Effect of TGF-ß1 on eosinophils to induce cysteinyl leukotriene E4 production in aspirin-exacerbated respiratory disease.

Cysteinyl leukotriene (cysLT) overproduction and eosinophil activation are hallmarks of aspirin-exacerbated respiratory disease (AERD). However, pathogenic mechanisms of AERD remain to be clarified. Here, we aimed to find the significance of transforming growth factor beta 1 (TGF-ß1) in association with cysteinyl leukotriene E4 (LTE4) production, leading to eosinophil degranulation. To evaluate levels of serum TGF-ß1, first cohort enrolled AERD (n = 336), ATA (n = 442) patients and healthy control subjects (HCs, n = 253). In addition, second cohort recruited AERD (n = 34) and ATA (n = 25) patients to investigate a relation between levels of serum TGF-ß1 and urinary LTE4. The function of TGF-ß1 in LTE4 production was further demonstrated by ex vivo (human peripheral eosinophils) or in vivo (BALB/c mice) experiment. As a result, the levels of serum TGF-ß1 were significantly higher in AERD patients than in ATA patients or HCs (P = .001; respectively). Moreover, levels of serum TGF-ß1 and urinary LTE4 had a positive correlation (r = 0.273, P = .037). In the presence of TGF-ß1, leukotriene C4 synthase (LTC4S) expression was enhanced in peripheral eosinophils to produce LTE4, which sequentially induced eosinophil degranulation via the p38 pathway. When mice were treated with TGF-ß1, significantly induced eosinophilia with increased LTE4 production in the lung tissues were noted. These findings suggest that higher levels of TGF-ß1 in AERD patients may contribute to LTE4 production via enhancing LTC4S expression which induces eosinophil degranulation, accelerating airway inflammation.

Potential Novel Biomarkers of Obstructive Nephropathy in Children with Hydronephrosis.

Obstructive nephropathy (ON) secondary to the congenital hydronephrosis (HN) is one of the most common causes of chronic kidney disease in children. Neither currently used imaging techniques nor conventional laboratory parameters are sufficient to assess the onset and outcome of this condition; hence, there is a need to prove the usefulness of newly discovered biomarkers of kidney injury in this respect. The purpose of the study was to assess the urinary excretion of alpha-GST, pi-GST, NGAL, and KIM-1 and the serum level of NGAL in children with congenital unilateral hydronephrosis secondary to ureteropelvic junction obstruction. The results were evaluated in relation to severity of HN, the presence of ON, relative function of an obstructed kidney, and the presence of proteinuria. The study comprised 45 children with HN of different grades and 21 healthy controls. Urinary and serum concentrations of biomarkers were measured using specific ELISA kits. Urinary biomarker excretions were expressed as a biomarker/creatinine (Cr) ratio. Patients with the highest grades of HN showed significantly increased values of all measured biomarkers, whereas those with the lowest grades of HN displayed only significant elevation of urinary alpha-GST and the serum NGAL. Urinary NGAL positively correlated with percentage loss of relative function of an obstructed kidney in renal scintigraphy. In patients with proteinuria, significantly higher urinary alpha-GST excretion was revealed as compared to those without this symptom. The ROC curve analysis showed the best diagnostic profile for urinary alpha-GST/Cr and NGAL/Cr ratios in the detection of ON. In conclusion, the results of the study showed that urinary alpha-GST and NGAL are promising biomarkers of ON. Ambiguous results of the remaining biomarkers, i.e., urinary pi-GST and KIM-1, and serum NGAL level may be related to a relatively small study group. Their utility in an early diagnosis of ON should be reevaluated.

Urinary biomarkers predict advanced acute kidney injury after cardiovascular surgery.

