The inhibitory effect of topical N-acetylcysteine application on myringosclerosis in perforated rat tympanic membrane

Effects of Papaverine on Experimentally Induced Myringosclerosis

OBJECTIVE

This study aims to investigate the effects of papaverine on experimentally induced myringosclerosis (MS). MS is characterized by hyaline degeneration and calcification of the lamina propria of the tympanic membrane and can adversely affect hearing function if left untreated. The study examined the potential effects of both systemic and topical applications of papaverine on this process.

MATERIALS AND METHODS

In the study, 20 Wistar albino rats were used. The rats were divided into 4 groups and different treatment methods were applied in each group. In group 1, myringotomy was performed, but no additional intervention was performed. In group 2, saline-impregnated gelfoam was applied after myringotomy. In groups 3 and 4, topical and systemic applications of papaverine hydrochloride were performed. Tympanic membranes were examined under a microscope after 21 days, and the severity of MS and histopathologic changes were evaluated.

RESULTS

The papaverine-treated groups observed a significant increase in otomicroscopic sclerosis, the degree of inflammation, and tympanic membrane thickness. The degree of fibrosis was higher in group 3 compared with the other groups. The results showed that papaverine administration increased the occurrence of MS.

CONCLUSION

This study suggests that papaverine may increase MS through its vasodilating effect. Vasodilation is thought to cause an increase in oxygen-derived free radicals, which may contribute to the pathogenesis of MS. The results suggest that the effects of papaverine on MS should be carefully evaluated.

The effect of N-acetyl cysteine on biofilm layers in an experimental model of chronic otitis media

Objectıve

The aim of this study was to investigate the efficacy of N-acetylcysteine (NAC) on biofilm layers and on the course of disease in chronic otitis media.

Methods

Twenty-five rats that were induced with chronic otitis media (COM) were separated into three groups. In Group 1 (N = 18), 0.2% ciprofloxacin + 0.1% dexamethasone sodium phosphate + 0.5 mg/ml NAC solution was locally injected to the right ear of the rats; in Group 2, (N=18) 0.2% ciprofloxacin + 0.1% dexamethasone sodium phosphate was locally injected to the left ear of the rats. No treatment was applied to either ear of rats in Group 3 (N = 5). Histopathological and scanning electron microscope (SEM) evaluations were performed in all groups.

Results

SEM revealed biofilm formation in all COM induced groups. No significant difference was seen between groups 1 and 2 in terms of suppuration levels, fibrosis, inner ear involvement, infection staging and biofilm formation (p > 0.05).

Conclusıons

In this study, while histopathological and SEM evaluation revealed no effect of 0.5 mg/ml NAC on the biofilm layer in COM-induced rats, further studies with NAC at different concentrations are still needed on different types of experimental animals.

The Short-Term Effect of Eugenol on the Prevention of Experimentally Induced Myringosclerosis in a Rat Model

Objective:

The aim of our study was to assess the possible short-term effects of topical and oral eugenol on the suppression of experimentally developed myringosclerosis (MS).

Methods:

Four groups of seven male Wistar albino rats were used in the study. The tympanic membranes (TMs) of all subjects were myringotomized, and group 1 was given no treatment (as control group), group 2 received saline, group 3 had received topical eugenol and group 4 received oral eugenol.

Results:

In macroscopic evaluation the control and saline groups showed much more MS compared to the topical and oral eugenol groups which had statistically significantly less changes (p<0.05). Fibrosis and inflammation regarding the lamina propria (LP) of the eardrums of the topical and oral eugenol groups were significantly less than those of the control and saline groups (p<0.001). In microscopic evaluation, TMs were found to be thicker in the control and saline groups (p<0.001).

Conclusion:

Our study showed that the application of topical and oral forms of eugenol reduced fibrosis and prevented the advancement of MS in the LP of the TMs in the short-term. More studies with different extracts are needed to investigate the efficacy of phytotherapeutic agents for preventing MS development following myringotomy.

Double-Layered (Cartilage Island + Extra Perichondrium) Graft for Type 1 Tympanoplasty

OBJECTIVE

To compare the graft success rates and hearing results of single-layered (composite island) grafting (SLG) vs double-layered (composite plus second layer of perichondrium) grafting (DLG) for over-under type 1 tympanoplasty techniques.

STUDY DESIGN

Retrospective chart review.

SETTINGS

Tertiary center otorhinolaryngology clinic.

SUBJECTS AND METHODS

Medical charts of the patients who underwent type 1 tympanoplasty via the microscopic technique by a single surgeon between 2015 and 2019 were analyzed.

RESULTS

A total of 48 patients were included. The DLG (n = 26) group had higher graft take rates as compared to the SLG group (n = 22) for all patients (P = .038) and for moderate- to high-risk patients according to Middle Ear Risk Index (MERI) scores (P = .029) but not for patients with mild disease (P = .429) or myringosclerotic patients (P = .242). The DLG group exhibited higher air-bone gap closure (C-ABG) values as compared to the SLG group for all patients (P = .018). However, there was no noticeable difference in C-ABG values within the patients with successful grafting (P = .217). Only graft success status had a significant effect on C-ABG values when the multivariate linear regression was performed. (P = .016). Higher MERI scores and presence of myringosclerosis were related to the unsuccessful grafting (P < .01).

CONCLUSION

DLG tympanoplasty is encouraged, especially for patients with higher MERI scores, to increase the graft success rates. Better hearing outcomes of DLG tympanoplasty were related to the higher graft success status of this technique; DLG had no additional hearing effect for patients with successful grafting. Higher MERI scores and presence of myringosclerosis were related to graft failure.

Analysis of Risk Factors for Myringosclerosis Formation after Ventilation Tube Insertion

BACKGROUND

This study examined possible risk factors for myringosclerosis formation after ventilation tube insertion (VTI).

METHODS

A retrospective study was performed in a single tertiary referral center. A total of 582 patients who underwent VTI were enrolled in this study. Patients were divided into two groups based on the presence or absence of myringosclerosis: MS+ and MS-. Characteristics of patients were collected through medical chart review; these included age, gender, nature and duration of effusion, type of ventilation tube (VT), duration and frequency of VTI, incidence of post-VTI infection, incidence of intraoperative bleeding, and presence of postoperative perforation. Incidences of risk factors for myringosclerosis and the severity of myringosclerosis in association with possible risk factors were analyzed.

RESULTS

Myringosclerosis developed in 168 of 582 patients (28.9%) after VTI. Patients in the MS+ group had an older mean age than those in the MS- group. The rates of myringosclerosis were higher in patients with older age, serous otitis media, type 2 VT, post-VTI perforation, and frequent VTI. However, there were no differences in occurrence of myringosclerosis based on gender, duration of effusion, duration of VT placement, incidence of post-VTI infection, or incidence of intraoperative bleeding. The severity of myringosclerosis was associated with the duration of effusion and frequency of VTI.

