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Shiga toxin-producing Escherichia coli-associated haemolytic uraemic syndrome (STEC-HUS) is one of the most important causes of acute kidney injury in patients of all ages, especially in children. It can occur sporadically or in outbreaks. STEC-HUS is a systemic illness caused by toxin-mediated injury to the vascular endothelium and a generalized inflammatory response. The kidney and the brain are the two primary target organs. Nearly 40% of patients with STEC-HUS require at least temporary renal replacement therapy and up to 20% will have permanent residual kidney dysfunction. Neurological injury can be sudden and severe and is the most frequent cause of acute mortality in patients with STEC-HUS. Over the past 30 years, a wide range of inflammatory mediators have been linked to the pathogenesis of STEC-HUS and associated renal and neurological complications. Recently, evidence has accumulated that abnormal activation of the alternative pathway of complement occurs in patients with STEC-HUS. In the large outbreak of STEC-HUS caused by E. coli O104:H4 that occurred in Germany in May 2011, a large number of patients received eculizumab, a monoclonal antibody directed against C5, in an open-label manner. We describe the experience with eculizumab under these emergent circumstances at one large centre. [ABSTRACT FROM AUTHOR]

Nitric oxide (NO) is a multifunctional mediator that has been implicated in the short-term hemodynamic alterations that occur in acute streptozocin (STZ)-induced diabetes. We investigated the role of NO produced by inducible nitric oxide synthase (iNOS) in chronic STZ diabetic nephropathy. Diabetes was induced in C57BL/6 and iNOS knockout (KO) mice with two intraperitoneal injections of STZ, 100 mg/kg. Animals were maintained without insulin treatment for 40 weeks. There were no significant differences between the strains in blood urea nitrogen (BUN), serum creatinine or glucose concentration, or urinary protein excretion during the entire observation period. Urinary nitrite + nitrate excretion was significantly lower in iNOS KO mice compared to control animals at all time points; in C57 mice, urinary nitrite declined progressively with more prolonged duration of diabetes. Renal hypertrophy (kidney weight/body weight) was noted in both strains of mice. However, histopathological assessment of renal tissue specimens at 16 and 40 weeks demonstrated increased mesangial hypercellularity and expansion as well as more prominent tubulointerstitial fibrosis in iNOS KO versus C57 mice. These changes were accompanied by increased interstitial deposition of type I collagen at 16 and 40 weeks in iNOS KO mice. Glomerular basement membrane staining for type IV collagen was also increased at 40 weeks in diabetic iNOS KO mice. While iNOS protein was undetectable in any of the kidney specimens obtained from either strain, eNOS was present throughout the course of chronic STZ diabetes. Moreover, eNOS expression was significantly increased by approximately 40% at 16 and 40 weeks of observation in iNOS KO versus C57 mice. There was no difference in renal cortical malondialdehyde content between the strains early or late in the disease course. In time control animals, there was no evidence of renal histopathological damage in iNOS KO or C57 mice after 40 weeks. We conclude tha... [ABSTRACT FROM AUTHOR]

Technological improvements have reduced the frequency of complications in children receiving a percutaneous renal biopsy. No study has systematically compared the safety of open and percutaneous kidney biopsy. Yet many nephrologists consider a single native kidney an absolute contraindication to percutaneous biopsy. We have established an international registry of single native kidney biopsies in children and we now report our early results. Eight biopsies are included. Seven patients had percutaneous biopsies and one an open biopsy. None of the patients had major complications, and adequate tissue was obtained from all. Our limited experience indicates that the presence of a single native kidney is not an absolute indication for an open approach. We encourage our colleagues to report to the international registry in order to further document the safety of percutaneous biopsy of the single native kidney in children. [ABSTRACT FROM AUTHOR]

