Nucleotide sequencing analysis of the 146-kilobase segment around the IkBL and MICA genes at the centromeric end of the HLA class I region

The biomechanics of medialization laryngoplasty are not well understood. An excised canine larynx model was used to test the effects of various sized silicon implants. The vocal fold length, position, and tension were measured. Medialization laryngoplasty did not affect vocal fold length. At the mid-membranous vocal fold, larger shims resulted in greater medialization and tension. Medialization laryngoplasty neither medialized nor stiffened the vocal process to resist lateralizing forces. We conclude that medialization laryngoplasty provides bulk and support for defects of the membranous region of the vocal fold, but does not appear to close a posterior glottal gap. The selection of a surgical procedure to treat glottal incompetence should take into account the unique biomechanical properties of the anterior (membranous vocal folds) and posterior (cartilaginous portion) glottis.     

Localization of laminin, fibronectin, E-cadherin, and integrins in endometrium and endometriosis

Stiffness of the vocal fold is a significant factor in determining mucosal wave propagation and in the control of the fundamental frequency of phonation. We measured pliability of the vocal fold mucosa in an in vivo canine model as an index of stiffness while the histological layer-by-layer structure of the vocal fold was not disrupted. The point 1 mm below the free edge showed a maximal pliability that gradually diminished toward the tracheal side and reached a minimum. When the thyroarytenoid (TA) muscle contracted, pliability of the mucosa was significantly increased (P < 0.001). Mucosal pliability of the excised larynx was significantly increased compared with that in vivo (P < 0.001). The point of minimal pliability in the absence of TA muscle contraction did not shift after excision of the larynx, while TA muscle contraction caused a downward shift of the point of minimal pliability. Mucosal pliability can thus be used to quantitatively assess the effects of TA muscle contraction on stiffness of the vocal fold mucosa.     

Correlation between vocal functions and glottal measurements in patients with unilateral vocal fold paralysis

Observations and analysis of glottal characteristics are critical in choosing the best modality for surgery in patients with unilateral vocal fold paralysis (UVP). This study suggests that multiple glottal characteristics influence the vocal product in patients with UVP. In addition to the horizontal position of the paralyzed vocal fold (deviation from the midline), the glottal area, degree of bowing of the paralyzed and contralateral vocal folds, maximum separation between vocal folds, compensatory glottal maneuvers, and the vertical glottic closure plane significantly influenced the quality of the voice. Clinicians should be aware of these observations to facilitate treatment planning and assessment of the results of surgical procedures used to improve voice quality in cases of UVP.     

Pleiotropic functions of neurotrophins in development

Laryngeal framework surgery can change the position and tension of the vocal folds safely without direct surgical intervention in the vocal fold proper. Some 23 years of experience with phonosurgery have proved its usefulness in treating dysphonia related to unilateral vocal fold paralysis, vocal fold atrophy, and pitch-related dysphonias . Meanwhile, much information about the mechanism of voice production has been obtained through intraoperative findings of voice and fiberscopic examination of the larynx . Based on such knowledge together with information obtained through model experiments, the human vocal organ was reconsidered mainly from the mechanical view point, and the roles of voice therapy and singing pedagogy were discussed in relation to phonosurgery. The vocal organ may not be an ideal musical organ and is rather vulnerable, but its potential is enormous.     

A nonlinear operator-based speech feature analysis method with application to vocal fold pathology assessment

Traditional speech processing methods for laryngeal pathology assessment assume linear speech production with measures derived from an estimated glottal flow waveform. They normally require the speaker to achieve complete glottal closure, which for many vocal fold pathologies cannot be accomplished. To address this issue, a nonlinear signal processing approach is proposed which does not require direct glottal flow waveform estimation. This technique is motivated by earlier studies of airflow characterization for human speech production. The proposed nonlinear approach employs a differential Teager energy operator and the energy separation algorithm to obtain formant AM and FM modulations from filtered speech recordings. A new speech measure is proposed based on parameterization of the autocorrelation envelope of the AM response. This approach is shown to achieve impressive detection performance for a set of muscular tension dysphonias. Unlike flow characterization using numerical solutions of Navier-Stokes equations, this method is extremely computationally attractive, requiring only a small time window of speech samples. The new noninvasive method shows that a fast, effective digital speech processing technique can be developed for vocal fold pathology assessment without the need for direct glottal flow estimation or complete glottal closure by the speaker. The proposed method also confirms that alternative nonlinear methods can begin to address the limitations of previous linear approaches for speech pathology assessment.     