CONCLUSION

Older age, serous effusion, type 2 VT, presence of post-VTI perforation, and frequent VTI may be risk factors for myringosclerosis after VTI; the severity of myringosclerosis may vary based on the duration of effusion and frequency of VTI.

In vitro inhibitory activity of N-acetylcysteine on tympanostomy tube biofilms from methicillin-resistant Staphylococcus aureus and quinolone-resistant Pseudomonas aeruginosa

OBJECTIVES

Biofilm formation in tympanostomy tubes causes persistent and refractory otorrhea. In the present study, we investigated the in vitro antibiofilm activity of N-acetylcysteine (NAC) against biofilm formation by methicillin-resistant Staphylococcus aureus (MRSA) and quinolone-resistant Pseudomonas aeruginosa (QRPA).

METHODS

We examined the antibiofilm activity of NAC against biofilms produced by MRSA and QRPA strains using in vitro biofilm formation assay, adhesion assay, and biofilm eradication assay. Additionally, the antibiofilm activity of different concentrations of NAC against tympanostomy-tube biofilms from MRSA and QRPA strains was compared using a scanning electron microscope.

RESULTS

The adhesion of MRSA and QRPA strains decreased significantly in a concentration-dependent manner after treatment with varying amounts of NAC. Treatment with NAC inhibited biofilm formation of both MRSA and QRPA strains and increased eradication of preformed mature biofilm produced by MRSA and QRPA. Besides, NAC exhibited significant eradication-activity against tympanostomy-tube biofilms produced by MRSA and QRPA strains.

CONCLUSIONS

Our results show potent inhibition of MRSA and QRPA biofilm after treatment with NAC. NAC shows potential for the treatment of biofilms and refractory post-tympanostomy tube otorrhea resulting from MRSA and QRPA infection.

The effect of rosmarinic acid on the prevention of myringosclerosis

OBJECTIVES

Myringosclerosis commonly occurs as a long-term complication of ventilation during the treatment of otitis media. We aimed to determine the effects of rosmarinic acid as an antioxidant on experimentally induced myringosclerosis.

METHODS

Twenty-four male Sprague-Dawley rats, weighing 250-300 g, were unilaterally myringotomized and randomly separated into three groups. Group 1 received no treatment (control group) (n = 8); Group 2 received topical rosmarinic acid (n = 8); Group 3 received oral rosmarinic acid (n = 8). On the twenty-first day, the right ears were examined by otomicroscope and findings of myringosclerosis were recorded. Finally, all of the rats were euthanized and the tympanic membrane (TM) thickness and the severity of middle ear mucosal inflammation were evaluated histopathologically.

RESULTS

The myringosclerosis severity, TM thickness, and inflammation scores were found to be significantly higher in the control group than in the topical and systemic treatment groups (p < 0.05). There were no statistically significant differences in terms of TM thickness and inflammation scores between the topical and systemic treatment groups (p > 0.05). While moderate and severe myringosclerosis were higher in the control group, mild myringosclerosis was found to be higher in both treatment groups.

CONCLUSION

The local and oral administration of rosmarinic acid suppressed inflammation, reduced TM thickness, and prevented the development of myringosclerosis in myringotomized rats.

Is there any effect of montelukast on prevention of myringosclerosis after myringotomy in a rat model?

OBJECTIVES

In this study, our aim was to identify the possible effects of montelukast sodium (ML) on the prevention of experimentally induced myringosclerosis.

MATERIALS AND METHODS

Twenty-eight female Wistar albino rats were used and they were divided into four groups randomly. Tympanic membranes (TM) of all animals were perforated and then group 1 received no treatment (control group), group 2 was treated with a topical saline solution, group 3 received topically ML and group 4 received orally ML. On the 15th day, all animals were euthanized. Tympanic membranes were evaluated otomicroscopically and histopathologically.

RESULTS

The histopathological findings, compared against a control and saline groups, showed the topically and orally ML groups had statistically significant differences of degree of myringosclerosis (p < 0.002) and median thickness of the TMs (p < 0.001). Suppression of inflammation was statistically significant only in the oral ML treatment group (p < 0.002).

CONCLUSION

Oral and topically administration of ML reduced myringosclerosis formation in myringotomies rats.

Does calcemia influence the onset of myringosclerosis after myringotomy with the insertion of ventilation tubes?

INTRODUCTION

Myringosclerosis is one of the most frequent late complications of the insertion of ventilation tubes, and its aetiopathogenesis remains unknown. The calcification that occurs in the formation of myringosclerosis plaque raises the hypothesis of the presence of a calcium metabolism disorder. The objective is to determine whether calcemia contributes to the development of myringoscelerosis after insertion of ventilation tubes.

MATERIAL AND METHODS

A longitudinal, prospective, analytical cohort study was conducted in patients undergoing myringotomy with the insertion of ventilation tubes due to otitis media with effusion. Calcemia was evaluated pre-operatively and in the follow-up the appearance of myringosclerosis and the percentage of the tympanum involved were evaluated.

RESULTS

The study included 156 patients (297 ears), with calcemia values ranging from 7.6 to 10.2mg/dl. Myringosclerosis was identified in 35.4% of the operated ears. No relationship was found between the appearance of myringosclerosis and calcemia (p=.596). It was found, however, that the greater the percentage of the tympanum affected by myringosclerosis, the lower the calcemia values (p=.014).

CONCLUSION

The population studied had calcemia values within the normal range, which allows us to infer that no changes in calcium metabolism are required for the development of myringosclerosis. Moreover, unlike in previous studies, higher calcium levels are not associated with more myringosclerosis. Calcemia did not influence the appearance of myringosclerosis after myringotomy with the insertion of ventilation tubes.

Effect of Topical Dexamethasone for Preventing Experimentally Induced Myringosclerosis

Objective

We aimed to examine the effect of topical dexamethasone by otomicroscopic and histologic examinations for preventing myringosclerosis induced by myringotomy in rat tympanic membranes.

Methods

Twenty-one Sprague Dawley rats (42 ears) were randomly divided into the following three groups after otomicroscopic examinations: experimental surgical group (5 rats), control group (8 rats), and study group (8 rats). The rats of all the groups underwent myringotomy in both tympanic membranes. Other than myringotomy, no additional procedure was performed for the rats in the experimental surgical group. In the control group, 0.9% NaCl was applied to the ears, whereas in the study groups, topical dexamethasone was applied to the ears. These applications in the control and study groups were repeated for nine days. On the 10th day of the study, the rat ears of all groups underwent otomicroscopic and histologic examinations. The prevalence and process of myringosclerosis were evaluated by otomicroscopic examination, whereas inflammation, membrane thickness, and myringosclerosis intensity were evaluated by histologic examination.

