Characterisation of wastes collected from beaches, coastlines, marine surface cleaning processes and ships: A case study of Istanbul.

Marine waste management is crucial for Istanbul because of the significant location for intercontinental transition, international trade, tourism, industry and shipping. This study is the first one realised in Turkey for the detailed characterisation of marine waste. The amount and characteristics of solid wastes originating from beaches, coastlines, sea surface cleaning processes and ships (both cargo and cruise ships) were determined. It was observed that marine wastes includes a significant amount of recyclable materials. Although, it was ascertained that the amount and composition of waste differs according to the collecting sources, the majority of wastes are composed of different types of plastics. The average calorific value of marine waste was determined as 2500 kcal kg-1, which is higher than that of mixed municipal solid waste. There is a lack of studies on the pathways of disposal alternatives of marine waste after collection. As landfilling is the common pathway for disposal after collecting, it is clear that recycle/reuse and energy recovery options are possible for marine waste.

The relationship between intoxication severity and blood interleukin 6, interleukin 10 and CRP levels in carbon monoxide-poisoned patients.

Carbon monoxide (CO) is one of the most common causes of death due to intoxications. No biochemical marker is available to evaluate the severity of CO intoxication. We measured high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6) and interleukin-10 (IL-10) levels in patients with different degrees of CO poisoning. We prospectively included 40 CO-poisoned patients admitted to emergency services. Blood samples were collected from the patients at admission (0 hour) and after treatment (six hours). While all patients received normobaric oxygen (NBO2) therapy, patients with severe CO poisoning received additional sessions of hyperbaric oxygen (HBO2) therapy. Blood samples were also collected from a group of healthy volunteers (n=40). Serum IL-6 and IL-10 levels were measured with the ELISA method while hs-CRP was quantified by turbidimetric analysis. At admission, IL-6 levels were significantly higher in the patient group compared to the control group (P=0.001), but IL-10 and hs-CRP levels were not significantly different between the groups. Compared to admission levels, IL-6 levels were higher at six hours (P=0.014). The patients were grouped according to treatment type (NBO2, HBO2) and history of syncope, but no significant differences were detected in patient subgroups regarding IL-6, IL-10 and hs-CRP levels. A weak positive correlation was found between COHb and lactate levels in patients (P=0.013; r=0.390).This study shows that IL-6 level increases in CO-poisoned patients, but it is not correlated with the severity of the intoxication.

The effect of hyperbaric oxygen therapy on rhabdomyolysis-induced myoglobinuric acute renal failure in rats.

Myoglobinuric acute renal failure (MARF) may develop after severe muscle injury. Heme oxygenase-1 (HO-1), a stress-response protein, has been implicated as a protective agent against MARF. We hypothesized that hyperbaric oxygen therapy (HBOT) may alleviate MARF by inducing renal HO-1 expression. Wistar-Albino rats were randomly assigned into three groups: Control (n = 4), MARF (n = 8), MARF + HBO (n = 8). MARF was induced by intramuscular glycerol (50%, 8 mL/kg) injection. Saline (8 mL/kg) was injected into the hind limb of the animals in the control group. Animals in the MARF + HBO group received two sessions of HBO therapy (90 min at 2.5 atm) 2 and 18 h after glycerol injection. Serum and tissue samples were taken at 24 h. Serum urea and creatinine levels increased in the MARF and MARF + HBO groups confirming the development of MARF. But, serum urea and creatinine levels were similar in MARF and MARF + HBO groups. Oxidative stress parameters were similar among all groups. Histological renal injury score was similar in MARF and MARF + HBO groups. HO-1 level, determined by immunohistochemistry, was significantly higher in MARF and MARF + HBO groups, compared to the control group. Although HO-1 level in MARF + HBO group was higher than MARF group, it was not statistically significant. We found that HBOT did not reduce renal injury in experimental MARF model. HBOT is used to reduce the muscle damage after crush injury, which may be accompanied by MARF. Therefore, more studies are needed to understand the effects of HBO treatment on renal functions after MARF.

