In vivo screening for toxicity-modulating drug interactions identifies antagonism that protects against ototoxicity in zebrafish.

Introduction: Ototoxicity is a debilitating side effect of over 150 medications with diverse mechanisms of action, many of which could be taken concurrently to treat multiple conditions. Approaches for preclinical evaluation of drug-drug interactions that might impact ototoxicity would facilitate design of safer multi-drug regimens and mitigate unsafe polypharmacy by flagging combinations that potentially cause adverse interactions for monitoring. They may also identify protective agents that antagonize ototoxic injury. Methods: To address this need, we have developed a novel workflow that we call Parallelized Evaluation of Protection and Injury for Toxicity Assessment (PEPITA), which empowers high-throughput, semi-automated quantification of ototoxicity and otoprotection in zebrafish larvae via microscopy. We used PEPITA and confocal microscopy to characterize in vivo the consequences of drug-drug interactions on ototoxic drug uptake and cellular damage of zebrafish lateral line hair cells. Results and discussion: By applying PEPITA to measure ototoxic drug interaction outcomes, we discovered antagonistic interactions between macrolide and aminoglycoside antibiotics that confer protection against aminoglycoside-induced damage to lateral line hair cells in zebrafish larvae. Co-administration of either azithromycin or erythromycin in zebrafish protected against damage from a broad panel of aminoglycosides, at least in part via inhibiting drug uptake into hair cells via a mechanism independent from hair cell mechanotransduction. Conversely, combining macrolides with aminoglycosides in bacterial inhibition assays does not show antagonism of antimicrobial efficacy. The proof-of-concept otoprotective antagonism suggests that combinatorial interventions can potentially be developed to protect against other forms of toxicity without hindering on-target drug efficacy.

In vivo screening for toxicity-modulating drug interactions identifies antagonism that protects against ototoxicity in zebrafish.

Ototoxicity is a debilitating side effect of over 150 medications with diverse mechanisms of action, many of which could be taken concurrently to treat multiple conditions. Approaches for preclinical evaluation of drug interactions that might impact ototoxicity would facilitate design of safer multi-drug regimens and mitigate unsafe polypharmacy by flagging combinations that potentially cause adverse interactions for monitoring. They may also identify protective agents that antagonize ototoxic injury. To address this need, we have developed a novel workflow that we call Parallelized Evaluation of Protection and Injury for Toxicity Assessment (PEPITA), which empowers high-throughput, semi-automated quantification of ototoxicity and otoprotection in zebrafish larvae. By applying PEPITA to characterize ototoxic drug interaction outcomes, we have discovered antagonistic interactions between macrolide and aminoglycoside antibiotics that confer protection against aminoglycoside-induced damage to lateral line hair cells in zebrafish larvae. Co-administration of either azithromycin or erythromycin in zebrafish protected against damage from a broad panel of aminoglycosides, at least in part via inhibiting drug uptake into hair cells via a mechanism independent from hair cell mechanotransduction. Conversely, combining macrolides with aminoglycosides in bacterial inhibition assays does not show antagonism of antimicrobial efficacy. The proof-of-concept otoprotective antagonism suggests that combinatorial interventions can potentially be developed to protect against other forms of toxicity without hindering on-target drug efficacy.

Association of Genetic Diagnoses for Childhood-Onset Hearing Loss With Cochlear Implant Outcomes.

