Report on the PET/CT Image-Based Radiation Dosimetry of [18F]FDHT in Women, a Validated Imaging Agent with New Applications for Evaluation of Androgen Receptor Status in Women with Metastatic Breast Cancer

In a prospective clinical trial, [18F]fluoro-5α-dihydrotestosterone ([18F]FDHT), the radiolabeled analog of the androgen dihydrotestosterone, was used as a PET/CT imaging agent for in vivo assessment of metastatic androgen receptor-positive breast cancer in postmenopausal women. To our knowledge, this article presents the first report of PET/CT image-based radiation dosimetry of [18F]FDHT in women. Methods: [18F]FDHT PET/CT imaging was performed on a cohort of 11 women at baseline before the start of therapy and at 2 additional time points during selective androgen receptor modulator (SARM) therapy for androgen receptor-positive breast cancer. Volumes of interest (VOIs) were placed over the whole body and within source organs seen on the PET/CT images, and the time-integrated activity coefficients of [18F]FDHT were derived. The time-integrated activity coefficients for the urinary bladder were calculated using the dynamic urinary bladder model in OLINDA/EXM software, with biologic half-life for urinary excretion derived from VOI measurements of the whole body in postvoid PET/CT images. The time-integrated activity coefficients for all other organs were calculated from VOI measurements in the organs and the physical half-life of 18F. Organ dose and effective dose calculations were then performed using MIRDcalc, version 1.1. Results: At baseline before SARM therapy, the effective dose for [18F]FDHT in women was calculated as 0.020 ± 0.0005 mSv/MBq, and the urinary bladder was the organ at risk, with an average absorbed dose of 0.074 ± 0.011 mGy/MBq. Statistically significant decreases in liver SUV or uptake of [18F]FDHT were found at the 2 additional time points on SARM therapy (linear mixed model, P < 0.05). Likewise, absorbed dose to the liver also decreased by a small but statistically significant amount at the 2 additional time points (linear mixed model, P < 0.05). Neighboring abdominal organs of the gallbladder wall, stomach, pancreas, and adrenals also showed statistically significant decreases in absorbed dose (linear mixed model, P < 0.05). The urinary bladder wall remained the organ at risk at all time points. Absorbed dose to the urinary bladder wall did not show statistically significant changes from baseline at any of the time points (linear mixed model, P ≥ 0.05). Effective dose also did not show statistically significant changes from baseline (linear mixed model, P ≥ 0.05). Conclusion: Effective dose for [18F]FDHT in women before SARM therapy was calculated as 0.020 ± 0.0005 mSv/MBq. The urinary bladder wall was the organ at risk, with an absorbed dose of 0.074 ± 0.011 mGy/MBq.

First-in-Human Studies of Pharmacokinetics and Safety of Utreloxastat (PTC857), a Novel 15-Lipooxygenase Inhibitor for the Treatment of Amyotrophic Lateral Sclerosis

Utreloxastat (PTC857) is a 15-lipoxygenase inhibitor being developed to treat amyotrophic lateral sclerosis. This first-in-human study investigated the safety and pharmacokinetics of utreloxastat in healthy volunteers (N = 82) in a double-blind, placebo-controlled trial. The effects of a single ascending dose (100-1000 mg), multiple ascending doses (150-500 mg), and food (500 mg) on the pharmacokinetics and safety of utreloxastat were evaluated. Following single doses, the time to maximum plasma concentration (C_max ) was observed ≈4 hours after dosing and the terminal half-life ranged from 20 to 25.3 hours. The C_max and area under the concentration-time curve (AUC) increased slightly over dose proportionally. Following multiple doses (once daily/twice daily), the apparent clearance reduced and terminal half-life was ≥33 hours. There was no apparent difference of exposure following morning or evening doses. Varying diets increased the C_max and AUCs of utreloxastat but did not alter time to C_max . There were no gender-based differences in exposure. Utreloxastat showed no marked safety signal following single doses up to 1000 mg and multiple doses over 14 days of 500 mg once daily or 250 mg twice daily. The results support further development of utreloxastat for the treatment of patients with amyotrophic lateral sclerosis at a 250-mg twice-daily dose administered with food.

