Frenotomy with breastfeeding support versus breastfeeding support alone for infants with tongue-tie and breastfeeding difficulties: the FROSTTIE RCT.

Background: Tongue-tie can be diagnosed in 3-11% of babies, with some studies reporting almost universal breastfeeding difficulties, and others reporting very few feeding difficulties that relate to the tongue-tie itself, instead noting that incorrect positioning and attachment are the primary reasons behind the observed breastfeeding difficulties and not the tongue-tie itself. The only existing trials of frenotomy are small and underpowered and/or include only very short-term or subjective outcomes. Objective: To investigate whether frenotomy is clinically and cost-effective to promote continuation of breastfeeding at 3 months in infants with breastfeeding difficulties diagnosed with tongue-tie. Design: A multicentre, unblinded, randomised, parallel group controlled trial. Setting: Twelve infant feeding services in the UK. Participants: Infants aged up to 10 weeks referred to an infant feeding service (by a parent, midwife or other breastfeeding support service) with breastfeeding difficulties and judged to have tongue-tie. Interventions: Infants were randomly allocated to frenotomy with standard breastfeeding support or standard breastfeeding support without frenotomy. Main outcome measures: Primary outcome was any breastmilk feeding at 3 months according to maternal self-report. Secondary outcomes included mother's pain, exclusive breastmilk feeding, exclusive direct breastfeeding, frenotomy, adverse events, maternal anxiety and depression, maternal and infant NHS health-care resource use, cost-effectiveness, and any breastmilk feeding at 6 months of age. Results: Between March 2019 and November 2020, 169 infants were randomised, 80 to the frenotomy with breastfeeding support arm and 89 to the breastfeeding support arm from a planned sample size of 870 infants. The trial was stopped in the context of the COVID-19 pandemic due to withdrawal of breastfeeding support services, slow recruitment and crossover between arms. In the frenotomy with breastfeeding support arm 74/80 infants (93%) received their allocated intervention, compared to 23/89 (26%) in the breastfeeding support arm. Primary outcome data were available for 163/169 infants (96%). There was no evidence of a difference between the arms in the rate of breastmilk feeding at 3 months, which was high in both groups (67/76, 88% vs. 75/87, 86%; adjusted risk ratio 1.02, 95% confidence interval 0.90 to 1.16). Adverse events were reported for three infants after surgery [bleeding (n = 1), salivary duct damage (n = 1), accidental cut to the tongue and salivary duct damage (n = 1)]. Cost-effectiveness could not be determined with the information available. Limitations: The statistical power of the analysis was extremely limited due to not achieving the target sample size and the high proportion of infants in the breastfeeding support arm who underwent frenotomy. Conclusions: This trial does not provide sufficient information to assess whether frenotomy in addition to breastfeeding support improves breastfeeding rates in infants diagnosed with tongue-tie. Future work: There is a clear lack of equipoise in the UK concerning the use of frenotomy, however, the effectiveness and cost-effectiveness of the procedure still need to be established. Other study designs will need to be considered to address this objective. Trial registration: This trial is registered as ISRCTN 10268851. Funding: This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment Programme (project number 16/143/01) and will be published in full in Health Technology Assessment; Vol. 27, No. 11. See the NIHR Journals Library website for further project information. The funder had no role in study design or data collection, analysis and interpretation. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care.

Many mothers and babies experience difficulties in establishing breastfeeding. In some babies it is thought that their difficulties may be linked to a condition called tongue-tie, in which a piece of skin tightly joins the middle part of the underside of the tongue to the base of the baby's mouth. This can be treated by an operation to divide the tight part/skin in the middle of the underneath of the tongue. We planned to carry out a trial of 870 babies to find out whether an operation together with breastfeeding support helps more mothers and babies with tongue-tie to continue breastfeeding until the baby is 3 months old compared to breastfeeding support on its own and whether the costs were different between the two groups of mothers and babies. We were only able to recruit 169 babies as the trial was stopped because of slow recruitment, changes to services in the COVID-19 pandemic and a high proportion of the babies in the breastfeeding support group going on to have an operation. There were no differences in the rate of breastfeeding at 3 months between the babies in the group who had an operation straightaway and those in the group that had breastfeeding support alone, or had an operation later. More than four in every five babies in both groups were still breastmilk feeding at 3 months. Three babies who had an operation, around 1 in 50 babies, had a complication of the operation (bleeding, scarring or a cut to the tube that makes saliva). Because of the small size of the study, we cannot say whether an operation to divide a tongue-tie along with breastfeeding support helps babies with tongue-tie and breastfeeding difficulties or has different costs. We will need to try different types of research to answer the question.

