The relationship of smooth muscle damage to age, severity of pre-operative hydronephrosis and post-operative outcome in obstructive uropathies

OBJECTIVE

To determine the relationship, in patients with pelvi-ureteric junction (PUJ) obstruction, of histopathological abnormalities to their age at surgery, the severity of pre-operative hydronephrosis and the post-operative outcome.

MATERIALS AND METHODS

Surgical specimens from 60 consecutive PUJ complexes excised at pyeloplasty were evaluated histologically.

RESULTS

There was a close relationship of smooth muscle abnormality and fibrosis with the severity of pre-operative hydronephrosis and post-operative outcome, with no significant correlation between histopathological abnormality and patient age.

CONCLUSION

This study appears to support the practice of the initial non-operative management of congenital PUJ obstruction, potentially reducing the number of early and/or unnecessary interventions. Further investigations and research are necessary to direct appropriate management.

Bilateral ureteral obstruction associated with Henoch-Schoenlein purpura

Renal involvement is common in Henoch-Schoenlein purpura (HSP) and, while ureteral obstruction has been described in patients with the disease, it is rare. We report a female with HSP who developed bilateral ureteral obstruction from peri-ureteral vasculitis and subsequent ureteral ischemia. Hydronephrosis and typical findings on contrast urography indicated the diagnosis.

[Burkitt lymphoma as a rare cause of hydronephrosis]

Involvement of the genitourinary tract by lymphoproliferative disorders is rare. Rapid proliferating Burkitt's lymphomas could mimic acute diseases. Due to the extreme chemosensitivity, the lymphoma is cureable and surgery should be done only for histology. Initial surgery should be restricted to acute abdominal complications or complete removal of localised resectable disease. In any case a multiagent chemotherapy is necessary.

Congenital defects in northern elephant seals stranded along the central California coast

Eleven cases of congenital anomalies were identified in 210 (5%) juvenile northern elephant seals (Mirounga angustirostris) found stranded along the central California (USA) coast from 1 January 1988 to 31 December 1995. Seven individuals had mild-to-moderate hydrocephalus involving the lateral ventricles bilaterally, or the lateral and third ventricles. Two animals had severe cardiac anomalies: hypoplasia of the right ventricle with overriding aorta, and ventricular septal defect. Other anomalies included single cases of hydronephrosis, focal pulmonary dysplasia, and congenital epidermal angiomatosis. Common intercurrent disease processes were verminous pneumonia and arteritis, verminous enteritis and coliti, and splenic and hepatic hemosiderosis. The more severe anomalies were considered to be the cause of debilitation and stranding. Milder anomalies were found incidentally during routine gross necropsy and histopathologic examination.

[A case of renal pelvic cancer associated with giant hydronephrosis of a horseshoe kidney]

A 71-year-old woman with loss of appetite was referred to our hospital. Imaging diagnosis revealed a large, cystically dilated left kidney with a solid tumor inside the cavity and right hydronephrosis. A chest X-ray revealed multiple metastatic lesions. A horseshoe kidney was found intraoperatively and left nephroureterectomy with partial cystectomy was performed. Histological diagnosis was poorly differentiated transitional cell carcinoma. She died of progressive pulmonary metastases 2 weeks after operation. This is the 19th case of a renal pelvic tumor associated with a horseshoe kidney reported in the Japanese literature. The diagnosis was confounded by the extreme dilation and deformity of the hydronephrotic kidney.

Influence of furosemide on the ureteric damage in a rat model of obstructive uropathy

Furosemide has been used in the diuretic renography and diuretic radionuclide scan to evaluate the severity of hydroureter and hydronephrosis. To elucidate the influence of furosemide on obstructed ureters, unilateral ligation of ureter was performed in 45 rats. Twenty-four of the rats received intramuscular injections of furosemide (6 mg/kg/day) after the third day postligation. Eight rats were sacrificed for examination on days 7, 10 and 14 after ligation, respectively. The remaining 21 untreated rats were also sacrificed for comparison. The severity of hydroureter and hydronephrosis in the ligated side of the furosemide-treated rats was significantly higher than that of the untreated rats. However, the histological changes in the treated and untreated rats showed no significant difference. The ultrastructural alterations aggravated along the course of ureteric obstruction. Intriguingly, the ultrastructural changes were significantly milder in the treated rats. We conclude that the administration of furosemide might increase the severity of hydroureter, but it does not accelerate the ureteric damage of the obstructed ureters.

Bilateral ureteric obstruction secondary to the prolonged use of tiaprofenic acid

There is increasing awareness that the long-term use of the non-steroidal anti-inflammatory agent tiaprofenic acid (Surgam) is associated with a severe form of cystitis. The condition is usually reversible with complete resolution of symptoms on stopping the drug. We present a case of tiaprofenic acid-induced cystitis resulting in bilateral hydronephrosis suggesting ureteric obstruction. The previous reported cases are reviewed and the risks of delay in withdrawal of the drug and of permanent ureteric damage are discussed.

[The surgical correction of hydronephrosis in children (the late results)]

Surgical interventions on 368 pelviureteral segments were made in 348 hydronephrosis patients under 14 years old. Bilateral disease occurred in 20 patients. Resection of the pelviureteral segment was performed with ureteropyeloplasty according to Anderson-Hynes-Kucera procedure. Good results were observed in 97.82% of cases followed-up from 1 to 2 years after the operation. Histological examination of the resected segments revealed structural changes in the wall of prepelvic part of the ureter primarily of congenital genesis, irrespective of low-polar vessels, high origin of the ureter, its fixed kink or narrowing. Irreversibility of structural lesions necessitated conduction of resection ureteropyeloplasty with creation of morphofunctionally patent pelviureteral anastomosis. High efficacy of the operation supports its pathogenetic validity. The effect persisted at the follow-up. After operative correction of hydronephrosis medication should be aimed at adequate therapy of pyelonephritis and stabilization of sclerosis in renal parenchyma, at improvement of immune status and urodynamics. Further follow-up, control of the kidneys in search for advanced postobstruction treatment are needed.

