Daniel Surbek

Concise review: Isolation and characterization of cells from human term placenta: Outcome of the First International Workshop on Placenta Derived Stem Cells

Placental tissue draws great interest as a source of cells for regenerative medicine because of the phenotypic plasticity of many of the cell types isolated from this tissue. Furthermore, placenta, which is involved in maintaining fetal tolerance, contains cells that display immunomodulatory properties. These two features could prove useful for future cell therapy‐based clinical applications. Placental tissue is readily available and easily procured without invasive procedures, and its use does not elicit ethical debate. Numerous reports describing stem cells from different parts of the placenta, using nearly as numerous isolation and characterization procedures, have been published. Considering the complexity of the placenta, an urgent need exists to define, as clearly as possible, the region of origin and methods of isolation of cells derived from this tissue. On March 23–24, 2007, the first international Workshop on Placenta Derived Stem Cells was held in Brescia, Italy. Most of the research published in this area focuses on mesenchymal stromal cells isolated from various parts of the placenta or epithelial cells isolated from amniotic membrane. The aim of this review is to summarize and provide the state of the art of research in this field, addressing aspects such as cell isolation protocols and characteristics of these cells, as well as providing preliminary indications of the possibilities for use of these cells in future clinical applications.

First-trimester serum levels of soluble endoglin and soluble fms-like tyrosine kinase-1 as first-trimester markers for late-onset preeclampsia

OBJECTIVE The aim of this investigation was to assess soluble endoglin (sEng) and soluble fms-like tyrosine kinase-1 (sFlt1) as first-trimester serum markers to predict preeclampsia. STUDY DESIGN First-trimester sera were obtained from 46 women with subsequent late-onset preeclampsia and from 92 controls. sEng and sFlt1 concentrations were determined immunoanalytically. Correlation analysis with inhibin A and placental growth factor levels was performed. RESULTS sEng and sFlt1 serum concentrations were higher in women with subsequent preeclampsia than in controls (mean +/- SD, sEng: 5.57 +/- 1.18 ng/mL vs 5.02 +/- 1.01 ng/mL, P = .009; sFlt1: 1764 +/- 757 pg/mL vs 1537 +/- 812 pg/mL, P = .036). Sensitivities and specificities for predicting preeclampsia were 63% and 57% for sEng and 64% and 56% for sFlt1, respectively. When sEng and inhibin A were combined, the sensitivity increased to 68%, whereas the specificity was 61%. CONCLUSION sEng and sFlt1 are increased in the first trimester in women with subsequent late-onset preeclampsia and might therefore prove useful to predict preeclampsia.

Salt Sensitivity of Children With Low Birth Weight

Compromised intrauterine fetal growth leading to low birth weight (<2500 g) is associated with adulthood renal and cardiovascular disease. The aim of this study was to assess the effect of salt intake on blood pressure (salt sensitivity) in children with low birth weight. White children (n=50; mean age: 11.3±2.1 years) born with low (n=35) or normal (n=15) birth weight and being either small or appropriate for gestational age (n=25 in each group) were investigated. The glomerular filtration rate was calculated using the Schwartz formula, and renal size was measured by ultrasound. Salt sensitivity was assigned if mean 24-hour blood pressure increased by ≥3 mm Hg on a high-salt diet as compared with a controlled-salt diet. Baseline office blood pressure was higher and glomerular filtration rate lower in children born with low birth weight as compared with children born at term with appropriate weight (P<0.05). Salt sensitivity was present in 37% and 47% of all of the low birth weight and small for gestational age children, respectively, higher even than healthy young adults from the same region. Kidney length and volume (both P<0.0001) were reduced in low birth weight children. Salt sensitivity inversely correlated with kidney length (r2=0.31; P=0.005) but not with glomerular filtration rate. We conclude that a reduced renal mass in growth-restricted children poses a risk for a lower renal function and for increased salt sensitivity. Whether the changes in renal growth are causative or are the consequence of the same abnormal “fetal programming” awaits clarification.

