[11C]PBR28 binds the 18-kDa Translocator Protein (TSPO) and is used in positron emission tomography (PET) to detect microglial activation. However, quantitative interpretations of signal are confounded by large interindividual variability in binding affinity, which displays a trimodal distribution compatible with a codominant genetic trait. Here, we tested directly for an underlying genetic mechanism to explain this. Binding affinity of PBR28 was measured in platelets isolated from 41 human subjects and tested for association with polymorphisms in TSPO and genes encoding other proteins in the TSPO complex. Complete agreement was observed between the TSPO Ala147Thr genotype and PBR28 binding affinity phenotype (P value=3.1 × 10−13). The TSPO Ala147Thr polymorphism predicts PBR28 binding affinity in human platelets. As all second-generation TSPO PET radioligands tested hitherto display a trimodal distribution in binding affinity analogous to PBR28, testing for this polymorphism may allow quantitative interpretation of TSPO PET studies with these radioligands.

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Oxytocin appears to be of crucial importance for understanding mother-infant relationships. The findings of this review suggest that the pioneering, but preliminary, research undertaken to date is promising and that replication with larger samples is needed. Research that draws on more robust measures of attachment and bonding, as well as improved measures of oxytocin that include both central and peripheral levels, will elucidate the role of oxytocin in human mother-infant relationships. As the production of oxytocin is by no means restricted to mothers, the extension of the oxytocin studies to fathering, as well as to alloparental caregiving, would be an intriguing next step.

Classically, late transition-metal organometallic compounds promote multielectron processes solely through the change in oxidation state of the metal centre. In contrast, uranium typically undergoes single-electron chemistry. However, using redox-active ligands can engage multielectron reactivity at this metal in analogy to transition metals. Here we show that a redox-flexible pyridine(diimine) ligand can stabilize a series of highly reduced uranium coordination complexes by storing one, two or three electrons in the ligand. These species reduce organoazides easily to form uranium-nitrogen multiple bonds with the release of dinitrogen. The extent of ligand reduction dictates the formation of uranium mono-, bis- and tris(imido) products. Spectroscopic and structural characterization of these compounds supports the idea that electrons are stored in the ligand framework and used in subsequent reactivity. Computational analyses of the uranium imido products probed their molecular and electronic structures, which facilitated a comparison between the bonding in the tris(imido) structure and its tris(oxo) analogue.

BackgroundPerinatal depression has a significant impact on both mother and child. However, the influence of hormonal changes during pregnancy and the postpartum period remains unclear. This article provides a systematic review of studies examining the effects of maternal cortisol function on perinatal depression.MethodA systematic search was conducted of six electronic databases for published research on the relationship between cortisol and perinatal depression. The databases included; MEDLINE complete, PsychINFO, SCOPUS, Psychology and Behavioural Sciences, Science Direct and EBSCO, for the years 1960 to May 2015. Risk of bias was assessed and data extraction verified by two investigators.ResultsIn total, 47 studies met criteria and studies showed considerable variation in terms of methodology including sample size, cortisol assays, cortisol substrates, sampling processes and outcome measures. Those studies identified as higher quality found that the cortisol awakening response is positively associated with momentary mood states but is blunted in cases of major maternal depression. Furthermore, results indicate that hypercortisolemia is linked to transient depressive states while hypocortisolemia is related to chronic postpartum depression.Discussion and ConclusionFuture research should aim to improve the accuracy of cortisol measurement over time, obtain multiple cortisol samples in a day and utilise diagnostic measures of depression. Future studies should also consider both antenatal and postnatal depression and the differential impact of atypical versus melancholic depression on cortisol levels, as this can help to further clarify the relationship between perinatal depression and maternal cortisol function across pregnancy and the postpartum period.Electronic supplementary materialThe online version of this article (doi:10.1186/s12884-016-0915-y) contains supplementary material, which is available to authorized users.

Background: With depression predicted to contribute to an increased disease burden in coming decades, prevention efforts have become increasingly important. In order to prevent depression it is valuable to identify and classify longitudinal patterns of depressive symptoms across development, ideally beginning early in childhood. To achieve this, longitudinal studies are increasingly using person-centered data-analytic methods to model subgroups with similar developmental patterns (trajectories) of depressive symptoms. Method: A search was completed for English language studies that longitudinally modeled depressive symptom trajectories in nonclinical populations with a baseline age of <19 years. Study characteristics were extracted, prevalence rates and risk factors were summarized, a random-effect meta-analysis was undertaken, and risk of bias analysis completed. Results: Twenty studies published between 2002 and 2015 were included. Participants were recruited at ages 4 through 17 (average age 12.34) and followed longitudinally for an average of 7.45 years. Between 3 and 11 trajectory subgroups were identified. A random pooled effect estimate identified 56% [95% Confidence Interval (CI) 46-65%] of the sampled study populations (N = 41,236) on 'No or low' depressive symptom trajectories and 26% (CI 14-40%) on a 'Moderate' trajectory. 'High', 'Increasing', and 'Decreasing' depressive symptom subgroups were evident for 12% (CI 8-17%). Moderate symptoms were associated with poorer adjustment and outcomes relative to low symptom groups. 'High' or 'Increasing' trajectories were predominantly predicted by: female gender, low socioeconomic status, higher stress reactivity; conduct issues; substance misuse, and problems in peer and parental relationships. Conclusions: The review highlighted consistent evidence of subgroups of children and adolescents who differ in their depressive symptom development over time. The findings suggest preventative interventions should evaluate the longer term benefits of increasing membership in low and moderate trajectories, while also targeting reductions in high-risk subgroups. Considerable between-study method and measurement variation indicate the need for future trajectory studies to use standardized methods. Key Practitioner Message• The review is the first to systematically summarize longitudinal studies of child and adolescent depressive symptoms that use new analytical approaches to identify subgroups of individuals that follow heterogeneous trajectories over time.• We found consistent evidence of subgroups of children and adolescents that differ in depressive symptom development over time and significant variation in trajectory group size.• Future studies should investigate whether children and adolescents with low trajectories show better longterm social adjustment and mental health relative to other subgroups.• The review identified the risk factors of female gender, socioeconomic status, stressful life events, conduct issues, substance use, and problems with parents and peers ...

Physical activity (PA) and cardiorespiratory fitness (CRF) are associated with better cognitive function in late life, but the neural correlates for these relationships are unclear. To study these correlates, we examined the association of both PA and CRF with measures of white matter (WM) integrity in 88 healthy low-fit adults (age 60–78). Using accelerometry, we objectively measured sedentary behavior, light PA, and moderate to vigorous PA (MV-PA) over a week. We showed that greater MV-PA was related to lower volume of WM lesions. The association between PA and WM microstructural integrity (measured with diffusion tensor imaging) was region-specific: light PA was related to temporal WM, while sedentary behavior was associated with lower integrity in the parahippocampal WM. Our findings highlight that engaging in PA of various intensity in parallel with avoiding sedentariness are important in maintaining WM health in older age, supporting public health recommendations that emphasize the importance of active lifestyle.

The current paper provides background to the development of the Multidimensional Inventory for Religious/Spiritual Well-being and then summarises findings derived from its use with other measures of health and personality. There is substantial evidence for religiosity/spirituality being positively related to a variety of indicators of mental health, including subjective well-being and personality dimensions. Furthermore, religiosity/spirituality can play an important role in the process of recovering from mental illness as well as providing a protective function against addictive or suicidal behaviours. However, further research is needed to examine the mechanisms through which religiosity/spirituality have an impact on health-related conditions.