Importance: In the US, most childhood-onset bilateral sensorineural hearing loss is genetic, with more than 120 genes and thousands of different alleles known. Primary treatments are hearing aids and cochlear implants. Genetic diagnosis can inform progression of hearing loss, indicate potential syndromic features, and suggest best timing for individualized treatment. Objective: To identify the genetic causes of childhood-onset hearing loss and characterize severity, progression, and cochlear implant success associated with genotype in a single large clinical cohort. Design, Setting, and Participants: This cross-sectional analysis (genomics) and retrospective cohort analysis (audiological measures) were conducted from 2019 to 2022 at the otolaryngology and audiology clinics of Seattle Children's Hospital and the University of Washington and included 449 children from 406 families with bilateral sensorineural hearing loss with an onset younger than 18 years. Data were analyzed between January and June 2022. Main Outcomes and Measures: Genetic diagnoses based on genomic sequencing and structural variant analysis of the DNA of participants; severity and progression of hearing loss as measured by audiologic testing; and cochlear implant success as measured by pediatric and adult speech perception tests. Hearing thresholds and speech perception scores were evaluated with respect to age at implant, months since implant, and genotype using a multivariate analysis of variance and covariance. Results: Of 406 participants, 208 (51%) were female, 17 (4%) were African/African American, 32 (8%) were East Asian, 219 (54%) were European, 53 (13%) were Latino/Admixed American, and 16 (4%) were South Asian. Genomic analysis yielded genetic diagnoses for 210 of 406 families (52%), including 55 of 82 multiplex families (67%) and 155 of 324 singleton families (48%). Rates of genetic diagnosis were similar for children of all ancestries. Causal variants occurred in 43 different genes, with each child (with 1 exception) having causative variant(s) in only 1 gene. Hearing loss severity, affected frequencies, and progression varied by gene and, for some genes, by genotype within gene. For children with causative mutations in MYO6, OTOA, SLC26A4, TMPRSS3, or severe loss-of-function variants in GJB2, hearing loss was progressive, with losses of more than 10 dB per decade. For all children with cochlear implants, outcomes of adult speech perception tests were greater than preimplanted levels. Yet the degree of success varied substantially by genotype. Adjusting for age at implant and interval since implant, speech perception was highest for children with hearing loss due to MITF or TMPRSS3. Conclusions and Relevance: The results of this cross-sectional study suggest that genetic diagnosis is now sufficiently advanced to enable its integration into precision medical care for childhood-onset hearing loss.

Sensitivity to Deaf Culture Among Otolaryngology and Audiology Trainees.

OBJECTIVE: The Deaf community is an ethnolinguistic minority group. Low sensitivity to Deaf culture contributes to health disparities among Deaf patients. This study determines the level of sensitivity to Deaf culture among otolaryngology-head and neck surgery (OHNS) and audiology trainees. METHODS: Cross-sectional survey study of OHNS and audiology trainees from 10 large US institutions. Trainees were queried on their exposure to and comfort with Deaf patients and their education on, attitude toward, and awareness and knowledge of Deaf culture. Sensitivity to Deaf culture was operationalized as awareness and knowledge of Deaf culture. These were assessed using a 35-item instrument that was previously developed using a d/Deaf community-based participatory approach to research. We used T-tests to compare the sample to previous samples of medical students with training in Deaf culture (MS-TDCs) and general practitioners (GPs). RESULTS: There were 91 completed surveys (response rate 44.5%). Almost all were aware of Deaf culture (97.8%). The mean knowledge score was 55.0% (standard deviation (SD) 13.4%), which was significantly higher than that for GPs at 43.0% (SD 15.0%) (95% confidence interval 8.1%, 15.8%, P < .0001) but significantly lower than that for MS-TDCs at 69.0% (SD 13.0%)(CI -20.3%, -7.6%, P < .0001). Knowledge scores were comparable for OHNS and audiology trainees (P = .09). CONCLUSION: This sample of OHNS and audiology trainees was more sensitive to Deaf culture than GPs but less sensitive than MS-TDCs. Developing specialty-specific education may be warranted. LEVEL OF EVIDENCE: 4.

Educational Environments and Secondary School Outcomes Among Students Who Are D/deaf and Hard of Hearing in Special Education.

