Showing papers by "Danube University Krems published in 2004"

Construction of a functional S-layer fusion protein comprising an immunoglobulin G-binding domain for development of specific adsorbents for extracorporeal blood purification.

Abstract: The chimeric gene encoding a C-terminally-truncated form of the S-layer protein SbpA from Bacillus sphaericus CCM 2177 and two copies of the Fc-binding Z-domain was constructed, cloned, and heterologously expressed in Escherichia coli HMS174(DE3). The Z-domain is a synthetic analogue of the B-domain of protein A, capable of binding the Fc part of immunoglobulin G (IgG). The S-layer fusion protein rSbpA31-1068/ZZ retained the specific properties of the S-layer protein moiety to self-assemble in suspension and to recrystallize on supports precoated with secondary cell wall polymer (SCWP), which is the natural anchoring molecule for the S-layer protein in the bacterial cell wall. Due to the construction principle of the S-layer fusion protein, the ZZ-domains remained exposed on the outermost surface of the protein lattice. The binding capacity of the native or cross-linked monolayer for human IgG was determined by surface plasmon resonance measurements. For batch adsorption experiments, 3-μm-diameter, biocompatible cellulose-based, SCWP-coated microbeads were used for recrystallization of the S-layer fusion protein. In the case of the native monolayer, the binding capacity for human IgG was 5.1 ng/mm2, whereas after cross-linking with dimethyl pimelimidate, 4.4 ng of IgG/mm2 was bound. This corresponded to 78 and 65% of the theoretical saturation capacity of a planar surface for IgGs aligned in the upright position, respectively. Compared to commercial particles used as immunoadsorbents to remove autoantibodies from sera of patients suffering from an autoimmune disease, the IgG binding capacity of the S-layer fusion protein-coated microbeads was at least 20 times higher. For that reason, this novel type of microbeads should find application in the microsphere-based detoxification system.

Pyrogen transfer across high- and low-flux hemodialysis membranes.

Abstract: The extent to which bacterial products from contaminated dialysate enter a patient's blood depends upon the type and permeability of the hemodialysis membrane in use. This study was performed to assess the transfer of pyrogenic substances across both high- and low-flux membranes (DIAPES, Fresenius Polysulfone, Helixone, Polyamide S). All experiments were carried out in the saline-saline model. The dialysate pool was contaminated either with purified lipopolysaccharide (LPS) (250 and 500 EU/mL) or with sterile bacterial culture filtrates (20 EU/mL), and in vitro dialysis was performed under diffusive and convective conditions. A significant transfer of endotoxin was observed for both low- and high-flux DIAPES challenged with either LPS or with bacterial culture filtrates. Under identical conditions, no transfer of endotoxins was detectable across Fresenius Polysulfone and Helixone upon challenge with purified LPS. With bacterial culture filtrates, endotoxin concentrations for Polyamide S and Fresenius Polysulfone were about 10% and 1%, respectively, of those measured for DIAPES, whereas no transfer of endotoxin was detectable for Helixone. Using an alternative assay (induction of interleukin-1 receptor antagonist, IL-1Ra, in whole blood), only the DIAPES membrane showed the passage of cytokine-inducing substances. Thus, when saline is present in both the blood and dialysate compartments (i.e., the situation during predialysis priming procedures), dialysis membranes differ profoundly with respect to their permeability to endotoxins.

Intercultural Factors in Web-based Training Systems.

Abstract: This paper is based on on-going research carried out in the framework of an EU project aimed at enhancing knowledge management (KM) in enterprises. It deals with the impact of intercultural factors on the accessibility and presentation of eLearning content. It reports on preliminary findings and discusses the issues which have emerged so far in the contextual study and requirements analysis conducted in preparation for designing Web- based training modules. Once the empirical research is completed and the data analyzed, guidelines will be proposed for developing Web-based training modules for culturally heterogeneous user groups sharing the same professional background. Special consideration will be given to interactive and community features.

Intercultural E-government

Abstract: One of the areas in knowledge management is the representation of information, an area of particular importance in e-Government, given the State’s social responsibility towards its citizens. Unlike the private industry, the State is not in a position to select its customers, and has the social responsibility to treat all citizens equally. Given this responsibility, three issues need to be addressed: the duty to provide information, the extent information is to be accessible to disabled individuals and to be provided in other languages.

The new mobility of our society caused by telecommunications

Abstract: There is no job which has remained unaffected by information and communication technology (ICT). Technologies have a profound influence on society and on other and future technologies. With the start of the 21st century we have noted the following change processes in the area of communication technologies: 1) Digitalisation: analogue forms of the media have been digitalised. 2) Less hardware - more software: hardware is being replaced by software. 3) In the future, cable-bound technology will be mobile, whilst mobile technology will be cable-bound. 4) Higher bandwidth. New applications such as video-on-demand require higher transmission rates. New communication networks follow ADSL and UMTS technologies. The demand for communication cannot be satisfied in all parts of the world - communication technologies are related to the financial power of a country or a region. In the richer countries, individuals are turning into "networked egoists "