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

In 12 mongrel dogs intravenous loading with ammonium chloride (4 mmol NH4+/kg body weight) was performed before and 2-9 weeks after unilateral hydronephrosis had been produced by ligation of the ureter over an indwelling catheter. In an attempt to satisfy the demand for adequate, constant, alveolar ventilation a special respirator of the high-frequency positive-pressure ventilation (HFPPV) type was used. The acid-base status of the blood was determined before and after the loading and the acidification capacity of each kidney was assessed by measuring the amount of titratable acid and ammonium ions excreted in the urine. In the hydronephrotic kidney the excretion of both titratable acid and ammonium ions was statistically significantly reduced, both compared with the initial values in session I and compared with the healthy kidney in session II. After additional loading with ammonium chloride in session II, however, both kidneys increased their excretions to approximately similar extents. When the excretion was calculated per ml glomerular filtrate, no statistically significant changes were found between sessions I and II, either for the intact or the hydronephrotic kidney. The renal pelvic volume on the hydronephrotic side was measured and related to the reduction of the capacity of the kidney to excrete titratable acid and ammonium ions. No statistically significant correlation was obtained.
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PMID:Renal function in experimental chronic hydronephrosis. V. Net acid excretion capacity in relation to renal pelvic volume after maximal loading with NH4Cl. 1 50

1. The effects of Na-free and K-free solutions, tetraethyl ammonium (TEA), Mn2+, verapamil and ouabain on the electrophysiological properties of the smooth muscle cells of guinea-pig ureter have been studied, using the double sucrose-gap method. 2. TEA (5 mM) increased the amplitude and duration of both the initial spike component and the subsequent plateau of the action potential. The repetitive spike discharge on the plateau was abolished. The amplitude and duration of the phasic contraction was increased. The threshold for excitation was lowered while the resting potential and membrane resistance were unaffected. 3. In Na-free solution the duration of the action potential decreased mainly due to the suppression of the plateau. A similar effect was produced by exposure to K-free solution and also by ouabain. 4. Mn2+ (2 mM) suppressed the spike component and raised the threshold for excitation. The amplitude of the remaining part of the action potential was markedly increased but the contraction was rapidly abolished. The resting potential and membrane resistance were unchanged. When Mn2+ was added to Na-free solution it produced an increase in the amplitude and duration of the remaining part of the action potential but the phasic contraction was abolished. 5. Verapamil did not specifically block the fast component of the action potential but initially increased the amplitude of the spike and shortened the plateau. Subsequently, both the action potential and the phasic contraction became smaller. 6. The observations indicate that the phasic contractions are triggered by the initial spike component of the action potential, whereas the plateau is associated with the amplitude and particularly the duration of the contraction.
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PMID:The effect of sodium-free and potassium-free solutions, ionic current inhibitors and ouabain on electrophysiological properties of smooth muscle of guinea-pig ureter. 84 26

1. The ionic mechanism of the excitatory action of catecholamines and histamine on the smooth muscle cells of guinea-pig ureter was studied with the double sucrose-gap method. 2. In normal conditions adrenaline and noradrenaline in a concentration of 10(-5) g/ml., and histamine in a concentration of 10(-6) g/ml., prolonged the duration of the plateau of the action potential and increased the amplitude and duration of the phasic contraction. Sometimes these changes were accompanied by a slight depolarization of the muscle membrane and by a small increase (with noradrenaline) or decrease (with histamine) of the membrane resistance. The amplitude and duration of the fast spike component of the action potential were not changed. 3. Isoprenaline in a concentration of 10(-5) g/ml. either caused no change or it decreased the duration of the plateau, reduced the amplitude of contractions and reduced excitability. 4. Tetraethyl ammonium (TEA; 5 mM), which blocks the delayed outward K current, did not prevent the increase in the duration of the plateau nor the increase of the amplitude and duration of the contractions by noradrenaline and histamine. 5. In Na-free or in K-free solution or in the presence of ouabain, i.e. in conditions in which the Na-gradient across the membrane was reduced, noradrenaline and histamine were unable to increase the duration of the plateau and the amplitude and duration of the contraction. 6. In the presence of Mn2+ (2 mM) which suppressed the spike component of tha action potential and the phasic contraction, theeffects of noradrenaline and histamine were almost abolished. 7. The results suggest a dual ionic mechanism of the alpha-action of catecholamines and of the action of histamine on the smooth muscle of ureter: (1) these drugs affect the passive ionic permeability of the membrane in a manner that results in depolarization; (2) they specifically activate the potential-dependent conductance of the slow Na channels, thereby increasing the plateau duration. The increased amplitude and duration of the contraction is the result of their primary effect on the plateau of the action potential.
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PMID:The mechanism of the excitatory action of catecholamines and histamine on the smooth muscle of guinea-pig ureter. 84 27

