Die Rolle der Lehrenden in intergenerationellen Lehrveranstaltungen: Eine multimethodale Untersuchung an der Universität Leipzig

Seit über 20 Jahren nehmen Regelstudierende und Seniorenstudierendegemeinsam an Lehrveranstaltungen der UniversitätLeipzig teil. Sie lernen miteinander. Doch lernensie auch voneinander? Lernen sie intergenerationell? Undwelche Rolle nehmen die Lehrenden in diesen intergenerationellenLehr-Lernarrangements ein? Wie können sie einenintergenerationellen Austausch fördern? Im Rahmen eineskooperativen Forschungsprojekts wurden mittels Fragebögen,teilnehmenden Beobachtungen und Interviews die Studierendenmeinungenerhoben. Die Ergebnisse präsentieren einenIst-Stand und zeigen Perspektiven auf

Die Rolle der Lehrenden in intergenerationellen Lehrveranstaltungen. Eine multimethodale Untersuchung an der Universität Leipzig

Seit über 20 Jahren nehmen Regelstudierende und Seniorenstudierende gemeinsam an Lehrveranstaltungen der Universität Leipzig teil. Sie lernen miteinander. Doch lernen sie auch voneinander? Lernen sie intergenerationell? Und welche Rolle nehmen die Lehrenden in diesen intergenerationellen Lehr-Lernarrangements ein? Wie können sie einen intergenerationellen Austausch fördern? Im Rahmen eines kooperativen Forschungsprojekts wurden mittels Fragebögen, teilnehmenden Beobachtungen und Interviews die Studierendenmeinungen erhoben. Die Ergebnisse präsentieren einen Ist-Stand und zeigen Perspektiven auf. (DIPF/Orig.

Evaluation of CDC-mediated by different anti-GD₂ Ab.

<p>Serial dilutions (final concentration of 1.0, 0.5, 0.25, 0.12, 0.06 and 0.03 µg/ml) of murine 14G2a (<b>A</b>, closed circles), chimeric human/murine ch14.18/CHO (<b>B</b>, closed circles), and IL-2 conjugated humanized hu14.18-IL-2 (<b>D</b>, closed circles) were used for CDC. Complement fixation deficient mutants chimeric ch14.18-delta-CH2 (<b>C</b>, closed circles) and humanized hu14.18 (<b>E</b>, closed circles) as well as rituximab (closed triangles) served as negative controls. To show GD₂-dependent specificity of CDC induced, additional controls containing respective anti-GD₂ Ab were pre-incubated with excess of GD₂-mimicking anti-Id Ab ganglidiomab (5 µg/ml; open circles). Data are shown as mean values ± SE of three independent experiments performed at least in triplicates.</p

Evaluation of ADCC-mediated by different effector cell subsets.

<p>Three populations of freshly isolated effector cells of a healthy donor were compared for ADCC: leukocytes (<b>A</b>), PBMCs (<b>B</b>) and granulocyte rich fraction (<b>C</b>). ADCC were performed using calcein-AM-based cytotoxicity assay as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0107692#s2" target="_blank">Materials and Methods</a>. Effector cells were incubated with 10 µg/ml ch14.18/CHO (closed circles) and calcein-labeled target cells LA-N-1 at different E:T ratios (80∶1, 40∶1, 20∶1, 10∶1, 5∶1, 2.5∶1 and 1.25∶1) and ADCC mediated by leukocytes (<b>D</b>), PBMCs (<b>E</b>) and effector cells of granulocytes rich fraction (<b>F</b>) were examined. In order to simulate the use of IL-2 in combination with ch14.18/CHO in clinical trials, effector cells were incubated for 64 h in cell culture medium supplemented with 1,000 IU/ml IL-2. ADCC mediated by IL-2 treated leukocytes (<b>G</b>), IL-2 treated PBMCs (<b>H</b>) and IL-2 treated cells of granulocyte rich fraction (<b>I</b>) were calculated as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0107692#s2" target="_blank">Materials and Methods</a>. Rituximab served as a negative control (closed triangles). GD₂-specific ADCC of NB cells was demonstrated by pre-incubation of ch14.18/CHO with excess of anti-Id Ab ganglidiomab (open circles). Data are shown as mean values ± SE of three independent experiments performed at least in triplicates. (<b>J</b>) Comparison of ADCC mediated by leukocytes at E:T ratio of 40∶1 and PBMCs at E:T ratio 20∶1 isolated from the same blood sample of five selected NB patients treated with a combination of IL-2 and ch14.18/CHO (black columns). Rituximab served as a negative control (white columns).</p

Genetic aberrations of <i>de novo</i> neuroblastoma cell lines.

