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)

From January 1988 to February 1992, a total of 26 patients with calculi in the middle third of the ureter underwent primary in situ ESWL in the prone position. All treatments were performed in sedoanalgesia using the Dornier HM 3 lithotriptor. During and after ESWL in the prone position, severe complications did not occur. Of the 26 patients, 10 (38%) were treated by a single application of ESWL. No auxiliary measures were necessary, and they became stone-free within 3 months following treatment. In another 9 patients (35%) auxiliary measures were required for visualization of radiolucent calculi or to relieve a urinary tract obstruction with incipient septicemia. All these auxiliary measures could be performed in sedoanalgesia. In the remaining 7 patients (27%), in whom stone disintegration following ESWL was incomplete, ureteroscopic lithotripsy techniques had to be applied. One of these 7 patients had to undergo an additional open operative procedure. The results of the present study demonstrate that a majority of patients with calculi in the middle portion of the ureter can become stone-free without invasive lithotripsy techniques following ESWL in the prone position, if necessary plus auxiliary measures, in sedoanalgesia. From these results it can be concluded that primary ESWL in the prone position should be considered for patients with calculi in the middle third of the ureter before invasive lithotripsy techniques are applied.
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PMID:[Treatment of ureteral calculi in bone coverage using in situ ESWL in prone position]. 828 60

Self-expandable metal stents 7 mm in diameter were percutaneously implanted into 13 ureters in 10 patients with malignant ureteral obstruction not amenable to double-J stent placement. In nine ureters, one stent was placed, and in four ureters, two overlapping stents were placed. Primary reconstitution of ureteral patency was achieved in all ureters. After 1-2 weeks, four ureters showed a urothelial reaction encroaching on the lumen of the ureter, and a double-J stent was placed coaxially. One ureter was occluded by urothelial hyperplasia 4 weeks after stent placement, and a double-J stent was therefore placed. One ureter was occluded 8 months after stent placement by distal tumor overgrowth. The other ureters showed no signs of obstruction during a follow-up of 3-14 (average, 5.8) months. Peristalsis was preserved at both ends of the stent in all ureters. The use of this stent alone or in combination with a double-J stent alleviated upper urinary tract obstruction and avoided external drainage in all patients.
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PMID:Malignant ureteral obstruction: preliminary results of treatment with metallic self-expandable stents. 841 59

Urinary tract obstruction is a common cause of acute renal failure (ARF). During unilateral ureteral obstruction (UUO) arteriolar vasoconstriction, increase in tubular pressure, and ultrafiltrate retrodiffusion occur. We studied renal function of rats with surgical UUO for 24 hr. After this period of UUO, the contralateral kidney was removed and the right ureter was deobstructed. The control uninephrectomized group consisted of normal rats submitted to left uninephrectomy (UNx). Functional studies were performed 12 and 24 hr, and 7 days after deobstruction and UNx. We measured creatinine clearance, and fractional excretion of sodium and lithium. Using conventional formulas we calculated fractional proximal and distal sodium reabsorption. Initially we observed a reduction in glomerular filtration rate (GFR) after deobstruction (12 and 24 hr). However, after 7 days, the GFR was significantly higher in deobstructed rats than in controls (340.3 +/- 18.3 vs. 286.4 +/- 9.3 microL/min/100 g, p < 0.01). The dry kidney weight was also increased in these rats. The fractional sodium excretion was increased in deobstructed rats, mainly in early studies (12 and 24 hr). Whereas fractional proximal reabsorption was reduced in both groups, the fractional distal reabsorption was significantly decreased in the deobstructed group compared to UNX controls (93.9 +/- 0.9 vs. 98.9 +/- 0.1% after 24 hr, p < 0.01). Our data showed that UUO influenced both glomerular and tubular functions. A salient finding was the overcorrection of GFR 7 days after deobstruction. The renal release of hormones and growth factors could mediate these alterations in renal function through their vascular, tubular, and proliferative actions.
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PMID:Acute ureteral obstruction and glomerulotubular function in rats. 910 12

