Development of a porcine animal model for urethral stricture repair using autologous urothelial cells.

OBJECTIVE: To present a versatile large animal model for endoscopic stricture repair using autologous urothelial cells. MATERIALS AND METHODS: 12 male minipigs were used. An artificial stricture model was established using suture-ligation, thermo-coagulation and internal urethrotomy. A vesicostomy served for urinary diversion. Stricture formation was confirmed radiologically and histologically. Autologous urothelial cells were harvested from bladder washings, cultivated and labeled. Internal urethrotomy was done in all, and the cultivated cells were injected into the urethrotomy wound. All animals were sacrificed after 4 or 8 weeks. Immunohistology was done to confirm the presence of autologous urothelial cells within the reconstituted urethra. RESULTS: Stricture formation was verified with all three methods. Histologically, no significant differences in the severity of stricture development could be observed with regard to the method used. The autologous urothelial cells in the area of the urethrotomy could be detected in the urothelium and the corpus spongiosum until 8 weeks after re-implantation. CONCLUSIONS: We created a reliable and reproducible porcine model for artificial urethral strictures. Autologous urothelial cells can be implanted into an artificial stricture after urethrotomy. These cells retain their epithelial phenotype and are integrated in the resident urothelium. Further comparative studies are needed to ultimately determine a superior efficacy of this novel approach.

[Bladder cancer screening with urine-based tumour markers - occupational medical experience]. / Das Screening von Harnblasenkarzinomen mittels urinbasierter Tumormarker - Erfahrungen aus der Arbeitsmedizin.

OBJECTIVE: Bladder cancer responds favourably to treatment and has a good survival rate, provided it is diagnosed at an early stage. Established methods exist for the early detection, however, their specificity and positive predictive value are not yet satisfactory. Innovative markers have been proposed, but still require validation in prospective studies. We provide a literature-based short overview on the currently available and some proposed markers for the early detection of bladder cancer and evaluate the need for validation in further studies. We further provide some first results of such a recently finished study in an occupational setting. MATERIAL AND METHODS: We conducted a prospective screening study over seven years in 1610 males with former occupational exposure to carcinogenic aromatic amines. Annual bladder cancer screening according to statutory requirements was offered. In addition to the regularly performed check for hematuria and urine cytology, the markers NMP22, UroVysion™ and survivin were performed in voided urine samples of the participants. Positive findings (not for survivin) were further followed through urethrocystoscopy. RESULTS AND CONCLUSIONS: A total of 7219 urine samples were screened. During the study period 16 incidental and 4 recurrent bladder tumours, thereof three papillomas, occurred in a total of 19 participants. 14 out of twenty tumours were marker-positive, and all but two were early stage findings. Cell-based markers (cytology, UroVysion™) und molecular markers (NMP22, survivin) were largely complementary, thus acting as a "multi-marker panel". Eight of the tumours were identified by a positive cytology. Six tumours were not detected by any of the tumour markers. The results will be further evaluated through the inclusion of confounding factors, which have so far rarely been examined in other studies. This may lead to the development of tiered diagnostic strategies with the aim to reduce the number of invasive diagnostic procedures in the future.

[Bioartificial urothelium generated from bladder washings. A future therapeutic option for reconstructive surgery]. / Bioartifizielles autologes Urothel etabliert aus Spülungen der Harnblase. Eine zukünftige Therapieoption für die rekonstruktive Urologie.

Reconstructive surgery of lower urinary tract disorders can be limited by a shortage of adequate autologous tissue. Tissue engineering is an option for surgical reconstruction with evolved biological substitutes. Urethral repair with bioartificial urothelial implants can be an innovative method for sustained urothelial regeneration in situ. The needed urothelial cells are commonly isolated from native urothelium requiring surgery.The aim of this study was to establish primary human urothelial cell cultures from bladder washings in serum-free media and to generate urothelial tissue without seeding of matrices in a feeder cell-free system. It could be demonstrated that under these conditions bioartificial urothelium can be developed successfully from bladder washings. Its multilayered cellular structure and the initial differentiation in vitro, similar to native-grown urothelial tissue, are promising with regard to intended clinical application. Current work focuses on establishing cell culture techniques according to legal regulations, terminal differentiation of the urothelial constructs in vitro, and techniques to surgically implant lab-grown bioartificial urothelium.

