253 research outputs found
Serum and urine vitamin D metabolite analysis in early preeclampsia
Vitamin D-deficiency is common in pregnant women, and may contribute to adverse events in pregnancy such as preeclampsia (PET). To date, studies of vitamin D and PET have focused primarily on serum concentrations vitamin D, 25-hydroxyvitamin D3 (25(OH)D3) later in pregnancy. The aim here was to determine whether a more comprehensive analysis of vitamin D metabolites earlier in pregnancy could provide predictors of PET. Using samples from the SCOPE pregnancy cohort, multiple vitamin D metabolites were quantified by liquid chromatography-tandem mass spectrometry in paired serum and urine prior to the onset of PET symptoms. Samples from 50 women at pregnancy week 15 were analysed, with 25 (50%) developing PET by the end of the pregnancy and 25 continuing with uncomplicated pregnancy. Paired serum and urine from non-pregnant women (n=9) of reproductive age were also used as a control. Serum concentrations of 25(OH)D3, 25(OH)D2, 1,25(OH)2D3, 24,25(OH)2D3, and 3-epi-25(OH)D3 were measured and showed no significant difference between women with uncomplicated pregnancies and those developing PET. As previously reported, serum 1,25(OH)2D3 was higher in all pregnant women (in the second trimester), but serum 25(OH)D2 was also higher compared to non-pregnant women. In urine, 25(OH)D3 and 24,25(OH)2D3 were quantifiable, with both metabolites demonstrating significantly lower (p<0.05) concentrations of both of these metabolites in those destined to develop PET. These data indicate that analysis of urinary metabolites provides an additional insight into vitamin D and the kidney, with lower urinary 25(OH)D3, and 24,25(OH)2D3 excretion being an early indicator of a predisposition towards developing PET.</p
No Difference between the Sexes in Fine-Scale Spatial Genetic Structure of Roe Deer
Background: Data on spatial genetic patterns may provide information about the ecological and behavioural mechanisms underlying population structure. Indeed, social organization and dispersal patterns of species may be reflected by the pattern of genetic structure within a population. [br/]
Methodology/Principal Findings: We investigated the fine-scale spatial genetic structure of a roe deer (Capreolus capreolus) population in Trois-Fontaines (France) using 12 microsatellite loci. The roe deer is weakly polygynous and highly sedentary, and can form matrilineal clans. We show that relatedness among individuals was negatively correlated with geographic distance, indicating that spatially proximate individuals are also genetically close. More unusually for a large mammalian herbivore, the link between relatedness and distance did not differ between the sexes, which is consistent with the lack of sex-biased dispersal and the weakly polygynous mating system of roe deer. [br/]
Conclusions/Significance: Our results contrast with previous reports on highly polygynous species with male-biased dispersal, such as red deer, where local genetic structure was detected in females only. This divergence between species highlights the importance of socio-spatial organization in determining local genetic structure of vertebrate populations
Актуальные вопросы совершенствования медико-психологической помощи детям с пороками грудной клетки
Врожденные деформации грудной клетки в виде воронкообразной и килевидной встречаются более чем у 0,3% населения. Воронкообразная деформация грудной клетки (ВДГК) встречается в 5-7 раз чаще, чем килевидная деформация грудной клетки (КДГК). Общепризнанным методом лечения деформации грудной клетки является исключительно хирургическая коррекция
Vitamin D, the placenta and early pregnancy:effects on trophoblast function
