Biomedical subjects
Publications and source records attributed to Hsing-Won Wang.
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Nitric oxide (NO) is a molecule involved in multiple functions including vasodilatation, neural transmission, immune response and inflammation. However, the role of NO in the pathophysiology of vocal cord diseases is not clear. The present study investigated the possible involvement of NO and its toxic metabolite, peroxynitrite, in the pathogenesis of vocal polyps and nodules. Vocal polyps and nodules were obtained from patients receiving surgery for their conditions. Immunohistochemistry was applied to evaluate the expression of the inducible form of nitric oxide synthase (iNOS) as well as the production of peroxynitrite represented by the formation of its biological footprint, 3-nitrotyrosine (3-NT). Each section was given a score of 0 to 4 according to the labeling intensity seen, with the highest number representing the highest labeling intensity. The results showed that vocal polyp had an average iNOS labeling score of 3.2, which was significantly higher than the value of 1.9 in vocal nodules. The average labeling score of 3-NT was 2.8 in vocal polyps, which was also significantly higher than the value of 1.8 in vocal nodules. There was also a positive correlation between the level of iNOS expression and the extent of 3-NT formation. These results suggest that increased peroxynitrite production, resulting from increased iNOS expression and NO formation, may have an important pathogenic role in these vocal diseases.
PURPOSE: Although difficult laryngeal exposure (DLE) is a common problem encountered after procedures using a rigid laryngoscope, to date, no anticipatory physical indicators have been formally noted as reliable predictors of DLE. The purpose of this paper is to identify useful and reliable indicators by which to predict, with acceptable accuracy, the occurrence of DLE following rigid laryngoscopy. STUDY DESIGN: Fifty-six patients, each of whom had undergone a rigid laryngoscope procedure, were classified as belonging to either the DLE group (n = 19) or the control group (n = 37) for purposes of this prospective study. METHODS: All patients were given a physical examination, which encompassed the following nine measures: age, sex, modified Mallampati index (MMI), body mass index (BMI), hyoid-mental distance (HMD), thyroid-mental distance (TMD), thyroid-mandible angle (TMA), horizontal thyroid distance (HTD), and vertical thyroid distance (VTD). Stepwise regression was employed on patient data to identify those with DLE. RESULTS The ages of patients in the DLE group ranged from 35 to 79 years, with a mean of 51.3 years. Among the nine variables, we found sex (P =.045, odds ratio = 69.159) and TMA (P =.004, odds ratio = 1.510) to be "reliable" DLE predictors. Using these two variables, 94.6% of study case patients could have been correctly classified preoperatively. Based on our comparison of case results, we found that a TMA value greater than 120 degrees in men and 130 degrees in women indicates a strong likelihood of DLE. CONCLUSIONS TMA is a sensitive, reliable, and useful predictor of DLE in both men and women. The combination of sex and TMA provide important initial clinical indicators that can alert a clinician regarding DLE probability.
We employed a glyoxylic catecholaminergic histofluorescence method to study the sympathetic innervation present in the rat tongue. One percent neutral red was used as a counterstain. Many noradrenergic fibers were demonstrated around the blood vessels, muscles, glands and submucosa of the tongue, but not in the epithelium or papilla. In a group of rats following neurectomy, the superior cervical ganglia (SCG) were removed unilaterally or bilaterally. Changes in sympathetic innervation of the tongue were examined 14 days after SCG ganglionectomy. In those animals after unilateral SCG ganglionectomy, we found no noradrenergic histofluorescence in the ipsilateral anterior 2/3 of the tongue, although some scant fluorescence was found in the ipsilateral posterior 1/3 of the tongue. However, no noradrenergic histofluorescence could be observed in animal's bilateral SCG ganglionectomies. Our results indicate that sympathetic innervation of the tongue in rats originates in the SCG, with some cross-innervation of the sympathetic fibers occurring in the posterior 1/3 of the tongue.
Autogenous fat augmentation for glottic insufficiency has been used previously in patient treatment regimes. However, relatively little information is currently available regarding the effectiveness of fat injection for patients with vocal fold atrophy who have complete glottal closure (VFACGC). This paper compares, in retrospect, the efficiency of fat injection after surgery in patients with VFACGC (n=21). The perceptual acoustic and phonatory functions and videolaryngostroboscopic data were evaluated before and after fat augmentation was performed on 13 patients. Mean follow-up time was 9.5 months. Fifteen patients displayed excellent results, four experienced post-procedure failure, and two were unavailable for follow-up analysis. The majority of VFACGC patients (71%) also suffered from muscular tension dysphonia (MTD) preoperatively. The procedure also resolved the MTD in half (54%) of the patients in this study. Perceptual rating showed significant improvement in grade, roughness and breathiness (P<0.05). The videolaryngostroboscopic rating showed significant improvements in vocal fold edge linearity (P<0.01), vocal fold vibration amplitude and mucosal wave excursion (P<0.05). VFACGC is commonly misdiagnosed as MTD and is, therefore, unresponsive to speech therapy that is targeted to the latter. Fat injection is an effective autogenous implant and should be considered as an option in the treatment of patients with VFACGC. Although fat re-absorption was identified as a problem, repeating the procedure could be considered to minimize the effect of such.