Results

The growth of myringosclerosis with otomicroscopic examination was lesser in the study group in which topical dexamethasone was applied than the control and the experimental surgical groups. Moreover, it was observed that myringosclerosis effected fewer quadrants in the study group.Histologic examinations revealed that inflammation was significantly lesser in the study group than in the experimental surgical and control groups. The average membrane thickness values were significantly lesser in the study group than in the experimental surgical group. With respect to myringosclerosis growth, no statistically significant difference was observed among all groups, whereas with respect to myringosclerosis intensity, the rat ears in the study group were less severely affected.

Conclusion

Thus, our study results suggest that applying topical dexamethasone after myringotomy has positive effects on limiting the intensity and prevalence of myringosclerosis.

The effect of Nigella sativa oil on prevention of myringosclerosis in a Guinea pig model

OBJECTIVES

In this study, our aim was to identify the possible effects of Nigella sativa L. (NS) [blackcumin] seed oil on the prevention of experimentally induced myringosclerosis (MS).

MATERIALS AND METHODS

Fourteen Guinea pigs were used and they were divided into three groups. Tympanic membranes (TM) of all animals were perforated and then group I was treated with saline soaked gel foams as a control group, group II was treated with 0.5 ml NS oil soaked gel foams at 0, 24 and 48 h and group III was treated with 5 ml NS oil orally at 0, 24, 48, 72 and 120 h. After 15 days, all animals were euthanized. Tympanic membranes were evaluated macroscopically and histopathologically.

RESULTS

Groups I showed extensive myringosclerosis in contrast to those of Groups II and III which had significantly less changes (p < 0.05). The fibrosis and inflammation in the lamina propria of the tympanic membranes of Groups I was found to be significantly more pronounced (p < 0.05). The tympanic membranes were found to be significantly thinner in Groups II and III when compared with Groups I (p < 0.05).

CONCLUSIONS

The results of this study suggested that topical or oral administration of NS oil supressed the inflammation and fibroblastic activity in the lamina propria of the myringotomized TMs of the Guinea pigs. For providing further evidence to use plant extracts as antioxidant and antiinflammatory therapy after myringotomy or ventilation tube insertion, further clinical studies with larger population will be essential.

Predictive factors for the appearance of myringosclerosis after myringotomy with ventilation tube placement: randomized study

Myringotomy with the insertion of ventilation tubes is the most frequent surgical procedure performed in children, and the appearance of myringosclerosis is one of its most frequent long-term complications. The objective of this study is to identify clinical factors and technique variations that may have a relation with the appearance of myringosclerosis, after tube insertion. Patients submitted to myringotomy with transtympanic short-term tube insertion were studied in a longitudinal prospective and analytical cohort study with the prospective randomized open, blinded endpoint (PROBE) methodology, to study the influence of the location of myringotomy (anterior-inferior quadrant or posterior-inferior), directions of the incision (radial or non-radial) and aspiration or not of the middle ear. Our study included 156 patients (297 ears). Myringosclerosis was observed in 35.7 % of the operated ears. It appeared more often in patients with greater number of otitis (p = .001) and with greater number of otorrhea episodes (p = .029) and in patients in whom the tympanogram after the tube extraction was type A (according to Jerger´s classification) (p = 0.016). We identified myringosclerosis in less patients, if the tube was in the tympanic membrane for less than 12 months (p = .009). Myringosclerosis was present more extensively if the tympanic incision was located in the anterior-inferior quadrant, with tympanic involvement superior to 25 % (p = .015). The results observed prove that, underlying the appearance of myringosclerosis, there exists an early inflammatory or infectious process and a final cicatricial process. It was also found that when myringotomy is made in the anterior-inferior quadrant, myringosclerosis appears in a higher percentage of the tympanic membrane; therefore, it is not recommended to do the incision in this quadrant, because it may lead to a reduction of the tympanic membrane vibration.

Efficacy of N-Acetylcysteine on Wound Healing of Nasal Mucosa

Postoperative nasal mucosa healing is a highly complex and organized process, and the success rates of endoscopic sinus surgery and septoplasty surgeries are closely associated with the postoperative wound healing processes. In this experimental study, the authors' aim was to use histopathologic examination to investigate the effects of N-Acetylcysteine (NAC) on the wound healing of rat nasal mucosa after mechanical trauma. Twenty-one Sprague-Dawley rats were randomly divided into 3 groups: the nontreated group (N = 7), the control saline group (N = 7), and the NAC group (N = 7). No treatment was given to the nontreated group for 15 days. The control saline group received intraperitoneal injection of saline (2.5  mL/kg, intraperitoneal) for 15 days and the NAC group was intraperitoneally injected with NAC at a dose of 300  mg/kg/day for 15 days. At the beginning of the study, unilateral mechanical nasal trauma was induced with an interdental brush inserted through the right nostril in all rats. Samples were stained using hematoxylin and eosin solution, and were examined by a pathologist using a light microscope. The severity of inflammation was milder in the NAC group compared with that in the nontreated and saline groups (P < 0.05). The subepithelial thickness index was lower in the experimental group (P < 0.05). Goblet cell loss was reduced in the experimental group compared with the nontreated and saline groups (P < 0.05). NAC decreases inflammation and goblet cell loss. Therefore, NAC has potential beneficial effects on the wound healing of nasal mucosa in rats.

The impact of topical and systemic enoxaparin sodium use on traumatic tympanic membrane perforation and myringosclerosis

The objective of this study is to investigate the effect of topical and systemic enoxaparin sodium on the healing pattern of experimentally induced tympanic membrane perforation and formation of myringosclerosis. A total of 24 Wistar-Albino strain rats were included in the study. Standard myringotomies were performed on each rat. In the first group, isotonic serum physiologic was dropped on external ear canal (control group). Topical enoxaparin was dropped on external ear canal and daily topical doses of enoxaparin were dropped on external ear canal of the rats for 14 days (topical treatment group). Third group received subcutaneous injections of enoxaparin for 14 days (systemic treatment group). Five micrometer thick sections of the bullae of the rats were stained with H&E. Inflammation, edema and sclerotic lesions and neovascularization observed in the lamina propria layer of the tympanic membrane, and total thickness of the tympanic membrane were evaluated. In intergroup comparisons, significant difference in the distribution pattern of severity of inflammation in all three groups was not observed (p = 0.784, p > 0.05). Total TM thickness differed among all three groups (p = 0.028, p < 0.05). A statistically significant difference was observed between the systemic enoxaparin and the control groups (p = 0.022, p < 0.05). A statistically significant difference was observed between the topical enoxaparin and the control groups (p = 0.037, p < 0.05). However, comparison between the topical and systemic treatment groups could not reveal any statistically significant intergroup difference (p = 0.682, p > 0.05). A significant difference was not observed among three groups as for the distribution of myringosclerotic plaques, severity of edema and neovascularization in the lamina propria (p = 0.539, p > 0.05), (p = 0.063, p > 0.05), (p = 0.152, p > 0.05). Topical and systemic enoxaparin treatment did not prevent formation of sclerotic plaques; however, it decreased TM thickness significantly in comparison with the control group.