Pregnancy is associated with significant changes in vitamin D metabolism, notably increased maternal serum levels of active vitamin D, 1,25-dihydroxyvitamin (1,25(OH)2D). This appears to be due primarily to increased renal activity of the enzyme 25-hydroxyvitamin D-1α-hydroxylase (CYP27B1) that catalyzes synthesis of 1,25(OH)2D, but CYP27B1 expression is also prominent in both the maternal decidua and fetal trophoblast components of the placenta. The precise function of placental synthesis of 1,25(OH)2D remains unclear, but is likely to involve localised tissue-specific responses with both decidua and trophoblast also expressing the vitamin D receptor (VDR) for 1,25(OH)2D. We have previously described immunomodulatory responses to 1,25(OH)2D by diverse populations of VDR-expressing cells within the decidua. The aim of the current review is to detail the role of vitamin D in pregnancy from a trophoblast perspective, with particular emphasis on the potential role of 1,25(OH)2D as a regulator of trophoblast invasion in early pregnancy. Vitamin D-deficiency is common in pregnant women, and a wide range of studies have linked low vitamin D status to adverse events in pregnancy. To date most of these studies have focused on adverse events later in pregnancy, but the current review will explore the potential impact of vitamin D on early pregnancy, and how this may influence implantation and miscarriage
Differential expression, function and response to inflammatory stimuli of 11β-hydroxysteroid dehydrogenase type 1 in human fibroblasts: a mechanism for tissue-specific regulation of inflammation
Stromal cells such as fibroblasts play an important role in defining tissue-specific responses during the resolution of inflammation. We hypothesized that this involves tissue-specific regulation of glucocorticoids, mediated via differential regulation of the enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1). Expression, activity and function of 11β-HSD1 was assessed in matched fibroblasts derived from various tissues (synovium, bone marrow and skin) obtained from patients with rheumatoid arthritis or osteoarthritis. 11β-HSD1 was expressed in fibroblasts from all tissues but mRNA levels and enzyme activity were higher in synovial fibroblasts (2-fold and 13-fold higher mRNA levels in dermal and synovial fibroblasts, respectively, relative to bone marrow). Expression and activity of the enzyme increased in all fibroblasts following treatment with tumour necrosis factor-α or IL-1β (bone marrow: 8-fold and 37-fold, respectively, compared to vehicle; dermal fibroblasts: 4-fold and 14-fold; synovial fibroblasts: 7-fold and 31-fold; all P < 0.01 compared with vehicle). Treatment with IL-4 or interferon-γ was without effect, and there was no difference in 11β-HSD1 expression between fibroblasts (from any site) obtained from patients with rheumatoid arthritis or osteoarthritis. In the presence of 100 nmol/l cortisone, IL-6 production – a characteristic feature of synovial derived fibroblasts – was significantly reduced in synovial but not dermal or bone marrow fibroblasts. This was prevented by co-treatment with an 11β-HSD inhibitor, emphasizing the potential for autocrine activation of glucocorticoids in synovial fibroblasts. These data indicate that differences in fibroblast-derived glucocorticoid production (via the enzyme 11β-HSD1) between cells from distinct anatomical locations may play a key role in the predeliction of certain tissues to develop persistent inflammation
Automated development of an LC-MS/MS method for measuring multiple vitamin D metabolites using MUSCLE software
This study describes the application of Multi-platform Unbiased optimization of Spectrometry via Closed-Loop Experimentation (MUSCLE) software to automate the development of an LC-MS/MS method to measure multiple metabolites of vitamin D.</p
Vitamin D promotes human extravillous trophoblast invasion in vitro
Introduction
Incomplete human extravillous trophoblast (EVT) invasion of the decidua and maternal spiral arteries is characteristic of pre-eclampsia, a condition linked to low maternal vitamin D status. It is hypothesized that dysregulated vitamin D action in uteroplacental tissues disrupts EVT invasion leading to malplacentation.
Methods
This study assessed the effects of the active vitamin D metabolite, 1,25-dihydroxyvitamin D3 (1,25-D3), and its precursor, 25-hydroxyvitamin D3 (25-D3), on primary human EVT isolated from first trimester pregnancies. Expression of EVT markers (cytokeratin-7, HLA-G), the vitamin D-activating enzyme (CYP27B1) and 1,25-D3 receptor (VDR) was assessed by immunocytochemistry. EVT responses following in vitro treatment with 1,25-D3 (0–10 nM) or 25-D3 (0–100 nM) for 48–60 h were assessed using quantitative RT-PCR (qRT-PCR) analysis of key target genes. Effects on EVT invasion through Matrigel® were quantified alongside zymographic analysis of secreted matrix metalloproteinases (MMPs). Effects on cell viability were assessed by measurement of MTT.
