Faculty Bibliography

Cervical chylomas are rare entities, as only four cases have been previously reported. All of these previous cases involved the left side, all were related to the thoracic duct, and all occurred following trauma or surgery. We report a new case of a left-sided chyloma that was unusual because it arose following a right-sided subtotal thyroidectomy. The chyloma arose as a left supraclavicular mass within 3 months of the thyroidectomy, and it slowly enlarged over a period of 9 years. Following evaluation by computed tomography, the mass was excised, and the patient recovered uneventfully. We also review what is known about the diagnosis and treatment of cervical chylomas

OBJECTIVES/HYPOTHESIS: Laser-assisted uvulopalatoplasty (LAUP) is a widely accepted procedure for the management of snoring, but its role in the treatment of obstructive sleep apnea syndrome is currently unclear. The objective of the study was to evaluate the role of LAUP in treating moderate and severe obstructive sleep apnea syndrome. STUDY DESIGN: Retrospective review of a surgical treatment protocol for obstructive sleep apnea syndrome. METHODS: Between October 1993 and January 1999, 80 patients with moderate or severe obstructive sleep apnea syndrome and a significant component of retropalatal obstruction were treated with surgery at the Department of Otolaryngology at Northwestern University Medical School (Chicago, IL). Surgery consisted of LAUP with tonsillectomy (if tonsils were present) with the patient under general anesthesia or LAUP alone with local anesthesia (if the tonsils were absent). No patients received traditional uvulopalatopharyngoplasty. Sixty-four of the 80 patients underwent both preoperative and postoperative polysomnograms. Surgical 'response' was defined as a 50% decrease in the apnea-hypopnea index (AHI) (the total number of apneic and hypopneic events per hour of sleep); surgical 'cure' was defined as a 50% decrease in AHI and a final AHI of less than 20. RESULTS: The surgical response rate was 59% (38 of 64 patients), and the surgical cure rate was 39% (25 of 64 patients). Twelve patients (18.8%) had a higher AHI after surgery. The AHI (mean +/- SD) changed significantly from 51.4 +/- 30.9 preoperatively to 26.3 +/- 20.8 on postoperative polysomnogram (P = 7.0 x 10-9). Laser-assisted uvulopalatoplasty alone was performed in 33 patients with a response rate of 61% and a cure rate of 42%. Laser-assisted uvulopalatoplasty with tonsillectomy was performed in 31 patients with a response rate of 58% and a cure rate of 35%. The overall incidence of nasopharyngeal insufficiency was 0%. CONCLUSION: The results of the study suggested that LAUP with adjunctive tonsillectomy is an effective treatment for patients with obstructive sleep apnea syndrome and retropalatal obstruction with a lower complication rate than standard surgical therapy (uvulopalatopharyngoplasty)

HYPOTHESES: Do cochlear implants provide enough information to allow adult cochlear implant users to understand words in ways that are similar to listeners with acoustic hearing? Can we use a computational model to gain insight into the underlying mechanisms used by cochlear implant users to recognize spoken words? BACKGROUND: The Neighborhood Activation Model has been shown to be a reasonable model of word recognition for listeners with normal hearing. The Neighborhood Activation Model assumes that words are recognized in relation to other similar-sounding words in a listener's lexicon. The probability of correctly identifying a word is based on the phoneme perception probabilities from a listener's closed-set consonant and vowel confusion matrices modified by the relative frequency of occurrence of the target word compared with similar-sounding words (neighbors). Common words with few similar-sounding neighbors are more likely to be selected as responses than less common words with many similar-sounding neighbors. Recent studies have shown that several of the assumptions of the Neighborhood Activation Model also hold true for cochlear implant users. METHODS: Closed-set consonant and vowel confusion matrices were obtained from 26 postlingually deafened adults who use cochlear implants. Confusion matrices were used to represent input errors to the Neighborhood Activation Model. Responses to the different stimuli were then generated by the Neighborhood Activation Model after incorporating the frequency of occurrence counts of the stimuli and their neighbors. Model outputs were compared with obtained performance measures on the Consonant-Vowel Nucleus-Consonant word test. Information transmission analysis was used to assess whether the Neighborhood Activation Model was able to successfully generate and predict word and individual phoneme recognition by cochlear implant users. RESULTS: The Neighborhood Activation Model predicted Consonant-Vowel Nucleus-Consonant test words at levels similar to those correctly identified by the cochlear implant users. The Neighborhood Activation Model also predicted phoneme feature information well. CONCLUSION: The results obtained suggest that the Neighborhood Activation Model provides a reasonable explanation of word recognition by postlingually deafened adults after cochlear implantation. It appears that multichannel cochlear implants give cochlear implant users access to their mental lexicons in a manner that is similar to listeners with acoustic hearing. The lexical properties of the test stimuli used to assess performance are important to spoken-word recognition and should be included in further models of the word recognition process

