810 research outputs found

    The role of orexins/hypocretins in alcohol use and abuse: an appetitive-reward relationship

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    Orexins (hypocretins) are neuropeptides synthesized in neurons located in the lateral (LH), perifornical, and dorsomedial (DMH) hypothalamus. These neurons innervate many regions in the brain and modulate multiple other neurotransmitter systems. As a result of these extensive projections and interactions orexins are involved in numerous functions, such as feeding behavior, neuroendocrine regulation, the sleep-wake cycle, and reward-seeking. This review will summarize the literature to date which has evaluated a role of orexins in the behavioral effects of alcohol, with a focus on understanding the importance of this peptide and its potential as a clinical therapeutic target for alcohol use disorders.NHMRC (Australia)Pratt FoundationVictorian Government's Operational Infrastructure Support ProgramConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Besen FoundationUniv Melbourne, Florey Neurosci Inst, Behav Neurosci Div, Addict Neurosci Lab, Parkville, Vic 3010, AustraliaUniversidade Federal de São Paulo, Escola Paulista Med, Dept Psicobiol, São Paulo, BrazilUniv Melbourne, Ctr Neurosci, Parkville, Vic 3010, AustraliaUniversidade Federal de São Paulo, Escola Paulista Med, Dept Psicobiol, São Paulo, BrazilWeb of Scienc

    Reliability of Standardized Assessment for Adults who are Deafblind

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    This study assessed the reliability of the interRAI Community Health Assessment (interRAI CHA) and Deafblind Supplement (DbS). The interRAI CHA and DbS represents a multidimensional, standardized assessment instrument for use with adults (18 and older) who are deafblind. The interrater reliability of the instrument was tested through the completion of dual assessments with 44 individuals who were deafblind in the province of Ontario, Canada. Overall, nearly 50% of items had a kappa value of at least 0.60, indicating fair to substantial agreement for these items. Several items related to psychosocial well-being, mood, and sense of involvement had kappa scores of less than 0.40. However, among these items with low kappa values, most (78%) showed at least 70% agreement between the two assessors. The internal consistency of several health subscales, embedded within the assessment, was also very good and ranged from 0.63 to 0.93. The interRAI was also very good and ranged from 0.63 to 0.93. The interRAI CHA and DbS represents a reliable instrument for assessing adults with deafblindness to better understand their needs, abilities, and preferences

    UV irradiation of skin regulates a murine model of Multiple Sclerosis

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    Objective: The prevalence of multiple sclerosis follows a latitude gradient, with increased disease at higher latitudes. Previous studies have focused on a vitamin D hypothesis; although recent evidence suggests that exposure to ultraviolet radiation (UVR) itself may be important. In this study, the effects of UVR on the development of experimental autoimmune encephalomyelitis (EAE) were examined. Methods: C57BL/6 mice were irradiated with a single erythemal dose of UVR (8 kJ/m2), or 4 daily sub-erythemal doses (1 kJ/m2), before sensitisation to myelin oligodendrocyte glycoprotein peptide. The UV irradiation protocols used do not increase 25-hydroxyvitamin D concentrations in serum of vitamin D-sufficient mice. The onset of EAE was recorded and mice were clinically monitored for 40 days. Results: A single dose of erythemal UVR (8 kJ/m2) significantly suppressed EAE onset and severity. Four daily exposures of sub-erythemal UVR (1 kJ/m2) also significantly delayed disease onset but was less effective than the erythemal dose. Conclusion: UV irradiation delayed the onset and reduced the severity of EAE. Continued administration of lower dose UVR following disease onset may be necessary to achieve similar results to a single higher dose delivered pre-sensitisation. Our results give further weight to suggestions that UVR exposure may delay MS onset and progression and UVB phototherapy may provide an option for treatment of MS

    Selected Toll-like Receptor Ligands and Viruses Promote Helper-Independent Cytotoxic T Cell Priming by Upregulating CD40L on Dendritic Cells

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    SummaryCD40L (CD154) on CD4+ T cells has been shown to license dendritic cells (DCs) via CD40 to prime cytotoxic T lymphocyte (CTL) responses. We found that the converse (CD40L on DCs) was also important. Anti-CD40L treatment decreased endogenous CTL responses to both ovalbumin and influenza infection even in the absence of CD4+ T cells. DCs expressed CD40L upon stimulation with agonists to Toll-like receptor 3 (TLR3) and TLR9. Moreover, influenza infection, which stimulates CTLs without help, upregulated CD40L on DCs, but herpes simplex infection, which elicits CTLs through help, did not. CD40L-deficient (Cd40lg−/−) DCs are suboptimal both in vivo in bone marrow chimera experiments and in vitro in mixed lymphocyte reactions. In contrast, Cd40lg−/− CD8+ T cells killed as effectively as wild-type cells. Thus, CD40L upregulation on DCs promoted optimal priming of CD8+ T cells without CD4+ T cells, providing a mechanism by which pathogens may elicit helper-independent CTL immunity

    Mycobacterium marinum Escapes from Phagosomes and Is Propelled by Actin-based Motility

