56 research outputs found
Systemic Oxidative Stress in Severe Early-Onset Fetal Growth Restriction Associates with Concomitant Pre-Eclampsia, Not with Severity of Fetal Growth Restriction
Background: Placental insufficiency is an important mechanism underlying early-onset fetal growth restriction (eoFGR). Reduced placental function causes impaired metabolic and gaseous exchange. This unfavorable placental environment is among other processes characterized by increased oxidative stress. Systemic free thiols (FT) are known for their reactive oxygen species scavenging capacity, and higher plasma levels of FT are associated with a better outcome in a multitude of ischemic and inflammatory diseases. We aimed to investigate the relationships between systemic FT levels and maternal and perinatal clinical characteristics and outcomes. Study design: In a post hoc analysis of the Dutch Strider study, a cohort of women with eoFGR, we investigated the association between the maternal redox status (FT) levels at study inclusion, placental biomarkers, and maternal and neonatal outcomes in 108 patients. Results: FT were significantly lower in pregnancies complicated with eoFGR with concurrent maternal hypertensive disorders (pregnancy-induced hypertension; ρ = −0.281 p = 0.004, pre-eclampsia; ρ = −0.505 p = 0.000). In addition, lower FT levels were significantly associated with higher systolic (ρ = −0.348 p = 0.001) and diastolic blood pressure (ρ = −0.266 p = 0.014), but not with the severity of eoFGR. FT levels were inversely associated with sFlt (ρ = −0.366, p < 0.001). A strong relation between systemic FT levels and PlGF levels was observed in women with pre-eclampsia at delivery (ρ = 0.452, p = 0.002), which was not found in women without hypertensive disorders (ρ = 0.008, p = 0.958). Conclusions: In women with pregnancies complicated with eoFGR, FT levels reflect the severity of maternal disease related to the underlying placental insufficiency rather than the severity of the placental dysfunction as reflected in eoFGR or perinatal outcomes
Oxidative stress biomarkers in fetal growth restriction with and without preeclampsia
INTRODUCTION: Oxidative stress as observed in fetal growth restriction (FGR) and preeclampsia (PE) can be identified by decreased levels of systemic free thiols (FT) and increased levels of plasma ischemia-modified albumin (IMA), which may serve as biomarkers in maternal blood for pregnancy complications. We evaluate the performance of oxidative stress-associated potential biomarkers for FGR and PE, and their relationship with clinical characteristics.METHODS: A prospective clinical pilot study was performed in healthy controls and women with pregnancies complicated by severe FGR with or without PE. Blood samples were taken directly after inclusion and analyzed for FT; IMA; soluble FMS-like tyrosine kinase-1 (sFlt-1); placenta growth factor (PlGF); and biomarkers like leptin and soluble receptors for advanced glycation end products (sRAGE). Placentas were examined microscopically. Descriptive statistics and receiver operating characteristics statistics were performed.RESULTS: Mothers with both severe FGR and PE had significantly reduced FT levels (p < 0.001) and PlGF levels (p < 0.001), and increased levels of plasma IMA (p < 0.05), sFlt (p < 0.001), leptin (p < 0.05) and sRAGE (p < 0.01) compared to women with FGR only. Systemic FT levels were significantly inversely associated with blood pressure (p < 0.01) and plasma IMA (p < 0.001), leptin (p = 0.01) and sRAGE (p < 0.001). Systemic FT and leptin showed significant discriminative ability to differentiate mothers with both FGR and PE from mothers with uncomplicated pregnancies or pregnancies complicated by FGR only.DISCUSSION: There is a significant discriminative capacity of FT, IMA, leptin and sRAGE that harbor potential as biomarkers of pregnancies complicated by combined FGR and PE.</p
Environmental drivers of the composition and diversity of the herb layer in mixed temperate forests in Hungary
The RhoGEF Pebble is required for cell shape changes during cell migration triggered by the Drosophila FGF receptor Heartless
Differential and overlapping functions of two closely related Drosophila FGF8-like growth factors in mesoderm development
Thisbe (Ths) and Pyramus (Pyr), two closely related Drosophila
homologues of the vertebrate fibroblast growth factor (FGF) 8/17/18 subfamily,
are ligands for the FGF receptor Heartless (Htl). Both ligands are required
for mesoderm development, but their differential expression patterns suggest
distinct functions during development. We generated single mutants and found
that ths or pyr loss-of-function mutations are semi-lethal
and mutants exhibit much weaker phenotypes as compared with loss of both
ligands or htl. Thus, pyr and ths display partial
redundancy in their requirement in embryogenesis and viability. Nevertheless,
