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Query: UMLS:C0403608 (ureter)
 9,655 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We used an impedance planimetric method to look at elastic wall properties of ureter in ten anaesthetized pigs. A balloon was stepwise inflated and deflated in the ureteropelvine junction, in the mid-ureter, and in the intramural part of the ureter at the ureterovesical junction with pressures up to 70 cmH2O, while the pressure and balloon cross-sectional area (Bcsa) were measured simultaneously. The elastic wall parameters were calculated from these measurements. At sacrifice, tissue samples were collected for analysis of collagen content of the ureteral wall. A non-linear clockwise relation (hysteresis loops) between Bcsa and balloon pressure was demonstrated. At maximal inflation of the balloon, the Bcsa, wall tension, and compliance were 35.28 +/- 3.52, 38.44 +/- 3.23, and 61.36 +/- 8.09 mm2, 230.71 +/- 12.82, 242.38 +/- 10.49, and 302.17 +/- 20.03 cmH2O x m, and 0.167 +/- 0.047, 0.124 +/- 0.002, and 0.182 +/- 0.040 mm2 x cmH2O-1 in the intramural part of the ureter, middle part, and ureteropelvine junction, respectively. The collagen content was 0.3249 +/- 0.0077, 0.3301 +/- 0.0066, and 0.3457 +/- 0.0060 mg x mg-1 dry defatted weight in the intramural part, in the middle, and in the ureteropelvine junction, respectively. The collagen content of the ureteropelvine junction was significantly higher than that of the middle of ureter (P < 0.02) and than that of the intramural part (P < 0.05). No significant correlations were found between the elastic parameters at maximal inflation of the balloon and the collagen content (P < 0.10). In conclusion the elastic wall properties were significantly different in the three ureteral segments and the collagen content of the ureteropelvine junction differed from that of the two distal locations. However, no relationship between the wall properties and the collagen content was found.
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PMID:Elastic wall properties and collagen content in the ureter: an experimental study in pigs. 783 75

Injection of polytetrafluoroethylene (Teflon) or collagen has been used in the endoscopic treatment of vesicoureteral reflux. Although the principle of an endoscopic treatment is valid, there are concerns regarding the long-term safety and effectiveness of these substances. In search of a different injectable material we conducted experiments using chondrocytes in a biodegradable polymer solution for the treatment of vesicoureteral reflux in an animal model. Reflux was created in 4 mini-pigs and confirmed with a cystogram. Cartilage was obtained from the auricular surface of each animal. Chondrocytes were harvested and expanded in vitro. The cells were individually quantitated and concentrated to 40 million cells per cc. The cell suspensions were mixed with a sodium alginate and calcium sulfate solution. Each pig was injected unilaterally in the subureteral region with the autologous chondrocyte suspension. The opposite ureter served as an internal control in all animals. Cystograms showed resolution of reflux in the treated side and persistence of reflux in the opposite untreated side in each instance. Excretory urograms revealed no evidence of obstruction. Histological examination of the subureteral region demonstrated cartilage. Autologous chondrocytes can be readily harvested, expanded in vitro and injected cystoscopically. The cells survive and form a cartilage nidus that is nonantigenic. This system is able to correct reflux without any evidence of obstruction.
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PMID:Endoscopic treatment of vesicoureteral reflux with a chondrocyte-alginate suspension. 802 88

A case of malignant giant cell tumor of the tendon sheath of the right hip, which developed in a 72-year-old Japanese woman, is described. The tumor exhibited histological similarities to a benign giant cell tumor of the tendon sheath (localized nodular tenosynovitis). The resected tumor, measuring 9 x 9 x 11 cm, was located in the adductor muscle and invaded the proximal femur and acetabulum. The nodule was encapsulated with a thin membrane which was soft and gelatinous in consistency and varied in color from yellow to brown. The synovium of the hip joint was normal. The primary lesion was composed of plump polyhedral and spindle-shaped cells. The nuclei were large, irregular and hyperchromatic, and contained prominent nucleoli. A moderated number of multinucleated giant cells was scattered throughout the lesion. There was little stromal collagen. In the majority of the specimens, pseudoglandular or alveolar spaces were predominant. An ultrastructural study demonstrated three cell types: fibroblast-like, histiocyte-like and an intermediate. The patient underwent reconstructive surgery with a Dacron fabric-enveloped alumina ceramic pelvic prosthesis and total hip components after resection of the primary lesion. Unfortunately, because of a local recurrence, a hemipelvectomy was required 10 months after the initial operation. At that time the intestines were involved with the recurrent tumor, and the patient subsequently died of perforative peritonitis. An autopsy revealed distant metastases to the right pelvis, urinary bladder, right ureter, ilium, mesenterium and lungs.
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PMID:Malignant giant cell tumor of the tendon sheath: an autopsy report and review of the literature. 823 Jul 58

