Acquired resistance to EGFR tyrosine kinase inhibitors alters the metabolism of human head and neck squamous carcinoma cells and xenograft tumours.

BACKGROUND: Acquired resistance to molecularly targeted therapeutics is a key challenge in personalised cancer medicine, highlighting the need for identifying the underlying mechanisms and early biomarkers of relapse, in order to guide subsequent patient management. METHODS: Here we use human head and neck squamous cell carcinoma (HNSCC) models and nuclear magnetic resonance (NMR) spectroscopy to assess the metabolic changes that follow acquired resistance to EGFR tyrosine kinase inhibitors (TKIs), and which could serve as potential metabolic biomarkers of drug resistance. RESULTS: Comparison of NMR metabolite profiles obtained from control (CAL(S)) and EGFR TKI-resistant (CAL(R)) cells grown as 2D monolayers, 3D spheroids or xenograft tumours in athymic mice revealed a number of differences between the sensitive and drug-resistant models. In particular, we observed elevated levels of glycerophosphocholine (GPC) in CAL(R) relative to CAL(S) monolayers, spheroids and tumours, independent of the growth rate or environment. In addition, there was an increase in alanine, aspartate and creatine+phosphocreatine in resistant spheroids and xenografts, and increased levels of lactate, branched-chain amino acids and a fall in phosphoethanolamine only in xenografts. The xenograft lactate build-up was associated with an increased expression of the glucose transporter GLUT-1, whereas the rise in GPC was attributed to inhibition of GPC phosphodiesterase. Reduced glycerophosphocholine (GPC) and phosphocholine were observed in a second HNSCC model probably indicative of a different drug resistance mechanism. CONCLUSIONS: Our studies reveal metabolic signatures associated not only with acquired EGFR TKI resistance but also growth pattern, microenvironment and contributing mechanisms in HNSCC models. These findings warrant further investigation as metabolic biomarkers of disease relapse in the clinic.

Knowledge and practice of confidential data handling in the Welsh Deanery: a brief report.

Recent large-scale personal data loss incidents highlighted the need for public bodies to more securely handle confidential data. We surveyed trainees from all specialties in the Welsh Deanery for their knowledge and practice. All registered trainees were invited to participate in an online anonymised survey. There were 880 completed and non-duplicated responses (52.9% response rate). Responses were analysed using Microsoft Access. Over 40% (388/880 (44.1%)) did not use formal guidelines on storage or disposal of confidential data. The majority appeared to dispose of confidential paper documents securely, that is, using shredders and white shredder bags. However, there were significant numbers of unmarked responses. Clinical documents, such as theatre lists, were taken home by 281/880 (31.9%) of trainees. The majority secured their computers (569/871 (65.3%)) by either not keeping patient identifiable data on them or using encryption. However, 302/871 (34.7%) did not adequately secure their computers. The surgical and anaesthetic specialties were least aware of formal confidentiality guidelines (95/178 (53.4%)) and 52/102 (51.0%) respectively) and least secured their computers (106/178 (59.6%) and 63/102 (61.8%) respectively). Education is needed to improve knowledge and practice of confidential data handling. This may be delivered through workshops during induction programmes or as part of European Computer Driving Licence (ECDL) modules. Training is especially indicated for the surgical and anaesthetic specialties.

Noise exposure in convertible automobiles.

OBJECTIVE: To quantify the noise exposure received while driving a convertible automobile with the top open, compared with the top closed. METHODS: Five different convertible automobiles were driven, with the top both closed and open, and noise levels measured. The cars were tested at speeds of 88.5, 104.6 and 120.7 km/h. RESULTS: When driving with the convertible top open, the mean noise exposure ranged from 85.3 dB at 88.5 km/h to 89.9 dB at 120.7 km/h. At the tested speeds, noise exposure increased by an average of 12.4-14.6 dB after opening the convertible top. CONCLUSION: Driving convertible automobiles at speeds exceeding 88.5 km/h, with the top open, may result in noise exposure levels exceeding recommended limits, especially when driving with the convertible top open for prolonged periods.

