(1/693) Obstructive uropathy and hydronephrosis in male KK-Ay mice: a report of cases.
Uropathy associated with hydronephrosis was observed frequently in our male KK-Ay mouse colony during a long-term study of diabetes. The lesion occurred in 24 of the 31 KK-Ay male mice and accounted for the greatest number of spontaneous deaths among them. It was observed after 4 months of age and involved about hard plugs of altered seminal material resembling the seminal vesicle secretion. The plugs became impacted in the urethral bulb and the bladder. The penile anatomy, with its flexure, pressure on the urethra from the bulbocavernosus muscle, and the characteristic ability of the seminal fluid to easily coagulate to form the vaginal plug may have contributed to the lesion. Correlation between development of the uropathy and diabetes has not been established. (+info)
(2/693) Recovery following relief of unilateral ureteral obstruction in the neonatal rat.
BACKGROUND: Obstructive nephropathy is a primary cause of renal insufficiency in infants and children. This study was designed to distinguish the reversible and irreversible cellular consequences of temporary unilateral ureteral obstruction (UUO) on the developing kidney. METHODS: Rats were subjected to UUO or sham operation in the first 48 hours of life, and the obstruction was removed five days later (or was left in place). Kidneys were removed for study 14 or 28 days later. In additional groups, kidneys were removed at the end of five days of obstruction. Immunoreactive distribution of renin was determined in arterioles, and the distribution of epidermal growth factor, transforming growth factor-beta1, clusterin, vimentin, and alpha-smooth muscle actin was determined in tubules and/or interstitium. The number of glomeruli, glomerular maturation, tubular atrophy, and interstitial collagen deposition was determined by morphometry. Renal cellular proliferation and apoptosis were measured by proliferating cell nuclear antigen and the TdT uridine-nick-end-label technique, respectively. The glomerular filtration rate was measured by inulin clearance. RESULTS: Renal microvascular renin maintained a fetal distribution with persistent UUO; this was partially reversed by the relief of obstruction. Although glomerular maturation was also delayed and glomerular volume was reduced by UUO, the relief of obstruction prevented the reduction in glomerular volume. Although relief of obstruction did not reverse a 40% reduction in the number of nephrons, the glomerular filtration rate of the postobstructed kidney was normal. The relief of obstruction did not improve tubular cell proliferation and only partially reduced apoptosis induced by UUO. This was associated with a persistent reduction in the tubular epidermal growth factor. In addition, the relief of obstruction reduced but did not normalize tubular expression of transforming growth factor-beta1, clusterin, and vimentin, all of which are evidence of persistent tubular injury. The relief of obstruction significantly reduced interstitial fibrosis and expression of alpha-smooth muscle actin by interstitial fibroblasts, but not to normal levels. CONCLUSIONS: The relief of obstruction in the neonatal rat attenuates, but does not reverse, renal vascular, glomerular, tubular, and interstitial injury resulting from five days of UUO. Hyperfiltration by remaining nephrons and residual tubulointerstitial injury in the postobstructed kidney are likely to lead to deterioration of renal function later in life. (+info)
(3/693) Idiopathic cervical and retroperitoneal fibrosis: report of a case treated with steroids.
Retroperitoneal fibrosis in a 12-year-old boy is reported. This was associated with a fibrotic mass in the neck which resolved spontaneously. Right-sided ureteric obstruction responded to treatment with steroids. (+info)
(4/693) Unilateral ureteral obstruction impairs renal antioxidant enzyme activation during sodium depletion.
