Análisis de la composición química de litiasis urinaria de 649 pacientes mediante espectroscopía infrarroja, primera experiencia nacional / Chemical composition analysis of 649 urinary stones

Background: Chemical composition analysis of urinary stones is a fundamental part of the metabolic workup of urolithiasis. Aim: To report the chemical composition of urinary stones using infrared spectroscopy. Material and Methods: The chemical composition of rinary stones recovered from 649 patients aged 1 to 97 years (68% males), were analyzed using a Perkin Elmer FTIR Spectrometer, Spectrum Two. Results: Calcium oxalate monohydrate was the most common composition found in 45% of cases, followed by mixed composition, which included three ammonium phosphate stones in 29% of cases. Pure uric acid composition was found in 16% of stones. Three cystine stones were detected. Conclusions: These findings do not differ from those found in developed countries.

Upper urinary tract stone compositions: the role of age and gender

ABSTRACT Objective: To analyze the compositions of upper urinary tract stones and investigate their distributions in different gender and age groups. Materials and Methods: Patients diagnosed with upper urinary tract stone disease between December 2014 and March 2018 were retrospectively reviewed. Patient's age, gender, BMI, comorbidities, stone event characteristics, and compositions were collected, and proportions of stone components in different gender and age groups were analyzed. Results: A total of 1532 stone analyses were performed (992 from males and 540 from females). The mean age was younger in males (p <0.001). Males included more cases with larger BMI, hyperuricemia, and obesity, while females had more urinary tract infections. Multiple components were present in 61.8% of stones. Calcium oxalate (CaOx) (67.0%) was the most common component, followed by uric acid (UA) (11.8%), infection stone (11.4%), calcium phosphate (CaP) (8.0%), cystine (1.1%), brushite (0.4%), and 2, 8-dihydroxyadenine (0.2%). Men contributed with more CaOx stones than women at age 30-49 years (all p <0.01) and more UA stones at 30-59 years (all p <0.05). Women contributed with more infection stones than men in age groups 30-49 and 60-69 years (all p <0.05), and more CaP stones at 30-49 years. The prevalence peak was 50-59 years in men and 60-69 years in women. Both genders had the lowest prevalence in adolescence. Prevalence of UA stones increased while that of infection stones decreased with aging in both genders. Conclusions: Age and sex had a strong association with distribution of stone compositions in this Chinese cohort.

Evaluation of low-dose dual energy computed tomography for in vivo assessment of renal/ureteric calculus composition

PURPOSE: This study aimed to assess the accuracy of low-dose dual-energy computed tomography (DECT) in predicting the composition of urinary calculi. MATERIALS AND METHODS: A total of 52 patients with urinary calculi were scanned with a 128-slice dual-source DECT scanner by use of a low-dose protocol. Dual-energy (DE) ratio, weighted average Hounsfield unit (HU) of calculi, radiation dose, and image noise levels were recorded. Two radiologists independently rated study quality. Stone composition was assessed after extraction by Fourier transform infrared spectroscopy (FTIRS). Analysis of variance was used to determine if the differences in HU values and DE ratios between the various calculus groups were significant. Threshold cutoff values to classify the calculi into separate groups were identified by receiver operating characteristic curve analysis. RESULTS: A total of 137 calculi were detected. FTIRS analysis differentiated the calculi into five groups: uric acid (n=17), struvite (n=3), calcium oxalate monohydrate and dihydrate (COM-COD, n=84), calcium oxalate monohydrate (COM, n=28), and carbonate apatite (n=5). The HU value could differentiate only uric acid calculi from calcified calculi (p80% sensitivity and specificity to differentiate them. The DE ratio could not differentiate COM from COM-COD calculi. No study was rated poor in quality by either of the observers. The mean radiation dose was 1.8 mSv. CONCLUSIONS: Low-dose DECT accurately predicts urinary calculus composition in vivo while simultaneously reducing radiation exposure without compromising study quality.

Can a dual-energy computed tomography predict unsuitable stone components for extracorporeal shock wave lithotripsy?