205 Vascular Outcomes in TIA Patients

Aim

To identify vascular outcomes in patients presenting with TIA

Method

We completed a closed loop audit at the University Hospital of Wales assessing vascular outcomes in TIA patients. We audited the first 100 patients with significant carotid ultrasound findings from January 1st, 2020, and then the first 75 patients with significant findings in the repeat study from July 1st, 2021. We assessed the time between symptom onset, referral, and consultation, whether that be geriatric or vascular, and the outcome of that consultation. If patients required surgical vascular intervention, we assessed whether this was conducted within the 14-day window outlined by national and international guidelines.

Results

We found that for a multitude of reasons, including delayed patient presentation and arduous referral processes, that patients with significant findings were not receiving vascular input within the 14-day window, let alone receive an operation. We suggested that a centralised vascular referral pathway and a consultant of the week would facilitate a more efficient TIA-vascular process, allowing for carotid endarerectomies to be performed within the internationally advised timeframe. The closed loop revealed that although patient presentation and referral times were obviously unaffected, that vascular consultations were occurring far more rapidly, as aided by the newly incorporated consultant of the week.

Conclusions

That a centralised departmental coordinator, and a consultant of the week delegated towards facilitating TIA referrals for potental carotid endarterecomy, was beneficial in terms of meeting standardised timeframes, but that more could be done to improve the service.

356 An Unfortunate Case of Spinal Injury and Bladder Dysfunction During the Covid-19 Pandemic

There is no doubt that COVID-19 has had a profound impact on every medical and surgical speciality. In the height of the pandemic many non-emergency services were shut down, including dental services, with unexpected consequences. We present a case which highlights the unexpected and indirect consequences of a national lockdown on a Urology patient and discuss learning points.

A 54-year-old male, previously fit and well suffered with a small dental abscess, media outlets were reporting that dental surgeries were closed, and he therefore attempted to drain the abscess himself. The infection spread to his epidural space, causing compression via a collection at L2 and consequently spinal cord injury. This was managed with urgent lumbar decompression and antibiotics.

A specialist functional urology team were involved after his transfer to the tertiary spinal unit 3 months after his first presentation. He was catheterised but suffered with recurrent catheter blockages. Video urodynamics demonstrated a stable bladder with a low-pressure leak point, managed with urethral catheterisation. A repeat video urodynamics demonstrated a loss of compliance and stress incontinence. Unclear as to whether he would regain function rehabilitation techniques are currently being attempted prior for definitive operative management with an artificial sphincter.

This case highlights the indirect impact of COVID-19 on UK urology services, and this has not been widely reported.

324 Outcomes of Prostate Artery Embolisation In Catheterised Patients: A Case Series

Aim

Prostate artery embolisation (PAE) is an approved treatment for men with lower urinary tract symptoms secondary to benign prostatic hyperplasia (BPH-LUTS). Evidence of efficacy for PAE in patients who are unable to void urine spontaneously is scant, however. Traditional treatments for BPH-LUTS have evidence in retention patients and this series aims to report outcomes for PAE in catheterised patients.

Method

The records of consecutive men with BPH-LUTS which required either an indwelling bladder catheter or clean intermittent self-catheterisation (CISC) who subsequently underwent PAE were retrospectively reviewed. Basic demographics were collected along with information on the prostate volume and PAE procedure specifics. The primary outcome was whether patients were catheter/CISC free at 3 months. Other outcomes include complications, use of medications and the need for other surgical treatments post-PAE.

Results

63 men underwent PAE for urinary retention and BPH-LUTS between 2013 and 2020. Of these, 7 underwent a unilateral embolisation for aberrant anatomy. The mean prostate volume was 128ml. 61% of men were free from a catheter/CISC post-treatment. 4 patients suffered post-PAE UTI, whilst 3 patients subsequently underwent Transurethral Resection of the Prostate following PAE for failure to become catheter free. 13 men were entirely free from BPH-LUTS medications.

Conclusions

PAE for catheterised men results in a similar catheter-free rate post procedure to several more invasive BPH treatments. It has a low side-effect profile and gives men with poor health an option to try to become catheter free. PAE should be discussed with men with catheters as a treatment option.

