Metabolic profile of in vitro derived human embryos is not affected by the mode of fertilization.

The pattern of metabolism by early embryos in vitro has been linked to a range of phenotypes, including viability. However, the extent to which metabolic function of embryos is modified by specific methods used during ART has yet to be fully described. This study has sought to determine if the mode of fertilization used to create embryos affects subsequent embryo metabolism of substrates. A metabolic profile, including consumption of key substrates and the endogenous triglyceride content of individual IVF and ICSI supernumerary embryos, was assessed and compared. Embryo development and quality was also recorded. All embryos were donated at a single clinical IVF center, on Day 5, from 36 patients aged 18-38 years, The data revealed that consumption of glucose and pyruvate, and production of lactate, did not differ between embryos created by IVF or ICSI. Similarly, the mode of insemination did not impact on the triglyceride content of embryos. However, ICSI-derived embryos displayed a more active turnover of amino acids (P = 0.023), compared to IVF embryos. The specific amino acids produced in higher quantities from ICSI compared to IVF embryos were aspartate (P = 0.016), asparagine (P = 0.04), histidine (P = 0.021) and threonine (P = 0.009) while leucine consumption was significantly lower (P = 0.04). However, importantly neither individual nor collective differences in amino acid metabolism were apparent for sibling oocytes subjected to either mode of fertilization. Embryo morphology (the number of top grade embryos) and development (proportion reaching the blastocyst stage) were comparable in patients undergoing IVF and ICSI. In conclusion, the microinjection of spermatozoa into oocytes does not appear to have an impact on subsequent metabolism and viability. Observed differences in amino acid metabolism may be attributed to male factor infertility of the patients rather than the ICSI procedure per se.

Human embryos from overweight and obese women display phenotypic and metabolic abnormalities.

STUDY QUESTION: Is the developmental timing and metabolic regulation disrupted in embryos from overweight or obese women? SUMMARY ANSWER: Oocytes from overweight or obese women are smaller than those from women of healthy weight, yet post-fertilization they reach the morula stage faster and, as blastocysts, show reduced glucose consumption and elevated endogenous triglyceride levels. WHAT IS KNOWN ALREADY: Female overweight and obesity is associated with infertility. Moreover, being overweight or obese around conception may have significant consequences for the unborn child, since there are widely acknowledged links between events occurring during early development and the incidence of a number of adult disorders. STUDY DESIGN, SIZE, DURATION: We have performed a retrospective, observational analysis of oocyte size and the subsequent developmental kinetics of 218 oocytes from 29 consecutive women attending for ICSI treatment and have related time to reach key developmental stages to maternal bodyweight. In addition, we have measured non-invasively the metabolic activity of 150 IVF/ICSI embryos from a further 29 consecutive women who donated their surplus embryos to research, and have related the data retrospectively to their body mass index (BMI). PARTICIPANTS/MATERIALS, SETTING, METHODS: In a clinical IVF setting, we compared oocyte morphology and developmental kinetics of supernumerary embryos collected from overweight and obese women, with a BMI in excess of 25 kg/m(2) to those from women of healthy weight. A Primovision Time-Lapse system was used to measure developmental kinetics and the non-invasive COnsumption/RElese of glucose, pyruvate, amino acids and lactate were measured on spent droplets of culture medium. Total triglyceride levels within individual embryos were also determined. MAIN RESULTS AND THE ROLE OF CHANCE: Human oocytes from women presenting for fertility treatment with a BMI exceeding 25 kg/m(2) are smaller (R(2) = -0.45; P = 0.001) and therefore less likely to complete development post-fertilization (P < 0.001). Those embryos that do develop reach the morula stage faster than embryos from women of a BMI < 25 kg/m(2) (<0.001) and the resulting blastocysts contain fewer cells notably in the trophectoderm (P = 0.01). The resulting blastocysts also have reduced glucose consumption (R(2) = -0.61; P = 0.001), modified amino acid metabolism and increased levels of endogenous triglyceride (t = 4.11, P < 0.001). Our data further indicate that these differences are independent of male BMI. LIMITATIONS, REASONS FOR CAUTION: Although statistical power has been achieved, this is a retrospective study and relatively small due to the scarcity of human embryos available for research. Consequently, subanalysis of overweight and obese was not possible based on the sample size. The analysis has been performed on supernumerary embryos, originating from a single IVF unit and not selected for use in treatment. Thus, it was not possible to speculate how representative the findings would be of the better quality embryos transferred or frozen for each patient. WIDER IMPLICATIONS OF THE FINDINGS: The data indicate that a high BMI of women at conception is associated with distinct phenotypic changes in the embryo during the preimplantation period, highlighting the importance of prepregnancy body weight in optimizing the chances of fertility and safeguarding maternal and offspring health. These changes to the metabolic fingerprint of human embryos which are most likely a legacy of the ovarian conditions under which the oocyte has matured may reduce the chances of conception for overweight women and provide good evidence that the metabolic profile of the early embryo is set by sub-optimal conditions around the time of conception. The observed changes could indicate long-term implications for the health of the offspring of overweight and obese women. STUDY FUNDING/COMPETING INTERESTS: This study was funded by the Hull IVF Unit Charitable Trust and the Hull York Medical School. There are no conflict of interests.