A case of diverticular stones in the male anterior urethra with retrocaval ureter is reported. A 26-year-old man visited our hospital for examination, who had experienced spontaneous stone discharge a few days earlier. Computed tomographic (CT) scan with ureteral catheterization and urethrography revealed a retrocaval ureter and urethral diverticular stones. Resection of urethral diverticulum with 7 stones and right ureteroplasty were performed. The urethrography and drip infusion pyelography (DIP) 9 months after operation showed no abnormal findings. The largest stone was 28 x 22 x 20 mm in size and 20 g in weight. The main components were ammonium dihydrogen-urate (70%), carbonate apatite and struvite. Histological feature of the epithelium of the urethral diverticulum indicated normal skin with hairs. Pathological diagnosis was para-urethral dermoid cyst. Our case is the 67th case of the male urethral diverticular stones and the first case of those with retrocaval ureter in Japan.
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PMID:[Anterior urethral diverticular stones and retrocaval ureter in male: a case report and review of literature in Japan]. 135 38

At Osaka City University Hospital, we performed extracorporeal shock-wave lithotripsy (ESWL) for 1277 patients in a total of 1788 sessions using Dornier kidney lithotripter Model HM III from July, 1985 to the end of December, 1988. Among the patients with a solitary stone, 911 cases were available for the follow-up study and we have compared the results among these cases in respect to the stone location and size. The results obtained were as follows: the ratio of kidney stone to ureter stone was found to be 2.2:1 in male, and 3.8:1 in female patients. This indicates that ureter stones are more frequently found in male than in female patients. In addition, we compared the size of kidney stones found in the patients including 415 male and 243 female patients. Stones larger than 20 mm were more frequently found in female than in male patients. Moreover, a stone composition study of these patients showed that the contents of both phosphate calcium and magnesium ammonium phosphate were higher in female than in male patients. ESWL performed against stones at pelvis and calyces exhibited the best results. The results obtained with the stones less than 20 mm in diameter were especially favorable with a success rate of 100% for the stones less than 10 mm and 83% for the stones 10-20 mm, in diameter, while the results with the stones larger than 20 mm in diameter were rather poor with a success rate of 31%. ESWL performed against ureter stones showed poor results with a success rate of 63% for the stones smaller than 20 mm in diameter.
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PMID:[Evaluation of the results of extracorporeal shock-wave lithotripsy (ESWL) for solitary upper urinary tract stone]. 226 41

During a seven-year period (1975-1981) a total of 1325 patients hospitalized for stone disease were studied as to the occurrence of positive urine cultures. Urinary stones from 535 surgically treated patients were analyzed with infrared spectrophotometry and the relationships between stone composition, level of surgery and bacteriological strains were studied. Positive urinary cultures were found in 34% of the surgically treated patients and in 21% of those not operated upon. Among the surgically treated patients with urinary tract infection (UTI) E. coli was the most frequent microorganism (35%), followed by Proteus (28%). Patients with Proteus infection had the highest frequency of UTI episodes, most of which occurred before hospitalization. There was a higher frequency of magnesium ammonium phosphate (MAP) calculi among patients with Proteus infection than among those with non-Proteus infection, in whom no difference in stone composition was found. Patients infected with E. coli had more phosphate-containing stones (CaP+MAP) than non-infected patients. The highest frequency of oxalate calculi (CaOx+CaOx/CaP) was found among patients without infection. No E. coli infections were seen in male patients with CaP and MAP calculi. MAP stones were most often found in the kidney and oxalate stones in the ureter.
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PMID:The relation between urinary tract infections and stone composition in renal stone formers. 266 13