Neuropsychological Evaluation of Children and Adolescents With Acute Carbon Monoxide Poisoning.

OBJECTIVES: Carbon monoxide (CO) poisoning is a worldwide health problem. We have limited information regarding psychological adversities of CO poisoning in children and adolescents. The aim of this study was (1) to investigate the effects of severe CO poisoning on cognitive functions, mood, and behaviors in children and adolescents and (2) to identify factors related to occurrence of neuropsychological symptoms. METHODS: This study included pediatric patients, who were evaluated after CO poisoning at the Department of Child and Adolescent Psychiatry between January 2012 and April 2013. The patients were evaluated at 2 time points. The first evaluation was done when they were discharged from emergency department, and the second evaluation was done 1 month after CO poisoning. Turkish versions of internationally recognized tests were used to evaluate anxiety, depressive symptoms, attention, visual-spatial skills, memory, and behaviors of patients. RESULTS: Twenty-seven patients were analyzed. The mean age of the patients was 11.8 ± 2.7 years (range, 6-18 years). The mean carboxyhemoglobin level was 31.5% ± 7.8% (range, 19%-51%) dir. Delayed neurological sequel was observed in only 1 patient, who had headache and tinnitus. We found that carboxyhemoglobin level was not correlated with later neuropsychiatric test scores. However, we found a correlation between history of loss of consciousness and anxiety symptom level, hyperbaric oxygen (HBO) therapy session and behavioral problems, and time to HBO therapy and attention problems. CONCLUSIONS: We suggest that CO exposure duration, history of loss of consciousness, time to HBO therapy, and the number of HBO therapy session affect neuropsychological symptom levels and occurrence of attention and behavioral problems.

Hyperbaric oxygen therapy in the treatment of osteonecrosis of the femoral head: a review of the current literature.

OBJECTIVE: To review the current literature on the use of hyperbaric oxygen (HBO2) therapy in the treatment of osteonecrosis of the femoral head (ONFH). SEARCH STRATEGY: We searched PubMed, Directory of Open Access Journals (DOAJ), EMBASE, Web of Science, Academic Search Complete, CINAHL and MEDLINE through April 2015. We hand-searched relevant textbooks, conference proceedings and the reference lists of review articles and clinical studies STUDY ELIGIBILITY CRITERIA: Randomized controlled trials (RCT) and observational studies (cohort study, case-control study, case series) that reported the outcome of patients who received HBO2therapy for ONFH were included. Only English-language articles were included. Study quality was not used as an exclusion criterion. STUDY APPRAISAL AND SYNTHESIS METHODS: Two authors independently assessed trials for inclusion, extracted data and presented to other authors. Disagreements were resolved by consensus. RESULTS: We identified eight clinical studies; two randomized controlled trials (RCTs); one historically controlled study; and five case series. The majority of the studies were small-scale, heterogeneous and methodologically weak. In four of the studies HBO2therapy was combined with other treatment modalities, making it impossible to draw firm conclusions on the specific effects of HBO2therapy. Hip survivorship in studies wherein HBO2therapy was used alone was 95.5% in Steinberg Stage I lesions, 89% in Steinberg Stage II lesions and 100% in Ficat Stage II lesions. CONCLUSIONS: There is a room for HBO2therapy in the management ONFH. Further RCTs, however, are required to better elucidate the role of HBO2therapy in the treatment of ONFH.

The use of hyperbaric oxygen therapy for carbon monoxide poisoning in Europe.

