Should personality traits be considered when refining substance misuse treatment programs?

The interplay between stable personality characteristics and environmental factors is emphasised in most contemporary approaches to individual differences. This interaction appears to be important in understanding the development of substance use and misuse. Impulsivity related personality traits such as sensation-seeking, novelty seeking, reward-sensitivity and behavioural disinhibition, are strongly linked to adolescent and adult substance use and misuse. The role of anxiety-related traits, in the development of substance misuse is less clear. Nonetheless, anxiety disorders are very common amongst adult substance misusers and almost certainly play a critical role in the maintenance of a substance use disorder and influence treatment effectiveness. The data suggest that personality influences treatment outcomes and yet these individual differences are generally not addressed in treatment. We argue in this review that interventions which are matched to these relevant personality traits may improve treatment outcomes for substance misusers. [Staiger PK, Kambouropoulos N, Dawe S. Should personality traits be considered when refining substance misuse treatment programs?

Use of in vitro critical inhibitory concentration, a novel approach to predict in vivo synergistic bactericidal effect of combined amikacin and piperacillin against pseudomonas aeruginosa in a systemic rat infection model

PURPOSE: This study was undertaken to explore the use of in vitro critical inhibitory concentration (CIC) as a surrogate marker relating the pharmacokinetic (PK) parameters to in vivo bactericidal synergistic effect [pharmacodynamic (PD)] of amikacin + piperacillin combination against Pseudomonas aeruginosa in a systemic rat infection model. METHODS: The in vitro antibacterial activities of amikacin and piperacillin, alone and in combinations at various ratios of the concentrations, were tested against a standard [5 x 10(5) colony-forming units (CFU)/ml] and a large (1.5 x 10(8) CFU/ml) inoculum of P. aeruginosa ATCC 9027 using a modified survival-time method. The CIC of each individual antibiotic for the different combinations was determined using a cup-plate method. In vivo studies were performed on Sprague-Dawley rats using a systemic model of infection with P. aeruginosa ATCC 9027. PK profiles and in vivo killing effects of the combination at different dosing ratios were studied. RESULTS: An inoculum effect was observed with the antibiotics studied. Synergy was seen against both the inocula at the following concentration ratios: 70% C(ami) + 30% C(pip) and 75% C(ami) + 25% C(pip), where C(ami) and C(pip) are the concentrations of amikacin and piperacillin to produce a 1000-fold decrease in bacterial population over 5 h, respectively. The CIC values determined corroborated with the order of in vitro bacterial killing observed for the antibiotic combinations. The dosing ratio of 12.6 mg/kg amikacin + 36 mg/kg piperacillin (a 70:30 ratio of the individual doses) exhibited the greatest killing in vivo when compared to the other ratios. The PK-PD relationships were described by simple, linear regression equations using the area under the in vivo killing curve as a PD marker and the AUCIC(ami)/CIC(ami) + AUCIC(pip)/CIC(pip), AUC(ami)/CIC(ami) + AUC(pip)/CIC(pip), C(max,ami)/CIC(ami) + C(max,pip)/CIC(pip), and AUCIC(ami)/MIC(ami) + AUCIC(pip)/MIC(pip) as PK markers for the amikacin + piperacillin combination. CONCLUSION: The combination of amikacin and piperacillin exhibited synergistic killing effect on P. aeruginosa that could be modeled using CIC as a surrogate marker relating the PK parameters to in vivo bactericidal effect.

Impaired K+ regulation contributes to exercise limitation in end-stage renal failure

Background

Patients with end-stage renal failure (ESRF) exhibit grossly impaired maximal exercise performance. This study investigated whether K+ regulation during exercise is impaired in ESRF and whether this is related to reduced exercise performance.

Methods

Nine stable hemodialysis patients and eight controls (CON) performed incremental cycling exercise to volitional fatigue, with measurement of peak oxygen consumption (VdotO2 peak). Arterial blood was sampled during and following exercise and analyzed for plasma [K+] (PK).