Umbilical cord blood from preterm human fetuses is rich in committed and primitive hematopoietic progenitors with high proliferative and self-renewal capacity

Human umbilical cord blood (CB) has been recognized as a source of hematopoietic stem cells for transplantation. While hematopoietic properties of neonatal CB from full-term pregnancies have been well characterized, little is known about CB from early gestational ages. We analyzed the content and the growth properties of primitive and committed hematopoietic progenitors in preterm CB from second trimester (week 16-28; n = 17) and early third trimester (week 29-34; n = 17) in comparison with term CB (n = 18). The frequency of CD34+ and CD34+CD38- cells was significantly higher in preterm than in term CB (mean, 2.51% and 0.56% vs 0.88% and 0.13%;p < 0.002). The number of colony forming units (CFU) in preterm CB was about twofold higher (230 +/- 6 vs 133 +/- 14/ 10(5) mononuclear cells; p < 0.05) and correlated with the content of CD34+ progenitors (r = 0.73). Long-term culture initiating cells (LTC-IC) were enriched about 2.5-fold (6.7 +/- 2.9 vs 2.6 +/- 1.2/10(5) cells; p < 0.05). Progenitors from preterm CB could be expanded in stroma-free liquid cultures supplemented with hematopoietic growth factors as efficiently as progenitors from term neonates. In short-term cultures containing erythropoietin (Epo), interleukin (IL)-1, IL-3, and IL-6, or granulocyte- (G-) and granulocyte-macrophage colony-stimulating factor (GM-CSF) together with stem cell factor (SCF) or Flt3 ligand (FL), expansion of CFUs was six- to eightfold at week 1. In long-term cultures containing thrombopoietin (TPO) and FL, an approximately 1000-fold expansion of multilineage progenitors was observed at week 10. In summary, we show that preterm CB compared with term CB is richer in hematopoietic progenitors, and that precursors from preterm CB can be extensively expanded ex vivo. This may have implications for the development of transplantation and gene transfer strategies targeting circulating fetal stem cells.

Prematurity Is Related to High Placental Cortisol in Preeclampsia

Fetal growth is compromised in animal models with high cortisol availability. In healthy pregnancies, the fetus is protected from high circulating cortisol levels by the placental 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), which is reduced in preeclampsia. We hypothesized increased placental cortisol availability in preeclampsia as missing link to fetal growth restriction and prematurity. Placental tissue was obtained from 39 pregnant women dichotomized normotensive (n = 16) or preeclamptic (n = 23). Placental steroid hormone metabolites were analyzed by gas chromatography-mass spectrometry. Apparent 11β-HSD2 enzyme activity was calculated as substrate to product ratio. Estradiol and pregnandiol positively correlated with gestational age. Cortisol was virtually absent in 93.8% of controls, yet detectable in 79.3% of preeclamptic samples resulting in an odds ratio (OR) of 0.019 (95% CI 0.002–0.185) for the presence of placental cortisol. Apparent 11β-HSD2 activity directly correlated with birth weight (R2 = 0.16; p < 0.02) and gestational age (R2 = 0.11; p < 0.04) ensuing a reduced risk of premature delivery (OR 0.12; 95% CI 0.02–0.58). We conclude that normotensive pregnancies are characterized by an almost completely inactivated placental cortisol. In line with our hypothesis, reduced 11β-HSD2 activity in preeclampsia is unable to abolish placental cortisol, a finding clearly associated with prematurity and low birth weight.

Regulation of Placental Growth by Aldosterone and Cortisol

During pregnancy, trophoblasts grow to adapt the feto-maternal unit to fetal requirements. Aldosterone and cortisol levels increase, the latter being inactivated by a healthy placenta. By contrast, preeclamptic placental growth is reduced while aldosterone levels are low and placental cortisol tissue levels are high due to improper deactivation. Aldosterone acts as a growth factor in many tissues, whereas cortisol inhibits growth. We hypothesized that in preeclampsia low aldosterone and enhanced cortisol availability might mutually affect placental growth and function. Proliferation of cultured human trophoblasts was time- and dose-dependently increased with aldosterone (P < 0.04 to P < 0.0001) and inhibited by spironolactone and glucocorticoids (P < 0.01). Mineralo- and glucocorticoid receptor expression and activation upon agonist stimulation was verified by visualization of nuclear translocation of the receptors. Functional aldosterone deficiency simulated in pregnant mice by spironolactone treatment (15 μg/g body weight/day) led to a reduced fetal umbilical blood flow (P < 0.05). In rat (P < 0.05; R(2) = 0.2055) and human (X(2) = 3.85; P = 0.0249) pregnancy, placental size was positively related to plasma aldosterone. Autocrine production of these steroid hormones was excluded functionally and via the absence of specific enzymatic transcripts for CYP11B2 and CYP11B1. In conclusion, activation of mineralocorticoid receptors by maternal aldosterone appears to be required for trophoblast growth and a normal feto-placental function. Thus, low aldosterone levels and enhanced cortisol availability may be one explanation for the reduced placental size in preeclampsia and related disorders.

