Dietary supplementation with concentrated RGJ improves the lipoprotein profile, reduces plasma concentrations of inflammatory biomarkers and oxidized LDL, and may favor a reduction in cardiovascular disease risk.

Background: Atherosclerotic cardiovascular disease is the most common cause of death among hemodialysis patients; it has been attributed to increased oxidative stress, dyslipidemia, malnutrition, and chronic inflammation. Activation of neutrophils is a wellrecognized feature in dialysis patients, and superoxide-anion production by neutrophil NADPH oxidase may contribute significantly to oxidative stress. Objective: The aim of the study was to compare the effects of dietary supplementation with concentrated red grape juice (RGJ), a source of polyphenols, and vitamin E on neutrophil NADPH oxidase activity and other cardiovascular risk factors in hemodialysis patients. Design: Thirty-two patients undergoing hemodialysis were recruited and randomly assigned to groups to receive dietary supplementation with RGJ, vitamin E, or both or a control condition without supplementation or placebo. Blood was obtained at baseline and on days 7 and 14 of treatment. Results: RGJ consumption but not vitamin E consumption reduced plasma concentrations of total cholesterol and apolipoprotein B and increased those of HDL cholesterol. Both RGJ and vitamin E reduced plasma concentrations of oxidized LDL and ex vivo neutrophil NADPH oxidase activity. These effects were intensified when the supplements were used in combination; in that case, reductions in the inflammatory biomarkers intercellular adhesion molecule 1 and monocyte chemoattractant protein 1 also were observed. Conclusions: Regular ingestion of concentrated RGJ by hemodialysis patients reduces neutrophil NADPH-oxidase activity and plasma concentrations of oxidized LDL and inflammatory biomarkers to a greater extent than does that of vitamin E. This effect of RGJ consumption may favor a reduction in cardiovascular risk.

The 2 year study results confirm that tacrolimus is a highly efficacious cornerstone immunosuppressant in kidney transplantation. Tacrolimus-based immunosuppression may induce long-term benefits with regard to graft function and graft survival. The overall side-effect profile is considered to be favourable.

Seroconversion after hepatitis B vaccine has been estimated to occur when the level of anti-HBs is higher than 10 IU/1, but recently is has been considered that an antibody titer above 100 IU/1 is necessary to guarantee an efficacious protection. We prospectively studied the evolution of anti-HBs after primary vaccination (3 doses; Engerix B, 40 µg each) in 56 seronegative and not previously vaccinated hemodialysis patients. Three months after vaccine administration, seroconversion (anti-HBs > 10 IU/1) was found in 43 patients (76.7%), but an adequate response (titer > 100 IU/1) was observed only in 30 (53.5%). At 1 year after vaccination only 1 (3.3%) of the 30 cases with an effective response had lost his anti-HBs, while 12 of the 13 patients (92.3%) with an inadequate response (anti-HBs between 10 and 100IU/1) had no detectable antibodies (p < 0.01, χ²). Considering that an antibody titer above 100IU/1 following vaccination is necessary in order to maintain that level of antibody 1 year later, we analyzed the factors which influenced obtaining this level of antibody. Age, time on hemodialysis, serum albumin, Kt/V and protein catabolic rate did not affect the response to the vaccine. Females had a better response than males, and interestingly we found that hepatitis C virus (HCV) infection influenced the level of immunity. 27 out of the 43 HCV-negative cases (62.7%) obtained anti-HBs levels greater than 100 IU/1, but only 3 out of the 13 HCV-infected patients (23%) had an anti-HBs above 100 IU/1 (p < 0.01, χ²). Our results suggest that after hepatitis B vaccine, an antibody titer higher than 100 IU/1 is necessary to maintain the antibody level 1 year later, and that HCV infection may reduce the effectiveness of hepatitis B vaccine in hemodialysis patients.

A prospective study on hypotension in hemodialysis was performed in 60 nondiabetic patients at two different dialysate temperatures during 12 months. A 37 °C bath (3,723 sessions) was used and after the first 6 months the temperature was changed to 35 °C (4,019 sessions). The prevalence of symptomatic hypotension was 15.3% and it was closely correlated with the presence of other symptoms. The most affected populations were women, patients over 55 years of age, patients with low body surface area and patients with a cardiovascular disease. A slight but significant decrease of symptomatic hypotension was seen by using a 35 °C dialysate (16.4 vs. 14.3%, p < 0.01). In patients with frequent hypotension (in up to 30% of sessions), cool dialysate significantly reduced the incidence of the symptom (44.2 vs. 34.1 %, p < 0.001). These results were obtained in spite of a greater interdialysis weight gain at low temperature (2 ± 0.6 vs. 1.9 ± 0.7 kg, p < 0.001). We consider that low-temperature dialysis is a simple, useful and economic procedure, especially for highly symptomatic patients. The association of cooling dialysate with higher sodium concentration, bicarbonate and special membranes could reduce dialysis symptoms dramatically.

An explicit analytical equation applicable to the study of reversible ion transfer at systems with two liquid/liquid polarizable interfaces is presented. This expression is valid for any multipotential step technique, which are all very adequate for the determination of standard transfer potentials and transport parameters of ions. The expression of the I/E response for linear sweep voltammetry and cyclic voltammetry can also be deduced as a particular case of this equation. The general solution given here is formally similar to that obtained for the application of any multipotential step sequence to a system with a single polarizable interface, since the method followed here is based on the same premises.

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This study showed that DGF did not adversely affect kidney graft survival in patients without rejection. However, it increased the length of hospitalization and the number of graft biopsies, thus increasing the cost of transplantation. Moreover, rejection was more frequent in patients with DGF, and it had a negative impact on graft outcome. Because the association of DGF and rejection gave the poorest outcome, an effort should be made to prevent both complications.