A novel polyarginine containing Smac peptide conjugate that mediates cell death in tumor and healthy cells.

The seven N-terminal amino acids AVPIAQK (SmacN7) of the mitochondrial protein Smac (second mitochondria-derived activator of caspase) promote caspase activation by binding specifically to inhibitor of apoptosis proteins (IAPs) and blocking their inhibitory activity. SmacN7 cannot pass through the cell membrane, but to be of therapeutic use it would be essential for it to enter the cell. To achieve transmembrane transport of SmacN7 we coupled it to a novel fluorescein isothiocyanate (FITC)-labelled transmembrane transport peptide RRRRK(FITC)RRRR via ss-alanine to produce the conjugate AVPIAQKssA RRRRK(FITC)RRRR. Because IAPs are much more strongly expressed in the cytoplasm of tumor cells, we expected this conjugate to produce staining of the cytoplasm, and for this to be stronger in tumor cells than in healthy cells. Surprisingly, we found strong nuclear uptake of the Smac conjugate and of the transport peptide alone without subsequent release in both tumor cells and healthy cells from the bladder, prostate, and brain. This was accompanied by cell death. In contrast to expectations, it appears that the apoptotic effects observed do not result from the SmacN7 cargo alone.

[Tissue engineering and stem cell research in urology for a reconstructive or regenerative treatment approach]. / "Tissue engineering" und Stammzellforschung in der Urologie für den rekonstruktiven bzw. regenerativen Therapieansatz.

With the involvement of clinical reconstructive urology in the field of tissue engineering, outstanding results have been achieved in basic research as well as in some clinics. Stem cell research has even opened up possibilities for regenerative aspects. In close cooperation with various disciplines, the Department of Urology at the University of Tübingen investigates different clinical aspects with regard to reconstructive and regenerative urology. The regeneration of the external urethral sphincter requires functionally integrated muscle cells. In addition stricture reconstruction with multilayer urothelium should become less invasive and the re-stricture rate reduced. After the application of differentiating stem cells was proven, the clinical setting needed to be set for legal issues. In addition to the specification of culture media and verification in the animal model, the possibility to harvest omnipotent stem cells out of human testis and to differentiate those into the three germ layers was demonstrated. With the reduced invasiveness of harvesting the urothelium cells by a bladder wash using specific culture fluids, the cell culture was significantly improved enabling successful creation of urothelium by stratification. In addition urothelial cells in a matrix are further improved for endoscopic application. The close cooperation of different disciplines shortens the time to develop therapeutic approaches with a close clinical relationship in reconstructive and regenerative urology.

[Value of stem cell therapy for the treatment of stress incontinence. Current status and perspectives]. / Stellenwert der Stammzelltherapie für die Behandlung der Belastungsinkontinenz. Aktueller Stand und Ausblick.

Parallel to a fundamental change in the therapeutic approach to managing stress incontinence, an increasing number of patients ask for reconstruction of the outer, striated urethral sphincter as therapy for urinary stress incontinence. Regenerative medicine is starting to offer solutions using stem cells as a part of oncological therapy or in reconstructive surgery. In addition to the many auspicious experimental approaches, one published study reports the effective therapeutic use of myogenic stem cells in urinary stress incontinent patients. Before this procedure is adopted into general clinical practice, further studies with validated evaluations and a sound legal basis are needed.

[Tumor marker tests in bladder cancer]. / Pruebas de marcadores tumorales en el cáncer de vejiga.

