Erin E. Devine

Bioengineered vocal fold mucosa for voice restoration

Primary human vocal fold mucosal cells recapitulate native physiologic function, offering voice restoration to patients with advanced laryngeal disease. Getting vocal about tissue engineering The power of the voice cannot be disputed. For instance, Adele’s lyrics would not elicit chills (or tears) without strategic pitch and harmonizing known as appoggiatura; the chant “Yes we can” garnered more than 69 million popular votes to win Obama the 2008 presidential election; and, more simply, voice is the primary means we all use to communicate with co-workers, loved ones, and the rest of society. Dysphonia—or difficulty speaking from vocal fold tissue damage or loss—can impair one’s ability to be an effective communicator. To provide a new option for those with dysphonia, Ling et al. used two different types of human vocal fold cells to create a functional mucosa. When grafted into the dog larynx ex vivo, the engineered vocal fold reproduced natural physiology, including the vibrations necessary to transmit sound. In vivo, in humanized mice, the engineered mucosa was tolerated by functional human immune cells. These data suggest feasibility for transplant and survival in the larynx as well as for function, ultimately giving patients back their voices. Patients with voice impairment caused by advanced vocal fold (VF) fibrosis or tissue loss have few treatment options. A transplantable, bioengineered VF mucosa would address the individual and societal costs of voice-related communication loss. Such a tissue must be biomechanically capable of aerodynamic-to-acoustic energy transfer and high-frequency vibration and physiologically capable of maintaining a barrier against the airway lumen. We isolated primary human VF fibroblasts and epithelial cells and cocultured them under organotypic conditions. The resulting engineered mucosae showed morphologic features of native tissue, proteome-level evidence of mucosal morphogenesis and emerging extracellular matrix complexity, and rudimentary barrier function in vitro. When grafted into canine larynges ex vivo, the mucosae generated vibratory behavior and acoustic output that were indistinguishable from those of native VF tissue. When grafted into humanized mice in vivo, the mucosae survived and were well tolerated by the human adaptive immune system. This tissue engineering approach has the potential to restore voice function in patients with otherwise untreatable VF mucosal disease.

A clinical study of serum lipid disturbance in Chinese patients with sudden deafness

BackgroundPathological levels of blood lipids could be one of the causes of sudden sensorineural hearing loss (SSNHL). The objective of this manuscript is therefore to evaluate the relationship between blood lipid content and sudden sensorineural hearing loss (SSNHL).MethodsThe correlation between serum lipid parameters, including total cholesterol (TC), triglycerides, high-density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), apolipoprotein AI (apo AI), apolipoprotein B (apo B), and lipoprotein A (Lp(a)), and the onset of SSNHL was analyzed from a data set of 250 patients and an age, gender and weight matched control group of 250 subjects.ResultsThe result of single factor logistic regression shows that TC (p<0.01), LDL-C (p<0.01), and apo B (p=0.03) of SSNHL group were significantly higher than those of the control group. The odds ratio of TC, LDL, and apo B are higher than 1, while the confidence intervals of the odds rations do not include 1. No significant difference was found with the prevalence of hypertension (P=0.818), diabetes (P=0.869) and smoking habits (P=0.653) between SSNHL group and control group.ConclusionTotal cholesterol, low density lipoprotein cholesterol and apolipoprotein B concentrations may be important factors in the pathogenesis of sudden sensorineural hearing loss, and should be assessed during the investigation of patients with this condition.

Ultrastructural and in vivo confocal microscopic evaluation of interface after Descemet's Stripping Endothelial Keratoplasty in rabbits.

Purpose:  To study healing at the donor–recipient interface after Descemet’s Stripping Endothelial Keratoplasty (DSEK) in rabbits by ultrastructural and in vivo confocal microscopic evaluation.

Devices and Methods on Analysis of Biomechanical Properties of Laryngeal Tissue and Substitute Materials

For understanding the phonatory process in human voice production, physical as well as numerical models have been suggested. Material properties within these models are crucial for achieving vocal fold dynamics being close to in vivo human laryngeal dynamics. Hence, different approaches have been suggested to gain insight into human laryngeal tissue, evaluate clinical treatment, as well as to analyze and verify parameters within synthetically built vocal folds. Purpose of Review: The authors want to give an overview of approaches on receiving material parameters being important in voice research. For the different devices and methods being applied for different set-ups, we will present the functionality and applicability. Hence, for future work, this review shall give an indication, what kind of measurement techniques are suitable for the intended study, advantages or disadvantages of the approaches, and what parameters can be

