title: Cell renewal and functional morphology of human lactating breast: presentation of a new mode of cell death ('magentosis') characterized by nuclear periodic acid-Schiff reactivity.
abstract: Cell kinetics and functional morphology of the human lactating breast were analyzed using 21 paraffin-embedded specimens of the lactating breast obtained by biopsy or surgery and two of the 'resting' breast. Four types (I-IV) of lactating lobules were categorized histologically, and were well correlated with their functional status demonstrated by immunohistochemistry for epithelial membrane antigen, beta-casein, lipase, lactoferrin, secretory component and IgA. Type I corresponded to a pre-lactating state, type II to an actively lactating state, type III to an early stage of regression, and type IV to an advanced stage of regression. Cell proliferation monitored by Ki-67 (MIB-1) immunostaining was at the highest level in type I lobules followed by type IV, while the labeling indices were low in types II and III. Apoptosis demonstrated by terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP)-biotin nick end-labeling (TUNEL) method showed labeling profiles comparable with the proliferative activity. Holocrine-type desquamative cells with intact-appearing nuclei were frequently recognized in type II lobules. In type III, a peculiar form of cell death, designated 'magentosis', was demonstrated. These degenerative cells occasionally shedding into the acinar lumen possessed homogeneous pale, TUNEL-negative nuclei with diastase-resistant periodic acid-Schiff (PAS) reactivity. 'Magentosis' specifically identified in an early phase of involution of the human lactating breast might represent a unique mode of cell death distinguishable from apoptosis and necrosis.
authors.affiliation: Department of Pathology, Tokai University School of Medicine, Isehara, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Umemura
authors.forename: R Y
authors.initials: RY
authors.lastname: Osamura
authors.forename: Y
authors.initials: Y
authors.lastname: Tsutsumi
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis; D001940:Breast / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D016923:Cell Death / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D002467:Cell Nucleus / Q000737:chemistry; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D020287:In Situ Nick-End Labeling; D019394:Ki-67 Antigen / Q000378:metabolism; D007774:Lactation / Q000502:physiology*; D009336:Necrosis; D010503:Periodic Acid-Schiff Reaction; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D013194:Staining and Labeling
chemical_list: D015415:Biomarkers; D019394:Ki-67 Antigen; D019253:Proto-Oncogene Proteins c-bcl-2