Upper Esophageal Sphincter Response to Laryngeal Adductor Reflex Elicitation in Humans.

OBJECTIVE: The laryngeal adductor reflex (LAR) is an important mechanism to secure the airways from potential foreign body aspiration. An involvement of the upper esophageal sphincter (UES) in terms of a laryngo-UES contractile reflex has been identified after laryngeal mucosa stimulation. However, the LAR-UES relationship has not yet been fully explained. This study aimed to determine the magnitude, latency, and occurrence rate of the UES pressure response when the LAR is triggered in order to elucidate the functional relationship between the larynx and the UES. METHODS: This prospective study included seven healthy volunteers (5 female, 2 male, age 22-34 years). Laryngeal penetration was simulated by eliciting the LAR 20 times in each individual by applying water-based microdroplets onto the laryngeal mucosa. UES pressures were measured simultaneously using high-resolution manometry. RESULTS: Two distinct pressure phases (P1, P2) associated with the LAR were identified. P1 corresponded with a short-term UES pressure decrease in two subjects and a pressure increase in five subjects occurring 200 to 500 ms after the stimulus. In P2, all subjects experienced an increase in UES pressure with a latency time of approximately 800 to 1700 ms and an average of 40 to 90 mmHg above the UES resting tone. CONCLUSION: Foreign bodies penetrating the laryngeal inlet lead to a reflex contraction of the UES. Phase P1 could be a result of vocal fold activity caused by the LAR, leading to pressure changes in the UES. The constriction during P2 could strengthen the barrier function of the UES in preparation to a subsequent cough that may be triggered to clear the airways. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E1778-E1784, 2021.

Non-Reflex Defense Mechanisms of Upper Airway Mucosa: Possible Clinical Application.

The sinonasal mucosa has an essential role in defense mechanisms of the upper respiratory tract. The innate immune system presents the primary defense against noxious microorganisms followed by induction of the adaptive immune mechanisms as a consequence of the presence of pathogens. This well-known activation of adaptive immune system in response to presence of the antigen on mucosal surfaces is now broadly applicated in vaccinology research. Prevention of infectious diseases belongs to substantial challenges in maintaining the population health. Non-invasive, easily applicable mucosal vaccination purposes various research opportunities that could be usable in daily practice. However, the existence of multiple limitations such as rapid clearance of vaccine from nasal mucosa by means of mucociliary transport represents a great challenge in development of safe and efficient vaccines. Here we give an updated view on nasal functions with focus on nasal mucosal immunity and its potential application in vaccination in nearly future.

Mucosal impedance of the larynx: A technical report.

INTRODUCTION: Mucosal impedance testing measures changes in resistance to alternating electrical current. The purpose of this study is to establish the feasibility of mucosal impedance (MI) measurement in the pediatric larynx. METHODS: A flexible plastic catheter, whose tip contains paired 2 mm mucosal impedance, is directly applied to the larynx under suspension microlaryngoscopy. Milliohms of resistance is relayed real-time from the catheter and output onto a PC. Results were obtained safely over the course of 5 min of intraoperative time for all 49 patients undergoing routine microlaryngoscopy at a tertiary care pediatric hospital. RESULTS: The technique was successful in identifying MI values with reliable and reproducible results. The risk was minimal with no adverse events occurring. Impedance noise reduction was improved by the use of an aqueous gel coating on the probe and an emphasis on measurements of the interarytenoid space, which enabled the sensor rings to contact 360° of the mucosa. CONCLUSION: Laryngeal MI can be safely and reliably performed with reproducible measurements and minimal added procedure time.

Morphology of GNAT3-immunoreactive chemosensory cells in the rat larynx.