OBJECTIVES: To identify distinct gene expression profiles of human head and neck squamous cell carcinomas (HNSCCAs) using complementary DNA (cDNA) microarray analysis and to create a preliminary, comprehensive database of HNSCCA gene expression. PATIENTS AND METHODS: Nine patients with histologically confirmed HNSCCAs, staged according to the American Joint Committee on Cancer, were enrolled. The HNSCCA tumor tissue and normal mucosal tissue were harvested at the time of surgery. A cDNA library was constructed from the paired fresh-frozen human surgical specimens of HNSCCAs and nonmalignant epithelial tissues. Biotinylated RNA was transcribed from the cDNA library and hybridized to high-density microarrays containing approximately 12 000 human genes. Altered gene expression of HNSCCAs was identified by comparison to corresponding normal mucosal tissues after a bayesian statistical analysis of variance. Results were analyzed using the gene database of the National Institutes of Health. Hierarchical clustering of the genomic data sets was determined by similarity metrics based on Pearson correlation. RESULTS: Hierarchical clustering analysis revealed that the gene expression profiles obtained from the nonselected panel of 12 000 genes could distinguish the tumors from nonmalignant tissues. Gene expression changes were reproducibly observed in 227 genes representing previously identified chemokines, tumor suppressors, differentiation markers, matrix molecules, membrane receptors, and transcription factors that correlated with neoplasia, including 46 previously uncharacterized genes. Moreover, significant expression of the collagen type XI alpha1 gene and a novel gene was reproducibly observed in all 9 tumors, whereas these genes were virtually undetectable in their corresponding, adjacent nonmalignant tissues. CONCLUSIONS: Complementary DNA microarray analysis of human HNSCCAs has produced a preliminary, comprehensive database of tumor-specific gene expression profiles and provided important insights into modeling gene expression changes implicated in carcinogenesis. A large-scale analysis of gene expression carries the future potential of identifying sensitive molecular markers for early tumor detection, prognosis, and novel targets for interceptive therapeutics

BACKGROUND: The effectiveness of chemotherapeutic agents is proportional to the dose of the agents at their targets; however, the dose is limited by systemic toxicity. Attempts have been made to improve therapeutic effectiveness by increasing maximum tolerated dose (MTD) of chemotherapeutic agents using various local and regional drug delivery systems. Herein we report the use of an injectable biodegradable polymer to deliver cisplatin for intratumoral treatment of human head and neck squamous cell carcinoma (HNSCC) in a chimeric mouse model. The objectives of this research project were (1) to determine the release kinetics of cisplatin from the polymer delivery system, (2) to identify the MTD of polymer-delivered cisplatin, and (3) to evaluate its therapeutic efficacy. METHODS: To determine the in vivo release kinetics, cisplatin-loaded polymer was injected subcutaneously into rats. Implants were removed and analyzed for remaining cisplatin by a high-performance liquid chromatography technique. Sera from these rats were assayed for platinum by atomic absorption spectrophotometry. For MTD determination, SCID mice were engrafted subcutaneously with fresh biopsy specimens of HNSCC. Various doses of free or polymer-loaded cisplatin were injected intratumorally. MTD was estimated based on the threshold at which all mice survived. The antitumor efficacy of free and polymer-loaded cisplatin at their respective MTD was assayed on the same chimeric mouse model. RESULTS: The polymer delivery system released 80% of the loaded cisplatin in vivo over a 7-day period. The polymer-delivered cisplatin exhibited higher MTD (36 mg/kg) than free cisplatin (18 mg/kg) and had a statistically significant tumor suppression effect compared with free cisplatin when used at their respective MTD. CONCLUSIONS: The polymer delivery system can sustain cisplatin release for a period of 7 days. It can increase MTD and potentially enhance the antitumor efficacy of cisplatin against human head and neck cancers