The 100 Most Cited Turkish Papers in the Otorhinolaryngology Journals of Web of Science

Objective

The aim of the study was to analyze the 100 most cited publications with Turkish origin in the Web of Science Otorhinolaryngology (ORL) journals.

Methods

The Web of Science database was searched in terms of citations for publications originating from Turkey in ORL journals since 1983. After the identification of the 100 most cited articles, analysis was performed for the first author, institution, city, publication type, subject related to subspecialty, and journals having the most cited articles. Moreover, the number of ORL publications and citations of countries was determined in descending order using the same database.

Results

A total of 3948 ORL articles with Turkish origin was identified. The number of citations was 181 for the first and 28 for the last in the 100 most cited articles. As there was more than one article with 28 citations, 101 articles were analyzed. The number of the articles was 76, 22, and 3 for the university, education/research, and state hospitals, respectively. Hacettepe University, Ankara Numune Hospital, and Gazi University were the three leading institutions having the most cited articles, and Ankara was the first city. While 98 of 101 articles were original research, the number of case reports and review articles were 2 and 1, respectively. Thirty-five articles were related to otology, 23 to pediatric ORL, 20 to rhinology and head and neck surgery, and 3 to facial plastic surgery. Laryngoscope, Otolaryngology-Head and Neck Surgery, and International Journal of Pediatric Otorhinolaryngology were the leading 3 journals with the most cited articles coming from Turkey. The evaluation of countries revealed that Turkey was among the first 10 countries in terms of number of ORL articles but fell behind for the number of citations.

Conclusion

This bibliometric study is the first one regarding the contribution of Turkish authors and institutions to ORL literature. Similar studies might be periodically repeated to determine national development in the field of ORL and place of Turkey in the world.

The effect of Hypericum perforatum L. (St. John's Wort) on prevention of myringosclerosis after myringotomy in a rat model

OBJECTIVES

The purpose of this study was to identify the possible effects of Hypericum Perforatum (HP) on the prevention of experimentally induced myringosclerosis (MS).

METHODS

Twenty eight Wistar Albino rats were used and they were divided into four groups. Tympanic membranes of all animals were perforated and then group I had no treatment as a control group, group II had treated with olive oil only, group III had treated with HP orally and group IV had treated with HP topically.

RESULTS

Groups I and II showed extensive myringosclerosis in contrast to those of Groups III and IV which had significantly less changes (p<0.05). The inflammation and fibrosis in the lamina propria of the tympanic membranes of Groups I and II were found to be significantly more pronounced (p<0.05). The tympanic membranes were found to be significantly thinner in Groups III and IV when compared with Groups I and II (p<0.05).

CONCLUSIONS

The results of the present study suggested that oral or topical administration of HP extract after myringotomy suppressed the inflammation and fibroblastic activity in the lamina propria of the myringotomized TMs of the rats. Further clinical studies with larger population using HP and other antioxidants will be essential to provide further evidence for use of antioxidant therapy in patients with myringotomy and ventilation tube insertion for otitis media with effusion.

Do all antioxidant supplements have the same potential effect on preventing myringosclerosis?

Objectives

Myringosclerosis is an irreversible pathological healing mechanism of the tympanic membrane which can result in the formation of sclerotic plaques. Antioxidant treatment is a recognised prevention therapy and coenzyme Q10 (CoQ10), lycopene, and grape seed extract (GSE), were used in this manner.

Methods

Forty-four Wistar rats were used in this experiment, and, following myringotomies, the animals were randomly divided into four groups. CoQ10, lycopene or GSE was administered orally to the respective groups, starting from the day of surgery. Otomicroscopy examination was performed on the 14th day. All tympanic membrane lesions were evaluated and compared otomicroscopically and histopathologically.

Results

The otomicroscopy and histopathological findings, compared against a control (saline) group, showed the CoQ10, lycopene, and GSE groups had statistically significant differences of degree of sclerosis (P<0.001).

Conclusion

CoQ10, lycopene, and GSE were compared against a saline group and their antioxidative and anti-inflammatory effects were similar. The formation of myringosclerotic plagues after experimental myringotomy in rats significantly decreased and diminished after systemic administration of the three different antioxidant supplements.

The effect of lycopene on experimental myringosclerosis

OBJECTIVES

The aim of this study was to investigate the effect of lycopene on myringosclerosis development using histopathological and immunohistochemical analyses.

METHODS

Fifty-six intact tympanic membranes of 28 guinea pigs were included in the study. Subjects were randomly divided into four groups (n=7/group). Group I (control group) did not receive any treatment after myringotomy. Group II (lycopene treatment after myringotomy) received oral lycopene (once daily at the same time, 10mg/kg, dissolved in water, administered with a catheter). The treatment lasted seven days. Group III (lycopene treatment before and after myringotomy), received lycopene treatment (same dose and route of administration) for seven days. Myringotomy was performed on day 8, and lycopene treatment was initiated immediately, and continued for seven days (same dose and route of administration). Group IV (lycopene treatment before myringotomy) received lycopene treatment one week before myringotomy using the same method and dose for seven days. Myringotomy was performed on day 8. Lycopene was not administered after myringotomy. Fourteen days after myringotomy, myringosclerosis was evaluated automicroscopically and scored. Following decapitation, bulla were removed and immersed in a 10% formaldehyde solution. Sections were cut for histopathological and immunohistochemical examination, and thickness, sclerosis, inflammation, and collagen-IV accumulation were scored semi-quantitatively.

RESULTS

In the present study, the level of myringosclerosis was significantly lower in lycopene-treated groups compared to the control group (p<0.05). In addition, thickness, inflammation, sclerosis, and collagen-IV accumulation were significantly lower in the lycopene-treated groups compared to the control group (p<0.05). The timing of lycopene administration - i.e. before and/or after surgery - did not cause any difference with respect to myringosclerosis development.

CONCLUSION

Lycopene, a strong antioxidant, may represent a good alternative treatment to prevent the development of myringosclerosis.

Does systemic clarithromycin therapy have an inhibitory effect on tympanosclerosis? An experimental animal study

Objective:

To demonstrate the inhibitory effects of clarithromycin on in vitro tympanosclerosis.

Method:

Twenty-eight rats were divided into three groups: a clarithromycin group, a non-clarithromycin group and a negative control group. Those in the first two groups were injected with Streptococcus pneumoniae following a myringotomy, and tympanosclerosis was experimentally induced. Oral clarithromycin therapy was administered in the clarithromycin group. The other groups received no medical treatment.

Results:

All eardrums in the clarithromycin and non-clarithromycin groups developed myringosclerosis, but there was only one eardrum, in the clarithromycin group, with very severe myringosclerosis. In the clarithromycin group, 11 ears showed no inflammation and there were no ears with severe inflammation. In the non-clarithromycin group, there were 11 ears with severe inflammation. The mean eardrum thickness in the clarithromycin group was 20.93 µm and in the non-clarithromycin group it was 42.71 µm.

