COVID-19 Stroke Apical Lung Examination Study 2: a national prospective CTA biomarker study of the lung apices, in patients presenting with suspected acute stroke (COVID SALES 2)

BACKGROUND

Apical ground-glass opacification (GGO) identified on CT angiography (CTA) performed for suspected acute stroke was developed in 2020 as a coronavirus-disease-2019 (COVID-19) diagnostic and prognostic biomarker in a retrospective study during the first wave of COVID-19.

OBJECTIVE

To prospectively validate whether GGO on CTA performed for suspected acute stroke is a reliable COVID-19 diagnostic and prognostic biomarker and whether it is reliable for COVID-19 vaccinated patients.

METHODS

In this prospective, pragmatic, national, multi-center validation study performed at 13 sites, we captured study data consecutively in patients undergoing CTA for suspected acute stroke from January-March 2021. Demographic and clinical features associated with stroke and COVID-19 were incorporated. The primary outcome was the likelihood of reverse-transcriptase-polymerase-chain-reaction swab-test-confirmed COVID-19 using the GGO biomarker. Secondary outcomes investigated were functional status at discharge and survival analyses at 30 and 90 days. Univariate and multivariable statistical analyses were employed.

RESULTS

CTAs from 1,111 patients were analyzed, with apical GGO identified in 8.5 % during a period of high COVID-19 prevalence. GGO showed good inter-rater reliability (Fleiss κ = 0.77); and high COVID-19 specificity (93.7 %, 91.8-95.2) and negative predictive value (NPV; 97.8 %, 96.5-98.6). In subgroup analysis of vaccinated patients, GGO remained a good diagnostic biomarker (specificity 93.1 %, 89.8-95.5; NPV 99.7 %, 98.3-100.0). Patients with COVID-19 were more likely to have higher stroke score (NIHSS (mean +/- SD) 6.9 +/- 6.9, COVID-19 negative, 9.7 +/- 9.0, COVID-19 positive; p = 0.01), carotid occlusions (6.2 % negative, 14.9 % positive; p = 0.02), and larger infarcts on presentation CT (ASPECTS 9.4 +/- 1.5, COVID-19 negative, 8.6 +/- 2.4, COVID-19 positive; p = 0.00). After multivariable logistic regression, GGO (odds ratio 15.7, 6.2-40.1), myalgia (8.9, 2.1-38.2) and higher core body temperature (1.9, 1.1-3.2) were independent COVID-19 predictors. GGO was associated with worse functional outcome on discharge and worse survival after univariate analysis. However, after adjustment for factors including stroke severity, GGO was not independently predictive of functional outcome or mortality.

CONCLUSION

Apical GGO on CTA performed for patients with suspected acute stroke is a reliable diagnostic biomarker for COVID-19, which in combination with clinical features may be useful in COVID-19 triage.

The attitudes of dental therapists, dental therapy educators and dental therapy students in the South of England towards domiciliary dentistry: a qualitative study

Introduction Dental therapists (DTs) are members of the dental team with a wide scope of practice, who support the provision of dental care to patient groups including those with vulnerabilities. One such group are older patients who are often unable to attend general dental practices to access their dental care. A domiciliary or 'home visit' may be required to deliver this care in a non-clinical setting.Aim To identify how dental therapists and dental therapy educators working in Southern England perceive domiciliary dental services and to explore the possible role of dental therapists in providing domiciliary dentistry.Method A qualitative research design using a thematic approach.Results A total of five focus groups from the three professional groups were held representing a diverse community of therapists. A number of themes emerged including: knowledge of the domiciliary patient; barriers to the provision of domiciliary care; barriers to accessing domiciliary dentistry; overcoming barriers; and benefits of providing domiciliary care.Conclusion The concept of DTs providing domiciliary care was in general viewed positively. Several perceived barriers were reported including contractual, education and training issues. These barriers would need to be overcome to improve dental workforce skill-mix in delivery of domiciliary dental care.

Inequalities in dental caries among Indigenous and non-Indigenous children in Australia: A literature review

Dental caries constitutes one of the most ubiquitous diseases in Australia, with Indigenous children presenting a notably higher prevalence than their non-Indigenous peers. This literature review aims to update the knowledge base developed by Christian and Blinkhorn in 2012, with a particular focus on the contemporary disparities in dental caries between Indigenous and non-Indigenous children. Our research strategy involved a thorough exploration of the Medline, PubMed, and Scopus databases to identify pertinent studies published between 2009 and 2022. Supplementary resources included various government websites and citation searches. We prioritised studies that focused on children aged 5-6 or 12 years-reflecting the World Health Organization's index ages for oral health-and that reported dental caries prevalence and experience indicators. Our review methodology was guided by the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. The updated search, spanning 2009 to 2023, retrieved studies that reported caries estimates exclusively from 2009 to 2014. Within this period, the prevalence of dental caries in Indigenous children's primary teeth ranged between 52% and 77%, while the prevalence in permanent teeth varied from 36% to 60%. This updated review indicated that Indigenous children continue to experience caries at an approximately twice higher rate than non-Indigenous children, sustaining the persisting disparity in caries estimates. The findings from this review show that no discernible improvement in dental caries rates among Australian Indigenous children has been observed in comparison to the previous review; and that Indigenous children continue to experience both higher prevalence and severity of dental caries compared to non-Indigenous children.

Hanna Rion and The Weekly Dispatch's twilight sleep crusade

The story of twilight sleep is an important, yet neglected, episode in the history of obstetric pain relief in Britain. One reason for its neglect in historical writing is that most of the discussion of the therapy took place in newspapers, particularly the Weekly Dispatch Using digitised newspapers, as well as medical journals, this article reconstructs the largely overlooked story of twilight sleep in Britain. Twilight sleep was comprised of two drugs, scopolamine and morphine, which acted together to remove the pain of labour, as well as memory of it. Twilight sleep gained popularity in 1915 in Britain, a year after it became popular in America, on which most scholarship has focused. One of the main advocates for the use of twilight sleep in Britain was Hanna Rion, who wrote a series of weekly articles in 1916 campaigning for its use. Rion's articles, and the response to them, show how the rise in popularity of twilight sleep reflected concerns about a declining birth rate amidst the backdrop of World War I. Through studying twilight sleep we see how women began to see themselves as consumers and shape medical practice, before the natural childbirth movement, which it has traditionally been attributed to. Therefore, twilight sleep provides us with the missing link in the story of obstetric anaesthetics, between the discovery of chloroform in 1847 and the natural childbirth movement in the 1930s.

Antidepressants for the prevention of depression following first-episode psychosis (ADEPP): study protocol for a multi-centre, double-blind, randomised controlled trial

BACKGROUND

Depressive episodes are common after first-episode psychosis (FEP), affecting more than 40% of people, adding to individual burden, poor outcomes, and healthcare costs. If the risks of developing depression were lower, this could have a beneficial effect on morbidity and mortality, as well as improving outcomes. Sertraline is a selective serotonin reuptake inhibitor and a common first-line medication for the treatment of depression in adults. It has been shown to be safe when co-prescribed with antipsychotic medication, and there is evidence that it is an effective treatment for depression in established schizophrenia. We present a protocol for a multi-centre, double-blind, randomised, placebo-controlled clinical trial called ADEPP that aims to investigate the efficacy and cost-effectiveness of sertraline in preventing depression after FEP.

