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

Liver cells were prepared from untreated controls, rats with various models of acute uraemia (uranyl nitrate-treated, bilaterally nephrectomised and ureter-ligated rats, rats with acute ischaemic renal failure) and sham-operated animals. Hepatocyte glucose output, pyruvate utilisation and lactate production were determined in the presence of Krebs-Ringer bicarbonate buffer with different pH values (7.1, 7.4, 7.6) using pyruvate, dihydroxyacetone, serine and fructose as substrates. In the presence of pyruvate and dihydroxyacetone a significant increase of glucose production in hepatocytes from bilaterally nephrectomised and ureter-ligated rats was observed. However, pyruvate-generated glucose production in the hepatocytes of uranyl nitrate-treated animals was unchanged, while a diminished glucose output was seen in the presence of dihydroxyacetone. A marked increase in glucose and lactate production in the presence of serine was observed in the hepatocytes of uranyl nitrate-treated, ureter-ligated and binephrectomised rats. However, lactate production from dihydroxyacetone in the liver cells of uranyl nitrate-treated animals was inhibited. In contrast to other types of uraemia, in acute ischaemic renal failure there is significantly lower hepatocyte glucose production using pyruvate as a substrate, but unchanged glucose generation from dihydroxyacetone or serine.
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PMID:The gluconeogenetic ability of hepatocytes in various types of acute uraemia. 681 Jan 92

Bilateral ureteric obstruction from prostatic carcinoma is not uncommon. A number of techniques for urinary diversion have been used in selected patients when uraemia develops. Reimplantation of the ureter(s) as an alternative to urinary diversion has been carried out in 21 patients over a 7-year period. In 6 of these patients bilateral reimplantation was done. In another 6 patients reimplantation of the ureter was not possible and cutaneous ureterostomy was carried out. The overall survival time was 10.6 months. In 13 patients living more than 6 months post-operatively, survival time was 1.8 years. Most patients had severe uraemia and advanced (clinical stage III or IV) prostatic carcinoma. The immediate management of these patients is outlined and the importance should be considered is stress. It is concluded that, whenever possible, ureteric reimplantation should be considered for relieving ureteric obstruction in patients selected for active treatment.
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PMID:Reimplantation of the ureter in prostatic carcinoma associated with bilateral ureteric obstruction. 726 May 50

Disturbances of carbohydrate metabolism during acute uraemia are characterized by the degradation of liver and muscle glycogen with a simultaneous activation of hepatic gluconeogenesis. After binephrectomy, the substitution of essential amino acids and keto analogues stimulate liver, but not skeletal muscle glycogen synthesis. Serine proves to be an optimal substrate for liver gluconeogenesis and muscle glycogen generation under acute uraemic conditions. Propranolol does not influence glycogenolysis of skeletal muscle in acutely uraemic rats. During starvation, acute uraemia leads to an increase of total carbohydrate content as well as of glycogen and glucose concentrations in heart muscle Alterations in carbohydrate contents are not observed in the kidney after ureter ligation. Enhanced glycogenolysis of skeletal muscle and liver during acute uraemia may be due to activation of phosphorylase kinase caused by the increased serum concentrations of various hormones (glucagon, catecholamines, parathormone) as well as free proteolytic activity, an increase of intracellular Ca2+-concentration and finally by alterations in the structure of contractile proteins.
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PMID:Carbohydrate metabolism and uraemia-mechanisms for glycogenolysis and gluconeogenesis. 745 93

We described some experimental models that were performed in rabbits and in swine in order to evaluate the efficacy of haemoperfusion treatment in hypochloremic alkalosis, uraemia and cytotoxic drug poisoning. In all the models, an extracorporeal circuit was used constituted mainly by a hematic sampling line and a cartridge, containing an anion exchange resin. Access to the blood stream was achieved by isolation and catheterization of the vessels either of the neck or of the leg, or both. The experimental model for the evaluation of haemoperfusion in hypochloremic alkalosis was carried out in rabbits by a pyloric stenosis because its size and weight are similar to new-born humans and its stomach is a simple monogastric one. The hypochloremia and alkalosis were achieved in only 4 hours. The other two experimental models were carried out in pigs because, in these cases, it was better to choose a large size animal with a nutritional similarity to humans, and with the capability to produce a stable chronic renal failure. The pigs were submitted to a bilateral ureter ligature to create a chronic renal failure or to a bilateral renal vessel ligature to avoid the physiologic precipitation of some drugs in renal tubules.
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PMID:In vivo experimental models on the evaluation of haemoperfusion. 819 4