BACKGROUND: The aim of this survey was to identify practice differences in the treatment of carbon monoxide (CO) poisoning with hyperbaric oxygen (HBO2) therapy among centers in Europe. MATERIALS AND METHODS: Using a commercial online survey website (surveymonkey.com), we created a questionnaire and invited the medical directors of hyperbaric centers in Europe by email to complete the survey. RESULTS: Sixty-eight centers from 23 countries participated in the survey. While transient or prolonged unconsciousness was unanimously recognized as an indication for HBO2 therapy, positive neurological findings, ECG suggesting acute ischemia and pregnancy were considered important indications of HBO2 therapy in more than 95% of the centers. Twenty-three (44%) centers reported that they used carboxyhemoglobin (COHb) levels as a criterion for patient selection. Among responders, 39% (18/46) reported delivering a single session within the first 24 hours of CO poisoning, and nine (19%) reported delivering three sessions in the first day. The majority of the centers (52%) replied that they initially gave a single session per patient, which was repeated if symptoms persisted. We identified a total of 21 different HBO2 profiles used in European centers. CONCLUSION: Our results showed that the indications of CO poisoning for HBO2 therapy are still not universally recognized. Additionally, HBO2 therapy protocols used at European hyperbaric centers varied significantly, suggesting a need for more education regarding the published guidelines.

Early treatment response predicts outcome in patients with idiopathic sudden sensorineural hearing loss treated with hyperbaric oxygen therapy.

Hyperbaric oxygen (HBO2) therapy is used in the treatment of idiopathic sudden sensorineural hearing loss (ISSNHL). Some patients, however, do not benefit from HBO2 therapy despite several weeks of treatment. We hypothesized that early treatment response could predict treatment failure. We conducted a retrospective chart review and identified patients diagnosed with ISSNHL and recorded the pure tone average (PTA) levels prior to, after the first week and at completion of HBO2 therapy. Early treatment response (ETR) was assessed after the first week of HBO2 therapy, and an increase ⟨10 decibels (dB) in mean PTA level was defined as a negative ETR. Factors associated with no recovery were determined using logistic regression analysis. Overall, 39 patients (22 males; mean age (±SD) 41.9 ±14.3 years) were assessed. At treatment completion, the improvement in hearing was 'very substantial' (≥20 dB) for 21 patients (53.8%), 'substantial' (10-19 dB) for eight (20.5%), 'minimal' (⟨10 dB) for five (12.8%) and absent for five (12.8%) patients. After the first week of HBO2 therapy, 18 (46.2%) patients displayed negative ETR. Multivariate logistic regression analysis revealed 'negative ETR' as the only significant predictor of treatment failure (odds ratio (95% confidence interval): 6.98 (1.59-30.61), p=0.010) in patients with ISSNHL treated with HBO2. In conclusion, we found that patients who fail to benefit from an initial set of HBO2 sessions were less likely to benefit from additional HBO2 sessions. Further prospective studies are necessary to confirm our findings.

Changes in pulmonary function in hyperbaric chamber inside attendants: a case-control study.

BACKGROUND: Inside attendants (IAs) [are] exposed to high pressure during hyperbaric oxygen (HBO2) therapy. The aim of this study was to evaluate the alterations of pulmonary functions in IAs over time. METHODS: IAs in our hyperbaric center constituted the IA group (n=11). A sex- and age-matched control group (n=15) was constituted from hospital staff who had not dived or been exposed to hyperbaric environments before. We measured the respiratory function of all subjects at two time points: 1) at the start of the study; and 2) 12 months after the first measurement. The following parameters were recorded: forced vital capacity (FVC), forced expiratory volume in one second (FEV1), rate of FEV1 to FVC (FEV1/FVC%), forced expiratory flow at 25% to 75% vital capacity (FEF25-75%), forced expiratory flow at 50% vital capacity (FEF50%), forced expiratory flow at 25% vital capacity (FEF25%). RESULTS: Both groups were similar in terms of age, sex, smoking and body mass index. We found that FEV1, FEV1/FVC%, FEF25-75% and FEF50% significantly reduced in both groups after 12 months (p⟨0.05). However, the rate of change in all parameters was similar in both groups (p⟩0.05). In the IA group, the total number of exposures within the 12 months was positively correlated with the rate of reduction in FEF25% (r=0.788, p=0.004). CONCLUSION: Working as an IA does not deteriorate pulmonary function in the short term. However, there is a need for long-term follow-up studies.

