445 research outputs found

    Relationships between affiliative social behavior and hair cortisol concentrations in semi-free ranging rhesus monkeys

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    Sociality is a fundamental aspect of human behavior and health. One benefit of affiliative social relationships is reduced short-term levels of glucocorticoids (GCs), which are indicative of physiological stress. Less is known, however, about chronic GC production in relation to affiliative social behavior. To address this issue, we studied a semi-free ranging troop of rhesus macaques (Macaca mulatta) and collected hair samples to measure hair cortisol concentrations (HCCs), as a measure of chronic GC production, during routine biannual exams. We collected social behavior (both aggressive and affiliative) and hair samples for 32 adult female rhesus macaques over one year (Experiment 1). Our results indicated that adult females who initiated higher levels of social affiliation had significantly lower levels of HCCs. Neither the initiation nor the receipt of aggression were significantly related to HCCs in this study. In a second experiment we studied 28 mother-infant dyads for the first 90 days postpartum to examine mother-infant facial interactions (i.e. mutual gazing). We analyzed HCCs during weaning approximately one year later, which is a major transitional period. We found that infants that engaged in higher levels of mutual gazing in the first 90 days postpartum had significantly lower levels of HCCs during weaning. Finally, we studied 17 infant rhesus macaques (13 males) to examine whether social behavior (such as play) in the first five months of life correlated with infant HCCs over those months (Experiment 3). We found that infant males that engaged in more social play had significantly lower levels of HCCs. By relying on an animal model, our study shows that affiliative social traits are associated with lower long-term GC production. Future research should address the complex interactions between social behavior, chronic GC production, and mental and physical health

    Lifetime determination of excited states in Cd-106

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    Two separate experiments using the Differential Decay Curve Method have been performed to extract mean lifetimes of excited states in 106 Cd. The inedium-spin states of interest were populated by the Mo-98(C-12, 4n) Cd-106 reaction performed at the Wright Nuclear Structure Lab., Yale University. From this experiment, two isomeric state mean lifetimes have been deduced. The low-lying states were populated by the Mo-96(C-13, 3n)Cd-106 reaction performed at the Institut fur Kernphysik, Universitat zu Koln. The mean lifetime of the I-pi = 2(1)(+) state was deduced, tentatively, as 16.4(9) ps. This value differs from the previously accepted literature value from Coulomb excitation of 10.43(9) ps

    Oligodendrocytes contribute to motor neuron death in ALS via SOD1 dependent mechanism

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    Oligodendrocytes have recently been implicated in the pathophysiology of ALS. Here we show that, in vitro, mutant SOD1 mouse oligodendrocytes induce wild-type motor neuron hyperexcitability and death. Moreover, we efficiently derived human oligodendrocytes from a large number of controls, sporadic and familial ALS patients using two different reprogramming methods. All ALS oligodendrocyte lines induced motor neuron death through conditioned medium and in co-culture. Conditioned medium-mediated motor neuron death was associated with decreased lactate production and release, while toxicity in co-culture was lactate independent, demonstrating that motor neuron survival is not only mediated by soluble factors. Remarkably, human SOD1 shRNA treatment resulted in motor neuron rescue in both mouse and human cultures when knockdown was achieved in progenitor cells, while it was ineffective in differentiated oligodendrocytes. Early SOD1 knockdown, in fact, rescued lactate impairment and cell toxicity in all lines tested with exclusion of samples carrying C9orf72 repeat expansions. These did not respond to SOD1 knockdown nor showed lactate release impairment. Our data indicate that SOD1 is directly or indirectly involved in ALS oligodendrocyte pathology and suggest that in this cell type some damage might be irreversible. In addition, we demonstrate that C9ORF72 patients represent an independent patient group that might not respond to the same treatment

    A global collaboration to study intimate partner violence-related head trauma: The ENIGMA consortium IPV working group

