Concentration of hyaluronic acid in human vocal folds in young and old subjects

Effect of Nebulization on Laryngeal Parameters: Analysis Using High-Speed Digital Videolaryngoscopy

INTRODUCTION

Superficial laryngeal hydration, obtained through nebulization, is related to the moisture level on the epithelial surfaces of the vocal folds, modifying their biomechanical and aerodynamic properties. Through high-speed videolaryngoscopy it is possible to obtain objective data for laryngeal analysis after nebulization and a better understanding of this phenomenon OBJECTIVE: To verify the effects of nebulization with saline solution on laryngeal parameters of digital videokymography obtained by high-speed videolaryngoscopy examination in women and men with and without laryngeal alterations METHOD: This is a clinical, comparative intra-subject study. Fifty-nine adults were selected, with and without laryngeal alterations, 30 females and 29 males. Digital videokymographs in the anterior, middle and posterior thirds of the vocal folds of the participants were analyzed before and after nebulization with 0.9% saline solution.

RESULTS

Women without laryngeal alterations showed more parameters changes after nebulization, in which there was a decrease in maximum and medium opening, amplitude of opening of the left and right vocal fold in the anterior glottal third, and an increase of the percentage of closure of the vocal folds. These results indicate a minor extent of lateral excursion of the vocal folds during phonation. In women with laryngeal alterations, the parameters that changed after nebulization were the increased frequency of opening of the left and right vocal folds in the topography of the posterior third. In men, nebulization did not change the variables studied, except for the amplitude of the right vocal fold in men with laryngeal alterations, in the analysis of the posterior glottic third.

CONCLUSION

The results suggest that surface hydration modifies laryngeal dynamics differently between genders. After nebulization with saline solution, women without laryngeal alterations showed a decrease in the lateralization of the vocal folds during phonation, suggesting a better phonatory efficiency.

Visual-perceptive assessment of glottic characteristics of vocal nodules by means of high-speed videoendoscopy

OBJECTIVE

Visual-perceptive assessment of glottic characteristics of vocal nodules by means of high-speed videoendoscopy.

METHODS

Descriptive observational research with convenience sampling of five laryngeal videos of women with an average age of 25 years. The diagnosis of vocal nodules was defined by two otolaryngologists, with 100% intra-rater agreement and 53.40% inter-rater agreement and five otolaryngologists as judge assessed the laryngeal videos based on an adapted protocol. The statistical analysis calculated measures of central tendency and dispersion, as well as percentage. The AC1 coefficient was used for agreement analysis.

RESULTS

In high-speed videoendoscopy imaging, vocal nodules are characterized by amplitude of the mucosal wave and muco-undulatory movement with magnitude between 50% and 60%. Non-vibrating segments of vocal folds are scarce, and the glottal cycle does not show a predominant phase, it is symmetric and periodic. Glottal closure is characterized by the presence of a mid-posterior triangular chink (double chink or isolated mid-posterior triangular chink), without movement of supraglottic laryngeal structures, with irregular contour of the free edge of vocal folds, which are vertically on-plane.

CONCLUSION

Vocal nodules present mid-posterior triangular chink and irregular free edge contour. Amplitude and mucosal wave were partially reduced.

LEVEL OF EVIDENCE

Level 4 (Case-series).

Hyaluronic Acid Concentration in Female Vocal Folds With Reinke's Edema

OBJECTIVE

The aim of the present study was to investigate hyaluronic acid (HA) concentrations in vocal folds among patients with Reinke's edema.

STUDY DESIGN

Prospective and experimental study.

SETTING

Single tertiary center.

METHODS

An HA binding protein isolated from bovine nasal cartilage was used to identify and isolate the HA from samples. Plates coated with biotin-conjugated binding protein and streptavidin-europium conjugate were sequentially incubated with 18 Reinke's edema samples and 11 female vocal fold cover samples from cadavers (the superficial layer of the lamina propria; control group). After the release of europium from streptavidin in enhancement solution, final fluorescence was measured in a fluorometer.

RESULTS

The mean HA concentration in Reinke's edema vocal folds was significantly higher than that in the control vocal folds (9.2 × 10³ vs 0.9 × 10³µg/g).

CONCLUSION

Vocal fold covers affected by Reinke's edema present a higher concentration of HA than do vocal fold covers with no edema.

Application of hyaluronic acid/carboxymethyl cellulose membrane for early continence after nerve-sparing robot-assisted radical prostatectomy

Background

To assess whether application of a hyaluronic acid-carboxymethyl cellulose membrane (HA/CMC) to the prostate bed and neurovascular plate facilitated early return of continence after nerve-sparing robot-assisted radical prostatectomy (RARP).

Methods

The subjects were 183 consecutive patients with organ-confined prostate cancer who underwent unilateral or bilateral nerve-sparing RARP. After vesicourethral anastomosis, HA/CMC was placed to cover Denonvilliers’ fascia (behind the anastomotic suture) and the preserved neurovascular plate. The time until complete continence after RARP and perioperative complications were compared between patients with or without HA/CMC.

Results

HA/CMC was applied in 13/46 patients (28.3%) receiving bilateral nerve-sparing surgery and 40/137 patients (29.2%) receiving unilateral nerve-sparing surgery. After bilateral nerve-sparing RARP, the median time until continence was significantly shorter in patients with HA/CMC than in those without HA/CMC (3.2 vs. 9.3 months, respectively, p < 0.01). After unilateral nerve-sparing RARP, the median time until continence was also significantly shorter in patients with HA/CMC than in those without HA/CMC (3.2 vs. 12.0 months, respectively, p < 0.01). Multivariate Cox proportional hazards regression analysis showed that an age < 70 years (hazard ratio [HR]: 1.74, 95% confidence interval [CI]: 1.12–2.80), institutional caseload > 200, (HR: 1.64, 95%CI: 1.10–2.47), and use of HA/CMC (HR: 1.84, 95%CI: 1.22–2.76) were independent predictors of early postoperative continence. Complication rates, including urinary leakage, did not differ significantly between patients with or without HA/CMC.

