struvite and Foreign-Body-Reaction

Two male dogs were presented with cystic uroliths composed of magnesium ammonium phosphate (struvite). Each had an atypical nidus, a mouse barley awn (Hordeum murinum). To our knowledge, this is the first report of grass awns located in the bladder lumen of dogs. The composition of uroliths and the pathophysiology of grass awn migration to the urinary bladder are discussed.

Topics: Animals; Dog Diseases; Dogs; Foreign-Body Migration; Foreign-Body Reaction; Hordeum; Magnesium Compounds; Male; Phosphates; Struvite; Urinary Bladder Calculi

Metallic stents have been used in the management of prostatic disease in patients unfit for surgery. A variety of stents have become available but the optimum design and metal of construction has not yet been defined. This study examined one of the potential complications of stent insertion by demonstrating that they are susceptible to encrustation. Using an in vitro model it compares the ability of the different materials used in their construction to resist this encrustation. Titanium appears less able to resist deposition than the other metals examined. The long-term complication of encrustation may inhibit the use of some of these stents.

Topics: Calcium Phosphates; Equipment Safety; Foreign-Body Reaction; Gold; Humans; Magnesium; Magnesium Compounds; Male; Microscopy, Electron, Scanning; Phosphates; Prostatic Diseases; Spectrophotometry, Infrared; Stainless Steel; Stents; Struvite; Titanium; Urethra; Urine

Urine of male Sprague-Dawley rats was supersaturated for struvite and often contained struvite crystals. Ethylene glycol administration to these rats resulted in elevation of urinary oxalate and calcium oxalate supersaturation, and induced calcium oxalate crystalluria. Implantation of foreign bodies in their urinary bladders and changing their urinary ambient conditions by administering ethylene glycol for two weeks at two week intervals resulted in the formation of urinary stones of mixed composition containing calcium oxalate and struvite. Crystal-onto-crystal epitaxy did not appear to play any role in the development of these stones.

Topics: Animals; Calcium Oxalate; Crystallization; Ethylene Glycol; Ethylene Glycols; Foreign Bodies; Foreign-Body Reaction; Magnesium; Magnesium Compounds; Male; Microscopy, Electron, Scanning; Phosphates; Rats; Rats, Inbred Strains; Struvite; Time Factors; Urinary Bladder; Urinary Bladder Calculi