Additively-manufactured Mg wire-reinforced PLDL-matrix composites for biomedical applications

Coupons of a medical grade PLDL polymer matrix uniaxially reinforced with a 15% volume fraction of Mg wires have been manufactured by fused filament fabrication for the first time. Two different types of Mg wires, without and with a surface treatment by plasma electrolytic oxidation were used. Both composite materials were subjected to degradation in phosphate buffer solution over a 3-week period, and their degradation and deformation micromechanisms were analysed in detail. Additionally, the materials were subjected to extensive mechanical testing under various loading conditions, and the interface strength was also analysed. It was found that the presence of the Mg wires improves the mechanical behaviour and accelerates the corrosion rate of the composite with respect that of the polymer matrix and these properties can be further tailored through the surface-modification of Mg wires by plasma electrolytic oxidation. The additive manufacturing strategy presented opens the path to fabricate multimaterial implants and scaffolds with complex shape and tailored properties provided by biodegradable polymers reinforced with either Mg and Zn particles and/or wires.

Improving hybrid image and structure-based deformable image registration for large internal deformations

Objective.Deformable image registration (DIR) is a widely used technique in radiotherapy. Complex deformations, resulting from large anatomical changes, are a regular challenge. DIR algorithms generally seek a balance between capturing large deformations and preserving a smooth deformation vector field (DVF). We propose a novel structure-based term that can enhance the registration efficacy while ensuring a smooth DVF.Approach.The proposed novel similarity metric for controlling structures was introduced as a new term into a commercially available algorithm. Its performance was compared to the original algorithm using a dataset of 46 patients who received pelvic re-irradiation, many of which exhibited complex deformations.Main results.The mean Dice Similarity Coefficient (DSC) under the improved algorithm was 0.96, 0.94, 0.76, and 0.91 for bladder, rectum, colon, and bone respectively, compared to 0.69, 0.89, 0.62, and 0.88 for the original algorithm. The improvement was more pronounced for complex deformations.Significance.With this work, we have demonstrated that the proposed term is able to improve registration accuracy for complex cases while maintaining realistic deformations.

Cytokine signature in convalescent SARS-CoV-2 patients with inflammatory bowel disease receiving vedolizumab

While differential antibody responses SARS-CoV-2 in patients with inflammatory bowel disease (IBD) receiving infliximab and vedolizumab are well-characterized, the immune pathways underlying these differences remain unknown. Prior to COVID-19 vaccine development, we screened 235 patients with IBD receiving biological therapy for antibodies to SARS-CoV-2 and measured serum cytokines. In seropositive patients, we prospectively collected clinical data. We found a cytokine signature in patients receiving vedolizumab who are seropositive compared with seronegative for SARS-CoV-2 antibodies that may be linked to repeated SARS-CoV-2 infections. However, there were no differences between seropositive and seronegative patients receiving infliximab. In this single-center cohort of patients with IBD with anti-SARS-CoV-2 antibodies at the onset of the COVID-19 pandemic, and therefore without influence of vaccination, there is a cytokine signature in patients receiving vedolizumab but not infliximab. These findings lay the groundwork for further studies on immune consequences of viral infection in patients with IBD, which is postulated to evolve from aberrant host-microbe responses.

Anaesthetic records: an evaluation of variation across England

We collected blank non-specialist anaesthetic records from 71 National Health Service Trusts in England. A data set was established by collating all data items found in an initial tranche of 28 records. All 71 records were subsequently analysed for each data item in this data set. We found significant variation: the most populated record included 216 data items and the least included 38 data items: a greater than five-fold variation. There was significant variation in the inclusion of data items commonly considered important to patient safety; 42% of records omitted documentation of fasting status, 72% omitted documentation of a discussion around the risk of accidental awareness during general anaesthesia, 92% omitted documentation of quantitative neuromuscular blockade monitoring and 63% omitted documentation for 'Stop Before You Block' when performing regional anaesthesia. The study highlights significant variability in the composition of anaesthetic records across England which may impact on its value as a data repository, an action trigger, a medicolegal account, and a tool to facilitate safe handover. Standardisation of the anaesthetic record or the establishment of standards of recording would help to allay potential risks to patient safety and assist in guiding future procurement of electronic solutions for anaesthetic records.

The efficacy of the "Talk-to-Me" suicide prevention and mental health education program for tertiary students: a crossover randomised control trial

Despite suicide ideation being one of the most frequently reported health issues impacting tertiary students, there is a paucity of research evaluating the efficacy of preventive interventions aimed at improving mental health outcomes for students studying at two tertiary institutes. The current study evaluated the efficacy of the "Talk-to-Me" Mass Open Online Course (MOOC) in improving tertiary students' abilities to support the mental health of themselves and their peers via a randomised controlled trial design, comparing them to a waitlist control group. Overall, 129 tertiary students (M = 25.22 years, SD = 7.43; 80% female) undertaking a health science or education course at two Western Australian universities were randomly allocated to either "Talk-to-Me" (n = 66) or waitlist control (n = 63) groups. The participants' responses to suicidal statements (primary outcome), knowledge of mental health, generalised self-efficacy, coping skills, and overall utility of the program (secondary outcomes) were collected at three timepoints (baseline 10-weeks and 24-weeks from baseline). Assessment time and group interaction were explored using a random-effects regression model, examining changes in the primary and secondary outcomes. Intention-to-treat analysis (N = 129) at 10-weeks demonstrated a significant improvement in generalised self-efficacy for "Talk-to-Me" compared to the control group (ES = 0.36, p = .04), with only the "Talk-to-Me" participants reporting increased knowledge in responding to suicidal ideation (primary outcome). This change was sustained for 24 weeks. Findings provide preliminary evidence suggesting that the "Talk-to-Me" MOOC can effectively improve tertiary students' mental health and knowledge of how to support themselves and others in distress. ACTRN12619000630112, registered 18-03-2019, anzctr.org.au.

