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

It has been reported that up to half of renal stones and associated urine specimens have been positive on culture, and that up to 50% of such stones contain magnesium ammonium phosphate. In a prospective study using infrared and wet chemical analysis, we found positive cultures in only 7 of 132 renal, 5 of 105 ureteral and 6 of 21 bladder stones obtained surgically and handled with sterility. Of the culture positive calculi only 43% from the kidney, none from the ureter and 50% from the bladder contained detectable magnesium ammonium phosphate. However, magnesium ammonium phosphate was detectable in 20% of renal, 2% of ureteral and 27% of bladder stones with negative cultures. Of the culture positive renal and ureteral calculi 42% were predominantly calcium phosphate and 17% were predominantly calcium oxalate. For culture negative stones 25% and 51% from the kidney, and 15% and 82% from the ureter were composed of predominantly calcium phosphate and calcium oxalate, respectively. Among the culture positive stones, related positive urine cultures were noted in 100% of the renal, 20% of the ureteral and 50% of the bladder cases, compared to 26%, 10% and 27%, respectively, of culture negative calculi. The same organism was found in the stone and urine in only 38% of the cases. The lower frequency of positive urine cultures, of stones with magnesium ammonium phosphate, and especially of culture positive renal and ureteral stones (5%) than in previous reports suggests that stone culture may be of less value than indicated previously, except for bladder calculi and large renal stones, such as the branched type.
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PMID:Bacteriology of urinary tract stones. 786 88

The objective of this study was to investigate the effects of a dihydropyridine calcium antagonist, manidipine HCl, and an angiotensin II receptor antagonist, CV-11974, on renal microvasculature in hypertensive rats. Hydronephrosis was induced by ligation of the left ureter in 8-week-old stroke-prone spontaneously hypertensive rats. Two months after the operation, the hydronephrotic kidney was split longitudinally and spread out as a thin sheet, and the renal microvasculature was observed directly under a light microscope. Administration of manidipine HCl (20 micrograms/kg) caused a gradual fall in blood pressure (-34 mmHg). The afferent arterioles were dilated, and maintained the same level of dilatation until 30 min (+20%). The efferent arterioles were also dilated (+8%). Glomerular blood flow was significantly increased (+38%). Administration of CV-11974 (100 micrograms/kg) caused a sharp fall in blood pressure at 2 min (-24 mmHg), with a continuous fall in blood pressure until 60 min (-46 mmHg). The afferent arterioles were gradually dilated (+15%). The efferent arteriole was also dilated until 60 min, but to a lesser extent than the afferent arteriole. Glomerular blood flow was immediately increased (+35%). We conclude that both manidipine HCl and CV-11974 dilated both the afferent and efferent arterioles and increased glomerular blood flow.
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PMID:Effects of a calcium antagonist and an angiotensin II receptor antagonist on rat renal arterioles. 788 6

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

Escherichia coli is the microorganism most commonly isolated from human urinary tract infections. Earlier studies by others have shown that bacterial attachment and production of toxins (e.g., lipopolysaccharides [LPS]) enhance recruitment of leukocytes to the infection site and mucosal inflammation. The mechanisms by which these changes occur have not been completely defined. In the present study, epithelial cell cultures isolated from the human ureter (UT cells) (A. Elgavish, J. J. Wille, F. Rahemtulla, and L. Debro, Am. J. Physiol. 261:C916-C926, 1991; J. J. Wille, J. Park, and A. Elgavish, J. Cell. Physiol. 150:52-58, 1992) served as a model system with which to explore the mechanisms of action of Escherichia coli and E. coli LPS in UT cells. E. coli adhered to UT cells and inhibited carrier-mediated sulfate uptake to half of that in untreated UT cells, suggesting that the intracellular pool of sulfate available for sulfation may be lower in infected cells and may lead to the production of undersulfated glycoconjugates. Incubation of UT cells with E. coli LPS inhibited carrier-mediated sulfate uptake to an extent similar to that caused by whole E. coli, indicating that the effect of E. coli on sulfate uptake may be mediated by LPS. LPS caused an increase in Na+ content in rapidly proliferating UT cells but not in quiescent cells. We postulated that this change in the intracellular ionic environment or changes coupled to it (e.g., pH or Ca2+ levels) may serve as a transducing signal. This possibility was supported by the fact that LPS stimulated clustering of ICAM-1 on the cell surface of rapidly proliferating but not quiescent UT cells. This study suggests that, in vivo, LPS stimulation of ICAM-1 clustering on the surface of the urothelium may allow more effective binding of leukocytes. This may be the mechanism underlying earlier findings in vivo indicating a role for LPS in the recruitment of leukocytes to the urinary tract as a host defense mechanism following urinary tract infection.
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PMID:Effects of Escherichia coli and E. coli lipopolysaccharides on the function of human ureteral epithelial cells cultured in serum-free medium. 810 8

