Aqueous Radical Initiated Oxidation of an Organic Monolayer at the Air–Water Interface as a Proxy for Thin Films on Atmospheric Aerosol Studied with Neutron Reflectometry

Neutron reflectometry has been used to study the radical initiated oxidation of a monolayer of the lipid 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) at the air-water interface, by aqueous-phase hydroxyl, sulfate and nitrate radicals. The oxidation of organic films at the surface of atmospheric aqueous aerosols can influence the optical properties of aerosol and consequently can impact the Earth’s radiative balance and contribute to modern climate change. The amount of material at the air-water interface was found to decrease on exposure to aqueous-phase radicals and follow a multi-step degradation mechanism. The multi-step degradation mechanism means that lipid molecules in the thin film degrade to form progressively shorter chain surface active products and several reactive steps are required to remove the film from the air-water interface. Calculations to determine the film lifetime indicate that it will take ~4-5 days for the film to degrade to 50 % of its initial amount in the atmosphere and therefore attack by aqueous radicals on organic films is atmospherically important relative to the typical lifetimes of atmospheric aerosol

Serum vitamin D levels, diabetes and cardio-metabolic risk factors in Aboriginal and Torres Strait Islander Australians

Assesses levels of serum 25(OH)D in Aboriginal and Torres Strait Islander Australians and explores relationships between 25(OH)D and cardio-metabolic risk factors and diabetes. Abstract Background: Low levels of serum 25 – hydroxy vitamin D (25(OH)D), have been associated with development of type 2 diabetes and cardiovascular disease (CVD); however there are limited data on serum 25(OH)D in Indigenous Australians, a population at high risk for both diabetes and CVD. We aimed to assess levels of serum 25(OH)D in Aboriginal and Torres Strait Islander Australians and to explore relationships between 25(OH)D and cardio-metabolic risk factors and diabetes. Methods: 592 Aboriginal and/or Torres Strait Islander Australian participants of The eGFR (estimated glomerular filtration rate) Study, a cross-sectional analysis of a cohort study performed in 2007 – 2011, from urban and remote centres within communities, primary care and tertiary hospitals across Northern Territory, Far North Queensland and Western Australia. Assessment of serum 25(OH)D, cardio-metabolic risk factors (central obesity, diabetes, hypertension, history of cardiovascular disease, current smoker, low HDL-cholesterol), and diabetes (by history or HbA1c ≥ 6.5%) was performed. Associations were explored between 25(OH)D and outcome measures of diabetes and number of cardio-metabolic risk factors. Results: The median (IQR) serum 25(OH)D was 60 (45 – 77) nmol/L, 31% had 25(OH)D <50 nmol/L. For participants with 25(OH)D < 50 vs ≥ 50 nmol/L, cardio-metabolic risk profile differed for: diabetes (54%, 36% p < 0.001), past history of cardiovascular disease (16%, 9%, p = 0.014), waist-hip ratio (0.98, 0.92, p < 0.001), urine albumin-creatinine ratio (2.7, 1.5 mg/mmol, p < 0.001). The OR (95% CI) for diabetes was 2.02 (1.03 – 3.95) for people in the lowest vs highest tertiles of 25(OH)D (<53 vs >72 nmol/L, respectively) after adjusting for known cardio-metabolic risk factors. Conclusion: The percentage of 25(OH)D levels <50 nmol/L was high among Aboriginal and Torres Strait Islander Australians from Northern and Central Australia. Low 25(OH)D level was associated with adverse cardio-metabolic risk profile and was independently associated with diabetes. These findings require exploration in longitudinal studies

Reduced cancer incidence in Huntington's disease: analysis in the Registry study

We dedicate this paper to the memory of Raviram Ramesh. BACKGROUND People with Huntington’s disease have been observed to have lower rates of cancers. OBJECTIVE To investigate the relationship between age of onset of HD, CAG repeat length and cancer diagnosis. METHODS Data were obtained from the European Huntington’s disease network REGISTRY study for 6540 subjects. Population cancer incidence was ascertained from the GLOBOCAN database to obtain standardised incidence ratios of cancers in the REGISTRY subjects. RESULTS 173/6528 HD REGISTRY subjects had had a cancer diagnosis. The age-standardised incidence rate of all cancers in the REGISTRY HD population was 0.26 (CI 0.22-0.30). Individual cancers showed a lower age-standardised incidence rate compared with the control population with prostate and colorectal cancers showing the lowest rates. There was no effect of CAG length on the likelihood of cancer, but a cancer diagnosis within the last year was associated with a greatly increased rate of HD onset (Hazard Ratio 18.94, p<0.001). CONCLUSIONS Cancer is less common than expected in the HD population, confirming previous reports. However, this does not appear to be related to CAG length in HTT. A recent diagnosis of cancer increases the risk of HD onset at any age, likely due to increased investigation following a cancer diagnosis

Experiences of men who have sex with men when initiating, implementing, and persisting with HIV pre-exposure prophylaxis