Background. We aimed to examine both whether vitamin E prevented and whether it reversed the growth inhibitory effect of high glucose. Methods. For the preventive experiment, rat mesangial cells (RMC) were grown in control glucose medium with the addition of 100 μM of vitamin E. High glucose (27.5 mM) was added to the medium concurrent with the vitamin E addition. The 3-(4,5-di-methylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) assay was used to measure RMC proliferation. Our data confirmed the growth inhibitory effect of high glucose and showed that the growth inhibition was prevented by vitamin E. To examine whether vitamin E reversed the growth inhibitory effects of high glucose, RMC were grown in control and high glucose medium. Contrary to previous prevention type studies, vitamin E was not added to the medium until growth inhibition of the RMC by the high glucose was established. Results. Our data show that it took 5 days of vitamin E administration to reverse the growth inhibitory effect of high glucose. Conclusion. This is the first time that vitamin E has been shown to reverse this high-glucose-induced inhibition of RMC, suggesting that vitamin E reverses a potentially important pathogenetic process. [ABSTRACT FROM AUTHOR]

Taurine is an abundant free amino acid in the plasma and cytosol. The kidney plays a pivotal role in maintaining taurine balance. Immunohistochemical studies reveal a unique localization pattern of the amino acid along the nephron. Taurine acts as an antioxidant in a variety of in vitro and in vivo systems. It prevents lipid peroxidation of glomerular mesangial cells and renal tubular epithelial cells exposed to high glucose or hypoxic culture conditions. Dietary taurine supplementation ameliorates experimental renal disease including models of refractory nephrotic syndrome and diabetic nephropathy. The beneficial effects of taurine are mediated by its antioxidant action. It does not attenuate ischemic or nephrotoxic acute renal failure or chronic renal failure due to sub-total ablation of kidney mass. Additional work is required to fully explain the scope and mechanism of action of taurine as a renoprotective agent in experimental kidney disease. Clinical trials are warranted to determine the usefulness of this amino acid as an adjunctive treatment of progressive glomerular disease and diabetic nephropathy. [ABSTRACT FROM AUTHOR]

A 17-year-old male with neurofibromatosis presented with severe hypertension secondary to an abdominal aortic coarctation and bilateral renal artery stenoses. Despite previous surgical bypass grafts and aggressive medical management, including treatment with diuretics, beta-blocker, calcium channel blocker, angiotensin converting enzyme (ACE) inhibitors, and direct vasodilator agents, severe hypertension persisted. Following intravascular stent placement in the aorta and both renal arteries, blood pressures normalized. [ABSTRACT FROM AUTHOR]

We describe a patient with signs and symptoms of classic Bartter syndrome. The patient tested negative for all known genetic abnormalities associated with this tubular disorder. Proteinuria was found within 1 year after the diagnosis of Bartter syndrome. A renal biopsy performed 6 months later, when her kidney function was normal, revealed focal segmental glomerulosclerosis (FSGS). We propose a link between stimulation of the renin-angiotensin system and sclerotic changes in the glomerulus. This lesion may explain previous reports of kidney failure in patients with Bartter syndrome. [ABSTRACT FROM AUTHOR]

A captopril challenge test (CCT) for renovascular disease in adults was described recently. We used it in 20 consecutive, untreated hypertensive children and adolescents. All had a normal urinalysis and glomerular filtration rate and non-diagnostic renal sonograms or intravenous urograms. Plasma renin activity (PRA) was measured before and 1 h after administration of captopril (0.76±0.17 mg/kg). The CCT was positive in 10 patients. Renal arteriograms were performed in 7 patients with a positive CCT and in 2 with a negative CCT. Renovascular disease was found in 4 patients, 1 of whom had a negative CCT. The PRA response to captopril was the same in patients with true- and the false-positive tests. The predictive value of the positive test was 43%. In conclusion, we did not find the CCT, as described for adults, to be of value in children and adolescents. [ABSTRACT FROM AUTHOR]

Discusses a reported case of a 19-month-old infant with mild acute glomerolunephritis, with a stool culture positive for a shigatoxin-producing strain of Escherichia coli. Difficulty of considering a diagnosis of paucisymptomatic hemolytic urmic syndrome (HUS) in the absence of a prodromal phase with diarrhea; Difficulty of considering a diagnosis of HUS without its three diagnostic features.