Free radical production by antibiotic-killed bacteria in the guinea pig middle ear

Plasma Selenium and Cadmium Levels in Patients with Chronic Otitis Media in a Turkish Population and Their Relation to Inflammation Markers

Chronic otitis media (COM) is a multifactorial process, for which a clear etiology has not yet been established. The aims of the present study were to evaluate selenium (Se) and cadmium (Cd) levels in patients with COM and to analyze the correlation between Se and Cd with inflammation markers. The study population consisted of 88 participants: 45 healthy controls (group 1) and 43 patients with COM (group 2). Demographic data, Se, Cd, C-reactive protein (CRP), and white blood cell count (WBC) levels were all recorded. Se and Cd measurements were performed in a graphite furnace atomic absorption spectrophotometer (Perkin Elmer Analyst 800) using Zeeman background correction. The Se and Cd levels were compared between the groups and the correlation between Se and Cd with inflammation markers was analyzed. No statistically significant difference was determined between the groups in terms of demographic data (p > 0.05). CRP and WBC levels were significantly higher in group 2 than in group 1 (p < 0.05). Se levels were significantly lower in group 2 than in group 1, at 23.40 ± 12.08 μg/L vs. 37.31 ± 22.44 μg/L (p < 0.05). Cd levels were significantly higher in group 2 than in group 1, at 1.79 ± 1.63 μg/L vs. 0.68 ± 0.45 μg/L (p < 0.05). When all the cases were evaluated together, a statistically significant negative correlation was determined between Se and CRP (r = - 0.239, p = 0.013) and a positive correlation between Cd and CRP (r = 0.266, p = 0.006), WBC (r = 0.258, p = 0.008). Our results could propose that Se deficiency and Cd excess could play a crucial and additive role in the etiopathogenesis of COM. However, further investigations with larger numbers of patients are warranted to determine the exact role of these elements.

Histopathological and Inflammatory Features of Chronically Discharging Open Mastoid Cavities: Secondary Analysis of a Randomized Clinical Trial

Importance

Many patients with an open radical mastoid cavity experience therapy-resistant otorrhea. Little is known about the underlying histopathological substrate of unstable cavities and the correlation with treatment failure.

Objective

To study the histopathological and inflammatory features of chronically discharging open radical mastoid cavities and the influence of different treatments.

Design, Setting, and Participants

This secondary analysis of a randomized clinical trial was a histopathology study of tissue samples of a cohort of 30 patients with a chronically discharging open mastoid cavity. Samples were taken from the cavities, which were treated with either honey gel or conventional eardrops in a tertiary center between 2012 and 2013. Tissue staining was performed in May 2014; final computer analysis/correlation studies were performed in June 2016.

Main Outcomes and Measures

Differences of epithelial tissue coverage, infiltration of T cells (CD3, CD4, CD8) and macrophage (CD68, isoenzyme nitric oxide synthase, arginase 1) (sub-)populations, infection status, and the correlation with clinical presentation.

Results

There were 30 patients (24 [80%] male; mean [SD] age, 59 [14] years). Cavities were covered with either stratified squamous (keratinized) epithelium (n = 10), respiratory columnar epithelium (n = 9), or granulation tissue (n = 10). The presence of respiratory epithelium was associated with lower treatment success (posttreatment VAS improvement of 3.1 [95% CI, 0.5 to 5.8] for discomfort and 3.6 [95% CI, 0.2 to 6.9] for otorrhea in the group with granulation tissue coverage vs 4.9 [95% CI, 0.2 to 9.6] and 5.8 [95% CI, -0.1 to 11.6] in the group with squamous [keratinized] epithelium coverage and 1.4 [95% CI, -1.2 to 4.1] and 2.5 [95% CI, -1.3 to 6.2] in the group with respiratory columnar epithelium coverage). In all 3 tissue types of cavity-covering tissues, T-cell infiltrates consisted of helper T cells and cytotoxic T cells, together with a lower number of macrophages. The immunopositivity for isoenzyme nitric oxide synthase and arginase 1 was high and not restricted to a macrophage subpopulation, but seen in various cell types. Inflammatory infiltrations varied strongly in all 3 tissue modalities.

Conclusions and Relevance

Discharging open mastoid cavities can be classified histologically into 3 different types, based on their coverage: squamous epithelium, respiratory epithelium, or granulation tissue. Treatment is less successful in cavities covered with respiratory epithelium, possibly explained by the status of bacterial infection and local immunological differences.

Anti-inflammatory and anti-oxidative effects of alpha-lipoic acid in experimentally induced acute otitis media

Objectives:

To investigate the anti-inflammatory, anti-oxidative and tissue protective effects, as well as the potential therapeutic role, of alpha-lipoic acid in experimentally induced acute otitis media.

