Effect of the direct renin inhibitor aliskiren in the prevention of experimental contrast-induced nephropathy in the rat.

BACKGROUND: Renal vasoconstriction, activated by the renin-angiotensin system, plays a pivotal role in the pathogenesis of contrast-induced nephropathy (CIN). The purpose of this study was to evaluate the effect of aliskiren, a direct renin inhibitor, for the prophylaxis of experimental CIN in the rat. METHODS: Thirty-two Wistar albino rats were divided into four groups of 8 rats each, namely the control (C), aliskiren (A), contrast media (CM) and aliskiren plus contrast media (ACM) groups. Aliskiren was given orally at a dose of 50 mg/kg/day once daily for 5 consecutive days. CIN was induced by intravenous administration of indomethacin, N-nitro-L-arginine methyl ester and high-osmolar contrast medium meglumine amidotrizoate. Renal function parameters, kidney histology and tubular expression of vascular endothelial growth factor were determined. RESULTS: Mean serum creatinine was significantly lower (p < 0.001) and mean creatinine clearance was higher (p < 0.001) in the ACM group compared with the CM group. However, there were no differences between the ACM and CM groups in terms of tubular necrosis, proteinaceous casts, medullary congestion and vascular endothelial growth factor expression. CONCLUSION: Our preliminary data seem to suggest a potential role of aliskiren for the prophylaxis of CIN in an experimental rat model.

Serum coenzyme Q10 levels are associated with coronary flow reserve in hemodialysis patients.

Accelerated atherosclerosis is the major cause of mortality in patients on chronic hemodialysis (HD). The aim of this study was to evaluate the relation between coenzyme Q10 (CoQ10) levels and coronary flow reserve (CFR) in HD patients as an indicator of atherosclerosis. Seventy-one chronic HD patients and 65 age- and sex-matched healthy individuals were included in the study. Plasma CoQ10 levels were performed by high-performance liquid chromatography measurements. CFR was assessed by transthoracic Doppler echocardiography. Serum CoQ10 levels (1.36 ± 0.43 vs. 2.53 ± 0.55, P < 0.001) and CFR values (1.73 ± 0.11 vs. 2.32 ± 0.28, P < 0.001) were significantly lower in HD patients compared with controls. There was a significant positive correlation between CFR and serum levels of CoQ10 (r = 0.669, P < 0.001). A linear regression analysis showed that serum levels of CoQ10 were still significantly and positively correlated with CFR (regression coefficient = 0.235, P < 0.001). Our data have demonstrated that HD patients exhibit decreased plasma CoQ10 levels and CFR values. The study also showed for the first time that serum CoQ10 levels independently predict CFR in HD patients.

Microalbuminuria in nondiabetic patients with nonalcoholic fatty liver disease: association with liver fibrosis.

Recent evidence has suggested an association between microalbuminuria and ultrasound-diagnosed nonalcoholic fatty liver disease (NAFLD) in patients with diabetes and prediabetes. However, few data are available on the occurrence of microalbuminuria in nondiabetic subjects with histologically proven NAFLD. We thus evaluated the relationships between microalbuminuria and liver histology in a hospital-based sample of 87 adults with biopsy-proven NAFLD from Turkey. An albumin excretion rate less than 30 mg/d was considered within the reference range, whereas an albumin excretion rate from 30 to 300 mg/d was considered to indicate microalbuminuria. Compared with those without microalbuminuria (n = 73), NAFLD patients with microalbuminuria (n = 14) had significantly higher homeostasis model assessment of insulin resistance values (3.9 +/- 1.3 vs 5.8 +/- 3.7, P < .001). There were no differences in the prevalence of microalbuminuria in patients with definite nonalcoholic steatohepatitis, borderline nonalcoholic steatohepatitis, and simple fatty liver. In the entire study cohort, mean fibrosis scores were significantly higher in patients with microalbuminuria than in those without (1.27 +/- 0.26 vs 0. 80 +/- 0.11, P < .05). This difference persisted after adjustment for potential confounders. These results indicate the presence of a significant association between the severity of insulin resistance and microalbuminuria in patients with NAFLD. In addition, microalbuminuria may identify NAFLD patients with higher fibrosis scores.

Cytokeratin-18 fragments and biomarkers of the metabolic syndrome in nonalcoholic steatohepatitis.

Nonalcoholic fatty liver disease (NAFLD) remains a leading cause of chronic liver disease. In the context of NAFLD, the presence of nonalcoholic steatohepatitis (NASH) portends an adverse prognosis with greater risk of liver fibrosis and cirrhosis. Although liver biopsy is the keystone of patient management in NAFLD, it is also increasingly clear that such evaluation has its limitations. The availability of biochemical markers of NAFLD and NASH has tremendous potential to radically alter management strategies for these conditions, as well as to monitor disease activity. Our article provides an overview of biomarker discovery and selection in the setting of NAFLD and highlights future directions in the field.

Human serum complement C3 and factor H in the syndrome of hemolysis, elevated liver enzymes, and low platelet count.

PROBLEM: Hemolysis, elevated liver enzymes, and low platelet count syndrome (HELLP syndrome) is a life-threatening variant of severe pre-eclampsia in pregnant women. The complement system may play a role in the pathogenesis of this condition. We sought to determine serum complement 3 (C3) levels and its regulatory protein complement factor H (FH) in the HELLP syndrome. METHOD OF STUDY: Twenty-two pre-eclamptic patients with HELLP syndrome (mean age: 27.8 +/- 6.2 years), 21 pre-eclamptic patients without HELLP syndrome (mean age: 27.5 +/- 6.8 years) and 24 normotensive, healthy pregnant women (mean age: 26.1 +/- 4.4 years) were included in this study. Serum concentrations of C3 and FH were measured in all participants. RESULTS: Concentrations of C3 and FH did not differ significantly between the study groups. In patients with the HELLP syndrome, FH levels were positively associated with platelet count. CONCLUSION: These findings did not support a major role of complement activation in the HELLP syndrome. In patients with HELLP, lower levels of FH are correlated with a reduced platelet count.

High-fat liquid "Lieber-DeCarli" diet for an animal model of nonalcoholic steatohepatitis: does it really work?

We could not reproduce the model described by Lieber et al for nonalcoholic steatohepatitis model in rats. In our trial the high fat liquid diet group of rats gained nearly 100 g or less weight compared to the mean weight gain stated in the original article. However, the fasting glucose level was statistically higher in this group as compared to the chow diet group. Some pathological abnormalities in the duodenum and jejunum samples were observed in the high fat liquid diet group. We do not know the exact reason for these changes. Overall, our study results arose some suspicions about the reproducibility of the model. Furthermore, to the best of our knowledge, no study using the proposed model has been published so far.