Results

The VdotO2 peak was approximately 44% less in ESRF than in CON (P < 0.001), whereas peak exercise PK was greater (7.23 plusminus 0.38 vs. 6.23 plusminus 0.14 mmol dot L-1, respectively, P < 0.001). In ESRF, the rate of rise in PK during exercise was twofold greater (0.43 plusminus 0.05 vs. 0.23 plusminus 0.03 mmol dot L-1dotmin-1, P < 0.005) and the ratio of rise in PK relative to work performed was 3.7-fold higher (90.1 plusminus 13.5 vs. 24.7 plusminus 3.3 nmol dot L-1dot J-1, P < 0.001). A strong inverse relationship was found between VdotO2 peak and the DeltaPKdot work-1 ratio (r = -0.80, N = 17, P < 0.001).

Conclusions

Patients with ESRF exhibit grossly impaired extrarenal K+ regulation during exercise, demonstrated by an excessive rise in PK relative to work performed. We further show that K+ regulation during exercise was correlated with aerobic exercise performance. These results suggest that disturbed K+ regulation in ESRF contributes to early muscle fatigue during exercise, thus causing reduced exercise performance.

Reflections on conducting educational research projects in Papua New Guinea

This article discusses how work on an AusAID-funded impact study of major elementary school reforms influenced the research design of a subsequent Australian Development Research Award project investigating the development of sustainable professional learning communities for primary school teachers in remote places of PNG. The authors reflect on how their different backgrounds, roles, experiences and expertise influenced the design and conduct of the projects and, in particular, how the experiences of the action research and survey methods used on the first project shaped the design of the second. The participating elementary school teachers were encouraged, through action research approaches, to develop self reflexive attitudes to their professional work, and to engage in critical reflection of their roles and practices. Accordingly, this article adopts a self-reflexive position towards the authors’ work as academics and researchers as they endeavoured to produce methodologies that are academically rigorous, contextually suitable, and epistemologically appropriate for PNG.

Rough justice : young people in the shadows

Even in an age of economic prosperity, there are young people who live on the edge of western societies and who are held accountable for their every indiscretion, sometimes even for those of others. This book employs a sociological imagination to make connections between the public issues and private troubles of youth living on the street.

A potential copper-regulatory role for cytosolic expression of the DNA repair protein XRCC5

Copper (Cu) has a critical role in the generation of oxidative stress during neurodegeneration and cancer. Reactive oxygen species generated through abnormal elevation or deficiency of Cu can lead to lipid, protein, and DNA damage. Oxidation of DNA can induce strand breaks and is associated with altered cell fate including transformation or death. DNA repair is mediated through the action of the multimeric DNA-PK repair complex. The components of this complex are the Ku autoantigens, XRCC5 and XRCC6 (Ku80 and Ku70, respectively). How this repair complex responds to perturbed Cu homeostasis and Cu-mediated oxidative stress has not been investigated. We previously reported that XRCC5 expression is altered in response to cellular Cu levels, with low Cu inhibiting XRCC5 expression and high Cu levels enhancing expression. In this study we further investigated the interaction between XRCC5 and Cu. We report that cytosolic XRCC5 is increased in response to Cu, but not zinc, iron, or nickel, and the level of cytosolic XRCC5 correlates with protection against oxidative damage to DNA. These observations were made in both HeLa cells and fibroblasts. Cytosolic XRCC5 interacted with the Cu chaperone and detoxification protein human Atox1 homologue (HAH), and down regulation of XRCC5 expression using siRNA led to enhanced HAH expression when cells were exposed to Cu. XRCC5 could also be purified from cytosolic extracts using a Cu-loaded column. These findings provide further evidence that cytosolic XRCC5 has a key role in protection against DNA oxidation from Cu, through either direct sequestration or signaling through other Cu-detoxification molecules. Our findings have important implications for the development of therapeutic treatments targeting Cu in neurodegeneration and/or cancer.

Production and applications of multi-layer 3D fabrics

In this paper, 3D textile structures, their types and applications have been discussed. Woven structures especially multi-layer woven structures are discussed in detail. A simple and quick method to produce 3D textile woven preforms on conventional looms is also given at the end of this paper. 3D textile fabrics give composite structures weight reduction with improved mechanical properties in comparison to traditionally used materials.

Tuning the amino acid sequence of minimalist peptides to present biological signals via charge neutralised self assembly

Nanofibrous materials yielded by the self-assembly of peptides are rich in potential; particularly for the formation of scaffolds that mimic the landscape of the host environment of the cell. Here, we report a novel methodology to direct the formation of supramolecular structures presenting desirable amino acid sequences by the self-assembly of minimalist peptides which cannot otherwise yield the desired scaffold structures under biologically relevant conditions. Through the rational modification of the pK?, we were able to optimise ordered charge neutralised assembly towards in vivo conditions.

