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)

The interaction of 14C-acetaminophen, 150 mg/kg (20 muCi/kg), and orally administered aspirin, 200 mg/kg, was studied in male guinea pigs. Aspirin-pretreated animals possessed higher 14C blood levels than controls. Paper chromatography of 0-6 hr urines demonstrated that pretreated animals excreted significantly greater amounts of mercapturate than controls; however, it was only a minor metabolite, accounting for 1-3% of the counts in the urine. The major metabolite, the glucuronide, accounted for 90% of the counts, with free acetaminophen and its sulfate responsible for the remaining counts. Tissue distribution studies indicated that blood plasma and kidneys from aspirin-pretreated animals possessed statistically higher 14C levels than did control tissues. Bile duct and ureter cannulation experiments indicated that aspirin inhibited the concentrating processes into the urine and bile.
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PMID:Effect of aspirin on fate of 14C-acetaminophen in guinea pigs. 115 53

There is controversy about the use of polytetrafluoroethylene (Teflon) paste in children for the endoscopic treatment of vesicoureteral reflux due to evidence of particle migration. However, there are definite advantages in treating patients endoscopically. It is evident that the ideal substance should be able to be delivered endoscopically, conserve its volume, and be nonmigratory and nonantigenic. Towards this goal we developed a catheter with an inflatable, detachable and self-sealing silicone balloon that would fit through a 19 gauge cystoscopic needle. Hydroxy-ethyl-methyl acrylate, a hydrophilic polymer that solidifies within 60 minutes after the addition of ferrous sulfate, was chosen as the filling material for the balloon. Conceptually, the sealed balloon would prevent the migration of hydroxy-ethyl-methyl acrylate and the solidified polymer would prevent volume loss. To test this system reflux was created in 6 Hanford mini-pigs by unroofing the ureters bilaterally. In 2 pigs a previously described method of open surgery was used and in the other 4 reflux was created endoscopically using the resectoscope and laparoscopic scissors. The presence of bilateral reflux was confirmed 4 weeks later with a cystogram and the balloon was implanted unilaterally through a cystoscope. The opposite ureter served as an internal control in all animals. A repeat cystogram was performed 2 to 4 weeks after implantation, demonstrating resolution of reflux in the treated side and persistence of reflux in the opposite untreated ureter. Serial cystograms, ultrasound and excretory urography showed no reflux on the implanted side nor any evidence of obstruction. Tissue sections from various organs showed no evidence of particle migration, granuloma formation or inflammatory reaction. Short-term results show that the balloon implants are able to correct reflux without evidence of obstruction.
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PMID:Endoscopic treatment of vesicoureteral reflux with a self-detachable balloon system. 164 May 55

Sulfate transport studies were carried out in secondary cultures of epithelial cells isolated from the human ureter. Results demonstrate the presence of carrier-mediated SO4(2-) transport as supported by three lines of evidence: 1) saturation kinetics, 2) substrate specificity, and 3) inhibition by the anion transport inhibitor 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS). The DIDS-insensitive component of SO4(2-) transport was markedly lower than the DIDS-sensitive component and was not affected by changes in extracellular pH (pHo) or Cl- concentration. The mechanism of this DIDS-insensitive component is not clear. The DIDS-sensitive component of SO4(2-) uptake was a saturable function of the extracellular sulfate concentration ([SO4(2-)]o). Increasing the extracellular chloride concentration ([Cl-]o) inhibited DIDS-sensitive SO4(2-) uptake competitively. Taken together with the fact that increasing [Cl-]o stimulated SO4(2-) efflux, these results suggest that SO4(2-) uptake in uroepithelial cells occurs via SO4(2-)-Cl- anion exchange. Cis-inhibition studies with a variety of anions indicate that this anion-exchange system may be shared by S2O3(2-) and MoO4(2-) but not by NO3- and H2PO4-. SO4(2-) uptake was stimulated at decreasing pHo with a pK approximately 7.4. Decreasing pHo from 7 to 6 lowered the apparent Michaelis constant significantly but had no significant effect on kcat, suggesting that protons may increase the affinity of the SO4(2-) transporter for SO4(2-). SO4(2-) efflux was inhibited at low pHo and was stimulated by increasing [Cl-]o. This study is the first to demonstrate an ion transport process in epithelial cell cultures isolated from the human ureter. In contrast to epithelial cells from the upper urinary tract, no Na(+)-dependent SO4(2-) transport could be demonstrated in these lower urinary tract epithelial cells. In conclusion, the major mechanism for SO4(2-) transport in ureteral epithelial cells is a carrier-mediated, DIDS-sensitive, pHo-sensitive SO4(2-)/Cl- anion-exchange mechanism. These studies suggest that varying [SO4(2-)]o and [Cl-]o or pHo in the ureteral lumen will affect SO4(2-) influx and efflux and may influence the size of the intracellular pool of SO4(2-) available for macromolecular sulfation in these cells.
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PMID:Carrier-mediated sulfate transport in human ureteral epithelial cells cultured in serum-free medium. 195 76