BACKGROUND: Acute kidney injury (AKI) after cardiovascular surgery is a serious complication. Little is known about the ability of novel biomarkers in combination with clinical risk scores for prediction of advanced AKI. METHODS: In this prospectively conducted multicenter study, urine samples were collected from 149 adults at 0, 3, 6, 12 and 24 h after cardiovascular surgery. We measured urinary hemojuvelin (uHJV), kidney injury molecule-1 (uKIM-1), neutrophil gelatinase-associated lipocalin (uNGAL), α-glutathione S-transferase (uα-GST) and π-glutathione S-transferase (uπ-GST). The primary outcome was advanced AKI, under the definition of Kidney Disease: Improving Global Outcomes (KDIGO) stage 2, 3 and composite outcomes were KDIGO stage 2, 3 or 90-day mortality after hospital discharge. RESULTS: Patients with advanced AKI had significantly higher levels of uHJV and uKIM-1 at 3, 6 and 12 h after surgery. When normalized by urinary creatinine level, uKIM-1 in combination with uHJV at 3 h post-surgery had a high predictive ability for advanced AKI and composite outcome (AUC = 0.898 and 0.905, respectively). The combination of this biomarker panel (normalized uKIM-1, uHJV at 3 h post-operation) and Liano's score was superior in predicting advanced AKI (AUC = 0.931, category-free net reclassification improvement of 1.149, and p <  0.001). CONCLUSIONS: When added to Liano's score, normalized uHJV and uKIM-1 levels at 3 h after cardiovascular surgery enhanced the identification of patients at higher risk of progression to advanced AKI and composite outcomes.

Acute Kidney Injury Urine Biomarkers in Very Low-Birth-Weight Infants.

BACKGROUND AND OBJECTIVES: Serum creatinine (SCr)-based AKI definitions have important limitations, particularly in very low-birth-weight (VLBW) neonates. Urine biomarkers may improve our ability to detect kidney damage. We assessed the association between 14 different urine biomarkers and AKI in VLBW infants. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We performed a prospective cohort study on 113 VLBW infants (weight ≤1200 g or <31 weeks' gestation) admitted to a regional neonatal intensive care unit at the University of Alabama at Birmingham between February 2012 and June 2013. SCr was measured on postnatal days 1, 2, 3, and 4 and was combined with clinically measured SCr to determine AKI according to Kidney Disease Improving Global Outcomes AKI definition (increase in SCr ≥0.3 mg/dl or ≥50% increase from previous lowest value). Urine was collected on the first 4 days (average number of urine collections, 3; range, 1-4). The maximum urine biomarkers and urine biomarker/creatinine levels were calculated for 12 urine biomarkers, and the minimum urine biomarker and biomarker/creatinine levels were assessed for two urine biomarkers. We compared these values between infants with and those without AKI. Ideal cutoffs, area under the receiver-operating characteristic curve , and area under the curve adjusted for gestational age were calculated. RESULTS: Cumulative incidence of AKI during the first 2 postnatal weeks was 28 of 113 (25%). Infants with AKI had higher maximum levels of urine cystatin C, neutrophil gelatinase-associated lipocalin, osteopontin, clusterin, and α glutathione S-transferase (2.0, 1.8, 1.7, 1.7, and 3.7 times higher, respectively) than infants without AKI. In addition, infants with AKI had lower minimum levels of epithelial growth factor and uromodulin than those without AKI (1.4 and 1.6 times lower, respectively). Most but not all participants had their maximum (or minimum) biomarker values preceding AKI. These associations remained after adjustment for gestational age. CONCLUSIONS: Urine biomarkers measured in the first 4 days of life are associated with AKI during the first postnatal weeks. Further evaluations are necessary to determine whether these biomarkers can predict important clinical outcomes. In addition, intervention studies that use biomarkers to stratify enrollment groups are needed before bedside evaluations can be incorporated into care.

Renal Function and Urinary Biomarkers in Cardiac Bypass Surgery: A Prospective Randomized Trial Comparing Three Surgical Techniques.

Background Cardiopulmonary bypass procedure is associated with an increased risk of renal impairment. To which extent structural damage causes functional decline is unknown. We evaluated perioperative kidney injury and function in patients treated with conventional extracorporeal circulation (CECC), minimized extracorporeal circulation (MECC), and off-pump coronary artery bypass grafting (OPCAB). Methods Blood and urine samples, collected at baseline and up to 72 hours after surgery from patients of the HEPCON trial (DRKS00007580, 120 patients randomized for heparin management and for surgical technique), were analyzed for differences in renal injury and function. Neutrophil gelatinase-associated lipocalin, α glutathione S-transferase, liver fatty acid-binding protein, and kidney injury molecule-1 were measured as urinary protein markers of renal tubular injury. Serum creatinine, blood urea levels, and estimated glomerular filtration rate were determined to monitor renal function. Results Markers of tubular injury differed significantly between surgical technique groups early after surgery, indicating the most detrimental effect in CECC. Hemolysis and hemodilution correlated with these early changes. A late rise did not show intergroup differences. Time courses of renal function parameters, as well as the development of acute kidney injury in 15 patients (13.5%), were irrespective of surgical technique. Heparin management did not influence renal parameters. Conclusion During coronary artery bypass grafting, CECC temporarily induces more tubular injury than MECC or OPCAB. However, late changes of renal function parameters occur irrespective of extracorporeal perfusion mode and even in off-pump surgery.

