Aims to characterize e-cigarette use, users, and effects, in a sample of Electronic Cigarette Causacian, 44% educated to degree level or above. Findings 74% reported not smoking for at least a few weeks since using the e-cigarette and 70% reported reduced urge to smoke.72% of participants used a 'tank' system, most commonly, the eGo-C (23%). Mean duration of use was 10 months. Only 1% reported exclusive use of non-nicotine (0mg) containing liquid. E-cigarettes were generally considered to: be satisfying to use; elicit few side effects; be healthier than smoking; improve cough/breathing; and be associated with low levels of craving. Among ex-smokers, 'time to first vape' was significantly longer than 'time to first cigarette' (t 1104 =11.16, P <0.001) suggesting a lower level of dependence to e-cigarettes. Exsmokers reported significantly greater reduction in craving than current smokers (χ 2 1 =133.66, P<0.0007) although few other differences emerged between these groups.Compared to males, females opted more for chocolate/sweet flavours (χ 2 1 =16.16, P< 0.001) and liked the e-cigarette because it resembles a cigarette(χ 2 3 = 42.65, P< 0.001). Conclusions E-cigarettes tend to be used for smoking cessation but for a longer duration than NRT and were generally regarded as efficacious. Future research should focus on possible long-term health risks, abuse liability and cessation efficacy.

The therapeutic application of siRNA shows promise as an alternative approach to small molecule inhibitors for the treatment of human disease. However, the major obstacle to its use has been the difficulty in delivering these large anionic molecules in vivo. In this study, we have investigated whether siRNA-mediated knockdown of p38 MAP kinase mRNA in mouse lung is influenced by conjugation to the non-viral delivery vector cholesterol and the cell penetrating peptides (CPP) TAT(48-60) and penetratin. Initial studies in the mouse fibroblast L929 cell line, showed that siRNA conjugated to cholesterol, TAT(48-60) and penetratin but not siRNA alone achieved a limited reduction of p38 MAP kinase mRNA expression. Intratracheal administration of siRNA resulted in localisation within macrophages and scattered epithelial cells and produced a 30-45% knockdown of p38 MAP kinase mRNA at 6hrs. As with increasing doses of siRNA, conjugation to cholesterol improved upon the duration but not the magnitude of mRNA knockdown whilst penetratin and TAT(48-60) had no effect. Importantly, administration of the penetratin or TAT(48-60) peptides alone caused significant reduction in p38 MAP kinase mRNA expression whilst the penetratin-siRNA conjugate activated the innate immune response. Overall, these studies suggest that conjugation to cholesterol may extend but not increase siRNA mediated p38 Figure S1, dose-dependent percentile p38 MAP kinase mRNA levels in vitro following lipofection with three mouse p38 MAP kinase siRNA or two mismatch controls; Figure S2, analytical HPLC and electrospray mass spectrograms of peptide-and cholesteryl-RNA constructs; Figure S3, analytical gels of CPP and cholesterol conjugate annealing products; Figure S4, cell viability following incubation with siRNA, CPP or siRNA conjugates; Figure S5, MAP kinase mRNA knockdown in the lung. Furthermore, the use of CPP may be limited due to as yet uncharacterized effects upon gene expression and a potential for immune activation.

The trans-activation response (TAR) RNA stem–loop that occurs at the 5′ end of HIV RNA transcripts is an important antiviral target and is the site of interaction of the HIV-1 Tat protein together with host cellular factors. Oligonucleotides and their analogues targeted to TAR are potential antiviral candidates. We have investigated a range of cell penetrating peptide (CPP) conjugates of a 16mer peptide nucleic acid (PNA) analogue targeted to the apical stem–loop of TAR and show that disulfide-linked PNA conjugates of two types of CPP (Transportan or a novel chimeric peptide R6-Penetratin) exhibit dose-dependent inhibition of Tat-dependent trans-activation in a HeLa cell assay when incubated for 24 h. Activity is reached within 6 h if the lysosomotropic reagent chloroquine is co-administered. Fluorescein-labelled stably-linked conjugates of Tat, Transportan or Transportan TP10 with PNA were inactive when delivered alone, but attained trans-activation inhibition in the presence of chloroquine. Confocal microscopy showed that such fluorescently labelled CPP–PNA conjugates were sequestered in endosomal or membrane-bound compartments of HeLa cells, which varied in appearance depending on the CPP type. Co-administration of chloroquine was seen in some cases to release fluorescence from such compartments into the nucleus, but with different patterns depending on the CPP. The results show that CPP–PNA conjugates of different types can inhibit Tat-dependent trans-activation in HeLa cells and have potential for development as antiviral agents. Endosomal or membrane release is a major factor limiting nuclear delivery and trans-activation inhibition.

Initial cognitive deficits in ecstasy polydrug users may be more apparent in tasks known to be sensitive to temporal functioning.

The recreational use of ecstasy/MDMA is associated with a range of psychiatric symptoms and psychobiological problems. However, these problems are not specific to ecstasy users but are also evident in other recreational polydrug users.

Twelve heavy recreational ecstasy drug users (30-1000 occasions), 16 light ecstasy users (1 -20 occasions) and 22 non ecstasy user controls, with group mean ages around 21 years, were compared. Three self-rating questionnaires were completed when drug-free: the SCL-90 (an outpatient psychiatric symptom checklist), the impulsiveness venturesomeness and empathy (IVE) scale; and the uplifts, hassles, stresses and cognitive failures questionnaire. Heavy Ecstasy users reported significantly higher scores than controls on the following SCL-90 factors: paranoid ideation, psychoticism, somatisation, obsessionality, anxiety, hostility, phobic anxiety, altered appetite and restless sleep, together with greater IVE impulsiveness. Light ecstasy users generally produced intermediate scores, with significantly higher scores than controls on two factors and significantly lower scores than heavy ecstasy users on another two. Previous reports have described various psychiatric and psychobiological disorders in recreational ecstasy users, but it is not known how typical they are, being mainly based on individual case studies. This is the first study to describe psychological problems in a non clinical sample of young recreational ecstasy users. However, our ecstasy users were polydrug users, with both groups showing significantly greater usage of amphetamine, LSD and cocaine, than the controls. These other illicit drugs probably contributed to their adverse psychobiological profiles, while there is also the possibility of pre-existing differences between ecstasy users and non users. However, since repeated MDMA can cause serotonergic neurotoxicity in laboratory animals and man, these problems may reflect reduced serotonin activity induced by regular ecstasy use.

No abstract

Synthetic siRNA duplexes are used widely as reagents for silencing of mRNA targets in cells and are being developed for in vivo use. Serum stability is a major concern if siRNA is to be used for therapeutic delivery within blood circulation. We have developed the use of MALDI-TOF mass spectrometry as a rapid and convenient analytical tool to identify the most vulnerable sites within siRNA to serum degradation. Using this approach, we found that one siRNA duplex (Dh3) with UpA sequences close to one end was particularly vulnerable to rapid cleavage. This produced a fragment of mass consistent with the presence of a 2′,3′-cyclic phosphate that was slowly hydrolysed to a 2′-(3′-)phosphate on extended incubation. Substitution of these sites with 2′-Omethyl U residues prevented cleavage and confirmed that the major pathway for initial degradation is via cleavage by an RNAse A-like activity. Mass spectral analysis was used to follow the serum degradation of siRNA over more prolonged periods to show the accumulation of many fragments, almost all showing cleavage following pyrimidine nucleoside residues. Overall, the MALDI-TOF mass spectral analysis technique should prove useful for preliminary screening of the serum stability of siRNA duplexes and for identification of the most vulnerable cleavage sites.