Search PubMed⌕ Search

Biomedical subjects

U Engelmann

Publications and source records attributed to U Engelmann.

At least 73 records · Page 4Linked to original sources
PubMed1998

Selective expression of inducible nitric oxide synthase in human prostate carcinoma.

BACKGROUND: Nitric oxide (NO) is synthesized by inducible nitric oxide synthase (iNOS) and plays an important role in tumor growth and angiogenesis. NO generation by iNOS also influences the cytotoxicity of macrophages and tumor-induced immunosuppression. Before now, the expression of iNOS in prostate carcinoma tissue had not been determined. METHODS: In this study, tissue sections from 16 patients with prostate carcinoma were studied immunohistochemically and compared with tissue specimens from 10 patients with benign hyperplasia. RESULTS: Positive iNOS immunostaining was detected in all sections from patients with prostate carcinoma. The malignant epithelial cells were highly positive. The antibody against iNOS also marked round cells, which had the same cell shape as that observed for macrophages. These cells were located in stroma and epithelium adjacent to tumor islets. However, round cells in benign tissue stained negative for iNOS. None of the benign hyperplasia specimens stained positive for iNOS immunohistochemically. CONCLUSIONS: Prostate carcinoma tissue had a high iNOS content, whereas benign tissue did not. The authors suggest that epithelial iNOS expression can be used as a specific immunohistochemical marker for prostate carcinoma. NO generation by iNOS may play multiple roles in the development of this disease.

Adenocarcinoma↗
PubMed1998

[Complete urethral rupture with symphysis injury and anterior pelvic ring fracture during spontaneous delivery].

We report on a complete longitudinal rupture of the urethra in combination with a rupture of the pubic symphysis and pelvic fracture during spontaneous vaginal delivery. Only after stabilisation of the pelvic fracture by external skeletal fixation adaptation of the urethra was possible. Three weeks later after removing of the transurethral catheter a mild stress incontinence could be observed. In the follow up one year later the patient was completely continent. The cosmetic result was satisfactory. There was no cystocele. An unclear haematuria after delivery needs a meticulous urological examination. Early repair of urethral disruption minimize the risk of severe incontinence. Coordinated care between the trauma surgeon and urologist is required for successful treatment of this rare combined injury after birth.

Adult↗
PubMed1998

Evidence for the involvement of endothelial nitric oxide synthase from smooth muscle cells in the erectile function of the human corpus cavernosum.

Nitric oxide (NO) is an important mediator in the relaxation of cavernosal smooth muscle. The present study examines the existence and location of the constitutive isoform eNOS (endothelial NO synthase) accompanying the already substantiated neurogenic NOS (nNOS) in the human corpus cavernosum of men with and without erectile dysfunction. Activities of NOS enzymes were examined in specimens of 11 potent and nine long-term impotent patients by means of light and electron microscopy using NADPH-diaphorase staining and immunohistochemical eNOS-specific, smooth muscle actin-specific and nNOS-specific markers. Cavernosal smooth muscle shows a distinct expression of eNOS. In contrast to the weaker expression of eNOS and nitrinergic innervation found in larger veins, the small intracavernosal helicine arteries express large quantities of eNOS and possess a dense nitrinergic innervation. Long-term impotent patients display a broad heterogeneity in eNOS expression and nitrinergic innervation while no overall correlation between NOS expression and erectile function was observed. The expression of eNOS indicates eNOS as a main source of NO alongside nNOS. The differentiated localization of eNOS supports at least a role of this isoform in vascular regulation.

Erectile Dysfunction↗
PubMed1998

The German teleradiology system MEDICUS: system description and experiences in a German field test.

MEDICUS is a teleradiology system which has been developed in a joint project of the German Cancer Research Center (Deutsches Krebsforschungszentrum) and the Transfer Center Medical Informatics (Steinbeis-Transferzentrum Medizinische Informatik) in Heidelberg, Germany. The system is designed to work on ISDN lines as well as in a local area network. Special attention has been given to the design of the user interface and data security, integrity, and authentication. The software is in use in 13 radiology departments in university clinics, small hospitals, private practices, and research institutes. More than 25 thousand images have been processed in 6 months. The system is in use in six different application scenarios. MEDICUS is running under the UNIX operating system. The connection of the modalities could in most cases not be realized with the DICOM protocol as older machines were not equipped with this standard protocol. Clinical experiences show that the MEDICUS system provides a very high degree of functionality. The system has an efficient and user friendly graphical user interface. The result of a comparison with other systems shows that MEDICUS is currently the best known teleradiology system. Cost reductions are already obvious, but additional research has to be performed in this field. An even more powerful commercial successor is currently under construction at the Steinbeis-Transferzentrum Medizinische Informatik in Heidelberg.

Ambulatory Care Facilities↗
PubMed1998

Pneumatic v electrokinetic lithotripsy in treatment of ureteral stones.