METHODS

The recruitment target is 452 participants between the ages of 18 and 65 years who are within 12 months of treatment initiation for FEP. Having provided informed consent, participants will be randomised to receive either 50 mg of sertraline daily or matched placebo for 6 months, in addition to treatment as usual. The primary outcome measure will be a comparison of the number of new cases of depression between the treatment and placebo arms over the 6-month intervention phase. Secondary outcomes include suicidal behaviour, anxiety, rates of relapse, functional outcome, quality of life, and resource use.

DISCUSSION

The ADEPP trial will test whether the addition of sertraline following FEP is a clinically useful, acceptable, and cost-effective way of improving outcomes following FEP.

TRIAL REGISTRATION

ISRCTN12682719 registration date 24/11/2020.

Dissection-related tandem occlusion may be different from atherothrombotic tandem occlusion

OBJECTIVES

The optimal endovascular treatment for tandem occlusion in anterior circulation ischaemic stroke remains unknown. The aim of this study was to examine how the aetiology of carotid pathology, dissection versus atherothrombosis, affects clinical outcomes.

MATERIALS AND METHODS

Data was obtained from prospectively collected registries from two stroke centres between April 2016 and December 2020. Tandem cases with complete cervical internal carotid artery (ICA) occlusion or near-total occlusion (≥90% stenosis) were included. Patients were divided into two groups based on carotid pathology: dissection versus atherothrombosis.

RESULTS

A total of 134 patients were included: 36 were dissection and 98 were atherothrombosis. The dissection group had better clinical outcomes compared to the atherothrombosis group, although after adjusting for age and stroke risk factors differences were non-significant. In the non-stented cohort, the dissection patients achieved a better outcome (modified Rankin scale 0-2) than atherothrombotic patients (57% vs. 34%, p=0.04) at 90-days.

CONCLUSION

Dissection-related tandem occlusions appear to have different clinical features from atherothrombotic tandem occlusions which suggests different management strategies are needed.

Veterinary nursing in the United Kingdom: Identifying the factors that influence retention within the profession

The UK regulatory body for registered veterinary nurses (RVNs), the Royal College of Veterinary Surgeons (RCVS), maintains the professional register of RVNs. Every year, a proportion fail to re-join the register. This research aimed to identify the factors that predict retention and to make recommendations to inform the Royal College of Veterinary Surgeons as the regulator as well as both the veterinary nursing and veterinary professions. An analysis of the raw quantitative data generated by the 2014 and 2019 RCVS surveys of the veterinary nurse profession was undertaken using multivariable logistic regression analysis. First, bivariable associations were estimated using unadjusted odds ratios to explore whether there are any (unconditional) associations between each predictor and the outcome. Predictors that were significant unconditional predictors of intention to leave were then entered into a multivariable logistic regression, yielding adjusted odds ratios. Quantitative analysis found significant relationships between intention to leave and the following factors in both the 2014 and 2019 survey data: job satisfaction; believing that veterinary nursing offers good opportunities for career progression; satisfaction with employer support; and having a second job. The following factors were significant in 2014, but not in 2019: undertaking nurse clinics, feeling valued, and being respected by veterinary surgeons. The factors that influence the retention of registered veterinary nurses (RVNs) within the profession are multifactorial and individual. Nurses are responsible for ensuring that those they work with are aware of their skill set and that they themselves are accountable for utilisation of those skills. When veterinary nurses are supported by their employers, they are more likely to stay in the profession. Having a clearly defined career structure and mapped routes for progression will be helpful with retention. A sense of job satisfaction was another important factor in retention. A pay structure linked to a career pathway framework, such as in human-centred nursing, is an area for further work.

Improving communication of the concept of 'treat-to target' in childhood lupus: a public and patient (PPI) engagement project involving children and young people

BACKGROUND

A treat-to-target (T2T) approach, where treatment is escalated until a specific target is achieved, and re-escalated if the target is lost, has been proposed as a strategy to improve Childhood Systemic Lupus Erythematosus (cSLE) outcomes. Previous studies involving children and young people (CYP) have identified that the concept of T2T can be difficult to understand by CYP and their families. We aimed to explore the views of CYP participating in existing public and patient involvement (PPI) groups in relation to a proposed animation that is being developed to explain the concept of T2T to CYP who will be eligible for a future cSLE T2T trial.

METHODS

An illustrated animation storyboard was developed on PowerPoint, to be used alongside a contemporaneous voiceover to simulate the animation for CYP participating in three existing CYP PPI groups (GenerationR, Lupus UK, and YOUR RHEUM). Mixed methods were used to generate CYP feedback on the resource, including on-line surveys and qualitative topic-guided discussion, noting CYP suggestions for improvement. Changes were made iteratively to the resources. Pre/post workshop questionnaires to assess the impact of the resource on their understanding of T2T were completed anonymously.

RESULTS

40 CYP were consulted; 16/40 (40%) from GenerationR (median age 15-years [IQR 12-15]), 12/40 (30%) from Lupus UK (median age 27-years [IQR 22-30]), and 12/40 (30%) from YOUR RHEUM (median age 17-years [IQR 16-21]). 62% of respondents had an underlying rheumatic condition. Pre-workshop median participant understanding of T2T was 2/10 [IQR 1-4], on a 1-10 scale (1 = "no understanding at all", 10 = "completely confident in my understanding"). After viewing the resource, participant understanding improved to a median of 9/10 [IQR 8-10], p < 0.0001). Overall, participants felt that the animation greatly improved their understanding of the concept of T2T, making several suggestions for improvement.

CONCLUSION

Involvement of CYP in research is crucial to help improve the design/delivery of studies, ensuring relevance to CYP and their families. This manuscript demonstrates the involvement of CYP in the development of an animation that will be integral to a future clinical trial, helping to describe the T2T approach in a comprehensible way to eligible CYP and their families, supporting study recruitment.

Alterations in white matter microstructure in alcohol and alcohol‐polydrug dependence: Associations with lifetime alcohol and nicotine exposure

Evidence suggests that alcohol dependence (AD) is associated with microstructural deficits in white matter, but the relationship with lifetime alcohol exposure and the impact of polydrug dependence is not well understood. Using diffusion tensor magnetic resonance (MR) imaging, we examined white matter microstructure in relation to alcohol and polydrug dependence using data from the Imperial College Cambridge Manchester (ICCAM) platform study. Tract‐based spatial statistics were used to examine fractional anisotropy (FA) in a cohort of abstinent AD participants, most of whom had a lifetime history of dependence to nicotine. A further subgroup also had a lifetime history of dependence to cocaine and/or opiates. Individuals with AD had lower FA throughout the corpus callosum, and negative associations with alcohol and nicotine exposure were found. A group‐by‐age interaction effect was found showing greater reductions with age in the alcohol‐dependent group within corpus callosum, overlapping with the group difference. We found no evidence of recovery with abstinence. A comparison of alcohol‐only‐ and alcohol‐polydrug‐dependent groups found no differences in FA. Overall, our findings show that AD is associated with lower FA and suggest that these alterations are primarily driven by lifetime alcohol consumption and cigarette smoking, showing no relationship with exposure to other substances such as cocaine, opiates or cannabis. Reductions in FA across the adult lifespan are more pronounced in AD and offer further support for the notion of accelerated ageing in relation to alcohol dependence. These findings highlight there may be lasting structural differences in white matter in alcohol dependence, despite continued abstinence.

