Efficacy and tolerability of magnesium plus protein for managing hypomagnesemia in pediatric kidney transplant patients.

We sought to investigate whether magnesium oxide bound to soy protein (MGP) increases serum magnesium concentrations with less diarrhea compared to commonly prescribed magnesium salts. Subjects were switched to MGP at a near-equivalent daily elemental magnesium dose. Mean serum magnesium levels were compared.

Immunogenicity of Augmented Compared With Standard Dose Hepatitis B Vaccine in Pediatric Patients on Dialysis: a Midwest Pediatric Nephrology Consortium Study.

Background And Objectives: Patients on maintenance dialysis have a higher risk of unresponsiveness to hepatitis B vaccination and loss of hepatitis B immunity. Adult guidelines recommend augmented dosing (40 mcg/dose), resulting in improved response in adults. We sought to determine whether children on dialysis mount a similar antibody response when given standard or augmented dosing of hepatitis B vaccine.

Renal transplantation in Bardet-Biedl Syndrome.

Background: Renal anomalies are common in patients with Bardet-Biedl syndrome (BBS), a renal cystic ciliopathy with multi-systemic features. Renal transplantation is indicated in cases of end-stage renal disease (ESRD), but transplant centers may be hesitant to perform the necessary transplant in light of the multitude of metabolic comorbidities these patients often face with the potential to complicate outcomes.

Methods: Data from the Clinical Registry Investigating BBS (CRIBBS) were used to investigate renal transplant outcomes in the largest BBS cohort described to date.

Applicability of the Schwartz Equation and the Chronic Kidney Disease in Children Bedside Equation for Estimating Glomerular Filtration Rate in Overweight Children.

Study Objective: To determine if significant correlations exist between glomerular filtration rate (GFR) prediction equation values, derived by using the original Schwartz equation and the Chronic Kidney Disease in Children (CKiD) bedside equation with a 24-hour urine creatinine clearance (Clcr ) value normalized to a body surface area of 1.73 m(2) in overweight and obese children.

Design: Prospective analysis (20 patients) and retrospective analysis (43 patients).

Comparison of cystatin C and Beta-2-microglobulin kinetics in children on maintenance hemodialysis.

Middle-molecules (MM) are not monitored in children on hemodialysis (HD), but are accumulated and increase the risk of cardiovascular disease and mortality. Molecular properties of Cystatin C (CyC), 13 kDa, potentially make it a preferred MM marker over Beta-2-Microglobulin (B2M), 12 kDa. We compared CyC and B2M kinetics to investigate if CyC can be used as preferred MM marker.

Cystatin C in children on chronic hemodialysis.

Background: Cystatin C (CyC) concentration has been suggested as a marker of middle-molecule accumulation, hemodialysis (HD) adequacy and for estimating residual renal function (RRF), but it has not been studied in pediatric HD. High CyC is associated with increased cardiovascular disease (CVD). We investigated CyC kinetics and the effect of RRF on CyC in a pediatric HD population.

Association between common iron store markers and hemoglobin in children with chronic kidney disease.

Background: Serum ferritin and transferrin saturation (TSAT) are used to assess iron status in children with chronic kidney disease (CKD), but their sensitivity in identifying those at risk of lower hemoglobin (HGB) values is unclear.

Methods: We assessed the association of iron status markers (ferritin, TSAT, and serum iron) with age- and gender-related HGB percentile in mild-to-moderate CKD in 304 children in the Chronic Kidney Disease in Children (CKiD) Study. Standardized HGB percentile values were examined by KDOQI-recommended ferritin (≥ 100 ng/ml) and TSAT (≥ 20 %) thresholds.

Transforming growth factor-β inhibits cystogenesis in human autosomal dominant polycystic kidney epithelial cells.

Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited cause of kidney failure and characterized by the formation of multiple fluid-filled cysts in the kidneys. It is believed that environmental factors may play an important role in the disease progression. However, the molecular identity of autocrine/paracrine factors influencing cyst formation is largely unknown.

Prostaglandin E2 stimulates cystogenesis through EP4 receptor in IMCD-3 cells.

