Faculty Bibliography

We report the results of our study of 25 children who underwent adenoidectomy under general anesthesia with a laryngeal mask airway to determine their risk of fire in the oropharynx. We explain the distinct advantage that such an anesthetic technique has with respect to minimizing the conditions that may contribute to an airway fire. We also discuss additional advantages of using a laryngeal mask airway during adenoidectomies

The Hodgkin-Reed-Sternberg (HRS) malignant cells in Hodgkin's lymphoma (HL) originate from germinal center B lymphocytes that did not undergo apoptosis. Protein Kinase C (PKC), a family of serine/threonine kinases, plays a crucial role in signal transduction modulating cell growth, differentiation and apoptosis. Here, we report the expression of PKC isoforms in two HL-derived cell lines, L428 and KMH2 and their correlation with drug resistance to CPT and doxorubicin. Among the PKC isoforms examined, only PKCeta and PKCbetaII were preferentially expressed in the drug resistant L428 cells. We have shown correlation between the response to apoptosis of L428 and KMH2 cells and PKCeta expression in these cell lines. In order to directly demonstrate a role for PKCeta in apoptosis, its expression was knocked-down by siRNA in the resistant L428 cells. Downregulation of PKCeta rendered L428 cells more sensitive to doxorubicin and CPT. Furthermore, PKCeta knocked-down cells showed increased PARP-1 cleavage, cytochrome c release and caspase 7 activation. It appears that PKCeta functions as an anti-apoptotic protein in HL-derived cell lines, and as we show here that it is also expressed in HRS of HL biopsies, it may have therapeutic relevance in HL. Thus, PKCeta could provide a new target aimed to reduce resistance to anti-cancer treatments of HL and other cancer patients.

OBJECTIVES: Tracheal tube cuff overinflation is a recognized risk factor for tracheal injury and stenosis. International studies report a 55% to 62% incidence of cuff overinflation among intensive care unit (ICU) patients. However, there are no data on tracheotomy tubes, and no recent data from ICUs in the United States. It is unknown whether routine cuff pressure measurement is beneficial. We sought to determine the incidence of cuff overinflation in the contemporary American ICU. METHODS: We performed an Institutional Review Board-approved, prospective, observational study of endotracheal and tracheotomy tubes at 2 tertiary-care academic hospitals that monitor cuff pressure differently. At hospital A, cuff pressures are assessed by palpation; at hospital B, cuff pressures are measured via manometry. We audited cuff pressures in an unannounced fashion at these hospitals, using a handheld aneroid manometer. Cuffs were considered overinflated above 25 cm H2O. RESULTS: We enrolled 115 patients: 63 at hospital A and 52 at hospital B. Overall, 44 patients (38%) were found to have overinflated cuffs. The incidence of overinflation was identical at the 2 hospitals (38%; p = .99). Of the endotracheal tubes, 43% were overinflated, as were 32% of the tracheotomy tubes (p = .24). CONCLUSIONS: Despite increasing awareness among intensivists and respiratory therapists, the incidence of tracheal tube overinflation remains high, with both endotracheal and tracheotomy tubes. Our finding that the use of manometry to assess cuff pressures did not reduce the incidence of overinflation suggests that a more vigilant management protocol may be necessary

OBJECTIVE: To determine if 2 commercial mouthrinses, 1 alcohol-based and 1 nonalcohol-based, affect salivary flow and symptoms of dry mouth in nonxerostomic adults. METHOD AND MATERIALS: This observer-blinded, randomized, crossover pilot study involved 20 adults. The primary endpoints of interest were whole salivary flow rates and the perceived mouth dryness VAS scores following 1 week of use. ANOVA was used to determine differences in these endpoints between groups, and ANCOVA was used to control for any variation in baseline flow rates and VAS scores (P <.05). RESULTS: There were no significant differences between groups at baseline. After 1 week of mouthrinse use, ANOVA and ANCOVA of combined data (before and after crossover) revealed no significant differences in either flow rates or VAS scores between groups (P >.05). CONCLUSION: There were no differences in objective or subjective measures of mouth dryness between alcohol- and nonalcohol-containing mouthrinses after 1 week in nonxerostomic subjects

