Oxidative Stress, HSP70/HSP90 and eNOS/iNOS Serum Levels in Professional Divers during Hyperbaric Exposition.

Heat shock proteins (HSPs) have protective effects against oxidative stress and decompression sickness. Nitric oxide may reduce bubble formation during decompression and its activity is regulated by HSPs. A simulated dive can cause the HSP response. The aim of this study was to describe the effect of simulated dives on the antioxidant system, HSPs, and nitric oxide synthase response and demonste the relationship between the concentration of HSPs and the intensification of oxidative stress. A total of 20 healthy professional divers took part in training, consisting of simulated dry dives in a hyperbaric chamber and split into experiment I (30 m exposure, 400 kPa) and experiment II (60 m exposure, 700 kPa) over 24 h. The activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) and the concentrations of malondialdehyde (MDA), heat shock protein 70 (HSP70), heat shock protein 90 (HSP90), endothelial (eNOS) and inducible (iNOS) nitric oxide synthase were measured. Increases in the activity of SOD and MDA concentration were demonstrated. The activity of GPx depended on the dive profile. The HSP70 serum level in both experiments was significantly lower after the dives. The mean HSP90 level was significantly higher after the simulated dive at 60 m. A significant relationship between HSP concentration and SOD/GPx activity was demonstrated. eNOS concentration increased after 60 m exposure. No change in iNOS concentration was observed. In conclusions, the simulated dive significantly affected the antioxidant system, heat shock protein expression and nitric oxide synthase; however, the changes depend on the diving conditions. There is a relationship between the expression of HSPs and the intensity of oxidative stress.

Analysis of the Increase of Vascular Cell Adhesion Molecule-1 (VCAM-1) Expression and the Effect of Exposure in a Hyperbaric Chamber on VCAM-1 in Human Blood Serum: A Cross-Sectional Study.

Background and Objectives: Vascular cell adhesion molecule-1 (VCAM-1) was identified as a cell adhesion molecule that helps to regulate inflammation-associated vascular adhesion and the transendothelial migration of leukocytes, such as macrophages and T cells. VCAM-1 is expressed by the vascular system and can be induced by reactive oxygen species, interleukin 1 beta (IL-1ß) or tumor necrosis factor alpha (TNFα), which are produced by many cell types. The newest data suggest that VCAM-1 is associated with the progression of numerous immunological disorders, such as rheumatoid arthritis, asthma, transplant rejection and cancer. The aim of this study was to analyze the increase in VCAM-1 expression and the impact of exposure in a hyperbaric chamber to VCAM-1 levels in human blood serum. Materials and Methods: The study included 92 volunteers. Blood for the tests was taken in the morning, from the basilic vein of fasting individuals, in accordance with the applicable procedure for blood collection for morphological tests. In both groups of volunteers, blood was collected before and after exposure, in heparinized tubes to obtain plasma and hemolysate, and in clot tubes to obtain serum. The level of VCAM-1 was determined using the immunoenzymatic ELISA method. Results: The study showed that the difference between the distribution of VCAM-1 before and after exposure corresponding to diving at a depth of 30 m was at the limit of statistical significance in the divers group and that, in most people, VCAM-1 was higher after exposure. Diving to a greater depth had a much more pronounced impact on changes in VCAM-1 values, as the changes observed in the VCAM-1 level as a result of diving to a depth of 60 m were statistically highly significant (p = 0.0002). The study showed an increase in VCAM-1 in relation to the baseline value, which reached as much as 80%, i.e., VCAM-1 after diving was almost twice as high in some people. There were statistically significant differences between the results obtained after exposure to diving conditions at a depth of 60 m and the values measured for the non-divers group. The leukocyte level increased statistically after exposure to 60 m. In contrast, hemoglobin levels decreased in most divers after exposure to diving at a depth of 30 m (p = 0.0098). Conclusions: Exposure in the hyperbaric chamber had an effect on serum VCAM-1 in the divers group and non-divers group. There is a correlation between the tested morphological parameters and the VCAM-1 level before and after exposure in the divers group and the non-divers group. Exposure may result in activation of the endothelium.

Rectal aberrant crypt foci (ACF) as a predictor of benign and malignant neoplastic lesions in the large intestine.

