Use of the probability of stone formation (PSF) score to assess stone forming risk and treatment response in a cohort of Brazilian stone formers

Introduction The aim was to confirm that PSF (probability of stone formation) changed appropriately following medical therapy on recurrent stone formers. Materials and Methods Data were collected on 26 Brazilian stone-formers. A baseline 24-hour urine collection was performed prior to treatment. Details of the medical treatment initiated for stone-disease were recorded. A PSF calculation was performed on the 24 hour urine sample using the 7 urinary parameters required: voided volume, oxalate, calcium, urate, pH, citrate and magnesium. A repeat 24-hour urine sample was performed for PSF calculation after treatment. Comparison was made between the PSF scores before and during treatment. Results At baseline, 20 of the 26 patients (77%) had a high PSF score (> 0.5). Of the 26 patients, 17 (65%) showed an overall reduction in their PSF profiles with a medical treatment regimen. Eleven patients (42%) changed from a high risk (PSF > 0.5) to a low risk (PSF < 0.5) and 6 patients reduced their risk score but did not change risk category. Six (23%) patients remained in a high risk category (> 0.5) during both assessments. Conclusions The PSF score reduced following medical treatment in the majority of patients in this cohort. .

Metabolic assessment of elderly men with urolithiasis

OBJECTIVE: To assess the presence of metabolic disorders in elderly men with urolithiasis. METHODS: We performed a case-control study. The inclusion criteria were as follows: (1) men older than 60 years of age and either (2) antecedent renal colic or an incidental diagnosis of urinary lithiasis after age 60 (case arm) or (3) no antecedent renal colic or incidental diagnosis of urolithiasis (control arm). Each individual underwent an interview, and those who were selected underwent all clinical protocol examinations: serum levels of total and ionized calcium, uric acid, phosphorus, glucose, urea, creatinine and parathyroid hormone, urine culture, and analysis of 24-hour urine samples (levels of calcium, citrate, creatinine, uric acid and sodium, pH and urine volume). Each case arm patient underwent two complete metabolic urinary investigations, whereas each control arm individual underwent one examination. ClinicalTrials.gov: NCT01246531. RESULTS: A total of 51 subjects completed the clinical investigation: 25 in the case arm and 26 in the control arm. In total, 56% of the case arm patients had hypocitraturia (vs. 15.4% in the control arm; p = 0.002). Hypernatriuria was detected in 64% of the case arm patients and in 30.8% of the controls (p = 0.017). CONCLUSION: Hypocitraturia and hypernatriuria are the main metabolic disorders in elderly men with urolithiasis.

Effects of repeated extracorporeal shock wave in urinary biochemical markers of rats / Avaliação dos fatores bioquímicos urinários de risco para nefrolitíase em ratos submetidos à aplicação repetida de ondas de choque eletro-hidráulicas

PURPOSE: To access the effect of repeated extracorporeal shock wave (ESW) on urinary biochemical markers METHODS: 20 rats were assigned for ESW (Direx Tripter X1® - 14 KV) to one of two groups: G1 (n=10) one ESW; G2 (n=10) two ESWs within a 14-day interval. Within the twenty-four hour period before and after the application of shock waves, the animals were placed in metabolic cages for 24 hour urine collection. The ph, creatinine, sodium, potassium, chlorides, calcium, magnesium, phosphorus, oxalates, alkaline phosphatase and citrates were measured. Twenty-four hours after the material was collected for urinary determination, the animals underwent nephrectomy of the kidney submitted to the ESW applications and were, then, sacrificed. The kidneys were processed for hispatological examination. RESULTS: Small variations in the biochemical markers were found in both groups, with no significant differences between the values obtained either prior to or following the ESW applications, except for citrate and alkaline phosphatase. Citraturia decreased significantly in group 2, following the second ESWL application (24.8 ± 3.0 mg/day after the first ESWL vs. 15.3 ± 2.2 mg/day after the second ESWL; p < 0.05). Alkaline phosphatase increased significantly following ESWL in group I (0.57 ± 0.02 vs. 0.79 ± 0.04 µmol/mg creatinine; p < 0.01) and also in group 2 (0.69 ± 0.05 vs. 0.83 ± 0.03 µmol/mg creatinine; p < 0.05). Glomerular, interstitial and sub-capsular hemorrhage with perivascular edema was found in the animals in both groups studied. CONCLUSIONS: A significant increase in urinary alkaline phosphatase was found in both groups studied, suggesting a proximal tubule lesion. In the group of rats undergoing more than one ESWL application, a smaller urinary citrate excretion was noticed, which may be a factor contributing for the formation of new calculi.

