Effect of preservation on the physical and chemical properties of the temporal fascia.

Objective: The temporal fascia has been widely used in tympanoplasty. In addition, the preserved fascia has been also used in the ear surgery. In this study, we planned the experiments to determine whether physical and chemical properties of the fascia preserved at a low temperature.

The minimum peptides of IGF-1 and substance P protect vestibular hair cells against neomycin ototoxicity.

Conclusions: Our data indicate that SSSR and SSSR + FGLM-NH2 protect sensory hair cells against neomycin-induced death in the vestibular epithelium. In addition, the results show that SSSR and FGLM-NH2 can be used as protective molecules against aminoglycoside ototoxicity.

Objectives: This study investigated the role of the peptides SSSR and SSSR + FGLM-NH2 in mammalian vestibular hair cell death induced by aminoglycoside.

Analysis of vestibular-balance symptoms according to symptom duration: dimensionality of the Vertigo Symptom Scale-short form.

Background: Dizziness or vertigo is associated with both vestibular-balance and psychological factors. A common assessment tool is the Vertigo Symptom Scale (VSS) -short form, which has two subscales: vestibular-balance and autonomic-anxiety. Despite frequent use, the factor structure of the VSS-short form has yet to be confirmed.

Coenzyme Q10 protects hair cells against aminoglycoside.

It is well known that the production of free radicals is associated with sensory cell death induced by an aminoglycoside. Many researchers have reported that antioxidant reagents protect sensory cells in the inner ear, and coenzyme Q10 (CoQ10) is an antioxidant that is consumed as a health food in many countries. The purpose of this study was to investigate the role of CoQ10 in mammalian vestibular hair cell death induced by aminoglycoside.

Effects of substance P during the recovery of hearing function after noise-induced hearing loss.

Substance P (SP) is a widely distributed neurotransmitter in living tissues and is involved in various repair processes. We investigated the possibility that SP may ameliorate cochlear hair cell damage produced by noise exposure. The present study examined the effect of SP in protecting the cochlea from noise damage in guinea pigs exposed to noise after an infusion of SP into the inner ear.

A novel treatment for vestibular disorder with FGLM-NH2 plus SSSR.

Topical FGLM-NH(2) (Phenylalanine-Glycine-Leucine-Methionine-Amide) plus SSSR (Serine-Serine-Serine-Arginine) facilitates recovery from vestibular disorders induced by (±)-α-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA) in guinea pigs and might offer a treatment strategy for patients with peripheral vestibular disorders. The tetrapeptide FGLM-NH(2) derived from substance P (SP) can be used to treat corneal disorders when combined with SSSR, which is a tetrapeptide derived from insulin-like growth factor-1 (IGF-1). We examined the influence of FGLM-NH(2) plus SSSR when locally applied to the unilateral inner ear of guinea pigs with vestibular disorder induced by AMPA.

Geranylgeranylacetone suppresses noise-induced expression of proinflammatory cytokines in the cochlea.

Objective: Heat shock transcription factor 1 (HSF1) is a master regulator of heat shock response, and also inhibits expression of inflammatory cytokines directly or indirectly. Here, we examined effects of HSF1 activation on the expression of proinflammatory cytokines in mouse cochlea after exposure to noise.

Methods: Male CBA/N mice with normal Preyer's reflex were exposed to intense noise for 3h.

Clinical characteristics of respiratory syncytial virus infection-associated acute otitis media.

Background: It is known that children with respiratory syncytial virus (RSV) infection frequently have complications of acute otitis media (AOM).

Methods: The hospital records of 148 inpatients aged 6-35 months who had RSV infection between January 2004 and December 2007, were retrospectively investigated.

Results: Forty-six out of 148 children (31%) had AOM.

Unilateral intra-perilymphatic infusion of substance P enhances ipsilateral vestibulo-ocular reflex gains in the sinusoidal rotation test.

Previous studies have reported localization of substance P (SP) within the inner ear and that SP exists abundantly within vestibular endorgans. While SP's functional role in the inner ear remains unclear, SP can act as a neuromodulator in the CNS and directly influences neuronal excitability. We hypothesized that SP might influence neuronal excitability within the vestibular periphery.

Effect of water-soluble coenzyme Q10 on noise-induced hearing loss in guinea pigs.

Conclusion: The results of this study indicate that coenzyme Q10 reduces cochlear oxidative stress induced by acoustic overstimulation.

Objective: We investigated the effects of coenzyme Q10 on noise-induced hearing loss in guinea pigs.

Materials And Methods: Animals received water-soluble coenzyme Q10 intraperitoneally 2 h before noise exposure.

Attenuation of progressive hearing loss in a model of age-related hearing loss by a heat shock protein inducer, geranylgeranylacetone.

Mechanisms of age-related hearing loss (ARHL) have not been elucidated as aging processes are extremely complex. Although oxidative stress and apoptotic cell death are involved in progression of ARHL, number of trial to treat ARHL is limited. Heat shock response is characterized by induction of heat shock proteins (HSPs) in response to stresses such as heat shock, which diminishes during aging.

Edaravone protects the vestibular periphery from free radical-induced toxicity in response to perilymphatic application of (+/-)-alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid.

Intracochlear infusion of (+/-)-alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA) was performed with a syringe pump in guinea pigs, and peripheral vestibular dysfunction was induced. Animals were administered edaravone systemically or topically. In the systemic application group, animals were administered edaravone once a day for 7 days after AMPA infusion.

The systemic application of diazepam facilitates the reacquisition of a well-balanced vestibular function in a unilateral vestibular re-input model with intracochlear tetrodotoxin infusion using an osmotic pump.