A 16-year-old boy ingested approximately 50 zinc sulfate tablets (ZnSO4; 500-mg tablets). After spontaneous emesis, ipecac-induced emesis, and orogastric lavage, an abdominal radiograph performed four hours after ingestion still demonstrated approximately 50 ZnSO4 tablets within the stomach and three pills within the colon. Whole-bowel irrigation was begun with a polyethylene glycol lavage solution (PEG; Golytely) that was administered through a nasogastric tube; within one hour, the patient began producing a rectal effluent that contained pills. The patient remained asymptomatic throughout whole-bowel irrigation. Stool guaiac tests were negative. The serum chloride, however, increased from 105 to 127 mEq/L. Follow-up kidney, ureter, and bladder studies demonstrated the clearance of the zinc tablets from the gastrointestinal tract during the next 24 hours.
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PMID:Whole-bowel irrigation as treatment for zinc sulfate overdose. 197 39

Formation of nephrons from primitive mesenchyme in fetal kidneys is induced by ureteric buds. Nephron induction is closely coordinated with branching morphogenesis of the ureteric bud. Having previously shown that branching of the primitive ureter is associated with de novo synthesis of chondroitin sulfate proteoglycan and release of free heparan sulfate glycosaminoglycan chains, we asked whether glycosaminoglycans influence nephron development. Fetal mouse kidneys were incubated in organ cultures containing heparan sulfate, heparin, chondroitin sulfate, or hyaluronate. After 48 hr the number of nephrons at each developmental stage was enumerated by light microscopic analysis of serial tissue sections. Kidneys incubated in heparin or in heparan sulfate contained up to 10-fold fewer nephrons than did kidneys incubated in control conditions or in chondroitin sulfate or hyaluronic acid. Maturation of nephrons, however, was unaffected. Inhibition of nephron development was associated with binding of labeled heparin to primitive mesenchyme and altered tissue distribution of fibronectin. Branching morphogenesis was impaired in kidneys exposed to heparin but not to heparan sulfate or to de-N-sulfated, N-acetylated heparin. The capacity of glycosaminoglycans to inhibit nephron formation depended on sugar composition and O-sulfation but not GAG chain size or charge density. Thus, heparan sulfate may have the capacity to specifically control formation of nephrons in fetal metanephric kidneys in vitro.
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PMID:Heparin and heparan sulfate delimit nephron formation in fetal metanephric kidneys. 214 Jan 4

To prevent their collapse, a certain amount of stiffness is generally required for prosthetic venous grafts, so EPTFE grafts have been used. However, the native vein is pliable without any stiffness. We developed a soft and pliable graft that can maintain patency of the lumen because of its compliance. Fresh porcine ureter was incubated in a ficin solution to remove cell components and noncollagenous proteins. One percent protamine sulfate solution was injected into the ureter lumen to impregnate the inner surface. The ureter was then crosslinked with a 1% glutaraldehyde solution, dipped into a 1% heparin solution for 5 hours, and rinsed with distilled water. This procedure made the ureter very soft and pliable, and also conferred antithrombogenicity to the graft by heparinization. The grafts were implanted into the posterior vena cavae of 20 dogs and were removed from 1 to 878 days after implantation. Eighteen grafts were patent, but two grafts were occluded at the anastomotic site at 218 and 107 days, respectively. As a control experiment, nonheparinized grafts were implanted into 15 dogs; all were occluded with fresh thrombi. All the patent grafts kept their original elasticity, which allowed them to heave in unison with the heartbeat, and were similar in appearance to the native vena cava. Heparinization was effective in preventing thrombus formation. These results indicate that this type of graft is an ideal prosthesis as a venous graft, having physiologic properties such as compliance and antithrombogenicity.
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PMID:Development of a soft, pliable, slow heparin release venous graft. 225 94