Distributed manufacturing of an open-source tourniquet testing system.

Tourniquets are effective for casualty-prevention in emergency situations. The use of centrally-manufactured commercial tourniquets, however, is not always possible due to supply chain disruptions. The open-source hardware model has been applied to overcome these disruptions in humanitarian crises and several low-cost digitally manufacturable open-source tourniquets have been developed. With the low reliability of improvised tourniquets, it is important to ensure that distributed manufacturing of tourniquets is effective and safe. Tourniquets can be tested, but existing tourniquet testers are expensive, bulky, and complex to operate, which limits their accessibility to an even greater extent than tourniquets in extreme settings. This article fulfills a need by providing a small, transportable, open-source additive-manufactured tourniquet tester that enables inexpensive and accurate testing of tourniquets against known clinical parameters. The <$100 tourniquet tester is validated and tested for operating force of tourniquets in the field or in distributed manufacturing facilities. The tourniquet tester has a significant economic and operational advantage compared to proprietary counterparts available on the market. Once calibrated with a blood pressure monitor, the built-in LCD displays the measuring range of the tester as 0 to 200 N, which is enough to test the validation of all tourniquets.

Mixed-methods feasibility study to inform a randomised controlled trial of proton pump inhibitors to reduce strictures following neonatal surgery for oesophageal atresia.

OBJECTIVES: This mixed-methods feasibility study aimed to explore parents' and medical practitioners' views on the acceptability and design of a clinical trial to determine whether routine prophylactic proton pump inhibitors (PPI) reduce the incidence of anastomotic stricture in infants with oesophageal atresia (OA). DESIGN: Semi-structured interviews with UK parents of an infant with OA and an online survey, telephone interviews and focus groups with clinicians. Data were analysed using reflexive thematic analysis and descriptive statistics. PARTICIPANTS AND SETTING: We interviewed 18 parents of infants with OA. Fifty-one clinicians (49 surgeons, 2 neonatologists) from 20/25 (80%) units involved in OA repair completed an online survey and 10 took part in 1 of 2 focus groups. Interviews were conducted with two clinicians whose survey responses indicated they had concerns about the trial. OUTCOME MEASURES: Parents and clinicians ranked the same top four outcomes ('Severity of anastomotic stricture', 'Incidence of anastomotic stricture', 'Need for treatment of reflux' and 'Presence of symptoms of reflux') as important to measure for the proposed trial. RESULTS: All parents and most clinicians found the use, dose and duration of omeprazole as the intervention medication, and the placebo control, as acceptable. Parents stated they would hypothetically consent to their child's participation in the trial. Concerns of a few parents and clinicians about infants suffering with symptomatic reflux, and the impact of this for study retention, appeared to be alleviated through the symptomatic reflux treatment pathway. Hesitant clinician views appeared to change through discussion of parental support for the study and by highlighting existing research that questions current practice of PPI treatment. CONCLUSIONS: Our findings indicate that parents and most clinicians view the proposed Treating Oesophageal Atresia with prophylactic proton pump inhibitors to prevent STricture (TOAST) trial to be feasible and acceptable so long as infants can be given PPI if clinicians deem it clinically necessary. This insight into parent and clinician views and concerns will inform pilot phase trial monitoring, staff training and the development of the trial protocol.

Comparing the effect of a lactation-specific relaxation and visualisation intervention versus standard care on lactation and mental health outcomes in mothers of very premature infants (the EXPRESS trial): study protocol for a multi-centre, unmasked, randomised, parallel-group trial.

