Struvite stones

Griffith, Donald P.

doi:10.1038/ki.1978.55

Cited by 337 publications

(154 citation statements)

References 74 publications

Supporting

Mentioning

144

Contrasting

Unclassified

Order By: Relevance

“…[1][2][3][4][5][6] The inference of infection from the presence of struvite is based more on in vitro studies than on clinical data, 6 but the reasoning seems irrefutable: Struvite forms only in the presence of high concentrations of ammonia and high pH, and such conditions will be seen in the urinary tract only when an infective organism is present that produces urease.…”

Section: Introductionmentioning

confidence: 99%

Stability of the Infection Marker Struvite in Urinary Stone Samples

Williams

Sacks

Englert

et al. 2012

Journal of Endourology

View full text Add to dashboard Cite

Background and Purpose: Struvite in kidney stones is an important marker for infection. In kidney stone samples, struvite is known to be prone to chemical breakdown, but no data exist on the stability of samples stored in dry form. The objective of this study was to examine stability of struvite under increasingly poor conditions of storage. Materials and Methods: Samples of struvite kidney stones were broken to obtain 38 pieces averaging 67 mg in weight, and these were randomized into four storage conditions: Airtight containers stored in the dark, open containers in the dark, open containers in ambient light, and open containers at elevated temperature (40°C). Pieces were left for 6 months, and then analyzed for changes using micro CT and Fourier transform infrared spectroscopy (FT-IR). Results: Initial samples proved to be struvite, indicating no transformation in the large specimens that had been stored in airtight containers in the dark for more than 6 years before this study. Pieces of struvite taken from these large specimens appeared unchanged by micro CT and FT-IR after being stored in closed containers for 6 months, but 8 of 9 pieces in open containers showed the presence of newberyite in surface layers, as did 10 of 10 pieces in open containers out in ambient light. All pieces stored at 40°C showed transformation of struvite, with 60% of the pieces showing the presence of amorphous phosphates, indicating complete breakdown of struvite in the surface layers of the pieces. Conclusion: We conclude that struvite in dry kidney stone samples is stable when the specimens are stored in airtight containers at room temperature, even after several years.

show abstract

Section: Introductionmentioning

confidence: 99%

Stability of the Infection Marker Struvite in Urinary Stone Samples

Williams

Sacks

Englert

et al. 2012

Journal of Endourology

View full text Add to dashboard Cite

show abstract

“…An increase of both alkalinity and the ammonium level must occur for urine to become supersaturated with magnesium ammonium phosphate and these conditions only occur in the presence of uratolysis. 9 Thus, these conditions may only arise in the presence of infection, presumably as a local event. However, in the clinical setting, the local event is hard to prove and urinary pH was only reported to be high throughout the whole day in patients with struvite stones.…”

Section: Discussionmentioning

confidence: 99%

Impact of citrate therapy on the circadian rhythm of urinary magnesium ammonium phosphate saturation in normal individuals

et al. 2000

View full text Add to dashboard Cite

Background: Alkaline citrate has been used widely in the prevention of stone formation. However, the risk of struvite stone during the alkalinizing therapy has not been adequately studied in terms of magnesium ammonium phosphate saturation. Methods:The circadian rhythm of the urinary saturation of magnesium ammonium phosphate was estimated by using the differential Gibbs' free energy values of magnesium ammonium phosphate before and during 5 days of treatment with sodium-potassium citrate (1 g t.i.d., 1 g q.i.d. or 3 g t.i.d.) in five healthy male volunteers. Results:The magnesium ammonium phosphate saturation varied during the day, peaking far below the solubility product between 08.00 and 10.30 h and between 13.00 and 18.00 h. The mean peak levels were increased by each treatment regimen in comparison with the control day. The mean increase on day 1 was significant between 10.30 and 23.00 h with the 3 g t.i.d. regimen, but the mean saturation still remained below the solubility product throughout the day. Conclusions:The urinary magnesium ammonium phosphate saturation appeared hard to exceed the solubility product with a high dose of alkaline citrate.

show abstract

“…[1,16] In this study, 8 (33.3%) patients had de novo stones after a median follow-up of 22.6 months. This is within the reported range of stone recurrence in patients with struvite stones.…”

Section: Discussionmentioning

confidence: 99%

“…They are formed in alkaline urine through the action of urea-splitting organisms such as Proteus, Klebsiella and Pseudomonas. [1,2] This process is facilitated by the action of urease enzyme that breaks down urea into ammonia and carbon dioxide, which both respectively hydrolyze into ammonia and bicarbonate, thus alkalinizing the urine. This milieu favours formation of struvite and carbonate apatite stones.…”

Section: Introductionmentioning

confidence: 99%

“…This milieu favours formation of struvite and carbonate apatite stones. [1,2] As a potent irreversible inhibitor of bacterial urease, acetohydroxamic acid (Lithostat, Mission Pharmacal, San Antonio, USA), was described in 1965. [3] In a randomized clinical trial, Williams et al [4] found that 7 patients (36.8%) who received placebo developed de novo urolithiasis when compared with none of the 18 patients who received acetohydroxamic acid (p<0.01).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Is it safe to prescribe ascorbic acid for urinary acidification in stone-forming patients with alkaline urine?

Noureldin

Silva

Fahmy

et al. 2017

Turkish Journal of Urology

View full text Add to dashboard Cite

Objective: To study the effect of ascorbic acid (AA) supplementation on urinary pH, metabolic stone workup parameters, and development of de novo urolithiasis in stone-forming patients. Material and methods:A retrospective review of the patients followed-up at a tertiary stone centre between September 2009 and October 2015 was performed. Patients with recurrent urolithiasis who received AA supplementation as a urinary acidifying agent were included in the study. Detailed metabolic stone work-up, including two 24-hour urine collections obtained pre-and post-AA supplementation were compared. In addition, imaging studies were reviewed to assess the development of de novo urolithiasis.Results: Twenty-four patients were included in the study with a mean age of 60.6 years and a median daily AA dose of 1000 mg (range: 500-2000 mg). Median follow-up period was 22.6 months (range: 19.7-32.1). After AA supplementation, there was a significant decrease in urinary pH (7.6 vs. 6.9, p= 0.02). Although there was no significant increase in the daily oxalate excretion, two patients (8.3%) had their AA dose reduced or discontinued due to de novo hyperoxaluria (342.9 vs 510.2 umol/day; p= 0.75). Other serum and urinary parameters did not show any significant changes. Eight (33.3%) patients developed de novo urolithiasis with struvite and carbonate apatite being the major components. Conclusion:AA supplementation resulted in significantly lower urinary pH in patients with recurrent urolithiasis and alkaline urine pH. Prospective studies are needed to assess whether this reduction in urinary pH is associated with lower stone recurrence rates.

show abstract

Struvite stones

Cited by 337 publications

References 74 publications

Stability of the Infection Marker Struvite in Urinary Stone Samples

Stability of the Infection Marker Struvite in Urinary Stone Samples

Impact of citrate therapy on the circadian rhythm of urinary magnesium ammonium phosphate saturation in normal individuals

Is it safe to prescribe ascorbic acid for urinary acidification in stone-forming patients with alkaline urine?

Contact Info

Product

Resources

About