Ultrastructure and peroxidase cytochemistry of normal human leukocytes at birth☆

[摘要] Atbirth,differentialandwhitebloodcellcountsofnormalnewborninfantsarestrikinglydifferentfromthoseofadultsinthatthenumberofleukocytesisincreasedandimmaturecellscoursethroughthecirculation.Inthisstudy,ourintentwastoexaminenormalneonatalcordbloodbyelectronmicroscopyandperoxidasecytochemistrytodeterminewhetheranydetectabledifferencesexistintheleukocytesofneonatalandadultblood.Thisinvestigationwasundertakenbecausenewborninfantshaveanincreasedsusceptibilitytoinfection,andalterationsinphagocytefunctionhavebeenimplicatedasthecause.Cordbloodwasfoundtocontainmatureleukocytesofallkinds,similarinultrastructureandperoxidaselocalizationtothoseofadults.Moreover,asindicatedearlierbylightmicroscopy,immatureforms(normallyfoundonlyinadultbonemarrow)werepresentinthebloodofnewborns.Wefoundthatnearlyallcelllineswererepresentedintheneonatalcirculationbysuchdevelopmentalformsaspromyelocytes,myelocytes,promonocytes,erythroblasts,megakaryocytes,rareunidentifiableblasts,anddividingcells—allresemblingtheircounterpartsinadultbonemarrow.Withthetechniquesusedhere,neonatalleukocytesweresimilartothoseoftheadultinultrastructureandperoxidaselocalization,althoughsomehadbeenmobilizedintothebloodinaremarkablyimmaturestate.Thisstudy,thefirstofitskind,willserveasahelpfulbackgroundforfutureinvestigationsofacquired,geneticorneoplasticleukocyteabnormalitieswhichmaybediscoveredatbirth.

[学科分类] 生物科学（综合）