357 research outputs found
Differential expression of placental glucocorticoid receptors and growth arrest-specific transcript 5 in term and preterm pregnancies: evidence for involvement of maternal stress.
This article has been made available through the Brunel Open Access Publishing Fund.Pregnancy-specific stress predicts birth outcomes. We hypothesized that there is a maternal stress-GR interaction that can influence fetal birth weight. This study examined the relationship between mothers' stress and attitude towards their pregnancies, placental glucocorticoid receptors (GRs) and growth arrest-specific transcript 5 (GAS5) expression, and the status of GR polymorphism, with their infants' birth weights. GAS5 and GR α were the predominant transcripts in both term and preterm placentas, with GAS5 being primarily localized in the syncytiotrophoblasts. In an attempt to mimic moderate and high stress environment in vitro, BeWo and JEG-3 cytotrophoblast cell lines were treated with 10ânM-1000ânM cortisol. Only expression of GAS5 was significantly upregulated by cortisol in all treatments compared with basal levels, but none of the GRs changed expression significantly. In an attempt to assess a stress versus gene interaction, we studied four GR polymorphisms. In the homozygous group for Tth111I polymorphism, mothers with negative attitudes towards the pregnancy gave birth to infants with significantly lower birth weights compared to women with positive/neutral attitudes. None of the GR splice variants were associated with maternal stress. However, placental GAS5 levels were inversely correlated with maternal stress. This study points towards a potential gene-environment interaction that could be of predictive value for fetal weight.Brunel Open Access Publishing Fun
3D microstructure of magnesium potassium phosphate ceramics from X-ray tomography: new insights into the reaction mechanisms
Magnesium potassium phosphate ceramics are chemically bonded ceramics employed as biomaterials, in nuclear waste encapsulation and for concrete repair. The microstructure dictates material performance and depends on the raw mix composition. Synchrotron X-ray computed microtomography was employed to describe the 3D microstructure and its time evolution during hardening and gain insights into the reaction mechanisms. Any excess water with respect to the stoichiometry of the reaction brought about an increase in porosity, but, notably, a reduction in the average pore size. Crystals filled the water âpocketsâ in the ceramic volume by growing larger, although less densely packed, increasing the complexity of the pore shape. Platelet over elongated crystal habit was favoured. Such a change in shape is likely related to a change in reaction mechanism, as crystallization from a gel-like amorphous precursor is hindered and progressively substituted by a through-solution mechanism. It is proposed that the time evolution of the microstructure is dictated by the balance between crystallization from amorphous precursor, prevailing in relatively âdenseâ systems (with stoichiometric water or in low excess), and water segregation, prevailing at higher water contents. The former mechanism was shown to produce an increase in porosity with time, because of the density mismatch between the amorphous and the crystalline phase
Risk of miscarriage following amniocentesis or chorionic villus sampling: systematic review of literature and updated meta-analysis
Objectives: To estimate the procedure-related risks of miscarriage after amniocentesis and trans-abdominal chorionic villus sampling (CVS) based on a systematic review of the literature and an updated meta-analysis.
Methods: A search of MEDLINE, EMBASE, and The Cochrane Library was carried out to identify studies reporting complications following CVS or amniocentesis. The inclusion criteria for the systematic review were studies reporting results from large controlled studies and those reporting data for pregnancy loss prior to 24 weeksâ gestation. Study authors were contacted when required to identify additional necessary data. Data for cases that had invasive procedure and controls groups were inputted in contingency tables and risk of miscarriage was estimated for each study. Summary statistics based on a fixed and random effects model were calculated after taking into account the weighting for each study included in the systematic review. Procedure-related risk of miscarriage was estimated as a weighted risk difference from the summary statistics for cases and controls. A subgroup analyses according to the similarity risk levels in the invasive testing and control groups was performed. Heterogeneity was assessed using Cochraneâs Q and I2 statistic. Egger Bias was estimated to assess reporting bias in published studies. Summary statistics for procedure-related risk of miscarriage were graphically represented in Forest plots.
Results: The electronic search from the databases yielded 2,943 potential citations, from which, we selected 20 controlled studies for inclusion in the systematic review to estimate the procedure-related risk of miscarriage from invasive procedures. There were a total of 580 miscarriages from 63,273 amniocentesis procedures with a weighted risk of pregnancy loss of 0.91% (95%CI: 0.73 to 1.09). In the control group, there were 1,726 miscarriages in 330,469 pregnancies with a loss rate of 0.58% (95CI%: 0.47 to 0.70). The weighted procedure-related risk of miscarriage was 0.30% (95%CI: 0.11 to 0.49, I2=70.1%). There were a total of 163 miscarriages from 13,011 CVS procedures with a risk of pregnancy loss of 1.39% (95%CI: 0.76 to 2.02). In the control group, there were 1,946 miscarriages in 232,680 pregnancies with a loss rate of 1.23% (95CI%: 0.86 to 1.59). The weighted procedure-related risk of miscarriage following CVS was 0.20% (95%CI: -0.12 to 0.52, I2=51.9%). However, when only studies with similar risk profiles between the intervention and control groups were considered, the procedure related risk for amniocentesis became 0.03% (95%CI -0.08 to 0.14, I2=0%) and for CVS -0.38 (95% CI -1.12 to 0.36, I2=0%).
Conclusion: The procedure-related risks of miscarriage following amniocentesis and CVS are lower than currently quoted to women. The risk appears to be negligible when these interventions are compared to control groups of the same risk profile
The preferences of participants in small-scale sport events: A conjoint analysis case study from Taiwan
The primary objective of this study was an investigation of participants\u27 preferences for a cycling orientated sport tourism event using conjoint analysis. Respondents in a survey were presented with a range of different event alternatives related to the characteristics of proposed small-scale cycling events to draw out useful conclusions about the ideal scenario of such a sporting event that would be the most attractive and desirable for those who compete. A questionnaire, in two parts, was developed and distributed to 195 bicyclers during an event in Kaohsiung, Taiwan and the data was analysed using SPSS Conjoint at the aggregate level (pooled data). Based on the preferences expressed by the athletes the three most important factors were: "preferred season to organizing the event", "parallel organised trade shows & exhibitions" and "entertainment & awards". The findings of this study provide event coordinators and sport marketers with practical insights into event planning and possibility of development of effective marketing strategies designed to reach and attract more participants to these types of activities. This investigation is unique since is one of the first to use a full design of seven parameters in the conjoint analysis model to comprehensively examine athlete\u27s preferences
- âŠ