Electron microscopy of L.E. phenomena. Description of the structure of the L.E. cell and L.E. mass.

After studies onphase-contrast microscopy, interferencemicroscopy, and microcinematography (Robineaux, 1959), theL.E.-cell phenomenon appears tohavethefollowing sequence: inthe presence ofan adequate concentration ofL.E. factor, aleucocyte isimmobilized andafter a few seconds showsasuddenswelling andhomogenizationofoneofits nuclear lobules. A rupture ofthe cytoplasmatic membraneoccursandtheswollen nuclear massispartially ortotally extruded fromthe cell andconstitutes theL.E.body.Theduration of thiswholeprocess varies from5 to10minutes. L.E.bodies arechemotactic toleucocytes, which engulf them, producing L.E.-cells orrosettes. Thus, theL.E.-cell isaleucocyte, generally polymorphonuclear, containing a homogeneous masswhich occupies approximately two-thirds ofthecell and compresses itsnucleus to theperiphery. The "included" massiscomposed ofmodified nuclear material. Theessential andindispensable characteristics oftheinclusion arethecomplete orpartial homogenization ofthenuclear structure andtheloss ofthechromatin network (Holman, 1960). Rosette formation ischaracterized byan amorphouscentral masssurrounded byavariable number ofpolymorphonuclears. Thismass,alsocalled Hargraves' mass (Hargraves, Richmond, and Morton, 1948), istheresult oftheagglutination of theL.E.bodies extruded fromleucocytes after the action oftheL.E.factor (Moore andGrimely, 1957). The onlypublished studyofL.E.-cell ultrastructure isthatofMaldonado, Alarc6n-Segovia, Pease, andBrown(1963), buttheir study doesnot mention rosettes andHargraves' masses.