TNF-alpha neutralization ameliorates obstruction-induced renal fibrosis and dysfunction.

Upper urinary tract obstruction results in tubulointerstitial fibrosis and a progressive decline in renal function. Although several inflammatory mediators have been implicated in the pathophysiology of renal obstruction, the contribution of TNF-alpha to obstruction-induced fibrosis and renal dysfunction has not been thoroughly evaluated. To study this, male Sprague-Dawley rats were subjected to left unilateral ureteral obstruction vs. sham operation. Rats received either vehicle or a pegylated form of soluble TNF receptor type 1 (PEG-sTNFR1) every 84 h. The kidneys were harvested 1, 3, or 7 days postoperatively, and tissue samples were analyzed for TNF-alpha expression (ELISA), macrophage infiltration (ED-1 staining), transforming growth factor-beta(1) expression (ELISA, RT-PCR), collagen I and IV activity (Western Blot, immunohistochemistry), alpha-smooth muscle actin accumulation (immunohistochemistry, Western blot analysis), and angiotensinogen expression (Western blot). In a separate arm, the glomerular filtration rate (inulin clearance) of rats subjected to unilateral ureteral obstruction in the presence of either vehicle or PEG-sTNFR1 was determined. Renal obstruction induced increased tissue TNF-alpha and transforming growth factor-beta(1) levels, collagen I and IV activity, interstitial volume, alpha-smooth muscle actin accumulation, angiotensinogen expression, and renal dysfunction, whereas treatment with PEG-sTNFR1 significantly reduced each of these markers of renal fibrosis. These results demonstrate that TNF-alpha mediates obstruction-induced renal fibrosis and identify TNF-alpha neutralization as a potential therapeutic option for the amelioration of obstruction-induced renal injury.

Use of the mobilized sinus with total urogenital mobilization.

PURPOSE: The surgical treatment of urogenital sinus anomalies has undergone significant advances in recent years. Total urogenital mobilization, which mobilizes the urogenital sinus, vagina and urethra en bloc toward the perineum, represents one of these advances. MATERIALS AND METHODS: We have improved our results with total urogenital mobilization by incorporating the mobilized urogenital sinus tissue into the repair rather than discarding it, as described originally. We have found this a readily available, easily manipulated and well vascularized flap that is a significant aid to reconstruction. RESULTS: We present our 3 favored means of using the mobilized sinus tissue to create a mucosa lined vestibule, a posterior vaginal wall flap and an anterior vaginal wall flap. CONCLUSIONS: We believe that our techniques result in a further advancement in the cosmetic and surgical outcomes in these patients, and are beneficial in the reconstructive surgery armamentarium.

Total continence reconstruction: a comparison to staged reconstruction of neuropathic bowel and bladder.

PURPOSE: Surgical treatment for neuropathic bowel and bladder has become an essential tool in maximizing the quality of life in patients with myelomeningocele. We present our results comparing results in patients who underwent total continence reconstruction of the urinary and gastrointestinal tracts to patients who underwent a separate or single operation. MATERIALS AND METHODS: We performed a retrospective chart review of all patients with myelomeningocele at our institution who underwent reconstruction with a cutaneous catheterizable urinary channel or Malone antegrade continence enema. We compared outcomes with regard to surgical revisions of the channel between patients who underwent the construction of each simultaneously, that is total continence reconstruction, to outcomes in those with a single channel or who underwent reconstruction at 2 or more operations. RESULTS: Most of our patients underwent genitourinary and gastrointestinal reconstruction, and few desired surgical intervention for only a single system. We were unable to find any differences in the continence rate or stomal complications. However, patients who underwent staged reconstruction usually had significant secondary reasons for repeat surgery. CONCLUSIONS: Surgical success for urinary and fecal continence can be safely and effectively achieved through single or multiple procedures. However, because of shared pathophysiology, we believe that most patients benefit from intervention in the gastrointestinal and the genitourinary tract. Therefore, a major advantage of total continence reconstruction is avoidance of the morbidity of a second major surgical procedure.

What is the need for additional bladder surgery after bladder augmentation in childhood?

