency modulated sine wave(27.1%), natural environmental sounds(20.8%), narrow bane noise(14.6%), artificial environmental sounds(12.5%) in order. The reliability of the selection of the most similar sounds on repeated tests were very high(94.1%). The spectrum of the environmental sounds selected were broad. CONCLUSIONS: The quality of tinitus can be evaluated more objectively by electronically generated sounds which are highly reproducible. The quality of tinnitus is quite consistent. Also in the majority, the quality of tinnitus is different from the quality of pure tone.
Noise ; Tinnitus*

BACKGROUND AND OBJECTIVES: Walking is an indispensable daily locomotion and requires highly organized and dynamic body balance which is maintained by visual, vestibular and proprioceptive system. This study was designed to measure the forefoot position and walking speed in normal cats. MATERIALS AND METHODS: Five normal cats were selected and trained to walk over a platform (188 cm long, 65 cm wide) of different upward and downward slope up to 15 degrees in a natural way. When a cat walks, the magnetic field generated from AC generators of two different frequencies through a coil in a cat's shoes was changed. The induced current of detecting coils under the platform was repeatedly measured. The sensitivity (minimal distance required to be separated in a different position) was 5 mm in the right and left axis, 10 mm in anterior and posterior axis. RESULTS: The mean crossing time over platform was 1.9+/-0.3 seconds. Mean walking speed was 648.2+/-76.5 mm/sec without significant differences between individuals or degrees of slope. The range of mean deviation was in between 4.4+/-48.8 mm to the right and 5.6+/-42.8 mm to the left with a different slope. There was a significant difference between 0 degree and upward 10, 15 degrees and downward 5, 15 degrees of slope but no difference between individuals. Walking distance in right-left and anterior-posterior axis were 53.1+/-10.3 and 213.1+/-79.4 mm, respectively, without a significant difference between individuals or degrees of slope. There was no change of foot position in standing 30 degrees upward or 30 dgrees downward. CONCLUSION: These results could be a baseline data for both normal and pathologic cat walking and this precise method will be also useful in clinical settings.
Animals ; Axis, Cervical Vertebra ; Cats* ; Foot ; Locomotion ; Magnetic Fields ; Shoes ; Walking*

BACKGROUND AND OBJECTIVES: Neurotrophins have been known to be responsible for the differentiation and survival of developing neurons as well as for aiding the recovery of adult neurons from injury. The neurotrophin family includes NGF, BDNF, NT-3, and NT-4/5, and they exert their biological functions through activation of the high-affinity binding receptors, that is trkA, trkB, and trkC, with high characteristic specificity. Previous studies indicate that spiral ganglion cells express trkB and trkC mRNAs, while auditory hair cells produce NT-3 mRNA that directly affect maturation and survival of auditory neurons. It has been reported that the loss of target innervation and the eventual degeneration of auditory neurons caused by aminoglycoside ototoxicity can be prevented by the infusion of neurotrophic factors. The purpose of this study is to provide the expression patterns of trkB and trkC in the normal chochleas and damaged cochleas with aminoglycoside ototoxicity. MATERIALS AND METHODS: Adult Sprague-Dawley rats were treated with amikacin 500 mg/kg for ten days, and sacrificed on the 7th, 14th, 21th, and 28th day following the last injection. Auditory brainstem response was measured in each animal. Immunohistochemical method was used to study the localization of trkB and trkC receptors in the cochleas of adult rats of either normal control group or ototoxicity group. RESULTS: Immunoreactivities to trkB and trkC receptors were strongly positive in the spiral ganglion cells of all cochleas, especially in the neuronal perikarya of the type I cells. No difference in staining pattern was seen among the cochleas with different hearing thresholds. CONCLUSION: The uniform expression pattern of trkB and trkC receptors in the spiral ganglion cells regardless of the degree of ototoxicity suggests that neurotrophic factors may bind to these receptors to initiate the cellular mechanisms for neuronal survival in the injured auditory system.
Adult ; Amikacin ; Animals ; Brain-Derived Neurotrophic Factor ; Cochlea* ; Evoked Potentials, Auditory, Brain Stem ; Hair Cells, Auditory ; Hearing ; Humans ; Immunohistochemistry ; Nerve Growth Factor ; Nerve Growth Factors ; Neurons ; Rats* ; Rats, Sprague-Dawley ; Receptor, trkC* ; RNA, Messenger ; Sensitivity and Specificity ; Spiral Ganglion

