Changes in calcium oxalate crystal morphology as a function of supersaturation
PURPOSE: To study the changes in calcium oxalate crystal morphology induced by different levels of supersaturation (SS) in human urine. MATERIALS AND METHODS: Twenty-four hours urine samples from 5 normal men were collected. Each specimen was centrifuged and filtered. About 200 mL of each sample was...
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| Format: | Article |
| Language: | English |
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Sociedade Brasileira de Urologia
2004-06-01
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| Series: | International Brazilian Journal of Urology |
| Subjects: | |
| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-55382004000300005 |
| _version_ | 1818512428121456640 |
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| author | Mauricio Carvalho Marcos A. Vieira |
| author_facet | Mauricio Carvalho Marcos A. Vieira |
| author_sort | Mauricio Carvalho |
| collection | DOAJ |
| description | PURPOSE: To study the changes in calcium oxalate crystal morphology induced by different levels of supersaturation (SS) in human urine. MATERIALS AND METHODS: Twenty-four hours urine samples from 5 normal men were collected. Each specimen was centrifuged and filtered. About 200 mL of each sample was dialyzed overnight. Aliquots of 2 mL of urine was then added to a 24-wells tissue culture plate and checked for crystal absence. Calcium oxalate crystals were precipitated from each sample by adding sodium oxalate and calcium chloride in sufficient quantities to induce spontaneous crystallization. Finally, each plate hole was examined with an inverted polarized microscope (X500 magnification). Initial SS of each sample relative to calcium oxalate was calculated using an iterative computer program. RESULTS: Crystal formation was connecte to relative calcium oxalate (CaOx) SS. At SS of 10, small crystals of similar shape were formed, mainly CaOx dihydrate morphology. At SS of 30, there was an enormous increase in the number of crystals, that kept the same size. SS greater than 50 produced larger crystals with different shapes and multiple crystalline aggregates. Urine was able to tolerate, i.e., to avoid crystal formation, until SS ratios of approximately 10. CONCLUSIONS: Relative CaOx SS and the concentration ratio of calcium to oxalate are important determinanting factors of crystal morphology. Non-dialyzable urinary proteins can act as inhibitors and influence the structure of formed crystals. Additional studies from patients with kidney stones are needed in order to establish whether crystal size and habit distribution are different from crystals in normal urine. |
| first_indexed | 2024-12-10T23:46:45Z |
| format | Article |
| id | doaj.art-ee4c63d4abc34fc088b723db19ec7882 |
| institution | Directory Open Access Journal |
| issn | 1677-5538 1677-6119 |
| language | English |
| last_indexed | 2024-12-10T23:46:45Z |
| publishDate | 2004-06-01 |
| publisher | Sociedade Brasileira de Urologia |
| record_format | Article |
| series | International Brazilian Journal of Urology |
| spelling | doaj.art-ee4c63d4abc34fc088b723db19ec78822022-12-22T01:28:55ZengSociedade Brasileira de UrologiaInternational Brazilian Journal of Urology1677-55381677-61192004-06-0130320520910.1590/S1677-55382004000300005Changes in calcium oxalate crystal morphology as a function of supersaturationMauricio CarvalhoMarcos A. VieiraPURPOSE: To study the changes in calcium oxalate crystal morphology induced by different levels of supersaturation (SS) in human urine. MATERIALS AND METHODS: Twenty-four hours urine samples from 5 normal men were collected. Each specimen was centrifuged and filtered. About 200 mL of each sample was dialyzed overnight. Aliquots of 2 mL of urine was then added to a 24-wells tissue culture plate and checked for crystal absence. Calcium oxalate crystals were precipitated from each sample by adding sodium oxalate and calcium chloride in sufficient quantities to induce spontaneous crystallization. Finally, each plate hole was examined with an inverted polarized microscope (X500 magnification). Initial SS of each sample relative to calcium oxalate was calculated using an iterative computer program. RESULTS: Crystal formation was connecte to relative calcium oxalate (CaOx) SS. At SS of 10, small crystals of similar shape were formed, mainly CaOx dihydrate morphology. At SS of 30, there was an enormous increase in the number of crystals, that kept the same size. SS greater than 50 produced larger crystals with different shapes and multiple crystalline aggregates. Urine was able to tolerate, i.e., to avoid crystal formation, until SS ratios of approximately 10. CONCLUSIONS: Relative CaOx SS and the concentration ratio of calcium to oxalate are important determinanting factors of crystal morphology. Non-dialyzable urinary proteins can act as inhibitors and influence the structure of formed crystals. Additional studies from patients with kidney stones are needed in order to establish whether crystal size and habit distribution are different from crystals in normal urine.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-55382004000300005urolithiasiscrystallizationcalcium oxalate |
| spellingShingle | Mauricio Carvalho Marcos A. Vieira Changes in calcium oxalate crystal morphology as a function of supersaturation International Brazilian Journal of Urology urolithiasis crystallization calcium oxalate |
| title | Changes in calcium oxalate crystal morphology as a function of supersaturation |
| title_full | Changes in calcium oxalate crystal morphology as a function of supersaturation |
| title_fullStr | Changes in calcium oxalate crystal morphology as a function of supersaturation |
| title_full_unstemmed | Changes in calcium oxalate crystal morphology as a function of supersaturation |
| title_short | Changes in calcium oxalate crystal morphology as a function of supersaturation |
| title_sort | changes in calcium oxalate crystal morphology as a function of supersaturation |
| topic | urolithiasis crystallization calcium oxalate |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-55382004000300005 |
| work_keys_str_mv | AT mauriciocarvalho changesincalciumoxalatecrystalmorphologyasafunctionofsupersaturation AT marcosavieira changesincalciumoxalatecrystalmorphologyasafunctionofsupersaturation |