A clinically derived guinea pig dosing model of cisplatin ototoxicity.

The guinea pig is a commonly-used animal model in hearing research, as their audible frequency range is similar to that of humans, and they possess comparatively large cochleae among rodents. Numerous studies have investigated the ototoxic effects of cisplatin in guinea pigs, but these have been mostly limited to single high-dose bolus injections of cisplatin. This method of drug administration is not consistent with human treatment schedules, and therefore lacks translational value to clinical applications. We tested several different cisplatin dosing schedules in guinea pigs based on common research based and clinical regimens, measuring the resulting hearing loss and morbidity (weight loss). We propose a dosing paradigm of once-weekly 4 mg/kg cisplatin injections for three weeks to best mimic clinical treatment schedules. This method resulted in a configuration of hearing loss similar to what is observed in humans along with minimal changes in weight.

Cool OtOprotective Ear Lumen (COOL) Therapy for Cisplatin-induced Hearing Loss.

HYPOTHESIS: Localized cooling of the external ear has a protective effect on the susceptibility to cisplatin-induced hearing loss. BACKGROUND: We previously demonstrated significant protection from cisplatin-induced hearing loss using cool water ear canal irrigation. However, the study was limited to a single bolus injection of cisplatin and an acute time period. Here, we examined the application of localized cooling of the ear canal with repeated doses of cisplatin, over an expanded period of time, and using two methods of cooling. METHODS: Twenty-four guinea pigs (12 male and 12 female) underwent auditory physiological testing (auditory brainstem response and distortion product otoacoustic emissions at 8-32 kHz) and pre/postadministration of cisplatin. Cisplatin (4 mg/kg i.p.) was administered in 3 weekly single injections for a total of 12 mg/kg. While anesthetized, the left ears of the guinea pigs were exposed to either cool water (22°C; ICS Water Caloric Irrigator), a cool ear bar (15°C, cooled by a Peltier device; TNM, Scion NeuroStim), or left uncooled as a sham control. The animals were tested 3 days post each dosage and 1 month post the final dose. At the end of the experiment the animals were euthanized for histological evaluation. RESULTS: We found that hearing loss was significantly reduced, and hair cell survival greatly improved, in animals that received cooling treatments compared to cisplatin-only control animals. No significant difference was observed between the two methods of cooling. CONCLUSION: Localized cooling of the ear canal during administration of cisplatin mitigated loss of auditory function and loss of hair cells.

Can contaminated water be rendered safe for nasal saline irrigations?

OBJECTIVES/HYPOTHESIS: To compare sterile water to three methods of sterilization (carbon filtration, boiling, and ultraviolet [UV] light) for preparation of nasal saline irrigants free of bacterial and amebic contaminants. STUDY DESIGN: Bench-top translational research and cost comparison. METHODS: Sterile water was compared to common sterilization methods. Sterile water was contaminated with known concentrations of Staphylococcus aureus, Pseudomonas aeruginosa, Moraxella catarrhalis, Acinetobacter baumannii, Klebsiella pneumonia, Legionella pneumophila, and Naegleria fowleri. Test samples were subjected to boiling, carbon filtration, or ultraviolet light (UV) and then cultivated on appropriate media. Controls included samples of sterile water (negative control) and untreated test samples (positive control). RESULTS: Carbon filtration reduced but did not eliminate the number of organisms present in test samples. Boiling test samples for 5 minutes and UV light treatment resulted in sterilization of all organisms. Negative (sham contaminated) samples produced no growth, whereas positive (untreated) samples grew numerous organisms as expected. A cost comparison between bottled water and UV water sterilization (with SteriPEN Ultra) became equal in less than 2 years of consistent use. CONCLUSIONS: Carbon filtration reduces contamination but does not sterilize water and is thus unsafe for preparation of nasal saline irrigant. Boiling and UV treatment resulted in sterilization and are equivalent to purchased sterile water. Ultraviolet treatment was found to be safe, convenient, and a cost-effective alternative to purchased sterile water. LEVEL OF EVIDENCE: NA Laryngoscope, 127:1513-1519, 2017.

Case presentation and images of a lingual osseous choristoma in a pediatric patient.

Since its original description in 1913, fewer than 100 lingual osseous choristomas have been reported in the literature; thus, prevalence is unknown. We describe a case of an 11 year old male who was seen in consultation after an incidental left posterior tongue mass was discovered on exam. The patient's presentation of an asymptomatic, hard, pedunculate posterior tongue lesion is typical; however, if one is to believe the proposed congenital remnant theory in regards to the etiology of this benign tumor, it is curious that no mention was made of a lesion of the tongue on prior evaluations by his pediatrician or on the otolaryngologic examinations performed 3 and 6 years prior to the most recent presentation. Included with the case description are interesting radiographs, intra-operative photos, gross specimen photo and microscopic images.