Effects of extracellular Na+ on the contractile action of vanadate were studied using depolarized smooth muscles of the guinea-pig vas deferens and ureter. Both sodium vanadate and ammonium vanadate induced tension development of the preparations in K-Tyrode's solution containing 12.3 mM Na+. The tension developments were enhanced greatly in K-60 mM solution with 89.3 mM Na+ and diminished in Na+-free K-Tyrode's or Na+-free K-60 mM Tyrode's solution, and slight relaxations were observed in the vas deferens soaked in the latter two Na+-free solutions. The addition of Na+ to Na+-free solution in the presence of vanadate induced a marked increase in tension. Vanadate induced slight tension development of depolarized preparations in the absence of Ca which was less affected by Na+. Ca-induced contraction of depolarized preparations was also markedly potentiated by vanadate. The potentiation was more prominent in the presence of Na+ and less prominent in the absence of Na+; the maximum tension was less affected by Na+ than the vanadate-induced contraction of depolarized preparation, but the tension decay was greatly accelerated in the absence of Na+. It was suggested that Na+ enhances the contractile action of vanadate through Ca extrusion mechanism of cell membrane.
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PMID:Influences of sodium on the contractile action of vanadate in depolarized vas deferens and ureter of the guinea-pig. 342 76

An 8-year-old boy who had suffered from recurrent stone formation since the age of 4 years, was admitted as an emergency due to anuria for a half day on November 20, 1986. Kidney-ureter-bladder film showed that the urethra was obstructed by a stone, and emergent cystoscopy was performed to remove it. He is the product of consanguinous marriage, his parents being first cousins. There was no family history of renal stone. Laboratory investigations showed hypokalemic, hyperchloremic metabolic acidosis. The ammonium chloride loading test revealed inability to acidify the urine and a markedly decreased excretion of titrable hydrogen ion and ammonium ion in the urine. These results indicate that this is a case of Type I renal tubular acidosis. His 24-hour urinary excretion of oxalate and glyoxylate were also markedly increased. There were no underlying causes leading to the development of secondary hyperoxaluria. These results also establish the diagnosis of Type I primary hyperoxaluria. The patient then received regimens of Polycitra 1ml/kg/day and Vitamin B6 50mg/day for 4 months. However, urinary stone developed again in this patient 4 months later. To our knowledge, Type I primary hyperoxaluria in association with Type I renal tubular acidosis has not been previously reported.
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PMID:Type I primary hyperoxaluria associated with type I renal tubular acidosis. 344 74

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

A 3-year-old Thoroughbred colt was presented for evaluation of azotemia and anorexia. Physical examination revealed a ureterolith in the left ureter, approximately 10 cm from the bladder, which was thought to obstruct urine flow by approximately 90% when viewed cystoscopically. Ultrasonographic examination of both kidneys revealed indistinct corticomedullary junctions, and the right kidney was more hyperechoic. A percutaneous biopsy of the right kidney revealed chronic interstitial nephritis with marked interstitial medullary fibrosis. Medical therapy consisting of IV fluids, sodium chloride PO, and ammonium chloride PO was initiated. Ureteroscopic electrohydraulic lithotripsy via a perineal urethrostomy was used to successfully remove the stone. Klebsiella oxytoca, which responded to oral enrofloxacin therapy, was cultured from the urine after surgery. Azotemia resolved and the horse resumed training.
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PMID:Resolution of a left ureteral stone using electrohydraulic lithotripsy in a thoroughbred colt. 852 27


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