BACKGROUND: Premature birth is the leading cause of neonatal death and can cause major morbidity. Maximising the amount of maternal breastmilk given to very premature infants is important to improve outcomes, but this can be challenging for parents. Parents of infants receiving neonatal care also have high rates of anxiety and distress. There is growing evidence for the impact of maternal relaxation interventions on lactation, as well as mental health. The trial will assess whether a brief self-directed relaxation and visualisation intervention, recommended for use several times a day during expression of milk, improves lactation and mental health outcomes for mothers of very premature infants. METHODS: Multi-centre, randomised, controlled, unmasked, parallel-group trial with planned 132 participants who have experienced premature birth between 23 weeks and 31 weeks and 6 days of gestation and plan to express milk for at least 14 days. The primary outcome is the highest 24-h expressed milk yield recorded on any of day 4, day 14 or day 21 after birth. Secondary outcomes include exclusive breastmilk feeding at 36 weeks post-menstrual age and at 4 months after the estimated date of delivery, Spielberger State Trait Anxiety Index at day 21 and Post-traumatic stress Check List (for DSM 5) at day 21. DISCUSSION: Breastmilk feeding for premature infants is an important research priority, but there are few randomised controlled trials assessing interventions to help parents reach lactation goals in this challenging context. This trial will assess whether a no cost, easily scalable relaxation tool has a role in this setting. Given the lack of harm and potential for immediate dissemination, even a small benefit could have an important global impact. TRIAL REGISTRATION: ISRCTN16356650 . Date assigned: 19/04/2021.

Transfer of thawed frozen embryo versus fresh embryo to improve the healthy baby rate in women undergoing IVF: the E-Freeze RCT.

BACKGROUND: Freezing all embryos, followed by thawing and transferring them into the uterine cavity at a later stage (freeze-all), instead of fresh-embryo transfer may lead to improved pregnancy rates and fewer complications during in vitro fertilisation and pregnancies resulting from it. OBJECTIVE: We aimed to evaluate if a policy of freeze-all results in a higher healthy baby rate than the current policy of transferring fresh embryos. DESIGN: This was a pragmatic, multicentre, two-arm, parallel-group, non-blinded, randomised controlled trial. SETTING: Eighteen in vitro fertilisation clinics across the UK participated from February 2016 to April 2019. PARTICIPANTS: Couples undergoing their first, second or third cycle of in vitro fertilisation treatment in which the female partner was aged < 42 years. INTERVENTIONS: If at least three good-quality embryos were present on day 3 of embryo development, couples were randomly allocated to either freeze-all (intervention) or fresh-embryo transfer (control). OUTCOMES: The primary outcome was a healthy baby, defined as a live, singleton baby born at term, with an appropriate weight for their gestation. Secondary outcomes included ovarian hyperstimulation, live birth and clinical pregnancy rates, complications of pregnancy and childbirth, health economic outcome, and State-Trait Anxiety Inventory scores. RESULTS: A total of 1578 couples were consented and 619 couples were randomised. Most non-randomisations were because of the non-availability of at least three good-quality embryos (n = 476). Of the couples randomised, 117 (19%) did not adhere to the allocated intervention. The rate of non-adherence was higher in the freeze-all arm, with the leading reason being patient choice. The intention-to-treat analysis showed a healthy baby rate of 20.3% in the freeze-all arm and 24.4% in the fresh-embryo transfer arm (risk ratio 0.84, 95% confidence interval 0.62 to 1.15). Similar results were obtained using complier-average causal effect analysis (risk ratio 0.77, 95% confidence interval 0.44 to 1.10), per-protocol analysis (risk ratio 0.87, 95% confidence interval 0.59 to 1.26) and as-treated analysis (risk ratio 0.91, 95% confidence interval 0.64 to 1.29). The risk of ovarian hyperstimulation was 3.6% in the freeze-all arm and 8.1% in the fresh-embryo transfer arm (risk ratio 0.44, 99% confidence interval 0.15 to 1.30). There were no statistically significant differences between the freeze-all and the fresh-embryo transfer arms in the live birth rates (28.3% vs. 34.3%; risk ratio 0.83, 99% confidence interval 0.65 to 1.06) and clinical pregnancy rates (33.9% vs. 40.1%; risk ratio 0.85, 99% confidence interval 0.65 to 1.11). There was no statistically significant difference in anxiety scores for male participants (mean difference 0.1, 99% confidence interval -2.4 to 2.6) and female participants (mean difference 0.0, 99% confidence interval -2.2 to 2.2) between the arms. The economic analysis showed that freeze-all had a low probability of being cost-effective in terms of the incremental cost per healthy baby and incremental cost per live birth. LIMITATIONS: We were unable to reach the original planned sample size of 1086 and the rate of non-adherence to the allocated intervention was much higher than expected. CONCLUSION: When efficacy, safety and costs are considered, freeze-all is not better than fresh-embryo transfer. TRIAL REGISTRATION: This trial is registered as ISRCTN61225414. FUNDING: This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 25. See the NIHR Journals Library website for further project information.

