Table 1—

Criteria used for electron microscopy quantification of activity status following lipopolysaccharide administration

StatusCharacterisation features
RestingIntact cells with normal nucleus, intact cell membrane and normal primary and secondary granules
ActivatedOne or more of the following features: granule alterations, vacuoles, phagosomes, extensive pseudopodia
ApoptosisIntact cell membrane, condensed and electron dense nucleus, often with blebs along the nuclear membrane
Primary necrosisRuptured cell membrane and normal or chromatolytic nucleus
Secondary necrosisAs apoptosis but with a ruptured cell membrane
Cell debrisGatherings of neutrophil-derived extracellular material, including the characteristic neutrophil granule