Darius J. Bägli

Isolation and Characterization of Multipotent Skin‐Derived Precursors from Human Skin

We have previously isolated, expanded, and characterized a multipotent precursor cell from mammalian dermis (termed skin‐derived precursors [SKPs]) that can differentiate into both neural and mesodermal progeny. In this study, we report the isolation, expansion, and characterization of a similar precursor cell from neonatal human foreskin tissue. Like their rodent counterparts, human SKPs grew in suspension as spheres in the presence of the mitogens fibroblast growth factor 2 and epidermal growth factor and expressed nestin, fibronectin, vimentin, and characteristic embryonic transcription factors. Human SKPs could be maintained in culture for long periods of time and would still differentiate into neurons, glia, and smooth muscle cells, including cells with the phenotype of peripheral neurons and Schwann cells. Clonal analysis indicated that single SKP cells were multipotent and could give rise to all of these progeny. Moreover, human SKPs apparently derive from an endogenous precursor within human foreskin; a subpopulation of dissociated primary foreskin cells could differentiate into neurons, a cell type never seen in skin, and the initial spheres to develop from skin expressed the same markers and had the same potential as do passaged SKPs. Together, these data indicate that SKPs are an endogenous multipotent precursor cell present in human skin that can be isolated and expanded and differentiate into both neural and mesodermal cell types.

THE DYSFUNCTIONAL VOIDING SCORING SYSTEM: QUANTITATIVE STANDARDIZATION OF DYSFUNCTIONAL VOIDING SYMPTOMS IN CHILDREN

PURPOSE Academic research on pediatric nonneurogenic voiding dysfunction has long been hampered by the lack of a standardized reporting system for voiding symptoms. We evaluated the performance of a newly devised, objective instrument to quantify or grade the severity of abnormal voiding behaviors of children. MATERIALS AND METHODS There were 10 voiding dysfunction parameters that were assigned scores of 0 to 3 according to prevalence, and possible total scores ranged from 0 to 30. The Dysfunctional Voiding Symptom Score was completed by 2 groups of patients. Group 1 consisted of patients 3 to 10 years old presenting to the pediatric urology clinic with a history of diurnal urinary incontinence, urinary tract infections or abnormal voiding habits. Group 2 consisted of an age matched cohort with no history of urological complaints presenting to hospital clinics outside of urology. Patients diagnosed with organic or anatomical disease, such as posterior urethral valves or meningomyelocele, were excluded from our analysis. RESULTS Group 1 consisted of 104 patients (female-to-male ratio 4:1) with a median symptom score of 14 and group 2 consisted of 54 patients (female-to-male ratio 1.3:1) with a median score of 4. The dysfunctional voiding odds ratio was 2.93 for females compared to that of males. Using receiver operating characteristics the optimum cutoff score was 6.026 (sensitivity 92.77% and specificity 87.09%) for females and 9.02 (sensitivity of 80.95% and specificity of 91. 30%) for males. In addition, we found certain questions to be more reflective than others of dysfunctional voiding symptoms in our population. CONCLUSIONS The Dysfunctional Voiding Symptom Score appears to provide accurate and objective, that is, numerical, grading of voiding behaviors of children. Comparative research studies of dysfunctional voiding diagnosis and response to therapy as well as objective measurements of treatment efficacy and outcomes analysis should be aided greatly by this system.

Complete Penile Disassembly for Epispadias Repair: The Mitchell Technique

PURPOSE We report a new technique for epispadias repair, which relies on the unique blood supply of the corpus cavernosum and glans. The epispadiac phallus is completely disassembled into 3 discrete components: the urethral plate, and the right and left hemicorporeal glandular bodies. MATERIALS AND METHODS Ten boys 10 months to 17 years old presented for repair of epispadias between 1990 and 1994 (6 primary and 4 secondary repair). One patient underwent bladder exstrophy closure at the time of epispadias surgery. Two patients underwent prior para-exstrophy flap procedures and neither had fistulas. RESULTS Followup (8 to 57 months) revealed a conical glans in 8 patients, straight shaft upward in 1 and ventral orthotopic meatus in 7. In 2 patients who underwent secondary repair 3 fistulas formed that were repaired on an outpatient basis. All patients are potent. CONCLUSIONS Complete disassembly allows tubularization and ventralization of the entire distal urethra; makes glans and urethral repair independent; separates the 2 corporeal glandular bodies, permitting easier and more complete release of the rotation contributing to dorsal chordee, and improves exposure for corporotomy or dermal grafts.

Laparoscopic dismembered pyeloplasty by a retroperitoneal approach in children

To report our experience with dismembered laparoscopic pyeloplasty by a retroperitoneal approach in children with pelvi‐ureteric junction (PUJ) obstruction.

Retroperitoneal laparoscopic vs open partial nephroureterectomy in children.

To compare the results of retroperitoneal laparoscopic with open partial nephroureterectomy.