During in vitro fertilisation, eggs and sperm are mixed in a laboratory to create embryos. An embryo is placed in the womb 2­5 days later (fresh-embryo transfer) and the remaining embryos are frozen for future use. Initial research suggested that freezing all embryos followed by thawing and replacing them a few weeks later could improve treatment safety and success. Although these data were promising, the data came from small studies and were not enough to change practice and policy. We conducted a large, multicentre, clinical trial to evaluate the two strategies: fresh-embryo transfer compared with later transfer of frozen embryos. We also compared the costs of both strategies during in vitro fertilisation treatment, pregnancy and delivery. This study was conducted across 18 clinics in the UK from 2016 to 2019, and 619 couples participated. Couples were allocated to one of two strategies: immediate fresh-embryo transfer or freezing of all embryos followed later by transfer of frozen embryo. The study's aim was to find out which type of embryo transfer gave participants a higher chance of having a healthy baby. We found that freezing all embryos followed by frozen-embryo transfer did not lead to a higher chance of having a healthy baby. There were no differences between strategies in the number of live births, the miscarriage rate or the number of pregnancy complications. Fresh-embryo transfer was less costly from both a health-care and a patient perspective. A routine strategy of freezing all embryos is not justified given that there was no increase in success rates but there were extra costs and delays to embryo transfer.

The Effect of Rapamycin and Ibrutinib on Antibody Responses to Adeno-Associated Virus Vector-Mediated Gene Transfer.

Adeno-associated virus (AAV) vector-mediated gene transfer is lessening the impact of monogenetic disorders. Human AAV gene therapy recipients commonly mount immune responses to AAV or the encoded therapeutic protein, which requires transient immunosuppression. Most efforts to date have focused on blunting AAV capsid-specific T cell responses, which have been implicated in elimination of AAV-transduced cells. Here, we explore the use of immunosuppressants, rapamycin given alone or in combination with ibrutinib to inhibit AAV vector- or transgene product-specific antibody responses. Our results show that rapamycin or ibrutinib given alone reduces primary antibody responses against AAV capsid, but the combination of rapamycin and ibrutinib is more effective, blunts recall responses, and reduces numbers of circulating antibody-secreting plasma cells. The drugs fail to lower B cell memory formation or to reduce the inhibitory effects of pre-existing AAV capsid-specific antibodies on transduction efficiency.

Elective freezing of embryos versus fresh embryo transfer in IVF: a multicentre randomized controlled trial in the UK (E-Freeze).