Negative association between treated osteoporosis and benign paroxysmal positional vertigo in women.

OBJECTIVE: To determine the degree of association, if any, between benign paroxysmal positional vertigo and osteoporosis, both of which are disorders of impaired calcium carbonate homeostasis. METHODS: A retrospective chart review was undertaken in two otology clinics to assess the prevalence of treated osteoporosis in 260 women with and without benign paroxysmal positional vertigo, between the ages of 51 and 80 years. RESULTS: There was a statistically significant, negative association between benign paroxysmal positional vertigo and treated osteoporosis in women aged 51 to 60 years. We also observed a trend towards a negative association for women in their 60s, and for the group as a whole. CONCLUSION: Osteoporosis, or the medication used to treat it, may provide protection against benign paroxysmal positional vertigo.

Effects of arbuscular mycorrhizas on ammonia oxidizing bacteria in an organic farm soil.

Arbuscular mycorrhizal fungi (AMF) are potentially important in nutrient cycling in agricultural soils and particularly in soils managed for organic production; little is known, however, about the interrelationships between AMF and other members of soil microbial communities. Ammonia oxidizing bacteria (AOB) are a trophic group of bacteria having an enormous impact on nitrogen availability in soils and are expected to be influenced by the presence of AMF. In a field study, we utilized a unique genetic system comprised of a mycorrhiza defective tomato mutant (named rmc) and its mycorrhiza wild-type progenitor (named 76RMYC+). We examined the effect of AMF by comparing AOB community composition and populations in soil containing roots of the two tomato genotypes in an organically managed soil. Responses of AOB to soil N and P amendments were also studied in the same experiment. Phylogenetic analysis of cloned AOB sequences, derived from excised denaturing gradient gel electrophoresis (DGGE) bands, revealed that the organic farm soil supported a diverse yet stable AOB community, which was neither influenced by mycorrhizal colonization of roots nor by N and P addition to the soil. Real-time TaqMan polymerase chain reaction (PCR) was used to quantify AOB population sizes and showed no difference between any of the treatments. An alternative real-time PCR protocol for quantification of AOB utilizing SYBR green yielded similar results as the TaqMan real-time PCR method, although with slightly lower resolution. This alternative method is advantageous in not requiring the detailed background information about AOB community composition required for adaptation of the TaqMan system for a new soil.

Bacteriophages for plant disease control.

The use of phages for disease control is a fast expanding area of plant protection with great potential to replace the chemical control measures now prevalent. Phages can be used effectively as part of integrated disease management strategies. The relative ease of preparing phage treatments and low cost of production of these agents make them good candidates for widespread use in developing countries as well. However, the efficacy of phages, as is true of many biological control agents, depends greatly on prevailing environmental factors as well as on susceptibility of the target organism. Great care is necessary during development, production and application of phage treatments. In addition, constant monitoring for the emergence of resistant bacterial strains is essential. Phage-based disease control management is a dynamic process with a need for continuous adjustment of the phage preparation in order to effectively fight potentially adapting pathogenic bacteria.

Integration of Biological Control Agents and Systemic Acquired Resistance Inducers Against Bacterial Spot on Tomato.

