53 research outputs found

    Psychotic-like experiences with cannabis use predict cannabis cessation and desire to quit- A cannabis discontinuation hypothesis

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    Background Evidence suggests that cannabis-induced psychotic-like experiences may be a marker of psychosis proneness. The effect of such experiences on cannabis use has not systematically been examined.Methods We undertook a mixed-methods online survey of 1231 cannabis users (including 926 continued users) using the Cannabis Experiences Questionnaire. We examined the effect of psychotic-like and pleasurable experiences on cessation of cannabis and intention to quit. Socio-demographic variables, cannabis use parameters and substance misuse history were included as covariates. Free-text data explored subjective reasons for changes in use.Results Cessation of cannabis use was associated with greater psychotic-like experiences [p < 0.001, Exp(B) 1.262, 95% confidence interval (CI) 1.179-1.351], whilst continued cannabis users were more likely to report pleasurable experiences [p < 0.001, Exp(B) 0.717, 95% CI 0.662-0.776]. Intention to quit cannabis in continued users was associated with greater psychotic-like experiences [p < 0.003, Exp(B) 1.131, 95% CI 1.044-1.225], whilst intention to not quit was significantly associated with increased pleasurable experiences [p < 0.015, Exp(B) 0.892, 95% CI 0.814-0.978]. Whereas former users clearly ascribed cessation to negative experiences, continued users who expressed intention to quit less readily ascribed the intention to negative experiences.Conclusions Elucidation of psychotic-like experiences may form the basis of a therapeutic intervention for those who wish to quit. Cessation in those with cannabis-induced psychotomimetic experiences may offset the risk for the development of a psychotic disorder, in this higher risk group

    Biasing effects of receptor-ligand complexes on protein-unfolding statistics

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    Protein receptor-ligand pairs are increasingly used as specific molecular handles in single-molecule protein-unfolding experiments. Further, known marker domains, also referred to as fingerprints, provide unique unfolding signatures to identify specific single-molecule interactions, when receptor-ligand pairs themselves are investigated. We show here that in cases where there is an overlap between the probability distribution associated with fingerprint domain unfolding and that associated with receptor-ligand dissociation, the experimentally measured force distributions are mutually biased. This biasing effect masks the true parameters of the underlying free energy landscape. To address this, we present a model-free theoretical framework that corrects for the biasing effect caused by such overlapping distributions

    Early life determinants induce sustainable changes in the gut microbiome of six-year-old children

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    While the association between early life determinants and the development of the gut microbiome composition in infancy has been widely investigated, a potential persistent influence of early life determinants on the gut microbial community after its stabilization at later childhood remains largely unknown. Therefore, we aimed to identify the association between several early life determinants and the gut microbiome composition in six-year-old children from the LISA birth cohort. A total number of 166 fecal samples were analyzed using 16S rRNA gene-based barcoding to assess bacterial diversity pattern. The bacterial profiles were investigated for their association with maternal smoking during pregnancy, mode of delivery, breastfeeding, antibiotic treatment between one and two years of age, gender and socioeconomic status (SES). While alpha and beta diversity of the infants' gut microbiome remained unaffected, amplicon sequence variants (ASVs) annotated to Firmicutes and Actinobacteria responded to early life determinants, mostly to feeding practice and antibiotics use. ASVs associated to Bacteriodetes remained unaffected. Our findings indicate that early life determinants could have a long-term sustainable effect on the gut microflora of six-year-old children, however, associations with early life determinates are weaker than reported for infants

    Mechanisms of Nanonewton Mechanostability in a Protein Complex Revealed by Molecular Dynamics Simulations and Single-Molecule Force Spectroscopy

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    Can molecular dynamics simulations predict the mechanical behavior of protein complexes? Can simulations decipher the role of protein domains of unknown function in large macromolecular complexes? Here, we employ a wide-sampling computational approach to demonstrate that molecular dynamics simulations, when carefully performed and combined with single-molecule atomic force spectroscopy experiments, can predict and explain the behavior of highly mechanostable protein complexes. As a test case, we studied a previously unreported homologue from; Ruminococcus flavefaciens; called X-module-Dockerin (XDoc) bound to its partner Cohesin (Coh). By performing dozens of short simulation replicas near the rupture event, and analyzing dynamic network fluctuations, we were able to generate large simulation statistics and directly compare them with experiments to uncover the mechanisms involved in mechanical stabilization. Our single-molecule force spectroscopy experiments show that the XDoc-Coh homologue complex withstands forces up to 1 nN at loading rates of 10; 5; pN/s. Our simulation results reveal that this remarkable mechanical stability is achieved by a protein architecture that directs molecular deformation along paths that run perpendicular to the pulling axis. The X-module was found to play a crucial role in shielding the adjacent protein complex from mechanical rupture. These mechanisms of protein mechanical stabilization have potential applications in biotechnology for the development of systems exhibiting shear enhanced adhesion or tunable mechanics

