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.     

Submarine escape from depths of 30 and 60 feet: 41,183 training ascents without serious injury

INTRODUCTION: In the case of a submerged, disabled submarine, survivors may be forced to escape by entering the water and ascending rapidly to the surface. The large pressure changes involved may produce pulmonary barotrauma, arterial gas embolism, or barotrauma. To assess the likelihood of such injuries, we retrospectively evaluated medical problems due to submarine escape training among military personnel. METHODS: We evaluated 41,183 controlled ascents performed over the past 21 yr in the escape training tank at G?lcük-Kocaeli, Turkey. Each trainee performed two free ascents from 30 ft and two hooded ascents from 60 ft. Before participating, candidates were screened by physical examination, spirometry, and chest X-rays; ear examinations for barotrauma were made after ascents. If a trainee failed to exhale properly during ascent, an instructor aborted the ascent and took him to a bell or side recess of the tank. RESULTS: No record of pulmonary barotrauma or other major complications were found. Middle-ear barotrauma was observed following 1,643 of the ascents (4.1%), with rupture of the tympanic membrane in 35 cases. DISCUSSION: Submarine escape ascents can be safely performed provided that subjects are medically screened and well trained.     

Observer variability based on the strength of MR scanners in the assessment of lumbar degenerative disc disease

OBJECT: aim of this study was to analyse the observer variability in the diagnosis and definition of disc pathologies with low and high-field strength MR scanners. MATERIAL AND METHODS: 95 patients with low back pain or radicular pain who were referred from two different centers were included in the study. Fifty-seven patients were scanned with 0.3 T MR (group 1) and 38 patients with 1.5 T (group 2). The intraobserver and interobserver reliability were assessed with the cappa coefficient which was characterised as follows: values less than 0.0 = 'poor' agreement, values 0.01-0.2 = 'slight' agreement beyond chance, 0.21-0.4 = 'fair' agreement, 0.41-0.60 = 'moderate' agreement, 0.61-0.80 = 'substantial' agreement and 0.81-1.00 = 'almost perfect' agreement. RESULTS: intraobserver agreement in group 1 and group 2 for both readers was 'almost perfect' in differentiating normal and pathological discs; 'substantial-almost perfect' in defining the disc pathologies, 'moderate-substantial' in root compression, and 'moderate-substantial' in spinal stenosis. Interobserver agreement was 'almost perfect' in differentiating normal and pathological discs, 'substantial' in defining disc pathologies, 'moderate' in root compression and 'moderate' in spinal stenosis in the group 1, whereas in group 2, it was 'almost perfect' in differentiating normal and pathological discs, 'almost perfect' in defining disc pathologies, 'slight-substantial' in root compression and 'moderate' in spinal stenosis. CONCLUSION: in the diagnosis of root compression and spinal stenosis, the intra and interobserver agreements were relatively poor with both high and low-strength field MRIs, indicating a need for more objective criteria. In differentiating normal and pathologic appearance of disc, the interobserver agreement was considerably better with high-field compared to low-field strength MRI. In cases where this definition is important, high-field strength scanners should be preferred.     

Stenotrophomonas maltophilia: the significance and role as a nosocomial pathogen

Stenotrophomonas maltophilia is a significant pathogen that primarily affects patients with co-morbid illnesses, usually malignancies, who have been hospitalized for prolonged periods and received broad-spectrum antibiotic therapy. The organism has been associated with an expanding spectrum of clinical manifestations associated with high case to fatality ratios. Therapy of these infections presents a significant challenge both for the clinician and the microbiologists because of its high-level antibiotic resistance to most of the currently used agents and methodological difficulties in susceptibility testing with this organism.     

Vertebral osteomyelitis after cardiac surgery

Background

Mediastinitis after open-heart surgery is a serious complication that has a decreasing incidence but still a significantly high mortality rate. Back pain may develop during the course of treatment for mediastinitis, and this should suggest vertebral osteomyelitis in the differential diagnosis. Diagnosis of vertebral osteomyelitis may be difficult because of the insidious onset and delayed diagnosis, and treatment may result in serious neurologic compromise and even death of the patient.

Methods

This retrospective study involves 5 patients who had open-heart surgery and mediastinitis that was further complicated by vertebral osteomyelitis. Average delay in diagnosis was 18 days after the onset of symptoms. Magnetic resonance imaging was the most helpful tool for diagnosis. Methicilline-resistant Staphylococcus aureus was identified as the responsible microorganism in all patients. Neurologic compromise occured (one paraplegia and one paraparesia) in 2 patients during medical treatment.

