The effect of genistein on cisplatin induced ototoxicity and oxidative stress / Efeito da genisteína na ototoxicidade induzida pela cisplatina e estresse oxidativo

Abstract Highlights Cisplatin is an antineoplastic agent used malignant diseases. Cisplatin ototoxicity is generally bilateral, irreversible, and progressive. Genistein is a phytoestrogen. Genistein functions as antioxidant and cell cycle inhibitor by inhibiting DNA topoisomerase. Genistein showed positive effects on ototoxicity with its antioxidant. Objective Cisplatin is an antineoplastic agent used in adults and children for the treatment of various malignant diseases. It can cause irreversible ototoxicity. Genistein is a phytoestrogen. Genistein functions as an antioxidant and cell cycle inhibitor by inhibiting the DNA topoisomerase and tyrosine protein kinase enzymes. The protective effect of genistein in preventing cisplatin-induced ototoxicity and levels of the oxidative stress was investigated. Methods 32 Sprague Dawley rats were used in 4 groups (control, cisplatin, cisplatin + genistein, genistein). Otoacoustic emission measurements of the distortion product were performed on the 1st, 2nd and 5th days of the test protocol. Serum malondialdehyde, superoxide dismutase, catalase, glutathione peroxidase, total antioxidant status, total oxidant status and oxidative stress index measurements were made. Results The hearing of the cisplatin + genistein group was found to be better than that of the cisplatin group. While the malondialdehyde, total oxidant status and oxidative stress index parameters decreased significantly in the cisplatin + genistein group compared to the cisplatin group, superoxide dismutase increased significantly (p < 0.05). Conclusion Genistein showed positive effects against ototoxicity with its antioxidant effect. Level of evidence Level 3.

Resumo DESTAQUES A cisplatina é um agente antineoplásico usado em lesões malignas. A ototoxicidade da cisplatina é geralmente bilateral, irreversível e progressiva. A genisteína é um fitoestrógeno. A genisteína funciona como antioxidante e inibidor do ciclo celular ao inibir a topoisomerase do DNA. A genisteína apresentou efeitos positivos sobre a ototoxicidade com seu efeito antioxidante. Objetivo A cisplatina é um agente antineoplásico usado em adultos e crianças para o tratamento de diversas lesões malignas. Pode causar ototoxicidade irreversível. A genisteína é um fitoestrógeno que funciona como antioxidante e inibidor do ciclo celular ao inibir as enzimas DNA topoisomerase e tirosina-quinase. O efeito protetor da genisteína na prevenção da ototoxicidade induzida pela cisplatina e os níveis de estresse oxidativo foram investigados. Método Trinta e dois ratos Sprague Dawley foram usados em 4 grupos (controle, cisplatina, cisplatina + genisteína, genisteína). As medidas das emissões otoacústicas por produto de distorção foram tomadas nos dias 1, 2 e 5 do protocolo do teste. Foram medidos os níveis séricos de malondialdeído, superóxido dismutase, catalase, glutationa peroxidase, estado antioxidante total, estado oxidante total e índice de estresse oxidativo. Resultados A audição do grupo cisplatina + genisteína foi melhor do que a do grupo cisplatina. Enquanto os parâmetros malondialdeído, estado oxidante total e índice de estresse oxidativo diminuíram significantemente no grupo cisplatina + genisteína em comparação com o grupo cisplatina, o superóxido dismutase mostrou aumento significantemente (p < 0,05). Conclusão A genisteína apresentou efeitos positivos contra a ototoxicidade com seu efeito antioxidante. Nível de evidência Nível 3.

Effects of Covid-19 on the audio-vestibular system.

