Conclusion To our knowledge this is the first

study that visualized hemostatic alterations in influenza Torin 2 ic50 virus infection in a controlled animal model resembling human disease. The drastic changes seen in a very short time period might be the result of consumptive coagulopathy. Interestingly even in the seasonal influenza group, with only relatively mild clinical ‘flu’ symptoms, infection had significant effects on systemic hemostasis. These results might help in further understanding the role of influenza infection in acute cardiovascular disease, while future research could indicate if alterations in coagulation have an important role in influenza pathogenesis. Methods Experimental design Samples from 104, 11-month old, male, outbred ferrets (Mustela putorius furo) were used

for this experiment as described previously [21]. Animals were inoculated both intratracheally and intranasally with one of three influenza viruses, or with control material (mock). All three influenza virus strains had been directly derived from patient isolates. For seasonal influenza, H3N2 virus (A/Netherlands/177/2008) [18], for pandemic influenza, pH1N1 influenza virus (A/Netherlands/602/2009) [44] and for highly pathogenic avian influenza virus (HPAI) NVP-BSK805 molecular weight the H5N1 strain (A/Indonesia/5/2005) were used [45]. Virus stocks were passaged three times in Madin-Darby Canine Kidney (MDCK) cells and titrated according to standard methods. The viruses were clarified and reached an infectious virus titer of 107.4 median tissue culture infectious dose (TCID50) per ml for H3N2 virus, and 107.8 TCID50 for both pH1N1 and HPAI-H5N1 virus [46]. The inoculum of the control group consisted Acyl CoA dehydrogenase of MDCK culture derived material which had been subjected to the same procedure to control

for respiratory tract damage not related to replicating virus [21]. Inocula consisted of 3 mL volumes of virus preparations with 106 TCID50 given per animal partly intratracheally and partly intranasally. Ferrets were randomly selected for any of the predefined time points before the start of the experiment. Four ferrets were euthanized per time point. Each ferret was sampled twice: before inoculation and when sacrificed. This resulted in 104 samples analyzed before inoculation (28 mock, 28 H3N2, 28 pH1N1 and 20 H5N1) and 4 samples per virus per time point (Table 4). During euthanasia, citrated blood was drawn by cardiac puncture in 3 mL citrate tubes and plasma was prepared for testing in coagulation assays. Table 4 Distribution of the ferrets used in this study Group P.I. ½ dpi 1 dpi 2 dpi 3 dpi 4 dpi 7 dpi 14 dpi X Mock 28 4 4 4 4 4 4 4   H3N2 28 4 4 4 4 4 4 4 pH1N1 28 4 4 4 4 4 4 4 H5N1 20 4 4 4 4 4 0 0 Total 104 16 16 16 16 16 12 12 Z Y Ferrets were sampled before inoculation with a mock control suspension, H3N2-, pH1N1- or H5N1 influenza virus.