This experiment examined whether the pre- or the post-mating diet had greater impact on embryo survival in Meishan gilts. Gilts received either a maintenance (1.15 kg day(-1); n = 12) or a high (3.5 kg day(-1); n = 12) diet during the oestrous cycle preceding mating. After mating, half the animals in each group received either the maintenance or the high diet until slaughter on Day 12. Gilts fed the high pre-mating diet had more corpora lutea (22.7 v. 19.0, SED = 0.98; P<0.001), increased embryo survival (95.5% v. 74.8%, SED = 7.58; P<0.01) and heavier corpora lutea (-0.71 log g v. -0.90 log g, SED = 0.09; P = 0.07) compared with gilts fed the maintenance diet prior to mating. The post-mating diet had no effect on embryo survival. There were no treatment effects on blastocyst developmental stage, luteal surface area or progesterone release. Gilts receiving the high post-mating diet had heavier livers than those fed the maintenance post-mating diet (1.45 v 1.08% of total bodyweight, SED = 0.07; P<0.001), suggesting that these gilts have a greater capacity to metabolize progesterone. Pre-mating nutritional status therefore appears to be a greater determinant of embryo numbers and survival than the post-mating diet.

SUMMARY BackgroundIntestinal failure (IF) affects a growing number of children due to increasing numbers of preterm infants surviving intestinal resection for necrotising enterocolitis and improving surgical techniques for congenital gut anomalies. Parenteral nutrition (PN) is the mainstay of therapy; enteral nutrition may have trophic effects on the gut.

The roe deer blastocyst is in diapause between August and December, after which time it expands and elongates rapidly before implantation. Blood samples were taken from 30 animals to define temporal changes in reproductively important hormones to investigate the physiological cues present at embryo reactivation. In 15 of these animals, changes in uterine and conceptus protein synthesis and secretion, and luteal progesterone release during diapause and reactivation, were assessed after culture of these tissues in vitro. Oestradiol concentrations remained low during diapause (1.07 +/- 0.4 pg ml(-1)) and expansion (1.2 +/- 0.4 pg ml(-1)) but increased by 30 times at trophoblast elongation (49.17 +/- 0.37 pg ml(-1)). Prolactin remained at basal concentrations (4.69 +/- 0.86 ng ml(-1)) and increased after implantation (12.34 +/- 2.71 ng ml(-1)). Peripheral progesterone concentrations and luteal progesterone release remained constant throughout diapause, reactivation and implantation (peripheral progesterone: 3.82 +/- 1.97 ng ml(-1); luteal progesterone: 6.72 +/- 0.81 ng mg(-1) protein). Incorporation of a radiolabel into conceptus secretory proteins increased by four times at expansion compared with diapause, whereas incorporation into endometrial secretions remained constant. At elongation, incorporation into endometrial secretions increased two times and conceptus secretions increased 32 times. Two-dimensional electrophoresis and fluorography showed that the profile of endometrial secretory proteins was constant until implantation when qualitative changes were evident. Although a role for an endocrine maternal trigger of reactivation from diapause cannot be dismissed, these data provide no supporting evidence and indicate that the conceptus itself may drive reactivation.

This experiment was designed to determine the effects of a nutritional regime, known to increase embryo survival, on blastocyst development and function. Day 12 blastocysts were recovered from Meishan gilts allocated in a 2x2 factorial design to receive either a high or a maintenance diet before or after mating (n = 4-6 gilts per group). The post-mating diet had no effect on individual blastocyst size, cell number, secretion of oestradiol-17beta or retinol binding protein, glucose metabolism or on the within-litter variability in these measures. Blastocysts recovered from gilts consuming the high pre-mating diet had more cells (13.501 v. 13.006 log cells; SED = 0.23; P = 0.05), greater production of CO2 from glucose (2.19 v. 1.23 log pmol(-1) blastocyst(-1) 3 h(-1), SED = 0.42; P = 0.05) and a lower within-litter standard deviation in blastocyst surface area (0.66 v. 1.18 log mm2, SED = 0.24; P = 0.04) compared with gilts fed the maintenance pre-mating diet. Collectively, these data suggest that a nutritional strategy that increases embryo survival is also associated with an increase in individual blastocyst cell number and reduced within-litter variability in blastocyst size.

In simple transposition of the great arteries (sTGA), balloon atrial septostomy is performed prior to arterial switch to improve mixing of systemic and pulmonary circulations. Following septostomy, some patients are also given prostaglandin E2 (PGE2) until surgical repair. The aims of our study were to identify how often PGE2 is given after septostomy, the indications for starting PGE2, and the effect this has on postoperative outcome. The study was a retrospective review of infants born with sTGA between 2000 and 2005, who underwent arterial switch at Yorkhill Children's Hospital, Glasgow. Over a 5-year period, 26 infants (16 male) with sTGA underwent septostomy. There was a significant rise in mean oxygen saturation following septostomy (mean, 61.4 +/- 11.5% before, 81.5 +/- 9.4% after; p < 0.05). Four of 26 (15%) did not receive PGE2 at all (group 1) and 8 of 26 (30%) received PGE2 before but not after septostomy (group 2). A total of 14 of 26 infants (54%) were given PGE2 following septostomy. This comprised 11 who received PGE2 before and after septostomy (group 3) and 3 who did not receive PGE2 prior to septostomy but did after (group 4). Groups 2 and 3 were compared directly, as they both received PGE2 before septostomy. In group 3, oxygen saturations were lower when PGE2 was started compared with saturations immediately after septostomy (45 +/- 23.6% vs. 80 +/- 10.3%; p < 0.05). Groups 2 and 3 showed no difference in atrial gap after septostomy (9.4 +/- 3 vs. 8 +/- 1 mm; p > 0.05). Fifty percent of infants in group 3 underwent echocardiography prior to restarting PGE2, which revealed a patent arterial duct in all but one patient. Despite PGE2, Group 3 had lower saturations at arterial switch compared with Group 2 (71 +/- 14% vs. 82 +/- 8%; p < 0.05). No difference was observed between group 2 and group 3 with regard to length of cardiopulmonary bypass (group 2, 173 +/- 101.4 min, vs. group 3, 157.9 +/- 42.1 min; p > 0.05). However, the Intensive Care Unit stay was longer for patients who received PGE2 following septostomy (8.5 +/- 10.3 vs. 5 +/- 0.93 days; p < 0.05). Total postoperative stay was also longer for infants who received PGE2 after septostomy (26.8 +/- 14.3 vs. 16.8 +/- 6.3 days; p < 0.05). In conclusion, the use of pulse oximetry has led to an increase in the administration of PGE2 after septostomy. PGE2 administration was associated with a longer ICU stay. The association between administration of PGE2 and longer postoperative stay supports the approach of early surgical repair with minimal preoperative medical intervention.