Faculty Bibliography

Hearing loss during development leads to central deficits that persist even after the restoration of peripheral function. One key class of deficits is due to changes in central inhibitory synapses, which play a fundamental role in all aspects of auditory processing. This review focuses on the anatomical and physiological alterations of inhibitory connections at several regions within the central auditory pathway following hearing loss. Such aberrant inhibitory synaptic function may be linked to deficits in encoding binaural and spectral cues. Understanding the cellular changes that occur at inhibitory synapses following hearing loss may provide specific loci that can be targeted to improve function

In the inferior colliculus (IC), a brief period of acoustic conditioning can transiently enhance evoked discharge rate. The cellular basis of this phenomenon was assessed with whole cell current-clamp recordings in a gerbil IC brain slice preparation. The current needed to elicit a single action potential was first established for each neuron. A 5s synaptic stimulus train was delivered to the lateral lemniscus (LL), and followed immediately by the initial current pulse to assess a change in postsynaptic gain. The majority of IC neurons (66%) displayed an increase in current-evoked action potentials (Positive Gain). Despite the blockade of ionotropic glutamate receptors, this effect was correlated with membrane depolarization that occurred during the synaptic train. The postsynaptic mechanism for positive gain was examined by selective blockade of specific neurotransmitter receptors. Gain in action potentials was enhanced by antagonists of metabotropic glutamate, acetylcholine, GABA(A) and glycine receptors. In contrast, the gain was blocked or reduced by an antagonist to ionotropic serotonin receptors (5-HT(3)R). Blocking voltage-activated calcium channels with verapamil also reduced the effect. These results suggest that 5-HT(3)R activation, coupled with increased intracellular calcium, can transiently alter postsynaptic excitability in IC neurons

Hedgehog signaling is often activated in tumors, yet it remains unclear how GLI2, a transcription factor activated by this pathway, acts as an oncogene. We show that GLI2 is a pleiotropic oncogene. The overexpression induces genomic instability and blocks differentiation, likely mediated in part by enhanced expression of the stem cell gene SOX2. GLI2 also induces transforming growth factor (TGF)B1-dependent transdifferentiation of foreskin and tongue, but not gingival fibroblasts into myofibroblasts, creating an environment permissive for invasion by keratinocytes, which are in various stages of differentiation having downregulated GLI2. Thus, upregulated GLI2 expression is sufficient to induce a number of the acquired characteristics of tumor cells; however, the stroma, in a tissue-specific manner, determines whether certain GLI2 oncogenic traits are expressed

BACKGROUND: Hyalinizing clear cell carcinoma (HCCC) is an uncommon malignant salivary gland tumor that was characterized only recently as a distinct entity. Because of its histologic similarity to several other primary and metastatic tumors and its purported favorable clinical outcome after local resection, it is important to recognize the features of this unusual tumor. METHODS: The authors present 8 new, fully characterized cases of HCCC and systematically reviewed 44 other cases of HCCC reported in the English language literature from 1980 to 2008. Historic cases were reviewed, and available data regarding morphology, special stains, demographics, clinical presentation, radiographic findings, management, and outcomes were extracted. Data from the current series were compared with the earlier published literature. RESULTS: To the best of the authors' knowledge, this was the largest reviewed series of HCCC and included a total of 52 cases. The findings, which included key histologic features, clinical presentation, and outcome, generally were consistent with what was reported previously. However, the current review revealed that 25% of patients reported in the literature had metastatases at initial presentation, including 10 of 44 patients who had metastases to regional lymph nodes and 1 patient who had metastasis to the lung. The authors were unable to identify any specific histologic features that would predict this behavior. CONCLUSIONS: The current results indicated that HCCC is less indolent than was believed previously; therefore, regional lymph node dissection should be considered in conjunction with wide local excision for patients with HCC

