Collagen synthesis, nitric oxide and asymmetric dimethylarginine in diabetic subjects undergoing hyperbaric oxygen therapy.

The main pathological condition in patients with impaired wound healing is diabetes mellitus. These patients have significantly low circulating nitric oxide (NO) levels because the stimulatory action of insulin on NO synthesis is absent. Additionally, asymmetric dimethylarginine (ADMA), an inhibitor of NO synthase, is increased owing to the generation of oxidative stress. NO was thought to contribute to wound healing. Hyperbaric oxygen (HBO) treatment is generally used in order to accelerate the healing of wounds. The aim of this study was to determine the changes in plasma procollagen type I and III N-terminal peptides (PINP and PIIINP), total nitrite/nitrate (NO(x)) and ADMA levels; and to evaluate their relation to healing during the HBO treatment of foot ulcers. Data obtained from 18 diabetic patients before and after the HBO therapy were compared statistically by the Wilcoxon test. NO(x) was increased in 11 and ADMA was decreased in 12 patients following HBO treatment. Both PINP (32.6 +/- 29.4 microg/l vs 44.3 +/- 33.4 microg/l) and PIIINP (6.97 +/- 3.01 microg/l vs 7.92 +/- 2.49 microg/l) were significantly increased (p < 0.05). Progressive reductions were observed in wound areas, as assessed by the digital wound imaging. In 12 patients, wounds healed by 50% or higher; whereas only two subjects had minimal improvements (15% or less healing). The duration of diabetes correlated negatively with wound healing (r = -498, p < 0.05). This study suggests that increased collagen synthesis is associated with wound healing during hyperbaric oxygen therapy. Nitric oxide generation may also contribute to the healing process.

Early and late effects of hyperbaric oxygen treatment on oxidative stress parameters in diabetic patients.

Exposure to hyperbaric oxygen leads to increased amount of reactive oxygen species (ROS) that are derived from various sources. After the discovery that ROS can function as signaling molecules, the idea of ROS being hazardous to biological tissues has been challenged. The aim of this study was to examine the changes in oxidative stress parameters in diabetics undergoing hyperbaric oxygen therapy (HBOT) due to foot ulcers. Twenty patients, who received HBOT for diabetic foot ulcers, were included in the study. Blood samples were taken before HBOT and 30 min after exit from the chamber, on the day of the first and the fifteenth HBOT sessions. They were used for the determinations of malondialdehyde (MDA), 8-isoprostane and advanced oxidation protein products (AOPPs). 8-Isoprostane and AOPP levels were not altered significantly after the first HBOT session, while both were increased on the fifteenth day (p<0.05). MDA was significantly increased only after the first HBOT session, and remained unchanged on the fifteenth day (within-day variations). Plasma AOPP levels were lowered significantly after fifteen consecutive HBOT sessions (between-day variations). Decreased AOPP levels suggest that increased oxygenation of tissues due to HBO therapy may activate some endogenous factors that prevent hazardous effects of the disease itself.

Antidepressant-like effect of hyperbaric oxygen treatment in forced-swimming test in rats.

The present study was undertaken to assess the antidepressant-like activity of hyperbaric oxygen (HBO) treatment and also to investigate whether in the forced-swimming test HBO treatment interacts with the antidepressant effects of fluoxetine, a selective serotonin reuptake inhibitor, and imipramine, which is mainly a noradrenaline reuptake inhibitor. HBO treatment (at 2.4 atmospheres absolute [ATA] for 60 min) significantly reduced the immobility time in this test; in other words, it displayed antidepressant-like activity. The coadministration of HBO with fluoxetine (5 mg/kg) or imipramine (5 mg/kg) at their ineffective doses produced greater inhibition of immobility time compared with HBO alone. In conclusion, HBO treatment might be an alternative approach to antidepressant therapy, alone or in combination with antidepressant drugs.

Hyperbaric oxygen treatment reduces carrageenan-induced acute inflammation in rats.

The present study was designed to assess the anti-inflammatory activity of hyperbaric oxygen treatment by comparing it with that of diclofenac, a nonsteroidal anti-inflammatory drug, and also to investigate whether hyperbaric oxygen treatment enhances the anti-inflammatory effect of diclofenac in carrageenan-induced paw edema which is commonly employed as an acute inflammation model in rats. Hyperbaric oxygen treatment and diclofenac (20 mg/kg) markedly reduced the carrageenan-induced paw edema in rats. In other words, they displayed anti-inflammatory activity. On the other hand, hyperbaric oxygen treatment did not consistently modify the anti-inflammatory effect of diclofenac in this model.

A new treatment modality for fibromyalgia syndrome: hyperbaric oxygen therapy.

Fibromyalgia syndrome (FMS) is characterized by longstanding multifocal pain with generalized allodynia/hyperalgesia. There are several treatment methods but none has been specifically approved for this application. We conducted a randomized controlled study to evaluate the effect of hyperbaric oxygen (HBO) therapy in FMS (HBO group: n = 26; control group: n = 24). Tender points and pain threshold were assessed before, and after the first and fifteenth sessions of therapy. Pain was also scored on a visual analogue scale (VAS). There was a significant reduction in tender points and VAS scores and a significant increase in pain threshold of the HBO group after the first and fifteenth therapy sessions. There was also a significant difference between the HBO and control groups for all parameters except the VAS scores after the first session. We conclude that HBO therapy has an important role in managing FMS.

Dysbaric osteonecrosis in Turkish sponge divers.

Skeletal radiographs were performed to determine the prevalence of dysbaric osteonecrosis (DON) in 51 Turkish sponge divers. DON was correlated with the diver's age and experience, maximum diving depth, and decompression sickness (DCS). Thirty-six of the 51 divers had radiographic evidence of one or more lesions, for a prevalence of 70.6% DON. Proximal humerus was the most effected site. Type B (head, neck, and shaft) lesions were most common, comprising 63.6% of all DON lesions. Type A (juxta-articular) lesions were observed in all 10 divers who complained of painful motion of their shoulder or hip joints. DON most commonly affected the proximal humerus. Reportedly, 38 of these 51 (74.5%) divers had experienced DCS. We did not fnd any significant relationship between DON and DCS, maximum diving depth, diving experience, and divers' age.

Should computed chest tomography be recommended in the medical certification of professional divers? A report of three cases with pulmonary air cysts.

Pulmonary barotrauma (PBT) is a recognised risk of compressed gas diving. Any reason that causes air trapping in the lung during ascent may cause PBT by increasing intrapulmonary pressure. Chest x ray examination is mandatory for medical certification of the professional divers in many countries, but pulmonary air trapping lesions such as an air cyst in the lungs cannot always be detected by plain chest x ray examination. Computed tomography (CT) is a reliable, but expensive measure for detecting pulmonary abnormalities in divers. Three cases with pulmonary air cysts are reported in which air cysts were invisible on the x ray pictures, but well defined by CT. It is impractical and not cost effective to perform CT for medical certification of all divers, but it can be an option to recommend CT once during the initial examination of the candidates for professional diving, especially if there is a history of predisposing factors, such as smoking or pulmonary infections.