title: Levels of S100B protein are higher in mature human milk than in colostrum and milk-formulae milks.
abstract: OBJECTIVE
  Human milk is believed to contain biological factors involved in the regulation of newborn growth, including brain development. Recently, it has also been shown to contain the calcium-binding S100B protein, regarded as a neurotrophic factor. The present study investigates the concentrations of this protein in colostrum, human milk at different levels of maturation and in milk-formulae.
  
  
  METHODS
  Samples for S100B measurements were collected from human colostrum (on day 1 after birth), from transition milk (on post-delivery days 7 and 14) and from mature milk (on day 30 after delivery) in 14 healthy women and from 14 milk-formulae. The S100B protein levels were measured using a commercially available specific immunoluminometric assay.
  
  
  RESULTS
  Mean S100B protein levels were significantly higher in mature human milk (117.9+/-36.7 microg/l) than in transition milk at 14 days (106.7+/-38.1 microg/l) and at 7 days (92.7+/-37.8 microg/l), colostrum (74.6+/-37.6 microg/l) or milk-formulae (24.8+/-19.5 microg/l) (P<0.001, for all). A correlation between human milk S100B levels and the gestational age at which samples were obtained was also found (r=0.39; P<0.01).
  
  
  CONCLUSIONS
  These findings, possibly related to S100B's neurotrophic role, offers useful information to the investigation of the role of S100B protein in brain maturation.
authors.affiliation: Department of Obstetrics and Pediatrics, Giannina Gaslini Children's University Hospital, I-16147 Genoa, Italy. dgazzlo@hotmail.com
authors.forename: Diego
authors.initials: D
authors.lastname: Gazzolo
authors.forename: Matteo
authors.initials: M
authors.lastname: Bruschettini
authors.forename: Mario
authors.initials: M
authors.lastname: Lituania
authors.forename: Giovanni
authors.initials: G
authors.lastname: Serra
authors.forename: Pierina
authors.initials: P
authors.lastname: Santini
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Michetti
mesh_terms: D000328:Adult; D001921:Brain / Q000254:growth & development* / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000032:analysis; D003126:Colostrum / Q000737:chemistry*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007225:Infant Food; D041943:Infant Formula / Q000737:chemistry*; D007227:Infant Nutritional Physiological Phenomena; D007231:Infant, Newborn; D008895:Milk, Human / Q000737:chemistry*; D009414:Nerve Growth Factors / Q000032:analysis*; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000032:analysis*
chemical_list: D002135:Calcium-Binding Proteins; D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; C579160:S100B protein, human