The neurotoxicity of acrylamide

The experiments described in this thesis compared conventional methods of screening for neurotoxins with potential electrophysiological and pharmacological tests in an attempt to improve the sensitivity of detection of progressive distal neuropathy. Adult male albino mice were dosed orally with the neurotoxicant acylamide and subjected to a test of limb strength and co-ordination and a functional observational battery. These methods established a no observable effect level of 10 mg/kg. A dose of 200 mg/kg resulted in abnormalities of gait and reduced limb strength and/or co-ordination. Analysis of the in vitro 'jitter' of the latency of trains of action potentials evoked at a frequency of 30 Hz in the mouse phrenic nerve/hemidiaphragm preparation showed this technique to be unsuitable for detection of the early phases of acrylamide induced peripheral neuropathy (l00 mg/kg). The evoked and spontaneous twitch responses of the hemidiaphragm preparation following in vitro exposure to the organophosphorous anticholinesterase compound ecothiopate were altered by in vivo pre treatment with acrylamide. Acrylamide caused an increase in the time course of the potentiation of stimulated twitches and a decrease in the maximum potentiation. Spontaneous twitches were reduced in amplitude and frequency. These effects occurred at an acrylamide dose level insufficient to cause clinical signs of neuropathy. Investigations into the mechanisms underlying these observations yielded the following observations. Analysis of miniature endplate potentials at this dose level indicated prolongation of the life of acetylcholine in the synaptic cleft but the implied decrease in cholinesterase activity could not be demonstrated biochemically or histologically. The electrical excitability of the nerve terminal region of phrenic motor nerves was reduced following acrylamide although a possible compromise of antidromic action potential conduction could not be confirmed. There was no histopathological evidence of neuropathy at this dose level. Further exploration of this phenomenon is desirable in order to ascertain whether the effect is specific to acrylamide and/or ecothiopate and to elucidate the mechanisms behind these novel observations

The effect of endometriosis on live birth rate and other reproductive outcomes in ART cycles: a cohort study

Study question: What is the effect of endometriosis compared to unexplained subfertility on live birth rate in women undergoing IVF and embryo transfer (ET)? Summary answer: Endometriosis decreases live birth rate in women undergoing IVF-ET treatment, particularly with increasing severity of the disease. What is known already: Endometriosis affects up to 50% of women seeking fertility treatment and is known to reduce fecundity. There remains a debate as to effects of endometriosis on the outcomes of IVF treatment, with live birth being a secondary outcome or not reported in most studies. Study design, size, duration: A retrospective cohort study analyzing data of IVF treatment cycles from January 2000 to December 2014 was carried out. Participants/materials, setting, methods: Women with endometriosis (n = 531) and women with unexplained subfertility (n = 737) undergoing a first cycle of IVF-ET in a tertiary fertility treatment center were included in the study. The primary outcome was live birth. Other outcome measures were response to ovarian stimulation, embryo development and implantation rate. Bivariate and multivariate logistic regression analysis was performed and differences compared using Chi squared test of Student’s t-test as appropriate. Main results and the role of chance: Women with endometriosis had 24% less likelihood of a live birth when compared to those with unexplained subfertility [odds ratio (OR) 0.76 (95% CI, 0.59–0.98) P = 0.035]. This effect became more apparent with increasing severity of endometriosis. Using multivariable logistic regression analysis, the trend for lower live birth rate remained but did not reach statistical significance [adjusted OR 0.76 (95% CI 0.56–1.03), P = 0.078]. Women with endometriosis were as likely as those with unexplained subfertility to have a singleton live birth when two embryos were transferred as opposed to a single ET [OR 1.38 (95% CI 0.73–2.62), P = 0.32 and OR 3.22 (95% CI 1.7–6.05), P = 0.0003, respectively]. Compared to women with unexplained subfertility, those with endometriosis had fewer oocytes retrieved [(10.54 (95% CI 10.13–0.95) and 9.15 (95% CI 8.69–9.6), respectively], lower blastocyst transfer [OR 0.24 (95% CI 0.12–0.5), P = 0.0001] and a significantly reduced implantation rate [OR 0.73 (0.58–0.92), P = 0.007]. Limitations reasons for caution: The study is limited by a retrospective design. By limiting the study to a single ET cycle, it was not possible to assess the cumulative outcome including use of all frozen embryos. Wider implications of the findings: Endometriosis has similar phenotypes among women in different populations and would be expected to have a similar effect on fertility. These results are therefore generalizable to other populations of women. Study funding/competing interest(s): None. Trial registration number: Not applicable