Effects of lung volume on the glottal voice source

According to experience in voice therapy and singing pedagogy, breathing habits can be used to modify phonation, although this relationship has never been experimentally demonstrated. In the present investigation we examine if lung volume affects phonation. Twenty-four untrained subjects phonated at different pitches and degrees of vocal loudness at different lung volumes. Mean subglottal pressure was measured and voice source characteristics were analyzed by inverse filtering. The main results were that with decreasing lung volume, the closed quotient increased, while subglottal pressure, peak-to-peak flow amplitude, and glottal leakage tended to decrease. In addition, some estimates of the amount of the glottal adduction force component were examined. Possible explanations of the findings are discussed.     

Prevalence of hypertension in patients with type II diabetes in referral versus primary care clinics

We report our clinical experience in managing a 59-year-old Italian male with Churg-Strauss syndrome (CSS) whose first clinical manifestation was a persistent dysphonia; the patient worked as a mechanic. Video-laryngostroboscopic examination revealed paresis of the right vocal fold with a reduction in adduction together with incomplete glottal closure. Spectrographic and spirometric tests both showed abnormal changes. Laryngeal electromyography revealed neurogenic damage of the right thyroarytenoid and crycoarytenoid muscles. Due to the appearance of typical signs of systemic involvement of CSS as a necrotizing vasculitis, the patient was admitted to the Rheumatology Unit of the University of Pisa. Histologic analysis of a skin lesion on the patient's foot confirmed the diagnosis. Treatment with 6-methylprednisolone quickly brought remission from systemic and laryngeal symptoms, as well as improvement in the results of video-laryngostroboscopic, spectrographic and laryngeal myographic tests.     

Lubrication mechanism of the larynx during phonation: an experiment in excised canine larynges

To evaluate how the viscosity of the laryngeal mucus influences vocal fold vibration, two fluids of differing viscosity were applied separately to excised canine larynges and experimental phonation was induced. Vibration of the vocal folds was measured by use of a laryngostroboscope and an X-ray stroboscope. With the high viscosity fluid, the amplitude of vibration of the free edge and the peak glottal area was decreased while the open quotient was increased. Because the viscosity of this fluid affected the wave motion of the vocal fold mucosa, changes in viscosity of the mucus may be involved in causing such disorders as hoarseness, in the absence of apparent changes in the vocal folds themselves.     

Analysis of pathological vocal fold vibrations using high-speed digital imaging

There have been various methods devised to monitor vocal fold vibration. Stroboscopy provides clinically-celevant information concerning pathology of the vocal folds. However, slow motion observation is based on the regularity of the vibration, and this ignores the role of irregularity of the vocal fold vibration in pathological cases. In order to know more about the nature of the vocal fold vibratory pattern, it is essential to monitor the vibration on a cycle by cycle basis. We analysed vocal fold vibrations of 22 pathological larynges using a computer-assisted high-speed digital imaging technique. Observed items included symmetry, regularity, phase difference, glottal closure, amplitude, mucosal wave and periodicity difference. Vibratory patterns were classified by location of lesion, severity of disease, expiratory pressure and laryngeal modulation. Analyses of pathological vocal fold vibrations using high-speed digital imaging techniques are providing the theoretical support for voice therapy and elucidating the causes of hoarseness.     