Conclusion:

Acute otitis media and myringotomies induced tympanosclerosis, but clarithromycin reduced the severity of tympanosclerosis.

Inhibitory effect of N-acetyl cysteine and ascorbic acid on the development of myringosclerosis: an experimental study

OBJECTIVES

This study investigated the effects of ascorbic acid and N-acetyl cysteine (NAC) antioxidants on the development of myringosclerosis (MS) in an experimental model.

METHODS

Myringotomies were performed in the ears of 15 guinea pigs, and Spongostan pieces were placed on the perforated regions of the tympanic membrane. The subjects were divided randomly into three groups and treated with three different solutions on the Spongostan-group 1: (control, 0.9% saline), group 2 (ascorbic acid), and group 3 (NAC). On day 15 after treatment, specimens from the tympanic membranes were obtained and examined via light microscopy. Sclerosis and inflammation scores and the tympanic membrane thicknesses were evaluated. Immunohistochemical methods were used to evaluate the expression of VEGF, TGF-β, iNOS, and IL1-β in all groups.

RESULTS

Lower sclerosis and inflammation scores and reduced tympanic membrane thicknesses were observed in groups treated with NAC or ascorbic acid compared with the control group. Immunohistochemical studies revealed significantly less expression of VEGF, TGF-β, and iNOS in groups 2 and 3 compared with group 1. Additionally, IL1-β expression was significantly less in group 3 than in group 1. Compared with group 1, group 2 animals exhibited reduced inflammation in the lamina propria, fewer active fibroblasts, less leukocyte infiltration, and decreased thickness of the vessels; group 3 animals exhibited decreased numbers of active fibroblasts and collagen fibers in the lamina propria.

CONCLUSIONS

Inflammation scores, cellular infiltration, and expression of VEGF, TGF-β, and iNOS were reduced by ascorbic acid and/or NAC treatments, thereby decreasing MS development. Decreased expression of IL1-β was observed only in animals treated with NAC.

Is there any effect of coenzyme Q10 on prevention of myringosclerosis? Experimental study with rats

Objective

Method

Results

Conclusion

Effect of local use of L-carnitine after myringotomy on myringosclerosis development in rats

OBJECTIVES

This study aimed to investigate the effect of local and intraperitoneal administration of L-carnitine on the prevention of experimentally induced myringosclerosis, and to compare treatment efficiency.

METHODS

Twenty-four Albino-Wistar rats (48 ears) were bilaterally myringotomised and divided randomly into four groups: group one received no treatment, group two received intraperitoneal L-carnitine, group three received local L-carnitine, and group four received both intraperitoneal and local L-carnitine. On the 15th day after treatment, tympanic membranes were harvested and evaluated histopathologically for myringosclerotic plaque formation, fibroblastic proliferation, tympanic membrane thickness and new vessel formation.

RESULTS

The group one tympanic membranes showed extensive thickness, and the incidence of myringosclerosis and fibroblast proliferation were greater than in groups two and four. There were statistically significant differences in tympanic membrane thickness between groups three and four, and in myringosclerosis incidence and fibroblast proliferation, comparing groups two, three and four.

CONCLUSION

Myringosclerosis development was significantly reduced in rats receiving myringotomy plus intraperitoneal L-carnitine. Intraperitoneal L-carnitine administration prevented fibroblastic proliferation and tympanic membrane thickening (both of which cause further tympanic membrane destruction), thus reducing myringotomy-associated morbidity. Local L-carnitine administration had limited effectiveness in this experimental setting.

N-acetylcysteine for the prevention of stricture after circumferential endoscopic submucosal dissection of the esophagus: a randomized trial in a porcine model

Background

Circumferential endoscopic submucosal dissection (CESD) of the esophagus would allow for both the eradication of Barrett’s esophagus and its related complications, such as advanced neoplasia. However, such procedures generally induce inflammatory repair resulting in a fibrotic stricture. N-acetylcysteine (NAC) is an antioxidant that has shown some efficacy against pulmonary and hepatic fibrosis. The aim of our study was to evaluate the benefit of NAC in the prevention of esophageal cicatricial stricture after CESD in a swine model.

Animals and methods

Two groups of six pigs each were subjected to general anesthesia and CESD: after randomization, a first group received an oral NAC treatment regimen of 100 mg/kg/day, initiated one week before the procedure, whereas a second group was followed without any prophylactic treatment. Follow-up endoscopies took place seven, fourteen, twenty-one, and twenty-eight days after CESD. Necropsy, histological assessment of esophageal inflammation, and fibrosis were performed on day 28.

Results

The median esophageal lumen diameter on day 21 (main judgment criterion) was 4 mm (range 2 to 5) in group 1 and 3 mm (range 1 to 7) in group 2 (P = 0.95). No significant difference was observed between the two groups regarding clinical evaluation (time before onset of clinically significant esophageal obstruction), number of dilations, esophageal inflammation and fibrosis, or oxidative stress damage on immunohistochemistry.

Conclusions

Despite its antioxidant effect, systemic administration of NAC did not show significant benefit on esophageal fibrosis in our animal model of esophageal wound healing within the experimental conditions of this study. Since the administered doses were relatively high, it seems unlikely that NAC might be a valuable option for the prevention of post-endoscopic esophageal stricture.

The preventive effect of N-nitro L-arginine methyl ester in experimentally induced myringosclerosis

OBJECTIVE

The purpose of this study was to investigate the antiinflammatory and antifibrotic effects of N-nitro L-arginine methyl ester (L-name) in experimentally induced myringosclerosis.

METHODS

Twenty Wistar albino rats were bilaterally myringotomized and divided randomly into four groups, each including five rats. Group I received no treatment, Group II was treated with topical saline solution, Group III received topical L-NAME and Group IV received intraperitoneally administered L-NAME. After 2 weeks, the tympanic membranes were examined and scored by otomicroscopy regarding the extent of the myringosclerosis. Then the tympanic membranes were harvested and evaluated histopathologically by light microscopy. The intensity of inflammation and degree of myringosclerosis were evaluated, the mean thickness of tympanic membranes were also measured.

RESULTS

The tympanic membranes of Groups I and II showed extensive myringosclerosis in contrast to those of Groups III and IV which had significantly less or no changes (p < 0.05). The inflammation and fibroblastic activity of the lamina propria in the tympanic membranes of Groups III and IV were found to be significantly less pronounced (p < 0.05). The tympanic membranes were found to be significantly thicker in Groups I and II when compared with Groups III and IV (p < 0.05).

CONCLUSION

Our results showed that both topical and intraperitoneal applications of L-NAME supressed inflammation, reduced fibroblastic proliferation and decreased the formation of myringosclerosis in myringotomized rat tympanic membranes.