BACKGROUND: Obstructive nephropathy leads to progressive renal tubular atrophy and interstitial fibrosis and is associated with sodium wasting and sodium depletion. Renal damage resulting from unilateral ureteral obstruction (UUO) may be aggravated by reactive oxygen species (ROS), which are produced by a variety of processes. Ideally, deleterious effects of ROS are attenuated by antioxidant enzymes, including the superoxide dismutases, glutathione peroxidases, catalase, and glutathione-S-transferases. The general paradigm is that tissue damage occurs when ROS production is greater than the protective capacity of the antioxidant enzymes. METHODS: This study was designed to investigate the response of renal antioxidant enzymes to UUO and sodium depletion. Adult, male Sprague-Dawley rats received normal-sodium or sodium-depleted siets and were subjected to UUO or sham operation. Obstructed (UUO), intact opposite, or sham-operated kidneys were harvested after 14 days, and antioxidant enzyme activities were measured in kidney homogenates. Thiobarbituric acid reactive substances were measured in these homogenates at 3 and 14 days after UUO or sham operation as an index of ROS production. RESULTS: Renal interstitial area, a measure of fibrosis, was increased by UUO and was doubled in sodium-depleted animals. Sodium depletion increased manganese superoxide dismutase, glutathione peroxidases, and glutathione-S-transferase activities in sham-operated kidneys but not in UUO kidneys. Relative to intact opposite kidneys, UUO kidneys had reduced activities of catalase, manganese superoxide dismutase, and glutathione-S-transferase in normal-sodium animals and all antioxidant enzymes tested in sodium-depleted animals. Renal thiobarbituric acid reactive substances were increased by three days of UUO and were increased further by 14 days of sodium depletion. CONCLUSION: In summary, sodium depletion increased several renal antioxidant enzymes, consistent with a stress response to increased ROS production. Further, UUO not only reduced antioxidant enzyme activities but also inhibited increases seen with sodium depletion. We conclude that suppression of renal antioxidant enzyme activities by UUO contributes to the progression of renal injury in obstructive nephropathy, a process exacerbated by sodium depletion. (+info)
(5/693) The renal lesions that develop in neonatal mice during angiotensin inhibition mimic obstructive nephropathy.
BACKGROUND: Inhibition of angiotensin action, pharmacologically or genetically, during the neonatal period leads to renal anomalies involving hypoplastic papilla and dilated calyx. Recently, we documented that angiotensinogen (Agt -/-) or angiotensin type 1 receptor nullizygotes (Agtr1 -/-) do not develop renal pelvis nor ureteral peristaltic movement, both of which are essential for isolating the kidney from the high downstream ureteral pressure. We therefore examined whether these renal anomalies could be characterized as "obstructive" nephropathy. METHODS: Agtr1 -/- neonatal mice were compared with wild-type neonates, the latter subjected to surgical complete unilateral ureteral ligation (UUO), by analyzing morphometrical, immunohistochemical, and molecular indices. Agtr1 -/- mice were also subjected to a complete UUO and were compared with wild-type UUO mice by quantitative analysis. To assess the function of the urinary tract, baseline pelvic and ureteral pressures were measured. RESULTS: The structural anomalies were qualitatively indistinguishable between the Agtr1 -/- without surgical obstruction versus the wild type with complete UUO. Thus, in both kidneys, the calyx was enlarged, whereas the papilla was atrophic; tubulointerstitial cells underwent proliferation and also apoptosis. Both were also characterized by interstitial macrophage infiltration and fibrosis, and within the local lesion, transforming growth factor-beta 1, platelet-derived growth factor-A and insulin-like growth factor-1 were up-regulated, whereas epidermal growth factor was down-regulated. Moreover, quantitative differences that exist between mutant kidneys without surgical obstruction and wild-type kidneys with surgical UUO were abolished when both underwent the same complete surgical UUO. The hydraulic baseline pressure was always lower in the pelvis than that in the ureter in the wild type, whereas this pressure gradient was reversed in the mutant. CONCLUSION: The abnormal kidney structure that develops in neonates during angiotensin inhibition is attributed largely to "functional obstruction" of the urinary tract caused by the defective development of peristaltic machinery. (+info)
(6/693) A case of ureteric obstruction, retroperitoneal fibrosis, and carcinoid tumour.
