Causes and Mechanisms of Intrauterine Hypoxia and Its Impact on the Fetal Cardiovascular System: A Review

Until today the role of oxygen in the development of the fetus remains controversially discussed. It is still believed that lack of oxygen in utero might be responsible for some of the known congenital cardiovascular malformations. Over the last two decades detailed research has given us new insights and a better understanding of embryogenesis and fetal growth. But most importantly it has repeatedly demonstrated that oxygen only plays a minor role in the early intrauterine development. After organogenesis has taken place hypoxia becomes more important during the second and third trimester of pregnancy when fetal growth occurs. This review will briefly adress causes and mechanisms leading to intrauterine hypoxia and their impact on the fetal cardiovascular system

Impacted fetal head at caesarean section:a national survey of practice and training

This is a national survey of UK obstetric trainees and consultant labour ward leads designed to investigate the current practice and training for an impacted foetal head (IFH) at Caesarean Section (CS). An anonymous, on-line survey was disseminated to trainees via Postgraduate Schools and RCOG trainee representatives, and to labour ward leads via their national network. Three hundred and forty-five obstetric trainees and consultants responded. The results show that IFH is variably defined and encountered by most UK obstetricians (98% had encountered IFH and 76% had experienced it before full cervical dilatation). There is significant variation in management strategies, although most respondents would use a vaginal push up to assist delivery prior to reverse breech extraction. Responses revealed a paucity of training and lack of confidence in disimpaction techniques: over one in ten respondents had not received any training for IFH and less than half had received instruction in reverse breech extraction.Impact statement What is already known on the subject? IFH is an increasingly recognised, technically challenging complication of intrapartum CS. A recent report suggested that birth injuries associated with IFH are now as common as with shoulder dystocia. However, there is no consensus nor guidelines regarding the best practice for management or training. What do the results of this study add? This study demonstrates that IFH is poorly defined and commonly encountered by UK obstetricians. It highlights that IFH is not restricted to CS at full dilatation and reveals the ubiquity of the vaginal push method in UK practice. We found evidence that UK obstetricians are using techniques which have not been investigated and are not recommended for managing an IFH. Moreover, this survey is an eye-opener as to the paucity of training, highlighting that UK obstetric trainees are not adequately prepared to manage this emergency. What are the implications of these findings for clinical practice and/or further research? There is a pressing need to standardise the definition, guidance and training for IFH at CS. Further research should clarify the appropriate techniques for IFH and establish consensus for the best practice. An evidence-based simulation training package, which allows clinicians to learn and practice recognised disimpaction techniques is urgently required

Intrauterine growth restriction is associated with persistent juxtamedullary expression of renin in the fetal kidney

Intrauterine growth restriction is associated with persistent juxtamedullary expression of renin in the fetal kidney.BackgroundIntrauterine growth restriction (IUGR) has been linked to impaired renal function and hypertension, suggesting that an adverse prenatal environment could alter kidney development and renin production.MethodsImmunohistochemistry and in situ hybridization were employed to localize renin-containing cells (RCCs) in the deep, middle, and superficial zones of autopsy kidney sections, in parallel with histologic maturation, from unexplained stillborn fetuses of normal weight (N = 26) and stillborn fetuses with IUGR (N = 17).ResultsIn the control group, the number of RCC per 100 glomeruli in the deep zone decreased with advancing gestation from 40 at 20weeks gestation to five at term (P < 0.001), whereas the opposite change was found in the superficial zone (increase from 5 per 100 to 55 per 100; P < 0.001). In the IUGR group, the density of RCCs in both the superficial and deep zones was similar to the control group at 20weeks, and no shift in renin gene expression was observed as gestation advanced. Histologic maturation was unaltered.ConclusionsRenin gene expression persists and predominates in the deep renal cortex of the stillborn IUGR fetus, and could contribute to the pathogenesis of neonatal oliguria and/or hypertension during postnatal life

Effects of glycol-split low molecular weight heparin on placental, endothelial, and anti-inflammatory pathways relevant to preeclampsia

The authors thank the donors, the Research Centre for Women’s and Infants’ Health BioBank program, the Lunenfeld-Tanenbaum Research Institute and the MSH/University Health Network Department of Obstetrics & Gynaecology for the human specimens used in this study.Peer reviewedPublisher PD

High resolution ultrasound-guided microinjection for interventional studies of early embryonic and placental development in vivo in mice

