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Self-reported Sleep Problems Related to Amyloid Deposition in Cortical Regions with High HOMER1 Gene Expression
<jats:title>Abstract</jats:title> <jats:p>Sleep problems are related to the elevated levels of the Alzheimer’s disease (AD) biomarker β-amyloid (Aβ). Hypotheses about the causes of this relationship can be generated from molecular markers of sleep problems identified in rodents. A major marker of sleep deprivation is Homer1a, a neural protein coded by the HOMER1 gene, which has also been implicated in brain Aβ accumulation. Here, we tested whether the relationship between cortical Aβ accumulation and self-reported sleep quality, as well as changes in sleep quality over 3 years, was stronger in cortical regions with high HOMER1 mRNA expression levels. In a sample of 154 cognitively healthy older adults, Aβ correlated with poorer sleep quality cross-sectionally and longitudinally (n = 62), but more strongly in the younger than in older individuals. Effects were mainly found in regions with high expression of HOMER1. The anatomical distribution of the sleep-Aβ relationship followed closely the Aβ accumulation pattern in 69 patients with mild cognitive impairment or AD. Thus, the results indicate that the relationship between sleep problems and Aβ accumulation may involve Homer1 activity in the cortical regions, where harbor Aβ deposits in AD. The findings may advance our understanding of the relationship between sleep problems and AD risk.</jats:p>
The structural basis for intermitochondrial communications is fundamentally different in cardiac and skeletal muscle.
NEW FINDINGS: What is the topic for this review? This review summarizes recent discoveries in mitochondrial development and morphology studied with electron microscopy. What advances does it highlight? Although mitochondria are generally considered to be isolated from each other, this review highlights recently discovered evidence for the presence of intermitochondrial communication structures in cardiac and skeletal muscle, in animal models and humans. Within striated muscles, the means of intermitochondrial exchange and the reaction of mitochondria to external stimuli are uniquely dependent on the tissue, and we clearly differentiate between nanotunnels, the active protrusion of cardiac mitochondria, and the connecting ducts of skeletal muscle derived from fusion-fission and elongation events. ABSTRACT: This review focuses on recent discoveries in skeletal and cardiac muscles indicating that mitochondria behave as an interactive cohort with inter-organelle communication and specific reactions to stress signals. Our new finding is that intermitochondrial communications in cardiac and skeletal muscles rely on two distinct methods. In cardiac muscle, mitochondria are discrete entities and are fairly well immobilized in a structural context. The organelles have developed a unique method of communication, via nanotunnels, which allow temporary connection from one mitochondrion to another over distances of up to several micrometres, without overall movement of the individual organelles and loss of their identity. Skeletal muscle mitochondria, in contrast, are dynamic. Through fusion, fission and elongation, they form connections that include constrictions and connecting ducts (distinct from nanotunnels) and lose individual identity in the formation of extensive networks. Connecting elements in skeletal muscle are distinct from nanotunnels in cardiac muscle.
<jats:title>Zusammenfassung</jats:title><jats:p>Wir kennen neurodynamische Tests und Behandlungsmethoden, nutzen diese alltäglich in der Praxis und gehen auf Kurse, um mehr darüber zu lernen. Aber was verstehen wir tatsächlich darunter? Kommen wir in unserem Verständnis darüber auf einen gemeinsamen Nenner? Dieser Artikel gibt einen Einblick in die Thematik Neurodynamik. Bisherige Überzeugungen stehen dabei auf dem Prüfstand.</jats:p>
Reduced drift rate: a biomarker of impaired information processing in functional movement disorders.
Functional neurological disorder is a common and phenomenologically diverse condition. Resultant disability is caused by both the dominant clinical presentation, e.g. paralysis or tremor and additional symptomatology such as cognitive symptoms. Recently the similarity of neuropsychiatric profiles across a range of functional syndromes has been highlighted. This is suggestive of a common underlying mechanism with a theoretical deficit of information processing proposed. Identification of an experimental biomarker for such deficits could offer novel assessment and therapeutic strategies. In this study, we took the temporal discrimination threshold as a paradigm that can be used to model sensory processing in functional movement disorders. Our hypothesis was that we would be able to delineate markers of slowed information processing in this paradigm removed from the phenomenological presentation with a movement disorder. We recorded both response accuracy and reaction time in a two-choice temporal resolution/discrimination task in 36 patients with functional movement disorders and 36 control subjects. A psychometric function was fitted to accuracy data for each individual revealing both abnormally high threshold values (P = 0.0053) and shallow psychometric slopes in patients (P = 0.0015). Patients with functional movement disorders also had significantly slower response times (P = 0.0065). We then used a well-established model for decision-making (the drift diffusion model) that uses both response accuracy and reaction time data to estimate mechanistic physiological dimensions of decision-making and sensory processing. This revealed pathologically reduced drift rate in the patient group, a parameter that quantifies the quality and rate of information accumulation within this sensory task (P = 0.002). We discuss how the deficits we observed in patients with functional movement disorders are likely to stem from abnormal allocation of attention that impairs the quality of sensory information available. Within a predictive coding framework sensory information could be down-weighted in favour of predictions encoded by the prior. Our results therefore offer a parsimonious account for a range of experimental and clinical findings. Reduced drift rate is a potential experimental marker for a generalized deficit in information processing across functional disorders that allows diverse symptomatology to be quantified under a common disease framework.