Antioxidant effect of pomegranate extract in reducing acute inflammation due to myringotomy

OBJECTIVE

To assess the effect of pomegranate extract on acute inflammation due to myringotomy.

DESIGN

Prospective, randomised study.

SUBJECTS

Thirty Sprague-Dawley rats were divided into three groups. Group one constituted controls. Group two underwent myringotomy. Group three underwent myringotomy and also received 100 µl/day pomegranate extract, via gavage, one day before and two days after surgery. Following sacrifice 48 hours after myringotomy, the animals' right ears were used to determine the concentration of reactive oxygen species, using the chemiluminescence method; left ears were used for histological study.

RESULTS

Reactive oxygen species levels were significantly decreased in group three compared with group two (p < 0.01). The density of inflammatory cells in group three was significantly less than that in group two (p < 0.01). Lamina propria thickness and vessel density were also significantly decreased in group three compared with group two (p < 0.01).

CONCLUSION

Our results indicate that oral pomegranate extract decreases reactive oxygen species concentration and acute inflammation in the tympanic membrane after myringotomy.

Myringosclerosis after tympanostomy tube insertion: relation with tube retention time and gender

OBJECTIVE

To determine relationship between myringosclerosis and tube retention time and sex in children with chronic otitis media with effusion who were treated with tympanostomy tube insertion. Also, the relationship between myringosclerosis both sex and initial age of tube insertion were investigated.

METHODS

A total of 101 children (195 ears) were reviewed. Ears were divided into four groups according to retention time of tympanostomy tubes. Group I: Retention time of tympanostomy tube less than 6 months. Group II: Retention time of tympanostomy tube from 6 months to 12 months. Group III: Retention time of tympanostomy tube of 12 months or more. Group IV: Myringotomy group without tympanostomy tube insertion.

RESULTS

The order of the myringosclerosis rates were as follows from the highest to lowest one; group III (44.1%), group II (42.4%), group I (14.3%), and group IV (7.7%). Myringosclerosis was more common in group I compared with group IV, but the difference was statistically not significant (p>0.05). There were no statistically significant differences in myringosclerosis rates between the group II and group III (p>0.05). On the other hand, statistically significant differences were observed in myringosclerosis rates between group I and group II (p<0.05), and between group I and group III (p<0.05); also similar significant differences were present in myringosclerosis rates between group IV and group II (p<0.05), and between group IV and group III (p<0.05). There was no significant difference between preschool age group and school age group. Myringosclerosis was observed in 40% of boys and in 51.2% of girls.

CONCLUSION

Myringosclerosis is frequent in patients who underwent tympanostomy tube insertion. The frequency of myringosclerosis is much higher in tympanic membranes with tympanostomy tube insertion than tympanic membranes with myringotomy, and the location of sclerotic plaques does not always correspond to the tympanostomy area. The myringosclerosis rate was increased when the tympanostomy tubes stay on tympanic membrane for a long time. Highest myringosclerosis rates were observed if the extrusion time was 12 months or longer. In our analysis, sex and initial age of tube insertion were not significant factors for the development of myringosclerosis after extrusion of tympanostomy tubes.

Evaluation of the polymorphism in the Toll-like receptor 4 (TLR4) genes of tympanosclerosis patients

OBJECTIVE

Although eardrum perforations which endure etiopathogenesis for a long-time and middle ear infections are proposed for causing the tympanosclerosis (TS), tympanosclerosis emerges in some chronic otitis media (COM), some of them do not appear although a continuing COM and enduring perforation last. In this study, the effect of the molecular reasons which display genetic differences in TS formation is evaluated; our aim is to determine the Asp299Gly polymorphism frequencies in the TLR4 gene of patients with TS who have COM, and patients who do not.

MATERIALS AND METHODS

Patients who have undergone COM surgery, were divided into two groups of 50 persons who were selected in accordance with the fact, whether they had TS in their middle ear cavity or not during operation. 100 healthy persons who had similar demographic data, were evaluated as the control group. The DNA isolation was executed by using standard methods with peripheric blood specimen of the diseased group and control group. The Restriction Fragment Length Polymorphism method was used in determining the Asp299Gly allel in the TLR4 gene. Items of 249 bc for the wild tip (Asp) post-restriction enzyme segment wild tip (Asp) allel, and 23 bc and 196 bc post-restriction enzyme segment polymorphic allel (Gly) were obtained.

RESULTS

TLR4 Asp299Gly polymorphism (10%) was asserted in a total of five specimens in the diseased group with TS. TLR4 Asp299Gly polymorphism was found positive in only one (2%) of the 50 phenomenons in the group without TS. TLR4 Asp299Gly polymorphism was found positive in six (6%) of the 100 phenomenons in the control group. The positive polymorphism in phenomenons with TS was significant in accordance with statistics, when compared with the group without TS (p<0.05). However, although the polymorphism rates were higher than the rates of the control group, it was not statistically significant (p>0.05).

CONCLUSION

TS may not appear in many patients who had undergone middle ear infection, and had perforation for many years. The polymorphism in arteriosclerosis in the TLR4 gene which caused the inflammatory cytokines oscillation recognize the bacterial LPS, was also accused. It is engrossing to find out from the results of our study on a restricted number of patients, and on only one gene, that molecular reasons which display genetic differences can also be effective in forming TS. Serial researches of greater dimensions are required.

The preventive effect of ginkgo biloba extract in myringosclerosis: study in rats

OBJECTIVE

To determine the preventive effect of Ginkgo biloba extract in the formation of myringosclerosis.

STUDY DESIGN

Prospective, randomized clinical study.

MATERIALS AND METHODS

Posterosuperior quadrant of tympanic membranes of twenty-five Wistar Albino rats were bilaterally myringotomized. They were divided into three groups randomly. Groups 1 and 2 were administered 100 mg/kg/day and 200 mg/kg/day systemic Ginkgo biloba extract. The third group was treated with 1 mL/day saline solution. After 10 days of treatment, myringotomized membranes were examined by otomicroscopy and harvested. They were evaluated histopathologically by light microscopy and compared according to the occurrence of myringosclerotic plaques and the thickness of membranes.

RESULTS

Tympanic membranes of groups 1 and 2 nearly had no existence of myringosclerosis (72.2% in group 1 and 83.3% in group 2, P = 0.434). However, in group 3, only 14.3 percent had no myringosclerosis (P < 0.001). Thickness of membranes in group 1 was 0.13 +/- 0.25, group 2 was 0.06 +/- 0.02, and group 3 was 0.19 +/- 0.35 mm. Group 3 had significantly thicker membranes compared with groups 1 and 2 (P < 0.001 for group 2 and P = 0.003 for group 1).

CONCLUSION

Formation of experimental myringosclerosis was reduced or inhibited and tympanic membranes were thinner after systemic Ginkgo biloba extract administration.

