Effects of subchronic inhalation exposure to an organophosphorus insecticide compound containing dichlorvos on wistar rats’ otoacoustic emissions

IntroductionConsidering that previous studies suggest that pesticides may cause hearing disorders in humans, as well as the lack of studies proving the specific mechanisms of injury and the difficulty of separating concomitant etiological factors of the hearing damage, such as noise and vibration, it is important to develop studies using animal models to elucidate the effects of exposure to those substances isolated from other hearing damage etiologies.ObjectiveTo evaluate if the exposure to a dichlorvos based organophosphorus insecticide may induce ototoxicity.Methods36 male Wistar rats were assigned to 3 groups (12 rats/group): control (exposed to water), positive control (treated with cisplatin to induce hearing damage) and experimental (exposed to dichlorvos based organophosphorus insecticide). The amplitude of distortion product otoacoustic emissions in the frequencies of 4, 6, 8, 10 and 12 kHz was evaluated before and after exposure, as well as systemic toxicity signs, body mass gain and plasma cholinesterase. Open field and plus maze tests were performed in 24 rats: experimental (n = 8), control (n = 8) and positive control group (n = 8 introduced new rats to induce anxiolytic activity) to evaluate the locomotor activity and anxiety, respectively.ResultsThere was no significant change in body mass gain and plasma cholinesterase in the dichlorvos based organophosphorus insecticide group, however, the animals showed transient piloerection, depression and dyspnea during exposure. The behavior was not affected in any group. The frequencies of 8 and 10 kHz were significantly affected bilaterally in the insecticide group, which also showed a significant difference of the control in 10 kHz on the right and 8 and 10 kHz on the left ear.ConclusionSubchronic inhalation exposure to dichlorvos based organophosphorus insecticide induced ototoxicity in the cochlear function of rats without relevant systemic toxicity.     

84例爆震性耳聋听力学分析

目的：分析暴震性耳聋的听力学改变,指导临床积极治疗。方法：对８４例爆震性耳聋行纯音测听及声阻抗测定。结果：感音神经性及混合性耳聋分别占３３．３％和３３．９％;听力曲线以水平下降、斜坡下降和陡坡下降为主;鼓室功能曲线“Ａ”型占多数达５８．９％;蹬骨肌反射同侧刺激引出同侧占５８．３％,对侧刺激引出同侧占４４％。结论：爆炸冲击波和脉冲波对内耳损伤严重,呈不可逆改变;对中耳结构影响相对较小。     

Prevalence of hearing impairment in a community population of adults with learning disability: access to audiology and impact on behaviour

There is a paucity of studies exploring the frequency of problem behaviours in people with learning disability and hearing impairment. Deafness in learning disability has been described as a ‘double jeopardy‘ because the difficulties are compounded to be more than the sum of their parts. The aim of the study was to ascertain the prevalence of hearing impairment in a community population of adults with learning disability and then investigate their access to audiology. We also aimed to collect information on the prevalence of problem behaviours in this population and explore links between hearing impairment and the use of hearing aids and problem behaviours. The prevalence of hearing impairment was 9.2%, 70% had been seen by audiology services at some time in their life but only 24% had ongoing assessments and hearing‐aid maintenance. Sixty‐two percent of the population had problem behaviours and 34% had self‐injurious behaviour. The high prevalence of problem behaviours and self‐injurious behaviour found in this population compared with other studies suggests a need for further research. These findings also reveal that the hearing status of people with a learning disability continues to be overlooked as the deafness often gets lost among their other problems.     