The gold standard for detecting bladder cancer is cystoscopy which identifies nearly all papillary and sessile lesions. However, it is an invasive procedure causing some discomfort for patients. Urine cytology is the standard non-invasive marker with very high specificity, but unfavourable poor sensitivity for Ta, G1, and T1 bladder tumors. To improve early detection of bladder cancer as well as to monitor treatment response and tumor recurrence, bladder tumor markers are eligible. An ideal bladder cancer test would have the potential to replace or delay cystoscopy in the follow-up of bladder cancer patients. In recent years, the FDA approved non-invasive tumor marker tests ImmunoCyt / uCyt+, BTA TRAK, BTA stat, NMP22, NMP22 BladderChek, and UroVysion have been investigated. The tests demonstrated higher sensitivity for diagnosis of bladder cancer compared to urine cytology. Overall, the mean sensitivity and mean specificity was 64-80% and 71-95% and the mean positive and negative predictive values to detect malignancy were 49-84% and 79-95%, respectively. BTA TRAK, BTA stat, NMP22, and NMP22 BladderChek assays are limited by false-positive results in patients with benign urological diseases such as hematuria, urocystitis, renal calculi or urinary tract infections. Due to low specificity BTA TRAK, BTA stat, NMP22, and NMP22 BladderChek should not be used without first ruling out benign or malignant genitourinary disease other than bladder cancer. With the exception of UroVysion achieving 80% sensitivity and 94% specificity, none of these non-invasive tests revealed a high sensitivity and specificity at the same time, which is a main demand to be made on an ideal tumor marker. Insufficient sensitivity along with limited specificity does not allow replacing cystoscopy in diagnosis of bladder cancer or treatment decisions based on a positive test result.

Correlation of bFGF expression in renal cell cancer with clinical and histopathological features by tissue microarray analysis and measurement of serum levels.

The prognostic value of bFGF for surgically treated renal cell cancer (RCC) patients was evaluated by immunohistochemistry (IHC) and the tissue microarray technique (TMA). Additionally, preoperative serum bFGF levels were correlated to tumour stage and the presence of metastases at initial diagnosis. Serum levels of bFGF were measured by ELISA in 39 healthy volunteers, in 37 patients with benign urologic diseases and in 74 RCC patients, 26 of whom revealed lymph node or distant metastases. bFGF expression as detected by IHC was investigated in 777 tissue cores from 259 different RCC patients [median follow-up: 138 (36-240) months]. Eighty eight patients died from tumour progression. For each patient, the TMA slides contained a tissue core from the primary tumour, its invasion front and the normal renal parenchyma. bFGF serum levels were higher in RCC patients vs healthy volunteers (P<0.01) and vs patients with benign urologic diseases (P<0.01). Metastasized patients revealed higher bFGF serum levels than organ-confined specimens (P<0.01). As detected by IHC only increased bFGF expression in the invasion front tissue correlated with the patients' long-term survival (log rank test) (P=0.03). In multivariate analysis regional LN metastases (P<0.01), the histological grading (P<0.01), and an increased bFGF expression in the invasion front (P=0.04) independently predicted the patients' clinical prognosis. Not the expression of bFGF in the primary tumour but in its invasion front reflects the aggressiveness of RCC, hereby indicating a different biological potential within both areas. The value of bFGF serum levels as indicators of systemic tumour dissemination remains to be determined.

[In vitro stratified urothelium and its relevance in reconstructive urology]. / In vitro stratifiziertes Urothelium und seine Bedeutung für die rekonstruktive Urologie.

There are two main objectives regarding tissue engineering in reconstructive urology: (1) to provide the surgeon with autologous tissue for urogenital reconstructive purposes and (2) to create the framework for experimental investigations to better understand the structure and function of the tissues involved. In the last years urothelial cell culture has become a routine laboratory technique. There is sufficient cellular output after isolation and propagation to seed cells as single cell suspensions on biodegradable matrices for the construction of cell-matrix implants. In recent publications attention was directed toward using established primary cell cultures for in vitro stratification of multilayered urothelial sheets. Urothelial sheets have been used quite successfully for covering acellular matrices for bladder augmentation in dog and minipig models. However, up to now there has been no clinical application in humans of urothelial sheets generated in vitro. Here we review facts about the different strategies for generating multilayered urothelial sheets.