Impact of 5 years of hepatitis C testing and treatment in the North East of England prisons

Hepatitis C virus infection (HCV) is prevalent in prisons. Therefore, effective prison HCV services are critical for HCV elimination programmes. We aimed to evaluate the efficacy of a regional HCV prison testing and treatment programme. Between July 2017 and June 2022, data were collected prospectively on HCV test offer and uptake rates, HCV Antibody (HCV-Ab) and HCV-RNA positivity, treatment starts and outcomes for new inmates incarcerated in three prisons. Rates of HCV-Ab and RNA positivity at reception, incidence of new HCV infections and reinfection following treatment were determined. From a total of 39,652 receptions, 33,028 (83.3%) were offered HCV testing and 20,394 (61.7%) completed testing. Including all receptions, 24.5% of tests (n = 4995) were HCV-Ab positive and 8.4% of tests (n = 1713) were HCV-RNA positive. When considering the first test for each individual (median age 34 years; 88.1% male), 14.8% (n = 1869) and 7.2% (n = 905) were HCV-Ab and HCV-RNA positive, respectively. The incidence of new HCV-Ab and RNA positivity was 5.1 and 3.3 per 100 person-years, respectively. Of 1145 HCV viraemic individuals, 18 died within 6 months and 150 were rapidly transferred out of area, leaving 977 individuals with outcomes. Of these, 835 (85.5%) received antivirals and 47 spontaneously cleared the infection, leaving 95 (9.7%) untreated. 607 (72.7%) achieved SVR. 95 patients had reinfection post-treatment (rate 10.1 cases per 100 person-years). Testing for HCV has increased in our prisons and the majority with viraemia are initiated on antiviral treatment. Reassuringly, a significant fall in frequency of HCV-RNA positivity at prison reception was observed suggesting progress towards HCV elimination.

Geography Influences Susceptibility to SARS-CoV-2 Serological Response in Patients With Inflammatory Bowel Disease: Multinational Analysis From the ICARUS-IBD Consortium

BACKGROUND

Beyond systematic reviews and meta-analyses, there have been no direct studies of serological response to COVID-19 in patients with inflammatory bowel disease (IBD) across continents. In particular, there has been limited data from Asia, with no data reported from India. The ICARUS-IBD (International study of COVID-19 Antibody Response Under Sustained immunosuppression in IBD) consortium assessed serological response to SARS-CoV-2 in patients with IBD in North America, Europe, and Asia.

METHODS

The ICARUS-IBD study is a multicenter observational cohort study spanning sites in 7 countries. We report seroprevalence data from 2303 patients with IBD before COVID-19 vaccination between May 2020 and November 2021. SARS-CoV-2 anti-spike and anti-nucleocapsid antibodies were analyzed.

RESULTS

The highest and lowest SARS-CoV-2 anti-spike seropositivity rates were found in Asia (81.2% in Chandigarh and 57.9% in Delhi, India; and 0% in Hong Kong). By multivariable analysis, country (India: odds ratio [OR], 18.01; 95% confidence interval [CI], 12.03-26.95; P < .0001; United Kingdom: OR, 2.43; 95% CI, 1.58-3.72; P < .0001; United States: OR, 2.21; 95% CI, 1.27-3.85; P = .005), male sex (OR, 1.46; 95% CI, 1.07-1.99; P = .016), and diabetes (OR, 2.37; 95% CI, 1.04-5.46; P = .039) conferred higher seropositivity rates. Biological therapies associated with lower seroprevalence (OR, 0.22; 95% CI, 0.15-0.33; P < .0001). Multiple linear regression showed associations between anti-spike and anti-nucleocapsid titers with medications (P < .0001) but not with country (P = .3841).

CONCLUSIONS

While the effects of medications on anti-SARS-CoV-2 antibody titers in patients with IBD were consistent across sites, geographical location conferred the highest risk of susceptibility to serologically detectable SARS-CoV-2 infection. Over half of IBD patients in India were seropositive prior to vaccination. These insights can help to inform shielding advice, therapeutic choices, and vaccine strategies in IBD patients for COVID-19 and future viral challenges.

South African Institute of Drug-Free Sport Position Statement on CBD (Cannabidiol) and THC (Tetrahydrocannabinol)

Cannabidiol (CBD) and Tetrahydrocannabinol (THC) have become easily available to athletes over the years. Using these substances may inadvertently expose an athlete to the possibility of an adverse analytical finding (a "positive" test) and a sanction. Athletes need to understand the risk of an anti-doping rule violation or adverse analytical finding should these products be used, especially if no therapeutic use exemption exists. This position statement attempts to clarify the use of CBD and THC and their associated risks with Anti-Doping Rule Violations (ADRV) in the athletic population. The South African Sports Medicine Association supports this position statement.

Immersive virtual reality: An effective strategy for reducing stress in young adults

Background:

Psychological stress is ubiquitous in young adults, but traditional relaxation strategies such as mindfulness or meditation are not consistently utilised. Immersive virtual reality (VR) is being increasingly used in mental health contexts with improved clinical outcomes. However, there is limited research exploring the perceived usefulness of VR for individuals without a mental health diagnosis.

Aim:

To identify if an immersive VR experience was effective in reducing stress for young adults and to explore the experience of the participants.

Methods:

Twenty-one young adults aged 18–25 years participated in an immersive VR experience. Heart rate was measured pre- and post-test to objectively establish the efficacy of VR to facilitate relaxation. Participants were invited to participate in a semi-structured interview ( n = 18) to gain a rich understanding of their experience.

Results:

Four themes emerged from analysis of the interviews: I felt relaxed and calm, It was time-efficient and easy to use, It took me to another place and It was different than I thought it would be. Heart rate reduced during the immersive VR experience.

