Kadir Dündar

Protective effects of exogenously administered or endogenously produced melatonin on hyperbaric oxygen‐induced oxidative stress in the rat brain

1. Hyperbaric oxygen (HBO) is a widely used treatment modality in many diseases. A known side‐effect of HBO is the production of reactive oxygen species (ROS). Many anti‐oxidants, such as vitamins C and E, riboflavin and selenium, have been used successfully to scavenge the ROS produced by HBO administration.

Time-dependent course of hyperbaric oxygen-induced oxidative effects in rat lung and erythrocytes.

1  The oxygen toxicity of hyperbaric oxygen (HBO) treatment has long been of interest. There is an extensive amount of information regarding the role oxidative stress plays after HBO exposure in different tissues, but the question of the persistence of this oxidative effect has not been thoroughly elucidated. 2 The present study was performed to elucidate the persistence of the oxidative effects of HBO on rat lungs and erythrocytes after they had been subjected to 100% oxygen exposure. 3 Rats were divided into five groups. All animals, except those in the control group, were subjected to 100% oxygen for 2 h at 3 ATA (≡ 300 kPa). Rats were killed at 30, 60, 90 or 120 min after exposure and thiobarbituric acid‐reactive substances (TBARS) levels and the activity of superoxide dismutase (SOD) and glutathione peroxidase (GPx) were determined. 4 Thiobarbituric acid‐reactive substances levels and SOD and GPx levels were found to be significantly increased in lung tissue up to 60 min after exposure. Superoxide dismutase activity persisted at significantly high values for 90 min after exposure in erythrocytes and the lung. The TBARS levels in erythrocytes were also significantly higher for 60 min, whereas increased GPx activity was observed to persist for only 30 min. 5 The oxidative effect of HBO exposure declines to physiological levels within 90 min at most for erythrocytes and in lung tissue in rats. Further studies should focus on the molecular mechanisms that can be activated during this time interval.

Effectiveness of hyperbaric oxygen on sudden sensorineural hearing loss : Prospective clinical research

The role of hyperbaric oxygen (HBO) treatment in sudden sensorineural hearing loss (SSNHL) is still controversial. In this study, 80 patients were treated for SSNHL. Fifty-five patients who received HBO and medical treatment and 25 patients who received medical treatment only were studied. There was a statistically significant difference between the HBO and medical treatment group and the medical treatment group for hearing gain and the degree of hearing loss after treatment (p<.05). In the HBO and medical treatment group, patients with tinnitus showed the highest hearing improvement. The patients who had tinnitus had a statistically significant difference for hearing gain in the HBO and medical treatment group (p<.05) but not in the medical treatment group (p>.05). In the HBO and medical treatment group, average hearing gain on each audiometric frequency was better than in the medical treatment group (p<.05).

Maggot Debridement Therapy in the Treatment of Chronic Wounds in a Military Hospital Setup in Turkey

Background: The medicinal use of maggots for the biological debridement of chronic wounds is increasing around the world, due to its efficacy, safety and simplicity. Thousands of patients have been treated in private and governmental hospitals during the last 10 years. Objective: To examine the efficacy of maggot debridement therapy (MDT) in the debridement of chronic wounds in a militaryhospital. Methods: MDT was applied for 1–9 days to 7 male and 4 female soldiers or their family members (21–72 years old) with chronic wounds. Results: Complete debridement was achieved in 10 out of 11 patients, while in 1 patient the wound could be cleaned only partially. A remarkable reduction in the odor emanating from the wound and notable granulation were observed in all debrided wounds. Increased pain was observed in 1 patient with a venous stasis ulcer. Conclusion: We believe that MDT is a rapid and effective method for the debridement of chronic wounds in a military environment especially in times of war in developing countries.

