Do tocolytic agents stop preterm labor? A critical and comprehensive review of efficacy and safety.

Objective: Our aim was to determine the efficacy and safety of tocolytic agents currently used to treat premature labor.

Study Design: We carried out a comprehensive review of tocolytic agents in the treatment of premature labor. Three hundred twenty-eight studies published between 1933 and 1992 were analyzed.

Rabbit endosalpinx inhibits implantation in vitro.

Objective: To evaluate the ability of rabbit endometrial or endosalpingeal cells to support implantation in vitro and to assess the effects of endosalpinx and endometrium-conditioned media (CM) on blastocyst-endometrial cell interaction.

Design: In one experiment, rabbit blastocysts were co-cultured in vitro with endometrial or endosalpingeal cells growing on Matrigel-coated plastic culture plates or Millicell-HA inserts. In a second experiment, rabbit blastocysts were co-cultured with endometrial cells in the presence of fresh medium or of endosalpinx- or endometrial-CM.

Rabbit endosalpinx suppresses ectopic implantation.

This study was undertaken to elucidate the mechanism underlying the absence of oviductal ectopic pregnancies in infraprimates. Endosalpingeal circumferential grafts were substituted for endometrium in a group of rabbits. The endosalpingeal grafts interfered with implantation as evidenced by four observations: (1) The nidation indices were lowered, (2) no implantations occurred on the grafted endosalpinx, (3) unattached blastocysts were found in animals grafted with endosalpinx, and (4) the implantation sites were significantly smaller in uterine horns containing endosalpingeal grafts.

Human transferrin. Expression and iron modulation of chimeric genes in transgenic mice.

Transferrin (TF) is a plasma protein that transports and is regulated by iron. The aim of this study was to characterize human TF gene sequences that respond in vivo to cellular signals affecting expression in various tissues and to iron administration. Chimeric genes were constructed containing 152, 622, and 1152 base pairs (bp) of the human TF5'-flanking region with the coding region of a reporter gene, CAT (chloramphenicol acetyltransferase), and introduced into the germ line of mice.