[Tissue engineering of the urethra and ureter]. / Tissue Engineering der Harnröhre und des Harnleiters.

Congenital or acquired disorders of the urethra or ureter often require adequate tissue transfer for reconstruction. A variety of biomaterials have proved to be useful in the reconstruction of the urethra or ureter in animal models and meanwhile even clinically. Innovative tissues such as acellular matrices can be placed in the host and function as a scaffold to allow the natural process of tissue regeneration. Biodegradable scaffolds can also be used as cell transplantation vehicles for the reconstruction of urethral or ureteral tissue. One of the limitations of cell-based tissue engineering techniques however is the difficulty of growing genitourinary-associated cells in large quantities in primary cultures. It can be speculated that stem cell research might help to overcome this specific problem in the future.

Renal tubular alteration by crystalluria in stone disease-an experimental study by means of MDCK cells.

OBJECTIVES: Physicochemical properties of urine do not explain the formation of urinary stones. Clinical findings and results of animal experiments suggest that alteration to the renal tubular cell plays a key role in the initiation of urinary stone formation. It is not clear whether this is a primarily intracellular alteration of metabolic origin which, after lysis of the renal tubular cell in the lumen, presents a nucleus for the formation of concretions, or whether in the lumen it is tubular cell damage induced by crystalluria that triggers the formation of urinary stones. MATERIALS AND METHOD: Using Madin-Darby canine kidney cells, the influence of crystalluria on the renal tubular cell was tested in cell cultures. The influence of parathyroid hormone, vitamin D(3), oxalate and calcium concentrations and the extent to which these processes can be inhibited by allopurinol and selenium were investigated. RESULTS: Calcium oxalate monohydrate crystals produced reproducible damage to the renal tubular cell which was independent of parathyroid hormone and vitamin D(3). The crystalluria-induced effects were unrelated to the oxalate and calcium concentration or the pH. Allopurinol and selenium were able to inhibit the processes. CONCLUSION: The results indicate secondary involvement of the renal tubular cell in lithogenesis as a result of luminal alteration caused by calcium oxalate crystals. Mechanical damage and interaction between crystal and tubular cell lead to the apposition of crystals. The nephroprotective effect of allopurinol and selenium as antioxidants might explain the benefit of allopurinol found clinically in terms of stone metaphylaxis.

[Advantages of nerve-sparing pelvic surgery. Animal experiments and clinical results]. / Vorteile der nerverhaltenden Beckenchirurgie. Tier experimentelle und klinische Ergebnisse.

Traditionally, oncological factors have been the only ones used in the evaluation of treatment outcome for urological tumor patients. With increased diagnoses of early, curable tumors in younger individuals, health-related quality of life and functional aspects are gaining importance. Sexual and urinary function are significant aspects of quality of life, which are especially vulnerable in urological patients. New insights into the anatomy and physiology of the pelvic organs have resulted in an improvement in surgical therapy. In this article, we present the results of current experimental and clinical studies, which underline the importance of nerve sparing techniques for maintaining a satisfying urinary and sexual function in this patient population.

[ImmunoCyt--a new urine test in diagnosis of bladder cancer]. / Urinzytologie beim Harnblasenkarzinom. Diagnostische Wertigkeit eines neuen immunologischen Fluoreszenztestes.

