Characterization of Ethyl Butyrate-Induced Cough Before and After Breath Control Techniques in Healthy Adults.

Purpose: Methods for cough elicitation frequently involve aerosolized tussive agents. Here, we sought to determine whether healthy individuals demonstrate a quantifiable cough response after inhaling a volatile ester and if breath control techniques modify this chemically induced cough response.

Method: Sixty adult male and female participants inhaled prepared liquid dilutions of ethyl butyrate dissolved in paraffin oil at 20%, 40%, and 60% v/v concentrations in triplicate, with presentation order randomized.

Voice Handicap Index Changes After Microflap Surgery for Benign Vocal Fold Lesions Are Not Associated With Recommended Absolute Voice Rest Duration.

Purpose: Voice rest is frequently prescribed after phonosurgery, but optimal type and duration for voice outcomes have not been demonstrated. Studies to date have been characterized by heterogeneity in surgical procedures and laryngeal diagnoses. We sought to analyze the effect of recommended absolute voice rest duration on outcomes of microflap surgery for benign vocal fold lesions.

Examining the Influence of Chemosensation on Laryngeal Health and Disorders.

Inhaled airborne stimuli are associated with laryngeal disorders affecting respiration. Clinically, several themes emerged from the literature that point to specific gaps in the understanding and management of these disorders. There is wide variation in the types of airborne stimuli that trigger symptoms, lack of standardization in provocation challenge testing using airborne stimuli, and vague reporting of laryngeal symptoms.

Lack of respiratory and ocular effects following acute propylene glycol exposure in healthy humans.

Objective: Propylene glycol (PG) is a widely used solvent, chemical intermediate and carrier substance for foods, pharmaceutical and cosmetic products. Professional and occupational exposure to PG aerosol and vapor may occur from theatrical smoke generators and during application of deicing products to airplanes. While PG is considered to have low toxicity, the results of one study suggested that brief (1-min) exposure to PG mist elicited ocular and respiratory effects in humans.

Recovery of Vocal Fold Epithelium after Acute Phonotrauma.

We investigated the timeline of tissue repair of vocal fold epithelium after acute vibration exposure using an in vivo rabbit model. Sixty-five New Zealand white breeder rabbits were randomized to 120 min of modal- or raised-intensity phonation. After the larynges were harvested at 0, 4, 8, and 24 h, and at 3 and 7 days, the vocal fold tissue was evaluated using electron microscopy and quantitative real-time polymerase chain reaction.

Apoptosis and Vocal Fold Disease: Clinically Relevant Implications of Epithelial Cell Death.

Purpose: Vocal fold diseases affecting the epithelium have a detrimental impact on vocal function. This review article provides an overview of apoptosis, the most commonly studied type of programmed cell death. Because apoptosis can damage epithelial cells, this article examines the implications of apoptosis on diseases affecting the vocal fold cover.

Acute exposure to vibration is an apoptosis-inducing stimulus in the vocal fold epithelium.

Clinical voice disorders pose significant communication-related challenges to patients. The purpose of this study was to quantify the rate of apoptosis and tumor necrosis factor-alpha (TNF-α) signaling in vocal fold epithelial cells in response to increasing time-doses and cycle-doses of vibration. 20 New Zealand white breeder rabbits were randomized to three groups of time-doses of vibration exposure (30, 60, 120min) or a control group (120min of vocal fold adduction and abduction).

Evaluation of Dying Vocal Fold Epithelial Cells by Ultrastructural Features and TUNEL Method.

Cell death is a regulated mechanism of eliminating cells to maintain tissue homeostasis. This study described 2 methodological procedures for evaluating cell death in the epithelium of immobilized, approximated and vibrated vocal folds from 12 New Zealand white breeder rabbits. The gold standard technique of transmission electron microscopy evaluated high-quality ultrastructural criteria of cell death and a common immunohistochemical marker, the terminal deoxynucleotidyl transferase dUTP nick end labeling method, to confirm cell death signaling.

Nonstimulated rabbit phonation model: Cricothyroid approximation.

Objectives/hypothesis: To describe a nonstimulated in vivo rabbit phonation model using an Isshiki type IV thyroplasty and uninterrupted humidified glottal airflow to produce sustained audible phonation.

Study Design: Prospective animal study.

Methods: Six New Zealand white breeder rabbits underwent a surgical procedure involving an Isshiki type IV thyroplasty and continuous airflow delivered to the glottis.

Subject-Specific Computational Modeling of Evoked Rabbit Phonation.

When developing high-fidelity computational model of vocal fold vibration for voice production of individuals, one would run into typical issues of unknown model parameters and model validation of individual-specific characteristics of phonation. In the current study, the evoked rabbit phonation is adopted to explore some of these issues. In particular, the mechanical properties of the rabbit's vocal fold tissue are unknown for individual subjects.

Randomized controlled trial of supplemental augmentative and alternative communication versus voice rest alone after phonomicrosurgery.

Objective: This randomized trial investigated voice rest and supplemental text-to-speech communication versus voice rest alone on visual analog scale measures of communication effectiveness and magnitude of voice use.

Study Design: Randomized clinical trial.

Setting: Multicenter outpatient voice clinics.

Effects of phonation time and magnitude dose on vocal fold epithelial genes, barrier integrity, and function.

Objectives/hypothesis: To investigate the effects of increasing time and magnitude doses of vibration exposure on transcription of the vocal fold's junctional proteins, structural alterations, and functional tissue outcomes.

Study Design: Animal study.

Methods: 100 New Zealand White breeder rabbits were studied.

Nonlinear analyses of elicited modal, raised, and pressed rabbit phonation.

Objectives/hypothesis: The purpose of this study was to use nonlinear dynamic analysis methods such as phase space portraits and correlation dimension (D2) as well as descriptive spectrographic analyses to characterize acoustic signals produced during evoked rabbit phonation.

Methods: Seventeen New Zealand white breeder rabbits were used to perform the study. A Grass S-88 stimulator (SA Instrumentation, Encinitas, CA) and constant current isolation unit (Grass Telefactor, model PSIU6; West Warwick, RI) were used to provide electrical stimulation to laryngeal musculature, and transglottal airflow rate and stimulation current (mA) were manipulated to elicit modal, raised intensity, and pressed phonations.

Quantification of acute vocal fold epithelial surface damage with increasing time and magnitude doses of vibration exposure.

Because the vocal folds undergo repeated trauma during continuous cycles of vibration, the epithelium is routinely susceptible to damage during phonation. Excessive and prolonged vibration exposure is considered a significant predisposing factor in the development of vocal fold pathology. The purpose of the present study was to quantify the extent of epithelial surface damage following increased time and magnitude doses of vibration exposure using an in vivo rabbit phonation model.

Test-retest reliability for aerodynamic measures of voice.

Objectives/hypothesis: The purpose of this study was to investigate the intrasubject reliability of aerodynamic characteristics of the voice within typical/normal speakers across testing sessions using the Phonatory Aerodynamic System (PAS 6600; KayPENTAX, Montvale, NJ).

Methods: Participants were 60 healthy young adults (30 males and 30 females) between the ages 18 and 31 years with perceptually typical voice. Participants were tested using the PAS 6600 (Phonatory Aerodynamic System) on two separate days with approximately 1 week between each session at approximately the same time of day.