Acute urinary tract obstruction, a common disease in daily practice, often requires performance of emergency intravenous urography (IVU). However, the spectrum of urographic abnormalities seen with acute obstruction has not been thoroughly addressed. The purpose of this study was to explore the IVU findings in patients with acute urinary tract obstruction. Records of 380 patients who underwent IVU in our hospital during a 6-mo period were reviewed for IVU evidence of acute urinary tract obstruction. Of the 380 patients, 53 (14%; 39 men, 14 women; average age = 43 yr) had acute urinary tract obstruction. All obstructions except one were located in the lower one-third of the ureter. The causes of acute urinary obstruction included ureteral stones in 34 (64%), ureteral edema or lucent stones in 16 (30%), neoplasms in 2 (4%), and inflammatory disease in 1 (2%). Abnormal radiologic findings were hydroureter in 46, nephropyelographic delay in 36, hydronephrosis in 35, interureteric ridge edema in 11, persistent dense nephrogram in 6, urine extravasation in 5, vicarious excretion in 1, striation in 1, and stricture in 1. Radiographic results were normal in one patient. The most common clinical indications of acute ureteral obstruction are flank pain and hematuria, and calculi are the major cause. In one-third of patients, radiopaque calculi are not detectable with IVU during acute urinary tract obstruction. A careful and thorough evaluation of the IVU should be performed in patients with clinical indications of acute urinary obstruction.
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PMID:Radiologic findings in acute urinary tract obstruction. 925 84

When perfusion pressure to the kidney falls, e.g., as a result of dehydration or mechanical hindrance to the renal arterial blood flow, the release of renin, hence angiotensin (Ang), surges. This feedback regulation is geared to preservation of renal hemodynamic environment by raising systemic blood pressure. We are aware that a surge of renin-angiotensin release also occurs when there is a mechanical hindrance to urine outflow. This phenomenon of ureteral pressure-sensitive activation of renin-angiotensin has been heretofore viewed as an error of nature. We have obtained evidence which challenges this traditional view when we examined strains of mutant mice which are completely devoid of either angiotensin type 1 (AT1) receptor gene (Agtr1-) or angiotensin type 2 (AT2) receptor gene (Agtr2-) as a result of genetic manipulation of these animals. These strains of mice display varying degrees of urinary tract obstruction. In Agtr2- mice obstructions develop during early kidney ontogenesis in ureto, and, in Agtr1- mice, during late ontogenesis ex utero. One may recall that, throughout its normal ontogenesis, the kidney is twice at risk for obstruction of urine outflow. Thus, in utero the ureter is transiently obliterated. This transient obliteration is believed to protect the kidney from the high pressure from the cloaca when urine is not yet formed. During this period, the ureter is surrounded by dense layers of undifferentiated mesenchymal cells. Subsequent expansive growth that the ureter must achieve, therefore, in concert with a timely disappearance of the surrounding mesenchymal cells. The study in Agtr2- embryos indicated that Ang, through the Agtr2 receptor, promotes disappearance of these mesenchymal cells, and that inactivation of this receptor results in congenital obstructive nephropathy. Our additional studies in human specimens indeed indicate that many infants with congenital anomalies of the kidney and urinary tract have a significant mutation within the AT2 gene. Once animals are born, the kidney comes to be of primary importance for preservation of body fluid homeostasis, and urinary output increases dramatically. The large volume of urine predisposes the kidney to obstructive nephropathy due to the high resistance offered to the urine by the downstream ureter. Normally, a special device develops within the urinary tract in a timely fashion, which enables the kidney to collect a bulk of urine, and then to expel it downward periodically without imposing positive pressure upon the renal parenchyma. This special device is the renal pelvis. In the studies on Agtr1 null mutant mice, we learned that Ang, through the AT1 receptor, promotes development of the pelvis shortly after birth, so that inactivation of this receptor in Agtr1- mice leads to absence of development of the pelvis, hence to obstructive nephropathy. Collectively, Agtr1 or Agtr2 null mutant mice suffer from urinary tract obstruction. Given that urinary tract obstruction per se is a potent stimulus for Ang generation, Ang is essential for the kidney to escape from obstructive injury.
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PMID:Role of angiotensin in the development of the kidney and urinary tract. 985 80

