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Biomedical subjects

U Schrader

Publications and source records attributed to U Schrader.

11 recordsLinked to original sources

Quality criteria for electronic publications in medicine.

This paper defines "electronic publications in medicine (EPM)" as computer based training programs, databases, knowledge-based systems, multimedia applications and electronic books running on standard platforms and available by usual distribution channels. A detailed catalogue of quality criteria as a basis for development and evaluation of EPMs is presented. The necessity to raise the quality level of electronic publications is stressed considering aspects of domain knowledge, software engineering, media development, interface design and didactics.

Publishing

Computer-based training and electronic publishing in the health sector: tools and trends.

CBT (computer-based training) applications and hypermedia publications are two different approaches to the utilisation of computers in medical education. Medical CBT software continues to play a minor role in spite of the increasing availability, whereas hypermedia have become very popular through the World Wide Web (WWW). Based on the HTML format they can be designed by non-programmers using inexpensive tools while the production of CBT applications requires programming expertise. HTML documents can be easily developed to be distributed by a web-server or to run as local applications. In developed countries CBT and hypermedia have to compete with an abundance of printed or audio-visual media and a wealth of lectures, conferences, etc., whereas in developing countries these media are scarce and expensive. Here CBT programs, and hypermedia publications in particular, may be a cost-effective way to improve quality of education in the health sector.

Computer Communication Networks

Critical success factors for a hospital-wide PACS.

Since 1996 a picture archiving and communications system (PACS) is installed at the university hospital of Freiburg. The PACS is integrated in the hospital information system (HIS) and several modalities of different vendors are attached to it. During the implementation phase three critical factors to the success of our PACS installation where identified: the support of the workflow, the interface of the radiological information system (RIS) to the modalities, and the security policy to allow hospital-wide access to the images and results in the PACS.

Computer Security

CareBase: a reference base for nursing.

Due to the lack of generally accepted nursing classifications and standards in Germany the introduction of nursing information systems for planning and documentation of care is a very time consuming process since the classifications and standards must be defined locally to adjust the systems. At the University Hospital Freiburg a nursing reference system was developed to collect this knowledge, make it available for easy reference and as a source usable for the initialisation of nursing information systems to be installed in the future.

Humans

[3H]naloxone as an opioid receptor label: analysis of binding site heterogeneity and use for determination of opioid affinities of casomorphin analogues.

The nonselective antagonist [3H]naloxone was used to identify opioid receptors in rat brain membranes. The multiple naloxone binding sites were related to different opioid receptors by means of selective opioid ligands as well as various beta-casomorphin analogues. Analysis of binding site heterogeneity was performed using several computer curve fitting methods. The results indicate that structurally modified casomorphin peptides are able to discriminate between mu 1- and mu 2-binding sites. The affinities to the mu-sites obtained with [3H]naloxone as label are in a good agreement with those from experiments with the mu-selective radioligand [3H]DAGO. The mu 1-site affinities of these casomorphin derivatives are well correlated with their antinociceptive potencies. This finding suggests the mediation of the analgesic activity via the high-affinity mu 1-subtype.

Affinity Labels

[Follow-up study of accuracy of fit of crowns, prepared for phantom head under practice conditions].

Mesial, distal, oral and vestibular measurement of fissure spaces in 39 crowns and 51 bridges (divided with interlock-connection) made in the context of propedeutic instruction showed a mean marginal discrepancy of 62-90 microns in a range of 30-160 microns. A simple method to evaluate the fissure space was described. In actually discussion the results would be helpful to determine criterions for quality on fixed restorations.

Crowns

Opioid receptor affinities of the blood-derived tetrapeptides hemorphin and cytochrophin.

Hemorphin-4 and cytochrophin-4 displayed affinities for mu- and delta-opioid receptors that were in the same range as those observed for the structurally related beta-casomorphins. However, they showed markedly higher affinities at kappa-opioid binding sites when compared to the beta-casomorphins. These blood-derived peptides could be involved in blood pressure regulation.

Animals

Nonopioid effects of beta-casomorphin-5 in guinea pig heart: alterations to the beta-adrenoceptor-G-protein complex and inhibition of myocardial responses to isoproterenol.

The influence of beta-casomorphin-5 on the beta-adrenoceptor complex in guinea pig heart membranes was studied by means of binding studies, G-protein investigations and isolated heart preparations. In nanomolar concentrations beta-CM-5 induced an increase in receptor affinity towards the agonist isoproterenol whereas the antagonist affinity was reduced. The isoproterenol-stimulated increase in cardiac contractility, moreover, is reduced by 10 nM beta-CM-5. Furthermore, beta-CM-5 was found to inhibit the isoproterenol-induced GDP/GTP exchange as well as the [35S]GTP[S] binding to guinea pig heart membranes, indicating an involvement of G-proteins. These findings suggest that low concentrations of beta-CM-5 modulate the functional properties of the myocardial beta-adrenoceptor-G-protein complex, presumably resulting in its desensitization. The observed effects of beta-CM-5 are not prevented by naloxone and, therefore, are nonopioid in nature.

Amino Acid Sequence