Oral Health in the Population Assessment of Tobacco and Health Study

Tobacco use is a well-established risk factor for multiple adverse oral conditions. Few nationally representative oral health data sets encompass the current diversity of tobacco and nicotine products. This investigation examines the validity of oral health measures in the Population Assessment of Tobacco and Health (PATH) Study to assess relationships between tobacco use and oral health. Cross-sectional data from PATH Study wave 4 (N = 33,643 US adults, collected 2016-2018) were used to obtain estimates for 6 self-reported oral conditions (e.g., bone loss around teeth, tooth extractions) and compared with analogous estimates from the National Health and Nutrition Examination Survey (NHANES) cycle 2017-2018 (N = 5,856). Within the PATH Study, associations were calculated between tobacco use status and lifetime and past 12-mo experience of adverse oral conditions using survey-weighted multivariable logistic regression. Nationally representative estimates of oral conditions between the PATH Study and NHANES were similar (e.g., ever-experience of bone loss around teeth: PATH Study 15.2%, 95% CI, 14.4%-15.9%; NHANES 16.6%, 95% CI, 14.9%-18.4%). In the PATH Study, combustible tobacco smoking was consistently associated with lifetime and past 12-mo experience of adverse oral health (e.g., exclusive cigarette smoking vs. never tobacco use, adjusted odds ratio [AOR] for loose teeth in past 12 mo: 2.02; 95% CI, 1.52-2.69). Exclusive smokeless tobacco use was associated with greater odds of loose teeth (AOR, 1.93; 95% CI, 1.15-3.26) and lifetime precancerous lesions (AOR, 3.85; 95% CI, 1.73-8.57). Use of other noncigarette products (e.g., pipes) was inconsistently associated with oral health outcomes. PATH Study oral health measures closely align with self-reported measures from NHANES and are internally concurrent. Observed associations with tobacco use and the ability to examine emerging tobacco products support application of PATH Study data in dental research, particularly to examine potential oral health effects of novel tobacco products and longitudinal changes in tobacco use behaviors.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

768 PREDICTORS OF INDEPENDENCE IN COMMUNITY-DWELLING OLDER PEOPLE

Introduction

Many people wish to retain their independence as they age. Therefore, identifying factors that can predict sustainability of independence for older people over time are essential for preventing functional decline and maintaining quality of life.

Method

Longitudinal, health, social and economic data, from community-dwelling older people aged ≥75 years (collected at baseline (BL), 6, 12, 24 and 48 months), were obtained from the ongoing Community Ageing Research (CARE 75+) cohort study. Linear regression models were used to identify predictors of independence. The Nottingham Extended Activities of Daily Living (NEADL) score (range 0–66) at 12 months from BL was the dependent variable (DV) to indicate independence. Independent variables (IV)s were selected based on interviews with CARE75+ participants and known predictors such as, ethnicity and frailty. Each IV was regressed against the DV in univariable analyses. All IVs with p value &lt;0.1 from univariable analyses, including baseline NEADL score, were included in the multivariable model.

Results

Data from 1,277 participants (mean (SD) age 84.61 (4.95); 49% male) were analysed. The multivariable model (adjusted R2: 0.71) showed that, in addition to higher BL NEADL (estimated effect 0.49, 95% confidence interval (CI) 0.41 to 0.58), white ethnicity, good sight, lower level of frailty, ability to perform basic activities of daily living, lower depression score, lower cognitive impairment, younger age, living circumstances, fewer hours of informal support, greater physical functioning and lower pain scores were predictors of a higher NEADL at 12 months (p &lt; 0.05 for all).

Conclusion

As well as physical health, social and psychological variables are important in predicting independence, based on NEADL score, over time. Further research into the mechanisms behind these relationships will be conducted.

696 UNDERSTANDING INDEPENDENCE—OLDER PEOPLE’S PERSPECTIVES

Introduction

Independence is an important personal goal for many older people. Achieving this goal in practice requires a shared-understanding of independence between older people and those supporting them, but a consensus of understanding remains elusive. This study aims to provide a basis for a person-centred understanding of independence by identifying which factors are important to the meaning, and experience, of independence for older people.

Method

In-depth interviews were conducted to explore the understandings of community-dwelling older people. Participants were purposively sampled from the Community Ageing Research 75+ cohort study. Analysis was guided by the Framework approach. Themes were identified through deductive and inductive exploration of the transcripts.

Results

Fourteen older people were interviewed ranging from 76–98 years old, six were male. Five themes were identified. The first three themes: participation, autonomy and control, underpinned participants’ understandings of independence. Engaging in meaningful activities, making decisions, and having control over help received were fundamental to participants’ understandings of independence. These three themes provided the common building blocks for unique configurations of independence. The importance of psychological qualities to the facilitation of independence, as they enabled participants to navigate environmental and social set-backs, presented a fourth theme, ‘Mind over Matter’. The final theme, ‘Participation reinforces psychological qualities’ represented the virtuous circle through which participation in meaningful activities reinforced the psychological attributes necessary to maintain independence.

Conclusion

Meanings of independence are as diverse as the people who develop them, whatever the age group. For the older participants of this study, despite differences, the meaning and facilitation of independence comprised several common themes. Achieving independence was a case of ‘Mind over Matter’ requiring personal effort, irrespective of environmental supports. Participation in meaningful activities was both a goal of independence and a means to reinforce the psychological qualities and energy needed to maintain it.

244 Traumatic Brain Injury Related Paediatric Mortality and Morbidity in Low- And Middle-Income Countries: A Systematic Review and Meta-Analysis

Aim

Three million cases of paediatric traumatic brain injury (pTBI) occur annually, the majority of which occur in low-and-middle-income countries (LMICs). However, there is a paucity of data on the outcomes of pTBI available. We aimed to systematically review and synthesise the reported morbidity and mortality from pTBI in the published literature about LMICs.

Method

A systematic review and meta-analysis were conducted. MEDLINE, EMBASE, Global Health, and Global Index Medicus were searched for relevant articles from January 2000 to May 2020. Observational or experimental studies on pTBI (individuals between the ages of 0 to 16 years) in LMICs were included. Morbidity data were descriptively analysed, and a random-effects model was used to pool mortality rates. PROSPERO ID: CRD42020171276.

Results

We included 145 studies from 38 countries representing 174073 patients with pTBI. Males were twice (95% CI: 1.6 – 2.4) as likely to have a pTBI than females. Where available, mild TBI represented ≥ 60% of all pTBI cases in most reports (n = 24/43, 56%). The commonest cited cause of pTBI was road traffic accidents (n = 16643/43083, 39%), followed by falls (n = 10927/43083, 25%). 4385 patients (n = 4385/18092, 24%) had a reduction from normal function on discharge. On average, there were 6.7 deaths per 100 cases of pTBI.

Conclusions

Only 38 LMICs have published data on the volume and burden of pTBI in their country. Limited data available suggests that young male children are at a high-risk of pTBIs in LMICs, particularly from road traffic accidents.