Nephrogenesis and renovascular development in angiotensinogen-deficient mice

Angiotensinogen-deficient mice provide a model to examine the roles of angiotensin II as a renal growth factor in vivo. We monitored nephrogenesis and renovascular development in angiotensinogen-deficient mice from Embryonic Day 13 (E13) to 4 weeks after birth. Northern analysis of homozygote (Atg-/-) mice confirmed the absence of angiotensinogen mRNA in the liver and the kidneys. Embryonic kidneys in Atg-/- mice from E13 to E18 exhibited active nephrogenesis, as also observed in Atg+/- mice and Atg+/+ mice. Furthermore, metanephroi harvested at E12 from Atg-/- embryos showed branching morphogenesis of ureteric bud and tubulogenesis similar to metanephrol from Atg-/- embryos grown with exogenous angiotensin II in serum-free culture. In newborn Atg-/- mice, we observed uniform dilation of the pelvis accompanied by a coarse medulla, which was not noted in Atg+/- or Atg+/+ mice. Hydronephrosis in Atg-/- mice continued, and renal papillae underwent atrophy for the 4 weeks after birth. Another characteristic aspect of the morphology of Atg-/- mice was the thickening of vascular walls as little as 2 weeks after birth. Immunohistochemistry revealed recruitment of renin in hyperplastic vascular smooth muscle cells (VSMC) in Atg-/- mice after 2 weeks. Electron microscopy confirmed that the majority of hyperplastic VSMC contained various sized renin granules with abundant endoplasmic reticulum. In situ hybridization demonstrated that expression of renin mRNA became prominent in parallel with hyperplasia of VSMC, as well as recruitment of renin protein. Furthermore, at 4 weeks, Atg-/- mice expressed alpha-smooth muscle actin in the mesangium, whereas none was ever found in that of Atg+/- mice and Atg+/+ mice. In conclusion, the renin-angiotensin system seems not be essential for nephrogenesis in vivo. Furthermore, hyperplasia of VSMC and expression of the smooth-muscle phenotype in the mesangium are inducible even in the absence of angiotensin II, with hypotension, in vivo.

Renal pelvic and ureteral carcinoma with huge hydronephrosis: US, CT, and MR findings

A 78-year-old man presented huge hydronephrosis with a calculus in the left kidney, and underwent left nephroureterectomy under the diagnosis of renal pelvic and ureteral tumor. Histological examination disclosed renal pelvic and ureteral tumors featuring mixed histologic types of carcinoma. Magnetic resonance (MR) imaging was superior to computed tomography (CT) in its complete, detailed demonstration of the renal pelvic lesions. The imaging characteristics of CT, MR imaging, ultrasonography, and retrograde ureterography were discussed in the report.

[The choice of the type of operation in hydronephrosis in children]

113 hydronephrosis children underwent Andersen-Hynes operation, 62 Calp de Werd operation. The ureteropelvic segment was examined morphologically. 3 macroscopic variants of ureteral structure and 5 variants of leiomyocyte presence in the muscular lining of the ureter are defined. Long-term follow-up results (1-10 years) are available. Resection gave positive results in 80%, graft plastic repair was effective in 92% of cases.

Vessels around the ureteropelvic junction: significance and imaging by conventional radiology

We studied the influence of vessels crossing the ureteropelvic junction and of the grade of hydronephrosis in 86 patients who underwent endoureteropyelotomy. With a follow-up ranging from 1 to 12 years, the presence of crossing vessels had a significant negative influence on the outcome and recurrence rate of the procedure. The success rate was 82% when no vessels were present but only 33% when crossing vessels were documented. In 13 of 15 failures (87%), a crossing vessel was found at open pyeloplasty. The degree of hydronephrosis was a less potent detrimental factor, with an 81% success rate in low-grade and 54% in high-grade hydronephrosis. The best results (90% success) were obtained in patients with no crossing vessels and low-grade hydronephrosis and the worst (30% success) in those with high-grade hydronephrosis in the presence of crossing vessels. Selection of patients according to those prognostic factors is recommended. Conventional intravenous urographic imaging techniques proved insufficient, and only angiography provided diagnostic accuracy; less-invasive methods are desirable.

Contrast-enhanced MRI with gadodiamide injection in rat disease models

The present study was designed to confirm the usefulness of contrast-enhanced magnetic resonance imaging (MRI) in diagnosing strokes of stroke-prone spontaneously hypertensive rats (SHRSP) and middle cerebral artery (MCA) occlusion, hepatocellular carcinoma and hydronephrosis of each experimental rat model. Male Sprague-Dawley rats (250-500 g), male SHRSP (ca. 250 g) and male F344 rats (ca. 300 g) were used for the investigation. Gadodiamide injection (Omniscan, Daiichi Pharmaceutical Co., Ltd. and Nycomed AS, Norway) was administered intravenously as the contrast agent at a dose of 0.1 mmol/kg except in hydronephrosis, where a dose of 0.05 mmol/kg was used. Magnetic resonance (MR) images were obtained with a 1.5T or a 2.0T magnetic field strength MRI unit. The signal intensity of the stroke lesions was increased after administration of gadodiamide injection in SHRSP and MCA-occluded rats. Hepatocellular carcinoma was undetectable without the use of the contrast agent, but the signal intensity of the tumor increased after administration of the gadodiamide injection, allowing the lesions to be detected. The signal intensity of the renal medulla increased in the non-ligated kidney, but not in the hydronephrotic kidney. The information given by the post-contrast images were superior to those obtained from the pre-contrast images in all the models. Contrast effects in SHRSP and MCA-occluded rats were related to differences in capillary permeability, those in rats with hepatocellular carcinoma depended on differences in vascularity, and those in hydronephrotic rats depended on blood flow and permeability.

Expression of subunits of the metalloendopeptidase meprin in renal cortex in experimental hydronephrosis

Meprin A is a metalloendopeptidase in the proximal tubular epithelium of rodents that is capable of hydrolyzing a great variety of peptides and proteins. The aim of the present investigation was to investigate effects of ureteral ligation on the expression of meprin subunits. Ureteral ligation resulted in marked decreases in the expression of both alpha- and beta-meprin subunits within 12 h of ureteral obstruction. Even greater downregulation of expression of meprin alpha- and beta-mRNA was noted at 24, 48, and 96 h after ureteral ligation. The greatest decrease in meprin mRNA expression in obstructed kidneys over contralateral unobstructed control kidneys (CUK) occurred at 24 h postunilateral ureteral obstruction (post-UUO) for the meprin alpha-subunit (20-fold decrease compared with controls) and at 48 h for the meprin beta-subunit (90-fold decrease). On immunolabeling, the intensity for the two meprin subunits at the corticomedullary junction was dramatically decreased at 24 to 96 h after ureteral ligation in contrast to the CUK specimens. Results of in situ hybridization indicated that the CUK specimens expressed meprin beta-mRNA at the corticomedullary junction, whereas the obstructed kidneys exhibited a decrease in mRNA signal for meprin beta-subunit. There was a steady increase in the interstitial macrophage number in UUO rat kidneys over the 96 h of evaluation post-UUO. ED-1-positive macrophages were observed almost exclusively in the peritubular cortical interstitial space in a ringlike pattern with a preponderance of macrophage clusters around glomeruli. Unexpectedly, after reversal of UUO, the interstitial macrophage number remained higher than controls, despite the demonstrable decompression of the renal pelvis and caliceal system. In summary, this investigation demonstrates downregulation of meprin alpha and beta within hours of UUO and indicates a novel tubular response to ureteral obstruction.