PURPOSE: To assess the potential of dual-energy computed tomography (DECT) to identify urinary stone components, particularly uric acid and calcium oxalate monohydrate, which are unsuitable for extracorporeal shock wave lithotripsy (ESWL). MATERIALS AND METHODS: This clinical study included 246 patients who underwent removal of urinary stones and an analysis of stone components between November 2009 and August 2013. All patients received preoperative DECT using two energy values (80 kVp and 140 kVp). Hounsfield units (HU) were measured and matched to the stone component. RESULTS: Significant differences in HU values were observed between uric acid and nonuric acid stones at the 80 and 140 kVp energy values (p or =90%, calcium oxalate dihydrate group: monohydrate<90%). Significant differences in HU values were detected between the two groups at both energy values (p<0.001). CONCLUSIONS: DECT improved the characterization of urinary stone components and was a useful method for identifying uric acid and calcium oxalate monohydrate stones, which are unsuitable for ESWL.

Medical and Dietary Therapy for Kidney Stone Prevention

The prevalence of kidney stone disease is increasing, and newer research is finding that stones are associated with several serious morbidities. These facts suggest that emphasis needs to be placed not only on stone treatment but also stone prevention. However, there is a relative dearth of information on dietary and medical therapies to treat and avoid nephrolithiasis. In addition, studies have shown that there are many misconceptions among both the general community and physicians about how stones should be managed. This article is meant to serve as a review of the current literature on dietary and drug therapies for stone prevention.

Investigação de nefrolitíase no Oeste do Paraná / Investigation of nephrolithiasis in the West of Paraná

INTRODUÇÃO: Nefrolitíase é comum e tem alta taxa de recorrência. OBJETIVOS: Avaliar a prevalência das principais alterações metabólicas e anatômicas e a análise química do cálculo encontrado em pacientes com nefrolitíase na região Oeste do Paraná. MÉTODOS: Foi realizado um estudo retrospectivo em 681 pacientes adultos com nefrolitíase. A investigação laboratorial incluiu pelo menos duas amostras de urina de 24 horas, com dosagens de cálcio, ácido úrico, citrato, oxalato, sódio e creatinina; cistinúria qualitativa, pH urinário após 12 horas de jejum e restrição hídrica, urocultura e análise química do cálculo, quando disponível. Técnicas de imagem renal incluíram pelo menos ultrassonografia e urografia excretora. RESULTADOS: As alterações metabólicas mais frequentemente encontradas foram: hipercalciúria (51,8 por cento), hiperuricosúria (27,6 por cento) e hipocitratúria (23,5 por cento). A análise química dos cálculos mostrou oxalato de cálcio em 85,7 por cento dos casos. As alterações anatômicas mais frequentes foram: cisto renal, duplicação pieloureteral e obstrução da junção pieloureteral. CONCLUSÕES: Este trabalho serviu de base para o conhecimento das características de pacientes com nefrolitíase na região Oeste do Paraná.

INTRODUCTION: Nephrolithiasis is com>mon and has a high rate of recurrence. OBJECTIVES: To assess the prevalence of the main metabolic and anatomical changes and the chemical analysis of stone found in patients with nephrolithiasis in the West region of Paraná. METHODS: Retrospective study with 681 adult patients with nephrolithiasis. The laboratory investigation included at least two samples of 24-hour urine test with doses of calcium, uric acid, citrate, oxalate, sodium and creatinine; qualitative cystinuria, urinary pH following 12-hour fast and water restriction, urine culture and chemical analysis, when the stones were available. Renal imaging techniques included at least renal ultrasound and excretory urogram. RESULTS: The metabolic changes most frequently found were: hypercalciuria (51.8 percent), hyperuricosuria (27.6 percent), and hypocitraturia (23.5 percent). Chemical analysis of stones showed calcium oxa late in 85.7 percent of the cases. The most frequently anatomical changes were renal cyst, duplicated ureter, and ureteropelvic junction obstruction. CONCLUSIONS: This paper served as a base for knowing the characteristics of patients with nephrolithiasis in the West area of Paraná.