Further studies of phonation threshold pressure in a physical model of the vocal fold mucosa

This paper reports results of further experimentation on a previously developed physical model of the vocal-fold mucosa [Titze et al., J. Acoust. Soc. Am. 97, 3080-3084 (1995)]. The effects of vocal-fold thickness, epithelial membrane thickness, and prephonatory glottal geometry on phonation threshold pressure were studied. Phonation threshold pressures in the range of 0.13 to 0.34 kPa were observed for an 11-mm-thick vocal fold with a 70-micron-thick "epithelial" membrane for different "mucosal" fluid viscosities. Higher threshold pressure was always obtained for thinner vocal folds and thicker membranes. In another set of experiments, lowest offset threshold pressure was obtained for a rectangular or a near-rectangular prephonatory glottis (with a glottal convergence angle within about +/- 3 degrees). It ranged from 0.07 to 0.23 kPa for different glottal half-widths between 2.0 and 6.0 mm. The threshold for more convergent or divergent glottal geometries was consistently higher. This finding only partially agrees with previous analytical work which predicts a lowest threshold for a divergent glottis. The discrepancy between theory and data is likely to be associated with flow separation from a divergent glottis.     

Long-term model of induced canine phonation

Experimental induced phonation in the dog has been used in short-term studies by several investigators and has proved quite useful in laryngeal research. In this study a long-term canine phonation model is described that uses permanently implanted electrodes on the superior and recurrent laryngeal nerves. A serial induced phonation model has not been previously reported and is needed for laryngeal research in which voice results are a primary end point. Inexpensive, reliable, nontoxic electrodes were designed and fabricated. The laryngeal nerves were found to be quite susceptible to injury, necessitating a series of changes in electrode design. Electrode durability and laryngeal nerve viability improved with each design modification; the final design gave a recurrent laryngeal nerve viability rate of 100% at 6 weeks, 83% at 9 weeks, and 73% at 12 weeks. Induced phonation was successfully produced on a repeated basis by stimulating the recurrent laryngeal nerves while passing air through the larynx, in 22 (95.6%) of 23 animals. Stimulation of the superior laryngeal nerves increased vocal fold length and tension but was not required for phonation. Technical aspects of chronic implantation and stimulation of the laryngeal nerves are discussed. The development and successful long-term implantation of electrodes on the laryngeal nerves and their use in repeated induced phonation have not been reported previously.     

Assessment of vocal function using simultaneous aerodynamic and calibrated videostroboscopic measures

Despite many attempts to model how vocal fold movements relate to the aerodynamic forces acting on them during phonation, there have been few simultaneous measurements of glottal area and transglottal air pressures and flows. A novel system is described that combines endoscopic measurement of glottal area with aerodynamic flow and pressure measures made during phonation. Results from bench top model tests and from one human subject are presented. For both tests, an aerodynamic model of airflow through a constriction was used to predict the area of the constriction (glottis), and these predictions were compared with endoscopic measurements. The results showed good correlation between predicted and observed areas; however, for small constrictions (<0.025 cm2), whether artificial or glottal, the errors in estimating areas with either optical or aerodynamic methods increase significantly. These results suggest that this measurement system has the potential to enhance the assessment of vocal function.     

Torque misuse revisited

The larynx is an hormonal target. Tone of the voice depends on the fact that there is or there is not male hormones, or on the presence of female hormones? At menopause, estrogens and gestagens may fade, and androgens may appear. Both are in harmony. But does the fact that estro-progestative hormones disappear at menopause allow androgenic action? Often androgens can be converted in estrogen and estron-sulfate. The voice, then, may stay feminine. Otherwise, the androgenic effects will affect the striated muscles of the vocal fold, the thickness of the stratified epithelium and the strength of the larynx. Of 100 women, our study has shown that 17 had a menopausal voice syndrome with lack of intensity, a voice fatigue, a narrow register. The hormonal replacement treatment is the treatment for voice professional. The singing voice, the speaking voice recover. For each woman, the specific treatment has to be adapted with vitamins and hormonal therapy to preserve the harmony of the voice and the being.     

