Background
Preeclampsia is thought to originate during placentation, with incomplete remodelling and perfusion of the spiral arteries leading to reduced placental vascular capacity. Nitric oxide (NO) ...and carbon monoxide (CO) are powerful vasodilators that play a role in the placental vascular system. Although family clustering of preeclampsia has been observed, the existing genetic literature is limited by a failure to consider both mother and child.
Methods
We conducted a nested case–control study within the Norwegian Mother and Child Birth Cohort of 1545 case‐pairs and 995 control‐pairs from 2540 validated dyads (2011 complete pairs, 529 missing mother or child genotype). We selected 1518 single‐nucleotide polymorphisms (SNPs) with minor allele frequency >5% in NO and CO signalling pathways. We used log‐linear Poisson regression models and likelihood ratio tests to assess maternal and child effects.
Results
One SNP met criteria for a false discovery rate Q‐value <0.05. The child variant, rs12547243 in adenylate cyclase 8 (ADCY8), was associated with an increased risk (relative risk RR 1.42, 95% confidence interval CI 1.20, 1.69 for AG vs. GG, RR 2.14, 95% CI 1.47, 3.11 for AA vs. GG, Q = 0.03). The maternal variant, rs30593 in PDE1C was associated with a decreased risk for the subtype of preeclampsia accompanied by early delivery (RR 0.45, 95% CI 0.27, 0.75 for TC vs. CC; Q = 0.02). None of the associations were replicated after correction for multiple testing.
Conclusions
This study uses a novel approach to disentangle maternal and child genotypic effects of NO and CO signalling genes on preeclampsia.
Background/Aims: Maternal and offspring cell contact at the site of placentation presents a plausible setting for maternal-fetal genotype (MFG) interactions affecting fetal growth. We test hypotheses ...regarding killer cell immunoglobulin-like receptor (KIR) and HLA-C MFG effects on human birth weight by extending the quantitative MFG (QMFG) test. Methods: Until recently, association testing for MFG interactions had limited applications. To improve the ability to test for these interactions, we developed the extended QMFG test, a linear mixed-effect model that can use multi-locus genotype data from families. Results: We demonstrate the extended QMFG test's statistical properties. We also show that if an offspring-only model is fit when MFG effects exist, associations can be missed or misattributed. Furthermore, imprecisely modeling the effects of both KIR and HLA-C could result in a failure to replicate if these loci's allele frequencies differ among populations. To further illustrate the extended QMFG test's advantages, we apply the extended QMFG test to a UK cohort study and the Norwegian Mother and Child Cohort (MoBa) study. Conclusion: We find a significant KIR-HLA-C interaction effect on birth weight. More generally, the QMFG test can detect genetic associations that may be missed by standard genome-wide association studies for quantitative traits.
There has been a thrilling development, as well as profound changes, in our understanding of the effect of fetal nutrition on the development and health of the child. The Norwegian Mother and Child ...Cohort Study (MoBa) is an ongoing nationwide population-based pregnancy cohort study that between 1999 and 2008 recruited 90,723 women with 106,981 pregnancies and 108,487 children. The objective of MoBa is to test specific etiologic hypotheses by estimating the association between exposures and diseases with a special focus on disorders that may originate in early life. An important aspect in this regard is maternal diet and nutritional status during pregnancy. Nutritional factors have long been considered to be important determinants of maternal and fetal health, and dietary information is currently being collected in a number of pregnancy cohorts in Europe and the United States. Thus far, pregnancy complications studied in MoBa are preterm birth, preeclampsia, and fetal growth; and the aim of this article is to report results of recently published studies of dietary factors in relation to these outcomes. Numerous studies are planned using MoBa data, and the aim is to add to the knowledge of the interplay between dietary factors, nonnutrients, and toxic dietary substances and epigenetic modulation on fetal development and health later in life. Am J Clin Nutr 2011;94(suppl):1970S–4S.
Scope
Birth cohorts typically measure plasma folate in midgestation, but effects of folic acid supplementation are sometimes specific to the periconceptional period. The relationship between ...midgestation plasma folate and periconceptional supplementation is not known. We compared plasma folate at week 18 of gestation with self‐report use of supplements comtaining folic acid from before pregnancy to week 17 of gestation.