Several signs to assist interpretation of unenhanced helical computed tomographic (CT) scans obtained for suspected ureterolithiasis have been described. Because signs such as perinephric stranding are not always readily apparent, a methodical approach to interpretation of CT studies is important in determining the presence or absence of ureterolithiasis. Evaluation of the poles of the kidneys is helpful in detecting subtle stranding of the perinephric fat. Inspection of the intrarenal collecting system within the poles of the kidneys is helpful in identifying subtle collecting system dilatation and can help prevent mistaking an extrarenal pelvis for hydronephrosis. Careful inspection of the ureter throughout its course is the most reliable method of distinguishing between ureteral stones and phleboliths. However, when the ureter cannot be followed antegrade, the pelvic portion can often be identified in a retrograde fashion. When secondary signs of obstruction are present but no stone is present, differential diagnostic considerations include a recently passed stone, pyelonephritis, urinary tract obstruction unrelated to stone disease, and protease inhibitor deposition disease.
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PMID:Pearls and pitfalls in the diagnosis of ureterolithiasis with unenhanced helical CT. 1071 42

Unenhanced helical computerized tomography (UHCT) has recently evolved as an accurate imaging modality for determination of the presence or absence of ureterolithiasis in patients with acute flank pain. Functional renal scintigraphy is considered the gold standard for urinary tract obstruction. The objective of this study was to correlate the secondary signs of urinary obstruction on UHCT with findings of functional renal scintigraphy. UHCT was performed in 30 patients admitted to the emergency room with acute flank pain. All patients had a calcified urinary stone identified on UHCT. The location of each urinary stone was classified as ureteral or in the ureterovesical junction. The presence of secondary CT signs of ureteral obstruction was determined for each patient. After oral or intravenous hydration, a technetium-99m diethylene triamine penta-acetic acid renal scan was performed in all patients within 12 h of the CT scan. Follow-up delayed scintigraphic images were obtained at 2 h and 24 h in patients with evidence of ureteral obstruction. The sensitivity, specificity and predictive values of each possible combination of CT findings were determined by comparison with the scintigraphic results. The distal ureter was the most common location for a calculus on UHCT, followed in frequency by the ureterovesical junction, proximal ureter and mid-ureter. The renograms showed high-grade, unilateral obstruction in 12 patients, indeterminate scans in five patients and normal renograms in 13 patients. The sensitivities and specificities of individual CT findings ranged from 50% to 75% and from 8% to 69%, respectively. Perinephric stranding gave the highest positive predictive value (PPV) for obstruction (69% including indeterminate renograms). None of the individual CT findings showed a statistically significant correlation with scintigraphic findings. A combination of one or two positive CT findings had a PPV of only 25% for obstruction. A combination of three or four positive CT findings gave a PPV of 70% for obstruction. Our preliminary study shows that secondary CT signs of ureterolithiasis correlate poorly with the scintigraphic findings and that they do not permit evaluation of the functional status of obstructed kidneys. Even a combination of the most frequent CT findings has a low predictive value, i.e. does not allow a decision to be made as to the most suitable treatment. Therefore, renal scintigraphy should be performed in conjunction with UHCT in all patients with ureteral calculi.
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PMID:The role of renal scintigraphy and unenhanced helical computerized tomography in patients with ureterolithiasis. 1080 18

This review comprises an overview of the current knowledge on experimental partial unilateral ureteral obstruction (PUUO) and a summary of our latest original experimental PUUO studies in rats. Neonatal PUUO is the type of obstruction that is most often encountered in pediatric clinical practice. However, the pathogenesis of PUUO is still incompletely understood. Most of our knowledge on PUUO has been derived from experimental studies in a variety of animal models. Although progress has been made, the natural history of congenital hydronephrosis is still incompletely described. The effects on kidney functions of long-term urinary tract obstruction, especially PUUO, have been less intensively studied. Recently, we created models with mild and severe PUUO in young rats by embedding the upper one fourth or the upper two thirds of the left ureter into the psoas muscle, respectively. Thereafter, the technique was used to create mild and severe PUUO in newborn rats and magnetic resonance imaging studies showed that both mild and severe obstruction caused a time-dependent decrease in renal blood flow. Compensatory increase in total kidney volume and renal vein blood flow in contralateral non-obstructed kidneys was not detectable when functional deterioration in the partially obstructed kidneys was present. Finally, we investigated the dynamic changes in renal relative signal intensity (RSI) of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) using magnetic resonance imaging in rats with partial, complete unilateral ureteral obstruction and sham-operated controls. The results showed that changes in Gd-DTPA RSI are compatible with the known physiological and anatomical changes in kidneys in response to ureteral obstruction and useful for distinguishing an obstructed from a non-obstructed collecting system and also for differentiating a partially obstructed from a completely obstructed collecting system.
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PMID:Partial unilateral ureteral obstruction in rats. 1194 17