Vocal process granuloma

Vocal process granuloma or contact ulcer is uncommon disease in which there is chronic irritation and granulation tissue formation at the posterior third of the vocal folds. Thirteen patients (11 men and two women) with vocal process granuloma were enrolled in this study; cases of intubation granuloma were excluded. The most frequent complaints were throat irritation, frequent throat clearing and voice change. Forty-seven percent of patients had a recurrence two to four months after surgery. Computed tomography (CT) of the larynx in four patients showed arytenoid sclerosis on the involved side and disclosed moderate enhancement of the vocal fold granuloma after contrast injection in one. Three patients had hyperacidity and four had hyperfunctioning granulomas: two used their voices excessively and the other two had bilateral sulcus vocalis. To our knowledge this is the first report of sulcus vocalis with vocal process granuloma, and of enhanced vocal process granuloma.     

Splenic-gonadal fusion of the continuous type in an adult female

The use of autogenous fat for augmentation of the paralyzed vocal fold is a promising substitute for alternate injectable material such as Teflon (polytef paste, polytetrafluoroethylene; Ethicon) and Gelfoam (absorbable gelatin sponge; Upjohn). Long-term histologic evaluation of fat grafts to the larynx has not previously been reported in the literature. We present a case report of autogenous fat augmentation of a paralyzed vocal fold with documentation of persistent fat graft present 5 months after transplant.     

Inhibition of the delayed rectifier K current in guinea-pig cardiomyocytes by thiamine tetrahydrofurfuryl disulfide

In this study, we attempted to determine which method was the best for reinnervating the laryngeal adductor muscles by comparing nerve suture, nerve implantation, and nerve-muscular pedicle (NMP) transfer, as well as the length of time that could elapse after denervation and still allow for successful reinnervation with the ansa cervicalis. Reinnervation was performed in 36 dogs, at 6-, 8-, 10-, 12- and 18-month intervals after denervation via the three methods of muscle reinnervation described above. We noted some return of adduction in the cases using nerve suture before a 10-month interval after denervation, and with nerve implantation and NMP transfer before the 8-month intervals. The variable adduction was caused by reinnervation of the adductor muscles from the ansa cervicalis, as demonstrated by laryngeal spontaneous and evoked electromyography, the strength of muscle contraction, and histologic findings. Adduction was not observed in the cases after the above-mentioned intervals but partial improvement of the bulk and strength of the reinnervated vocal cord was still achieved. An analysis of the experimental results showed that nerve suture was superior to nerve implantation and the NMP technique. Little difference was noted between nerve implantation and the NMP technique.     

Estimating phonation threshold pressure

Phonation threshold pressure (PTP) is the minimum subglottal pressure required to initiate vocal fold oscillation. Although potentially useful clinically, PTP is difficult to estimate noninvasively because of limitations to vocal motor control near the threshold of soft phonation. Previous investigators observed, for example, that trained subjects were unable to produce flat, consistent oral pressure peaks during/pae/syllable strings when they attempted to phonate as softly as possible (Verdolini-Marston, Titze, & Druker, 1990). The present study aimed to determine if nasal airflow or vowel context affected phonation threshold pressure as estimated from oral pressure (Smitheran & Hixon, 1981) in 5 untrained female speakers with normal velopharyngeal and voice function. Nasal airflow during /p/occlusion was observed for 3 of 5 participants when they attempted to phonate near threshold pressure. When the nose was occluded, nasal airflow was reduced or eliminated during /p/;however, individuals then evidenced compensatory changes in glottal adduction and/or respiratory effort that may be expected to alter PTP estimates. Results demonstrate the importance of monitoring nasal flow (or the flow zero point in undivided masks) when obtaining PTP measurements noninvasively. Results also highlight the need to pursue improved methods for noninvasive estimation of PTP.     

