No abstract

OBJECTIVE: Liver failure following ischemia-reperfusion (I/R) injury is a major concern in liver surgery. The purpose of this study was to evaluate combination pretreatment with melatonin (MEL) and dexamethasone (DEX) on liver I/R model. Male Wistar rats (n = 60) were assigned to 5 groups of 12 animals each: (1) Sham: laparotomy without I/R; (2) I/R: hepatic I/R; (3) I/R+MEL: hepatic I/R+melatonin injected intraperitoneally (20 mg/kg); (4) I/ R+DEX: hepatic I/R+ dexamethasone injected intravenously (10 mg/kg); (5) I/R+MEL+DEX: hepatic I/R+ melatonin injected intraperitoneally+dexamethasone injected intravenously. The liver was subjected to ischemia by clamping the portal triad for 30 minutes and then reperfused for 6 hours after ischemia by removing the clamps. RESULTS: The levels of glutathione peroxidase (GPx) and superoxide dismutase (SOD) decreased after hepatic I/R in all groups. Levels of GPx and SOD were higher in I/R+MEL+DEX group compared to I/R, I/R+MEL and I/ R+DEX groups and they were signifi cantly higher in I/R+MEL group compared to I/R and I/R+DEX groups (p < 0.05). Levels of ALT, AST, TNF-α, hepatic tissue malondialdehyde (MDA), liver injury index, and apoptotic index increased after hepatic I/R. Levels of ALT, AST, tissue MDA, tissue injury index and apoptotic index were lower in I/R+MEL+DEX group compared to those in I/R, I/R+MEL and I/R+DEX groups, and in I/R+MEL they were signifi cantly lower than in I/R+DEX group (p < 0.05). TNF-α level was lower in I/R+MEL+DEX group compared to other groups and it was signifi cantly lower in I/R+DEX group than in I/R+MEL and I/R groups (p < 0.05). CONCLUSION: Combination therapy with melatonin and dexamethasone had better results in decreasing the liver injury compared to when each of them was administered alone (Tab.

Hepatitis B virus (HBV) infection is a serious global health problem.The prevalence of viral hepatitis is higher in dialysis patients than in the general population because of the opportunity for exposure during the dialysis procedure. Immunization is the most effective way to prevent transmission of hepatitis B virus (HBV) and hence the development of acute or chronic hepatitis B. It is well established that patients with end-stage renal disease including dialysis-dependent patients, have an impaired immune response to hepatitis B vaccine. End stage renal diseases (ESRD) patients have lower seroconversion rates compared with the subjects with intact renal function. Moreover, even after the completion of vaccination schedule anti-hepatitis B (anti-HBs) titers of responder dialysis, patients are low and decline logarithmically with time. The impaired efficacy of HBV vaccine in patients with ESRD has been attributed to numerous factors such as immune compromise because of uremia and some other factors. One approach to improve the immunogenicity of existing HBV vaccines is adjuvantation, and it's very important to find more effective adjutants for improving HBV vaccine efficacy. In this paper we have a brief review on recently known new ways for improving HBV vaccine efficacy.

Objective: To study the effect of erythropoietin (EPO) treatment on renal and lung injury following renal ischemia/reperfusion (I/R). Materials and Methods: Thirty male Wistar rats were assigned to three groups of 10 rats each. The first group was sham-operated, the second was subjected to renal I/R (30 min of ischemia followed by 24 h of reperfusion). The third group was subjected to renal I/R and treated with EPO in two doses: the first dose 1 h prior to ischemia (1,000 U/kg) and the second dose 6 h after ischemia (1,000 U/kg). Results: The renal and lung tissue injury index, tissue serum blood urea nitrogen and creatinine (Cr) were higher in the renal I/R group compared to the renal I/R + EPO group; the difference was statistically significant (p < 0.05). Kidney and lung tissue glutathione peroxidase and superoxide dismutase levels were higher in the renal I/R + EPO group than the renal I/R group; the difference was also statistically significant (p < 0.05). Conclusion: The data showed that EPO pretreatment could be effective in reducing renal and lung injury following renal I/R and could improve the cellular antioxidant defense system. Hence EPO pretreatment may be effective for attenuating renal and lung injury after renal I/R-induced injury during surgical procedures, hypotension, renal transplantation and other conditions inducing renal I/R.

Objective: Lipoic acid (LA) is an effective anti-oxidant agent that can scavenge free radicals in biological systems. The aim of this research was to study the probable protective effect of LA in spinal ischemic/reperfusion (I/R) injury. Materials and Methods: Thirty male Wistar rats, weighing 230–285 g, were assigned randomly into 3 groups (10 animals in each group): sham spinal I/R, and spinal I/R + LA. The spinal I/R + LA rats received LA 100 mg/kg subcutaneously 3 days prior to ischemia induction and 3 days after. The induction of ischemia lasted for 30 min. Results: At 72 h postoperatively, the neurological status was worse in the I/R group than the sham group (p < 0.05). The neurological status of animals in the LA-treated group appeared better than the I/R group (p < 0.05). In the I/R group, tissue glutathione peroxidase (GPx) and super oxide dismutase (SOD) activity were significantly less compared to the control group (p < 0.05). In the LA-treated group, tissue GPx and SOD levels were higher compared to the I/R group (p < 0.05). Conclusions: LA pretreatment reduced neurologic injury in the rats, most probably by maintaining the oxidant/anti-oxidant ion balance during spinal cord ischemia. Reperfusion may have contributed to the protective effects seen in the LA pretreatment.