The most recent experimental work in urology is presented inthis volume. Itcontinues the biennial publication of thereports given at the internationalsymposia for experimentalurological research; the tenth symposium was held in Munichin June, 1990. The wide range of subjects covers renal cellcancer and adenoma, bladder cancer, urinary diversion, uro-dynamics, renal pathophysiology and transplantation as wellas the pathogenesis and treatment of urolithiasis.I. Renal Cancer.- 31 P MRI In Vivo Studies of Human Renal Cell and Transitional Cell Carcinomas Xeno-grafted into Nude Mice.- Characterization of a Differentiation Antigen Defined by Monoclonal Antibody Due ABC 3.- Lymphocyte Subpopulations and Tumor Necrosis Factor during Interferon-? 2b and Interleukin-2 Therapy in Patients with Metastasized Renal Cell Cancer.- Effects of Buthionine Sulfoximine Mediated Glutathione Depletioin in Chemoresistant Human Renal Cell Carcinomas.- Renin-Producing Renal Cell Carcinoma Clinical and Experimental Investigation of a Special Form of Renal Hypertension.- II. Andrology and Testicular Cancer.- Experimental Approach for Assessment of Tumor Biology in Clinical Stage I Nonseminomatous Germ Cell Tumors (NSGCT).- Turbidimetrical Determination of Inflammatory Parameters in Seminal Plasma.- The Arteries of the Spermatic Cord and Testis: A Dynamic Angiographic Study and its Clinical Relevance.- Comparison of Duplex Sonography and Color-Coded-Flow Duplex Sonography for Evaluation of Erectile Dysfunction.- Registration of Cavernous Electrical Activity and its Interpretation.- III. BPH, Prostate Cancer.- Imprint and Scrape Cytology: Advantages and Possible Uses in Urology.- 31 P-NMR Spectroscopy and 1 H Imaging of the Prostate Differences between Benign Hyperplasia and Cancers.- IV. Bladder, Bladder Cancer.- Evaluation of Acute-Phase Proteins for Clinical Monitoring of Urinary Tract Infections and Postoperatively.- Lysosomal Enzymuria in the Diagnosis of Uppelc+