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At least 109 records · Page 6Linked to original sources
PubMed2001

Effects of fibrin glue on injured rabbit ureter.

BACKGROUND AND OBJECTIVE: Fibrin glue is used as a hemostatic agent, has potential as a tissue adhesive, and may promote tissue healing. The histologic effects of fibrin glue on the ureter have not yet been fully investigated. We studied the effect of fibrin glue on the thickness of various layers of injured and uninjured ureters and its effect on vessel density in the rabbit model. MATERIALS AND METHODS: Rabbits were divided into two groups. The ureters were exposed using a midline abdominal incision. In the study group, one of the ureters was crushed, and fibrin glue was instilled around both ureters. In the control group, one of the ureters was crushed, but no fibrin glue was instilled. The animals were sacrificed at 6 weeks and the ureters examined histologically. Using NIH Image Analysis solftware, the thickness of the urothelium, muscular, and adventitial layers and the cross-sectional area of the ureters were measured. The vessel density of the ureters was also assessed. RESULTS: Whereas the thickness of the epithelium was increased in the crushed ureters treated with fibrin glue (20.7 microm v 15.3 microm), the thickness was reduced in the uncrushed ureters treated with fibrin glue compared with controls (16.3 microm v 19.8 microm). There was no statistically significant difference in the thickness of the muscular or adventitial layers in the study and control groups. There was a reduction in the cross-sectional area of the uncrushed ureters treated with fibrin glue compared with controls (7,095 microm2 v 9,409 microm2). In addition, the vessel density in the crushed ureters was reduced in ureters treated with fibrin glue compared with controls (0.00067/microm2 v 0.00108/micro2). In the uncrushed ureters, the difference was not statistically significant. CONCLUSIONS: Fibrin glue has potential as an adhesive agent in the ureter and may promote healing. It may affect epithelial layer thickness and vessel density of the ureter, but these effects were variable. Fibrin glue does not appear to have significant effects on the ureteral muscular and adventitial layers or on the overall cross-sectional area of all three layers. These results indicate that fibrin glue does not appear to have a detrimental effect on the ureter.

Animals↗
PubMed1995

A quantitative histological evaluation of the dilated ureter of childhood. II: Ectopia, posterior urethral valves and the prune belly syndrome.

A quantitative histological study was performed on specimens of 33 ureters obtained from 14 male and 19 female patients 5 days to 14 years old (mean age 1.2 years). A high resolution color image video analysis system was used to quantify and compare collagen and smooth muscle components of the muscularis layers to normal control ureters from patients of similar ages. In comparing ureters with ectopia (7), ureters with ectopic ureteroceles (20) and control ureters (4) there was not a statistically different collagen-to-smooth muscle ratio among the groups. In the patients with posterior urethral valves the amount of collagen and smooth muscle was not statistically different from controls (p > 0.01), although the collagen-to-smooth muscle ratio was increased. The 4 patients with the prune belly syndrome had a collagen-to-smooth muscle ratio that was markedly elevated (1.21 versus 0.39) compared with controls. When this group was analyzed as 2 separate groups (obstructed versus refluxing ureters) the difference was more apparent (p < 0.004). Ureters with ectopia or ectopic ureteroceles and ureters associated with posterior urethral valves had similar quantitative amounts of smooth muscle (60%, 56% and 52%, respectively). In patients with the prune belly syndrome obstructed ureters had 65% muscle and refluxing ureters had 38% muscle on evaluation. The percentage of collagen was 33% in ureters with ectopia, 37% in those with ureteroceles and 48% in those associated with posterior urethral valves compared with 23% in controls. In the group with the prune belly syndrome there was 30% collagen in obstructed ureters and 62% collagen in refluxing ureters. Our findings demonstrate that while these dilated ureters had different etiologies the overall quantitative composition of collagen-to-smooth muscle ratios was similar except in refluxing ureters associated with the prune belly syndrome. Our study provides further insight into the pathological nature of such ureters and considerations for surgical repair.

Adolescent↗
PubMed2003

[Measurement of microcirculation during experimental ureter implantation].

