A new concept of a unified parameter management, experiment control, and data analysis in fMRI: application to real-time fMRI at 3T and 7T.

In functional MRI (fMRI) complex experiments and applications require increasingly complex parameter handling as the experimental setup usually consists of separated soft- and hardware systems. Advanced real-time applications such as neurofeedback-based training or brain computer interfaces (BCIs) may even require adaptive changes of the paradigms and experimental setup during the measurement. This would be facilitated by an automated management of the overall workflow and a control of the communication between all experimental components. We realized a concept based on an XML software framework called Experiment Description Language (EDL). All parameters relevant for real-time data acquisition, real-time fMRI (rtfMRI) statistical data analysis, stimulus presentation, and activation processing are stored in one central EDL file, and processed during the experiment. A usability study comparing the central EDL parameter management with traditional approaches showed an improvement of the complete experimental handling. Based on this concept, a feasibility study realizing a dynamic rtfMRI-based brain computer interface showed that the developed system in combination with EDL was able to reliably detect and evaluate activation patterns in real-time. The implementation of a centrally controlled communication between the subsystems involved in the rtfMRI experiments reduced potential inconsistencies, and will open new applications for adaptive BCIs.

Epstein-Barr virus-induced increase in the concanavalin-A receptor density of established EBV-negative lymphoma lines in vitro.

Infection of two human EBV-genome negative lymphoma lines with the EBV-variants P3HR-I and B95-8 converts the lines to permanent carriers of EBV-DNA and the EBV-determined nuclear antigen. This process is accompanied by a series of biologic changes similar to those in oncogenic transformation by known tumor viruses (e.g. polyoma, SV40, Rous SV). They include altered growth properties and membrane changes, one of which is expressed in an increased agglutinability by Con-A. Although most transformed cell systems are more agglutinable than the non-transformed counterparts it is controversial whether they possess similar or changed numbers of lectin receptors. Since little was known about lectin receptor densities of virus transformed lymphoma cells, we set out to determine the densities of Con-A receptors on the EBV-negative lymphoma lines BJAB and Ramos and their EBV-converted sublines by simultaneous recording of the cell membrane fluorescence of FITC-Con-A and the cell volume using the FLUVO-METRICELL flow cytometer. We found that EBV infection gave rise to cell lines with a significantly elevated Con-A receptor density compared to the EBV-negative parental lines. The similar changes found in a number of independently converted sublines suggest that they are due to the direct or indirect action of the viral genome.

Changes in the protein composition of Epstein-Barr Virus-negative lymphoma cells after EBV-conversion.

Two-dimensional protein separation, combining high resolution isoelectric focussing with SDS gel electrophoresis, was applied to analyse Epstein-Barr Virus (EBV)-induced changes in the protein composition of lymphoma cells. Total lysates of the EBV-negative Burkitt lymphoma lines Ramos and BJAB were compared with their permanently converted EBV-genome positive sublines, after 35S-methionine labelling. Five out of seven EBV-infected lines showed a 68k protein, which was absent from both EBV-free parental lines, and was identified as a glycoprotein (gp 68) by metabolic sugar labelling. We conclude that presence of this protein is a direct or indirect consequence of the presence of the EBV genome.

The influence of laterally inhomogeneous corrosion on electrical and optical calcium moisture barrier characterization.

The reaction of calcium thin films with water - monitored optically or electrically - is widely used for evaluating ultrahigh barrier foils for the encapsulation of organic electronic devices. We studied the common optical and the electrical method and compared them with in situ atomic force microscope topography scans. All three methods were applied at the same sample in parallel in a typical test design containing a gas volume for water distribution next to the calcium layer of 60 and 1000 nm thickness, respectively. The common assumption for the interpretation of such measurement data is laterally homogeneous calcium consumption of the layer from top to bottom. In contrast, we observed a significant ratio of laterally inhomogeneous corrosion of the calcium on the micro-scale for both thicknesses. Some areas were strongly or completely corroded through the whole layer while others exhibited less or no corrosion. Furthermore, those corroded spots grew in lateral direction. As a consequence of lateral inhomogeneous calcium corrosion the electrical calcium measurement method underestimates the amount of calcium left; according to our results this does not affect the water vapor transmission rate (WVTR). Optical data evaluated by Lambert-Beer law underestimate the amount of calcium left as well and also underestimate the WVTR. If the data are evaluated, using a linear relationship between transmission and amount of calcium left, the both values are more precise. The scope of this study is to call attention to the existence of lateral inhomogeneity in calcium corrosion and its impact on the calcium permeation measurements. While more investigations would be needed to quantify the effect of this inhomogeneity on the electrical and optical method in general, the discussion sheds light on the way, calcium test data are influenced by lateral inhomogeneous calcium corrosion. Our observations highlight the need for careful interpretation of calcium test results, but also demonstrate its capabilities for precise ultrahigh barrier measurements.

Hexose transport in Epstein-Barr virus (EBV) negative lymphoma lines and their EBV converted, virus genome carrying sublines.

Increased hexose uptake is a marker for viral transformation, as has been shown in non-human fibroblasts transformed by oncogenic viruses. If this phenomenon is a general expression of viral induced transformation it should also apply on different oncogenic virus-cell systems. Recently two human EBV-negative lymphoma lines were converted to a stable EBV-positive state by infection with EBV. According to their biochemical and biological properties they enable us to study events associated with EBV-transformation. We analysed the uptake of (3H) glucosamine and (3H) 2-deoxy-D-glucose into BJAB and Ramos and their EBV-converted sublines and found a clear increase of the rate of uptake of both sugars in the EBV-positive sublines. Control experiments confirmed that the increased uptake was due to alterations on the level of the hexose membrane carriers and not due to increased metabolism. The observation of increased hexose uptake in the only presented available virus transformed human cell system is a strong argument for the general importance of this transformation-associated membrane change.