The Potential Role of Subglottal Convergence Angle and Measurement

OBJECTIVE This study aimed to explore subglottal convergence angle measurement. We hypothesize that the angle will change with glottis closure condition. Changes to the angle may alter vocal fold stress distribution, which could result in vocal fold pathologies. METHODS Three vocal fold positions were evaluated by the degree of glottal closure and divided into three groups. Neck computed tomographic images of the subjects were gathered, and three-dimensional (3D) models of the vocal folds and the airway were reconstructed using Mimics software, through which the subglottal convergence angle was measured. Using one-way factor analysis of variance, we compared the angle among three groups. We explored the effect of the angle on vibration based on the material oblique section stress analysis. RESULTS The subglottal convergence angle was effectively measured from 3D models. The angle changed with degree of glottal closure, with statistically significant differences among the three groups (P < 0.01). Changes to the angle alter subglottal stress distribution in the subglottal shear or normal direction by the material oblique section stress analysis theory. Larger subglottal convergence angle might reduce subglottal pressure in the shear direction below the vocal folds, which would make vibration and vocal fold mucosal wave generation more difficult. CONCLUSION 3D model generation from computed tomographic data is an effective method of measuring the subglottal convergence angle, which changes with the degree of glottis closure, and may affect subglottal pressure distribution in the subglottal shear or normal direction and influence vocal fold vibration.

Evaluation of auditory and visual feedback for airflow interruption.

INTRODUCTION Clinical application of mechanical interruption methods for measuring aerodynamic parameters has been hindered by relatively high intrasubject variability. To improve the intrasubject reliability, we evaluated the effect of auditory and visual feedback on subject performance when measuring aerodynamic parameters with the airflow interrupter. METHODS Eleven subjects performed four sets of 10 trials with the airflow interrupter: no feedback (control); auditory feedback (tone matching subjects F0 played over headphones); visual feedback (real-time feedback of sound pressure level, frequency, and airflow); and combined auditory and visual feedback. Task order was varied across subjects. The effect of each feedback method on mean and coefficient of variation (CV) of subglottal pressure (Ps), mean flow rate (MFR), and laryngeal airway resistance (RL; Ps/MFR) compared with that of the control trials was determined using paired t tests. Feedback methods were compared against each other using one-way repeated measures analysis of variance. RESULTS Each feedback method significantly decreased CV of RL compared with that of the control trials (auditory feedback: P=0.005; visual feedback: P=0.008; and combined feedback: P<0.001). Auditory feedback (P=0.011) and combined feedback (P=0.026) also decreased CV of MFR. Mean MFR was significantly higher during trials with visual feedback compared with that of the auditory feedback. CONCLUSIONS Each feedback method improved the intrasubject consistency when measuring RL. Feedback appeared to have a greater effect on MFR than Ps. Although there is no clear optimal feedback method, each is preferable to not providing any feedback during trials. Evaluating new methods of visual feedback to further improve MFR and thus RL measurement would be valuable.

Classification of Glottic Insufficiency and Tension Asymmetry Using a Multilayer Perceptron

Laryngeal function can be evaluated from multiple perspectives, including aerodynamic input, acoustic output, and mucosal wave vibratory characteristics. To determine the classifying power of each of these, we used a multilayer perceptron artificial neural network (ANN) to classify data as normal, glottic insufficiency, or tension asymmetry.

An Excised Canine Model of Anterior Glottic Web and Its Acoustic, Aerodynamic, and High-speed Measurements.

OBJECTIVES This study aims to build an excised anterior glottic web (AGW) model and study the basic voice-related mechanisms of the AGW through investigating the acoustic, aerodynamic, and vibratory properties. STUDY DESIGN AND METHODS Overall, four conditions were tested for each of the eight canine larynges used. At baseline, 10%, 20%, and 33% occlusion (as determined by the placement of the suture), acoustic, aerodynamic, and high-speed video data were collected while each larynx was phonated in a soundproof booth. RESULTS The phonation threshold pressure (PTP) and the phonation threshold flow significantly increased as percent occlusion increased (P < 0.001). There were significant increases in jitter % and shimmer % from baseline group to AGW model groups at PTP, 1.25 PTP, and 1.5 PTP (P = 0.039, P < 0.001, P < 0.001, P < 0.001, P < 0.001, and P = 0.001, respectively). The fundamental frequency significantly increased as percent occlusion increased at all given pressures (P < 0.001). Correlation dimension (D2) was significantly higher in the AGW model groups than in the baseline group at PTP, 1.25 PTP, and 1.5 PTP (P = 0.002, P < 0.001, P = 0.01, respectively). High-speed videos revealed that, the left phase shift in the AGW model groups compared with the baseline at 1.25 PTP was significant (P = 0.027) and right phase shift at 1.5 PTP (P < 0.001). CONCLUSIONS We presented an anatomically similar model of a type 1 AGW and confirmed its validity through aerodynamic, acoustic, and high-speed video analysis in our study. We observed and investigated the glottic web movement, which may be a new explanation for the pathologic voice-related mechanism of AGW.

Permeability of canine vocal fold lamina propria

Determine the permeability of excised canine vocal fold lamina propria.

Excised larynx evaluation of wedge-shaped adjustable balloon implant for minimally invasive type I thyroplasty

To describe the method of inserting a wedge‐shaped adjustable balloon implant (wABI) via a minithyrotomy for medialization thyroplasty and evaluate its effect on a range of phonatory parameters using the excised larynx bench apparatus.