PURPOSE: Bladder augmentation has revolutionized the care of children with a neuropathic bladder but it remains a major surgical procedure. However, the need for subsequent bladder surgery has not been well defined in a large series with long-term followup. MATERIALS AND METHODS: We retrospectively reviewed the records of the first 500 bladder augmentations performed from 1978 to 2003 at our institution. Charts were reviewed for complications requiring additional surgery, including malignancy, bladder perforation, repeat augmentation, bowel obstruction and bladder calculi. Mean and median followup was 13.3 years. RESULTS: Complications occurred in 169 patients (34%) resulting in a total of 254 surgeries. The cumulative risk of further surgery at the bladder level was 0.04 operations per patient per year of augmentation. Three patients (0.6%) had transitional cell carcinoma, of whom all presented with metastatic disease and died. Bladder perforation occurred in 43 patients (8.6%) with a total of 53 events. Of the patients 16 (3.2%) required laparotomy for bowel obstruction and 47 (9.4%) required repeat augmentation. Bladder stones were treated in 75 patients (15%), who required a total of 125 surgeries. CONCLUSIONS: Bladder augmentation provides immeasurable improvements in quality of life but it requires lifelong dedication from the patient, family and health care providers. While the requirements for additional surgery are not trivial, 66% of our patients have not required any further surgery in the augmented bladder.

Treatment of the occult tethered spinal cord for neuropathic bladder: results of sectioning the filum terminale.

PURPOSE: Occult tethered cord syndrome applies to patients with signs and symptoms consistent with a caudal spinal cord malformation despite normal neuroimaging. Although several reports of successful surgical treatment exist, controversy remains with respect to patient selection and efficacy. We present a large series with excellent clinical followup, neuroimaging and urodynamic characterization. MATERIALS AND METHODS: We present our experience with 36 patients at a single institution with preoperative clinical findings, neuroimaging and urodynamics available. Postoperative outcomes were assessed clinically and with urodynamics. We determined predictive parameters to improve patient selection. RESULTS: Approximately 0.04% of pediatric urology clinic visits resulted in neurosurgical referral for the potential of an occult tethered cord. They occurred after failure of a mean of 2 years of aggressive medical management. Daytime urinary incontinence was present in 83% of patients and 47% had encopresis. Preoperative urodynamics were markedly abnormal in all patients with mean bladder capacity 55% of expected capacity. Clinical improvement in urinary symptoms was seen in 72% of patients with resolution of incontinence in 42%. Bowel symptoms improved in 88% of cases, including resolution of encopresis in 53% within 3 months of surgery. Urodynamic improvements were demonstrated in 57% of cases. We were unable to determine preoperative factors that were more likely associated with surgical success. CONCLUSIONS: In a highly select population with severe urinary and fecal dysfunction sectioning a normal-appearing filum terminale can result in significant improvement. We were unable to identify factors that may increase the chance of surgical success.

Spontaneous bladder perforations: a report of 500 augmentations in children and analysis of risk.

PURPOSE: The spontaneous perforation of an augmented bladder is an uncommon but serious complication. To our knowledge our institution has the largest reported series of bladder augmentations. We examined our data to determine the incidence of spontaneous bladder perforation and to delineate associated risk factors. MATERIALS AND METHODS: We performed a retrospective chart review of 500 bladder augmentation procedures performed during the preceding 25 years with a minimum followup of 2 years. RESULTS: Spontaneous perforations occurred in 43 patients (8.6%), for a total of 54 events. The calculated risk was 0.0066 perforations per augmentation-year at risk. Approximately a third of the cases had perforated within 2 years of surgery, a third between 2 and 6 years postoperatively, and a third at more than 6 years after augmentation. Patients who underwent augmentation between 1997 and 2003 had a higher rate of perforation within 2 years of surgery than those operated on between 1978 and 1987. Increased risk of perforation was observed with the use of sigmoid colon and bladder neck surgery. A decreased risk was associated with the presence of a continent catheterizable channel. CONCLUSIONS: We believe that this large and comprehensive series gives valuable insight into this serious complication. The delineation of these potential risk factors serves as a guide for further discussion and investigation.

Partial urogenital mobilization: a limited proximal dissection.

INTRODUCTION: The treatment of urogenital sinus malformations is complex and controversial. Despite numerous and significant contemporary surgical advances, the dissection of the urogenital sinus remains technically challenging. METHODS: Based on total urogenital mobilization, we describe a technique whereby this dissection is limited to the pubourethral ligament. Our short-term results with partial urogenital mobilization (PUM) performed on 15 patients are retrospectively reviewed. RESULTS: There were no intraoperative complications and the short-term cosmetic results are excellent. No patients have developed voiding dysfunction or urinary tract complications. CONCLUSIONS: While total urogenital mobilization is a very effective procedure, we believe that the PUM approach limits potential morbidity in the reconstruction of these complex problems.