Short versus extended progesterone supplementation for luteal phase support in fresh IVF cycles: a systematic review and meta-analysis

This review and meta-analysis aim to assess the effect of prolonged progesterone support on pregnancy outcomes in women undergoing fresh embryo transfer after IVF/intracytoplasmic sperm injection (ICSI). Two independent authors searched Embase, MEDLINE and grey literature from inception to January 2019 for randomized controlled trials (RCT) of prolonged progesterone support versus early cessation. Risk of bias was assessed. Outcome measures were live birth, miscarriage and ongoing pregnancy rate. The study was registered with PROSPERO (CRD42018088605). Seven trials involving 1627 participants were included: three reported live birth rate (672/830), seven the miscarriage rate (178/1627) and seven the ongoing pregnancy rate (1351/1627). Clinical outcomes were similar between early progesterone cessation versus progesterone continuation: live birth rate (risk ratio [RR] 0.94, 95% confidence interval [CI] 0.88–1.00), miscarriage rate (RR 0.91, 95% CI 0.69–1.20) and ongoing pregnancy rate (RR 0.98, 95% CI 0.91–1.05). Ongoing pregnancy rates were similar when analyses were restricted to those with cessation of progesterone on the day of a positive human chorionic gonadotrophin (RR 0.93, 95% CI 0.83–1.06). This meta-analysis suggests that prolonged progesterone support may be unnecessary after fresh embryo transfer. Further larger RCT would be useful to corroborate and lead to standardized duration of progesterone luteal phase support across IVF/ICSI centres

SARS-Cov-2 viral and serological screening of staff in 31 European fertility units

Study Question: What is the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral presence and seroconversion in staff members in European fertility units prior to recommencement of clinical activity? Summary Answer: A large proportion of fertility clinic staff remain susceptible to SARS-CoV-2 with no evidence of seroconversion, indicating that continued comprehensive risk mitigation strategies are essential. What is Known Already: In response to the coronavirus disease 2019 (COVID-19) pandemic, caused by SARS-CoV-2, routine fertility treatment was temporarily stopped in several European countries. The SARS-CoV-2 prevalence and seroconversion in fertility clinic staff, who are at potentially lower risk than routine healthcare workers, are unknown. Study Design, Size, Duration: This cross-sectional study included 554 staff in 16 European IVF clinics, 13 ultrasound clinics, one diagnostic laboratory and one head office in four European countries (Austria, Denmark, Germany and the UK) between 15 April and 30 June 2020. Participants/Materials, Setting, Methods: There were 554 staff members returning for resumption of clinical activity. Paired nucleic acid amplification tests of oropharyngeal swabs for SARS-CoV-2 and serological testing for SARS-CoV-2 IgG were performed. Main Results and the Role of Chance: Of the 554 staff members tested, 0.19% (95% CI 0.03, 1.10%) had evidence of SARS-CoV-2 as detected by RT-PCR. In contrast, 23 staff members, i.e. 4.15% (95% CI 2.78, 6.15%), had antibodies against SARS-CoV-2, with a wide range of antibody titres. There was no evidence of differences in seroconversion between countries with estimates ranging from 2.78% (95% CI 0.77, 9.58) in Austria to 6.75% (95% CI 4.46, 10.1) for the UK. There was no strong evidence of clustering within the clinics, with 21 of the 30 facilities having no staff members affected (prevalence estimates ranging from 0% to 35%), and one clinic having seven staff members affected (35% (95% CI 18.1%, 56.7%)). The single staff member who tested positive for SARS-CoV-2 virus was in the pre-symptomatic phase and was isolated, with no contacts having evidence of infection on repeat testing. Limitations, Reasons for Caution: This was a cross-sectional study prior to resumption of clinical activity, with repeat testing not undertaken. Wider Implications of the Findings: The low prevalence of seroconversion of fertility clinic staff highlights the need for continued comprehensive risk mitigation strategies and engagement with national endeavours to identify and isolate new cases and their contacts as we embark on the resumption of fertility services. Study Funding/Competing Interest(s): The Fertility Partnership funded the study. S.M.N. reports personal fees from Access Fertility, personal fees from Merck, personal fees from Ferring, grants and personal fees from Roche Diagnostics, personal fees from The Fertility Partnership and personal fees from Modern Fertility, outside the submitted work. T.C. reports personal fees from Merck and personal fees from Ferring, outside the submitted work. G.T. reports personal fees from Merck, personal fees from Ferring and personal fees from Roche Diagnostics, outside the submitted work. S.E. and P.S.G. report no conflicts of interest

