Placenta Imaging Workshop 2018 report:Multiscale and multimodal approaches

The Centre for Medical Image Computing (CMIC) at University College London (UCL) hosted a two-day workshop on placenta imaging on April 12th and 13th 2018. The workshop consisted of 10 invited talks, 3 contributed talks, a poster session, a public interaction session and a panel discussion about the future direction of placental imaging. With approximately 50 placental researchers in attendance, the workshop was a platform for engineers, clinicians and medical experts in the field to network and exchange ideas. Attendees had the chance to explore over 20 posters with subjects ranging from the movement of blood within the placenta to the efficient segmentation of fetal MRI using deep learning tools. UCL public engagement specialists also presented a poster, encouraging attendees to learn more about how to engage patients and the public with their research, creating spaces for mutual learning and dialogue

Prehospital ticagrelor in ST-segment elevation myocardial infarction

Background:The direct-acting platelet P2Y receptor antagonist ticagrelor can reduce the incidence of major adverse cardiovascular events when administered at hospital admission to patients with ST-segment elevation myocardial infarction (STEMI). Whether prehospital administration of ticagrelor can improve coronary reperfusion and the clinical outcome is unknown. Methods: We conducted an international, multicenter, randomized, double-blind study involving 1862 patients with ongoing STEMI of less than 6 hours' duration, comparing prehospital (in the ambulance) versus in-hospital (in the catheterization laboratory) treatment with ticagrelor. The coprimary end points were the proportion of patients who did not have a 70% or greater resolution of ST-segment elevation before percutaneous coronary intervention (PCI) and the proportion of patients who did not have Thrombolysis in Myocardial Infarction flow grade 3 in the infarct-related artery at initial angiography. Secondary end points included the rates of major adverse cardiovascular events and definite stent thrombosis at 30 days. Results: The median time from randomization to angiography was 48 minutes, and the median time difference between the two treatment strategies was 31 minutes. The two coprimary end points did not differ significantly between the prehospital and in-hospital groups. The absence of ST-segment elevation resolution of 70% or greater after PCI (a secondary end point) was reported for 42.5% and 47.5% of the patients, respectively. The rates of major adverse cardiovascular events did not differ significantly between the two study groups. The rates of definite stent thrombosis were lower in the prehospital group than in the in-hospital group (0% vs. 0.8% in the first 24 hours; 0.2% vs. 1.2% at 30 days). Rates of major bleeding events were low and virtually identical in the two groups, regardless of the bleeding definition use

Extending the scope of pooled analyses of individual patient biomarker data from heterogeneous laboratory platforms and cohorts using merging algorithms

Background: A common challenge in medicine, exemplified in the analysis of biomarker data, is that large studies are needed for sufficient statistical power. Often, this may only be achievable by aggregating multiple cohorts. However, different studies may use disparate platforms for laboratory analysis, which can hinder merging. Methods: Using circulating placental growth factor (PIGF), a potential biomarker for hypertensive disorders of pregnancy (HDP) such as preeclampsia, as an example, we investigated how such issues can be overcome by inter-platform standardization and merging algorithms. We studied 16,462 pregnancies from 22 study cohorts. PIGF measurements (gestational age >= 20 weeks) analyzed on one of four platforms: R & Systems, Alere (R) Triage, Roche (R) Elecsys or Abbott (R) Architect, were available for 13,429 women. Two merging algorithms, using Z-Score and Multiple of Median transformations, were applied. Results: Best reference curves (BRC), based on merged, transformed PIGF measurements in uncomplicated pregnancy across six gestational age groups, were estimated. Identification of HDP by these PIGF-BRCS was compared to that of platform-specific curves. Conclusions: We demonstrate the feasibility of merging PIGF concentrations from different analytical platforms. Overall BRC identification of HDP performed at least as well as platform-specific curves. Our method can be extended to any set of biomarkers obtained from different laboratory platforms in any field. Merged biomarker data from multiple studies will improve statistical power and enlarge our understanding of the pathophysiology and management of medical syndromes. (C) 2015 International Society for the Study of Hypertension in Pregnancy. Published by Elsevier B.V. All rights reserved.Peer reviewe

The use of ruminants for biomedical research in perinatalogy

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Quantification of placental vascularization in a rabbit model of IUGR with three-dimensional power Doppler angiography

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Analysis of placental vascularization in a pharmacological rabbit model of IUGR induced by l-NAME, a nitric oxide synthase inhibitor