The upper airways play important roles in respiratory defensive reflexes. Although solitary chemosensory cells and chemosensory cell clusters have been reported in the laryngeal mucosa of mammalian species, the distribution and cellular morphology of chemosensory cells remain unclear. In the present study, the distribution and morphology of solitary chemosensory cells and chemosensory cell clusters were examined by immunofluorescence for GNAT3 on whole-mount preparations of the rat laryngeal mucosa. Electrophysiological experiments were performed to analyze the respiratory reflexes evoked by bitter stimuli to the laryngeal cavity. In the whole area of the laryngeal mucosa, the numbers of GNAT3-immunoreactive solitary chemosensory cells and chemosensory clusters were 421.0 ± 20.3 and 62.7 ± 6.9, respectively. GNAT3-immunoreactive solitary chemosensory cells were mainly distributed in the mucosa overlying epiglottic and arytenoid cartilage, and chemosensory clusters were mainly distributed on the edge of the epiglottis and aryepiglottic fold. GNAT3-immunoreactive solitary chemosensory cells were slender with elongated processes or had a flask-like/columnar shape. The number of GNAT3-immunoreactive cells in chemosensory clusters was 6.1 ± 0.4, ranging between 2 and 14 cells. GNAT3-immunoreactive cells in the cluster were variform and the tips of apical processes gathered at one point at the surface of the epithelium. The tips of apical cytoplasmic processes in solitary chemosensory cells and cells in the cluster were immunoreactive for espin, and faced the laryngeal cavity. Physiological experiments showed that the application of 10 mm quinine hydrochloride to the laryngeal cavity decreased respiratory frequency. The present results revealed the chemosensory field of the larynx and the morphological characteristics of the laryngeal chemosensory system for respiratory depression.

Viscoelastic properties of human aryepiglottic fold and ventricular fold tissues at phonatory frequencies.

OBJECTIVE: The purpose of this study was to quantify the viscoelastic shear properties of the human ventricular fold (or false vocal fold) mucosa and aryepiglottic fold mucosa at frequencies of phonation. METHODS: Linear viscoelastic shear properties of the mucosa of false vocal fold and aryepiglottic fold specimens from seven cadaveric subjects were determined as functions of frequency (5-250 Hz) and compared to those of the true vocal fold cover. Measurements of elastic shear modulus (G') and dynamic viscosity (η') were made with a controlled-strain simple-shear rheometer. Linear least-squares regression was conducted to curve-fit log G' and log η' versus log frequency, and statistical analysis was performed with one-way analysis of variance. RESULTS: All specimens showed similar frequency dependence of the viscoelastic functions G' and η', with G' gradually increasing with frequency and η' monotonically decreasing with frequency. The magnitudes of G' and η' of the false fold mucosa were generally higher than those of the aryepiglottic fold mucosa and true vocal fold cover, but there were no significant differences in G' and η' among the false fold, aryepiglottic fold, and true vocal fold. CONCLUSION: The false vocal fold and aryepiglottic fold mucosa showed similar frequency dependence and a similar range of tissue viscoelastic behavior as the true vocal fold. These preliminary findings suggested that such tissues could become candidates for the replacement of the true vocal fold lamina propria in patients with significant tissue loss and deficiencies, for those requiring laryngeal reconstruction following partial laryngectomy or airway reconstruction. LEVEL OF EVIDENCE: NA. Laryngoscope, E296-E301, 2018.

The Macula Flava of the Human Vocal Fold as a Stem Cell Microenvironment.

1. There is growing evidence to suggest that the cells in the maculae flavae are tissue stem cells of the human vocal fold and maculae flavae are a candidate for a stem cell niche. 2. The latest research shows that the cells in the human maculae flavae are involved in the metabolism of extracellular matrices that are essential for the viscoelasticity in the human vocal fold mucosa as a vibrating tissue, and considered to be important cells in the growth, development, and aging of the human vocal fold mucosa. 3. The cells in the human maculae flavae possess proteins of all three germ layers, indicating they are undifferentiated and have the ability of multipotency. 4. The cell division in the human adult maculae flavae is reflective of asymmetric self-renewal and cultured cells form a colony-forming unit. Therefore, the phenomenon gives rise to the strong possibility that the cells in the human maculae flavae are tissue stem cells. 5. Recent research suggests that the cells in the human maculae flavae arise from the differentiation of bone marrow cells via peripheral circulation. 6. The hyaluronan concentration in the maculae flavae is high and contains cells which possess hyaluronan receptors, indicating that the maculae flavae are hyaluronan-rich matrix, which is required for a stem cell niche. 7. A proper microenvironment in the maculae flavae of the human vocal fold mucosa is necessary to be effective as a stem cell niche maintaining the stemness of the contained tissue stem cells.

