Restricted dispersal in a sea of gene flow

How far do marine larvae disperse in the ocean? Decades of population genetic studies have revealed generally low levels of genetic structure at large spatial scales (hundreds of kilometres). Yet this result, typically based on discrete sampling designs, does not necessarily imply extensive dispersal. Here, we adopt a continuous sampling strategy along 950 km of coast in the northwestern Mediterranean Sea to address this question in four species. In line with expectations, we observe weak genetic structure at a large spatial scale. Nevertheless, our continuous sampling strategy uncovers a pattern of isolation by distance at small spatial scales (few tens of kilometres) in two species. Individual-based simulations indicate that this signal is an expected signature of restricted dispersal. At the other extreme of the connectivity spectrum, two pairs of individuals that are closely related genetically were found more than 290 km apart, indicating long-distance dispersal. Such a combination of restricted dispersal with rare long-distance dispersal events is supported by a high-resolution biophysical model of larval dispersal in the study area, and we posit that it may be common in marine species. Our results bridge population genetic studies with direct dispersal studies and have implications for the design of marine reserve networks.

18F-Fluordeoxyglukose PET beim Ovarialkarzinom: Methodik und erste Ergebnisse

Ziel der vorliegenden Studie war die Evaluierung der PET mit 18F-Fluor-deoxyglukose in der Primär- und Rezidivdiagnostik von Ovarialkarzino-men. Methoden: Untersucht wurden 26 Patientinnen mit Verdacht auf primäres Ovarialkarzinom (n = 17) bzw. Rezidiwerdacht (n = 9). Die PET-Untersuchung von Abdomen und Becken erfolgte mit einem ECAT 953/15-Scanner beginnend 45 min nach i.v. Applikation von im Mittel 245 MBq 18FDG. Die PET-Ergebnisse wurden anhand von intraoperativem Befund, Histologie und Zytologie validiert. Ergebnisse: Der richtige Nachweis eines primären, malignen Ovarialtumors bzw. eines Rezidivs gelang in 16 von 19 Fällen, der Malignomausschluß in sechs von sieben Fällen. Falsch negative PET-Befunde wurden bei zwei Borderline-Karzinomen und einem gut differenzierten, serös-muzinösen Ovarialkarzinom erhoben. Ein falsch positiver PET-Befund ergab sich bei einer abszedierenden Salpingoophoritis. Die quantitative Analyse erbrachte einen SUV von 6,8 ± 2,3 für primäre, epitheliale Ovarialkarzinome gegenüber 2,6 ± 1,2 bei benignen, nicht entzündlichen Raumforderungen (p <0,05). Schlußfolgerung: Diese vorläufigen Ergebnisse zeigen, daß PET mit 18FDG zwar geeignet ist zur Rezidivdiagnostik von Ovarialkarzinomen, jedoch limitiert ist in der Differenzierung von Borderline-Karzinomen gegenüber benignen Veränderungen sowie malignen Tumoren des Ovars gegenüber entzündlichen Prozessen. Die quantitative Bildanalyse führt hierbei nicht zu einer Verbesserung der diagnostischen Genauigkeit.

In Vitro Analysis of Modified Surfaces of Silicone Breast Implants

Background

Although silicone breast implants are well tolerated, local complications such as capsular contracture occur because of insufficient integration with surrounding tissues. In this study, cell behaviour on hydrophilized silicone breast implant foils was analysed qualitatively and quantitatively under in vitro conditions in order to provoke the desired responses in a defined environment.

Methods

Silicone breast implant foils with different surface modifications were tested after 24 hours, 5 days and 7 days. The following modifications of silicone implant foils were tested: Unmodified silicone, silicone after-graft polymerisation for polyacrylic acid (pAAc), silicone-pAAc-fibronectin adsorptive, silicone-pAAC-fibronectin covalent, positive and negative controls. Experiments were conducted using cell culture with murine mouse fibroblasts L-929. Cytotoxicity assays were carried out in direct and indirect contact with cells grown on the material. For the viability test and qualitative analysis of cell proliferation on different foils, both fluoresceine-diacetate and ethidiumbromide were used and in addition the morphologic description of hemalaun-stained cells were used. Quantitative cell analysis was carried out using XTT after resuspension.