Recently, a new device (Combilith) for electrokinetic lithotripsy (EKL) has become available which is very similar to the well-known device for pneumatic (ballistic) lithotripsy (Swiss Lithoclast). The Lithoclast uses air pressure to push a projectile within the handpiece against the end of a metal probe, which is thereby accelerated and thrown like a jackhammer against the stone. In principle, the same stroking movement of a small metal probe is provided by EKL; the difference is that instead of a projectile, a magnetic core within the handpiece is accelerated by the electromagnetic principle. This paper compares the clinical efficacy and the features of the two devices. Testing the devices on a stone model, taking into account stone propulsion, the systems turned out to equally effective regarding stone disintegration. However, stone displacement was more pronounced with the Lithoclast applied on easily breaking stones. In a second experiment, an optoelectronic movement-measuring apparatus (Zimmer camera) was employed to measure the range and velocity of the movement of the probe tip without any contact. The linear acceleration velocity ranged from 5 to a maximum of 12.5 m/sec with both systems, but the maximum height of the stroke was 2.5 mm with the Lithoclast and 1 mm with EKL. After the initial break-up of soft stones, further impact of the probe tip against the stone resulted merely in propulsion; thus, the greater probe stroke height is the cause of the stone displacement. In a clinical trial, 22 ureteral stones were treated with the Lithoclast and 35 with the EKL. The two devices were equally effective in terms of stone disintegration and safety margin. Fixation using a Dormia basket was necessary in 12 cases (8 Lithoclast, 4 EKL). Although a difference in probe stroke height was noted when comparing pneumatic and electrokinetic lithotripsy, there were no clinically significant differences in the efficacy of stone fragmentation or stone-free rates. At the current time, EKL is less costly.

Air↗
PubMed1998

A three-generation model for teleradiology.

This paper proceeds from the definition of teleradiology. It identifies three different generations of teleradiology systems and includes those systems that are not regarded as teleradiology systems by the authors. A list of requirements pertinent to users of first-generation teleradiology systems is introduced. Most of the requirements have been realized in a new generation teleradiology system called CHILI.

Computer Simulation↗
PubMed1998

Cryoablation of localized prostate cancer. Experience in 48 cases, PSA and biopsy results.

OBJECTIVES: As the first German center to perform perineal cryoablation of localized prostate cancer, we present our experience in a series of 48 consecutive patients. METHODS: 7 patients staged T1, 21 with T2 disease and 20 patients with T3 tumor were treated. 62.5% of the patients received neoadjuvant hormonal downsizing. Follow-up ranged from 4 to 27 months with a median of 15 +/- 5.7 months. RESULTS: Positive control biopsies after 6 months were obtained in 0% of T1 tumors, 16.7% of T2 tumors and 26.7% of T3 tumors. Prostate-specific antigen persistence above 1 ng/ml was diagnosed in 14.3, 33.3, and 40%, respectively. Complications were acceptable. 22.9% of the patients had prolonged urinary retention, requiring transurethral resection in 5 patients (10.4%) to relieve obstruction. In 5 cases (10.4%) incontinence was found, in 2 of these patients mild urge incontinence declined over time, in 3 cases moderate to severe stress incontinence developed. Two of these patients were pretreated with radiotherapy. No fistulae were noted. CONCLUSIONS: Cryoablation of the prostate is not a substitution for radical prostatectomy but enables the surgeon to perform a radical curative procedure in patients unfit for other radical forms of treatment or unwilling to undergo these. Long-term follow-up and prospective studies are necessary to define the clinical significance of this procedure.

Aged↗
PubMed1998

Transurethral needle ablation of the prostate: an alternative minimally invasive therapeutic concept in the treatment of benign prostate hyperplasia.

Alternative minimally invasive methods treating benign prostate hyperplasia (BPH) have become more and more important. Transurethral needle ablation (TUNATM) has been demonstrated to be effective in both canine and the human prostate. The goal of our study was to prove the safety, feasibility and tolerance of this new procedure. In this prospective nonrandomized study, 33 patients underwent TUNATM-treatment. One, 3 and 6 months postoperatively, follow-up examinations were carried out assessing urodynamic parameters such as urinary flow rates, residual urine levels, and IPSS-scores. During the last visit additional cystomanometry and urethrocystoscopy were done. Six months postoperatively IPSS-score and residual urine volumes were decreased by 50% (range: 1-72%) and 75% (range: 12-97%). Improvement in maximum flow rate was 63% (range: 5-125%). No serious postoperative complications occurred. After a short 'learning period' most of the treatments where performed as an out-patient-procedure so the patients could leave the hospital without the need for indwelling catheters. The TUNATM appears to be a minimally invasive and safe out-patient procedure for the treatment of selected cases of BPH.