Tubular Injury Biomarkers to Detect Gentamicin-Induced Acute Kidney Injury in the Neonatal Intensive Care Unit.

OBJECTIVE: We evaluated whether urinary excretion of tubular injury markers could be useful for early detection of gentamicin (GM)-induced renal damage in neonates. STUDY DESIGN: We conducted a prospective, observational trial in neonates admitted to the neonatal intensive care unit (26 GM treated, 20 control). Kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), N-acetyl-ß-D-glucosaminidase (NAG), and π- and α-glutathione-S-transferase (GSTP1-1 and GSTA1-1) were measured every 2 hours during admission and compared with serum creatinine (sCr) and urine output. RESULTS: Nine neonates developed AKI during the course of the study. The peak in excretion of urinary biomarkers preceded the peak in sCr (p < 0.0001). GM administration resulted in a more pronounced increase of sCr compared with control (13 [12-28] vs. 10 µmol/L [8.5-17]; p < 0.05). The urinary excretion of NAG (178 [104-698] vs. 32 ng/mol Cr [9-82]; p < 0.001) and NGAL (569 [168-1,681] vs. 222 ng/mol Cr [90-497]; p < 0.05) was higher in the GM group compared with control and preceded the peak of sCr and urine output decrease. CONCLUSION: GM administration to neonates is associated with renal damage reflected by a more pronounced increase in sCr preceded by urinary excretion of biomarkers. Urinary biomarkers may be useful for earlier identification of renal injury in neonates.

A novel protective formulation of Palmitoylethanolamide in experimental model of contrast agent induced nephropathy.

Contrast-induced nephropathy (CIN) is a complication in patients after administration of iodinated contrast media. Several risk factors contribute to the development and progression of CIN, including hypertension, diabetes, and dyslipidemia. Animal models of CIN by surgical intervention to reproduce its clinical and pathology has been developed, and thus, therapeutic methods tested. Palmitoylethanolamide (PEA) is a member of the fatty acid ethanolamine family with analgesic and anti-inflammatory effects. In this study, we analyzed streptozotocin-induced diabetes model and in an another set of experiment a surgical remotion of the kidney with the aim of evaluating effect of ultramicronized Palmitoylethanolamide (PEA-um(®)) on contrast induced renal disfunction and glomerular morphology alteration. In a first step of our study, we demonstrated that PEA-um(®) significantly reduced CIN-mediated glomerular dysfunction, modulates Na(+) and K(+) levels in plasma and decreased urine and plasma NGAL levels and α-GST urine levels. Moreover, in a second set of experiment we investigated how PEA-um(®) reduced creatinine and BUN plasma levels after nephrectomy, ameliorate renal and medullary blood flow and re-established renal parenchymal after CIN induction as well as after nephrectomy. Take together our results demonstrated that PEA-um(®) are able to preventing CIN in diabetic rats and alteration of biochemical parameters after nephrectomy.

A urine-based methylation signature for risk stratification within low-risk prostate cancer.

BACKGROUND: Prostate cancer overdiagnosis and overtreatment represents a major problem. Many men with low-grade disease on biopsy are undergraded and they harbour high-grade disease at prostatectomy with no reliable way to identify these men. We used a novel urine-based 2-gene methylation test to identify prostate cancers with aggressive features. METHODS: Following a proof of concept study in 100 post-radical prostatectomy tissue samples, urine samples were tested from 665 men at multiple U.S. centers undergoing prostate needle biopsy for elevated prostate-specific antigen (2-10 ng ml(-1)). A prediction model was then developed from a combination of clinical factors and the urine-based markers. It was then prospectively tested for accurate prediction of adverse disease (surgical Gleason score ⩾7 and/or a pathological stage ⩾T3a) using urine from a separate cohort of 96 men before radical prostatectomy. RESULTS: Among pre-prostatectomy men with a biopsy Gleason score <7, 41% had adverse disease of which 100% were correctly identified by the test with a negative predictive value of 100% (95% confidence interval, 86-100%). CONCLUSIONS: This urine-based test accurately identifies men with clinical low-risk disease who do not have adverse pathology in their prostates and would be excellent candidates for active surveillance.

