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Este es un estudio ex vivo donde se evalúa la variación en peso de veintiún piezas dentarias sometidas a un ácido dental de uso dental y, posteriormente, a la acción del gel remineralizante, objeto de este estudio, obteniéndose por diferencia de peso la cantidad de material mineral, que queda retenida en la pieza. La acción del ácido ortofosfórico ha producido una disminución del peso entre 28-30% de la pieza dentaria. Luego de la aplicación del gel remineralizante, ésta aumentó entre 15-18% del peso, considerando este aumento como significativo (p menor 0.05). Este aumento demuesta la acción remineralizante, ya que después del lavado este aumento se mantiene (AU)

This is an in vitro study where the variation in weight of twenty-one dental pieces subjected to a dental acid and subsequently to the action of the remineralizing gel is evaluated, obtaining by weight difference the amount of hydroxyapatite that is retained in the piece. The action of orthophosphoric acid causes a decrease in weight between 28-30% of the tooth. After the application of the remineralizing gel, it increases between 15-18% by weight considering this significant increase (p less 0.05) (AU)

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En un grupo de 46 niños y adolescentes (5-14 años de edad) con trastornos del espectro autista, consumo elevado de harinas y azucares en su dieta y antecedentes de consumo de antibióticos frecuentes, se analizan muestras de saliva, orina y materia fecal (n=15). Comparados con muestras de un grupo normal (n=10), se detectan variaciones significativas en el pH salival, tiempo de recuperación del pH, viscosidad, flujo, y valores elevados de IgA e IgG en saliva. En orina predomina la proteinuria y la acidez, en la materia fecal no se hallaron parásitos ni C albicans. Estos cambios pueden responder a fenómenos alérgicos y alteraciones de la permeabilidad intestinal aspectos que deben ser investigados luego, pero los resultados muestran variantes significativas que permitirán elegir los sujetos preferentes para futuras investigaciones y/o generar la sospecha para la derivación temprana de pacientes sin diagnóstico y con síntomas mínimos (AU)

Samples of saliva, urine and fecal (n=15) was analyzed in a group of 46 children and teenagers (5-14 years old) with autism spectrum disorders, high consumption of flour and sugar with diet, and a history of frequent antibiotic consumption. Compared to a group of normal children (n=10), significant variations in saliva composition as pH, time to pH recovery, viscosity, flux and IgA and IgG concentration were observed, proteinuria and acidity findings predominate in the urinalysis, and the absence of parasites and C Albicans were notices at the fecal samples. These changes can respond to immune-allergic and intestinal permeability conditions, aspects that should be further investigated. Patients with these findings can be preferentially select for future studies and/ or generate suspects in undiagnosed individuals with minimal symptoms that can be early derive to proper treatment (AU)

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The purpose of the present study was to compare the clinical characteristics of "pure" uric acid (UA) stone formers with that of "pure" calcium oxalate (CaOx) stone formers and to determine whether renal handling of UA, urinary pH, and urinary excretion of promoters and inhibitors of stone formation were different between the two groups. Study subjects comprised 59 patients identified by records of stone analysis: 30 of them had "pure" UA stones and 29 had "pure" CaOx nephrolithiasis. Both groups underwent full outpatient evaluation of stone risk analysis that included renal handling of UA and urinary pH. Compared to CaOx stone formers, UA stone formers were older (53.3 +/- 11.8 years vs. 44.5 +/- 10.0 years; P = 0.003); they had higher mean weight (88.6 +/- 12.5 kg vs. 78.0 +/- 11.0 kg; P = 0.001) and body mass index (29.5 +/- 4.2 kg/m(2) vs. 26.3 +/- 3.5 kg/m(2); P = 0.002) with a greater proportion of obese subjects (43.3% vs. 16.1%; P = 0.01). Patients with "pure" UA lithiasis had significantly lower UA clearance, UA fractional excretion, and UA/creatinine ratio, with significantly higher serum UA. The mean urinary pH was significantly lower in UA stone formers compared to CaOx stone formers (5.17 +/- 0.20 vs. 5.93 +/- 0.42; P < 0.0001). Patients with CaOx stones were a decade younger, having higher 24-h urinary calcium excretion (218.5 +/- 56.3 mg/24 h vs. 181.3 +/- 57.1 mg/24 h; P = 0.01) and a higher activity product index for CaOx [AP (CaOx) index]. Overweight/obesity and older age associated with low urine pH were the principal characteristic of "pure" UA stone formers. Impairment in urate excretion associated with increased serum UA was also another characteristic of UA stone formers that resembles patients with primary gout. Patients with pure CaOx stones were younger; they had a low proportion of obese subjects, a higher urinary calcium excretion, and a higher AP index for CaOx.