Ectopic ureter with complete ureteric duplication: conservative surgical management

To assess the outcome of conservative procedures, the authors reviewed their experience in the management of 31 ectopic ureters with complete ureteric duplication. Twenty-eight girls and three boys (aged 19 days to 10 years; mean, 30 months) were operated on between 1968 and 1994. Twenty-four of the children presented for evaluation of dribbling urinary incontinence and/or febrile urinary tract infections; seven presented after prenatal ultrasonographic diagnosis of hydronephrosis. The location of the ectopic orifice was identified in 25 children: bladder neck (6), posterior urethra (6), vagina (7), and vestibule (6). Upper pole nephroureterectomy was performed in 16 children who had nonfunctioning renal segments. Ureterovesical reimplantation was performed in 10 children who had functioning segments. In five borderline cases, temporary cutaneous ureterostomy was performed, followed by ureteropyelostomy (2), ureterovesical reimplantation (2), and upper pole nephrectomy (1). Histological examination of the polar nephrectomy specimens showed lesions of dysplasia in only four cases (24%). The follow-up period ranged from 6 months to 20 years (mean, 66 months). All children who presented with incontinence became continent after polar nephrectomy or conservative surgery. One child required surgical revision of the ureteropyelostomy anastomosis. Of the 12 children who had ureterovesical reimplantation, none needed further procedures. Ectopic ureters in duplex systems with functioning renal segments should be conserved.

Tissue factor expression in an animal model of hydronephrosis

BACKGROUND

Hydronephrosis is associated with interstitial fibrosis and occlusion of renal capillaries by fibrin. However, the mechanisms leading to fibrin formation is unknown.

METHODS AND RESULTS

Twenty days after unilateral ligation of the ureter, interstitial fibrosis occurred in the ligated kidney. Fibrosis was preceded by infiltration of inflammatory cells (macrophages, B and T lymphocytes). Staining with an antibody against von Willebrand factor demonstrated newly formed capillaries in the fibrosing tissue as well as prominent fibrin deposition. Fibrin staining was found around vessels, in the interstitium, the glomeruli, and tubuli. Fibrin deposition was less prominent in the non-ligated kidney and almost absent in sham-operated animals. The expression of tissue factor, the central initiator of coagulation, was induced within 5 days after ligation in the operated kidney but not in the sham-operated animals. Tissue factor positivity was observed by immunohistochemistry in vascular endothelial cells, the vessel wall, tubular epithelial cells, glomerular capsular cells, Bowman's space and in the interstitium. Tissue factor induction was due to increased transcription, since in-situ hybridization showed increased levels of mRNA in the ligated kidney compared to sham-operated rats. The tissue factor gene is under control of the transcription factors activator protein-1 (AP-1) and nuclear factor-kappa B (NF-kappa B). When extracts of operated organs were compared with kidneys of sham-operated rats or contralateral kidneys in electrophoretic mobility shift assays, an increase in AP-1 and NF-kappa B binding activity to their respective binding sites in the tissue factor gene was observed in the operated, but not in the contralateral kidney or kidneys of sham-operated animals.

CONCLUSION

Ureteral ligation leads to infiltration of inflammatory cells, increased AP-1 and NF-kappa B expression in the kidney, resulting in increased tissue factor transcription and translation, and ultimately in increased fibrin deposition.

The temporal relationship between the severity of hydroureter and the dynamic changes of obstructed ureters in a rat model

OBJECTIVE

To investigate dynamic changes in the obstructed rat ureter and to evaluate the usefulness of the rat model in the study of obstructive uropathy.

MATERIALS AND METHODS

Unilateral ligation of the ureter was performed in 26 rats. After ureteric ligation, four to seven rats were killed and examined after 1, 3, 7, 10, and 14 days. The severity of hydroureter and hydronephrosis was assessed by pyelography and the hydroureter-hydronephrosis index. The middle portion of the ureter was prepared for light and electron microscopic observation. Five rats which received a sham operation were also examined as controls.

RESULTS

The severity of hydroureter and hydronephrosis in the ligated ureters progressively increased during the period of obstruction (P < 0.005) and reached a maximum 10-14 days after ligation. Hypertrophy of the smooth muscle layer developed on the third day after ligation and proliferation of submucosal connective tissue occurred on the 10th day after ligation. The changes in smooth muscle and connective tissue layers also progressed consistently during ureteric obstruction (P < 0.001 and < 0.005, respectively). The number and size of granular endoplasmic reticulum and Golgi apparatus in the smooth muscle cells increased after ureteric ligation and then caveolae exocytosis developed. Deposition of collagen fibres between muscle cells became apparent later.

CONCLUSION

The rat model of hydrouropathy demonstrated a clear temporal relationship between the severity of hydroureter and the dynamic changes in the obstructed ureter and could be used as a conventional method for the study of obstructive ureter.

[MR urography with the T2-weighted turbo-spin-echo sequence]

Tumor-induced dilatation of the urinary tract is difficult to diagnose in the distal part of the ureter, including the stenosis, by ultrasound and X-ray. Often on account of renal insufficiency and allergy, i.v.-contrast media cannot be used. The present study should show the suitability of fast T2-weighted (turbo-) spin-echo sequences (T2-TSE) for MR-urography (MRU). Seven patients (62.3 +/- 6.1 years) were examined in the coronal plane with T2-TSE sequence (TR = 4500 ms, TE = 160 ms) and an MRU was calculated by using the MIP method (maximal intensity projection). This technique enabled urogram-like morphological representation of dilated urinary tract including stenosis in 6 of 7 patients. Assuming a high magnetic field homogeneity, MRU by using a T2-TSE-sequence, without i.v.-contrast media administration, can visualize the urinary tract dilatation and localize tumor-induced stenosis.

