Effect of 3-[bis-(2-hydroxyethyl)-amino]-acetophenone-[4.5-diphenyl-oxazolyl-(2)]-hydrazone (IMET 98/69) on lethal mengo virus encephalitis.

3-[Bis-(2-hydroxyethyl)-amino]-acetophenone-[4.5-diphenyl-oxazolyl-(2)]-hydrazone (IMET 98/69) was found to afford maximum "rates of protection" in intraperitoneally (i.p.) or intranasally (i.n.) induced Mengo virus encephalitis in mice when administered once daily at doses of 1 mmole/kg (456.5 mg/kg) subcutaneously (s.c.) or 4 mmoles/kg (1 826 mg/kg) perorally (p.o.). Three days of treatment were sufficient if started on the day before or at the time of virus inoculation. Initiation of treatment 6 hours after inoculation was no longer effective. In a remarkable number of brains from infected and treated mice no virus was detectable, while in the remaining brains the appearance of virus was strongly delayed, and its amount significantly reduced.