Imaging Androgen Receptors in Breast Cancer with 18F-fluoro-5α-dihydrotestosterone-PET: A Pilot Study

Most breast cancers express androgen receptors (AR). This prospective imaging sub-study explored imaging AR with ¹⁸F-fluoro-5α-dihydrotestosterone (FDHT)-PET in patients with metastatic breast cancer (MBC) receiving selective AR modulation (SARM) therapy (GTx-024, GTx, Inc). Methods: 11 post-menopausal women with estrogen receptor positive MBC underwent FDHT-PET/CT at baseline, 6, and 12 weeks after starting SARM therapy. Abnormal tumor FDHT uptake was quantified using maximum SUV (SUVmax). AR status was determined from tumor biopsy specimens. FDHT-SUVmax percent change between scans was calculated. Best overall response was categorized as clinical benefit (CB: non-progressive disease [PD]), or PD using RECIST 1.1. Results: Median baseline FDHT-SUVmax was 4.1 (range 1.4-5.9) for AR+ tumors versus 2.3 (range 1.5-3.2) for AR- tumors (p=0.22). Quantitative AR expression and baseline FDHT uptake were weakly correlated (Pearson rho=0.39, p=0.30). Seven participants with CB at 12 weeks tended to have larger declines in FDHT uptake compared to those with PD at both 6 (median decline, range: -26.8%, -42.9 to -14.1% vs. -3.7%, -31% to +29%, respectively, p=0.11) and 12 weeks (median decline, range: -35.7%, -69.5 to -7.7% vs. -20.1%, -26.6% to +56.5%, respectively, p=0.17) after starting GTx-024. Conclusion: This hypothesis-generating data suggests that FDHT-PET/CT is worth further study as an imaging biomarker for evaluating response of MBC to SARM therapy and reiterates the feasibility of including molecular imaging in multidisciplinary therapeutic trials.

The association between secondary care multimorbidity in mid-life and premature mortality

Background

Multimorbidity (MM) is the co-existence of two or more health conditions. Whilst its prevalence is higher in older adults, in absolute numbers there are more multimorbid young people. Recently, the trends for increasing life expectancy observed in high income countries have stalled or reversed. The relationship between MM and premature mortality requires exploration. We assessed the prevalence of secondary care MM in mid-life and its association with premature mortality in the Scottish Aberdeen Children of the 1950s (ACONF) cohort.

Methods

Prospective cohort study. ACONF members were linked to electronic hospital records and mortality records. Secondary care MM was assessed using hospital records in 2001 when participants were aged 45-51 years. The association between MM and mortality over 15 years (to age 60-66 years) was assessed using Cox proportional hazards regression. There was adjustment for key covariates: age, gender, social class at birth, childhood intelligence, educational attainment, alcohol, smoking, body mass index and adult social class.

Results

Of 9,625 participants (51% male), 3% had MM. Higher childhood intelligence and adult social class were associated with reduced MM. In relation to the reference group (no MM), those with MM had a mortality hazard ratio of 4.5 (95% CI 3.4-6.0) over 15 years. The association remained when adjusted for the covariates (2.5 [95% CI 1.5-4.0]).

Conclusions

Secondary care MM prevalence was 3% in mid-life and associated with premature mortality. Younger adults with MM are an important group at risk of premature mortality which should be the focus of public health action. This includes reducing the impact of social inequality and reconfiguring secondary care services to offer comprehensive management of younger multimorbid adults.

Key messages

Multimorbidity in mid-life is associated with premature mortality and may be an important influence on reducing life expectancy trends. Much focus is upon multimorbidity in older adults, however younger adults with multimorbidity are at risk of premature mortality, requiring public health action.

The epidemiology of polypharmacy in a large cohort with linked health records in Scotland

Background

Our understanding of the potential harm of taking multiple medications in older, multi-morbid populations is limited. We aimed to investigate the prevalence of polypharmacy and its association with hospitalisation in a large cohort with linked health data.

Methods

Prescription data and hospital admission records of the Aberdeen Children of the 1950s (ACONF) Cohort were extracted from the National Health Services Scotland database and linked from 2011-2016. We estimated polypharmacy by measuring monthly drug exposure for 1) total number of prescribed medications and 2) total number of defined daily doses (DDDs). Cox proportional hazard models (adjusted for demographics, socioeconomic circumstances and health conditions) were used to examine the association of polypharmacy and hospitalisation.

Results

Prescription records were linked for 8,713 cohort members. Mean age at baseline was 58.5 years (SD = 1.5) and 50% were female. 1,994 individuals (23%) had at least one health condition and 8% of population had multimorbidity. The proportion of cohort with polypharmacy assessed using taking 5+ medications and taking 5+ DDDs at baseline were 12.7% (female=12.6% vs male=12.7%, P = 0.179), and 15.5% (female=13.8% vs male=17.1%, P &lt; 0.001) respectively. Of all the cohort, 4,365 admitted to hospital (mean follow-up of 3.5 years, total 30,269 person-years). Adjusted hazard ratios for hospitalisation were 1.51 (95 % CI 1.39,1.64, P &lt; 0.001) for polypharmacy measured by number of medications and 1.40 (95 % CI 1.29,1.51 P &lt; 0.001) for polypharmacy estimated by number of daily doses.

