This study was designed to assess the role of adrenergic receptors in the control of cochlear blood flow. Laser Doppler flowmetry was used to determine the effects of adrenergic drugs topically applied to the round window membrane of the cochlea. The relative influence of the various receptor types (alpha 1, alpha 2, beta 1, and beta 2) was examined by a selection of agonists and antagonists. T...

Introduction: Multidrug-resistant tuberculosis is a significant public health problem for which drugs are used with many adverse effects. Among the devastating consequences of these diseases, there wide variation in incidence ototoxicity and hearing loss patients multidrug-resistant extremely resistant tuberculosis. Cochlear implants may be indicated unilateral/severe bilateral no benefit from ...

INTRODUCTION Cochlear implantation can facilitate the development of communication skills in children with profound hearing loss. The objectives of our study were to determine the average ages at suspicion and diagnosis of hearing loss, amplification, intervention, and performing the cochlear implantation and to investigate the effects of the parents' level of education and economic circumstanc...

Aging listeners experience greater difficulty understanding speech in adverse listening conditions and exhibit degraded temporal resolution, even when audiometric thresholds are normal. When threshold evidence for peripheral involvement is lacking, central and cognitive factors are often cited as underlying performance declines. However, previous work has uncovered widespread loss of cochlear a...

BACKGROUND Exposure to intense sound or high doses of aminoglycoside antibiotics can increase hearing thresholds, induce cochlear dysfunction, disrupt hair cell morphology and promote hair cell death, leading to permanent hearing loss. When the two insults are combined, synergistic ototoxicity occurs, exacerbating cochlear vulnerability to sound exposure. The underlying mechanism of this synerg...

BACKGROUND Ceramide-1-phosphate (C1P) is a phosphorylated form of ceramide. While ceramide is known to be an inducer of apoptosis of cochlear hair cells in cisplatin ototoxicity, little is known about the function of C1P in cochlear diseases. PURPOSE The present study was designed to examine whether C1P could protect cochlear hair cells against cisplatin ototoxicity. MATERIALS AND METHODS E...

To identify candidate genes for human hearing disorders and to understand better human hearing at the molecular level, we constructed a human cochlear cDNA library. An aliquot of the unsubtracted cochlear library was contributed to the IMAGE Consortium at Lawrence Livermore National Laboratory for the generation of expressed sequence tags (ESTs) by the Merck/WashU EST project. Over 4000 ESTs we...

While many studies have been devoted to investigating the homeostatic plasticity triggered by cochlear hearing loss, the cellular and molecular mechanisms involved in these central changes remain elusive. In the present study, we investigated the possibility of reactive neurogenesis after unilateral cochlear nerve section in the cochlear nucleus (CN) of cats. We found a strong cell proliferatio...

Objective: Cochlear nerve size is a prognostic factor for successful cochlear implantation. Reports about the cochlear nerve size in normal-hearing patients and differences among societies in the cochlear nerve size are not satisfactory. The purpose of this study was to determine the average cochlear nerve size in normal-hearing adults and to investigate whether there is a difference among soci...

BACKGROUND A reduction in cochlear blood flow plays an essential role in noise-induced hearing loss (NIHL). The timely regulation of cochlear perfusion determines the progression and prognosis of NIHL. Hydrogen sulfide (H(2)S) has attracted increasing interest as a vasodilator in cardiovascular systems. This study identified the role of H(2)S in cochlear blood flow regulation and noise protecti...