An Autopsy of Nanofiltration Membrane Used for Landfill Leachate Treatment.

Komurcuoda leachate treatment plant, Istanbul, which consists of membrane bioreactor (MBR) and nanofiltration (NF) system, faced rapid flux decline in membranes after 3-year successful operation. To compensate rapid flux decline in membranes, the fouled membranes were renewed but replacement of the membranes did not solve the problem. To find the reasons and make a comprehensive analysis, membrane autopsy was performed. Visual and physical inspection of the modules and some instrumental analysis were conducted for membrane autopsy. Membranes were found severely fouled with organic and inorganic foulants. Main foulant was iron which was deposited on surface. The main reason was found to be the changing of aerator type of MBR. When surface aerators were exchanged with bottom diffusers which led to increasing of dissolved oxygen (DO) level of the basin, iron particles were oxidized and they converted into particulate insoluble form. It was thought that probably this insoluble form of the iron particles was the main cause of decreased membrane performance. After the diagnosis, a new pretreatment alternative including a new iron antiscalant was suggested and system performance has been recovered.

A case of tension pneumothorax during hyperbaric oxygen therapy in an earthquake survivor with crush injury complicated by ARDS (adult respiratory distress syndrome).

Pneumothorax (PTX) is rarely reported in patients receiving hyperbaric oxygen (HBO2) therapy. Patients with air-trapping lesions in the lungs and those with a history of spontaneous PTX, lung disease, mechanical ventilation or chest trauma are at an increased risk for PTX during HBO2 therapy. A 28-year-old male earthquake survivor was referred to our center for multiple wounds 21 days after being rescued from the debris. He had been intubated and put on mechanical ventilation for three days because of adult respiratory distress syndrome (ARDS). At initial presentation, he was conscious, well-oriented and hemodynamically stable. The initial six HBO2 treatments were uneventful. On the seventh HBO2 treatment, the patient lost consciousness and developed cardiopulmonary arrest near the end of decompression. The HBO2 specialist accompanying the patient inside the chamber immediately initiated CPR. A diagnosis of tension PTX was made. After the patient was removed from the chamber, a chest tube was inserted, which improved the symptoms. Although rare, tension PTX can occur during HBO2 therapy. Early diagnosis and intervention are crucial for saving a patient's life. Increased vigilance is required during treatment of patients with risk factors for PTX.

The effect of hyperbaric oxygen therapy on ischemia-modified albumin levels in people with diabetes with foot ulcers.

INTRODUCTION: Hyperbaric oxygen (HBO2) treatment accelerates the healing process of diabetic foot ulcers (DFU) by increasing tissue oxygenation in hypoxic tissues. Ischemia-modified albumin (IMA) is produced as a result of serum albumin flowing through ischemic tissues. We aimed to investigate the effect of HBO2 therapy on IMA levels in patients with DFU. METHODS: Thirty (22 male, eight female) patients with DFU were enrolled into this study. HBO2 therapy was performed five times a week. Blood samples were drawn before the first treatment, after the 10th (IMA10) and 20th (IMA20) hyperbaric sessions. RESULTS: Pretreatment IMA levels [median (25%-75% quartiles)] of the patients were 0.010 (0.002-0.150) absorbance units (ABSU). Compared to pretreatment values, IMA levels did not change significantly after the 10th session [0.006 (0.003-0.025) ABSU] and 20th session [0.009 (0.005-0.019) ABSU] (p = 0.527). We found statistically significant negative correlations between diabetic age and IMA10 (r = -0.448, p = 0.013) and IMA20 (r = -0.414, p = 0.023). CONCLUSION: In contrast to our expectations, IMA levels did not change with HBO2 therapy in patients with DFU. We think that IMA levels did not decrease due to the production of free oxygen radicals during HBO2 therapy. Further studies with larger groups may give more accurate results.