Impact of COVID-19 Pandemic on a Regional Stroke Thrombectomy Service in the United Kingdom

INTRODUCTION

We examined the impact of the coronavirus disease 2019 (COVID-19) pandemic on our regional stroke thrombectomy service in the UK.

METHODS

This was a single-center health service evaluation. We began testing for COVID-19 on 3 March and introduced a modified "COVID Stroke Thrombectomy Pathway" on 18 March. We analyzed the clinical, procedural and outcome data for 61 consecutive stroke thrombectomy patients between 1 January and 30 April. We compared the data for January and February ("pre-COVID," n = 33) versus March and April ("during COVID," n = 28).

RESULTS

Patient demographics were similar between the 2 groups (mean age 71 ± 12.8 years, 39% female). During the COVID-19 pandemic, (a) total stroke admissions fell by 17% but the thrombectomy rate was maintained at 20% of ischemic strokes; (b) successful recanalization rate was maintained at 81%; (c) early neurological outcomes (neurological improvement following thrombectomy and inpatient mortality) were not significantly different; (d) use of general anesthesia fell significantly from 85 to 32% as intended; and (e) time intervals from onset to arrival, groin puncture, and recanalization were not significantly different, whereas internal delays for external referrals significantly improved for door-to-groin puncture (48 [interquartile range (IQR) 39-57] vs. 33 [IQR 27-44] minutes, p = 0.013) and door-to-recanalization (82.5 [IQR 61-110] vs. 60 [IQR 55-70] minutes, p = 0.018).

CONCLUSION

The COVID-19 pandemic has had a negative impact on the stroke admission numbers but not stroke thrombectomy rate, successful recanalization rate, or early neurological outcome. Internal delays actually improved during the COVID-19 pandemic. Further studies should examine the effects of the COVID-19 pandemic on longer term outcome.

0314 Resilience to Inhibitory Deficits During Sleep Deprivation is Predicted by Gray Matter Volume in the Ventrolateral and Ventromedial Prefrontal Cortex

Introduction

Stable, trait-like inter-individual resilience to sleep loss has been demonstrated for psychomotor vigilance, mood, subjective sleepiness, and some reasoning tasks, some of which have been associated with specific genetic or neurobiological markers. Resilience to executive control deficits induced by sleep deprivation (SD) has not been explored in terms of neurobiological markers. We, therefore, collected magnetic resonance imaging (MRI) scans of healthy individuals when well rested and correlated gray matter volume with resistance to inhibitory declines during 29 hours of SD.

Methods

Forty-five healthy individuals (22 female) ranging in age from 20 to 43 underwent structural MRI. Within 2-4 days after scanning, participants returned to the lab to undergo one night of SD, during which they completed a standard go/no-go task involving inhibitory processing every 4 hours. Scores were calculated as throughput (correct responses per working minute). The difference between performance in the evening (22:45) versus the performance the next morning (06:45) was calculated as an index of “inhibitory resilience.” Gray matter volume was regressed against the inhibitory resilience measure. Based on prior research, regions were constrained to the ventrolateral prefrontal cortex and ventromedial prefrontal cortex.

Results

Greater resilience against declines in inhibitory capacity during SD was predicted by 1) larger gray matter volume within the ventrolateral prefrontal cortex and 2) reduced volume within the ventromedial prefrontal cortex (p&lt;.05, FWE cluster corrected). These two clusters contributed significant unique explanatory variance to the model (R2=.45, p&lt;.0001).

Conclusion

The ability to sustain performance during an inhibitory go/no-go task during SD was predicted by greater gray matter volume within the ventrolateral prefrontal cortex, a region that has been previously associated with inhibitory capacity, and reduced volume within an area of the ventromedial prefrontal cortex, which is often related to the default mode network. Findings suggest that specific brain networks may confer task-specific resistance to SD.

Support

Defense Advanced Research Projects Agency, DARPA Young Faculty Award: DARPA-12-12-11-YFA-FP-029

0079 Blue Light Exposure Enhances Neural Efficiency of the Task Positive Network During a Cognitive Interference Task

Introduction

Light exposure has powerful effects on the circadian timing of sleep and wake, primarily through the regulation of the secretion of melatonin. However, it is becoming clear that light has additional alerting effects beyond its primary effect on the circadian system. Exposure to light, particularly blue-wavelength light, has been shown to acutely increase brain activation, alertness, and some elementary aspects of cognitive performance such as working memory and emotional anticipation during the day. Whether blue light exposure can have longer-lasting effects on brain activation and performance during more complex cognitive control tasks up to 30-minutes after light cessation is unknown.

Methods

In a sample of 30 healthy adults, we examined the effects of a single 30-minute exposure to either blue (n=14) or amber placebo (n=16) light on subsequent brain activation and performance during the Multi-Source Interference Task (MSIT) measured a half-hour after light cessation using functional magnetic resonance imaging. Mean activation in all regions showing increased task-related activation (i.e., Task Positive Network; TPN) and regions showing decreased activation (i.e., Default Mode Network; DMN) at p&lt;.001 (FWE corrected) was extracted separately for each network in SPM12 and compared between light conditions.

Results

Performance metrics for the MSIT, including accuracy, response time, and cognitive throughput, did not differ between the blue and amber conditions, suggesting that performance was sustained equally between light conditions. However, brain activation within the TPN to the interference condition of the MSIT was significantly lower (p=.024) in the blue relative to the amber condition, with no group differences observed for suppression of the DMN.

Conclusion

Compared to amber, a single exposure to blue light was associated with enhanced neural efficiency a half-hour later as demonstrated by reduced TPN activation to achieve the same level of cognitive performance. Blue light may be an effective method for optimizing neurocognitive performance under some conditions.

Support

US Army Medical Research and Materiel Command: W81XWH-14-1-0571

0315 Gray Matter Volume of the Rostral Medial Prefrontal Cortex is Associated with Resilience to Mood Decline During Overnight Sleep Deprivation

Introduction

Vulnerability to sleep deprivation (SD) has been attributed to inter-individual trait-like differences in the ability to sustain vigilance and subjective alertness, which may have distinct neurobiological substrates. We have previously shown that reduced suppression of the Default Mode Network (DMN) during a cognitive task was predictive of global vulnerability to SD. However, little is known about vulnerability to mood decrements during SD and the underlying neurobiological mechanisms. Using voxel-based morphometry (VBM), we assessed structural differences in gray matter volume (GMV) of a region of the anterior DMN, the medial prefrontal cortex and its association with self-reported mood during 29 hours of SD.

Methods

45 healthy participants (23 male; Ages 20-43) underwent 3T structural magnetic resonance imaging (MRI). Within 4 days, participants underwent an overnight SD session (29 hours awake total) which included hourly mood assessments with several visual analog mood scales (VAMS) assessing positive and negative affect. Hourly VAMS data were converted into a comparative metric of percent worsening of mood scores from 19:00 until noon the next day. These scores were averaged to determine a “mood resilience” score, with higher scores indicating greater mood sustainment. Using SPM12, the mean mood resilience scores were correlated with whole-brain gray matter volume, restricted to the medial prefrontal cortex, p&lt;.05, FWE corrected, with a cluster threshold of 137 voxels.

Results

Overnight mood resilience was significantly correlated with greater grey matter volume in right rostral medial prefrontal cortex (p&lt;.05, corrected; k=137).