Quantifying the Subharmonic Mucosal Wave in Excised Larynges via Digital Kymography.

OBJECTIVES: In this paper, a nonlinear least squares fitting method was proposed to quantify subharmonic mucosal waves. STUDY DESIGN AND METHODS: Subharmonic mucosal waves from 10 excised canine larynges were recorded using digital kymography and analyzed using nonlinear least squares and linear least squares methods. Amplitudes of fundamental and subharmonic mucosal wave components of right-upper, right-lower, left-upper, and left-lower vocal fold lips were calculated. Lastly, phase differences of fundamental and subharmonic components of the left and right vocal folds were compared. RESULTS: The results showed that the nonlinear least squares analysis method provides a more effective complement to the linear fitting method for subharmonic mucosal wave extraction. There was a significant difference in amplitudes between the subharmonic and the fundamental components of mucosal waves (P < 0.05). The phase differences of the fundamental and the subharmonic components of the right and left vocal folds were not significantly different. CONCLUSIONS: The application of the nonlinear least squares analysis method in digital kymography is useful for the characterization of subharmonic mucosal waves.

[Wound healing following laser cordectomy for early glottic carcinoma].

OBJECTIVE: To study the wound healing following CO2 laser microsurgery for early glottic cancer, and to evaluate the treatment outcomes and cost-effectiveness of microsurgery, open surgery and radiotherapy for early glottic cancer. METHODS: Thirty-six patients with early glottic carcinoma (T1-T2) treated by transoral CO2 laser microsurgery from January 2011 to June 2014 were observed, and 112 patients undergoing open approach and 27 receiving radiotherapy from January 2008 to June 2014 in our hospital were used as control. The wound healing process, the hospital stay, the cost, the oncologic and functional results were evaluated. RESULTS: The mean time of laryngeal mucous membrane stabilization in morphology was 93 days, less than 120 days in 91% cases. The average score of VHI-10 was 5.9, which was better in the cases with T1 than the cases with T2, and was worse in cases with the anterior commissure involvement. Transoral CO2 laser microsurgery offered a similar oncologic result, shorter hospital stay and lower cost compared with open surgery or radiotherapy. CONCLUSION: The transoral laser surgery could be a better choice for early glottic carcinoma because of good oncologic and functional results and less cost.

Effects of vocal fold epithelium removal on vibration in an excised human larynx model.

This study investigated the impact of selective epithelial injury on phonation in an excised human larynx apparatus. With intact epithelium, the vocal folds exhibited a symmetrical vibration pattern with complete glottal closure during vibration. The epithelium was then enzymatically removed from one, then both vocal folds, which led to left-right asymmetric vibration and a decreased closed quotient. Although the mechanisms underlying these vibratory changes are unclear, these results demonstrate that some component of an intact surface layer may play an important role in achieving normal symmetric vibration and glottal closure.

Quantitative Study for the Surface Dehydration of Vocal Folds Based on High-Speed Imaging.

OBJECTIVES: From the perspective of the glottal area and mucosal wave, quantitatively estimate the differences of vocal fold on laryngeal activity during phonation at three different dehydration levels. STUDY DESIGN: Controlled three sets of tests. METHODS: A dehydration experiment for 10 excised canine larynges was conducted at 16 cm H2O. According to the dehydration cycle time (H), dehydration levels were divided into three degrees (0% H, 50% H, 75% H). The glottal area and mucosal wave under three dehydration levels were extracted from high-speed images and digital videokymography (DKG) image sequences. Direct and non-direct amplitude components were derived from glottal areas. The amplitude and frequency of mucosal wave were calculated from DKG image sequences. These parameters in condition of three dehydration levels were compared for statistical analysis. RESULTS AND DISCUSSIONS: The results showed a significant difference in direct (P = 0.001; P = 0.005) and non-direct (P = 0.005; P = 0.016) components of glottal areas between every two different dehydration levels. Considering the right-upper, right-lower, left-upper, and left-lower of vocal fold, the amplitudes of mucosal waves consistently decreased with increasing of dehydration levels. But, there was no significant difference in frequency. CONCLUSIONS: Surface dehydration could give rise to complex variation of vocal fold on tissues and vibratory mechanism, which should need analyzing from multiple perspectives. The results suggested that the combination of glottal area and mucosal wave could be better to research the change of vocal fold at different dehydrations. It would become a better crucial research tool for the clinical treatment of dehydration-induced laryngeal pathologies.