Methods:

Twenty-five guinea pigs were assigned to one of five groups: a control (non-otitis) group, and otitis-induced groups treated with saline, penicillin G, alpha-lipoic acid, or alpha-lipoic acid plus penicillin G. Tissue samples were histologically analysed, and oxidative parameters in tissue samples were measured and compared between groups.

Results:

The epithelial integrity was better preserved, and histological signs of inflammation and secretory metaplasia were decreased, in all groups compared to the saline treated otitis group. In the alpha-lipoic acid plus penicillin G treated otitis group, epithelial integrity was well preserved and histological findings of inflammation were significantly decreased compared to the saline, penicillin G and alpha-lipoic acid treated otitis groups. The most favourable oxidative parameters were observed in the control group, followed by the alpha-lipoic acid plus penicillin G treated otitis group.

Conclusion:

Alpha-lipoic acid, with its antioxidant, anti-inflammatory and tissue protective properties, may decrease the clinical sequelae and morbidity associated with acute otitis media.

The Role of Oxidants and Antioxidants in Otitis Media with Effusion in Children

OBJECTIVE: Determine the possible role of oxidants and antioxidants in the pathogenesis of otitis media with effusion in children.

STUDY DESIGN AND SETTING: Randomized controlled trial, tertiary referral center. The study group was made up of children with otitis media with effusion who were to undergo bilateral ventilation tube insertion and adenoidectomy. The control group was comprised of otherwise healthy children. The blood levels of antioxidants (retinol, β-carotene, (α-tocopherol, laycopene, ascorbic acid, superoxide dismutase, glutathione peroxidase, GSH) and oxidation products (malondialdehyde) were determined before and 1 month after the operation in the study group and once only in the control group. These substances were also measured in the adenoid tissue and middle ear fluids.

RESULTS: In the study group, the blood levels of antioxidants and oxidants before and after the operation were significantly different when compared with the control group ( P < 0.05). In the study group, the blood antioxidant levels increased and oxidant levels decreased significantly after the operation ( P < 0.05). The levels after the operation never reached those of the control group.

CONCLUSIONS AND SIGNIFICANCE: Oxidants and antioxidants played a significant role in the pathogenesis of otitis media with effusion in children. These children are under significant oxidative stress. Insertion of a ventilation tube and adenoidectomy significantly decreased the oxidative stress in these patients, but could not normalize it completely. Additional studies are necessary in the clinical use of antioxidants in otitis media with effusion.

Antioxidant role of selenium in rats with experimental acute otitis media

The aim of this prospective experimental animal study was to determine whether selenium had a protective effect on oxidative stress in rats with acute otitis media, by measuring the alterations of antioxidant parameters and lipid peroxidation on days 4 and 10 after inoculation into the middle ear. Streptococcus pneumoniae was inoculated into the middle ear cavities of 32 rats in animal laboratory of a tertiary medical center. Group 1 served as the control group and the animals were administered 1.5 ml/day saline. Group 2 received 0.2 mg/kg/day oral selenium for 10 days. The blood samples of each group were obtained on post-inoculation days 4 and 10. The levels of thiobarbituric acid reactive substances, albumin, total sulphydryl, superoxide dismutase and glutathione peroxidase were investigated. Day 10 level of thiobarbituric acid reactive substance in group 2 was lower than the day 4 level of the same substance in the control group. Although glutathione peroxidase and superoxide dismutase levels significantly decreased starting from 4th day until 10th day in group 1, their levels increased in group 2. Day 10 levels of albumin and total sulphydryl in group 1 were significantly higher than day 4 levels in group 2. We found that selenium supplementation for 10 days decreased thiobarbituric acid reactive substances and increased glutathione peroxidase and superoxide dismutase levels when compared to the control group. We believe that selenium supplementation may be beneficial to prevent the clinical sequelae and recurrence of otitis media.

Effect of Ginkgo leaf parenteral solution on blood and cochlea antioxidant and immunity indexes in OM rats

Oxidative stress is involved in the development and progression of otitis media (OM). In this study, we investigated the effect of Ginkgo leaf parenteral solution on blood and cochlea antioxidant and immunity indexs in OM rats. In OM model rats, blood and cochlea malondialdehyde (MDA), nitric oxide (NO), tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8) and interleukin-10 (IL-10) levels were significantly increased, whereas antioxidant enzymes activities (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and glutathione reductase (GR)) were significantly decreased compared with normal rats. Treatment with Ginkgo leaf parenteral solution restored the altered parameters in a dose-dependent manner. We conclude that Ginkgo leaf parenteral solution confers protection against oxidative injuries in OM rats by increasing activities of antioxidants and immunity, suggesting a potential drug for the prevention and therapy of OM.