PURPOSE: The purpose of this study is to provide updated national estimates on the annual number, educational environments, and secondary school outcomes of students who are D/deaf and hard of hearing (D/HH) receiving special education (SpEd) and related services in the United States. METHOD: We performed a retrospective cross-sectional descriptive analysis of Individuals with Disabilities Education Act, Part B, Section 618 data from 2012 to 2018. Participants included students 6-21 years old in SpEd with "hearing impairment" reported as their primary disability. The general population of students in secondary school served as a comparator, via Current Population Survey data. We described the annual number of students (a) overall, (b) by educational environment, and (c) by reason for exiting SpEd, including the proportion graduating from and dropping out of secondary school. We described variation over time. RESULTS: The median annual number of students was 67,655, with minimal variation by year. The proportion in general education (GenEd) for ≥ 80% of the day increased by 4.2% over 6 years from 57.8% to 62.0%, whereas the proportions in GenEd for < 40% and 40%-79% of the day decreased by 1.6% and 1.3%, respectively. Proportions in the remainder of the environments changed < 1.0% each. Of exiters, 86.8% of students graduated, whereas 3.9% dropped out, compared to a dropout rate of 5.0% in the general population. CONCLUSION: From 2012 to 2018, students who are D/HH receiving SpEd in the United States have spent increasingly more time in GenEd, most graduated from high school, and few dropped out, with dropout patterns appearing similar to the general population.

Impact of Eliminating Local Anesthesia on Immediate Postoperative Analgesia in Pediatric Ambulatory Adenotonsillectomy.

Our goal was to standardize intraoperative analgesic regimens for pediatric ambulatory tonsillectomy by eliminating local anesthetic use and to determine its impact on postoperative pain measures, while controlling for other factors. METHODS: We assembled a quality improvement team at an ambulatory surgery center. They introduced a standardized anesthetic protocol, involving American Society of Anesthesiologists Classification 1 and 2 patients undergoing adenotonsillectomy. Local anesthesia elimination was the project's single intervention. We collected pre-intervention data (79 cases) from July 5 to September 17, 2019 and post-intervention data (59 cases) from September 25 to December 17, 2019. The intervention requested that surgeons eliminate the use of local anesthetics. The following outcomes measures were evaluated using statistical process control charts and Shewhart's theory of variation: (1) maximum pain score in the post-anesthesia care unit, (2) total post-anesthesia care unit minutes, and (3) postoperative opioid rescue rate. RESULTS: No special cause variation signal was detected in any of the measures following the intervention. CONCLUSIONS: Our data suggest that eliminating intraoperative local anesthetic use does not worsen postoperative pain control at our facility. The intervention eliminated the added expenses and possible risks associated with local anesthetic use. This series is unique in its standardization of anesthetic regimen in a high-volume ambulatory surgery center with the exception of local anesthesia practices. The study results may impact the standardized clinical protocol for pediatric ambulatory adenotonsillectomy at our institution and may hold relevance for other centers.

Defining Essential Services for Deaf and Hard of Hearing Children during the COVID-19 Pandemic.

COVID-19 is a rapidly growing global pandemic caused by a novel coronavirus. With no vaccine or definitive treatment, public health authorities have recommended a strategy of "social distancing," reducing individual interaction, canceling elective procedures, and limiting nonessential services. Health care providers must determine what procedures are considered "elective," balancing risk of treatment delays with that of coronavirus exposure to patient, family, and providers. Given critical periods for language development and the long-term impact of auditory deprivation, some audiologic and otologic services should be considered essential. In this article, we describe the experience of a quaternary referral pediatric hospital in Seattle, the epicenter of COVID-19 in the United States, and share strategies for risk minimization employed by Seattle Children's Hospital. We hope that this work can be a reference for other centers continuing care for children who are deaf and hard of hearing during the COVID-19 and future resource-limiting crises.

Reliability of Measuring Insertion Depth in Cochlear Implanted Infants and Children Using Cochlear View Radiography.