The requirements of organ cryopreservation differ from those of conventional organ preservation. The encouraging results of Karow's group with dog kidneys transplanted after perfusion with more than 4 M dimethyl sulfoxide were based on an RPS-2 (renal preservation solution 2) vehicle solution, but transplantation of rabbit kidneys after perfusion with RPS-2 has not been reported. We evaluated RPS-2 in comparison to Euro-Collins solution (EC) using a modified technique for rabbit kidney autotransplantation and a computer-based organ perfusion machine designed for the introduction and removal of cryoprotective agents. Consistent success in rabbit kidney transplantation was found to depend on the anesthetic used, the hydration volumes administered, and direct ureter-to-ureter anastomosis. RPS-2 was found to be equivalent to EC for short-term (about 5 h) preservation by either perfusion or simple cold storage. However, good results with EC were associated with perfusion at 4 degrees C, recovery being significantly worse at 2 degrees C. In addition, we found that the solitary rabbit kidney is not able to fully compensate for the loss of the contralateral kidney, the result being persistent (to 3 weeks) mild elevation of serum creatinine, potassium, and calcium and persistent moderate reduction of serum phosphate. These results establish perfusates, perfusion conditions, transplantation techniques, computer-based perfusion control techniques, and a general clinical baseline that are permissive of further direct experiments on cryoprotectant introduction and removal.
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PMID:Cryopreservation of the mammalian kidney. I. Transplantation of rabbit kidneys perfused with EC and RPS-2 at 2-4 degrees C. 815 95

We discuss the effectiveness of in situ extracorporeal shock wave lithotripsy (ESWL) for the ureteral stones causing acute renal failure in 5 patients (4 men and 1 woman, mean age 56.2 years). Three of them had a sole functioning kidney, one had a solitary kidney and the other had bilateral ureteral stones. The obstructing stones were located in the upper ureter in one, lower ureter in 2, upper and lower ureter in one and bilateral upper ureter in one with the average length of the stones being 9.2 mm. We used the EDAP LT-01 device for these stones. The obstructing stones were successfully disintegrated by ESWL alone in three cases, but could not be disintegrated in the other 2 cases in which the obstruction had occurred gradually or there were multiple stones. In the latter 2 cases, we performed ESWL again with percutaneous nephrostomy or hemodialysis. We thus believe that ESWL is a safe and effective procedure and is the first choice of emergency treatment for some ureteral stones causing acute renal failure. However, the subject is limited to acute cases, and the stone must be easily detected, single with its size being less than 12 mm and composed of calcium.
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PMID:[In situ extracorporeal shock wave lithotripsy for ureteral stones causing acute renal failure]. 819 66

