Detection of iso‐α‐acids to confirm beer consumption in postmortem specimens

Iso‐α‐acids (IAAs) can be used as markers for the consumption of beer. Postmortem specimens from a range of coronial cases were analyzed for IAAs in order to determine the prevalence of beer consumption and any correlation to blood alcohol concentrations (BAC). A total of 130 cases were included in this study including those where beer was mentioned in the case circumstances, cases where beer was not mentioned specifically but alcohol was detected, and cases where neither beer was mentioned nor a positive BAC was present. Available blood, serum, vitreous humour and urine specimens were analyzed. Of the 50 cases where beer was mentioned, 86% had one or more IAAs detected. In cases that only had a positive BAC (n = 60), 57% of these cases also showed the presence of these beer markers. IAAs were detected in specimens obtained from traumatized, burnt, and decomposed cases with a mention of beer consumption or where BAC was positive in blood. No IAAs were detected in cases where BAC was negative. There was little or no correlation between blood IAA concentrations and BAC. This study demonstrates the possible detection of IAAs as a marker for beer consumption. Copyright © 2014 John Wiley & Sons, Ltd.     

The transition from patient to mental health peer worker: A grounded theory approach

Peer workers are increasingly being engaged in contemporary mental healthcare. To become a peer worker, patients must evolve from having a patient identity to a peer worker identity. This study aims to understand how mental health peer workers experience their transition and how it affects their view of themselves and their direct working context. A grounded theory approach was used. Seventeen mental health peer workers in Belgium were recruited through theoretical sampling. Semi‐structured interviews were conducted and analysed according to the constant comparative method. The results indicate that novice peer workers experience peer work as an opportunity to liberate themselves from the process of mental suffering and realise an acceptable form of personal self‐maintenance. As peer workers become more experienced, they are confronted with external factors that influence their self‐maintenance and personal development. Experiencing clarity in their duties and responsibilities, equality, and transparency in the workplace reinforce their experience of self‐maintenance and positively influence their self‐development. Experiencing a lack of clarity in their duties and responsibilities, inequality, and lack of openness discourage peer workers’ self‐development process. These experiences challenge their personal motivations to become peer workers, which are usually linked to building a meaningful life for themselves. The insights can encourage organisations to build up a supportive environment collaboratively with peer workers and ensure that peer workers can exert their authentically unique role in mental healthcare.     

Associations of delay discounting and drinking trajectories from ages 14 to 22

Background

While drinking alcohol, one must choose between the immediate rewarding effects and the delayed reward of a healthier lifestyle. Individuals differ in their devaluation of a delayed reward based on the time required to receive it, i.e., delay discounting (DD). Previous studies have shown that adolescents discount more steeply than adults and that steeper DD is associated with heavier alcohol use in both groups.

Methods

In a large-scale longitudinal study, we investigated whether higher rates of DD are an antecedent or a consequence of alcohol use during adolescent development. As part of the IMAGEN project, 2220 adolescents completed the Monetary Choice Questionnaire as a DD measure, the Alcohol Use Disorders Identification Test, and the Timeline Follow Back interview at ages 14, 16, 18, and 22. Bivariate latent growth curve models were applied to investigate the relationship between DD and drinking. To explore the consequences of drinking, we computed the cumulative alcohol consumption and correlated it with the development of discounting. A subsample of 221 participants completed an intertemporal choice task (iTeCh) during functional magnetic resonance imaging at ages 14, 16, and 18. Repeated-measures ANOVA was used to differentiate between high-risk and low-risk drinkers on the development of neural processing during intertemporal choices.

Results

Overall, high rates of DD at age 14 predicted a greater increase in drinking over 8 years. In contrast, on average, moderate alcohol use did not affect DD from ages 14 to 22. Of note, we found indicators for less brain activity in top-down control areas during intertemporal choices in the participants who drank more.

Conclusions

Steep DD was shown to be a predictor rather than a consequence of alcohol use in low-level drinking adolescents. Important considerations for future longitudinal studies are the sampling strategies to be used and the reliability of the assessments.

