Figure 4.

Histological examination and immunohistochemical results of in vivo study. One-day-old mice were i.p challenged with lethal doses of BJCA08/CA16 (54CCID₅₀), then i.p. treated with 10 μg/g NA11F12 or MEM at day 1 post-infection. (A) Dynamic changes of clinical symptoms in newborn mice model. Uninfected CA16 mice (Health control) (left), MEM-treated mice (middle) and NA11F12-treated (right) in each picture. MEM-treated mice showed visible clinical symptoms: (a) waste, (b) hind legs paralysis, (c) quadriplegic (arrows). (B) HE staining of different tissues from BALB/c neonatal mice. Positive reactions were observed in heart, brain and limb muscle tissues by H&E staining. Infected mice (grades 4–5) exhibited severe inflammation in heart and limbs and cranial nerve necrosis (arrows). In contrast, no histological change was observed in the mice of health control group and NA11F12-treated group. Magnification×100 (a, b, e, g, h), Magnification×200 (c, d, f, i). (C) IHC staining of different tissues from BALB/c neonatal mice. Positive reactions were observed in heart, brain and limb muscle tissues by IHC straining. Numerous viral antigen-positive reactions were observed in the heart, limb muscle and brain (arrows) in the infected mice. In contrast, no viral antigen was observed in the mice of health control group and NA11F12-treated group. Magnification×100 (a, b, c, e, g), Magnification×200 (h, i), Magnification×400(d, f).