Congenital cystic disease of the liver and kidney in a pygmy goat.
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A 1-month-old pygmy goat was presented with abdominal distension and hematuria. Anemia, leukocytosis, and increased bilirubin and blood urea nitrogen levels suggested renal and hepatic disease. Radiographs revealed bilateral renomegaly, and ultrasound confirmed bilateral hydronephrosis. Necropsy findings determined that the renomegaly was due in part to edema and marked cystic tubular distension. Similarly, intrahepatic bile ducts were ectatic. The character and distribution of the gross and histologic lesions were consistent with a polycystic disorder, presumably congenital, affecting the liver and the kidney. (+info)
Erythrocyte water permeability and renal function in double knockout mice lacking aquaporin-1 and aquaporin-3.
(26/384)
Aquaporin (AQP) water channel AQP3 has been proposed to be the major glycerol and non-AQP1 water transporter in erythrocytes. AQP1 and AQP3 are also expressed in the kidney where their deletion in mice produces distinct forms of nephrogenic diabetes insipidus. Here AQP1/AQP3 double knockout mice were generated and analyzed to investigate the functional role of AQP3 in erythrocytes and kidneys. 53 double knockout mice were born out of 756 pups from breeding double heterozygous mice. The double knockout mice had reduced survival and impaired growth compared with the single knockout mice. Erythrocyte water permeability was 7-fold reduced by AQP1 deletion but not further reduced in AQP1/AQP3 null mice. AQP3 deletion did not affect erythrocyte glycerol permeability or its inhibition by phloretin. Daily urine output in AQP1/AQP3 double knockout mice (15 ml) was 9-fold greater than in wild-type mice, and urine osmolality (194 mosm) was 8.4-fold reduced. The mice remained polyuric after DDAVP administration or water deprivation. The renal medulla in most AQP1/AQP3 null mice by age 4 weeks was atrophic and fluid-filled due to the severe polyuria and hydronephrosis. Our data provide direct evidence that AQP3 is not functionally important in erythrocyte water or glycerol permeability. The renal function studies indicate independent roles of AQP1 and AQP3 in countercurrent exchange and collecting duct osmotic equilibration, respectively. (+info)
Microvasculature of hydronephrotic kidneys in KK-A(Y) mice.
(27/384)
Spontaneous hydronephrosis in KK-A(Y) mice was studied using light and electron microscopy and scanning electron microscopy of resin casts to evaluate micro vascular changes in the kidney. The renal parenchyma was extremely thin as a result of tubular atrophy. Histologically, varying degrees of glomerulosclerosis were observed. Ultrastructurally, marked thickenings of the glomerular basal lamina, an increase in mesangial cells and matrix, and marked effacement of foot processes were observed. In resin casts, a marked reduction in number of glomeruli was evident. The capillaries were thin, strangulated and tom-off to varying degrees in severely affected glomeruli. In the medulla, the three-dimensional capillary network running along the tubules was lost and changed to a two-dimensional vascular bed. Despite severe hydronephrosis, the glomerular capillary network was relatively well preserved, being either slightly or moderately injured in approximately 60% of surviving glomeruli. (+info)
The increase of renal pelvis dilatation in the fetus and its significance.
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OBJECTIVE: To determine the effects of the changes in fetal renal pelvis dilatation on post-natal diagnosis and outcome. METHODS: Prenatal sonographic fetal renal anteroposterior diameters of > or = 4 mm in the second trimester, which persisted to > or = 7 mm in the third trimester, were the inclusion criteria. Fifty-six fetuses and 73 renal units with normal karotypes and a solitary sonographic finding of renal pyelectasis, which met the inclusion criteria, were followed, post-natally, until the age of 30 months. The neonates were categorized into three groups, according to their final diagnosis: No hydronephrosis, pelvi-ureteric junction obstruction and hydronephrosis from other causes. The neonates were also categorized according to their outcome: no treatment, follow-up only and surgical treatment. RESULTS: In 17 neonates (30.4%), and 19 renal units, the diagnosis of hydronephrosis was excluded post-natally. In 39 neonates (69.6%), and 54 renal units, an urinary tract pathology was confirmed. The dynamics of pyelectasis in the second and third trimesters of pregnancy differed significantly among the neonates when categorized according to the final diagnosis (P < 0.05), or according to outcome (P < 0.05). CONCLUSION: It is possible to predict, and distinguish between, long-term conservative and surgical treatments of renal pelvis dilatation in the third trimester of pregnancy. (+info)
Ablation of uroplakin III gene results in small urothelial plaques, urothelial leakage, and vesicoureteral reflux.
