RESUMO
Despite its widespread use, sperm cryopreservation induces serious detrimental alterations in sperm function; indeed, it is commonly associated with decreased sperm viability and motility, and DNA fragmentation. Mechanisms of human sperm cryodamage are thought to be multifactorial, but oxidative stress seems to have a prominent role. A huge amount of data supported the cryoprotective effect of different antioxidants able to minimize the detrimental effects of reactive oxygen species (ROS) and improve the quality of spermatozoa. Among others, myo-inositol is one of the most powerful and has been reported to be effective in improving sperm quality and motility when used both in vivo and in vitro. This study aimed to determine the in vitro impact of myo-inositol in ameliorating sperm oxidative status during sperm cryopreservation. In particular, we demonstrated a significant improvement of sperm parameters (vitality and motility) when myo-inositol was added after sperm thawing (p < 0.05). Moreover, we showed that myo-inositol induces a significant increase in oxygen consumption, the main index of oxidative phosphorylation efficiency and ATP production. Finally, by means of 2D-electrophoresis, we demonstrated a significant decrease in the level of carbonyl groups, the main structural changes occurring in conditions of oxidative stress (p < 0.05). In conclusion, the sperm cryopreservation procedure we developed, assuring the reduction of ROS-induced sperm modifications, may improve the in vitro procedure currently used in ART laboratory for sperm cryostorage.
RESUMO
OBJECTIVE: Acute renal failure is common in septic patients. Fenoldopam, a dopamine-1 receptor agonist, increases renal blood flow and may, therefore, reduce the risk of acute renal failure in such patients. Accordingly, we sought to determine the safety and efficacy of fenoldopam for the prevention of acute renal failure in septic patients. DESIGN: Prospective, double-blind, placebo-controlled trial. SETTING: Three multidisciplinary intensive care units at a university hospital. PATIENTS: Three hundred septic patients with baseline serum creatinine concentrations <150 micromol/L. INTERVENTIONS: We randomized patients to a continuous infusion of either fenoldopam (n = 150) at 0.09 microg x kg x min or placebo (n = 150) while in the intensive care unit. The primary outcome measure was the incidence of acute renal failure, defined as a serum creatinine concentration increase to >150 micromol/L, during study drug infusion. MEASUREMENTS AND MAIN RESULTS: The incidence of acute renal failure was significantly lower in the fenoldopam group compared with the control group (29 vs. 51 patients; p = .006). The odds ratio of developing acute renal failure for patients treated with fenoldopam was estimated to be 0.47 (p = .005). The difference in the incidence of severe acute renal failure (creatinine >300 mumol/L), however, failed to achieve statistical significance (10 vs. 21; p = .056). The length of intensive care unit stay in surviving patients was significantly lower in the fenoldopam group compared with the control group (10.64 +/- 9.3 vs. 13.4 +/- 14.0; p < .001). There were no complications of fenoldopam infusion. A direct effect of treatment on the probability of death, beyond its effect on acute renal failure, was not significant (odds ratio = 0.68, p = .1). CONCLUSIONS: Compared with placebo, low-dose fenoldopam resulted in a smaller increase in serum creatinine in septic patients. The clinical significance of this finding is uncertain. A large multiple-center trial is now needed to confirm these findings.