We report the incidental finding at surgery for retroperitoneal fibrosis of a carcinoid tumour causing complete right ureteric obstruction. Retroperitoneal fibrosis is an uncommon inflammatory disease that leads to extensive fibrosis throughout the retroperitoneum. It can occur at any age, peak incidence being in patients between 40 and 60 years of age. Carcinoid tumours arise from enterochromaffin or amine precursor uptake and decarboxylation cells that occur in gastrointestinal tract. Carcinoid tumours are an uncommon clinical entity and incidence varies with gender and age. No association between retroperitoneal fibrosis and carcinoid tumour has been previously reported in the English literature, although one case has been reported in a French journal. (+info)
(7/693) The value of intra-operative cystoscopy at the time of laparoscopic hysterectomy.
The aim of this study was to determine the usefulness of routine intra-operative cystoscopy in documenting ureteral injury during total laparoscopic hysterectomy with vault suspension and to document the incidence of this complication in a large series. The charts of 118 patients who underwent laparoscopic hysterectomy with vault suspension from January 1992 to January 1998 were retrospectively reviewed. The patients underwent intra-operative cystoscopic evaluation to verify ureteral permeability and bladder integrity. Intra-operative ureteral obstruction occurred in four patients (3.4%). All complications were immediately fixed and there were no postoperative ureteral problems. No late ureteral complications were observed. Intra-operative cystoscopy allows for early recognition and treatment of obstructive ureteral injuries and may reduce the rate of late postoperative complications during advanced laparoscopic procedures. (+info)
(8/693) Quantitative SPECT of 99mTc-DMSA uptake in kidneys of infants with unilateral ureteropelvic junction obstruction: assessment of structural and functional abnormalities.
We evaluated individual renal function using quantitative SPECT of dimercaptosuccinic acid (DMSA) uptake by the kidneys (QDMSA) in infants with unilateral ureteropelvic junction (UPJ) obstruction and compared our findings with infants without obstruction. METHODS: QDMSA was performed on 13 infants (mean age of 2.8 +/- 2.8 mo) with unilateral UPJ obstruction and on 15 age-matched controls without obstruction. RESULTS: Control kidneys (n = 30) had a volume of 43.5 +/- 8.8 mL, a percentage injected dose (%ID)/mL 0.62 +/- 0.12 and uptake of 26.1% +/- 3.9%. Kidneys with UPJ obstruction (n = 13) had a volume of 61.2 +/- 19.3 mL, a %ID/mL of 0.42 +/- 0.11 and uptake of 25.4% +/- 8.2%. Contralateral kidneys (n = 13) had a volume of 44.0 +/- 11.9 mL, a %ID/mL of 0.57 +/- 0.16 and uptake of 24.2% +/- 4.6%. The uptake in obstructed kidneys was similar to that observed in contralateral and control kidneys (t = -0.77, P = 0.45; t = -0.37, P = 0.71; respectively). UPJ kidneys had a statistically significant increased volume and decreased %ID/mL, compared with contralateral kidneys (t = 3.35, P < 0.006 and t = 3.75, P < 0.003, respectively) and control kidneys (t = -4.2, P < 0.001 and t = 4.7, P < 0.001, respectively). There was no significant difference between contralateral kidneys and control kidneys regarding volume (t = -0.16, P = 0.87), %ID/mL (t = 0.98, P = 0.33) and uptake (t = -1.41, P = 0.16). Of 13 infants, 11 (85%) showed large kidneys with thinning of the renal cortex. In 1 infant, there was no difference between the obstructed and contralateral kidneys regarding volume, %ID/mL and uptake, and 1 infant showed significant decreased uptake in the UPJ kidney compared with the contralateral kidney. CONCLUSION: Although the overall renal function of the obstructed kidneys remained unchanged, there was a statistically significant decrease in the %ID/mL of renal tissue in UPJ kidneys, which may represent renal dysfunction. Increased functional volume with a thin cortex may represent a compensatory mechanism of the obstructed kidney. Such changes may contribute to the understanding of pathophysiologic mechanisms and may be an early sign of obstruction in infants with hydronephrosis. Further longitudinal studies with an extended number of infants and serial measurements of kidney volumes and %ID/mL are warranted to assess the significance of QDMSA in the management of infants with asymptomatic unilateral renal pelvic dilatation. (+info)