PURPOSE: It was aimed to investigate the effects of COVID-19 infection on hearing and the vestibular system. METHODS: Twenty-six patients whose treatment had been completed and who had no previous hearing or balance complaints were included in the study. Patients diagnosed with the disease by PCR were included in the study. Patients with at least one month of illness were included in the study. The hearing of patients was evaluated with transient evoked otoacoustic emissions (TEOAE) and pure-tone audiometry. Bedside tests, the European Evaluation of Vertigo scale (EEV), Video Head Impulse Test (vHIT), Ocular Vestibular Myogenic Evoked Potential (oVEMP), Cervical Vestibular Myogenic Evoked Potential (cVEMP) and Videonystagmography (VNG) tests were applied to evaluate the vestibular system. RESULTS: A statistically significant difference was found between the COVID-19 positive and control groups according to the mean values of the 4000 Hz and 8000 Hz in both the right and left ears (p < 0.05). No statistically significant difference was found in the other frequencies and TEOAE. No statistically significant difference was found between the COVID-19 positive and control groups in terms of their normal or pathological VNG saccade, optokinetic and spontaneous nystagmus values (p > 0.05). The normal and pathological VNG head shake values were found to be significantly different between the COVID-19 positive and control groups (p < 0.05). CONCLUSiON: The high frequencies in audiometry in the COVID-19 positive group were worse than those in the control group. In the vestibular system, especially in oVEMP and cVEMP, asymmetric findings were obtained in comparison to the control group, and a low gain in vHIT was shown. This study shows that the audiovestibular system of people with COVID-19 infection may be affected.

The effect of genistein on cisplatin induced ototoxicity and oxidative stress.

OBJECTIVE: Cisplatin is an antineoplastic agent used in adults and children for the treatment of various malignant diseases. It can cause irreversible ototoxicity. Genistein is a phytoestrogen. Genistein functions as an antioxidant and cell cycle inhibitor by inhibiting the DNA topoisomerase and tyrosine protein kinase enzymes. The protective effect of genistein in preventing cisplatin-induced ototoxicity and levels of the oxidative stress was investigated. METHODS: 32 Sprague Dawley rats were used in 4 groups (control, cisplatin, cisplatin + genistein, genistein). Otoacoustic emission measurements of the distortion product were performed on the 1st, 2nd and 5th days of the test protocol. Serum malondialdehyde, superoxide dismutase, catalase, glutathione peroxidase, total antioxidant status, total oxidant status and oxidative stress index measurements were made. RESULTS: The hearing of the cisplatin + genistein group was found to be better than that of the cisplatin group. While the malondialdehyde, total oxidant status and oxidative stress index parameters decreased significantly in the cisplatin + genistein group compared to the cisplatin group, superoxide dismutase increased significantly (p < 0.05). CONCLUSION: Genistein showed positive effects against ototoxicity with its antioxidant effect. LEVEL OF EVIDENCE: Level 3.

Improving clinical outcome predictions using convolution over medical entities with multimodal learning.

Early prediction of mortality and length of stay (LOS) of a patient is vital for saving a patient's life and management of hospital resources. Availability of Electronic Health Records (EHR) makes a huge impact on the healthcare domain and there are several works on predicting clinical problems. However, many studies did not benefit from the clinical notes because of the sparse, and high dimensional nature. In this work, we extract medical entities from clinical notes and use them as additional features besides time-series features to improve proposed model predictions. The proposed convolution based multimodal architecture, which not only learns effectively combining medical entities and time-series Intensive Care Unit (ICU) signals of patients but also allows to compare the effect of different embedding techniques such as Word2vec and FastText on medical entities. Results show that the proposed deep multimodal method outperforms all other baseline models including multimodal architectures and improves the mortality prediction performance for Area Under the Receiver Operating Characteristics (AUROC) and Area Under Precision-Recall Curve (AUPRC) by around 3%. For LOS predictions, there is an improvement of around 2.5% over the time-series baseline. The code for the proposed method is available at https://github.com/tanlab/ConvolutionMedicalNer.

The Complication of Tension Pneumocephalus After Septoplasty.