Conclusion:

These findings suggest that immersive VR can reduce psychological stress, and it is perceived by young adults as a useful and time-effective strategy to reduce psychological stress.

Mega-disturbances cause rapid decline of mature conifer forest habitat in California

Mature forests provide important wildlife habitat and support critical ecosystem functions globally. Within the dry conifer forests of the western United States, past management and fire exclusion have contributed to forest conditions that are susceptible to increasingly severe wildfire and drought. We evaluated declines in conifer forest cover in the southern Sierra Nevada of California during a decade of record disturbance by using spatially comprehensive forest structure estimates, wildfire perimeter data, and the eDaRT forest disturbance tracking algorithm. Primarily due to the combination of wildfires, drought, and drought-associated beetle epidemics, 30% of the region's conifer forest extent transitioned to nonforest vegetation during 2011-2020. In total, 50% of mature forest habitat and 85% of high density mature forests either transitioned to lower density forest or nonforest vegetation types. California spotted owl protected activity centers (PAC) experienced greater canopy cover decline (49% of 2011 cover) than non-PAC areas (42% decline). Areas with high initial canopy cover and without tall trees were most vulnerable to canopy cover declines, likely explaining the disproportionate declines of mature forest habitat and within PACs. Drought and beetle attack caused greater cumulative declines than areas where drought and wildfire mortality overlapped, and both types of natural disturbance far outpaced declines attributable to mechanical activities. Drought mortality that disproportionately affects large conifers is particularly problematic to mature forest specialist species reliant on large trees. However, patches of degraded forests within wildfire perimeters were larger with greater core area than those outside burned areas, and remnant forest habitats were more fragmented within burned perimeters than those affected by drought and beetle mortality alone. The percentage of mature forest that survived and potentially benefited from lower severity wildfire increased over time as the total extent of mature forest declined. These areas provide some opportunity for improved resilience to future disturbances, but strategic management interventions are likely also necessary to mitigate worsening mega-disturbances. Remaining dry mature forest habitat in California may be susceptible to complete loss in the coming decades without a rapid transition from a conservation paradigm that attempts to maintain static conditions to one that manages for sustainable disturbance dynamics.

Pyrocumulonimbus affect average stratospheric aerosol composition

Pyrocumulonimbus (pyroCb) are wildfire-generated convective clouds that can inject smoke directly into the stratosphere. PyroCb have been tracked for years, yet their apparent rarity and episodic nature lead to highly uncertain climate impacts. In situ measurements of pyroCb smoke reveal its distinctive and exceptionally stable aerosol properties and define the long-term influence of pyroCb activity on the stratospheric aerosol budget. Analysis of 13 years of airborne observations shows that pyroCb are responsible for 10 to 25% of the black carbon and organic aerosols in the "present-day" lower stratosphere, with similar impacts in both the North and South Hemispheres. These results suggest that, should pyroCb increase in frequency and/or magnitude in future climates, they could generate dominant trends in stratospheric aerosol.

Exploration of caregiver experiences of reported first signs of autism

AIM

This study explored caregiver-reported first signs of autism and caregiver experiences of reporting these signs to health professionals using a multiple methods approach.

BACKGROUND

Within the Australian context, children who have been diagnosed with autism represent a significant proportion of individuals requiring access to disability services. Due to the importance of accessing early intervention services to support future outcomes, it is vital that first signs are noticed, reported, and the diagnosis process begun as soon as possible.

METHOD

Phase 1 of the study included a secondary analysis of a survey of caregivers, while phase 2 consisted of focus groups of caregivers of children on the autism spectrum.

RESULTS

Survey data indicated that most children were aged 12-18 months when first signs were noticed, with first signs noticed earlier in females than males. Children were age 2-6 years when caregivers sought advice and received a diagnosis. Uncertainty and a lack of information often left caregivers feeling frustrated and under-supported when seeking advice and diagnosis. Despite first signs being recognised early by caregivers, barriers to information and seeking help and support resulted in significant delays in receiving a diagnosis.

CONCLUSIONS

The study provides valuable consideration of the caregiver perspective regarding reported first signs of autism and the additional challenges faced by caregivers living in regional and rural areas. By being more informed of what caregivers first notice, health professionals may also be able to provide better support and advice to caregivers in regard to access to diagnosis and early intervention services.

Characteristics and outcomes of patients with heart failure discharged from different speciality units in Australia: an observational study

BACKGROUND

Previous studies have reported differing clinical outcomes among hospitalized heart failure (HF) patients admitted under cardiology and general medicine (GM) without consideration of patients' frailty.

AIMS

To explore outcomes in patients admitted under the two specialities after taking into account their frailty and other characteristics.

METHODS

This retrospective study included all HF patients ≥18 years admitted between 1 January 2013 and 31 December 2019 at two Australian tertiary hospitals. Frailty was determined by use of the Hospital Frailty Risk Score (HFRS) and patients with HFRS ≥ 5 were classified as frail. Propensity score matching (PSM) was used to match 11 variables between the two specialities. The primary outcomes included the days-alive-and-out-of-hospital (DAOH90) at 90 days of discharge, 30-day mortality and readmissions.

RESULTS

Of 4913 HF patients, mean age 76.2 (14.1) years, 51% males, 2653 (54%) were admitted under cardiology compared to 2260 (46%) under GM. Patients admitted under GM were more likely to be older females, with a higher Charlson index and poor renal function than those admitted under cardiology. Overall, 23.8% patients were frail and frail patients were more likely to be admitted under GM than cardiology (33.6% vs. 15.3%, P < 0.001). PSM created 1532 well-matched patients in each group. After PSM, the DAOH90 was not significantly different among patients admitted in GM when compared to cardiology (coefficient -5.36, 95% confidence interval -11.73 to 1.01, P = 0.099). Other clinical outcomes were also similar between the two specialities.