Renal preservation despite 35 days of partial bladder obstruction in the fetal lamb

To determine whether the increase in renal blood flow and preservation of renal function that we demonstrated after 10 days of chronic partial bladder obstruction in the third trimester fetal lamb also occur after earlier longer obstruction, we modified our preparation and studied the effects of 35 days of obstruction begun during the second trimester. Partial bladder obstruction was created in 10 fetal lambs at 90 days of gestation (term equals 147 days). At repeat surgical intervention 28 days later vascular catheters and a left renal artery flow transducer were placed, and catheters were externalized. We then studied renal blood flow and function at gestational ages 120 days and 125 days after 30 days and 35 days of obstruction, respectively. Tissue was obtained for histology at the time of sacrifice. Eight control fetal lambs without obstruction were studied in a similar way. Bilateral hydroureteronephrosis was noted in all fetal lambs after partial obstruction, whereas the kidneys and bladders of the control animals had a normal appearance. Renal blood flow was higher in the obstructed fetal lambs than in controls (20.2 +/- 4.9 versus 10.2 +/- 0.9 ml. per minute per kg., p < 0.05 after 30 days and 17.1 +/- 2.7 versus 9.7 +/- 0.9 per minute per kg., p < 0.05 after 35 days). There was no evidence of decreased renal function by any parameter and, in fact, glomerular filtration rate and urine volume were increased after 30 days of obstruction (1.59 +/- 0.32 versus 0.69 +/- 0.07 ml. per minute per kg., p < 0.05 and 15.7 +/- 4.3 versus 5.2 +/- 0.8 ml. per hour per kg., p < 0.05, respectively). Histological studies demonstrated normal architecture of the kidneys but thinned cortex. We conclude that the physiological responses of the fetus are such that partial lower urinary tract obstruction in our preparation results in a prolonged increase in renal blood flow and preservation of renal function.

Renal histological changes secondary to ureteropelvic junction obstruction

The treatment of children with apparent ureteropelvic junction obstruction is controversial. In an asymptomatic infant or child the decision to recommend pyeloplasty usually is based on interpretation of the renal scan. We retrospectively analyzed the renal biopsy obtained during pyeloplasty in 55 children. Histological changes were compared to the differential renal function revealed on the preoperative renal scan. Histological changes were graded on a scale of I to V; I--normal, II--mild dilatation of the collecting tubules or Bowman's space and III to V--progressively severe changes of obstructive uropathy, including reduced glomerular number, glomerular hyalinization, cortical cysts and interstitial inflammation. Patient age ranged from 4 days to 19 years (mean 4.8 years). Mean differential function according to histological grade was I--49%, II--43%, III--42%, IV--30% and V--25%. Of 33 patients with a differential function of 40% or greater 26 (79%) had a grade I or II biopsy, while 21% had a more significant alteration in renal histology. In contrast when the differential function was less than 40% 6 of 18 patients (33%) had grade I or II disease on biopsy. In conclusion, in approximately 25% of children with ureteropelvic junction obstruction there is a disparity between preoperative differential renal function computed during diuretic renography and renal biopsy.

Correlation of renal biopsy and radionuclide renal scan differential function in patients with unilateral ureteropelvic junction obstruction

To understand better the relationship among radionuclide renal scan differential function, renal histology and the outcome of pyeloplasty we performed ipsilateral renal biopsies in a series of patients undergoing primary pyeloplasty. A total of 17 consecutive patients with unilateral ureteropelvic junction obstruction underwent renal biopsy at the time of pyeloplasty. Biopsies were examined systematically after sections were stained with hematoxylin and eosin, periodic acid, Schiff, Jones modified silver or Masson trichrome stains, and they were reviewed by 1 pathologist. Biopsy results were correlated with preoperative and postoperative radionuclide renal scan differential functions. Patient age ranged from 1 month to 7 years (mean 19.8 months). Renal biopsy was abnormal in 6 kidneys, of which 5 had a preoperative differential function of less than 33%. None of these kidneys had evidence of postoperative improvement in renal function on followup scans despite a technically successful result. All remaining 11 kidneys had normal biopsies and a preoperative differential function of greater than 44%. We conclude from these data that patients with ureteropelvic junction obstruction with a differential function of less than 35% have a high probability of significant histological changes on biopsy and a low probability of postoperative improvement in differential function.

Macrophages and progressive renal disease in experimental hydronephrosis

Many recent clinical and experimental studies have clearly demonstrated that one of the initial events taking place in the process of progressive renal injury is monocytic infiltration of the glomerular and tubulointerstitial compartments. In this report, experimental data supporting the role of the infiltrating renal macrophage (M phi) as a mediator of interstitial fibrosis during the course of obstructive nephropathy will be reviewed as it pertains to the unilateral ureteral obstruction model in the rat. The central pathobiologic theme drawn on data from this model is that fibrogenic cytokines, especially transforming growth factor-beta, are, in part, M phi-derived and represent pivotal links between the initial postobstructive renal inflammation and the late development of renal scarring. The tubular epithelium, as a consequence of the mechanical disturbance produced by ureteral obstruction, may elaborate a host of M phi chemoattractant moieties. Many substances can be released by these infiltrating M phi; however, our studies have focused on transforming growth factor-beta 1. Transforming growth factor-beta is an important regulator of extracellular matrix, through its direct effects and modulation of other growth factors to maintain matrix homeostasis. We propose that the markedly increased expression of transforming growth factor-beta 1 following ureteral ligation, as detected by a number of laboratories, induces a profibrogenic state and initiates a cascade of dysregulatory events, including the upregulation of tissue inhibitors of metalloproteinase. Transforming growth factor-beta 1 also may serve as a potent stimulus for the modulation of quiescent interstitial fibroblasts into myofibroblasts. From a therapeutic standpoint, targeting these early cellular and molecular events may be extremely important in interrupting the interstitial fibrotic response to long-term obstructive uropathy.

[Pseudocystic ureteritis. Apropos of a case]

The authors report one case of ureteritis cystica in a young adult. The diagnosis was made by intravenous urography and confirmed by histologic examination. The patient was treated surgically (nephro-ureterectomy). The etiopathogenic, clinical and therapeutic aspects are discussed with a review of literature.