Methods and Results
The sample comprised 2911 women from The Norwegian Mother and Child Cohort Study. For women reporting continuous supplementation from gestational week −4 to 17 (N = 238), median plasma folate was 15.72 at week 18 (in nmol/L). This was about threefold higher than the median plasma folate of 5.67 for women reporting no supplementation from week −4 to 17 (N = 844), but only slightly higher than the median plasma folate of 13.34 for all women reporting supplementation in weeks 13–17 (N = 1158). Reported supplementation before week 8 was not associated with plasma folate at week 18, in an analysis that adjusted for continued supplementation after week 8.
Conclusion
Overall we found a strong and coherent relationship between self‐reported folic acid use and plasma folate at week 18. We also found that plasma folate at week 18 did not reflect self‐reported supplementation before week 8. For periconceptional supplementation per se, self‐report data may offer a better measure.
Aims: To describe the prevalence of consanguinity among Norwegian Pakistani parents in the period from 1995 to 2005. Methods: All first births to women of Pakistani origin in 1995-2005 (n = 1962) ...were identified by linking the Medical Birth Registry of Norway with information on country of origin and country of birth from Statistics Norway. Prevalence ratios (PRs) and prevalence differences were calculated by multiple binomial regression analyses with adjustment for maternal age and education. Women born in Pakistan who gave birth in Norway in 1995-97 formed the reference group. Results: The proportion of women who were consanguineously related to their co-parent decreased from 45.5% in 1995-97 to 27.3% in 2002-2005 among those who were born in Pakistan, and from 48.3% to 18.8% among women of Pakistani origin who were born in Norway. The proportion of women who were related to their co-parent as first cousin decreased from 37.7% to 24.7% among women born in Pakistan, and from 43.3% to 16.7% among women of Pakistani origin who were born in Norway. The proportion of births to women with an unrelated co-parent increased by 25% for women born in Pakistan (PR= 1.25, 95% confidence interval (CI) = 1.12-1.39), and by 53% for women of Pakistani origin born in Norway (PR=1.53, 95% CI= 1.35-1.74). Conclusions: In contrast to previous reports from the UK, our analysis suggests that there is a decrease in the proportion of consanguineously related parents of children born to women of Pakistani origin in Norway.
We show by in situ microscopy that the effects of electron beam irradiation during transmission electron microscopy can be used to lock microstructural features and enhance the structural thermal ...stability of a nanostructured polymer:fullerene blend. Polymer:fullerene bulk-heterojunction thin films show great promise for use as active layers in organic solar cells but their low thermal stability is a hindrance. Lack of thermal stability complicates manufacturing and influences the lifetime of devices. To investigate how electron irradiation affects the thermal stability of polymer:fullerene films, a model bulk-heterojunction film based on a thiophene-quinoxaline copolymer and a fullerene derivative was heat-treated in-situ in a transmission electron microscope. In areas of the film that exposed to the electron beam the nanostructure of the film remained stable, while the nanostructure in areas not exposed to the electron beam underwent large phase separation and nucleation of fullerene crystals. UV–vis spectroscopy shows that the polymer:fullerene films are stable for electron doses up to 2000kGy.
•Thermal stability of a polymer: fullerne blend is increased using electron irradiation.•Using in-situ transmission electron microscopy the nanostructure is studied.•Electron irradiation stops phase separation between the polymer and fullerene.•Electron irradiation quenches the formation and nucleation of fullerene crystals.
To increase knowledge of health services utilization and related factors in adult acquired major upper-limb amputees.
Population-based cross-sectional study conducted in Norway.
Two hundred and ...twenty four adult acquired major upper-limb amputees (57.4% response rate). Mean age was 53.7 years, 83.5% were men and mean post-amputation time was 24.0 years.
Data were collected by postal questionnaires. Amputation-related health services utilization, perceived benefit and unmet needs were reported and associations between these factors and background factors were estimated by multivariate logistic regression analyses.
Reported health services utilization was relatively low. The reported benefit of utilized services was generally high. For several non-utilized services, considerable unmet needs for utilization were reported. Several background factors were significantly associated with different aspects of the services examined. A considerable discrepancy between reported pain and utilization of specified pain treatments was noted.
The findings of this study suggest that several health services available to acquired major upper-limb amputees should be strengthened. Establishing routines to ensure access to optimal, individualized rehabilitation may prevent disability. We recommend additional, longitudinal studies to further assess the need for mental health care and pain treatment in acquired major upper-limb amputees.
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