[Laser treatment of urethral strictures]. / Die Laserbehandlung von Harnröhrenstrikturen.

Since the late 1970s different laser systems have been applied for the treatment of urethral strictures. Thermal effects adjacent on tissue have made the long term results of Nd:-YAG and Ar+ laser application discouraging. New laser systems (KTP, Excimer, Ho: YAG) still have to prove their efficacy in randomized clinical trials against cold knife urethrotomy.

[Laser coagulation treatment of urothelial tumors of the upper urogenital tract with the Nd:-YAG laser]. / Laserkoagulationsbehandlung von Urotheltumoren des oberen Urogenitaltrakts mit dem Nd:-YAG Laser.

Six patients with upper urinary tract tumors were treated in our department with the Nd:-YAG laser between 1989 and 1993. The average follow-up was 23.8 months. The mean age of the patients was 65.7 years. The patients were selected for organ-conserving treatment because of bilateral synchronous tumors (2 cases), a solitary renal unit (2 cases), renal insufficiency with high surgical risk (1 case) and high surgical risk alone (1 case). Two patients were treated with open tumor excision and laser, two patients with ureteroscopic and percutaneous procedures one patient with percutaneous treatment and one patient with ureteroscopy. Two patients underwent nephroureterectomy; one of them died of metastatic bladder cancer 9 months later. Local relapses were observed in one patient who had been treated endoscopically. In a follow-up period of 6-36 months there were three patients who had no relapses. Three patients received intracavitary therapy. Kidney conserving procedures with the Nd:-YAG laser in patients with upper urinary tract tumors should be reserved for highly selected cases.

Immunocytochemical detection and phenotypic characterization of micrometastatic tumour cells in bone marrow of patients with prostate cancer.

Monoclonal antibodies (mAbs) specific for cytokeratins are potent probes for the identification of disseminated individual epithelial tumour cells in mesenchymal organs such as bone marrow. We have used a monoclonal antibody (mAB) against cytokeratin 18 (CK18) for the detection of individual metastatic tumour cells in bone marrow aspirates from 84 patients with carcinoma of the prostate. CK18+ cells were detected in a sensitivity of 1 per 8 x 10(5) marrow cells using the alkaline phosphatase anti-alkaline phosphatase (APAAP) system for staining. We were able to detect CK18+ tumour cells in the marrow of 33% of patients with stage N0M0 prostate cancers. The incidence of CK18+ cells showed a significant correlation with established risk factors, such as local tumour extent, distant metastases and tumour differentiation. For further characterization of such cells in patients with prostate cancer, we developed an immunocytochemical procedure for simultaneous labelling of cytokeratin component no. 18 (CK18) and prostate-specific antigen (PSA). In a first step, cells were incubated with a murine mAb against PSA, followed by gold-conjugated goat anti-mouse antibodies. In a second step, a biotinylated mAb to CK18 was applied as primary antibody and subsequently incubated with complexes of streptavidin-conjugated alkaline phosphatase, which were developed with Newfuchsin substrate. The binding of gold-labelled antibodies was visualized by silver enhancement. CK18+ cells co-expressing PSA were found in bone marrow aspirates from 5 out of 14 patients with carcinomas of the prostate. The specificity of CK18 for epithelial tumour cells in bone marrow was supported by negative staining of 12 control aspirates from patients with benign prostatic hyperplasia (BPH).(ABSTRACT TRUNCATED AT 250 WORDS)