Immunocytochemical localization of aspartate and glutamate in the peripheral vestibular system.

Controversy exists concerning the identity of the neurotransmitter in the mammalian peripheral vestibular system. Several candidates have been proposed, including the excitatory amino acids glutamate and aspartate and the inhibitory amino acid gamma-aminobutyric acid (GABA). Previous studies have demonstrated vestibuloneural electrophysiological activity associated with glutamate and aspartate. Paraffin sections of rat vestibular ganglia and end-organs were examined for the presence of glutamate-like and aspartate-like immunoreactivity. Our results demonstrate the presence of both aspartate-like and glutamate-like immunoreactivity in vestibular hair cells, peripheral vestibular nerve fibers, and vestibular ganglion cells. Minimal immunoreactivity was noted in the tissues surrounding these cells. These data add support to the hypothesis that the excitatory amino acids glutamate and aspartate are involved in vestibular neurotransmission.

Tracheotomy and the intensive care unit patient.

Transportation of the intensive care unit (ICU) patient to the operating room for tracheotomy has been implicated as an unnecessary source of complications and has been cited as a relative indication for percutaneous tracheotomy. However, there is very little evidence in the literature to support this claim. We evaluated 100 consecutive patients who were transported from the ICU to the operating room for tracheotomy. There were no complications related to patient transportation. A total of five complications occurred, all unrelated to patient transportation. Two patients receiving pressure control ventilation developed a pneumothorax on postoperative days 7 and 8, respectively. There were three minor complications directly related to the tracheotomy: peristomal cellulitis, tracheitis, and hemorrhage of less than 25 cc on postoperative day 1. The minor complications were treated appropriately and resolved without any adverse sequelae. We provide a detailed review of 100 consecutive ICU patient tracheotomy cases and compare this with 109 tracheotomies in non-ICU patients. Transportation of the ICU patient does not appear to increase the risk of complications during tracheotomy and should not be cited as a cause of complications in the percutaneous tracheotomy literature. The results with standard surgical tracheotomy in the controlled setting of the operating room should serve as the standard by which other procedures are judged.

Outpatient uvuloplasty: an inexpensive, single-staged procedure for the relief of symptomatic snoring.

Outpatient uvulopalatoplasty is an inexpensive alternative to laser-assisted uvulopalatoplasty for relief of symptomatic snoring. This single-stage procedure successfully reduced snoring in properly selected patients. Patients reported improvement in most cases, with 55% indicating great improvement or complete resolution. Spouses reported 83% of the patients were significantly improved or resolved. To date we have had no complications, including bleeding, infection, or velopharyngeal insufficiency or stenosis.

Nitric oxide in the rat vestibular system.

Nitric oxide is known to function as a neurotransmitter in the central nervous system. It is also known to be involved in the central nervous system excitatory amino acid neurotransmission cascade. Activation of excitatory amino acid receptors causes an influx of calcium, which activates nitric oxide synthase. The resulting increase in intracellular nitric oxide activates soluble guanylate cyclase, leading to a rise in cyclic guanosine monophosphate. The excitatory amino acids glutamate and aspartate are found in the vestibular system and have been postulated to function as vestibular system neurotransmitters. Although nitric oxide has been investigated as a neurotransmitter in other tissues, no published studies have examined the role of nitric oxide in the vestibular system. Neuronal NADPH-diaphorase has been characterized as a nitric oxide synthase. This enzyme catalyzes the conversion of L-arginine to L-citrulline, producing nitric oxide during the reaction. We used a histochemical stain characterized by Hope et al. (Proc Natl Acad Sci 1991;88:2811) as specific for neuronal nitric oxide synthase to localize the enzyme in the rat vestibular system. An immunocytochemical stain was used to examine rat inner ear tissue for the presence of the enzyme's end product, L-citrulline, thereby demonstrating nitric oxide synthase activity. Staining of vestibular ganglion sections showed nitric oxide synthase presence and activity in ganglion cells and nerve fibers. These results indicate the presence of active nitric oxide synthase in these tissues and suggest modulation of vestibular neurotransmission by nitric oxide.

The Carolina Children's Communicative Disorders Program. An opportunity for North Carolina's children.

The CCCDP provides devices and services to underprivileged children with communication disorders. Since its organization, the program has helped 197 children, including 21 given cochlear implants, and has disbursed 258 hearing aids or devices. It is cost-efficient program that has potential to help many of our state's needful children. We solicit referrals from all NC physicians, audiologists, speech pathologists, educators, and other professionals. Applications and financial forms will be furnished on request.

Fibromatosis colli: a common cause of neonatal torticollis.

In infants and children, cervical masses originate from a variety of pathologic, congenital and developmental conditions, and it is important to distinguish benign from serious lesions. Fibromatosis colli is a rare cervical lesion that typically presents in the neonatal period. It is the most common cause of neonatal torticollis and should be recognized by physicians caring for neonates and infants.