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Biomedical subjects

U Engelmann

Publications and source records attributed to U Engelmann.

160 records · Page 9Linked to original sources
PubMed1978

Experiments on the chemotheraphy of a transplantable glioblastoma in the rat, employing 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU).

A glioblastoma was induced in BD-II rats by weekly i.v. injections of methylnitrosourea and transplanted intracerebrally in numerous passages. The take rate was 100%. For the experiments with CCNU, solid pieces of tumour were implanted into the right parietal region. The cytostatically treated animals lived significantly longer. The untreated tumour rats had an average survival time of 18 days (counted from the time of transplantation), and the rats treated with CCNU had an average survival time of 28 days. The median values were 19 and 28 days.

Animals↗
PubMed1978

[Evaluation of bone structure].

Changes in the bone structure, the periodontal space and the interdental alveolar septa are decisive criteria for evaluating the state of health of the alveolar bone. The pathological processes of alveolar bone destruction are subdivided into: reduction in height, vertical reduction and a mixed from resulting from these two.

Alveolar Process↗
PubMedDate not supplied

Penetration of ampicillin and sulbactam into human epididymis and testis.

Urologic refertilization microsurgery such as vaso-vasostomy or vaso-epididymostomy benefits from perioperative antibiotic prophylaxis. The ability of ampicillin and sulbactam to penetrate sufficiently into mixed epididymis or testis tissue was investigated in nine patients (bodyweights ranged from 58 kg to 92 kg, mean 77.3 kg) undergoing orchiectomy for testicular cancer or advanced prostatic cancer. Each patient received a single infusion of 3 g ampicillin/sulbactam (ratio 2:1) preoperatively for antibiotic prophylaxis. The concentrations of both components were determined in serum and in epididymis/testis tissue samples taken 30 min to 65 min after infusion. Ampicillin was determined by bioassay and sulbactam was determined by gas chromatography/ mass spectrometry. Mean tissue concentrations of ampicillin were 38.5 +/- 15.9 mg/kg. Mean tissue concentrations of sulbactam at the same time were 19.8 +/- 5.2 mg/kg. Comparison of the tissue/serum ratios for both agents showed no significant difference. These values indicate that both compounds achieve high concentrations in the scrotal organs. The concentrations exceed the MIC (minimal inhibitory concentration) values of important bacterial pathogens such as Staphylococcus aureus involved in postoperative wound infections. The combination of ampicillin and sulbactam may be effective for perioperative prophylaxis in reconstructive scrotal urologic surgery.

Adult↗
PubMedDate not supplied

Extending a teleradiology system by tools for 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 three-dimensional-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 a 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 ray-tracing model and the graphics acceleration capabilities of modern workstations. Several tools for volumetric analysis extend the three-dimensional-viewing. They are controlled by adequate input devices to select locations in the data volume, measure anatomical structures or initiate a segmentation process. Moreover, a haptic interface can be connected to provide a more realistic feedback while navigating within the three-dimensional-reconstruction. The work is closely related to research in the field of heart, liver and head surgery. In cooperation with our medical partners the development of tools as presented facilitates the integration of image analysis into the clinical routine.

Humans↗
PubMedDate not supplied

Borderless teleradiology with CHILI.

Teleradiology is one of the most evolved areas of telemedicine, but one of the basic problems which remains unsolved concerns system compatibility. The DICOM (Digital Imaging and Communications in Medicine) standard is a prerequisite, but it is not sufficient in all aspects. Examples of other currently open issues are security and cooperative work in synchronous teleconferences. Users without a DICOM radiological workstation would benefit from the ability to join a teleradiology network without any special tools. Drawbacks of many teleradiology systems are that they are monolithic in their software design and cannot be adapted to the actual user's environment. Existing radiological systems currently cannot be extended with additional software components. Consequently, every new application usually needs a new workstation with a different look and feel, which must be connected and integrated into the existing infrastructure. This paper introduces the second generation teleradiology system CHILI. The system has been designed to match both the teleradiology requirements of the American College of Radiology (ACR), and the functionality and usability needs of the users. The experiences of software developers and teleradiology users who participated in the first years of the clinical use of CHILI's predecessor MEDICUS have been integrated into a new design. The system has been designed as a component-based architecture. The most powerful communication protocol for data exchange and teleconferencing is the CHILI protocol, which includes a strong data security concept. The system offers, in addition to its own secure protocol, several different communication Methods: DICOM, classic e-mail, Remote Copy functions (RCP), File Transfer Protocol (FTP), the internet protocols HTTP (HyperText Transfer Protocol) and HTTPS (HyperText Transfer Protocol Secure),and CD-ROMs for off-line communication. These transfer METHODS allow the user to send images to nearly anyone with a computer and a network. The drawbacks of the non-CHILI protocols are that teleconferences are not possible, and that the user must take reasonable precautions for data privacy and security. The CHILI PlugIn mechanism enables the users or third parties to extend the system capabilities by adding powerful image postprocessing functions or interfaces to other information systems. Suitable PlugIns can be either existing programs, or dedicated applications programmed with interfaces to the CHILI components. The developer may freely choose programming languages and interface toolkits. The CHILI architecture is a powerful and flexible environment for Picture Archiving and Communications Systems (PACS)and teleradiology. More than 40 systems are currently running in clinical routine in Germany. More than 300,000 images have been distributed among the communication partners in the last two years. Feedback and suggestions from the users influenced the system architecture by a great extent. The proposed and implemented system has been optimized to be as platform independent, open, and secure as possible.

Radiology Information Systems↗
PubMedDate not supplied

Sperm motility under conditions of weightlessness.

The aim of this study was to determine the differences in motility of frozen and thawed bull spermatozoa under conditions of weightlessness compared with ground conditions. The tests were performed within a series of scientific and technologic experiments under microgravity using sounding rockets in the Technologische Experimente unter Schwerelosigkeit (TEXUS) program launched in Kiruna, North Sweden. Using a computerized sperm motility analyzer, significant differences were found in sperm motility under microgravity compared with sperm under gravitational conditions on earth. Computer analysis showed alterations in straight line and curvilinear velocity, as well as in linearity values. The amount of progressively motile spermatozoa, including all spermatozoa with a velocity > 20 microns/second, increased significantly from 24% +/- 9.5% in the reference test to 49% +/- 7.6% in the microgravity test. In conclusion, there is strong evidence that gravity influences sperm motility.

Animals↗
PubMedDate not supplied

Modern techniques of sperm preparation--do they influence the sex of offspring?

Four different semen preparation methods--migration-Sedimentation technique, Sperm Select, Percoll gradient centrifugation and swim-up technique--have been tested and compared in regard to progressive motility, viability and morphology. The data obtained clearly demonstrate significant enhancement of all parameters using the techniques mentioned above. The study also demonstrated significant differences in Y chromatin-positive spermatozoa before and after semen preparation. The rate of F-body-positive spermatozoa was significantly increased by all four methods.

Female↗