ABSTRACT: This paper presents a case of tension pneumocephalus with severe headache 2 days after septoplasty surgery. In such cases, endoscopic sinus surgery (ESS) or open approach can be used for repair of the defect. However, pneumocephalus, especially caused by minor defects, improves spontaneously with conservative treatment. In our case, the pneumocephalus was responsive to conservative treatment with bed rest, head elevation. His examinations in the 3rd and 8th months after discharge were uneventful and CT scan revealed no signs of pneumocephalus. In severe headaches developing after septoplasty, the possibility of intracranial complications should be evaluated. Simple conservative treatment should be tried before surgery, but then the patient should be examined at regular intervals.

A Convolutional Deep Clustering Framework for Gene Expression Time Series.

The functional or regulatory processes within the cell are explicitly governed by the expression levels of a subset of its genes. Gene expression time series captures activities of individual genes over time and aids revealing underlying cellular dynamics. An important step in high-throughput gene expression time series experiment is clustering genes based on their temporal expression patterns and is conventionally achieved by unsupervised machine learning techniques. However, most of the clustering techniques either suffer from the short length of gene expression time series or ignore temporal structure of the data. In this work, we propose DeepTrust, a novel deep learning-based framework for gene expression time series clustering which can overcome these issues. DeepTrust initially transforms time series data into images to obtain richer data representations. Afterwards, a deep convolutional clustering algorithm is applied on the constructed images. Analyses on both simulated and biological data sets exhibit the efficiency of this new framework, compared to widely used clustering techniques. We also utilize enrichment analyses to illustrate the biological plausibility of the clusters detected by DeepTrust. Our code and data are available from http://github.com/tanlab/DeepTrust.

Are long-term auditory results following ossiculoplasty with bone cement as successful as early-middle period results?

PURPOSE: Bone-cement (BC) ossiculoplasty is one of the options to solve ossicular chain problems. Many authors reported successful results in the early or mid-follow-up period; however, there is no long-term result in the literature. We aim to evaluate long term results of BC ossiculoplasty. MATERIALS AND METHODS: Forty-eight patients who underwent BC ossiculoplasty as incudostapedial re-bridging by the same surgeon were invited to evaluation. Postoperative otomicroscopic examination was performed. Pre-operative and post-operative audiological results after longer follow up and graft success rate were noted. RESULTS: Fourteen patients came for control examination. The follow-up period was between 87 and 135 months (mean 102 months). None of the patients had graft failure. Ten patients had early postoperative follow-up results (between 10 and 52; mean 24 months). In the comparison of preoperative and early postoperative air-bone gap, there were significant differences in all frequencies while the comparison of preoperative and long-term postoperative results showed a significant difference only in 250 and 500 Hz. Early postoperative results were better than late with significant difference only in the 2000 and 4000 Hz. CONCLUSIONS: As reported by many studies, bone cement application provides a significant auditory improvement in the early postoperative period. The results of the present study showed that this early auditory success may decrease over time with a long-term follow-up. Further studies should be conducted with larger patient groups to clarify the long-term benefits of this treatment and possible causes for its deterioration.

A Rare Cause of Headache That Should Be Kept in Mind: Isolated Concha Bullosa Fungus Ball.

Concha bullosa is characterized by pneumotization of the middle turbinate and is a common variation of sinonasal anatomy and is often asymptomatic. The presence of a fungus ball in concha bullosa and the associated clinic symptoms are very rare. Concha bullosa fungus balls are a rare differential diagnosis in a patient presenting to the otorhinolaryngology outpatient clinic with headache.In this article, the authors aimed to present an isolated fungus ball case in concha bullosa as a rare cause of headache differential diagnosis.

Drug response prediction by ensemble learning and drug-induced gene expression signatures.

Chemotherapeutic response of cancer cells to a given compound is one of the most fundamental information one requires to design anti-cancer drugs. Recently, considerable amount of drug-induced gene expression data has become publicly available, in addition to cytotoxicity databases. These large sets of data provided an opportunity to apply machine learning methods to predict drug activity. However, due to the complexity of cancer drug mechanisms, none of the existing methods is perfect. In this paper, we propose a novel ensemble learning method to predict drug response. In addition, we attempt to use the drug screen data together with two novel signatures produced from the drug-induced gene expression profiles of cancer cell lines. Finally, we evaluate predictions by in vitro experiments in addition to the tests on data sets. The predictions of the methods, the signatures and the software are available from http://mtan.etu.edu.tr/drug-response-prediction/.

