Objectives/Hypothesis: The aim of this study is to determine the role of free radicals and antioxidants in nasal polyps. Study Design: Prospective, randomized, controlled study. Methods: Thirty-one patients with nasal polyposis and a control group consisting of 19 patients with septal deviation and lower turbinate hypertrophy were included in the study. Levels of the antioxidants retinol, ␤-carotene, ␣-tocopherol, and ascorbic acid were measured from the sera of the patients with nasal polyposis and the control group. Plasma levels of superoxide dismutase activity (SOD), glutathione peroxidase (GSHPX) activity, and reduced glutathione (GSH) were also obtained. As a peroxidation product, the levels of the malondialdehydethiobarbituric acid (MDA) combination were measured from the plasma of patient and control groups. Measurements of MDA, GSH, and ␣-tocopherol levels were also taken from the polyp tissue and turbinate mucosa of the control group. Results: The blood levels of antioxidants and MDA as an oxidant were significantly different in the patient group compared with the control group (P < .01). The tissue levels of antioxidants and MDA were significantly different in the patients with polyposis compared with the control group (P < .01). The blood and tissue antioxidant levels were found to be decreased, and MDA levels as an oxidant increased significantly in the patient group with polyposis when compared with the control group, and there was a negative correlation between oxidative stress and antioxidants. Conclusion: This study demonstrates that oxidative stress and tissue and blood antioxidants in the patients with polyposis were significantly different compared with the control group. The blood and tissue antioxidant levels decreased, and MDA levels, as an oxidant, increased significantly in the patient group with polyposis when compared with the control group. The current study demonstrates that there is strong evidence related to oxidative stress in the pathogenesis of nasal polyposis, and antioxidants can have a preventive role in free-radicalmediated tissue damage in nasal polyposis.

The aim of this study is to control the residual vibrations of a clamped-free beam subjected to a moving load. The dynamic response of the beam is calculated by using the finite element method in order to design a suitable control technique and the numerical results are verified by vibration measurements. All the numerical calculations are performed by a commercial finite element package. Two laser displacement sensors are used to measure the dynamic response of the beam. The moving load is obtained by pressured air directed to the beam via a nozzle, and the movement of the load is achieved by an industrial robot manipulator having 6 degrees of freedom. In this study, the suppression of the residual vibrations that occur after the moving load has left the beam is considered as the main subject. Piezoelectric actuators are used for active vibration control study and displacement feedback is employed. The numerical results agree well with the experimental results. The results show that the finite element method can be used effectively for designing a suitable vibration control strategy.

In the light of objective evaluations, and by applying the study treatment protocol, these results suggest that normal voice can be maintained after intervention, at six months' follow up.

Hearing loss has commonly been reported in association with thyroid disorders and during treatment with propylthiouracil. The relationship between hyperthyroidism and the auditory system has not been previously investigated. The aim of this cross-sectional, case-control study was to investigate hearing loss in patients with Graves' disease (GD). The study population consisted of patients with newly diagnosed GD and healthy controls. Pure tone audiometry at frequencies of 250, 500, 1000, 2000, 4000 and 8000 Hz, along with immittance measures including tympanometry and acoustic reflex tests, were performed in all participants. Twenty-two GD patients and 22 healthy controls consented to inclusion in the study. The differences between groups with regards to age and gender distribution were statistically insignificant (P = 0.567 and P = 0.757, respectively). The hearing thresholds of right and left ears were also similar in both groups (P > 0.05). When single-ear evaluations were taken into account (total of 44 ears for both groups), hearing thresholds in the GD group were significantly higher than healthy controls at all frequencies (P < 0.05). Following testing at the designated frequencies, the only significant effect of thyrotoxicosis was observed with frequencies of 4000 and 8000 Hz. The odds ratio for having hearing loss at a frequency of 8000 HZ associated with GD was 14.97 (95% confidence interval 4.03-55.64). In patients with GD, right and left pure tone audiometric findings at a frequency of 8000 Hz correlated positively with FT3, FT4 and negatively with TSH. Our results are highly suggestive of a decrease in hearing ability in patients with GD, particularly at high frequencies. Further studies are needed to help elucidate the mechanisms behind hearing loss which develops in association with GD.

To determine the usefulness of sheep cadaver ear as a complementary model for training of stapedectomy at residency programs, 2 of our 4 year residents were included in the study and each operated 20 sheep ears. All routine steps of stapedectomy operation were performed, and their success and complication scores were recorded. Performance of residents for stapedectomy and teflon piston placement in sheep ears were evaluated by the authors. Success of both residents improved progressively. Success and complications were impressively better in the second 10 ears than the initial 10 for each resident. Both residents had better outcomes in last 10 ears. Sheep cadaver ear is an excellent model for stapedectomy training in residency and helps to improve surgical skills. We offer sheep cadaver ear training model especially in the countries where obtaining human cadaver temporal bone is difficult.