    Ultrastable cellulosome-adhesion complex tightens under load

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    Challenging environments have guided nature in the development of ultrastable protein complexes. Specialized bacteria produce discrete multi-component protein networks called cellulosomes to effectively digest lignocellulosic biomass. While network assembly is enabled by protein interactions with commonplace affinities, we show that certain cellulosomal ligand-receptor interactions exhibit extreme resistance to applied force. Here, we characterize the ligand-receptor complex responsible for substrate anchoring in the Ruminococcus flavefaciens cellulosome using single-molecule force spectroscopy and steered molecular dynamics simulations. The complex withstands forces of 600-750 pN, making it one of the strongest bimolecular interactions reported, equivalent to half the mechanical strength of a covalent bond. Our findings demonstrate force activation and inter-domain stabilization of the complex, and suggest that certain network components serve as mechanical effectors for maintaining network integrity. This detailed understanding of cellulosomal network components may help in the development of biocatalysts for production of fuels and chemicals from renewable plant-derived biomass

    Towards Precision Muonic X-Ray Measurements of Charge Radii of Light Nuclei

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    Precision studies of the properties of nuclei are essential both for understanding nuclear physics at low energy, and for confronting experiment and theory in simple atomic systems. Such comparisons advance our understanding of bound-state quantum electrodynamics and are useful for searching for new physics beyond the Standard Model. The energy levels of muonic atoms are highly susceptible to nuclear structure, especially to the RMS charge radius. The radii of the lightest nuclei (Z=1,2Z=1,2) have been determined with high accuracy via laser spectroscopy in muonic atoms, while those of medium mass and above, from X-ray spectroscopy with semiconductor detectors. In this communication we present a new experiment aiming at precision measurements of the radii of light nuclei 3≤Z≤103 \leq Z \leq 10 via single-photon energy measurements with cryogenic microcalorimeters; a quantum sensing technology capable of high efficiency and outstanding resolution for low-energy X-rays

    Classic ketogenic diet versus further antiseizure medicine in infants with drug-resistant epilepsy (KIWE): a UK, multicentre, open-label, randomised clinical trial

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    BACKGROUND: Many infancy-onset epilepsies have poor prognosis for seizure control and neurodevelopmental outcome. Ketogenic diets can improve seizures in children older than 2 years and adults who are unresponsive to antiseizure medicines. We aimed to establish the efficacy of a classic ketogenic diet at reducing seizure frequency compared with further antiseizure medicine in infants with drug-resistant epilepsy. METHODS: In this phase 4, open-label, multicentre, randomised clinical trial, infants aged 1-24 months with drug-resistant epilepsy (defined as four or more seizures per week and two or more previous antiseizure medications) were recruited from 19 hospitals in the UK. Following a 1-week or 2-week observation period, participants were randomly assigned using a computer-generated schedule, without stratification, to either a classic ketogenic diet or a further antiseizure medication for 8 weeks. Treatment allocation was masked from research nurses involved in patient care, but not from participants. The primary outcome was the median number of seizures per day, recorded during weeks 6-8. All analyses were by modified intention to treat, which included all participants with available data. Participants were followed for up to 12 months. All serious adverse events were recorded. The trial is registered with the European Union Drug Regulating Authorities Clinical Trials Database (2013-002195-40). The trial was terminated early before all participants had reached 12 months of follow-up because of slow recruitment and end of funding. FINDINGS: Between Jan 1, 2015, and Sept 30, 2021, 155 infants were assessed for eligibility, of whom 136 met inclusion criteria and were randomly assigned; 75 (55%) were male and 61 (45%) were female. 78 infants were assigned to a ketogenic diet and 58 to antiseizure medication, of whom 61 and 47, respectively, had available data and were included in the modifified intention-to-treat analysis at week 8. The median number of seizures per day during weeks 6-8, accounting for baseline rate and randomised group, was similar between the ketogenic diet group (5 [IQR 1-16]) and antiseizure medication group (3 [IQR 2-11]; IRR 1·33, 95% CI 0·84-2·11). A similar number of infants with at least one serious adverse event was reported in both groups (40 [51%] of 78 participants in the ketogenic diet group and 26 [45%] of 58 participants in the antiseizure medication group). The most common serious adverse events were seizures in both groups. Three infants died during the trial, all of whom were randomly assigned a ketogenic diet: one child (who also had dystonic cerebral palsy) was found not breathing at home; one child died suddenly and unexpectedly at home; and one child went into cardiac arrest during routine surgery under anaesthetic. The deaths were judged unrelated to treatment by local principal investigators and confirmed by the data safety monitoring committee. INTERPRETATION: In this phase 4 trial, a ketogenic diet did not differ in efficacy and tolerability to a further antiseizure medication, and it appears to be safe to use in infants with drug-resistant epilepsy. A ketogenic diet could be a treatment option in infants whose seizures continue despite previously trying two antiseizure medications. FUNDING: National Institute for Health and Care Research