     

A descending dopamine pathway conserved from basal vertebrates to mammals

Dopamine neurons are classically known to modulate locomotion indirectly through ascending projections to the basal ganglia that project down to brainstem locomotor networks. Their loss in Parkinson’s disease is devastating. In lampreys, we recently showed that brainstem networks also receive direct descending dopaminergic inputs that potentiate locomotor output. Here, we provide evidence that this descending dopaminergic pathway is conserved to higher vertebrates, including mammals. In salamanders, dopamine neurons projecting to the striatum or brainstem locomotor networks were partly intermingled. Stimulation of the dopaminergic region evoked dopamine release in brainstem locomotor networks and concurrent reticulospinal activity. In rats, some dopamine neurons projecting to the striatum also innervated the pedunculopontine nucleus, a known locomotor center, and stimulation of the dopaminergic region evoked pedunculopontine dopamine release in vivo. Finally, we found dopaminergic fibers in the human pedunculopontine nucleus. The conservation of a descending dopaminergic pathway across vertebrates warrants re-evaluating dopamine’s role in locomotion.Dopaminergic neurons represent a vital neuromodulatory component essential for vertebrate motor control, and their loss in neurodegenerative disease is devastating. The meso-diencephalic dopamine (DA) neurons are known to provide ascending projections to the basal ganglia, which, in turn, provide input to cortical structure in mammals but also project caudally to the mesencephalic locomotor region (MLR), a highly conserved structure that controls locomotion in all vertebrates investigated to date (1–7; for review, see ref. 8). A growing body of evidence supports the view that basal ganglia connectivity is highly conserved among vertebrates, from lampreys to mammals (9–11; for review, see ref. 12), with some interspecies differences recently highlighted (13). As such, the homology between DA cell populations remains to be resolved in vertebrates. As a general rule, DA neurons from the meso-diencephalon send projections to the striatum in all vertebrates. In lampreys and teleosts, those neurons are located only in the diencephalon (posterior tuberculum), but in tetrapods and cartilaginous fishes (14) they are located in both the diencephalon and the mesencephalon. An increasing number of authors seem to agree with the hypothesis that at least some of the meso-diencephalic DA neurons located in the diencephalon are homologous in all vertebrates, and thus, homologous to at least a portion of the mammalian substantia nigra pars compacta (SNc)/ventral tegmental area (VTA) (13, 15–19; for review, see ref. 20). Alternatively, it was suggested that the posterior tuberculum DA neurons projecting to the striatum in zebrafish are homologs of the mammalian DA neurons of the A11 group (21). This will be discussed below in light of the results of the present study.In lampreys, only a few meso-diencephalic DA neurons send ascending projections to the striatum (9, 22); the majority of DA neurons send a direct descending projection to the MLR (22, 23), where DA is released and increases locomotor output through D1 receptors (22). These results demonstrate that the descending dopaminergic pathway to the MLR is an important modulator of locomotor output, but it remains to be determined whether this pathway is conserved in higher vertebrates.The existence of a descending dopaminergic pathway that powerfully increases locomotor output has important implications for Parkinson’s disease, which involves the meso-diencephalic DA neurons. A loss of descending dopaminergic projections could play a role in the locomotor deficits systematically observed in that disease. Because of the highly conserved nature of both the dopaminergic system and brainstem locomotor circuitry in vertebrates, we hypothesized that a direct descending dopaminergic pathway to the MLR also exists in higher vertebrates. Previous anatomical (24, 25) and electrophysiological (26) studies in rats support the idea of a descending connection from the SNc to the pedunculopontine nucleus [PPN, considered part of the MLR (2)]. Moreover, dopaminergic terminals were found in the PPN of monkeys (27), but the origin of this projection is still unknown in mammals.Here, we investigated whether the direct descending projection from meso-diencephalic DA neurons to the MLR is present in two tetrapods, the salamander and the rat. Moreover, we supplement our analyses with anatomical data from human brain tissue. Using traditional and virogenetic axonal tracing, immunofluorescence, in vivo voltammetry, and calcium imaging of reticulospinal neurons, we provide anatomical and functional evidence strongly supporting a conserved role for the descending projections of meso-diencephalic DA neurons in the regulation of brainstem locomotor networks across the vertebrate subphylum.     