CONCLUSIONS

Clinical characteristics of HF patients differ between GM and cardiology; however, clinical outcomes were not significantly different after taking into account frailty and other variables.

Developing a Pediatric EHR Testing & Certification Program in the USA: Initial Phase

In 2016, the 21st Century Cures Act included ONC's 10 functionality recommendations for voluntary testing and certification of pediatric EHRs. Since 2019, Drummond has been developing a new pediatric EHR testing and certification program with pediatric and industry experts. The testing criteria are based upon AAP's 47 requirements that include ONC's 10 recommendations. It is anticipated the program will be operationalized and ready for EHR vendors in 1Q2022.

AB1209 MECHANISTIC FACTORS CONTRIBUTING TO PAIN AND FATIGUE IN FIBROMYALGIA AND ME/CFS: AUTONOMIC AND INFLAMMATORY INSIGHTS FROM AN EXPERIMENTAL MEDICINE STUDY

Background

Fibromyalgia and ME/CFS are multifaceted conditions with overlapping symptoms(1); the pathoaetiological mechanisms are complex and debated(2), however there is a strong association with features of hereditary disorders of connective tissue (hypermobility) and autonomic and inflammatory abnormalities (1,2).

Objectives

To determine potential autonomic and inflammatory mechanisms of pain and fatigue in fibromyalgia and ME/CFS

Methods

After excluding participants with WCC higher than 10 (suggesting acute infection) baseline markers of inflammation (CRP and ESR) were available for 60 patients with confirmed diagnoses of Fibromyalgia and/ or ME/CFS and 23 matched controls. Participants then underwent full research diagnostic evaluation including a hypermobility assessment(1) and autonomic challenge (60 degree head up tilt, ISRCTN78820481). Subjective pain and fatigue were assessed before and after challenge (VAS). Linear regression models were used to explore predictors, with adjustment for confounders as appropriate. Mediation analyses (looking for mechanistic effects) were conducted according to the method of Hayes (3) and mediation considered significant if bootstrapped confidence intervals of the estimated indirect effect did not cross zero. In these mediation analyses predictor variable was group membership (patient or control), outcome variable was change in 1)pain and 2)fatigue induced by challenge and mediatiors 1)no of connective tissue features in hypermobility diagnostic criteria endorsed by participant; 2)baseline inflammatory markers.

Results

ESR and CRP were significantly higher in patients rather than controls, even after correcting for BMI, age and sex (B=5.15, t=2.05, p=0.044; B=1.77, t=2.15, p=0.044 respectively). Adjusted ESR and CRP correlated with both subjective fatigue (B=0.44, t=2.09, p=0.04; B=1.63, t=2.60, p=0.011) and pain severity (B=0.13, t=2.51, p=0.014; B=0.45, t=3.01, p=0.004) at baseline. Autonomic challenge amplified pain (B=14.20, t=2.87, p=0.005) and fatigue (B=31.48, t=5.95, p=<0.001) in patients to a significantly greater degree than controls, controlling for baseline levels. Baseline ESR and CRP also predicted challenge-induced increase in fatigue (B=0.78, t=370, p=<0.001; B=1.91, t=3.36, p=<0.001) and ESR challenge-induced increases in pain (B=0.46, t=2.35, p=0.021).

Mediation analysis demonstrated that number of connective tissue features expressed in hypermobility criteria mediated the degree to which subjective pain was increased by the autonomic challenge (Bootstraped 95% CI of indirect effect do not cross zero, 0.1572 – 6.8171). ESR mediated the degree to which subjective fatigue was increased by the autonomic challenge (Bootstraped 95% CI of indirect effect do not cross zero,0.7541 – 7.3888).

Conclusion

To our knowledge this is the first study to directly explore autonomic and inflammatory mechanisms of pain and fatigue in a combined population of Fibromyalgia and ME/CFS. This study this adds to the evidence-base of baseline inflammatory abnormalities in fibromyalgia and ME/CFS. It highlights their potential role in predicting symptom severity and their potential mechanistic role in autonomic induced pain and fatigue, suggesting future treatment strategies.

References

[1]Eccles JA, Thompson B, Themelis K, Amato ML, Stocks R, Pound A, et al. Beyond bones: The relevance of variants of connective tissue (hypermobility) to fibromyalgia, ME/CFS and controversies surrounding diagnostic classification: an observational study. Clin Med (Lond). 2021;21(1):53-8.

[2]Eccles JA, Davies KA. The challenges of chronic pain and fatigue. Clin Med (Lond). 2021;21(1):19-27.

[3]Hayes AF. Partial, conditional, and moderated moderated mediation: Quantification, inference, and interpretation. Commun Monogr. 2018;85(1):4-40.

Disclosure of Interests

Jessica Eccles: None declared, Charlotte Thompson: None declared, Beth Thompson: None declared, Marisa Amato: None declared, Kristy Themelis: None declared, Hugo Critchley: None declared, Neil Harrison Grant/research support from: speakers bureau, Kevin Davies: None declared

Processing and mechanical properties of novel biodegradable poly-lactic acid/Zn 3D printed scaffolds for application in tissue regeneration

The feasibility to manufacture scaffolds of poly-lactic acid reinforced with Zn particles by fused filament fabrication is demonstrated for the first time. Filaments of 2.85 mm in diameter of PLA reinforced with different weight fractions of μm-sized Zn - 1 wt.% Mg alloy particles (in the range 3.5 to 17.5 wt.%) were manufactured by a double extrusion method in which standard extrusion is followed by precision extrusion in a filament-maker machine. Filaments with constant diameter, negligible porosity and a homogeneous reinforcement distribution were obtained for Zn weight fractions of up to 10.5%. It was found that the presence of Zn particles led to limited changes in the physico-chemical properties of the PLA that did not affect the window temperature for 3D printing nor the melt flow index. Thus, porous scaffolds could be manufactured by fused filament fabrication at 190 °C with poly-lactic acid/Zn composites containing 3.5 and 7 wt.% of Zn and at 170 °C when the Zn content was 10.5 wt.% with excellent dimensional accuracy and mechanical properties.

