Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0403608 (ureter)
 9,655 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A case of an aggressive desmoid tumor in a patient with familial adenomatous polyposis is described. The lesion rapidlyenlarged with compression of adjacent structures including the ureter and small bowel, and the patient died because of small bowel perforation and hydronephrosis 3 years after detection of small desmoid tumors at the time of a prophylactic coloproctectomy for a colon carcinoma. Immunohistochemically, proliferating cell nuclear antigen (PCNA), p21WAF1/CIP1 and cathepsin D indices, but not the bcl-2 index, which were defined as the numbers of immunoreactive tumor cells per 1000 tumor cells, increased in line with tumor progression. The tumor did not show staining for collagen IV, but was characterized by intense staining for basic fibroblast growth factor (bFGF). Accordingly, tumor aggression was related to increases in both cell proliferation and protease activity, as well as an enhanced expression of bFGF. In addition, the desmoid tumor showed deregulation between PCNA and p21WAF1/CIP1 because the normal inverse relation between these two was not apparent.
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PMID:An aggressive desmoid tumor in a patient with familial adenomatous polyposis: immunohistochemical findings. 1002 64

Urethral reconstruction following failed hypospadias repair or post-traumatic chronic stricture requires adequate amounts of tissue. Many surgical techniques utilizing different types of biological tissues have been attempted: (a) vascularized skin flaps from the prepuce, scrotum or penile shaft; (b) full-thickness free skin grafts; (c) vesical or buccal mucosa grafts; (d) ureter; artery; vein and appendix tissue. More recently, biodegradable polymers have also been used as delivery vehicles of urothelial cells in animals. It has been demonstrated that the implant of an acellular tissue matrix in the bladder can guide the regeneration of urothelium, blood vessels, smooth muscle and nerves. The aim of this study was to create an experimental model of urethral defect, and then repair it by implanting homologous acellular aortic grafts as urethral substitutes. An acellular matrix was obtained by detergent enzymatic treatment of rabbit thoracic aorta. The growth of urethral epithelium was verified in vitro, and homologous acellular vessels were then implanted in rabbits, bridging a previous surgical urethral defect. The outcome of reconstructive surgery was evaluated histologically at 10 days, 3 weeks, 3 and 12 months. As the time after surgery increased, the neourothelium became less thick, signs of inflammatory response disappeared, and the orientation of collagen fibrils and smooth muscle fascicles resembled that of a normal urethra. The implants displayed abundant vascularization, and the luminal surface started to become irregular. Acellular blood vessels may represent a promising approach to urethral defect therapy for different reasons: (a) unlimited availability, (b) readily obtainable in different lengths and gauges, (c) the potential for being organized as tissue bank, and (d) that just one simple surgical procedure is needed. Nevertheless, before this technique can be applied in humans, it must be tested in more species and animals.
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PMID:Experimental defect in rabbit urethra repaired with acellular aortic matrix. 1073 95

Vesico-ureteral reflux, a common pathology in children, can be treated cystoscopically by injection of a bulking material underneath the most distal, intramural ureter, which forces the latter to do a detour, increasing its submucosal path. This increase of the length of the submucosal path of the ureter within the bladder is directly responsible for the anti-reflux effect. So far Teflon and collagen paste have been commonly used as bulking materials. We suggest replacing these materials by living tissue consisting of bladder smooth muscle, normally present at this location. The aim of this work is to provide a long-term effective treatment by producing bioresorbable microspheres which can act as a support matrix and an entrapment substance for bladder smooth muscle cells, with the goal of an in vivo transfer of the in vitro cultured cells with a minimal surgical procedure. By the use of Spinning Disk Atomization, which has specifically been developed for this purpose, we have shown two methods for the preparation of porous poly(lactic acid) microspheres with tunable sizes from 160 to 320 microm. The controlled solvent burst method has shown the advantage over the crystal leaching method in the direct creation of microspheres with large closed pores, by atomizing the polymer solution in controlled temperature conditions. Microspheres with various closed pore structures have thus been prepared. The innovation of this work is in the direct and rapid formation of porous microspheres with a pore morphology which is designed to create cavities suitable for adherence and growth of cells by adapting the temperature conditions of atomization. Injection tests have shown promising results in using these cell-loaded microspheres for future non-invasive tissue engineering.
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PMID:Bioresorbable microspheres by spinning disk atomization as injectable cell carrier: from preparation to in vitro evaluation. 1081 66

