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Neurochemical substances in the ganglionic cells of the canine intrinsic laryngeal muscles
Otolaryngology Head and Neck Surgery Volume 117 Number2
nerve fibers immunoreactive to protein gene product 9.5, a sensitive neuronal marker, calcitonin gene-related peptide, and substance P in the pharyngeal epithelium was analyzed in both intact animals and in animals subjected to partial denervation by means of sectioning two of the three nerve trunks consisting of the glossopharyngeal nerve (GPN), the superior laryngeal nerve (SLN), and the PhB, while leaving one intact. The present results show that the GPN and SLN carry nerve fibers to the pharyngeal epithelium rostral and caudal to the middle level of the epiglottis, respectively, while the PhB carries nerve fibers to the mesopharyngeal epithelium. Tracer experiments, performed by applying wheat germ agglutinin-horseradish peroxidase to the PhB, demonstrate retrogradely labeled primary sensory neurons in the jugular ganglion and transganglionic labeling of terminals in the interstitial subnucleus of the nucleus of the tractus solitarius (NTSis). These results thus indicate that the PhB contains a sensory component that originates from the jugular ganglion, innervates the mesopharyngeal epithelium, and projects to the NTSis. P o s t e r 47
Neurochemical Substances in the Ganglionic Cells of the Canine Intrinsic Laryngeal Muscles SHINOBU KOIKE, MD (presenter), YASUO HISA, MD, TOSHIYUKI UNO, MD, NOBUHISA TADAKI, MD, and HITOSHI BAMBA, MD, Kyoto, Japan
The existence of nitrergic neurons in the intrinsic laryngeal muscles (ILM) has been demonstrated in rat and dog, and it has been suggested that nitric oxide (NO) may participate in the regulation of various laryngeal functions. The authors have previously reported in detail in the dog ILM the distribution of intramuscular ganglia with nitrergic neurons. Neurons without nitric oxide synthase immunoreactivity were also seen in such intramuscular ganglia. The present study investigates the participation of vasoactive intestinal polypeptide (VIP), calcitonin gene-related peptide (CGRP), and heme oxygenase-2 (HO2) in the regulation of neurons in the ILM of the dog with immunohistochemical techniques. Mongrel dogs were perfused through the left cardiac ventricle with 0.1 mol/L phosphate buffer with 2% paraformaldehyde under deep anesthesia, and the larynx was extirpated then postfixed in the same fixative. The cricothyroid and posterior cricoarytenoid muscles were removed and sectioned on a cryostat. The sections were then immunohistochemically stained with an anti-VIP, anti-CGRP, or anti-HO2 serum. Neurons with VIP-like immunoreactivity were seen in ganglia found between the striated muscle fibers of the ILM. Most of the ganglia also contained cells without VIP-like immunoreactivity. H02-positive neurons were also seen in ganglia found between the muscle fibers, and these ganglia also contained varying numbers of nonstaining cells. No neuronal cell bodies in the ILM were CGRP-positive, although nerve fibers with CGRP-like immunoreactivity were seen in the sections. There is much to be clarified concerning the function of these intramuscular ganglia, but the results of this study sug-
Research Forum - - Monday
P99
gest that VIP may participate in neuronal regulation of the ILM, and thus at least some of the neurons in the intramuscular ganglia may be parasympathetic in nature. The existence of H02-positive neurons in the ILM shows that carbon monoxide may also play a role in control of these muscles. P o s t e r 48
The Impact of the Palmaz Balloon Expandable Metallic Stent in the Tracheas of Pigs JOSEPH L. RUEGEMER, MD (presenter), and JONATHAN A. PERKINS, DO, Tacoma, Wash.
Objective: Significant narrowing of the trachea and main stem bronchi by congenital anomalies in the pediatric airway is a challenging management problem. Open surgical procedures have inherently high morbidity and are sometimes not ideal for lengthy stenoses. Endoscopic management of severe airway narrowing through use of expandable metallic stents has been reported. The balloon-mounted Palmaz stent resists compressive forces and allows controlled expansion and removal, unlike self-expanding stents. Development of an animal model comparable to the pediatric airway and amenable to endoscopic instrumentation is necessary to assess usefulness of balloon expandable metallic stents in treating pediatric airway stenosis. In addition, effect of stent implantation on tracheal growth needs to be determined. Methods: Six, 4-week-old piglets (Sus Scrofa) and one control were utilized in the study. Midtracheal placement of the Palmaz stent was performed under direct vision by passing balloon-mountedstents through a Karl Storz 3.5 bronchoscope. Initial expansion and stent position was verified fluoroscopically and endoscopically. Serial endoscopic examination and stent re-expansion was performed at 2-week intervals, through completion at 4 to 6 weeks. Animal weight, tracheal growth, and stent integrity were observed. Tracheal inflammation was evaluated grossly and by histopathological analysis. Results~Conclusions: Successful endotracheal stent placement and expansion were accomplished in all pigs. One pig died of anesthesia complications less than 24 hours after stent placement. The remaining pigs tolerated the endotracheal stent without event through study completion. Minimal stent migration was noted in one pig at 2 weeks. No detrimental effect on overall pig and tracheal growth was noted. Gross and histopathological fmdings will be presented. Palmaz metallic stents were well tolerated in this study. This pig trachea appears to be an excellent model for further evaluation of endoscopic management of congenital airway stenosis. Poster 49
Effects of Sound Pressure Levels on Fundamental Frequency in Tracheoesophageal Speakers DANIEL G. DESCHLER,MD (presenter), E. THOMAS DOHERTY, PhD, and MARK I. SINGER, MD, Philadelphia, Pa., and Novato and San Francisco, Calif.
