Faculty Bibliography

PURPOSE OF REVIEW: Degeneration of spiral ganglion neurons following hair cell loss carries critical implications for efforts to rehabilitate severe cases of hearing loss with cochlear implants or hair cell regeneration. This review considers recently identified neurotrophic factors and therapeutic strategies which promote spiral ganglion neuron survival and neurite growth. Replacement of these factors may help preserve or regenerate the auditory nerve in patients with extensive hair cell loss. RECENT FINDINGS: Spiral ganglion neurons depend on neurotrophic factors supplied by hair cells and other targets for their development and continued survival. Loss of this trophic support leads to spiral ganglion neuron death via apoptosis. Hair cells support spiral ganglion neuron survival by producing several peptide neurotrophic factors such as neurotrophin-3 and glial derived neurotrophic factor. In addition, neurotransmitter release from the hair cells drives membrane electrical activity in spiral ganglion neurons which also supports their survival. In animal models, replacement of peptide neurotrophic factors or electrical stimulation with an implanted electrode attenuates spiral ganglion neuron degeneration following deafferentation. Cell death inhibitors can also preserve spiral ganglion neuron populations. Preliminary studies show that transfer of stem cells or neurons from other ganglia are two potential strategies to replace lost spiral ganglion neurons. Inducing the regrowth of spiral ganglion neuron peripheral processes to approximate or contact cochlear implant electrodes may help optimize signaling from a diminished population of neurons. SUMMARY: Recent studies of spiral ganglion neuron development and survival have identified several trophic and neuritogenic factors which protect these specialized cells from degeneration following hair cell loss. While still preliminary, such strategies show promise for future clinical applications

To analyze the impact of resection margin status and histologic prognosticators on local recurrence (LR) and overall survival (OS) for patients with oral squamous cell carcinoma (OSCC). This study was both retrospective and prospective in design. Cohort 1 refers to the entire group of 292 patients with OSCC. The slides from the earliest resection specimens from Cohort 1 were examined in an exploratory manner for multiple parameters. Cohort 2 refers to a subset of 203 patients, who did not receive any neoadjuvant therapy and had outcome data. Cohort 3 represents a subset of Cohort 2 (n = 168) wherein the histologic resection margin status could be reconfirmed. Cohort 4 refers a subset of 85 patients with tongue/floor of mouth tumors. Margin status was designated as follows: group 1, clearance of > or =5 mm with intraoperative analysis, no need for supplemental margins (n = 46); group 2, initial margins were measured as <5 mm during intraoperative frozen section; supplemental resection margins were negative on final pathology (n = 73); group 3, the final pathology revealed resection margins <5 mm (n = 30); group 4, the final pathology revealed frankly positive resection margins (n = 19). The endpoints of LR and OS were queried with respect to T stage, tumor site, margin status, and numerous histologic variables, by Cox regression and Kaplan-Meier survival analyses. Tumor stage (T) was significantly associated with LR (P = 0.028). Kaplan-Meier analysis for stage and for intraoral site was significantly associated with LR for T4 tumors. The increased likelihood of LR was higher for T4 OSCC of the buccal mucosa (75%), sinopalate (50%), and gingiva (100%) compared with mobile tongue (27%), and oropharynx (13%) (P = 0.013). Margin status was not associated with LR or OS (Cohort 3). This was so when all tumors were grouped together and when separate analyses were performed by tumor stage and oral subsite. No significance was demonstrated when margin status was examined for patients with similar treatment (surgery alone or surgery with adjuvant RT). However, the administration of adjuvant RT did significantly increase local disease-free survival (P = 0.0027 and P = 0.001 for T1 and T2 SCC, respectively). On exploratory analyses of histologic parameters, worst pattern of invasion was significantly associated with LR (P = 0.015) and OS (P < 0.001). Perineural invasion involving large nerves (>1 mm) was associated with LR (P = 0.005) and OS (P = 0.039). Limited lymphocytic response was also significantly associated with LR (P = 0.005) and OS (P = 0.001). When used as covariates in a multivariate Cox regression model, worst pattern of invasion, perineural invasion, and lymphocytic response were significant and independent predictors of both LR and OS, even when adjusting for margin status. Thus, these factors were used to generate our risk assessment. Our risk assessment classified patients into low-, intermediate-, or high-risk groups, with respect to LR (P = 0.0004) and OS (P < 0.0001). This classification retained significance when examining patients with uniform treatment. In separate analyses for each risk group, we found that administration of adjuvant radiation therapy is associated with increased local disease-free survival for high-risk patients only (P = 0.0296) but not low-risk or intermediate-risk patients. Resection margin status alone is not an independent predictor of LR and cannot be the sole variable in the decision-making process regarding adjuvant radiation therapy. We suggest that the recommendation for adjuvant radiation therapy be based on, not only traditional factors (inadequate margin, perineural invasion, bone invasion) but also histologic risk assessment. If clinicians want to avoid the debilitation of adjuvant radiation therapy, then a 5-mm margin standard may not be effective in the presence of high-risk score