© 2019 Creative Commons. Predicting the onset of sepsis from clinical data is challenging, as physiological and laboratory measurements are sampled at different frequencies and missing data are not randomly distributed. Our team ("CRASHers") propose a two-model approach, where the first predicts a probability of sepsis and the second estimates the uncertainty of these predictions. We then optimize a "decision rule" using both the probability and uncertainty to make the final prediction. A set of derived features was used to train a Gradient Boosting Machine (GBM) classification model to predict sepsis (within 6 hours). A second GBM regression model was trained to estimate the uncertainty of those predictions using a different set of derived features. Optimal hyperparameters for both models were determined using Bayesian optimisation with 5-fold cross validation (using 70% records from each training set). The outputs from both models were then combined using logistic regression (using 15% of records available) to re-calibrate the probability of sepsis. Due to an error in setting up the test environment for our entries, we did not obtain a valid score in the hidden test set. The combined model was evaluated on the remaining 15% of records available for training (i.e., our validation set). Our uncertainty-aware approach achieved a Utility score of 0.412 on our validation set.
© 2019 Elsevier Inc. Nonhuman primate neuroimaging is on the cusp of a transformation, much in the same way its human counterpart was in 2010, when the Human Connectome Project was launched to accelerate progress. Inspired by an open data-sharing initiative, the global community recently met and, in this article, breaks through obstacles to define its ambitions.
Regulation of emotional behavior is essential for human social interactions. Recent work has exposed its cognitive complexity, as well as its unexpected reliance on portions of the anterior prefrontal cortex (aPFC) also involved in exploration, relational reasoning, and counterfactual choice, rather than on dorsolateral and medial prefrontal areas involved in several forms of cognitive control. This study anatomically qualifies the contribution of aPFC territories to the regulation of prepotent approach-avoidance action-tendencies elicited by emotional faces, and explores a possible structural pathway through which this emotional action regulation might be implemented.We provide converging evidence from task-based fMRI, diffusion-weighted imaging, and functional connectivity fingerprints for a novel neural element in emotional regulation. Task-based fMRI in human male participants (N = 40) performing an emotional approach-avoidance task identified aPFC territories involved in the regulation of action-tendencies elicited by emotional faces. Connectivity fingerprints, based on diffusion-weighted imaging and resting-state connectivity, localized those task-defined frontal regions to the lateral frontal pole (FPl), an anatomically-defined portion of the aPFC that lacks a homologous counterpart in macaque brains. Probabilistic tractography indicated that 10-20% of inter-individual variation in emotional regulation abilities is accounted for by the strength of structural connectivity between FPl and amygdala. Evidence from an independent replication sample (N = 50; 10 females) further substantiated this result. These findings provide novel neuroanatomical evidence for incorporating FPl in models of control over human action-tendencies elicited by emotional faces.Significance statementSuccessful regulation of emotional behaviors is a prerequisite for successful participation in human society, as is evidenced by the social isolation and loss of occupational opportunities often encountered by people suffering from emotion-regulation disorders such as social-anxiety disorder and psychopathy. Knowledge about the precise cortical regions and connections supporting this control is crucial for understanding both the nature of computations needed to successfully traverse the space of possible actions in social situations, and the potential interventions that might result in efficient treatment of social-emotional disorders. This study provides evidence for a precise cortical region (FPl) and a structural pathway (the ventral amygdalofugal bundle) through which a cognitively complex form of emotional action regulation might be implemented in the human brain.
Effective T cell responses against infections and tumors require a swift and ample production of cytokines, chemokines, and cytotoxic molecules. The production of these effector molecules relies on rapid changes of gene expression, determined by cell-intrinsic signals and environmental cues. Here, we review our current understanding of gene-specific regulatory networks that define the magnitude and timing of cytokine production in CD8+ T cells. We discuss the dynamic features of post-transcriptional control during CD8+ T cell homeostasis and activation, and focus on the crosstalk between cell signaling and RNA-binding proteins. Elucidating gene-specific regulatory circuits may help in the future to rectify dysfunctional T cell responses.
Protocol for direct reporting of awareness in maternity patients (DREAMY): a prospective, multicentre cohort study of accidental awareness during general anaesthesia.