Epidermal growth factor mediated healing in stem cell-derived vocal fold mucosa.

BACKGROUND: The goal of vocal fold wound healing is the reconstitution of functional tissue, including a structurally and functionally intact epithelium. Mechanisms underlying reepithelialization in vocal folds are not known, although it is suspected that healing involves the interplay between several growth factors. We used a three-dimensional human embryonic stem cell-derived model of vocal fold mucosa to examine the effects of one growth factor, exogenous epidermal growth factor (EGF), on wound healing. MATERIALS AND METHODS: A scratch wound was created in the in vitro model. Rate of wound healing, epidermal growth factor receptor (EGFR) activation, and cell proliferation after injury were analyzed with and without application of both exogenous EGF and an EGFR inhibitor, gefitinib. RESULTS: Wound repair after injury was significantly hastened by application of exogenous EGF (13.3 µm/h, ± 2.63) compared with absence of exogenous EGF (7.1 µm/h ± 2.84), but inhibited with concurrent addition of Gefitinib (5.2 µm/h, ± 2.23), indicating that EGF mediates wound healing in an EGFR-dependent manner. Immunohistochemistry revealed that EGFR activation occurred only in the presence of exogenous EGF. Although not statistically significant, increased density of Ki67 staining in the epithelium adjacent to the scratch wound was observed after treatment with EGF, suggesting a tendency for exogenous EGF to increase epithelial cell proliferation. CONCLUSIONS: Exogenous EGF increases the rate of wound healing in an EGFR-dependent manner in a three-dimensional stem cell-derived model of vocal fold mucosa. This model of wound healing can be used to gain insight into the mechanisms that regulate vocal fold epithelial repair after injury.

Afferent nerve ending density in the human laryngeal mucosa: potential implications on endoscopic evaluation of laryngeal sensitivity.

Laryngeal sensitivity is crucial for maintaining safe swallowing, thus avoiding silent aspiration. The sensitivity test, carried out by fiberoptic endoscopic examination of swallowing, plays an important role in the assessment of dysphagic patients. The ventricular folds appear to be more sensitive than the epiglottis during the sensitivity test. Therefore, this study aimed to investigate the mechanical sensitivity of the supraglottic larynx. In seven healthy adults undergoing microlaryngoscopy to remove vocal cord polyps, we excised mucosal samples from the epiglottis and ventricular folds. We measured afferent nerve fiber density by immunoelectron microscopy. All of the subjects underwent an endoscopic sensitivity test based on lightly touching the laryngeal surface of the epiglottis and ventricular folds. The discomfort level was self-rated by the subjects on the visual analog scale. Samples were fixed and stored in cryoprotectant solution at 4 °C. Sections were stained with the protein gene product 9.5, a pan-neuronal selective marker. Nerve fiber density was calculated as the number of fibers per millimeter length of section. The mean nerve fiber density was higher in ventricular samples than in epiglottis samples (2.96 ± 2.05 vs 0.83 ± 0.51; two-sided p = 0.018). The mean visual analog scale scores were significantly higher for touching the ventricular folds than for touching the epiglottis (8.28 ± 1.11 vs 4.14 ± 1.21; two-sided p = 0.017). The higher sensitivity of the ventricular region should be considered for further refining clinical endoscopic evaluation of laryngeal sensitivity.

Rayleigh wave propagation method for the characterization of a thin layer of biomaterials.