BACKGROUND: The importance of ACF is not fully explained, however, their number may be a good predictor of synchronous and metachronic adenoma or other polyps whose removal reduces the risk of CRC. Due to the epidemiological and genetic association of ACF with pre-cancer lesions, they may be a potential CRC biomarker. The aim of our study was to show that the number and type of rectal ACF may be a good predictive factor for the presence of polyps located proximally from the splenic flexure and that the type and number of ACF can correlate with the number and specific types of polyps in the large intestine. METHODS: The study included 131 patients who underwent colonoscopy combined with rectal mucosa staining with 0.25% methylene blue. The number of rectal ACF was determined and bioptats were sampled for histopathological examination to assess the type of ACF. Endoscopic ACF assessment criteria given by L. Roncucci were used. The obtained material was subjected to statistical analysis using probability distribution, U-test, t-student test, and chi 2 as well as the Statistica 7.1 software package. RESULTS: The study population was divided into three subgroups according to the number of ACF observed, i.e. ACF < 5, 5-10 and > 10. ACF < 5 were found in 35 patients (29.41%), 5-10 ACF in 70 (58.82%) and ACF > 10 in 14 individuals (11.76%). The study revealed the presence of normal ACF (p = 0.49), hyperplastic ACF (p = 0.34), dysplastic ACF (p = 0.11), and mixed ACF (p = 0.06). A single type of ACF was most commonly observed (n = 88, p = 0.74). In the researched group a larger number of ACF is concurrent with adenomas and hyperplastic polyps. The number of ACF clearly correlates with the dysplasia advancement in the adenoma and the number of polyps found. CONCLUSIONS: Rectal ACF are a useful marker for the presence of cancerous lesions in the proximal and distal sections of the large intestine.

Dehydration of a diver during a hyperbaric chamber exposure with oxygen decompression.

Objective: An analysis of factors that may indicate both the type and degree of dehydration of a diver's body following a dry chamber hyperbaric exposure. Methods: The study was participated by 63 men - professional divers, with extensive diving experience, aged 24-51 years (average age 32.6). The subjects underwent two hyperbaric exposures, one to a pressure of 0.3 MPa and one to a pressure of 0.6 MPa, with oxygen decompression. The exposures were carried out in a hyperbaric chamber pursuant to the decompression tables of the Polish Navy, with the observance of a 24-hour interval between exposures. Blood samples were collected from the participants in order to perform a blood morphology test. Body weight was measured with the bioelectrical impedance method using the Maltron BioScan 920 device.The results were subjected to statistical analysis. The following blood morphology parameters were analyzed: hematocrit (Ht), erythrocyte size (MCV), color index (MCHC) and body weight composition: total water (TBW), extracellular water (ECW), intracellular water (ICW). Results: The studies have shown that during a hyperbaric exposure in the chamber the diver's body becomes dehydrated, with observable loss of both intracellular water as evidenced by the reduction of hematocrit content and erythrocyte size, as well as extracellular water, with the accompanying increase in the color index. Conclusions: Hyperbaric conditions are conducive to the dehydration of the diver's body, however to a degree which does not lead to an occurrence of health hazards. Good care for one's health through proper nutrition and hydration are sufficient preventive and protective measures.

Fatty acids and sphingolipids profile in the blood plasma of experienced divers in response to hyperbaric exposure.

INTRODUCTION: Hyperbaric exposure mimics air-breathing scuba diving, which is reaching enormous popularity around the world. The diver's body is subjected to a broad range of divergent effects exerted by, e.g.: an increased partial pressure of inert gases, microclotting, oxidative stress and/or production of gas bubbles. However, very little is known regarding the impact of hyperbaric exposure on plasma fatty acids content and composition, together with the body's sphingolipids profile. MATERIAL AND METHODS: The aim of this study was to investigate the contents of major fatty acids present in the plasma as well as sphingolipids, namely: sphingosine (SPH); sphingosine-1-phosphate (S1P); sphinganine (SPA); and ceramide (CER), after hyperbaric exposure corresponding to dives conducted to the depths of 30 and 60 meters of seawater. For the plasma lipids measurements, high-performance liquid chromatography together with gas-liquid chromatography were applied. RESULTS: We demonstrated that hyperbaric exposure does not affect the content and composition of plasma fatty acids of experienced divers. Similarly, the amounts of major sphingolipids fractions were not influenced, as only the content of sphingosine-1-phosphate in the plasma was significantly decreased. CONCLUSIONS: Observed lack of significant changes in plasma lipid profile after hyperbaric exposure suggests that the procedure might be considered as secure. However, decreased sphingosine-1-phosphate content in the plasma might possibly exert some adverse effects.

Influence of exposure in hyperbaric chambers on selected parametersof oxidative stress in professional divers.