Characterisation of microsatellite markers in the stone curlew Burhinus oedicnemus

We characterized twenty unique polymorphic microsatellite loci in the Eurasian stone curlew Burhinus oedicnemus, a bird of conservation concern in Europe. The loci were genotyped in 24 individuals and displayed between 2 and 21 alleles per locus. All twenty loci were autosomal based on the genotyping of individuals of known sex and seventeen loci were in Hardy–Weinberg equilibrium. These microsatellites will be used to investigate population structure in this species with the aim of informing those responsible for creating conservation management strategies.     

A miRNA signature for defining aggressive phenotype and prognosis in gliomas

Gliomas represent a disparate group of tumours for which there are to date no cure. Thus, there is a recognized need for new diagnostic and therapeutic approaches based on increased understanding of their molecular nature. We performed the comparison of the microRNA （miRNA） profile of 8 WHO grade II gliomas and 24 higher grade tumours （2 WHO grade III and 22 glioblastomas） by using the Affymetrix GeneChip miRNA Array v. 1.0. A relative quantification method （RT-qPCR） with standard curve was used to confirm the 22 miRNA signature resulted by array analysis. The prognostic performances of the confirmed miRNAs were estimated on the Tumor Cancer Genome Atlas （TCGA） datasets. We identified 22 miRNAs distinguishing grade II gliomas from higher grade tumours. RT-qPCR confirmed the differential expression in the two patients＇groups for 13 out of the 22 miRNAs. The analysis of the Glioblastoma Multiforme （GBM） and Lower Grade Glioma （LGG） datasets from TCGA demonstrated the association with prognosis for 6 of those miRNAs. Moreover, in the GBM dataset miR-21 and miR-210 were predictors of worse prognosis in both univariable and multivariable Cox regression analyses （ HR 1.19, P = O. 04, and HR 1.18, P = 0. 029 respectively）. Our results support a direct contribution of miRNAs to glioma cancerogenesis and suggest that miR-21 and miR-210 may play a role in the aggressive clinical behaviour of glioblastomas.     

Is there a role for lung perfusion [99mTc]-MAA SPECT/CT to rule out pulmonary embolism in COVID-19 patients with contraindications for iodine contrast?

European Journal of Nuclear Medicine and Molecular Imaging -     

Disentangling dynamic networks: Separated and joint expressions of functional connectivity patterns in time

Resting‐state functional connectivity (FC) is highly variable across the duration of a scan. Groups of coevolving connections, or reproducible patterns of dynamic FC (dFC), have been revealed in fluctuating FC by applying unsupervised learning techniques. Based on results from k‐means clustering and sliding‐window correlations, it has recently been hypothesized that dFC may cycle through several discrete FC states. Alternatively, it has been proposed to represent dFC as a linear combination of multiple FC patterns using principal component analysis. As it is unclear whether sparse or nonsparse combinations of FC patterns are most appropriate, and as this affects their interpretation and use as markers of cognitive processing, the goal of our study was to evaluate the impact of sparsity by performing an empirical evaluation of simulated, task‐based, and resting‐state dFC. To this aim, we applied matrix factorizations subject to variable constraints in the temporal domain and studied both the reproducibility of ensuing representations of dFC and the expression of FC patterns over time. During subject‐driven tasks, dFC was well described by alternating FC states in accordance with the nature of the data. The estimated FC patterns showed a rich structure with combinations of known functional networks enabling accurate identification of three different tasks. During rest, dFC was better described by multiple FC patterns that overlap. The executive control networks, which are critical for working memory, appeared grouped alternately with externally or internally oriented networks. These results suggest that combinations of FC patterns can provide a meaningful way to disentangle resting‐state dFC. Hum Brain Mapp 35:5984–5995, 2014. © 2014 The Authors. Human Brain Mapping published by Wiley Periodicals, Inc.