New Spectrophotometric Method for Measuring Calcium-Oxalate-Monohydrate Crystal Aggregation in the Absence of Supersaturation

Urolithiasis ◽  
1989 ◽  
pp. 55-57 ◽  
Author(s):  
B. Hess ◽  
Y. Nakagawa ◽  
F. L. Coe
1989 ◽  
Vol 257 (1) ◽  
pp. F99-F106 ◽  
Author(s):  
B. Hess ◽  
Y. Nakagawa ◽  
F. L. Coe

Normal urine inhibits both the growth and the aggregation of calcium oxalate monohydrate (COM) crystals but the molecules that inhibit aggregation are not well defined. We have developed a spectrophotometric assay method to measure the aggregation of COM crystals in vitro under conditions that avoid simultaneous crystal growth. At pH 7.2 and 90 mM NaCl, Tamm-Horsfall glycoprotein (THP) and nephrocalcin (NC), a major urinary inhibitor of COM crystal growth, inhibit COM crystal aggregation at concentrations as low as 2 X 10(-9) and 1 X 10(-8) M, respectively. When increasing NaCl to 270 mM or lowering pH to 5.7, inhibition by both glycoproteins, but more markedly by THP, is decreased. Urinary NC from calcium oxalate renal stone formers (SF NC) and NC isolated from calcium oxalate renal stones (stone NC) both inhibit COM crystal aggregation 10-fold less than NC from normal urine. Citrate is ineffective even at millimolar concentrations. Thus THP and NC are two major inhibitors of COM crystal aggregation in normal urine; SF NC and stone NC are defective aggregation inhibitors.


1991 ◽  
Vol 260 (4) ◽  
pp. F569-F578 ◽  
Author(s):  
B. Hess ◽  
Y. Nakagawa ◽  
J. H. Parks ◽  
F. L. Coe

Tamm-Horsfall glycoprotein (THP) inhibits self-aggregation of calcium oxalate monohydrate (COM) crystals and may therefore be part of the natural defenses against deposition of COM in the kidney in the form of stones or nephrocalcinosis. We have studied THP from six patients with severe nephrolithiasis and have found that their THP inhibits COM self-aggregation less than normal THP under conditions of NaCl and THP concentration and pH similar to those of human urine. The reason for the reduced inhibition of COM crystal aggregation seems to be an enhanced self-aggregation of patient THP, which removes it from effective interactions with the COM crystals. In one family, the father and the oldest son both excreted THP that behaved abnormally and in similar ways, whereas THP from the other son and from the wife behaved normally.


1989 ◽  
Vol 80 (7) ◽  
pp. 1000-1003
Author(s):  
Yumiko Shirane ◽  
Akihiro Yamamoto ◽  
Koji Mizuta ◽  
Susumu Kagawa

1993 ◽  
Vol 265 (6) ◽  
pp. F784-F791 ◽  
Author(s):  
B. Hess ◽  
L. Zipperle ◽  
P. Jaeger

We measured the effects of Tamm-Horsfall glycoprotein (THP) on calcium oxalate monohydrate (COM) crystal aggregation (Ac) in vitro as well as intrinsic viscosities (Vi) of THP at pH 5.7 and 200 mM NaCl and studied the effects of calcium and citrate on these parameters. THP were isolated from 24-h urines of seven male recurrent calcium stone formers (RCSF) and eight age-matched male healthy volunteers (N, normal). At basal conditions, RCSF-THP inhibited Ac by 28 +/- 10% and normal THP by 60 +/- 6% (P = 0.028). In the presence of calcium, increasing THP concentrations from 16 to 28 and 40 mg/l progressively lowered inhibition by RCSF-THP, but not by N-THP. At 40 mg/l, inhibition by N-THP was 27 +/- 9% vs. -43 +/- 8% by RCSF-THP (P = 0.001), i.e., all stone former THP promoted Ac. With an additional 3.5 mM of citrate, inhibition of Ac was 56 +/- 5% by normal and 34 +/- 6% by stone former THP (P = 0.021), and all seven stone former THP again inhibited Ac. Vi of RCSF-THP was higher than that of N at basal conditions (162 +/- 21 vs. 93 +/- 15 ml/g, P = 0.021) and in the presence of 5 mM calcium (352 +/- 54 vs. 118 +/- 17 ml/g, P = 0.001), i.e., RCSF-THP were more self-aggregated, but not when citrate was added (185 +/- 29 vs. 123 +/- 19 ml/g). (ABSTRACT TRUNCATED AT 250 WORDS)


2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Mohamed Gadelmoula ◽  
Ahmed M. Moeen ◽  
Ahmed Elderwy ◽  
Mohamed S. Abdel-Kader ◽  
Ayman Elqady ◽  
...  

Abstract Background The stone composition has a great influence on the outcome of its treatment. There are several tests to predict the composition of stones preoperatively and stone analysis postoperatively. Herein, we want to evaluate if the stone composition could be predicted from plain X-ray KUB (PKUB) and/or non-contrast CT (NCCT) validated by in vitro X-ray powder diffraction analysis (XRD). Methods Between April 2014 and March 2016, 100 cases with urinary tract stones were included in the study. The radio-opacity of the stones in PKUB, stone density by NCCT, and after stone extraction, XRD were performed. Statistical analysis for the results was performed using Chi-square and Fisher exact tests for categorical variables and Mann–Whitney U and Kruskal–Wallis H for the nonparametric variables. The receiver operating characteristic curve was constructed to determine the best cutoff value. Results This study included 74 males and 26 females with a median age of 32 years (range 2–70). Regarding the radio-opacity by PKUB, there were 30 stones dense opaque, 44 opaque, 21 faint opaque, and 5 radiolucent. XRD revealed 97 mixed and 3 pure stones. The calcium oxalate monohydrate (COM) stone composition could be predicted in dense opaque stone by PKUB in 75.9% and urate composition in the radiolucent stone by 40%. The cutoff value of HU density by NCCT to the dense opaque stones in the PKUB was > 1020 and for radiolucent stones was < 590. Conclusion Stone radio-opacity by PKUB and its attenuation value by NCCT could successfully predict its calcium oxalate monohydrate, struvite, and urate composition. However, the chemical stone analysis is still required as most stones are mixed.


1987 ◽  
Vol 118 (2) ◽  
pp. 379-386 ◽  
Author(s):  
R.P. Singh ◽  
S.S. Gaur ◽  
D.J. White ◽  
G.H. Nancollas

2003 ◽  
Vol 91 (3) ◽  
pp. 2035-2041 ◽  
Author(s):  
W. O. S. Doherty ◽  
C. M. Fellows ◽  
S. Gorjian ◽  
E. Senogles ◽  
W. H. Cheung

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