Comparison of quality of life between hemodialysis patients waiting and not waiting for kidney transplant from a poor region of Brazil / Comparação da qualidade de vida entre pacientes em hemodiálise aguardando e não aguardando transplante renal em uma região pobre do Brasil

INTRODUCTION: There are few data about the quality of life (QOL) level among patients undergoing hemodialysis (HD) and not eligible for kidney transplant. OBJECTIVE: The QOL level was compared between HD patients waiting and not waiting for kidney transplant. METHODS: We included 161 end-stage renal disease patients undergoing HD, during April, 2009. All patients were older than 18 years old, had been on HD at least three months, and had no previous transplantation. To measure QOL, the SF-36 was used. We also collected data about death and transplants in the 12 months after April, 2009. QOL scores were compared by analysis of variance with covariates. RESULTS: Patients not awaiting transplantation were older (53.7 versus 36.3 years old; p < 0.001), more often had diabetes (15.8 versus 4.7 percent; p = 0.032) and hypertension (35.5 versus 12.9 percent; p < 0.001), and had no lupus (0 versus 4.7 percent; p = 0.001). They also presented lower creatinine levels (11.5 versus 13.5 mg/dL; p = 0.001) and were submitted to a lower dose of dialysis, estimated by Kt/V (1.6 versus 2.0; p = 0.026). Patients not awaiting transplant died more often in the following 12 months (21.1 versus 5.9 percent; p = 0.005). Adjusted mean scores were lower among patients not awaiting transplant regarding six dimensions of QOL: functional capacity (42.0 versus 53.4; p = 0.022), physical limitation (29.9 versus 49.2; p = 0.030); pain (45.0 versus 64.0; p = 0.003), social aspects (56.3 versus 75.9; p = 0.003), emotional aspects (45.1 versus 79.0; p = 0.001), and mental health (50.1 versus 64.3; p = 0.004). CONCLUSIONS: Patients undergoing HD and not awaiting transplant are at risk of poor QOL level, mainly regarding role-emotional and role-physical aspects. We recommend psychological approaches and physical rehabilitation for this group of patients.

INTRODUÇÃO: Há pouca informação acerca do nível de qualidade de vida (QV) entre pacientes em hemodiálise (HD) não-elegíveis para transplante renal. OBJETIVO: Foi comparado o nível de QV entre pacientes em HD inscritos e não-inscritos na lista de espera para transplante renal. MÉTODOS: Foram incluídos 161 pacientes portadores de doença renal crônica terminal, mantidos em HD durante abril de 2009, com mais de 18 anos, mais de três meses em HD e sem realização de transplante prévio. Para medida de QV, utilizou-se o SF-36. Também foram coletados dados sobre óbito e transplante ocorridos nos 12 meses seguintes a abril de 2009. As pontuações de QV foram comparadas pela análise de variância com covariáveis. RESULTADOS: Pacientes que não aguardavam transplante eram mais velhos (53,7 versus 36,3 anos; p < 0,001), tinham mais diabetes (15,8 versus 4,7 por cento; p = 0,032) e hipertensão (35,5 versus 12,9 por cento; p < 0,001) e não apresentavam lúpus (0 versus 4,7 por cento; p = 0,001). Esses pacientes também apresentavam creatinina mais baixa (11,5 versus 13,5 mg/dL; p = 0,001) e eram submetidos a menor dose de diálise, estimada pelo Kt/V (1,6 versus 2,0; p = 0,026). Pacientes que não aguardavam transplante evoluíram mais frequentemente para óbito no período de 12 meses (21,1 versus 5,9 por cento; p = 0,005). As médias ajustadas das pontuações foram mais baixas entre os pacientes que não aguardavam transplante em seis dimensões da QV: capacidade funcional (42,0 versus 53,4; p = 0,022); limitação por aspectos físicos (29,9 versus 49,2; p = 0,030); dor (45,0 versus 64,0; p = 0,003); aspectos sociais (56,3 versus 75,9; p = 0,003); limitação por aspectos emocionais (45,1 versus 79,0; p = 0,001) e saúde mental (50,1 versus 64,3; p = 0,004). CONCLUSÕES: Pacientes em HD que não aguardam transplante estão em risco de vivenciar baixa QV, principalmente no que se refere à limitação por aspectos emocionais e físicos...

Characterization of biominerals in species of Canna (Cannaceae)

Plant biominerals are not always well characterized, although this information is important for plant physiology and can be useful for taxonomic purposes. In this work, fresh plant material of seven wild neotropical species of genus Canna, C. ascendens, C. coccinea, C. indica, C. glauca, C. plurituberosa, C. variegatifolia and C. fuchsina sp. ined., taken from different habitats, were studied to characterize the biominerals in their internal tissues. For the first time, samples from primary and secondary veins of leaves were investigated by means of infrared spectroscopy, complemented with X-ray powder diffractometry and scanning electron microscopy. The spectroscopic results, supported by X-ray powder diffractometry, suggest that the calcium oxalate is present in the form of whewellite (CaC2O4×H2O) in all the investigated samples. It is interesting to emphasize that all IR spectra obtained were strongly similar in all species studied, thus indicating an identical chemical composition in terms of the biominerals found. In this sense, the results suggest that the species of Canna show similar ability to produce biogenic silica and produce an identical type of calcium oxalate within their tissues. These results can be an additional trait to support the relationship among the families of Zingiberales. Rev. Biol. Trop. 58 (4): 1507-1515. Epub 2010 December 01.

