Clinical Chemistry AACC Online Job Center
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Clinical Chemistry 49: 281-285, 2003; 10.1373/49.2.281
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Submit an electronic Letter to
the Editor about this paper
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (10)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Laube, N.
Right arrow Articles by Hesse, A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Laube, N.
Right arrow Articles by Hesse, A.
Related Collections
Right arrow General Clinical Chemistry
Right arrow Endocrinology and Metabolism
(Clinical Chemistry. 2003;49:281-285.)
© 2003 American Association for Clinical Chemistry, Inc.

Influence of Urinary Stones on the Composition of a 24-Hour Urine Sample

Norbert Laube1a, Michael Pullmann2, Stefan Hergarten2 and Albrecht Hesse1

1 Division of Experimental Urology, Department of Urology, and
2 Geodynamics and Physics of the Lithosphere, University of Bonn, D-53105 Bonn, Germany.

aAddress correspondence to this author at: Klinik und Poliklinik für Urologie, Experimentelle Urologie, Sigmund-Freud-Strasse 25, D-53105 Bonn, Germany. Fax 49-228-287-6344; e-mail norbert.laube{at}ukb.uni-bonn.de.

Background: It can be assumed that stones in the urinary tract continuously increase in size by incorporating material from urine. Consequently, urine will exhibit depleted concentrations of lithogenic constituents when urinary stones are present in the patient’s urinary tract.

Methods: To calculate the influence of the depletion effect, we considered two different models of stone growth. In the first model, the increase in stone size depends only on the urinary concentration of a lithogenic substance; the second model also considers the surface area of the growing stone. The case of only one kidney being affected by stone formation is considered separately. We discuss example calculations involving the formation of calcium oxalate.

Results: The calculated depletion effects are of a nonnegligible order of magnitude. Assuming both a measured oxalate concentration of, e.g., 0.37 mmol/L and a reasonable in vivo stone growing rate of 10 mm3/day, a relative underestimation of the real "in situ" oxalate concentration between ~21% (model 1) and ~42% (model 2) occurs. The depletion effect increases markedly with increasing stone growth rate.

Conclusions: Metabolic status can be evaluated correctly only in patients who have been declared "stone-free", e.g., after stone removal. Because the expected stone-related depletion effect in most cases is of high clinical relevance, we recommend estimating the effect of the order of magnitude of the depletion on actual urinary composition.




The following articles in journals at HighWire Press have cited this article:


Home page
 Clin. Chem.Home page
M. Pullmann, S. Hergarten, and N. Laube
Influence of a Variable Differential Function on the Stone-Growth-Related Urinary Depletion Effect
Clin. Chem., September 1, 2004; 50(9): 1675 - 1678.
[Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2003 by the American Association for Clinical Chemistry.