Bernd Tillig

Chronology and urodynamic characterization of micturition in neurohormonally induced experimental prostate growth in the rat

The purpose of this study was to evaluate the impact of chronic urinary tract obstruction which was produced in the rat using neurohormonally induced experimental prostate growth. In this model, we considered the chronology of changes in the micturition characteristics of awake rats relative to prostate weight and stiffness. The corresponding urodynamic characteristics of both the upper and lower tracts were evaluated in anesthetized animals relative to the development and extent of the obstruction produced.

Effect of ?1 adrenoceptor antagonist on the urodynamics of the upper and lower urinary tract of the male rat

In this investigation, we examined the impact of the α1 adrenoceptor (α1‐ADR) antagonist prazosin on the urodynamic characteristics of upper urinary tract function and associated micturition characteristics of the adult male rat. The focus of the study was to evaluate the extent to which prazosin affects urine production and ureteral transport relative to its effect on micturition. Control micturition studies were first performed using 28 awake Sprague‐Dawley rats that were placed in metabolic cages for characterization of the frequency and mean and total volume voided over a 4‐hr period. Following the control studies, the effect of intraperitoneal prazosin, 30 μg/kg, was evaluated under identical conditions. Urodynamic studies were done to identify the bladder filling and voiding characteristics of anesthetized rats that were infused with saline at a rate of 0.22 ml/min. From the urodynamic studies the parameters of bladder pressure (Pves) and volume (V) during filling, urethral opening (Puo) measured at the moment of micturition, and maximum detrusor pressure during voiding (Pdetmax) were evaluated. External sphincter electromyography was also monitored and recorded together with bladder pressure during voiding. Renal pelvic pressure was measured via a nephrostomy catheter and recordings were made simultaneously with bladder filling and voiding. The upper urinary tract was visualized using microscopic video imaging of the ureter, contrasted by perfusing the renal pelvis with indigo carmine. Characterization of upper tract transport was made in terms of renal pelvic pressure, ureteral peristaltic rate, and bolus length and velocity. The results show that in the awake rat, 30 μg/kg of prazosin decreased the urine production rate from 4.8 ± 0.074 to 1.6 ± 0.23 ml (P < 0.001) and micturition frequency by a similar proportion from 1.99 ± 0.44 to 0.53 ± 0.08/hr. In the lower urinary tract, prazosin did not change the baseline pressure of the bladder but produced significant dose‐dependent decreases in Pdetmax, Puo, and frequency of micturition. In the upper urinary tract, ureteral and pelvic frequencies decreased, whereas the length of bolus increased significantly corresponding to increased doses of prazosin. These results suggest that, although prazosin facilitates micturition by reducing urethral opening pressure, it also reduces the rate of urine production and modulates the function of urine transport in the upper urinary tract. Neurourol. Urodynam. 17:213–229, 1998.

A new concept for a real-time ultrasound transmission camera

Ultrasound transmission imaging is an alternative promising modality because unlike x-ray transmission this concept is not ionizing and has a good contrast in tissue imaging. Our concept enables also real time imaging. Earlier designs of transmission cameras with a 2D-array and an acoustic lens suffered from high costs, large size and a limited imaging quality, which finally caused those cameras not to become a commercial product. We developed a novel compact low-cost ultrasound transmission camera. With a center frequency of 3 MHz a resolution of 1 mm in both lateral dimensions was achieved over a field of view of 80/spl times/80 mm/sup 2/. Real time images of moving joints and tendons are displayed with a frame-rate of 25 1/s. The major fields of application are orthopedics, pediatrics and diagnosis of rheumatic arthritis.

Videomicroscopic imaging of ureteral peristaltic function in rats during cystometry

Videomicroscopic imaging of the upper urinary tract was performed in 26 female anesthetized rats during bladder filling and micturition. Recordings were made of the pressure of the renal pelvis through a nephrostomy and visualization of the dynamics of the ureteral bolus. Peristaltic velocity, frequency, bolus length, and direction urine bolus propagation were derived on the basis of image processing using indigo carmine for contrast. In addition, nonstop cystometrograms were performed at an infusion rate of 0.22 ml/min characterizing bladder filling and micturition reflexes. Using this setup the pharmacological response of the upper and lower urinary tract dynamics to intravenous oxybutynin and LY274614 was evaluated and compared to observations made with placebo time controls. The data, obtained from the time controls, indicate that there is a significant time-dependent influence on the upper urinary function caused by the experimental methodology in the frequency of ureteral peristalsis and length of the bolus. Oxybutynin produced a significant increase in the length of the but not in the velocity of the bolus. LY274614 depressed pelvic pressure and ureteral frequency and increased bolus length. It is concluded that videomicroscopic imaging, in association with nonstop cystometry, provides a unique method to investigate the pharmacological effects of centrally and peripherally acting drugs on the upper and lower urinary tract function without mechanical manipulation of the ureter.