Exaggerated elastin turnover in young individuals with Marfan Syndrome – new insights from the AIMS trial

Background and aims: The fragmentation and loss of elastic fibre in the tunica media of the aorta is a pathological hallmark of Marfan syndrome (MFS) but the dynamics of elastin degradation and its relationship to aortic size and physiological growth remain poorly understood.Methods: In this post-hoc analysis of the AIMS randomised-controlled trial, the association of plasma desmosine (pDES) - a specific biomarker of mature elastin degradation - with age and aortic size was analysed in 113 patients with MFS and compared to 109 healthy controls.Results: There was a strong association between age and pDES in both groups, with higher pDES levels in the lower age groups compared to adults. During childhood, pDES increased and peaked during early adolescence, and thereafter decreased to lower adult levels. This trend was exaggerated in young individuals with MFS but in those above 25 years of age, pDES levels were comparable to controls despite the presence of aortic root dilation. In MFS children, increased aortic diameter relative to controls was seen at an early age and although the increase in diameter was less after adolescence, aortic root size continued to increase steadily with age. In MFS participants there was an indication of a positive association between baseline pDES levels and aortic root dilatation during up to 5 years of follow up.Conclusion: This study has shown that developmental age has a significant effect on levels of elastin turnover as measured by pDES in MFS individuals as well as healthy controls. This effect is exaggerated in those with MFS with increased levels seen during the period of physiologic development which plateaus towards adulthood. This suggests an early onset of pathophysiology that may present an important opportunity for disease modifying intervention

Clomifene citrate or low-dose FSH for the first-line treatment of infertile women with anovulation associated with polycystic ovary syndrome : a prospective randomized multinational study

BACKGROUND: Clomifene citrate (CC) is accepted as the first-line method for ovulation induction (OI) in patients with polycystic ovary syndrome (PCOS) associated with infertility owing to anovulation. Low-dose FSH has been reserved for women failing to conceive with CC. In this RCT, we tested the hypothesis that pregnancy rate (PR) and live birth rates (LBR) are higher after OI with low-dose FSH than with CC as first-line treatment. METHODS: Infertile women (<40 years old) with PCOS-related anovulation, without prior OI treatment, attending 10 centres in Europe/South America were randomized to OI with either CC (50-150 mg/day for 5 days) or FSH (starting dose 50 IU) for up to three treatment cycles. The primary outcome was clinical PR. RESULTS: Patients (n = 302) were randomized to OI with FSH (n = 132 women; 288 cycles) or CC (n = 123; 310 cycles). Per protocol analysis revealed that reproductive outcome was superior after OI with FSH than with CC with respect to PR per first cycle [30 versus 14.6%, respectively, 95 confidence interval (CI) 5.3-25.8, P = 0.003], PR per woman, (58 versus 44% of women, 95% CI 1.5-25.8, P = 0.03), LBR per woman (52 versus 39%, 95% CI 0.4-24.6, P = 0.04), cumulative PR (52.1 versus 41.2%, P = 0.021) and cumulative LBR (47.4 versus 36.9%, P = 0.031), within three cycles of OI. CONCLUSIONS: Pregnancies and live births are achieved more effectively and faster after OI with low-dose FSH than with CC. This result has to be balanced by convenience and cost in favour of CC. FSH may be an appropriate first-line treatment for some women with PCOS and anovulatory infertility, particularly older patients.peer-reviewe