The coexistence of lung cancer and glomerular lesion is not commonly reported. Malignancy-related glomerulopathy is commonly membranous glomerulonephritis. Other glomerulopathies are seldom reported. We report two cases presenting with non-small-cell lung cancer, acute renal failure and nephrotic syndrome secondary to membranoproliferative glomerulonephritis and amyloidosis

OBJECTIVES/HYPOTHESIS: Peptide receptor imaging with Indium pentetreotide is useful in the diagnosis of diffuse neuroendocrine system tumors (DNEST) of the head and neck. Uses of Indium pentetreotide scintigraphy include tumor and metastases detection, familial tumor screening, and surveillance for recurrence. Using target to background ratios (TBR) could generate a comparative scale for these tumors. STUDY DESIGN: A retrospective study evaluated the size, TBR, conventional imaging, and outcomes of patients imaged with Indium pentetreotide scintigraphy for suspected head and neck DNEST. METHODS: Patients with head and neck tumors imaged by Indium pentetreotide scintigraphy during a nine-year period were reviewed. Data analyzed were age, sex, scintigraphy, pathology, and conventional radiology. Tumor data included dimension, multiplicity, metastases, and tumor and brain counts. RESULTS: Fifty-three patients underwent 58 scans. The sensitivity and specificity were 93% and 92%. Several different DNEST were successfully evaluated, including familial paragangliomas and multiple paragangliomas. TBRs were variable depending on type of DNEST. CONCLUSIONS: Indium pentetreotide scintigraphy is accurate in determining the presence of paragangliomas, carcinoid tumors, esthesioneuroblastomas, small cell neuroendocrine tumors, andmetastases. It is an excellent surveillance tool. Screening patients for familial paragangliomas can be accomplished. No reliable comparative scale to distinguish amongst the various DNEST could be developed using TBR

BACKGROUND: We recently identified MUC1 as a target driving selection for 1q21 amplification and validated it as an independent marker of aggressive behavior in thyroid cancer (TC). The aims of this study were to determine whether TC cell lines retain MUC1 expression patterns that are seen in primary tumors, assess the role of MUC1 in tumor maintenance, and develop a virally delivered anti-MUC1 RNA interference (RNAi) that is effective in decreasing MUC1 expression in vitro. METHODS: Fifteen TC cell lines were screened for MUC1 protein expression. Cell lines with varying MUC1 protein levels were treated with anti-MUC1 monoclonal antibody to assess cell viability. A recombinant retroviral short hairpin RNAi delivery system against MUC1 was developed. Efficacy and optimal dosing of short hairpin RNA against MUC1 was determined. RESULTS: MUC1 expression patterns in TC cell lines were found to be similar to that seen in primary tumors. Treatment with anti-MUC1 antibody resulted in a significant decrease in cell viability in MUC1 over-expressing cell lines. MUC1-779 RNAi construct showed excellent infection efficiency and reproducible silencing. CONCLUSION: These data offer functional evidence that implicates MUC1 over-expression as a key molecular event in the pathogenesis of aggressive TC. Retrovirally delivered anti-MUC1 RNAi is effective in silencing MUC1 and merits further investigation to establish therapeutic efficacy and safety in anticipation of potential clinical application

We examined measures of oral and pharyngeal residues from scintigraphic studies and estimates/observations from videofluorographic (modified barium swallow) studies taken on the same day but not concurrently in 16 dysphagic patients of varying etiologies presenting with oral and/or pharyngeal dysphagia. Oral and pharyngeal residuals following the swallow were quantified scintigraphically and were then compared with measures of residuals obtained from the modified barium swallow. Estimates of oral and pharyngeal residues from the modified barium swallows were generated by a trained observer who was blinded to the scintigraphic data. Positive and significant Spearman correlations between oral and pharyngeal residue measures from scintigraphy and observations of oral and pharyngeal residues from modified barium swallows were found. This supports the validity of observations of oral and pharyngeal residues in clinical studies. Limitations of these observations are discussed

