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

The mechanosensitivity and chemosensitivity of afferent fibres were investigated in an in vitro preparation of the guinea-pig ureter. Electrophysiological recordings were obtained from 5 U-1 (low mechanical threshold, contraction-sensitive) and 74 U-2 units (high threshold). U-2 units had significant higher levels of spontaneous activity, lower conduction velocities, higher mechanical thresholds (U-1: 7 mmHg; U-2: 39 mmHg), less pronounced phasic responses and longer latencies in the response to distensions than the U-1 units. For chemical stimulation, guinea-pig urine (> 800 mosmol/L), bradykinin and capsaicin were applied intraluminally. The responses of U-1 units mainly corresponded to the contractions induced by the chemical stimulation. The vast majority of the U-2 units were excited by urine, bradykinin (threshold: 0.1-1 microM) and capsaicin (threshold: 0.03-0.3 microM). The responses to urine could be mimicked by high concentrations of potassium ions (> 200 mM), but not by an equiosmolar solution of NaCl, urea and mannitol. Chemical stimulation could also result in a transient sensitization of the U-2 units to mechanical stimuli. In the anaesthetized guinea-pig, pseudo-affective responses could be evoked by ureteric distension (threshold: 30-60 mmHg) and serosal application of capsaicin. Intraluminal application of urine in vivo did not evoke any reactions, suggesting that the responses of the U-2 units to urine might be due to an impaired barrier function of the urothelium in vitro. The data are in agreement with the hypothesis that U-2 units are visceral polymodal nociceptors. Since the U-1 units were also able to encode at least noxious mechanical stimuli, their involvement in visceral nociception cannot be excluded.
 ...
PMID:Chemosensitivity of nociceptive, mechanosensitive afferent nerve fibres in the guinea-pig ureter. 974 84

Green toads (Bufo viridis) were acclimated to either tap water, 230 mOsmol NaCl kg-1 H2O (saline), 500 mOsmol NaCl kg-1 H2O (high saline), or 500 mmol L-1 urea. Renal functions for each acclimation group were studied on conscious animals that had one ureter chronically catheterized. Reciprocal immersion of tap-water- and saline-acclimated toads in the opposite solution did not stress the animals osmotically, and plasma osmolality increased or decreased by no more than 15%. However, urine osmolality and ionic composition changed immediately and profoundly on exposure to the other solution. Exposure of tap-water-acclimated toads to saline decreased urine flow by 30%, whereas the reciprocal immersion led to an increase of 30%. Immersion of tap-water-acclimated toads in high saline led to immediate cessation of urine flow, whereas immersion of 500 NaCl- or urea-acclimated toads in tap water led to a large increase in urine flow, with an overshoot that lasted 10 h (as a result of either salt or urea diuresis). Urine flow then stabilized at a level 5-6 times higher than the value attained at high-salt environment. On immersion of 500 urea-acclimated toads in 500 NaCl, urine flow doubled, accompanied by a change in ion composition, without change in the osmolality. In all experimental conditions, plasma potassium concentration was maintained within a narrow range. The results show that the toad's kidneys contributed efficiently both to osmo- and ionoregulation in a wide range of ambient solutions.
 ...
PMID:Renal response of euryhaline toad (Bufo viridis) to acute immersion in tap water, NaCl, or urea solutions. 1006 26

This study describes a new method for joining the donor ureter to the recipient bladder during mouse kidney transplantation. The donor left kidney was harvested using methods previously published, except that bladder tissue was not harvested with the end of the ureter. The recipient left kidney was removed and the donor kidney was attached using end-to-side anastomosis. The recipient bladder was pierced with a 21-gauge needle allowing curved forceps to be inserted through the bladder, to pull through the ureter, and the periuretal tissue was stitched to the exterior wall of the bladder. The donor ureter was allowed to retract inside the bladder. Following a right nephrectomy, grafts were monitored by blood serum creatinine and urea. With a technical success rate of 83%, this technique reduced donor harvest time by 20 minutes and ureter attachment time by 15 minutes making it the best method available for mouse kidney transplantation.
 ...
PMID:Modified technique for kidney transplantation in mice. 1046 41

