Sulfate: a neglected (but potentially highly relevant) anion.

Sulfate is an important anion as sulfonation is essential in modulation of several compounds, such as exogens, polysaccharide chains of proteoglycans, cholesterol or cholesterol derivatives and tyrosine residues of several proteins. Sulfonation requires the presence of both the sulfate donor 3'-phosphoadenosine-5'-phosphosulfate (PAPS) and a sulfotransferase. Genetic disorders affecting sulfonation, associated with skeletal abnormalities, impaired neurological development and endocrinopathies, demonstrate the importance of sulfate.

Assessment of Kidney Function in Children.

A good understanding of kidney function tests is essential for patient care. Urinalysis is the commonest used test for screening purposes in ambulatory settings. Glomerular function is assessed further by urine protein excretion and estimated glomerular filtration rate and tubular function by various tests such as urine anion gap and excretion of sodium, calcium, and phosphate.

Carboplatin Dosing in Children Using Estimated Glomerular Filtration Rate: Equation Matters.

Renal function-based carboplatin dosing using measured glomerular filtration rate (GFR) results in more consistent drug exposure than anthropometric dosing. We aimed to validate the Newell dosing equation using estimated GFR (eGFR) and study which equation most accurately predicts carboplatin clearance in children with retinoblastoma. In 13 children with retinoblastoma 38 carboplatin clearance values were obtained from individual fits using MWPharm++.

Concordance between creatinine- and cystatin C-based eGFR in clinical practice.

The mean of GFR-estimates based on serum creatinine (eGFR) and cystatin C (eGFR) has superior accuracy than each estimate alone. Recent studies have shown that agreement between eGFR and eGFR is an indicator for the accuracy of the mean of the two estimates. As long as the difference between the two (|ΔeGFR|) is below 40%, a high P accuracy rate of more than 90% was documented in research settings using gold-standard GFR measurements.

Evidence for shrunken pore syndrome in children.

The link between cystatin C and mortality independent of glomerular filtration rate (GFR) in adults has prompted the "Shrunken Pore Syndrome" (SPS) hypothesis, where high serum cystatin C with normal creatinine is explained by smaller glomerular pores, through which creatinine can pass freely, while the larger cystatin C, beta-trace protein (BTP) and pro-inflammatory molecules are retained. This study set out to apply the definition of SPS to children. In 294 children who underwent inulin clearance (Cin) test, serum creatinine, cystatin C and BTP were measured.

Estimation of GFR in children using rescaled beta-trace protein.

Introduction: Beta-trace protein (BTP) is a low molecular weight protein, produced mainly in the cerebrospinal fluid. It has been proposed as a marker for kidney function. Recently, a new method for GFR estimation using mean normal values to rescale GFR marker concentrations has been described for creatinine and cystatin C, two commonly used endogenous markers for kidney function.

GFR-estimation by serum creatinine during glucocorticosteroid therapy.

Background: While glucocorticosteroids (GCS) are widely used in patients with kidney disease, little is known about their effect on serum creatinine, the most commonly used endogenous marker of kidney function.

Methods: We assessed the effect of GCS on the relationship between estimated GFR using the Schwartz equation (eGFR) and measured GFR using a single-injection inulin clearance (Cin) in children both in a paired analysis and a cross-sectional study. Primary outcome variable was the difference between eGFR and Cin (ΔGFR) in a paired analysis involving 22 patients during and off GCS treatment (mean GFR 103.

Combining GFR estimates from cystatin C and creatinine-what is the optimal mix?

Background: Combining estimated glomerular filtration rate (eGFR) equations based on creatinine and cystatin C has been shown to improve the accuracy of GFR estimation. This study aims to optimize this strategy for height-independent GFR estimation in children.

Methods: Retrospective study of 408 inulin clearance tests with simultaneous International Federation of Clinical Chemistry-calibrated measurements of creatinine, cystatin C, and urea in children (mean age 12.

Endogenous markers for kidney function in children: a review.

Although glomerular filtration rate (GFR) in children can be measured using a gold-standard technique following injection of an exogenous marker, this invasive and cumbersome technique is not widely available and GFR is commonly estimated using serum levels of endogenous markers. Creatinine, urea, cystatin C, beta-trace protein, and beta-2 microglobulin are well-established endogenous markers of kidney function. These markers differ in site of production and effects of diet and medication, as well as renal-tubular handling and extra-renal elimination.

Accurate eGFR reporting for children without anthropometric data.

Introduction: Reporting estimated glomerular filtration rate (eGFR) instead of serum concentrations is advised in current guidelines. Most creatinine-based eGFR equations for children require height, a parameter not readily available to laboratories. Combining height-dependent creatinine- and cystatin C-based eGFR improves performance.

Estimating glomerular filtration rate (GFR) in children. The average between a cystatin C- and a creatinine-based equation improves estimation of GFR in both children and adults and enables diagnosing Shrunken Pore Syndrome.

Estimating glomerular filtration rate (GFR) in adults by using the average of values obtained by a cystatin C- (eGFR) and a creatinine-based (eGFR) equation shows at least the same diagnostic performance as GFR estimates obtained by equations using only one of these analytes or by complex equations using both analytes. Comparison of eGFR and eGFR plays a pivotal role in the diagnosis of Shrunken Pore Syndrome, where low eGFR compared to eGFR has been associated with higher mortality in adults. The present study was undertaken to elucidate if this concept can also be applied in children.

Barriers to conducting effective obstetric audit in Ifakara: a qualitative assessment in an under-resourced setting in Tanzania.

Objective: To explore barriers to and solutions for effective implementation of obstetric audit at Saint Francis Designated District Hospital in Ifakara, Tanzania, where audit results have been disappointing 2 years after its introduction.

Methods: Qualitative study involving participative observation of audit sessions, followed by 23 in-depth interviews with health workers and managers. Knowledge and perceptions of audit were assessed and suggestions for improvement of the audit process explored.