The ethics of Canadian entry-to-practice pain competencies: how are we doing?

BACKGROUND: Although unrelieved pain continues to represent a significant problem, prelicensure educational programs tend to include little content related to pain. Standards for professional competence strongly influence curricula and have the potential to ensure that health science students have the knowledge and skill to manage pain in a way that also allows them to meet professional ethical standards. OBJECTIVES: To perform a systematic, comprehensive examination to determine the entry-to-practice competencies related to pain required for Canadian health science and veterinary students, and to examine how the presence and absence of pain competencies relate to key competencies of an ethical nature. METHODS: Entry-to-practice competency requirements related to pain knowledge, skill and judgment were surveyed from national, provincial and territorial documents for dentistry, medicine, nursing, pharmacy, occupational therapy, physiotherapy, psychology and veterinary medicine. RESULTS: Dentistry included two and nursing included nine specific pain competencies. No references to competencies related to pain were found in the remaining health science documents. In contrast, the national competency requirements for veterinary medicine, surveyed as a comparison, included nine pain competencies. All documents included competencies pertaining to ethics. CONCLUSIONS: The lack of competencies related to pain has implications for advancing skillful and ethical practice. The lack of attention to pain competencies limits the capacity of health care professionals to alleviate suffering, foster autonomy and use resources justly. Influencing professional bodies to increase the number of required entry-to-practice pain competencies may ultimately have the greatest impact on education and practice.

Exploring the selenium-over-sulfur substrate specificity and kinetics of a bacterial selenocysteine lyase.

Selenium is a vital micronutrient in many organisms. While traces are required for microbial utilization, excess amounts are toxic; thus, selenium can be regarded as a biological double-edged sword. Selenium is chemically similar to the essential element sulfur, but curiously, evolution has selected the former over the latter for a subset of oxidoreductases. Enzymes involved in sulfur metabolism are less discriminate in terms of preventing selenium incorporation; however, its specific incorporation into selenoproteins reveals a highly discriminate process that is not completely understood. We have identified SclA, a NifS-like protein in the nosocomial pathogen, Enterococcus faecalis, and characterized its enzymatic activity and specificity for l-selenocysteine over l-cysteine. It is known that Asp-146 is required for selenocysteine specificity in the human selenocysteine lyase. Thus, using computational biology, we compared the bacterial and mammalian enzymes and identified His-100, an Asp-146 ortholog in SclA, and generated site-directed mutants in order to study the residue's potential role in the l-selenocysteine discrimination mechanism. The proteins were overexpressed, purified, and characterized for their biochemical properties. All mutants exhibited varying Michaelis-Menten behavior towards l-selenocysteine, but His-100 was not found to be essential for this activity. Additionally, l-cysteine acted as a competitive inhibitor of all enzymes with higher affinity than l-selenocysteine. Finally, we discovered that SclA exhibited low activity with l-cysteine as a poor substrate regardless of mutations. We conclude that His-100 is not required for l-selenocysteine specificity, underscoring the inherent differences in discriminatory mechanisms between bacterial NifS-like proteins and mammalian selenocysteine lyases.

Evaluation of epigenetic marks in human embryos derived from IVF and ICSI.

BACKGROUND: It has long been appreciated that environmental cues may trigger adaptive responses. Many of these responses are a result of changes in the epigenetic landscape influencing transcriptional states and consequently altering phenotypes. In the context of human reproductive health, the procedures necessary for assisted reproduction may result in altered phenotypes by primarily influencing DNA methylation. Among the well-documented effects of assisted reproduction technologies (ART), imprinted genes appear to be frequently altered, likely owing to their reliance on DNA methylation to impose parent-specific monoallelic expression. However, the generality of the potential deregulation of DNA methylation in ART-derived human embryos has not been evaluated. METHODS: In this study, we evaluate the genome-wide DNA methylation together with chromatin organisation in human embryos derived by either IVF (n = 89) or ICSI (n = 76). DNA methylation was assessed using an antibody against 5-methyl-cytidine, and chromatin organisation by DNA staining. RESULTS: Irrespective of the ART procedure, similar errors were observed in both groups and abnormal chromatin was positively correlated (P < 0.001) with inappropriate DNA methylation. Development up to the blastocyst stage was consistent with normal DNA methylation and chromatin organisation, reinforcing the importance of epigenetic regulation to form the early lineages of the blastocyst. Most importantly, we found no evidence that ICSI blastocysts were more severely affected than those derived by IVF. CONCLUSIONS: We conclude that ICSI does not lead to an increased incidence of epigenetic errors (DNA methylation and chromatin) compared with IVF.