A double-blind comparison of the safety and efficacy of intravaginal misoprostol and prostaglandin E2 to induce labor

OBJECTIVE Our purpose was to compare the safety and efficacy of intravaginally administered misoprostol versus prostaglandin E2 for labor induction in a double-blind, randomized trial. STUDY DESIGN One hundred three patients with indications for labor induction (including prelabor rupture of membranes) were randomized and received either misoprostol 50 micrograms or prostaglandin E2 (dinoprostone) 3 mg intravaginally. The dose was repeated 6, 24, and 30 hours after the first dose until active labor was achieved. For proper blinding, the drugs were prepared as identical-looking vaginal tablets. RESULTS With use of a random number-generated table 52 patients were allocated to the misoprostol group and 51 to the prostaglandin E2 group. After exclusion of 3 patients, 50 in each group were evaluated. Delivery within 24 hours after administration occurred more often in the misoprostol group (70% vs 46% in the prostaglandin E2 group, p = 0.009), and fewer patients in this group needed more than two doses (12% vs 30%, p = 0.027). No difference in cesarean section rate (12% vs 14%, p = 0.67), fetal heart rate anomalies (33% vs 34%, p = 0.89), tachysystole (8% vs 14%, p = 0.37), hyperstimulation syndrome (0% vs 2%, not significant), meconium passage (28% vs 18%, p = 0.22), and fetal outcome (Apgar score at 1 and 5 minutes, arterial and venous umbilical cord blood pH, transfer to neonatal intensive care unit) was noted between the two groups. CONCLUSION Intravaginal misoprostol is a safe drug for labor induction with superior effectiveness compared with intravaginal prostaglandin E2.

Perinatal care at the limit of viability between 22 and 26 completed weeks of gestation in Switzerland 2011 Revision of the Swiss recommendations

Perinatal care of pregnant women at high risk for preterm delivery and of preterm infants born at the limit of viability (22-26 completed weeks of gestation) requires a multidisciplinary approach by an experienced perinatal team. Limited precision in the determination of both gestational age and foetal weight, as well as biological variability may significantly affect the course of action chosen in individual cases. The decisions that must be taken with the pregnant women and on behalf of the preterm infant in this context are complex and have far-reaching consequences. When counselling pregnant women and their partners, neonatologists and obstetricians should provide them with comprehensive information in a sensitive and supportive way to build a basis of trust. The decisions are developed in a continuing dialogue between all parties involved (physicians, midwives, nursing staff and parents) with the principal aim to find solutions that are in the infants and pregnant womans best interest. Knowledge of current gestational age-specific mortality and morbidity rates and how they are modified by prenatally known prognostic factors (estimated foetal weight, sex, exposure or nonexposure to antenatal corticosteroids, single or multiple births) as well as the application of accepted ethical principles form the basis for responsible decision-making. Communication between all parties involved plays a central role. The members of the interdisciplinary working group suggest that the care of preterm infants with a gestational age between 22 0/7 and 23 6/7 weeks should generally be limited to palliative care. Obstetric interventions for foetal indications such as Caesarean section delivery are usually not indicated. In selected cases, for example, after 23 weeks of pregnancy have been completed and several of the above mentioned prenatally known prognostic factors are favourable or well informed parents insist on the initiation of life-sustaining therapies, active obstetric interventions for foetal indications and provisional intensive care of the neonate may be reasonable. In preterm infants with a gestational age between 24 0/7 and 24 6/7 weeks, it can be difficult to determine whether the burden of obstetric interventions and neonatal intensive care is justified given the limited chances of success of such a therapy. In such cases, the individual constellation of prenatally known factors which impact on prognosis can be helpful in the decision making process with the parents. In preterm infants with a gestational age between 25 0/7 and 25 6/7 weeks, foetal surveillance, obstetric interventions for foetal indications and neonatal intensive care measures are generally indicated. However, if several prenatally known prognostic factors are unfavourable and the parents agree, primary non-intervention and neonatal palliative care can be considered. All pregnant women with threatening preterm delivery or premature rupture of membranes at the limit of viability must be transferred to a perinatal centre with a level III neonatal intensive care unit no later than 23 0/7 weeks of gestation, unless emergency delivery is indicated. An experienced neonatology team should be involved in all deliveries that take place after 23 0/7 weeks of gestation to help to decide together with the parents if the initiation of intensive care measures appears to be appropriate or if preference should be given to palliative care (i.e., primary non-intervention). In doubtful situations, it can be reasonable to initiate intensive care and to admit the preterm infant to a neonatal intensive care unit (i.e., provisional intensive care). The infants clinical evolution and additional discussions with the parents will help to clarify whether the life-sustaining therapies should be continued or withdrawn. Life support is continued as long as there is reasonable hope for survival and the infants burden of intensive care is acceptable. If, on the other hand, the health care team and the parents have to recognise that in the light of a very poor prognosis the burden of the currently used therapies has become disproportionate, intensive care measures are no longer justified and other aspects of care (e.g., relief of pain and suffering) are the new priorities (i.e., redirection of care). If a decision is made to withhold or withdraw life-sustaining therapies, the health care team should focus on comfort care for the dying infant and support for the parents.

