For challenge infections, mice lightly anesthetized with isoflurane were intranasally infected with a lethal dose of A/PR8 virus (20× LD50) in 50 µl of PBS at 5 weeks after a single dose immunization.
All vaccine formulations were made up to a total volume of 50 μL with phosphate-buffered saline (PBS Sigma Chemical Co.., Saint Louis, MO) and administered by intramuscular (IM) injection in the left tibialis anterior (TA) muscle of mice lightly anaesthetized with Isoflurane (CDMV, Saint Hyacinthe, QC).
3 M-mode echocardiography was performed using two Visual-Sonics VEVO 770 and VEVO 2100 systems and a 30 MHz linear array transducer, on mice lightly anaesthetized using 2% isofluorane and 80 mL/min of 100% oxygen, as described by Aries et al., 3 and echocardiographic indices were calculated as described by Yang et al. 24 Heart failure was defined as an EF <45%.
To avoid making excessive mouse movements, lightly rest the heel of your palm on the desk.
For infection, mice were lightly anesthetized using isofluorane and intranasally (in) inoculated with PBS or equivalent mouse infectious dose 50 (MID50) of PR/8 (1×104 TCID50), CA/09 (1×105 TCID50), or VN/1194 1×104 TCID500) in 25 µl PBS.
Eight week-old male C57BL/6 mice were lightly anesthetized.
First, female bone marrow transplant recipient mice were lightly anesthetized with isoflurane.
For viral and bacterial challenge, 7 to 9 week old mice were lightly anaesthetized by isofluorane inhalation.
Adult mice were lightly anesthetized with 2,2,2-tribromoethanol then photographed live (Canon Powershot SD600, Canon, NY, USA).
Twenty-four hours after passive immunization, mice were lightly anesthetized by inhalation of CO2 and challenged intranasally (i.n).n