52 cases of postrenal acute renal failure (ARF) from 1985 to 1995 were studied. 50 cases underwent emergency operation, and 2 were drained with ureter intubation by cystoscope. 37 cases (71.2%) were cured, 14 (26.9%) were improved, and 1 (1.9%) died. Oliguria, anuria and progressive increase of blood urea nitrogen and serum creatinine are the main points of diagnosis. Renal percussive pain is the important sign. B-ultrasonography examination is the first choice and often indicate the increase of the volume of kidney and mild hydronephrosis. Obstruction should be removed as quickly as possible, infection should be prevented and treated to protect renal function. The way of treatment should be adopted according to the variant causes and conditions of disease. The etiology, clinical findings, diagnosis, operating methods and cautions were discussed.
 ...
PMID:[Diagnosis and treatment of postrenal acute renal failure]. 1067 77

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.
 ...
PMID:Congenital bilateral ureteral stenosis and hydronephrosis in a neonatal puppy. 1104 Aug 73

Urea transporter UT-B has been proposed to be the major urea transporter in erythrocytes and kidney-descending vasa recta. The mouse UT-B cDNA was isolated and encodes a 384-amino acid urea-transporting glycoprotein expressed in kidney, spleen, brain, ureter, and urinary bladder. The mouse UT-B gene was analyzed, and UT-B knockout mice were generated by targeted gene deletion of exons 3-6. The survival and growth of UT-B knockout mice were not different from wild-type littermates. Urea permeability was 45-fold lower in erythrocytes from knockout mice than from those in wild-type mice. Daily urine output was 1.5-fold greater in UT-B- deficient mice (p < 0.01), and urine osmolality (U(osm)) was lower (1532 +/- 71 versus 2056 +/- 83 mosM/kg H(2)O, mean +/- S.E., p < 0.001). After 24 h of water deprivation, U(osm) (in mosM/kg H(2)O) was 2403 +/- 38 in UT-B null mice and 3438 +/- 98 in wild-type mice (p < 0.001). Plasma urea concentration (P(urea)) was 30% higher, and urine urea concentration (U(urea)) was 35% lower in knockout mice than in wild-type mice, resulting in a much lower U(urea)/P(urea) ratio (61 +/- 5 versus 124 +/- 9, p < 0.001). Thus, the capacity to concentrate urea in the urine is more severely impaired than the capacity to concentrate other solutes. Together with data showing a disproportionate reduction in the concentration of urea compared with salt in homogenized renal inner medullas of UT-B null mice, these data define a novel "urea-selective" urinary concentrating defect in UT-B null mice. The UT-B null mice generated for these studies should also be useful in establishing the role of facilitated urea transport in extrarenal organs expressing UT-B.
 ...
PMID:Urea-selective concentrating defect in transgenic mice lacking urea transporter UT-B. 1179 14