Occupational therapists’ perspectives on current practice in chronic pain and sleep disturbances

Background

Chronic pain and sleep disturbances are often co-morbid. Sleep disturbances can negatively affect self-care occupations, cognition, mood, emotional functioning and physical wellbeing.

Aim

To explore occupational therapists’ experience working with clients with chronic pain and sleep difficulties.

Method

Semi-structured interviews were conducted with 11 occupational therapists with experience working with clients with sleep disturbances and chronic pain.

Findings

The relationship between sleep disturbances and chronic pain was described as being complex and multifaceted. Participants believed they were uniquely placed to work with clients experiencing these two conditions. They felt inadequately equipped to treat sleep disturbances and chronic pain. Participants indicated that best practice required multiple interventions and a team-based approach. Finally, the participants noted that sleep disturbances and chronic pain are a growing area of practice.

Conclusion

The findings suggest that occupational therapists tailor their intervention strategies to be early, multi-pronged and individualised. Institutional barriers need to be addressed to further develop occupational therapists’ skill set when working in the areas of sleep and chronic pain. Further research to support the interventions currently used in practice to treat these two conditions is needed.

Diagnostic accuracy of an automated artificial intelligence derived right ventricular to left ventricular diameter ratio tool on CT pulmonary angiography to predict pulmonary hypertension at right heart catheterisation

AIM

To determine the diagnostic accuracy of an automated artificial intelligence derived right ventricle/left ventricle diameter ratio (RV/LV) computed tomography pulmonary angiography (CTPA) analysis tool to detect pulmonary hypertension (PH) in patients with suspected PH referred to a specialist centre.

MATERIALS AND METHODS

The present study was a retrospective analysis of a prospectively maintained database of 202 consecutive patients with suspected PH, who underwent CTPA within 12 months of right heart catheterisation (RHC). Automated ventricular segmentation and RV/LV calculation (Imbio LLC, Minneapolis, MN, USA) was undertaken on the CTPA images. PH diagnosis was made using the RHC reference standard.

RESULTS

The automated RV/LV correlated more strongly with RHC metrics than main pulmonary artery (MPA) diameter and MPA to ascending aorta diameter ratio (MPA/AA) measured manually (mean pulmonary arterial pressure [mPAP] r=0.535, R² = 0.287 p<0.001; pulmonary vascular resistance [PVR] r=0.607, R² = 0.369 p<0.001). In the derivation cohort (n=100), the area under the receiver-operating curve for automated RV/LV discriminating PH was 0.752 (95% confidence interval [CI] 0.677-0.827, p<0.001). Using an optimised Youden's Index of ≥1.12 classified from derivation, automated RV/LV ratio analysis was more sensitive for the detection of PH with higher positive predictive value (PPV) when compared with manual MPA and MPA/AA in the validation cohort (n=102). Automated RV/LV compromise (1.12) and specific (1.335) thresholds were strongly predictive of mortality (log-rank 7.401, p=0.007 and log-rank 16.075, p<0.001 respectively).

CONCLUSION

In suspected PH, automated RV/LV diameter thresholds have high sensitivity for PH, outperform manual MPA and MPA/AA and can predict survival.

Genomic Characterisation Reveals a Dominant Lineage of SARS-CoV-2 in Papua New Guinea

The coronavirus disease pandemic has highlighted the utility of pathogen genomics as a key part of comprehensive public health response to emerging infectious diseases threats, however, the ability to generate, analyse, and respond to pathogen genomic data varies around the world. Papua New Guinea (PNG), which has limited in-country capacity for genomics, has experienced significant outbreaks of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with initial genomics data indicating a large proportion of cases were from lineages that are not well defined within the current nomenclature. Through a partnership between in-country public health agencies and academic organisations, industry, and a public health genomics reference laboratory in Australia a system for routine SARS-CoV-2 genomics from PNG was established. Here we aim to characterise and describe the genomics of PNG’s second wave and examine the sudden expansion of a lineage that is not well defined but very prevalent in the Western Pacific region. We generated 1797 sequences from cases in PNG and performed phylogenetic and phylodynamic analyses to examine the outbreak and characterise the circulating lineages and clusters present. Our results reveal the rapid expansion of the B.1.466.2 and related lineages within PNG, from multiple introductions into the country. We also highlight the difficulties that unstable lineage assignment causes when using genomics to assist with rapid cluster definitions.

Prevalence and duration of anti-SARS-CoV-2 antibodies in healthcare workers

INTRODUCTION

Knowledge of the seroprevalence and duration of antibodies against SARS-CoV-2 was needed in the early phases of the COVID-19 pandemic and is still necessary for policy makers and healthcare professionals. This information allows us to better understand the risk of reinfection in previously infected individuals.

METHODS

We investigated the prevalence and duration of detectable antibodies against SARS-CoV-2 in sequentially collected samples from 379 healthcare professionals.

RESULTS

SARS-CoV-2 seroprevalence at inclusion was 5.3% (95% confidence interval (CI): 3.3-8.0%) and 25% of seropositive participants reverted during follow-up. At the end of follow-up, the calculated probability of having detectable antibodies among former seropositive participants was 72.2% (95% CI: 54.2-96.2%).

CONCLUSION

Antibodies against SARS-CoV-2 were detectable in a subset of infected individuals for a minimum of 39 weeks.

FUNDING

The assays performed at Rigshospitalet were developed with financial support from the Carlsberg Foundation (CF20-0045) and the Novo Nordisk Foundation (NFF205A0063505 and NNF20SA0064201).

