Lymphocyte characterization of decidua basalis spiral arteries with acute atherosis in preeclamptic and normotensive pregnancies.

Uteroplacental acute atherosis (AA) is a common spiral arterial lesion in preeclampsia, characterized by intramural foam cells, fibrinoid necrosis, and a perivascular immune cell infiltrate. A clear definition of this infiltrate is lacking. Therefore, our aim was to characterize lymphocytes in pre-defined zones regarding spiral arteries with or without AA, from preeclamptic and normotensive pregnancies. Lymphocytes were characterized in decidua basalis samples (n = 91), previously evaluated for AA, around spiral arteries in three pre-defined zones; 1) intramural, 2) perivascular and 3) interstitial. Adjacent serial sections were immunostained to identify different T-cell populations (CD3+, CD8+, FOXP3+), and NK-cells (CD56+). CD3+CD8- T-cells were also identified. These were presumed to be largely CD4+ T-cells. AA was associated with significantly higher intramural CD3+ cell concentrations in Zone 1, in both normotensives and preeclamptics. In preeclamptics only, this difference extended into Zone 2. Similar results were observed for CD3+CD8- cells. AA was also associated with increased intramural CD8+ concentration; however, the number of cells was low. Regulatory T-cells (FOXP3+) were generally scarce or absent in all pre-defined zones. Although intramural NK-cells (CD56+) were scarce, the intramural concentration was significantly lower in spiral arteries with AA compared to without AA in preeclamptics. Our main finding was that CD3+CD8-FoxP3- T-cells were associated with AA. We therefore suggest that T-cells, of a non-regulatory CD4+ subtype, could be involved in the formation of spiral artery AA in the decidua basalis. Whether AA gives rise to, or is partly mediated by increased T-cell concentration around the lesions, remains to be determined.

Vasa praevia: risk-adapted modification of the conventional management--a retrospective study.

PURPOSE: Undiagnosed vasa praevia carries an imminent risk of fetal death and increases with IVF. When diagnosed, the question arises as to whether the conventional prenatal management of routine steroid administration for fetal lung maturation and elective caesarean section in week 35 is generally justified in face of the risks involved. We present a retrospective study of a risk-adapted modification of the conventional management of vasa praevia. MATERIAL AND METHODS: We analysed 11 years of records involving 18 cases of antenatally diagnosed vasa praevia at our perinatal centre. Each case was managed by a risk-adapted modification of the conventional treatment where both, the steroid administration and the timing of delivery, were dependent on the patient history and clinical signs for preterm birth. RESULTS: There were no lethal fetal, neonatal, or maternal complications. The earliest caesarean section took place at 34 weeks 1 day, the latest at 37 weeks 1 day, and in more than half of the cases at ≥ 36 weeks. CONCLUSION: Steroid application is generally recommended for pregnancies before 34 weeks carrying a risk for preterm birth. Thus, retrospectively, none of our cases required steroid administration. This supports our protocol of not obligatorily administering steroids. Delaying the caesarean section up to two weeks beyond the conventionally recommended date of 35 weeks in 78% of our cases resulted in no complications. This justifies the suitability of determining the timing of delivery based on our individual patient assessment. In conclusion, the following recommendations for a risk-adapted management of vasa praevia can be made: 1. weekly evaluation of risk factors for preterm delivery; 2. steroid administration only at risk for preterm birth; 3. admission to hospital with full obstetric and neonatal care facilities between 32 and 34 weeks; 4. elective caesarean section between 35 and 37 weeks, risk-adapted.

[Management of dichorionic twin delivery at term with cephalic-presenting first twin - a monocentric retrospective cohort study]. / Geburtsleitung bei dichorialen Zwillingen am Termin bei vorangehendem Zwilling in Schädellage - eine monozentrische retrospektive Kohortenstudie.