Myofibroblasts in experimental hydronephrosis

Interstitial fibrosis is a common outcome of longterm ureteral obstruction. One pathological arm of the fibrotic reaction in diverse tissue loci and experimental models is the retraction of granulation tissue. The role of the myofibroblast in granulation tissue contraction and fibrocontractive diseases has been well established, but the mechanisms leading to differentiation of fibroblastic cells into myofibroblasts during the evolution of inflammation are not yet fully clarified. Investigators using other model systems have shown that macrophage-derived transforming growth factor-beta 1 (TGF-beta 1) may be pivotal in the process of myofibroblast modulation. Our laboratory has shown that the unilateral ureteral obstruction in the rat is characterized by a 20-fold increment in infiltrating renal cortical interstitial macrophages, an increase in cortical TGF-beta 1 gene expression, which parallels the infiltrating macrophage burden, and immunolocalization of this peptide growth factor in close proximity to resident interstitial fibroblasts. Because of this model's features, it was our aim to assess whether a myofibroblastic modulation was operant in the renal cortex of obstructed rat kidneys versus the control contralateral unobstructed kidney specimens. Immunolabeling for alpha-smooth muscle actin and the intermediate filament protein, desmin, was detected and steadily intensified from 24 to 96 hours after unilateral ureteral obstruction in obstructed kidneys only. In temporal concert with the detection of alpha-smooth muscle actin protein, the mRNA expression for this cytoskeletal component exhibited 3.7-, 15.7-, and 4.1-fold increments in the renal cortex of obstructed kidneys versus the contralateral unobstructed kidney specimens at 24, 48, and 96 hours after unilateral ureteral obstruction, respectively. Whole body X-irradiation, administered to rats 11 days before proximal left ureteral ligation, significantly lowered cortical interstitial macrophage number, cortical TGF-beta and alpha-smooth muscle actin mRNA levels as well as the intensity of immunolabeling for alpha-smooth muscle actin from 12 to 96 hours after unilateral ureteral obstruction. These data support a postulate that renal cortical TGF-beta 1, derived from the infiltrating macrophage, in part, contributes to the subsequent interstitial fibrosis response to renal injury by fostering the modulation of fibroblasts to myofibroblasts within the renal cortex after ureteral obstruction.

Trisomy 7 in nonneoplastic epithelial kidney cells

Trisomy 7 has been found as the sole clonal chromosome aberration in a number of tumor types, including renal cell carcinomas (RCC), and also in non-neoplastic kidney tissue. It has recently been proposed that the cells harboring trisomy 7 in RCC and in the surrounding tissue may be tumor infiltrating T-helper lymphocytes. We performed cytogenetic analysis of metaphase cells and FISH of interphase nuclei in uncultured and cultured non-neoplastic kidney tissues from 13 patients with renal or urothelial carcinomas, and 4 patients with inflammatory kidney diseases. FISH analysis showed that the frequency of +7 varied between 1.0-8.9% (mean 3.3%) in uncultured cells and between 0.4-8.6% (mean 4.4%) after one week of cell culture. The frequency of +7 after one week of culture was 1.0-19.0% (mean 6.1%) as determined by cytogenetic analysis. Immunoenzymatic staining of both uncultured and cultured cells with the alkaline phosphatase reaction and monoclonal antibodies for CD3 showed that the frequency of T-cells in uncultured cells and in primary cultures varied between 2.9-10%. The number of T-cells decreased with time and number of in vitro passages to less than 1% after 7-8 weeks, but the frequency of +7 remained fairly constant. Combination of FISH with immunostaining using CD3 for T-lymphocytes and cytokeratins for epithelial cells showed that the cells with +7 were mainly epithelial cells whereas only 0-5% were T-lymphocytes. The results have obvious implications for the interpretation of the significance of trisomy 7 in neoplasia.

Long-term urethral catheterization increases risk of chronic pyelonephritis and renal inflammation

OBJECTIVE

To determine the prevalences of chronic pyelonephritis and chronic renal inflammation in elderly nursing home patients at the time of death and to assess correlation with urethral catheterization and other putative risk factors.

DESIGN

Prospective assessment of risk factors with the prevalences of chronic pyelonephritis and renal inflammation at autopsy.

SETTING

A 240-bed long-term care facility.

PARTICIPANTS

All residents > or = 65 years old who died and were autopsied during a 2-year period.

MEASUREMENTS

Antemortem assessment of risk factors for renal inflammation, including a search for any urethral catheterization in the person's life. Prospective assessment of urethral catheterization, catheter obstruction, and use of anti-inflammatory medications and urine cultures. Urinary tract pathology was assessed for gross and microscopic evidence of inflammation and urinary tract stones.

RESULTS

The duration of catheterization was significantly associated with increasing prevalence of bacteriuria, polymicrobial bacteriuria, chronic pyelonephritis, and chronic renal inflammation. The prevalence of chronic pyelonephritis at death was 10 percent (5/52) for patients catheterized > 90 days during their last year of life and zero (0/65) when catheterized < or = 90 days (P < 0.02; Fisher's exact test). Chronic pyelonephritis was significantly associated with renal stones and hydronephrosis. The prevalence of chronic renal inflammation without chronic pyelonephritis was significantly greater than that of chronic pyelonephritis: the prevalence was 43 percent (20/47) when catheterized > 90 days and 18 percent (12/65) when < or = 90 days (P < 0.05). Chronic renal inflammation was associated with hydronephrosis, ureteral dilatation, acute pyelonephritis and diastolic hypertension.

CONCLUSION

Chronic pyelonephritis and chronic renal inflammation are associated with long-term catheterization.

Pathology of urinary tract malformations in a paediatric autopsy series

In a series of 3172 consecutive autopsies of stillbirths, infants and children performed over a 12-year period from 1978 to 1989 at the Department of Pathology, Outram Road, Singapore, urinary tract malformations were found in 78 cases (2.5%). The urinary tract abnormalities were of 6 major groups: hydronephrosis and/or hydroureter (35.9%), cystic disorders (29.5%), renal agenesis (26.9%), horseshoe kidney (11.5%), renal hypoplasia (5.1%) and pelvic kidney (1.3%). Other series have reported incidences of urinary tract malformations ranging between 2.7% and 11%, depending on the source of the study material. Our local incidence appears to fall below the lower end of the scale, but may not reflect an accurate comparison because of the differences in the denominational base.