OBJETIVO: Avaliar os efeitos renais das ondas de choque eletro-hidráulicas (OCEH), utilizando como parâmetros marcadores bioquímicos urinários. MÉTODOS: Foram utilizados 20 ratos machos, EPM - Wistar, distribuídos aleatoriamente em dois grupos: G1 (n=10) Animais submetidos a uma sessão de OCEH. G2 (n=10) Animais submetidos a duas sessões de OCEH separadas por um intervalo de 14 dias. Para coleta da urina os animais foram mantidos em gaiolas metabólicas 24 horas antes e depois da aplicação das OCEH. Foram medidos o pH, a creatinina, sódio, potássio, cloretos, cálcio, magnésio, fósforo, oxalato, fosfatase alcalina e citrato. Vinte e quatro horas após a coleta da urina os animais foram submetidos à nefrectomia do rim envolvido no experimento e, em seguida, sacrificados. Os rins foram então submetidos aos procedimentos de fixação e coloração histológica com hematoxilina e eosina. RESULTADOS: Pequenas variações nos marcadores bioquímicos foram detectadas nos dois grupos, sem diferenças significantes nos valores obtidos antes e após a aplicação das OCEH, exceto para os valores urinários de citrato e fosfatase alcalina. A citratúria diminuiu significantemente nos animais do Grupo 2 após a segunda aplicação das OCEH( 24,8 ± 3,0 mg/dia após a primeira sessão de OCEH e 15,3 ± 2,2 mg/dia após a segunda sessão de OCEH; p < 0.05). A fosfatase alcalina urinária aumentou de forma significante no grupo 1 após a sessão de OCEH (0,57 ± 0,02 vs. 0,79 ± 0,04 µmol/mg de creatinina; p < 0,01) e também no grupo 2 (0,69 ± 0,05 vs. 0,83 ± 0,03 µmol/mg de creatinina; p < 0,05). Os achados histológicos observados nos animais dos dois grupos foram: hemorragia glomerular, intersticial e subcapsular, acompanhada de edema perivascular. CONCLUSÕES: Observou-se um aumento significante da fosfatase alcalina urinária nos dois grupos estudados, sugerindo uma lesão dos túbulos proximais causada pelas ondas de choque eletro-hidráulicas. Nos animais submetidos a mais de uma ...

Litiasis renal: modificaciones bioquimicas durante el seguimiento / Renal lithiasis: biochemical changes in the follow-up

Con el objeto de evaluar si se producen modificaciones bioquímicas durante el seguimiento de pacientesnefrolitiásicos, se estudiaron 237 pacientes (115 mujeres y 122 hombres con una edad promediode 39 ± 8 y 42 ± 7 años respectivamente) controlados durante 23.7 ± 19.3 meses. A todos se les realizó un estudio metabólico de litiasis renal inicial y como mínimo uno o más posteriormente con las mismas características que el basal. No fueron incluidos pacientes con los diagnósticos de riñón en esponja, acidosis renotubular, hiperparatiroidismo primario, malformaciones renales o infecciones urinarias. Del total de pacientes, 139 (Grupo I) presentaron en el seguimiento una modificación metabólica no evidenciada en el estudio inicial, mientras que 98 (Grupo II) no. El tiempo de seguimiento de los primeros, no fue significativamente diferente de aquellos que no modificaron el diagnóstico basal. Las alteraciones bioquímicas agregadas más frecuentes fueron, hipocitraturia en el 43.1%, hipercalciuria idiopática en 20.8% y alteraciones del ácido úrico en 16.5%. De 110 pacientes seguidos más de 3 años, 37 (33%) recurrieron. De éstos, 25 (23%) modificaron el diagnóstico metabólico basal vs. 12 (11%) que mantuvieron el mismo diagnóstico (p < 0.002). Cambios en las alteraciones bioquímicas fueron observados con frecuencia en el seguimiento de pacientes con nefrolitiasis. Estos cambios no se asocian necesariamente a la dieta o a las drogas administradas. La hipocitraturia fue el diagnóstico bioquímico más frecuentemente agregado. Observamos mayor recurrencia en aquellos que modificaron el diagnóstico inicial y cuya modificación no fue corregida durante el seguimiento.