Conclusion

Individuals with greater gray matter volume within a circumscribed region of the right medial prefrontal cortex demonstrated greater resilience to mood degradation over 29 hours of continuous wakefulness. This same region of the brain has been shown to be critical for the passive maintenance of emotions. We speculate that greater GMV could protect against mood decline by better sustaining emotional state during SD.

Support

Defense Advanced Research Projects Agency Young Faculty Award: DARPA-12-12-11-YFA11-FP-029

0263 Later Bedtime is Associated with Differences in Prefrontal Gray Matter Volume and Executive Function Deficits

Introduction

Evening chronotypes tend to have reduced white matter integrity within their axonal tracts and reduced functional connectivity compared to morning types, a pattern that has been attributed to chronic “social jet lag” and its attendant disrupted sleep patterns. It is not clear whether brain differences are due to chronotype, total sleep time (TST), or whether they are associated with actual bedtime exclusive of these other factors. Here we examined morphometric gray matter volume (GMV) and its correlation with bedtime, after controlling for confounding factors.

Methods

Forty-five healthy adults (22 female; aged 20 to 43), completed the Horne-Ostberg Morningness-Eveningness Questionnaire (MEQ) and the Tower of London (TOL), an executive function task of planning and sequencing. Participants wore an actigraph for 7 days and completed structural MRI imaging during the period of actigraphy. Morphometric GMV data were processed using standard procedures in SPM12. After controlling for age, sex, and intracranial volume, actigraphic bedtime was entered into a regression analysis to predict orbitofrontal GMV. Regional GMV was extracted and correlated with TOL performance. Effects of TST and MEQ were also examined during regression.

Results

Later bedtime was associated with increased GMV in the left superior orbitofrontal gyrus (p=.044, FWE corrected). This association remained significant after controlling for TST and MEQ. Moreover, greater GMV in this cluster was associated with poorer planning and sequencing on TOL in terms of excess moves (r=.357, p=.017), and faster response times (r=-.356, p=.018), suggesting impulsivity.

Conclusion

Later bedtime was associated with greater GMV of the orbitofrontal cortex, even after controlling for TST and chronotype, and this pattern was associated with greater impulsiveness and poorer planning. The causal direction of the relationship between bedtime and executive deficits remains unclear and will require further research. However, it is clear that sleep patterns, brain structure, and behavior are intimately related.

Support

Defense Advanced Research Projects Agency Young Faculty Award: DARPA-12-12-11-YFA11-FP-029

1083 Nightmares Are Negatively Associated With Immediate Memory And Visuospatial Performance In Individuals With Ptsd

Introduction

Disturbing dreams and nightmares are common in individuals with post-traumatic stress disorder (PTSD). At present, little research has investigated the associations between nightmares and cognition in these individuals. However, a robust body of research has shown memory and attention impairments among those with PTSD. The present study sought to investigate the potential relationships between cognitive performance and nightmares in this population.

Methods

Seventy-five individuals (49 female; Mage=31.8, SDage=8.8) were administered the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), the PTSD Checklist for the DSM-5 (PCL-5), the Insomnia Severity Index (ISI), the Functional Outcomes of Sleep Questionnaire (FOSQ), the Clinician-Administered PTSD Scale (CAPS), and the Disturbing Dreams and Nightmares Index (DDNSI). Five linear regressions were conducted with index scores on the RBANS subscales (immediate memory, visuospatial/constructional, language, attention, and delayed memory) as the dependent variables and PCL-5, ISI, FOSQ, CAPS symptom class subscales (intrusion, avoidance, cognition, and arousal), and DDNSI scores entered stepwise.

Results

A linear regression revealed that nightmares predicted 15% of the variance in RBANS immediate memory scores (R2 change=.152, β=-.390, p=.003). A second linear regression revealed that nightmares predicted 9.6% of the variance in RBANS visual memory scores (R2 change=.096, β=-.310, p=.019). No other independent variables added to either model. None of the independent variables predicted any variance in language, attention, or delayed memory scores.

Conclusion

Our analysis revealed a unique contribution of nightmares to immediate memory and visuospatial performance in individuals with PTSD. This finding was not better explained by variation in PTSD severity or sleep. Because sleep and dreams are implicated in memory consolidation, one explanation for our finding is that highly distressing trauma-related dreams (i.e. nightmares) may lack the same memory-improving qualities as ordinary dreams. Additionally, given that immediate memory and visuospatial functioning utilize working memory, perhaps nightmares and deficits in working memory share similar mechanisms.

Support

W81XWH-14-1-0570

1076 Self-referential Language In Trauma Narratives Predicts Shorter Sleep Duration In Women With Ptsd

Introduction

The use of self-referential language, defined as first-person singular pronouns (e.g. I, me, my), in trauma narratives has been found to predict post-traumatic stress disorder (PTSD) severity. Additionally, taking a self-immersed perspective correlates with higher blood pressure reactivity than a self-distanced perspective. Given this relationship between self-immersed perspectives and physiological processes, we investigated the relationship between self-referential language and sleep in people with PTSD, as dysfunctional sleep is a major treatment target in this disorder.

Methods

Seventy-five participants (49 females; Mage=31.8, SDage=8.8) meeting DSM-5 criteria for PTSD were administered the PTSD Checklist for the DSM-5 (PCL-5) and the Pittsburg Sleep Quality Index (PSQI). Sleep duration was assessed with the PSQI. Participants provided typed descriptions of their traumatic event, which were then analyzed using the Linguistic Inquiry and Word Count 2015 software to count instances of first-person singular pronouns (“I” words). Linear regression, with PCL-5 scores and “I” words entered stepwise, was used to predict scores on the PSQI sleep duration subscale. Use of “I” words between the sexes was also compared.

Results

For females but not males, PTSD severity significantly predicted sleep duration (R2=.207, p=.001). Additionally, the number of “I” words in the trauma narratives predicted an additional 8% of the variance in sleep duration for females (R2 change=.083, β=.288, p=.029) but not males. Females used significantly more self-referential language in their narratives (M=11.84, SD=8.42) compared to males (M=5.25, SD=6.10, p=.001).

Conclusion

After controlling for PTSD severity, self-referential language in trauma narratives significantly predicted shorter sleep duration in females. While speculative, this finding suggests that treatment approaches for PTSD may benefit from a focus on targeting self-referential processes to improve sleep and PTSD in females but not males. As dysfunctional sleep is a hallmark of PTSD, further investigation into this relationship may illuminate a new treatment avenue for this disorder.

Support

W81XWH-14-1-0570

1077 The Association Between Sleep Problems And Risk-taking Behavior Differs Between Racial Majority And Minority Groups

Introduction

Individuals with Post-Traumatic Stress Disorder (PTSD) often experience poor sleep quality and elevated self-destructive behaviors. Among healthy individuals, poor sleep quality can lead to increased risk-taking behavior through decreased inhibition and/or increased willingness to take risks. However, it is unclear whether racial/ethnic background may influence this relationship, in particular among individuals with PTSD. We examined whether the relationship between sleep quality and risk propensity would differ between majority and minority racial groups in individuals with PTSD.

