We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure no-reply@cambridge.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Knowledge of the status of ecosystems is vital to help develop and implement conservation strategies. This is particularly relevant to the Arctic where the need for biodiversity conservation and monitoring has long been recognised, but where issues of local capacity and logistic barriers make surveys challenging. This paper demonstrates how long-term monitoring programmes outside the Arctic can contribute to developing composite trend indicators, using monitoring of annual abundance and population-level reproduction of species of migratory Arctic-breeding waterbirds on their temperate non-breeding areas. Using data from the UK and the Netherlands, countries with year-round waterbird monitoring schemes and supporting relevant shares of Arctic-breeding populations of waterbirds, we present example multi-species abundance and productivity indicators related to the migratory pathways used by different biogeographical populations of Arctic-breeding wildfowl and wader species in the East Atlantic Flyway. These composite trend indicators show that long-term increases in population size have slowed markedly in recent years and in several cases show declines over, at least, the last decade. These results constitute proof of concept. Some other non-Arctic countries located on the flyways of Arctic-breeding waterbirds also annually monitor abundance and breeding success, and we advocate that future development of “Arctic waterbird indicators” should be as inclusive of data as possible to derive the most robust outputs and help account for effects of current changes in non-breeding waterbird distributions. The incorporation of non-Arctic datasets into assessments of the status of Arctic biodiversity is recognised as highly desirable, because logistic constraints in monitoring within the Arctic region limit effective population-scale monitoring there, in effect enabling “monitoring at a distance”.
Gestational diabetes mellitus (GDM) is the most common medical complication of pregnancy and a severe threat to pregnant people and offspring health. The molecular origins of GDM, and in particular the placental responses, are not fully known. The present study aimed to perform a comprehensive characterisation of the lipid species in placentas from pregnancies complicated with GDM using high-resolution MS lipidomics, with a particular focus on sphingolipids and acylcarnitines in a semi-targeted approach. The results indicated that despite no major disruption in lipid metabolism, placentas from GDM pregnancies showed significant alterations in sphingolipids, mostly lower abundance of total ceramides. Additionally, very long-chain ceramides and sphingomyelins with twenty-four carbons were lower, and glucosylceramides with sixteen carbons were higher in placentas from GDM pregnancies. Semi-targeted lipidomics revealed the strong impact of GDM on the placental acylcarnitine profile, particularly lower contents of medium and long-chain fatty-acyl carnitine species. The lower contents of sphingolipids may affect the secretory function of the placenta, and lower contents of long-chain fatty acylcarnitines is suggestive of mitochondrial dysfunction. These alterations in placental lipid metabolism may have consequences for fetal growth and development.
Better indicators of prognosis are needed to personalise post-traumatic stress disorder (PTSD) treatments.
Aims
We aimed to evaluate early symptom reduction as a predictor of better outcome and examine predictors of early response.
Method
Patients with PTSD (N = 134) received sertraline or prolonged exposure in a randomised trial. Early response was defined as 20% PTSD symptom reduction by session two and good end-state functioning defined as non-clinical levels of PTSD, depression and anxiety.
Results
Early response rates were similar in prolonged exposure and sertraline (40 and 42%), but in sertraline only, early responders were four times more likely to achieve good end-state functioning at post-treatment (Number Needed to Treat = 1.8, 95% CI 1.28–3.00) and final follow-up (Number Needed to Treat = 3.1, 95% CI 1.68–16.71). Better outcome expectations of sertraline also predicted higher likelihood of early response.
Conclusions
Higher expectancy of sertraline coupled with early response may produce a cascade-like effect for optimal conditions for long-term symptom reduction. Therefore, assessing expectations and providing clear treatment rationales may optimise sertraline effects.
Developmental programming is a rapidly advancing discipline of great importance to basic scientists and health professionals alike. This text integrates, for the first time, contributions from world experts to explore the role of the placenta in developmental programming. The book considers the materno-fetal supply line, and how perturbations of placental development impact on its functional capacity. Chapters examine ways in which environmental, immunological and vascular insults regulate expression of conventional and imprinted genes, along with their impact on placental shape and size, transport, metabolism and endocrine function. Research in animal models is integrated with human clinical and epidemiological data, and questions for future research are identified. Transcripts of discussions between the authors allow readers to engage with controversial issues. Essential reading for researchers in placental biology and developmental programming, as well as specialists and trainees in the wider field of reproductive medicine.