The purpose of this study is to show whether selective (celecoxib) and non-selective (piroxicam) inhibitors of COX-2 can alter the morphological and functional changes after the release of a 24 h complete ureteric obstruction in tissue from solitary rat kidney. Forty male Sprague-Dawley rats weighing 225-250 g were used. The animals were divided into four groups. In group 1 rats (control, n=10), only right nephrectomy was performed. Group 2 rats (untreated, n=10) underwent right nephrectomy and the left ureter was completely obstructed. In group 3 rats (celecoxib), the same operation was performed as described for group 2 and than celecoxib was administered by gavage for a period of 24 h. Group 4 rats (piroxicam) underwent the same operation as described for group 2, then piroxicam was administered intramuscularly at least 1 h before the release of the for 24 h complete ureteric obstruction. All animals were then prepared for functional and histopathological studies. The administration of celecoxib produced a significant decrease in blood urea nitrogen levels when compared to the animals receiving piroxicam and the animals with no treatment. Moreover, celecoxib caused a significant decreased in creatinine levels when compared to the untreated group. Urine volume and the urinary sodium values were increased in the celecoxib group when compared with the other groups. The administration of celecoxib and piroxicam caused a significant decrease in the number of interstitial macrophages when compared to the untreated group. The Bowman space was significantly increased in the untreated group when compared with the celecoxib and the piroxicam groups. These studies indicate that celecoxib may be an important factor affecting renal morphological and functional changes after the release of a 24 h complete ureteric obstruction.
 ...
PMID:Renal effects on a solitary kidney of specific inhibition of cyclooxygenease-2 after 24 h of complete ureteric obstruction in rats. 1220 39

A 54-year-old woman was admitted to our hospital for oliguria and left lower abdominal pain. She had renal dysfunction with a serum creatinine of 9.1 mg/dl and blood urea nitrogen of 96.5 mg/dl. Plain computed tomography and magnetic resonance imaging revealed right dwarf kidney and left giant hydronephrosis with extravasation of urine. MR-urography revealed left dilated ureter caused by ureterovesical junction (UVJ) stenosis. Therefore, percutaneous nephrostomy was immediately performed to treat postrenal failure, with resulting collection of approximately 1,650 ml of urine. Subsequently, left ureterocystoneostomy was performed for the treatment of UVJ stenosis because improvement of left UVJ stenosis had not been confirmed by nephrostography during follow-up. Judging from the past history of myoma operated and reactive fibrosis of stump of left ureter histopathologically, it was considered that acquired UVJ stenosis had led to giant hydronephrosis.
 ...
PMID:[A case of unilateral giant hydronephrosis with contralateral dwarf kidney]. 1289 39

The stop flow technique was used to investigate the permeability characteristics of the dog nephron to various C(14)-labeled non-electrolytes. 12 minutes after clamping the ureter, creatinine, PAH, and C(14) compound were injected intravenously. 2 minutes later, urine samples were collected. Urea and glycerol were able to enter the tubular urine along the entire nephron at rates which were commensurate with their molecular weights. No significant movement of larger molecules (D-arabinose, D-glucose, and mannitol) could be detected. However, after administration of twenty units of pitressin, D-arabinose was able to diffuse across the distal and proximal tubular epithelium.
 ...
PMID:Transcellular diffusion of non-electrolytes across the renal tubular epithelium. 1448 56

Although ultrasonography is regarded as the gold standard in the diagnosis of obstructive nephropathy, dilatation is sometimes not observed by ultrasonography. We report upon a case of minimally dilated obstructive nephropathy due to an ureter stone in a kidney donor with volume depletion. A 54-year-old man was admitted due to anuria and abdominal pain of 2 days duration. Ten years previously, his right kidney was donated for transplantation, and one month before admission, he abstained from all food except water and salt, for 30 days for religious reasons. He had lost 8 kg of body weight. On admission, he had clinical signs of volume depletion, i.e., a dehydrated tongue and decreased skin turgor. Laboratory data confirmed severe renal failure, his blood urea nitrogen level was 107.3 mg/dL, and his serum creatinine 16.5 mg/dL. The plain X-ray was unremarkable and ultrasonography showed only minimal dilatation of the renal collecting system. On follow-up ultrasonography, performed on the 5th hospital day, the dilatation of the collecting system had slightly progressed and a small stone was found at ureter orifice by cystoscopy. Removal of stone initiated dramatic diuresis with a rapid return of renal function to normal by the third day.
 ...
PMID:Minimally dilated obstructive nephropathy initially suspected as pre-renal azotemia in a kidney donor with volume depletion. 1471 34


<< Previous 1 2 3 4 5 6 7 8 9 Next >>