Collagen studies in newborn rats with incomplete ureteric obstruction were performed to describe and quantify changes in collagen deposition resulting from urinary tract obstruction at an early developmental age. Incomplete ureteric obstruction was created in three-day-old rats by placing the left ureter in a tunnel formed by the psoas muscle, and sham-operated controls underwent a laparotomy. The rats were sacrificed at 10, 17, 24 or 31 days. Collagen types I, III, IV, and V were localized by indirect immunofluorescence microscopy, the total collagen content of the kidney was quantitated using hydroxyproline analysis, and collagen types I and III were quantitated using cyanogen bromide (CNBr) peptide analysis. Increased immunofluorescent staining for all of the collagens was found in the diffusely widened medullary interstitium of the obstructed kidney, and more focally in the cortical interstitium. Collagen types I, III and V, but not collagen type IV, were also found in bands in the interstitium at the junction of the cortex with the medulla. Increased staining for collagen type IV was found in thickened and tortuous tubular basement membranes (TBM) of the obstructed kidneys. The total collagen content of the obstructed kidney was significantly increased compared to the amounts in both the contralateral kidneys and in the kidneys from sham-operated controls at 24 and 31 days of age (P < 0.01 in each case, Wilcoxon matched pairs rank sum test and Mann Whitney U-test, respectively). The amount of collagen in the kidneys correlated with the degree of hydronephrosis (Spearman correlation test, r = 0.78, P < 0.02). CNBr peptide analysis demonstrated that over 50% of the collagen in the normal neonatal rat kidney was collagen type I and approximately 25% was collagen type III. In the obstructed kidneys most of the collagen was also collagen type I and collagen type III, although the proportion of total collagen comprised by these collagen types was decreased compared with the controls. The amount of collagen type III in the contralateral kidneys was reduced compared to that in the controls. Thus, the neonatal renal response to obstruction resulted in increased amounts of a range of collagens in the interstitium and TBM, and the extent of this response was partially related to the degree of hydronephrosis.
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PMID:Collagen studies in newborn rat kidneys with incomplete ureteric obstruction. 823 Oct 33

The collagen fibres of rabbit and human ureter were exposed by digestion with trypsin and hyaluronidase. The fibre structure was examined using an SEM and examples of the inner and outer fibre structures are shown together with the effects of different types of mechanical strain. An interesting difference between the arrangements of the inner fibres of human and rabbit was seen where the human ureter had a cross-ply structure while in the rabbit it was helical.
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PMID:Collagen arrangements in ureter. 827 87

The clinical controversy regarding the timing of surgery for asymptomatic newborns with obstructed hydronephrosis was addressed using a model of reversible partial ureteral obstruction in the newborn rabbit. The histomorphometric changes in the ureteropelvic junction complex (for example, pelvis, ureteropelvic junction and upper ureter) and kidney in 44 normal cases were determined and compared with the effects of 47 cases of ongoing partial obstruction and timed reversal of partial obstruction at 1 week in 9 cases, at 2 weeks in 10 or at 4 weeks in 10 (end of the study at age 8 weeks). After partial obstruction hydronephrosis appeared by 1 week postoperatively. There were progressive increases in the thickness of the lamina muscularis and mass index of smooth muscle and collagen (all p < 0.001). However, since the per cent surface area of smooth muscle did not change significantly in comparison to normal, there was disproportionately more collagen. For reversals at 1 week the muscle and collagen in the lamina muscularis were not significantly different from normal. For reversals at 2 weeks the mass index of collagen was greater than normal (p < 0.05) and reversal at 1 week (p < 0.05). For reversals at 4 weeks the lamina muscularis was thicker, and the mass index of collagen and muscle was greater than the earlier reversal groups and normal (all p < 0.05). In conclusion, partial ureteral obstruction causes progressive thickening of the lamina muscularis by collagen and muscle with a disproportionately greater increase in collagen than muscle. The earlier the obstruction can be reversed, the more normal is the ureteropelvic junction complex histology. The functional significance of these changes needs to be determined.
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PMID:Response of the newborn ureteropelvic junction complex to induced and later reversed partial ureteral obstruction in the rabbit model. 832 46