TRIAL REGISTRATION

The study was registered with the Danish National Committee on Health Research Ethics (H-20022312).

Invasive Management of Acute Myocardial Infarctions During the Initial Wave of the COVID-19 Pandemic

BACKGROUND

The initial wave of the coronavirus disease 2019 (COVID-19) pandemic resulted in an influx of patients with acute viral illness and profound changes in healthcare delivery in New York City. The impact of this pandemic on the presentation and invasive management of acute myocardial infarction (MI) is not well described.

METHODS

This single-center retrospective study compared patients with MI who underwent invasive coronary angiography at New York University from March-April 2020, during the peak of the first wave of the pandemic, with those presenting in March-April 2019.

RESULTS

Only 35 patients with MI underwent angiography during the study period in 2020 vs 109 patients in 2019. No differences in comorbidities or baseline medications were identified. The proportion of patients with ST-segment elevation MI (STEMI) was higher in 2020 than in 2019 (48.6% vs 24.8%, respectively; P=.01). Median peak troponin concentration was higher (14.5 ng/mL vs 2.9 ng/mL; P<.01) and left ventricular ejection fraction was lower (43.34% vs 51.1%; P=.02) during the pandemic. Among patients with non-STEMI, time from symptom onset to presentation was delayed in 2020 compared with 2019 (median, 24 hours vs 10 hours; P=.04).

CONCLUSION

There was a dramatic decrease in the number of patients with MI undergoing coronary angiography during the first wave of the COVID-19 pandemic. Of those who presented, patients tended to seek care later after symptom onset and had excess myocardial injury. These data indicate a need for improved patient education to ensure timely cardiovascular care during public health emergencies.

The "Talk-to-Me" MOOC intervention for suicide prevention and mental health education among tertiary students: Protocol of a multi-site cross-over randomised controlled trial

INTRODUCTION

Mental health problems are common among tertiary education students, with concerning levels of suicide ideation frequently observed in this population. There is a need for evidence-based mental health education and suicide prevention programs designed to meet the specific needs of these students. The "Talk-to-Me" Mass Open Online Course (MOOC) is a strengths-based mental health education program underpinned by a six-phase model for managing a suicidal crisis.

METHODS

To evaluate the efficacy of the "Talk-to-Me" MOOC in improving student knowledge of appropriate responses to suicide crisis via a randomised control trial (RCT) comparing tertiary education health science and education students attending the program to a waitlist control group. Overall, 170 will be screened and randomly allocated to either the "Talk-to-Me" MOOC or a waitlist control group, with data collection occurring at three-time points (baseline, 10-weeks and 24-weeks from baseline) over one year. The primary outcome will be participants' knowledge and responses to suicidal statements as measured by the Suicide Intervention Response Inventory. Secondary outcomes will be knowledge of mental health and coping skills as well as the overall utility of the program.

CONCLUSIONS

This pragmatic RCT will demonstrate the efficacy of the "Talk-to-Me" MOOC in improving the students' ability to respond to suicidal and mental health concerns compared to the waitlist group. This design will enable rigorous evaluation of the "Talk-to-Me" MOOC, contributing to a greater understanding of the online-delivered safe-paced suicide prevention programs for tertiary students. Australian New Zealand Clinical Trials Registry (ANZCTR): #12619000630112.

Recommendations for the return of spectators to sport stadiums: A South African Sports Medicine Association (SASMA) position statement – Part 4

All sports were discontinued in 2020 with the arrival of COVID-19. Since then most have been reinstated, albeit without spectators. However, several countries have put together a number of different risk-mitigating strategies to allow spectators back into stadiums. This position statement gives an outline of the minimum requirements that should be considered upon the return of spectators at live sporting events.

Recommendations for athletes and COVID-19 vaccinations: A South African Sports Medicine Association (SASMA) position statement – Part 3

The COVID-19 pandemic initially led to the shutdown of all sport at a high cost to both the economy and athlete health. As risk-mitigating protocols evolved and were implemented, the playing of sport returned slowly to normal. The introduction of COVID-19 vaccinations enhances the means of protection and risk management for all. This South African Sports Medicine Association position statement provides recommendations for the vaccination of athletes.

Production, Titration, Neutralisation, Storage and Lyophilisation of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Lentiviral Pseudotypes

This protocol details a rapid and reliable method for the production and titration of high-titre viral pseudotype particles with the SARS-CoV-2 spike protein (and D614G or other variants of concern, VOC) on a lentiviral vector core, and use for neutralisation assays in target cells expressing angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2). It additionally provides detailed instructions on substituting in new spike variants via gene cloning, lyophilisation and storage/shipping considerations for wide deployment potential. Results obtained with this protocol show that SARS-CoV-2 pseudotypes can be produced at equivalent titres to SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV) pseudotypes, neutralised by human convalescent plasma and monoclonal antibodies, and stored at a range of laboratory temperatures and lyophilised for distribution and subsequent application.

Safety and efficacy of dedicated guidewire, microcatheter, and guide catheter extension technologies for chronic total coronary occlusion revascularization: Primary results of the Teleflex Chronic Total Occlusion Study

BACKGROUND

Description of procedural outcomes using contemporary techniques that apply specialized coronary guidewires, microcatheters, and guide catheter extensions designed for chronic total occlusion (CTO) percutaneous revascularization is limited.

METHODS

A prospective, multicenter, single-arm study was conducted to evaluate procedural and in-hospital outcomes among 150 patients undergoing attempted CTO revascularization utilizing specialized guidewires, microcatheters and guide extensions. The primary endpoint was defined as successful guidewire recanalization and absence of in-hospital cardiac death, myocardial infarction (MI), or repeat target lesion revascularization (major adverse cardiac events, MACE).