TNF-alpha mediates obstruction-induced renal tubular cell apoptosis and proapoptotic signaling.

Obstruction of the upper urinary tract induces a progressive loss in renal mass through apoptotic renal cell death. Although TNF-alpha has been implicated in ischemia-reperfusion-induced apoptotic renal cell death, its role in obstructive renal cell apoptosis remains unknown. To study this, male Sprague-Dawley rats were subjected to left unilateral ureteral obstruction vs. sham operation. Twenty-four hours before surgery and every 84 h thereafter, rats received either vehicle or a pegylated form of soluble TNF receptor type 1 (PEG-sTNFR1). The kidneys were harvested 1, 3, or 7 days postoperatively, and tissue samples were subsequently analyzed for TNF-alpha (ELISA, RT-PCR), Fas ligand (RT-PCR), apoptosis (TUNEL, ELISA), and caspase 8 and 3 activity (Western blot). Renal obstruction induced increased tissue TNF-alpha and Fas ligand mRNA levels, TNF-alpha protein production, apoptotic renal tubular cell death, and elevated caspase 8 and 3 activity, whereas treatment with PEG-sTNFR1 significantly reduced obstruction-induced TNF-alpha production, renal tubular cell apoptosis, and caspase activity. PEG-sTNFR1 did not significantly alter Fas ligand expression. These results demonstrate that TNF-alpha mediates obstruction-induced renal tubular cell apoptosis and proapoptotic signaling and identify TNF-alpha neutralization as a potential therapeutic option for the amelioration of obstruction-induced renal injury.

Simulated ischemia induces renal tubular cell apoptosis through a nuclear factor-kappaB dependent mechanism.

PURPOSE: Ischemia-reperfusion injury is a relatively common cause of renal tubular cell death and acute renal failure. While nuclear factor-kappaB has been implicated in the pathophysiology of renal ischemia-reperfusion injury, the effect of nuclear factor-kappaB inhibition on ischemia induced renal tubular cell death remains unknown. MATERIALS AND METHODS: Renal tubular cells (LLC-PK1) were exposed to simulated ischemia in the presence or absence of 10 microM. pyrrolidine dithiocarbamate (nuclear factor-kappaB inhibitor). Nuclear factor-kappaB activation (electrophoretic mobility shift assay and immunohistochemistry) and the effect of pyrrolidine dithiocarbamate on nuclear factor-kappaB activation (electrophoretic mobility shift assay) and ischemia induced apoptosis (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling) were determined. RESULTS: Simulated ischemia induced nuclear factor-kappaB activation and renal tubular cell apoptosis versus controls (mean plus or minus standard error of mean 62 +/- 5.2 versus 0.4 +/- 0.3 apoptotic nuclei per high power field, p <0.05). In contrast, previous cellular exposure to pyrrolidine dithiocarbamate effectively inhibited nuclear factor-kappaB activation and prevented ischemia induced apoptosis (mean 14 +/- 6 apoptotic nuclei per high power field). CONCLUSIONS: Simulated ischemia induces nuclear factor-kappaB intranuclear translocation and activation in renal tubular cells. Furthermore, nuclear factor-kappaB mediates ischemia induced renal tubular cell apoptosis. Further elucidation of the complex role of nuclear factor-kappaB in inflammatory injury may lead to the development of targeted therapeutic strategies that ameliorate ischemic renal injury.

Hugh Hampton Young: a pioneer in pediatric urology.

PURPOSE: Hugh Hampton Young (1870-1945) is regarded as a major force in urology during the first half of the 20th century. While he is acknowledged for many advances in open and transurethral prostatic surgery, his contributions to pediatric urology have been less well recognized. MATERIALS AND METHODS: The manuscripts and autobiography of Hugh Hampton Young were reviewed and major contributions to pediatric urology were identified. Patient records corresponding to these areas were then obtained from the Alan Mason Chesney Medical Archives and reviewed. RESULTS: Hugh Hampton Young was the first clinically to recognize and surgically treat posterior urethral valves, the first to develop a procedure to correct incontinence in patients with the epispadias-exstrophy complex and the first to describe bilateral subtotal adrenalectomy for virilization secondary to congenital adrenal hyperplasia. He was successful in his endeavors and his techniques are still in use today or have become the building blocks of future modifications. CONCLUSIONS: The contributions of Hugh Hampton Young to pediatric urology were numerous. In addition to his accomplishments in academic and adult urology, Young should be recognized as a true pioneer in pediatric urology.

p38 MAPK mediates renal tubular cell TNF-alpha production and TNF-alpha-dependent apoptosis during simulated ischemia.