Combination of biomarkers for diagnosis of acute kidney injury after cardiopulmonary bypass.

Novel acute kidney injury (AKI) biomarkers offer promise of earlier diagnosis and risk stratification, but have yet to find widespread clinical application. We measured urinary α and π glutathione S-transferases (α-GST and π-GST), urinary l-type fatty acid-binding protein (l-FABP), urinary neutrophil gelatinase-associated lipocalin (NGAL), urinary hepcidin and serum cystatin c (CysC) before surgery, post-operatively and at 24 h after surgery in 93 high risk patient undergoing cardiopulmonary bypass (CPB) and assessed the ability of these biomarkers alone and in combination to predict RIFLE-R defined AKI in the first 5 post-operative days. Twenty-five patients developed AKI. π-GST (ROCAUC = 0.75), lower urine Hepcidin:Creatine ratio at 24 h (0.77), greater urine NGAL:Cr ratio post-op (0.73) and greater serum CysC at 24 h (0.72) best predicted AKI. Linear combinations with significant improvement in AUC were: Hepcidin:Cr 24 h + post-operative π-GST (AUC = 0.86, p = 0.01), Hepcidin:Cr 24 h + NGAL:Cr post-op (0.84, p = 0.03) and CysC 24 h + post-operative π-GST (0.83, p = 0.03), notably these significant biomarkers combinations all involved a tubular injury and a glomerular filtration biomarker. Despite statistical significance in receiver-operator characteristic (ROC) analysis, when assessed by ability to define patients to two groups at high and low risk of AKI, combinations failed to significantly improve classification of risk compared to the best single biomarkers. In an alternative approach using Classification and Regression Tree (CART) analysis a model involving NGAL:Cr measurement post-op followed by Hepcidin:Cr at 24 h was developed which identified high, intermediate and low risk groups for AKI. Regression tree analysis has the potential produce models with greater clinical utility than single combined scores.

Metabolic polymorphisms and biomarkers of effect in the biomonitoring of occupational exposure to low-levels of benzene: state of the art.

Current levels of occupational exposure to benzene, a genotoxic human carcinogen, in Western countries are reduced by two-three orders of magnitude (from ppm to ppb) as compared to the past. However, as benzene toxicity is strongly dependent on biotransformation and recent evidence underlines a higher efficiency of bio-activation pathways at lower levels of exposure, toxic effects at low doses could be higher than expected, particularly in susceptible individuals. Currently, biological monitoring can allow accurate exposure assessment, relying on sensitive and specific enough biomarkers of internal dose. The availability of similarly reliable biomarkers of early effect or susceptibility could greatly improve the risk assessment process to such an extent that risk could even be assessed at the individual level. As to susceptibility biomarkers, functional genetic polymorphisms of relevant biotransformation enzymes may modulate the risk of adverse effects (NQO1) and the levels of biomarkers of internal dose, in particular S-phenylmercapturic acid (GSTM1, GSTT1, GSTA1). Among biomarkers of early effect, genotoxicity indicators, although sensitive in some cases, are too aspecific for routine use in occupational health surveillance programmes. Currently only the periodical blood cell count seems suitable enough to be applied in the longitudinal monitoring of effects from benzene exposure. Novel biomarkers of early effect are expected from higher collaboration among toxicologists and clinicians, also using advanced "omics" techniques.

Age-related differences in kidney injury biomarkers induced by cisplatin.