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    Intimate partner violence includes psychological aggression, physical violence, sexual violence, and stalking from a current or former intimate partner. Past research suggests that exposure to intimate partner violence can impact cognitive and psychological functioning, as well as neurological outcomes. These seem to be compounded in those who suffer a brain injury as a result of trauma to the head, neck or body due to physical and/or sexual violence. However, our understanding of the neurobehavioral and neurobiological effects of head trauma in this population is limited due to factors including difficulty in accessing/recruiting participants, heterogeneity of samples, and premorbid and comorbid factors that impact outcomes. Thus, the goal of the Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) Consortium Intimate Partner Violence Working Group is to develop a global collaboration that includes researchers, clinicians, and other key community stakeholders. Participation in the working group can include collecting harmonized data, providing data for meta- and mega-analysis across sites, or stakeholder insight on key clinical research questions, promoting safety, participant recruitment and referral to support services. Further, to facilitate the mega-analysis of data across sites within the working group, we provide suggestions for behavioral surveys, cognitive tests, neuroimaging parameters, and genetics that could be used by investigators in the early stages of study design. We anticipate that the harmonization of measures across sites within the working group prior to data collection could increase the statistical power in characterizing how intimate partner violence-related head trauma impacts long-term physical, cognitive, and psychological health

    Major histocompatibility complex class I molecules protect motor neurons from astrocyte-induced toxicity in amyotrophic lateral sclerosis

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    Astrocytes isolated from individuals with amyotrophic lateral sclerosis (ALS) are toxic to motor neurons (MNs) and play a non–cell autonomous role in disease pathogenesis. The mechanisms underlying the susceptibility of MNs to cell death remain unclear. Here we report that astrocytes derived from either mice bearing mutations in genes associated with ALS or human subjects with ALS reduce the expression of major histocompatibility complex class I (MHCI) molecules on MNs; reduced MHCI expression makes these MNs susceptible to astrocyte-induced cell death. Increasing MHCI expression on MNs increases survival and motor performance in a mouse model of ALS and protects MNs against astrocyte toxicity. Overexpression of a single MHCI molecule, HLA-F, protects human MNs from ALS astrocyte–mediated toxicity, whereas knockdown of its receptor, the killer cell immunoglobulin-like receptor KIR3DL2, on human astrocytes results in enhanced MN death. Thus, our data indicate that, in ALS, loss of MHCI expression on MNs renders them more vulnerable to astrocyte-mediated toxicity

    Argonaute2 Suppresses Drosophila Fragile X Expression Preventing Neurogenesis and Oogenesis Defects

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    Fragile X Syndrome is caused by the silencing of the Fragile X Mental Retardation gene (FMR1). Regulating dosage of FMR1 levels is critical for proper development and function of the nervous system and germ line, but the pathways responsible for maintaining normal expression levels are less clearly defined. Loss of Drosophila Fragile X protein (dFMR1) causes several behavioral and developmental defects in the fly, many of which are analogous to those seen in Fragile X patients. Over-expression of dFMR1 also causes specific neuronal and behavioral abnormalities. We have found that Argonaute2 (Ago2), the core component of the small interfering RNA (siRNA) pathway, regulates dfmr1 expression. Previously, the relationship between dFMR1 and Ago2 was defined by their physical interaction and co-regulation of downstream targets. We have found that Ago2 and dFMR1 are also connected through a regulatory relationship. Ago2 mediated repression of dFMR1 prevents axon growth and branching defects of the Drosophila neuromuscular junction (NMJ). Consequently, the neurogenesis defects in larvae mutant for both dfmr1 and Ago2 mirror those in dfmr1 null mutants. The Ago2 null phenotype at the NMJ is rescued in animals carrying an Ago2 genomic rescue construct. However, animals carrying a mutant Ago2 allele that produces Ago2 with significantly reduced endoribonuclease catalytic activity are normal with respect to the NMJ phenotypes examined. dFMR1 regulation by Ago2 is also observed in the germ line causing a multiple oocyte in a single egg chamber mutant phenotype. We have identified Ago2 as a regulator of dfmr1 expression and have clarified an important developmental role for Ago2 in the nervous system and germ line that requires dfmr1 function

    New fossil remains of Homo naledi from the Lesedi Chamber, South Africa

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    The Rising Star cave system has produced abundant fossil hominin remains within the Dinaledi Chamber, representing a minimum of 15 individuals attributed to Homo naledi. Further exploration led to the discovery of hominin material, now comprising 131 hominin specimens, within a second chamber, the Lesedi Chamber. The Lesedi Chamber is far separated from the Dinaledi Chamber within the Rising Star cave system, and represents a second depositional context for hominin remains. In each of three collection areas within the Lesedi Chamber, diagnostic skeletal material allows a clear attribution to H. naledi. Both adult and immature material is present. The hominin remains represent at least three individuals based upon duplication of elements, but more individuals are likely present based upon the spatial context. The most significant specimen is the near-complete cranium of a large individual, designated LES1, with an endocranial volume of approximately 610 ml and associated postcranial remains. The Lesedi Chamber skeletal sample extends our knowledge of the morphology and variation of H. naledi, and evidence of H. naledi from both recovery localities shows a consistent pattern of differentiation from other hominin species