Hydronephrotic type of bilateral multicystic dysplastic kidney. An unusual case

25 year-old pregnant woman was admitted at week 29 of fetal development for routine ultrasonic evaluation of growth. Sonography of the fetal body revealed two cystic anechoic septated structures bilaterally. At autopsy of the stillborn neonate pathology confirmed congenital multicystic dysplastic kidney. We believe this is the first case reported.

Renal tubular apoptosis after partial ureteral obstruction

Partial ureteral obstruction in the weanling rat leads to hydronephrosis of the ipsilateral kidney and renal cell deletion through the process of programmed cell death known as apoptosis. The apoptotic response following partial ureteral obstruction in weanling Sprague-Dawley rats was studied using the traditional markers of apoptosis, including deoxyribonucleic acid (DNA) laddering pattern on agarose gel electrophoresis, in situ gap labeling of fragmented DNA for quantitative apoptotic body determination, polyadenylated messenger ribonucleic acid (mRNA) expression of sulfated glycoprotein-2, and polyadenylated mRNA expression of epidermal growth factor and transforming growth factor-beta. Partial ureteral obstruction resulted in a progressive increase in the intensity of DNA fragmentation associated with apoptosis during the initial 3 weeks. Quantitative apoptotic body counting revealed a 3-fold increase by week 3 of partial obstruction. This increase represented a level of apoptosis, which is 65% of that observed in complete ureteral obstruction. By week 2 of partial obstruction there was a 13-fold increase in the expression of sulfated glycoprotein-2 mRNA, as well as changes in the growth factor environment characterized by a decline in the constitutive expression of epidermal growth factor mRNA and an increase in the expression of transforming growth factor-beta mRNA. These altered levels represent changes in expression comparable to those observed during the apoptotic response following complete ureteral obstruction, although the time course is delayed by 2 to 3 weeks.

Contradictory supranormal differential renal function during nuclear renographic investigation of hydroureteronephrosis

We selected a group of children with unilateral hydroureteronephrosis to assess the significance of the differential renal function as determined by nuclear renography as a factor in defining obstructive dilatation. All children who presented to our institution during a 21-month period with unilateral hydroureteronephrosis and a normal contralateral kidney were reviewed. Patients with reflux or bladder pathology were excluded, resulting in 13 evaluable patients younger than age 2 years. Diuretic renography was performed using 99mtechnetium-diethylenetriaminepentaacetic acid in accordance with the well tempered renogram. Ancillary studies included voiding cystourethrography, ultrasonography and/or excretory urography. Of the 13 patients 5 had a differential function greater than 55% in the hydronephrotic kidney. Ten of the 13 patients, including the 5 with supranormal function, underwent surgical correction in the form of ureteral reimplantation for recurrent infections, increasing hydronephrosis, decreasing or decreased function and loss of parenchyma. Stenotic distal adynamic ureteral segments with proximal dilatation were confirmed in all cases. The implication by nuclear renography that a dilated kidney has better function than its morphologically normal counterpart is at variance with any available clinical or experimental data. The etiology of this apparently elevated function is unclear and its presence on a renographic study should not be interpreted as suggestive that the kidney is free of risk of nephron loss. Management decisions should not be based solely on the differential function as determined by nuclear renography.

Effects of angiotensin converting enzyme inhibition on glomerular number, juxtaglomerular cell activity and renin content in experimental unilateral hydronephrosis

OBJECTIVE

To determine the effects of hydronephrosis on glomerular number and juxtaglomerular cell synthetic activity and the protective influence of angiotensin converting enzyme inhibition.

DESIGN

A comparison of sham and contralateral kidneys with 8-week ipsilateral ureteral ligated hydronephrotic kidneys in BALB/c mice. Enalapril was administered from 5 weeks in additional sham and hydronephrotic kidney groups.

METHODS

Renin and prorenin immunohistochemistry was applied to sections of perfusion-fixed kidneys at the light and electron microscope level. Glomerular number was estimated by a physical disector-fractionator stereological method. An enzyme kinetic renin assay was performed in kidney tissue and plasma.

RESULTS

Glomerular number in hydronephrotic kidneys decreased significantly compared with sham and contralateral kidneys. Renin content in hydronephrotic kidneys did not change compared with sham or contralateral kidneys, but the renin content in the glomerulus was significantly greater in hydronephrotic than in contralateral kidneys and similar to in sham kidneys. Contralateral kidneys enlarged significantly and their total renin content decreased significantly compared with hydronephrotic and sham kidneys. Plasma renin was unchanged. Fewer juxtaglomerular cells were labelled for renin and prorenin in contralateral than in hydronephrotic or sham kidneys. Granulopoiesis and exocytotic profiles were markedly greater in hydronephrotic than in contralateral or sham kidneys. Following enalapril, glomerular number was significantly higher in hydronephrotic kidneys and renin content increased proportionally more in contralateral than in hydronephrotic or sham kidneys.

CONCLUSION

Hydronephrosis for 8 weeks results in atrophy of 50% of glomeruli and exerts an inhibitory influence on contralateral juxtaglomerular cells while augmenting ipsilateral renin production per remaining glomerulus with maintenance of plasma renin. Enalapril preserves glomeruli and reverses the contralateral inhibitory influence, suggesting an angiotensin-related mechanism.

Chronic hydronephrosis: renographic drainage patterns and renal morphology in an animal model

OBJECTIVE

To develop an animal model of chronic progressive hydronephrosis; to establish patterns of diuretic renography during development of the condition; and to relate renographic abnormality to morphological change in the renal parenchyma.

MATERIALS AND METHODS

The cellophane sclerosis technique was used to produce a hydronephrosis in the left kidney of six rabbits. Post-operatively MAG3 diuretic renography was performed at weekly intervals. When a steady renographic trend was noted the rabbits were killed and the kidneys examined histologically.

RESULTS

Four rabbits had persistent type II renographic curves on the left for 12 weeks. The measured split renal function fell steadily to < 20% in this time. Morphologically there was hydronephrosis with marked structural changes in the parenchyma seen on histological examination. Two rabbits had stable type IIIa renographic drainage patterns on the left with preserved renal function. Morphologically there was hydronephrosis but histologically the kidneys were normal. There were no renographic or structural changes in a control rabbit after a sham laparotomy.