Although used for treating vascular malformations, KTP (532 nm) lasers have not been used to treat microvascular lesions of the vocal fold. The efficiency of KTP laser operation in the continuous mode with a 0.4- or 0.6-mm beam (1- to 2-W aim for 3 to 7 seconds delivering a total energy of 3 to 7 J) was studied retrospectively in patients with microvascular lesions of the vocal fold (n = 14). The perceptual acoustic, phonatory function, and videolaryngostroboscopic data were evaluated before and after operation in 10 patients. At follow-up (mean, 7 months), the results were excellent in all patients. Their phonatory function (jitter, shimmer, grade, breathiness, and roughness) significantly improved (p < .01). The videolaryngostroboscopic rating showed significant improvement in the amplitude of vocal fold vibration and excursion of the mucosal wave (p < .05). No postoperative recurrence or complications were noted. The KTP laser operation is a useful, cost-effective, and time-saving procedure and can be considered as an option in management of patients with microvascular lesions of the vocal fold, particularly those with repeated hemorrhages. Because the operation is easy (compared to other surgical methods) and has no major side effects, the prospect of total patient recovery is excellent.
Voice disorders can cause problems for patients emotionally, physically, economically and functionally. Neither subjective nor objective voice examinations are able to evaluate such factors adequately. For this study, a retrospective analysis of 79 dysphonic cases was conducted using the voice handicap index (VHI) to gather comprehensive data across a variety of voice disorders. Of the 79 cases, 41 involved glottic insufficiency, 26 involved vocal polyps or mass, and 12 involved functional voice disorders. Cases were assessed with the VHI using physical (P), functional (F), emotional (E) parameters and a total (T) of the three. P, F, E and T variables were entered into a statistical programme and analysed using one-way analysis of variance (ANOVA). Mean +/-SE values for P, F, E and T, respectively, in glottic insufficiency cases were 31.61 +/- 1.10, 26.49 +/- 1.43, 26.06 +/- 1.54, and 84.20 +/- 4.21. Mean +/-SE values for P, F, E and T, respectively, in vocal mass cases were 30.69 +/- 1.73, 25.23 +/- 1.90, 23.96 +/- 1.82, and 79.88 +/- 5.08. The mean +/-SE values of P, F, E and T, respectively, in functional voice disorders were 20.92 +/- 2.06, 18.33 +/- 1.82, 16.83 +/- 1.86, and 56.08 +/- 5.23. We found the mean glottic insufficiency was significantly greater than functional voice disorders for each measure. There were significant differences between vocal mass and functional voice disorders means for P and T. Glottic insufficiency and vocal mass means were not significantly different for any measure. Problems in the physical realm were identified as the most severe amongst all patients. Glottic insufficiency patients were found to suffer the most in every VHI value. Although VHI is a relatively new method by which to measure discomfort in voice-disordered patients, it provides a mechanism for patients to define their discomfort and for therapists to better target recovery programmes to patient's needs.
Previously, we designed a ribozyme that targets the H-ras oncogene at the 12th codon mutation site (Chang et al., 1997). Ribozymes have antisense molecule and site-specific ribonuclease potential. In this study, an adenoviral vector was used to transduce the H-ras ribozyme into laryngeal cancer cells (HEp-2). This served to downregulate the H-ras gene expression in which this ribozyme performed antisense activity due to HEp-2 cells containing wild-type alleles in the 12th H-ras codon. Together, our data demonstrated that the recombinant adenovirus encoding H-ras ribozyme can be broadly regarded as a cytotoxic gene therapy in laryngeal cancer cells regardless of containing wild-type or mutant ras gene. In addition, the mechanism through which the H-ras ribozyme inhibited tumor growth was apoptosis and involved both caspase- and mitochondria-mediated pathways. The activators caspase-8 and -9 as well as the effector caspase-3 in the induction phase of apoptosis and the substrate PARP of caspase-3 in the execution phase were activated 48h following the H-ras ribozyme treatment. Mitochondrial events characterized by the production of superoxide anion and the release of cytochrome c started at 24h. Mitochondrial transmembrane potential loss occurred 48h after the ribozyme treatment. However, Bcl-2 delayed cytochrome c release to the cytosol, but it could not protect the apoptosis effect, suggesting that cytochrome c release from mitochondria may not play a role in H-ras ribozyme-induced apoptosis.
