65 research outputs found
Circulating antimullerian hormone and steroid hormone levels remain high in pregnant women with polycystic ovary syndrome at term
Objective: To investigate plasma antimullerian hormone (AMH) concentration and its relation to steroid hormone levels in pregnant women with polycystic ovary syndrome (PCOS) and controls at term. Design: Case-control study. Setting: University-affiliated hospital. Patient(s): A total of 74 pregnant women at term: 25 women with PCOS (aged 31.6 +/- 3.9 years [mean +/- standard deviation], body mass index 24.0 +/- 3.9 kg/m2, mean gestational length 279 +/- 9 days) and 49 controls (aged 31.7 +/- 3.3 years, body mass index 24.0 +/- 3.3 kg/m2, mean gestational length 281 +/- 9 days). Intervention(s): None. Main Outcome Measure(s): Plasma AMH and steroid hormone levels. Result(s): Antimullerian hormone, T, and androstenedione levels were higher in women with PCOS at term compared with controls, whereas estrogen and P levels were similar. The differences were pronounced in women carrying a female fetus. Testosterone and AMH levels correlated positively in both groups, but E2 levels only in women with PCOS. Conclusion(s): Pregnant women with PCOS present with elevated AMH and androgen levels even at term, suggesting a hormonal imbalance during PCOS pregnancy. Differences were detected especially in pregnancies with a female fetus, raising the question of whether female pregnancies are more susceptible to AMH and steroid hormone actions. (C) Copyright (C) 2018 The Authors. Published by Elsevier Inc. on behalf of the American Society for Reproductive Medicine. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Peer reviewe
Evolutionary History of Endogenous Human Herpesvirus 6 Reflects Human Migration out of Africa.
Human herpesvirus 6A and 6B (HHV-6) can integrate into the germline, and as a result, ∼70 million people harbor the genome of one of these viruses in every cell of their body. Until now, it has been largely unknown if 1) these integrations are ancient, 2) if they still occur, and 3) whether circulating virus strains differ from integrated ones. Here, we used next-generation sequencing and mining of public human genome data sets to generate the largest and most diverse collection of circulating and integrated HHV-6 genomes studied to date. In genomes of geographically dispersed, only distantly related people, we identified clades of integrated viruses that originated from a single ancestral event, confirming this with fluorescent in situ hybridization to directly observe the integration locus. In contrast to HHV-6B, circulating and integrated HHV-6A sequences form distinct clades, arguing against ongoing integration of circulating HHV-6A or "reactivation" of integrated HHV-6A. Taken together, our study provides the first comprehensive picture of the evolution of HHV-6, and reveals that integration of heritable HHV-6 has occurred since the time of, if not before, human migrations out of Africa
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Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation
Regulation of Nutrient Transport across the Placenta
Abnormal fetal growth, both growth restriction and overgrowth, is associated with perinatal complications and an increased risk of metabolic and cardiovascular disease later in life. Fetal growth is dependent on nutrient availability, which in turn is related to the capacity of the placenta to transport these nutrients. The activity of a range of nutrient transporters has been reported to be decreased in placentas of growth restricted fetuses, whereas at least some studies indicate that placental nutrient transport is upregulated in fetal overgrowth. These findings suggest that changes in placental nutrient transport may directly contribute to the development of abnormal fetal growth. Detailed information on the mechanisms by which placental nutrient transporters are regulated will therefore help us to better understand how important pregnancy complications develop and may provide a foundation for designing novel intervention strategies. In this paper we will focus on recent studies of regulatory mechanisms that modulate placental transport of amino acids, fatty acids, and glucose
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The pregnancy outcome prediction (POP) study: Investigating the relationship between serial prenatal ultrasonography, biomarkers, placental phenotype and adverse pregnancy outcomes
Placental dysfunction is implicated in many major complications of pregnancy associated with adverse maternal and infant outcome, such as preeclampsia, fetal growth restriction and stillbirth. Yet, despite years of intensive research, screening for these complications is still largely based upon clinical grounds rather than ultrasonic and/or biochemical assessment of placental function. One of the few widely employed methods for assessment of risk, low first trimester levels of PAPP-A (Pregnancy Associated Plasma Protein A), was identified through secondary analysis of data collected to identify new methods of screening for Down's syndrome rather than as a purposeful search for screening tests for abnormal placentation. Development of improved methods for population screening requires better mechanistic understanding of the pathways leading to placentally-related complications of human pregnancy. This is in addition to a need for identification of biomarkers which reflect the underlying pathology, while predicting associated disease with high sensitivity and specificity. In this paper, we outline some of the challenges and opportunities in this area. Furthermore, we illustrate how some of these can be addressed in research studies using the example of the Pregnancy Outcome Prediction (POP) study, a prospective cohort study conducted in Cambridge, UK.This study was funded by the NIHR Cambridge Comprehensive Biomedical Research Centre [grant number A019057], the Medical Research Council [grant number MR/K021133/1] and the Stillbirth and Neonatal Death Society (SANDS)
Cytokines and lipids in pregnancy – effects on developmental programming and placental nutrient transfer
Metabolic disturbances, in particular those associated with nutritional challenges, that take place during development, both in utero and early postnatal life, have long-lasting health consequences on an individual. The most pronounced evidence of these challenges is a deviation in birth weight. This is a process recognized as developmental programming of adult health and disease. The etiologies of metabolic health disorders such as insulin resistance and obesity are complex; and developmental programming may be a factor contributing to the increased worldwide prevalence. Women who are overweight or diabetic have a higher risk for delivering large infants, and such infants are themselves at an increased risk of developing metabolic disturbances. Fetal growth is intimately linked to placental nutrient transport capacity. We hypothesized that the altered nutritional, hormonal, and metabolic environment of overweight or diabetic women (hyperlipidemia, pro-inflammatory status) modifies placental nutrient transport and contributes to altering the adult phenotype of these children. The aim of this thesis was to investigate the importance of maternal interleukin-6 during development for offspring adiposity and insulin sensitivity at an adult age in mice, examine the effects of cytokines and lipids on human placental nutrient transport functions and to describe mechanisms underlying these changes.