Results

Toxic influence on cell cultures could be excluded for coated and uncoated surfaces in contact with dissolved biomaterials. Unmodified silicone surfaces showed poor cell growth in direct contact. We found a gradual improvement of cell morphology, with the spread and proliferation depending on the type of surface modification. Better results were achieved with covalently coupled fibronectin and GRGDS than with pAAc.

Conclusion

Covalent immobilisation of hydrophobic silicone rubber can improve the initial cellbiomaterial interactions that are required to aid the successful development of tissue-like structures.

Maternal Serum Lipid, Estradiol, and Progesterone Levels in Pregnancy, and the Impact of Placental and Hepatic Pathologies

OBJECTIVE

Lipids and steroid hormones are closely linked. While cholesterol is the substrate for (placental) steroid hormone synthesis, steroid hormones regulate hepatic lipid production. The aim of this study was to quantify circulating steroid hormones and lipid metabolites, and to characterize their interactions in normal and pathological pregnancies with a focus on hepatic and placental pathologies.

METHODS

A total of 216 serum samples were analyzed. Group A consisted of 32 patients with uncomplicated pregnancies who were analyzed at three different time-points in pregnancy (from the first through the third trimester) and once post partum. Group B consisted of 36 patients (24th to 42nd week of gestation) with pregnancy pathologies (IUGR n = 10, preeclampsia n = 13, HELLP n = 6, intrahepatic cholestasis n = 7) and 31 controls with uncomplicated pregnancies. Steroid profiles including estradiol, progesterone, and dehydroepiandrosterone were measured by GC-MS and compared with lipid concentrations.

RESULTS

In Group A, cholesterol and triglycerides correlated positively with estradiol (cholesterol ρ = 0.50, triglycerides ρ = 0.57) and progesterone (ρ = 0.49, ρ = 0.53) and negatively with dehydroepiandrosterone (ρ = - 0.47, ρ = - 0.38). Smoking during pregnancy affected estradiol concentrations, leading to lower levels in the third trimester compared to non-smoking patients (p < 0.05). In Group B, cholesterol levels were found to be lower in IUGR pregnancies and in patients with HELLP syndrome compared to controls (p < 0.05). Steroid hormone concentrations of estradiol (p < 0.05) and progesterone (p < 0.01) were lower in pregnancies with IUGR.

DISCUSSION

Lipid and steroid levels were affected most in IUGR pregnancies, while only minor changes in concentrations were observed for other pregnancy-related disorders. Each of the analyzed entities displayed specific changes. However, since the changes were most obvious in pregnancies complicated by IUGR and only minor changes were observed in pregnancies where patients had impaired liver function, our data suggests that placental rather than maternal hepatic function strongly determines lipid and steroid levels in pregnancy.

[Pharmacological Thromboprophylaxis during Pregnancy and the Puerperium: Recommendations from Current Guidelines and their Critical Comparison]

Venous thromboembolism (VTE) is one of the leading causes of maternal deaths worldwide. Due to the increasing number of pregnant women with risk factors, the incidence of VTE has risen over the past decades. Mortality and morbidity of VTE are potentially preventable, since more than two-thirds of these women have identifiable risk factors and may benefit from appropriate thromboprophylaxis. The cornerstones for prevention of VTE are the individual and careful assessment of preexisting and new-onset/transient risk factors during pregnancy as well as before and after delivery and a risk-stratified pharmacological thromboprophylaxis. Current recommendations for thromboprophylaxis must rely on consensus statements and expert opinions. The recently published German AWMF-Guideline 003/001 and the Green-top Guideline No. 37a from the Royal College of Obstetricians and Gynaecologists (RCOG) are discussed. The RCOG Guideline recommends antenatal thromboprophylaxis in women with previous VTE, high-risk thrombophilia or in the presence of ≥ 4 risk factors from the beginning of pregnancy, in women with 3 current risk factors from 28 weeks of gestation. After delivery women with intermediate risk should receive prophylactic LMWH for at least 10 days and women with high risk for 6 weeks postnatally. All women who have had an elective caesarean section and who have>1 additional risk factor should be given prophylactic NMH as well as all women who have had a caesarean section in labour or an emergency caesarean section. At the onset of labour, in case of any vaginal bleeding, prior to scheduled labour induction or at least 12 h before an elective caesarean section, antenatal LMWH prophylaxis should be discontinued. LMWH prophylaxis can be continued 4-6 h after vaginal delivery and 6-12 h after caesarean delivery when women do not have an increased risk of haemorrhage. Current guidelines recommend weight-based LMWH.

