Low-Frequency Electromagnetic Fields Do Not Affect Cell Growth, Erythroid Differentiation, and Virus Production in Variant Lines of Untreated and Dimethyl Sulfoxide-Treated Friend Erythroleukemia Cells

Influence of magnetic field on the kinetics of activated sludge

This investigation was performed as a background study for magnetically stabilized fluidized bed biofilm reactors for wastewater treatment. The aim of this study is to show the influence of magnetic field application on microbial growth and to use a simplified method in batch wise study to determine this influence on the biological kinetic parameters. The kinetic parameters of mu(max), K(s), Y(x/s) and m of the activated sludge on glucose removal as a model substrate for wastewater treatment were determined in a simple way by using the data of only one batch experiment at a definite condition. At the same condition, instead of the difficult, expensive and time consuming several continuous steady state studies with different influent substrate concentrations the results of only one batch experiment of two identical reactors, one with and the other without magnetic field application, could be enough for the evaluation. It was found that kinetic parameters were changing with magnetic field strengths of 8.9, 17.8, 24.4, 36.6 and 46.6 mT and 17.8 mT is the optimum strength for biological glucose removal under the studied conditions. While mu(max) and m are increasing with the application of optimum magnetic field strength of 17.8 mT, K(s) and Y(x/s) are decreasing implying that average affinity of microorganisms present in activated sludge to the substrate and their growth rates are increasing but a smaller amount of sludge corresponding to the amount of substrate removal was produced with the application of magnetic field. This result shows an improvement in the treatment efficiency by the application of magnetic field.

Bone and bone marrow interactions: hematological activity of osteoblastic growth peptide (OGP)-derived carboxy-terminal pentapeptide. II. Action on human hematopoietic stem cells

Osteogenic growth peptide (OGP) is a peptide exerting regulatory effects on the bone and on bone marrow. The carboxy-terminal pentapeptide (OGP10-14) is the biologically active portion of OGP. We evaluated OGP10-14 hematopoietic activity performing colony-forming tests on human stem cells derived by bone marrow, peripheral blood and cord blood. Granulocyte-macrophage colony-forming unit (CFU) were significantly increased in OGP10-14-treated samples, while granulocyte-erythrocyte-monocyte-megakaryocyte CFU and burst-forming unit (BFU) erythroid were increased only in the cord blood test.Moreover, OGP10-14 preserves stem cells self renewal potential in long-term culture (LTC) initiating cells and acts directly on CD34+ enriched cells or by increasing activity of stem cell factor (SCF) and granulocyte-megakaryocyte colony-stimulating factor.

Early effects of electrical stimulation on osteogenesis

The mechanism by which electrical stimulation causes osteogenesis is unknown. Bone marrow of the rabbit was stimulated by direct electrical current or electromagnetic fields to clarify the mechanism of osteogenesis by electrical stimulation. A total of 105 rabbits were separated into five groups: a direct current stimulation by Kirshner wire insertion group; a pulsed electromagnetic fields stimulation (PEMF) group; a PEMF with Kirshner wire insertion group; a Kirshner wire insertion group; and an intramedullary drilling control group. Measurement of intramedullary new bone formation and determination of alkaline phosphatase activity within the bone marrow were performed. Argylophilic nuclear organizer region (AgNOR) staining was done to evaluate the change in proliferative activity of the osteoblasts during electrical stimulation. In the direct current stimulation group and the PEMF accompanied by the insertion of the Kirshner wire group, alkaline phosphatase activity in the bone marrow and AgNOR staining increased at 7 days after surgery. At 14 days after surgery, alkaline phosphatase activity and proliferative activity of osteoblast were significantly higher in these two groups than in the other groups (PEMF group, Kirshner wire insertion alone group, intramedullary drilling group). Intramedullary new bone formation was most active in the direct current stimulation group. Electromagnetic stimulation of the inserted Kirshner wire also promoted bone formation significantly. The Kirshner wire insertion alone group and the intramedullary drilling group showed bone formation, but it was significantly less. Electromagnetic stimulation without the insertion of the Kirshner wire showed little bone formation. These findings revealed that the degree of osteogenesis induced by electrical stimulation is influenced by the tissue environment, and that osteogenesis is promoted markedly when electrical stimulation is provided in the environment of inflammation and reactive cells.