An experimental method based on Rayleigh wave propagation was developed for quantifying the frequency-dependent viscoelastic properties of a small volume of expensive biomaterials over a broad frequency range. Synthetic silicone rubber and gelatin materials were fabricated and tested to evaluate the proposed method. Planar harmonic Rayleigh waves at different frequencies, from 80 to 4000 Hz, were launched on the surface of a sample composed of a substrate with known material properties coated with a thin layer of the soft material to be characterized. A transfer function method was used to obtain the complex Rayleigh wavenumber. An inverse wave propagation problem was solved and a complex nonlinear dispersion equation was obtained. The complex shear and elastic moduli of the sample materials were then calculated through the numerical solution of the obtained dispersion equation using the measured wavenumbers. The results were in good agreement with those of a previous independent study. The proposed method was found to be reliable and cost effective for the measurement of viscoelastic properties of a thin layer of expensive biomaterials, such as phonosurgical biomaterials, over a wide frequency range.

Descrição de periodicidade do sinal eletroglotográfico durante a emissão dos exercícios de vibração sonorizada de língua e lábios comparados à vogal sustentada /E/ / Comparison of tongue and lip trills with phonation of the sustained vowel /E/ regarding the periodicity of the electroglottographic waveform and the amplitude of the electroglottographic signal

INTRODUÇÃO: Os exercícios de vibração sonorizada de lábios e língua têm-se se mostrado eficientes quando utilizados tanto no tratamento de pacientes disfônicos como no aquecimento ou preparação vocal. Há grande variação do coeficiente de contato de um mesmo sinal eletroglotográfico e dificuldade na sincronização da luz estroboscópica durante a emissão dos exercícios de vibração sonorizada de língua e lábios, sendo levantada a possibilidade de aperiodicidade de vibração das pregas vocais durante a execução desses exercícios. OBJETIVO: descrever a vibração das pregas vocais durante a emissão de vibrações sonorizadas de língua e lábios comparando-as com a emissão da vogal /E/ sustentada quanto à regularidade e amplitude dos ciclos vibratórios na eletroglotografia, em cantores eruditos profissionais. METODOLOGIA: Participaram desse estudo 10 cantores eruditos profissionais, que emitiram a vogal /E/ sustentada e os exercícios de vibração sonorizados de língua e de lábios na mesma frequência e intensidade durante a execução da eletroglotografia. Foi realizada a inspeção visual da onda eletroglotográfica, quanto à periodicidade e amplitude, além do espectrograma do sinal quanto aos harmônicos presentes em cada amostra. As amostras foram randomizadas e analisadas por 3 avaliadoras. Além disso, foram extraídas as medidas de jitter e shimmer do sinal eletroglotográfico para confirmação dos resultados, além da frequência da variação de vibração dos exercícios de vibração sonorizada. RESULTADOS: Os avaliadores tiveram coeficiente alfa de Cronbach em mais de 0,9 na maior parte das amostras, indicando alto grau de concordância. Na inspeção visual do sinal eletroglotográfico foi considerada na vogal /E/ sustentada: onda periódica com amplitude regular e harmônicos múltiplos da frequência fundamental. Durante o exercício de vibração sonorizada de língua e lábios foram consideradas onda quase-periódica com amplitude oscilante (frequencia aproximada de 23Hz e 24Hz)...