<p>Genetic aberrations of <i>de novo</i> neuroblastoma cell lines were evaluated using high resolution SNP array analysis. N.D; not done.</p><p>Genetic aberrations of <i>de novo</i> neuroblastoma cell lines.</p

Within-assay precision, inter-assay precision and sample stability.

<p>For reliable and reproducible evaluation of cytotoxicity, within-assay and inter-assay precision analyses were performed (<b>A</b> and <b>C</b>). Both parameters were calculated according to the formula: SD/mean×100% and found to be under 20%. To determine within-assay precision (<b>A</b>), triplicated serum samples of a healthy donor (12.5% final concentration) with defined ch14.18/CHO concentrations (1.0 µg/ml) and calcein-labeled LA-N-1 target cells were analyzed. The cytotoxicity analysis was repeated ten times on the same plate. Results are presented as mean CDC of triplicates ± SD for ten data sets. Inter-assay precision (<b>C</b>) was determined on different days by different operators. Ten independent measurements of serum samples containing 1.0 µg/ml ch14.18/CHO and calcein-labeled LA-N-1 target cells were performed. The analyzed cytotoxicity levels are given as mean values ± SD for ten independent assays. To determine stability of CDC (<b>B</b> and <b>D</b>), two ch14.18/CHO concentrations 1.0 µg/ml (closed circles) and 0.1 µg/ml (open circles) prepared in 12.5% serum of a healthy donor were analyzed with established cytotoxicity assay. Samples were subjected to either storage at room temperature for up to 96 h (<b>B</b>) or to five freeze-thaw cycles (<b>D</b>). Rituximab containing (closed triangles) and Ab-free controls (open triangles) were included as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0107692#s2" target="_blank">Materials and Methods</a>. Data are shown as mean CDC values ± SE of two independent experiments performed at least in triplicates.</p

Assessment of variables for the complement-dependent cytotoxicity bioassay.

<p>(<b>A</b>) Analysis of CDC mediated by different serum concentrations (100%, 50%, 25%, 12.5%, 6.3%, 3.1%, 1.6%, 0.8%, 0.4%) using NB cell line LA-N-1 as a target cell line and two defined concentrations of anti-GD₂ Ab ch14.18/CHO (1.0 µg/ml (black column) and 0.1 µg/ml (white column). (<b>B</b>) Concentration-dependent inhibition of CDC mediated by 1.0 µg/ml ch14.18/CHO (closed circle) by complement inhibitor eculizumab (closed triangles). Pre-incubation with excess of anti-Id Ab ganglidiomab (5.0 µg/ml; open circle) was performed to show GD₂-specific target cell lysis. Rituximab (1.0 µg/ml; closed square) served as a negative control. (<b>C</b>) Evaluation of CDC mediated by different NB cell lines, 12.5% serum and anti-GD₂ Ab ch14.18/CHO (1 µg/ml; black column). Ganglidiomab (5.0 µg/ml; grey columns) and rituximab (1.0 µg/ml; white columns) served as controls. Data are shown as mean values ± SE of three independent experiments performed at least in triplicates. <i>t</i>-test; *P < 0.05.</p

Evaluation of donor-specific CDC.

<p>Serum samples (12.5% final concentration) of four healthy donors D1 (<b>A</b>), D2 (<b>B</b>), D3 (<b>C</b>) and D4 (<b>D</b>) were analyzed using calcein-AM-based cytotoxicity assay as described in section “<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0107692#s2" target="_blank">Materials and Methods</a>”. Serial dilutions of 1.0 µg/ml ch14.18/CHO were used for CDC (closed circles). Rituximab served as a negative control (1 µg/ml; open triangles). To show GD₂-specific target cell lysis, samples were pre-incubated with excess of GD₂-mimicking anti-Id Ab ganglidiomab (5 µg/ml; closed squares). Data are shown as mean values ± SE of three independent experiments performed at least in triplicates.</p

Effect of anticoagulants on leukocyte count and viability.

<p>Leukocytes were isolated from sodium-heparin- and EDTA whole blood samples followed by analysis of cell viability and count. Values are represented as mean ± SE of two independent experiments.</p><p>Effect of anticoagulants on leukocyte count and viability.</p