Hanssonholdt4179
Background Hyperbaric oxygen (HBO2) therapy can have a positive effect on wound healing, angiogenesis and blood flow. No prior study has described the effects of HBO2 therapy and gene expression of this process. The goal of our research was to show the effects of HBO2 and its impact at the molecular level on angiogenesis, proliferation, differentiation, oxidative stress, inflammation, and extracellular matrix formation. Live animal subjects were used for simulating the process of wound healing under standard conditions and under the influence of HBO2. Methods Two experimental groups were created using injured rabbits (N=24), one group (N=12) treated with hyperbaric therapy twice a day and one (N=12) with standard wound care management. Wounds were surgical, uninfected, and in healthy animal test subjects. We compared the whole genomic analysis of the transcriptome with the use of microarray technology at three intervals during treatment. Results The induction of the wounds in rabbit skin increased expression of hundreds of genes in both treatment groups. The numbers of elevated and decreased genes gradually reduced as the wound healed. Gene expression analysis showed elevated expression of several genes associated with inflammation in both groups of injured animals. Genes connected to the process of angiogenesis, proliferation, differentiation, oxidative stress and extracellular matrix formation were without statistically significant changes. Conclusion The evidence did not support that HBO2 had any significant effect on gene expression during wound healing. Additionally, there was no evidence to support that there were changes in gene expression in either treatment group. Copyright© Undersea and Hyperbaric Medical Society.Background Acute kidney injury (AKI) as a consequence of ischemia is a common clinical event that can lead to unacceptably high morbidity and mortality. Hyperbaric oxygen (HBO2) preconditioning has been shown to prevent ischemia-reperfusion injury (IRI) in different tissues. Objectives The aim of our study was to compare the effects of HBO2 preconditioning on renal hemodynamics, kidney function and oxidative stress in normotensive and spontaneously hypertensive rats that suffered kidney IRI. Methods An experiment was performed on Wistar (normotensive) and spontaneously hypertensive rats (SHR). The animals were divided into the following experimental groups sham-operated rats and rats with or without HBO2 preconditioning 24 hours before post-ischemic AKI induction. Treated rats were placed into experimental HBO2 chambers and exposed to pure oxygen twice a day for two consecutive days (2.026 bar of oxygen) for 60 minutes. AKI was performed the next morning. The right kidney was removed and the renal ischemia was performed by clamping the left renal artery for 45 minutes. Results In this study, HBO2 preconditioning significantly improved disturbed renal hemodynamics, major markers of kidney function in plasma (creatinine, urea and phosphate) as well as antioxidant enzymes (superoxide dismutase and catalase) activities in erythrocytes after AKI induction. Also, HBO2 preconditioning decreased lipid peroxidation in plasma after ischemic AKI. Positive effects were observed in both strains of rats. Conclusions Our results suggest that HBO2 treatment improves renal hemodynamic and kidney function and decreases oxidative stress of Wistar and SHR rats with an AKI episode. Furthermore, it also implies that pre-existing hypertension does not affect the beneficial effects of HBO2 preconditioning. Copyright© Undersea and Hyperbaric Medical Society.Background Hyperbaric oxygen therapy has been demonstrated to lower blood glucose levels in patients with diabetes. Continuous glucose monitoring (CGM) allows glucose monitoring in real time. Battery-operated CGM transmitters have yet to be formally tested and given safety approval for use in a hyperbaric environment. Materials and Methods We evaluated and tested commercially available Dexcom® G6 CGM transmitters under hyperbaric conditions. Each transmitter contains a 3V, 130-mAh (0.39 Wh) lithium manganese dioxide battery (IEC CR1632) and circuit board that are fully encapsulated in epoxy. Each transmitter is pressurized to 90 pounds per square inch (psi) in an autoclave at 40°C for up to 72 hours during manufacturing to ensure that all enclosed air spaces are eliminated from the epoxy. We compared the CGM components against section 14.2.9.3.17.5 of the 2018 National Fire Protection Association 99 (NFPA 99) Health Care Facilities Code requirements. Six CGM transmitters attached to estimated glucose value generators (EGVGs) underwent 11 pressurization cycles to 45 feet of seawater (fsw). All transmitters were returned to the manufacturer to assess post-exposure structural integrity. G6 sensors, which contain no electrical components or compressible air spaces, do not pose a risk in the hyperbaric environment. Results There was no observed change in preset EGVG readings during hyperbaric exposures. Post-exposure testing revealed no structural compromise after repeated hyperbaric exposures. Conclusions The CGM transmitter meets section 14.2.9.3.17.5 of the 2018 NFPA 99 requirements for battery-operated devices allowed for use in a hyperbaric environment. This analysis revealed no significant safety concerns with subjecting Dexcom G6 CGM transmitters to hyperbaric environments. Copyright© Undersea and Hyperbaric Medical Society.Decompression sickness (DCS) occurs when nitrogen gas (N2) comes out of solution too quickly, forming bubbles in the blood and tissues. These bubbles can be a serious condition; thus it is of extreme interest in the dive community to model DCS risk. Diving models use tissue compartments to calculate tissue partial pressures, often using data obtained from other mammalian species (i.e., pigs). Adipose tissue is an important compartment in these models because N2 is five times more soluble in fat than in blood; at any blood/tissue interface N2 will diffuse into the fat and can lead to bubble formation on ascent. Little is known about many characteristics of adipose tissue relevant to diving physiology. Therefore, we measured microvessel density and morphology, lipid composition, and N2 solubility in adipose tissue from humans and pigs. Human adipose tissue has significantly higher microvascular density (1.79 ± 0.04 vs. selleck chemicals llc 1.21 ± 0.30%), vessel diameter (10.25 ± 0.28 vs. 6.72 ± 0.60 µm), total monounsaturated fatty acids (50.