OBJECTIVES: Cochlear implant depth of insertion affects audiologic outcomes and can be measured in adults using plain films obtained in the "cochlear view." The objective of this study was to assess interrater and intrarater reliability of measuring depth of insertion using cochlear view radiography. STUDY DESIGN: Prospective, observational. SETTING: Tertiary referral pediatric hospital. SUBJECTS AND METHODS: Patients aged 11 months to 20 years (median, 4 years; interquartile range [IQR], 1-8 years) undergoing cochlear implantation at our institution were studied over 1 year. Children underwent cochlear view imaging on postoperative day 1. Films were deidentified and 1 image per ear was selected. Two cochlear implant surgeons and 2 radiologists evaluated each image and determined angular depth of insertion. Images were re-reviewed 6 weeks later by all raters. Inter- and intrarater reliability were calculated with intraclass correlation coefficients (ICCs). RESULTS: Fifty-seven ears were imaged from 42 children. Forty-nine ears (86%) had successful cochlear view x-rays. Median angular depth of insertion was 381° (minimum, 272°; maximum, 450°; IQR, 360°-395°) during the first round of measurement. Measurements of the same images reviewed 6 weeks later showed median depth of insertion of 382° (minimum, 272°; maximum, 449°; IQR, 360°-397°). Interrater and intrarater reliability ICCs ranged between 0.81 and 0.96, indicating excellent reliability. CONCLUSIONS: Postoperative cochlear view radiography is a reliable tool for measurement of cochlear implant depth of insertion in infants and children. Further studies are needed to determine reliability of intraoperatively obtained cochlear view radiographs in this population.

Pediatric Otolaryngology Divisional and Institutional Preparatory Response at Seattle Children's Hospital after COVID-19 Regional Exposure.

Coronavirus disease 2019 (COVID-19) is a novel coronavirus resulting in high mortality in the adult population but low mortality in the pediatric population. The role children and adolescents play in COVID-19 transmission is unclear, and it is possible that healthy pediatric patients serve as a reservoir for the virus. This article serves as a summary of a single pediatric institution's response to COVID-19 with the goal of protecting both patients and health care providers while providing ongoing care to critically ill patients who require urgent interventions. A significant limitation of this commentary is that it reflects a single institution's joint effort at a moment in time but does not take into consideration future circumstances that could change practice patterns. We still hope dissemination of our overall response at this moment, approximately 8 weeks after our region's first adult case, may benefit other pediatric institutions preparing for COVID-19.

Mitochondrial calcium uptake underlies ROS generation during aminoglycoside-induced hair cell death.

Exposure to aminoglycoside antibiotics can lead to the generation of toxic levels of reactive oxygen species (ROS) within mechanosensory hair cells of the inner ear that have been implicated in hearing and balance disorders. Better understanding of the origin of aminoglycoside-induced ROS could focus the development of therapies aimed at preventing this event. In this work, we used the zebrafish lateral line system to monitor the dynamic behavior of mitochondrial and cytoplasmic oxidation occurring within the same dying hair cell following exposure to aminoglycosides. The increased oxidation observed in both mitochondria and cytoplasm of dying hair cells was highly correlated with mitochondrial calcium uptake. Application of the mitochondrial uniporter inhibitor Ru360 reduced mitochondrial and cytoplasmic oxidation, suggesting that mitochondrial calcium drives ROS generation during aminoglycoside-induced hair cell death. Furthermore, targeting mitochondria with free radical scavengers conferred superior protection against aminoglycoside exposure compared with identical, untargeted scavengers. Our findings suggest that targeted therapies aimed at preventing mitochondrial oxidation have therapeutic potential to ameliorate the toxic effects of aminoglycoside exposure.

Canertinib induces ototoxicity in three preclinical models.

Neuregulin-1 (NRG1) ligand and its epidermal growth factor receptor (EGFR)/ERBB family regulate normal cellular proliferation and differentiation in many tissues including the cochlea. Aberrant NRG1 and ERBB signaling cause significant hearing impairment in mice. Dysregulation of the same signaling pathway in humans is involved in certain types of cancers such as breast cancer or non-small cell lung cancer (NSCLC). A new irreversible pan-ERBB inhibitor, canertinib, has been tested in clinical trials for the treatment of refractory NSCLC. Its possible ototoxicity was unknown. In this study, a significant dose-dependent canertinib ototoxicity was observed in a zebrafish model. Canertinib ototoxicity was further confirmed in two mouse models with different genetic backgrounds. The data strongly suggested an evolutionally preserved ERBB molecular mechanism underlying canertinib ototoxicity. Thus, these results imply that clinical monitoring of hearing loss should be considered for clinical testing of canertinib or other pan-ERBB inhibitors.