Methods

Seventy-six individuals (61.8% female; mean age=31.7, SD=8.8) with a clinical diagnosis of PTSD were administered the Functional Outcomes of Sleep Questionnaire (FOSQ) as a measure of sleep-related functional impairment of daily activities, and the Evaluation of Risk (EVAR) Scale as a measure of risk-taking propensity. Forty-seven individuals identified with the majority racial group (Caucasian) and 29 individuals identified themselves within the minority.

Results

There were no significant group differences for FOSQ and total EVAR risk-taking scores. However, the strength of association between measures differed significantly between groups (Z=1.95, p=.051). For the racial/ethnic majority, functional impairments due to lack of sleep were positively associated with risk-taking propensity (r=.460, p=.001); this relationship was not present for the minority group (r=.016, p=.936).

Conclusion

Self-reported functional impairments due to sleep loss significantly correlated with risk-taking propensity for those who identified themselves as part of the majority racial group but not for individuals who identified as part of a racial minority. Findings suggest that broad conclusions regarding the association between sleep disruption and risk-taking may not apply equally across racial/ethnic groups and such factors should be considered when evaluating studies of sleep and risk behaviors. Whether these differing effects are due to cultural factors or stable differences in biology is not known and will require additional research.

Support

W81XWH-14-1-0570

0430 Meta-Analysis on the Effects of Caffeine on Neurodegenerative Cognitive Decline

Introduction

Mild cognitive impairment (MCI), Alzheimer’s disease (AD), and dementia are common forms of neurodegenerative cognitive decline in aging populations. Alertness, attention, and sleep patterns are often impaired in dementia and MCI and can affect ongoing cognition. Given the current lack of treatment options, it is important to identify protective factors. Caffeine is a commonly consumed substance which has been demonstrated in previous observational studies to have a protective effect on the onset of MCI and the progression of MCI to AD.

Methods

A meta-analysis of longitudinal prospective cohort studies published up to December 2017 was conducted comparing highest vs lowest reported category of caffeine consumption on neurodegenerative outcomes. Three databases were searched including PubMed, EMBASE, and Web of Science. Two investigators independently extracted data and assessed study quality. 13 studies were selected including 94880 participants. The effect size was reported as RRs with ORs and HRs treated as approximations of the RRs.

Results

A meta-analysis conducted using random effects showed a pooled RR of .84, 95% CI (0.75, 0.93) indicating a moderate protective effect in higher levels of caffeine consumption compared to lower levels. By outcome, AD had a RR of 1.14 with 95% CI (0.69, 1.90); dementia had a RR of 0.81 (0.72, 0.92); cognitive decline had a RR of 0.81 (0.55, 1.18); and MCI had a RR of 0.78 (0.65, 0.93).

Conclusion

Overall this meta-analysis suggests that compared with the lowest category, the highest caffeine intake category is inversely related to the incidence of age-related cognitive disorders, with this relationship being most apparent for dementia and MCI. Given that caffeine is well accepted and consumed widely in a variety of forms, caffeine in moderate doses, may prove beneficial in sustaining cognitive functioning. Further work will examine the hypothesis that increased alertness and attention with caffeine may sustain cognition through use dependent plasticity or circadian modulation.

Support

None

Disturbances across whole brain networks during reward anticipation in an abstinent addiction population

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Analytical methods can capture key features of whole brain networks in addiction.

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We compared reward network connectivity in addiction (ADD) and control (CON) groups.

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The ADD group showed disruptions in global network connectivity.

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Global network measures may be more sensitive than traditional voxel-wise analyses.

The prevalent spatial distribution of abnormalities reported in cognitive fMRI studies in addiction suggests there are extensive disruptions across whole brain networks. Studies using resting state have reported disruptions in network connectivity in addiction, but these studies have not revealed characteristics of network functioning during critical psychological processes that are disrupted in addiction populations. Analytic methods that can capture key features of whole brain networks during psychological processes may be more sensitive in revealing additional and widespread neural disturbances in addiction, that are the provisions for relapse risk, and targets for medication development. The current study compared a substance addiction (ADD; n = 83) group in extended abstinence with a control (CON; n = 68) group on functional MRI (voxel-wise activation) and global network (connectivity) measures related to reward anticipation on a monetary incentive delay task. In the absence of group differences on MID performance, the ADD group showed reduced activation predominantly across temporal and visual regions, but not across the striatum. The ADD group also showed disruptions in global network connectivity (lower clustering coefficient and higher characteristic path length), and significantly less connectivity across a sub-network comprising frontal, temporal, limbic and striatal nodes. These results show that an addiction group in extended abstinence exhibit localised disruptions in brain activation, but more extensive disturbances in functional connectivity across whole brain networks. We propose that measures of global network functioning may be more sensitive in highlighting latent and more widespread neural disruptions during critical psychological processes in addiction and other psychiatric disorders.

Fronto-striatal Brain Dysfunction in Adults with Hyperactive/inattentive Behaviours Followed up from Childhood During Interference Inhibition and Attention Allocation

Functional magnetic resonance imaging studies (fMRI) in children with Attention Deficit Hyperactivity Disorder (ADHD) have observed functional abnormalities in fronto-striatal and temporo-parietal brain regions during tasks of inhibitory and attention control. However, hardly any modern functional imaging studies have investigated functions of interference inhibition or attention control in adult ADHD.

We used fMRI combined with a variant of the Simon task that measures interference inhibition as well as attention allocation to compare 11 medication-naïve adults (26-30 yrs) with inattentive/hyperactive behaviours and 15 age-matched healthy controls. Patients were followed up from childhood ADHD, recruited from a 20-year prospective longitudinal epidemiological study. All met criteria for inattentive/hyperactive behaviours on an Adult Hyperactive Interview, but only 8 met clinical diagnostic criteria for ADHD. Correlation analyses were furthermore conducted within patients to correlate symptoms with brain activation. Functional connectivity analyses for group differences in fronto-striatal connectivity will be presented at the conference.

No differences were observed in task performance. During interference inhibition, adults with persistent inattentive/hyperactive compared to controls showed reduced activation in predominantly left orbitofrontal and medial cortex, caudate and putamen. During attention allocation adults with hyperactive behaviours showed dysfunction in left inferior/dorsolateral prefrontal cortex and in right inferior and superior parietal areas. Correlation analysis showed a significant negative correlation between inattentive/hyperactive behaviours and the parietal activation cluster during interference inhibition. The study demonstrates the continuity of the pattern of fronto-striatal and parietal neurofunctional abnormalities during tasks of interference inhibition and attention allocation from childhood to adult ADHD even with symptomatic improvement.

Can solvated intermediates inform us about nucleation pathways? The case of β-pABA

Using crystallography to search for nucleation pathways: α and β polymorphs of p-aminobenzoic acid.

P1754 Regional left ventricular longitudinal myocardial dysfunction in mitral valve prolapse could be primary

Background

Regional left ventricular dysfunction in patients with mitral valve prolapse (MVP) and normal ejection fraction has been described by different Authors, and recent data point to a dysfunction (prevalently longitudinal strain) of the myocardium of the LV base secondary to dilatation of the mitral annulus.

Purpose

To investigate degree and extent of regional LV dysfunction and its mechanisms in patients with MVP, severe regurgitation and normal global systolic function, compared to patients with equivalent degree of regurgitation but functional etiology (FMR).