Modifying the risk associated with an impulsive temperament: a prospective study of drug dependence treatment

The evidence linking the personality trait of impulsivity and substance misuse is well established. Importantly, impulsivity not only predicts substance misuse problems but has an association with duration in treatment, likelihood of completing treatment and time to relapse. Treatment that focuses on increasing awareness and acceptance of thoughts and emotions may potentially address impulsive behaviour and in this respect improve treatment outcomes for substance misuse. The current paper investigated the relationship between the facet of impulsivity that taps into poor inhibitory control and treatment outcome. In addition, there was a specific focus on ascertaining the impact of an increase in awareness and attentional control measured in 144 adult substance users receiving treatment in a residential therapeutic community. Impulsivity predicted poorer treatment outcome (measured as drug use severity). Increases in awareness and acceptance of emotions and thoughts during treatment were related to better outcome although this was not associated with baseline levels of impulsivity. Clinical and theoretical implications are discussed.

Pathways to social anxiety: the role of reinforcement sensitivities and emotion regulation

Past research has demonstrated a strong relationship between threat sensitivity and social anxiety; however, the relationship between reward sensitivity and social anxiety is less clear. Further, the role that emotion regulation (ER) may play in the expression of social anxiety disorder (SAD) is rarely considered. The current study tested whether two emotion regulation strategies (emotional suppression and cognitive reappraisal) mediated associations between threat sensitivity and reward sensitivity and social anxiety in a community sample (402 adults, 78% female; Mage=32.49, S.D.age=11.53). Path analyses indicated that low reappraisal mediated the relationship between high threat sensitivity and high social anxiety; and both low reappraisal and high suppression mediated the relationship between low reward sensitivity and high social anxiety. These results highlight the potential role that emotion regulation plays in the relationship between trait motivation and social anxiety.

When social anxiety co-occurs with substance use: does an impulsive social anxiety subtype explain this unexpected relationship?

Although most conceptualizations of social anxiety emphasise that socially anxious individuals are overtly shy, and utilise avoidant behavioural strategies (e.g., risk-aversion, passivity, and submissiveness), there is tentative support for the existence of an approach-motivated subtype, characterised by risk taking and a greater propensity for substance misuse. It is likely that this subtype may help explain the reported co-occurrence of substance misuse and social anxiety. The current study sought to test via latent class analysis whether an approach-motivated social anxiety subtype could be identified within a community sample. A self-report questionnaire was completed by 351 participants (age: 18-74 years). Two distinct social anxiety subgroups were identified: one characterised by prototypical SAD symptomatology (i.e., behavioural inhibition and risk-avoidance), the second by elevated levels of rash impulsiveness, reward sensitivity, risk-taking and co-occurring substance use problems. The current findings provides support for the existence of a distinct approach-motivated social anxiety subtype and indicates that impulsivity may be critical to understanding the comorbid substance use symptomatology of these individuals.

A protocol for a discrete choice experiment: understanding preferences of patients with cancer towards their cancer care across metropolitan and rural regions in Australia.

Medical decision-making in oncology is a complicated process and to date there are few studies examining how patients with cancer make choices with respect to different features of their care. It is also unknown whether patient choices vary by geographical location and how location could account for observed rural and metropolitan cancer differences. This paper describes an ongoing study that aims to (1) examine patient and healthcare-related factors that influence choices of patients with cancer; (2) measure and quantify preferences of patients with cancer towards cancer care using a discrete choice experiment (DCE) and (3) explore preference heterogeneity between metropolitan and rural locations.

Benzodiazepine use and aggressive behaviour: a systematic review

The relationship between benzodiazepine consumption and subsequent increases in aggressive behaviour in humans is not well understood.

How profitable is the Indian stock market?

In this paper, using a range of technical trading and momentum trading strategies, we show that the Indian stock market is profitable. We find robust evidence that investing in some sectors is relatively more profitable than investing in others. We show that sectoral heterogeneity with respect to profitability is a result of the gradual diffusion of information from the market to the sectors. Specifically, we show that while the market predicts returns of sectors, the magnitude of predictability varies with sectors. Our results are robust to a range of trading strategies. © 2014 Elsevier B.V.