RESULTS

The prevalence of diabetes was 32.7%; prior MI, 48.0%; and previous bypass surgery, 32.7%. Average (mean ± standard deviation) CTO length was 46.9 ± 20.5 mm, and mean J-CTO score was 1.9 ± 0.9. Combined radial and femoral arterial access was performed in 50.0% of cases. Device utilization included: support microcatheter, 100%; guide catheter extension, 64.0%; and mean number of study guidewires/procedure was 4.8 ± 2.6. Overall, procedural success was achieved in 75.3% of patients. The rate of successful guidewire recanalization was 94.7%, and in-hospital MACE was 19.3%. Achievement of TIMI grade 2 or 3 flow was observed in 93.3% of patients. Crossing strategies included antegrade (54.0%), retrograde (1.3%) and combined antegrade/retrograde techniques (44.7%). Clinically significant perforation resulting in hemodynamic instability and/or requiring intervention occurred in 16 (10.7%) patients.

CONCLUSIONS

In a multicenter, prospective registration study, favorable procedural success was achieved despite high lesion complexity using antegrade and retrograde guidewire maneuvers and with acceptable safety, yet with comparably higher risk than conventional non-CTO PCI.

Distribution of trespass cannabis cultivation and its risk to sensitive forest predators in California and Southern Oregon

Illegal cannabis cultivation on public lands has emerged as a major threat to wildlife in California and southern Oregon due to the rampant use of pesticides, habitat destruction, and water diversions associated with trespass grow sites. The spatial distribution of cultivation sites, and the factors influencing where they are placed, remain largely unknown due to covert siting practices and limited surveillance funding. We obtained cannabis grow-site locality data from law enforcement agencies and used them to model the potential distribution of cultivation sites in forested regions of California and southern Oregon using maximum entropy (MaxEnt) methods. We mapped the likely distribution of trespass cannabis cultivation sites and identified environmental variables influencing where growers establish their plots to better understand the cumulative impacts of trespass cannabis cultivation on wildlife. We overlaid the resulting grow-site risk maps with habitat distribution maps for three forest species of conservation concern: Pacific fisher (Pekania pennanti), Humboldt marten (Martes caurina humboldtensis), and northern spotted owl (Strix occidentalis caurina). Results indicate that cannabis cultivation is fairly predictably distributed on public lands in low to mid-elevation (~800-1600m) forests and on moderate slopes (~30-60%). Somewhat paradoxically, results also suggest that growers either preferred sites inside of recently disturbed vegetation (especially those burned 8-12 years prior to cultivation) or well outside (>500m) of recent disturbance, perhaps indicating avoidance of open edges. We ground-truthed the model by surveying randomly selected stream courses for cultivation site presence in subsets of the modeling region and found previously undiscovered sites mostly within areas with predicted high likelihood of grow-site occurrence. Moderate to high-likelihood areas of trespass cultivation overlapped with 40 to 48% of modeled habitats of the three sensitive species. For the endangered southern Sierra Nevada fisher population, moderate-high likelihood growing areas overlapped with over 37% of modeled fisher denning habitat and with 100% of annual female fisher home ranges (mean overlap = 48.0% + 27.0 SD; n = 134) in two intensively studied populations on the Sierra National Forest. Locating and reclaiming contaminated cannabis grow sites by removing all environmental contaminants should be a high priority for resource managers.

Development of an In Vitro Hemorrhagic Hydrocephalus Model for Functional Evaluation of Magnetic Microactuators Against Shunt Obstructions

OBJECTIVE

Occlusion of ventriculoperitoneal shunts placed after intraventricular hemorrhage occurs frequently. The objective of this study was to develop a hemorrhagic hydrocephalus model to assess the ability of an oscillating microactuator within the ventricular catheter (VC) to prevent shunt obstruction.

METHODS

An in vitro hydrocephalus model with extreme risk of shunt obstruction was created. Phosphate-buffered saline, blood, and thrombin were driven through ventriculoperitoneal shunts for 8 hours. Five VCs were fitted with a microactuator and compared with 5 control VCs. The microactuator was actuated by an external magnetic field for 30 minutes. Pressure within the imitation lateral ventricle was measured.

RESULTS

In the 5 control shunts, 6 obstructions developed (3 VC, 3 valve-distal catheter) compared with 1 obstruction (VC) in the 5 microactuator shunts. In the control and microactuator groups, the median volume exiting the shunts in 8 hours was 30 mL versus 256 mL. Median time to reach an intraventricular pressure of 40 mm Hg (13.8 minutes vs. >8 hours), median total time >40 mm Hg (6.2 hours vs. 0.0 hours), and median maximum pressure (192 mm Hg vs. 36 mm Hg) were significantly improved in the microactuator group (P < 0.01).

CONCLUSIONS

In addition to protecting the VC, the microactuator appeared to prevent hematoma obstructing the valve or distal catheter, resulting in a much longer duration of low intraventricular pressures. A microactuator activated by placing the patient's head in an external magnetic field could reduce shunt obstructions in hemorrhagic hydrocephalus.

Preventing suicide in post-secondary students: a scoping review of suicide prevention programs

Suicide among students enrolled in post-secondary education, including university or college, is a major public health concern. Previous research has examined the effectiveness of suicide prevention programs for this population. However, the effective elements of these interventions remain unknown. This study reviewed the literature on suicide prevention programs for post-secondary students, exploring and identifying those elements likely contributing to their effectiveness. A scoping review process was undertaken exploring suicide prevention programs for post-secondary students. Methodological quality of the articles was assessed, and content analysis was used to explore the programs and their effective elements. Twenty seven articles were included in this review, covering a variety of approaches. Gatekeeper training programs were the most common type of suicide prevention program. Programs for post-secondary students may be effective in improving student rates of engagement with mental health services and were associated with greater knowledge, and help-seeking attitudes and behaviors, and gatekeeper-related outcomes. While evidence was found supporting the effectiveness of some interventions such as gatekeeper programs to influence suicide-related knowledge, attitudes and behaviour, further and more rigorous research surrounding suicide prevention programs for post-secondary students is required, with a particular emphasis on student outcomes.