The main findings of this thesis were:
Interleukin-6 deficient mice weighed more and had a more pronounced adiposity which developed at a younger age if born of interleukin-6 deficient dams compared to dams with a heterozygote interleukin-6 genotype. At an older age (6 to 7 months of age) both groups had enlarged adipocytes and reduced insulin sensitivity. Wild-type mice fostered by interleukin-6 deficient dams also weighed more, had an augmented adiposity and larger adipocytes, and higher systemic leptin levels at an adult age compared to wild-type mice fostered by wild-type dams. Milk from interleukin-6 deficient dams contained twofold higher leptin concentrations compared to milk from wild-type dams. These observations suggest that lack of maternal interleukin-6 or, alternatively, factors modified by this cytokine have developmental programming effects that contribute to the development of adipose tissue and obesity.
Using primary cell cultures of human trophoblast cells, we demonstrated the production site of placental lipoprotein lipase to be cytotrophoblast cells and syncytiotrophoblast. We also observed that elevated levels of free fatty acids and triglycerides reduce trophoblast lipoprotein lipase activity; while insulin, interleukin-6, and tumor necrosis factor-α had no regulatory effect on lipoprotein lipase. Interleukin-6 did however increase placental lipid accumulation. Free fatty acids changed the release of cytokines from trophoblast cells and stimulated amino acid uptake through the System A transporter. Using RNA interference techniques, we demonstrated that toll-like receptor 4 is required for fatty acids to stimulate placental amino acid uptake.
In summary, we found that an altered maternal hormonal or metabolic environment can affect the developing fetus, causing long-term programming effects on adult phenotype. The effects of cytokines on placental lipid transport were moderate; however, there was a pronounced effect of fatty acids upon amino acid uptake. Therefore maternal circulating factors known to be altered in obesity may augment placental nutrient transport and contribute to an accelerated fetal growth
Alcohol exposure prior to pregnancy-does hazardous consumption affect placenta- and inflammatory-mediated pregnancy outcomes? A Swedish population-based cohort study
INTRODUCTION: Alcohol consumption during pregnancy is related to severe birth complications such as low birthweight, preterm birth and birth defects. During the last decade, the Alcohol Use Disorders Identification Test (AUDIT) has been used as a screening tool in Swedish maternal healthcare units to identify hazardous, pre-pregnancy alcohol use. However, evaluation of the screening with AUDIT, as well as adverse maternal or neonatal outcomes, has not been assessed at a national level. MATERIAL AND METHODS: This was a population-based cohort study of 530 458 births from 2013 to 2018 using demographic, reproductive and maternal health data from the Swedish Pregnancy Register. Self-reported alcohol consumption in the year before pregnancy, measured as AUDIT scores, was categorized into moderate (6-13 points) and high-risk (14-40 points) consumption, with low-risk (0-5 points) consumption as the reference group. Associations with pregnancy- and birth outcomes were explored with logistic regressions using generalized estimating equation models, adjusting for maternal and socioeconomic characteristics. Estimates are presented as adjusted odds ratios (aORs) with 95% confidence intervals (CIs). RESULTS: High-risk and moderate pre-pregnancy alcohol consumption was associated with preeclampsia, preterm birth and birth of an infant small for gestational age (SGA), but these associations were nonsignificant after adjustments. Prior moderate-risk (aOR 1.29, 95% CI 1.17-1.42) and high-risk consumption (aOR 1.62, 95% CI 1.17-2.25) increased the likelihood of intrapartum and neonatal infections. CONCLUSIONS: Apart from identifying hazardous alcohol consumption prior to pregnancy and the offer of counseling, screening with the AUDIT in early pregnancy indicates a high risk of inflammatory-/placenta-mediated pregnancy and birth outcomes. For most outcomes, AUDIT was not an independent contributor when adjusting for confounding factors. Hazardous alcohol use prior to pregnancy was independently linked to intrapartum and neonatal infections; conditions associated with morbidity and long-term sequalae. These associations may be explained by alcohol-induced changes in the maternal or fetal immune system in early pregnancy or persistent alcohol intake during pregnancy, or may depend on unidentified confounding factors
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Detecting eukaryotic microbiota with single-cell sensitivity in human tissue.
BACKGROUND: Fetal growth restriction, pre-eclampsia, and pre-term birth are major adverse pregnancy outcomes. These complications are considerable contributors to fetal/maternal morbidity and mortality worldwide. A significant proportion of these cases are thought to be due to dysfunction of the placenta. However, the underlying mechanisms of placental dysfunction are unclear. The aim of the present study was to investigate whether adverse pregnancy outcomes are associated with evidence of placental eukaryotic infection. RESULTS: We modified the 18S Illumina Amplicon Protocol of the Earth Microbiome Project and made it capable of detecting just a single spiked-in genome copy of Plasmodium falciparum, Saccharomyces cerevisiae, or Toxoplasma gondii among more than 70,000 human cells. Using this method, we were unable to detect eukaryotic pathogens in placental biopsies in instances of adverse pregnancy outcome (n = 199) or in healthy controls (n = 99). CONCLUSIONS: Eukaryotic infection of the placenta is not an underlying cause of the aforementioned pregnancy complications. Possible clinical applications for this non-targeted, yet extremely sensitive, eukaryotic screening method are manifest.National Institute for Health Research (NIHR) Cambridge Biomedical Research Centre (Women’s Health theme)
Wellcome Trust Sanger Institut
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