The Influence of Hyperbaric Oxygen Treatment on the Healing of Experimental Defects Filled with Different Bone Graft Substitutes

To assess potential effects of hyperbaric oxygen (HBOT) on artificial bone grafts, β - Tricalcium phosphate (β-TCP) and calcium phosphate coated bovine bone (CPCBB) substitutes were applied to standard bone defects in rat tibiae. The control defects were left empty. Half of the animals received 60 minutes of 2.4 atmosphere absolute (ATA) of HBOT. Rats were sacrificed at one, two and four weeks. Bone healing was assessed histologically and histomorphometrically using light microscopy. The periosteum over the bone defects was examined ultrastructurally. Cardiac blood was collected to determine the serum osteocalcin levels. The HBOT increased new bone formation in the unfilled controls and β-TCP groups and significantly decreased cartilage matrix and fibrous tissue formations in all groups. Active osteoblasts and highly organized collagen fibrils were prominent in the periosteum of β-TCP and control groups. Serum osteocalcin levels also increased with HBOT. The healing of defects filled with CPCBB was similar to the controls and it did not respond to HBOT. These findings suggested that the HBOT had beneficial effects on the healing of unfilled bone defects and those filled with β-TCP bone substitute but not with CPCBB, indicating a material-specific influence pattern of HBOT

Morphologic changes and lipid peroxidation in renal tissues of young rats following intestinal ischemia-reperfusion

Intestinal ischemia-reperfusion (IIR) is a complex phenomenon causing local and remote tissue destruction, and even multiple-organ failure. To examine the hypothesis that IIR affects renal function, 21-day-old male Sprague-Dawley rats underwent 45 min superior mesenteric artery occlusion and control rats were subjected to a sham laparotomy. After 2 and 24 h and 1 week of reperfusion, blood was sampled for urea and the kidneys were harvested for lipid peroxidation and histologic examination. Malondialdehyde (MDA) levels as an indicator of lipid peroxidation were significantly increased in renal tissue after 2 h of reperfusion, and this finding was in accordance with serum urea levels (SU) and endothelial injury. However, at 24 h of reperfusion MDA and SU had returned to normal. These data were supported by electron-microscopic studies suggesting reversibility of the changes. It is concluded that IIR leads to renal injury and that free radicals may be responsible for this injury

Ischemia-reperfusion injury following superior mesenteric artery occlusion and strangulation obstruction

Background. Intestinal ischemia-reperfusion injury (IRI) is a serious and common clinical entity resulting in severe tissue injury. This study was designed to compare IRI in superior mesenteric artery (SMA) occlusion and strangulation obstruction (SO)

Effects of valsartan on stress-induced changes of serum vascular endothelial growth factor and nitric oxide in mice

This study investigated the effects of renin- angiotensin system ( RAS) blockade on stress- induced changes of serum vascular endothelial growth factor ( VEGF) and nitric oxide ( NO) in mice. Chronic stress increased the serum NO levels significantly compared to control group ( p =.0172). Valsartan, an angiotensin II receptor antagonist, alone, did not make significant difference versus control group. In chronic stress + valsartan group, serum NO levels decreased nonsignificantly compared to chronic stress group. There was a nonsignificant increase in serum VEGF levels after chronic stress. Valsartan alone or with chronic stress did not significantly affect the serum VEGF levels. In conclusion, there was no correlation between NO and VEGF changes during the stress response. In this respect, there may be other mechanisms to explain the stress- induced NO increase

Changes in Prooxidant-Antioxidant Balance in Tissues of Rats Following Long-term Hyperglycemic Status

Introduction. Reactive oxygen species play an important role in the pathogenesis of organ damage in diabetes mellitus. Streptozotosin (STZ) is a commonly employed compound to produce diabetes mellitus and these animals exhibit most of diabetic complications. Methods. In our study, diabetes was induced by a single intraperitoneal injection of STZ at a dose of 50 mg/kg in rats and they were killed 12 weeks after STZ. Endogenous lipid peroxide levels, enzymatic and non-enzymatic antioxidants were measured in liver, heart, kidney, brain, and testis tissues to investigate the effect of long-term hyperglycemic state. The susceptibility of diabetic tissues to oxidative stress was also examined in in vitro oxidizing system containing ascorbic acid and iron. Results. We found that prooxidant and antioxidant balance has changed in favor of prooxidation in the tissues of diabetic rats. The susceptibility of liver to oxidative stress increased; however, this susceptibility did not change in heart, kidney, brain, and testis of diabetic rats. Conclusion. Our results indicate that long-term hyperglycemic state disturbs hepatic prooxidant-antioxidant balance at an earlier period and more pronouncedly than other tissues

Beneficial effects of taurine and carnosine in experimental ischemia/reperfusion injury in testis

Testicular torsion can be thought of as an ischemia/reperfusion (I/R) injury to the testis. This study aimed to investigate the effects of taurine (TAU) and carnosine (CAR), which are strong antioxidants, on experimental testicular I/R injury model