BACKGROUND AND OBJECTIVES: Unilateral vestibular dysfunction evokes many bothersome symptoms such as nausea, vomiting, vertigo, ataxia, and positional change. We attempted to understand the vestibular signs after a loss of unilateral vestibular function. MATERIALS & METHOD: We evaluated the serial changes of eye movements and body posture after unilateral labyrinthectomy which was performed on five cats. Data obtained from three of these cats. The eye movements were measured in vertical, horizontal and torsional planes using magnetic search coils, with eyes open in light and eyes open in darkness. The eye movements were recorded with head in neutral, tilted, hanging, and Dix-Hallpike position, and after head was shaken. RESULTS: 1) Spontaneous nystagmus was present for the first three days. 2) Head tilting positional nystagmus was present only on the first day after the operation. Head hanging position produced nystagmus with high slow phase eye velocity for 4 weeks. 3) Positioning nystagmus was recorded for 4 weeks and it was more prominent when labyrinthectomized ear was undermost. 4) Head shaking nystagmus around the pitch and roll axis was evoked within one week, but in the yaw axis it persisted for 4 weeks. When the cat was tilted to the lesion side, the intensitiy of positional and positioning nystagmus was stronger. CONCLUSION: Unusual positions such as head hanging and Dix-Hallpike position evoked prolonged nystagmus. Head shaking in the yaw axis could be used on a long term basis to understand unilateral vestibular dysfunction.
Animals ; Ataxia ; Axis, Cervical Vertebra ; Cats* ; Darkness ; Ear ; Eye Movements ; Head* ; Nausea ; Nystagmus, Physiologic ; Posture ; Vertigo ; Vomiting

BACKGROUND AND OBJECTIVES: Measuring the eye movements including nystagmus is an essential step in the evaluation of dizzy patients. Therefore, it is necessary to observe and record the eye movements in animal for better understanding of human vestibular function. In this study, we investigated spontaneous, positional, positioning (Dix-Hallpike), post head shaking nystagmus in normal cats. MATERIALS AND METHODS: In ten normal cats, we measured the eye movements in vertical, horizontal and torsional planes using magnetic search coils with eyes open (EO), and eyes open in darkness (EOD). The eye movements were recorded with the head in neutral, tilted, hanging, and Dix-Hallpike positions as well as after head-shaking. RESULTS: 1) Positional nystagmus was present in 3 cats on the head hanging position. 2) Among the three cats which had positional nystagmus, one cat also had positioning nystagmus on Dix-Hallpike maneuver. 3) On repeated positional stimulations, the latency of nystagmus was increased and the duration and the slow phase velocity were decreased. 4) In the follow-up experiment after one month, the positional nystagmus was induced in the two same cats. 5) Spontaneous and post head shaking nystagmus were not present in any of the ten cats.
Animals ; Cats* ; Darkness ; Eye Movements ; Follow-Up Studies ; Head* ; Humans ; Nystagmus, Physiologic

BACKGROUND AND OBJECTIVES: Tonsillectomy for upper airway obstruction in children has increased but there isn't enough objective data to support such assessment. The purpose of this study was to establish some objective guide for surgery in obstructive apneic children using polysomnography and to compare the polysomnographic results with predictive clinical data, so as to determine the prevalence of obstructive sleep apnea (OSA) with suggestive history. We also tried to understand the characteristics of OSA in children. MATERIALS AND METHODS:Predictive value of OSA was scored based on history, physical examination and X-ray images and compared with the standard overnight polysomnography in fifty-one children who were suggestive of OSA. Postoperative polysomnography was performed in five children who remained apneic. RESULTS: Twenty-two (43%) children with suggestive OSA had respiratory disturbance index (RDI) greater than 5. Among thirty-five (68.6%) who underwent surgery, five (9.8%) children remained apneic with snoring but mean and the longest apnea duration reduced significantly. There was no difference between the obstructive group and non-obstructive group in sleep architecture but minimum oxygen saturation, apnea index, mean apnea duration and hypopnea index showed significant difference. Predictive clinical score and RDI had weak correlation (r=0.25). Non-obstructive group showed higher composition of centeral apnea than the obstructive group. CONCLUSION: History, physical examination and X-ray studies alone are not sufficient to assess the severity of OSA. Polysomnographic study adjusted for children should be done for correct diagnosis in children who do not show any other indication for surgery.
Airway Obstruction ; Apnea ; Child* ; Diagnosis ; Humans ; Oxygen ; Physical Examination ; Polysomnography ; Prevalence ; Sleep Apnea, Obstructive* ; Snoring ; Tonsillectomy