STUDY QUESTION: Does a policy of elective freezing of embryos, followed by frozen embryo transfer result in a higher healthy baby rate, after first embryo transfer, when compared with the current policy of transferring fresh embryos? SUMMARY ANSWER: This study, although limited by sample size, provides no evidence to support the adoption of a routine policy of elective freeze in preference to fresh embryo transfer in order to improve IVF effectiveness in obtaining a healthy baby. WHAT IS KNOWN ALREADY: The policy of freezing all embryos followed by frozen embryo transfer is associated with a higher live birth rate for high responders but a similar/lower live birth after first embryo transfer and cumulative live birth rate for normal responders. Frozen embryo transfer is associated with a lower risk of ovarian hyperstimulation syndrome (OHSS), preterm delivery and low birthweight babies but a higher risk of large babies and pre-eclampsia. There is also uncertainty about long-term outcomes, hence shifting to a policy of elective freezing for all remains controversial given the delay in treatment and extra costs involved in freezing all embryos. STUDY DESIGN, SIZE, DURATION: A pragmatic two-arm parallel randomized controlled trial (E-Freeze) was conducted across 18 clinics in the UK from 2016 to 2019. A total of 619 couples were randomized (309 to elective freeze/310 to fresh). The primary outcome was a healthy baby after first embryo transfer (term, singleton live birth with appropriate weight for gestation); secondary outcomes included OHSS, live birth, clinical pregnancy, pregnancy complications and cost-effectiveness. PARTICIPANTS/MATERIALS, SETTING, METHODS: Couples undergoing their first, second or third cycle of IVF/ICSI treatment, with at least three good quality embryos on Day 3 where the female partner was ≥18 and <42 years of age were eligible. Those using donor gametes, undergoing preimplantation genetic testing or planning to freeze all their embryos were excluded. IVF/ICSI treatment was carried out according to local protocols. Women were followed up for pregnancy outcome after first embryo transfer following randomization. MAIN RESULTS AND THE ROLE OF CHANCE: Of the 619 couples randomized, 307 and 309 couples in the elective freeze and fresh transfer arms, respectively, were included in the primary analysis. There was no evidence of a statistically significant difference in outcomes in the elective freeze group compared to the fresh embryo transfer group: healthy baby rate {20.3% (62/307) versus 24.4% (75/309); risk ratio (RR), 95% CI: 0.84, 0.62 to 1.15}; OHSS (3.6% versus 8.1%; RR, 99% CI: 0.44, 0.15 to 1.30); live birth rate (28.3% versus 34.3%; RR, 99% CI 0.83, 0.65 to 1.06); and miscarriage (14.3% versus 12.9%; RR, 99% CI: 1.09, 0.72 to 1.66). Adherence to allocation was poor in the elective freeze group. The elective freeze approach was more costly and was unlikely to be cost-effective in a UK National Health Service context. LIMITATIONS, REASONS FOR CAUTION: We have only reported on first embryo transfer after randomization; data on the cumulative live birth rate requires further follow-up. Planned target sample size was not obtained and the non-adherence to allocation rate was high among couples in the elective freeze arm owing to patient preference for fresh embryo transfer, but an analysis which took non-adherence into account showed similar results. WIDER IMPLICATIONS OF THE FINDINGS: Results from the E-Freeze trial do not lend support to the policy of electively freezing all for everyone, taking both efficacy, safety and costs considerations into account. This method should only be adopted if there is a definite clinical indication. STUDY FUNDING/COMPETING INTEREST(S): NIHR Health Technology Assessment programme (13/115/82). This research was funded by the National Institute for Health Research (NIHR) (NIHR unique award identifier) using UK aid from the UK Government to support global health research. The views expressed in this publication are those of the author(s) and not necessarily those of the NIHR or the UK Department of Health and Social Care. J.L.B., C.C., E.J., P.H., J.J.K., L.L. and G.S. report receipt of funding from NIHR, during the conduct of the study. J.L.B., E.J., P.H., K.S. and L.L. report receipt of funding from NIHR, during the conduct of the study and outside the submitted work. A.M. reports grants from NIHR personal fees from Merck Serono, personal fees for lectures from Merck Serono, Ferring and Cooks outside the submitted work; travel/meeting support from Ferring and Pharmasure and participation in a Ferring advisory board. S.B. reports receipt of royalties and licenses from Cambridge University Press, a board membership role for NHS Grampian and other financial or non-financial interests related to his roles as Editor-in-Chief of Human Reproduction Open and Editor and Contributing Author of Reproductive Medicine for the MRCOG, Cambridge University Press. D.B. reports grants from NIHR, during the conduct of the study; grants from European Commission, grants from Diabetes UK, grants from NIHR, grants from ESHRE, grants from MRC, outside the submitted work. Y.C. reports speaker fees from Merck Serono, and advisory board role for Merck Serono and shares in Complete Fertility. P.H. reports membership of the HTA Commissioning Committee. E.J. reports membership of the NHS England and NIHR Partnership Programme, membership of five Data Monitoring Committees (Chair of two), membership of six Trial Steering Committees (Chair of four), membership of the Northern Ireland Clinical Trials Unit Advisory Group and Chair of the board of Oxford Brain Health Clinical Trials Unit. R.M. reports consulting fees from Gedeon Richter, honorarium from Merck, support fees for attendance at educational events and conferences for Merck, Ferring, Bessins and Gedeon Richter, payments for participation on a Merck Safety or Advisory Board, Chair of the British Fertility Society and payments for an advisory role to the Human Fertilisation and Embryology Authority. G.S. reports travel and accommodation fees for attendance at a health economic advisory board from Merck KGaA, Darmstadt, Germany. N.R.-F. reports shares in Nurture Fertility. Other authors' competing interests: none declared. TRIAL REGISTRATION NUMBER: ISRCTN: 61225414. TRIAL REGISTRATION DATE: 29 December 2015. DATE OF FIRST PATIENT'S ENROLMENT: 16 February 2016.

Challenges of a simplified opt-out consent process in a neonatal randomised controlled trial: qualitative study of parents' and health professionals' views and experiences.