Conclusions

Polypharmacy is independently associated with increased risk of hospitalisation. This association could signify polypharmacy as a risk factor and a marker of poor outcome. Data linkage can generate evidence-based information for future policy and health services to improve polypharmacy measurement and management.

Key messages

Data linkage is a cost effective and contemporary return on the investment in data collection and research in public health. Improvement in evidence to better understand the relationship between polypharmacy and health outcomes should be a priority to optimise treatment in older people with various chronic conditions.

Co-design of data collection with participants of the Aberdeen Children of the 1950s cohort study

Background

The Aberdeen Children of the 1950s (ACONF) cohort comprises 12,150 people born in Scotland in the 50s. It contains rich early life data, questionnaire data from mid-life and linked electronic health records. Involving participants in designing future data collection is key to ensure research is acceptable and reflects public priorities.

Aim

Gather ACONF members views to inform how to: research healthy ageing, optimise recruitment and maximise participation.

Methods

3 co-design workshops with 30 ACONF members. A discussion was led by a facilitator using guidance questions developed by the study team. Workshops were recorded and transcribed.

Results

Participants viewed healthy ageing as keeping socially and physically active, taking responsibility for oneself and having a positive attitude to ageing. Research priorities were dementia, improvements in the social care system and engaging hard-to-reach groups. Members were keen for future research involvement. Recruitment may be maximised by: more information online, involving participants in recruiting other study members and clarity about potential benefits to themselves or others. It was acceptable to ask their offspring to participate. There were high levels of trust in researchers, but ongoing data protection is vital. Participation may be improved by regular contact (informing members of results, engagement events, phone “apps”). Participants viewed various data collection methods (questionnaires, applications, wearable devices, in-person tests, DNA collection and electronic record linkage) as acceptable.

Conclusions

Participant involvement is a fundamental part of securing a social license for research. Participants were in favour of ongoing research, including recruitment of their children. The workshops highlighted key considerations for future research and data collection.

Key messages

Co-design is vital for highlighting research topics which are important and relevant to the general population. Co-design can highlight strategies for maximising research participation and securing a social license for research.

The association between psychological distress in mid-life and hospital-based multimorbidity

Background

Mental ill-health is common with significant impact on individuals and services. Using healthcare records to identify poor mental health missed individuals who do not seek healthcare treatment. A screening questionnaire (General Health Questionnaire (GHQ)) can detect psychological distress. However, before considering implementing such a screening tool, we need to understand if it detects those at high risk of experiencing poorer outcomes. Hospital-based multimorbidity is a rising healthcare challenge. The aim was to assess the prevalence of psychological distress in mid-life and its influence on hospital-based multimorbidity by older age in the Aberdeen Children of the 1950s (ACONF) cohort.

Methods

Prospective cohort study using ACONF. GHQ-4 was measured in mid-life from questionnaire. Multimorbidity (2 or more co-existing conditions) was measured using linked hospital records in older age (15 years after the questionnaire). The relationship between psychological distress (GHQ-4 score of 1 or more) and multimorbidity was assessed using logistic regression with adjustment for key life-course variables.

Results

Of 5,839 individuals (48% male, mean age 48), psychological distress prevalence was 20% and was associated with being female, lower childhood cognition, lower educational attainment, lower adult social class, unemployment, higher adult body mass index, smoking and alcohol misuse. In comparison to the asymptomatic reference group, the odds ratio for multimorbidity in older age in those with psychological distress was 2.2 (95% CI 1.8-2.7) in the unadjusted model. In the adjusted model this was 1.4 (95% CI 1.1-1.8).

Conclusions

1 in 5 individuals in the general population in mid-life had psychological distress. This was associated with hospital-based multimorbidity by older age. Intervening early could reduce costs to both individuals and healthcare services. The next step is research of the cost-effectiveness of population screening for psychological distress.

Key messages

Psychological distress in mid-life is associated with hospital-based multimorbidity by older age. Screening for psychological distress early in life should be explored as an intervention to reduce costs to individuals and healthcare services.