Aged↗
PubMed1998

Cryoablation of localized prostate cancer: neoadjuvant downsizing of prostate cancer with LH-RH analogue depot before cryosurgery.

Radical prostatovesiculectomy, radiation therapy, and complete androgen deprivation are acknowledged therapeutic concepts in the treatment of organ-confined prostate cancer. With cryoablation of the prostate, minimal invasive therapy has become available since 1991. Improvements in cryotechnique and progress in transrectal high-resolution ultrasound permit thermo-induced damage to the whole gland to be curative. Downstaging of prostate cancer by hormone ablative therapy remains a controversial issue at this time, but the use of androgen ablation decreases the size of the prostate gland which facilitates cryosurgery and improves the results. The freezing equipment has a limited capacity, and in certain instances large gland volumes prevent adequate freezing of the prostate. Since percutaneous prostate cryosurgery leaves dead tissue in situ to be resorbed over time, downsizing reduces the amount of necrotic tissue to be resorbed, reducing the potential for complications, particularly abscesses. The use of androgen ablation also increases the deposition of fat in the area of the Denonvillier's fascia, making freezing of the rectum less likely during the procedure. In our study androgen ablative therapy was completed before performing cryosurgery in 26 of 43 patients (58%). The 17 patients not given androgen ablation therapy had gland volumes < 40 ml, tumor volumes < 3 ml, and no evidence of extracapsular tumor. The neoadjuvant therapy consisted of a 3- to 10-month course of leuprolide acetate combined with an antiandrogen.

Androgen Antagonists↗
PubMed1998

The evolution of a German teleradiology system.

This paper describes the evolution of a german teleradiology system. The development started from simple image file transfer, continued with a dedicated teleradiology system and ended up with a general radiology workstation with teleradiology features. The main features, advantages and drawbacks of the different generations are described. The own developments are compared with developments at other places. The influence by standards is also included in this investigation. The latest systems are mainly used by the radiologists and the image transfer for scientific cooperation is nowadays just one of several application fields of teleradiology.

Germany↗
PubMed1998

Extending a teleradiology system by tools for 3D-visualization and volumetric analysis through a plug-in mechanism.

This paper describes ongoing research concerning interactive volume visualization coupled with tools for volumetric analysis. To establish an easy to use application, the 3D-visualization has been embedded in a state of the art teleradiology system, where additional functionality is often desired beyond basic image transfer and management. Major clinical requirements for deriving spatial measures are covered by the tools, in order to realize extended diagnosis support and therapy planning. Introducing the general plug-in mechanism this work exemplarily describes the useful extension of an approved application. Interactive visualization was achieved by a hybrid approach taking advantage of both the precise volume visualization based on the Heidelberg Raytracing Model and the graphics acceleration of modern workstations. Several tools for volumetric analysis extend the 3D-viewing. They offer 3D-pointing devices to select locations in the data volume, measure anatomical structures or control segmentation processes. A haptic interface provides a realistic perception while navigating within the 3D-reconstruction. The work is closely related to research work in the field of heart, liver and head surgery. In cooperation with our medical partners the development of tools as presented proceed the integration of image analysis into clinical routine.

Humans↗
PubMed1997

Distribution of nitric oxide synthase implies a regulation of circulation, smooth muscle tone, and secretory function in the human prostate by nitric oxide.

BACKGROUND: Nitric oxide (NO) is suggested as a mediator involved in the regulation of smooth muscle tone, blood flow, and secretory function of the genitourinary tract and originates from different NO synthase (NOS) isoforms located in endothelial, neuronal, and epithelial structures. The aim of the present study was to determine the location of endothelial and neuronal NOS in the human prostate. METHODS: Histochemical NADPH-diaphorase (NADPH-d) staining, ultrastructural NADPH examination, and NOS immunohistochemistry were performed on histologically verified nonmalignant prostate tissue from normal nonobstructive and hyperplastic obstructive human prostates. RESULTS: In the prostatic tissue, NADPH-d staining and immunohistochemistry with bNOS antibody revealed the existence of a dense nitrinergic innervation of glandular epithelium, fibromuscular stroma, and blood vessels. NADPH-d reaction in glandular epithelium was not confirmed by ecNOS or bNOS immunohistochemistry. In benign prostatic hyperplasia (BPH), the nitrinergic innervation is reduced. The vascular distribution of ecNOS provides evidence for a segmental differentiation of the NO-mediated vascular regulation. CONCLUSIONS: NO plays an important role in the autonomic innervation of all compartments of prostatic tissue. In obstructive BPH, the nitrinergic innervation is reduced compared to that in normal prostate tissue. Further studies are necessary to elucidate the complex role of NO in the prostate.

Aged↗
PubMed1997

[Requirements for a teleradiology system. Experiences with the MEDICUS-2 field test].

