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Background. Serum creatinine (SCR) and blood urea nitrogen (BUN) determine the glomerular filtration rate (GFR) improperly in acute renal failure. Serum cystatin C (CYS) has the potential to be a more precise marker for GFR. The aim of this study was to compare the sensitivity of SCR, BUN and CYS with respect to the detection of acute renal failure in mice. Methods. In an ischaemia reperfusion (I/R) injury model, mice suffered 60-min left kidney ischaemia and right nephrectomy. In a nephrectomy model, mice were nephrectomized to a different extent: from unilateral (3/6Nx) to bilateral nephrectomy (BiNx). Blood samples were collected 2, 12 or 24 h post-op. Results. SCR, BUN and CYS increased significantly in the I/R-model in comparison to sham mice and 3/6Nx mice at 12 and 24 h post-op (SCR P = 0.009; BUN P P P P P = 0.13, 5/6Nx 1.00 ± 0.29, P P Conclusions. CYS can be used as a reliable and precise marker for renal function in mouse models. CYS is more sensitive than SCR, and it shows renal damage earlier than SCR and BUN. [ABSTRACT FROM AUTHOR]

Background. Proximal tubules subjected to hypoxia in vitro under conditions relevant to ischaemia in vivo develop an energetic deficit that is not corrected even after full reoxygenation. We have provided evidence that accumulation of nonesterified fatty acids (NEFA) is the primary reason for this energetic deficit. In this study, we have further investigated the mechanism for the NEFA-induced energetic deficit. Methods. Mitochondrial membrane potential (Δψ) was measured in digitonin-permeabilized, freshly isolated proximal tubules by safranin O uptake. Addition of the potassium/proton exchanger nigericin enables the determination of the mitochondrial proton motive force (Δp) and the proton gradient (ΔpH). ATP was measured luminometrically and NEFA colorimetrically. Results. Tubule ATP content was depleted after hypoxia and recovered incompletely, even after full reoxygenation. Mitochondrial safranin O uptake was decreased in proximal tubules after hypoxia and reoxygenation (H/R). This decrease was attenuated by delipidated bovine serum albumin (dBSA) or citrate. Addition of nigericin increased safranin O uptake of mitochondria in normoxic proximal tubules, but not in proximal tubules after H/R. Addition of dBSA restored the effect of nigericin to increase mitochondrial safranin O uptake. Addition of the NEFA oleate had the same impact on mitochondrial safranin O uptake as subjecting proximal tubules to H/R. Conclusion. The mechanism of the NEFA-induced energetic deficit in freshly isolated rat proximal tubules induced by H/R is characterized by impaired ATP production after full reoxygenation, impaired recovery of Δψ and Δp, abrogation of ΔpH and sensitivity to citrate, consistent with involvement of the tricarboxylate carrier. The data support the concept that protonophoric uncoupling by NEFA movement on anion carriers plays a critical role in proximal tubule mitochochondrial dysfunction after H/R. [ABSTRACT FROM AUTHOR]

Background. An increased CD4+ CD25+ T-cell population is observed in Wegeners granulomatosis (WG). This T-cell population is not well characterized yet and their contribution to the disease pathogenesis remains obscure. Methods. Thirty patients with WG and 18 healthy controls (HC) were included in this study. The disease activity and extension were measured by the Birmingham Vasculitis Activity Score (BVAS) and the Disease Extent Index (DEI). Lymphocytes from peripheral blood were analysed by FACS for the expression of CD4, CD25, CD134 and GITR. Cytokine expression in these subsets was assessed too. Nasal, lung and renal tissues from WG patients were immunohistochemically stained for CD3 and CD134. Results. The percentage of CD134+ as well as GITR+ expressing CD4+CD25+ lymphocytes was increased in patients as compared to HC (37 ± 12% versus 27 ± 8%, P = 0.005; 18 ± 9% versus 11 ± 6%, P = 0.003). The expression of CD134 and GITR showed a significant correlation with disease activity (r = 0.5, P = 0.009; r = 0.55, P = 0.001). Most of these displayed the phenotype of effector memory T-cells (94 ± 4% and 91 ± 6%). CD134 T-cells were found in tissues affected by WG. Conclusions. CD4+CD25+ effector memory T-cells expressing CD134 and GITR seem to play a role in disease mechanisms, as suggested by their close association with disease activity and their participation in inflammatory process. [ABSTRACT FROM AUTHOR]

Background. Acute kidney injury (AKI) is a serious and frequent complication after coronary artery bypass grafting (CABG). Cardiopulmonary bypass (CPB) was identified as a major AKI risk factor after CABG. Our aim was to assess the impact of the off-pump coronary artery bypass (OPCAB) compared to the on-pump coronary artery bypass (ONCAB) technique on the rate and severity of AKI, while taking other risk factors for AKI into account. Methods. An observational study of 201 consecutive adult patients was conducted; 100 were operated by the OPCAB and 101 by the ONCAB technique. All patients in each group were operated by a single, experienced surgeon. Fifteen pre-, intra- and postoperative variables that were repeatedly identified in previous studies as independent AKI risk factors were included in this analysis. AKI was defined as an increase of serum creatinine ≥50% or ≥0.3 mg/dL within 48 h and AKI severity was classified, according to current AKIN definitions. Results. Significantly fewer OPCAB patients developed AKI compared to ONCAB (14.0 versus 27.7%; P = 0.03). OPCAB was associated with milder stages of AKI, whereas ONCAB patients had more severe AKI. Congestive heart failure and chronic kidney disease were independent risk factors for AKI. The OPCAB technique for CABG was identified as the only independent factor associated with lower incidence of AKI. Conclusions. Using current AKI definitions and classifications, the OPCAB technique for CABG, which avoids CPB; was associated with a significantly lower rate and less severe AKI compared to ONCAB. The OPCAB technique was identified as the only modifiable and potentially protective factor against postoperative AKI. [ABSTRACT FROM AUTHOR]

Background. Ezetimibe has shown efficacy in the therapy of hypercholesterolemia in renal transplant patients. This is the first study investigating the effect of ezetimibe on renal function in kidney transplant recipients. Methods. Fifty-six patients with statin-resistant hypercholesterolemia (total cholesterol >200 mg/dl) after renal transplantation received additional ezetimibe therapy (10 mg/day) for 12 months. A group receiving statin therapy (n = 28) served as controls in this prospective study. Results. Total cholesterol and LDL cholesterol concentrations decreased significantly in the ezetimibe-treated patients but remained stable in the control group (delta total cholesterol: −24 ± 49 mg/dl vs 19 ± 49 mg/dl, P vs − 3 ± 31 mg/dl, P vs − 4.8 ± 12.8 ml/min, P = 0.025; delta Modification of Diet in Renal Disease: −0.4 ± 6.2 ml/min/1.73 m2 vs 4.7 ± 8.8 ml/min/1.73 m2, P = 0.033). Conclusions. The data of our prospective case–control study suggest that ezetimibe appears to ameliorate the decline of renal function after renal transplantation. [ABSTRACT FROM AUTHOR]