Methods

Speckle-tracking echocardiography was performed in 30 controls (N), and in severe primary (MVP, n= 50) or functional (FMR, n= 20) mitral regurgitation, to measure global, regional and segmental longitudinal peak systolic strain (LPSS, %), and time delay of peak maximum strain (TTPd, ms, calculated as time to peak maximum strain - time of aortic valve closure). Maximum and minimum mitral annulus diameters and area were measured with 3D echo. We also evaluated as recommended: LV end-diastolic volume index (EDVi, ml/m2), ejection fraction (EF, %), and left atrial end-systolic volume index (LAESVi, ml/m2) with 2D echo; LV stroke volume index, and non-invasive pulmonary systolic (PSP, mmHg) and diastolic pressures (PDP), mmHg) with Doppler echo.

Results

Age, heart rate, BSA and systolic blood pressure were similar between groups. Atrial fibrillation was present in 34% of MVP and 71% of FMR patients. LV EF was normal in MVP and reduced in FMR (43 ± 14 % vs N, p&lt;.001). LV EDVi (MVP: 77 ± 20 ml/m2; FMR: 107 ± 35, both p&lt;.001 vs N) and LAESVi (MVP: 91 ± 26 ml/m2; FMR: 80 ± 30, both p&lt;.001 vs N) were similarly increased (volume overload) in MVP and FMR, as were PSP (MVP: 42 ± 23 ml/m2; FMR: 52 ± 25, both p&lt;.001 vs N) and PDP (MVP: 16 ± 6 ml/m2; MVP: 15 ± 5, both p&lt;.001 vs N). In FMR, LPSS was reduced globally (-12.8 ± 3.3, p&lt;.001 vs N and MVP) and similarly at LV base, papillary and apical levels. In contrast, in MVP global (-19.4 ± 3.7%) and apical (-23.4 ± 4.5%) LPSS were normal, whereas LV base (-12.3 ± 5.8%, p=.003 vs N) and papillary (-17.1 ± 4%, p=.024 vs N) LPSS were reduced; further, LPSS reduction was localized to the anterior (-16 ± 4, p=.028 vs N), lateral (-17 ± 5, p=.006 vs N) and posterior (-16 ± 6, p=.007 vs N) segments, and was associated with an increased TTPd in the same segments in MVP but not in FMR patients. At multivariate analysis, degree and localisation of regional myocardial dysfunction in patients with MVP was not related to the prolapsing scallop, dimension of the mitral annulus, degree of volume overload or pulmonary pressures, or stroke volume index.

Conclusions

In patients with MVP, severe regurgitation and normal EF, there is a specific dysfunction pattern of regional LV longitudinal function which appears to be primary and not dependent on the degree of preload increase, mitral annulus dilatation, or localization of the prolapsing scallop.

Naltrexone differentially modulates the neural correlates of motor impulse control in abstinent alcohol-dependent and polysubstance-dependent individuals

Identifying key neural substrates in addiction disorders for targeted drug development remains a major challenge for clinical neuroscience. One emerging target is the opioid system, where substance-dependent populations demonstrate prefrontal opioid dysregulation that predicts impulsivity and relapse. This may suggest that disturbances to the prefrontal opioid system could confer a risk for relapse in addiction due to weakened 'top-down' control over impulsive behaviour. Naltrexone is currently licensed for alcohol dependence and is also used clinically for impulse control disorders. Using a go/no-go (GNG) task, we examined the effects of acute naltrexone on the neural correlates of successful motor impulse control in abstinent alcoholics (AUD), abstinent polysubstance-dependent (poly-SUD) individuals and controls during a randomised double blind placebo controlled fMRI study. In the absence of any differences on GNG task performance, the AUD group showed a significantly greater BOLD response compared to the control group in lateral and medial prefrontal regions during both placebo and naltrexone treatments; effects that were positively correlated with alcohol abstinence. There was also a dissociation in the positive modulating effects of naltrexone in the orbitofrontal cortex (OFC) and anterior insula cortex (AIC) of the AUD and poly-SUD groups respectively. Self-reported trait impulsivity in the poly-SUD group also predicted the effect of naltrexone in the AIC. These results suggest that acute naltrexone differentially amplifies neural responses within two distinct regions of a salience network during successful motor impulse control in abstinent AUD and poly-SUD groups, which are predicted by trait impulsivity in the poly-SUD group.

Tricho-hepatic-enteric syndrome (THES) without intractable diarrhoea

Tricho-hepatic-enteric syndrome (THES) is a genetically heterogeneous rare syndrome (OMIM: 222470 (THES1) and 614602 (THES2)) that typically presents in the neonatal period with intractable diarrhoea, intra-uterine growth retardation (IUGR), facial dysmorphism, and hair and skin changes. THES is associated with pathogenic variants in either TTC37 or SKIV2L; both are components of the human SKI complex, an RNA exosome cofactor. We report an 8 year old girl who was diagnosed with THES by the Undiagnosed Disease Program-WA with compound heterozygous pathogenic variants in SKIV2L. While THES was considered in the differential diagnosis, the absence of protracted diarrhoea delayed definitive diagnosis. We therefore suggest that SKIV2L testing should be considered in cases otherwise suggestive of THES, but without the characteristic diarrhoea. We expand the phenotypic spectrum while reviewing the current knowledge on SKIV2L.

Modelling the growth of popliteal artery aneurysms

Background

Popliteal artery aneurysms (PAAs) comprise up to 85 per cent of all peripheral aneurysms. Few longitudinal studies track their progression. This study aimed to track the growth of asymptomatic PAAs in a hospital-based ultrasound service, and compare models of aneurysm growth.

Methods

This retrospective single-centre cohort study included patients who had a PAA on arterial duplex ultrasound imaging of the lower limbs between 1 January 2011 and 1 January 2016. Progression of PAA size and progression to event or intervention were the primary outcome measures.

Results

Some 282 images were analysed: 47 limbs with PAA were included in a cohort of 32 patients (15 had bilateral PAAs). Twenty patients also had an abdominal aortic aneurysm (AAA). Linear multilevel modelling estimated that PAA growth was 2·4 (95 per cent c.i. 1·6 to 3·7) mm a year. Growth was estimated at 0·8 (0·1 to 1·5) mm per year in patients without an AAA and 3·5 (2·9 to 4·2) mm per year in those with a known AAA (previous open repair, previous endovascular aneurysm repair or AAA under surveillance) (P &lt; 0·001).

Conclusion

Growth rates of PAA were heterogeneous but were optimally predicted by multilevel modelling. Patients with an existing AAA may have faster PAA progression than those without.

Characterizing the PAHs in surface waters and snow in the Athabasca region: Implications for identifying hydrological pathways of atmospheric deposition

The composition of polycyclic aromatic hydrocarbons present in snow and surface waters in the Athabasca Oil Sands Region (AOSR) was characterized in order to identify major contributors to the organics detected in rivers and lakes in the region. PAH concentrations, measured by three monitoring programs in 2011, were used to compare the PAH compositions of snow and surface waters across the AOSR. The 2011 dataset includes total (dissolved+particulate) concentrations of thirty-four parent and alkylated PAH compounds in 105 snow, 272 river, and 3 lake samples. The concentration of PAHs in rivers varies seasonally, with the highest values observed in July. The timing of increases in PAH concentrations in rivers coincides with the high river discharge during the spring freshet, indicating that this major hydrological event may play an important role in delivering PAHs to rivers. However, the composition of PAHs present in rivers during this period differs from the composition of PAHs present in snow, suggesting that direct runoff and release of PAHs accumulated on snow may not be the major source of PAHs to the Athabasca River and its tributaries. Instead, snowmelt may contribute indirectly to increases in PAHs due to hydrological processes such as erosion of stream channels, remobilization of PAH-containing sediments, increased catchment runoff, and snowmelt-induced groundwater inputs during this dynamic hydrologic period. Better understanding of transformations of PAH profiles during transport along surface and subsurface flow paths in wetland-dominated boreal catchments would improve identification of potential sources and pathways in the region. The compositional differences highlight the challenges in identifying the origins of PAHs in a region with multiple potential natural and anthropogenic sources particularly when the potential transport pathways include air, soil and water.

