Hyperoxaluria in a Model of Mini-Gastric Bypass Surgery in Rats.

BACKGROUND: Bariatric surgery is associated with hyperoxaluria hence predisposing to nephrolithiasis. The present study aimed to investigate the underlying mechanisms contributing to increased urinary oxalate in a mini-gastric bypass (MGB) surgery model in rats under different dietary conditions. The expression of intestinal oxalate transporters was also evaluated. METHODS: Male rats underwent MGB (n = 21) or Sham procedure (n = 21) and after recovery were fed a standard or high-fat diet with or without oxalate for 8 weeks. Stool and urine were collected before surgery (baseline) and at the end of protocol (final), when intestinal fragments were harvested for expression of Slc26a3 and Slc26a6 oxalate transporters. RESULTS: MGB groups fed with fat, irrespective of oxalate supplementation, presented steatorrhea. In MGB animals fed with fat and oxalate (Fat + Ox), final values of urinary oxalate and calcium oxalate supersaturation risk were markedly and significantly increased versus baseline or Sham animals under the same diet, as well as MGB groups under other diets. Slc26a3 was decreased in biliopancreatic limbs of MGB rats, probably reflecting a physiological adaptation to the restriction of food passage. Slc26a6 was not altered in any harvested intestinal fragment. CONCLUSIONS: A high-fat and oxalate diet induced hyperoxaluria and elevation in calcium oxalate supersaturation risk in a MGB rat model. The presence of fat malabsorption and increased dietary oxalate absorption, but not modifications of Slc26a3 and Slc26a6 oxalate transporters, accounted for these findings, suggesting that bariatric patients may benefit from a low-fat and low-oxalate diet.

Circumcisions for medical reasons in the Brazilian public health system: epidemiology and trends.

OBJECTIVE: To evaluate the epidemiological factors associated to medical circumcision, based on data from the Brazilian public health system. METHODS: Using the Unified Health System public database between 1984 and 2010, hospital admissions associated with surgical treatment of phimosis were searched. A total of 668,818 men admitted to public hospitals who underwent circumcision were identified and included in the present study. RESULTS: A mean±standard deviation of 47.8±13.4 circumcisions/100,000 men/year was performed through the Unified Health System for medical reasons. During the 27-year period evaluated, 1.3% of the male population required circumcision for medical reasons. Total number of circumcisions and circumcision rate increased in childhood, declined progressively after 5 years of age and rose again progressively after the sixth decade of life. In the regions of the country with better access to healthcare, 5.8% of boys aged 1 to 9 years old required circumcisions. From 1992 to 2010 there were 63 deaths associated with circumcisions (mortality rate of 0.013%). CONCLUSION: In conclusion, yearly circumcision rates could be estimated in Brazil, and a very low mortality rate was associated with this procedures. Circumcision is mostly performed in children in the first decade of life and a second peak of incidence of penile foreskin diseases occurs after the sixth decade of life, when circumcision is progressively performed again.