Conclusion

Application of HA/CMC to the prostate bed and neurovascular plate resulted in significantly faster postoperative return of continence after both unilateral and bilateral nerve-sparing RARP.

Sulfated glycosaminoglycans in human vocal fold lamina propria

Introduction

The distribution, concentration and function of glycosaminoglycans in the various vocal fold tissues are still unclear.

Objective

To evaluate the distribution and concentration of sulfated glycosaminoglycans in different layers of the human vocal fold according to gender and age.

Methods

We used 11 vocal folds obtained from cadavers (7 men and 4 women) with no laryngeal lesion, less than 12 h after death, and aged between 35 and 98 years. The folds underwent glycosaminoglycans extraction from the cover and ligament, and post-electrophoresis analysis. Data were compared according to the layer, age and gender.

Results

The concentration of dermatan sulfate was significantly higher in all layers. No differences were observed in the total concentrations of glycosaminoglycans in layers studied according to gender. It is significantly lower in the cover of individuals aged below 60 years.

Conclusion

Dermatan sulfate, chondroitin sulfate, and heparan sulfate were observed in the human vocal folds cover and ligament of both genders, with the concentration of dermatan sulfate being significantly higher in all layers. Glycosaminoglycans concentration on the cover is significantly lower in individuals below 60 years compared with elderly.

The urethral rhabdosphincter, levator ani muscle, and perineal membrane: a review

Detailed knowledge of the anatomy of the rhabdosphincter and adjacent tissues is mandatory during urologic surgery to ensure reliable oncologic and functional outcomes. To characterize the levator ani (LA) function for the urethral sphincter, we described connective tissue morphology between the LA and urethral rhabdosphincter. The interface tissue between the LA and rhabdosphincter area in males contained abundant irregularly arrayed elastic fibers and smooth muscles. The male rhabdosphincter was positioned alongside the LA to divide the elevation force and not in-series along the axis of LA contraction. The male perineal membrane was thin but solid and extends along the inferior margin or bottom of the rhabdosphincter area. In contrast, the female rhabdosphincter, including the compressor urethrae and urethrovaginal sphincter muscles, was embedded in the elastic fiber mesh that is continuous with the thick, multilaminar perineal membrane. The inferomedial edge of the female LA was attached to the upper surface of the perineal membrane and not directly attached to the rhabdosphincter. We presented new diagrams showing the gender differences in topographical anatomy of the LA and rhabdosphincter.

Coexistence of elastic fibers with hyaluronic acid in the human urethral sphincter complex: a histological study

PURPOSE

To promote the prevention and treatment of urethral sphincteric dysfunction, we examined the distribution of elastic fibers around the urethral sphincter complex and the histological localization of hyaluronic acid in relation to elastic fiber architecture.

MATERIALS AND METHODS

Using elastica-Masson staining as well as biotinated hyaluronic acid binding protein, we examined specimens of the urethral sphincter complex obtained from 14 elderly Japanese cadavers, including 10 men and 4 women. As a control, we also observed other striated muscles in male cadavers.

RESULTS

Elastic fibers were densely distributed throughout the submucosal and smooth muscle layers along the entire length of the male urethra, including the prostatic urethra. The levator ani fascia and rhabdosphincter also contained abundant elastic fibers. An intramuscular elastic net was seen in the rhabdosphincter but not in other striated muscles. Strong staining for hyaluronic acid was evident in the submucosa and smooth muscle sphincter of the urethra but not in the levator ani fascia or rhabdosphincter, suggesting that elastic fibers and hyaluronic acid might interact at the former sites. Gender related differences in the distribution of elastic fibers and hyaluronic acid were noted with a much lower density of elastic fibers and hyaluronic acid staining in women than in men.

CONCLUSIONS

Urethral sites where elastic fibers and hyaluronic acid coexist could be targeted for the prevention and treatment of urethral sphincteric insufficiency. These findings should improve our understanding of the human urethral sphincter complex.

Elastic fiber-mediated enthesis in the human middle ear

Adaptation to constant vibration (acoustic oscillation) is likely to confer a specific morphology at the bone-tendon and bone-ligament interfaces at the ear ossicles, which therefore represent an exciting target of enthesis research. We histologically examined (i) the bone attachments of the tensor tympani and stapedius muscles and (ii) the annular ligament of the incudostapedial joint obtained from seven elderly donated cadavers. Notably, both aldehyde-fuchsin and elastic-Masson staining demonstrated that the major fibrous component of the entheses was not collagen fibers but mature elastic fibers. The positive controls for elastic fiber staining were the arterial wall elastic laminae included in the temporal bone materials. The elastic fibers were inserted deeply into the type II collagen-poor fibrocartilage covering the ear ossicles. The muscle tendons were composed of an outer thin layer of collagen fibers and an inner thick core of elastic fibers near the malleus or stapes. In the unique elastic fiber-mediated entheses, hyaluronan, versican and fibronectin were expressed strongly along the elastic fibers. The hyaluronan seemed to act as a friction-reducing lubricant for the elastic fibers. Aggrecan was labeled strongly in a disk- or plica-like fibrous mass on the inner side of the elastic fiber-rich ligament, possibly due to compression stress from the ligament. Tenascin-c was not evident in the entheses. The elastic fiber-mediated entheses appeared resistant to tissue destruction in an environment exposed to constant vibration. The morphology was unlikely to be the result of age-related degeneration.