BACKGROUND: More effective recruitment strategies like alternative approaches to consent are needed to facilitate adequately powered trials. Witholding Enteral feeds Around Transfusion was a multicentre, randomised, pilot trial that compared withholding and continuing feeds around transfusion. The primary clinical outcome was necrotising enterocolitis. The trial used simplified opt-out consent with concise parent information and no consent form. OBJECTIVE: To explore the views and experiences of parents and health professionals on the acceptability and feasibility of opt-out consent in randomised comparative effectiveness trials. METHODS: A qualitative, descriptive interview-based study nested within a randomised trial. Semistructured interview transcripts were analysed using inductive thematic analysis. SETTING: Eleven neonatal units in England. PARTICIPANTS: Eleven parents and ten health professionals with experience of simplified consent. RESULTS: Five themes emerged: 'opt-out consent operationalised as verbal opt-in consent', 'opt-out consent normalises participation while preserving parental choice', 'opt-out consent as an ongoing process of informed choice', 'consent without a consent form' and 'choosing to opt out of a comparative effectiveness trial', with two subthemes: 'wanting "normal care"' and 'a belief that feeding is better'. CONCLUSION: Introducing a novel form of consent proved challenging in practice. The principle of a simplified, opt-out approach to consent was generally considered feasible and acceptable by health professionals for a neonatal comparative effectiveness trial. The priority for parents was having the right to decide about trial participation, and they did not see opt-out consent as undermining this. Describing a study as 'opt-out' can help to normalise participation and emphasise that parents can withdraw consent.

E-Freeze - a randomised controlled trial evaluating the clinical and cost effectiveness of a policy of freezing embryos followed by thawed frozen embryo transfer compared with a policy of fresh embryo transfer, in women undergoing in vitro fertilisation: a statistical analysis plan.

BACKGROUND: The E-Freeze trial is a multi-centre randomised controlled trial of fresh versus frozen embryo transfer for women undergoing in vitro fertilisation. This paper describes the statistical analysis plan for the E-Freeze trial. METHODS AND DESIGN: E-Freeze is a two-arm parallel-group, multi-centre, individually randomised controlled trial to determine if a policy of freezing embryos, followed by thawed frozen embryo transfer, results in a higher healthy baby rate when compared with the current policy of transferring fresh embryos. Couples undergoing their first, second or third cycle of in vitro fertilisation at fertility centres in the UK were randomised to either fresh or frozen embryo transfer. The primary outcome is a healthy baby, defined as a live singleton baby born at term with an appropriate weight for gestation. This paper describes the statistical analysis plan for the trial, including the analysis principles, definitions of outcomes, methods for primary analysis, pre-specified subgroup analysis and sensitivity analysis. This plan was finalised prior to completion of recruitment to the trial. TRIAL REGISTRATION: ISRCTN registry: ISRCTN61225414 . Registered on 29 December 2015.

Study protocol: E-freeze - freezing of embryos in assisted conception: a randomised controlled trial evaluating the clinical and cost effectiveness of a policy of freezing embryos followed by thawed frozen embryo transfer compared with a policy of fresh embryo transfer, in women undergoing in vitro fertilisation.

BACKGROUND: Infertility affects one in seven couples; many of these need in vitro fertilisation (IVF). IVF involves external hormones to stimulate a woman's ovaries to produce eggs which are harvested surgically. Embryos, created in the laboratory by mixing eggs with sperm, are grown in culture for a few days before being replaced within the uterus (fresh embryo transfer). Spare embryos are usually frozen with a view to transfer at a later point in time - especially if the initial fresh transfer does not result in a pregnancy. Despite improvements in technology, IVF success rates remain low with an overall live birth rate of 25-30% per treatment. Additionally, there are concerns about health outcomes for mothers and babies conceived through IVF, particularly after fresh embryo transfer, including maternal ovarian hyperstimulation syndrome (OHSS) and preterm delivery. It is believed that high levels of hormones during ovarian stimulation could create a relatively hostile environment for embryo implantation whilst increasing the risk of OHSS. It has been suggested that freezing all embryos with the intention of thawing and replacing them within the uterus at a later stage (thawed frozen embryo transfer) instead of fresh embryo transfer, may lead to improved pregnancy rates and fewer complications. We aim to compare the clinical and cost effectiveness of fresh and thawed frozen embryo transfer, with the primary aim of identifying any difference in the chance of having a healthy baby. METHODS: E-Freeze is a pragmatic, multicentre two-arm parallel group randomised controlled trial where women aged ≥18 and < 42 years, with at least three good quality embryos are randomly allocated to receive either a fresh or thawed frozen embryo transfer. The primary outcome is a healthy baby, defined as a term, singleton, live birth with appropriate weight for gestation. Cost effectiveness will be calculated from a healthcare and societal perspective. DISCUSSION: E-Freeze will determine the relative benefits of fresh and thawed frozen embryo transfer in terms of improving the chance of having a healthy baby. The results of this pragmatic study have the potential to be directly transferred to clinical practice. TRIAL REGISTRATION: ISRCTN registry: ISRCTN61225414 . Date assigned 29/12/2015.

