Fig. 4
From: All-trans retinoic acid increases the pathogenicity of the H9N2 influenza virus in mice
Effects of therapeutic dose of ATRA on clinical signs and survival of mice infected with H9N2 virus. (a–c) Body weight is presented as mean of the rate of weight change (%) ± SD. Rate of weight change (%) = daily weight/initial weight × 100%. n = 10–12. (d–f) Food intake is presented as mean of the change rate of food intake (%). Change rate of food intake (%) = food intake per day/initial food intake × 100%. n = 10–12. (g–i) Survival rate (%) = the number of mice alive/total number of mice observed. n = 22–24. Mice that lost more than 30% of their original body weight were euthanized and considered dead on that day. Data were analyzed with one-way ANOVA or the log-rank test. ATRA group or H9N2 group compared with blank group: ∆, P < 0.05; ∆∆, P < 0.01; ATRA + H9N2 group compared with ATRA group: #P < 0.05; ##P < 0.01; ATRA + H9N2 group compared with H9N2 group: *P < 0.05; **P < 0.01. Blank, mice receiving sterile PBS inoculation and cottonseed oil injection at 0–9 days after inoculation; ATRA1-ATRA3, mice receiving sterile PBS inoculation and ATRA injection (1, 5, and 10 mg/kg, respectively) at 0–9 days after inoculation; H9N2, mice receiving H9N2 virus (105.5 TCID50) inoculation and cottonseed oil injection at 0–9 days after inoculation; ATRA1 + H9N2-ATRA3 + H9N2, mice receiving H9N2 virus (105.5 TCID50) inoculation and ATRA injection (1, 5, and 10 mg/kg, respectively) at 0–9 days after inoculation. ATRA, all-trans retinoic acid; TCID50, median tissue culture infective dose