Feasibility of Continuous Infusions of Acyclovir.

Current guidelines for severe herpes simplex virus infection recommend 21 days of intravenous therapy. The thrice-daily administration of intravenous acyclovir makes it challenging to deliver as outpatient therapy. We describe 2 cases with confirmed or presumed neonatal herpes simplex virus encephalitis treated with acyclovir administered as a continuous-infusion at home and review the pharmacologic and clinical evidence for continuous infusions of acyclovir.

Analysing the performance of in vitro fertilization clinics in the United Kingdom.

During the past century, the manufacturing industry has achieved major successes in improving the quality of its products. An essential factor in these successes has been the use of Walter A. Shewhart's pioneering work in the economic control of variation, which culminated in the development of a simple yet powerful theory of variation, which classifies variation as having a common or special cause and thus guides the user to the most appropriate action to effect improvement. Using publicly available performance data, which includes percentage of live births and multiple births, for in vitro fertilization (IVF) clinics in the United Kingdom, we show a central role for Shewhart's approach in moving away from the limitations and controversies associated with performance league tables towards data analyses to support continual improvement. We outline strategies for dealing with common and special causes of variation in IVF clinic performance data.

How should we choose the 'best' embryo? A commentary on behalf of the British Fertility Society and the Association of Clinical Embryologists.

Embryo selection to improve pregnancy rates remains a significant challenge in IVF. Non-invasive and invasive methods of embryo selection include morphological assessment, metabolomics, time-lapse imaging and preimplantation genetic screening. To date, none has been shown conclusively to yield improved implantation and live birth rates. This review summarises current understanding of methods for embryo selection.

Turning team-based care into a winning proposition.

Team-based care can go a long way toward improving patient outcomes. This review--with accompanying tips and resource lists--can help.

Sperm content of pre-ejaculatory fluid.

This study was designed to establish whether motile spermatozoa are released with pre-ejaculatory fluid and whether this fluid therefore poses a risk for unintended pregnancy. Forty samples of pre-ejaculatory fluid were examined from 27 volunteer men. Samples were obtained by masturbation and by touching the end of the penis with a Petri dish prior to ejaculation. Eleven of the 27 subjects (41%) produced pre-ejaculatory samples that contained spermatozoa and in 10 of these cases (37%), a reasonable proportion of the sperm was motile. The volunteers produced on up to five separate occasions and sperms were found in either all or none of their pre-ejaculatory samples. Hence, condoms should continue to be used from the first moment of genital contact, although it may be that some men, less likely to leak spermatozoa in their pre-ejaculatory fluid, are able to practice coitus interruptus more successfully than others.

Steady-state pharmacokinetics of an extended-regimen oral contraceptive with continuous estrogen.

BACKGROUND: This study was conducted to evaluate the steady-state blood concentrations and potential accumulation of levonorgestrel (LNG) and ethinyl estradiol (EE) administered for up to 84 days and EE alone for 7 additional days as an extended-regimen 91-day oral contraceptive (OC). STUDY DESIGN: An open-label, single-site study was conducted in 30 healthy female volunteers. Subjects received daily doses of 0.15 mg LNG/0.03 mg EE for 84 consecutive days followed by 0.03 mg EE alone for 7 days. Pharmacokinetic (PK) monitoring was conducted on Days 1, 21, 84 and 91. RESULTS: The observed plasma concentrations of LNG after 84 days and of EE after 84 and 91 days were comparable to the steady-state concentrations observed at 21 days. Pharmacokinetic parameters over the 24-h dosing period were similar at all time points measured after achieving steady-state plasma concentrations. CONCLUSION: This study demonstrated that an extended-regimen OC providing 84 days of LNG/EE and 7 days of EE alone has a PK profile similar to a 28-day conventional OC regimen and does not result in any additional accumulation of these hormones.

Derivation of a human blastocyst after heterologous nuclear transfer to donated oocytes.

This paper describes the derivation of a blastocyst following heterologous nuclear transfer (NT) into a human oocyte. It also demonstrates that a major obstacle to continuing research in human NT is the availability of suitable human oocytes. In this study, 36 oocytes were donated by 11 women undergoing four different treatments and their developmental potential was evaluated after NT. The time from oocyte collection to NT seems to be crucial, and only oocytes that were enucleated within 1 h proved successful. After enucleation of oocytes, fusion with undifferentiated human embryonic stem cells and in-vitro culture, early cleavage and blastocyst development of fused complexes was observed. The DNA fingerprinting comparison of the donor cells and derived blastocyst revealed successful heterologous NT, since both oocytes and donor cells were recovered from different patients. It has therefore been demonstrated that NT can be achieved in humans, using heterologous donor nuclei and surplus and donated oocytes. However, if the promise of this new science is to achieve its potential in the foreseeable future, it will be necessary to identify new sources of oocytes that can be used immediately after retrieval.