We used reconstructed SIS (ReSIS), a photocrosslinked biomaterial, to create grafts in various shapes and sizes. Sheets of ReSIS were placed in 14 swine to repair bladder defects, and ReSIS tubes were placed in six swine to replace a segment of excised ureter. Histologic analysis of the bladder repair revealed transitional urothelial cells lining the ReSIS by 1 week. After 2 weeks, fibroblasts and mononuclear cells had infiltrated the ReSIS, neovascularization had occurred, and the urothelial lining was more complex, containing multiple cell layers. After 4 weeks, a definite submucosa was present and the ReSIS was starting to degrade. An initial muscular regeneration was demonstrated at 12 weeks. No foreign body reaction, calcification, or sedimentation was noted in any animal. The ureteral implants showed identical histologic changes, without obstruction or leakage of the replaced segment. The ReSIS allowed rapid urothelial regeneration, ingrowth of new blood vessels, and the orderly deposition and organization of new collagen. Our study demonstrates that the photocrosslinking technique used to create larger sheets and tubes of this biomaterial (ReSIS) does not detract from the positive attributes of the SIS and should improve its usefulness in accomplishing larger bladder augmentations and ureter replacements.
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PMID:Use of reconstructed small intestine submucosa for urinary tract replacement. 1082 34

Recent initiatives in the development of biomaterials for functional reconstruction involve the alloplasts, the biological and the bioengineered biomaterials. Anti-infective alloplastic biomaterials (Foley catheters coated with rifampicin/minocycline bonded to silicone or ciprofloxacin liposome-containing hydrogel) allow a reduction in the rate of bacterial contamination, but the risk of future bacterial resistance is a matter for concern. New generations of biologic collagen-based tissue-matrix grafts are derived from bladder (bladder acellular matrix graft and bladder submucosa collagen matrix), ureter or small intestine (subintestinal submucosa). There are high hopes that these materials may have applications in augmentation cystoplasty. Using tissue engineering (autologous cells expanded in vitro and grafted onto biodegradable matrix), biocompatible malleable penile prostheses have been obtained experimentally. Most of the results obtained with these new biomaterials are exclusively experimental, but they offer great hope for future functional reconstruction of the urinary tract.
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PMID:Biomaterials in functional reconstruction. 1085 97

Three days after an uneventful parturition, a Brittany spaniel/beagle puppy (Canis familiaris) was nursing but not gaining weight as rapidly as were its littermates. Although its diet was supplemented, the puppy died 10 days after birth. The renal pelves were enlarged and filled with urine. Both ureters were thin throughout their length, and urine could not be expressed from either kidney into its respective ureter. The bladder contained no urine and was firmly embedded in the umbilicus. Histologically, both kidneys were hydronephrotic and contained hypoplastic collecting tubules. The diameter of the right (0.55 mm) and left (0.57 mm) ureters at the uteropelvic junction were narrower than those of an age-matched control of the same breed (1.03 mm and 1.02 mm) and were lined by hypoplastic urothelium. Trichrome staining of the ureters revealed excessive collagen and disorganized smooth muscle fibers; in contrast, the control had predominantly circular smooth muscle fibers and less fibrous tissue. Although neither blood nor aqueous humor could be evaluated for urea nitrogen, we suspect that the puppy died from uremia. The congenital bilateral ureteral stenosis and hydronephrosis of the described puppy is similar to a form of uteropelvic obstruction in humans.
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PMID:Congenital bilateral ureteral stenosis and hydronephrosis in a neonatal puppy. 1104 Aug 73

Endothelin-1 (ET-1) has been implicated in many chronic renal glomerular diseases. The purpose of this study was to investigate whether the levels of mRNA expression of endothelin-converting enzyme-1 (ECE-1) and endothelin-A- and -B- (ET(A) and ET(B)) receptors are altered during the progression of interstitial fibrosis following ureter ligation. Rats were subjected to left ureter ligation or a sham operation and euthanized 5 days afterward. Kidneys were fixed in Carnoy's fixative, embedded in paraffin, and sectioned for assessment of interstitial fibrosis by staining for collagen III using immunofluorescence techniques. The area occupied by collagen staining was quantified by image analysis. Kidneys from obstructed rats showed a 54% increase in the area occupied by collagen III staining compared to the contralateral kidney, and an 89% increase compared to sham-operated kidneys. The mRNA levels of ECE-1, as well as ET(A)- and ET(B)-receptors in the kidney were analyzed by Northern blots. It was found that the ECE-1 and ET(A)-receptor mRNA levels in kidneys subjected to ureter ligation increased by 92% and 71%, respectively, when compared with those obtained from the contralateral kidneys. In contrast, mRNA levels of ET(B)-receptors were not significantly different between the two groups. These results suggest that ET-1, through interaction with the ET(A)-receptors, may play a role in the progression of interstitial fibrosis following ureter ligation.
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PMID:Enhanced expression of renal endothelin-converting enzyme-1 and endothelin-A-receptor mRNA in rats with interstitial fibrosis following ureter ligation. 1107 91