With the advance of effective anti-tuberculosis drugs and the natural decline of tuberculosis (TB) in the developed world, the incidence of laryngeal TB has decreased and remains stable. However, compared to the situation in the past, the otolaryngologist may encounter uncommon clinical presentation of laryngeal TB nowadays. We describe one such case presenting with a laryngeal lesion with clinical and radiological features of a neoplastic rather than an infectious process.
Anterior glottic web (AGW) is a challenge for otolaryngologists to treat because of the wide range of symptoms and the involvement of the patient's airway. We were presented with an 18-year-old male patient suffering from exertional dyspnea and moderate dysphonia. Two attempts at microlarnygeal surgery, using a CO(2) laser to try to lysis the AGW, failed to achieve satisfactory results. Further examination indicated AGW, with compromised bilateral vocal fold movement and voice generation capabilities. A two-stage endoscopic buccal mucosal grafting (EBMG) was recommended to accomplish anterior commissure reconstruction to treat the epithelial loss resulting from AGW. In our postoperative assessment, the patient's symptoms had improved dramatically, with clear, smooth voice production without dyspnea. Therefore, EBMG is believed to be a technically viable and feasible approach to treating AGW and is also recommended as an effective alternative to treatments such as laryngofissure and tracheostomy.
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OBJECTIVES: Autogenous fat augmentation has been used as a treatment for glottic insufficiency. However, no information is available on the effectiveness of fat injection in patients with vocal nodules or recurrent vocal nodules after surgery. STUDY DESIGN: The retrospective study reviews the efficiency of fat injection after surgery in patients with vocal nodules (n = 18) and recurrent vocal nodules (n = 5). METHODS: The perceptual acoustic, phonatory function, and video laryngostroboscopic data were evaluated before and after surgery in 23 patients. RESULTS: Mean follow-up time was 7.5 months. Nineteen patients had excellent results. Two patients had improvement, and no change was observed in two patients. Phonatory function showed significant improvement in shimmer, harmonic-to-noiseratio (P <.05), maximum phonation time, grade, roughness, and breathiness (P <.001). Video laryngostroboscopic rating showed significant improvement in linearity of the vocal fold edge, amplitude of vocal fold vibration, and excursion of the mucosal wave (P <.001). Less improvement was observed in recurrent vocal nodules than in nonrecurrent vocal nodules. CONCLUSIONS: Fat injection is an effective autogenous implant and may be considered as an option in management of patients with vocal nodules after surgery. Recurrence of nodules is a problem, but the procedure may be repeated.
Autogenous fat augmentation has been proven effective in the treatment of glottic insufficiency (GI) using both subjective and objective methods of evaluation. However, no information is available in published research regarding the effectiveness and predictability of value parameters with regard to patients' perceptions and concerns. This article retrospectively examines the correlation between subjective and objective examinations and subjective ratings (SRs) in patients with presbylaryngis (n = 14) and sulcus vocalis (n = 2). Acoustic analysis, phonatory function, magnetic resonance imaging (MRI) assessment, and perceptual rating data were evaluated against SRs using pre- and postoperative test results in 16 patients. The mean time over which subjective and objective examinations were performed was 10 months. Twelve patients reported excellent results, while no change was observed in 4 patients. When compared against SR, the kappa value of jitter, shimmer, harmonic to noise ratio, phonation time, grade, roughness, breathiness, and MRI were 0.25, 0, -0.08, -0.11, -0.11, 0.18, 0, and 1, respectively. The agreement between the MRI and SR values was complete, and was the only relationship shown to be significant (p < 0.001). MRI assessment is an effective and reliable examination tool which can be considered for use in assessing the progress of the post-fat injection operation in GI patients during follow-up examinations. Furthermore, due to the excellent agreement between MRI assessment and the patients' subjective feelings, the SR value may serve as a good index of fat survival.
