Summary An animal tumour model that mimics the human counterpart is essential for preclinical evaluation of new treatment modalities. The objective of this study was to develop and characterize such a model. To accomplish this, the established AY-27 rat bladder transitional cell carcinoma (TCC) cell line was transplanted orthotopically into Fischer CDF344 female rats. AY-27 TCC cells were grown in monolayer cell culture and instilled intravesically as single cell suspensions into bladders that had been conditioned with mild acid washing. Tumour growth was assessed weekly by subjecting the rats to magnetic resonance imaging (MRI). At intervals following implantation and MRI tumour detection, the animals were sacrificed for necropsy, histological examination and immunocytochemical studies. Flow cytometry was also performed for detection of Fas or Fas-ligand expression on AY-27 cells. The overall tumour establishment was 95% (97/102 rats) at 12-50 days, while in a subgroup of animals sacrificed at 16 days, 80 out of 82 animals (97%) developed TCC, the majority of which was superficial. Tumour stage was assessed by gross pathology and light microscopy. Histological examination of the tumour specimens confirmed the presence of grade II-III TCC. Immunocytochemistry confirmed that the tumour model maintained the features of TCC. The changes seen on MRI correlated well with the extent of tumour invasion identified histologically. Patchy carcinoma in situ could be detected histologically 12-13 days post-inoculation, and progressed to papillary tumour or invasive disease thereafter. Neither Fas nor Fas-ligand was expressed on AY-27 cells. The orthotopic AY-27 TCC model is highly reproducible and is ideal for preclinical studies on experimental intravesical therapies.

An association between congenital bilateral absence of the vas deferens (CBAVD), normal renal anatomy and cystic fibrosis (CF) gene mutations is well established (CF/CBAVD). We postulate that unilateral renal agenesis (URA) and CBAVD (URA/CBAVD) may have a non-CF mutation-mediated genetic basis that leads to abnormal development of the entire mesonephric duct at a very early stage in embryo development (< or =7 weeks). The physical, laboratory and radiographic findings of men with URA/CBAVD (n = 17) and CF/CBAVD (n = 97) were compared; the fertilization and pregnancy rates in the URA/CBAVD population calculated, and the incidence of renal agenesis in immediate family members and offspring of men with URA/CBAVD analysed. No statistical differences could be identified within any of the above comparisons. The fertilization rate for the URA/CBAVD group was 58.2 +/- 26.3%. Eight infants and two fetuses had normal renal anatomy, while one terminated male fetus had bilateral renal and vasal agenesis. Thirty first-order relatives had normal renal units. Anatomical expression of the reproductive ductal derivatives in men with URA/CBAVD and CF/CBAVD was similar, but the phenotypic outcome of the renal portion of the mesonephric duct was different. The potential for transmission of this fatal anomaly reinforces the need for prenatal ultrasounds with all pregnancies involving URA/CBAVD men.

Photodynamic therapy (PDT) has been considered as a potential therapy for superficial bladder carcinomas. Cutaneous photosensitivity and reduction of bladder capacity are the two well-known complications following systemic administration of the commonly used photosensitizer, Photofrin II (PII). The objective of the present study was to evaluate whether intravesical (i.b.) instillation of photosensitizers for PDT of bladder cancer might be a more suitable treatment method. Female Fischer rats were utilized to develop orthotopic and heterotopic bladder tumor models. Rats bearing orthotopic bladder tumors were treated either intravesically or intravenously with graded doses of 5-aminolevulinic acid (ALA) or PII. Normal rats received the same doses of ALA or PII. As well, rats bearing heterotopic tumor were studied for comparison. The biodistribution times (times allowed for tissue uptake and bioconversion following drug administration) were 2, 4 or 6 h. Porphyrin fluorescence intensities within tumor, urothelium, submucosa, bladder muscularis and abdominal muscle were quantitated by confocal laser scanning microscopy. Following intravenous (i.v.) injection of ALA, tumor protoporphyrin IX (PpIX) levels peaked at 4 h and diminished by 6 h. The PpIX ratios of tumor-to-bladder mucosa, submucosa and muscle layers were 3:1, 5:1 and 8:1, respectively, 4 h following 1000 mg/kg ALA injection. After ALA instillation, the optimal biodistribution time appeared to be 4 h. Bladder instillation provided comparable tumor labeling with the i.v. route, but lost selectivity of PpIX accumulation between tumor and normal urothelium. The PpIX ratio of tumor-to-bladder muscularis was 5:1. After i.b. instillation of PII, porphyrin fluorescence was detected only within tumor and urothelium, while porphyrin fluorescence was mainly located in bladder submucosa following i.v. injection. Intravesical administration of ALA or PII might be feasible for PDT of superficial bladder cancers.

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