Structural basis of the effect of activating mutations on the EGF receptor

Mutations within the kinase domain of the epidermal growth factor receptor (EGFR) are common oncogenic driver events in non-small cell lung cancer. Although the activation of EGFR in normal cells is primarily driven by growth-factor-binding-induced dimerization, mutations on different exons of the kinase domain of the receptor have been found to affect the equilibrium between its active and inactive conformations giving rise to growth-factor-independent kinase activation. Using molecular dynamics simulations combined with enhanced sampling techniques, we compare here the conformational landscape of the monomers and homodimers of the wild-type and mutated forms of EGFR ΔELREA and L858R, as well as of two exon 20 insertions, D770-N771insNPG, and A763-Y764insFQEA. The differences in the conformational energy landscapes are consistent with multiple mechanisms of action including the regulation of the hinge motion, the stabilization of the dimeric interface, and local unfolding transitions. Overall, a combination of different effects is caused by the mutations and leads to the observed aberrant signaling

Ethanol reversal of tolerance to the respiratory depressant effects of morphine

Opioids are the most common drugs associated with unintentional drug overdose. Death results from respiratory depression. Prolonged use of opioids results in the development of tolerance but the degree of tolerance is thought to vary between different effects of the drugs. Many opioid addicts regularly consume alcohol (ethanol), and post-mortem analyses of opioid overdose deaths have revealed an inverse correlation between blood morphine and ethanol levels. In the present study, we determined whether ethanol reduced tolerance to the respiratory depressant effects of opioids. Mice were treated with opioids (morphine, methadone, or buprenorphine) for up to 6 days. Respiration was measured in freely moving animals breathing 5% CO(2) in air in plethysmograph chambers. Antinociception (analgesia) was measured as the latency to remove the tail from a thermal stimulus. Opioid tolerance was assessed by measuring the response to a challenge dose of morphine (10 mg/kg i.p.). Tolerance developed to the respiratory depressant effect of morphine but at a slower rate than tolerance to its antinociceptive effect. A low dose of ethanol (0.3 mg/kg) alone did not depress respiration but in prolonged morphine-treated animals respiratory depression was observed when ethanol was co-administered with the morphine challenge. Ethanol did not alter the brain levels of morphine. In contrast, in methadone- or buprenorphine-treated animals no respiratory depression was observed when ethanol was co-administered along with the morphine challenge. As heroin is converted to morphine in man, selective reversal of morphine tolerance by ethanol may be a contributory factor in heroin overdose deaths

Improving Empathy in Healthcare Consultations-a Secondary Analysis of Interventions.

A recent systematic review of randomised trials suggested that empathic communication improves patient health outcomes. However, the methods for training healthcare practitioners (medical professionals; HCPs) in empathy and the empathic behaviours demonstrated within the trials were heterogeneous, making the evidence difficult to implement in routine clinical practice. In this secondary analysis of seven trials in the review, we aimed to identify (1) the methods used to train HCPs, (2) the empathy behaviours they were trained to perform and (3) behaviour change techniques (BCTs) used to encourage the adoption of those behaviours. This detailed understanding of interventions is necessary to inform implementation in clinical practice. We conducted a content analysis of intervention descriptions, using an inductive approach to identify training methods and empathy behaviours and a deductive approach to describe the BCTs used. The most commonly used methods to train HCPs to enhance empathy were face-to-face training (n = 5), role-playing (n = 3) and videos (self or model; n = 3). Duration of training was varied, with both long and short training having high effect sizes. The most frequently targeted empathy behaviours were providing explanations of treatment (n = 5), providing non-specific empathic responses (e.g. expressing understanding) and displaying a friendly manner and using non-verbal behaviours (e.g. nodding, leaning forward, n = 4). The BCT most used to encourage HCPs to adopt empathy behaviours was "Instruction on how to perform behaviour" (e.g. a video demonstration, n = 5), followed by "Credible source" (e.g. delivered by a psychologist, n = 4) and "Behavioural practice" (n = 3 e.g. role-playing). We compared the effect sizes of studies but could not extrapolate meaningful conclusions due to high levels of variation in training methods, empathy skills and BCTs. Moreover, the methods used to train HCPs were often poorly described which limits study replication and clinical implementation. This analysis of empathy training can inform future research, intervention reporting standards and clinical practice

De Novo Mutations in PDE10A Cause Childhood-Onset Chorea with Bilateral Striatal Lesions.