Misoprostol for Labour Induction after Previous Caesarean Section - Forever a "No Go"?

Misoprostol in oral or vaginal form is an established method of labour induction worldwide. Its use after previous caesarean section is associated with a high rate of uterine rupture; according to international guidelines it is therefore contraindicated in this setting. However the evidence base for this recommendation comprises case reports, one randomised trial that was discontinued prematurely, and numerous low quality retrospective data analyses published between 1997 and 2004. New insights into e.g. resorption kinetics, dosage and application intervals, dose dependant uterine hyperstimulation rates, as well as increasing clinical experience with misoprostol have lead to a critical reappraisal of these "historical" studies. Accordingly the evidence supporting a ban on vaginal and particularly oral misoprostol for labour induction in the context of a scarred uterus is currently insufficient for a convincing guideline recommendation. In view of the clear advantages of misoprostol over prostaglandin E₂ (cheaper, more effective) a retrospective review of registry data should be conducted to determine the incidence of uterine rupture following misoprostol and the circumstances in which it occurs. A prospective, randomised trial could then be conducted on the basis of these findings (e.g. oral misoprostol vs. vaginal prostaglandin E₂); known risk factors for uterine rupture including the type of uterine scar would need to be taken into account when selecting patients for vaginal delivery. Until new data from well-designed studies are available, misoprostol will continue to be contraindicated in clinical guidelines for use in labour induction after previous caesarean section.

The Renaissance of Transcervical Balloon Catheters for Cervical Ripening and Labour Induction

Due to rising rates of labour induction in industrialised countries, safe and effective methods of induction have once again become a focus of interest and research. Prostaglandins are effective for cervical ripening and induction of uterine contractions. They do, however, cause overstimulation of the uterus in up to 20 % of cases, sometimes causing changes in fetal heart rate. Transcervical balloon catheters provide an alternative to prostaglandins for labour induction and have been used for this purpose for almost 50 years. This induction method has experienced a recent renaissance in clinical practice that is reflected in an annually rising number of publications on its use. Balloon catheters allow gentle ripening of the cervix without causing uterine overstimulation. The two catheters available are the Foley catheter (off-label use) and the double balloon catheter, which is licensed for use in induction of labour. Both are as effective as prostaglandins, and do not increase the risk of infection to mother or child. Catheter induction also requires less monitoring compared to prostaglandins resulting in improved patient satisfaction. Balloon catheters provide a useful and promising option to achieve vaginal delivery despite failed prostaglandin induction. Intravenous oxytocin is nevertheless required in up to 85 % of cases for adequate induction/augmentation of contractions. Balloon catheters, vaginal PGE₂ and misoprostol are equally effective in the context of an unripe/unfavourable cervix, the rate of uterine hyperstimulation being significantly lower, and the need for oxytocin significantly higher for catheters. Balloon catheters are increasingly being used in combination or sequentially with oral/vaginal misoprostol, although there is currently inadequate published data on the subject. International guidelines recommend the use of balloon catheters for labour induction with an unripe cervix (also following previous caesarean section) as an alternative to prostaglandins, particularly when these are not available or are contraindicated.

