Thirteen newborn infants, 8 preterm and 5 term, with either mild or serious neonatal asphyxia were studied. From the first 24 hours of life to day 13, glomerular filtration rate (GFR) estimated by creatinine clearance was compared with the values obtained using Schwartz's formula: GFR (ml/min per 1.73 m2) = 0.55 x length (cm)/plasma creatinine (mg/100 ml). Both in term and preterm infants, valu...

Cystatin C is a 13 KD basic protein that is a member of the cystatin superfamily of cysteine protease inhibitors. The cystatin C gene seems to be a house keeping gene, which is compatible with a stable production rate of cystatin C by most cells. This protein is freely filtered through the glomerulus and almost completely reabsorbed and catabolized by proximal tubular cells. Because of the...

Creatinine-based glomerular filtration rate estimation (eGFRcr) has been improved and refined since the 1970s through both the Modification of Diet in Renal Disease (MDRD) Study equation in 1999 and the CKD Epidemiology Collaboration (CKD-EPI) equation in 2009, with current clinical practice dependent primarily on eGFR for accurate assessment of GFR. However, researchers and clinicians have rec...

BACKGROUND/AIMS Several studies suggested that serum cystatin C (CysC) is more useful than serum creatinine (Cr) for the assessment of renal function in patients with liver cirrhosis. This study evaluated the clinical significance of CysC in patients with cirrhotic ascites and normal Cr level. METHODS We enrolled patients with cirrhotic ascites and a normal serum Cr level (<1.2 mg/dL). GFR wa...

Clinical assessment of kidney function is central to the practice of medicine. Glomerular filtration rate (GFR) is widely accepted as the best index of kidney function in health and disease and accurate values are required for optimal decisionmaking in many clinical settings. GFR is generally not measured in clinical practice, but is estimated from the serum level of an endogenous filtration ma...

Teleologically speaking kidney’s function is designed to maintain life parameters as close as possible to the normal level. Clearance is a tool to compare renal function among different individuals independently on urine flow, body size and solute concentration in blood. Since the tubulus manipulates the glomerular filtrate composition, for the computation of clearance as a surrogate of GFR, we...

Estimating glomerular filtration rate (GFR) is essential for clinical practice, research, and public health. Appropriate interpretation of estimated GFR (eGFR) requires understanding the principles of physiology, laboratory medicine, epidemiology, and biostatistics used in the development and validation of GFR estimating equations. Equations developed in diverse populations are less biased at h...

BACKGROUND AND OBJECTIVES Intrauterine growth restriction (IUGR) and prematurity are associated with a low nephron endowment. It can therefore be expected that neonates who are born premature and/or after IUGR have a lower GFR. Measurement of GFR in neonates is difficult, but the clearance of amikacin has been proven to be a reliable marker. We hypothesized that amikacin clearance is lower afte...

Serum cystatin C has been suggested as a new marker of GFR. For the introduction of this marker into clinical use a rapid and automated method is required. We have developed and validated an assay for serum cystatin C using latex particle-enhanced immunoturbidimetry. Intra- and inter-assay precision were < 3% and < 5% across the assay range. Analytical recovery was 93 +/- 3.8% and no lack of pa...

Glomerular filtration rate (GFR), which measures the amount of plasma filtered through the kidney within a given time, is an essential and clinically important indicator of kidney function. Here, we report a new ratiometric measurement technique based on intravital fluorescence microscopy that allows rapid evaluations of renal function in rodent models. By using this technique, plasma clearance...