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

Taking up again inquiries already known in the past, documents of pathological anatomy of his own person experience, and facts of embryology, the authors explain the etiology of the obstructive malformation of pyelo-ureteral function the etiology brings out two phenomena: --The insufficient hollowing of the cephalic end of the ureteral bud, which is initially grooved, when it detaches itself from the Wolffian canal, can transform itself into a full cellular cord which secondarily forms a groove after 23 mm stage.--The insufficient vascularization of the ureter just below the pelvis because of an abnormal anatomical disposition which causes displacement of the longitudinal uretero-pelvic arteries to a point clearly below the ureteropelvic junction. There an ischemia impedes the muscular development of the ureter just below the pelvic of which the wall becomes more sclerotic and fibrous than muscular. Thus a defect in the grooving of the ureteral bud and an arterial blood deficit results in a congenital ureteral stenosis. Pathological anatomical documents illustrate this theory from which flow two imperative technics; the necessity to eliminate the initial obstructive ureteral segment; care to protect the pelvic vessels which will have to vascularize the ureter which will be anastomosed to the cut edge of the pelvis.
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PMID:[Etiopathogenesis of so-called congenital hydronephrosis]. 43 96

Currently, the most favored surgical procedure used to restore normal peristalsis to massively dilated adynamic ureters is ureteral tailoring. This procedure, however, seriously jeopardizes the ureter's blood supply and frequently results in ischemia with ureteral stenosis and further renal deterioration. To preserve the distal ureter's vasculature a new technique of reducing ureteral caliber and restoring normal peristalsis with minimal disruption of the blood supply was developed and performed in 14 dogs with excellent results.
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PMID:Ureteral plication. A new concept in ureteral tailoring for megaureter. 46 16

Glomerular hemodynamics were studied, by micropuncture, in Munich-Wistar rats submitted to 24-hour unilateral ureteral ligation (UUL). Glomerular capillary pressure (PG), intratubular pressure (PT) and pressure in the first-order peritubular capillaries (EAP) were measured with a servonulling device. Single nephron filtration fraction (SNIFF) was calculated fmom arterial and peritubular blood protein concentration. SNGFR was both measured by conventional micropuncture techniques and calculated from efferent arteriole blood flow (EABF) and SNFF. Afferent arteriole blood flow (AABF) and resistance of afferent (Ra) and efferent (Re) arterioles were calculated. Measurements were repeated 1 to 2 hours after the release of the ureter. Sham-operated rats were used as control. UUL caused a marked increase in Ra (from 4.9 +/- [SD] 2.4 to 12.7 +/- 5.1 dynes/sec/cm-5). The fall in SNGFR (from 111.9 +/- [SD] 23.9 to 34.4 +/- 23.1 nl/min/kg body wt) was secondary to a decrease in both PG and AABF. A further increase in Ra (16.0 +/- 6.7 dynes.sec.cm-5) occurred after releasing the ureter. SNGFR, however, was unaltered (33.7 +/- 16.6 nl/min/kg body wt) since PG decreased parallel to PT, but AABF did not significantly change. Conclusion. Ureteral obstruction determines, in 24 hours, a marked cortical ischemia that is not promptly reversed by ureteral release.
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PMID:Effects of 24-hour unilateral ureteral obstruction on glomerular hemodynamics in rat kidney. 48 Jul 81

Uretero-cystostomy was used as reconstructive procedure in 298 cadaver kidney transplantations. Necrosis of the graft ureter occured in 10 cases (3.4%). 2 of these graft ureters had malformations and 1 was denuded at donor nephrectomy. The occurrence of ureteral necrosis was not related to histocompatibility or number of rejection crises nor to the duration of the warm ischemia. A higher incidence of ureteral necrosis after long cold ischemia is demonstrated, but the material is too small to permit conclusive evidence on this point.
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PMID:Ureteric necrosis after kidney transplantation. 80 Oct 99

Ischemia was produced in the inner cortex of the rat kidney by clamping the pedicle (artery, vein, and ureter) and severing collateral connections. After 30 minutes of ischemia, a slight aggregation of membrane-associated particles was observed in the freeze-fractured plasma membranes. The aggregation was progressive after 60 and 120 minutes of ischemia. These changes were reversible after 15 and 240 minutes of reflow of blood following 30 or 60 minutes of ischemia. The changes were irreversible after 120 minutes of ischemia. The cells were vacuolated after ischemic periods of 30 minutes or longer and after 120 minutes of ischemia the tissue was severely damaged and aggregation of membrane-associated particles was evident in the vacuolar membranes. No changes in the tissue or plasma membrane were observed after 5 or 20 minutes of ischemia.
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PMID:Plasma membrane changes in freeze-fractured rat kidney cortex following renal ischemia. 94 Mar 22

Total ureteropelvic necrosis of the transplanted kidney occurred more than one month after transplantation in 5 of 575 consecutive renal transplants performed at the University of Minnesota Hospital since 1963. Necrosis became evident long after normal renal function had been established. Histologic signs of rejection were minimal, but perinephric or periureteral hematomas were found in 3 of 5 patients: post-transplant acute tubular necorsis requiring hemodialysis occurred in all. The pathogenesis of this complication probably involves (1) a primary deficit of blood supply from the renal vessels to the pelvis and ureter, (2) a failure to develop a new ureteral blood supply because of surrounding hematoma, (3) early swelling of the ischemic ureter resulting in oliguria interpreted as acute tubular necrosis, (4) resolution of edema resulting in diuresis, and (5) late patchy ureteral necrosis and fistula formation due to ureteral ischemia.
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PMID:Late ureteropelvic necrosis after transplantation. 109 Oct 63