Angiotensin-converting enzyme (ACE) inhibitors have been shown to minimize fibrosis of the kidney tubulointerstitium in several diseases. In addition to lowering angiotensin II levels, ACE inhibitors can increase kinin levels and subsequently increase nitric oxide formation. To determine whether nitric oxide generation is a component of the beneficial effect of ACE inhibitors on renal fibrosis, enalapril, enalapril plus NG-nitro-L-arginine methyl ester (L-NAME) or L-arginine was administered to rats that had undergone unilateral ureteral obstruction (UUO). Ureteral obstruction caused significant increases in interstitial volume, monocyte macrophage infiltration, interstitial collagen IV and alpha-smooth muscle actin expression, transforming growth factor-beta 1 mRNA, collagen IV mRNA, and tissue inhibitor of metalloproteinase-1 mRNA. Enalapril treatment significantly blunted the increase in all parameters during UUO. Cotreatment of the animals with enalapril and L-NAME reversed the beneficial effect of enalapril in the obstructed kidney for all parameters. Treatment of animals with UUO with L-arginine significantly blunted the increase in all parameters except for transforming growth factor-beta 1 mRNA expression. In the enalapril- plus-L-NAME-treated animals, there were modest but significant increases in monocyte/macrophage infiltration of the interstitium and glomerulus, and collagen IV and alpha-smooth muscle actin expression in the interstitium of the contralateral unobstructed kidney. The urine nitrite concentration was significantly increased by either enalapril or L-arginine treatment, whereas L-NAME significantly reduced urine nitrite concentration. These results suggest that treatment modalities that increase nitric oxide formation have a beneficial effect on the progression of cellular and molecular parameters of tubulointerstitial fibrosis caused by obstruction of the ureter.
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PMID:Nitric oxide generation ameliorates the tubulointerstitial fibrosis of obstructive nephropathy. 891 81

Four variants of segmentary dysplasia in paravesical ureter are described: segmentary aplasia, segmentary atresia, segmentary hypoplasia, fibrous block. Segmentary dysplasia manifests in the absence of muscular layer in the wall of paravesicular ureter. In fibrous block the layer is replaced by embryonal collagen fibers. These anomalies cause ureteral obstruction and ureterohydronephrosis. 72 operative interventions were performed. Reoperations were made in such complications as vesicoureteral reflux, stenosis of ureterocystoanastomosis. It is necessary to differentiate between ectopy of the ureteral ostium, ureterocele and ureteral dysplasia in the form of segmentary hypoplasia and/or fibrous block causing the obstruction in the paravesicular ureter.
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PMID:[Segmentary dysplasia of the perivesical portion of the ureter]. 912 59

Fibroinflammatory disorders constitute heterogeneous clinical conditions whose cause and pathogenesis are largely unknown. Inflammatory pseudotumor has been applied in a generic sense to several of these disorders, which present as a mass displacing surrounding anatomic structures or leading to organ dysfunction secondary to compressive growth around the ureter(s), common bile duct, or great vessels in the mediastinum. The fibrosclerosing disorders of retroperitoneal fibrosis, sclerosing mediastinitis, sclerosing cholangitis, orbital pseudotumor, and Riedel thyroiditis are seemingly related in a clinical sense because there are well-documented cases of patients with two or more of these conditions and reports of these disorders presenting in family members. Although the pathogenesis of the fibrosclerotic disorders has not been elucidated, autoimmunity in the context of an established collagen vascular disease or the setting of inflammatory periaortitis in retroperitoneal fibrosis has been one suggested mechanism. In the course of the diagnostic evaluation of an individual with a suspected fibrosclerotic disorder, it is imperative to exclude an underlying infection or malignancy. This caveat is especially relevant to sclerosing mediastinitis as a presentation of histoplasmosis or to retroperitoneal fibrosis secondary to a sclerosing large cell lymphoma. Sclerosing mesenteritis has some clinical and pathological overlap with the fibrosclerotic disorders, but its nosologic and pathogenetic relationship is uncertain at this time. There are several other fibroinflammatory processes, such as focal myositis, inflammatory fibroid polyp of the gastrointestinal tract, calcifying fibrous pseudotumor, and sclerosing peritonitis, which are probably unrelated to inflammatory myofibroblastic tumor or the primary fibrosclerotic disorders.
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PMID:Idiopathic fibrosclerotic disorders and other inflammatory pseudotumors. 960 7

Cellular and molecular events contributing to tubulointerstitial fibrosis of the kidney during obstructive nephropathy are driven in large part through increased angiotensin II levels in the obstructed kidney. Angiotensin converting enzyme inhibition or AT1 receptor antagonism have been shown to ameliorate the fibrosis of the kidney due to obstruction of the ureter. In this investigation, we determine the effects of the AT2 receptor antagonist PD-123319 on pathophysiological events within the kidneys of rats with unilateral ureteral obstruction. Treatment with PD-123319 was found to exacerbate the increase in interstitial volume and collagen IV matrix score of the ureteral obstructed kidney. Monocyte/macrophage infiltration of the injured kidney was no different between treated and untreated animals. The AT2 receptor antagonist did, however, inhibit apoptosis of tubular cells, alpha-smooth muscle actin expression within the interstitium, and p53 expression in the ureteral obstructed kidney. These results suggest that angiotensin II operating through the AT2 receptor exerts an antifibrotic effect on the kidney during obstructive nephropathy in opposition to the profibrotic effects of angiotensin II operating through the AT1 receptor.
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PMID:Effect of AT2 receptor blockade on the pathogenesis of renal fibrosis. 988 78


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