Acute kidney injury (AKI) occurs in a half of cisplatin (CDDP)-treated patients. Traditional biomarkers including blood urea nitrogen (BUN) and serum creatinine (SCr) are still used for detection of CDDP-induced AKI, but these biomarkers are not specific or sensitive. The aim of this study was to identify the specific and sensitive biomarkers against CDDP-induced renal injury between young (3-week-old) and old (20-week-old) rats. All animals were intraperitoneally injected once with CDDP (6 mg/kg). After 3 days, all animals were sacrificed and serum, urine, and kidney tissues were collected. Urinary and serum biomarkers as well as histological changes were measured. CDDP-induced proximal tubular damage was apparent from histopathological examination, being more severe in 3-week-old rats accompanied by increased number of TUNEL-positive apoptotic cells. This was associated with elevated urinary kidney injury molecule-1 (KIM-1), glutathione-S-transferase alpha (GST-α), vascular endothelial growth factor (VEGF), and tissue inhibitor of metalloproteinases-1 (TIMP-1). In contrast, the levels of neutrophil gelatinase-associated lipocalin (NGAL) and osteopontin were significantly increased in 20-week-old rats after CDDP treatment. These results indicate that the use of age-specific urinary biomarkers is necessary to diagnosis of CDDP-induced AKI. Especially, urinary KIM-1, GST-α, TIMP-1, and VEGF levels may help in the early diagnosis of young patients with CDDP-induced AKI.

Time of injury affects urinary biomarker predictive values for acute kidney injury in critically ill, non-septic patients.

BACKGROUND: The predictive value of acute kidney injury (AKI) urinary biomarkers may depend on the time interval following tubular injury, thereby explaining in part the heterogeneous performance of these markers that has been reported in the literature. We studied the influence of timing on the predictive values of tubular proteins, measured before the rise of serum creatinine (SCr) in critically ill, non-septic patients. METHODS: Seven hundred adult critically ill patients were prospectively included for urine measurements at four time-points prior to the rise in serum creatinine (T = 0, -16, -20 and -24 h). Patients with sepsis and or AKI at ICU entry were excluded. The urinary excretion of the proteins, neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1), which are up-regulated in the distal and proximal tubules, respectively, were measured as well as the constitutive cytoplasmatic enzymes, π- and α-glutathione-S-transferase (GST), which are released by the distal and proximal tubules, respectively. RESULTS: Five hundred and forty-three subjects were eligible for further analyses; however, 49 developed AKI in the first 48 h. Both NGAL (P = 0.001 at T = -24 vs. non-AKI patients) and KIM-1 (P < 0.0001 at T = 0 vs. non-AKI patients) concentrations gradually increased until AKI diagnosis, whereas π- and α-GST peaked at T = -24 before AKI (P = 0.006 and P = 0.002, respectively vs. non-AKI patients) and showed a rapid decline afterwards. The predictive values at T = -24 prior to AKI were modest for π- and α-GST, whereas NGAL sufficiently predicted AKI at T = -24 and its predictive power improved as the time interval to AKI presentation decreased (area under the receiver operating characteristic curve; AUC = 0.79, P < 0.0001). KIM-1 was a good discriminator at T = 0 only (AUC = 0.73, P < 0.0001). CONCLUSIONS: NGAL, KIM-1, pi- and alpha-GST displayed unique and mutually incomparable time dependent characteristics during the development of non-sepsis related AKI. Therefore, the time-relationship between the biomarker measurements and the injurious event influences the individual test results.

Urinary α- and π-glutathione s-transferases for early detection of acute kidney injury following cardiopulmonary bypass.

CONTEXT: Urinary α-GST and π-GST are renal tubular leakage markers. OBJECTIVE: To evaluate the performance characteristics of these markers for the early detection of acute kidney injury (AKI). MATERIALS AND METHODS: Multicenter prospective cohort study of 252 adults undergoing cardiopulmonary bypass (CPB). RESULTS: AKI developed in 72 patients. The 2 h post-CPB π-GST level modestly predicted the development of AKI, including higher stages of severity, whereas α-GST did not. DISCUSSION: Small number of events and absence of subsequent post-operative biomarker measurements. CONCLUSIONS: Among adults undergoing CPB, urinary π-GST outperformed α-GST for predicting AKI, but neither marker displayed good discrimination.

Renal function and arterial blood pressure alterations after exposure to acetaminophen with a potential role of Nigella sativa oil in adult male rats.