Identification of small molecule inhibitors of cisplatin-induced hair cell death: results of a 10,000 compound screen in the zebrafish lateral line.

HYPOTHESIS: The zebrafish lateral line can be used to identify small molecules that protect against cisplatin-induced hair cell death. BACKGROUND: Cisplatin is a commonly used chemotherapeutic agent, which causes hearing loss by damaging hair cells of the inner ear. There are currently no FDA-approved pharmacologic strategies for preventing this side effect. The zebrafish lateral line has been used successfully in the past to study hair cell death and protection. METHODS: In this study, we used the zebrafish lateral line to screen a library of 10,000 small molecules for protection against cisplatin-induced hair cell death. Dose-response relationships for identified protectants were determined by quantifying hair cell protection. The effect of each protectant on uptake of a fluorescent cisplatin analog was also quantified. RESULTS: From this screen, we identified 2 compounds exhibiting dose-dependent protection: cisplatin hair cell protectant 1 and 2 (CHCP1 and 2). CHCP1 reduced the uptake of a fluorescent cisplatin analog, suggesting its protective effects may be due to decreased cisplatin uptake. CHCP2 did not affect uptake, which suggests an intracellular mechanism of action. Evaluation of analogs of CHCP2 revealed 3 additional compounds that significantly reduced cisplatin-induced hair cell death, although none exceed the effectiveness or potency of the parent compound. CONCLUSION: The zebrafish lateral line was used to identify 2 small molecules that protected against cisplatin-induced hair cell death.

Upper aerodigestive magnetic foreign bodies in children.

OBJECTIVES/HYPOTHESIS: Small, powerful magnets are increasingly available in toys and other products, and are responsible for increasing numbers of foreign body injuries in children. Small, spherical, neodymium magnets available since 2008 are of particular concern. We aimed to identify all cases of upper aerodigestive foreign bodies at our institution over 15.5 years of study. STUDY DESIGN: Case series including all patients treated at an urban, tertiary care children's hospital who had upper aerodigestive magnetic foreign bodies, from January 1, 1998 through April 30, 2013. METHODS: We manually reviewed 7,049 patient records abstracted from billing data to identify all patients 0 to 20 years of age who had upper aerodigestive magnetic foreign bodies. RESULTS: We identified four cases of upper aerodigestive magnetic foreign bodies, one involving the hypopharynx, and three involving the upper esophagus. Three occurred in 2010 or later. Two cases involve the ingestion of multiple, spherical, neodymium magnets recently marketed as desktop toys. In both of these cases, there was a rapid development of mucosal injury at the site of attraction between two magnets. CONCLUSIONS: As small, powerful magnets become more ubiquitous, pediatric magnet foreign body injuries are increasing. Although most are gastrointestinal, we identified four recent cases involving the upper aerodigestive tract. Multiple magnets lodged in the hypopharynx or esophagus can rapidly cause pressure necrosis of mucosal tissues, and merit prompt management. Education regarding magnet safety and improved magnet safety standards are needed to reduce the risk of these injuries. LEVEL OF EVIDENCE: 4.

Functional mechanotransduction is required for cisplatin-induced hair cell death in the zebrafish lateral line.

Cisplatin, one of the most commonly used anticancer drugs, is known to cause inner ear hair cell damage and hearing loss. Despite much investigation into mechanisms of cisplatin-induced hair cell death, little is known about the mechanism whereby cisplatin is selectively toxic to hair cells. Using hair cells of the zebrafish lateral line, we found that chemical inhibition of mechanotransduction with quinine and EGTA protected against cisplatin-induced hair cell death. Furthermore, we found that the zebrafish mutants mariner (myo7aa) and sputnik (cad23) that lack functional mechanotransduction were resistant to cisplatin-induced hair cell death. Using a fluorescent analog of cisplatin, we found that chemical or genetic inhibition of mechanotransduction prevented its uptake. These findings demonstrate that cisplatin-induced hair cell death is dependent on functional mechanotransduction in the zebrafish lateral line.