During the Medicus field test we gained experience using the teleradiology system for almost daily teleconferences between a radiology department and clinics for internal medicine, urology, and gynecology. The existing system has a high degree of functionality. The full 12-bit data format is available using the DICOM protocol. A data security concept is implemented, ensuring data integrity, privacy and authentication of communication partners. This concept covers the areas of organization, technique, user training, and software implementation. A future system should be a general purpose radiology workstation covering viewing functionality, image manipulation, and digital archive access. Dedicated teleradiology features have to be a part. Specialized evaluation software, e.g. for dynamic MRI, should be integratable in a modular way. For data exchange with other systems and for the synchronization of teleconference sessions, the protocols should be independent of the network standard used (ISDN, Ethernet, ATM) and based on the DICOM protocol. Extensions of the existing standard are therefore necessary. Besides future technical developments, reimbursement for teleradiology must be accomplished.

Computer Communication Networks↗
PubMed1997

[Pattern of distribution of constitutive isoforms of NO synthase in the normal prostate and obstructive prostatic hyperplasia].

Nitric oxide (NO) is suggested as an important mediator for the regulation of biological processes. In the present study we tried to determine histochemically and immunohistochemically the localization and distribution of the constitutive NO-synthase Isoforms (bNOS and eNOS) of 14 normal non-obstructive and 12 hyperplastic obstructive human prostates. Differentiated nitrinergic innervation was shown for the prostate glands, fibromuscular stroma and blood vessels by NADPH-diaphorase staining and immunohistochemically with specific NOS antibodies. In the specimens with benign prostatic hyperplasia nitrinergic innervation seems to be distinctly reduced. The vascular distribution of NOS provides evidence for segmental differentiation of NO-mediated vascular regulation. The NADPH-diaphorase reaction was not confirmed immunohistochemically by the specific NOS antibody in the glandular epithelium. The distribution of NO synthase shows the importance of nitric oxide in the regulation of smooth muscle tone, blood flow and secretory function in the normal and hyperplastic human prostate.

Adult↗
PubMed1997

How to deal with security issues in teleradiology.

The use of teleradiological systems for medical image communication is increasing significantly. Digital images can be transferred over public telephone (e.g. ISDN) lines to colleagues for interpretation and/or consultation. Thus, a new quality is being introduced into the process of radiological diagnostics. However, technical implementation of such systems is accompanied by little consideration of legal, i.e. data protection and security, issues. In this paper we describe a concept for data protection in teleradiology which unites aspects of privacy and security as well as user aspects. After highlighting the legal situation in Germany we describe the methodology used for deriving the security profile for teleradiology in Germany. As a result the set of security measures which have to be employed with a teleradiology system is listed. A detailed description follows of how the software requirements are implemented in the teleradiology software MEDICUS.

Computer Security↗
PubMed1997

Experiences with the german teleradiology system MEDICUS.

This paper introduces the teleradiology system, MEDICUS, which has been developed at the Deutsches Krebsforschungszentrum (German Cancer Research Center) in Heidelberg, Germany. The system is designed to work on ISDN lines as well as in a local area network. The global software architecture is explained in the article. Special attention has been given to the design of the user interface and data security, integrity and authentication. The software has been evaluated in a German field test at 13 radiology departments in university clinics, small hospitals, private practices and research institutes. More than 30 thousand images have been transmitted using this system during a 9 month period. Realized application scenarios are: in-house communication, image and report delivery to referring hospitals, remote reporting, radiotherapy treatment planning and research cooperation. Experience has shown that the system is easy to use and saves time. It obviates the need for patient transport and reduces film costs. Experiences of individuals while using the system during the field test helped define the functionality of the second generation teleradiology system which is even more flexible and is also available as a commercial product.

Computer Communication Networks↗
PubMed1997

Nuclear medical assessment of penile hemodynamics following revascularization surgery.

Variations of Hauri's penile revascularization have been in clinical use since 1983. The hemodynamics of the so-called three-vessel anastomosis remain uncertain despite successful, clinically reproducible results. The goal of this study was to depict the increased perfusion of the erectile system of the penis following revascularization by means of the inferior epigastric artery. Ten milliliters of heparinized peripheral venous blood was drawn from 10 patients prior to surgery. The radioactively tagged erythrocytes (1 mCi 99mTc) were reinjected via an additional incision in the donor vessel proximal to the anastomosis following completion of the three-vessel anastomosis and intracavernous injection of 20 micrograms PGE1. Once again, blood was drawn during the tumescence phase from both a peripheral vein and the corpora cavernosa within the normal circulatory duration and compared to the original specimen. Eight of ten patients displayed evidence of primary reperfusion of the corpora cavernosa via the inferior epigastric artery as the donor vessel. Using strict indications, revascularization of the penis is an effective mode of therapy for arterial erectile dysfunction.

Anastomosis, Surgical↗