caa a22 4500 475742737 CHVBK 20180406123504.0 cr unu---uuuuu 170329e20000801xx s 000 0 eng 10.1007/s002400000124 doi (NATIONALLICENCE)springer-10.1007/s002400000124 A new approach to calculate the risk of calcium oxalate crystallization from unprepared native urine [Elektronische Daten] [Norbert Laube, Anke Schneider, Albrecht Hesse] This work focuses on the in vitro calcium-oxalate (CaOx) crystallization behaviour of native and synthetic urine samples in order to establish a CaOx crystallization risk index for unprepared native urine. Native 24-h urine samples from healthy persons and from stone-formers were examined. Within a [Ca2+] versus added oxalate (Ox2−) diagram, we observed fields which allow the discrimination of each urine sample in terms of more or less risk. The [Ca2+]/(Ox2−) ratio is calculated and termed the "Bonn-Risk Index” (BRI; per litre). We propose that BRIs >1/l denote samples "at risk”, whereas BRIs ≤ 1/l denote those "without risk”. Second, the effects of different concentrations of citrate and Mg2+ on BRI were investigated in artificial urine. The transferability of BRI between native and synthetic urine samples is proved. To evaluate the impact of the proposed BRI, it is compared with the more familiar relative urine saturation index calculated for CaOx and brushite. Urine sampled from stone-formers shows risk indexes between 0.278 and 23.0/l (mean 2.87/l), while urine from healthy persons varied between 0.060 and 4.890/l (mean 1.05/l). Comparing the results of healthy volunteers and patients, the significance of BRI and relative urine supersaturation (RS) with respect to CaOx is P < 0.0005 and P=0.013, respectively. Fast and easy to perform, determination of the risk index is a suitable tool for estimating the actual CaOx formation "status”-"at risk” or "without risk”- from the native urine of any person. Springer-Verlag Berlin Heidelberg, 2000 Laube Norbert Klinik und Poliklinik für Urologie, Experimentelle Urologie, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany e-mail: laube@mailer.meb.uni-bonn.de Tel.: +49-228-2879106, Fax: +49-228-2876344, DE aut Schneider Anke Division of Experimental Urology, Department of Urology, Bonn University, 53105 Bonn, Germany, DE aut Hesse Albrecht Division of Experimental Urology, Department of Urology, Bonn University, 53105 Bonn, Germany, DE aut https://doi.org/10.1007/s002400000124 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s002400000124 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Laube Norbert Klinik und Poliklinik für Urologie, Experimentelle Urologie, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany e-mail: laube@mailer.meb.uni-bonn.de Tel.: +49-228-2879106, Fax: +49-228-2876344, DE aut NATIONALLICENCE 700 1- Schneider Anke Division of Experimental Urology, Department of Urology, Bonn University, 53105 Bonn, Germany, DE aut NATIONALLICENCE 700 1- Hesse Albrecht Division of Experimental Urology, Department of Urology, Bonn University, 53105 Bonn, Germany, DE aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer