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

Endoscopic treatment of vesicoureteral reflux (VUR) is based on transurethral injection of Teflon paste or collagen gel into the submucosa of the bladder wall beneath the distal ureter, resulting in support of the intramural part. This endoscopic procedure was performed in 75 children with VUR of varying severity. Altogether 111 ureters were treated, 94 with injections of Teflon paste and 17 with collagen gel. Improvement of VUR in the early postoperative period was achieved in 91.5% of the ureters treated with Teflon and in 82.4% of the ureters treated with collagen. No complications were observed. Endoscopic treatment of VUR seems to be an worthwhile alternative to open surgery. However, since long-term follow-up has not been completed, the efficacy of the method cannot yet be finally assessed.
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PMID:[Early results of endoscopic treatment of vesico-ureteral reflux in children]. 192 75

Following preliminary in vitro and in vivo experiments a new collagen Vicryl mesh has been devised. The membrane has been extensively tested in the laboratory and has been found to resist the passage of urine. It holds sutures well and has been shown on an experimental animal to be biodegradable. The membrane has now been applied in human subjects. It has been particularly efficacious in renal surgery and as a means of sealing a bladder after it has been opened. With respect to the ureter the sealing effect is excellent, to the extent of having produced a urinoma. The membrane has been found to be easily applied in vesicovaginal fistulae but difficulties have been experienced in the presence of infection. It is also an ideal membrane for repair of a urethrovaginal fistula--an area where natural tissues are less easily available. This is the first recorded use of this new biodegradable membrane in the human subject.
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PMID:First clinical report of a new biodegradable membrane for use in urological surgery. 193 66

The sequential changes in maximum active stress, contractile proteins and collagen contents in the dilated ureter were determined in the rabbit ureters, which was partially obstructed for the intervals of 2 to 48 weeks. Maximum active stress and myosin content showed similar changes with the obstruction interval, i.e., both decreased first and then increased from week 2, and reached maximum at week 8, and after that, gradually decreased. Actin content did not show any significant changes. Collagen content showed almost the same changes as myosin content and maximum active stress by week 2. Then the collagen content increased rapidly from week 6 to week 10, and continued to increase gradually until 48 weeks after obstruction. A significant correlation was demonstrated between maximum active stress and myosin content while no significant correlation was found between maximum active stress and actin content. The maximum active stress decreased as the collagen content increased after week 8. Thus, there was a significant, negative correlation between them. Finally, the ratio of myosin content to collagen content (myosin/collagen) was related to maximum active stress. This ratio was more closely correlated with maximum active stress, indicating that myosin-collagen ratio is a good means of predicting contractility of the obstructed ureter.
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PMID:[Sequential changes in maximum active stress, contractile proteins and collagen contents in obstructed ureters]. 204 4

The ureter structure was analyzed under light microscope on serial sections in newborn children affected by obstruction of the pyelo-ureteric junction. In the obstructive segments, preceded by ureter portions dilated and provided with close-packed layers of smooth muscle layers, the tunica mucosa was lacking epithelial cover, its lamina propria was thickened, being built by conspicuous bundles of collagen fibers, and the tunica muscularis showed scarce and disrupted groups of muscle cells invaded by connective tissue. Numerous mastocytes were seen in the mucosa and muscularis tunicae. The results suggest that the breaking of the epithelium may be a primary pathogenetic event followed by passage of urine in the subjacent tissues in turn responsible for a diffuse connective reaction, and, therefore for a final fibrosis of the ureter wall. The role of the mastocytes in the etiopathogenesis of the pyelo-ureteric junction obstruction was also discussed.
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PMID:[Histologic study of the pyelo-ureteral junction]. 235 37

A subepithelial multilayer of abundant fusiform cells has been distinguished cytochemically in the urinary bladder and ureter in mice and rats. These distinctive cells stained selectively for carbonic anhydrase (CA) isozymes I and III. Immunonegativity for keratin and Na+,K+-ATPase differentiated the CA-positive cells from epithelial cells and their lack of immunoreactivity for actin distinguished them from smooth muscle cells. Immunostaining for vimentin, blue staining with the trichrome method, location in an exceptionally dense collagen stroma, and ultrastructural appearance related the multilayer cells to fibroblasts. A loosely collagenous, less cellular lamina propria separated the CA-positive suburothelial zone from the smooth muscle wall in the rodent urinary bladder. Ureter lacked the loose lamina propria, and the presence of such a collageneous layer in bladder therefore correlated with distensability of the organ. The presence of CA uniquely in the fibroblastoid cells applied intimately to ureter and bladder epithelium implies a specialized function of these cells, possibly one concerned with the barrier between blood and hypertonic urine. Cytochemical demonstration of keratin and fucose-rich glycoconjugate in the plasmalemma of superficial urothelial cells indicates a role for these components in passively maintaining the blood-urine barrier. The observed distribution of Na+,K+-ATPase in mid and deep urothelial cells implicates this enzyme and these cells in actively maintaining the urine's hypertonicity. Basal urothelial cells contained glycoconjugate with terminal galactose in their plasmalemma. Ultrastructural features suggesting involution of superficial urothelial cells further evidence restriction of active ion transport to the deeper cells.
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PMID:Evidence for the blood-urine barrier depending on urothelium and carbonic anhydrase positive fibroblasts. 244 48

An antibody against rat kallikrein was produced in rabbits and its localization was studied in various organs of the rat to confirm its specificity. The distribution of immunoreactive kallikrein was studied in rat ureter by use of immunochemical techniques. Ureteral tissue was fixed in Zamboni's-glutaraldehyde fixative and immunostained with indirect immunofluorescence and the peroxidase-antiperoxidase (PAP) method for light and electron microscopy. Preabsorption of the primary polyclonal antiserum with purified rat urinary kallikrein and substitution with normal serum were used as controls. By light microscopy, kallikrein was localized in the lamina propria and in the adventitial connective tissue surrounding the entire ureter. Immunoelectron microscopy confirmed this immunolocalization. Immunoreactive kallikrein was concentrated in fibroblasts of connective tissue and was not present in collagen fibers. Immunoreactivity was associated with the Golgi complex, free polyribosomes, and rough endoplasmic reticulum. No immunostaining was observed in other subcellular components of fibroblasts.
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PMID:Localization of a renal kallikrein immunoreactive-like substance in rat ureter. 305 70

This investigation assessed a biodegradable collagen membrane which can be sutured around the ureter to prevent urine leakage, thus permitting healing to proceed more rapidly while the membrane itself is resorbed. Following an early in vitro investigation in which collagen was assessed, a more comprehensive survey has now been carried out. Tissue compatibility and biodegradation were assessed by implanting the film into the lumbar muscles of rats; it was then used to cover experimental ureterotomies in New Zealand White rabbits. The data obtained from the rabbits confirmed that a collagen membrane can prevent leakage of urine from the ureter during healing while it itself is biodegraded, indicating that a collagen membrane could be used to repair the injured urinary tract.
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PMID:Assessment of collagen film for use in urinary tract surgery. 369 37

A new method was developed inducing antithrombogenicity to biologic materials. A basic protein, protamine, was used to increase heparin binding to collagenous materials. Protamine sulfate solution was poured into a collagen-rich material (porcine ureter). The protamine adsorbed to the collagen was then cross-linked to the material by glutaraldehyde. The collagen-protamine complex was then interacted with a heparin solution to ionically bind heparin to the material. The amount and the distribution of the bound heparin can be controlled by changing the protamine fixation to the material. A heparinized porcine ureter as a vascular substitute showed excellent antithrombogenicity in experimental animal studies. This method is expected to be used as method for developing antithrombogenic artificial organs, and as a method for the development of antiadhesive membranes.
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PMID:A simple method to heparinize biological materials. 395 68

The use of a collagen sponge tube graft as a material for segmental ureteral replacement was investigated. The structural design of the collagen sponge graft was achieved by cell culture on the matrix. MGH-U1 cells, derived from bladder cell carcinoma, were grown in vitro on the collagen sponge matrix with excellent biocompatibility and without evidence of cytotoxicity. The collagen sponge demonstrated biodegradability when implanted subcutaneously in dogs. However, a urine exposure test of collagen sponge in rat bladders revealed extensive salt deposits on its surface in some rats, as observed by crystallographic examination. Segmental ureteral replacements by collagen sponge tube grafts, accompanied by ureteral splint catheters, were performed in dogs. There was extensive uro-epithelial cell regeneration on the inner surface of the collagen grafts, without evidence of severe hydronephrosis, 5 to 12 weeks following the procedure. The results indicate the potential for ureteral replacement by collagen sponge tube grafts, which would act as non-toxic, biodegradable scaffolds inducing the regenerative activity of the ureter.
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PMID:Ureteral replacement using collagen sponge tube grafts. 398 29

Scanning electron microscopy is a useful method to study the organization distribution and orientation of the collagen fibers in the ureteral wall. Different collagen structural patterns have been observed in normal ureter, primary obstructive megaureter and refluxing megaureter. A pathogenic hypothesis is advanced based on the different functional characteristics of each one of these entities. Collagenous proliferation in primary obstructive megaureter and refluxing megaureter could be related to ureteric smooth muscle cell disfunction.
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PMID:Ultrastructural characteristics of collagen tissue in normal and congenitally dilated ureter. 407 71


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