Decompression sickness cases treated with recompression therapy between 1963 and 1998 in Turkey: review of 179 cases.

The purpose of this study was to review the cases diagnosed as decompression sickness (DCS) with recompression therapy treament between 1963 and 1998 in Turkey. The records of 179 cases were analyzed for age, gender, type of DCS, presenting signs and symptoms, time to onset of symptoms, time to recompression therapy, recompression table used, total number of treatments and outcomes. The diving depth on the day of injury ranged between 60 and 215 fsw (18 and 65 msw). The symptoms developed during ascent or within 10 minutes after surfacing in 47% of divers and within the first hour in 87% of the divers. The most frequent symptom was sensory loss in the extremities. The dive before the symptoms was a repetitive dive in 50% of the cases and the diagnosis was Type II DCS in 79% of these divers. Most of the divers (84%) received recompression therapy after a delay of more than 12 hours. Healing rate was 68% with the air recompression tables and 86% with the oxygen tables. Repetitive dives were associated with a higher incidence of Type II DCS than single dives (79% and 66%, respectively). The results using recompression tables with oxygen were more successful than the treatment with air tables.

Development of underwater and hyperbaric medicine as a medical specialty in Turkey.

Underwater and hyperbaric medicine focuses on diving physiology, prevention and treatment of health problems related to the exposure to high ambient pressure and therapeutic use of hyperbaric oxygen for several medical conditions. Adequate educational standards should be developed for physicians working in the field of underwater and hyperbaric medicine. In Turkey, underwater and hyperbaric medicine is one of the medical specialties. The history of underwater and hyperbaric medicine as a medical specialty is dated back to the 1960s. In this paper, we review standards and the development of underwater and hyperbaric medicine as a medical specialty in Turkey.

Fungal Pathogens Associated with Crown and Root Rot in Wheat-Growing Areas of Northern Kyrgyzstan.

Fungal species associated with crown and root rot diseases in wheat have been extensively studied in many parts of the world. However, no reports on the relative importance and distribution of pathogens associated with wheat crown and root rot in Kyrgyzstan have been published. Hence, fungal species associated with wheat crown/root rot were surveyed in three main wheat production regions in northern Kyrgyzstan. Fungal species were isolated on 1/5 strength potato-dextrose agar amended with streptomycin (0.1 g/L) and chloramphenicol (0.05 g/L). A total of 598 fungal isolates from symptomatic tissues were identified using morphological features of the cultures and conidia, as well as sequence analysis of the nuclear ribosomal internal transcribed spacer (ITS) region, the translation elongation factor 1α (TEF1), and the RNA polymerase II beta subunit (RPB2) genes. The percentage of fields from which each fungus was isolated and their relative percentage isolation levels were determined. Bipolaris sorokiniana, the causal agent of common root rot, was the most prevalent pathogenic species isolated, being isolated from 86.67% of the fields surveyed at a frequency of isolation of 40.64%. Fusarium spp. accounted for 53.01% of all isolates and consisted of 12 different species. The most common Fusarium species identified was Fusarium acuminatum, which was isolated from 70% of the sites surveyed with an isolation frequency of 21.57%, followed by Fusarium culmorum, Fusarium nygamai, Fusarium oxysporum, and Fusarium equiseti, all of which had a field incidence of more than 23%. Inoculation tests with 44 isolates representing 17 species on the susceptible Triticum aestivum cv. Seri 82 revealed that Fusarium pseudograminearum and F. culmorum isolates were equally the most virulent pathogens. The widespread distribution of moderately virulent B. sorokiniana appears to be a serious threat to wheat culture, limiting yield and quality. With the exception of F. culmorum, the remaining Fusarium species did not pose a significant threat to wheat production in the surveyed areas because common species, such as F. acuminatum, F. nygamai, F. oxysporum, and F. equiseti, were non-pathogenic but infrequent species, such as Fusarium redolens, Fusarium algeriense, and F. pseudograminearum, were highly or moderately virulent. Curvularia inaequalis, which was found in three different fields, was mildly virulent. The remaining Fusarium species, Fusarium solani, Fusarium proliferatum, Fusarium burgessii, and Fusarium tricinctum, as well as Microdochium bolleyi, Microdochium nivale, and Macrophomina phaseolina, were non-pathogenic and considered to be secondary colonizers. The implications of these findings are discussed.