The role of goats as reservoir hosts for bovine herpes virus 1 under field conditions.

Bovine herpesvirus 1 (BoHV1) is the cause of economically significant viral infections in cattle. Respiratory symptoms associated with the infection are known as Infectious Bovine Rhinotracheitis (IBR). Sheep and goats are less sensitive to the infection although their role in inter-species viral transmission under field conditions is subject to controversy. The objective of this study was to investigate seroprevalence of BoHV1 infections in cattle, sheep, and goats raised together for at least a year. Blood serum samples were taken from 226 cattle, 1.053 sheep, and 277 goats from 17 small- to medium-scale farms. BoHV1-specific antibody presence and titers were determined using virus neutralization test. In total, 73 of the 226 cattle (32.3%) were seropositive. The infection was detected in 13 of the 17 farms. Infection rates ranged from 5.8 to 88.8%. Only one of the 1053 sheep (0.09%) was seropositive. However, 58 of the 277 (20.9%) goats were seropositive. Goat samples taken from 8 of the 17 farms were seropositive with infection rates ranging from 17 to 38.9%. Statistical analysis showed a significant correlation in infection rates between cattle and goats but not sheep. These results suggest that goats may be more sensitive to the BHV1 infection than sheep and the role of goats as possible reservoirs for BoHV1 in the control and eradication of BHV1 in cattle should be considered in future studies.

Prediction of anti-cancer drug response by kernelized multi-task learning.

MOTIVATION: Chemotherapy or targeted therapy are two of the main treatment options for many types of cancer. Due to the heterogeneous nature of cancer, the success of the therapeutic agents differs among patients. In this sense, determination of chemotherapeutic response of the malign cells is essential for establishing a personalized treatment protocol and designing new drugs. With the recent technological advances in producing large amounts of pharmacogenomic data, in silico methods have become important tools to achieve this aim. OBJECTIVE: Data produced by using cancer cell lines provide a test bed for machine learning algorithms that try to predict the response of cancer cells to different agents. The potential use of these algorithms in drug discovery/repositioning and personalized treatments motivated us in this study to work on predicting drug response by exploiting the recent pharmacogenomic databases. We aim to improve the prediction of drug response of cancer cell lines. METHODS: We propose to use a method that employs multi-task learning to improve learning by transfer, and kernels to extract non-linear relationships to predict drug response. RESULTS: The method outperforms three state-of-the-art algorithms on three anti-cancer drug screen datasets. We achieved a mean squared error of 3.305 and 0.501 on two different large scale screen data sets. On a recent challenge dataset, we obtained an error of 0.556. We report the methodological comparison results as well as the performance of the proposed algorithm on each single drug. CONCLUSION: The results show that the proposed method is a strong candidate to predict drug response of cancer cell lines in silico for pre-clinical studies. The source code of the algorithm and data used can be obtained from http://mtan.etu.edu.tr/Supplementary/kMTrace/.

Effective gene expression data generation framework based on multi-model approach.