A microsurgical technique for en bloc kidney and whole pancreaticoduodenal transplantation with bladder drainage employing triple vascular anastomoses without the need for a vascular cuff is described. Nineteen combined isografts were performed using this technique in inbred male Lewis (RT1:I) rats with streptozotocin-induced diabetes. Six recipients died within 1 month from early complications (two from uremia, two from pancreatitis, one from bleeding, one from peritonitis); the other 13 survived more than 1 month after transplantation with both the pancreas and kidney grafts functioning. Four of the 13 rats died after 1 month (one from uremia secondary to an obstructed ureter, one from unexplained uremia, one from peritonitis after a biopsy, and one of unknown causes). The pancreas isografts of two animals were excised at 1 and 3 months to confirm dependence on the graft; both animals became hyperglycemic after graft pancreatectomy and had immediate declines of urine amylase activity to normal. One animal was sacrificed at 3 months to determine the insulin content of its native and transplanted pancreas; insulin was very low in the former and normal in the latter. The remaining rats survived with both grafts functioning for at least 6 months (normoglycemic, high urinary amylase levels, normal or near-normal plasma creatinine concentrations), before being sacrificed within the context of other experiments and for histological observations. Both the kidney and pancreas isografts were well preserved microscopically.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:En bloc kidney and whole pancreaticoduodenal transplantation with bladder drainage in the rat: microsurgical technique and outcome. 847 21

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

Several clinical studies have confirmed that histomorphometric changes in the tubulointerstitial compartment contain the best correlating parameters to predict the development of progressive renal insufficiency. The process of interstitial fibrosis is accompanied by an influx of inflammatory cells, up-regulation of fibrogenic cytokines such as transforming growth factor-beta and basic fibroblast growth factor, transient down-modulation of their antagonists, generation and proliferation of myofibroblasts, and, finally, by accumulation of interstitial collagens and proteoglycans. A careful morphometric analysis of interstitial fibrosis requires sensitive parameters through which the severity can be quantified and by which the progression into renal insufficiency can be predicted. We have addressed these issues by morphometric analysis of both human biopsies and by refining existing experimental models in the rat. Morphometric analysis was performed using a Zeiss microscope equipped with a full colour 3CCD camera and KS-400 image analysis software from Zeiss-Kontron. For studies with human material, biopsies were examined from patients with various renal diseases including patients with chronic allotransplant dysfunction. The development of interstitial fibrosis was correlated with clinical parameters. In experimental models, we analysed the interstitial composition and eventual glomerular alterations in rats with bovine serum albumin (BSA)-induced protein overload nephropathy and with human IgG-induced chronic serum sickness nephritis. Finally, we adapted and refined the model of ureter obstruction-induced interstitial fibrosis in the rat. For this purpose, custom-made titanium clips (S&T, Neuhaus, Switzerland) were implanted around the ureter in the abdomen of rats to obstruct the ureter without causing necrosis. The clips were removed at various time points after obstruction of the ureter (1-14 days). The subsequent remodelling of the interstitium was studied thereafter, in order to establish whether uraemia-induced interstitial fibrosis remains reversible at all times. In rat models, we have found that both protein overload-induced and serum sickness-induced interstitial fibrosis are accompanied by the development of focal and segmental glomerulosclerosis. Only in the ureter obstruction model did selective interstitial fibrosis develop, and remained reversible at all times studied. For the reliable assessment of interstitial fibrosis we have found that the best correlating parameters of interstitial fibrosis with renal function were: (i) the ratio of protein accumulation of TGF-beta-1 and its antagonist decorin; (ii) interstitial expression of smooth muscle alpha-actin; and (iii) accumulation of interstitial collagens (as determined by immunoperoxidase and by Sirius red staining).
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PMID:Morphometry of interstitial fibrosis. 1114 98

First reports in German literature on the effective removal of uremic toxins by means of extracorporeal hemodialysis in bi-nephrectomized, acute uremic dogs were given by Heinrich Necheles and Georg Haas. These methods were viewed with great scepticism by Georg Ganter who criticized in particular the extensive operative procedure by use of the femoral artery and vein, the size and fragility of the dialysers, as well as the potential toxic effects of the anticoagulant hirudin. As an alternative approach, he suggested the use of the peritoneum as an especially large endogenous dialysis membrane. In 1923, in experiments on ureter-ligated guinea pigs and rabbits, he demonstrated that the single or repeated instillation (after effective draining) of physiological NaCl solution improves both the symptoms of uremia and the blood urea nitrogen level. In patients this new procedure was implemented only sporadically and in the form of a single fluid instillation after a first observation in a uremic patient where a pleura exudate was substituted: in a female patient with acute uremia as a consequence of a ureter occlusion, due to uterus carcinoma, and in a patient with a diabetic coma. In spite of these limited experiences, Ganter was convinced of the superiority of his method over the troublesome hemodialysis therapy and recommended its broader clinical application.
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PMID:Georg Ganter--a pioneer of peritoneal dialysis and his tragic academic demise at the hand of the Nazi regime. 1536 72

