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In order to evaluate the niche of extended embryo culture in an IVF programme, retrospective analysis of non-selected IVF patients, who underwent ovarian stimulation from April 1998 to June 1999 in a single private practice assisted reproductive technology centre, was performed. Embryos were cultured for 48 h in S1/G1.2 medium followed by 48 to 72 h of culture in S2/G2.2 to day 5 or day 6. Only fertilized oocytes exhibiting two pronuclei from donor and non-donor IVF and intracytoplasmic sperm injection (ICSI) cases were examined to determine the relationship between embryo cell number on day 3 and subsequent rate of blastocyst formation. Results indicated that a proportional relationship existed between the number of blastomeres present in day 3 embryos and the rate of blastocyst formation. Fifty-four per cent of embryos that had six cells on day 3 formed blastocysts, while 76% of those embryos with eight cells formed blastocysts. Blastocyst development did not increase further when embryos had more than eight cells on day 3, indicating that embryos with greater cell numbers on day 3 are not always predictive of a greater likelihood of blastocyst formation. Fertilized oocytes exhibiting two pronuclei from donors produced significantly more blastocysts (67%) than those from IVF patients (52%; P < 0.01), and had a significantly higher implantation rate (54%) compared with IVF patients (30%; P < 0.01). Furthermore, blastocyst cryopreservation resulted in significantly higher implantation rates than cryopreserved cleavage stage embryos (P < 0.001).

IntroductionIneffective coping may lead to impaired job performance and burnout, with adverse consequences to staff well-being and patient outcomes. We examined the relationship between coping styles and burnout in emergency physicians, nurses and support staff at seven small, medium and large emergency departments (ED) in a Canadian health region (population 500 000).MethodsLinear regression with the Coping Inventory for Stressful Situations (CISS) and Maslach Burnout Inventory (MBI) was used to evaluate the effect of coping style on levels of burnout in a cross-sectional survey of 616 ED staff members. CISS measures coping style in three categories: task-oriented, emotion-oriented and avoidance-oriented coping; MBI, in use for 30 years, assesses the level of burnout in healthcare workers.ResultsTask-oriented coping was associated with decreased risk of burnout, while emotion-oriented coping was associated with increased risk of burnout.DiscussionSpecific coping styles are associated with varied risk of burnout in ED staff across several different types of hospitals in a regional network. Coping style intervention may reduce burnout, while leading to improvement in staff well-being and patient outcomes. Further studies should focus on building and sustaining task-oriented coping, along with alternatives to emotion-oriented coping.

We have examined the levels of expression of mRNA species encoding cholesterol side-chain cleavage cytochrome P-450 (P-450scc), 17α-hydroxylase cytochrome P-450 (P-45017α), aromatase cytochrome P-450 (P-450AROM) and 3β-hydroxy-steroid dehydrogenase (3β-HSD) in rat ovaries throughout the oestrous cycle, during pregnancy and in immature animals treated with pregnant mare serum gonadotrophin (PMSG). Total or poly(A)+-enriched RNA was prepared from adult rat ovaries throughout the oestrous cycle, from immature rat ovaries 24 and 48 h after treatment and from adult rat ovaries on days 10, 14, 17 and 21 of gestation. Expression of the mRNA species was examined by Northern analysis using specific [32P]cDNA probes. During the oestrous cycle P-450sccmRNA of ∼1·9 kb was detected at low levels, while 3β-HSD mRNA of 1·7 kb was in relatively high abundance throughout the oestrous cycle. While P-45017αmRNA of 1·9 kb and P-450AROMof 2·7, 2·2 and 1·7 kb were highly abundant during dioestrus, pro-oestrus and oestrus, the levels of these mRNA species decreased markedly to be nearly undetectable during metoestrus. During pregnancy there was considerably more variation in the expression of the mRNA species examined. Expression of P-450sccmRNA was at low, but detectable, levels until day 14, thereafter expression increased to high levels (day 14–21 of gestation). Levels of P-45017αmRNA on day 10 of gestation were lower than at pro-oestrus during the oestrous cycle and decreased further on days 14 and 17. Expression of 3β-HSD was decreased on day 10, but on days 14, 17 and 21 of gestation high mRNA levels were detectable. Ovarian expression of the three P-450AROMspecies was dramatically increased between days 14 and 17 of pregnancy, but declined by day 21. In immature rats, P-450sccmRNA was detected at low levels in unstimulated animals and increased markedly after treatment with PMSG, while subsequent treatment with human chorionic gonadotrophin (hCG) had a minimal effect on expression. Expression of P-45017αmRNA was high in unstimulated immature and PMSG-treated rats, but diminished after treatment with hCG. All three P-450AROMmRNA species were undetectable in ovaries from unstimulated immature animals; however, induction of all three was observed in PMSG-treated rats, but this expression decreased to undetectable levels upon subsequent administration of hCG. Further RNA blot analysis utilizing a 3′ portion of the P-450AROMcDNA as probe, which contains an intronic segment instead of the steroid-binding region, revealed that the two mRNA species of lower molecular weight hybridized to this probe. In contrast, only the largest aromatase mRNA band hybridized to a probe specific for the steroid-binding region. These findings indicate that a majority of the P-450AROMmRNA species in rat ovarian tissue during the oestrous cycle and throughout pregnancy represents alternatively spliced products, which presumably lack the ability to encode for aromatase activity. These results indicate that the pattern of steroid secretion in the rat can be explained, in part, by the differential expression of mRNA species encoding the various key steroidogenic enzymes throughout the ovarian cycle, during pregnancy and following administration of gonadotrophins.