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New pathophysiological aspects of growth and prevention of kidney stones.

Baumann JM, Affolter B - Adv Urol (2012)

Bottom Line: To induce rapid crystallization, high Ox additions (0.5-0.8 mM) were necessary.The most important finding was retardation of crystal AGN by UM.Also growth and sedimentation rate of crystals were significantly reduced by UM.

View Article: PubMed Central - PubMed

Affiliation: Laboratories Viollier, Departement of Stone Research, Gartenstrasse 9, 2502 Biel, Switzerland.

ABSTRACT
Kidney stones probably grow during crystalluria by crystal sedimentation and aggregation (AGN) on stone surfaces. This process has to occur within urinary transit time (UT) through the kidney before crystals are washed out by diuresis. To get more information, we studied by spectrophotometry the formation and AGN of Ca oxalate (Ca Ox) crystals which were directly produced in urine of 30 stone patients and 30 controls by an oxalate (Ox) titration. Some tests were also performed after removing urinary macromolecules (UMs) by ultrafiltration. To induce rapid crystallization, high Ox additions (0.5-0.8 mM) were necessary. The most important finding was retardation of crystal AGN by UM. In urine of 63% of controls but only 33% of patients, no AGN was observed during an observation of 60 minutes (P < 0.05). Also growth and sedimentation rate of crystals were significantly reduced by UM. For stone metaphylaxis, especially for posttreatment residuals, avoiding dietary Ox excesses to prevent crystal formation in the kidney and increasing diuresis to wash out crystals before they aggregate are recommended.

No MeSH data available.


Related in: MedlinePlus

Crystallization parameters (see Figure 2) in urine of controls (UCs), in ultrafiltrate of the same urine (UF), and in control solution (shaded area).
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fig3: Crystallization parameters (see Figure 2) in urine of controls (UCs), in ultrafiltrate of the same urine (UF), and in control solution (shaded area).

Mentions: To get more information about the source of urinary inhibition of nucleation, growth, and AGN, we compared metastable limit (ML), maximal OD (mOD), and suspension stability (SS) observed in urine of 10 controls before and after ultrafiltration of urine by a membrane with an exclusion limit of 5 kD. Results of urine of controls (UCs) containing urinary macromolecules >5 kD (UM) and ultrafiltrate (UF) containing only low-molecular-weight compounds were compared with results obtained in the control solution (CS). Figure 3 shows that inhibition of crystal nucleation can be attributed to low-molecular-weight compounds of urine since no significant difference was found with respect to ML between UC and UF. On the other hand, elevated values of mOD indicating inhibition of crystal growth and of SS representing retardation of AGN were exclusively found in UC and therefore seems to be caused by UM.


New pathophysiological aspects of growth and prevention of kidney stones.

Baumann JM, Affolter B - Adv Urol (2012)

Crystallization parameters (see Figure 2) in urine of controls (UCs), in ultrafiltrate of the same urine (UF), and in control solution (shaded area).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3362812&req=5

fig3: Crystallization parameters (see Figure 2) in urine of controls (UCs), in ultrafiltrate of the same urine (UF), and in control solution (shaded area).
Mentions: To get more information about the source of urinary inhibition of nucleation, growth, and AGN, we compared metastable limit (ML), maximal OD (mOD), and suspension stability (SS) observed in urine of 10 controls before and after ultrafiltration of urine by a membrane with an exclusion limit of 5 kD. Results of urine of controls (UCs) containing urinary macromolecules >5 kD (UM) and ultrafiltrate (UF) containing only low-molecular-weight compounds were compared with results obtained in the control solution (CS). Figure 3 shows that inhibition of crystal nucleation can be attributed to low-molecular-weight compounds of urine since no significant difference was found with respect to ML between UC and UF. On the other hand, elevated values of mOD indicating inhibition of crystal growth and of SS representing retardation of AGN were exclusively found in UC and therefore seems to be caused by UM.

Bottom Line: To induce rapid crystallization, high Ox additions (0.5-0.8 mM) were necessary.The most important finding was retardation of crystal AGN by UM.Also growth and sedimentation rate of crystals were significantly reduced by UM.

View Article: PubMed Central - PubMed

Affiliation: Laboratories Viollier, Departement of Stone Research, Gartenstrasse 9, 2502 Biel, Switzerland.

ABSTRACT
Kidney stones probably grow during crystalluria by crystal sedimentation and aggregation (AGN) on stone surfaces. This process has to occur within urinary transit time (UT) through the kidney before crystals are washed out by diuresis. To get more information, we studied by spectrophotometry the formation and AGN of Ca oxalate (Ca Ox) crystals which were directly produced in urine of 30 stone patients and 30 controls by an oxalate (Ox) titration. Some tests were also performed after removing urinary macromolecules (UMs) by ultrafiltration. To induce rapid crystallization, high Ox additions (0.5-0.8 mM) were necessary. The most important finding was retardation of crystal AGN by UM. In urine of 63% of controls but only 33% of patients, no AGN was observed during an observation of 60 minutes (P < 0.05). Also growth and sedimentation rate of crystals were significantly reduced by UM. For stone metaphylaxis, especially for posttreatment residuals, avoiding dietary Ox excesses to prevent crystal formation in the kidney and increasing diuresis to wash out crystals before they aggregate are recommended.

No MeSH data available.


Related in: MedlinePlus