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    Mycobacteria are responsible for a number of human and animal diseases and are classical intracellular pathogens, living inside macrophages rather than as free-living organisms during infection. Numerous intracellular pathogens, including Listeria monocytogenes, Shigella flexneri, and Rickettsia rickettsii, exploit the host cytoskeleton by using actin-based motility for cell to cell spread during infection. Here we show that Mycobacterium marinum, a natural pathogen of fish and frogs and an occasional pathogen of humans, is capable of actively inducing actin polymerization within macrophages. M. marinum that polymerized actin were free in the cytoplasm and propelled by actin-based motility into adjacent cells. Immunofluorescence demonstrated the presence of host cytoskeletal proteins, including the Arp2/3 complex and vasodilator-stimulated phosphoprotein, throughout the actin tails. In contrast, Wiskott-Aldrich syndrome protein localized exclusively at the actin-polymerizing pole of M. marinum. These findings show that M. marinum can escape into the cytoplasm of infected macrophages, where it can recruit host cell cytoskeletal factors to induce actin polymerization leading to direct cell to cell spread

    Etiology of Severe Non-malaria Febrile Illness in Northern Tanzania: A Prospective Cohort Study.

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    The syndrome of fever is a commonly presenting complaint among persons seeking healthcare in low-resource areas, yet the public health community has not approached fever in a comprehensive manner. In many areas, malaria is over-diagnosed, and patients without malaria have poor outcomes. We prospectively studied a cohort of 870 pediatric and adult febrile admissions to two hospitals in northern Tanzania over the period of one year using conventional standard diagnostic tests to establish fever etiology. Malaria was the clinical diagnosis for 528 (60.7%), but was the actual cause of fever in only 14 (1.6%). By contrast, bacterial, mycobacterial, and fungal bloodstream infections accounted for 85 (9.8%), 14 (1.6%), and 25 (2.9%) febrile admissions, respectively. Acute bacterial zoonoses were identified among 118 (26.2%) of febrile admissions; 16 (13.6%) had brucellosis, 40 (33.9%) leptospirosis, 24 (20.3%) had Q fever, 36 (30.5%) had spotted fever group rickettsioses, and 2 (1.8%) had typhus group rickettsioses. In addition, 55 (7.9%) participants had a confirmed acute arbovirus infection, all due to chikungunya. No patient had a bacterial zoonosis or an arbovirus infection included in the admission differential diagnosis. Malaria was uncommon and over-diagnosed, whereas invasive infections were underappreciated. Bacterial zoonoses and arbovirus infections were highly prevalent yet overlooked. An integrated approach to the syndrome of fever in resource-limited areas is needed to improve patient outcomes and to rationally target disease control efforts

    Children\u27s Sleep during COVID-19: How Sleep Influences Surviving and Thriving in Families

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    Objective The COVID-19 pandemic has the potential to disrupt the lives of families and may have implications for children with existing sleep problems. As such, we aimed to: (1) characterize sleep changes during the COVID-19 pandemic in children who had previously been identified as having sleep problems, (2) identify factors contributing to sleep changes due to COVID-19 safety measures, and (3) understand parents and children s needs to support sleep during the pandemic. Methods Eighty-five Canadian parents with children aged 4 14 years participated in this explanatory sequential, mixed-methods study using an online survey of children s and parents sleep, with a subset of 16 parents, selected based on changes in their children s sleep, participating in semi-structured interviews. Families had previously participated in the Better Nights, Better Days (BNBD) randomized controlled trial. Results While some parents perceived their child s sleep quality improved during the COVID-19 pandemic (14.1%, n 12), many parents perceived their child s sleep had worsened (40.0%, n 34). Parents attributed children s worsened sleep to increased screen time, anxiety, and decreased exercise. Findings from semi-structured interviews highlighted the effect of disrupted routines on sleep and stress, and that stress reciprocally influenced children s and parents sleep. Conclusions The sleep of many Canadian children was affected by the first wave of the COVID-19 pandemic, with the disruption of routines influencing children s sleep. eHealth interventions, such as BNBD with modifications that address the COVID-19 context, could help families address these challenges

    Identification of Brain Nuclei Implicated in Cocaine-Primed Reinstatement of Conditioned Place Preference: A Behaviour Dissociable from Sensitization

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    Relapse prevention represents the primary therapeutic challenge in the treatment of drug addiction. As with humans, drug-seeking behaviour can be precipitated in laboratory animals by exposure to a small dose of the drug (prime). The aim of this study was to identify brain nuclei implicated in the cocaine-primed reinstatement of a conditioned place preference (CPP). Thus, a group of mice were conditioned to cocaine, had this place preference extinguished and were then tested for primed reinstatement of the original place preference. There was no correlation between the extent of drug-seeking upon reinstatement and the extent of behavioural sensitization, the extent of original CPP or the extinction profile of mice, suggesting a dissociation of these components of addictive behaviour with a drug-primed reinstatement. Expression of the protein product of the neuronal activity marker c-fos was assessed in a number of brain regions of mice that exhibited reinstatement (R mice) versus those which did not (NR mice). Reinstatement generally conferred greater Fos expression in cortical and limbic structures previously implicated in drug-seeking behaviour, though a number of regions not typically associated with drug-seeking were also activated. In addition, positive correlations were found between neural activation of a number of brain regions and reinstatement behaviour. The most significant result was the activation of the lateral habenula and its positive correlation with reinstatement behaviour. The findings of this study question the relationship between primed reinstatement of a previously extinguished place preference for cocaine and behavioural sensitization. They also implicate activation patterns of discrete brain nuclei as differentiators between reinstating and non-reinstating mice
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