Interaction of pneumococcal phase variation and middle ear pressure/gas composition: an in vitro model of simulated otitis media

Streptococcus pneumoniae, a leading cause of otitis media (OM), undergoes spontaneous intra-strain variations in colony morphology. Transparent (T) variant is more efficient in colonizing the nasopharynx while the opaque (O) variant exhibits greater virulence during systemic infections. We hypothesized that changes in middle ear (ME) gas pressure/composition during Eustachian tube (ET) dysfunction and the treatment of that dysfunction, e.g., tympanostomy tube (TT) insertion, play a role in selecting the S. pneumoniae variant that can efficiently colonize/infect the ME mucosa. Human ME epithelial cells were preconditioned for 24h under one of three conditions that simulated (1) normal ME, (2) ME with ET obstruction (ETO) and (3) ME with TT; subsequently exposed to a dose (approximately 10(7)CFU/ml) of either T or O variant of S. pneumoniae, and then incubated for 1h and 3h. Under the simulated ETO and TT conditions, T variant exhibited a higher growth rate and greater epithelial adherence and killing than did O variants. Attachment of T variant to epithelial cells was documented by scanning electron microscopy. These results suggest that the T variant is more highly adapted to various ME environments than the O variants.

Exhaled methyl nitrate as a noninvasive marker of hyperglycemia in type 1 diabetes

Recent technical advances allow detection of several hundred volatile organic compounds (VOCs) in human exhaled air, many of which reflect unidentified endogenous pathways. Our group has previously estimated plasma glucose levels in healthy adults during a standard oral glucose tolerance test via exhaled VOC analysis. As a result of the metabolic characteristics of hyperglycemia in the diabetic (low insulin and increased free fatty acids and ketones), we hypothesized that different exhaled VOC profiles may be present in children with type 1 diabetes mellitus (T1DM) during spontaneous hyperglycemia. Exhaled methyl nitrate strongly correlated specifically with the acute, spontaneous hyperglycemia of T1DM children. Eighteen experiments were conducted among 10 T1DM children. Plasma glucose and exhaled gases were monitored during either constant euglycemia (n = 5) or initial hyperglycemia with gradual correction (n = 13); all subjects received i.v. insulin and glucose as needed. Gas analysis was performed on 1.9-liter breath samples via gas chromatography using electron capture, flame ionization, and mass selective detection. Among the approximately 100 measured exhaled gases, the kinetic profile of exhaled methyl nitrate, commonly present in room air in the range of 5-10 parts per trillion, was most strongly statistically correlated with that of plasma glucose (P = 0.003-0.001). Indeed, the kinetic profiles of the two variables paralleled each other in 16 of 18 experiments, including repeat subjects who at different times displayed either euglycemia or hyperglycemia.

Oxidant and antioxidant levels in children with acute otitis media and tonsillitis: a comparative study

OBJECTIVE

Recurrent episodes of acute otitis media (AOM) and acute tonsillitis (AT) are a common problem in infectious disorders during childhood and are major cause of morbidity in children. The organism maintains defense systems including nonenzymatic antioxidants such as Vitamins A, E and C and reduced glutathione (GSH) against reactive oxygen species (ROS). In the present study, lipid peroxidation status and nonenzymatic antioxidant capacity were investigated in children with AOM and AT. Our aim was to compare the lipid peroxidation and responses of the body's antioxidant status in the closely associated infections such as AOM and acute tonsillitis.

METHODS

The study included 23 (14 males, 9 females) children with AOM, 27 (14 males, 13 females) with AT and 29 (16 males, 13 females) healthy control subjects. The ages of the study and control subjects were between 2 and 7 years. Serum beta-carotene, retinol, Vitamin E, Vitamin C, and whole blood malondialdehyde (MDA) (as an indicator of lipid peroxidation) and GSH levels were studied in all subjects.

RESULTS

There was a statistically significant difference between the groups for all parameters (P<0.05). All of the antioxidant vitamins such as beta-carotene, retinol, Vitamin E, and Vitamin C levels were observed to be significantly decreased in the both patient groups. Nevertheless, GSH levels were also decreased in the patient groups. MDA levels were found to be higher in children with AOM and AT than in the healthy control subjects. When compared the AOM and AT groups, there was statistically significant difference between the groups for whole blood MDA (P<0.05).

CONCLUSION

Even though they seem to react in a similar way against ROS, in the cases of AOM and AT, it is possible to see the different approaches in these tissues for the oxidative stress.

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.