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

Experimental data demonstrate that sinusoidal modulated currents are capable of increasing the frequency and amplitude of smooth muscle biopotentials in animal ureter. Basing on these findings, the authors conducted stone fragments elimination from the upper urinary tracts of patients subjected to pulse lithotripsy by means of an original physiotherapeutic complex: oral mineral water, sodium chloride baths, dynamic amplipulse therapy with 3-4 electrodes pairs applied on the renal area and different ureteral regions. The stones passage from the upper urinary tracts was reported in 91.7% of the cases. Functional improvement in the affected kidney is attributed to the stone elimination and antiinflammatory action of the above balneotherapeutic complex.
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PMID:[The action of dynamic amplipulse therapy on the urodynamics of the upper urinary tract in patients with kidney and ureteral stone fragments following extracorporeal shockwave lithotripsy]. 129 19

The energy of high frequency ultrasound is used to disrupt cellular structures. Since the water content of each individual cell is of utmost importance for the physical destruction of the cell, there may be a tissue-selective effect in respect of tissues such as epithelium (high water content) and mesenchyma (low water content). The various therapeutic modalities are described in the following four cases. Ultrasonic tumor destruction was highly effective with regard to maximum reduction of tumor masses, especially for tumor sites which could not be removed by conventional tumor surgery. Blood vessels and nerves surrounded by tumor could be carefully and completely dissected--even in advanced stages. Peritoneal metastases from an ovarian carcinoma could be removed entirely, as well as the metastases within a tumor bulk (e.g. ureter within tumor mass); also the layers of tissue which were lost could be visualized again. So far, no increase in complications during and after surgery has been observed.
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PMID:[Experiences up to now with the ultrasound dissection instrument in gynecologic oncology]. 132 76

Tissue distribution, elimination, and metabolism of 3H-labelled leukotriene (LT) C4 were studied in ureter-catheterized conscious marine toads, Bufo marinus. Six and 24 h after injection, organs containing the highest percent of injected radioactivity were small intestine, liver, and kidney. Radioactivity declined in these organs at 24 h by approximately threefold. Peak elimination time for radioactivity in the urine was between 2 and 4 h after the injection. During the 24-h collection period, 55.2 +/- 0.2% of the injected radioactivity was eliminated in the urine. Polar metabolites represented 40.3 +/- 1.1, 57.3 +/- 5.6, and 62.8 +/- 1.6% of the radioactivity at 2, 4, and 6 h, respectively. The primary urinary polar metabolite was 20-carboxy-LTE4, with 18-carboxydinor-LTE4 and 20-hydroxy-LTE4 also present. [3H]LTE4 decreased from 37.2 +/- 1.8% at 2 h to 15.8 +/- 3.3 and 15.0 +/- 2.1% of the radioactivity at 4 and 6 h, respectively. Bile radioactivity was low. N-Acetyl-LTE4 was not detected in urine or bile samples. Radioactivity in the pan water was 14.3 +/- 2.4 and 15.8 +/- 2.5% of the injected radioactivity, at 6 and 24 h, respectively, suggesting that the skin was a route for excretion of leukotrienes. The marine toad is an interesting model demonstrating both similarities and differences from mammals in distribution, elimination, and metabolism of peptide leukotrienes.
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PMID:Tissue distribution, elimination, and metabolism of [3H]leukotriene C4 by the conscious marine toad, Bufo marinus. 133 72

Preliminary studies determined that, unlike other purported alpha-2 adrenoceptor agonists, 2,6-dimethyl clonidine (2,6-DMC) increased urine flow rate independent of vasopressin. We therefore compared the dose-response curves of three alpha-2 adrenoceptor agonists, clonidine, UK 14,304 and 2,6-DMC. Unilaterally nephrectomized Sprague-Dawley rats were anesthetized and the left kidney was exposed and the ureter cannulated. A 31-gauge needle was advanced into the renal artery to permit direct intrarenal infusion of the study drugs. All three agonists produced a dose-related increase in urine flow rate and sodium excretion. A clear opposite rank order of potency was observed when the urine flow rate was analyzed as free water and osmolar clearance. For free water clearance, clonidine much greater than UK 14,304 much greater than 2,6-DMC, with 2,6-DMC producing little change. The effect on osmolar clearance was opposite with 2,6-DMC much greater than clonidine = UK 14,304. The V2 antagonist [1-(beta-mercapto-beta,beta-pentamethylene-proprionic acid), 2-d-isoleucine,4-isoleucine]arginine-vasopressin blocked the effects of clonidine but not 2,6-DMC. In a water-loaded rat model, 2,6-DMC but not clonidine increased the delivery of filtrate out of the proximal segments of the nephron. These results are consistent with the postulate that lower doses of 2,6-DMC increase solute excretion independent of vasopressin, possibly in proximal segments of the nephron. Clonidine on the other hand increases free water clearance and this effect is mediated through an interaction with the renal actions of vasopressin. Whether these disparate effects represent two distinct receptors or two sites of alpha-2 adrenoceptors in the kidney is not known.
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PMID:Opposite rank order of potency for alpha-2 adrenoceptor agonists on water and solute excretion in the rat: two sites and/or receptors? 135 Oct 96

