A comparison of methods to assess the antimicrobial activity of nanoparticle combinations on bacterial cells

Copyright: © 2018 Bankier et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.BACKGROUND: Bacterial cell quantification after exposure to antimicrobial compounds varies widely throughout industry and healthcare. Numerous methods are employed to quantify these antimicrobial effects. With increasing demand for new preventative methods for disease control, we aimed to compare and assess common analytical methods used to determine antimicrobial effects of novel nanoparticle combinations on two different pathogens. METHODS: Plate counts of total viable cells, flow cytometry (LIVE/DEAD BacLight viability assay) and qPCR (viability qPCR) were used to assess the antimicrobial activity of engineered nanoparticle combinations (NPCs) on Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa) bacteria at different concentrations (0.05, 0.10 and 0.25 w/v%). Results were analysed using linear models to assess the effectiveness of different treatments. RESULTS: Strong antimicrobial effects of the three NPCs (AMNP0-2) on both pathogens could be quantified using the plate count method and flow cytometry. The plate count method showed a high log reduction (>8-log) for bacteria exposed to high NPC concentrations. We found similar antimicrobial results using the flow cytometry live/dead assay. Viability qPCR analysis of antimicrobial activity could not be quantified due to interference of NPCs with qPCR amplification. CONCLUSION: Flow cytometry was determined to be the best method to measure antimicrobial activity of the novel NPCs due to high-throughput, rapid and quantifiable results.Peer reviewe

The Implications of Cannabis Policy Changes in Washington on Adolescent Perception of Risk, Norms, Attitudes, and Substance Use

There is increasing interest in the effect of legalization (particularly recreational legalization) of cannabis on prevalence of use and related problems. However, there is no consensus about the impact of policy change on cannabis use, particularly among adolescents. Legalization may increase adolescent use through mediating factors such as perceived risk and normative beliefs regarding the use of cannabis. Washington State enacted Initiative 502 on December 2012, which legalized and taxed recreational cannabis for adults aged ⩾21 years. This paper used data from a randomized, controlled intervention trial for cannabis-using adolescents that was recruiting participants in Seattle before and after the policy change to evaluate the following goals: assess differences in substance use, problems, and symptomatology pre- and post-policy change; evaluate several proposed risk factors that may be associated with such differences; and describe participants’ understanding of the law and how this understanding may relate to rates of use. Analyses revealed no significant differences pre- to post-policy in rate of substance use. However, there were significant post-policy increases in problems and use disorder symptoms. Despite these differences, there were no significant increases in norms, attitudes, or perceptions of risk. Participants were able to answer most questions regarding policy changes correctly, indicating a good understanding of the policy. Results provided no evidence that policy change influenced heavy-using adolescents’ rates of use nor the proposed risk factors associated with problematic use patterns

The Role of Self-Efficacy, Adaptive Coping, and Smoking Urges in Long-term Cessation Outcomes

ObjectiveSmoking cessation self-efficacy and adaptive coping are posited as two important treatment targets in smoking cessation interventions, especially in the context of handling strong urges to smoke. Yet, less is known about whether intervention-related changes in these constructs predict long-term smoking outcomes. The current study aimed to examine changes in smoking urges, smoking cessation self-efficacy, and adaptive coping following a health-focused and cognitive-behavioral telephone-delivered smoking cessation treatment, and the association to smoking reduction during long-term, 12-month follow-up.MethodsParticipants (n = 61) were daily smokers enrolled in a 12-week pilot trial that tested the efficacy of two different health-focused interventions with an adjunct of traditional telephone-delivered cessation counseling. Smoking urges, smoking cessation self-efficacy, and adaptive coping were assessed as baseline and immediately post-treatment. Average of seven-day cigarettes use per day were assessed at post-treatment, and 6- and 12-months post-baseline follow-up timepoints.ResultsSmoking urges were significantly lower post-treatment, and smoking cessation self-efficacy and adaptive coping were significantly higher post-treatment, relative to baseline. After adjusting for baseline values, post-treatment smoking urges were significantly positively associated with cigarette use at post-treatment and 6-month follow-up. Post-treatment smoking cessation self-efficacy, but not adaptive coping, was significantly negatively predictive of cigarette use at post-treatment and 6- and 12-month follow-up timepoints. Post-treatment smoking cessation self-efficacy emerged as significant indirect predictor of the association between post-treatment smoking urges and post-treatment cigarette use.ConclusionsInterventions that target smoking cessation self-efficacy may facilitate long-term reductions in smoking among daily smokers undergoing a quit attempt

A Smartphone Physical Activity App for Patients in Alcohol Treatment: Single-Arm Feasibility Trial

BackgroundAlcohol use disorder (AUD) is a significant public health concern worldwide. Alcohol consumption is a leading cause of death in the United States and has a significant negative impact on individuals and society. Relapse following treatment is common, and adjunct intervention approaches to improve alcohol outcomes during early recovery continue to be critical. Interventions focused on increasing physical activity (PA) may improve AUD treatment outcomes. Given the ubiquity of smartphones and activity trackers, integrating this technology into a mobile app may be a feasible, acceptable, and scalable approach for increasing PA in individuals with AUD. ObjectiveThis study aims to test the Fit&Sober app developed for patients with AUD. The goals of the app were to facilitate self-monitoring of PA engagement and daily mood and alcohol cravings, increase awareness of immediate benefits of PA on mood and cravings, encourage setting and adjusting PA goals, provide resources and increase knowledge for increasing PA, and serve as a resource for alcohol relapse prevention strategies. MethodsTo preliminarily test the Fit&Sober app, we conducted an open pilot trial of patients with AUD in early recovery (N=22; 13/22, 59% women; mean age 43.6, SD 11.6 years). At the time of hospital admission, participants drank 72% of the days in the last 3 months, averaging 9 drinks per drinking day. The extent to which the Fit&Sober app was feasible and acceptable among patients with AUD during early recovery was examined. Changes in alcohol consumption, PA, anxiety, depression, alcohol craving, and quality of life were also examined after 12 weeks of app use. ResultsParticipants reported high levels of satisfaction with the Fit&Sober app. App metadata suggested that participants were still using the app approximately 2.5 days per week by the end of the intervention. Pre-post analyses revealed small-to-moderate effects on increase in PA, from a mean of 5784 (SD 2511) steps per day at baseline to 7236 (SD 3130) steps per day at 12 weeks (Cohen d=0.35). Moderate-to-large effects were observed for increases in percentage of abstinent days (Cohen d=2.17) and quality of life (Cohen d=0.58) as well as decreases in anxiety (Cohen d=−0.71) and depression symptoms (Cohen d=−0.58). ConclusionsThe Fit&Sober app is an acceptable and feasible approach for increasing PA in patients with AUD during early recovery. A future randomized controlled trial is necessary to determine the efficacy of the Fit&Sober app for long-term maintenance of PA, ancillary mental health, and alcohol outcomes. If the efficacy of the Fit&Sober app could be established, patients with AUD would have a valuable adjunct to traditional alcohol treatment that can be delivered in any setting and at any time, thereby improving the overall health and well-being of this population. Trial RegistrationClinicalTrials.gov NCT02958280; https://www.clinicaltrials.gov/ct2/show/NCT0295828