Abstract Introduction HIV pre‐exposure prophylaxis (PrEP) involves the use of antiretroviral medication in HIV‐negative individuals considered to be at risk of acquiring HIV. It has been shown to prevent HIV and has been available in Wales since July 2017. Measuring and understanding adherence to PrEP is complex as it relies on the simultaneous understanding of both PrEP use and sexual activity. We aimed to understand the experiences of men who have sex with men (MSM) living in Wales initiating, implementing and persisting with HIV PrEP. Methods We conducted semistructured interviews with MSM PrEP users in Wales who participated in a cohort study of PrEP use and sexual behaviour. Following completion of the cohort study, participants were invited to take part in a semistructured interview about their experiences of taking PrEP. We aimed to include both individuals who had persisted with and discontinued PrEP during the study. The interview topic guide was informed by the ABC taxonomy for medication adherence and the theory of planned behaviour. We analysed our data using reflexive thematic analysis. Results Twenty‐one participants were interviewed, five having discontinued PrEP during the cohort study. The developed themes focused on triggers for initiating PrEP, habitual behaviour, drivers for discontinuation and engagement with sexual health services. Stigma surrounding both PrEP and HIV permeated most topics, acting as a driver for initiating PrEP, an opportunity to reduce discrimination against people living with HIV, but also a concern around the perception of PrEP users. Conclusion This is the first study to investigate PrEP‐taking experiences incorporating established medication adherence taxonomy. We highlight key experiences regarding the initiation, implementation and persistence with PrEP and describe how taking PrEP may promote positive engagement with sexual health services. These findings may be useful for informing PrEP rollout programmes and need to be explored in other key populations. Patient and Public Contribution PrEP users, in addition to PrEP providers and representatives of HIV advocacy and policy, were involved in developing the topic guide for this study

Between- and within-individual sociodemographic and psychological determinants of PrEP adherence among men who have sex with men prescribed a daily PrEP regimen in Wales

We investigated the determinants of daily PrEP use and coverage of condomless anal sex (CAS) by PrEP among men who have sex with men in Wales, UK. We measured PrEP use by electronic monitors and CAS by secure online surveys. We defned PrEP use based on daily medication cap openings and coverage as CAS episodes preceded by≥3 days of PrEP use and followed by≥2 days of PrEP use. We included 57 participants (5463 observations). An STI diagnosis was associated with lower PrEP use but also lower PrEP coverage. Older adults had higher PrEP use. A belief that other PrEP users took PrEP as prescribed was associated with lower PrEP coverage. An STI diagnosis is an important cue for an intervention, refecting episodes of high-risk sexual behaviour and low PrEP coverage. Other results provide a basis for the development of an evidence-informed intervention for promoting coverage of PrE

General practitioners' views on reattribution for patients with medically unexplained symptoms: a questionnaire and qualitative study

Background: The successful introduction of new methods for managing medically unexplained symptoms in primary care is dependent to a large degree on the attitudes, experiences and expectations of practitioners. As part of an exploratory randomised controlled trial of reattribution training, we sought the views of participating practitioners on patients with medically unexplained symptoms, and on the value of and barriers to the implementation of reattribution in practice. Methods: A nested attitudinal survey and qualitative study in sixteen primary care teams in north-west England. All practitioners participating in the trial (n = 74) were invited to complete a structured survey. Semi-structured interviews were undertaken with a purposive sub-sample of survey respondents, using a structured topic guide. Interview transcripts were used to identify key issues, concepts and themes, which were grouped to construct a conceptual framework: this framework was applied systematically to the data. Results: Seventy (95%) of study participants responded to the survey. Survey respondents often found it stressful to work with patients with medically unexplained symptoms, though those who had received reattribution training were more optimistic about their ability to help them. Interview participants trained in reattribution (n = 12) reported that reattribution increased their confidence to practice in a difficult area, with heightened awareness, altered perceptions of these patients, improved opportunities for team-building and transferable skills. However general practitioners also reported potential barriers to the implementation of reattribution in routine clinical practice, at the level of the patient, the doctor, the consultation, diagnosis and the healthcare context. Conclusion: Reattribution training increases practitioners' sense of competence in managing patients with medically unexplained symptoms. However, barriers to its implementation are considerable, and frequently lie outside the control of a group of practitioners generally sympathetic to patients with medically unexplained symptoms and the purpose of reattribution. These findings add further to the evidence of the difficulty of implementing reattribution in routine general practice

Early impact of COVID-19 social distancing measures on reported sexual behaviour of HIV pre-exposure prophylaxis users in Wales

Objectives To describe the early impact of COVID-19 and associated control measures on the sexual behaviour of pre-exposure prophylaxis (PrEP) users in Wales. Methods Data were obtained from an ecological momentary assessment study of PrEP use and sexual behaviour. Participants were individuals accessing PrEP through the National Health Service (NHS) sexual health clinics across four health boards in Wales. Weekly data documenting condomless sex in the preceding week were analysed between 03/02/2020 and 10/05/2020. The introduction of social distancing measures and changes to sexual health clinics in Wales occurred on the week starting 16/03/2020. Two-level logistic regression models were fitted to condomless sex (yes/no) over time, included an indicator for the week starting 16/03/2020, and were extended to explore differential associations by relationship status and sexual health clinic. Results Data were available from 56 participants and included 697 person-weeks (89% of the maximum number that could have been obtained). On average, 42% of participants reported condomless sex in the period prior to the introduction of social distancing measures and 20% reported condomless sex after (OR=0.16, 95% CI 0.07 to 0.37, p<0.001). There was some evidence to suggest that this association was moderated by relationship status (OR for single participants=0.09, 95% CI 0.06 to 0.23; OR for not single participants=0.46, 95% CI 0.16 to 1.25). Conclusions The introduction of social distancing measures and changes to PrEP services across Wales was associated with a marked reduction in reported instances of condomless sexual intercourse among respondents, with a larger reduction in those who were single compared with those who were not. The long-term impact of COVID-19 and associated control measures on this population’s physical and mental health and well-being requires close examination