Ischemia causes renal tubular cell loss through apoptosis; however, the mechanisms of this process remain unclear. Using the renal tubular epithelial cell line LLC-PK(1), we developed a model of simulated ischemia (SI) to investigate the role of p38 MAPK (mitogen-activated protein kinase) in renal cell tumor necrosis factor-alpha (TNF-alpha) mRNA production, protein bioactivity, and apoptosis. Results demonstrate that 60 min of SI induced maximal TNF-alpha mRNA production and bioactivity. Furthermore, 60 min of ischemia induced renal tubular cell apoptosis at all substrate replacement time points examined, with peak apoptotic cell death occurring after either 24 or 48 h. p38 MAPK inhibition abolished TNF-alpha mRNA production and TNF-alpha bioactivity, and both p38 MAPK inhibition and TNF-alpha neutralization (anti-porcine TNF-alpha antibody) prevented apoptosis after 60 min of SI. These results constitute the initial demonstration that 1) renal tubular cells produce TNF-alpha mRNA and biologically active TNF-alpha and undergo apoptosis in response to SI, and 2) p38 MAPK mediates renal tubular cell TNF-alpha production and TNF-alpha-dependent apoptosis after SI.

A novel model of ischemia in renal tubular cells which closely parallels in vivo injury.

PURPOSE: Renal ischemia-reperfusion (IR) injury is a devastating clinical problem. While effective animal models have been developed to investigate this condition, they are limited by differential renal cell inflammatory mediator production and heterogeneous cell sensitivity to ischemia. We therefore developed an in vitro model of renal tubular cell ischemia that simulates the cellular injury observed in animal models of renal IR injury. MATERIALS AND METHODS: Using the established renal tubular cell line, LLC-PK1, simulated ischemia was induced by immersing the cellular monolayer in mineral oil. The effect of simulated ischemia on renal tubular cells was then determined by measuring the time course of TNF-alpha protein expression (ELISA), TNF-alpha mRNA induction (RT-PCR), and renal tubular cell apoptosis (TUNEL). RESULTS: Maximal TNF-alpha protein expression occurs following 60 min of simulated ischemia and 2 h of substrate replacement (reimmersion in media), and maximal TNF-alpha mRNA induction occurs following 60 min of simulated ischemia. Cellular apoptosis peaks following 60 min of simulated ischemia and 24 h of reperfusion. CONCLUSION: The time course of TNF-alpha production and apoptosis induction in this model closely parallels the time course for these markers in vivo. This study constitutes the initial demonstration that an in vitro oil immersion model of ischemia simulates the cellular injury (TNF-alpha production and apoptosis) observed in animal models of renal ischemia-reperfusion. This model may be used to study cellular mechanisms of IR in the absence of the systemic confounding variables.

Heat shock prevents simulated ischemia-induced apoptosis in renal tubular cells via a PKC-dependent mechanism.

Heat shock produces cellular tolerance to a variety of adverse conditions; however, the protective effect of heat shock on renal cell ischemic injury remains unclear. Protein kinase C (PKC) has been implicated in the signaling mechanisms of acute preconditioning, yet it remains unknown whether PKC mediates heat shock-induced delayed preconditioning in renal cells. To study this, renal tubular cells (LLC-PK1) were exposed to thermal stress (43 degrees C) for 1 h and heat shock protein (HSP) 72 induction was confirmed by Western blot analysis. Cells were subjected to simulated ischemia 24 h after thermal stress, and the effect of heat shock (delayed preconditioning) on ischemia-induced apoptosis (terminal deoxynucleotidyl transferase dUTP nick-end labeling) and B cell lymphoma 2 (Bcl(2)) expression (Western) was determined. Subsequently, the effect of PKC inhibition on HSP72 induction and heat stress-induced ischemic tolerance was evaluated. Thermal stress induced HSP72 production, increased Bcl(2) expression, and prevented simulated ischemia-induced renal tubular cell apoptosis. PKC inhibition abolished thermal induction of HSP72 and prevented heat stress-induced ischemic tolerance. These data demonstrate that thermal stress protects renal tubular cells from simulated ischemia-induced apoptosis through a PKC-dependent mechanism.