INTRODUCTION: Lip and tongue trills have been effectively used as vocal warmups in the treatment of dysphonia and in the training of professional voice users. In a previous study, we found that the closed quotient varied widely during tongue and lip trills. We encountered difficulty in synchronizing the stroboscopic illumination with the vocal fold vibration during the trill exercises. We hypothesize that there is aperiodicity of vocal fold vibration during tongue and lip trills. AIM: to compare the vocal fold vibration seen during lip and tongue trills with that seen during phonation of the sustained vowel /E/, in terms of the periodicity of the EGG wave form and the amplitude of the EGG signal, in professional voice users. METHODS: We used electroglottography (EGG) to compare the vocal fold vibration seen during tongue and lip trills with that seen during phonation of the sustained vowel /E/, in terms of the EGG waveform periodicity and signal amplitude, in 10 classically trained, professional singers. The participants produced the sustained vowel /E/ and performed tongue and lip trills at the same frequency and intensity. The periodicity of the waveform and the amplitude of the signal were visually analyzed by three blinded, experienced readers. To confirm the visual analysis results, we measured the jitter and shimmer of the signal and the frequency of variation in vocal fold vibration during the trill exercises. RESULTS: Cronbach's alpha coefficient values were high (>0,9), indicating high inter-rater reliability. In sustained vowel /E/ was considered periodic wave and regular amplitude. In tongue and lip trills the waveform EGG was considered quasi-periodic and the amplitude of the EGG signal was classified as oscillating. The mean amplitude was as follows: 24.4 Hz during lip trills performed at high intensity; 24.7 Hz during tongue trills performed at high intensity; 23.3 Hz during lip trills performed at low intensity; and 24.3 Hzl...

Effects of surface dehydration on mucosal wave amplitude and frequency in excised canine larynges.

OBJECTIVE: Evaluate the effect of vocal fold surface dehydration on mucosal wave amplitude and frequency. STUDY DESIGN: Controlled test-retest. SETTING: Larynges were mounted on an excised larynx phonation system and attached to a pseudolung in a triple-walled sound-attenuated room that eliminated background noise and maintained a stabilized room temperature and humidity level. SUBJECTS AND METHODS: High-speed video was recorded for 8 excised canine larynges during exposure to dehumidified air at 20 cm H(2)O. Control trials consisted of high-speed videos recorded for 2 excised canine larynges during exposure to humidified air at the same pressure. RESULTS: In the majority of larynges, increased levels of dehydration were correlated with decreased amplitude and frequency. The slope of the linear regression fitted to the change in amplitude (P = .003) and the percent change (P < .001) between the initial and final trials were significantly decreased in dehydrated larynges. These measurements with respect to the change in frequency were also significantly decreased in dehydrated larynges (P < .001; P = .027). CONCLUSION: Vocal fold surface dehydration caused a decrease in mucosal wave amplitude and frequency. This study provides objective, quantitative support for the mechanism of voice deterioration observed after extreme surface dehydration.

Endotracheal tube and laryngeal mask airway cuff pressures can exceed critical values during ascent to higher altitude.

OBJECTIVES: Tracheal mucosal perfusion is compromised at an endotracheal tube (ETT) cuff pressure of 30 cm H(2)O, and blood flow is obstructed at a pressure of 50 cm H(2)O. METHODS: We measured the change in pressure of air-filled cuffs of 6.0 and 7.5 ETTs and a size 4 laryngeal mask airway (LMA) from sea level to 2400 m. The ETTs and LMA cuff measurements were done with the devices uncontained, and an additional 6.0 ETT was placed in a 10-mL syringe barrel to mimic placement in a trachea. This restricted cuff expansion simulating what would occur when it is placed within the trachea. The pressure of fluid-filled 6.0 ETT cuffs was also measured. RESULTS: Intracuff pressure increases linearly with increasing altitude, in all air-filled ETT and LMAs. Water-filled cuffs demonstrated no significant change in pressure with changes in altitude. The rate of ETT cuff pressure increase was greater for the ETT restricted within the syringe barrel compared with the unrestricted ETT cuff. The rate of LMA cuff pressure increase was greater than the rate of increase for all the ETTs (restricted and unrestricted). CONCLUSIONS: This model indicates that ETT cuffs inflated before air transport are likely to exceed critical pressure levels rapidly during flight. In addition, there will be loss of ETT cuff pressure, with loss of a good seal, during descent if a cuff is initially inflated at peak altitudes. Therefore, we suggest ETT cuff pressures should be monitored and adjusted continuously during ascent and decent.

Mucosal wave measurement and visualization techniques.