Two strains of plant growth-promoting rhizobacteria, two systemic acquired resistance inducers (harpin and acibenzolar-S-methyl), host-specific unformulated bacteriophages, and two antagonistic bacteria were evaluated for control of tomato bacterial spot incited by Xanthomonas campestris pv. vesicatoria in greenhouse experiments. Untreated plants and plants treated with copper hydroxide were used as controls. The plant growth-promoting rhizobacteria or a tap water control were applied as a drench to the potting mix containing the seedlings, while the other treatments were applied to the foliage using a handheld sprayer. The plant growth-promoting rhizobacteria strains, when applied alone or in combination with other treatments, had no significant effect on bacterial spot intensity. Messenger and the antagonistic bacterial strains, when applied alone, had negligible effects on disease intensity. Unformulated phage or copper bactericide applications were inconsistent in performance under greenhouse conditions against bacterial spot. Although acibenzolar-S-methyl completely prevented occurrence of typical symptoms of the disease, necrotic spots typical of a hypersensitive reaction (HR) were observed on plants treated with acibenzolar-S-methyl alone. Electrolyte leakage and population dynamics experiments confirmed that acibenzolar-S-methyl-treated plants responded to inoculation by eliciting an HR. Application of bacteriophages in combination with acibenzolar-S-methyl suppressed a visible HR and provided excellent disease control. Although we were unable to quantify populations of the bacterium on the leaf surface, indirectly we determined that bacteriophages specific to the target bacterium reduced populations of a tomato race 3 strain of the pathogen on the leaf surface of acibenzolar-S-methyl-treated plants to levels that did not induce a visible HR. Integrated use of acibenzolar-S-methyl and phages may complement each other as an alternative management strategy against bacterial spot on tomato.

Improved Efficacy of Newly Formulated Bacteriophages for Management of Bacterial Spot on Tomato.

Bacteriophages are currently used as an alternative method for controlling bacterial spot disease on tomato incited by Xanthomonas campestris pv. vesicatoria. However, the efficacy of phage is greatly reduced due to its short residual activity on plant foliage. Three formulations that significantly increased phage longevity on the plant surface were tested in field and greenhouse trials: (i) PCF, 0.5% pregelatinized corn flour (PCF) + 0.5% sucrose; (ii) Casecrete, 0.5% Casecrete NH-400 + 0.5% sucrose + 0.25% PCF; and (iii) skim milk, 0.75% powdered skim milk + 0.5% sucrose. In greenhouse experiments, the nonformulated, PCF-, Casecrete-, and skim milk-formulated phage mixtures reduced disease severity on plants compared with the control by 1, 30, 51, and 62%, respectively. In three consecutive field trials, nonformulated phage caused 15, 20, and 9% reduction in disease on treated plants compared with untreated control plants, whereas plants treated with PCF- and Casecrete-formulated phage had 27, 32, and 12% and 30, 43, and 24% disease reduction, respectively. Plants receiving copper-mancozeb treatments were included in two field trials and had a 20% decrease in disease in the first trial and a 13% increase in the second one. Skim milk-formulated phage was tested only once and caused an 18% disease reduction. PCF-formulated phage was more effective when applied in the evening than in the morning, reducing disease on plants by 27 and 13%, respectively. The Casecrete-formulated phage populations were over 1,000-fold higher than the nonformulated phage populations 36 h after phage application.

Apoptosis is associated with triacylglycerol accumulation in Jurkat T-cells.

Magnetic resonance spectroscopy is increasingly used as a non-invasive method to investigate apoptosis. Apoptosis was induced in Jurkat T-cells by Fas mAb. (1)H magnetic resonance spectra of live cells showed an increase in methylene signal as well as methylene/methyl ratio of fatty acid side chains at 5 and 24 h following induction of apoptosis. To explain this observation, (1)H magnetic resonance spectra of cell extracts were investigated. These demonstrated a 70.0+/-7.0%, 114.0+/-8.0% and 90.0+/-5.0% increase in the concentration of triacylglycerols following 3, 5 and 7 h of Fas mAb treatment (P<0.05). Confocal microscopy images of cells stained with the lipophilic dye Nile Red demonstrated the presence of lipid droplets in the cell cytoplasm. Quantification of the stained lipids by flow cytometry showed a good correlation with the magnetic resonance results (P > or =0.05 at 3, 5 and 7 h). (31)P magnetic resonance spectra showed a drop in phosphatidylcholine content of apoptosing cells, indicating that alteration in phosphatidylcholine metabolism could be the source of triacylglycerol accumulation during apoptosis. In summary, apoptosis is associated with an early accumulation of mobile triacylglycerols mostly in the form of cytoplasmic lipid droplets. This is reflected in an increase in the methylene/methyl ratio which could be detected by magnetic resonance spectroscopy.

