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.

Enfermedad celíaca del adulto / Adult celiac disease

Celiac disease is a chronic enteropathy caused by intolerance to gluten. The true prevalence of this condition is much greater than previously recognized, with more silent cases being diagnosed and a greater proportion of cases diagnosed later in adulthood. It presents with a spectrum of clinical manifestations and histological abnormalities. Duodenal biopsy remains the gold standard for diagnosis of celiac disease, even though there are new serologic tests that are very specific. Correlation of clinical, serologic, and histological features are essential for a definitive diagnosis of celiac disease. The pathogenesis consists in an interaction between genetic, immunologic and environmental factors, which interact with HLA molecules to activate an immunologic response in the small bowel mucosa causing tissue damage. The main treatment is a free gluten diet. Health risks for untreated celiac disease appear to be greater compared with those patients who adhere to this treatment.

Fat absorption after total gastrectomy in rats submitted to Roux-en-Y or Rosanov-like double-transit technique / Absorção de gordura após gastrectomia total em ratos com reconstrução em Y de Roux e em duplo trânsito tipo Rosanov modificado

PURPOSE: Steatorrhea is one of the most common complications in reconstruction after total gastrectomy. Many reconstruction techniques after total gastrectomy have been developed in order to avoid these undesirable effects, but each one of them has some inconvenience. In this experiment, a modified Rosanov technique that keeps duodenal transit, evaluation of fat absorption after gastrectomy was tested. METHODS: Three groups of rats with the same characteristics were used. Total gastrectomy was performed in two groups: one was operated on and transit was reestablished by the Roux-en-Y technique (group Y), while the other was submitted to the modified Rosanov technique (group R). Following surgery, a handmade hyper fatty diet (11 percent of fat) was offered. A third group (control - group C) was not operated but was submitted to the same conditions of the other groups, and used for reference steatocrit values. The animals underwent laparotomy 14 days after surgery and had their feces collected from cecum to determine their steatocrit by analysis of their values. RESULTS: Steatocrit values for groups R and C (mean 5.16 percent and 4.15 percent respectively) were similar (p > 0.1), while group Y had significantly higher values (mean = 28.18 percent, p = 0.0001 - p < 0,05). This was attributed to the fact that group R animals had their duodenal transit patent, decreasing the complications expected in the Roux-en-Y reconstruction. CONCLUSIONS: Steatorrhea in the modified Rosanov technique was similar to the control group, while Roux-en-Y reconstruction presented higher steatorrhea and fat malabsorption.(AU)

OBJETIVO: Uma das principais complicações tardias da gastrectomia total com reconstrução de trânsito excluindo duodeno é a esteatorréia. Várias técnicas de reconstrução após gastrectomia total foram descritas para que se pudesse evitar esses efeitos indesejáveis, mas cada uma apresentou seus inconvenientes. Nesse estudo foi avaliada a técnica descrita por Rosanov com uma pequena modificação, que mantém o trânsito através do duodeno, para avaliar a absorção de gorduras. MÉTODOS: Foram utilizados três grupos de ratos Wistar machos, com peso e características semelhante. Dois grupos foram submetidos à gastrectomia total: o primeiro teve sua reconstrução com técnica de Y de Roux (grupo Y), e o segundo com Rosanov modificado (grupo R). Após a cirurgia, foi introduzida dieta com teor de gorduras conhecido (11 por cento). Um terceiro grupo (grupo C) esteve sob mesmas condições dos outros animais, sem ter sido submetido à cirurgia, e foi utilizado como grupo controle para o esteatócrito. Após 14 dias, antes de serem sacrificados, foram submetidos a laparotomia para coleta de fezes do ceco e dosagem de esteatócrito. Os valores de esteatócrito foram analisados estatisticamente pelo método de Kruskal-Wallis. RESULTADOS: O esteatócrito dos grupos R (média = 5,16 por cento) e C (média = 4,15 por cento) foram semelhantes (p > 0,1), enquanto o grupo Y teve valores significativamente maiores (média = 28,18 por cento, p-=0.0001 - p< 0,05). CONCLUSÃO: A gastrectomia total com reconstrução tipo Rosanov modificada mostrou esteatorréia semelhante ao grupo controle, enquanto a reconstrução tipo Y de Roux apresentou esteatorréia mais elevada, e portanto malabsorção de gordura.(AU)