Hyperbaric Oxygen Prevents Bacterial Translocation in Thermally Injured Rats

This study was designed to evaluate the effects of hyperbaric oxygen (HBO 2 ) on intestinal microflora and bacterial translocation (BT) caused by experimentally induced thermal injury in rats. Rats were separated into four groups, namely, HBO 2 group, thermal injury (TI) group, TI + HBO 2 group, and control group. All groups were further separated into short-term (2 days) and long-term (7 days) treatment or injury groups. Control group was neither exposed to thermal injury nor was given any treatment. Thirty percent second-degree thermal burn was induced on the dorsal body part of the rats in TI groups. In the HBO 2 groups, rats received HBO 2 treatment either without TI or following TI induction, for 2 and 7 days, respectively. Sampling from tissues and portal vein was performed on day 3 in the short-term groups and on day 8 in the long-term groups. Samples were cultured for identification of bacteria and colony counts. HBO 2 treatment significantly reduced the colony counts of endogenous microflora in distal ileum of healthy rats ( p < .05), while TI significantly increased the colony counts of endogenous microflora in distal ileum in short and long-term TI groups ( p < .05). Presence of bacterial translocation was proven by bacterial isolation in mesenteric lymph nodes, liver, spleen and blood. Both short- and long-term HBO 2 treatment following TI significantly reduced the colony counts of intestinal microflora ( p < .05) and prevented bacterial translocation almost completely. It is concluded that thermal injury causes both bacterial overgrowth within intestinal lumen and bacterial translocation across the intestinal wall. HBO 2 administration prevents both bacterial overgrowth and translocation.

DNA integrity in patients undergoing hyperbaric oxygen (HBO) therapy.

Hyperbaric oxygen (HBO) therapy is successfully applied for a wide variety of diseases. However, recent studies in humans undergoing (HBO) therapy have revealed that HBO is able to induce oxidative DNA damage especially in lymphocytes while the biological significance of this outcome is still not clear. HBO mediated DNA damage in lymphocytes has been determined by using the alkaline version of the comet assay in order to detect DNA strand breakages in patients undergoing HBO therapy. Blood samples were obtained from 100 voluntary patients and were drawn by venipuncture before and immediately after the first session of HBO treatment. The DNA damaging effect of HBO has also been evaluated in the fifth session of HBO therapy. DNA strand breakages were significantly increased after the first session of HBO treatment. However the elevated DNA strand breaks returned to their normal levels in lymphocytes after two hours of in vitro incubation. The elevated DNA strand breaks consistently decreased and reached to the baseline levels after the fifth session of HBO therapy. The results of this study, conducted in patients undergoing HBO therapy, support the existence of the previously reported cellular adaptive response against HBO mediated oxidative DNA damage in experimental studies.

A Special Issue of Dermatology Dedicated to Theo Rufli

Accessible online at: www.karger.com/drm It is hard to believe that Theo Rufli will turn 65 on February 15, 2005, and therefore will step back and retire at the end of the winter term. Beginning over 35 years ago, he had been first coworker and then – for 19 years – director of the Department of Dermatology at the University Hospital of Basel. After 2 years of internal medicine, he received his training as a dermatology resident from 1969 to 1973 as a scholar of Prof. Rudolf Schuppli. He spent some time abroad in dermatology departments at Warsaw and in several institutions in London. After returning, he became ‘Oberarzt’ in 1973 and received the ‘venia docendi’ in 1977. He then served many years as vice-chairman until he was elected Ordinary Professor for Dermatology and Venereology in 1985. This was in a long-standing tradition as his precedessors Wilhelm Lutz (1922–1956) and Rudolf Schuppli (1956–1985) had also been first members of the clinic staff and had then both been elected as ordinary professor and director. All three chairmen were excellent clinicians, histopathologists and allrounders just as it is required in a clinic with few permanent staff members. His first and central interest has always been the patient, his disease but also the care for the person behind, because he had a deep compassionate understanding for the suffering patient. As a director of the clinic, he always had an open heart and office door for the problems of every coworker. Perhaps more than anyone else, Theo Rufli directly supervised the training of residents and always guarded the quality of graduate students and the respect that dermatology gained from other physicians. He is an outstanding teacher; countless medical students have followed his famous lectures spiced with humor and anecdotes. Because of his obvious love for his own specialty and his ability to communicate this commitment to his students, many of them entered the field of dermatology, and residents held him in high regard. He taught clinical dermatology as an essential part of modern medicine and always reminded students and residents of the value of looking, examining and talking to patients. Although