Diversity of Service Systems in Pediatric Surgery for Fetuses, Neonates, Infants, Children, and Adolescents in Europe

D ramatic improvements in surgical care have allowed neonates, children, and adolescents who once would have perished to survive. For example, there are novel therapeutic approaches to organ failure or congenital anomalies managed by surgeons that have led to improvements in survival and quality of life. These changes have been driven by evidence in most cases. The clinical management of children with rare diseases was often based on registries and multicenter trials, for example, the European biliary atresia registry. However, the same cannot be said of the models and pathways of surgical care used in different European child health care service systems. These systems were often products of history and not of science. Arbitrary divisions, such as which services are provided in a general hospital, in a children’s hospital, or in the community, may have their origins in professional boundaries established decades ago. “Many things that should be done are not.” To avoid fragmentation of child health care services and to integrate surgical centers into the organizational structure of primary, secondary, and tertiary pediatric care is of utmost importance. A successful approach should include centralized organization, coordination, and decision making by special designated centers of pediatric surgery and a decentralized provision of treatment whenever possible to guarantee childfriendly health care. We offer a grounded basis for discussion on which the future of pediatric surgery in Europe should be organized. We provide a short summary of 3 published surveys and 1 ongoing survey on the organization of pediatric surgery in a representative number of European countries.

Einsatzmöglichkeiten der Transmissionssonographie in der Kinderchirurgie

Zielsetzung: Bereits in den 1930er Jahren wurde die Transmissionssonografie als Alternative zur konventionellen Rontgenuntersuchung entwickelt. Mit diesem Verfahren konnen unter Nutzung von transmittierten Schallwellen in Echtzeit ahnliche Bildinformationen wie mit der Rontgendurchleuchtung erziehlt werden. Aufgrund bisheriger technischer Unzulanglichkeiten hat sich dieses Verfahren bisher jedoch noch nicht in der klinischen Praxis etabliert. Ziel der Untersuchungen war die Uberprufung der Einsatzmoglichkeiten der Transmissions-sonografie in der Kinderchirurgie im Vergleich zur konventionellen Rontgendiagnostik und der Echosonografie. Material und Methoden: Fur die aktuellen Untersuchungen wurde ein von der Siemens AG, Corporate Technology, in Zusammenarbeit mit dem Institut fur Hochfrequenztechnik der Ruhr-Universitat Bochum entwickelter, prinzipiell neuartiger Prototyp einer Ultraschall-Transmissionskamera angewendet, Die Studie beinhaltet die Anwendung der Transmissionssonografie zur Darstellung von Verletzungen im Bereich des Sehnen- und Bandapparates der Extremitaten von Kindern sowie die Darstellung innerer Organe bei Neugeborenen und Sauglingen im Vergleich zur konventionellen Sonografie und Rontgendiagnostik. Ergebnisse: Mit Hilfe der Transmissionssonografie konnen Bewegungsablaufe im Bereich der Sehnen und Gelenke bei Kindern dargestellt und dokumentiert werden. Bei Neugeborenen und Sauglingen ist es moglich, die abdominellen Organe darzustellen, wobei durch Einsatz von Kontrastmittel die Aussagefahigkeit der Untersuchung noch wesentlich erhoht werden kann. Die Hauptvorteile der Transmissionssonografie gegenuber dem konventionellen Rontgen und der Echosonografie bestehen darin, das eine ‚Durchleuchtung’ des Korpers in Echtzeit ohne Belastung durch ionisierende Strahlen moglich ist. Die bisherigen Untersuchungen haben gezeigt, das bei der Transmissionssonografie ein deutlich hoherer Weichteilkontrast erreicht werden konnte. Zusammenfassungg: Die Transmissionssonografie ist ein neues digitales Verfahren zur Bildgebung. Sie bietet eine Erweiterung des Anwendungsspektrums und hat im Vergleich zur konventionellen Echosonografie und Rontgendiagnostik in einzelnen bekannten Anwendungsbereichen Vorteile. Fur die routinemasige klinische Anwendung dieser Methode sind weitere technische Verbesserungen hinsichtlich der Bildqualitat und des Anwendungsmodus (Applikation) sowie weitere klinische Studien erforderlich.

NEW DEVELOPMENT OF AN ULTRASOUND TRANSMISSION CAMERA

Several research groups developed transmission ultrasound systems for diagnostic imaging with promising qualities during the 1970s and 1980s. In comparison to x-ray systems, which have comparable imaging modalities like the orientation of the images, transmission ultrasound systems invoke no radiation and image definite slices within an object, where x-ray systems image the integrated attenuation along the rays. Compared with pulse-echo systems, transmission devices measure the transmitted (attenuated) part of the acoustic waves and the orientation of the cross-sectional slices is transversal to the sound propagation direction.