Effects of age, BMI and sex on the glial cell marker TSPO - a multicentre [C-11]PBR28 HRRT PET study

Purpose The purpose of this study was to investigate the effects of ageing, sex and body mass index (BMI) on translocator protein (TSPO) availability in healthy subjects using positron emission tomography (PET) and the radioligand [C-11]PBR28. Methods [C-11]PBR28 data from 140 healthy volunteers (72 males and 68 females; N = 78 with HAB and N = 62 MAB genotype; age range 19-80 years; BMI range 17.6-36.9) were acquired with High Resolution Research Tomograph at three centres: Karolinska Institutet (N = 53), Turku PET centre (N = 62) and Yale University PET Center (N = 25). The total volume of distribution (V-T) was estimated in global grey matter, frontal, temporal, occipital and parietal cortices, hippocampus and thalamus using multilinear analysis 1. The effects of age, BMI and sex on TSPO availability were investigated using linear mixed effects model, with TSPO genotype and PET centre specified as random intercepts. Results There were significant positive correlations between age and V-T in the frontal and temporal cortex. BMI showed a significant negative correlation with V-T in all regions. Additionally, significant differences between males and females were observed in all regions, with females showing higher V-T. A subgroup analysis revealed a positive correlation between V-T and age in all regions in male subjects, whereas age showed no effect on TSPO levels in female subjects. Conclusion These findings provide evidence that individual biological properties may contribute significantly to the high variation shown in TSPO binding estimates, and suggest that age, BMI and sex can be confounding factors in clinical studies

Paradox of the institution: findings from a hospital labour ward ethnography

BackgroundInterest in the influence of culture on birth practices is on the rise, and with it comes a sense of urgency to implement practices that aid the normalisation and humanisation of birth. This groundswell is occurring despite a broader cultural milieu of escalating technology-use and medicalisation of birth across the globe. Against this background, rates of epidural analgesia use by women in labour are increasing, despite the risk of side effects. Socio-cultural norms and beliefs are likely to influence pain relief choices but there is currently scant research on this topic.MethodsThis study was undertaken to gain insight into the personal, social, cultural and institutional influences on women in deciding whether or not to use epidural analgesia in labour. The study had an ethnographic approach within a theoretical framework of Critical Medical Anthropology (CMA), Foucauldian and feminist theory. Given the nature of ethnographic research, it was assumed that using the subject of epidural analgesia to gain insight into Western birth practices could illuminate broader cultural ideals and that the epidural itself may not remain the focus of the research.ResultsFindings from the study showed how institutional surveillance, symbolised by the Journey Board led to an institutional momentum that in its attempt to keep women safe actually introduced new areas of risk, a situation which we named the Paradox of the institution.ConclusionsThese findings, showing a risk/safety paradox at the centre of institutionalised birth, add a qualitative dimension to the growing number of quantitative studies asserting that acute medical settings can be detrimental to normal birth practices and outcomes

Modeling soil processes: Review, key challenges, and new perspectives

The remarkable complexity of soil and its importance to a wide range of ecosystem services presents major challenges to the modeling of soil processes. Although major progress in soil models has occurred in the last decades, models of soil processes remain disjointed between disciplines or ecosystem services, with considerable uncertainty remaining in the quality of predictions and several challenges that remain yet to be addressed. First, there is a need to improve exchange of knowledge and experience among the different disciplines in soil science and to reach out to other Earth science communities. Second, the community needs to develop a new generation of soil models based on a systemic approach comprising relevant physical, chemical, and biological processes to address critical knowledge gaps in our understanding of soil processes and their interactions. Overcoming these challenges will facilitate exchanges between soil modeling and climate, plant, and social science modeling communities. It will allow us to contribute to preserve and improve our assessment of ecosystem services and advance our understanding of climate-change feedback mechanisms, among others, thereby facilitating and strengthening communication among scientific disciplines and society. We review the role of modeling soil processes in quantifying key soil processes that shape ecosystem services, with a focus on provisioning and regulating services. We then identify key challenges in modeling soil processes, including the systematic incorporation of heterogeneity and uncertainty, the integration of data and models, and strategies for effective integration of knowledge on physical, chemical, and biological soil processes. We discuss how the soil modeling community could best interface with modern modeling activities in other disciplines, such as climate, ecology, and plant research, and how to weave novel observation and measurement techniques into soil models. We propose the establishment of an international soil modeling consortium to coherently advance soil modeling activities and foster communication with other Earth science disciplines. Such a consortium should promote soil modeling platforms and data repository for model development, calibration and intercomparison essential for addressing contemporary challenges