A single dose consisting of a solution of lead @entity1507 containing 1 mg lead in 0.1 ml distilled water was injected into the air chamber of @entity1573 eggs on the tenth day of incubation. The injected embryos were killed 24, 48, or 72 hours after the injection. Control embryos were injected with a similar volume of distilled water or of an equimolar @entity47436 solution on the tenth day and killed 72 hours after. Portions of the optic lobes were processed for their electron microscopic study. Multiple hemorrhagic foci appeared 24 hours after the administration of lead. Red blood cells were found to exit the blood vessels through the spaces between otherwise normal-looking endothelial cells; tight junctions were always found blocking the interendothelial spaces except during the migration of red blood cells through them. Vacuolization of the cytoplasm and mitochondrial swelling and disorganization were observed in the endothelial cells only during the third day after the injection. Similarly, histological and ultrastructural alterations of nerve cells were only found on the third day after the treatment. @entity548 foci were never found in control embryos. Our observations are consistent with the idea that the @entity548 constitute the @entity75 produced by lead. They also suggest that the @entity548 are not the result of @entity397 of previously altered endothelial walls but occur by diapedesis through the interendothelial clefts.

Lead-induced @entity75 in the brain of the XXXX embryo.

@entity548 :: ('MESH:D006470', 'Disease') :: ['Hemorrhagic', 'hemorrhages'] @entity75 :: ('MESH:D001927', 'Disease') :: ['primary lesion'] @entity1507 :: ('CHEBI:48107', 'Chemical') :: ['nitrate'] @entity47436 :: ('MESH:C059948', 'Chemical') :: ['calcium nitrate'] @entity1573 :: ('9031', 'Species') :: ['chicken'] @entity397 :: ('MESH:D012421', 'Disease') :: ['rupture']
@entity1573 :: (9031,Species) :: ['chick']