ImmunoCyt is a new immunocytologic fluorescence test promising a higher diagnostic sensitivity, esp. for TaG1 carcinomas. The aim of the study was to evaluate the sensitivity of the test in diagnosis of bladder cancer as compared to both urinary cytology and histopathology. A total of 121 spontaneous urine samples of 92 patients (age range 28 to 86, mean 62.5 years) was examined. 41 of the samples were of patients suspicious of transitional cell carcinoma, 46 of patients in whom symptoms were suggestive of tumor recurrence, and 34 of patients who were part of a follow-up protocol. Cystoscopy was performed in all patients. The ImmunoCyt-test was carried out according to the manufacturers protocol using 3 fluorescent monoclonal antibodies. A total of 113 specimens could be evaluated. In 87 cystoscopy and/or histology was negative (control group). There was histologic evidence of 7 pTaG1, 4 pTaG2, 8 pT1G2/G3, and 7 pT2G2/G3 bladder cancers. As for ImmunoCyt and cytology specificity was 83.9% and 91.9%, resp. The combined specificity was 81.6%. Sensitivity amounted to 38.5% and 34.6%, resp., the combined sensitivity to 53.8%. Sensitivity for TaG1 carcinomas was 14.3% each, for TaG2 carcinomas 25% and 50%, for T1G2/G3 carcinomas 37.5% each, and for T2G2/G3 carcinomas 71.4% and 42.9%, resp. In our study the ImmunoCyt test did not show the expected increase in the detection of TaG1 bladder cancers. Because of false-positive results the test should only be used in combination with urinary cytology which reveals a higher specificity. In conclusion the ImmunoCyt test can not replace cystoscopy (with biopsy) in diagnosis and monitoring of bladder cancer.

Comparison of cytology and nuclear matrix protein 22 for the detection and follow-up of bladder cancer.

OBJECTIVES: This study was designed to determine the clinical usefulness of the nuclear matrix METHODS: 84 patients suffering from bladder cancer or suspected bladder cancer, 25 patients with benign urological lesions and 60 healthy controls participated in a prospective study. Freshly voided spot urine samples were taken for cytological examination and determination of NMP 22 levels by enzyme-linked immunoassay. RESULTS: The sensitivity of the NMP 22 test according to the tumor grading was (results of cytology in brackets): G1 25.0% (20.0%); G2 68.2% (59.1%), and G3 100.0% (66.7); overall sensitivity was 62.5% (45.0%). The sensitivity for superficial bladder cancer was 46.7% (36.7%) and for invasive bladder cancer 90.0% (70.0%). The specificity was 65.9% (88.9%). CONCLUSIONS: NMP 22 is a reliable tool for detecting invasive bladder cancer. Results for the frequently occurring low grade superficial bladder cancer are as poor as those obtained with cytology. In addition benign lesions such as urolithiasis or urinary tract infection lead to false-positive results. Therefore cystoscopy has to be performed when trying to detect and follow-up bladder cancer.

Schistosomiasis: a critical review.

Precise data on epidemiology, morbidity, post-treatment resolution, reinfection, and resurgence of schistosomiasis could be helpful in establishing purposeful treatment plans for the disease in endemic populations. Here we give a concise overview of recent publications on bilharziasis. A main emphasis is placed on studies on the prevalence of schistosomiasis, partly including long term surveillance of morbidity following treatment with praziquantel. As genito-urinary schistosomiasis may be a risk factor for the spread of HIV, the involvement of the reproductive tract has become another focus in research on the disease. A novel diagnostic tool, eosinophil cationic protein (ECP), is proposed to correlate with the degree of inflammation of the genito-urinary tract.

Molecular genetic methods in the diagnosis of invasive bladder cancer.

Development and progression of tumours is generally driven by an accumulation of genetic alterations. In this study we correlated chromosome 17 aneuploidy to invasiveness of bladder cancer by the method of fluorescence in situ hybridisation (FISH) in urinary cytospins. We investigated the value of FISH compared to DNA cytophotometry in the diagnosis of bladder cancer. 39 patients with or suspicious for bladder tumour were analyzed. 19 patients had a bladder tumor at the time of diagnosis, 14 superficial (Ta-T1) and 5 invasive (T2-3). The remaining 20 patients had no tumour at the time of diagnosis, however 9 of them had one in prehistory (Ta-T2). For FISH we used the DNA probe of HER-2/neu located on chromosome 17. DNA image cytometry was performed according to single cell interpretation of Böcking. Our results showed a correlation between HER-2/neu CEP 17 alterations and invasive bladder cancer to the extent of 10-70% aberrant cells for patients with current invasive bladder tumour as well as for patients who had been cured but with as invasive bladder cancer in prehistory. On the other hand, the percentage of aneuploid cells for negative biopsy and superficial tumour was 0-2%. The DNA cytophotometry brought an uniform aneuploidy only for present invasive tumours: negative biopsies, superficial cancer and invasive tumour just in prehistory, showed mixed diploid-aneuploid DNA patterns. Our results showed that for the detection of aberrant tumour cells the method of FISH is more sensitive than DNA cytometry. FISH could provide important information in the prognosis of bladder cancer.

