Diet as culprit or therapy. Stone disease, chronic renal failure, and nephrotic syndrome

Nutritional Management of Idiopathic Nephrotic Syndrome in Pediatric Age

Nephrotic syndrome (NS) is a common pediatric disease characterized by a dysfunction in the glomerular filtration barrier that leads to protein, fluid, and nutrient loss in urine. Corticosteroid therapy is the conventional treatment in children. Long-term complications of NS and prolonged exposure to steroids affect bones, growth, and the cardiovascular system. Diet can play an important role in preventing these complications, but there is a scarcity of scientific literature about nutritional recommendations for children with NS. They need individualized nutrition choices not only during the acute phase of the disease but also during remission to prevent the progression of kidney damage. The correct management of diet in these children requires a multidisciplinary approach that involves family pediatricians, pediatric nephrologists, dietitians, and parents.

Renal stone disease in children

Renal stone disease has been regarded as an uncommon problem in children compared to adults. However, increased awareness of this problem in children may lead to early intervention preventing long-term consequences on the kidney and the urinary tract. This article reviews the epidemiology, pathogenesis, and the most common etiologies of renal stones in children. The clinical features and diagnostic and therapeutic modalities for the specific etiologies are also outlined. Using these guidelines may be helpful not only in the treatment but also in the prevention of renal stones.

Control of endothelial leukocyte adhesion molecules by fatty acids

Dietary balance of long-chain fatty acids (FA) may influence human susceptibility to pathological processes which involve the interaction of leukocytes with vascular endothelium, such as atherogenesis and inflammation. Such interaction is largely mediated by the de novo or increased expression of endothelial leukocyte adhesion molecules on vascular endothelial cells, able to tether and stably bind leukocytes onto the vessel wall, and by the production of leukocyte chemoattractants. Endothelial cells do not normally support high levels of leukocyte adhesion. They do so, however, when exposed to a number of stimuli, such as oxidized low density lipoprotein bacterial lipopolysaccharides, and inflammatory cytokines, which induce phenotypic changes generally referred to as "endothelial activation." We compared various FA in their ability to modulate endothelial activation by cytokines. FA included linoleic, arachidonic, oleic, eicosapentaenoic and, docosa-hexaenoic acid (DHA) as representatives of the n-6, n-3 polyunsaturated FA and of the monounsaturated FA. The n-3 FA DHA, and, to a lesser extent, oleate, at nutritionally compatible concentrations, were able to reduce endothelial expression of Vascular Cell and Adhesion Molecule-1 (VCAM-1). In further studies, DHA dose- and time-dependently reduced also the expression of E-selectin, Intercellular Adhesion Molecule-1, interleukin (IL)-6 and IL-8, in response to IL-1, IL-4, tumor-necrosis factor, or bacterial endotoxin. The magnitude of this effect paralleled its incorporation into cellular phospholipids. Also, coordinate with reduced surface adhesion molecule expression, DHA reduced the adhesion of human monocytes and of monocytic U937 cells to cytokine-stimulated endothelial cells. These effects were accompanied by a quantitatively consistent reduction in VCAM-1 mRNA, indicating a pretranslational control of adhesion molecule gene expression. These novel properties of FA as modulators of endothelial activation may help to explain the influence of dietary FA intake on atherogenesis and inflammation.

Idiopathic calcium oxalate urolithiasis and endogenous oxalate production

Despite the great effort that has gone into investigating urolithiasis, this condition still persists as one of the major ailments of the urinary tract. Calcium oxalate urolithiasis is the most common form, accounting for some 60 to 80% of total stones. This review examines the elements (i.e., urine volume and pH and urinary excretion of calcium, oxalate, citrate, urate, magnesium, pyrophosphate, and glycosaminoglycans) that give rise to idiopathic calcium oxalate urolithiasis. Treatment strategies for idiopathic calcium oxalate urolithiasis, including lithotripsy, also are discussed. Urinary oxalate excretion is a major risk factor for calcium oxalate urolithiasis, with 85 to 95% of the urinary load derived endogenously. The factors controlling endogenous oxalate production are reviewed, including pathways for the diversion of glyoxylate from oxalate production. The use of beta-aminothiols and other substances to reduce endogenous oxalate production in subjects with idiopathic calcium oxalate urolithiasis is also discussed. A review of current methodologies for the determination of urinary oxalate is also included.