Hepatic injury by acetaminophen (APAP) has been extensively studied, although the alterations of renal functions and arterial blood pressure (ABP) after APAP exposure are still uncertain, and the impact of Nigella sativa oil (NSO) in this case is poorly defined. Sixty adult male albino rats were involved in two sets of experiments. The first was exposed to a single high dose of APAP (2.5 g/kg) orally preceded by 4 ml NSO/kg orally, while the second received 750 mg APAP/kg/day orally for seven consecutive days and was pretreated with 2 ml NSO/kg/day. Proximal tubular injury was assessed by laboratory and histological studies, and arterial blood pressure was recorded in all animals. In both experiments, urinary α-glutathione S-transferase and neutral endopeptidase, and microproteinuria were dramatically increased early indicating glomerulus and proximal tubule dysfunction that was mediated by raising 8-isoprostanes. Concomitantly, urinary albumin, total protein, creatinine, urea, glomerular filtration rate, Na and K levels, plasma creatinine, and urea were all changed significantly after APAP administration. Currently, ABP increased significantly after APAP which was mostly mediated by renal impairment and increased both renin activity and aldosterone secretion. Pretreatment with NSO produced significant normalization of physiological parameters as well as suppression of structural changes. In conclusion, measurement of urinary biomarkers can be considered a powerful tool for early screening of renal injury and alteration of ABP after APAP treatment. Concomitant administration of NSO can counterbalance these detrimental effects.

Deceased-donor kidney perfusate and urine biomarkers for kidney allograft outcomes: a systematic review.

BACKGROUND: Accurate and reliable assessment of kidney quality before transplantation is needed to predict recipient outcomes and to optimize management and allocation of the allograft. The aim of this study was to systematically review the published literature on biomarkers in two mediums (the perfusate from deceased-donor kidneys receiving machine perfusion and deceased-donor urine) that were evaluated for their possible association with outcomes after kidney transplantation. METHODS: We searched the Ovid Medline and Scopus databases using broad keywords related to deceased-donor biomarkers in kidney transplantation (limited to humans and the English language). Studies were included if they involved deceased-donor kidneys, measured perfusate or urine biomarkers and studied a possible relationship between biomarker concentrations and kidney allograft outcomes. Each included article was assessed for methodological quality. RESULTS: Of 1430 abstracts screened, 29 studies met the inclusion criteria. Of these, 23 were studies of perfusate (16 biomarkers examined) and 6 were studies of urine (18 biomarkers examined). Only 3 studies (two perfusate) met the criteria of 'good' quality and only 12 were published since 2000. Perfusate lactate dehydrogenase, glutathione-S-transferase (GST) and aspartate transaminase were all found to be significantly associated with delayed graft function in a majority of their respective studies (6/9, 4/6 and 2/2 studies, respectively). Urine neutrophil gelatinase-associated lipocalin, GST, Trolox-equivalent antioxidant capacity and kidney injury molecule-1 were found to be significantly associated with allograft outcomes in single studies that examined diverse end points. CONCLUSION: Higher quality studies are needed to investigate modern kidney injury biomarkers, to validate novel biomarkers in larger donor populations and to determine the incremental predictive value of biomarkers over traditional clinical variables.

Urine α-Glutathione S-transferase, systemic inflammation and arterial function in juvenile type 1 diabetes.