Cochlear implants are electrical prostheses that partially replace the functions of the human ear. They bypass normal hearing operation to directly simulate the auditory nerve with electric current. The input acoustic signal passes through a filter bank and the output of each filter modulates the energy of a stimulation waveform delivered to a different intra-cochlear electrode. This approach attempts to mimic the signal processing that takes place in a normal ear. When fitting a cochlear implant to a patient who has lost his hearing after learning language, one important problem is how to optimize the frequency range of the filter bank This optimization seeks a tradeoff between maximum speech perception and the patient\\\\\\\'s subjective preference. Unfortunately, currently available tools to change the frequency-to-electrode mapping (i.e., the frequencies of the filter bank) are cumbersome to use. In a previous project we developed a real time speech processor for the Nucleus-22 and Nucleus-24 cochlear implants, based on a common PC and additional hardware drivers. The present project involves the development of a similar system that is adjustable in real time. In other words, the patient can modify the frequency-to-electrode map using computer keystrokes, and a visual representation of the frequency range employed by the filter bank is displayed on the monitor. The patient adjusts the frequency range interactively and selects the preferred setting in a much faster way than can be accomplished with commercially available hardware. If successful, this approach may be implemented in the next generation of hardware used to program cochlear implants in the clinic

OBJECTIVES/HYPOTHESIS: The objective was to determine whether there is an increased incidence of otorrhea in young children with tympanostomy tubes who swim and bathe without water precautions as compared with children who use water precautions in the form of ear plugs. STUDY DESIGN: Prospective, randomized, investigator-blinded, controlled trial. METHODS: Two hundred one children (age range, 6 mo-6 y) who had undergone bilateral myringotomy and tube insertion were randomly assigned into one of two groups: swimming and bathing with or without ear plugs. Children were seen monthly for 1 year and whenever there was intercurrent otorrhea. RESULTS: Ninety children with and 82 children without ear plugs returned for at least one follow-up visit. Mean (SD) duration of follow-up was 9.4 (4.1) months for the children with ear plugs and 9.1 (4.4) months for the children without ear plugs. Forty-two children (47%) who wore ear plugs developed at least one episode of otorrhea, as compared with 46 (56%) who did not use ear plugs (logistic regression adjusting for stratification variables, P = .21). The mean (SD) rate of otorrhea per month was 0.07 (0.31) for the children who wore ear plugs as compared with 0.10 (0.31) for the children who did not wear ear plugs (Poisson regression adjusting for stratification variables, P = .05). CONCLUSION: There is a small but statistically significant increase in the rate of otorrhea in young children who swim and bathe without the use of ear plugs as compared with children who use ear plugs. Because the clinical impact of using ear plugs is small, their routine use may be unnecessary

Beta-6 Integrin, tenascin-C, and MMP-1 (matrix metalloproteinase-1) are invasion-related proteins that are frequently overexpressed in many human malignancies. The objective of this study was to determine whether there is overexpression of these molecules in three types of salivary neoplasms showing markedly different behavior. A total of 55 formalin-fixed, paraffin-embedded archived specimens comprising 19 adenoid cystic carcinomas (ACC), 18 polymorphous low-grade adenocarcinomas (PLGA) and 18 pleomorphic adenomas (PA) were utilized in this study. A standard immunohistochemical technique was used to determine the expression levels of beta-6 integrin, tenascin-C, and matrix metalloproteinase-1 (MMP-1) proteins. Sections were assessed semiquantitatively, and tumors were divided into two groups, low-expressors (0-1+) and high-expressors (2-3+) for statistical analysis. Staining was graded as 0 (<1% positive tumor cells), 1+ (<25% positive tumor cells), 2+ (25-50% positive tumor cells), and 3+ (>50% positive cells). The results showed that the malignant tumors were higher expressors of beta-6 than the benign tumors. ACCs showed significantly higher expression of beta-6 than PAs (p=0.04). No significant difference was observed between ACCs and PLGAs. beta-6 expression was rarely seen in normal salivary gland epithelium and was occasionally present in mucosa overlying the tumors. PAs were high-expressors of tenascin-C with a significant difference relative to ACCs (p=0.03). A majority of tumors in all three tumor types showed high expression of MMP1 with expression significantly greater in the PAs compared to ACCs (p=0.008). We conclude that ACCs and PLGAs express beta-6, tenascin-C, and MMP-1, but that their expression patterns are not significantly different. beta-6 appears to be more closely associated with the malignant tumors, and MMP-1 more closely associated with the benign tumors. We believe that beta-6, tenascin-C, and MMP-1 proteins are part of the molecular repertoire used by salivary tumors for malignant invasion and benign tumor expansion