BACKGROUND: Accidental awareness during general anaesthesia (AAGA) is a complex and rare outcome to investigate in surgical patient populations, particularly obstetric patients. We report the protocol of the Direct Reporting of Awareness in Maternity patients (DREAMY) study, illustrating how the research was designed to address practical and methodological challenges for studying to investigating AAGA in an obstetric cohort. METHODS: This is the trial protocol of a prospective, multicentre cohort study of patients undergoing obstetric surgery under general anaesthesia. Accidental awareness during general anaesthesia will be detected using three repetitions of standardised direct questioning over 30 days, with responses indicating memories during general anaesthesia verified using structured interviews. Reports will be adjudicated, then classified, in accordance with pre-defined and pre-validated structures, including the Michigan Awareness Classification tool. Quantitative data will be collected on general anaesthesia conduct for all participants. This descriptive study is being conducted in England and aims to recruit a minimum of 2015 patients. RESULTS: The DREAMY study was prospectively registered (ClinicalTrials.gov Identifier: NCT03100396) and ethical approval granted. Participant recruitment began in May 2017 and one year follow up concluded in August 2019. Publication of the results is anticipated in 2020. CONCLUSIONS: The DREAMY study will provide data on incidence, experience and implications of AAGA for obstetric patients, using a robust methodology that will reliably detect and translate subjective AAGA reports into objective outcomes. In addition, the study is expected to improve vigilance for AAGA in participating hospitals and encourage adoption of recommendations for support of patients experiencing AAGA.
© 2020, © 2020 Informa UK Limited, trading as Taylor & Francis Group. Introduction: Retinitis pigmentosa (RP) is the most common form of inherited retinal degenerations with an estimated prevalence of 1 in 4,000 and more than 1 million individuals affected worldwide. With the introduction of the first retinal gene therapy in 2017, the importance of understanding the mechanisms of retinal degeneration and its natural progression has shifted from being of academic interest to being of pivotal for the development of new therapies. Areas covered: This review covers standard and innovative diagnostic techniques and complementary examinations needed for the evaluation and treatment of RP. It includes chapters on the assessment of visual function, retinal morphology, and genotyping. Expert opinion: Monitoring the progression of RP can best be achieved by combining assessments of both visual function and morphology. Visual acuity testing using ETDRS charts should be complemented by low-luminance visual acuity and color vision tests. Assessment of the visual field can also be useful in less advanced cases. In those with central RP involvement measuring retinal sensitivity using microperimetry is recommended. Retinal morphology is best assessed by OCT and autofluorescence. Genetic testing is pivotal as it contributes to the pathophysiological understanding and can guide clinical management as well as identify individuals that could benefit from retinal gene therapy.
Preemptive Morphine During Therapeutic Hypothermia After Neonatal Encephalopathy: A Secondary Analysis.
Although therapeutic hypothermia (TH) improves outcomes after neonatal encephalopathy (NE), the safety and efficacy of preemptive opioid sedation during cooling therapy is unclear. We performed a secondary analysis of the data from a large multicountry prospective observational study (Magnetic Resonance Biomarkers in Neonatal Encephalopathy [MARBLE]) to examine the association of preemptive morphine infusion during TH on brain injury and neurodevelopmental outcomes after NE. All recruited infants had 3.0 Tesla magnetic resonance imaging and spectroscopy at 1 week, and neurodevelopmental outcome assessments at 22 months. Of 223 babies recruited to the MARBLE study, the data on sedation were available from 169 babies with moderate (n = 150) or severe NE (n = 19). Although the baseline characteristics and admission status were similar, the babies who received morphine infusion (n = 141) were more hypotensive (49% vs. 25%, p = 0.02) and had a significantly longer hospital stay (12 days vs. 9 days, p = 0.009) than those who did not (n = 28). Basal ganglia/thalamic injury (score ≥1) and cortical injury (score ≥1) was seen in 34/141 (24%) and 37/141 (26%), respectively, of the morphine group and 4/28 (14%) and 3/28 (11%) of the nonmorphine group (p > 0.05). On regression modeling adjusted for potential confounders, preemptive morphine was not associated with mean (standard deviation [SD]) thalamic N-acetylaspartate (NAA) concentration (6.9 ± 0.9 vs. 6.5 ± 1.5; p = 0.97), and median (interquartile range) lactate/NAA peak area ratios (0.16 [0.12-0.21] vs. 0.13 [0.11-0.18]; p = 0.20) at 1 week, and mean (SD) Bayley-III composite motor (92 ± 23 vs. 94 ± 10; p = 0.98), language (89 ± 22 vs. 93 ± 8; p = 0.53), and cognitive scores (95 ± 21 vs. 99 ± 13; p = 0.56) at 22 months. Adverse neurodevelopmental outcome (adjusted for severity of encephalopathy) was seen in 26 (18%) of the morphine group, and none of the nonmorphine group (p = 0.11). Preemptive morphine sedation during TH does not offer any neuroprotective benefits and may be associated with increased hospital stay. Optimal sedation during induced hypothermia requires further evaluation in clinical trials.