BACKGROUND: Despite marked improvement in therapy and monitoring of patients with insulin-dependent (type 1) diabetes, diabetic nephropathy remains a serious complication, with subsequent end-stage renal disease in about 20% of cases. OBJECTIVE: To investigate in young patients with type 1 diabetes whether urine α-Glutathione S-transferase to creatinine ratio (α-GST:crea) relates to markers of systemic inflammation and subclinical vasculopathy. DESIGN: Children and adolescents (median age and diabetes duration 14 and 6 years, respectively) with type 1 diabetes screened in a previous study for proximal tubular (urine α-GST:crea ratio) and renal (plasma creatinine, cystatin C glomerular filtration rate (GFR), and timed urine albumin excretion rate (AER)) function were, within the same timeframe, also investigated for vascular (blood pressure, carotid artery intima-media thickness (IMT) and compliance (CAC), brachial artery flow-mediated dilatation (FMD) and plasma cyclic guanosine monophosphate (cGMP) and inflammatory (C-reactive protein (CRP), and tumor necrosis factor-alpha (TNF-α)) profiles. Exposure to environmental tobacco smoke (ETS) was assessed through questionnaire (n=67 respondents). RESULTS: None of the patients (n=69) had overt renal insufficiency. AER correlated with age (p=0.01, r=0.3), diabetes duration (p=0.02, r=0.3), FMD (p=0.04, r=-0.3, n=52), CAC (p=0.03, r=-0.3, n=62) and cGMP (p=0.01, r=-0.3, n=59). α-GST:crea was lower (p=0.03) in patients than in controls. α-GST:crea appeared to be particularly lower in older patients (p=0.004, r=-0.34 vs age), in those with worse diabetic control (p=0.03, r=-0.26 vs HbA1c), and in those with lower carotid artery elasticity (p=0.017, r=0.3 vs CAC). Although ETS had no direct significant impact on α-GST:crea, α-GST:crea correlated with FMD only in patients with ETS (r=0.5, p=0.009, n=13). α-GST:crea showed positive association with TNF-α (p=0.01, r=0.3). CONCLUSION: In children and adolescents with type 1 diabetes, lower levels of urine excretion of α-GST:crea appear to be associated with decreasing elasticity and endothelial vasomotor function of peripheral arteries, especially in patients with ETS. In contrast, higher levels of α-GST:crea are more common in patients with elevated markers of systemic inflammation. Large scale prospective studies are needed to clarify the meaning and mechanisms of this association.

Protective effect of apocynin, a NADPH-oxidase inhibitor, against contrast-induced nephropathy in the diabetic rats: a comparison with n-acetylcysteine.

The aim of this study was to investigate the effects of apocynin, a NADPH (nicotinamide adenine dinucleotide phosphate)-oxidase inhibitor, in diabetic rats with nephropathy induced by contrast medium (CIN). Diabetes was induced in male Wistar rats by a single dose of streptozotocin (60 mg/kg i.v.). Animals were then divided into the following groups: 1) control group (diabetic rats treated i.v. with saline solution); 2) iomeprol group (iomeprol at 10 ml/kg was injected i.v. 30 min after saline administration); 3) apocynin group (identical to the iomeprol group, except for pre-treatment with apocynin 5mg/kg i.v., 30 min before iomeprol injection) and 4) N-acetylcysteine group (NAC) (same as iomeprol group, except for the treatment with NAC 20 mg/kg i.v. 30 min before iomeprol injection). CIN in animals were assessed 24h after administration of iomeprol. Apocynin significantly attenuates the impaired glomerular function, concentration of Na(+), K(+), alpha glutathione S-transferase levels in urine and neutrophil gelatinase-associated lipocalin levels in plasma caused by iomeprol. In kidney, immunohistochemical analysis of some inflammatory mediators, such as nitrotyrosine, poly-ADP-ribosyl polymerase, tumor necrosis factor-α, interleukin-1ß as well as apoptosis (evaluated as terminal deoxynucleotidyltransferase-mediated UTP end labeling assay) revealed positive staining in tissue obtained from iomeprol group. These parameters were markedly reduced in animals treated with apocynin. Similarly, these parameters were also markedly modified by NAC pre-treatment. Here, we have shown that apocynin attenuates the degree of iomeprol-induced nephropathy in diabetic rats.

Nephrotoxicity of hexachloro-1:3-butadiene in the male Hanover Wistar rat; correlation of minimal histopathological changes with biomarkers of renal injury.

Hexachloro-1:3-butadiene (HCBD) causes damage specifically to the renal proximal tubule in rats. In the present study, injury to the nephron of male Hanover Wistar rats was characterized at 24 h following dosing with HCBD in the range 5-90 mg kg⁻¹ to determine the most sensitive biomarkers of damage, that is, the biomarkers demonstrating significant changes at the lowest dose of HCBD, using a range of measurements in serum and urine, renal histopathology, and renal and hepatic gene expression. Histologically, kidney degeneration was noted at doses as low as 10 mg kg⁻¹ HCBD. Significant changes in the hepatic and renal gene expression categories of xenobiotic metabolism and oxidative stress were observed at 5 mg kg⁻¹ HCBD, and in the kidney alone, evidence of inflammation at 90 mg kg⁻¹ HCBD. Increases in the urinary excretion of α-glutathione S-transferase (α-GST) and kidney injury molecule-1 (KIM-1) were seen at 10 mg kg⁻¹ HCBD, and increases in urinary excretion of albumin and total protein were evident at 15 mg kg⁻¹ HCBD. The most sensitive, noninvasive biomarkers of HCBD-induced renal toxicity in Hanover Wistar rats were urinary α-GST and KIM-1. Urinary albumin measurement is also recommended as, although it is not the most sensitive biomarker, together with α-GST, albumin showed the largest relative increase of all the biomarkers investigated, and the protein is easily measured.