BACKGROUND: Tumors involving the parapharyngeal space present a challenge of surgical access. METHODS: We reviewed all parapharyngeal space tumors resected at the University of California, San Francisco, between 2003 and 2006 and identified 14 patients who had a mandibular osteotomy to enhance surgical access to the parapharyngeal space. RESULTS: The surgical approach for the 14 patients who had a mandibulotomy was accomplished via either 1 or 2 mandibular osteotomies. A single paramedian osteotomy between the canine and the first premolar was used in 4 cases, whereas a combination of a horizontal osteotomy above the lingula and a paramedian osteotomy between the canine and first premolar was employed in 8 cases. A lingual dental splint and rigid fixation were used to achieve mandibular stabilization and fixation. CONCLUSION: We found that the single and double mandibular osteotomies provided excellent surgical access allowing for total tumor removal with few sequelae

OBJECTIVE: To determine whether a 3-day course of postoperative antibiotics is as effective as a 7-day course in reducing pain and reducing time to resumption of a normal diet and level of activity following pediatric tonsillectomy. DESIGN: A prospective, randomized, placebo-controlled trial. SETTING: Academic medical center. PATIENTS: Forty-nine patients were enrolled in the study. Preoperative demographic information was obtained. INTERVENTIONS: Tonsillectomy with or without adenoidectomy was performed by the senior author (J.J.) using electrocautery. Patients were randomized to receive either a 3- or 7-day course of amoxicillin. MAIN OUTCOME MEASURES: Parents were asked to record the following information: analgesic use for the first 7 postoperative days, postoperative days the child initiated his or her usual diet and level of activity, and medical treatment for oral hemorrhage or dehydration. RESULTS: Of the 49 patients, 26 were randomized to receive 7 days of postoperative antibiotics (group A) and 23 to receive 3 days of antibiotics, followed by 4 days of placebo (group B). Results were obtained for 47 of the enrolled patients (96%). No statistically significant difference was noted between the 2 groups with regard to postoperative pain or time to resumption of a normal diet and level of activity. CONCLUSION: A 3-day course of antibiotics following pediatric tonsillectomy is as effective as a 7-day course with regard to postoperative analgesic use and resumption of normal diet and level of activity. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00662987

Chondromyxoid fibroma (CMF) is a rare benign primary tumor which usually affects the metaphyses of the long bone of the lower extremities in childhood and young adults. Rarely, CMF occurs in the skull base and parasinuses, which may be difficult to distinguish from chondrosarcoma or chordoma and other tumors in the head. It is composed of chondroid, myxoid, and fibrous tissue growth in a lobular pattern, infrequently with calcifications. We report one case of CMF involving the sphenoid sinus mimicking a chondrosarcoma. The tumor mass showed calcifications on images and histology

This study investigates the effect of the Nucleus CI24RE implant's neural response telemetry (NRT) system, which has less internal noise compared to its predecessor, the CI24M/R implant, on the NRT threshold (TNRT) profile across the array. CI24M/R measurements were simulated by ignoring CI24RE measurements with response amplitudes below 50 uV. Comparisons of the estimated TNRTs from the CI24RE measurements and the CI24M/R simulations suggest that, apart from a constant level difference, the TNRT profiles from the newer implant generally would not have differed very much from those of its predecessor. This view was also reflected by principal component analysis (PCA) results which revealed a 'shift' component similar to that reported by Smoorenburg et al (2002). On the whole, there is no indication that current practices of using the TNRT profiles for assisting with speech processor programming need to be revised for the CI24RE implant

The purpose of this report is to summarize the salient points made during a panel discussion at the 88th Annual Meeting of the American Broncho-Esophagological Association about the efficacy and oncological safety of endoscopic laser treatment of laryngeal cancer. Guidelines for endoscopic laser management of early glottic and supraglottic cancer, including contraindications for this treatment modality, are presented. On the basis of all currently available data, the panel, which critically considered the question of oncological safety, is of the opinion that endoscopic laser resections are oncologically safe when applied judiciously and by a skilled oncological surgeon. Relative contraindications for endoscopic laser resection of laryngeal cancer include instances in which the whole tumor cannot be visualized; large tumors that require removing too much of the functional laryngeal unit, severely decreasing airway protection and leading to aspiration; and cartilage invasion. Specific contraindications for supraglottic cancer include bilateral arytenoid involvement and direct extension into the neck