92 research outputs found

    Deletion of the gabra2 gene results in hypersensitivity to the acute effects of ethanol but does not alter ethanol self administration

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    Human genetic studies have suggested that polymorphisms of the GABRA2 gene encoding the GABA(A) α2-subunit are associated with ethanol dependence. Variations in this gene also convey sensitivity to the subjective effects of ethanol, indicating a role in mediating ethanol-related behaviours. We therefore investigated the consequences of deleting the α2-subunit on the ataxic and rewarding properties of ethanol in mice. Ataxic and sedative effects of ethanol were explored in GABA(A) α2-subunit wildtype (WT) and knockout (KO) mice using a Rotarod apparatus, wire hang and the duration of loss of righting reflex. Following training, KO mice showed shorter latencies to fall than WT littermates under ethanol (2 g/kg i.p.) in both Rotarod and wire hang tests. After administration of ethanol (3.5 g/kg i.p.), KO mice took longer to regain the righting reflex than WT mice. To ensure the acute effects are not due to the gabra2 deletion affecting pharmacokinetics, blood ethanol concentrations were measured at 20 minute intervals after acute administration (2 g/kg i.p.), and did not differ between genotypes. To investigate ethanol's rewarding properties, WT and KO mice were trained to lever press to receive increasing concentrations of ethanol on an FR4 schedule of reinforcement. Both WT and KO mice self-administered ethanol at similar rates, with no differences in the numbers of reinforcers earned. These data indicate a protective role for α2-subunits, against the acute sedative and ataxic effects of ethanol. However, no change was observed in ethanol self administration, suggesting the rewarding effects of ethanol remain unchange

    An early history of T cell-mediated cytotoxicity.

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    After 60 years of intense fundamental research into T cell-mediated cytotoxicity, we have gained a detailed knowledge of the cells involved, specific recognition mechanisms and post-recognition perforin-granzyme-based and FAS-based molecular mechanisms. What could not be anticipated at the outset was how discovery of the mechanisms regulating the activation and function of cytotoxic T cells would lead to new developments in cancer immunotherapy. Given the profound recent interest in therapeutic manipulation of cytotoxic T cell responses, it is an opportune time to look back on the early history of the field. This Timeline describes how the early findings occurred and eventually led to current therapeutic applications

    Toll-like receptor signaling and stages of addiction

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    Athina Markou and her colleagues discovered persistent changes in adult behavior following adolescent exposure to ethanol or nicotine consistent with increased risk for developing addiction. Building on Dr. Markou's important work and that of others in the field, researchers at the Bowles Center for Alcohol Studies have found that persistent changes in behavior following adolescent stress or alcohol exposure may be linked to induction of immune signaling in brain. This study aims to illuminate the critical interrelationship of the innate immune system (e.g., toll-like receptors [TLRs], high-mobility group box 1 [HMGB1]) in the neurobiology of addiction. This study reviews the relevant research regarding the relationship between the innate immune system and addiction. Emerging evidence indicates that TLRs in brain, particularly those on microglia, respond to endogenous innate immune agonists such as HMGB1 and microRNAs (miRNAs). Multiple TLRs, HMGB1, and miRNAs are induced in the brain by stress, alcohol, and other drugs of abuse and are increased in the postmortem human alcoholic brain. Enhanced TLR-innate immune signaling in brain leads to epigenetic modifications, alterations in synaptic plasticity, and loss of neuronal cell populations, which contribute to cognitive and emotive dysfunctions. Addiction involves progressive stages of drug binges and intoxication, withdrawal-negative affect, and ultimately compulsive drug use and abuse. Toll-like receptor signaling within cortical-limbic circuits is modified by alcohol and stress in a manner consistent with promoting progression through the stages of addiction

    Self management, joint protection and exercises in hand osteoarthritis: a randomised controlled trial with cost effectiveness analyses

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    Background: There is limited evidence for the clinical and cost effectiveness of occupational therapy (OT) approaches in the management of hand osteoarthritis (OA). Joint protection and hand exercises have been proposed by European guidelines, however the clinical and cost effectiveness of each intervention is unknown. This multicentre two-by-two factorial randomised controlled trial aims to address the following questions: • Is joint protection delivered by an OT more effective in reducing hand pain and disability than no joint protection in people with hand OA in primary care? • Are hand exercises delivered by an OT more effective in reducing hand pain and disability than no hand exercises in people with hand OA in primary care? • Which of the four management approaches explored within the study (leaflet and advice, joint protection, hand exercise, or joint protection and hand exercise combined) provides the most cost-effective use of health care resources Methods/Design: Participants aged 50 years and over registered at three general practices in North Staffordshire and Cheshire will be mailed a health survey questionnaire (estimated mailing sample n = 9,500). Those fulfilling the eligibility criteria on the health survey questionnaire will be invited to attend a clinical assessment to assess for the presence of hand or thumb base OA using the ACR criteria. Eligible participants will be randomised to one of four groups: leaflet and advice; joint protection (looking after your joints); hand exercises; or joint protection and hand exercises combined (estimated n = 252). The primary outcome measure will be the OARSI/OMERACT responder criteria combining hand pain and disability (measured using the AUSCAN) and global improvement, 6 months post-randomisation. Secondary outcomes will also be collected for example pain, functional limitation and quality of life. Outcomes will be collected at baseline and 3, 6 and 12 months post-randomisation. The main analysis will be on an intention to treat basis and will assess the clinical and cost effectiveness of joint protection and hand exercises for managing hand OA. Discussion: The findings will improve the cost-effective evidence based management of hand OA
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