Thomas Zwergel

Novel amplification unit at chromosome 3q25-q27 in human prostate cancer.

In prostate carcinoma, amplification of the genes c‐MYC, Her2/NEU, and the androgen receptor gene has been documented, with gene amplification being related to progressive tumor growth. Recently, using comparative genomic hybridization (CGH), we provided evidence for DNA copy number gains at chromosome 3q25–q26 in prostate cancer [Sattler et al.: Prostate 39:79–86, 1999].

Comparative genomic hybridization reveals DNA copy number gains to frequently occur in human prostate cancer.

Despite intensive studies over many years, there is only limited knowledge on the genetic changes underlying the development and progression of prostate cancer. No specific prostate carcinoma‐related genetic event has yet been identified.

Long-Term Results following Transurethral Resection of the Prostate

Two subsets of a single-center study population with benign prostatic hyperplasia (n(1) = 232; n(2) = 214) undergoing transurethral resection (TUR) of the prostate (TURP 1979 and 1995) entered a retrospective study designed to examine the long-term follow-up. The actual data were assessed with a patient-addressed questionnaire. Preoperative voiding patterns did not differ significantly; postoperative micturition revealed comparable results for both groups. Mortality and TUR syndrome rates were reduced to very low levels. The most significant improvement was found in blood transfusions. The postoperative incidence of urethral stricture (1.7 vs. 1.5%) or bladder neck contracture (2.7 vs. 2.4%) were low and did not alter significantly. Urinary incontinence changed for both collectives (11.4 vs. 3.3%). Urodynamic investigations revealed that all (n = 21) but 1 of the patients with TURP 1979 had the incontinence due to different bladder dysfunctions, but not because of postoperative stress incontinence. The questionnaire about the patient’s actual contentment after TURP 1979 showed 79% of the patients still satisfied, 12% neutral and 9% dissatisfied with their micturition. Overall the patients reported a generally favorable view of TURP outcome in the long-term follow-up.

Results and clinical management of extracorporeal piezoelectric lithotripsy (EPL) in 1321 consecutive treatments

SummaryThe Piezolith 2200 uses piezoelectrically generated high-energy sonic pulses for extracorporeal urinary stone disintegration. The generator is self-focussing. Calculi as small as 1 mm in diameter can be localized by an integrated ultrasound location system. As treatment with the Piezolith does not cause any pain, patients are treated without anesthesia and without analgesia. Considering that cardiac arrhythmia does not occur with the piezoelectric equipment, the procedure is preferred for treatment of high-risk cardiac patients. Since the lithotriptor consists of a special mobile table with an opening in the surface to apply shock waves, the correct focus-position for lithotripsy can be found without difficulty, even in obese or small patients, or those with skeletal deformations.From January 1986 to August 1987, 740 patients representing 764 renal units were successfully treated. A total of 710 calculi (92.9%) were located in the kidney; the rest (7.1%) consisted in stones of the upper and lower ureter treated in situ. To reduce post-therapy auxiliary procedures, internal stents are applied retrogradely in all calculi larger than 15 mm.

Focal intratumoral heterogeneity for telomerase activity in human prostate cancer.

PURPOSE The value of telomerase activity as a marker in clinical decision-making is closely related to how representative the analysis of a small tumor sample is for the whole tumor. We therefore evaluated the intratumoral distribution pattern of telomerase activity in prostatic carcinomas. MATERIALS AND METHODS From 50 prostate cancer patients treated with radical prostatectomy, telomerase activity was determined using the telomeric repeat amplification protocol (TRAP assay). Comparative analysis of at least two separate cancer areas from a single tumor was performed in 42 cases. RESULTS Telomerase activation has been demonstrated in 90% of the prostatic carcinomas. Focal intratumoral heterogeneity was found in 38.1% of the tumors with at least two different areas examined. Telomerase positivity of all samples from one given tumor was detected in 50%, telomerase negativity of all samples in 11.9%. A heterogeneous telomerase activity pattern was more frequently detected in tumors with a Gleason score < or = 7 than in those with a Gleason score > 7. Furthermore, there was an increase in the proportion of homogeneously telomerase-positive tumors with increase in severity of the Gleason score. The differences reached statistical significance. Telomerase activity was also detected in non-cancerous prostatic tissue samples. CONCLUSIONS Telomerase activation is nearly ubiquitous in prostatic carcinomas, although a heterogeneous telomerase activity pattern within tumors might produce a false-negative result in the telomerase activity assay. This limits the value of telomerase activity assays for diagnostic means. There is evidence for a shift from telomerase-negative prostate cancer tissue toward telomerase positivity during the progression process of prostate cancer. The relatively high proportion of telomerase-positive nonmalignant prostatic tissue samples argues against cancer-specificity of telomerase activation.

