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The effect of hydrogen peroxide on certain enzymes contained in endothelial cells was investigated in vitro. Specifically in this study the influence of hydrogen peroxide on the non-specific esterase activity in endothelial cells of the perfused pig aorta was examined. We perfused an isolated segment of the pig aorta for 10 h and added 5, 10, 12, 15 ml 10% hydrogen peroxide to 100 ml perfused medium. In unperfused pig aorta 99.34% of the endothelial cells reacted positive. After 10 h of perfusion without hydrogen peroxide administration 93.25% endothelial cells still showed positive enzyme reactivity. In presence of hydrogen peroxide in the perfusion medium the activity of non-specific esterase was progressively inhibited, finally causing complete inactivation.

Stress incontinence is the most frequent form of incontinence found in females. The usual method of surgery for this is to lift the bladder neck towards cranial and ventral. Two competitive techniques--bladder neck suspension in accordance with Stamey and colposuspension in accordance with Burch--were retrospectively investigated. A total of 95 women underwent surgery and it was possible to evaluate the postoperative course in 46 and 30 (total 76) patients respectively. Initially, both surgical techniques demonstrated a very good success rate (91.3% and 96.7% resp.). However, the continence rate of the Stamey patients deteriorated after 6 weeks down to 78.3% and after more than 2 years only 28.6% of these patients were still completely continent (mean follow-up 40.4 mths), whereas deterioration in the Burch patients was only 87% (mean follow-up 44.25 mths). The disappointing results with the Stamey technique did not correlate with the degree of initial continence. It was noted here that obese patients showed a greater tendency towards regression. The three cases of recurring incontinence after Burch colposuspension were already relapses at the time of surgery. With respect to long-term follow-up, our results with the Stamey method were distinctly poorer than with the Burch technique: Therefore, in our opinion, the Burch colposuspension procedure and fascioplasty should be the method of choice for the management of stress incontinence.

Conservative treatment of genuine stress urinary incontinence in females gained more and more interest. The use of mini-devices is one of the newly developed therapeutical options however, its clinical relevance and longterm-results are still under debate. This review article gives a critical evaluation of the available urethral plugs and regulators and new developments as well according to the long-term-follow-up studies in the literature and own experience with those devices. The continence rates that can be obtained with the different plugs or regulators are dependent upon the degree of stress incontinence, ability to insert the plug and compliance of the patient. Reported longterm results vary between 48% and 100%. The most frequent side effects are urinary infection, haematuria and/or handling problems with the devices. According to the published material it is impossible to give therapeutical standards for treatment of female stress urinary incontinence with urethral mini-devices. Although proper Patient selection might give excellent longterm-results in patient continence rates.

Retroperitoneal haemorrhages mostly occur as a result of trauma. Besides a traumatic origin of retroperitoneal haemorrhage, the other most common cause is an anticoagulation therapy. Further potential sources of retroperitoneal hematoma are benign and malignant tumours of the adrenal gland.

Using ureterorenoscopes with unidirectional flow, the urologist faces a conflict between a good view on one hand and high pressure in the ureter and the pelvic collecting system of the kidney on the other hand. The ureterorenoscope designed by Gelet, which has continuous (bidirectional) flow and separate irrigation and working channels, was compared with the instrument by Pérez-Castro, which has a common irrigation and working access. The features investigated were optical quality, flow-irrigation characteristics, and handling. The latest generation of ureterorenoscopes provides small total diameters because of minimized working channels and fiberoptic image and light transmission. These semirigid instruments combine the features of flexible endoscopes and traditional ureterorenoscopes. The Gelet instrument offers continuous flow, achieved by separation of the irrigation and working channel, and provides a good view even when working instruments are inserted. The additional outlet channel prevents high pressure in the ureter and renal pelvis and offers another access for instrumentation, if necessary, which means maximum safety for the patient. Because the connection of camera and light source on a flexible system is separated from the instrument, ureterorenoscopy is a more convenient procedure for the urologist.