BACKGROUND AND OBJECTIVES: The etiology and pathogenesis of otitis media with effusion (OME) have not been fully elucidated, although multiple theories exist. These pathogenic factors are eustachian tube dysfunction, allergy, local immune dysfunction and bacterial infection. Recently, many studies have focused on the immune regulation and cytokines associated with the pathogenesis of OME. Interleukin 2 (IL-2) is produced by activated T cells which act on T cells, promoting their proliferation and inducing the production of other cytokines involved in the cell-mediated immunity. This study tested the hypothesis that IL-2 in the middle ear cleft can induce OME and that an IL-2 antagonist can prevent IL-2 induced OME. In addition, we examined histopathological changes in the middle ear. MATERIALS AND METHODS: IL-2 (group 1: 0.01ng, group 2: 0.1ng) or with its antagonist (group 3: 0.1ng) were injected transtympanically into the middle ear of normal rats. RESULTS: After 24 hours, IL-2 had produced a cellular effusion (group 1: 75%, group 2: 88%) and histopathological changes including thickening of the subepithelial space and increased infiltration of inflammatory cells. Neutrophils were the predominant cell type. Finally, transtympanic injection of the IL-2 antagonist prevented IL-2 induced OME. CONCLUSION: This study demonstrated that the IL-2 injection into middle ear can induce OME and that IL-2 antagonist can effectively prevent IL-2 induced OME. These findings suggest that IL-2 plays an important role in the pathogenesis of OME and that the IL-2 antagonist may be applied for the treatment of human OME.
Animals ; Bacterial Infections ; Cytokines ; Ear, Middle ; Eustachian Tube ; Humans ; Hypersensitivity ; Immunity, Cellular ; Interleukin-2* ; Interleukins* ; Neutrophils ; Otitis Media with Effusion* ; Otitis Media* ; Otitis* ; Rats ; T-Lymphocytes

BACKGROUND AND OBJECTIVES: Epidermal-mesenchymal interactions control epidermal growth and differentiation and thus regulate tissue homeostasis in the epidermis. So the function of fibroblasts is, in addition to producing extracellular matrix as a structural framework, to act as a cellular communication bridge between epidermis and dermis by synthesizing various mediators, such as growth factors and cytokines. Although the epithelial-mesenchymal cell interaction is still not known clearly, cytokines like interleukine-1beta from keratinocyte promote Keratinocyte growth factor (KGF) which is a member of the fibroblast growth factor (FGF-7) group. IL-1beta was shown to be an important modulator of KGF expression by fibroblast cells. Like hepatocyte growth factor, KFG is best characterized as paracrine mediators of stromal-epithelial interactions produced by fibroblast cells to regulate the functions of epithelial cells and the KGF receptors (KGFR) which is a transmembrane tyrosine kinase that is a splice variant of the FGFR-2/bek gene. To study the regulation of epidermal cell proliferation and differentiation by fibroblasts via paracrine effects of oropharyngeal mucosa, an in-vitro model system has been developed to mimic epidermal-dermal interactions. Material and Method: A co-culture of fibroblasts and keratinocytes in three-dimensional collagen gels was treated with IL-1beta after carrying out the tissue culture from oropharyngeal mucosa. Immuno-histochemistry for localization of KFG and KFGR was done in these artificial tissue and in the mucosa. RESULTS: KGF and KGFR proteins were strongly expressed in cytoplasm of intermediate and superficial layers of the epithelium of the oropharyngeal mucosa. In four out of the five cases, three-dimensional oral mucosa cultures were successfully reconstructed on fibroblast-populated collagen lattice. KGF expression was found focally in the keratinocyte of epithelial layer and diffusely in fibroblast-populated collagen lattice. KGFR was only expressed focally in Keratinocyte of epithelial layer. CONCLUSION: Epidermal-mesenchymal interactions in oropharyngeal mucosa via IL-1beta, KGF and KGFR were observed in a three-dimesional culture system, showing that this system could be used as a study model of epidermal-mesenchymal interactions in oropharyngeal mucosa with some limitations.
Cell Communication ; Cell Proliferation ; Coculture Techniques ; Collagen ; Cytokines ; Cytoplasm ; Dermis ; Epidermis ; Epithelial Cells ; Epithelium ; Extracellular Matrix ; Fibroblast Growth Factor 7* ; Fibroblast Growth Factors ; Fibroblasts* ; Gels ; Hepatocyte Growth Factor ; Homeostasis ; Intercellular Signaling Peptides and Proteins ; Interleukin-1beta ; Keratinocytes* ; Mouth Mucosa ; Mucous Membrane ; Protein-Tyrosine Kinases