Diagnosis and Treatment of Hypertensive Pregnancy Disorders. Guideline of DGGG (S1-Level, AWMF Registry No. 015/018, December 2013)

Purpose: Official guideline published and coordinated by the German Society of Gynecology and Obstetrics (DGGG). Hypertensive pregnancy disorders contribute significantly to perinatal as well as maternal morbidity and mortality worldwide. Also in Germany these diseases are a major course for hospitalization during pregnancy, iatrogenic preterm birth and long-term cardiovascular morbidity. Methods: This S1-guideline is the work of an interdisciplinary group of experts from a range of different professions who were commissioned by DGGG to carry out a systematic literature search of positioning injuries. Members of the participating scientific societies develop a consensus in an informal procedure. Afterwards the directorate of the scientific society approves the consensus. Recommendations: This guideline summarizes the state-of-art for classification, risk stratification, diagnostic, treatment of hypertensive pregnancy disorders.

[Progesterone for Prevention of Preterm Birth--Evidence-based Indications]

BACKGROUND

The prevention and treatment of preterm birth remains an unsolved problem in modern obstetrics. Progesterone has a variety of actions on the myometrium and the cervix, among others inhibition of myometrial contractility and a cervix strengthening effect by inhibiting the production of proinflammatory cytokines and prostaglandins as well as by reducing the synthesis of proteins, which play a crucial role in initiating labour. Consequently, progesterone may be a promising candidate for the prevention of preterm birth.

MATERIAL AND METHODS

We searched PubMed from 1956 to August 2014 using a combination of key words and text words related to preterm birth and progesterone. ('progesterone', progestins, 17-OHPC). The aim of the literature search was to determine evidence-based indications for the use of progesterone in the prevention of preterm birth.

RESULTS

(i) Patients with a singleton pregnancy and history of preterm birth should receive vaginal progesterone daily (200 mg capsule or 90 mg containing gel) from 16+0 to 36+0 weeks of gestation (alternatively 250 mg intramuscular 17-OHPC weekly): level of evidence 1a, grade of recommendation ++ . Prophylactic progesterone reduces the incidence of preterm birth <34 and <37 weeks of gestation and perinatal mortality significantly. (ii) Patients with singleton pregnancies and a sonographically short cervix (≤25 mm) before 24 weeks of gestation should receive vaginal progesterone daily (200 mg capsule or 90 mg containing gel) until 36+6 weeks of gestation: level of evidence 1a, grade of recommendation ++ . Prophylactic progesterone leads to a significant reduction in the incidence of preterm birth <28, <33, and <35 weeks of gestation and is associated with a significant reduction of neonatal morbidity. (III) There is a lack of evidence to recommend vaginal progesterone or intramuscular 17-OHPC for primary tocolysis or for "adjunctive" tocolysis (in combination with conventional tocolytic agents). (IV) There is a growing body of evidence that vaginal progesterone (400 mg/day) after successful tocolysis ("maintenance therapy") is a promising option for prolongation of pregnancy: level of evidence 1b, grade of recommendation +. (V) Data from the literature are insufficient to recommend progesterone in patients with preterm rupture of membranes or in the perioperative management of patients requiring transvaginal cervical cerclage. (VI) The vaginal administration of progesterone is well-tolerated by the patients and has only minor maternal side effects, whereas intramuscular injections of 17-OHPC are associated with a significant higher rate of side effects (e. g. local pain, nausea, diarrhoea). It is mandatory to inform patients on the off-label use of progesterone in pregnancy.

DISCUSSION

Prophylactic progesterone administration is an evidence-based method for the prevention of preterm birth in women with a previous preterm birth and in pregnant women with a sonographically short cervix (≤25 mm) before 24 weeks of gestation. Vaginal progesterone is favoured over intramuscularly applied 17-OHPC, especially because of the lower rate of maternal side effects. Whether progesterone is an effective approach for the treatment of preterm birth as a tocolytic agent (primary, adjunctive) or for maintenance therapy after arrest of preterm labour has to be shown in further well-designed randomised and controlled trials with adequate statistical power.