Dipyridamole augments the antiinflammatory response during human endotoxemia.

INTRODUCTION: In animal models of systemic inflammation, the endogenous nucleoside adenosine controls inflammation and prevents organ injury. Dipyridamole blocks the cellular uptake of endogenous adenosine and increases the extracellular adenosine concentration. We studied the effects of oral dipyridamole treatment on innate immunity and organ injury during human experimental endotoxemia. METHODS: In a randomized double-blind placebo-controlled study, 20 healthy male subjects received 2 ng/kg Escherichia coli endotoxin (lipopolysaccharide; LPS) intravenously after 7-day pretreatment with dipyridamole, 200 mg slow release twice daily, or placebo. RESULTS: Nucleoside transporter activity on circulating erythrocytes was reduced by dipyridamole with 89% ± 2% (P < 0.0001), and the circulating endogenous adenosine concentration was increased. Treatment with dipyridamole augmented the LPS-induced increase in the antiinflammatory cytokine interleukin (IL)-10 with 274%, and resulted in a more rapid decrease in proinflammatory cytokines tumor necrosis factor-α (TNF-α) and IL-6 levels directly after their peak level (P < 0.05 and < 0.01, respectively). A strong correlation was found between the plasma dipyridamole concentration and the adenosine concentration (r = 0.82; P < 0.01), and between the adenosine concentration and the IL-10 concentration (r = 0.88; P < 0.0001), and the subsequent decrease in TNF-α (r = -0.54; P = 0.02). Dipyridamole treatment did not affect the LPS-induced endothelial dysfunction or renal injury during experimental endotoxemia. CONCLUSIONS: Seven-day oral treatment with dipyridamole increases the circulating adenosine concentration and augments the antiinflammatory response during experimental human endotoxemia, which is associated with a faster decline in proinflammatory cytokines. TRIAL REGISTRATION: ClinicalTrials (NCT): NCT01091571.

Urinary glutathione S-transferases in the pathogenesis and diagnostic evaluation of acute kidney injury following cardiac surgery: a critical review.

PURPOSE OF REVIEW: A focused review of the nature, source, physiological role and rapidly expanding evidence for glutathione S-transferase (GST) subtypes π and α as biomarkers of acute kidney injury (AKI) in patients undergoing cardiac surgery. Expanded insights into the site-specific expression of the GSTs in defined parts of the nephron during renal damage are presented, with particular emphasis on the pathogenesis of cardiac surgery and cardiopulmonary bypass (CPB)-associated AKI and the role of GSTs in oxygen radical disposal. RECENT FINDINGS: Recent developments have highlighted a potential role of urinary α-GST and π-GST in the diagnostic evaluation of cardiac surgery-associated AKI. Both urinary α-GST and π-GST are detected in the postoperative period. π-GST performed best at predicting AKI severity at the time of the initial diagnosis of AKI. α-GST was able to predict the future development of both stage 1 and stage 3 AKI. SUMMARY: The current data from a small number of patients suggest a potential role of urinary GSTs in the clinical diagnostic evaluation of AKI following cardiac surgery. The performance of the GSTs for the early diagnosis of AKI needs to be validated in larger multicentre studies and in other patient populations at increased risk of AKI (e.g. patients with acute transplant rejection, septic patients). Comparison with other emerging AKI biomarkers is required to continue the development of π-GST and α-GST. Finally, additional studies examining the pathophysiological role of the GSTs in minimizing oxygen free radical exposure in the renal tubules during CPB may shed further light into their role as promising biomarkers of cardiac surgery-associated AKI.