A14 GUT-RESIDING BACTERIA CAN SHAPE HOST DRUG METABOLISM IN THE SMALL INTESTINE THROUGH AN INNATE LYMPHOID CELL-IL-22 DRIVEN AXIS

Background

The ability of the intestinal microbiota to influence drug metabolism has been recognized, however the mechanisms through which this occurs remain unexplored. Recent work in germ-free mice showed that conventionalization with specific pathogen free (SPF) microbiota influences the expression of cytochrome P450 (CYP) enzymes in the liver and small intestine (SI), two important sites of drug metabolism. Given that CYP enzymes, including CYP3A11 in mice, account for roughly 70% of total drug metabolism, we hypothesized that commensal gut bacteria can shape the CYP landscape to influence drug metabolism and therapeutic outcomes.

Aims

To investigate the role of specific gut-residing microbes in shaping the expression and activity of host drug metabolism enzymes.

Methods

Segmented filamentous bacteria (SFB)-free mice were obtained from Jackson Lab (Jax) and colonized with feces from SFB-mono-associated mice via oral gavage. 14 days later, expression of drug metabolism enzymes in the SI were probed using PCR arrays, and lamina propria cells isolated for flow cytometry. A monoclonal antibody for Thy1.2 was used to deplete innate lymphoid cells (ILCs) in RAG1-/- mice (lacking T- and B-cells). CYP3A11 activity was determined through the colorimetric breakdown of the CYP3A11-specific substrate 7-benzyloxyresorufin. SI organoids were generated from mice and humans, and treated with IL-22 to further assess the dynamics of CYP3A11/CYP3A4 expression and activity.

Results

Colonization of Jax mice with immunomodulatory SFB altered the expression of various CYP enzymes in the SI (but not liver), with Cyp3a11 being the most downregulated gene. Further analysis showed that SFB-induced IL-22 production by type 3 ILCs (ILC3) correlated with reduced SI Cyp3a11 expression. Additionally, SFB colonization had no effect on the expression of Cyp3a11 in the SI of mice in which ILCs were depleted. Both SFB colonization and administration of IL-23, to induce IL-22 from ILC3, increased the ability of the CYP3A11-metabolized drug glyburide to decrease blood glucose levels when given orally. In mouse SI enteroid cultures, IL-22 dose-dependently reduced the expression of Cyp3a11 and decreased the ability of enteroids to metabolize CYP3A11-specific substrates. Finally, IL-22 induced wide changes in the transcriptome of human SI enteroids, with substantial effects on a drug metabolism pathway centred around CYP3A.

Conclusions

Our data suggest that a gut-resident microbe (SFB) can influence the expression and activity of the drug metabolising enzyme CYP3A11 in the SI through an ILC3-IL-22 dependent mechanism. These findings provide an understanding of how the intestinal microbiota may modulate host drug metabolism to influence the efficacy and toxicity of various pharmaceutical compounds.

Funding Agencies

CAG, CIHRAbbvie, Lloyd Sutherland Investigatorship

Quantitative data analysis of perceived barriers and motivators to physical activity in stroke survivors

BACKGROUND

Levels of physical activity after stroke are low, despite multiple health benefits. We explored stroke survivors' perceived barriers, motivators, self-efficacy and intention to physical activity.

METHODS

Fifty independently mobile stroke survivors were recruited prior to hospital discharge. Participants rated nine possible motivators and four possible barriers based on the Mutrie Scale, as having 'no influence', 'some influence' or 'a major influence' on physical activity. Participants also rated their self-efficacy and intention to increasing walking.

RESULTS

The most common motivator was 'physical activity is good for health' [34 (68%)]. The most common barrier was 'feeling too tired' [24 (48%)]. Intention and self-efficacy were high. Self-efficacy was graded as either 4 or 5 (highly confident) on a five-point scale by [34 (68%)] participants, while 42 (84%) 'strongly agreed' or 'agreed' that they intended to increase their walking.

CONCLUSION

Participants felt capable of increasing physical activity but fatigue was often perceived as a barrier to physical activity. This needs to be considered when encouraging stroke survivors to be more active.

Achieving Self-Directed Integrated Cancer Aftercare (ASICA) in melanoma: protocol for a randomised patient-focused pilot trial of delivering the ASICA intervention as a means to earlier detection of recurrent and second primary melanoma

BACKGROUND

Melanoma is common; 15,906 people in the UK were diagnosed with melanoma in 2015 and incidence has increased fivefold in 30 years. Melanoma affects old and young people, with poor prognosis once metastatic. UK guidelines recommend people treated for cutaneous melanoma receive extended outpatient, hospital follow up to detect recurrence or new primaries. Such follow up of the growing population of melanoma survivors is burdensome for both individuals and health services. Follow up is important since approximately 20% of patients with early-stage melanoma experience a recurrence and 4-8% develop a new primary; the risk of either is highest in the first 5 years. Achieving Self-directed Integrated Cancer Aftercare (ASICA) is a digital intervention to increase total-skin-self-examination (TSSE) by people treated for melanoma, with usual follow up.