The effect of caffeic acid phenethyl ester on the prevention of experimentally induced myringosclerosis

OBJECTIVES

Myringosclerosis is a common sequela of ventilation tube insertion for the treatment of the otitis media with effusion. Several antioxidants have been identified to prevent myringosclerosis. The objective of this study was to investigate the effect of caffeic acid phenethyl ester (CAPE) on the prevention of experimentally induced myringosclerosis.

METHODS

Thirty-five Sprague-Dawley rats were unilaterally myringotomized. The rats were divided into four groups randomly: group 1 received no treatment, group 2 received intraperitoneally administered saline and group 3 received intraperitoneally administered CAPE. The tympanic membranes were examined by otomicroscopy on the 15th day after treatment. The membranes were then harvested and evaluated histologically by light microscopy.

RESULTS

The tympanic membranes from group 1 showed extensive myringosclerosis; those from group 2 showed a similar occurrence of myringosclerosis. However, group 3 had a reduced occurrence of myringosclerosis by otomicroscopic evaluation. Under light microscopic examination, the lamina propria of the pars tensa was found to be thicker and more sclerotic in groups 1 and 2 when compared with group 3.

CONCLUSIONS

Systemic treatment with CAPE was found to be effective in the prevention of sclerotic lesions in myringotomized rat tympanic membranes.

Evaluation of plasma fibronectine level as a probable indicator for tympanosclerosis

OBJECTIVES

Wound healing, epithelial regrowth and collagen synthesis are very important factors in the repair of the traumatised tympanic membrane. The aim of the present study was to determine the role of plasma fibronectine in the aetiopathogenesis of tympanosclerosis.

METHODS

This prospective study included 58 patients with and 49 without tympanosclerosis. No inflammation or trauma was noted in either patient group. All patients underwent otoscopic and otomicroscopic examination, and the degree of tympanosclerosis was graded from mild (stage I) to severe (stage III). Following otological examination, blood samples were taken for plasma fibronectine measurement.

RESULTS

Following otoscopic and otomicroscopic examinations, patients' tympanosclerosis was graded as follows: 18 patients were stage I; 29 were stage II; and 11 were stage III. Statistical analyses revealed that the plasma fibronectine concentrations were significantly lower in the study group compared with the control group (p = 0.031). In addition, fibronectine levels were lowest in the patients with severest tympanosclerosis (p = 0.0001 in each comparison).

CONCLUSION

The results of the present study show that serum fibronectine is important in the development and severity of tympanosclerosis.

Effects of Ciprofloxacin-Dexamethasone on Myringotomy Wound Healing

OBJECTIVE

To evaluate the effects of the ciprofloxacin-dexamethasone (CDX) combination ototopical treatment after myringotomy on tympanic membrane (TM) healing in ears with eustachian tube obstruction (ETO) and unobstructed ears.

STUDY DESIGN

Prospective, randomized, masked, controlled.

METHODS

ETO was created in the left ear of 30 rats to induce a model of otitis media with effusion (OME). After 3 weeks, bilateral myringotomy was performed (day 0). Animals were randomized into three groups to receive no treatment or bilateral once daily ototopical treatment with balanced salt solution (BSS, vehicle) or CDX for 13 days. Bilateral otomicroscopy was performed on days 7, 14, and 28. On day 14, five randomly selected animals per group were humanely euthanized and the TM harvested for histology. Three additional rats provided normal negative control ears for histologic comparisons.

RESULTS

On day 14, TM perforation healing rates were 100% in all ears of untreated and BSS-treated animals, 89% (8/9) in CDX-treated obstructed ears, and 30% (3/10) in CDX-treated unobstructed ears (P < .05 vs. BSS). On day 28, 100% (5/5) of the CDX-treated unobstructed ears and 80% (4/5) of the CDX-treated obstructed ears were healed. Histology showed initial TM thickening postmyringotomy in all ears but no significant qualitative differences between groups on day 28.

CONCLUSION

Myringotomy healing was transiently modulated by treatment with CDX but proceeded normally after CDX discontinuation. This early modulation might enhance middle ear drainage and middle ear concentrations of CDX when tympanostomy tube surgery is performed in patients with active OME and ETO, thus potentially reducing otorrhea and preventing or treating infection. It would not be expected to increase the risk of premature tube extrusion or adversely affect normal healing of the TM after usual spontaneous extrusion.

The Anti-Oxidant Effect of Alpha-Tocopherol in the Prevention of Experimentally Induced Myringosclerosis

HYPOTHESIS

The objective of this study was to investigate the possible effect of alpha-tocopherol on the prevention of experimentally induced myringosclerosis.

BACKGROUND

Myringosclerosis is a common sequela of ventilation tube treatment of otitis media with effusion. The relationship between oxygen-derived free radicals and occurrence of myringosclerosis has been proven in experimental models, and it was also shown that the formation of myringosclerosis after experimental myringotomy could be reduced by application of various free radical scavengers.

METHODS

Eighteen Wistar albino rats were myringotomized on the left side and randomly separated into two groups: group A consisted of rats which received intramuscular alpha-tocopherol injections 100 mg/kg daily and group B which were injected with physiological serum only. The occurrence of myringosclerotic plaques in the tympanic membranes of the two groups was compared by otomicroscopy, histopathology, and tympanometry, which is a novel method of quantification. Blood samples were collected for biochemical evaluation, and the tympanic membranes were harvested on the 15th day of the experiment.

RESULTS

In otomicroscopic evaluation, tympanic membranes in group B revealed varying degrees of myringosclerotic plaques; on the other hand, tympanic membranes in group A showed faint or no existence of myringosclerosis. The mean malondialdehyde levels were 1.33 +/- 0.11 micromol/L in group A and 7.49 +/- 1.37 micromol/L in group B (Z = -1.906, p = 0.057). In all ears from group B, the magnitude of the maximum admittance measured by tympanometry reduced to approximately 40% of the values obtained from group A (Z = -2,160, p = 0.031). The mean magnitude of the maximum admittance from group A was very close to the standardization values of Wistar albino rats, which predicts a functional outcome.

CONCLUSION

The formation of myringosclerosis after experimental myringotomy can be diminished by intramuscular alpha-tocopherol injections.

The effect of Vitamin E treatment on the development of myringosclerosis after ventilation tube insertion

OBJECTIVES

Recent studies have established the relationship between the reactive oxygen species and myringosclerosis. Furthermore several antioxidants have been known to prevent myringosclerosis. All the previous studies supporting this hypothesis have been performed on animals. The aim of our study is to investigate the possible effect of Vitamin E on the development of tympanosclerosis after VT insertion on human subjects.

METHODS

72 children undergoing myringotomy and VT insertion were included in the study. Vitamin E was applied to the right ear and no treatment was applied to the left ear. Both ears were examined at the end of 9 months with otomicroscopy. Myringosclerosis formation at the end of the study period was noted for each ear.