Host suitability of soybean cultivars and breeding lines to reniform nematode in tests conducted in 2001.

Reproduction of reniform nematode Rotylenchulus reniformis on 139 soybean lines was evaluated in a greenhouse in the summer of 2001. Cultivars and lines (119 total) were new in the Arkansas and Mississippi Soybean Testing Programs, and an additional 20 were submitted by C. Overstreet, Louisiana State Extension Nematologist. A second test of 32 breeding lines and 2 cultivars from the Clemson University soybean breeding program was performed at the same time under the same conditions. Controls were the resistant cultivars Forrest and Hartwig, susceptible Braxton, and fallow infested soil. Five treatment replications were planted in sandy loam soil infested with 1,744 eggs and vermiform reniform nematodes, grown for 10 weeks in 10 cm-diam.- pots. Total reniform nematodes extracted from soil and roots was determined, and a reproductive factor (final population (Pf)/ initial inoculum level (Pi)) was calculated for each genotype. Reproduction on each genotype was compared to the reproduction on the resistant cultivar Forrest (RF), and the log ratio [log(RF + 1) is reported. Cultivars with reproduction not significantly different from Forrest (log ratio) were not suitable hosts, whereas those with greater reproductive indices were considered suitable hosts. These data will be useful in the selection of soybean cultivars to use in rotation with cotton or other susceptible crops to help control the reniform nematode and to select useful breeding lines as parent material for future development of reniform nematode resistant cultivars and lines.

Use of the malleus handle as a landmark for localizing the round window membrane.

Localization of the round window membrane is desirable in order to allow a more direct application of medication to the inner ear. A new procedure has been developed to deliver direct, near-continuous inner ear perfusion to the round window with the Silverstein MicroWick. In this office procedure, the wick is inserted through a tympanostomy tube into the round window niche. Accurate localization of the round window is a necessary component of this procedure. In an effort to ascertain the precise location of the round window, we examined 25 cadaveric human temporal bones and measured the distance from the umbo to the round window in each sample. We found that the round window was an average of 3.44 mm (+/- 0.68) from the umbo and was situated at an average angle of 113.2 degrees (+/- 9.8) from the long process of the malleus. Our simple and reliable determination of the relationship between the malleus handle and the round window niche allows for the accurate placement of the Silverstein MicroWick and other devices.

Pediatric laser-assisted tympanostomy.

OBJECTIVE: To evaluate effectiveness of laser-assisted tympanostomy in treatment of pediatric patients with chronic otitis media with effusion. STUDY DESIGN: Retrospective review of 23 pediatric patients who received office laser-assisted tympanostomy. METHODS: A CO2 laser attached to an operating microscope with a microscope laser adaptor device or the handheld Oto-LAM (Needham, MA) was used to perform all of the tympanostomies. The average diameter of tympanostomy was 2 mm; on average, 13.6 W was applied for 0.13 seconds. RESULTS: Laser-assisted tympanostomy was performed on 37 pediatric ears (patient age range, 2-16 y) for the diagnosis of chronic otitis media with effusion. Average follow-up time was 4.7 weeks. At the time of the follow-up examination, 46% of the ears had no evidence of fluid and required no further intervention. Forty-nine percent of the ears required placement of pressure equalization tubes. The average SRT improved from 30.8 dB preoperatively to 21.03 dB postoperatively. CONCLUSIONS: Laser-assisted tympanostomy appears to be an effective treatment for chronic otitis media with effusion in pediatric patients.

Magnetic resonance detects changes in phosphocholine associated with Ras activation and inhibition in NIH 3T3 cells.

