Diagnostic Value of the Aminopeptidase N,N-Acetyl-β-D-Glucosaminidase and Dipeptidylpeptidase IV in Evaluating Tubular Dysfunction in Patients with Glomerulopathies

Aim. The aim of the present study was to investigate the value of the urine cell glycoprotein 1 (PC-1), aminopeptidase N (APN), N-acetyl-β-D-glucosaminidase (NAGA), and dipeptidylpeptidase IV (DPP IV) in the evaluation of tubular damage in patients with primary glomerulonephritis, diabetic nephropathy, and lupus nephritis. Subjects and Methods. PC-1, APN, NAGA, and DPP IV activities were determined in serum, urine, and lymphocytes of 178 subjects, including 10 patients with membranous nephropathy, 38 with IgA nephropathy, 29 with lupus nephritis, 51 with diabetic nephropathy, and 50 control subjects. Results. Urinary PC-1 excretion in IgA nephropathy group was significantly higher (p < 0.05) than in controls. Urinary NAGA excretion was markedly (p < 0.01) higher in membranous nephropathy group, and APN excretion in diabetic nephropathy group was significantly higher (p < 0.01) than in healthy controls. Urinary APN activity was significantly (p < 0.01) higher in both type 1 and type 2 diabetic patients with microalbuminuria, as well as urinary NAGA and DPP IV activities in type 2 diabetics with microalbuminuria (p < 0.01 and p < 0.05, respectively) compared to controls. Serum PC-1 and APN activities were significantly higher than the control level in membranous nephropathy group, as well as serum PC-1 and DPP IV activities in IgA nephropathy patients (p < 0.05). However, significantly lower serum DPP IV and APN activity was observed in type 2 diabetics with microalbuminuria compared to controls (p < 0.05). Conclusion. Damage of tubules in primary glomerulonephritis, lupus nephritis, and diabetic nephropathy is accompanied by a release of several tubular enzymes, with possible diagnostic and prognostic significance. Increased serum PC-1, APN, and DPP IV activities could be also of diagnostic significance.     

Xanthine oxidase and lens oxidative stress markers in diabetic and senile cataract patients

Xanthine oxidase (XOD) is a prooxidant enzyme possibly implicated in diabetic lens injury and genesis of senile cataract (SC). We evaluated the impact of diabetes on XOD activity and its relationships with lens oxidative stress markers in patients operated on for SC. Serum and lens XOD activities, lens malondialdehyde (MDA), conjugated dienes, superoxide dismutase (SOD), glutathione peroxidase (GPx) and reduced glutathione (GSH) levels were measured in 62 non-diabetic and 29 diabetic patients operated on for SC. Lens XOD, SOD, GPx and GSH levels were gradually declining, while MDA and serum XOD were increasing with patient's age. Lens XOD activity was positively correlated with conjugated dienes concentration (rho = 0.316; p = 0.003) while being inversely correlated with age (rho = ? 0.371; p < 0.001), indicating that low ocular expression of XOD could be related to lower intensity of oxidative stress and delayed occurrence of SC. When samples were adjusted for confounding factors, serum XOD (p < 0.001), lens XOD (p = 0.003) and conjugated dienes (p = 0.002) were significantly higher in diabetic than in non-diabetic group. Lens SOD and GPx were moderately increased while MDA and GSH were unchanged in diabetic, compared with non-diabetic SC group. Blood HbA_1C concentration was positively correlated with lens XOD (rho = 0.346; p < 0.001) as well as serum XOD activity (rho = 0.485; p < 0.001). These results suggest that poor glycemic control may upregulate systemic and ocular XOD activities contributing to lens oxidative stress and possibly to earlier onset of cataract.     

The partnership between renalase and ejection fraction as a risk factor for increased cardiac remodeling biomarkers in chronic heart failure patients

Abstract

Objective: Heart failure (HF) represents a huge socio-economic burden. It has been demonstrated, experimentally, that renalase, a newly discovered protein, prevents cardiac hypertrophy and adverse remodeling, which is seen in HF. We postulated the following aims: to investigate associations of renalase with biomarkers of cardiac remodeling: galectin-3, soluble suppression of tumorigenicity, (sST2), growth differentiation factor 15 (GDF-15) and syndecan-1, myocardial stretch (BNP) and cardio-renal axis (cystatin C) in HF patients with reduced ejection fraction (HFrEF) and preserved ejection fraction (HFpEF) to determine whether renalase, in combination with left ventricular ejection fraction (LVEF), represents a risk factor for plasma elevation in biomarkers.