Extracorporeal lithotripsy does not always provide satisfactory results for the treatment of ureteral stones. Such cases appear to be excellent indications for endocorporeal lithotripsy based on an association of ureteroscopy and laser. To compare the performances of 2 pulsed lasers, the pulsed dye laser (Candela) and solid Q switched laser (HMT), for the treatment of these calculi 161 ureteral stones were treated successively from November 1990 to March 1992 by a combination of ureteroscopy and laser. Endocorporeal lithotripsy was performed in 102 cases with the Candela laser, in 47 with the HMT laser and in 7 with both lasers. With a stable success rate greater than 90%, both lasers demonstrated equivalent performances regardless of the location of the stone along the ureter. However, while stone fragmentation was more rapid with the Candela laser, the HMT laser appeared to be more effective for dark stones (monohydrate calcium oxidate).
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PMID:Comparison of 2 pulsed lasers for lithotripsy of ureteral calculi: report on 154 patients. 823 May 9

We report a case of milk of calcium renal stone within a calyceal diverticulum in the patient with left ureteral tumor. The patient was a 77-year-old-man with the chief complaint of asymptomatic microscopic hematuria. A plain film revealed round opaque calcific densities in the left kidney in the supine position and a dense crescent-shaped shadow with a horizontal border in the upright position. An intravenous pyelography showed left hydronephrosis and calculi within a calyceal diverticulum. Computed tomography in the supine position revealed layering of the calcifications in cystic lesion of the left kidney accompanied by left hydronephrosis due to a soft mass in the left ureter and a right renal cyst. Retrograde pyelography revealed a filling defect of the middle portion of the left ureter. Under the diagnosis of milk of calcium renal stone and left ureteral tumor, left total nephroureterectomy and partial cystectomy was performed. Pathological findings indicated transitional epithelium of the diverticulum wall and grade 1 transitional cell carcinoma of the left ureteral tumor.
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PMID:[Milk of calcium renal stone in a patient with ureteral tumor: a case report]. 826 71

The Electromechanical Impactor was conceived as a safe and effective device for intracorporeal stone fragmentation. It is a 3 French EHL electrode enclosed within a stainless steel sheath. The interior is irrigated with saline. Discharge of the system causes an EHL spark which vaporizes saline and produces a cavitation bubble and subsequent shock wave. The shock wave propels a conical titanium tip forward for a distance of 2.7 mm with an impact pressure of 900 bar. Bench and animal testing has proven its effectiveness for stone fragmentation and safety for use within the ureter. The mean lifetime of each probe is approximately 700 pulses. It is used under direct vision through the straight operating port of a rigid or semi-rigid 9.5 French ureteroscope. Clinical studies at the Massachusetts General Hospital (reported herein) and the Mayo Clinic demonstrate approximately 90% efficacy. It is especially effective on cystine, calcium oxalate dihydrate, struvite and mixed calcium oxalate monohydrate calculi. Shiny-smooth black calcium oxalate monohydrate calculi will fragment but are more resistant. There has been no evidence of ureteral wall injury. The EMI is currently 5 French and is used both safely and effectively under direct vision of fragment ureteral calculi. Larger sizes are designed for percutaneous use and for bladder stone fragmentation.
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PMID:The electromechanical impactor: a new device for intracorporeal stone fragmentation. 834 87

Effects of prostaglandin E1, E2 and F2 alpha (PGE1, PGE2 and PGF2 alpha) on the changes in the adenylate cyclase (AC) activities of rabbit urinary tract tissues were studied in order to clarify whether the PGs' actions are mediated by cAMP in the urinary tract. AC activities were measured by the method of Salomon et al. The three PGs studied were all found to increase the AC activities dose-dependently in the renal pelvis, ureter, bladder dome and bladder base. Among the changes in AC activities, PGE1 and PGE2 significantly increased the AC activities of the renal pelvis and ureter. PGE1 significantly increased the AC activities of the bladder dome. It was reported that Ca2+ influx plays an important role in the PGs' action on the urinary tract. Our data suggest that the PGs act on the urinary tract via cAMP as well as Ca2+ influx.
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PMID:[Effects of prostaglandin E1, E2 and F2 alpha on the changes in the adenylate cyclase activities of rabbit urinary tract tissues]. 838 21


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