Peripheral infusion of rat bone marrow derived endothelial progenitor cells leads to homing in acute lung injury

<p>Abstract</p> <p>Background</p> <p>Bone marrow-derived progenitors for both epithelial and endothelial cells have been observed in the lung. Besides mature endothelial cells (EC) that compose the adult vasculature, endothelial progenitor cells (EPC) are supposed to be released from the bone marrow into the peripheral blood after stimulation by distinct inflammatory injuries. Homing of <it>ex vivo </it>generated bone marrow-derived EPC into the injured lung has not been investigated so far. We therefore tested the hypothesis whether homing of EPC in damaged lung tissue occurs after intravenous administration.</p> <p>Methods</p> <p>Ex vivo generated, characterized and cultivated rat bone marrow-derived EPC were investigated for proliferation and vasculogenic properties in vitro. EPC were tested for their homing in a left-sided rat lung transplant model mimicking a severe acute lung injury. EPC were transplanted into the host animal by peripheral administration into the femoral vein (10⁶cells). Rats were sacrificed 1, 4 or 9 days after lung transplantation and homing of EPC was evaluated by fluorescence microscopy. EPC were tested further for their involvement in vasculogenesis processes occurring in subcutaneously applied Matrigel in transplanted animals.</p> <p>Results</p> <p>We demonstrate the integration of intravenously injected EPC into the tissue of the transplanted left lung suffering from acute lung injury. EPC were localized in vessel walls as well as in destructed lung tissue. Virtually no cells were found in the right lung or in other organs. However, few EPC were found in subcutaneous Matrigel in transplanted rats.</p> <p>Conclusion</p> <p>Transplanted EPC may play an important role in reestablishing the endothelial integrity in vessels after severe injury or at inflamatory sites and might further contribute to vascular repair or wound healing processes in severely damaged tissue. Therapeutic applications of EPC transplantation may ensue.</p

Air temperature at 90 km altitude in the Artic obtained using meteor radar : validation, characterization and climate change.

Temperatures at 90 km altitude above Ramfjordmoen (69°N, 19°E) have been obtained with the Nippon/Norwegian Tromsø Meteor Radar. The temperatures have been derived from meteor radar decay rates using two techniques: the pressure based and the temperature gradient based methods. The results have been compared to the Microwave Limb Sounder (MLS) instrument on board the Aura spacecraft. It was found that the pressure method was simpler to implement than the temperature gradient method and gave better results in relation to the MLS temperatures. With the use of a technique for statistical comparison of geophysical data, the intrinsic uncertainty of the radar temperatures was estimated to be less than 4 K. Two attempts to combine the two techniques in order to measure both temperatures and pressure with the meteor radar have been carried out. One of the approaches proved to be feasible and gave promising results. This indicates that the meteor radar may have the potential of producing continuous temperature and pressure measurements virtually independent of external data. A new collocated sodium lidar is introduced and some initial comparisons are carried out between the two instruments. At times there were large discrepancies, but more data is necessary in order to obtain reliable results. Finally, some possible uses of the radar temperatures are proposed. A method for investigating long term trends is discussed in detail. The data available resulted in a trend of - 2.2 K per decade, but more data is required to establish a trend with higher confidence. It was estimated that approximately 13 years of data are needed to determine the trend with a probability of 90 %

Peripheral infusion of rat bone marrow derived endothelial progenitor cells leads to homing in acute lung injury-3

<p><b>Copyright information:</b></p><p>Taken from "Peripheral infusion of rat bone marrow derived endothelial progenitor cells leads to homing in acute lung injury"</p><p>http://respiratory-research.com/content/8/1/50</p><p>Respiratory Research 2007;8(1):50-50.</p><p>Published online 9 Jul 2007</p><p>PMCID:PMC2000890.</p><p></p> with VEGF (50 ng/ml) exhibited more tubular formation and with a particular tendency to multiple links between cell nest (Figure 4B) than observed with the control: hL-MVEC (Figure 4A) However, EPC have the capability to form capillary like structures when seeded at low cell numbers even in the absence of high concentrations of cytokines which suggests their high angiogenic potential. Picture represents a 20× magnification phase contrast microscopic picture (Figure 4C)

Peripheral infusion of rat bone marrow derived endothelial progenitor cells leads to homing in acute lung injury-2

<p><b>Copyright information:</b></p><p>Taken from "Peripheral infusion of rat bone marrow derived endothelial progenitor cells leads to homing in acute lung injury"</p><p>http://respiratory-research.com/content/8/1/50</p><p>Respiratory Research 2007;8(1):50-50.</p><p>Published online 9 Jul 2007</p><p>PMCID:PMC2000890.</p><p></p>-2 containing bFGF (Figure 3B). Figure 3A shows the differential growth capacities of EPC and mature rPAEC in the presence of EBM-2 supplemented with 20% FCS. Figure 3B shows the proliferative kinetics of EPC cultured in EBM-2 supplemented with 0.5% FCS towards increasing concentrations of bFGF (100 ng/ml to 100 μg/ml). Cells were seeded in 96-well plates, grown for 24 h in culture medium, washed twice with HEPES/EDTA and treated with bFGF in EBM-2 medium containing 0.5% FCS for 48 h as indicated. Cells were incubated with MTT solution, lysed and the absorbance was read. MTT activity is expressed as Optical Density and represents mean ± SEM of five independent experiments, ** < 0.01, * < 0.05