International audienceWe have previously validated the use of l-nitro-arginine methyl ester (l-NAME), a nitric oxide synthase inhibitor, to induce placental hypoperfusion in a rabbit model. Here, the effects of l-NAME on placental vascularization were explored. Transplacental transfer of l-NAME and/or its active metabolite, NG-nitro-l-arginine (L-NOARG), was evaluated. 25 pregnant female rabbits were allocated on day 24 to one of 5 groups: l-NAME groups (31.35, 62.5, 125 and 250 mg/kg/day) or Control group (C). On Day 28, the labyrinthine area was analyzed for stereology and gene expression. l-NAME and L-NOARG were quantified in maternal and fetal blood. The volume density of fetal vessels was significantly decreased in l-NAME (including 62.5-250 mg/kg/day which induced an IUGR) compared to C groups. l-NAME induced an increase of the volume and surface density of the maternal blood space. The trophoblast volume density remained unchanged as well as the surface density of fetal vessels. Relative expression of eNOS, VEGFA, VEGFR-1 and VEGFR-2 in placentas was not affected by 125 mg/kg/day l-NAME treatment, whereas IGF-2 expression was significantly increased in this l-NAME group compared to C. l-NAME was not detected in maternal nor fetal plasma. In contrast, fetal to maternal L-NOARG ratio was 100% in all l-NAME groups. These data demonstrate that l-NAME induced placental hypovascularization. The active L-NOARG metabolite is found in maternal and fetal plasma at similar concentrations. This could impact the fetal growth and reduces the interest of this model to study fetal outcomes of placental hypoperfusion

Analysis of placental vascularization in a pharmacological rabbit model of IUGR induced by L-NAME, a nitric oxide synthase inhibitor

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Evidence for contamination as the origin for bacteria found in human placenta rather than a microbiota.

Until recently the in utero environment of pregnant women was considered sterile. Recent high-sensitivity molecular techniques and high-throughput sequencing lead to some evidence for a low-biomass microbiome associated with the healthy placenta. Other studies failed to reveal evidence for a consistent presence of bacteria using either culture or molecular based techniques. Comparing conflicting "placental microbiome" studies is complicated by the use of varied and inconsistent protocols. Given this situation, we undertook an evaluation of the in utero environment sterility using several controlled methods, in the same study, to evaluate the presence or absence of bacteria and to explain contradictions present in the literature. Healthy pregnant women (n = 38) were recruited in three maternity wards. Placenta were collected after cesarean section with or without Alexis® and vaginal delivery births. For this study we sampled fetal membranes, umbilical cord and chorionic villi. Bacterial presence was analyzed using bacterial culture and qPCR on 34 fetal membranes, umbilical cord and chorionic villi samples. Shotgun metagenomics was performed on seven chorionic villi samples. We showed that the isolation of meaningful quantities of viable bacteria or bacterial DNA was possible only outside the placenta (fetal membranes and umbilical cords) highlighting the importance of sampling methods in studying the in utero environment. Bacterial communities described by metagenomics analysis were similar in chorionic villi samples and in negative controls and were dependent on the database chosen for the analysis. We conclude that the placenta does not harbor a specific, consistent and functional microbiota

Predictive factors of cytomegalovirus seropositivity among pregnant women in Paris, France.

Cytomegalovirus (CMV) is the most frequent cause of congenital infection. The objective of this study was to evaluate predictive factors for CMV seronegativity in a cohort of pregnant women in Paris, France.Pregnant women enrolled in a prospective cohort during the 2009 A/H1N1 pandemic were tested for CMV IgG antibodies. Variables collected were age, geographic origin, lifestyle, work characteristics, socioeconomic status, gravidity, parity and number of children at home. A multivariate logistic regression model was used to identify independent predictive factors for CMV seropositivity.Among the 826 women enrolled, 389 (47.1%) were primiparous, and 552 (67.1%) had Metropolitan France as a geographic origin. Out of these, 355 (i.e. 57.0%, 95% confidence interval (CI): [53.6%-60.4%]) were CMV seropositive: 43.7% (95% CI:[39.5%-47.9%]) in those whose geographic origin was Metropolitan France and 84.1% in those with other origins (95% CI:[79.2%-88.3%]). Determinants associated with CMV seropositivity in a multivariate logistic regression model were: (i) geographic origin (p<0.001(compared with Metropolitan France, geographic origins of Africa adjusted odds ratio (aOR) 21.2, 95% CI:[9.7-46.5], French overseas departments and territories and other origin, aOR 7.5, 95% CI:[3.9-14.6], and Europe or Asia, aOR 2.2, 95% CI: [1.3-3.7]); and (ii) gravidity (p = 0.019), (compared with gravidity = 1, if gravidity≥3, aOR = 1.5, 95% CI: [1.1-2.2]; if gravidity = 2, aOR = 1.0, 95% CI: [0.7-1.4]). Work characteristics and socioeconomic status were not independently associated with CMV seropositivity.In this cohort of pregnant women, a geographic origin of Metropolitan France and a low gravidity were predictive factors for CMV low seropositivity. Such women are therefore the likely target population for prevention of CMV infection during pregnancy in France

Prenatal and post-natal cost of small for gestational age infants: a national study

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