[Nephrolithiasis as a nephrectomy surgical indication. A multicentric study]. / Nefrolitiasis como indicación de nefrectomía. Estudio multicéntrico.

BACKGROUND: urolithiasis is endemic in Yucatan, Mexico, and its complications are abscesses and renal exclusion which end up in a nephrectomy. Our objective in this paper was to know the nephrectomy indications in Yucatecan population. METHODS: the nephrectomies from four concentrations hospitals of the Health Services, were analyzed. Patients older than 18 years were included; surgical indication, evolution time of the disease, and associated illnesses were registered. The diagnosis was confirmed by laboratory, X-rays or anatomopathological study. Statistics were t Student test and chi(2). RESULTS: 206 (70.5 %) women and 86 (29.5 %) men were included; they were 48 + or - 14 years of age with an evolution time 40 + or - 70 months. Nephrolithiasis was observed in 59.6 %, renal tumors 21.9 %, hydronephrosis 7.9 % and abscess 3.4 %. No cases with nephrolithiasis had metabolic studies. The cases with lithiasis (n = 174) had a longer evolution time and were younger at the time of the surgical procedure (p < 0.05) than those not related to lithiasis (n = 118). CONCLUSIONS: nephrolithiasis is the most frequent indication for nephrectomy in the Yucatecan population which differs from others reports.

[Four years experience in the follow up of nursing children with urolithiasis]. / Litiasis urinaria en lactantes. Seguimiento a cuatro años.

OBJECTIVE: to describe clinical data, metabolic profile, treatment and evolution of a nursing children cohort with urolithiasis. METHODS: using a descriptive, prospective and longitudinal design, were registered all patients with urolithiasis, of Pediatric Division at the Hospital General "Agustín O'Horán," in Yucatan, Mexico. We included all patients who were 36 months old and younger. We did not include children with malformations or associated disease which causes urolithiasis. Clinical and metabolic profiles, evaluation of the applied treatment as well as an evolution by four years period were done. RESULTS: 63 patients were recruited with ages ranging from 2 to 36 months; 39 (61.9 %) were male. The most common clinical signs were crying upon urination (49.2 %), urinary retention (31.7 %), hematuria (30.2 %), and pollakiuria (28.6 %). Calculus were most frequently located in the kidney (58.7 %). The most common complications were acute urinary tract infection (61.9 %), malnutrition (47.6 %) and acute renal failure (12.7 %). Documented metabolic alterations included hyperuricosuria (57.1 %), hypomagnesiuria (11.1 %) and hypercalciuria (9.5 %). CONCLUSIONS: urolithiasis should be suspected in children with crying upon urination and urinary symptoms; it should be considered among the different causes of renal failure; hyperuricosuria was the most frequent metabolic alteration.

Metabolic abnormalities and polymorphisms of the vitamin D receptor (VDR) and ZNF365 genes in children with urolithiasis.

Composition of urinary stones in children from Yucatán, México, is calcium and uric acid. Polymorphisms in VDR and ZNF365 genes have been associated to calcium and uric acid lithiasis, respectively. We evaluated the association of polymorphisms TaqI and FokI of VDR gene and Ala62Thr of ZNF365 gene with the metabolic disorders (MD) in children with urolithiasis (UL). We included 109 children with UL. Creatinine, calcium, phosphorus, magnesium, uric acid, oxalates and citrates were measured in fresh urine. Urinary indices were calculated for determining the MD. VDR and ZNF365 polymorphisms were determined by PCR-RFLP. Genotype frequencies were compared with the frequency of MD and with the averages of excretion of the analytes, using the statistical package STATA 11.0. The most frequent MD were hypocitraturia (35.8 %) and hyperuricosuria (22.9 %). The comparison of genotype frequencies with the frequency of MD did not show significant differences (p > 0.05). The comparison of the urinary excretion averages of analytes with respect to the genotype showed that GG homozygotes have higher concentrations of uric acid and citrate than AG heterozygotes (p = 0.03), and that fF heterozygotes have lower concentrations of citrate (p = 0.009). Hypocitraturia and hyperuricosuria were the most common metabolic disorders. The frequency of MD is not associated with polymorphisms. However, in children with urolithiasis of Yucatan, GG homozygotes excrete higher concentrations of uric acid and citrates, and fF heterozygotes have lower concentrations of citrates.

Epidemiología y clínica de la litiasis urinaria en niños / Epidemiological and clinical characteristics of urolithiasis in children

Establecer las características clínicas y demográficas de los pacientes pediátricos con litiasis urinaria (LU) de Yucatán, México. Métodos: Mediante diseño prospectivo y longitudinal se estudiaron todos los menores de 16 años con diagnóstico de LU, durante un período de 9 años; se registraron los datos clínicos, las alteraciones metabólicas, el tratamiento instituido, las complicaciones, las recurrencias, etcétera. Resultados: Se observaron 69 casos nuevos por año, con un aumento de la tasa de prevalencia del 19% en relación con lo informado en años previos. En los 474 pacientes estudiados se observó una relación varones: mujeresde 1:1.6, con edades desde 3 hasta 180 meses, con predominio de lactantes y escolares. Las alteraciones metabólicas más frecuentes fueron hiperuricosuria, hipercalciuria e hipocitraturia. El 27% tuvo sobrepeso u obesidad y el 32.7% talla baja. El 63.9% tuvo antecedente familiar y el 20.8% antecedente personal positivo de LU. El 7.1% se asoció con malformaciones urinarias. El 7.8% de los cálculos fueron hallazgos, detectándose en más de un sitio anatómico en el 29.1% de los casos. El cuadro clínico varió desde casos asintomáticos, hasta casos con datos clínicos de insuficiencia renal aguda o crónica. Conclusiones: Deben diseñarse programas de prevención, diagnóstico y tratamiento oportunos para disminuir la incidencia y complicaciones en niños con LU de Yucatán...