title: Recombinant human leukemia inhibitory factor does not enhance in vitro human blastocyst formation.
abstract: OBJECTIVE
  To assess the effect of human recombinant leukemia inhibitory factor in different doses on human blastocyst formation.
  
  
  METHODS
  A university-based tertiary referral center (The Toronto Hospital).
  
  
  METHODS
  Nontransferable human embryos (n = 473) at the two- to six-cell stage were obtained from patients undergoing IVF and were split randomly into five groups. Embryos in group A (n = 164) were cultured as the control group in Ham's F-10 (GIBCO-BRL, Grand Island, NY) + 10% human sera. Embryos in groups B, C, D, and E (n = 54, 78, 87, and 80, respectively) were cultured in the same medium supplemented with human recombinant leukemia inhibitory factor in four different concentrations (5, 7.5, 10, and 20 ng/mL, respectively). Morphological assessment of embryo development was recorded daily.
  
  
  METHODS
  Human blastocyst formation.
  
  
  RESULTS
  No significant difference was detected in the rate of blastocyst formation of embryos in the study groups when compared with embryos in group A.
  
  
  CONCLUSIONS
  This study shows that 5 to 20 ng/mL of recombinant leukemia inhibitory factor in standard medium does not enhance in vitro human blastocyst formation. It is possible that recombinant leukemia inhibitory factor may play a role at later stages of human embryogenesis and during implantation.
authors.affiliation: Department of Obstetrics and Gynecology, Toronto Hospital Research Institute, Ontario, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Jurisicova
authors.forename: A
authors.initials: A
authors.lastname: Ben-Chetrit
authors.forename: S L
authors.initials: SL
authors.lastname: Varmuza
authors.forename: R F
authors.initials: RF
authors.lastname: Casper
mesh_terms: D001755:Blastocyst / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D005314:Embryonic and Fetal Development / Q000187:drug effects / Q000502:physiology; D005260:Female; D005307:Fertilization in Vitro; D006131:Growth Inhibitors / Q000494:pharmacology*; D006801:Humans; D015850:Interleukin-6; D053605:Leukemia Inhibitory Factor; D008222:Lymphokines / Q000494:pharmacology*; D011994:Recombinant Proteins / Q000494:pharmacology
chemical_list: D006131:Growth Inhibitors; D015850:Interleukin-6; C507837:LIF protein, human; D053605:Leukemia Inhibitory Factor; D008222:Lymphokines; D011994:Recombinant Proteins