Persistent remnants of the caudal müllerian ducts can manifest in several forms and are often associated with other urogenital disorders, especially hypospadias. Inadequate activity of the müllerian inhibiting factor, in addition to fetal testosterone deficiency, is responsible for this syndrome. The etiology, diagnosis and management of müllerian duct remnants are discussed. A complex case of penile-scrotal hypospadia, hypoplastic prostate gland, testicular ectopia and retrovesical cyst is presented.

The complex and multifactorial phenomenon of urinary stone disease remains unclear. Anatomical and physiochemical theories do not adequately deal with certain aspects of idiopathic calcium oxalate nephrolithiasis in particular or of nephrolithiasis. One of the reasons for this could be that nephrolithiasis is not only a primary disorder but may also be a symptom of other disorders or various pathologic changes in the metabolism of lithogenic substances. Both affirmative and contradictory reports have been published since Randall's first description of papillary calcifications and their possible active role in the genesis of calcium oxalate nephrolithiasis. Our intention is to discuss focal calcified lesions as an etiologic factor of renal stone disease as well as the change from historical to modern concepts regarding the development of medullary calcifications and their relationship to idiopathic calcium oxalate nephrolithiasis.

We developed a new resection device-the Rotoresect -with the aim of reducing morbidity during transurethral resection of the prostate (TURP). During rotoresection, a rotating ablator electrode enables simultaneous tissue coagulation by high-frequency current and mechanical tissue ablation. The tissue ablation rate and the extent of bleeding were quantified ex vivo using a blood-perfused porcine kidney (N = 30) and then compared with loop resection and electrovaporization (grooved roller/Rollerball). Additionally, transurethral rotoresection of the prostate and open partial resection of the liver were carried out in five dogs. With the blood-perfused porcine kidney, we demonstrated that the tissue ablation rate increases with increasing of the coagulation current and rotation speed of the ablator electrode. The Rotoresect achieved a tissue ablation rate comparable to that of the resection loop (5.5-6.0 g/min), which was more than twice the rate achieved by electrovaporization (1.7-2.0 g/min). The extent of bleeding during standard loop resection was many times higher (16.5-18.0 g/min) than that induced by rotoresection and electrovaporization (2.3 g/min). In our in vivo canine trials, we performed transurethral prostate resection and open segmental liver resection with minimal bleeding. The Rotoresect is a promising instrument for ablation of parenchymal organs during transurethral, laparoscopic, and open surgical procedures.

Laser therapy for benign prostatic hyperplasia (BPH) is now the most impressive alternative to transurethral resection of the prostate (TUR-P). Transurethral laser ablation of the prostate (TULAP) is a new technique that combines non-contact and contact laser treatment of BPH. From November 1992 to August 1994, 188 patients were treated by the TULAP technique. Their median age was 70.3 (58-87) years. The mean prostatic volume determined by transrectal ultrasound, was 49.2 ml. A 6-month follow up was possible for 102 patients. The AUA 7-Symptom Score decreased from 29 points preoperatively to 6 points after 6 months. Residual urine volume decreased from 205 ml to 27 ml after 6 months. Maximum flow rate increased from 7.2 ml/s to 19.3 ml/s after 6 months. No severe complications were observed, and in particular no major bleeding or TUR syndrome. We regard the TULAP procedure as an effective treatment alternative for obstructive symptoms caused by BPH.

The effects of a very short pulsed infrared mini-TEA-CO2-laserbeam at the wavelength of 10.6 microns on dentine were studied. The results of the light- and scanning electron microscopic investigation indicated the possibility of a precise removal of hard tooth structure without causing thermal damage of the tissue. Removing material by photoablation leads to a retentive surface on dentine and to a partially closure of the dentinetubuli at the bottom of the treated cavity. Undesirable thermal effects like surface-cracking and carbonisation were not observed.