"In-bone" utricle cultures--a simplified, atraumatic technique for in situ cultures of the adult mouse (Mus musculus) utricle.

HYPOTHESIS: The "in-bone" method of culturing utricles described here is a reliable and atraumatic technique for culturing mature mouse hair cells and studying hair cell death and protection. BACKGROUND: The current in vitro technique for studying hair cells of the mature mouse utricle involves removal from the temporal bone and free floating culture in media. This technique can be problematic because of variability in the preservation of the sensory epithelium and a steep learning curve that results in injury of the sensory epithelium in less experienced hands. We present a new atraumatic technique of culturing the utricle in situ within the temporal bone. METHODS: Leaving the temporal bone largely intact, a window is opened in the bony vestibule overlying the mouse utricle. The entire temporal bone is then placed into culture media. Utricles were cultured in situ for several days with minimal damage to the epithelium. The utricles are then fixed in situ, removed from the temporal bone, and processed. A standardized aminoglycoside-induced hair cell damage protocol was developed. RESULTS: Mature mouse utricles maintained hair cell numbers for 3 days in culture. Exposure to neomycin resulted in significant dose-dependent hair cell toxicity (p < 0.0001, 1-way analysis of variance). Exposure to the protective drug tacrine resulted in significant protection against neomycin (p < 0.05, 3-way analysis of variance). CONCLUSION: The "in-bone" technique is a reliable and atraumatic method for culturing mature mouse utricles and studying hair cell death and protection. It is easily mastered and can make in vitro study of hair cells accessible to more research groups.

Quinoline ring derivatives protect against aminoglycoside-induced hair cell death in the zebrafish lateral line.

We have previously published results from a screen of 1,040 FDA-approved drugs and bioactives (NINDS Custom Collection) for drugs that protect against neomycin-induced hair cell death (Ou et al., J Assoc Res Otolaryngol 10:191-203, 2009). Further evaluation of this drug library identified eight protective drugs that shared a common quinoline scaffold. These drugs were tested further in terms of their protection against other aminoglycosides, as well as their effect on aminoglycoside uptake. All of the eight quinolines that protected against neomycin were found to protect against short- and long-term gentamicin damage protocols. We then tested the structurally related compounds quinoline, isoquinoline, naphthalene, and indole for protective effects. Of these compounds, indole demonstrated a small but significant amount of protection against neomycin, while quinoline and isoquinoline partially protected against long-term gentamicin damage. We examined whether the protective activity of this group of compounds was related to known targets of the quinoline derivatives. The protective effects did not seem linked to either the cholinergic or histaminergic pathways that are regulated by some members of the quinoline family. However, all eight protective drugs were found to reduce the uptake of aminoglycosides into hair cells. Subsequent experiments suggest that reduction of uptake is the primary mechanism of protection among the quinoline drugs.

Hair cell toxicity in anti-cancer drugs: evaluating an anti-cancer drug library for independent and synergistic toxic effects on hair cells using the zebrafish lateral line.

Inner ear hair cell loss is the most common pathology seen after ototoxic drug injury. While certain drugs such as aminoglycosides and cisplatin are well-known to have dramatic ototoxic effects, it is probable that there are other drugs that cause occult degrees of hair cell loss and lesser degrees of hearing loss. Anti-cancer drugs are particularly strong candidates due to their general cytotoxicity. We have screened a library of 88 anti-cancer drugs (National Cancer Institute Approved Oncology Drugs Set) for drugs that damage hair cells of the zebrafish lateral line. The screen identified four out of five known ototoxic drugs. The screen also identified four out of seven suspected ototoxic drugs (drugs that have isolated case reports of patients developing hearing loss after administration). Five additional drugs with no known ototoxicity were identified as potentially novel ototoxins. Additional dose-response curves were performed to evaluate relative toxicity. Since anti-cancer drugs are often used clinically in combination, we also performed dose-response curves for a variety of anti-cancer drug combinations and demonstrated synergistic toxicity in five out of ten drug combinations that we tested. These findings support the use of the zebrafish lateral line as a screening tool to detect ototoxic effects in drugs and also suggest that ototoxicity should be considered in terms of drug regimens rather than individual drugs.