Morphology and de novo incorporation of [35S]sulfate into proteoglycans were studied in fetal mouse kidneys at the onset of organogenesis. Branching morphogenesis and nephron development in organ culture and in vivo were associated with de novo synthesis of chondroitin-SO4 and heparan-SO4 proteoglycans. The role of proteoglycan metabolism in metanephrogenesis was then studied by analysis of the effects of p-nitrophenyl-beta-D-xylopyranoside (beta-D-xyloside) on renal development and proteoglycan metabolism. Incubation of fetal kidneys in beta-D-xyloside at concentrations of 1.0 and 0.5 mM, but not at 0.1 mM, caused inhibition of ureteric branching and markedly diminished synthesis of a large Mr 2.0 X 10(6) Da chondroitin-SO4 proteoglycan. Incorporation of [35S]sulfate was stimulated at all beta-D-xyloside concentrations, reflecting synthesis of xyloside initiated dermatan-35SO4 chains. In contrast to dramatic effects on chondroitin-SO4 synthesis and ureteric branching, beta-D-xyloside had no effect on heparan-SO4 synthesis or on development of the glomerulus and glomerular basement membrane. We thus characterize the proteoglycans synthesized early in the course of renal organogenesis and describe observations which suggest an association between metabolism of chondroitin-SO4 proteoglycan and development of the ureter.
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PMID:Proteoglycan metabolism associated with mouse metanephric development: morphologic and biochemical effects of beta-D-xyloside. 365 8

We produced renal stones in rabbits by modifying Itatani's method, ligation of the right ureter followed by ureteroneocystostomy 1 week later. Renal stones formed in all animals within 2 weeks after ureteroneocystostomy. We measured the components of glycosaminoglycan in the stone matrix, renal tissue and urine by 2-dimensional electrophoresis. Glycosaminoglycan of the stone matrix consisted solely of hyaluronate. Glycosaminoglycan of the control normal urine consisted of only chondroitin sulfate, although hyaluronate was contained in urine in the hydronephrotic and stone forming period. Glycosaminoglycan of the control normal kidney consisted mainly of hyaluronate and chondroitin sulfate, while hyaluronate was the main component of glycosaminoglycan in the stone forming kidney. From these results, it is clear that hyaluronate is the most important component of glycosaminoglycan in the early stone forming period.
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PMID:Possible role of hyaluronate in experimental renal stone formation in rabbits. 396 59

The investigation was designed to determine the effect of experimental renal failure on the retention of free (inorganic) sulfate and on the pharmacokinetics of acetaminophen in rats. Adult male Sprague-Dawley rats with renal failure produced by uranyl nitrate treatment or ligation of ureters had much higher serum free sulfate concentrations (about 2 and 5 mM, respectively) than normal animals (about 1 mM). The time-averaged total clearance of a 100-mg/kg dose of acetaminophen was higher in animals with renal failure than in normal rats and was positively correlated with serum free sulfate concentration (r = 0.76, P less than .001). Renal failure had no effect on the total clearance of a 15-mg/kg dose of acetaminophen, apparently because free sulfate was not appreciably depleted by this small dose. A 6-hr infusion of acetaminophen, at 36 mg/kg/hr, produced steady-state plasma concentrations of about 20 micrograms/ml within 2 hr in renal failure (ureter-ligated) animals, whereas in normal animals the plasma concentrations increased continuously to about 100 micrograms/ml at 6 hr. Free sulfate concentrations in serum at the end of the infusion were about 0.2 mM in normal animals and generally greater than 1 mM in the renal failure animals. The rats with renal failure converted most of the administered dose to acetaminophen sulfate, whereas normal animals metabolized much of the drug to acetaminophen glucuronide. These observations demonstrate the important effect of the endogenous free sulfate level in the body on the elimination kinetics and metabolic fate of a drug that is subject to conjugation with sulfate.
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PMID:Effect of experimental renal failure on sulfate retention and acetaminophen pharmacokinetics in rats. 706 93

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


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