Generation of IL-8 and TNF-alpha in platelet concentrates during storage

Platelet transfusion is accompanied by febrile nonhemolytic transfusion reactions. The generation of cytokines [like IL-1 beta, IL-6, IL-8, and TNF-alpha] in platelet concentrates by white cells is suggested to be responsible for febrile nonhemolytic transfusion reactions. The number of white cells in the platelet concentrates is crucial to cytokine generation. This study was performed to determine whether WBC reduction in platelet concentrates by prestorage leukodepletion filters or inactivation by gamma radiation reduced the levels of these cytokines during storage for 3 days. Each of the platelet concentrates [n = 54] was prepared from a single random donor by platelet-rich plasma. This was then divided into four groups: 1] unfiltered, nonirradiated random-donner platelet concentrates [n = 13]; 2] unfiltered, gamma-irradiated random-donner platelet concentrates [n = 16]; 3] filtered, nonirradiated random- donner platelet concentrates [n = 14]; and 4] filtered, gamma-irradiated random-donner platelet concentrates [n = 11]. Cytokine levels in platelet concentrates supernatants were measured by ELISA kits according to the manufacturer's recommendations. Our results showed that IL-8 was detected in unfiltered, nonirradiated, and gamma-irradiated random-donner platelet concentrates but not in the filtered random-donner platelet concentrates. TNF-alpha was only detected in unfiltered, nonirradiated units. Compared with unfiltered platelet concentrates, prestorage filtration prevented a rise in the IL-8 and TNF-alpha on day 3 of storage. The concentration of IL-1 beta was lower than the minimum concentration value of the kit used for this purpose. IL-6 was detected only in 7 units of all filtered platelet concentrates on day 3. These data indicate that gamma irradiation can not prevent generation of IL-8 in platelet concentrates during storage, but prestorage leukoreduction of platelet concentrates can prevent accumulation of IL-6, IL-8, and TNF-alpha during storage

CFU-GM like colonies derived from embryonic stem cells cultured on the bone marrow stromal cells

The aim of this study was to isolate mouse embryonic stem cells from late blastocyst stage embryos and to use them as a model system for the study of hematopoietic induction outside the embryo by coculturing of embryonic stem cells with bone marrow stromal cells. Blastocyst stage embryos from pregnant NMRI mice were obtained and cultured for 1-2 days in DMEM medium. The inner cell masses formed colonies 4-6 days after embryo hatching they were collected and trypsinized. Several subcultures were prepared in the medium containing 0.1 mM 2 mercaptoethanol, 1000 U/ml leukemia inhibitory factor and 10% fetal bovine serum. The embryonic stem cells were recognized by alkaline phosphatase histochemistry. Embryonic stem cells were cultured on inactivated mouse bone marrow stromal cells for 3 weeks at 37°C and 33°C. The colony assay was performed on semisolid medium containing murine IL-3 and IL-6 to determine the differentiation of embryonic stem cells to hematopoietic progenitor cells in vitro. Our results showed that with the effect of bone marrow stromal cells, a highly pluripotent stem cell which is derived from blastocyst stage embryo was able to primarily differentiated into the hematopoietic progenitor cells. CFU-GM like colonies were recognized according to their morphology after culturing the embryonic stem cells on the condition medium supplemented with IL-3 and IL-6