Measuring Residual Renal Function in Hemodialysis Patients without Urine Collection

This is the peer reviewed version of the following article: Wong, J., Kaja Kamal, R. M., Vilar, E. and Farrington, K. (2017), 'Measuring Residual Renal Function in Hemodialysis Patients without Urine Collection', Seminars in Dialysis, Vol. 30 (1): 39–49, which has been published in final form at doi: 10.1111/sdi.12557. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. © 2016 Wiley Periodicals, Inc.Many patients on hemodialysis retain significant residual renal function (RRF) but currently measurement of RRF in routine clinical practice can only be achieved using inter-dialytic urine collections to measure urea and creatinine clearances. Urine collections are difficult and inconvenient for patients and staff, and therefore RRF is not universally measured. Methods to assess RRF without reliance on urine collections are needed since RRF provides useful clinical and prognostic information and also permits the application of incremental hemodialysis techniques. Significant efforts have been made to explore the use of serum based biomarkers such as cystatin C, β-trace protein and β2 -microglobulin to estimate RRF. This article reviews blood-based biomarkers and novel methods using exogenous filtration markers which show potential in estimating RRF in hemodialysis patients without the need for urine collection.Peer reviewedFinal Accepted Versio

PLASMA BILIRUBIN DETERMINATION IN THE NEWBORN INFANT

A method for plasma bilirubin determination is described. It is a modification of the Jendrassik and Grof alkaline diazo-coupling procedure and allows determination of both conjugated and unconjugated bilirubin in small amounts of plasma. Five commonly used diazo-coupling methods are compared with special reference to the influence of hemolysis in the sample. The Jendrassik and Grof method as modified by Nosslin and Michaëlsson is shown to have the smallest methodological error and to be insignificantly influenced by hemolysis in the sample, in contrast to the methods of Malloy and Evelyn, Lathe and Ruthven, Ducci and Watson, and Powell. The bilirubin standardization procedure, methodological errors, and the influence of hemolysis in the sample are discussed.</jats:p

Catabolic rate of α1-antitrypsin of Pi type M and Z in man

1. Human α1-antitrypsin was isolated from three Pi M and two Pi Z subjects without alteration of its microheterogeneity. The purified proteins were labelled with either 125I or 131I by a lactoperoxidase method. 2. The disappearance rate of two types of α1-antitrypsin were studied after simultaneous injection of labelled M-protein and Z-protein into Pi M subjects. 3. The ratio of extra vascular to plasma pools of α1-antitrypsin ranged between 1·2 and 1·6 with no difference between M- and Z-protein. The mean fractional catabolic rates of M-protein and Z-protein were respectively 0·26 and 0·40 per day. 4. The difference in catabolic rate of Z- and of M-protein is too small to explain why the α1-antitrypsin content of the blood in Pi ZZ subjects is only 15% of that normally found in Pi MM subjects. The low α1-antitrypsin in Pi ZZ subjects appears mainly to be due to a low rate of biosynthesis.</jats:p