Genotyping demonstrates that the strains of Proteus mirabilis from bladder stones and catheter encrustations of patients undergoing long-term bladder catheterization are identical.

PURPOSE: We established the incidence of bladder stones in patients who experienced recurrent encrustation and blockage of indwelling bladder catheters and examined the relationship between isolates of Proteus mirabilis from the stones and from the crystalline biofilms on the catheters. MATERIALS AND METHODS: The first 100 patients attending a clinic for patients experiencing problems with the management of long-term bladder catheters were studied. Flexible cystoscopy was used to detect bladder stones. Catheter encrustation was assessed visually and by electron microscopy. Bacteriological analysis was performed on the stones and catheter biofilms. P. mirabilis isolates were genotyped by pulsed field gel electrophoresis of restriction enzyme digests of bacterial DNA. RESULTS: Most patients (85%) had been referred because of catheter blockage and in 61 (72%) the catheters were encrusted. P. mirabilis was recovered from 37 of 47 encrusted catheters (79%) that were examined but not from any nonencrusted catheters. Of the 61 patients with encrusted catheters 38 (62%) had bladder stones. Pairs of isolates of P. mirabilis from the stones and the catheter biofilms from 6 patients were genotyped. The DNA profiles of each pair of isolates were identical. CONCLUSIONS: The majority of patients (62%) with recurrent catheter encrustation had bladder stones. The stones harbored the strains of P. mirabilis that rapidly colonize replacement catheters with crystalline biofilm. Flexible cystoscopy to detect and remove stones might help resolve the problem of recurrent catheter encrustation.

New concepts in the treatment of ureteral calculi.

The management of patients with ureteral stones remains under debate in several areas. The ability to predict spontaneous passage has improved but remains imprecise, whilst the range of therapeutic options continues to widen. Excellent results can be obtained by both shockwave lithotripsy and ureteroscopic methods, with relatively minimal complications. Routine ureteral stenting is not warranted whichever treatment is chosen. In future, directly comparative studies should be designed to incorporate quality-of-life parameters rather than just stone-free status, to improve our understanding of the effect of treatment decisions on patients.

Body composition of growing and adult cats as measured by use of dual energy X-ray absorptiometry.

BACKGROUND AND PURPOSE: Total body scans were performed on 89 domestic cats of various ages, using dual energy x-ray absorptiometry (DEXA) to determine body composition, including fat, lean, and bone mineral content. Bone mineral density results from scans also are presented. METHODS: This cross sectional study included data for cats from a closed colony and from privately owned cats. Data were grouped by age and were analyzed by sex and reproductive status to provide information as to the rate of growth of the individual components of body composition. RESULTS: The results indicate that the rate of accretion of bone mineral, fat, and lean tissue differs throughout maturation and by sex. Regressions are provided to highlight age- and sex-related differences. CONCLUSIONS: The results of this study emphasize the benefits of examining the growth of each component of body composition when studying the effects of nutrition, disease processes, or therapeutic interventions.

Angiotensin II and monocrotaline-induced pulmonary hypertension: effect of losartan (DuP 753), a nonpeptide angiotensin type 1 receptor antagonist.

Administration of the pyrrolizidine alkaloid monocrotaline (MCT) to rats results in hypertensive pulmonary vascular disease characterized by a structurally based increase in pulmonary vascular resistance and right ventricular hypertrophy. Alterations in lung angiotensin converting enzyme activity in MCT-treated rats have suggested a role for angiotensin II (AII) in the pathogenesis of this model of hypertensive pulmonary vascular disease. To determine if increases in AII contribute to the development of pulmonary hypertension in MCT-treated rats, we examined the effect of chronic administration of the nonpeptide AII receptor antagonist Losartan on indices of pulmonary hypertension, Losartan (DuP 753; 10 mg/kg s.c.) administration for 21 days did not prevent the development of hypertensive pulmonary vascular disease in MCT-treated rats. However, 18 hr after the last dose of Losartan, AII (0.1 micrograms/kg i.v.)-induced pressor responses were inhibited by 63% in Losartan-treated rats. Losartan administration in MCT-treated rats did not prevent increases in pulmonary artery pressure or development of right ventricular hypertrophy. Additionally, increases in medial arterial thickness in pulmonary artery vessels (less than 50 microns and 50-100 microns external diameter) from MCT-treated rats were still evident in Losartan-treated rats. However, Losartan administration decreased medial pulmonary artery thickness of 50 to 100 microns external diameter vessels in control rats. These results demonstrate that AII. acting at the AT1 receptor subtype, does not contribute to pulmonary hypertension in this animal model.