Renal peripelvic multicystic lymphangiectasia is a benign disease characterized by multiple cysts arising from the lymphatic vessels of the renal sinus. Cysts, almost always bilateral, surround the profiles of the calices; the biggest cysts can compress pelvis or iuxtapielic ureter and it is difficult to differentiate RPML from hydronephrosis at the Ultrasound. Cysts are asymptomatic, the profiles of calices appear irregular with thin membrane separating each other, the cortical of the kidney is preserved: these are principle elements to distinguish RPML to hydronephrosis at the Ultrasound. Usually it is necessary to confirm the diagnosis at IVP and CT scan evaluation. From 1995 to March 2002, 10 cases of RPML with a long-term follow-up have been studied. IVP in 8 patients and CT scan in 2 have shown compression of the collecting system by multiple cysts. We followed the cases with periodic lab tests of kidney function, ultrasound, IVP, CT scan. In order to valuate the presence of "true obstruction", we tested in over-night urine EGF and MCP-1 as markers of urinary tract obstruction and subsequent renal damage. A valuable data regarding how to differentiate RPML from hydronephrosis at Ultrasound show that RPML does not modify renal function and cyst volume has not changed in the time. In long-term follow-up the prognosis of the RPML is not clear. Particolarly this renal sinus disease has not neoplastic degeneration and the effect of cysts on kidney function is unknown. RPML is an uncommon disease and it can be enclosed in the group of renal sinus pathologies. The absence of symptoms, the hystologic diagnosis, the unchanged dimensions of the cysts confirm the benign prognosis of RPML which does not need a close functional and morphologic monitoring in the long-term follow-up.
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PMID:[Long-term follow-up of peripelvic renal multicystic lymphangiectasia]. 1250 31

Cervical cancer traditionally has been staged clinically. Advances in imaging could improve the staging of cervical cancer by facilitating the detection of lymph node metastases and micrometastases in distant organs. Such progress could lead to improvements in treatment selection and therefore increase overall survival rates. At the Second International Conference on Clinical Cancer (Houston, TX, April 11-14, 2002), a panel composed of gynecologic oncologists, radiation oncologists, and diagnostic radiologists reviewed relevant technologies. Advances in lymphangiography, ultrasonography, computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), and lymphatic mapping were reviewed, along with the impact of these advances on the diagnosis, treatment, and survival of patients with cervical cancer. Few cancer centers still use lymphangiography, but the sensitivity of this method ranges from 28% to 83%, with specificity ranging from 47% to 100%. The roles of transabdominal and transvaginal ultrasonography in evaluating cervical cancer are expected to expand when new contrast agents increase the sensitivity of these techniques to parametrial invasion and lymph node metastases; meanwhile, ultrasonography's most significant contributions may involve the identification of uterine and cervical leiomyomas and the evaluation of urinary tract obstruction. Advances in CT have made it a rival technique to MRI, but limitations prevent CT from providing definitive information on certain parameters. MRI, which is valuable because of its superior soft tissue contrast resolution, multiplanar capabilities, and cost-effectiveness, is used to determine the size of the cervix and to detect certain types of invasion, characteristics of lymph nodes, and the presence of disease in the ureter, lung, and liver. PET with 2-[fluorine-18]fluoro-2-deoxy-D-glucose has been found to detect abnormal lymph node regions better than CT does but PET can also be used in conjunction with CT to measure tumor dimensions. PET also has become a method for identifying tumors that are unresponsive to chemoradiation. When used together with immunohistochemical and molecular techniques as well as conventional stains, sentinel lymph node mapping, an important development in the surgical management of solid tumors, is expected to improve gynecologic cancer management. Advances in imaging methods and in contrast agents, along with advances in the combined use of the two, are expected to make imaging technologies more valuable in cervical cancer assessment.
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PMID:Imaging in cervical cancer. 1460 39


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