Ultrasonography has been an invaluable tool in the field of urology for its noninvasiveness, safety, and relatively low cost. However, examination of the ureter with ultrasound is difficult because of the distance of the transducer from the ureter and because of intervening structures such as nonconductive bowel gas. As smaller probes have become available, attempts have been made to apply them to endoluminal use. Endoluminal ultrasonography has been employed in urology to examine the proper placement of injected collagen, diagnose urethral diverticula, diagnose and stage upper tract transitional-cell carcinoma, locate crossing vessels to guide endopyelotomy, diagnose submucosal calculi, and examine the severity and length of ureteral strictures.
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PMID:Experience with endoluminal ultrasonography in the urinary tract. 1124 23

Epithelial-mesenchymal tissue interactions regulate the formation of signaling centers that play a role in the coordination of organogenesis, but it is not clear how their activity leads to differences in organogenesis. We report that type XVIII collagen, which contains both a frizzled and an endostatin domain, is expressed throughout the respective epithelial bud at the initiation of lung and kidney organogenesis. It becomes localized to the epithelial tips in the lung during the early stages of epithelial branching, while its expression in the kidney is confined to the epithelial stalk region and is lost from the nearly formed ureter tips, thus displaying the reverse pattern to that in the lung. In recombinants, between ureter bud and lung mesenchyme, type XVIII collagen expression pattern in the ureter bud shifts from the kidney to the lung type, accompanied by a shift in sonic hedgehog expression in the epithelium. The lung mesenchyme is also sufficient to induce ectopic lung surfactant protein C expression in the ureter bud. Moreover, the shift in type XVIII collagen expression is associated with changes in ureter development, thus resembling aspects of early lung type epigenesis in the recombinants. Respecification of collagen is necessary for the repatterning process, as type XVIII collagen antibody blocking had no effect on ureter development in the intact kidney, whereas it reduced the number of epithelial tips in the lung and completely blocked ureter development with lung mesenchyme. Type XVIII collagen antibody blocking also led to a notable reduction in the expression of Wnt2, which is expressed in the lung mesenchyme but not in that of the kidney, suggesting a regulatory interaction between this collagen and Wnt2. Respecification also occurred in a chimeric organ containing the ureter bud and both kidney and lung mesenchymes, indicating that the epithelial tips can integrate the morphogenetic signals independently. A glial cell line-derived neurotrophic factor signal induces loss of type XVIII collagen from the ureter tips and renders the ureter bud competent for repatterning by lung mesenchyme-derived signals. Our data suggest that differential organ morphogenesis is regulated by an intra-organ patterning process that involves coordination between inductive signals and matrix molecules, such as type XVIII collagen.
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PMID:Induced repatterning of type XVIII collagen expression in ureter bud from kidney to lung type: association with sonic hedgehog and ectopic surfactant protein C. 1129 Feb 96

We wished to determine whether small-intestinal submucosa (SIS) will epithelialize when used as a ureteral replacement material. An 11-mm segment of native ureter was excised from eight New Zealand White rabbits and replaced with an 11-mm porcine SIS graft, which was circumferentially wrapped around a ureteral stent. The SIS ureteral grafts were harvested at 11 days or 35 days postimplantation and examined grossly and by standard light microscopy techniques. Partial epithelialization with the ingrowth of urothelium, smooth muscle cells, and blood vessels was observed in the grafts harvested at 11 days postimplantation. The SIS ureteral grafts examined at 35 days postimplantation showed additional restructuring of the smooth muscle cell layer and more organized epithelialization in comparison to the SIS graft examined at 11 days. After 35 days of regenerative healing, elements of all three layers of the native ureter were observed within the collagen matrix of the SIS graft. No significant complications were observed, but all subjects (8/8) demonstrated mild intra-abdominal adhesions. Mild collecting system dilatations were observed in 4/4 (100%) of the animals harvested at 35 days and in 0/4 (0%) of the animals harvested at 11 days. We have this demonstrated in this preliminary study that SIS xenografts will epithelialize when used as a ureteral replacement material. The repair mechanism of these ureteral grafts occurred through a regenerative healing process rather than by scar formation. With further studies, this material may prove to be a useful treatment option in patients with ureteral injuries.
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PMID:Ureteral segment replacement using a circumferential small-intestinal submucosa xenogenic graft. 1170 Sep 19


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