耳鼻咽喉科教学中听力学专题的教改实践

听力学是耳鼻咽喉科教学中的重要环节和教学难点。通过对听力学教学内容和方法的一系列改革, 收到了良好的成效并获得师生的普遍肯定。这一教改举措既提高了学员学习的积极性、主动性,又有利于培养和锻炼其临床分析问题和解决问题的综合能力。     

Auditory semantic, syntactic, and retention errors made by aphasic subjects on the token test

The Token Test was administered to 25 mild aphasic and 25 matched normal subjects for the purpose of determining the linguistic nature of the auditory verbal comprehension error responses. As was expected,the aphasic subjects obtained significantly poorer scores on the Token Test than did the normal subjects, with minimal overlap between the two groups. In Parts I–IV, the errors were exclusively semantic, and reflected only the amount of required verbal memory. Im Part V, the syntactic structures vary, and the aphasic subjects showed a similar pattern of difficulty as did the normal subjects. Syntactic errors were more prevalent than semantic errors in Part V, suggesting that syntactic complexity was the most important factor in verbal comprehension on this part. In comparison to previous research utilizing the Token Test with normal children, the aphasic subjects in the present study generally had high error rates on the same items as did the children.     

Hearing health network: a spatial analysis

IntroductionIn order to meet the demands of the patient population with hearing impairment, the Hearing Health Care Network was created, consisting of primary care actions of medium and high complexity. Spatial analysis through geoprocessing is a way to understand the organization of such services.ObjectiveTo analyze the organization of the Hearing Health Care Network of the State of Minas Gerais.MethodsCross-sectional analytical study using geoprocessing techniques. The absolute frequency and the frequency per 1000 inhabitants of the following variables were analyzed: assessment and diagnosis, selection and adaptation of hearing aids, follow-up, and speech therapy. The spatial analysis unit was the health micro-region.ResultsThe assessment and diagnosis, selection, and adaptation of hearing aids and follow-up had a higher absolute number in the micro-regions with hearing health services. The follow-up procedure showed the lowest occurrence. Speech therapy showed higher occurrence in the state, both in absolute numbers, as well as per population.ConclusionThe use of geoprocessing techniques allowed the identification of the care flow as a function of the procedure performance frequency, population concentration, and territory distribution. All procedures offered by the Hearing Health Care Network are performed for users of all micro-regions of the state.     

A 3-year study of patients with tinnitus and jaw muscle tenderness

Objective: This study evaluated three-year results of treatment with an interocclusal appliance in 89 tinnitus patients with jaw muscle tenderness.

Methods: Subjective tinnitus severity was recorded using a visual analog scale (VAS). The number of tender muscles was registered. The patients were followed annually. After three years, 64 patients were examined (72%).

Results: Tinnitus severity at baseline was high (mean VAS value 68.3). After one year, the VAS values were substantially lower (mean 37.4; p < 0.001). During the following two years, there were no significant changes in VAS values. The mean number of tender muscles decreased from seven to two after one year and remained at this number for up to three years.

Conclusion: In many tinnitus patients with signs of temporomandibular disorders (TMDs), intraoral splint therapy reduced tinnitus severity and jaw muscle symptoms. The favorable results after one year remained for up to three years without significant changes.     

Clinician,student and faculty perspectives on the audiology-industry interface: implications for ethics education

Objective: Supporting audiologists to work ethically with industry requires theory-building research. This study sought to answer: How do audiologists view their relationship with industry in terms of ethical implications? What do audiologists do when faced with ethical tensions? How do social and systemic structures influence these views and actions?

Design: A constructivist grounded theory study was conducted using semi-structured interviews of clinicians, students and faculty.

Study sample: A purposive sample of 19 Canadian and American audiologists was recruited with representation across clinical, academic, educational and industry work settings. Theoretical sampling of grey literature occurred alongside audiologist sampling. Interpretations were informed by the concepts of ethical tensions as ethical uncertainty, dilemmas and distress.

Results: Findings identified the audiology–industry relationship as symbiotic but not wholly positive. A range of responses included denying ethical tensions to avoiding any industry interactions altogether. Several of our participants who had experienced ethical distress quit their jobs to resolve the distress. Systemic influences included the economy, professional autonomy and the hidden curriculum.

Conclusions: In direct response to our findings, the authors suggest a move to include virtues-based practice, an explicit curriculum for learning ethical industry relations, theoretically-aligned ethics education approaches and systemic and structural change.