Electron imaging of calcium oxalate crystals in beagle dogs’ urine

Calcium oxalate crystalluria appears to be a common problem in most of small animal clinics. This current study aimed at inducing a condition of oxalate crystalluria in beagles and record the primary changes in canine blood and urine on response to oxalates injection. 15 dogs were divided into two groups; those in the treatment group were injected intravenously with 0.5 M potassium oxalate and the dogs of control group were injected with physiological saline for five successive days. Urine test revealed a significant decrease in urinary creatinine and urinary urea nitrogen levels. The ultrastructural examination of urine sediment showed typical and atypical phases of calcium oxalate crystals and the X-ray defractionation of these crystals showed high content of calcium in addition to other minerals. Therefore potassium oxalate injection may provide an example of calcium oxalate crystalluria which may answer some question around the pathogenesis of this problem in dogs

Osteopontin and Tamma-Horsefall proteins – Macromolecules of myriad values

In the past two decades, calcium oxalate urolithiasis (COU) has been a frustrating problem worldwide. Several recent studies, indicate that the macromolecules are of greater importance to the inhibitory effects on crystal growth and aggregation. Various macromolecules modulate various steps of stone formation. Osteopontin and Tamm-Horsfall glycoprotein are two important proteins involved in the process of retention of crystals and stone formation. Osteopontin is a potent inhibitor of crystallization of calcium phosphate and calcium oxalate, the most common crystals found in the urine and kidney stones. On the other side it is a multifunction protein. It is involved in divers’ biological processes. Tamm-Horsfall glycoprotein modulates aggregation and growth of supersaturated salts and their crystals, respectively. It in addition contributes to the colloid osmotic pressure of urine, helping to prevent urinary tract infections. The aim of this review is to outline some important aspects of these two macromolecules especially regarding renal stone diseases