ABSTRACT
1) All students but 1 correctly typed the ABO blood groups, but only 33.2% of students and 63.9% of physicians properly performed cross-matching.<br>2) Most failures in cross-matching were due to the inability to detect allogeneic antibodies, but 5.2% of students and 2.9% of physicians failed to detect ABO mismatching.<br>3) Although laboratory practice is suggested to help students to solidify knowledge and comprehend principles, achieving an official goal of residency - gaining competence in performing and interpreting cross-matching independently - appeared difficult.
ABSTRACT
To investigate the tumoricidal activity of dendritic cell (DC) stimulated by interferon-gamma (IFN-gamma) against freshly isolated myeloid leukemia cells and its mechanism, the peripheral blood monocytes collected from healthy donors were cocultured with interleukin-4 and granulocyte-macrophage colony-stimulating factor in medium to induce DC for 7 days. After 12 hour culture in the absence or presence of IFN-gamma, the changes of costimulatory molecules were analyzed with flow cytometry. To assay the cytotoxicity of DC against freshly isolated acute myeloid cells, they were cocultured at various effector-to-target ratio for 18 hours, then the percentage of tumoricidal activity was measured with (51)Cr release assay. To explore the mechanism of DC-mediated cytotoxicity, the change of DC surface or intracellular protein expression of Fas ligand (Fas L), TNF-alpha and TNF related apoptosis-inducing ligand (TRAIL) were analyzed with flow cytometry. The results showed that IFN-gamma enhanced cytotoxicity of DC against AML cells was (33.8 +/- 1.6)% at E:T as 20:1, compared with unstimulated DC (P < 0.05); IFN-gamma up-regulated expression of costimulatory molecules of DC surface such as CD86 and CD83; after stimulation with IFN-gamma, expression of intracellular TRAIL of DC was significantly enhanced, but expression of TRAIL on cell surface of DC was low; while the significant changes of Fas L and TNF-alpha expression neither on cell surface or in cells were not observed before or after stimulation with IFN-gamma. It is concluded that DC stimulated by IFN-gamma exhibit tumoricidal activity against AML cells. The cytotoxicity is partially related to maturation of DC and TRAIL inducing apoptosis, but not associated with death domain-independent mechanism of Fas L and TNF-alpha.