OBJECTIVE: Overcome the lack of enough samples in gene expression data sets having thousands of genes but a small number of samples challenging the computational methods using them. METHODS AND MATERIAL: This paper introduces a multi-model artificial gene expression data generation framework where different gene regulatory network (GRN) models contribute to the final set of samples based on the characteristics of their underlying paradigms. In the first stage, we build different GRN models, and sample data from each of them separately. Then, we pool the generated samples into a rich set of gene expression samples, and finally try to select the best of the generated samples based on a multi-objective selection method measuring the quality of the generated samples from three different aspects such as compatibility, diversity and coverage. We use four alternative GRN models, namely, ordinary differential equations, probabilistic Boolean networks, multi-objective genetic algorithm and hierarchical Markov model. RESULTS: We conducted a comprehensive set of experiments based on both real-life biological and synthetic gene expression data sets. We show that our multi-objective sample selection mechanism effectively combines samples from different models having up to 95% compatibility, 10% diversity and 50% coverage. We show that the samples generated by our framework has up to 1.5x higher compatibility, 2x higher diversity and 2x higher coverage than the samples generated by the individual models that the multi-model framework uses. Moreover, the results show that the GRNs inferred from the samples generated by our framework can have 2.4x higher precision, 12x higher recall, and 5.4x higher f-measure values than the GRNs inferred from the original gene expression samples. CONCLUSIONS: Therefore, we show that, we can significantly improve the quality of generated gene expression samples by integrating different computational models into one unified framework without dealing with complex internal details of each individual model. Moreover, the rich set of artificial gene expression samples is able to capture some biological relations that can even not be captured by the original gene expression data set.

Multi-scale modularity and motif distributional effect in metabolic networks.

Metabolism is a set of fundamental processes that play important roles in a plethora of biological and medical contexts. It is understood that the topological information of reconstructed metabolic networks, such as modular organization, has crucial implications on biological functions. Recent interpretations of modularity in network settings provide a view of multiple network partitions induced by different resolution parameters. Here we ask the question: How do multiple network partitions affect the organization of metabolic networks? Since network motifs are often interpreted as the super families of evolved units, we further investigate their impact under multiple network partitions and investigate how the distribution of network motifs influences the organization of metabolic networks. We studied Homo sapiens, Saccharomyces cerevisiae and Escherichia coli metabolic networks; we analyzed the relationship between different community structures and motif distribution patterns. Further, we quantified the degree to which motifs participate in the modular organization of metabolic networks.

Assessment of mucosal changes associated with nasal splint in a rabbit model / Avaliação sobre alterações na mucosa, associadas ao uso de splints nasais, utilizando coelhos como cobaias

INTRODUCTION: There is no consensus on duration of the nasal splint after nasal septum surgeries. The pressure of nasal splint on the mucosa may cause tissue necrosis and nasal septum perforation. OBJECTIVES: To investigate the histopathological changes of the nasal mucosa caused by nasal splints in a rabbit model. METHODS: No splint was used in group A. Bilateral silicone nasal splints were placed for five, ten, and 15 days in groups B, C, and D, respectively. Biopsy of the nasal mucosa was performed after removal of splint. Histopathologic evaluations were performed. The severity and depth of the inflammation were scored. RESULTS: Group A had a normal histological appearance. Comparison of the results of groups B, C, and D with group A demonstrated statistically significant differences with regards to the severity of histopathological findings. There was no statistically significant difference between groups B and C. There were statistically significant differences between the groups B and D, and also between groups C and D. CONCLUSIONS: Longer duration of nasal splint had a higher risk for septal perforation. Therefore, removal of the splint as soon as possible may be helpful for preventing potential perforations. .

INTRODUÇÃO: Não existe consenso acerca do tempo de permanência de splints nasais no pós-operatório de cirurgias no septo. A pressão causada pelos mesmos na mucosa nasal pode causar necrose e perfurações septais. OBJETIVOS: Investigar mudanças histopatológicas da mucosa nasal causadas por splints nasais em coelhos. MÉTODO: Nenhum splint foi utilizado no grupo A. Splints de silicone foram utilizados por 5, 10 e 15 dias nos grupos B, C e D, respectivamente. Biópsia da mucosa nasal foi realizada após a remoção dos mesmos. Avaliações histopatológicas foram realizadas, e a gravidade e a profundidade do processo inflamatório foram medidas. RESULTADOS: Grupo A apresentou uma aparência histológica normal. Comparações de resultados entre os grupos B, C e D com o grupo A demonstraram diferenças estatísticas relevantes na gravidade histopatológica. Não houve diferenças estatísticas relevantes entre os grupos B e D, assim como entre os grupos C e D. CONCLUSÃO: De acordo com os resultados, quanto maior a duração no uso de splints nasais maior o risco de perfuração septal. Portanto, a remoção de splints nasais deve ser realizada assim que possível, prevenindo potenciais perfurações. .