Immunohistochemical examinations (Ki67, p53, nm23) and DNA cytophotometry in bladder cancer.

Bladder cancer is clinically characterized by a high recurrence rate for superficial tumours up to 70% and by the invasiveness of advanced bladder cancer. To learn more about the biological behaviour of an individual bladder cancer different tumour markers have been investigated. The aim of our study was to compare the potential of aggression of both superficial and invasive bladder tumours by means of the proliferation marker Ki67, the tumour suppressor gene p53, the non metastasizing protein nm23 and the evaluation of DNA ploidy. We examined 36 patients, 28 with a bladder tumour (Ta-T4) and 8 without as a control group. For immunohistochemistry (Ki67, p53, nm23) we took paraffin sections and scored semiquantitatively under a microscope. The DNA cytophotometry was done on bladder washings by evaluating the DNA ploidy of single cells. The results showed that benign tissues were negative for Ki67 and p53 but positive for nm23. The DNA diagnosis was diploid for all benign samples. The superficial bladder cancer (Ta, T1) showed, in comparison to the invasive tumours, significantly lower numbers of aneuploid cells and a higher rate of p53 mutations. On the other hand the invasive tumours (T2-4) were correlated to significantly higher proliferation rates and higher potencies for metastasizing. The combination of the investigated tumour markers allowed a graduation of the biological behavior of an individual bladder cancer. Especially a high p53 mutation rate and a non aneuploid DNA diagnosis were indicators for the recurrence of superficial bladder tumours. Invasive growth of bladder cancer was characterized by high Ki67 proliferation and low nm23 protein binding.

Serologic angiogenesis factors and microvascular density in renal cell carcinoma: two independent parameters.

Renal Cell Carcinoma (RCC) is characterized by high intratumoral microvascular density (iMVD) and significantly elevated serologic titers of angiogenesis factors, basic fibroblast growth factor (bFGF), vascular endothelial growth factor (vEGF) and angiogenin (Ag). The goal of the present study was to find whether a correlation exists between any of these factors and intratumoral microvascular density (iMVD). Serologic angiogenesis factors were determined directly before nephrectomy of a tumorous kidney in 12 patients (average age: 67.6 years [49-78] with localized clear-cell RCC (Robson I-II) (Quantikine', R&D Systems Europe, Abington, UK). Sections were taken in each case from the microscopically most aggressive area of the tumorous kidney preparations. Staining was carried out with a primary antibody against CD31 (DAKO M 0823, Hamburg, Germany). iMVD was counted at 160x magnification at five "hot spots" 200 x 200 microns in size, and the individual factors were then correlated with the areas of maximum and average iMVD (iMVDmax, iMVD-d). Average concentrations of 38 pg/ml +/- 68 were found for bFGF, 712 pg/ml +/- 791 for vEGF, and 358 ng/ml +/- 97 for Ag. iMVDmax was 20 +/- 11 per area, iMVD-d was 410/mm2 +/- 243. No correlation was found between microvascular density and serologic angiogenesis factors for any parameter. Actual tumor vascularization, expressed as iMVD, was not correlated with the 3 angiogenesis parameters which were studied. On the one hand, this raises the question whether angiogenesis can be measured at all with these parameters; on the other, it remains nuclear whether the continuous process of angiogenesis can be registered at all by chronologic, specific factor analysis.