Abstract
LD50 of ectromelia virus Dobashi strain was found to be 10-6.2 by intracerebral cnoculation made on mice. Then, the mice inoculated intracerebrally with 100% lethal dose of the virus was sacrificed on every other day following the inoculation for the comparison of the histological changes produced in the brain. Then, each virus of different disease days was subjected to the quantitative determination for the calculation of the motality rate, lethal power and LD50 in order to know the biological changes produced in the nature of the intracerebral virus.
Small vacuoles formed along the vascular wall of capillaries are considered to be the primary manifestation of the rupture of blood-brain barrier indicating the tissue disturbance of central nerves and the starting point of visceral stage. On the other hand, retardation of the proliferation of intracerebral virus by the inhibition of blood-brain barrier was known from the growth curve of the virus.
Marked proliferation of the fibrous macrogyria observed on Ammon horn is considered to have the primary significance in relation to the appearance of spasms like in the case of epilepsy rather than the secondary reparative changes.