Ras is frequently mutated in cancer, and novel therapies are being developed to target Ras signalling. To identify non-invasive surrogate markers of Ras activation and inhibition, we used(31)P magnetic resonance spectroscopy (MRS) and investigated NIH 3T3 cells compared to a mutant ras transfected counterpart. The MR spectra indicated that phosphocholine (PC) levels increased significantly from 3 +/- 2 fmol cell(-1)in NIH 3T3 cells to 13 +/- 4 fmol cell(-1)in the transfected cells. The PC/NTP ratio increased significantly from 0.3 +/- 0.1 to 0.7 +/- 0.3. This could not be explained by either a faster proliferation rate or by alterations in cell cycle distribution. Both cell lines were treated with simvastatin, 17-AAG and R115777, agents which inhibit Ras signalling. Cell proliferation was inhibited in both cell lines. The spectrum of NIH 3T3 cells was not affected by treatment. In contrast, in the ras transfected cells growth inhibition was associated with an average 35 +/- 5% drop in PC levels and a comparable drop in PC/NTP. Thus the MRS visible increase in phosphocholine is associated with Ras activation, and response to treatment is associated with partial reversal of phosphocholine increase in ras transfected cells. MRS might therefore be a useful tool in detecting Ras activation and its inhibition following targeted therapies.

Host suitability in soybean cultivars for the reniform nematode, 2000 tests.

In greenhouse pot experiments during summer 2000, 118 soybean cultivars were tested to determine their suitability as hosts for the reniform nematode, Rotylenchulus reniformis. The cultivars included 115 new entries into the Arkansas and Mississippi soybean variety testing programs and three entries submitted by an extension nematologist from Texas. Also included in the tests were the R. reniformis-resistant cultivars Forrest and Hartwig, the susceptible cultivar Braxton, and fallow R. reniformis-infested soil that served as controls. Total number of eggs and nematodes extracted from both the soil and roots from each pot and reproductive indices (Pf/Pi) were calculated for each cultivar. The ratio of the Pf/Pi of each cultivar to the Pf/Pi of Forrest (RF), and the log ratio[log(10) (RF + 1)], are reported. Cultivars with reproductive indices that were greater than the reproductive index on Forrest were considered to be suitable hosts for R. reniformis. These data will be useful in the selection of soybean cultivars to use in rotation with cotton or other susceptible crops to help control the reniform nematode.

Treatment of SW620 cells with Tomudex and oxaliplatin induces changes in 2-deoxy-D-glucose incorporation associated with modifications in glucose transport.

UNLABELLED: Many studies suggest that changes in the uptake of the glucose analog FDG after therapy, compared with pretreatment uptake, predicts tumor response to therapy. However, clinical interpretation is compromised by a limited understanding of the effect of therapy on FDG and 2-deoxy-D-glucose (DG) uptake at the tumor cell level. METHODS: Uptake of 2-deoxy-D-[1-(3)H]glucose (3H-DG) by SW620 colonic tumor cells was measured before and 8, 16, 24, and 48 h after treatment with the novel platinum drug oxaliplatin and the novel thymidylate synthase inhibitor Tomudex. Glucose transport was determined by measuring the initial rate of uptake of the nearly nonmetabolized glucose analog 3-O-methyl-D-[1-(3)H]glucose (3H-OMG). The effect of these drugs on cell cycle kinetics was determined using flow cytometry. RESULTS: Treatment of SW620 cells with oxaliplatin was found to decrease uptake of 3H-DG after up to 24 h, but uptake returned to control levels after longer treatment. The initial decrease in 3H-DG incorporation was associated with a lower rate of glucose transport. Treatment of cells with Tomudex induced an increase in 3H-DG uptake that depended on treatment duration. Both glucose transport and the volume of distribution of 3H-OMG were higher in Tomudex-treated cells than in control cells. Flow cytometry showed that oxaliplatin induced a G2 and M arrest, whereas a buildup of cells in the S phase was associated with Tomudex treatment. Both treatments induced apoptosis in SW620 cells. CONCLUSION: Changes in uptake of DG by SW620 colonic tumor cells responding to therapy is specific to the drug type. Modulation of glucose transport was associated with changes in 3H-DG uptake.

Acoustic neuroma surgery: use of cochlear nerve action potential monitoring for hearing preservation.