RESULTS

Myringosclerosis was found in 33 of the 144 ears. The overall incidence was 22.9%. While 22 (30.6%) of the 72 left ears showed myringosclerosis otomicroscopically, in only 11 (15.3%) of the 72 right ears that were treated with Vitamin E was myringosclerosis observed at the end of the study period. Of these nine cases were bilateral.

CONCLUSION

Animal studies have well documented the development of myringosclerosis after myringotomy and VT insertion and beneficial effects of different antioxidants. Our study has shown similar results in human subjects. Further clinical studies consisting of a larger patient population are needed to bring about routine clinical use of antioxidants in myringotomy and VT insertion.

Vitamin e-coated tympanostomy tube insertion decreases the quantity of free radicals in tympanic membrane

OBJECTIVE

Tympanosclerosis is a common sequela of ventilation tube treatment of otitis media with effusion causing hearing disability. It is associated with an increased production of free radicals (also known as reactive oxygen species) after myringotomy. Vitamin E is a scavenger of different free radicals by working as an antioxidant. The aim of the present study was to evaluate the effect of vitamin E-coated tympanostomy tube insertion at quantity of free radicals in rat tympanic membrane.

METHODS

This prospective, controlled animal study consisted of male Sprague-Dawley rats divided into two groups of 10 animals each. Ordinary silcone tubes were applied to the right ears of the first group and vitamin E-coated silcone tubes were applied to the right ears of the second group. The left ears were used as controls. Then, the animals were killed and chemiluminescence measurements were made for tympanic membranes.

RESULTS

Reactive oxygen species levels (ROS) were significantly increased in right ears of the first group when compared with the control ears (P < .0001), and the levels were statistically significant decreased in right ears of the second group as compared with the operated ears of the first group (P < .0001). The free radical levels of right and left ears in the second group were similar.

CONCLUSIONS

Our results indicate that vitamin E-coated tube insertion decreases the quantity of reactive oxygen species in tympanic membrane after myringotomy and tympanostomy tube insertion.

Determination of Reactive Oxygen Species in Myringotomized Tympanic Membranes: Effect of Vitamin E Treatment

OBJECTIVES/HYPOTHESIS

Recent studies have established a strong relationship between the development of myringosclerosis and reactive oxygen species (ROS). The aims of the present study were to directly detect ROS in the tympanic membrane and middle ear mucosa of rats by measuring luminol amplified chemiluminescence, to evaluate the changes in the levels of ROS after treatment with vitamin E, and to examine the possible changes in the tympanic membranes otomicroscopically and histologically.

STUDY DESIGN

Prospective controlled animal study.

METHODS

Forty healthy Sprague-Dawley rats were divided into five groups of eight animals each. Animals in all groups except group 1 were bilaterally myringotomized. Group 2 received no treatment, group 3 was treated with topical olive oil, group 4 received topical vitamin E, and group 5 received intramuscular vitamin E. After 24 hours of myringotomy, tympanic membranes were examined otomicroscopically; thereafter, tympanic membranes and middle ear mucosa were peeled off. The right ears of the animals were used for biochemical assay, and the left ears were used for histological study.

RESULTS

Reactive oxygen species levels were significantly decreased in group 4 with topical application of vitamin E compared with untreated and myringotomized animals in group 2. Reactive oxygen species levels were also decreased in group 5, although the decrease was not statistically significant when compared with groups 2 and 3. Histological studies confirmed sclerotic changes in the untreated myringotomized animals. The tympanic membranes of animals in groups 2 and 3 showed a white, chalk-like pattern of sclerotic changes, whereas animals in groups 4 and 5, with the exception of two animals in group 5, lacked these changes.

CONCLUSION

Although the relationship between the development of myringosclerosis and ROS had been well documented previously, the present study is the first that has directly measured the levels of ROS in the tympanic membrane and middle ear mucosa. These results are relevant because they correlate with histological findings. It has also been demonstrated that topically applied vitamin E is effective in decreasing the ROS levels.

Comparison of Free Radicals and Antioxidant Enzymes in Chronic Otitis Media With and Without Tympanosclerosis

OBJECTIVE/HYPOTHESIS

The pathogenesis of tympanosclerosis is unclear. The study was performed to investigate the role of nitric oxide, free oxygen radicals, and antioxidants in development of tympanosclerosis in patients with chronic otitis media.

STUDY DESIGN

A prospective study in patients with nasal polyps.

METHODS

Sixty-five patients who underwent tympanoplasty or tympanoplasty together with mastoidectomy were included in the study. Preoperative venous blood samples were drawn, and serum sodium, potassium, calcium, alkaline phosphatase, inorganic phosphorus, parathormone, and calcitonin levels were measured. The patients who had tympanosclerotic plaques on tympanic membrane or middle ear mucosa or near the ossicular chain or mastoid bone were designated as group 1 (n = 34), and the remaining patients as group 2 (n = 31). Intraoperatively, specimens were obtained from the middle ear mucosa and tympanic membrane to measure nitric oxide and malondialdehyde levels. In addition, plasma malondialdehyde levels and erythrocyte superoxide dismutase and catalase activity were determined.

RESULTS

All patients had similar demographic features and serum electrolyte and hormone levels. Nitric oxide and malondialdehyde levels of the specimens obtained from the middle ear mucosa (P =.001) and tympanic membrane (P =.01) and, in parallel to this, the plasma malondialdehyde activity level were higher in group 1 than in group 2. Moreover, group 2 had significantly lower erythrocyte catalase activity levels (P =.001) compared with group 1, whereas such a significant difference was not present for superoxide dismutase activity levels (P >.05).

CONCLUSION

The study results suggest that nitric oxide, free oxygen radicals, and catalase may have a role in the development of tympanosclerosis in patients with chronic otitis media.

The effect of L-carnitine on the prevention of experimentally induced myringosclerosis in rats

The objective of this study was to investigate the possible effect of L-carnitine on the prevention of experimentally induced myringosclerosis. Twenty Sprague-Dawley rats were bilaterally myringotomized. The rats were divided into two groups randomly: group 1 which were intraperitoneally administered saline and group 2 which were intraperitoneally administered L-carnitine. Blood samples were collected for biochemical evaluation and the tympanic membranes were harvested after 28 days. Histopathological and immunohistochemical evaluation were done under light microscopy. The mean malondialdehyde levels were 3.9+/-0.9 in group 2, and 7.9+/-1.1 in group 1 (P<0.001), nitric oxide levels were 25.6+/-6.4 in group 2 and 30.8+/-8.2 in group 1 (P=0.14) and acetylcholinesterase was 1035+/-60 in group 2 and 678+/-35 in group 1 (P=0.001). Myringosclerosis was more frequent and severe in group 1 than group 2 (P<0.007). Immunoreactivity was seen in 16 of 20 tympanic membranes in group 2 and six of 20 tympanic membranes in group 1 (P=0.005). We conclude that L-carnitine diminishes the occurrence of myringosclerosis in rats after myringotomy possibly by antioxidant activity and decreasing the formation of reactive oxygen species.