Chorea is a hyperkinetic movement disorder resulting from dysfunction of striatal medium spiny neurons (MSNs), which form the main output projections from the basal ganglia. Here, we used whole-exome sequencing to unravel the underlying genetic cause in three unrelated individuals with a very similar and unique clinical presentation of childhood-onset chorea and characteristic brain MRI showing symmetrical bilateral striatal lesions. All individuals were identified to carry a de novo heterozygous mutation in PDE10A (c.898T>C [p.Phe300Leu] in two individuals and c.1000T>C [p.Phe334Leu] in one individual), encoding a phosphodiesterase highly and selectively present in MSNs. PDE10A contributes to the regulation of the intracellular levels of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). Both substitutions affect highly conserved amino acids located in the regulatory GAF-B domain, which, by binding to cAMP, stimulates the activity of the PDE10A catalytic domain. In silico modeling showed that the altered residues are located deep in the binding pocket, where they are likely to alter cAMP binding properties. In vitro functional studies showed that neither substitution affects the basal PDE10A activity, but they severely disrupt the stimulatory effect mediated by cAMP binding to the GAF-B domain. The identification of PDE10A mutations as a cause of chorea further motivates the study of cAMP signaling in MSNs and highlights the crucial role of striatal cAMP signaling in the regulation of basal ganglia circuitry. Pharmacological modulation of this pathway could offer promising etiologically targeted treatments for chorea and other hyperkinetic movement disorders

Conserving Conflict? Transfrontier Conservation, Development Discourses and Local Conflict Between South Africa and Lesotho

This paper describes and analyses how discourses of conservation and development as well as migrant labour practices can be understood as transnational dynamics that both cement and complicate transnational relations. It also looks into how these dynamics articulate with, shape and are being shaped by ‘the local’. Focusing on the north-eastern boundary of Lesotho in the area of the ‘Maloti-Drakensberg transfrontier conservation and development project’, we show how conflictual situations put the ethnographic spotlight on the ways in which ‘local people’ in Lesotho deal with dual forces of localisation and transnationalisation. We argue that they accommodate, even appropriate, these dual pressures by adopting an increasingly flexible stance in terms of identity, alliances, livelihood options and discourses

Clinician views on optimism and empathy in primary care consultations.

BACKGROUND: Practitioner expressions of optimism and empathy may improve treatment engagement, adherence and patient satisfaction but are not delivered consistently amidst the challenges of everyday clinical practice. AIMS: To explore primary care practitioner (PCP) views about optimistic and empathic communication in consultations; and to identify behavioural, attitudinal and/or contextual issues likely to encourage or deter PCPs from practising such communication. DESIGN & SETTING: Qualitative interview study with 20 PCPs (General Practitioners, Practice Nurses, Primary Care Physiotherapists). METHOD: Semi-structured telephone interviews with 20 PCPs. Data was analysed thematically. RESULTS: A conceptual mismatch between optimism and patient expectations became apparent; when asked how PCPs communicate about the likely effects of a treatment answers were focussed around managing patient expectations. When prompted, it became clear PCPs were open to communicating optimistically with patients, but emphasised the need for realism. Concerns arose that patients may not be receptive to optimistic messages, especially when holding negative expectations. PCPs felt that expressing empathy is fundamental to all clinical consultations, noting that it can be challenging. Some PCPs worried that increasing expressions of empathy might increase their risk of clinician burnout and felt guilty about (appropriately) communicating empathy whilst maintaining some emotional distance. CONCLUSION: PCPs agreed expressing realistic optimism during consultations could aid communication and would constitute a novel change to practice. PCPs strive for clinical empathy but can struggle to manage emotional self-protection. Specific training to help PCPs express realistic optimism and empathy, and better utilise efficient non-verbal skills could help these issues