REGENERATION OF FUNCTIONAL BLADDER SUBSTITUTES USING LARGE SEGMENT ACELLULAR MATRIX ALLOGRAFTS IN A PORCINE MODEL

PURPOSE We previously reported on the short-term (4 weeks) morphometric analysis of a large bladder acellular matrix allograft used as a bladder bioprosthesis (average size 24 cm.2). We demonstrated cellular repopulation through the entire thickness of the graft. We now present the long-term (12 weeks) morphometric results of graft regenerated porcine bladders using segments measuring an average of 40 cm.2. MATERIALS AND METHODS Bladders harvested from pigs were subjected to detergent and enzymatic extractions to render them acellular. Partial cystectomy was performed in 21 pigs and the defect was repaired with a bladder acellular matrix allograft (average size 40.52 cm.2). Of the animals 8 were sacrificed at 1, 2 and 4 weeks and 13 were sacrificed at 8 and 12 weeks. To evaluate cellular repopulation and matrix reorganization the native bladder and graft were analyzed using standard histological and immunofluorescent techniques. To evaluate for calcium deposits in the grafts a radiological evaluation of the graft was performed after explantation. RESULTS All animals survived the surgical procedure and there were no significant urinary leaks. No stones were noted in any of the bladders. At 1 week there was a diffuse infiltration with acute inflammatory cells. At 2 weeks the luminal surface of the graft was lined with a single layer of urothelium, and there was stromal infiltration with unorganized smooth muscle cells and angiogenesis. At 4 weeks the urothelium was multilayered with organizing groups of smooth muscle cells and angiogenesis. At 8 and 12 weeks there was repopulation throughout the bladder acellular matrix allograft implant with all native cellular components participating. CONCLUSIONS We present evidence that large patch bladder acellular matrix allograft implantation is technically feasible and may prove to be a viable surgical alternative to bladder augmentation with intestinal segments. Its advantages may include the potential for complete and functional regeneration of a bladder substitute.

Acellular bladder matrix allografts in the regeneration of functional bladders : evaluation of large-segment (> 24 cm2) substitution in a porcine model

Objectives To evaluate the use of a large‐segment (> 24 cm2) bladder substitution with porcine bladder acellular matrix allograft (BAMA) in a large animal model.

Outcome Analysis of Retroperitoneal Laparoscopic Heminephrectomy in Children

Purpose: Retroperitoneal laparoscopic heminephrectomy is a relatively new, well tolerated, minimally invasive alternative to open surgery for children with a nonfunctioning moiety in a duplex kidney. We collected data to assess outcomes in our experience with this procedure.Materials and Methods: Data were retrospectively gathered on all patients operated on for retroperitoneal laparoscopic heminephrectomy at our institution between February 2001 and November 2004. Followup ultrasound was performed in all patients, and additional imaging was done only when clinically indicated.Results: Retroperitoneal laparoscopic heminephrectomy was performed in 18 girls and 4 boys (18 upper and 5 lower pole moieties). Indications included ureterocele (12 patients), ectopic ureter (9) and vesicoureteral reflux (5). Mean age at surgery was 5 years (range 4 months to 18 years). Four patients required conversion to an open procedure due to inadequate exposure and were excluded from further review. Urine leaks developed post...

The bladder extracellular matrix. Part I: architecture, development and disease

From the earliest studies with epithelial cells implanted into detrusor muscle to later experiments on smooth muscle in defined collagen gels, cell niche and extracellular matrix (ECM) have been clearly shown to orchestrate cellular behavior and fate whether quiescent, migratory, or proliferative. Normal matrix can revert transformed cells to quiescence, and damaged matrix can trigger malignancy or dedifferentiation. ECM influence in disease, development, healing and regeneration has been demonstrated in many other fields of study, but a thorough examination of the roles of ECM in bladder cell activity has not yet been undertaken. Structural ECM proteins, in concert with adhesive proteins, provide crucial structural support to the bladder. Both structural and nonstructural components of the bladder have major effects on smooth muscle function, through effects on matrix rigidity and signaling through ECM receptors. While many ECM components and receptors identified in the bladder have specific known functions in the vascular smooth musculature, their function in the bladder is often less well defined. In cancer and obstructive disease, the ECM has a critical role in pathogenesis. The challenge in these settings will be to find therapies that prevent hyperproliferation and encourage proper differentiation, through an understanding of matrix effects on cell biology and susceptibility to therapeutics.

Analysis of Trends On Serial Ultrasound for High Grade Neonatal Hydronephrosis

PURPOSE We sought to validate the role of serial ultrasound studies for detecting and excluding obstruction in high grade neonatal hydronephrosis. MATERIALS AND METHODS Between January 1996 and December 1998 all patients with prenatally diagnosed hydronephrosis underwent a protocol of antibiotic prophylaxis, ultrasound and voiding cystourethrography. All reflux-free patients underwent diuretic renography. Patients with high grade isolated unilateral hydronephrosis were included in the study. They were followed with 3 serial ultrasound examinations every 3 months in year 1 of life, biannually in year 2 and yearly thereafter. The trends in the changes in these studies were studied. RESULTS Of the 153 patients 45 (29%) met study inclusion criteria. During a mean followup of 38 months (range 23 to 52) 16 patients (36%) who showed a trend of progressive hydronephrosis underwent pyeloplasty. The remaining 29 patients showed a trend of improvement in hydronephrosis. The drainage pattern on initial diuretic renography had only 63% sensitivity and 59% specificity for diagnosing obstruction. The same was true for the decrease in differential function of below 40% with 56% sensitivity and 66% specificity. Logistic regression analysis revealed that neither the initial grade of hydronephrosis on prenatal ultrasound nor the drainage-functional pattern on initial diuretic renography was a predictor of the subsequent need for pyeloplasty. All 16 patients who underwent pyeloplasty had improved or stabilized hydronephrosis after pyeloplasty. CONCLUSIONS A trend of progressive hydronephrosis on 2 consecutive serial renal ultrasound examinations serves as an early diagnostic sign of obstruction. Initial grade of hydronephrosis on initial ultrasound as well initial functional-drainage patterns on diuretic renography are not predictors of obstruction. Serial ultrasound is noninvasive and could replace serial invasive renal scans. Diuretic renal scans still have a role, especially as a baseline study to guide the frequency of serial ultrasound examinations.