OBJECTIVES: To compare the hearing preservation results obtained with use of two intraoperative eighth nerve monitoring methods, cochlear nerve action potential (CNAP) and auditory brainstem response (ABR), during complete acoustic neuroma (AN) resection. STUDY DESIGN: Retrospective. SETTING: Tertiary referral center. PATIENTS: Thirty-three consecutive patients who underwent hearing preservation AN surgery. INTERVENTIONS: Intraoperative monitoring by CNAP and/or ABR during AN resection. MAIN OUTCOME MEASURE: Postoperative hearing. Hearing preservation was considered achieved for pure-tone average < or =50 dB and speech discrimination > or =50%. RESULTS: Thirty-two patients met inclusion criteria for the study. Monitoring was successfully performed in 23 of 25 patients (92%) who underwent attempted CNAP monitoring and 13 of 27 (48%) who underwent attempted ABR monitoring. When tumor size was < or =20 mm in greatest dimension, hearing preservation was achieved in 12 of 18 patients (67%) monitored with CNAP, versus 2 of 8 patients (25%) not monitored with CNAP (p = 0.05). Monitoring by ABR did not improve hearing preservation rates compared with those not monitored with ABR (40% vs. 63%). At the completion of surgery, the presence or absence of CNAP predicted the presence or absence of hearing preservation in 18 of 23 cases (p = 0.01), while ABR successfully predicted hearing results in 10 of 13 cases (p = 0.05). CONCLUSIONS: When CNAP and ABR monitoring techniques during AN surgery were compared, CNAP was more frequently obtainable. Monitoring by CNAP was significantly associated with a higher chance of hearing preservation. Monitoring by ABR did not have a positive influence on hearing preservation results. Both ABR and CNAP were useful for predicting postoperative hearing.

Host suitability in soybean cultivars for the reniform nematode, 1999 tests.

Two hundred twenty-six soybean cultivars were tested in greenhouse pot experiments during summer 1999 to determine their suitability as hosts for the reniform nematode, Rotylenchulus reniformis. The cultivars included new entries into the Arkansas and Mississippi soybean variety testing programs and entries submitted by extension nematologists from Auburn University and Louisiana State University. Also included in the R. reniformis tests were the resistant cultivars Forrest and Hartwig, the susceptible control Braxton, and fallow infested soil that served as controls. Total number of eggs + nematodes extracted from the soil and roots per pot, reproductive indices (Pf/Pi) based on the number of nematodes extracted from the soil and roots/initial inoculum level, calculated for each cultivar, and the ratio of the Pf/Pi of each cultivar to the Pf/Pi of Forrest are reported. Cultivars with reproduction not significantly different from Forrest were not suitable hosts, whereas those with greater reproductive indices were considered suitable hosts. One of the 12 cultivars of the relative maturity group (RMG) <=4.4 was not a suitable host. For the 4.5 to 4.9 RMG, 24 of 72 cultivars were not suitable hosts, whereas 9 of 41 cultivars in RMG 5.0 to 5.4 were not suitable hosts. In the 5.5 to 5.9 RMG cultivars, 11 of 66 were not suitable hosts; for the 6.0 or greater RMG, 11 of 35 were not suitable hosts. These data will be useful in the selection of soybean cultivars to use in rotation with cotton or other susceptible crops to help control the reniform nematode.

Vagal nerve monitoring in surgery of the skull base: a comparison of efficacy of three techniques.