While the effectiveness of autogenous fat augmentation after microsurgical removal (FAMSR) of the vocal nodules (VN) has been previously shown in patient treatment programs, relatively little information is available regarding the long-term effectiveness of such a procedure. This paper examines, in retrospect, the long-term effectiveness of FAMSR in patients with VN (n = 41) using pre- and post-FAMSR perceptual acoustic and phonatory function data and videolaryngostroboscopic findings for 33 patients. The mean follow-up time was 18 months. Thirty-three (80.4%) patients displayed excellent results; 4 (9.8%) experienced improvement, and 4 (9.8%) postprocedure failure. Patient phonatory functions showed significant improvements in shimmer, harmonic-to-noise ratio, phonation time (p < 0.05), grade, roughness and breathiness (p < 0.001). The videolaryngostroboscopic rating showed significant improvements in vocal fold edge linearity, vocal fold vibration amplitude, and mucosal wave excursion (p < 0.001). Improvements observed through long-term follow-up tended to be less dramatic in patients with recurrent VN than those with nonrecurrent VN. FAMSR is an easy, safe, and fast procedure which should be considered as an option in treating VN patients who either require surgery or do not have the time or perseverance to complete a lengthy program of speech therapy.
While autogenous fat augmentation for glottic insufficiency has been used before, relatively little information is currently available on the effectiveness of fat injection in patients with nonparalytic glottic insufficiency resulting from problems such as various defects of vocal atrophy or sulcus vocalis. This paper compares retrospectively the efficiency of fat injection after surgery in patients with vocal atrophy (n = 16) and sulcus vocalis (n = 8). The perceptual acoustic and phonatory functions and videolaryngostroboscopic data were evaluated before and after fat augmentation in 24 patients. The mean follow-up time was 19.5 months. Fifteen patients displayed excellent results; 1 showed some improvement; 6 experienced postprocedure failure, and 2 were not available for follow-up analysis. Perceptual rating showed significant improvement in grade, roughness and breathiness (p < 0.05). The videolaryngostroboscopic rating showed significant improvements in vocal fold edge linearity, vocal fold vibration amplitude and mucosal wave excursion (p < 0.05). More improvement in vocal atrophy was observed compared with sulcus vocalis following fat injection procedures. Our research showed that middle defects improved more compared to those in the anterior and posterior area. Fat injection is an effective autogenous implant and may be considered as an option in the treatment of patients with vocal atrophy or sulcus vocalis. Although fat reabsorption was a problem, repeating the procedure could be considered.
BACKGROUND: Exposure to cold causes cutaneous vasoconstriction to reduce body heat loss, while the nasal cavity warms up the inspired cold air. This suggests cooling might evoke a different response in nasal mucosa blood vessels than in cutaneous blood vessels. Thus, the aim of this study was to evaluate the effect of cooling (to 24 degrees C) on the vascular response of isolated nasal mucosa. METHODS: An in vitro isometric contraction of nasal mucosa excised from patients suffered from chronic nasal congestion was continuously recorded. Either electrical field stimulation (EFS) or exogenous norepinephrine (NE) was applied to the turbinate mucosa strip at 37 and 24 degrees C, and the influence of cooling (to 24 degrees C) was evaluated. RESULTS: EFS (1, 2, 4, and 8 Hz) produced frequency-dependent contractions at 37 and 24 degrees C. Cooling did not alter the magnitude but significantly prolonged the duration of EFS-induced contraction. Exogenous NE (10(-8) to 10(-4) M) produced concentration-dependent contractions at 37 and 24 degrees C. Cooling significantly enhanced the contractile responses evoked by NE between 3 x 10(-6) and 1 x 10(-4) M. CONCLUSION: Cooling (to 24 degrees C) prolonged the EFS-induced and enhanced NE (3 x 10(-6) to 1 x 10(-4) M)-induced contraction of isolated human nasal mucosa.
BACKGROUND: Nitric oxide (NO) is implicated in inflammation. Its role in the pathogenesis of nasal polyposis is not clear. METHODS: The expression of inducible NO synthase (iNOS), and the production of peroxynitrite represented by the formation of 3-nitrotyrosine (3-NT) were examined by immunohistochemistry in nasal polyps. The contents of superoxide dismutases (SODs) in nasal polyps and nasal mucosa were assessed by Western blot analyses. RESULTS: iNOS expression and 3-NT accumulation were noted in mucosal epithelium, vascular endothelium, and interstitial cells of nasal polyps. In comparison with our previous study on the nasal mucosa from patients with rhinitis, the stromal cells of the nasal polyp had higher labeling intensity for both iNOS and 3-NT. The polyp showed similar levels of CuZnSOD and MnSOD as those of nasal mucosa. CONCLUSIONS: The iNOS/NO system may be important in the pathophysiology of nasal polyposis. The increased peroxynitrite may result from increased iNOS expression but is not related to decreased SODs.