Influence of hyperbaric oxygen therapy on central corneal thickness.

BACKGROUND/AIMS: Hyperbaric oxygen (HBO) therapy is used in the treatment of several disorders. Little is known about the effects of HBO treatment on corneal thickness. The aim of this study was to investigate the effect of HBO treatment on central corneal thickness. METHODS: Thirty-two subjects (18 males and 14 females, mean age 57.3 ± 16.7 years) undergoing HBO treatment were consecutively enrolled. The subjects were assigned into diabetic (n = 16) and nondiabetic groups (n = 16). Best-corrected visual acuity was recorded before HBO treatment, and anterior and posterior segment examinations were performed on a slit lamp biomicrosope. Central corneal thickness was measured with an ultrasonic pachymeter before and immediately after HBO treatment, which lasted 120 min at 2.4 atmospheres absolute with three 30-min oxygen and two 5-min air breathing periods. RESULTS: HBO treatment did not change the central corneal thickness in diabetic subjects (547.6 ± 34.5 vs. 548.6 ± 34.6 µm; p = 0.606). In nondiabetic subjects, however, the central corneal thickness was significantly reduced after HBO treatment (576.5 ± 34.8 vs. 569.0 ± 34.8 µm; p < 0.001). CONCLUSION: A single exposure to HBO treatment reduced the central corneal thickness in nondiabetic subjects but not in diabetic subjects. However, the change in central corneal thickness was minor.

Evaluation of the oxidative effect of long-term repetitive hyperbaric oxygen exposures on different brain regions of rats.

Hyperbaric oxygen (HBO(2)) exposure affects both oxidative and antioxidant systems. This effect is positively correlated with the exposure time and duration of the treatment. The present study aims enlightening the relation of HBO(2) with oxidative/antioxidant systems when administered in a prolonged and repetitive manner in brain tissues of rats. Sixty rats were divided into 6 study (n = 8 for each) and 1 control (n = 12) group. Rats in the study groups were daily exposed 90-min HBO(2) sessions at 2.8 ATA for 5, 10, 15, 20, 30 and 40 days. One day after the last session, animals were sacrificed; their whole brain tissue was harvested and dissected into three different regions as the outer grey matter (cortex), the inner white matter and cerebellum. Levels of lipid peroxidation and protein oxidation and activities of superoxide dismutase and glutathione peroxidase were measured in these tissues. Malondialdehyde, carbonylated protein and glutathione peroxidase levels were found to be insignificantly increased at different time-points in the cerebral cortex, inner white matter and cerebellum, respectively. These comparable results provide evidence for the safety of HBO treatments and/or successful adaptive mechanisms at least in the brain tissue of rats, even when administered for longer periods.

Diversity and Identification of Plant-Parasitic Nematodes in Wheat-Growing Ecosystems.

