It is well known that the principal disadvantage of any method for the determination of calcium involving precipitation as calcium oxalate lies in washing the precipitate. The solubility of the precipitate in water or in dilute ammonium hydroxide is appreciable and, in centrifuging, a small amount of calcium oxalate tends to float on the surface of the liquid and is lost in decanting. The satis...

Renal lithiasis is a multifactorial disease. An important number of etiologic factors can be adequately modified through diet, since it must be considered that the urine composition is directly related to diet. In fact, the change of inappropriate habitual diet patterns should be the main measure to prevent kidney stones. In this paper, the relation between different dietary factors (liquid int...

A 59 year-old woman with chronic renal disease presented in renal failure with a creatinine of 4.1 mg %. She had had a Roux-en-Y gastric bypass performed 10 years earlier. A diagnosis of oxalate nephropathy was made on renal biopsy. Oxalate nephropathy is a known complication of gastric bypass. Calcium and oxalate in the intestine form calcium oxalate complexes that are then excreted. In the se...

Nephrolithiasis is a multi-factorial disease which, in the majority of cases, involves the renal deposition of calcium oxalate. Oxalate is a metabolic end product excreted primarily by the kidney. Previous studies have shown that elevated levels of oxalate are detrimental to the renal epithelial cells; however, oxalate renal epithelial cell interactions are not completely understood. In this st...

Fat sand rats Psammomys obesus feed exclusively on plants of the family Chenopodiaceae, which contain high concentrations of chloride salts (NaCl, KCl) and oxalate salts. Ingestion of large quantities of oxalate is challenging for mammals because oxalate chelates Ca(2+) cations, reducing Ca(2+) availability. Oxalate is a metabolic end-point in mammalian metabolism, however it can be broken-down...

Herein we describe bimetallic di-nickel and di-copper complexes [Ni2(L)Br4] (1) and [Cu2(L)Br4(NCMe)2] (2) (L = (1E,1'E)-N,N'-(1,4-phenylenebis(methylene))bis(1-(6-(2,4,6-triisopropylphenyl)pyridin-2-yl)methanimine)) that bind oxalate intramolecularly to form [Ni2(L)Br2(C2O4)(NCMe)] (3) and [Cu2(L)Br2(C2O4)] (4). For the di-nickel complex 1, oxalate incorporation is accompanied by a significant...

Utilizing a purified basolateral plasma membrane vesicle (BLMV) preparation containing a sulfate/oxalate antiporter, it was demonstrated that sulfate exhibited similar binding characteristics to the transporter whether bound internally or externally. It was also demonstrated that oxalate had similar binding characteristics to the antiporter whether it was bound internally or externally. Oxalate...

Chemical kinetic data, complemented with scanning electron-microscope observations of the crystalline phase, show that seed crystals of hydroxyapatite have the ability to induce the growth of calcium oxalate monohydrate crystals epitaxially from a metastable supersaturated solution of calcium oxalate. The rate of growth of calcium oxalate crystals is dependent on the surface area of the seed ma...

OBJECTIVE To study the chemical composition of upper renal tract (renal and ureteric) calculi in Multan. SETTING Department of Urology, Nishtar Hospital, Multan. STUDY PERIOD September 1992 to February 1999. MATERIAL AND METHODS A total of 700 renal and ureteric calculi were analyzed by chemical method of Hodgkinson. RESULTS The commonest were uric acid (28.1%) calculi, followed in freq...

Oxalate biosensors (OBs) are based on either measurement of oxygen or electrons generated from splitting of H 2 O 2 or heat released during oxidation of oxalate by immobilized oxalate oxidase. OBs are grouped in four classes based on probe used (DO meter, electrochemical, SIRE technology and thermochip). OBs work optimally at: time, 5 s to 15 min; pH, 2.8 8.0; temp., 30 38°C and linearity, 1.0 ...