CONCLUSIONS

The cellophane sclerosis technique can be used to create a reproducible chronic progressive hydronephrosis. In this animal model hydronephrosis and a persistent type II curve are associated with renographic evidence of deteriorating renal function and disruption of renal architecture histologically. Hydronephrosis and a type IIIa curve are associated with preservation of normal renal function and histological structure.

Evaluation of RARE-MR urography in the assessment of ureterohydronephrosis

OBJECTIVE

The goal of this prospective study was to evaluate the value of the fast imaging sequence called RARE-MR urography (RMU) for the diagnosis of ureterohydronephrosis.

MATERIALS AND METHODS

Sixty-nine patients underwent this procedure. The results were compared with those obtained by intravenous urography (IVU) and ultrasonography (US).

RESULTS

The accuracy of RMU in the detection of urinary tract dilatation and the localization of the level of obstruction was excellent (100%). The determination of the type of obstruction, intrinsic versus extrinsic, was 80% by IVU and 60% for RMU. The RMU sequence alone could not specify the nature of the obstruction. Functional information about the obstructed collecting system could not be obtained.

CONCLUSION

The RMU technique may be considered in the following circumstances: contraindications to IVU (allergy to contrast medium, severe renal failure), impairment of renal excretion, and failure to locate the level of obstruction by US. The absence of ionizing radiations favors the promotion of this procedure to study ureterohydronephrosis during pregnancy.

[Hydronephrosis as the first manifestation of primary metastatic breast cancer]

Hydronephrosis as the first symptom of primary metastasised breast cancer is described in two case reports. The literature regarding this topic is also discussed. Although retroperitoneal metastases are rarely found, patients with breast cancer should undergo a regular sonographic control of the kidneys, simultaneously with the routine ultrasound of the upper abdomen.

[The characteristics of an acute infectious-inflammatory process in the single remaining kidney (experimental and clinical study)]

The paper is concerned with acute pyelonephritis pathogenesis in patients with a solitary kidney. Upon nephrectomy, the remaining kidney undergoes compensatory-adaptive processes giving rise to injury of the first barrier of the local nonspecific resistance. This results in more rapid and severe course of acute pyelonephritis, development of pyodestructive disease, protracted run. Active surgical policy in acute obturation pyelonephritis in patients with a single kidney, early recovery of adequate urine outflow can prevent progression to destructive pyelonephritis and advance treatment results.

[Histological study of fetal hydronephrosis. Development background of prenatal treatment]

It is still unclear whether prenatal decompression of the dilated urinary tracts can preserve renal development and function. Following the previous report on the relationship between the nephrogenesis and the gestational weeks in normal fetuses, we studied the hydronephrotic kidneys to find the histological background of the fetal treatment. Of the fetuses autopsied in the Department of Pathology of our Institute from 1982 to 1992, 32 kidneys from 21 fetuses associated with dilatation of the upper urinary tracts irrespective of the presence of urethral obstruction on macroscopic inspections were reviewed. The underlying disorders causing hydronephrosis included urethral obstruction in 7, vesico-intestinal fissure in 3, hydrometrocolpos in 2 and double ureter in 1. The etiology of the hydronephrosis was not clarified in another 8. The position and configuration of the ureteral orifices were not described in the autopsy reports. Microscopic examination was done to define the radial glomerular count (RGC), presence or absence of the nephrogenic zone, cortical cysts and dysplastic elements, changes of the collecting tubules and interstitium. Of the kidneys 19 had cortical cysts of various sizes. In some kidneys, the normal cortex was mixed with pathological segments where there were subcapsular small cysts and tubular dilatation. Nephrogenic zone, which was observed in specimens of 33-weeks fetus with moderate hydronephrosis, was already missing by 28 weeks in severe hydronephrosis. Collecting tubules were dilated in 12 kidneys with mild to moderate hydronephrosis. Tubular atrophy and increase in the interstitium were seen in 12 kidneys, eleven of which were of the fetus over 30 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

A quantitative study of normal nephrogenesis in the human fetus: its implication in the natural history of kidney changes due to low obstructive uropathies

An evaluation of nephrogenesis according to fetal age was performed by quantifying the state of the nephrogenic blastema (NB) and the number of glomeruli (GN) on frontal renal sections in 99 control fetuses (gestational age ranging from 9 to 40 weeks) and in 17 aborted fetuses with low urinary tract obstruction (gestational age ranging from 14 to 36 weeks). In the control group, GN increases slowly from the 10th to the 18th week, then abruptly from the 18th to the 32nd week, reaching an upper limit with NB disappearance by the 32nd week. In the uropathy group, the renal changes show a wide range of severity clearly accounted for by the impairment of both NB and GN. The dysplastic effect of urinary backpressure is the more consistent pathogeny with the spectrum of observed renal changes. It is likely, from GN used as a time-dependent marker of renal development, that the most severe dysplasia is the result of early obstruction with abnormal disappearance of NB and subsequent arrest of nephrogenesis.

Response of the newborn ureteropelvic junction complex to induced and later reversed partial ureteral obstruction in the rabbit model

The clinical controversy regarding the timing of surgery for asymptomatic newborns with obstructed hydronephrosis was addressed using a model of reversible partial ureteral obstruction in the newborn rabbit. The histomorphometric changes in the ureteropelvic junction complex (for example, pelvis, ureteropelvic junction and upper ureter) and kidney in 44 normal cases were determined and compared with the effects of 47 cases of ongoing partial obstruction and timed reversal of partial obstruction at 1 week in 9 cases, at 2 weeks in 10 or at 4 weeks in 10 (end of the study at age 8 weeks). After partial obstruction hydronephrosis appeared by 1 week postoperatively. There were progressive increases in the thickness of the lamina muscularis and mass index of smooth muscle and collagen (all p < 0.001). However, since the per cent surface area of smooth muscle did not change significantly in comparison to normal, there was disproportionately more collagen. For reversals at 1 week the muscle and collagen in the lamina muscularis were not significantly different from normal. For reversals at 2 weeks the mass index of collagen was greater than normal (p < 0.05) and reversal at 1 week (p < 0.05). For reversals at 4 weeks the lamina muscularis was thicker, and the mass index of collagen and muscle was greater than the earlier reversal groups and normal (all p < 0.05). In conclusion, partial ureteral obstruction causes progressive thickening of the lamina muscularis by collagen and muscle with a disproportionately greater increase in collagen than muscle. The earlier the obstruction can be reversed, the more normal is the ureteropelvic junction complex histology. The functional significance of these changes needs to be determined.