Los biominerales de las plantas no siempre han sido bien caracterizados aunque esta información es importante en fisiología vegetal y puede ser de utilidad para fines taxonómicos. En este trabajo se estudió material vegetal fresco de siete especies silvestres neotropicales: Canna, C. ascendens, C. coccinea, C. indica, C. glauca, C. plurituberosa, C. variegatifolia and C. fuchsina sp. ined., provenientes de diferentes localidades, con el fin de caracterizar los biominerales presentes en sus tejidos foliares internos. Por vez primera, muestras de venas primarias (ejes foliares) y secundarias de hojas de estas especies se investigaron por medio de espectroscopia de infarrojo, complementada con estudios por difracción de rayos X de polvos y microscopía electrónica de barrido. Los resultados indicaron la presencia de ópalo (sílice biogénica) y oxalato de calcio en los tejidos vegetales analizados. Además, se determinó que el oxalato de calcio está presente en forma de whewellita (CaC2O4×H2O), información nueva para el género. Tanto el ópalo como la whewellita están presentes en todas las especies analizadas, que representan aproximadamente un tercio de las especies silvestres del género. La capacidad de biomineralizar SiO2 en forma de ópalo en especies de Canna de diversos ambientes resulta también un rasgo altamente sugerente para futuros estudios.

A nefrocalcina é uma proteína ligada à membrana?: uma hipótese bioquímica / Is nephrocalcin a membrane-bound protein?: a biochemical generate hypothesis

Introdução: A nefrocalcina (NC) é uma glicoproteína urinária que desempenha papel importante na inibição da cristalização do oxalato de cálcio (OxCa). A NC ocorre em pelo menos quatro isoformas (NC-A, B, C e D). As isoformas da NC são fosfoproteínas, mas a quantidade anormalmente elevada de resíduos de fosfato, em especial nas NC-C e D é intrigante. A NC poderia revestir a superfície de células epiteliais renais para evitar adesão de cristais de OxCa e conjugar fosfolípides da membrana em sua molécula. Objetivo: O objetivo deste trabalho foi identificar e caracterizar os fosfolipídios presentes na molécula de NC. Material e Métodos: A NC e suas isoformas foram isoladas da urina de indivíduo não portador de nefrolitíase. O conteúdo de fosfato foi determinado em cada isoforma. A taxa de inibição de crescimento de cristais de OxCa causada pela NC foi medida pelo consumo do ácido oxálico. A separação de lipídios, fosfolípides e proteínas foi realizada utilizando-se o método de separação Triton X-114. Resultados: Foram identificados os seguintes compostos: fosfatidilcolina, fosfoeta-nolamina, fosfatidilinositol, triglicérides e lipídios neutros. A composição de aminoácidos das isoformas da NC não se alterou. Após a extração com Triton X-114, os resíduos de fosfato das isoformas B, C e D diminuíram quase 1/10 do valor original e os da isoforma A não se alteraram. A constante de dissociação em direção ao oxalato de cálcio não foi alterada. Conclusão: Estes dados indicam a presença de fosfolípides típicos de membrana celular presentes na molécula de NC. A NC, incluindo-se todas as suas isoformas, pode ser uma proteína ligada à membrana, ao conjugar fosfolípides e revestir a superfície de células epiteliais tubulares.