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

Acknowledgements The E-Freeze Collaborators Group contributed to the overall design of the E-Freeze trial. Funding The trial is approved and funded by the National Institute of Health Research (NIHR) Health Technology Assessment (HTA) programme. Availability of data and materials Applications for data sharing should be made to the NPEU CTU, using [email protected], with an accompanying protocol for the intended use of the data. This will be reviewed by the Trial Steering Committee if still operational or Data Sharing Committee/Data Controller. If approved, a Data Sharing Agreement will be compiled laying out the conditions to which the requestor must abide. Protocol E-Freeze Protocol, Version 2.0 (18/01/2017). Author notes All authors contributed equally to this work.Peer reviewedPublisher PD

Progress report no. 2

Statement of responsibility on title-page reads: Editors: I.A. Forbes, M.J. Driscoll, N.C. Rasmussen, D.D. Lanning and I. Kaplan; Contributors: S.T. Brewer, G.J. Brown, P.DeLaquil, III, M.J. Driscoll, I.A. Forbes, C.W. Forsberg, E.P. Gyftopoulos, P.L. Hendrick, C.S. Kang, I. Kaplan, J.L. Klucar, D.D. Lanning, T.C. Leung, E.A. Mason, N.R. Ortiz, N.A. Passman, N.C. Rasmussen, I.C. Rickard, V.C. Rogers, G.E. Sullivan, A.T. Supple, and C. P. TzanosIncludes bibliographical referencesProgress report; June 30, 1971U.S. Atomic Energy Commission contract AT(11-1)306

ST2 and IL-33 in Pregnancy and Pre-Eclampsia

Normal pregnancy is associated with a mild systemic inflammatory response and an immune bias towards type 2 cytokine production, whereas pre-eclampsia is characterized by a more intense inflammatory response, associated with endothelial dysfunction and a type 1 cytokine dominance. Interleukin (IL)-33 is a newly described member of the IL-1 family, which binds its receptor ST2L to induce type 2 cytokines. A soluble variant of ST2 (sST2) acts as a decoy receptor to regulate the activity of IL-33. In this study circulating IL-33 and sST2 were measured in each trimester of normal pregnancy and in women with pre-eclampsia. While IL-33 did not change throughout normal pregnancy, or between non-pregnant, normal pregnant or pre-eclamptic women, sST2 was significantly altered. sST2 was increased in the third trimester of normal pregnancy (p<0.001) and was further increased in pre-eclampsia (p<0.001). This increase was seen prior to the onset of disease (p<0.01). Pre-eclampsia is a disease caused by placental derived factors, and we show that IL-33 and ST2 can be detected in lysates from both normal and pre-eclampsia placentas. ST2, but not IL-33, was identified on the syncytiotrophoblast layer, whereas IL-33 was expressed on perivascular tissue. In an in vitro placental perfusion model, sST2 was secreted by the placenta into the ‘maternal’ eluate, and placental explants treated with pro-inflammatory cytokines or subjected to hypoxia/reperfusion injury release more sST2, suggesting the origin of at least some of the increased amounts of circulating sST2 in pre-eclamptic women is the placenta. These results suggest that sST2 may play a significant role in pregnancies complicated by pre-eclampsia and increased sST2 could contribute to the type 1 bias seen in this disorder