[Gigantic pyohydronephrosis and contralateral ureteral bud. Problems of differential diagnosis]

Both giant hydronephrosis and blind-ending ureteral bud are rare conditions. We report on a patient with an impacted ureteral stone leading to giant pyohydronephrosis (6.51) on the right side, which in turn caused displacement of the ureter containing the stone to the left. An asymptomatic blind-ending ureteral bud initially complicated the diagnosis. After nephrectomy, a unsuspected transitional cell carcinoma of the right renal pelvis and the ureter was found.

[Effect of hydronephrosis on the contralateral blood flow and glomerular volume]

We designed a following experiment to appraise the effect of unilateral hydronephrosis on the contralateral kidney using weanling rats whose kidneys were in a growing stage. Rats were divided into 4 groups. Complete unilateral (left) ureteral obstruction (CUUO) was made on the experiment rats, and these went through the following procedures on the day 3 after CUUO; 1) Group R: CUUO released, 2) Group N: left nephrectomy performed, 3) Group S: CUUO continued. Sham-operations were performed on the days 0 and 3 to the controls. Renal cortical blood flow and glomerular volume of the contralateral (right) kidneys were determined on the days 5, 7, 9, 14 and 21. Blood flow to the renal cortex per unit volume (ml/min/100 cm3; measured with Laser blood perfusion monitor) in the contralateral kidneys increased gradually in the all groups, but statistical significance was not confirmed in the observed period between any groups. Increases in total renal blood flow (wet kidney weight times renal cortical blood flow per unit volume; g x ml/min/100 cm3) were proportional to the measured wet kidney weight in the all groups. Notably in the group N, a significant increase was noted compared to the group R and the controls. Glomerular volume (GV) of the contralateral kidneys did not show significant changes on the day 3 compared to the controls. GV significantly grew up during the day 5 to the day 14 (2 to 11 days after the relief of CUUO) in the group R and then it settled to the level of the controls on the day 21.(ABSTRACT TRUNCATED AT 250 WORDS)

[Abdominal actinomycosis]

Twelve years after adnexectomy, performed for actinomycosis of the left ovary, a 32-year-old woman developed abdominal and back pain. A solid tumour was palpated in the left lower abdomen. Colon contrast examination revealed a subtotal stenosis in the sigmoid colon, while sonography showed a complete stenosis of the left ureter with left hydronephrosis. Relaparotomy demonstrated a stone-hard tumour at the rectosigmoid junction, which involved the right ovary and ureter, as well as having infiltrated the retroperitoneum, predominantly on the left. After resection of the sigmoid colon, uterus and right ovary, as well as of the ureteric stenosis with reanastomosis, the further course was without complication. Histological examination confirmed actinomycosis of the left ovary, sigmoid colon and pelvic mesocolon. Therapy with amoxycillin, 500 mg three times daily, was started. As the patient had worn an intrauterine pessary for several years, primary infection of the uterus with spread into the abdominal cavity via tube and ovaries is likely to have been the course of events. The recurrence was probably caused by reactivation of residual actinomycetes in the retroperitoneum and pelvic mesocolon.

[Hydronephrosis in a horseshoe kidney]

The authors studied hydronephrosis characteristics for horseshoe kidney in 170 patients aged 15-70. Basing on anatomic and functional features and urethral condition in each patient 136 operative interventions on one or two parts of the fused kidney in 125 patients were conducted. 26 heminephrectomies were carried out in hydronephrosis stage III, pyonephrosis and acute purulent focal pyelonephritis. 110 stage I-II hydronephrosis patients underwent an original reconstructive combined surgery on the fused kidney ending in formation of two separate organs. High incidence of hydronephrosis in horseshoe kidney against that in normal kidney (64 and 7%, respectively) and not infrequent bilateral involvement (63%) can be explained by anomalous structure of the organ conducive to obstruction of the urinary tracts. In 136 surgical cases the obstruction was due to: peripelvic compression of the ureter above the isthmus of the kidney (128 cases), high branching of the ureter from the renal pelvis with formation of the "spur" (114 cases), periurethritis and the fixed peripelvic ureteral kink by the adhesions (64 cases), congenital stricture of the peripelvic ureter (42 cases) or its compression by the accessory vessel (12 cases). To correct these abnormalities, it is reasonable to employ reconstructive surgery proposed by E. M. Shimkus. The procedure implies the isthmus resection with renal segment part, resection of the lower calyx, pelvic plasty according to Anderson-Hines technique, pyelolithotomy and nephropexy. This surgery abolishes all the underlying causes of fused kidney hydronephrosis and reestablishes urodynamics. It secured positive results by 2-28-year follow-up in 95% of the patients and is recommended as a method of choice.

[The effect of unilateral ureteral obstruction on the contralateral renal growth in weanling rats]

The effect of unilateral hydronephrosis on the growth of contralateral kidney were evaluated with weanling rats of which kidneys were in growing stage (body weighted between 80 g and 90 g). These rats underwent complete unilateral ureteral obstruction (CUUO) on day 0. They were divided into 3 groups and went through second operations on day 3 (CUUO-3) as follows; a) CUUO released, b) nephrectomy performed and c) CUUO continued. Sham-operation was performed on day 0 and on day 3 to the controls. Wet weights and bromodeoxy-uridine (BrdU) labeling index (L.I.) (index for cell proliferation in the uriniferous tubules) of the contralateral kidneys were measured for the evaluation. The wet weights were significantly higher in all the groups than that of the controls throughout the observation period on and after the day 3. The group that underwent nephrectomy demonstrated a sharp rise in L.I. after the day 7. In the group that was continued in CUUO, the L.I. started to rise later than its rise in nephrectomised group but the index caught up at the time when the blood flow completely disappeared in the kidneys of the ligated side. L.I. in the group of which CUUO was released became significantly higher than that of controls on the day 7 and remained its significance until the day 21 in spite of resolution of the hydronephrosis. To reveal the effect of length of obstructed term, the same trial was carried out that rats endured in CUUO for 5 days (CUUO-5) till the second operation. This turned out lower L.I. in the CUUO-5 than the CUUO-3. These results suggest that the presence of hydronephrosis made by CUUO suppress the growth (cell proliferation) of contralateral kidney and also duration of obstruction can be critical on the renal growth that shorter obstructed period turns out preferable for cell proliferation after relief of CUUO.