Dynamic remodeling of neuromuscular junction (NMJ) structure is postulated as a cause of age-related muscular atrophy. Direct study of NMJ morphology in laryngeal muscles is important to our understanding of age-related decrements in voice and swallowing. The morphology of NMJs was studied in a rat model to compare young and old specimens of thyroarytenoid muscle--a muscle critical to airway protection and phonation. Fluorescent, triple-label immunohistochemical analysis and confocal microscopic visualization were used to analyze the structure of NMJs. We found that laryngeal NMJs underwent significant changes that were similar to those observed after denervation. Specifically, the axon terminal area was significantly reduced, there were a number of postsynaptic acetylcholine receptor areas unoccupied by nerve terminals, and there was increased variability in end plate architecture in the old muscles. The results of this study increase our understanding of the age-related morphological changes in the larynx, and may serve as a baseline to test the effectiveness of future interventions.

Approximately one-fourth of the patients in this series showed pathologic evidence of residual carcinoma in the neck at the time of postradiotherapy neck dissection. The majority of these cases showed microscopic residual carcinoma in a single lymph node. Although in the early postradiotherapy setting, we cannot accurately predict the viability and growth potential of microscopic residual carcinoma in lymph nodes, these findings, combined with the modest overall morbidity of selective neck dissection, suggest that planned postradiotherapy neck dissection should be strongly considered for patients presenting with advanced neck disease. This remains a prevailing clinical practice at our institution.

Transoral collagen injection in patients with PRD is safe, well tolerated, and is an effective temporary method of subjectively improving voice and speech in selected patients with IPD. Reduction of glottal gap with collagen improves MPT and subglottal PTP. The resulting gain of vocal efficiency may reduce vocal fatigue and provide a useful adjunct to voice therapy for PRD.

To evaluate the effect of different dosing regimens of mitomycin on skin wound contraction.Methods: Full-thickness skin wounds were created in 5 groups of hairless mice, which represented different dosing regimens or a sterile water control: A, control; B, mitomycin (0.5 mg/mL) applied immediately after creation of the lesion (day 1); C, mitomycin (1.0 mg/mL) applied on day 1; D, mitomycin (0.5 mg/mL) applied on days 1 and 3; and E, mitomycin (1.0 mg/mL) applied on days 1 and 3. Wound surface area was measured immediately after drug application (day 1), and thereafter every 3 to 5 days until day 29 by means of computerassisted image analysis.Results: All dosing regimens of mitomycin application resulted in an initially exponential rate of wound contraction that was significantly slower than in the sterile water control group, with a significantly larger wound surface area on day 29. Wound area in the control group contracted approximately 9 times more rapidly than in the treatment groups. No difference was observed among the different dosing regimens. Conclusion:Application of mitomycin, at the lowest dose and frequency of application used in this study, resulted in improved outcomes with regard to contraction of full-thickness skin wounds.

Tracheomalacia (TM) is associated with expiratory airway collapse and potentially fatal respiratory distress. Internal and external tracheal stents and, recently, resorbable biopolymers have been used to treat this condition. In this study, the efficacy and biocompatibility of internal Palmaz stents and external poly-L-lactic acid-polyglycolic acid (PLPG) stents were compared in a model of severe TM induced in piglets. The tracheas were repaired with one of two stenting methods, and the animals survived for up to 16 weeks. Weight gain, adverse respiratory signs and symptoms, tracheal or lung histopathologic changes, and internal and external tracheal diameters were measured. The animals in the PLPG group uniformly were free of respiratory distress and tracheal stenosis or inflammation, whereas all animals in the Palmaz group developed respiratory distress as a result of pneumonia or tracheal stenosis caused by intraluminal granulation tissue. In conclusion, superior efficacy of external, resorbable PLPG stents was found relative to internal Palmaz stents for the surgical repair of severe TM.