Treatment with the immunomodulator FTY720 does not promote spontaneous bacterial infections after experimental stroke in mice

Background: FTY720, an immunomodulator derived from a fungal metabolite which reduces circulating lymphocyte counts by increasing the homing of lymphocytes to the lymph nodes has recently gained interest in stroke research. The aim of this study was to evaluate the protective efficacy of FTY720 in cerebral ischemia in two different application paradigms and to gather first data on the effect of FTY720 on the rate of spontaneous bacterial infections in experimental stroke. Methods: Middle cerebral artery occlusion (MCAO) in C57BL/6 mice (strain J, groups of 10 animals) was performed with two different durations of ischemia (90 min and 3 h) and FTY720 was applied 2 h after vessel occlusion to study the impact of reperfusion on the protective potency of FTY720. Lesion size was determined by TTC staining. Mice treated with FTY720 or vehicle were sacrificed 48 h after 90 min MCAO to determine the bacterial burden in lung and blood. Results: FTY720 1 mg/kg significantly reduced ischemic lesion size when administered 2 h after the onset of MCAO for 3 h (45.4 +/- 22.7 mm3 vs. 84.7 +/- 23.6 mm3 in control mice, p = 0.001) and also when administered after reperfusion, 2 h after the onset of MCAO for 90 min (31.1 +/- 28.49 mm3 vs. 69.6 +/- 27.2 mm3 in control mice, p = 0.013). Bacterial burden of lung homogenates 48 h after stroke did not increase in the group treated with the immunomodulator FTY720 while there was no spontaneous bacteremia 48 h after MCAO in treated and untreated animals. Conclusions: Our results corroborate the experimental evidence of the protective effect of FTY720 seen in different rodent stroke models. Interestingly, we found no increase in bacterial lung infections even though FTY720 strongly reduces the number of circulating leukocytes

Effect of Phase Transitions on the TSEC and TSEE from Solid Methanol

Thermally Stimulated Electric Current (TSEC) and Thermally Stimulated Exoemission (TSEE) from solid methanol have been measured during a cooling process in the temperature range 170–80 K. Both TSEC and TSEE result from the subjugation of solid methanol to a temperature ramp. It has been found that both TSEC and TSEE intensities depend strongly on whether or not a methanol sample has been cooled diretly from the liquid phase. It has also been found that the TSEC intensity increases with the temperature difference which exists across a sample during the solidification process, whereas the TSEE peak value remains approximately constant for the same conditions. Also, a non-stable broadening of peaks could be observed. </jats:p

Exoemission Excitation of Ferroelectrics in Vacuum by Alternating Voltage

Measurements of exoemission under vacuum conditions from KDP (KH2PO4) single crystals during continuous repolarization by an alternating voltage have been performed. The temperature position of the main peak of the exoelectron emission intensity observed on the TSEE curve coincided with the phase-transition temperature (123 K) of KH2PO4 crystalline samples. It has been found that TSEE curves are reproducible in the vicinity of the Curie temperature region under continuous excitation with an alternating voltage. </jats:p

The Influence of Experimental Parameters on Exoemission under UHV Conditions

The surface cleanness of equipment and the parameters regarding electron-beam excitation are discussed as factors having significant influence on the shape of observed TSSE spectra. Attempts to explain problems involving the reproducibility of TSEE peaks are given. Also, improvements in UHV preparation for securing clean surfaces are discussed. </jats:p