Evaluation of an undergraduate occupational health program in Iran based on alumni perceptions: a structural equation model / 보건의료교육평가

PURPOSE: Evaluating educational programs can improve the quality of education. The present study evaluated the undergraduate occupational health program at the Semnan University of Medical Sciences in Semnan, Iran, with a focus on the associations between alumni perceptions of the learning environment and the outcomes of the occupational health program. METHODS: A cross-sectional questionnaire survey was conducted among alumni of the undergraduate occupational health program. We asked alumni to rate their perceptions of the items using a 4-point Likert scale. The associations between alumni perceptions of the educational program and curriculum, faculty, institutional resources, and learning outcomes were modeled and described using structural equation modeling procedures. RESULTS: A descriptive analysis of alumni perceptions indicated low evaluations for the administrative system, practical and research-based courses, and the number of faculty members. We found that a structural model of the evaluation variables of curriculum, faculty qualifications, and institutional resources significantly predicted undergraduate educational outcomes. The curriculum had direct and indirect effects on learning outcomes, mediated by faculty. CONCLUSION: The findings of our study highlight the usefulness of the structural equation modeling approach for examining links between variables related to the learning process and learning outcomes. Surveys of alumni can provide data for reassessing the learning environment in the light of the professional competencies needed for occupational health graduates.

[Protective effect of N-acetylcysteine [NAC] administration on prevention of noise-induced hearing loss [NIHL] in rabbit]

Oxidative stress due to free radicals formation plays an important role in noise-induced hearing loss [NIHL]. Many hypotheses have been proposed regarding the biochemical prevention of this complication. This study was performed with the purpose of determining the preventive effect of N-acetylcysteine [NAC] administration, as an antioxidant agent, on NIHL in Rabbit. In an experimental study, 24 adult white male rabbits were divided into four groups, including: 1] control, 2] noise exposure [100dB octave band noise centered at 4000Hz for 40h], 3] noise exposure plus NAC administration [325mg/kg, daily ip injection], and 4] no exposure and NAC administration. Audiometric test of rabbits was assessed by auditory brainstem response [ABR] technique in three stages. The Kruskal-Wallis and Mann-Whitney tests were used to compare the groups, and a p<0.05 was considered significant. The mean ABR threshold shift for the noise exposure plus NAC administration group, 1 hour after exposure at 1, 2, 4 and 8kHz frequencies were, respectively, 16.66 +/- 1.63, 21.66 +/- 1.75, 33.5 +/- 2.34, and 39.33 +/- 2.25dB. These values were significantly less than the same values in the noise exposure group. The results of this study showed that NAC can provide a proper protective effect against hearing loss resulting from noise exposure

[Effect of sound conditioning on click auditory brainstem response threshold shifts in guinea pigs]

Sound conditioning is exposure to a non-traumatic, moderate level of sound which increases inner ear resistance against further severe noise. In this study, we aimed to survey the effect of sound conditioning on auditory brainstem response [ABR] threshold shifts using click stimulus, and the effect of the frequency of conditioning on hearing protection. Fifteen guinea pigs were randomly divided into 3 groups. Two conditioned groups were exposed to 1 kHz, and 4 kHz octave band noise at 85 dB SPL, 6 hours per day for 5 days, respectively. On the sixth day, the animals were exposed to 4 kHz octave band noise at 105 dB SPL, for 4 hours. The control group was exposed to intense noise, 4 kHz at 105 Db SPL for 4 hours [without conditioning]. After exposure, ABR thresholds using click were recorded an hour, and 7 days after noise exposure. The results of the ABR with click stimulus showed less thresold shifts in conditioned groups than control [p 0.05]. Electrophysiological data of our study showed that sound conditioning has a protective effect against subsequent intensive noise exposure, and the frequency of conditioning does not have significant effect on ABR threshold shifts when using click stimulus

[Protective effect of n-acetylcysteine on the hearing of rabbits exposed to noise and carbon monoxide]

One of the chemical pollutions which is frequently common in industry-other than noise is carbon monoxide. The present study aimed to assess the putative protective effect of N-acetylcysteine on the function of outer hair cells of rabbits exposed simultaneously to noise and carbon monoxide. 24 male rabbits are entered in this interventional study. After obtaining baseline distortion product otoacoustic emissions, rabbits were randomly devided into four groups. The groups included: exposed with noise and received saline, exposed with noise and carbon monoxide and received saline, exposed with noise and received N-acetylcysteine, and exposed with noise and carbon monoxide and received N-acetylcysteine. Subsequently, they were evaluated again with distortion product otoacoustic emissions in two stages [two hours and one week after the exposure]. Data were recorded and analyzed using paired and independent sample t-tests. Exposure to noise, and also simultaneous exposure to noise and carbon monoxide, and moreover using N-acetylcysteine in both groups, produced significant changes in distortion product otoacoustic emissions amplitudes [p<0.005]. The findings of the present research reveal that simultaneous exposure to noise and carbon monoxide may potentiate noise induced hearing loss. In addition, utilizing N-acetylcysteine can be used as a preventive agent for noise induced hearing loss and to avoid its potentiation with carbon monoxide