Biomedical subjects

Thomas Baumeister

Publications and source records attributed to Thomas Baumeister.

3 recordsLinked to original sources

PubMed2006

Case-based e-learning in occupational medicine--The NetWoRM Project in Germany.

The aim of the NetWoRM Project is the development, evaluation and implementation of a case-based e-learning tool for occupational medicine to increase the knowledge in clinical aspects of occupational medicine. To date, 19 e-learning cases have been developed. Cases were validated by 2 experts and user evaluated. Results of the user evaluation at 3 German Medical Schools are presented. Of 557 medical students registered for the online course 377 answered the online evaluation form (68%). Depending on the case, the median time spent on a case ranged from 25-43 minutes. Students enjoyed working with the cases and asked to replace more seminars by case-based e-learning. The level of knowledge required to work on the cases was rated high. This was supported by the fact that on median only 47-71% of the questions were answered correctly. Cases focusing on occupational health problems such as needle stick injuries were rated highest with respect to fun, importance for future career and the overall score. Students enjoy working on e-learning cases as an add-on to traditional teaching. Because of the high international interest the NetWoRM project is currently shared on an international base.

Computer-Assisted Instruction↗

PubMed2004

IL-4 supports the generation of a dendritic cell subset from murine bone marrow with altered endocytosis capacity.

Dendritic cells (DC) of myeloid origin can be generated from mouse bone marrow (BM) using granulocyte macrophage-colony stimulating factor (GM-CSF). Immature major histocompatibility complex (MHC) II(low) DC are known to bear a high endocytosis capacity, in contrast to DC precursors and mature DC. Now we found that a subset of MHC II(low) DC in BM-DC cultures is unable to exert mannose receptor-mediated endocytosis of fluorescein isothiocyanate (FITC)-dextran (DX) and resembles immature Langerhans cells (LC). The FITC-DX endocytosis activity of LC-like cells occurs at an earlier stage of development, where the surface MHC II expression is absent or very weak. This LC-like subset expresses higher levels of E-cadherin but lower amounts of the markers Gr-1, scavenger receptor 2F8, and CD11b, when compared with the highly endocytic DC subset. The latter myeloid DC resemble monocyte-derived DC (MoDC). The sorted LC-like population develops completely and exclusively into mature MHC IIhigh DC, and the MoDC-like cells remain immature MHC II(low) DC or develop into adherent MHC IIneg macrophages or mature into MHC IIhigh DC. The development of LC-like cells is promoted by interleukin-4. Thus, we show here that the simultaneous development of LC-like and MoDC-like DC subsets occurs in standard bulk cultures with GM-CSF, suggesting the existence of two different precursors for LC and MoDC in BM.

Animals↗

PubMed2003

Interleukin-3Ralpha+ myeloid dendritic cells and mast cells develop simultaneously from different bone marrow precursors in cultures with interleukin-3.

The distinct developmental routes of dendritic cells and mast cells from murine bone marrow cultures with interleukin-3 are unclear. We found that short-term bone marrow cultures with interleukin-3 after 8-10 d consist of about 10%-30% dendritic cells and 70%-90% mast cell precursors, and only after 4-6 wk do homogeneous populations of mast cells emerge. Phenotypical and functional analysis of interleukin-3/dendritic cells revealed a high similarity with myeloid dendritic cells generated with granulocyte-macrophage colony stimulating factor in the expression of myeloid dendritic cell markers (CD11c+ B220- CD8alpha- CD11b+), major histocompatibility complex II and costimulatory molecules, endocytosis, maturation potential, interleukin-12 production, and T cell priming. Interleukin-3/dendritic cells expressed higher levels of interleukin-3 receptor, however. To dissect the interleukin-3/dendritic cell and mast cell development, we sorted fresh bone marrow cells into six subsets by the antibodies ER-MP12 (CD31) and ER-MP20 (Ly-6C). Both interelukin-3/dendritic cells and granulocyte-macrophage colony stimulating factor/dendritic cells develop from the same bone marrow populations, including the ER-MP12neg, ER-MP20high bone marrow monocytes. In contrast, mast cells only developed from ER-MP12(int+high), ER-MP20neg bone marrow cell subsets, indicating that different precursors exist for interleukin-3/dendritic cells and mast cells. Established mast cell cultures could not be converted to dendritic cells or stimulated to express major histocompatibility complex II molecules in vitro or home to lymph node T cell areas in vivo. In summary, we show that dendritic cells generated from bone marrow precursors with interleukin-3 are clearly myeloid and develop via a different pathway compared to bone marrow mast cells.

Animals↗