Fat malabsorption induced by gastrointestinal lipase inhibitor leads to an increase in urinary oxalate excretion

BACKGROUND: Unabsorbed fat and bile acids may react with calcium in the intestinal lumen, limiting the amount of free calcium binding with oxalate and thereby raising intestinal oxalate absorption leading to hyperoxaluria. The aim of the present study was to determine whether orlistat (Xenical), a gastrointestinal lipase inhibitor, might increase urinary oxalate in an experimental rat model. METHODS: Thirty-nine male adult Wistar rats were fed a standard diet alone (controls) or supplemented with either 2% sodium oxalate (NaOx) or 3.2 mL of soy oil, or with both (NaOx + soy oil) for 4 weeks (diet period). Orlistat (16 mg/day) was added to the diet from the 5th to the 8th week (diet + orlistat period). Urinary oxalate (uOx), calcium (uCa), magnesium (uMg), and citrate (uCit) were determined and the ion-activity product of calcium oxalate [AP (CaOx) index(rat)] was estimated. RESULTS: Compared to baseline uOx significantly increased after diet + orlistat in controls (0.64 +/- 0.1 mg/24 hours vs. 0.56 +/-0.1 mg/24 hours), soy oil (0.80 +/- 0.3 mg/24 hours vs. 0.49 +/-0.2 mg/24 hours), and NaOx (2.48 +/- 0.8 mg/24 hours vs. 0.57 +/- 0.2 mg/24 hours), but the most marked increase occurred in NaOx + soy oil (3.87 +/- 0.7 mg/24 hours vs. 0.47 +/- 0.1 mg/24 hours). All groups except controls presented a significant reduction in uCa and uMg. Orlistat induced a significant increase in AP (CaOx) index(rat) compared, respectively, to baseline and to the diet period in NaOx (4.52 +/- 2.34 mg/24 hours vs. 0.94 +/- 0.86 and 1.53 +/- 0.93 mg/24 hours) and NaOx + soy oil (6.49 +/- 4.03 mg/24 hours vs. 0.54 +/- 0.17 and 1.76 +/- 1.32 mg/24 hours). CONCLUSION: These data suggest that the use of lipase inhibitors, especially under a diet rich in oxalate alone or associated with fat, leads to a significant and marked increase in urinary oxalate and a slight reduction in uCa and uMg that, taken together, resulted in an increase in AP (CaOx) index(rat), elevating the risk of stone formation.     

Immobilization and hypercalciuria in children

Intermediate-term immobilization may lead to an increase in serum and urinary calcium. In order to test this hypothesis, we evaluated 46 children, 21 with Legg–Calvé–Perthes disease (LCP; 7.2±1.8 years old) and 25 with developmental dysplasia of the hip joint (DDH; 10±5 months of age), submitted to immobilization for up to 16 weeks. These two conditions require intermediate-term immobilization as treatment modality, and no studies evaluating calcium metabolism in these groups of patients have been conducted. In LCP patients, blood and 24-h urine samples were obtained before the beginning of treatment and after 1, 6, 8, 14 and 16 weeks of immobilization, while in DDH patients, blood and spot urine samples were collected before treatment and after 6 and 14 weeks of treatment. Urinary calcium, creatinine, potassium and sodium as well as serum calcium, phosphorus, parathyroid hormone, creatinine and alkaline phosphatase were determined in those samples. Renal ultrasound was performed before and after treatment. A mean increase of 2.3 times baseline values of urinary calcium was observed in 40% of previously normocalciuric LCP patients after only 1 week of immobilization. Among the DDH children, who had never previously ambulated, there was no significant variation in the urinary calcium excretion. None of the serum parameters changed in either group throughout the study. Urinary stones were not evidenced by renal ultrasound. Therefore, the present data suggested that intermediate-term immobilization led to a transient increase in urinary calcium in 40% of LCP patients. Complications such as urinary stones were not observed. In conclusion, this modality of treatment does not impose an increased risk of urinary stone formation in LCP and DDH patients.     