Diazepam is a popular medicine used in the treatment of acute vertigo. In the past, many studies investigating the effect of diazepam in peripheral vestibular destruction have been reported. However, no previous study has yet investigated the effect of diazepam on a model with a transient and reversible vestibular function similar to recurrent vertigo as seen in Meniere's disease.

CGRP expression in the vestibular periphery after transient blockage of bilateral vestibular input.

This study aimed to establish an animal model of reversible bilateral vestibular disorders that is suitable for examining the mechanisms of vestibular plasticity, and to observe the changes in the plasticity of vestibular efferent systems. Tetrodotoxin (TTX) was infused continuously for 7 days into the bilateral perilymph of guinea pig cochlea. We assessed the vestibulo-ocular reflex (VOR) for evaluating the vestibular function.

Geranylgeranylacetone, a heat shock protein inducer, prevents acoustic injury in the guinea pig.

Geranylgeranylacetone (GGA) used widely as anti-ulcer agent is accepted as an inducer of the heat shock proteins (Hsps) at gastric mucosa, liver, heart, and brain. However, there have been no reports that GGA could induce Hsps in the cochlea leading up to the oto-protection. The purpose of the present study was to investigate whether single oral dose of GGA could induce Hsps at cochlea and oral administration had protective effect to the cochlea against noise trauma.

Post-exposure administration of edaravone attenuates noise-induced hearing loss.

We investigated the effects of the antioxidant edaravone against acoustic trauma in guinea pigs. Edaravone (1.722 x 10(-2) M) was infused into the right ear by an osmotic pump, and the left ear was untreated for control.

Inhibition of caspases alleviates gentamicin-induced cochlear damage in guinea pigs.

The efficacy of caspase inhibitors for protecting the cochlea was evaluated in an in vivo study using guinea pigs, as the animal model system. Gentamicin (12 mg/ml) was delivered via an osmotic pump into the cochlear perilymphatic space of guinea pigs at 0.5 microl/h for 14 days.

Peripheral vestibular disorder induced by (+/-)-alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA).

An intracochlear infusion of (+/-)-alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA) was done in guinea pigs with a syringe pump and peripheral vestibular disorder was induced. Spontaneous nystagmus toward the intact side reached a peak 9 h after the infusion and disappeared within 18 h. As a control, artificial perilymph was infused and animals had no nystagmus.

Effect of edaravone on streptomycin-induced vestibulotoxicity in the Guinea pig.

Objectives/hypothesis: The effect of topical administration of edaravone to the inner ear was investigated in guinea pigs with streptomycin-induced vestibulotoxicity.

Methods: Vestibulotoxicity was induced in 20 animals by delivery of streptomycin into the inner ear through osmotic pump for 24 hours. Edaravone (n = 8, systemic administration group) or saline (n = 6, control group) was injected intraperitoneally once a day for 7 days or edaravone-soaked Gelfoam was placed on the round window before wound closure (n = 6, topical administration group).

Novel method for homogeneous gene transfer to the inner ear.

Viral vectors are widely used in gene therapy due to their efficiency. In this paper we describe a novel method for transfecting the whole inner ear of a guinea pig using adenoviral vectors. Very small perforations are made in both the cochlea and lateral semicircular canal, into which 50 microl of adenoviral suspension (8.

Cochlear administration of adenosine triphosphate facilitates recovery from acoustic trauma (temporary threshold shift).

Background: Adenosine triphosphate (ATP) has often been used in the treatment of acoustic trauma although evidence supporting its clinical use was lacking. The aim of this study was to evaluate the chronic effects of ATP on acoustic trauma in guinea pigs.

Methods: We infused ATP into the perilymph of the guinea pig cochlea concurrently with intense noise exposure to investigate the effect of ATP on the process of recovery after acoustic trauma.

Inner ear changes with intracochlear gentamicin administration in Guinea pigs.

Objectives/hypothesis: Transtympanic administration of gentamicin is reported to be a useful treatment for vertigo in such conditions as Meniere's disease, and determining appropriate clinical dosage of gentamicin is difficult. The authors examined the relation between gentamicin dosages and inner ear function in guinea pigs.

Study Design: This study is a basic science project designed to examine cochlear and vestibular function in animal models.

The clinical free radical scavenger, edaravone, protects cochlear hair cells from acoustic trauma.

It is known that reactive oxygen species have toxicity to the cochlea. We investigated the effect of edaravone, a free radical scavenger for clinical use, on the cochleae of guinea pigs subjected to acoustic trauma. We assessed auditory brainstem response (ABR) thresholds to evaluate cochlear function and observed the sensory epithelium.

Heat shock transcription factor HSF1 is required for survival of sensory hair cells against acoustic overexposure.

To analyze the role of heat shock response in the cochleae, we induced major heat shock proteins, Hsp70, Hsp90, and Hsp27 by perfusion of hot saline into the middle ear cavity (called 'local heat shock') in guinea pigs. Hsps were induced in almost all of the cochlear cells including the sensory hair cells in the organ of Corti. We showed that loss of both the sensory hair cells and the auditory function induced by acoustic overexposure was inhibited by pretreatment of the inner ear with local heat shock.

Protective effect of edaravone against streptomycin-induced vestibulotoxicity in the guinea pig.

This study investigated alleviation of streptomycin-induced vestibulotoxicity by edaravone in guinea pigs. Edaravone, a free radical scavenger, has potent free radical quenching action and is used in clinical practice to treat cerebral infarction. Streptomycin was administered to the inner ear by osmotic pump for 24 h, and edaravone (n=8) or saline (n=6) was intraperitoneally injected once a day for 7 days.