Studies of safety improvement of artificial red blood cell. 1. Effect of Hb endoplasmic reticulum on cerebral nerve tissue. 2. Solution viscosity of Hb endoplasmic reticulum dispersed and diluted in various plasma expanders. 3. Difference of ligand binding reaction between Hb endoplasmic reticulum and modified Hb (noncell type) solutions. 4. Measurement of spleen microcirculation kinetics.