Results

Along with the medical treatment, all patients were surgically treated due to either one or more of the following reasons: unresolving symptoms, sudden neurologic compromise, or impaired spinal column stability despite appropriate conservative treatment. One patient died 10 days postoperatively. The mean follow-up period for the remaining 4 patients was 47 (12 to 95) months. Complete recovery was achieved, and they were able to return to their routine daily activities.

Conclusions

Vertebral osteomyelitis should be borne in mind when a patient develops back pain during the course of mediastinitis. Suspicion, early diagnosis with appropriate imaging, and proper treatment are crucial to prevent catastrophic complications.     

Correlation between hand preference and intraocular pressure from right- and left-eyes in right- and left-handers

To test whether there is a relationship between handedness and the intraocular pressure and there is a lateralization in the intraocular pressure, the intraocular pressures of the right- and left-eyes were compared in right- and left-handed students. The intraocular pressures were higher in the right-eye than in the left-eye in men, right-handers, and right-eyed subjects; there was no right-left difference in females, left-handers, left-eyed, and both-eyed subjects. The intraocular pressure of right- and left-eyes was higher in left-handers than right-handers. And there were significant negative correlations between hand preference and the intraocular pressure of both right- and left-eyes. We have concluded that the dominant eye has higher intraocular pressure compared to the nondominant one, and there is a relationship between hand preference and the intraocular pressure.     

Failure strength of bioabsorbable interference screws: effects of in vivo degradation for 12 weeks

We investigated the effect of in vivo degradation for 6-12 weeks on the fixation strength of polylactide bioabsorbable interference screws. Ten bioabsorbable interference screws were used to fix the patellar tendon autograft in ten live sheep knees, which were equally divided into two groups and killed in the 6th or 12th week. The control group consisted of four cadaveric knees. Following the killing of the animals the screws were retrieved and reused to fix patellar tendon grafts in cadaveric sheep knees. Tendon pull-out tests were performed for the partially degraded screws, for the control group, and for the reused screws of the control group. Macroscopic and microscopic examinations of the 6- and 12-week specimens were performed. Tendons pulled-out with an average force of 357+/-30 N in the cadaveric control group on the first use and with 465+/-118 N on the second use. The partially degraded screws failed with a mean load of 399+/-119 N in the 6-week group, and 12-week screws at 447+/-72 N. No macroscopic sign of degradation was observed on the retrieved screws. Histological examination of the 6 week specimens showed necrotic changes in the tendon around screw contact areas. Healing with granulation tissue was present in the same area in the 12th week. Foreign body reaction or an excessive inflammatory reaction was not observed. In vivo degradation of poly- l-lactide interference screws for 12 weeks thus causes neither a loss in the fixation strength of the screws nor an obvious inflammatory reaction.     

Subacromial impingement syndrome: pathogenesis, clinical features, and examination methods

Although subacromial impingement syndrome is the most common cause of shoulder pain with a specific diagnosis, it is not the only cause of pain in the anterosuperior aspect of the shoulder. Appreciation of the pathophysiology plays a key role in the diagnosis and management of this syndrome. The purpose of this paper is to review some essential aspects of pathogenesis, physical examination, and diagnosis in the light of the current literature.     

Diagnosis of asymptomatic atrial septal aneurysms using two-dimensional color

Objective To evaluate the dimensions of atrial septal aneurysm (ASA), the presence and characteristics of interatrial shunt, the movement of the wall of the aneurysm, and correlation between these findings and sign and/or symptoms suggesting embolism in Manisa, a district of a western Anatolian city of Turkey.Methods Two thousand five hundred cases were examined by routine transthoracic echocardiography (TTE) in both pediatric and adult cardiology outpatient clinics. ASA was detected in 20 cases and evaluated by two-dimensional color Doppler echocardiography (CDE). The length of the base, the maximum radius and the maximum displacement of ASA were measured. The shunt between the atria was examined by CDE. In cases where a shunt could not be found, galactose and palmitic acid was injected. Standard 12-lead electrocardiogram (ECG) and exercise stress test were also performed.Results No clinical signs or symptoms were found, suggesting a systemic or cerebral embolism.The maximum displacement of ASA was between 2 and 5 mm. All of the aneurysms were localized in the right atrium, and the walls of the aneurysrn did not move beyond the base of the left atrium during the maximum displacement. Interatrial shunt was detected in 14 of 20 patients (70%) by CDE and in the remaining six cases by contrast TTE. Frequent ventricular ectopic beats were observed in one patient.Conclusions During routine TTE we observed 0. 8% asymptomatic ASA in our population. The use of a contrast agent was found to be a valuable additional method in patients with ASA when the shunt could not be detected by CDE. The risk for embolism is not high when the maximum displacement of the wall of ASA was 5 mm or less and no bulge into the left atrium was observed. Based on our experience with this method, TTE is easy to perform, well-tolerated and acceptable.