The quality of tracheoesophageal voice following laryngectomy is dependent on numerous factors. The rela-
nerve fibers immunoreactive to protein gene product 9.5, a sensitive neuronal marker, calcitonin gene-related peptide, and substance P in the pharyngeal epithelium was analyzed in both intact animals and in animals subjected to partial denervation by means of sectioning two of the three nerve trunks consisting of the glossopharyngeal nerve (GPN), the superior laryngeal nerve (SLN), and the PhB, while leaving one intact. The present results show that the GPN and SLN carry nerve fibers to the pharyngeal epithelium rostral and caudal to the middle level of the epiglottis, respectively, while the PhB carries nerve fibers to the mesopharyngeal epithelium. Tracer experiments, performed by applying wheat germ agglutinin-horseradish peroxidase to the PhB, demonstrate retrogradely labeled primary sensory neurons in the jugular ganglion and transganglionic labeling of terminals in the interstitial subnucleus of the nucleus of the tractus solitarius (NTSis). These results thus indicate that the PhB contains a sensory component that originates from the jugular ganglion, innervates the mesopharyngeal epithelium, and projects to the NTSis. P o s t e r 47
Neurochemical Substances in the Ganglionic Cells of the Canine Intrinsic Laryngeal Muscles SHINOBU KOIKE, MD (presenter), YASUO HISA, MD, TOSHIYUKI UNO, MD, NOBUHISA TADAKI, MD, and HITOSHI BAMBA, MD, Kyoto, Japan
The existence of nitrergic neurons in the intrinsic laryngeal muscles (ILM) has been demonstrated in rat and dog, and it has been suggested that nitric oxide (NO) may participate in the regulation of various laryngeal functions. The authors have previously reported in detail in the dog ILM the distribution of intramuscular ganglia with nitrergic neurons. Neurons without nitric oxide synthase immunoreactivity were also seen in such intramuscular ganglia. The present study investigates the participation of vasoactive intestinal polypeptide (VIP), calcitonin gene-related peptide (CGRP), and heme oxygenase-2 (HO2) in the regulation of neurons in the ILM of the dog with immunohistochemical techniques. Mongrel dogs were perfused through the left cardiac ventricle with 0.1 mol/L phosphate buffer with 2% paraformaldehyde under deep anesthesia, and the larynx was extirpated then postfixed in the same fixative. The cricothyroid and posterior cricoarytenoid muscles were removed and sectioned on a cryostat. The sections were then immunohistochemically stained with an anti-VIP, anti-CGRP, or anti-HO2 serum. Neurons with VIP-like immunoreactivity were seen in ganglia found between the striated muscle fibers of the ILM. Most of the ganglia also contained cells without VIP-like immunoreactivity. H02-positive neurons were also seen in ganglia found between the muscle fibers, and these ganglia also contained varying numbers of nonstaining cells. No neuronal cell bodies in the ILM were CGRP-positive, although nerve fibers with CGRP-like immunoreactivity were seen in the sections. There is much to be clarified concerning the function of these intramuscular ganglia, but the results of this study sug-
Research Forum - - Monday
P99
gest that VIP may participate in neuronal regulation of the ILM, and thus at least some of the neurons in the intramuscular ganglia may be parasympathetic in nature. The existence of H02-positive neurons in the ILM shows that carbon monoxide may also play a role in control of these muscles. P o s t e r 48
The Impact of the Palmaz Balloon Expandable Metallic Stent in the Tracheas of Pigs JOSEPH L. RUEGEMER, MD (presenter), and JONATHAN A. PERKINS, DO, Tacoma, Wash.
Objective: Significant narrowing of the trachea and main stem bronchi by congenital anomalies in the pediatric airway is a challenging management problem. Open surgical procedures have inherently high morbidity and are sometimes not ideal for lengthy stenoses. Endoscopic management of severe airway narrowing through use of expandable metallic stents has been reported. The balloon-mounted Palmaz stent resists compressive forces and allows controlled expansion and removal, unlike self-expanding stents. Development of an animal model comparable to the pediatric airway and amenable to endoscopic instrumentation is necessary to assess usefulness of balloon expandable metallic stents in treating pediatric airway stenosis. In addition, effect of stent implantation on tracheal growth needs to be determined. Methods: Six, 4-week-old piglets (Sus Scrofa) and one control were utilized in the study. Midtracheal placement of the Palmaz stent was performed under direct vision by passing balloon-mountedstents through a Karl Storz 3.5 bronchoscope. Initial expansion and stent position was verified fluoroscopically and endoscopically. Serial endoscopic examination and stent re-expansion was performed at 2-week intervals, through completion at 4 to 6 weeks. Animal weight, tracheal growth, and stent integrity were observed. Tracheal inflammation was evaluated grossly and by histopathological analysis. Results~Conclusions: Successful endotracheal stent placement and expansion were accomplished in all pigs. One pig died of anesthesia complications less than 24 hours after stent placement. The remaining pigs tolerated the endotracheal stent without event through study completion. Minimal stent migration was noted in one pig at 2 weeks. No detrimental effect on overall pig and tracheal growth was noted. Gross and histopathological fmdings will be presented. Palmaz metallic stents were well tolerated in this study. This pig trachea appears to be an excellent model for further evaluation of endoscopic management of congenital airway stenosis. Poster 49
Effects of Sound Pressure Levels on Fundamental Frequency in Tracheoesophageal Speakers DANIEL G. DESCHLER,MD (presenter), E. THOMAS DOHERTY, PhD, and MARK I. SINGER, MD, Philadelphia, Pa., and Novato and San Francisco, Calif.
The quality of tracheoesophageal voice following laryngectomy is dependent on numerous factors. The rela-