Paragangliomas most commonly occur in the carotid body, jugulotympanic area, and vagus nerve but have also been reported in other areas of the head and neck. These tumors are highly vascular and characteristically have early blood vessel and neural involvement, making their treatment particularly challenging. Surgery has traditionally been the preferred method of treatment, especially in light of recent advances in technique. However, compared to radiation therapy, it can result in a higher incidence of cranial nerve dysfunction. Radiation therapy has the advantage of avoiding the increased morbidity of surgery while offering an equal possibility of cure. Part 1 of this two-part article focuses on techniques for diagnosing paraganglioma and the indications for and use of surgery as primary treatment. The complications commonly associated with surgery are reviewed, and strategies for rehabilitation of affected patients are presented.

Epidermoid inclusion cysts are benign lesions that occasionally occur in the distal phalanges of the fingers but are less frequently identified and underreported in the toes. We describe a 55-year-old man with a history of work-related trauma followed by painful expansion of his right great toe, resulting in great anxiety. Imaging studies revealed a radiolucent lesion in the distal phalanx of his right hallux. Clinical differential diagnoses included the possibility of an intramedullary inclusion cyst and other various radiolucent lesions. During surgery, a cystic lesion that contained creamy material was discovered. Frozen section diagnosis of the lesion was an intraosseous epidermoid inclusion cyst. The lesion was removed and the patient recovered uneventfully. Although it has been reported that an unduly large number of phalangeal cysts have been treated by amputation, the judicious use of intraoperative frozen sections can prevent this scenario

We determined how the perceived naturalness of music and speech (male and female talkers) signals was affected by various forms of linear filtering, some of which were intended to mimic the spectral 'distortions' introduced by transducers such as microphones, loudspeakers, and earphones. The filters introduced spectral tilts and ripples of various types, variations in upper and lower cutoff frequency, and combinations of these. All of the differently filtered signals (168 conditions) were intermixed in random order within one block of trials. Levels were adjusted to give approximately equal loudness in all conditions. Listeners were required to judge the perceptual quality (naturalness) of the filtered signals on a scale from 1 to 10. For spectral ripples, perceived quality decreased with increasing ripple density up to 0.2 ripple/ERB(N) and with increasing ripple depth. Spectral tilts also degraded quality, and the effects were similar for positive and negative tilts. Ripples and/or tilts degraded quality more when they extended over a wide frequency range (87-6981 Hz) than when they extended over subranges. Low- and mid-frequency ranges were roughly equally important for music, but the mid-range was most important for speech. For music, the highest quality was obtained for the broadband signal (55-16,854 Hz). Increasing the lower cutoff frequency from 55 Hz resulted in a clear degradation of quality. There was also a distinct degradation as the upper cutoff frequency was decreased from 16,845 Hz. For speech, there was a marked degradation when the lower cutoff frequency was increased from 123 to 208 Hz and when the upper cutoff frequency was decreased from 10,869 Hz. Typical telephone bandwidth (313 to 3547 Hz) gave very poor quality