Cognitive enhancers for facilitating drug cue extinction: insights from animal models

Given the success of cue exposure (extinction) therapy combined with a cognitive enhancer for reducing anxiety, it is anticipated that this approach will prove more efficacious than exposure therapy alone in preventing relapse in individuals with substance use disorders. Several factors may undermine the efficacy of exposure therapy for substance use disorders, but we suspect that neurocognitive impairments associated with chronic drug use are an important contributing factor. Numerous insights on these issues are gained from research using animal models of addiction. In this review, the relationship between brain sites whose learning, memory and executive functions are impaired by chronic drug use and brain sites that are important for effective drug cue extinction learning is explored first. This is followed by an overview of animal research showing improved treatment outcome for drug addiction (e.g. alcohol, amphetamine, cocaine, heroin) when explicit extinction training is conducted in combination with acute dosing of a cognitive-enhancing drug. The mechanism by which cognitive enhancers are thought to exert their benefits is by facilitating consolidation of drug cue extinction memory after activation of glutamatergic receptors. Based on the encouraging work in animals, factors that may be important for the treatment of drug addiction are considered.     

Digital image-based colourimetric [corrected] tests for amphetamine and methylamphetamine

Digital image analysis was applied to the products of simple colorimetric [corrected] tests for amphetamine and methylamphetamine. Adobe Photoshop software was used for colour analysis to obtain analytical data in the form of a Red Green Blue (RGB) value. Calibration curves were developed for each compound and a number of illicit amphetamine samples were analyzed to demonstrate the application of the technique. A wide linear range and low detection limit for both drugs under test facilitated the application to illicit samples. Good agreement with gas chromatographic quantification results was obtained for the illicit samples analyzed by this method. The results show great potential for use as a semi-quantitative field test for illicit drug compounds.     

Beta receptor-mediated modulation of the late positive potential in humans

Rationale  

Electrophysiological studies have identified a scalp potential, the late positive potential (LPP), which is modulated by the emotional intensity of observed stimuli. Previous work has shown that the LPP reflects the modulation of activity in extrastriate visual cortical structures, but little is known about the source of that modulation.     

Effects of altitude exposure on brain natriuretic peptide in humans

Acute mountain sickness (AMS) is common at high altitude (HA) and associated with a relative failure of the natriuresis and diuresis that occurs at HA. The role of Brain Natriuretic Peptide (BNP) in this context has not been thoroughly investigated. We aimed to clarify if BNP rises in response to exercise at HA and if so whether this is related to AMS. 32 healthy subjects had assessments of BNP, aldosterone and AMS scores [as assessed by the AMS-C score of the Environmental Symptom Questionnaire (ESQ) and Lake Louise questionnaire] made following exertion at sea-level (SL), 3,400, 4,300 and 5,150 m. Data were analysed in the 23 subjects who did not consume drugs known to affect acclimatization. BNP (pg/ml, mean ± SEM) was significantly higher at 5,150 m versus the lower altitudes (p < 0.001 for all): 7.1 ± 1; 6.1 ± 0.3; 6.8 ± 0.9 and 17.7 ± 5.1 at sea-level; 3,400, 4,300 and 5,150 m. In those that showed a BNP response at 5,150 m (n = 19) versus those that did not demonstrate a BNP response (n = 4) there was a significant difference in Lake Louise (LL) AMS scores at 5,150 m on day 10 of the expedition (mean LL score 3.3 vs. 0.75, p = 0.034) and day 11 (mean LL score 3.3 vs. 0, p = 0.003). This is the first report to demonstrate a significant rise in BNP at HA. A BNP response at 5,150 m may be associated with a greater likelihood of suffering AMS.     

A quartz-lined carbon-11 target: striving for increased yield and specific activity

IntroductionThe increased demand for high specific radioactivity neuroreceptor ligands for positron emission tomography (PET) requires the production of high specific radioactivity carbon-11 in high yields. We have attempted to address this issue with the development of a new quartz-lined aluminium target for the production of [¹¹C]methane or [¹¹C]carbon dioxide.MethodsThe new target has been tested with respect to yields of [¹¹C]methane and [¹¹C]carbon dioxide, and the effect of the quartz liner has been evaluated. The specific radioactivities of a large number of radiopharmaceuticals produced using this target have also been measured.ResultsThe described target produces [¹¹C]-labelled gases in excellent yields, and losses of radioactivity in the target on production of [¹¹C]methane have been reduced significantly by the use of a quartz liner. Radiopharmaceuticals with specific radioactivities up to 9000 GBq/μmol at end of bombardment (EOB) (243 Ci/μmol) have been produced using this target.ConclusionsWe have developed a reliable, high-yielding carbon-11 gas target which is now routinely used in our department for the production of high specific activity radiopharmaceuticals.     

Being safe practitioners and safe mothers: A critical ethnography of continuity of care midwifery in Australia

Objective

to examine how midwives and women within a continuity of care midwifery programme in Australia conceptualised childbirth risk and the influences of these conceptualisations on women's choices and midwives' practice.

Design and setting

a critical ethnography within a community-based continuity of midwifery care programme, including semi-structured interviews and the observation of sequential antenatal appointments.

Participants

eight midwives, an obstetrician and 17 women.

Findings

the midwives assumed a risk-negotiator role in order to mediate relationships between women and hospital-based maternity staff. The role of risk-negotiator relied profoundly on the trust engendered in their relationships with women. Trust within the mother–midwife relationship furthermore acted as a catalyst for complex processes of identity work which, in turn, allowed midwives to manipulate existing obstetric risk hierarchies and effectively re-order risk conceptualisations. In establishing and maintaining identities of ‘safe practitioner’ and ‘safe mother’, greater scope for the negotiation of normal within a context of obstetric risk was achieved.

Key conclusions and implications for practice

the effects of obstetric risk practices can be mitigated when trust within the mother–midwife relationship acts as a catalyst for identity work and supports the midwife's role as a risk-negotiator. The achievement of mutual identity-work through the midwives' role as risk-negotiator can contribute to improved outcomes for women receiving continuity of care. However, midwives needed to perform the role of risk-negotiator while simultaneously negotiating their professional credibility in a setting that construed their practice as risky.     

The perception of health professionals of two definitions of frailty in elderly people

The objective of this study was to understand the perception of health professionals of two definitions of frailty in elderly people. The sample consisted of twelve health professionals, who work in a Geriatrics Ambulatory. The tools used for data collection were individual semi-structured interviews, and the questionnaire Definitions of Frailty, developed for that purpose. Data were organized and analyzed using the Collective Subject Discourse method, which consists of key-expressions, central-ideas and collective subject discourse. The results indicated that the health professionals have got difficulties to accept a one-dimensional definition of frailty, which is in accordance with the international literature. The six Central Ideas (CI) that emerged from the discourses were: 1) the definitions are complementary; 2) there is no potential for prevention; 3) defining frailty is a complex task; 4) what is the concept of frailty? 5) the multidimensional definition is complete; 6) frailty is a state that can last for life. The participants believe that these definitions complement each other, since frailty encompasses an interaction of biological, psychological, and social factors throughout the lifespan. Only one professional accepted the multidimensional definition as complete. Defining frailty is a rather complex task.