Assessment of mucosal changes associated with nasal splint in a rabbit model.

INTRODUCTION: There is no consensus on duration of the nasal splint after nasal septum surgeries. The pressure of nasal splint on the mucosa may cause tissue necrosis and nasal septum perforation. OBJECTIVES: To investigate the histopathological changes of the nasal mucosa caused by nasal splints in a rabbit model. METHODS: No splint was used in group A. Bilateral silicone nasal splints were placed for five, ten, and 15 days in groups B, C, and D, respectively. Biopsy of the nasal mucosa was performed after removal of splint. Histopathologic evaluations were performed. The severity and depth of the inflammation were scored. RESULTS: Group A had a normal histological appearance. Comparison of the results of groups B, C, and D with group A demonstrated statistically significant differences with regards to the severity of histopathological findings. There was no statistically significant difference between groups B and C. There were statistically significant differences between the groups B and D, and also between groups C and D. CONCLUSIONS: Longer duration of nasal splint had a higher risk for septal perforation. Therefore, removal of the splint as soon as possible may be helpful for preventing potential perforations.

The effect of Beta glucan on Cisplatin ototoxicity.

This study was undertaken to investigate the effect of betaglucan in ameliorating cisplatin ototoxicity. Rats were divided into four groups: cisplatin (C), cisplatin plus beta glucan (CB), beta glucan (B), and control (K). Distortion product otoacoustic emissions were elicited in 0th, 1st, and 5th days. For the group C differences were observed at 8,003 and 9,515 Hz between 0th and 5th days' measurements. In the group CB there were differences at frequencies of 3,996, 4,757, 5,660, and 6,726 Hz between 0th and 5th days' measurements. For the group B there were significant recovery in some frequencies. The observation of significant deterioration in terms of hearing in the group treated with cisplatin plus betaglucan may be suggested that depended on the increase of permeability and tissue conductance into the inner ear which may be caused by betaglucan. Further long-term follow-up studies by using different doses may clarify this matter.

Evidence of zoonotic pseudocowpox virus infection from a cattle in Turkey.

Pseudocowpox virus (PCPV) infects cattle throughout the world and has zoonotic potential. However, it is not known to infect cattle in Turkey. In August 2013, we observed ulcerative nodular swelling and pustules on udder and teats of a cow in a small village nearly Lake of Bafa, Milas, Mugla locate in southwestern part of Turkey. Interestingly, the similar lesions were also observed on skin of milkier women's hand at the same time. A PCPV strain was characterized based on the major envelop gene sequence. The phylogenetic analysis showed that the isolated strain was closely related to the members of other parapoxvirus genus. This study provides the first description of PCPV infection in Turkey.

The Protective Effect of Chrysin Against Cisplatin Induced Ototoxicity in Rats.

Ototoxicity is a common side effect of cisplatin chemotherapy. The aim of this study was to investigate the potential protective effect of chrysin against cisplatin-induced ototoxicity. Thirty-four adult female Wistar albino rats were separated into four groups: a cisplatin group (Group A), with cisplatin administered to ten rats once daily for three consecutive days at doses of 8 mg/kg body weight intraperitoneally (i.p.); a cisplatin plus chrysin group (Group B), with 8 mg/kg of cisplatin administered i.p. daily to ten rats for three consecutive days and 25 mg/kg of chrysin administered via oral gavage in a corn oil for 5 days: a chrysin group (Group C), with 25 mg/kg of chrysin administered via oral gavage in corn oil for 5 days to seven rats; and a control group (Group D), with 5 ml/kg of corn oil administered to seven rats via oral gavage for 5 days. Distortion product otoacoustic emission measurements were performed in the same ear of the rats under general anesthesia at baseline and on the first and fifth days after drug administration. No significant differences were noted between the measurements either in the chrysin group or in the control group. In the cisplatin group, there was a significant worsening of hearing compared to baseline and the measurements on the fifth day at all frequencies. In the statistical analysis, a statistically significant difference was observed at 5039, 6351, 8003, and 10078 Hz frequencies between the measurements on the first and fifth days. In the cisplatin plus chrysin group, there were statistically significant differences at frequencies of 2,003 and 5,039 Hz between the measurements at baseline and on the fifth day, at 3,175 and 5,039 Hz between the measurements on the first and fifth days, and at 8,003 and 100,078 Hz between the measurements at baseline and on the first day. According to these results, this study demonstrates that cisplatin-related ototoxicity can be prevented in rats by the administration of chrysin.