With the aim of assessing if biochemicalchanges occur in the follow up of patients with renal lithiasis, 237 patients were studied (115 womenand 122 men, mean age 39 ± 8 and 42 ± 7 years, respectively) and controlled during 27.3 ± 19.3 months. All ofthem had previously undergone metabolic evaluations at baseline and one or more than one control studies afterwards. Patients with a diagnosis of sponge kidney, renal tubular acidosis, primary hyperparathyroidism, anatomical malformations of the urinary tract, or urinary infections were not included. Two populations were identified: those who presented changes in the baseline diagnosis (139 patients, Group I) and those who presentedno changes (98 patients, Group II). In these groups, no differences were observed in baseline metabolic diagnoses or in the follow-up period. Hypocitraturia was the additional diagnosis most frequently observed (43.1%), followed by Idiopatic hypercalciuria (20.8%) and abnormalities of uric acid (16.5%). In the group of 110 patients followed up for more than 3 years, 37 patients recurred (33%). Among the latter, 25 (23%) changed the baseline metabolic diagnosis vs. 12 (11%) that maintained the same diagnosis (p < 0.002). Changes in metabolic disorders were frequently observed in the follow up of patients with nephrolithiasis. These changes are not necessarily associated with the diet indicated or drug treatment. Hypocitraturia was the additional metabolic disorder mostfrequently found. In general, there is a higher recurrence rate in those patients who present changes in their biochemical parameters and undergo no treatment.

Comparison of 24 hours urinary citrate levels in urolithiasis patients and healthy controls

To identify the difference in urinary citrate excretion between Stone Formers [SF] and Healthy Volunteers [HV] as a metabolic risk factor, that predisposes to urinary stone formation and to compare levels of urinary citrate in [HV] with reference values. The 24 hours urinary citrate was evaluated in 40 patients treated for renal citrate and declared stone free, and 40 age matched healthy adults taken as controls. Both the groups had a similar living environment, extrinsic factors, diet and similar genetic descent. There was no significant difference in urinary citrate excretion level among stone formers [mean 262 SD 197] and normal volunteer subjects [mean 269 SD 140]. Using the previously defined normal values [200] of urinary citrate in the local population, 55% of stone patients in our study group were hypocitric. While using the same value, 45% of our normal volunteers were also hypocitric. If 320 was taken as normal limit, 70% of the patient's population and 72% of controls were hypocitric. The prevalence of hypocitraturia was similar in the age matched adult groups. Certain intrinsic factors in our local subjects may account for the high prevalence of urolithiasis than in western population. Although the urinary citrate excretion of stone patients is similar to normal volunteers, uniformly low urinary citrate excretion may be a feature as a nation and not a predisposing factor for the lithogenesis. This supports the view that there may be more often prominent influences in stone formers possibly of genetic origin

Valores de referência de parâmetros urinários envolvidos na litogênese / Reference values of urinary parameters that participate in lithogenesis

Neste trabalho determinamos em nossa populaçao, os valores normais de parâmetros urinários que participam na formaçao de cálculos renais, bem como de creatinina comparando-os com os relatados na literatura. Os valores em média + desvio padrao (X+DP) do grupo controle (N=200) e do grupo formador de cálculos (N=200) sao respectivamente: citrato (525 + 160 vs 263 + 90 mg/24h, p<0,05), cálcio (149 + 50 vs 223 + 80 mg/24h, p<0,05), ácido úrico (556 + 130 vs 620 + 160 mg/24h, p<0,05), sódio (192 + 60 vs 208 + 60 mEq/24h, p<0,05), potássio (37 + 10 vs 43 + 10 mEq/24h, p<0,05), magnésio (81 + 17 vs 67 + 25 mg/24h, p<0,05) e creatinina (1409 + 340 vs 1436 + 320 mg/24h, p<0,05). Os valores para o citrato, cálcio, ácido úrico, sódio e creatinina para as mulheres-controles neste trabalho foram similares, enquanto que os valores para o potássio foram maiores e para o magnésio foram menores que os valores descritos na literatura. Os homens-controle apresentaram todos os parâmetros mais elevados, exceto para o citrato e potássio que foram menores que os da literatura. Comparando estes resultados com os valores da literatura internacional, observamos diferenças significantes, realçando a necessidade em normalizar os valores de referência para distintas populaçoes de formadores de cálculos renais.