Results
EVT co-expressed mRNA and protein for CYP27B1 and VDR, and demonstrated induction of mRNA encoding vitamin D-responsive genes, 24-hydroxylase (CYP24A1) and cathelicidin following 1,25-D3 treatment. EVT could respond to 1,25-D3 and 25-D3, both of which significantly increased EVT invasion, with maximal effect at 1 nM 1,25-D3 (1.9-fold; p < 0.01) and 100 nM 25-D3 (2.2-fold; p < 0.05) respectively compared with untreated controls. This was accompanied by increased pro-MMP2 and pro-MMP9 secretion. The invasion was independent of cell viability, which remained unchanged.
Discussion
These data support a role for vitamin D in EVT invasion during human placentation and suggest that vitamin D-deficiency may contribute to impaired EVT invasion and pre-eclampsia
Large herbivore migration plasticity along environmental gradients in Europe: life-history traits modulate forage effects
The most common framework under which ungulate migration is studied predicts that it is driven by spatio–temporal variation in plant phenology, yet other hypotheses may explain differences within and between species. To disentangle more complex patterns than those based on single species/ single populations, we quantified migration vari-ability using two sympatric ungulate species differing in their foraging strategy, mating system and physiological constraints due to body size. We related observed variation to a set of hypotheses. We used GPS-collar data from 537 individuals in 10 roe Capreolus capreolus and 12 red deer Cervus elaphus populations spanning environmental gra-dients across Europe to assess variation in migration propensity, distance and tim-ing. Using time-to-event models, we explored how the probability of migration varied in relation to sex, landscape (e.g. topography, forest cover) and temporally-varying environmental factors (e.g. plant green-up, snow cover). Migration propensity varied across study areas. Red deer were, on average, three times more migratory than roe deer (56% versus 18%). This relationship was mainly driven by red deer males which were twice as migratory as females (82% versus 38%). The probability of roe deer migration was similar between sexes. Roe deer (both sexes) migrated earliest in spring. While territorial male roe deer migrated last in autumn, male and female red deer migrated around the same time in autumn, likely due to their polygynous mating system. Plant productivity determined the onset of spring migration in both species, but if plant productivity on winter ranges was sufficiently high, roe deer were less likely to leave. In autumn, migration coincided with reduced plant productivity for both species. This relationship was stronger for red deer. Our results confirm that ungulate migration is influenced by plant phenology, but in a novel way, that these effects appear to be modulated by species-specific traits, especially mating strategies.publishedVersio
Back and forth: day–night alternation between cover types reveals complementary use of habitats in a large herbivore
Context The Complementary Habitat Hypothesis posits that animals access resources for different needs by moving between complementary habitats that can be seen as ‘resource composites’. These movements can occur over a range of temporal scales, from diurnal to seasonal, in response to multiple drivers such as access to food, weather constraints, risk avoidance and human disturbance. Within this framework, we hypothesised that large herbivores cope with human-altered landscapes through the alternate use of complementary habitats at both daily and seasonal scales. Objectives We tested the Complementary Habitat Hypothesis in European roe deer (Capreolus capreolus) by classifying 3900 habitat-annotated movement trajectories of 154 GPS-monitored individuals across contrasting landscapes. Methods We considered day-night alternation between open food-rich and closed refuge habitats as a measure of complementary habitat use. We first identified day–night alternation using the Individual Movement - Sequence Analysis Method, then we modelled the proportion of day–night alternation over the year in relation to population and individual characteristics. Results We found that day-night alternation is a widespread behaviour in roe deer, even across markedly different landscapes. Day–night alternation followed seasonal trends in all populations, partly linked to vegetation phenology. Within populations, seasonal patterns of open/closed habitat alternation differed between male and female adults, but not in juveniles. Conclusion Our results support the Complementary Habitat Hypothesis by showing that roe deer adjust their access to the varied resources available in complex landscapes by including different habitats within their home range, and sequentially alternating between them in response to seasonal changes and individual life history.publishedVersio
- …