BACKGROUND: In utero microinjection has proven valuable for exploring the developmental consequences of altering gene expression, and for studying cell lineage or migration during the latter half of embryonic mouse development (from embryonic day 9.5 of gestation (E9.5)). In the current study, we use ultrasound guidance to accurately target microinjections in the conceptus at E6.5–E7.5, which is prior to cardiovascular or placental dependence. This method may be useful for determining the developmental effects of targeted genetic or cellular interventions at critical stages of placentation, gastrulation, axis formation, and neural tube closure. RESULTS: In 40 MHz ultrasound images at E6.5, the ectoplacental cone region and proamniotic cavity could be visualized. The ectoplacental cone region was successfully targeted with 13.8 nL of a fluorescent bead suspension with few or no beads off-target in 51% of concepti microinjected at E6.5 (28/55 injected). Seventy eight percent of the embryos survived 2 to 12 days post injection (93/119), 73% (41/56) survived to term of which 68% (38/56) survived and appeared normal one week after birth. At E7.5, the amniotic and exocoelomic cavities, and ectoplacental cone region were discernable. Our success at targeting with few or no beads off-target was 90% (36/40) for the ectoplacental cone region and 81% (35/43) for the exocoelomic cavity but tended to be less, 68% (34/50), for the smaller amniotic cavity. At E11.5, beads microinjected at E7.5 into the ectoplacental cone region were found in the placental spongiotrophoblast layer, those injected into the exocoelomic cavity were found on the surface or within the placental labyrinth, and those injected into the amniotic cavity were found on the surface or within the embryo. Following microinjection at E7.5, survival one week after birth was 60% (26/43) when the amniotic cavity was the target and 66% (19/29) when the target was the ectoplacental cone region. The survival rate was similar in sham experiments, 54% (33/61), for which procedures were identical but no microinjection was performed, suggesting that surgery and manipulation of the uterus were the main causes of embryonic death. CONCLUSION: Ultrasound-guided microinjection into the ectoplacental cone region at E6.5 or E7.5 and the amniotic cavity at E7.5 was achieved with a 7 day postnatal survival of ≥60%. Target accuracy of these sites and of the exocoelomic cavity at E7.5 was ≥51%. We suggest that this approach may be useful for exploring gene function during early placental and embryonic development

Better use of capital to deliver sustainable water supply and sanitation services: Practical examples and suggested next steps

The costs of meeting the SDG WASH targets will be several times higher than investment levels during the MDG era (2000–15). The immense scale of the financing gap calls for innovative solutions. In addition to mobilizing more funding another approach is to deliver the needed infrastructure more efficiently and effectively and thus reduce the financing gap. Capital expenditure efficiency (CEE)—the efficient and effective use of capital—is less documented compared to operational efficiency. Although improving operating efficiency is frequently highlighted and readily evaluated, the scope for capital cost efficiencies is poorly understood, frequently overlooked, and difficult to evaluate, even though the scale of savings can be significant—in fact, capital and operating costs are equally important when considering full cost recovery. This study compiles case studies that show the "art of the possible" in CEE. The report is not encyclopedic—many more examples could surface from a comprehensive study. It also doesn’t quantify the savings possible through increasing CEE. However, almost all the examples show capital savings of 25 percent or more compared to traditional solutions. This alone this should give policy makers, donors, and utility managers pause for thought and encourage them to develop CEE in their sectors, projects, or utilities. A 25 percent improvement in CEE would allow existing investments to deliver a 33 percent increase in benefits

Проектирование ВЛ 500 кВ Берёзовская ГРЭС - ПС Итатская

Реферат Дипломная работа 93 с., 8 рисунков, 22 таблицы, 26 источников, 7 приложений. Ключевые слова: проектирование ВЛ, опоры, линейная арматура, спецпереход, социальная ответственность, экономическая эффективность. Объектом исследования является ВЛ 500 кВ Берёзовская ГРЭС- ПС «Итатская». В работе проводится проектирование ВЛ 500 кВ. Осуществляется выбор провода и проектирование механической части. Произведен экономический расчет для определения затрат на строительство. Так же произведен анализ социальной ответственности. Выпускная квалификационная работа выполнена в текстовом редакторе MSWord 7.0 и представлена на компакт - диске (в конверте на обороте обложки).abstract Thesis 93 p., 8 figures, 22 tables, 26 sources, 7 applications. Keywords: design of overhead lines, supports, linear valves, special transmission, social responsibility, economic efficiency. The object of this study is 500 kV Substation Berezovskaya GRES "Itatsky". The work is carried out the design of 500 kV. Selects the wire and the design of the mechanical part. Produced by economic calculation to determine the construction costs. Just made social responsibility analysis. Final qualifying work is done in a text editor MSWord 7.0 and is represented on the CD - ROM (in an envelope on the back cover)