Food dyes and impairment of performance in hyperactive children.

cyclic GMP during phagocytosis implies a difference in mechanism of action for these nucleotides. Since cyclic GMP is consistently found within the granular cytoplasmic region of the cell, it is likely, as others have suggested (8, 13, 21), that cyclic GMP plays a rol.e in the functional process of secretion. KATHERINE B. PRYZWANSKY Department ofBacteriology and Immunology, University ofNorth Carolina, Chapel Hill 27514 ALTON L. STEINER* Department ofMedicine and Pharmacology, University ofNorth Carolina JOHN K. SPITZNAGELt Department of Bacteriology and Immunology, University ofNorth Carolina CHIRANJIv L. KAPOOR Department ofMedicine and Pharmacology, University ofNorth Carolina