Drug screening for hearing loss: using the zebrafish lateral line to screen for drugs that prevent and cause hearing loss.

Several animal models have been used for the study of mechanosensory hair cells and hearing loss. Because of the difficulty of tissue acquisition and large animal size, these traditional models are impractical for high-throughput screening. The zebrafish has emerged as a powerful animal model for screening drugs that cause and prevent hair cell death. The unique characteristics of the zebrafish enable rapid in vivo imaging of hair cells and hair cell death. We have used this model to screen for and identify multiple drugs that protect hair cells from aminoglycoside-induced death. The identification of multiple drugs and drug-like compounds that inhibit multiple hair cell death pathways might enable the development of protective cocktails to achieve complete hair cell protection.

Polymerase chain reaction for pathogen identification in persistent pediatric cervical lymphadenitis.

OBJECTIVE: To study routine culture-negative persistent cervical lymphadenitis in children treated surgically during a 10-year period (December 26, 1997, to October 1, 2007) at a single institution. DESIGN: Retrospective case series. SETTING: Tertiary university-based pediatric referral center. PATIENTS: Patients 18 years or younger with cervical lymphadenitis managed surgically (incision and drainage, curettage, and/or excisional lymphadenectomy) and medically (antibiotic therapy), culture-negative after 48 hours, and subsequently diagnosed using the polymerase chain reaction, extended culture incubation, and/or histopathologic evaluation. MAIN OUTCOME MEASURES: Number of surgical interventions, causative organisms, histopathologic features, and resolution of lymphadenitis. RESULTS: Ninety surgical procedures were performed in 60 patients. The cure rate was 23% (approximately 14 patients) with incision and drainage, 58% (approximately 35 patients) with curettage, and 95% (57 patients) with excisional lymphadenectomy. Nontuberculous mycobacteria were the most prevalent causative organisms, followed by Bartonella and Legionella organisms. Four of 6 patients with Bartonella infection had a history of cat exposure, and 4 of 6 patients with Legionella infection had a history of hot tub exposure. CONCLUSIONS: Excisional lymphadenectomy is the preferred treatment of mycobacterial persistent cervical lymphadenitis in children. Sufficient data are lacking for similar recommendations in patients with disease caused by Bartonella organisms, whereas for neck disease caused by Legionella organisms, excisional lymphadenectomy may be superior to incision and drainage. The polymerase chain reaction is useful for pathogen identification in pediatric cervical lymphadenitis, although it is less sensitive in identification of mycobacteria. To our knowledge, our study is the first to report multiple cases of legionellosis in otherwise healthy children. Legionella seems to be a previously unrecognized but relatively common pathogen in culture-negative persistent cervical lymphadenitis in children.

Identification of FDA-approved drugs and bioactives that protect hair cells in the zebrafish (Danio rerio) lateral line and mouse (Mus musculus) utricle.

The hair cells of the larval zebrafish lateral line provide a useful preparation in which to study hair cell death and to screen for genes and small molecules that modulate hair cell toxicity. We recently reported preliminary results from screening a small-molecule library for compounds that inhibit aminoglycoside-induced hair cell death. To potentially reduce the time required for development of drugs and drug combinations that can be clinically useful, we screened a library of 1,040 FDA-approved drugs and bioactive compounds (NINDS Custom Collection II). Seven compounds that protect against neomycin-induced hair cell death were identified. Four of the seven drugs inhibited aminoglycoside uptake, based on Texas-Red-conjugated gentamicin uptake. The activities of two of the remaining three drugs were evaluated using an in vitro adult mouse utricle preparation. One drug, 9-amino-1,2,3,4-tetrahydroacridine (tacrine) demonstrated conserved protective effects in the mouse utricle. These results demonstrate that the zebrafish lateral line can be used to screen successfully for drugs within a library of FDA-approved drugs and bioactives that inhibit hair cell death in the mammalian inner ear and identify tacrine as a promising protective drug for future studies.