Evaluation of the protective effect of Beta glucan on amikacin ototoxicity using distortion product otoacoustic emission measurements in rats.

OBJECTIVES: This experimental study investigated the possible protective effect of beta glucans on amikacin ototoxicity. METHODS: Thirty-eight rats with normal distortion product otoacoustic emissions (DPOAEs) were divided into four groups. Group K was the control group. Group A was injected intramuscularly (i.m.) with amikacin 600 mg/kg/day between days 1-15. Group AB was given beta glucan gavage 1 mg/kg/day on days 0-15 and given amikacin 600 mg/kg/day i.m. on days 1-15. Group B was administered only beta glucan gavage, 1 mg/kg/day, on days 0-15. The DPOAEs were elicited in different frequency regions between 2,003 and 9,515 Hz, as distortion product diagrams (DPgrams), before and after the medication was administered, in all groups, on days 1, 5, 10, and 15. RESULTS: No significant changes in the DPgrams were observed in group K. In group A, significant deterioration was observed at the 8,003 and 9,515 Hz frequencies on day 10, and at the 3,991, 4,557, 5,660, 6,726, 8,003, and 9,515 Hz frequencies on day 15. For group AB, statistically significant deterioration was observed at the 2,824, 8,003, and 9,515 Hz frequencies on day 15. The results for group B showed a significant improvement of hearing at the 2,378, 2,824, 3,363, and 3,991 Hz frequencies on day 1, at the 3,363, 3,991, and 8,003 Hz frequencies on day 10, and at the 8,003 Hz frequency on day 15. CONCLUSION: This study suggests that amikacin-induced hearing loss in rats may be limited to some extent by concomitant use of beta glucan.

The use of bone cement for ossicular chain defects.

Bone cement is a good and cheap option for some ossicular chain problems such as incudostapedial re-bridging. The purpose of this retrospective study is to evaluate the audiologic results after reconstruction of three different types of ossicular chain defects, using bone cement. Group 1 consists of 42 patients who underwent an ossiculoplasty using bone cement between the damaged long process of the incus and an intact stapes superstructure. Group 2 consists of 46 patients in which incus interposition between malleus and stapes superstructure was performed, using bone cement to fix the interposed incus. For group 3, consisting of 32 patients who had a present malleus, a defective long process of the incus and a missing stapes superstructure, a re-shaped incus was placed between the stapes footplate and the malleus and bone cement was again used as a fixator. Preoperative and postoperative pure-tone audiometric findings were obtained and hearing differences were assessed. The mean preoperative and postoperative air-bone gaps were 34.8 and 15.6, 35 and 18.4, and 43.4 and 19.8 for groups 1, 2, and 3, respectively. There was a significant improvement in hearing outcomes in all the groups when comparing preoperative and postoperative mean air-bone gaps (p < 0.001). The postoperative air-bone gap was ≤20 dB in 76 % of patients in group 1, 64 % of patients in group 2, and 46 % of patients in group 3. Bone cement is an effective and cheap option for some ossicular chain problems such as incudostapedial re-bridging. It may also be used to fix the interposed incus to the stapes superstructure and/or malleus to avert displacement.