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Urothelium synthesizes a group of integral membrane proteins called uroplakins, which form two-dimensional crystals (urothelial plaques) covering >90% of the apical urothelial surface. We show that the ablation of the mouse uroplakin III (UPIII) gene leads to overexpression, defective glycosylation, and abnormal targeting of uroplakin Ib, the presumed partner of UPIII. The UPIII-depleted urothelium features small plaques, becomes leaky, and has enlarged ureteral orifices resulting in the back flow of urine, hydronephrosis, and altered renal function indicators. Thus, UPIII is an integral subunit of the urothelial plaque and contributes to the permeability barrier function of the urothelium, and UPIII deficiency can lead to global anomalies in the urinary tract. The ablation of a single urothelial-specific gene can therefore cause primary vesicoureteral reflux (VUR), a hereditary disease affecting approximately 1% of pregnancies and representing a leading cause of renal failure in infants. The fact that VUR caused by UPIII deletion seems distinct from that caused by the deletion of angiotensin receptor II gene suggests the existence of VUR subtypes. Mutations in multiple gene, including some that are urothelial specific, may therefore cause different subtypes of primary reflux. Studies of VUR in animal models caused by well-defined genetic defects should lead to improved molecular classification, prenatal diagnosis, and therapy of this important hereditary problem. (+info)
Clinical experience with 99mTc-DMSA (dimercaptosuccinic acid), a new renal-imaging agent.
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Results are reported from the clinical evaluation of a new radiopharmaceutical for renal imaging, 99mTc-DMSA (dimercaptosuccinic acid). Sixty-five patients were studied and six of these patients' scintiphotos are illustrated. The physical characteristics of 99mTc and the mercurial-like kinetics of the chelate produced high-resolution scintiphotos of the renal parenchyma in patients of all ages and with a variety of disease entities. The commercial availability of the material in kit form permits its usage in all nuclear medicine facilities. (+info)
Functional evidence for an inward rectifier potassium current in rat renal afferent arterioles.
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An inward rectifier potassium current, Kir, has been identified in cerebral and coronary resistance vessels, where it is considered to be an important determinant of resting membrane potential (RMP) and to play a role in blood flow regulation. We investigated the functional role of Kir in the renal afferent arteriole using the in vitro-perfused hydronephrotic rat kidney. Increasing external KCl from 5 to 15 mmol/L induced afferent arteriolar vasodilation. This response was inhibited by 10 to 100 micromol/L Ba(2+), concentrations selective for blockade of Kir, and by chloroethylclonidine (100 micromol/L) but was not blocked by glibenclamide (10 micromol/L) or ouabain (3 mmol/L). Reducing external KCl from 5 to 1.5 mmol/L to enhance rectification of Kir caused vasoconstriction at low renal arterial pressure (40 mm Hg) and vasodilation during myogenic vasoconstriction (120 mm Hg), suggesting that this current dominates RMP at low perfusion pressures. When administered to kidneys perfused at 40 mm Hg renal arterial pressure, 30 micromol/L Ba(2+) elicited afferent arteriolar depolarization, reducing RMP from -47+/-2 to -34+/-2 mV (n=10, P:<0.0001), and vasoconstriction, reducing diameters from 14.5+/-1 to 10.9+/-0.8 microm (n=10, P:=0.0016). Although Ba(2+) reduced resting diameter, blockade of Kir did not prevent myogenic signaling in this vessel. Our findings thus demonstrate the presence of Kir in rat renal afferent arterioles and suggest that this current is an important determinant of RMP in situ. (+info)
Lipodystrophy, pancreatitis, and eosinophilia.
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Two patients suffering from partial lipodystrophy, pancreatitis, and recurrent eosinophilia are described. In one patient the duodenum and the terminal ileum were narrowed, the appearances suggesting eosinophilic gastroenteritis: bilateral hydronephrosis was also present without ureteric obstruction. An association between lipodystrophy and renal disease is recognized; it is possible that there is also an association between lipodystrophy and pancreatitis, and eosinophilia with or without an intestinal lesion may be a further association. (+info)