The tissue effects of a holmium:YAG (Ho:YAG) laser operating at a wavelength of 2.1 mu with a maximum power of 15 watts (W) and 10 different energy-pulse settings was systematically evaluated on kidney, bladder, prostate, ureteral, and vasal tissue in the dog. In addition, various urologic surgical procedures (partial nephrectomy, transurethral laser incision of the prostate, and laser-assisted vasovasostomy) were performed in the dog, and a laparoscopic pelvic lymph node dissection was carried out in a pig. Although the Ho:YAG laser has a strong affinity for water, precise tissue ablation was achieved in both the contact and non-contact mode when used endoscopically in a fluid medium to ablate prostatic and vesical tissue. Using the usual parameters for tissue destruction (blanching without charring), the depth of thermal injury in the bladder and ureter was kept superficial. In performing partial nephrectomies, a 2-fold reduction in the zone of coagulative necrosis was demonstrated compared to the use of the continuous wave Neodymium:YAG laser (Nd:YAG). When used through the laparoscope, the Ho:YAG laser provided precise cutting and, combined with electrocautery, allowed the dissection to proceed quickly and smoothly. Hemostatic control was adequate in all surgical procedures. Although the results of these investigations are preliminary, our initial experience with the Ho:YAG laser has been favorable and warrants further investigations.
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PMID:Use of the holmium:YAG laser in urology. 138 43

The effect of saline and/or water load on diuresis, natriuresis and kaliuresis in control and in neonatal or adult capsaicin-pretreated awake rats has been assessed. Urine was collected by means of metabolic cages or intra-abdominally from a previously catheterized ureter. Neonatal but not adult capsaicin-pretreated animals exhibited a remarkable reduction in volume of urine output and in electrolytes excretion. This effect was more evident following saline as compared to water load. Similar results were also obtained when urine was directly collected from the ureters, suggesting that pharmacological ablation, at neonatal stage, of a subset of capsaicin-sensitive sensory nerves could impair the excretory kidney function.
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PMID:Impairment of renal urinary excretion in neonatal, but not in adult capsaicin-pretreated rats. 154 25

Although most ureters can now be stented, the rate of ureteral obstruction from extrinsic compression remains relatively high. To illuminate the mechanisms of obstruction in these patients we performed 20 in vivo pressure-flow investigations in 14 patients with indwelling ureteral Double-J stents. All patients had a percutaneous nephrostomy tube in place. Our investigations revealed proper drainage to the bladder in 17 of the 20 studies at an average renal pelvic pressure of 19.9 cm. water. Vesicorenal reflux was noted at an average bladder pressure of 20 cm. water in 17 studies. Three stents appeared to be obstructed. They showed no drainage to the bladder but also no reflux. To evaluate the in vivo results we then performed an in vitro study of pressure-flow characteristics under conditions simulating ureteral obstruction. At physiological flow rates different ureteral stents showed no major differences in pressure-flow characteristics. With compression and kinking, flow resistance in softer stents was notably greater than in hard stents. Therefore, we believe that in patients with suspected extrinsic compression of the ureter hard Double-J stents should be used. Vesicorenal reflux appears to be a reliable predictor of stent function.
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PMID:The double-J ureteral stent: in vivo and in vitro flow studies. 163 17