Competition between engrams influences fear memory formation and recall.

Collections of cells called engrams are thought to represent memories. Although there has been progress in identifying and manipulating single engrams, little is known about how multiple engrams interact to influence memory. In lateral amygdala (LA), neurons with increased excitability during training outcompete their neighbors for allocation to an engram. We examined whether competition based on neuronal excitability also governs the interaction between engrams. Mice received two distinct fear conditioning events separated by different intervals. LA neuron excitability was optogenetically manipulated and revealed a transient competitive process that integrates memories for events occurring closely in time (coallocating overlapping populations of neurons to both engrams) and separates memories for events occurring at distal times (disallocating nonoverlapping populations to each engram).

FoxO6 regulates memory consolidation and synaptic function.

The FoxO family of transcription factors is known to slow aging downstream from the insulin/IGF (insulin-like growth factor) signaling pathway. The most recently discovered FoxO isoform in mammals, FoxO6, is highly enriched in the adult hippocampus. However, the importance of FoxO factors in cognition is largely unknown. Here we generated mice lacking FoxO6 and found that these mice display normal learning but impaired memory consolidation in contextual fear conditioning and novel object recognition. Using stereotactic injection of viruses into the hippocampus of adult wild-type mice, we found that FoxO6 activity in the adult hippocampus is required for memory consolidation. Genome-wide approaches revealed that FoxO6 regulates a program of genes involved in synaptic function upon learning in the hippocampus. Consistently, FoxO6 deficiency results in decreased dendritic spine density in hippocampal neurons in vitro and in vivo. Thus, FoxO6 may promote memory consolidation by regulating a program coordinating neuronal connectivity in the hippocampus, which could have important implications for physiological and pathological age-dependent decline in memory.

MEF2 negatively regulates learning-induced structural plasticity and memory formation.

Memory formation is thought to be mediated by dendritic-spine growth and restructuring. Myocyte enhancer factor 2 (MEF2) restricts spine growth in vitro, suggesting that this transcription factor negatively regulates the spine remodeling necessary for memory formation. Here we show that memory formation in adult mice was associated with changes in endogenous MEF2 levels and function. Locally and acutely increasing MEF2 function in the dentate gyrus blocked both learning-induced increases in spine density and spatial-memory formation. Increasing MEF2 function in amygdala disrupted fear-memory formation. We rescued MEF2-induced memory disruption by interfering with AMPA receptor endocytosis, suggesting that AMPA receptor trafficking is a key mechanism underlying the effects of MEF2. In contrast, decreasing MEF2 function in dentate gyrus and amygdala facilitated the formation of spatial and fear memory, respectively. These bidirectional effects indicate that MEF2 is a key regulator of plasticity and that relieving the suppressive effects of MEF2-mediated transcription permits memory formation.

Cerebellar abnormalities in purine nucleoside phosphorylase deficient mice.