    Clinical and cost-effectiveness of contingency management for cannabis use in early psychosis: the CIRCLE randomised clinical trial

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    Background Cannabis is the most commonly used illicit substance among people with psychosis. Continued cannabis use following the onset of psychosis is associated with poorer functional and clinical outcomes. However, finding effective ways of intervening has been very challenging. We examined the clinical and cost-effectiveness of adjunctive contingency management (CM), which involves incentives for abstinence from cannabis use, in people with a recent diagnosis of psychosis. Methods CIRCLE was a pragmatic multi-centre randomised controlled trial. Participants were recruited via Early Intervention in Psychosis (EIP) services across the Midlands and South East of England. They had had at last one episode of clinically diagnosed psychosis (affective or non-affective); were aged 18 to 36; reported cannabis use in at least 12 out of the previous 24 weeks; and were not currently receiving treatment for cannabis misuse, or subject to a legal requirement for cannabis testing. Participants were randomised via a secure web-based service 1:1 to either an experimental arm, involving 12 weeks of CM plus a six-session psychoeducation package, or a control arm receiving the psychoeducation package only. The total potential voucher reward in the CM intervention was ÂŁ240. The primary outcome was time to acute psychiatric care, operationalised as admission to an acute mental health service (including community alternatives to admission). Primary outcome data were collected from patient records at 18 months post-consent by assessors masked to allocation. The trial was registered with the ISRCTN registry, number ISRCTN33576045. Results: 551 participants were recruited between June 2012 and April 2016. Primary outcome data were obtained for 272 (98%) in the CM (experimental) group and 259 (95%) in the control group. There was no statistically significant difference in time to acute psychiatric care (the primary outcome) (HR 1.03, 95% CI 0.76, 1.40) between groups. By 18 months, 90 (33%) of participants in the CM group, and 85 (30%) of the control groups had been admitted at least once to an acute psychiatric service. Amongst those who had experienced an acute psychiatric admission, the median time to admission was 196 days (IQR 82, 364) in the CM group and 245 days (IQR 99,382) in the control group. Cost-effectiveness analyses suggest that there is an 81% likelihood that the intervention was cost-effective, mainly resulting from higher mean inpatient costs for the control group compared with the CM group, however the cost difference between groups was not statistically significant. There were 58 adverse events, 27 in the CM group and 31 in the control group. Conclusions Overall, these results suggest that CM is not an effective intervention for improving the time to acute psychiatric admission or reducing cannabis use in psychosis, at least at the level of voucher reward offered

    Impact of clinical phenotypes on management and outcomes in European atrial fibrillation patients: a report from the ESC-EHRA EURObservational Research Programme in AF (EORP-AF) General Long-Term Registry

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    Background: Epidemiological studies in atrial fibrillation (AF) illustrate that clinical complexity increase the risk of major adverse outcomes. We aimed to describe European AF patients\u2019 clinical phenotypes and analyse the differential clinical course. Methods: We performed a hierarchical cluster analysis based on Ward\u2019s Method and Squared Euclidean Distance using 22 clinical binary variables, identifying the optimal number of clusters. We investigated differences in clinical management, use of healthcare resources and outcomes in a cohort of European AF patients from a Europe-wide observational registry. Results: A total of 9363 were available for this analysis. We identified three clusters: Cluster 1 (n = 3634; 38.8%) characterized by older patients and prevalent non-cardiac comorbidities; Cluster 2 (n = 2774; 29.6%) characterized by younger patients with low prevalence of comorbidities; Cluster 3 (n = 2955;31.6%) characterized by patients\u2019 prevalent cardiovascular risk factors/comorbidities. Over a mean follow-up of 22.5 months, Cluster 3 had the highest rate of cardiovascular events, all-cause death, and the composite outcome (combining the previous two) compared to Cluster 1 and Cluster 2 (all P &lt;.001). An adjusted Cox regression showed that compared to Cluster 2, Cluster 3 (hazard ratio (HR) 2.87, 95% confidence interval (CI) 2.27\u20133.62; HR 3.42, 95%CI 2.72\u20134.31; HR 2.79, 95%CI 2.32\u20133.35), and Cluster 1 (HR 1.88, 95%CI 1.48\u20132.38; HR 2.50, 95%CI 1.98\u20133.15; HR 2.09, 95%CI 1.74\u20132.51) reported a higher risk for the three outcomes respectively. Conclusions: In European AF patients, three main clusters were identified, differentiated by differential presence of comorbidities. Both non-cardiac and cardiac comorbidities clusters were found to be associated with an increased risk of major adverse outcomes
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