Essential oils components as a new path to understand ion channel molecular pharmacology.

The discovery and development of new drugs targeting voltage-gated ion channels are important for treating a variety of medical conditions and diseases. Ion channels are molecular nanostructures expressed ubiquitously throughout the whole body, and are involved in many basic physiological processes. Over the years, natural products have proven useful in the pharmacological assessment of ion channel structure and function, while also contributing to the identification of lead molecules for drug development. Essential oils are complex chemical mixtures isolated from plants which may possess a large spectrum of biological activities most of them of clinical interest. Among their bioactive constituents, terpenes are small to medium-sized components and belong to different chemical groups. Various reports have drawn our attention to the fact that terpenes are novel compounds targeting voltage-gated ion channels. The purpose of this review is to provide a focused discussion on the molecular interaction between monoterpenes and phenylpropenes with voltage-gated ion channels in different biological scenarios.

Resurgent Na+ current: a new avenue to neuronal excitability control.

Integrative and firing properties are important characteristics of neuronal circuits and these responses are determined in large part by the repertoire of ion channels they express, which can vary considerably between cell types. Recently, a new mode of operation of voltage dependent sodium channels has been described that generates a so-called resurgent Na+ current. Accumulating evidence suggests resurgent Na current participates in the generation of sub-threshold inward Na+ current causing membrane depolarization which provides the necessary drive to fire high-frequency action potentials. Recent studies indicate that resurgent Na+ current could be a more widespread feature than previously thought.

Triagem auditiva escolar no município de Porto Alegre: resultados do estudo piloto / School hearing screening in the city of Porto Alegre: results of the pilot study

OBJETIVO: descrever os resultados do estudo piloto realizado para orientar o processo de implementação da triagem auditiva escolar, no Município de Porto Alegre. MÉTODOS: foram aplicados 134 protocolos em crianças de seis a oito anos de idade de uma Escola Municipal de Ensino Fundamental de Porto Alegre. Os resultados apresentados no protocolo de triagem eram: medida do Nível de Pressão Sonora no ambiente, durante a realização da triagem audiométrica; resposta à triagem audiométrica em 20 dB nas frequências de 1000Hz, 2000Hz e 4000Hz, em ambas as orelhas; Medidas de Imitância Acústica: curva timpanométrica e reflexos acústicos ipsilaterais nas frequências de 500Hz, 1000Hz, 2000Hz e 4000Hz, em 100 dB nas duas orelhas, utilizando o critério passa-falha. RESULTADOS: em relação ao sexo, 50,75% eram meninos. A idade média foi 6,86 anos (± 0.46). Na triagem audiométrica a grande maioria das crianças passou e a curva timpanométrica mais encontrada foi a Tipo A (51,7%), seguida da Tipo C (24,1%) na orelha direita, e na orelha esquerda 55,7% eram Tipo A e 21,6% Tipo C. O ruído ambiental manteve-se abaixo de 50 dBNA em 90,5%. CONCLUSÃO: a maioria das crianças que falharam na TAE tinha seis anos de idade. A curva timpanométrica mais prevalente foi do Tipo A, seguida do Tipo C. Não se observou diferenças estatisticamente significantes ao comparar as orelhas testadas e os sexos. .

PURPOSE: to describe the results of the pilot study carried out to guide the implementation process of the hearing screening in schools in the City of Porto Alegre. METHODS: 134 protocols were applied to children between the ages of six and eight, from a Municipal Elementary School in Porto Alegre. The results presented in the screening protocol were: the measurement of the Sound Pressure Level in the environment during the audiometric screening; response to audiometric screening at 20 dB with frequencies of 1000Hz, 2000Hz and 4000Hz in both ears; Acoustic Immittance Measures: tympanometric curve and ipsilateral acoustic reflexes at the frequencies of 500Hz, 1000Hz, 2000Hz and 4000Hz, at 100 dB in both ears, using the pass-fail criterion. RESULTS: in relation to sex, 50.75% were boys. The average age was 6.86 (±0.46). Most children passed the audiometric screening and the most frequent tympanometric curve was Type A (51.7 %), followed by Type C (24.1 %) in the right ear. In the left ear, 55.7% were Type A and 21.6%, Type C. The environmental noise remained below 50dBSPL in 90.5%. CONCLUSION: the majority of children who failed the audiometric screening were six years old. The most prevalent tympanometric curve was Type A, followed by Type C. No statistically significant differences were observed when genders and tested ears were compared. .