Brown Norway kininogen-deficient rats had very low levels of plasma kininogens and lower levels of plasma prekallikrein, compared with those of normal rats of the same strain. Systolic blood pressure, determined by the tail-cuff method, of 5-week-old kininogen-deficient rats (106 +/- 0.4 mm Hg, n = 7) and the rate of systolic blood pressure increase with age were not different from those in normal rats. Weekly injections of deoxycorticosterone acetate (5 mg/kg s.c.) with 1% sodium chloride solution in drinking water after uninephrectomy at 7 weeks of age caused a gradual increase in the blood pressure of normal rats, reaching a plateau at 18 weeks of age, whereas that of deficient rats rose rapidly to 158 +/- 6 mm Hg 2 weeks after the start of treatment and continued to increase slightly, becoming significantly higher than normal rats at 8, 9, 10, 11, and 12 weeks of age (p less than 0.05 or 0.01). The levels of urinary prokallikrein and active kallikrein were slightly higher in deficient rats before deoxycorticosterone acetate-salt treatment but were not significantly increased after this treatment, whereas these levels in normal rats were increased 3.6- and 4.7-fold by this treatment. Urinary free kinin, collected from the ureter in untreated deficient rats, was below the detection limit. The plasma level of low molecular weight kininogen, the substrate of glandular kallikrein, was decreased in normal rats during the treatment. Continuous subcutaneous injection of aprotinin by an osmotic pump to normal rats induced significant increase in blood pressure. These results indicate that glandular kallikrein may play a suppressive role in deoxycorticosterone acetate-salt hypertension.
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PMID:Suppression of rat deoxycorticosterone-salt hypertension by kallikrein-kinin system. 171 Jun 5

The relationship between bladder movements and the intramural ureter was studied in the dog by recording electromyograms of the intramural and extravesical ureters recorded during bladder filling and contraction. Bladder filling was achieved by instilling physiological saline at a rate of 10 ml/min to a volume of 5 ml/kg, while bladder contraction was induced by electrical stimulation. For electromyography, an electrode was inserted transperitoneal into both the extravesical ureter and the intramural ureter after it had been separated from the extravesical ureter. A cystostomy for the instillation of water and another cystostomy for the measurement of intravesical pressure were also made in the bladder. During bladder filling at an intravesical pressure of about 10 cmH2O, the frequency of the action potentials in the intramural ureter showed no significant difference to those in the extravesical ureter. In addition, during bladder contraction at a greatly increased intravesical pressure of about 5 times the precontraction level, the frequency of the action potentials in the intramural ureter was not significant by different from those in the extravesical ureter, and also from its own precontraction value. The above findings suggest that action potentials in the intramural ureter are not affected by bladder movements such as filling or contraction, and that the ureter continues to actively transport urine to the bladder during such movements.
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PMID:[Ureteral function at the ureterovesical junction. Action potentials of the canine intramural ureter during bladder filling or bladder contraction]. 176 65

A 3.3F electrohydraulic electrode (Wolf 2137.23) has been confined within a spring with a metal end cap, irrigated with water and covered with a 0.003-inch metal sheath (outside diameter 5F). The electrohydraulic lithotripsy discharge (Wolf Generator 2137.50) at E1 causes the metal cap to extend 3 mm. at 1,500 cm. per second and creates an impact pressure of 600 to 800 bar. Stone fragmentation efficiency of the electromechanical impactor was equivalent to unshielded electrohydraulic lithotripsy (gallstone 2.83 mg. per pulse, struvite/apatite 1.41 mg. per pulse, cystine 0.41 mg. per pulse, uric acid 1.48 mg. per pulse and 100% calcium oxalate monohydrate 0.10 mg. per pulse). Studies of the discharge of the electromechanical impactor within the pig ureter showed that minimal ureteral submucosal edema and hemorrhage occurred at 300 shocks discharged at a single point, and disruption of the mucosa and partial injury to the muscle layer occurred after 600 shocks given at the site of a pinched pig ureter. Pushing the electromechanical impactor perpendicular to the wall of the pig bladder will create a mechanical perforation within 35 shocks (electrohydraulic lithotripsy within 2 shocks). One patient had excellent fragmentation of a lower ureteral mixed monohydrate and dihydrate stone under direct vision performed with the electromechanical impactor passed via a 9.5F ureteroscope. There was no evidence of mucosal injury with 500 shocks. The electromechanical impactor has been developed to provide a safe and inexpensive method of ureteral stone fragmentation or disimpaction. These studies were performed to establish limits of safety that may allow use of the electromechanical impactor for stone fragmentation in the ureter without the need for ureteroscopy.
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PMID:Conversion of the electrohydraulic electrode to an electromechanical stone impactor: basic studies and a case report. 187 85


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