Several nematode species can be found in different densities in almost any soil ecosystem, and their diversity in those ecosystems depends on numerous reasons, such as climatic conditions and host presence. Cereals are one of the main hosts of plant-parasitic nematodes (PPN), chiefly root-lesion nematodes (RLN, Pratylenchus spp.) and cereal cyst nematodes (CCN, Heterodera spp.). These nematodes are known as major parasites of the cereal crops; however, agricultural areas accommodate various nematodes showing biological variation. The diversity of parasitic nematodes on cereals in the Sakarya provinces of Türkiye, where cereals are intensively grown and located in the middle of two climatic zones, has not been well studied. Therefore, in this study, we aimed to determine the diversity, identification, and molecular phylogeny of PPNs in wheat-growing ecosystems in the Hendek, Pamukova, Geyve, Akyazi, and Central districts of Sakarya. The diversity of PPNs was calculated using the Shannon diversity index. Thirteen PPN genera were detected in 92% of soil samples. Heterodera filipjevi was identified in 24% of the soil samples using morphological, morphometrical, and molecular tools. In the morphological and molecular analyses, intraspecific polymorphism was observed in H. filipjevi populations. The result indicated that the high infestation rate of H. filipjevi was recorded from Geyve and Pamukova, followed by Hendek and Akyazi; however, a low infestation rate was detected in the Central district. The moderate value of the Shannon index of migratory nematode species was obtained in wheat fields as 2.31, whereas the value of evenness was 0.93, implying moderate diversity and high evenness of nematodes. This study is the first comprehensive report on H. filipjevi from wheat cropping areas in the Sakarya province. Intensified cereal cropping systems with/without non-cereal rotations increased the risk of plant-parasitic nematodes, especially RLNs and H. filipjevi infection of wheat production areas in the province.

Long-term exposure to repetitive hyperbaric oxygen results in cumulative oxidative stress in rat lung tissue.

CONTEXT: Despite its known benefits, hyperbaric oxygen (HBO) is also reported to enhance the production of reactive oxygen species and can cause oxidative stress in several tissues. Previous studies had shown that HBO-induced oxidative stress is directly proportional to both its exposure pressure and duration. Nevertheless, these studies were usually performed with single-session HBO exposure but its clinical use commonly depends on long-term exposure periods. OBJECTIVE: To clarify the oxidative effect of long-term repetitive HBO in the lung tissue of rats. MATERIALS AND METHODS: Male Sprague-Dawley rats were divided into six study groups exposed to consecutive HBO sessions (2.8 atm/90 min) for 5, 10, 15, 20, 30, and 40 days. Animals were sacrificed 24 h after the last HBO session. An additional control group was set to obtain normal data. Lung malondialdehyde (MDA) and carbonylated protein (PCC) levels were determined as measures of oxidative stress along with the activities of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase. RESULTS: None of the measured parameters showed any changes among the groups exposed to 5-15 HBO sessions. However, MDA, PCC, and SOD were found to be significantly increased in the 20 to 40 session groups. DISCUSSION AND CONCLUSION: These results indicate that repetitive treatment with HBO may cause oxidative stress in critical tissues including the lung. Although HBO-mediated free radicals are accepted to be responsible for the benefits of this therapeutic modality, especially in cases with prolonged exposure, possible injurious effects of supranormal values of bio-oxidative products need to be considered.

Paranasal sinus mucosal hypertrophy in experienced divers.

INTRODUCTION: Due to the increasing popularity in recreational diving long-term health consequences of this sport have aroused interest in the diving community. Although not as important as dysbaric osteonecrosis, ischemic brain lesions, or neurophysiological symptoms, paranasal sinus mucosal hypertrophy (PSMH) has also been discussed as being more prevalent among divers. In this study, we used magnetic resonance imaging (MRI) to compare asymptomatic divers with control subjects for PSMH. METHODS: We enrolled 79 male divers (34.0 +/- 5.7 yr) and 79 nondiving age- and sex-matched controls (33.8 +/- 6.1 yr). We used a questionnaire to elicit diving history. Divers with a history of sinus barotrauma, subjects with a history of chronic sinusitis or nasal allergies, and those with retention cysts, nasal polyps, or mastoiditis were excluded. T1-, T2-weighted axial and coronal images of the paranasal sinuses were taken with a 1.5-T MRI device. The threshold for PSMH was defined as mucosal thickness above 3 mm. RESULTS: MRI revealed PSMH in 33 (41.8%) divers and 18 (22.8%) controls. There were no significant differences between the groups with respect to age, smoking history, or alcohol consumption. PSMH identified in divers did not show an association with age or diving history. DISCUSSION: The higher rate of PSMH identified in divers suggests that diving may cause changes in the paranasal sinus mucosa.