OBJECTIVE: To compare three techniques of monitoring the vagal nerve during skull base surgery using laryngeal electromyography (EMG). STUDY DESIGN: Prospective comparison. SETTING: California Ear Institute at Stanford, tertiary referral center. PATIENTS: Seventeen consecutive patients undergoing lateral skull base surgery potentially placing the vagal nerve at risk. INTERVENTIONS: Each patient was simultaneously monitored intraoperatively with three separate EMG techniques: 1) endolaryngeal surface electrodes mounted on an endotracheal tube (ETT) (Xomed Surgical Products, Inc., Jacksonville, FL); 2) endoscopically placed endolaryngeal thyroarytenoid intramuscular hookwire electrodes; and 3) percutaneously placed cricothyroid intramuscular hookwire electrodes. MAIN OUTCOME MEASURES: Sensitivity, reliability, response magnitude, incidence of false-positive responses, and complications were recorded. Preoperative and postoperative vagal nerve function was noted. RESULTS: The study was completed in 13 patients. The endolaryngeal intramuscular electrode technique responded at the lowest current stimulus (mean, 0.073 mA) with the highest average magnitude response. It responded in 100% of patients. The percutaneous intramuscular technique was similarly sensitive (mean stimulus, 0.089 mA) with a large average magnitude response but was much less reliable (responded in 69.2% of patients). The Xomed ETT was less sensitive (mean stimulus, 0.120 mA), had the lowest average magnitude response, and demonstrated medium reliability (responded in 76.9% of patients). The ETT exhibited the lowest incidence of spontaneous false-positive EMG activity. No complications were noted, and vagal nerve function was not compromised in any patient. CONCLUSIONS: Although the Xomed ETT exhibited ease of placement and a low false-positive response rate, it demonstrated lowest sensitivity compared with electrodes placed intramuscularly. The percutaneous intramuscular electrode technique was the least reliable, likely related to blind insertion, making it a less-desirable technique. Because of its highest relative sensitivity and reliability, the endolaryngeal intramuscular electrode technique of vagal monitoring is best supported by this study.

Acoustic neuroma surgery: absent auditory brainstem response does not contraindicate attempted hearing preservation.

OBJECTIVE: Absence of auditory brainstem response (ABR) waveforms has been associated with a poor likelihood of hearing preservation following resection of acoustic neuromas. Our experience is reviewed for patients with absent preoperative ABR regarding hearing preservation, hearing improvement, and return of ABR. STUDY DESIGN: Retrospective review of 22 cases of acoustic neuroma resection. Nine patients with absent preoperative ABR were identified. All underwent tumor resection utilizing intraoperative cochlear nerve action potential (CNAP) monitoring. Postoperative hearing results and ABR waveforms were examined. METHODS: Charts were reviewed and tabulated for age, sex, tumor side, tumor size, preoperative and postoperative audiometric and ABR results, intraoperative monitoring results by ABR and CNAP, and surgical complications. RESULTS: Hearing preservation was achieved in seven of nine patients (78%) with absent preoperative ABR, as well as six of seven patients (86%) with tumors less than or equal to 20 mm in greatest dimension. Although intraoperative ABR monitoring was not possible in any of these patients, CNAP monitoring was successful in all. Return of ABR waveforms was observed in four of the six patients (67%) tested from 3 to 22 months postoperatively. Four of the seven patients (57%) enjoyed improvement in hearing class as defined by the guidelines of the American Academy of Otolaryngology-Head and Neck Surgery. CONCLUSIONS: Absent ABR waveforms have not been a negative prognostic sign regarding hearing preservation. CNAP monitoring is possible in these patients and likely helps to minimize iatrogenic cochlear nerve trauma. Patients with no ABR waveforms have hope of hearing preservation and even improvement following acoustic neuroma resection performed utilizing CNAP monitoring and hearing preservation surgical techniques.

Controversies in the management of inferior turbinate hypertrophy: a comprehensive review.

Nasal obstruction must frequently be addressed during functional rhinoplasty. Even after a properly performed septorhinoplasty correcting septal deflection and/or nasal valve collapse, nasal obstruction may persist due to turbinate hypertrophy. Turbinates have many important functions, including warming and humidification of inspired air, and numerous factors can contribute to pathologic enlargement. Management of inferior turbinate hypertrophy has been actively debated for more than a century. The primary goal of therapy is to maximize the nasal airway for as extended a period as possible while minimizing complications of therapy, such as nasal drying and hemorrhage. This review describes the various medical and surgical therapeutic modalities widely used today, with emphasis placed on surgical management of the inferior turbinates. Advantages, disadvantages, complications, and controversies of each form of treatment are reviewed and discussed. A staged protocol of increasingly invasive interventions is proposed.