Diffusion-weighted MR Imaging of the Placenta in Fetuses with Placental Insufficiency

PURPOSE To evaluate diffusion-weighted magnetic resonance (MR) imaging of the human placenta in fetuses with and fetuses without intrauterine growth restriction (IUGR) who were suspected of having placental insufficiency. MATERIALS AND METHODS The study was approved by the local ethics committee, and written informed consent was obtained. The authors retrospectively evaluated 1.5-T fetal MR images from 102 singleton pregnancies (mean gestation ± standard deviation, 29 weeks ± 5; range, 21-41 weeks). Morphologic and diffusion-weighted MR imaging were performed. A region of interest analysis of the apparent diffusion coefficient (ADC) of the placenta was independently performed by two observers who were blinded to clinical data and outcome. Placental insufficiency was diagnosed if flattening of the growth curve was detected at obstetric ultrasonography (US), if the birth weight was in the 10th percentile or less, or if fetal weight estimated with US was below the 10th percentile. Abnormal findings at Doppler US of the umbilical artery and histopathologic examination of specimens from the placenta were recorded. The ADCs in fetuses with placental insufficiency were compared with those in fetuses of the same gestational age without placental insufficiency and tested for normal distribution. The t tests and Pearson correlation coefficients were used to compare these results at 5% levels of significance. RESULTS Thirty-three of the 102 pregnancies were ultimately categorized as having an insufficient placenta. MR imaging depicted morphologic changes (eg, infarction or bleeding) in 27 fetuses. Placental dysfunction was suspected in 33 fetuses at diffusion-weighted imaging (mean ADC, 146.4 sec/mm(2) ± 10.63 for fetuses with placental insufficiency vs 177.1 sec/mm(2) ± 18.90 for fetuses without placental insufficiency; P < .01, with one false-positive case). The use of diffusion-weighted imaging in addition to US increased sensitivity for the detection of placental insufficiency from 73% to 100%, increased accuracy from 91% to 99%, and preserved specificity at 99%. CONCLUSION Placental dysfunction associated with growth restriction is associated with restricted diffusion and reduced ADC. A decreased ADC used as an early marker of placental damage might be indicative of pregnancy complications such as IUGR. SUPPLEMENTAL MATERIAL http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.10092283/-/DC1.

Diagnosis and treatment of peripartum bleeding

Abstract Severe peripartum hemorrhage (PPH) contributes to maternal morbidity and mortality and is one of the most frequent emergencies in obstetrics, occurring at a prevalence of 0.5–5.0%. Detection of antepartum risk factors is essential in order to implement preventive measures. Proper training of obstetric staff and publication of recommendations and guidelines can effectively reduce the frequency of PPH and its resulting morbidity and mortality. Therefore, an interdisciplinary expert committee was formed, with members from Germany, Austria, and Switzerland, to summarize recent scientific findings. An up-to-date presentation of the importance of embolization and of the diagnosis of coagulopathy in PPH is provided. Furthermore, the committee recommends changes in the management of PPH including new surgical options and the off-label use of recombinant factor VIIa.