Experiences of Parents of Specialist Peer Mentored Autistic University Students

ABSTRCTBackground: Parents continue to support to autistic university students, and consequently, experience considerable stress.Aim: To explore the experiences of parents of specialist peer mentored university students and to examine these using the ICF as a theoretical framework.Method: Thirteen semi-structured interviews were completed and analyzed using thematic analysis. Directive content analysis linked the data to the ICF core set for autism spectrum disorders (ASD).Results: Five interrelated themes emerged: The mentoring relationship is a facilitator, Developing skills for university, Mentoring changes lives, Mentoring is not a substitute for other supports, and University is an emotional rollercoaster. Specialist peer mentoring was linked to Activity and Participation (44%) and Environmental factors (32%) of the ICF core set for ASD.Conclusion: These results add to the specialist peer mentoring evidence-base, and indicate perceived benefits for autistic university students and their parents. An unintended consequence was that parents broadened their participation in activities.

Development of Lentiviral Vectors Pseudotyped With Influenza B Hemagglutinins: Application in Vaccine Immunogenicity, mAb Potency, and Sero-Surveillance Studies

Influenza B viruses (IBV) cause respiratory disease epidemics in humans and are therefore components of seasonal influenza vaccines. Serological methods are employed to evaluate vaccine immunogenicity prior to licensure. However, classical methods to assess influenza vaccine immunogenicity such as the hemagglutination inhibition assay (HI) and the serial radial hemolysis assay (SRH), have been proven to have many limitations. As such, there is a need to develop innovative methods that can improve on these traditional assays and provide advantages such as ease of production and access, safety, reproducibility, and specificity. It has been previously demonstrated that the use of replication-defective viruses, such as lentiviral vectors pseudotyped with influenza A hemagglutinins in microneutralization assays (pMN) is a safe and sensitive alternative to study antibody responses elicited by natural influenza infection or vaccination. Consequently, we have produced Influenza B hemagglutinin-pseudotypes (IBV PV) using plasmid-directed transfection. To activate influenza B hemagglutinin, we have explored the use of proteases in increasing PV titers via their co-transfection during pseudotype virus production. When tested for their ability to transduce target cells, the influenza B pseudotypes produced exhibit tropism for different cell lines. The pseudotypes were evaluated as alternatives to live virus in microneutralization assays using reference sera standards, mouse and human sera collected during vaccine immunogenicity studies, surveillance sera from seals, and monoclonal antibodies (mAbs) against IBV. The influenza B pseudotype pMN was found to effectively detect neutralizing and cross-reactive responses in all assays and shows promise as an effective and versatile tool in influenza research.

Low-frequency rTMS to the parietal lobe increases eye-movement carryover and decreases hazard rating

The persistence of attentional set from one task to a secondary unrelated task, revealed through carryover of eye movements, has been attributed to increased activation in the parietal lobe and decreased activation to the frontal lobe. To directly test this, we adopted a modified version of the Thompson and Crundall (2011) paradigm using low-frequency repetitive TMS to P3 and F3. In each trial, participants viewed letter-strings that were arranged horizontally, vertically, or randomly across the screen before viewing a road image and providing a hazardousness rating for it. The orientation of the letter search influenced eye movements to the road images and this carryover was greater following stimulation to F3 than to P3 (or sham). Furthermore, hazardous ratings were lower following P3 stimulation. These results confirm the involvement of attentional orienting and switching mechanisms in the carryover of eye movements. It is suggested that this "attentional inertia" effect will increase with greater orienting of attentional resources in an initial task and poor inhibition of previously-relevant settings between tasks.

The antigenic anatomy of SARS-CoV-2 receptor binding domain

Antibodies are crucial to immune protection against SARS-CoV-2, with some in emergency use as therapeutics. Here, we identify 377 human monoclonal antibodies (mAbs) recognizing the virus spike and focus mainly on 80 that bind the receptor binding domain (RBD). We devise a competition data-driven method to map RBD binding sites. We find that although antibody binding sites are widely dispersed, neutralizing antibody binding is focused, with nearly all highly inhibitory mAbs (IC50 < 0.1 μg/mL) blocking receptor interaction, except for one that binds a unique epitope in the N-terminal domain. Many of these neutralizing mAbs use public V-genes and are close to germline. We dissect the structural basis of recognition for this large panel of antibodies through X-ray crystallography and cryoelectron microscopy of 19 Fab-antigen structures. We find novel binding modes for some potently inhibitory antibodies and demonstrate that strongly neutralizing mAbs protect, prophylactically or therapeutically, in animal models.

T cell assays differentiate clinical and subclinical SARS-CoV-2 infections from cross-reactive antiviral responses

Identification of protective T cell responses against SARS-CoV-2 requires distinguishing people infected with SARS-CoV-2 from those with cross-reactive immunity to other coronaviruses. Here we show a range of T cell assays that differentially capture immune function to characterise SARS-CoV-2 responses. Strong ex vivo ELISpot and proliferation responses to multiple antigens (including M, NP and ORF3) are found in 168 PCR-confirmed SARS-CoV-2 infected volunteers, but are rare in 119 uninfected volunteers. Highly exposed seronegative healthcare workers with recent COVID-19-compatible illness show T cell response patterns characteristic of infection. By contrast, >90% of convalescent or unexposed people show proliferation and cellular lactate responses to spike subunits S1/S2, indicating pre-existing cross-reactive T cell populations. The detection of T cell responses to SARS-CoV-2 is therefore critically dependent on assay and antigen selection. Memory responses to specific non-spike proteins provide a method to distinguish recent infection from pre-existing immunity in exposed populations.