Introduction: Nephrocalcin (NC) is a urinary glycoprotein that plays an important role in the inhibition of calcium oxalate crystallization. NC occurs in at least four isoforms (NC-A, -B, -C, and -D). NC isoforms are phosphoproteins, but the abnormally high phosphate residues, particularly in NC-C and NC-D, are intriguing. It is possible that NC molecules could coat the surface of renal epithelial cells for preventing attachment of calcium oxalate crystals, and could conjugate membrane phospholipids (PL). Our objective was to identify and characterize PL in NC. Material and Methods: NC and its four isoforms were isolated from non-stone forming urine. Phosphate contents were determined. Crystal growth inhibition rate of NC toward calcium oxalate monohydrate crystals (COM) was measured by decrease of oxalic acid. Phase separation of lipids and PL from proteins was carried out by a phase separation method using Triton X-114. Results: The following compounds were identified: phosphatidylcholine, phosphoethanolamine, phosphatidylinositol, triglycerides, and neutral lipids. Amino acid composition of the four NC isoforms before and after extraction did not change. After Triton X-114 extraction, phosphate residues in isoforms B, C, and D were decreased nearly 1/10 of the original value. However, isoform A phosphate residues showed no change. Dissociation constant toward calcium oxalate was not significantly altered. Conclusions: These data indicate the presence of typical membrane PL in NC molecule. NC, including all its isoforms, could be a membrane bound protein, conjugating membrane PL and coating the surface of the epithelial renal cells.

Primary hyperoxaluria type 1 with a novel mutation.

Primary hyperoxaluria type 1 [PH1] is an autosomal recessive disorder caused by a deficiency of alanine-glyoxylate aminotransferase AGT, which is encoded by the AGXT gene. We report an Indian family with two affected siblings having a novel mutation in the AGXT gene inherited from the parents. The index case progressed to end stage renal disease at 5 months of age. His 4 month old sibling is presently under follow up with preserved renal function.

Pediatric urolithiasis in coastal Tunisia

We will try to show an outline of the clinical and biological characteristics of pediatric urolithiasis among Tunisian children in the coastal region. This retrospective study included 168 children below 16 years [100 boys and 68 girls] presented with urinary stones. Patients were reviewed in a multi-centric study with regard to age at diagnosis, sexual, historical, physical, laboratory, and radiologic findings. The physical and chemical analysis of stones was carried out by a stereomicroscope and infra-red spectroscopy respectively. Statistical analysis of data was carried out using software SPSS 11.0 for Windows. Statistical significance was determined using chi-square test. The sex ratio was 1.47. Clinical presentation of this pathology was dominated by abdominal pain [28%], hematuria [25.6%], dysuria [16.7%] and urinary tract infection [14.3%]. Stones were located in the upper urinary tract in 75.6% of cases. Of the urine cultures, 14.3% were positive. Whewellite is found more frequently in children stones than infants [P < 0.05] and was the main component in 46.4% of stone section and 55.4% of stone surface. Stuvite stones were more frequent among boys stones than girls' [11 Vs 2.9%] [P < 0.05]. The male prevalence of pediatric urolithiasis is less obvious in Tunisia. Calcium oxalate is the most frequent chemical compound in Tunisian pediatric urolithiasis

Renal stone disease: causes, evaluation and medical treatment / Calculose renal: causas, avaliação e tratamento médico

The purpose of the present review is to provide an update about the most common risk factors or medical conditions associated with renal stone formation, the current methods available for metabolic investigation, dietary recommendations and medical treatment. Laboratory investigation of hypercalciuria, hyperuricosuria, hyperoxaluria, cystinuria, hypocitraturia, renal tubular acidosis, urinary tract infection and reduction of urinary volume is based on the results of 24-hr urine collection and a spot urine for urinary sediment, culture and pH. Blood analysis for creatinine, calcium and uric acid must be obtained. Bone mineral density has to be determined mainly among hypercalciurics and primary hyperparathyroidism has to be ruled out. Current knowledge does not support calcium restriction recommendation because it can lead to secondary hyperoxaluria and bone demineralization. Reduction of animal protein and salt intake, higher fluid intake and potassium consumption should be implemented. Medical treatments involve the use of thiazides, allopurinol, potassium citrate or other drugs according to the metabolic disturbances. The correction of those metabolic abnormalities is the basic tool for prevention or reduction of recurrent stone formation.

