Limited Predictive Role of the Revised Cardiac Risk Index in Kidney Transplant: Single Center Evaluation and Comparison With International Literature.

Perioperative risk factors predicting major cardiovascular events (MACE) and the performance of the Revised Cardiac Risk Index (RCRI) in a retrospective cohort of 325 consecutive adult patients undergoing kidney transplant from deceased donor grafts were assessed. Primary outcome was a composite of MACE up to 30 days post-transplant. Incidence of MACE was 5.8% at 30 days. Overall proportion of patients with RCRI ≥ 4 was 5%, but was higher (28%) among those who developed MACE. Patients with RCRI ≥ 4 had lower survival free of MACE compared to those with RCRI < 4 (P <0.001); however, in multivariable analysis, RCRI was not a predictor of cardiovascular events. The RCRI demonstrated poor discrimination to predict MACE at 30 days [area under the curve 0.64 (95% CI 0.49-0.78)]. Revised Cardiac Risk Index was not associated with reduced MACE-free survival adjusted analysis and its predictive ability was poor.

Encapsulated platelets modulate kupffer cell activation and reduce oxidative stress in a model of acute liver failure.

Acute liver failure (ALF) is characterized by massive hepatocyte cell death. Kupffer cells (KC) are the first cells to be activated after liver injury. They secrete cytokines and produce reactive oxygen species, leading to apoptosis of hepatocytes. In a previous study, we showed that encapsulated platelets (PLTs) increase survival in a model of ALF. Here, we investigate how PLTs exert their beneficial effect. Wistar rats submitted to 90% hepatectomy were treated with PLTs encapsulated in sodium alginate or empty capsules. Animals were euthanized at 6, 12, 24, 48, and 72 hours after hepatectomy, and livers were collected to assess oxidative stress, caspase activity, and gene expression related to oxidative stress or liver function. The number of KCs in the remnant liver was evaluated. Interaction of encapsulated PLTs and KCs was investigated using a coculture system. PLTs increase superoxide dismutase and catalase activity and reduce lipid peroxidation. In addition, caspase 3 activity was reduced in animals receiving encapsulated PLTs at 48 and 72 hours. Gene expression of endothelial nitric oxide synthase and nuclear factor kappa B were elevated in the PLT group at each time point analyzed. Gene expression of albumin and factor V also increased in the PLT group. The number of KCs in the PLT group returned to normal levels at 12 hours but remained elevated in the control group until 72 hours. Finally, PLTs modulate interleukin (IL) 6 and IL10 expression in KCs after 24 hours of coculture. In conclusion, these results indicate that PLTs interact with KCs in this model and exert their beneficial effect through reduction of oxidative stress that results in healthier hepatocytes and decreased apoptosis. Liver Transplantation 22 1562-1572 2016 AASLD.

N-acetylcysteine Plus Deferoxamine Improves Cardiac Function in Wistar Rats After Non-reperfused Acute Myocardial Infarction.

The antioxidant N-acetycysteine can turn into a prooxidant molecule in presence of iron ions. Thus, our goal was to test if the association of N-acetylcysteine (NAC) and an iron chelator (deferoxamine--DFX) in a rodent model of acute myocardial infarction (AMI) improves cardiac function. Male Wistar rats were subjected to a SHAM surgery or AMI. The animals were randomized: vehicle, NAC (25 mg/kg for 28 days), DFX (40 mg/kg for 7 days), or NAC plus DFX (NAC plus DFX, respectively). Animals were killed 28 days after the AMI. Animals treated with NAC/DFX showed an increase in left ventricular ejection fraction at 28 days when compared with vehicle group (45.2 ± 10.9 % vs. 34.7 ± 8.7 %, p = 0.03). Antioxidant effect of NAC/DFX treatment decreased 4-hydroxynonenal when compared to AMI group (p = 0.06). In conclusion, we showed beneficial effect of NAC/DFX association in improving left ventricle function in an experimental AMI.

Behaviour of the oxidant scavenger metallothionein in hypoxia-induced neotropical fish.

The pacu (Piaractus mesopotamicus) is a hypoxia-tolerant neotropical fish species. There is little or no information in this species regarding biochemical adaptations to waters with different oxygen concentrations, such as the production of reactive oxygen species and antioxidant scavengers, which might be of interest in the study of antioxidant defense mechanisms. Metallothioneins (MT) have been widely applied as biomarkers for metal exposure in fish liver, and, recently, in bile. These metalloproteins, however, have also been reported as free radical scavengers, although studies in this regard are scarce in fish. In this context, normoxic and hypoxic controlled experiments were conducted with pacu specimens and MT levels were quantified in both liver and bile. Reduced glutathione (GSH) indicative of oxidative stress, and thiobarbituric acid reactive substances (TBARS), indicative of lipid peroxidation, were also determined in liver. The results demonstrate that hypoxic fish present significantly lower metallothionein levels in liver and bile and lower reduced glutathione levels in liver, whereas lipid peroxidation was not significantly different between hypoxic and normoxic fish. The results of the present study seem to suggest that metallothioneins may actively participate in redox regulation in hypoxic fish in both bile and liver. MT levels in these organs may be temporarily suppressed, supporting the notion that down-regulation of oxidant scavengers during the oxidative burst is important in defense signaling in these adapted organisms.