    Enablers and Barriers to Implementing ICU Follow-Up Clinics and Peer Support Groups Following Critical Illness: The Thrive Collaboratives

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    OBJECTIVES: Data are lacking regarding implementation of novel strategies such as follow-up clinics and peer support groups, to reduce the burden of postintensive care syndrome. We sought to discover enablers that helped hospital-based clinicians establish post-ICU clinics and peer support programs, and identify barriers that challenged them. DESIGN: Qualitative inquiry. The Consolidated Framework for Implementation Research was used to organize and analyze data. SETTING: Two learning collaboratives (ICU follow-up clinics and peer support groups), representing 21 sites, across three continents. SUBJECTS: Clinicians from 21 sites. MEASUREMENT AND MAIN RESULTS: Ten enablers and nine barriers to implementation of "ICU follow-up clinics" were described. A key enabler to generate support for clinics was providing insight into the human experience of survivorship, to obtain interest from hospital administrators. Significant barriers included patient and family lack of access to clinics and clinic funding. Nine enablers and five barriers to the implementation of "peer support groups" were identified. Key enablers included developing infrastructure to support successful operationalization of this complex intervention, flexibility about when peer support should be offered, belonging to the international learning collaborative. Significant barriers related to limited attendance by patients and families due to challenges in creating awareness, and uncertainty about who might be appropriate to attend and target in advertising. CONCLUSIONS: Several enablers and barriers to implementing ICU follow-up clinics and peer support groups should be taken into account and leveraged to improve ICU recovery. Among the most important enablers are motivated clinician leaders who persist to find a path forward despite obstacles

    Key mechanisms by which post-ICU activities can improve in-ICU care: results of the international THRIVE collaboratives

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    Objective: To identify the key mechanisms that clinicians perceive improve care in the intensive care unit (ICU), as a result of their involvement in post-ICU programs. Methods: Qualitative inquiry via focus groups and interviews with members of the Society of Critical Care Medicine’s THRIVE collaborative sites (follow-up clinics and peer support). Framework analysis was used to synthesize and interpret the data. Results: Five key mechanisms were identified as drivers of improvement back into the ICU: (1) identifying otherwise unseen targets for ICU quality improvement or education programs—new ideas for quality improvement were generated and greater attention paid to detail in clinical care. (2) Creating a new role for survivors in the ICU—former patients and family members adopted an advocacy or peer volunteer role. (3) Inviting critical care providers to the post-ICU program to educate, sensitize, and motivate them—clinician peers and trainees were invited to attend as a helpful learning strategy to gain insights into post-ICU care requirements. (4) Changing clinician’s own understanding of patient experience—there appeared to be a direct individual benefit from working in post-ICU programs. (5) Improving morale and meaningfulness of ICU work—this was achieved by closing the feedback loop to ICU clinicians regarding patient and family outcomes. Conclusions: The follow-up of patients and families in post-ICU care settings is perceived to improve care within the ICU via five key mechanisms. Further research is required in this novel area

    Preterm birth: inflammation, fetal injury and treatment strategies

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    Preterm birth (PTB) is the leading cause of childhood mortality in children under 5 and accounts for approximately 11% of births worldwide. Premature babies are at risk of a number of health complications, notably cerebral palsy, but also respiratory and gastrointestinal disorders. Preterm deliveries can be medically indicated/elective procedures or they can occur spontaneously. Spontaneous PTB is commonly associated with intrauterine infection/inflammation. The presence of inflammatory mediators in utero has been associated with fetal injury, particularly affecting the fetal lungs and brain. This review will outline (i) the role of inflammation in term and PTB, (ii) the effect infection/inflammation has on fetal development and (iii) recent strategies to target PTB. Further research is urgently required to develop effective methods for the prevention and treatment of PTB and above all, to reduce fetal injury
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