Previous investigators have found that complete occlusion of the ureter may lead either to hydronephrosis or to atrophy. In Lindemann's series of six dogs;, for instance: Two animals showed simple hydronephrosis, three animals showed simple atrophy, and in one animal the kidney was slightly enlarged and the ureter and pelvis dilated, but fluid was absent. In his series of four rabbits, all showed hydronephrosis. The result, whether hydronephrosis or atrophy, is evidently not determined by the time elapsing after the operation. Lindemann found that the intrapelvic pressure resulting from the ligation obliterates the lumen of the vessels, first of the veins and subsequently of the arteries; but that this is compensated by an increase of the collateral blood supply through the capsule, the degree of this compensation determining the presence or absence of hydronephrosis. If the blood supply is free, the fluid after tapping will accumulate again and again. It is somewhat remarkable that all of our dogs showed hydronephrosis after the first operation. The results of establishing a urinary fistula differed in the two cases in which it was tried: The fluid did not re-form in Dog 3 even when sodium sulphate was injected: whereas in Dog 4, a very abundant quantity of fluid reaccumulated spontaneously; but it differed notably in composition from the original fluid, having more the character of a purulent inflammatory exudate. The histological changes consist in necrosis of the renal cells, obliteration of the glomeruli, increase of connective tissue, and endarteritis and periarteritis. Different areas in the same kidney are affected in very different degree, some areas appearing almost normal. The glomeruli are generally less altered than the tubules. The collecting tubules are generally displaced so as to run parallel to the surface; many are dilated. The changes correspond closely to those described by Lindemann. The sound kidneys showed slight hyperaemia and hypertrophy, but no necrosis. This corresponds with the findings of Pearce and of Ames. The uniformity in chemical composition of the fluid obtained, after the first operation, from the four dogs, as shown by Column III of Table I, is very striking, and points to a uniform origin by a process which is but little affected by the interval elapsing after the operation. The specific gravity, total solids and proteids correspond to those of a very dilute lymph, being but a trifle above those of cerebro-spinal fluid and aqueous humor, and much lower than those of serum, lymph and most cystic fluids (the proteid content of the latter being generally from 2 to 6.5 per cent.). The human fluid (Column II) which had remained in the kidney for a very long time had a particularly low proteid percentage; while that of the second fluid of Dog 4 (Column VIII) was very much higher; this last fluid having a pronounced inflammatory character and being of recent formation. The absence of notable amounts of the specific urinary constituents is particularly important.(4) Odorous principles are entirely absent. Urinary pigments appear to be present in the four dogs' urines, but absent from the human case,(5) and after the second operation in case of the dogs. It seems fair to assume that the pigments were secreted shortly after the ligation, when the kidneys were still functional, and that they were reabsorbed with extreme slowness. Urea was present in all the fluids, but its quantity was very small in the dogs, and probably in the human case. It is on the whole somewhat greater than in the serum (0.103 per cent., in place of 0.05 per cent.), but the difference may be within the analytical error. The same applies to the ammonia, phosphates and sulphates. An important difference between these fluids on the one hand and blood serum, lymph and ordinary exudate on the other, lies in the higher contents of chlorid, and the consequently greater molecular concentration. The ordinary chlorid content of body fluid varies between 0.55 and 0.70 per cent., mean about 0.6 per cent (as NaCl), while that of the first kidney fluid, in the dogs, varied between 0.68 and 0.75 per cent., mean 0.725 per cent.; that of the human fluid was 0.83 per cent., that of the second fluid of Dog 4 only 0.52 per cent. The depression of the freezing point in the human case was 0.715 degrees C., as against the normal value, for human serum, of 0.491 to 0.562. (Possibly the blood of this patient had a higher concentration than normal, since uraemia existed.) The high chlorid percentage has evidently no relation to the length of time during which the fluid sojourned in the kidney. It is probably to be explained by the relatively slow absorption of this ion from the kidney pelvis. It is also to be remarked that cerebrospinal fluids generally have a somewhat high chlorid content (0.573 and 0.6 per cent.), but this never reaches the height of these ureteral fluids.
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PMID:EXPERIMENTAL ATRESIA OF THE URETER. 1986 74


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