Avaliaçäo da saturaçäo urinária em pacientes com doença inflamatória intestinal / Evaluation of urinary saturation in patients with inflamatory bowel disease

A doença inflamatória intestinal (DII), como a doença de Crohn (DC) e a retocolite ulcerativa (RCU), pode associar-se à litogênese devido a hiperoxalúria entérica. Na avaliaçao metabólica de 12 pacientes DII (6 DC e 6 RCU), sendo 3 com litíase recente, nao se observou alteraçao significante da média de excreçao de cálcio, ácido úrico e oxalato versus pacientes com litíase (LIT) sem DII. Hipocitratúria foi evidenciada em 6112 (5O por cento) e hiperuricosúria em 3/12 (25 por cento) dos pacientes. Estes dados sugerem que pacientes DII, mesmo sem apresentar hiperoxalúria, podem expor-se a maior risco de formaçao de cálculos, devido à hiperuricosúria e também à hipocitratúria, possivelmente decorrente do quadro diarréico crônico.

Seasonal changes in serum and erythrocyte potassium among renal stone formers from northeastern Thailand.

Hypocitraturia, hypokalemia and low urinary excretion of potassium are common findings in nephrolithiasis in Northeastern Thailand. However, intracellular potassium has not been studied. We measured serum potassium, erythrocyte potassium, 24-hour urinary excretion of sodium, potassium, citrate, ammonium, titratable acid and pH in 17 nephrolithiasis patients from Northeastern Thailand during 2 seasons: the cool and hot months. There were no significant differences in urinary pH, ammonium, titratable acid, citrate and potassium during these 2 seasons. However, hypocitraturia and hypokaliuria were observed in the majority of cases in both periods. Seasonal variation in serum potassium, erythrocyte potassium, urine volume and urinary excretion of sodium was observed. Values were significantly lower in the hot months. In the cool months, the urinary excretion of citrate correlated linearly with that of potassium (r = 0.696, p < 0.002). Such a correlation was not found in the hot months. We concluded that extracellular and intracellular potassium depletion might be present in these patients and is greater during the hot than during the cool months. The pathogenesis may be multi-factorial.

Avaliaçäo da citratúria normal em ratos / Evaluation of normal citraturia in rats

Em uma populaçäo de ratos Wistar, foi avaliado o padräo normal de excreçäo do citrato urinário, sendo observado que: 1) a citratúria normal variou amplamente, de animal para animal; 2) os animais mais idosos (AM > 350) excretaram menos citrato por mg de creatinina (4,7 vs. 7,8 umol de cit/mg de creat) ou citrato/100G PC (12,9 vs. 22,0umol cit/100G) rato do que os ratos mais jovens (AJM); 3) a concentraçäo urinária do citrato, creatinina, cálcio, fósforo, sódio e potássio tiveram correlaçäo linear negativa (p < 0,05) com o volume urinário; 4) a excreçäo do citrato (umol/24h) apresentou correlaçäo positiva (p < 0,05) com a excreçäo de 24 h da creatinina, cálcio, fósforo, sódio e potássio; 5) a concentraçäo e excreçäo urinária do citrato, em ratos Wistar, foi significatemente maior no período diurno (8 às 20hs) vs. período noturno (20 às 8h); 6) a excreçäo do citrato em urina de 24h dos ratos machos adultos jovens (AJM: 7,8 umol cit/mg creat ou 22,0umol cit/100g de rato) foi significantemente maior do que a das fêmeas adultas jovens (AJF: 6,0umol cit/mg creat ou 13,3umol/100g de rato

