Faculty Bibliography

Cartilaginous tumors of the larynx represent less than 1% of laryngeal tumors. Chondroma and 'low-grade' chondrosarcoma are the most common; 70%-75% of these tumors arise on the endolaryngeal surface of the posterior lamina of the cricoid cartilage. The clinical presentation is varied and directly dependent on the size and location of the tumor; stridor, hoarseness, dyspnea, or a neck mass are common presenting signs. CT scanning in the axial plane is the mainstay of radiographic imaging due to its ability to show size, extent of the tumor, and invasion into surrounding structures. Surgical extirpation is the standard therapy with no role for radiation therapy or chemotherapy. Although significant recurrence rates have been reported, there is not a significant difference between initial conservative therapy followed by salvage therapy versus initial radical therapy

BACKGROUND: Aberrant expression of the facilitative glucose transporter GLUT1 is found in a wide spectrum of epithelial malignancies. The authors describe an immunohistochemical study of GLUT1 expression in benign, borderline, and malignant ovarian epithelia. METHODS: One hundred forty one formalin-fixed, paraffin-embedded sections were immunostained with rabbit anti-GLUT1 using the streptavidin-biotin method. The samples were as follows: 3 endometriotic cysts, 9 serous cystadenomas, 15 mucinous cystadenomas, 17 noninvasive borderline implants, 3 invasive borderline implants, and 3 endosalpingiosis. In addition, 35 borderline tumors (26 serous, 7 mucinous, 2 seromucinous) and 56 adenocarcinomas (50 serous, 4 endometrioid, 2 mucinous) were stained. RESULTS: Benign serous and mucinous cystadenomas and endosalpingiosis were non-staining with GLUT1 antiserum. Twenty-eight of 35 borderline tumors (80%) stained positively, with weak to moderate (1-2+ out of 3) staining intensity and focal or patchy distribution. Seventeen noninvasive serous borderline implants were negatively stained; however, three invasive serous borderline implants were positively stained with GLUT1 antiserum. Fifty four of 56 ovarian carcinomas (96%) stained positively, with moderate to strong (2-3+ out of 3) intensity and multifocal distribution. CONCLUSIONS: GLUT1 is a consistent marker of ovarian epithelial malignancy. GLUT1 staining is absent in benign ovarian epithelial tumors, and shows progressively more staining in invasive tumors as compared to borderline tumors. Anti-GLUT1 antibody may be useful in distinguishing invasive from noninvasive serous borderline implants

Presynaptic I(h) channels become activated during a tetanus through membrane hyperpolarization resulting from Na(+) accumulation and electrogenic Na(+)/K(+) exchange. I(h) activation is obligatory for inducing long-term facilitation (LTF), a long-lasting synaptic strengthening. cAMP-induced synaptic enhancement also requires I(h) activation, and both processes are sensitive to actin depolymerization. Other mechanisms are responsible for expression of the responses. Once initiated, continued response to cAMP is I(h) and actin independent. Moreover, LTF-induced activation of I(h) renders subsequent cAMP enhancement insensitive to both I(h) blockers and actin depolymerization. This actin-stabilized 'temporal synaptic tagging' set by I(h) activation is prolonged when I(h) is activated concurrent with an elevation in presynaptic calcium concentration ([Ca(2+)]i), permitting the further strengthening of synapses given appropriate additional stimuli

Neurons of the thalamic reticular nucleus (TRN) provide inhibitory input to thalamic relay cells and generate synchronized activity during sleep and seizures. It is widely assumed that TRN cells interact only via chemical synaptic connections. However, we show that many neighboring pairs of TRN neurons in rats and mice are electrically coupled. In paired-cell recordings, electrical synapses were able to mediate close correlations between action potentials when the coupling was strong; they could modulate burst-firing states even when the coupling strength was more modest. Electrical synapses between TRN neurons were absent in mice with a null mutation for the connexin36 (Cx36) gene. Surprisingly, inhibitory chemical synaptic connections between pairs of neurons were not observed, although strong extracellular stimuli could evoke inhibition in single TRN neurons. We conclude that Cx36-dependent gap junctions play an important role in the regulation of neural firing patterns within the TRN. When combined with recent observations from the cerebral cortex, our results imply that electrical synapses are a common mechanism for generating synchrony within networks of inhibitory neurons in the mammalian forebrain.