Thyroarytenoid muscle activity and infraglottic aspect of canine vocal fold vibration

OBJECTIVES: To investigate the effect of contraction of the thyroarytenoid (TA) muscle on the location of the mucosal upheaval (MU) and to estimate the location of the MU in relation to the histologic structure of the vocal fold. BACKGROUND: The MU is a small mucosal ridge arising on the lower surface of the vocal fold during phonation and is thought to be the lower border of the vibrating structure. METHODS: Vibrations were elicited under three conditions: during bilateral TA muscle contraction, without TA muscle stimulation, and during vocal fold lengthening. The vibrations were recorded from the tracheal side by high-speed cinematography or videotape recording combined with stroboscopic illumination. The larynx was prepared for histologic observation in the frontal plane. Tattooed marks on the lower surface of the vocal fold were used to locate macroscopically observed landmarks with reference to microscopic structures. RESULTS: The MU shifted laterally toward the tracheal side during TA muscle contraction. When the vocal fold was lengthened, the MU shifted medially toward the free edge. Histologic examination showed that the MU in the absence of TA muscle contraction arose slightly above the area where the muscular layer approached the epithelial layer. CONCLUSION: When the TA muscle contracts, the vibrating area expands toward the tracheal side, and a more dynamic mucosal wave occurs in the vertical direction. We believe that a part of the body and the cover are probably involved in the vibratory movement of the vocal fold.     

Critical review of phonosurgical methods in the treatment of sulcus vocalis

INTRODUCTION: Sulcus vocalis is an epithelial invagination along the free edge of the membranous vocal fold. It interferes with the glottic closure and vibration pattern. Sulcus vocalis provokes voice fatigue, hoarseness and breathiness, and it usually appears in association with hyperkinetic phonatory pattern. Hyperkinesis develops secondarily, due to the compensatory effort to overcome the deficiency in glottic closure. The treatment of sulcus vocalis is very difficult. Phonosurgery is used, and is followed by postoperative voice therapy. PHONOSURGICAL OPERATIONS: Various surgical techniques are used in the therapy of sulcus vocalis. Over a 10-year period we have operated on 1550 patients with benign lesion of the vocal folds, of whom only 11 had sulcus vocalis (0.7%). We carried out various surgical techniques. a) Excision of sulcus A longitudinal incision of mucosa is performed along the upper surface of the vocal fold, distant of the free edge. Mucosa is undermined caudally, and sulcus is detached from its base. Sulcus is then removed by surgical scissors. With this technique we could not provide physiological phonation and vibration pattern, in spite of an apparent improvement in the voice. b) "Slicing mucosa" technique This procedure was suggested by Pontes, and it also begins with a longitudinal incision followed by creation of inferiorly based slices of mucosa. c) Excision plus rhyroplasty Excision of sulcus is combined with thyroplasty type I in order to achieve medialization of the vocal fold. It can be used in cases with severe glottal gap in order to improve the results of excision. d) Implants Various materials were used in order to enlarge the mass of the vocal fold. In our patients, the results of this procedure were inferior as related to excision surgery. DISCUSSION: The surgical procedure which is safe and accepted by the majority of surgeons has not yet been at our disposal. The treatment of sulcus vocalis should start with voice therapy, which lasts as long as the patient shows a progress. Only then the surgical procedure can be discussed. We obtained the best results with the combination of excision and voice therapy. However, the surgeon and the patient must be aware that the treatment is demanding and long-lasting.     

Vowel-related differences in laryngeal articulatory and phonatory function

The purpose of this investigation was to study the interaction between the supralaryngeal and laryngeal components of the speech mechanism by examining vowel-related effects for a variety of vocal fold articulatory and phonatory measures. Secondary issues were to determine if vowel-related differences were influenced by the nature of the speaking task or gender. Between-vowel differences in estimated subglottal air pressure, peak oral air flow, mean phonatory air flow, air flow near the termination of the vowel, electroglottograph cycle width (EGGW), fundamental frequency, and voice onset time were examined for men and women during syllable repetitions and sentence productions. Significant vowel-related differences were found for all of the measures except mean phonatory air flow, and generally were not influenced by speaking task or gender. Vowel-related effects for estimated subglottal air pressure, peak oral air flow, fundamental frequency, and VOT were consistent with some earlier studies. New findings included vowel-related differences in EGGW and air flow near the termination of the vowel. We propose a model that includes the contribution of mechanical forces, reflexive neural activity, and learned neural activity to explain vowel-related effects. When vowel height is varied, changes in laryngeal cartilage positioning and vocal fold and vocal tract tension appear to influence laryngeal articulatory and phonatory function.