In vitro and in vivo effects of lutein against cisplatin-induced ototoxicity.

INTRODUCTION: Cisplatin is a commonly prescribed drug that produces ototoxicity as a side effect. Lutein is a carotenoid with antioxidant and anti-inflammatory properties previously tested for eye, heart and skin diseases but not evaluated to date in ear diseases. AIM: To evaluate the protective effects of lutein on HEI-OC1 auditory cell line and in a Wistar rat model of cisplatin ototoxicity. MATERIALS AND METHODS: In vitro study: Culture HEI-OC1 cells were exposed to lutein (2.5-100 µM) and to 25 µM cisplatin for 24h. In vivo study: Twenty eight female Wistar rats were randomized into three groups. Group A (n=8) received intratympanic lutein (0.03 mL) (1mg/mL) in the right ear and saline solution in the left one to determine the toxicity of lutein. Group B (n=8) received also intraperitoneal cisplatin (10mg/kg) to test the efficacy of lutein against cisplatin ototoxicity. Group C (n=12) received intratympanic lutein (0.03 mL) (1mg/mL) to quantify lutein in cochlear fluids (30 min, 1h and 5 days after treatment). Hearing function was evaluated by means of Auditory Steady-State Responses before the procedure and 5 days after (groups A and B). Morphological changes were studied by confocal laser scanning microscopy. RESULTS: In vitro study: Lutein significantly reduced the cisplatin-induced cytotoxicity in the HEI-OC1 cells when they were pre-treated with lutein concentrations of 60 and 80 µM. In vivo study: Intratympanic lutein (1mg/mL) application showed no ototoxic effects. However it did not achieve protective effect against cisplatin-induced ototoxicity in Wistar rats. CONCLUSIONS: Although lutein has shown beneficial effects in other pathologies, the present study only obtained protection against cisplatin ototoxicity in culture cells, but not in the in vivo model. The large molecule size, the low dose administered, and restriction to diffusion in the inner ear could account for this negative result.

Hearing threshold levels for an otologically screened population in Spain.

OBJECTIVE: The aim of the present study was to provide thresholds data as a function of age for an otologically normal population in Spain, compared to the current ISO 7029 (2000) standard. DESIGN: A prospective study in an otologically screened population. STUDY SAMPLE: Data was collected from 1175 otologically-normal persons aged between 5 and 90 years. Inclusion criteria involved those listed in ISO 389-1 (1998) and the 8253-1 (2010). Suitability for inclusion was evaluated through interview, based on a questionnaire, and physical examination. RESULTS: The hearing thresholds decreased slightly from 125 to 2000 Hz. From 2000 Hz onwards the thresholds increased; this increase being more pronounced with increasing frequency and age. No statistically significant sex differences were found. The hearing threshold levels in the present study were higher (poorer) than the ones provided by ISO 7029 (2000). CONCLUSIONS: Results from this study suggest that the thresholds listed in ISO 7029 (2000) may be too restrictive, and could be useful in formulating the ISO 7029 update.

Earphones in extended high-frequency audiometry and ISO 389-5.

OBJECTIVE: To determine common reference equivalent threshold sound pressure levels (RETSPL) for the earphones used in the extended high-frequency (EHF) range, as different earphones are commercially available, but there are not RETSPLs for each model. DESIGN: Hearing threshold sound pressure levels were measured up to 20 kHz for the Sennheiser HDA 200 audiometric earphone, and were compared to the ISO 389-5 (2006) norm and other investigations using that earphone and different ones. STUDY SAMPLE: A total of 223 otologically-normal subjects (aged 5-25 years old) participated in the hearing determination. RESULTS: The results are in good agreement with previous studies of hearing thresholds using the same and other earphones. CONCLUSIONS: The results of the present investigation are relevant for the international standard for the calibration of audiometric equipment in the 8 to 16 kHz frequency range, ISO 389-5. The data may be used for a future update of the RETSPL for circumaural and insert audiometric earphones.

Effect of intratympanic dimethyl sulphoxide (DMSO) in an in vivo model of cisplatin-related ototoxicity.

Although dimethyl sulfoxide (DMSO) is one of the most common solvents employed in otoprotection studies, its effect on the inner ear remains unknown. Only a few in vitro studies have addressed the effect of DMSO in cochlear cells. Up to the date, no in vivo functional studies have been reported. To determine the effect of intratympanic DMSO application in the inner ear, and to evaluate its effect in combination with cisplatin in Wistar rats, twelve Wistar rats were randomly assigned into two groups. Group A received intratympanic 1 % DMSO in both ears. Group B received intraperitoneal cisplatin (10 mg/kg) and intratympanic 0.5 % DMSO in the right ear and saline solution in the left ear. Functional changes were evaluated with Auditory Steady-State Responses before and 5 days after the procedure. Morphological changes were studied by means of confocal laser scanning microscopy following the removal of the temporal bones and cochlear dissection. Hearing threshold levels in group A did not show any statistically significant changes after the treatment. In group B, significant differences between pre- and post-treatment were found, with no statistically significant variations between right (DMSO) and left ear (saline solution). We suggest that DMSO could be safely used to dissolve hydrophobic compounds in otoprotection studies without interfering with the cochlear damage produced by cisplatin.

Bleeding control in endoscopic sinus surgery: a systematic review of the literature.

In the literature various methods are described to reduce bleeding in endoscopic sinus surgery. Scientific evidence and results were gathered and analysed to determine the effectiveness of the various methods used. A total of 20 articles fulfilled the inclusion criteria. Two retrospective articles studied the differences between local and general anaesthesia. Three articles analysed the use of local methods to control bleeding. The majority of the articles analysed the use of different systemic drugs to control intraoperative bleeding. Certain procedures, such as the reverse Trendelenburg position, the use of high doses of epinephrine, the infiltration of phenylephrine and lidocaine into the pterygopalatine fossa, the preoperative use of prednisone, and the control of the heart rate (with dexmedetomidine or remifentanil), appear to reduce the intraoperative blood loss and/or improve the visualisation of the surgical field. However, the evidence supporting these conclusions is poor. The benefits of other procedures, such as the preoperative use of ß-blockers, antihypertensive agents, and surgical pledgets with oxymetazoline, phenylephrine, or cocaine, for bleeding control are not evidenced in the literature. In addition, the literature does not present any evidence on the benefits of local anaesthesia compared with general anaesthesia or the use of propofol compared to inhaled analgesics in terms of intraoperative bleeding or complication rates.

Young systemic lupus erythematosus patients with no hearing involvement: 10-year follow up.

OBJECTIVE: To evaluate patients with systemic lupus erythematosus and normal hearing over 10 years, compared with healthy controls. METHODS: Thirty patients diagnosed with systemic lupus erythematosus were evaluated in a prospective, descriptive study. Eight patients fulfilled the inclusion criteria, i.e. normal otoscopy, normal hearing, normal imaging and disease duration of less than one year. Eleven healthy companions of ENT patients were recruited as controls. RESULTS: At study commencement, the mean patient age was 32.75 years (range, 15-49 years) and there were no statistically significant audiometric differences between patients and controls. No statistically significant audiometric changes were found either within or between the patient and control groups at 10-year follow up. CONCLUSION: These results supply no evidence for progressive hearing loss in systemic lupus erythematosus patients with no hearing involvement at study commencement. Therefore, we recommend audiometric tests only for systemic lupus erythematosus patients complaining of hearing loss, or for other clinical purposes. It is conceivable that asymptomatic hearing loss could be observed over a more extended follow-up period (i.e. more than 10 years).