This chapter reviews the key roles of the different layers of the maternofetal interface in supplying essential nutrients to the developing fetus before the placental circulations are fully established. Focal trophoblastic oxidative damage and progressive villous degeneration trigger the formation of the fetal membranes that remodel the uteroplacental interface. The distribution of the placental-specific protein human chorionic gonadotrophin (hCG) in yolk sac and coelomic fluid samples, and the absence of hCG mRNA expression in yolk sac tissue, suggests the secondary yolk sac (SYS) has an absorptive function. During the 10th week of gestation, the yolk sac starts to degenerate and rapidly ceases to function. The anatomy of the materno-fetal interface in the first trimester is the result of the need for a delicate balance between the metabolic requirements of the developing fetus and the potential harmful effects of oxygen during embryogenesis and organogenesis.
This introduction provides an overview of the concepts discussed in the book The Placenta and Human Developmental Programming. Developmental programming of the fetus is a phenomenon that has profound implications for the health of individuals and societies. This book explores the current knowledge of the ways in which various aspects of placental development and function may influence fetal programming, and aims to promote further scientific research in their respective fields. The development of the placenta is not autonomous, but is clearly heavily influenced by the uterine mucosa with which the trophoblast interacts. Assessment of placental function in vivo is obviously important for clinical diagnosis and monitoring. The capacity of the placenta to supply adequate nutrients to the fetus is obviously of central importance to the role of the organ in developmental programming, but other aspects of placental function may also operate.
Imprinted genes are regulated by parent-of-origin-specific epigenetic marks, notably DNA methylation, leading to monoallelic expression of these genes in the offspring. All of these genes are conserved in mice and humans, although there are a few differences in imprinting status in the two species, with a slightly greater number of genes imprinted in mice than in humans. Given the frequent function as growth rheostats, imprinted genes are interesting candidates for a role in intrauterine growth restriction (IUGR). IUGR is a common medical condition that often leads to expensive neonatal hospitalization and predisposes to serious postnatal complications. Owing to their action in the placenta, there are a number of genetic models involving imprinted genes that already seem promising for investigating DOHAD. Very few genes are expressed only in the placenta, and even some legendary placenta specific genes are, in fact, expressed in the adult animal, an example being Ascl2.
Impaired development of the early placenta has long been implicated in aberrations of placental shape at term. It has become possible to construct a hypothesis linking placental shape and complications of pregnancy based on oxidative and endoplasmic reticulum stress. The onset of maternal circulation is interlinked with remodelling of the chorion frondosum into the definitive placenta, and oxidative stress plays a key role in this process. This chapter proposes that a spectrum of defects may occur, ranging from variations at the physiological end in clinically 'normal' placentas that may relate to programming, to frank pathological changes associated with severe complications of pregnancy. It discusses spiral artery conversion, the onset of the maternal arterial circulation to the human placenta, abnormal villus regression, abnormal maternal blood flow, and the implications for developmental programming. Conversion of the spiral arteries is associated with invasion of the endometrium and the arterial walls by extravillous trophoblast.
Placental vasculature, in particular the relationship between maternal and fetal blood circulations, has been a contentious issue for a long time. In his magnificent Anatomy of the human gravid uterus William Hunter included the first drawing of spiral arteries (convoluted arteries), in what must have been the very first illustration of a human placental bed. The French anatomist Mathias Duval was probably the first to recognize the invasion of trophoblast into endometrial arteries, in this case in the rat. It it became clear that deep trophoblast invasion and associated spiral artery remodeling are essential for a healthy pregnancy. The actual depth of invasion was underrated for a long time, partly because of the increasing popularity of the decidual barrier concept. Early observations of trophoblast invasion into the spiral arteries set the stage for understanding the maternal blood supply to the placenta via the spiral arteries of the placental bed.
Oxidative stress of the placenta is a key element in the pathogenesis of pre-eclampsia, although its precise contribution remains uncertain (Hubel, 1999; Redman and Sargent, 2000). The aim of this chapter is to address the origin of that oxidative stress and, as the title suggests, to consider the effects of different oxygen concentrations on placental tissues. In the past it has widely been assumed that the vascular abnormalities in the endometrial arteries of women with pre-eclampsia result in reduced placental perfusion, and hence chronic hypoxia within the feto-placental unit. More recently, the converse has been proposed, and that in pre-eclampsia associated with intrauterine growth restriction (IUGR) the placenta is in fact hyperoxic due to less oxygen than normal being extracted from the intervillous space by the smaller fetus (Kingdom and Kaufmann, 1997). Hypoxia and hyperoxia are relative terms, however, and these assessments have of necessity been based on data obtained at the time of delivery, which, in the majority of cases, represents the end-stage of a process that may have been developing over many weeks. It is therefore difficult to separate primary from secondary effects, and to elucidate earlier stages in the pathogenesis of the disorder. The situation is further complicated by the fact that pre-eclampsia varies widely in severity. Late onset pre-eclampsia is often associated with normal birthweight, whereas early onset of the disease is generally linked with IUGR (Douglas and Redman, 1994).