OBJECTIVE: To assess neonatal outcome and delivery mode in dichorionic twin delivery at term with a cephalic-presenting first twin. METHODS: A retrospective cohort study of 308 twin deliveries after 37 completed weeks of gestation with a cephalic-presenting first twin undertaken in one perinatal center with active management of second twin delivery. The neonatal outcome was measured by the Apgar score, the umbilical artery pH and the transfer into the neonatal unit. RESULTS: In the whole group, 57% were vaginally delivered and 43% needed a Cesarean delivery. The planned vaginal delivery group contained 71% while the planned elective Cesarean delivery group contained 29%. In the planned vaginal delivery group 80% were delivered vaginally, in 15% an emergency Cesarean was necessary, 5% had a vaginal delivery of the first twin followed by Cesarean delivery of the second twin. The neonatal outcome of the second twin shows a higher risk. There are significant differences in the rates of the second twin having lower rates of the umbilical artery pH >7.20 in the group of planned vaginal delivery. The higher risks are compensated in the group of planned elective Cesarean delivery. CONCLUSIONS: Planned vaginal delivery of dichorionic twins at term and active second-stage management is associated with lower rate of normal neonatal outcome. These risks should be considered in prenatal informed consent discussions with the pregnant woman.

Imprinted control of gene activity in Drosophila.

Genetic imprinting is defined as a reversible, differential marking of genes or chromosomes that is determined by the sex of the parent from whom the genetic material is inherited [1]. Imprinting was first observed in insects where, in some species, most notably among the coccoids (scale insects and allies), the differential marking of paternally and maternally transmitted chromosome sets leads to inactivation or elimination of paternal chromosomes [2]. Imprinting is also widespread in plants and mammals [3,4], in which paternally and maternally inherited alleles may be differentially expressed. Despite imprinting having been discovered in insects, clear examples of parental imprinting are scarce in the model insect species Drosophila melanogaster. We describe a case of imprint-mediated control of gene expression in Drosophila. The imprinted gene - the white+ eye-color gene - is expressed at a low level when transmitted by males, and at a high level when transmitted by females. Thus, in common with coccoids, Drosophila is capable of generating an imprint, and can respond to that imprint by silencing the paternal allele.

FLP-mediated DNA mobilization to specific target sites in Drosophila chromosomes.

The ability to place a series of gene constructs at a specific site in the genome opens new possibilities for the experimental examination of gene expression and chromosomal position effects. We report that the FLP- FRT site-specific recombination system of the yeast 2mu plasmid can be used to integrate DNA at a chromosomal FRT target site in Drosophila. The technique we used was to first integrate an FRT- flanked gene by standard P element-mediated transformation. FLP was then used to excise the FRT- flanked donor DNA and screen for FLP-mediated re-integration at an FRT target at a different chromosome location. Such events were recovered from up to 5% of the crosses used to screen for mobilization and are easily detectable by altered linkage of a white reporter gene or by the generation of a white + gene upon integration.

Engineering the Drosophila genome: chromosome rearrangements by design.

We show that site-specific recombination can be used to engineer chromosome rearrangements in Drosophila melanogaster. The FLP site-specific recombinase acts on chromosomal target sites located within specially constructed P elements to provide an easy screen for the recovery of rearrangements with breakpoints that can be chosen in advance. Paracentric and pericentric inversions are easily recovered when two elements lie in the same chromosome in opposite orientation. These inversions are readily reversible. Duplications and deficiencies can be recovered by recombination between two elements that lie in the same orientation on the same chromosome or on homologues. We observe that the frequency of recombination between FRTs at ectopic locations decreases as the distance that separates those FRTs increases. We also describe methods to determine the absolute orientation of these P elements within the chromosome. The ability to produce chromosome rearrangements precisely between preselected sites provides a powerful new tool for investigations into the relationships between chromosome arrangement, structure, and function.

A quantitative measure of the mitotic pairing of alleles in Drosophila melanogaster and the influence of structural heterozygosity.

In Drosophila there exist several examples of gene expression that can be modified by an interaction between alleles; this effect is known as transvection. The inference that alleles interact comes from the observations that homologous chromosomes pair in mitotically dividing cells, and that chromosome rearrangements can alter the phenotype produced by a pair of alleles. It is thought that heterozygous rearrangements impede the ability of alleles to pair and interact. However, because the existing data are inconsistent, this issue is not fully settled. By measuring the frequency of site-specific recombination between homologous chromosomes, we show that structural heterozygosity inhibits the pairing of alleles that lie distal to a rearrangement breakpoint. We suggest that some of the apparent conflicts may owe to variations in cell-cycle lengths in the tissues where the relevant allelic interactions occur. Cells with a longer cell cycle have more time to establish the normal pairing relationships that have been disturbed by rearrangements. In support, we show that Minute mutations, which slow the rate of cell division, partially restore a transvection effect that is disrupted by inversion heterozygosity.