Electrophysiological monitoring of hearing function during cochlear perilymphatic perfusions.

Conclusion: The cochlear perilymphatic perfusion produces, by itself, significant effects in the cochlear physiology that could be associated with the surgical procedure. These effects need to be well characterized to allow a reliable quantification of the effects of the experimental agent being tested.

Objectives: The study focused on the accurate description of the electrophysiological effects on the cochlear potential recordings of perilymphatic perfusions.

Pharyngo-cutaneous fistula: an old problem revisited.

Conclusion: Pharyngo-cutaneous fistula is the most common complication after total laryngectomy (TL), with many factors linked to its emergence. However, it has rarely been associated with the type of pharyngeal suture. We conclude that the technique of surgical closure of the pharynx and care in the tightness of the suture seem to be fundamental factors for pharyngo-cutaneous fistula development.

The impact of comorbidity on the survival of patients with laryngeal squamous cell carcinoma.

Unlabelled: Abstract Conclusions: In survival analysis, the combined Charlson comorbidity index (CCI) can be considered as a prognostic factor independent of the tumor node metastasis (TNM) classification, tumor stage, and tumor location. Severe comorbidity was the factor that had the greatest impact on prognosis in cases of initial tumor.

Objective: To study the influence of comorbidity on the survival of patients undergoing surgery for larynx cancer.

In vitro long-term development of cultured inner ear stem cells of newborn rat.

The adult mammalian auditory receptor lacks any ability to repair and/or regenerate after injury. However, the late developing cochlea still contains some stem-cell-like elements that might be used to regenerate damaged neurons and/or cells of the organ of Corti. Before their use in any application, stem cell numbers need to be amplified because they are usually rare in late developing and adult tissues.

Cellular and molecular bases of neuroplasticity: brainstem effects after cochlear damage.

After a cochlear lesion or auditory nerve damage, afferent connections from auditory ganglia can be highly altered. This results in a clear reduction of auditory input and an alteration of connectivity of terminals on cochlear nuclei neurons. Such a process could stimulate the reorganization of the neural circuits and neuroplasticity.

Immunocytochemical detection of synaptophysin in C57BL/6 mice cochlea during aging process.

Aged mammals frequently exhibit a bilateral, progressive, and symmetric deafness related to the degeneration of auditory receptor. However, little is still known about aging effects on synapses in this receptor. Synaptophysin (Syp) is a 38 kDa Ca2+ binding glycoprotein widely found in presynaptic membrane and vesicles.

[General indications of middle-ear implants].

Middle ear implants are indicated in bilateral neurosensorial hearing loss in the following situations: bilateral neurosensorial hearing loss with maximal thresholds of air conduction or air conduction within an established range. The differential threshold in frequencies of 500, 1,000, 2,000 and 4,000 Hz should not be above 10 dB in two or more of these frequencies. Minimal speech recognition must be 50% or more.

Cochlear microphonic audiometry: a new hearing test for objective diagnosis of deafness.

Conclusions: Objective audiometric tests could constitute a valuable tool for detection of deafness. This could be especially useful in children (universal newborn hearing screening) and non-collaborative patients, who are especially difficult candidates for classic audiometry. The cochlear microphonic audiometry (CMA) technique offers the possibility of obtaining objective audiometric profiles, highly correlated with those obtained by pure tone audiometry (PTA).

Magnetoencephalography for research of auditory cortex.

Conclusion: The results could indicate that, during phylogeny and human ontogeny, the central nervous system has enhanced the speech activity from any other activity even though other frequencies could be relevant for survival.

Objective: People of all ages can experience alterations of auditory perception that progressively increase with aging. The whole approach to these alterations needs not only peripheral (cochlear) or brainstem studies but also an analysis of the auditory cortex.

Serotonergic innervation of the inner ear: is it involved in the general physiological control of the auditory receptor?

The auditory pathway of mammals is composed of two complementary ascending afferent and descending efferent independent systems. The brainstem nuclei and cochlear projections for these systems are now well-known. In addition, a highly conspicuous distribution for serotonergic fibers was recently reported.

Effect of recombinant human growth hormone administration on body composition and vascular function and structure in old male Wistar rats.

The process of ageing affects negatively both cardiovascular system and body composition. On the other hand, the hormones of the somatotrophic axis, growth hormone (GH) and insulin-like growth factor-I (IGF-I), whose production is reduced by age, are involved in the regulation of the cardiovascular system. The aim of this study was to investigate the effect of GH on body composition, vascular function and structure in old male rats.

Biochemical evidence for the presence of serotonin transporters in the rat cochlea.

Cochlear serotonergic innervation is constituted by efferent fibers projecting both to the area below the inner and the outer hair cells. Previous detection of serotonin (5-HT) metabolites and 5-HT receptor mRNAs suggests the existence of serotonergic synaptic activity in the cochlea. The present study explores this possibility through the effect of 6-nitroquipazine (6-NQ), a 5-HT selective reuptake inhibitor, on the basal turnover of 5-HT.

[Deafness and aging: studies in experimental models].

Since 1970 a progressive aging of the world population, mainly in the most developed countries, has been observed. Spain could have, around 2050, the most aged human population of the world. Therefore, scientist show an increasing interest on the study of the aging-related pathologies (i.

Simultaneous HPLC quantification of monoamines and metabolites in the blood-free rat cochlea.

Monoamine quantification in peripheral sensory receptors, such as the cochlea, is of major interest since monoamines could play a role in neurotransmission. A three-step biochemical protocol was developed to analyze monoamine content within the cochlea. Removal of the blood by aortic perfusion was carried out with an anticoagulant solution prior to the dissection of the cochlea from the temporal bone.

Effects of aging on cochlear monoamine turnover.

The aging of the cochlear dopaminergic system has been analyzed by quantifying the levels of dopamine (DA) and its metabolites (3,4-dihydroxyphenylacetic acid, DOPAC, and homovanillic acid, HVA) in adult rats aged 3, 12 or 24 months. The main results were an increase in DA, DOPAC and HVA basal concentrations in aged females with respect to the adults (3 or 12 months old), while just DA and DOPAC increased in aged males. A higher synthesis of DA in aged animals could support these findings, which could indicate some kind of compensatory mechanism related to presbycusis.

Effects of aging on C57BL/6J mice: an electrophysiological and morphological study.

Presbycusis is a progressive hearing loss associated with aging that manifests as deafness linked to cochlear morphological degeneration. The effects of aging on the auditory system were studied in C57BL/6J mice using electrophysiological (brainstem auditory evoked potentials; BAEP) and morphological techniques. Cochleae of animals aged 1, 6, 9, 12, 15, 18, 21, or 24 months old were used for that purpose.

Age- and gender-related changes in the cochlear sympathetic system of the rat.

The sympathetic innervation projecting to the cochlea plays an important role in the auditory function, there is, however, no information about whether it is altered with advancing age. High performance liquid chromatography coupled to electrochemical detection was used to quantify both basal and noise-induced concentrations of norepinephrine (NE) in the rat cochlea. The cochlear concentration of NE was found to be independent of age in adult (3-12 months old) and aged (19 and 24 months old) males and the adult females.