Differential effects of UTP, ATP, and adenosine on ciliary activity of human nasal epithelial cells.

The purinergic regulation of ciliary activity was studied using small, continuously superfused explants of human nasal epithelium. The P2Y(2) purinoceptor (P2Y(2)-R) was identified as the major purinoceptor regulating ciliary beat frequency (CBF); UTP (EC(50) = 4.7 microM), ATP, and adenosine-5'-O-(3-thiotriphosphate) elicited similar maximal responses, approximately twofold over baseline. ATP, however, elicited a post-peak sustained plateau in CBF (1.83 +/- 0.1-fold), whereas the post-peak CBF response to UTP declined over 15 min to a low-level plateau (1.36 +/- 0.16-fold). UDP also stimulated ciliary beating, probably via P2Y(6)-R, with a maximal effect approximately one-half that elicited by P2Y(2)-R stimulation. Not indicated were P2Y(1)-R-, P2Y(4)-R-, or P2Y(11)-R-mediated effects. A(2B)-receptor agonists elicited sustained responses in CBF approximately equal to those from UTP/ATP [5'-(N-ethylcarboxamido)adenosine, EC(50) = 0.09 microM; adenosine, EC(50) = 0.7 microM]. Surprisingly, ADP elicited a sustained stimulation in CBF. The ADP effect and the post-peak sustained portion of the ATP response in CBF were inhibited by the A(2)-R antagonist 8-(p-sulfophenyl)theophylline. Hence, ATP affects ciliary activity through P2Y(2)-R and, after an apparent ectohydrolysis to adenosine, through A(2B)AR.

Sinonasal undifferentiated carcinoma: a review of the literature.

Sinonasal undifferentiated carcinoma is a relatively rare and aggressive malignancy of the nose and paranasal sinuses. It is often difficult to distinguish from other poorly differentiated sinonasal malignancies. Since it was first described in 1986, advances have been made in the understanding of the histology and immunohistochemical markers of sinonasal undifferentiated carcinoma, but the treatment options and prognosis remain poor. Presenting signs and symptoms, patient demographics, risk factors as well as immunohistochemical findings are reviewed. While no treatment is standard for sinonasal undifferentiated carcinoma, several modalities and combinations including chemotherapy, radiation, and surgery have been used with varied success. The several case series reported are examined and future directions of therapy discussed.

Superior semicircular canal dehiscence: a new cause of vertigo.

There are many known causes of vertigo, but many cases remain unexplained. Sound-induced, pressure-induced, or positional vertigo caused by bony dehiscence of the superior semicircular canal into the middle cranial fossa is a newly described etiology of vertigo. Three case studies of patients with CT evidence and surgical confirmation of bony dehiscence of the superior semicircular canal with variable presentations are described. The history, symptoms, CT findings, vestibular studies, and method of surgical repair are presented. Two patients had disabling vertigo and one had no vestibular symptoms. All underwent exploration via a middle cranial fossa approach with repair of the dehiscence. The bony dehiscence of the superior semicircular canal of the asymptomatic patient was identified and closed at the time of an encephalocele repair procedure. All patients did well postoperatively and both patients with vertigo improved. Bony dehiscence of the superior semicircular canal may cause vertigo or be asymptomatic and should be added to the differential diagnosis of vertigo.

Otolaryngologic manifestations of gastroesophageal reflux disease.

Gastroesophageal reflux disease (GERD) is the abnormal retrograde flow of gastric contents into the esophagus. While disorders of the esophagus related to GERD are fairly well characterized, supraesophageal symptoms may be nonspecific and easily missed. Fewer than half of the patients with otolaryngologic complications of reflux exhibit the classic findings of heartburn and regurgitation. GERD has been implicated in a broad range of disorders including laryngitis, chronic hoarseness, globus pharyngeus, laryngeal carcinoma, cricopharyngeal hypertension, Zenker's diverticulum, and chronic cough. A high index of suspicion is essential for timely diagnosis and treatment of the otolaryngologic manifestations of GERD.

Complications of neck dissection.

Neck dissection is a surgical procedure used in the diagnosis and treatment of head and neck cancer. The neck dissection involves excising the lymph nodes in specified regions of the neck with or without removing the sternocleidomastoid muscle, the internal jugular vein, and the spinal accessory nerve. The removal of cervical lymph nodes not only aids in staging the malignancy but also treats the nodal disease and dictates further treatment such as radiation therapy. Because of the proximity of vital structures, certain risks and complications are inherent to this operation. The prevention, recognition, and treatment of early and late complications of neck dissection are discussed.