Organized vibration of the vocal folds is critical for high-quality voice production. When the vocal folds oscillate, the superficial tissue of the vocal fold is displaced in a wave-like fashion, creating the so-called "mucosal wave." Because the mucosal wave is dependent on vocal fold structure, physical alterations of that structure cause mucosal wave abnormalities. Visualization and quantification of mucosal wave properties have become useful parameters in diagnosing and managing vocal fold pathology. Mucosal wave measurement provides information about vocal fold characteristics that cannot be determined with other assessment techniques. Here, we discuss the benefits, disadvantages, and clinical applicability of the different mucosal wave measurement techniques, such as electroglottography, photoglottography, and ultrasound and visualization techniques that include videokymography, stroboscopy, and high-speed digital imaging. The various techniques and their specific uses are reviewed with the intention of helping researchers and clinicians choose a method for a given situation and understand its limitations and its potential applications. Recent applications of these techniques for quantitative assessment demonstrate that additional research must be conducted to realize the full potential of these tools. Evaluations of existing research and recommendations for future research are given to promote both the quantitative study of the mucosal wave through accurate and standardized measurement of mucosal wave parameters and the development of reliable methods with which physicians can diagnose vocal disorders.

Objective detection and quantification of mucosal wave propagation.

In this work a detection algorithm for mucosal wave propagation is presented. By incorporating physiological knowledge of mucosal wave properties and taking the segmented lateral movement of both vocal fold edges as a basis, the spatio-temporal position of the traveling mucosal wave is identified and quantitatively captured. The course of mucosal wave propagation can be successfully detected and analyzed with regard to discriminating different types of mucosal wave activity (in terms of spread velocity and symmetry). The preliminary results obtained for six exemplary laryngeal high-speed recordings are promising and demonstrate the potential of the proposed detection and objective description approach.

High-throughput sequencing of microRNAs in adenovirus type 3 infected human laryngeal epithelial cells.

Adenovirus infection can cause various illnesses depending on the infecting serotype, such as gastroenteritis, conjunctivitis, cystitis, and rash illness, but the infection mechanism is still unknown. MicroRNAs (miRNA) have been reported to play essential roles in cell proliferation, cell differentiation, and pathogenesis of human diseases including viral infections. We analyzed the miRNA expression profiles from adenovirus type 3 (AD3) infected Human laryngeal epithelial (Hep2) cells using a SOLiD deep sequencing. 492 precursor miRNAs were identified in the AD3 infected Hep2 cells, and 540 precursor miRNAs were identified in the control. A total of 44 miRNAs demonstrated high expression and 36 miRNAs showed lower expression in the AD3 infected cells than control. The biogenesis of miRNAs has been analyzed, and some of the SOLiD results were confirmed by Quantitative PCR analysis. The present studies may provide a useful clue for the biological function research into AD3 infection.

High-speed digital imaging laryngoscopy of the neoglottis following supracricoid laryngectomy with cricohyoidoepiglottopexy.

OBJECTIVES: This study aimed to analyse vocal performance and to investigate the nature of the neoglottal sound source in patients who had undergone supracricoid laryngectomy with cricohyoidoepiglottopexy, using a high-speed digital imaging system. METHODS: High-speed digital imaging analysis of neoglottal kinetics was performed in two patients who had undergone supracricoid laryngectomy with cricohyoidoepiglottopexy; laryngotopography, inverse filtering analysis and multiline kymography were also undertaken. RESULTS: In case one, laryngotopography demonstrated two vibrating areas: one matched with the primary (i.e. fundamental) frequency (75 Hz) and the other with the secondary frequency (150 Hz) at the neoglottis. In case two, laryngotopography showed two vibrating areas matched with the fundamental frequency (172 Hz) at the neoglottis. The interaction between the two areas was considered to be the sound source in both patients. The waveform of the estimated volume flow at the neoglottis, obtained by inverse filtering analysis, corresponded well to the neoglottal vibration patterns derived by multiline kymography. These findings indicated that the specific sites identified at the neoglottis by the present method were likely to be the sound source in each patient. CONCLUSIONS: High-speed digital imaging analysis is effective in locating the sites responsible for voice production in patients who have undergone supracricoid laryngectomy with cricohyoidoepiglottopexy. This is the first study to clearly identify the neoglottal sound source in such patients, using a high-speed digital imaging system.