What role does diet play in the decline of puffins?

Eleanor Taylor explains how bird lovers are helping conservation charity RSPB understand puffin populations.

Acute naltrexone does not remediate fronto-striatal disturbances in alcoholic and alcoholic polysubstance-dependent populations during a monetary incentive delay task

There is a concerted research effort to investigate brain mechanisms underlying addiction processes that may predicate the development of new compounds for treating addiction. One target is the brain's opioid system, because of its role in the reinforcing effects of substances of abuse. Substance-dependent populations have increased numbers of the mu opioid receptor (MOR) in fronto-striatal regions that predict drug relapse, and demonstrate disturbances in these regions during the processing of non-drug rewards. Naltrexone is currently licensed for alcohol and opiate dependence, and may remediate such disturbances through the blockade of MORs in fronto-striatal reward circuitry. Therefore, we examined the potential acute modulating effects of naltrexone on the anticipation of, and instrumental responding for, non-drug rewards in long-term abstinent alcoholics, alcoholic poly substance-dependent individuals and controls using a monetary incentive delay (MID) task during a randomized double blind placebo controlled functional MRI study. We report that the alcoholic poly substance-dependent group exhibited slower and less accurate instrumental responding compared to alcoholics and controls that was less evident after acute naltrexone treatment. However, naltrexone treatment was unable to remediate disturbances within fronto-striatal regions during reward anticipation and 'missed' rewards in either substance-dependent group. While we have not been able to identify the underlying neural mechanisms for improvement observed with naltrexone in the alcoholic poly-substance dependent group, we can confirm that both substance-dependent groups exhibit substantial neural deficits during an MID task, despite being in long-term abstinence.

Acute D3 Antagonist GSK598809 Selectively Enhances Neural Response During Monetary Reward Anticipation in Drug and Alcohol Dependence

This corrects the article DOI: 10.1038/npp.2016.289.

Acute D3 Antagonist GSK598809 Selectively Enhances Neural Response During Monetary Reward Anticipation in Drug and Alcohol Dependence

Evidence suggests that disturbances in neurobiological mechanisms of reward and inhibitory control maintain addiction and provoke relapse during abstinence. Abnormalities within the dopamine system may contribute to these disturbances and pharmacologically targeting the D3 dopamine receptor (DRD3) is therefore of significant clinical interest. We used functional magnetic resonance imaging to investigate the acute effects of the DRD3 antagonist GSK598809 on anticipatory reward processing, using the monetary incentive delay task (MIDT), and response inhibition using the Go/No-Go task (GNGT). A double-blind, placebo-controlled, crossover design approach was used in abstinent alcohol dependent, abstinent poly-drug dependent and healthy control volunteers. For the MIDT, there was evidence of blunted ventral striatal response to reward in the poly-drug-dependent group under placebo. GSK598809 normalized ventral striatal reward response and enhanced response in the DRD3-rich regions of the ventral pallidum and substantia nigra. Exploratory investigations suggested that the effects of GSK598809 were mainly driven by those with primary dependence on alcohol but not on opiates. Taken together, these findings suggest that GSK598809 may remediate reward deficits in substance dependence. For the GNGT, enhanced response in the inferior frontal cortex of the poly-drug group was found. However, there were no effects of GSK598809 on the neural network underlying response inhibition nor were there any behavioral drug effects on response inhibition. GSK598809 modulated the neural network underlying reward anticipation but not response inhibition, suggesting that DRD3 antagonists may restore reward deficits in addiction.

Polypectomy practices of sub-centimeter polyps in the English Bowel Cancer Screening Programme

BACKGROUND

Most colonic polyps are small, and several polypectomy techniques are available. We aimed to describe the variation in polypectomy techniques employed for the removal of sub-centimeter polyps in relation to polyp characteristics, completeness of histological excision and safety.

METHODS

Prospectively collected data relating to the removal of sub-centimeter polyps over a 3-year period (between January 2010 and December 2012) were retrieved from the English Bowel Cancer Screening Programme.

RESULTS

A total of 147,174 sub-centimeter polyps were removed during 62,679 procedures. For pedunculated polyps, hot snare was most common in the left (median 92 %, IQR 83.3-97.0 %) and right colon (median 75 %, IQR 3-92 %). For non-pedunculated polyps, cold snare was most common in the right colon (median 24 %, IQR 9-47 %); whereas hot snare remained most common in the left colon (median 32 %, IQR 19-49 %). Surgeons were more likely than physicians to use diathermy-assisted techniques (65.6 vs. 56.5 %, p < 0.001). Twelve (0.03 %) bleeding episodes required transfusion with no polypectomy technique dominating and 16 (0.04 %) perforations with 81 % of polypectomies performed using diathermy-assisted techniques. There was substantial variation between screening centers for the completeness of histological excision. For non-pedunculated polyps, histologically confirmed complete excision was more after EMR (23.4 %) compared with other techniques (cold biopsy forceps 17.7 %, cold snare 15.1 %, hot biopsy forceps 19.1 %, hot snare 21.5 %). The use of cold techniques and EMR has increased over time, whereas the use of hot biopsy forceps and hot snare has decreased (p < 0.001).

CONCLUSIONS

The removal of sub-centimeter polyps within the BCSP is safe despite wide variations in practice. The use of cold resection techniques and EMR has increased over time. The histological assessment for completeness of excision is limited and should be confirmed endoscopically at the time of polypectomy.

Observation of the Leggett-Rice effect in a unitary Fermi gas

We observe that the diffusive spin current in a strongly interacting degenerate Fermi gas of (40)K precesses about the local magnetization. As predicted by Leggett and Rice, precession is observed both in the Ramsey phase of a spin-echo sequence, and in the nonlinearity of the magnetization decay. At unitarity, we measure a Leggett-Rice parameter γ=1.08(9) and a bare transverse spin diffusivity D(0)(⊥)=2.3(4)ℏ/m for a normal-state gas initialized with full polarization and at one-fifth of the Fermi temperature, where m is the atomic mass. One might expect γ=0 at unitarity, where two-body scattering is purely dissipative. We observe γ→0 as temperature is increased towards the Fermi temperature, consistent with calculations that show the degenerate Fermi sea restores a nonzero γ. Tuning the scattering length a, we find that a sign change in γ occurs in the range 0<(k(F)a)(-1)≲1.3, where k(F) is the Fermi momentum. We discuss how γ reveals the effective interaction strength of the gas, such that the sign change in γ indicates a switching of branch between a repulsive and an attractive Fermi gas.