Determinación cuantitativa de oxalato y citrato en orina por isotacofóresis analítica capilar / Quantitative determination of oxalate and citrate in urine by capillary analytical isotachophoresis

En la urolitiasis activa, la hiperoxaluria y la hipocitraturia son considerados factores importantes en la producción de los cálculos renales. La determinación cuantitativa de oxalato en orina, hasta el momento actual, presenta una gran diversidad de métodos y ninguno estable, la determinación cuantitativa de citrato resulta costosa por los métodos actualmente establecidos. Presentamos un método isotacoforético aniónico para la cuantificación de oxalato y citrato en orina de forma simultánea con detección conductimétrica y diferencial acopladas ambas sobre la base del comportamiento iónico de estos metabolitos en los fluídos biológicos

Electrokinetic energy conversion by aqueous oxalic acid, citric acid, ascorbic acid, hippuric acid, and acetyl salicylic acid across urinary bladder membranes.

Efficiency of energy conversion for electro-osmosis and streaming potential and the degree of coupling of acids across urinary bladder membranes of goat have been computed using non-equilibrium thermodynamic theory. The energy conversion maxima and degree of coupling for acids responsible for the formation of urinary calculi are found to be much low as compared to urea and urine.

Determinaçäo do citrato urinário por técnica enzimática / Enzimatic estimation of urinary citrate

O citrato é um inibidor natural de cristais de exalato e fosfato de cálcio, que formam cálculos na urina. Portadores de urolitíase cálcica apresentam níveis urinários de citrato dominuídos. Sua dosagem é feita através de métodos enzimáticos com o uso de citrato lyase. Os autores descrevem a técnica enzimática empregada para dosagem de citrato urinário, testada num grupo de 10 voluntários, com resultados variando entre 150 e 720 mg/24h

Valores de citrato urinario en litiasis renal cálcica y úrica / Urinary citrate values in calcium nephrolithiasis and urolithiasis

El citrato urinario es uno de los compuestos inhibidores de la cristalización urinaria de fosfato, oxalato de calcio y de úrico, los cuales son los componentes demás del 80% de todos los cálculos renales. Es por ello que decidimos dosificar este inhibidor en la orina de pacientes productores de litiasis renal cálcica o úrica. El método empleado para dosificarlo fue la técnica enzimática de la de citrato liasa (Boheringer Mannheim) según la descripción de Moellering y Gruber. Nuestro estudio demostró que los valores de excreción urinaria de citrato en pacientes litiásicos está notablemente disminuida, sin importar el sexo, edad del paciente, tipo de cálculo formado o tipo de anomalía metabólica causante del trastorno. Además se encontró correlación inversa entre el valor de citrato urinario y el número total de cálculos producido por paciente

Citrato e urolitíase / Citrate and urolithiasis

Existem substâncias naturais na urina com propriedades inibitórias sobre a formaçäo de cálculos urinários. Uma das mais estudadas é o citrato, um ácido orgânico natural capaz de inibir "in vitro" o crescimento de cristais de fosfato e oxalato de cálcio. Estudos em portadores de cálculos urinários de cálcio mostraram a ocorrência de níveis baixos de citrato urinário e a possibilidade de tratamento com citrato de potássio via oral. Os autores revisaram o papel do citrato na inibiçäo da formaçäo de cálculos urinários de cálcio, juntamente com uma descriçäo do seu metabolismo, métodos de detecçäo, ocorrência de hipocitratúria e sua correçäo

Saturación urinaria con oxalato de calcio en urolitiasis / Urine saturation with calcium oxalate in urolithiasis

Mediante un programa de computación iterativo se calculó el Producto de Actividad (PA) del oxalato de calcio (OxCa) con datos de orina de 24 h de 30 pacientes litiásicos formadores de cálculos de OxCa y 30 controles sanos. Los resultados muestran una diferencia estadísticamente significativa entre los valores medios de ambos grupos, tanto en el PA como en la concentración urinaria de calcio, magnesio, citrato y oxalato. La mayor contribución relativa del oxalato y el citrato en el aumento y descenso, respectivamente, del PA es puesta de manifiesto. Se confirma la utilidad del cálculo del PA para establecer el riesgo aumentado de formar cálculos y el seguimiento del tratamiento instaurado