OBJECTIVE: To present an unusual case of recurrent facial palsy resulting from acute leukemic infiltration of the parotid gland. STUDY DESIGN: Case report. METHODS: An 11-year-old boy who had been treated for acute lymphoblastic leukemia (ALL) from 3 to 6 years of age presented with intermittent left facial nerve palsy with concurrent ipsilateral parotid fullness. The initial findings at diagnosis and workup are presented, and the disease progression and resolution with therapy are documented. RESULTS: The patient had been off therapy when this finding developed. A workup for central and viral etiologies for the facial palsy was unrevealing. Biopsy of the parotid gland demonstrated a lymphoblastic leukemic infiltrate. The patient was placed on a chemotherapy protocol for relapsed leukemia, resulting in complete resolution of the facial palsy. CONCLUSION: Isolated facial nerve dysfunction, albeit rare, has been documented as a sign of central nervous system involvement in leukemia, but until now this presentation has not been described in the setting of leukemic relapse presenting with acute infiltration of the parotid gland

The author's current perspective of blepharoplasty is a product of a 30-year evolution in treating the aging eyelid. A review of the literature highlighting the most recent techniques can provide the reader with state of the art thinking by many authors on the subject. Some-times, however, a single surgeon's lifetime experience with a surgical procedure also can be insightful. The article details the author's experience with blepharoplasty

The clinical and aspiration cytologic details of a case of temporomandibular joint pigmented villonodular synovitis are presented and correlated with imaging, surgical, histopathologic, and clinical follow-up findings; the origin of such lesions is discussed. The lesion originally presented in a 36-year-old, otherwise healthy, white man as a unilateral mass involving the temporal fossa and temporomandibular joint region. The tumor's extent was defined by magnetic resonance imaging and computed tomographic scan; there was destruction of the temporomandibular joint and erosion of the temporal cranial bones by a lesion whose maximum dimensions were estimated by imaging to be 2.75 x 3.25 cm. The lesion was initially sampled and classified by computed tomography-guided fine-needle aspiration biopsy. Following complete resection, the original diagnosis was confirmed with both hematoxylin-eosin-stained paraffin sections and immunohistochemical staining. The patient remains free of disease 7 years postoperatively.

OBJECTIVES: Cyclooxygenases (COX) are enzymes that catalyze the conversion of arachidonic acid to prostaglandins. COX-2, unlike the constitutively expressed COX-1, is an inducible enzyme upregulated during cell proliferation and inflammation. More recently, COX-2 has been implicated in the development of numerous types of epithelial cancers. In addition, COX-2 is highly expressed in several inflammatory diseases. Because of its dual role in inflammation and cancer, we were interested in determining if COX-2 plays a role in the development of human thyroid carcinoma and Hashimoto's thyroiditis, an autoimmune condition frequently associated with thyroid malignancy. MATERIALS AND METHODS: Twenty paraffin-embedded human tissue specimens, including normal, inflammatory, and neoplastic thyroid sections, were analyzed by immunohistochemical staining for expression of human COX-2. In addition, COX-2 protein expression was verified by Western blot in two specimens. RESULTS: Immunohistochemical staining confirmed the presence of COX-2 in thyroid epithelial neoplasms, including papillary and follicular carcinomas. Moreover, COX-2 expression was observed in patients with Hashimoto's thyroiditis. COX-2 expression, however, was not observed in normal thyroid tissue, multinodular goiter, or anaplastic carcinoma. CONCLUSIONS: We have shown that cyclooxygenase-2 is expressed in thyroid carcinoma and thyroid epithelium from patients with Hashimoto's thyroiditis but not in normal thyroid. The expression of COX-2 in both of these thyroid pathologies may provide a basis for the relationship between carcinogenesis and autoimmunity.