PURPOSE: This study evaluated the influence of hyperbaric exposure chambers on selected parameters of oxidative stress in divers' blood. METHODS: 25 healthy men (non-smoking experienced divers) ages 18-40 took part in the experiment. Subjects were exposed to hyperbaric conditions similar to those at 30 meters of depth while diving. A control group consisted of 20 healthy men who have never dived or been exposed to hyperbaric conditions. Blood was drawn from the cubital vein after overnight fasting. Superoxide dismutase (SOD-1) activity and malondialdehyde (MDA) concentration were marked in red blood cells (RBCs), carbonyl group concentration marked in serum proteins, and nitrate/nitrite concentrations were estimated in plasma. RESULTS: Statistically significant differences were found between the divers and the control group in MDA concentration in erythrocytes and carbonyl group concentration in serum proteins. Nitrite/nitrate concentrations in plasma plus SOD-1 activity in RBCs decreased significantly in the diver group compared with the control group. After hyperbaric exposure MDA concentration in erythrocytes increased considerably in the test group and a significant increase in SOD-1 activity was observed. A significant increase of nitrite/nitrate concentration was noted in plasma as well as an increase in the carbonyl group in serum proteins. CONCLUSION: Considerably weak enzymatic antioxidative defense was observed in the RBCs of individuals exposed to hyperbaric pressures versus those in normobary. This issue indicates that a diver's system has a larger susceptibility for negative effects from oxidative stress. The results also indicate that hyperbaric conditions can intensify reactions via free radicals.

Experimental modeling of pulmonary barotrauma.

The main causes of pulmonary barotrauma include loss of consciousness or panic attack of a diver and emergence from underwater with a constricted glottis. However, numerous publications and our observations indicate that the majority of fully symptomatic cases of pulmonary barotrauma develop without any evident errors in the ascending technique. Therefore, an attempt was made to examine such cases using the experimental model of pulmonary barotrauma designed by the authors. The experiment was conducted on 32 rabbits divided into three groups: Group C--not subjected to any treatment; Group E--with induced pulmonary barotrauma; and Group CT--subjected only to compression followed by quick decompression. In Groups E and CT, the same morphological markers of pulmonary barotrauma were detected in the lungs, although their severity varied. Morphological markers of pulmonary barotrauma were observed both in the group where the tube was not ob-structed (E) and in animals exposed only to rapid decompression (CT)

Risk factors increasing health hazards after air dives.

The aim of the present study was to determine the effect of postprandial hypertriglyceridemia on the risk of decompression stress following hyperbaric air exposures. The study involved 55 male individuals aged 20-48 years (31.47 ± 5.49 years), body mass index 20.3-33.2 kg/m2 (25.5 ± 2.58 kg/m2). Blood was sampled two hours after a meal each participant had in accordance with individual dietary preferences to determine the following parameters: blood cell counts, activity of aspartate aminotransferase (AST) and alanine ammotransterase (ALT), concentrations of total cholesterol and triglycerides. After each hyperbaric exposure, the presence and intensity of decompression stress were assessed using the Doppler method. Decompression stress was found in 30 individuals. Postprandial hypertriglyceridemia and hypercholesterolemia increased the risk of decompression stress after hyperbaric air exposures.

The influence of high-fat diets on the occurrence of decompression stress after air dives.

INTRODUCTION: In hyperbaric air exposures, the diver's body is subjected to an increased gas pressure, which simulates a real dive performed in water with the presence of hydrostatic pressure. The hyperbaric effect depends on pressure, its dynamics and exposure time. During compression, physical dissolution of inert gas in body fluids and tissues takes place. The decompression process should result in safe physiological disposal of excess gas from the body. However, despite the correct application of decompression tables we observe cases of decompression sickness. The study aim was to find factors affecting the safety of diving, with a particular emphasis on the diet, which thus far has not been taken into account. METHODS: The study subjects were 56 divers. Before hyperbaric exposure, the following data were collected: age, height and weight; plus each divers filled out a questionnaire about their diet. The data from the questionnaires allowed us to calculate the approximate fat intake with the daily food for each diver. Moreover, blood samples were collected from each diver for analysis of cholesterol and triglycerides. Hyperbaric exposures corresponded to dives conducted to depths of 30 and 60 meters. After exposures each diver was examined via the Doppler method to determine the possible presence of microbubbles in the venous blood. RESULTS AND DISCUSSION: Decompression stress was observed in 29 subjects. A high-fat diet has a direct impact on increasing levels of cholesterol and triglycerides in the blood serum. A high-fat diet significantly increases the severity of decompression stress in hyperbaric air exposures and creates a threat of pressure disease.