Inherited defects in purine nucleoside phosphorylase (PNP) cause severe T cell immunodeficiency and progressive neurological dysfunction, yet little is known about the effects of PNP deficiency on the brain. PNP-KO mice display metabolic and immune anomalies similar to those observed in patients. Our objectives were to characterize brain abnormalities in PNP-KO mice and determine whether restoring PNP activity prevents these abnormalities. We analyzed structural brain defects in PNP-KO mice by magnetic resonance imaging, while assessing motor deficits using the accelerating rotarod and stationary balance beam tests. We detected morphological abnormalities and apoptosis in the cerebellum of PNP-KO mice by hematoxylin and eosin, electron microscopy, TUNEL and activated caspase 3 staining. We treated PNP-KO mice with PNP fused to the HIV-TAT protein transduction domain (TAT-PNP) from birth or from 4 weeks of age. Magnetic resonance imaging revealed a smaller than normal cerebellum in PNP-KO mice. PNP-KO mice displayed motor abnormalities including rapid fall from the rotating rod and frequent slips from the balance beam. The cerebellum of PNP-KO mice contained reduced purkinje cells (PC), which were irregular in shape and had degenerated dendrites. PC from the cerebellum of PNP-KO mice, expanded ex vivo, demonstrated increased apoptosis, which could be corrected by supplementing cultures with TAT-PNP. TAT-PNP injections restored PNP activity in the cerebellum of PNP-KO mice. TAT-PNP from birth, but not treatment initiated at 4 weeks of age, prevented the cerebellar PC damage and motor deficits. We conclude that PNP deficiency cause cerebellar abnormalities, including PC damage and progressive motor deficits. TAT-PNP treatment from birth can prevent the neurological abnormalities in PNP-KO mice.

Spine growth in the anterior cingulate cortex is necessary for the consolidation of contextual fear memory.

Remodeling of cortical connectivity is thought to allow initially hippocampus-dependent memories to be expressed independently of the hippocampus at remote time points. Consistent with this, consolidation of a contextual fear memory is associated with dendritic spine growth in neurons of the anterior cingulate cortex (aCC). To directly test whether such cortical structural remodeling is necessary for memory consolidation, we disrupted spine growth in the aCC at different times following contextual fear conditioning in mice. We took advantage of previous studies showing that the transcription factor myocyte enhancer factor 2 (MEF2) negatively regulates spinogenesis both in vitro and in vivo. We found that increasing MEF2-dependent transcription in the aCC during a critical posttraining window (but not at later time points) blocked both the consolidation-associated dendritic spine growth and subsequent memory expression. Together, these data strengthen the causal link between cortical structural remodeling and memory consolidation and, further, identify MEF2 as a key regulator of these processes.

Increasing CREB in the auditory thalamus enhances memory and generalization of auditory conditioned fear.

Although the lateral nucleus of the amygdala (LA) is essential for conditioned auditory fear memory, an emerging theme is that plasticity in multiple brain regions contributes to fear memory formation. The LA receives direct projections from the auditory thalamus, specifically the medial division of the medial geniculate nucleus (MGm) and adjacent posterior intralaminar nucleus (PIN). While traditionally viewed as a simple relay structure, mounting evidence implicates the thalamus in diverse cognitive processes. We investigated the role of plasticity in the MGm/PIN in auditory fear memory. First we found that auditory fear conditioning (but not control manipulations) increased the levels of activated CREB in both the MGm and PIN. Next, using viral vectors, we showed that exogenously increasing CREB in this region specifically enhanced formation of an auditory conditioned fear memory without affecting expression of an auditory fear memory, formation of a contextual fear memory, or basic auditory processing. Interestingly, mice with increased CREB levels in the MGm/PIN also showed broad auditory fear generalization (in contrast to control mice, they exhibited fear responses to tones of other frequencies). Together, these results implicate CREB-mediated plasticity in the MGm/PIN in both the formation and generalization of conditioned auditory fear memory. Not only do these findings refine our knowledge of the circuitry underlying fear memory but they also provide novel insights into the neural substrates that govern the degree to which acquired fear of a tone generalizes to other tones.

Formation of primary amines on silicon nitride surfaces: a direct, plasma-based pathway to functionalization.

Silicon nitride is the most commonly used passivation layer in biosensor applications where electronic components must be interfaced with ionic solutions. Unfortunately, the predominant method for functionalizing silicon nitride surfaces, silane chemistry, suffers from a lack of reproducibility. As an alternative, we have developed a silane-free pathway that allows for the direct functionalization of silicon nitride through the creation of primary amines formed by exposure to a radio frequency glow discharge plasma fed with humidified air. The aminated surfaces can then be further functionalized by a variety of methods; here we demonstrate using glutaraldehyde as a bifunctional linker to attach a robust NeutrAvidin (NA) protein layer. Optimal amine formation, based on plasma exposure time, was determined by labeling treated surfaces with an amine-specific fluorinated probe and characterizing the coverage using X-ray photoelectron spectroscopy (XPS). XPS and radiolabeling studies also reveal that plasma-modified surfaces, as compared with silane-modified surfaces, result in similar NA surface coverage, but notably better reproducibility.