O propósito desta revisão é apresentar uma atualização sobre os fatores de risco ou condições médica comuns associadas com a formação de cálculos renais, os métodos atualmente disponíveis para investigação metabólica, recomendações dietéticas e tratamento médico. A investigação laboratorial para hipercalciúria, hiperuricosuria, hiperoxalúria, cistinúria, hipocitratúria, acidose tubular renal, infecção do trato urinário e redução do volume urinário, é baseada nos resultados das coleções de urina de 24h e amostra isolada para sedimento urinário, cultura e pH. Deve-se obter análises sanguíneas para creatinina, cálcio e ácido úrico. Deve-se determinar a densidade mineral óssea especialmente entre pacientes hipercalciúricos, e o hiperparatiroidismo primário deve ser excluído. O conhecimento atual não endossa as recomendações de restrição de cálcio, já que isto pode levar o hiperaxalúria secundária e desmineralização óssea. Redução da ingesta de proteína animal e de sal deve ser implementada junto com aumento da ingesta de líquidos e do consumo de potássio. Tratamento medicamentoso envolve o uso de tiazídicos, alopurinol, citrato de potássio ou outras drogas, conforme o distúrbio metabólico. A correção dessas anormalidades metabólicas é o instrumento básico para a prevenção ou redução da formação recorrente de cálculos.

Radiological morphology of calcium oxalate stones and their fragility in relation to their mono and dihydrate content

Eighty patients were treated for calcium oxalate urolithiasis with a diameter between 10 and 22 mm were subjected to a radiomorphological study of the surgically or endourologically extracted stones. X-ray densitometry of the stones and infrared spectroscopic urolith analysis were also performed. Sixty patients were treated with ESWL monotherapy. The success rate of stone fragmentation was determined by the total energy required in joules to fragment the stones. A definite radiological pattern was illustrated for the monohydrate, dihydrate and the mixed stones. Also, calcium oxalate monohydrate, stones acquired the highest optical density and required the highest energy for complete fragmentation. There was also an insignificant difference in the optical density regarding the different diameters of the oxalate stones. Therefore, calcium oxalate monohydrate stones are characterized by particular hardness and might not be recommended for ESWL monotherapy even in the 10-20 mm diameter zone

Biochemical and bacteriological study of urinary calculi.

Biochemical and bacteriological study of urine, nidus and chemical analysis of 100 calculi from 100 patients admitted in the Regional Institute of Medical Sciences, Imphal from November, 1997 to October 1999 were done. About 47% of the cases had positive urine culture and nidus culture. Escherichia coli was the commonest bacteria isolated both in the urine and nidus of calculi. The commonest radical present in the calculi was calcium while the rarest was uric acid. The stones were composed mainly of calcium oxalate and/or phosphate followed by struvite, then mixed stone.

Pattern of urinary calculi in Faisalabad

To find out the pattern of constituents of urinary calculi in Faisalabad. DESIGN: Consecutive case study. SETTING: Urinary stones received from government and private hospitals by pathology department of Punjab Medical College, Faisalabad. PERIOD: January, 1992 to December, 1994. SUBJECT: One hundred and eighty three patients [n = 183] with urinary stones disease [n

Observations: the chemical profile of urinary calculi

Rental stone disease is an etiologically heterogenous problem associated with a high rate of recurrence. The biochemical profile of urinary calculi removed from the urinary tract of 48 patients in urology ward, Mayo Hospital Lahore was determined. The distribution of stone analysis was calcium oxalate with uric acid 46%, calcium oxalate with phosphate 27%, pure calcium oxalate 19%. Magnesium ammonium phosphate with calcium oxalate 6%, and pure uric acid 2%. The incidence of urolithiasis in upper urinary tract was higher than lower urinary tract in adults. This study suggests calcium oxalate stones to be the most common type

Evaluation of Musa (Paradisiaca Linn. cultivar)--"Puttubale" stem juice for antilithiatic activity in albino rats.

The fresh juice of Musa stem (Puttubale) was tested for its antilithiatic activity. Zinc discs were implanted in the urinary bladder of albino rats to induce urolithiasis. The stones formed were mainly of magnesium ammonium phosphate with traces of calcium oxalate. Musa stem juice (3 mL/rat/day orally) was found to be effective in reducing the formation and also in dissolving the pre-formed stones.

Análisis de cálculos urinarios por el método de espectroscopía de rayos infrarrojos / Urinary calculi analysis by infrared spectroscopy technique

Se analizaron 437 cáclculos por el método de espectroscopia de rayos infrarrojos, los principales componentes químicos encontrados fueron: oxalato de calcio, oxalato y fosfato de calcio, ácido úrico, fosfato amónico magnésico y fosfato de calcio. El método utilizado es uno de los más recomendables para el análisis de estos cálculos en un laboratorio clínico, por lo que se debe descartar el método químico cualitativo, pues sus resultados no son confiables