Previously, we demonstrated that prostaglandin E(2) (PGE(2)) induced cAMP and cyst formation through PGE(2) receptor-2 (EP2) activity in human autosomal-dominant polycystic kidney disease (ADPKD) epithelial cells. In this study, we determined the role of EP2 and EP4 receptors in mediating PGE(2) stimulation of cAMP signaling and cystogenesis in mouse renal epithelial cells using the inner medullary collecting duct-3 (IMCD-3) cell line. In contrast to human ADPKD cells, using novel EP2 and EP4 antagonists, we found that IMCD-3 cells expressed functional EP4 but not EP2, which stimulated cAMP formation and led to cyst formation in 3D culture system.

Arteriovenous fistulas for hemodialysis access in children and adolescents using the proximal radial artery inflow site.

Introduction: Hemodialysis (HD) for children and adolescents with renal failure is increasingly common in the United States. Consensus opinion views an arteriovenous fistula (AVF) as the best long-term access option, although catheter-based HD remains the most common vascular access in children and has greater risks of complications and higher mortality rates than AVF access. This report reviews our experience with children and adolescents undergoing vascular access operations.

Use of conivaptan to allow aggressive hydration to prevent tumor lysis syndrome in a pediatric patient with large-cell lymphoma and SIADH.

The available treatment options for hyponatremia secondary to SIADH are limited and not completely effective. Conivaptan is a vasopressin 1a and 2 receptor antagonist recently approved by the US Food and Drug Administration (FDA) for treating euvolemic and hypervolemic hyponatremia in adult patients. However, data on efficacy and safety of conivaptan in pediatrics are limited.

MKL1 mediates TGF-beta1-induced alpha-smooth muscle actin expression in human renal epithelial cells.

Transforming growth factor-beta1 (TGF-beta1) is known to induce epithelial-mesenchymal transition in the kidney, a process involved in tubulointerstitial fibrosis. We hypothesized that a coactivator of the serum response factor (SRF), megakaryoblastic leukemia factor-1 (MKL1), stimulates alpha-smooth muscle actin (alpha-SMA) transcription in primary cultures of renal tubular epithelial cells (RTC), which convert into myofibroblasts on treatment with TGF-beta1. Herein, we study the effect of MKL1 expression on alpha-SMA in these cells.

Plasticity of epithelial cells derived from human normal and ADPKD kidneys in primary cultures.

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by cyst formation initiated by dedifferentiation and proliferation of renal tubular epithelial cells. Renal tubular epithelial cells (RTC, derived from normal kidney tissue) in primary cultures exhibit both homogeneous expression of gamma-glutamyl transferase and low molecular weight cytokeratin, two different markers for proximal and distal renal epithelial cells, respectively. RTC in cultures also abnormally express the dedifferentiation markers vimentin and PAX-2, which are proteins normally expressed in epithelial cells lining cysts in ADPKD kidneys but not tubular cells in normal kidneys.

EP2 receptor mediates PGE2-induced cystogenesis of human renal epithelial cells.

Autosomal-dominant polycystic kidney disease (ADPKD) is characterized by formation of cysts from tubular epithelial cells. Previous studies indicate that secretion of prostaglandin E2 (PGE2) into cyst fluid and production of cAMP underlie cyst expansion. However, the mechanism by which PGE2 directly stimulates cAMP formation and modulates cystogenesis is still unclear, because the particular E-prostanoid (EP) receptor mediating the PGE2 effect has not been characterized.

Limitations of commonly used internal controls for real-time RT-PCR analysis of renal epithelial-mesenchymal cell transition.

Background/aims: Progressive renal fibrotic disease is accompanied by the massive accumulation of myofibroblasts as defined by alpha smooth muscle actin (alphaSMA) expression. We quantitated gene expression using real-time RT-PCR analysis during conversion of primary cultured human renal tubular cells (RTC) to myofibroblasts after treatment with transforming growth factor-beta1 (TGF-beta1). We report herein the limitations of commonly used reference genes for mRNA quantitation.

Proteinuric nephropathy in acquired and congenital generalized lipodystrophy: baseline characteristics and course during recombinant leptin therapy.

Generalized lipodystrophy is characterized by adipose tissue absence, hypoleptinemia, hypertriglyceridemia, insulin resistance, diabetes, hepatomegaly, and nonalcoholic steatohepatitis. In the course of recruiting patients for treatment with recombinant leptin, we were struck by the frequency and severity of proteinuria. We evaluated 25 patients with generalized lipodystrophy.