The development of an experimental model for ureteral autotransplantation without kidney transplantation, in an attempt to confirm viability of the ureter after denervation and total ischemia, is reported. Stages of the study and the experimental microsurgical technique used are discussed. Experiments were carried out in 30 Sprague-Dawley rats distributed in two experimental stages. The absence of histologic lesions was demonstrated by exeresis of the autotransplantated ureter and latter pathological study. Size, colour, renal consistency, ureteral peristalsis and the macroscopic appearance of the surgical piece were recorded. Histological examination confirmed macro- and microscopic normality of the autotransplanted ureteral segment.
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PMID:Experimental model for ureteral autotransplantation in the rat. 142 50

Present techniques for renal transplantation in the rat include a period of 20-25 minutes warm ischemia. Our method combines a recently described sleeve anastomotic technique for the renal artery, conventional end-to-end anastomosis of the renal vein, and implantation of the ureter into the bladder. This has resulted in a reproducible ischemic interval of 12-14 minutes. Plasma creatinine and histological features in animals sacrificed from 10 to 30 days after transplantation were within normal limits with no evidence of ischemic damage. A further advantage of the technique is that kidneys can be exchanged between the donor and recipient. It is recommended that this procedure, which reduces the ischemic interval by up to 50%, should be learned and employed in studies of renal transplantation in the rat, especially if such studies include the prior administration of cyclosporine, which may aggravate the effects of ischemia.
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PMID:New rapid technique for renal transplantation in the rat. 145 38

Phosphocreatine (PCr) is a critical intracellular energy reservoir used in the regeneration of ATP. The aim of this study was to determine the efficacy of exogenously added PCr on preservation of renal function in an in vitro model. The renal artery and ureter of a rat were cannulated and the kidney was subjected to 45 min of normothermic in vivo ischemia. The kidneys were then perfused ex vivo with either a Krebs-bicarbonate solution (Krebs) or a Krebs solution containing 3 mM PCr or an osmotically balanced solution containing 3 mM PCr. Our results indicate that the perfusion of kidneys subjected to 45 min of warm ischemia with solutions containing PCr resulted in significant improvements in GFR, RPF, and V, FRNa and FRH2O compared to KREBS alone. This suggests that the important factor in preservation of kidney function after an initial ischemic insult may be the addition of PCr rather that the electrolyte solution used.
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PMID:Amelioration of renal ischemic injury by phosphocreatine. 192 64

1. Electrophysiological techniques were used to characterize responses of afferent fibers in pelvic nerve of adult, virgin female rats to mechanical or chemical stimulation of internal reproductive organs and to mechanical stimulation of other pelvic organs. 2. In an in vivo barbiturate-anesthetized preparation, pelvic nerve afferent fibers responded to a wide variety of mechanical stimulation applied to restricted regions of the vaginal canal, caudal uterus (body and cervix), bladder, ureter, colon, or anus. 3. Single-fiber mechanoreceptive fields were invariably confined to a single organ. Notably, responses could be evoked not only by gentle stimulation of the unit's receptive field directly on the organ itself, but also by stimulating the field indirectly with intense stimulation through the appropriate part of a contiguous organ. This innervation feature is consistent with the separability of pelvic organ functions under innocuous conditions but their confusion under noxious ones. 4. Receptive fields on the reproductive organs extended from the caudal edge of the vagina to the uterine body (including the cervix) but were most often located in the fornix (vaginocervical junction). Most units had no or low levels of spontaneous activity. Their responses to mechanical stimuli were usually slowly or moderately adapting and time-locked to the stimulus. 5. Fibers with vaginal receptive fields (including the fornix) responded best either to vaginal distension with a balloon or, more often, to a probe moving along the internal vaginal surface in a direction toward the cervix. They were observed most frequently during the proestrus stage of the rat's estrous cycle. These fibers, therefore, seem particularly suited for relaying information about stimuli that occur during mating. 6. Fibers with receptive fields on the uterine cervix and body responded best to static pressure and were observed less frequently than those with vaginal fields, regardless of estrous stage. They were, however, sensitized by hypoxia. In addition, irritation of the uterus increased the probability of observing them. These fibers, therefore, may exert their primary function during reproductive conditions different from those of virgin rats, such as parturition. 7. Response activity of most of the mechanoreceptive afferent fibers supplying reproductive organs increased as the stimulus intensity increased into the noxious range; i.e., into a range in which the stimulus momentarily produced ischemia at the stimulus site. In addition, in an in vitro preparation, pelvic nerve fibers responded in a dose-dependent manner to injections through the uterine artery of bradykinin (BRAD) as well as to other algesic chemicals, 5-hydroxytryptamine (5-HT) and KCl.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Functional properties of afferent fibers supplying reproductive and other pelvic organs in pelvic nerve of female rat. 231 44


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