Methods: We classified HF patients (n?=?76) according to LVEF (preserved/reduced), applied a median plasma renalase (113?ng/mL) as a cut-off value (low/high) and created four subgroups of HF patients: HFpEF/low renalase (n?=?19), HFrEF/low renalase (n?=?19), HFrEF/high renalase (n?=?32) and HFpEF/high renalase (n?=?6). A control group (n?=?35) consisted of healthy volunteers.

Results: Plasma concentrations of evaluated biomarkers were determined using an ELISA technique and were highest in HF patients with reduced EF (p?<?.001, respectively), and renalase’s positive correlations were obtained relating to all biomarkers: galectin-3 (r?=?0.913; p?<?.001), sST2 (r?=?0.965; p?<?.001), GDF-15 (r?=?0.887; p?<?.001), syndecan-1 (r?=?0.922; p?<?.001), BNP (r?=?0.527; p?<?.001) and cystatin C (r?=?0.844; p?<?.001) and strong and negative correlation with LVEF (r?=??0.456, p?<?.001). Increased renalase, regardless of the EF (preserved/reduced), was shown to be an independent risk factor for an increase in all evaluated cardiac remodeling biomarkers, p?<?.001, respectively. However, increased renalase and reduced EF was the only independent risk factor for BNP and cystatin C elevation, p?<?.001, respectively. Results after multivariable adjustments (age/gender) were identical.

Conclusion: When elevated plasma renalase and HF are present, regardless of EF being reduced or preserved, that represents a significant risk factor for increase in cardiac remodeling biomarker plasma concentrations. However, only elevated renalase and reduced EF demonstrated significance as a risk factor for BNP and cystatin C plasma elevation. Renalase may be considered a promising molecule for the improved predictive abilities of conventional biomarkers and is worthy of further investigation.     

The Educational Attainment of Children in Care in British Columbia

The purpose of this study was to determine if there was a difference in academic performance between children in care (referred to in British Columbia as children in continuing custody (CCC) and the general population of students in Grades 4, 7, and 10 in the areas of writing, reading, and numeracy. Data for the study consisted of merging information on children in continuing custody with the Foundation Skills Assessment (FSA) scores on all students in the public school system in British Columbia. Academic performance among CCC was found to be significantly lower than in the general population of students. This finding occurs across all grades studied and across all subject categories. Implications of the findings are discussed and a comprehensive strategic model is presented.     

Influence of cataract maturity on aqueous humor lipid peroxidation markers and antioxidant enzymes

Purpose

The impact of cataract maturity on the aqueous humor (AH) oxidant/antioxidant balance is largely controversial. This study was aimed at assessing the relationships between cataract maturity and AH lipid peroxidation markers and enzymatic antioxidants.

Patients and methods

The concentrations of conjugated dienes (CD), lipofuscin-like fluorescent end-products (LLF), soluble proteins, as well as the activities of superoxide dismutase (SOD) and catalase (CAT) were measured in AH samples from nondiabetic patients with either immature (n=15) or mature (n=15) cataract.

Results

In the overall AH sample, the mean values of CD, LLF, SOD, and CAT were 0.160±0.024 (OD₂₃₄), 166±27 RFU, 24.5±7.1 U/ml, and 31.9±3.9 pmol/ml, respectively. CD was positively correlated with SOD (r=0.647; P<0.001), CAT (r=−0.394; P=0.031), and LLF (r=−0.399; P=0.029). The LLF was negatively correlated with SOD (r=−0.461; P=0.010). In samples adjusted for confounding factors, differences between immature and mature cataract groups regarding SOD, CD, LLF, and total proteins were significant (P<0.05; for all variables). The multiple logistic regression analysis identified LLF (OR=4.08; P=0.038) and SOD (OR=4.99; P=0.031) as independent predictors of cataract maturity.

Conclusions

These results suggest that AH lipid peroxidation markers and antioxidants may significantly depend on the cataract maturity stage.     

Erratum to: Vascular access registry of Serbia: a 4-year experience

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