we find that pyr and ths single mutants display defects in
gastrulation and mesoderm differentiation. We show that localised expression
of pyr is required for normal cell protrusions and high levels of
MAPK activation in migrating mesoderm cells. The results support the model
that Pyr acts as an instructive cue for mesoderm migration during
gastrulation. Consistent with this function, mutations in pyr affect
the normal segmental number of cardioblasts. Furthermore, Pyr is essential for
the specification of even-skipped-positive mesodermal precursors and
Pyr and Ths are both required for the specification of a subset of somatic
muscles. The results demonstrate both independent and overlapping functions of
two FGF8 homologues in mesoderm morphogenesis and differentiation. We propose
that the integration of Pyr and Ths function is required for robustness of
Htl-dependent mesoderm spreading and differentiation, but that the functions
of Pyr have become more specific, possibly representing an early stage of
functional divergence after gene duplication of a common ancestor
Regulation of the Rac GTPase pathway by the multifunctional Rho GEF Pebble is essential for mesoderm migration in the Drosophila gastrula
The Drosophila guanine nucleotide exchange factor Pebble (Pbl) is
essential for cytokinesis and cell migration during gastrulation. In dividing
cells, Pbl promotes Rho1 activation at the cell cortex, leading to formation
of the contractile actin-myosin ring. The role of Pbl in fibroblast growth
factor-triggered mesoderm spreading during gastrulation is less well
understood and its targets and subcellular localization are unknown. To
address these issues we performed a domain-function study in the embryo. We
show that Pbl is localized to the nucleus and the cell cortex in migrating
mesoderm cells and found that, in addition to the PH domain, the conserved
C-terminal tail of the protein is crucial for cortical localization. Moreover,
we show that the Rac pathway plays an essential role during mesoderm
migration. Genetic and biochemical interactions indicate that during mesoderm
migration, Pbl functions by activating a Rac-dependent pathway. Furthermore,
gain-of-function and rescue experiments suggest an important regulatory role
of the C-terminal tail of Pbl for the selective activation of Rho1-versus
Rac-dependent pathways
Natural variation of the amino-terminal glutamine-rich domain in Drosophila argonaute2 is not associated with developmental defects
The Drosophila argonaute2 (ago2) gene plays a major role in siRNA mediated RNA silencing pathways. Unlike mammalian Argonaute proteins, the Drosophila protein has an unusual amino-terminal domain made up largely of multiple copies of glutamine-rich repeats (GRRs). We report here that the ago2 locus produces an alternative transcript that encodes a putative short isoform without this amino-terminal domain. Several ago2 mutations previously reported to be null alleles only abolish expression of the long, GRR-containing isoform. Analysis of drop out (dop) mutations had previously suggested that variations in GRR copy number result in defects in RNAi and embryonic development. However, we find that dop mutations genetically complement transcript-null alleles of ago2 and that ago2 alleles with variant GRR copy numbers support normal development. In addition, we show that the assembly of the central RNAi machinery, the RISC (RNA induced silencing complex), is unimpaired in embryos when GRR copy number is altered. In fact, we find that GRR copy number is highly variable in natural D. melanogaster populations as well as in laboratory strains. Finally, while many other insects share an extensive, glutamine-rich Ago2 amino-terminal domain, its primary sequence varies drastically between species. Our data indicate that GRR variation does not modulate an essential function of Ago2 and that the amino-terminal domain of Ago2 is subject to rapid evolution
An Improved Implementation of Elliptic Curves over GF(2 n) when Using Projective Point Arithmetic
Demographic change and the supply of potential family supporters in Britain, Finland and France in the period 1911-2050
We consider the contribution of changes in mortality and fertility to availability of living mothers and living children among older people in Britain, Finland and France. The proportion of people aged around 60 with a mother alive will more than double between those born in 1911 and 1970 before starting to decline slightly. Conversely, a higher proportion of elderly people are likely to have a surviving child than for any generation ever born in all three countries in the next quarter century or so, with about 85% of 80-year-old women having at least one surviving child, and about two-thirds having two or more
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