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BACKGROUND: The usefulness of bone mass measurements and bone turnover markers to estimate the risk of fracture and the type of underlying renal osteodystrophy are not well established in patients on peritoneal dialysis (PD). OBJECTIVE: To assess bone mass using total and regional bone densitometry in a group of patients on PD and to determine if serum markers of bone turnover identify patients with low bone mass. METHODS: Bone densitometry was studied by dual-energy x-ray absorptiometry (DEXA), and bone turnover using several serum markers, in 65 patients on PD. Bone mass was classified as normal, osteopenic, or osteoporotic according to World Health Organization criteria based on bone mineral density (BMD) T scores. RESULTS: T scores in the osteopenia range were present at the lumbar spine (LS) in 44.6% (45% of men and 44.4% of women) of patients and at the femoral neck (FN) in 56.9% (55% of men and 58% of women). T scores in the osteoporosis range were present at the LS in 13.8% of patients (10% of men and 15.5% of women) and at the FN in 21.5% (30% of men and 17.7% of women). Patients with BMD T scores in the osteoporosis range at both regions had increased serum intact parathyroid hormone (iPTH) levels compared to patients in the osteopenic/normal range. Bone mineral content in the whole skeleton (TBMC) correlated negatively with iPTH (r = -0.34) and with total time on dialysis (r = -0.26); in multivariate analysis, only iPTH correlated negatively with TBMC (B = -0.26, p = 0.03). No correlations were found between the other bone markers and BMD T scores at the FN or LS. There were no significant differences in absolute BMD or BMD T scores at the LS or FN between patients with and patients without fractures. CONCLUSIONS: BMD T scores in the osteopenia/osteoporosis range were observed at the LS in 58.4% of these patients on PD and at the FN in 78.4%. TBMC correlated negatively with iPTH. There were no correlations between markers of bone turnover and bone mass measurements at the two skeletal regions, although patients with BMD T scores in the osteoporosis range had increased serum iPTH levels. Bone mass measurements were not different between patients with and patients without fractures.

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Although urine phosphate loss has been associated with hypercalciuria, it is debated how frequently renal phosphate leak is present in hypercalciuric patients. We reviewed the records of 100 consecutive adult patients who were diagnosed with idiopathic hypercalciuria and calcium urolithiasis, searching for the presence of renal phosphate leak. The renal phosphate threshold, normalized for the glomerular filtration rate (TmPO4/GFR), of the hypercalciuric patients followed a normal distribution and had a good correlation with serum phosphate ( r=0.77; p<0.0001). There were no correlations between TmPO4/GFR and urinary calcium or between serum phosphorus and urinary calcium. We found only nine patients (9%) with renal phosphate leak. These patients had a mean TmPO4/GFR of 2.19 mg% (0.70 mmol/l) and serum phosphorus of 2.65 mg% (0.85 mmol/l). Nevertheless, urinary calcium was not significantly different between patients with or without low TmPO4/GFR. We conclude that renal phosphate leak is an infrequent finding in patients with idiopathic hypercalciuria and is not associated with a higher urinary calcium loss.

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OBJECTIVE: The aim of this study was to gain insight into the pathogenesis of bone mass loss and weakening affecting patients with celiac disease, according to the new concepts of bone structure/strength and muscle/bone interrelationships. METHODS: We studied serum variables and tomographic indicators of bone structure and strength and regional muscle masses in a series of patients at diagnosis and after 1 yr on a gluten-free diet and in gender- and age-matched controls. RESULTS: At diagnosis, serum levels of calcium and vitamin D were low, and indicators of parathyroid hormone activity and bone formation and resorption were increased. All these parameters were normalized by treatment. Peripheral quantitative CT scans of the distal radius revealed that cortical bone was generally more affected than trabecular bone. The cross-sectional area (CSA) and the volumetric mineral content and density of cortical bone (indicators of cortical tissue mass and mechanical quality), and moments of inertia (CSMI, indicator of the bone architectural design) were in the lower end of normal range in men, and below that in 50% of women. In men, the CSMI/CSA ratio (indicator of the architectural efficiency of distribution of the available cortical tissue) was lower than expected and remained unchanged after treatment. In women, the baseline ratio was normal, but both the ratio and the CSMI were low at diagnosis and normalized after treatment. Both baseline values and the treatment-induced changes of cortical and trabecular bone in the radius and the axis (L3) correlated inversely with serum parathyroid hormone levels. Baseline values or changes in the mineral content of the vertebral bone correlated with the CSA of psoas and spine-extensor muscles. Multiple regression analyses showed that metabolic and mechanical parameters were independent determinants of different aspects of the vertebral bone weakening. CONCLUSIONS: Our results show that bone weakening in celiac disease might result from both 1) a metabolic disturbances of bone remodeling affecting trabecular and cortical bone masses and the mechanical quality of the bone material, and 2) a reduction of muscle strength impairing the modeling-dependent optimization of bone architectural design and mass of cortical bone. Dietary treatment seems to correct almost exclusively the metabolically induced disturbances, which were predominant in women.

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