A new serial transfer explant cell culture system for human prostatic cancer tissues preventing selection toward diploid cells

An improved explant cell culture technique to avoid selection of prostatic adenocarcinoma cells toward diploid cells is described. This method is based on 1) histologically characterized tissue explants, 2) the use of polyethylenteraphthalate (PET) membranes as growth surface, which are part of special inserts in six-well-plates to allow 3) cocultivation with heterologous fibroblasts, and 4) coating of the membranes with elements of the extracellular matrix. The main characteristic of this particular approach is the serial transfer of the tissue explant from one membrane to the other. Up to ten serial transfer steps could be performed to produce cell monolayers growing out of the same tissue specimen. Using this approach, 21 prostatic carcinoma specimens that were obtained from 13 primary prostatic adenocarcinomas after radical prostatectomy were cultivated. Ploidy of the cells was monitored by fluorescence in situ DNA hybridization using the centromere specific DNA probes pUC1.77, p alpha 7t1, and pY3.4. Interestingly, a high aneuploidy rate of the cell cultures was found with maintainance of aneuploidy in 18 (86%) of the 21 paraffin-embedded cancer tissue specimens with proved aneuploidy. Although a slight decrease of the proportion of aneuploid cells during serial transfer was observed, significant aneuploid cell populations were retained up to a maximum of ten transfer steps. These findings indicate that selection toward diploid cells can be prevented by improved cell culture techniques that mimic the in vivo situation.

Selection toward diploid cells in prostatic carcinoma derived cell cultures

For elucidation of the growth‐regulatory mechanisms in prostatic carcinoma, in vitro investigations on prostatic cell cultures are required. However, one major problem of cell culturing is the selection of particular cell types such that the cell lines representing only some of the features as compared with the tumor of origin. We studied the chromosomal composition of 20 prostatic tissue‐derived cell cultures and 12 original (fresh) tissue specimens that were obtained from 13 patients with prostatic adenocarcinoma. Using fluorescence in situ DNA hybridization (FISH), evident clonal abnormalities were detected in 78% of the fresh cancer samples and in 47% of the cultured cancer samples. Of the seven cases revealing clonal abnormalities in the fresh cancer specimen, aneuploidy was detected in only two samples after cell culturing at the earliest passage studied. The aneuploid cell populations in the cultured samples were all lost during progressive subcultivation (after passage 4). Interestingly, by performing FISH on cytogenetic preparations aneuploidy was confined to the interphases, with the metaphases being found to be diploid. This finding indicates that the aneuploid cells have a proliferation disadvantage in cell culture resulting in an overgrowth of diploid cells.

Effects of Prostaglandins and Prostaglandin Synthetase Inhibitors on Acutely Obstructed Kidneys in the Dog

An intact canine model was developed to study the effects of prostaglandins (PG) and prostaglandin synthetase inhibitors on acutely obstructed kidneys. Totally implanted nephrostomy tubes were placed to measure renal pelvic pressure. Complete ureteral obstruction was obtained with a Fogarty balloon catheter inflated in the distal ureter; by this method renal pelvic pressure reached 40-50 mm Hg. Renal pelvic pressure was reduced after intravenous indomethacin and dipyrone administration, whereas blood pressure showed no major changes. Exogenous prostaglandins had both immediate and contrary effects: PGE2 caused a significant decrease, whereas PGF2 alpha caused a significant increase in renal pelvic and blood pressure. The reduced rise in renal pelvic pressure appears to be the main reason for the analgesic effects of prostaglandin synthetase inhibitors. The efficiency of these drugs in the treatment of renal colic is supported by this study, that of prostaglandins cannot be proved.

Effects of prostaglandin synthetase inhibitors on the upper urinary tract

SummaryProstaglandin inhibitors such as indomethacin have been used for the treatment of renal colic. While opioids have a central analgesic effect, the effects of indomethacin are mainly peripheral, acting directly on the kidney. Pharmacourodynamic investigations of the upper urinary tract in men have demonstrated that intravenous indomethacin reduces renal pelvic pressure. These effects are more intense with indomethacin than with metamizol and are not found with hyoscine butylbromide. We have determined that indomethacin reduces the smooth muscle activity of human renal pelvis preparations in a tissue bath. These findings may represent a further possible direct effect of indomethacin on the upper urinary tract during the treatment of renal colic.

Two different forms of p53 localized differently within cells of urogenital tumours

We analyzed the subcellular localization of p53 in prostate and bladder carcinoma cells. Using laser scanning microscopy and PAb1620, a monoclonal antibody recognizing the wildtype conformation of p53, and another monoclonal antibody directed against the mutant conformation of the protein (PAb240), we found two different subsets of p53 within the same cell. The wildtype subgroup was found in the nucleolus, whereas the mutant protein was confined to the nucleus. The results obtained by immunofluorescence were verified by Western blot analysis and immunoprecipitation. Thus, our findings demonstrate an unusual subcellular localization pattern of p53 in prostate and bladder cancer cells which may indicate another mechanism of inactivation of p53.