Selective estrogen receptor modulators in chronic renal failure

BACKGROUND: In addition to renal osteodystrophy, postmenopausal women on dialysis could be at risk of osteoporosis. Hormone replacement therapy (HRT) could have beneficial effects as well as potentially serious risks, especially in uremic women, due to the pharmacokinetics of estradiol in renal failure. Therapeutic alternatives, such as the selective estrogen receptor modulators (SERMs), have shown the benefits of estrogen on bone and serum lipid levels, without its adverse effects on the breast and endometrium, in nonuremic women. METHODS: Recent data on the effect of the SERM raloxifene in bone and lipid metabolism in osteoporotic postmenopausal women on dialysis is reviewed. Since the estrogen receptor (ER) gene has been suggested as a candidate marker for osteoporosis, we investigated whether ER polymorphism could have predicted the BMD response to raloxifene. RESULTS: Hemodialyzed women on raloxifene demonstrated increased trabecular bone mineral density (BMD) and decreased bone resorption markers. Similarly, LDL-cholesterol values dropped significantly. ER gene polymorphism analysis of baseline BMD parameters did not differ between PP/xx or Pp/Xx groups. Nevertheless, patients on raloxifene with PP/xx genotypes, but not those with Pp/Xx, showed a higher trabecular BMD after one year on treatment, suggesting that homozygous women for P or x alleles of the ER have a better BMD response to raloxifene. CONCLUSION: Raloxifene and, most likely, other SERMs, could represent a good alternative to HRT in postmenopausal uremic women.     

Scrotal Pneumatocoele in the Newborn

Ip, Henrietta Man-Hing (1978). Aust. Paediatr. J., 14, 107–108. Scrotal pneumatocoele in the newborn. A case of scrotal pneumatocoele secondary to spontaneous pneumothorax with subsequent pneumoperitoneum and subcutaneous emphysema in a newborn infant is reported. Spontaneous recovery occurred.     

Phyllanthus niruri as a promising alternative treatment for nephrolithiasis

In spite of considerable efforts to identify effective treatments for urolithiasis, this is a goal yet to be achieved. This review summarizes experimental and clinical data evaluating the effect of the plant Phyllanthus niruri, a plant with worldwide distribution, as a potential agent to prevent and/or to treat urolithiasis The review is based on data from the literature and on the results obtained by our group from either in vivo/in vitro experiments or clinical studies. Phyllanthus niruri has been shown to interfere with many stages of stone formation, reducing crystals aggregation, modifying their structure and composition as well as altering the interaction of the crystals with tubular cells leading to reduced subsequent endocytosis. The clinical beneficial effects of Phyllanthus niruri may be related to ureteral relaxation, helping to eliminate calculi or to clear fragments following lithotripsy, or also to a putative reduction of the excretion of urinary crystallization promoters such as calcium. No adverse renal, cardiovascular, neurological or toxic effects have been detected in either of these studies. Altogether, these studies suggest a preventive effect of Phyllanthus niruri in stone formation or elimination, but still longer-term randomized clinical trials are necessary to confirm its therapeutic properties.     

Ectophosphatase activity in Candida albicans influences fungal adhesion: study between HIV‐positive and HIV‐negative isolates

Oral Diseases (2010) 16 , 431–438 Objective: This study describes the expression of acidic ectophosphatase activity on twenty isolates of C. albicans from oral cavities of HIV‐infected children (HIV+) and compares them with fifteen isolates from HIV‐negative children (HIV?), as well as the fungal adhesion to epithelial cells and medical records. Methods: The activities were measured in intact cells grown in BHI medium for 48 h at 37°C. Phosphatase activity was assayed at pH 5.5 using 4‐methylumbelliferyl phosphate. Yeast adhesion was measured using the MA 104 epithelial cell line. Results: Mean values of ectophosphatase activity were 610.27 ± 166.36 and 241.25 ± 78.96 picomoles 4‐methylumbelliferone/h/10⁷ cells for HIV+ and HIV? group, respectively (P = 0.049). No correlation between C. albicans enzyme activity from HIV children with viral load and CD4 percentual was observed. Yeasts with high enzyme activity, isolated from HIV+ children showed greater adherence than yeasts with basal levels of ectophosphatases from HIV? (Spearman correlation, r = 0.8). Surface phosphatase activity was apparently involved in the adhesion to host cells, as the enhanced attachment of C. albicans to host epithelial cells was reversed by pretreatment of yeast with sodium orthovanadate (1 mM), an acid phosphatase inhibitor. Conclusion: These results show that C. albicans from HIV+ has an ectophosphatase activity significantly higher than the other isolates. Yeasts expressing higher levels of surface phosphatase activity showed greater adhesion to epithelial cells. So, the activity of acidic surface phosphatases on these cells may contribute to the early mechanisms required for disease establishment.