INTRODUCTION: Various types of ureter neoimplantation methods can be used in diseases that affect the distal part of the ureter. The most common techniques are the Cohen and the Politano. When the ureter is dilatated tapering of the enlarged ureter is necessary during neoimplantation using excisional or plication techniques. The aim of the study was to compare the effect of these different methods on the ureter tissue microcirculation in animal model and to answer the question which technique has better outcome. METHOD: The authors investigated tissue microcirculation patterns of ureter segments under surgical conditions employing Laser Doppler flowmetry in dogs. Different surgical procedures were compared in the function of tissue microcirculation as measured in the affected ureter segments. Measurements both in the intra- and postoperative periods were performed to compare different methods of ureter neoimplantation (Cohen vs. Politano-Leadbetter) and tapering (excisional technique, i.e. tailoring vs. plication of the lower ureter). The status of the ureter microcirculation was compared before and after catheterisation. 9 cases of Politano-Leadbetter and 9 cases of Cohen procedure as well as ureter tailoring in 7 and plication in 6 cases were performed in mongrel dogs. The microcirculation patterns of the ureter were detected intraoperatively and postoperatively using Laser Doppler Flowmetry device. The influence of catheter insertion on ureter microcirculation was examined in each case. RESULTS: Among the neoimplantation methods the Cohen procedure whereas among the tapering procedures the plication of the ureter were found to affect the least the microcirculation of the ureter tissue. The catheter insertion had significantly worsened the blood supply. CONCLUSION: Based on these results better outcome can be expected with the Cohen neoimplantation method and plication of ureter as compared with others.

Animals↗
PubMed2006

Development and differentiation of the ureteric bud into the ureter in the absence of a kidney collecting system.

Six1-/- mice were found to have apparently normal ureters in the absence of a kidney, suggesting that the growth and development of the unbranched ureter is largely independent of the more proximal portions of the UB which differentiates into the highly branched renal collecting system. Culture of isolated urinary tracts (from normal and mutant mice) on Transwell filters was employed to study the morphogenesis of this portion of the urogenital system. Examination of the ureters revealed the presence of a multi-cell layered tubule with a lumen lined by cells expressing uroplakin (a protein exclusively expressed in the epithelium of the lower urinary tract). Cultured ureters of both the wild-type and Six1 mutant become contractile and undergo peristalsis, an activity preceded by the expression of alpha-smooth muscle actin (alphaSMA). Treatment with a number of inhibitors of signaling molecules revealed that inhibition of PI3 kinase dissociates the developmental expression of alphaSMA from ureter growth and elongation. Epidermal growth factor also perturbed smooth muscle differentiation in culture. Moreover, the peristalsis of the ureter in the absence of the kidney in the Six1-/- mouse indicates that the development of this clinically important function of ureter (peristaltic movement of urine) is not dependent on fluid flow through the ureter. In keeping with this, isolated ureters cultured in the absence of surrounding tissues elongate, differentiate and undergo peristalsis when cultured on a filter and undergo branching morphogenesis when cultured in 3-dimensional extracellular matrix gels in the presence of a conditioned medium derived from a metanephric mesenchyme (MM) cell line. In addition, ureters of Six1-/- urinary tracts (i.e., lacking a kidney) displayed budding structures from their proximal ends when cultured in the presence of GDNF and FGFs reminiscent of UB budding from the wolffian duct. Taken together with the above data, this indicates that, although the distal ureter (at least early in its development) retains some of the characteristics of the more proximal UB, the growth and differentiation (i.e., development of smooth muscle actin, peristalsis and uroplakin expression) of the distal non-branching ureter are inherent properties of this portion of the UB, occurring independently of detectable influences of either the undifferentiated MM (unlike the upper portion of the ureteric bud) or more differentiated metanephric kidney. Thus, the developing distal ureter appears to be a unique anatomical structure which should no longer be considered as simply the non-branching portion of the ureteric bud. In future studies, the ability to independently analyze and study the portion of the UB that becomes the renal collecting system and that which becomes the ureter should facilitate distinguishing the developmental nephrome (renal ontogenome) from the ureterome.

Actins↗