Although sensorineural hearing loss (SNHL) is known to compromise central auditory structure and function, the impact of milder forms of hearing loss on cellular neurophysiology remains mostly undefined. We induced conductive hearing loss (CHL) in developing gerbils, reared the animals for 8-13 d, and subsequently assessed the temporal features of auditory cortex layer 2/3 pyramidal neurons in a thalamocortical brain slice preparation with whole-cell recordings. Repetitive stimulation of the ventral medial geniculate nucleus (MGv) evoked robust short-term depression of the postsynaptic potentials in control neurons, and this depression increased monotonically at higher stimulation frequencies. In contrast, CHL neurons displayed a faster rate of synaptic depression and a smaller asymptotic amplitude. Moreover, the latency of MGv evoked potentials was consistently longer in CHL neurons for all stimulus rates. A separate assessment of spike frequency adaptation in response to trains of injected current pulses revealed that CHL neurons displayed less adaptation compared with controls, although there was an increase in temporal jitter. For each of these properties, nearly identical findings were observed for SNHL neurons. Together, these data show that CHL significantly alters the temporal properties of auditory cortex synapses and spikes, and this may contribute to processing deficits that attend mild to moderate hearing loss

BACKGROUND: The management of cerebrospinal fluid (CSF) leaks can be challenging. Acellular dermal grafts derived from human cadavers can be used as a replacement material when autogenous materials are unavailable. Fibrin tissue adhesive (FTA) is a wound support product that has been used for hemostatic and tissue fixation purposes. The combined use of acellular dermis in conjunction with FTA for dural repair remains a subject of study. The aim of this study was to evaluate wound healing and tissue compatibility characteristics of acellular dermal substitute material when used both with and without FTA, for repair of a dural tear in a chinchilla model. METHODS: Forty-nine chinchillas were included in this randomized case-control study. The squamous portion of the temporal bone was removed to expose the tegmen. A 2 x 2 mm dural defect was removed to create an iatrogenic CSF leak. Then, animals were randomly assigned to one of three treatment groups: group 1, acellular dermis alone; group 2, acellular dermis with FTA; group 3, fibrinogen, acellular dermis, and FTA. Surgical sites were examined grossly at 1- and 2-week intervals. Temporal bones were examined histologically. RESULTS: Grossly, groups 2 and 3 had significantly less visible CSF leak and brain herniation noted at both 1- and 2-week intervals when compared with group 1. Histological results confirmed the gross results showing the best seal in group 2 and 3. CONCLUSION: Acellular dermis combined with FTA provided superior support compared with acellular dermis alone in repair of induced dural defects

Studies of transtympanic gentamicin have focused on clinical use and outcomes. This study presents evidence of bilateral uptake and retention of gentamicin in certain inner ear cells and structures following transtympanic gentamicin application. Middle ear application of gentamicin was performed by either minipump (Alza model, 2002) or transtympanic injection in a chinchilla model. Histological sections of decalcified temporal bones were stained to identify the distribution of gentamicin. Using both anti-gentamicin immunohistochemistry and autoradiography of tracer amounts of tritiated gentamicin, Scarpa's and spiral ganglion cells, stria vascularis, and vestibular dark cells of the injected ear were found to have higher levels of gentamicin and retain it within cell bodies while staining levels fell to background levels in the rest of the injected ear over the course of 14 days. There was no evidence of an apical to basal gradient of anti-gentamicin staining within the spiral ganglion. Contralateral inner ear cells showed light anti-gentamicin staining. Cell bodies in the ipsilateral dorsal cochlear nucleus bordering the cochlear aqueduct (CA) showed a lateral to medial gradient of gentamicin staining, suggesting the CA as a potential site of transfer of gentamicin to the contralateral ear. Direct effects of aminoglycosides on ganglion cells may have implications on both the success of cochlear implantation in patients deafened following systemic aminoglycoside therapy and on the advisability of clinical practices of transtympanic gentamicin therapy and ototopic aminoglycoside treatment

OBJECTIVE: Common peroneal nerve (CPN) paresis or paralysis presents with weakness of the toe extensors as well as of the ankle dorsiflexors and evertors, causing foot drop and hypesthesia or paresthesia in the CPN distribution. Previous studies have shown associations with weight loss and leg crossing. Although CPN neuropathy has been described in cancer patients, it has not been described in head and neck cancer (HNC) patients specifically. Our objective was to describe a series of patients who developed CPN neuropathy during the course of their disease. MATERIALS AND METHODS: A retrospective review of the charts of patients with HNC and CPN neuropathy who were seen at our institution between 1995 and 2004 was performed. RESULTS: Four HNC patients with CPN neuropathy were identified. All had significant weight loss. One patient became symptomatic before treatment, 2 patients became symptomatic during treatment, and 1 patient developed foot drop 4 years after treatment when his free jejunal flap developed a stricture. Two patients had electrodiagnostic study findings that revealed conduction block at the fibular head and denervation of peroneal innervated muscles. Imaging studies revealed no evidence of metastatic disease in the lumbosacral region. All 4 patients improved after weight gain. CONCLUSIONS: Common peroneal nerve neuropathy may be seen in HNC patients. The CPN may be susceptible in weight loss because of the associated loss of subcutaneous tissue, which cushions the nerve from the fibular head. Consideration should be given to prevention, appropriate neurologic consultation, and patient counseling