METHODS

We aim to recruit 240 adults with a previous first-stage 0-2C primary cutaneous melanoma, from secondary care in North-East Scotland and the East of England. Participants will be randomised to receive the ASICA intervention (a tablet-based digital intervention to prompt and support TSSE) or control group (treatment as usual). Patient-reported and clinical data will be collected at baseline, including the modified Melanoma Worry Scale (MWS), the Hospital Anxiety and Depression Scale (HADs), the EuroQoL 5-dimension 5-level questionnaire (EQ-5D-5 L), and questions about TSSE practice, intentions, self-efficacy and planning. Participants will be followed up by postal questionnaire at 3, 6 and 12 months following randomization, along with a 12-month review of clinical data. The primary timepoint for outcome analyses will be12 months after randomisation.

DISCUSSION

If the ASICA intervention improves the practice of TSSE in those affected by melanoma, this may lead to improved psychological well-being and earlier detection of recurrent and new primary melanoma. This could impact both patients and National Health Service (NHS) resources. This study will determine if a full-scale randomised controlled trial can be undertaken in the UK NHS to provide the high-quality evidence needed to determine the effectiveness of the intervention. ASICA is a pilot study evaluating the effectiveness of the practice of digitally supported TSSE in those affected by melanoma.

TRIAL REGISTRATION

Clinical Trials.gov, NCT03328247 . Registered on 1 November 2017.

IN MEMORIAM

John (Jack) B. Hay, PhDDecember 24, 1942 - February 25, 2019Lymphoimmunologist and Mentor Extraordinaire

The Relationship of Antiphospholipid Antibodies to Thromboembolic Disease in Systemic Lupus Erythematosus: A Cross-Sectional Study

In order to determine whether an association exists between antiphospholipid antibodies (APLA) and thromboembolic events in patients with systemic lupus erythematosus (SLE), we performed a cross-sectional study of consecutive unselected SLE patients. The occurrence of previous thromboembolic events was determined by investigators blinded to the APLA status of the patients by critical review of objective tests that had been performed at the time of symptomatic presentation and by performing venous Doppler ultrasound of the legs to elicit venous reflux as an indication of previous venous thrombosis. The presence of APLA was determined by coagulation assays for the lupus anticoagulant (LA) using five tests with well-defined control ranges and by ELISA assay for anticardiolipin antibodies (ACLA). These tests were measured on two separate occasions. The results of the study demonstrate a statistically significant association between persistently abnormal ACLA assays and thromboembolic events and a non-significant trend between persistently abnormal LA and thromboembolic events. Transient abnormalities of LA and ACLA were less strongly associated with thromboembolic events. We conclude that in patients with SLE, there is a significant association between thromboembolism and APLA.

Free Protein S Deficiency May Be Found in Patients with Antiphospholipid Antibodies who Do not Have Systemic Lupus Erythematosus

In order to determine if there is a relationship between antiphospholipid antibodies and reduced free protein S levels, we evaluated 21 patients who had an antiphospholipid antibody but had neither a history of venous thromboembolism nor systemic lupus erythematosus (cases) and 55 matched controls, who did not have an antiphospholipid antibody, a history of thrombosis or systemic lupus erythematosus. Cases and controls had similar protein C and antithrombin levels. Six of 21 cases had reduced free protein S antigen levels, compared to 5 of 55 controls (x 2 = 5.823 p <0.025). In addition, the mean free protein S level was significantly lower in cases than in controls (0.30 ± 0.09 units vs 0.39 ± 0.13 units, p <0.01, two-tailed Student’s t-test). We conclude that antiphospholipid antibodies are associated with a significant decrease in free protein S levels, and that this acquired free protein S deficiency may contribute to the thrombotic diathesis seen in patients with antiphospholipid antibodies.

Multicenter Evaluation of Lyophilized and Deep-frozen Plasmas for Assignment of the International Normalized Ratio

The interlaboratory variation of the International Normalized Ratio (INR) in various external quality assessment schemes is still relatively high. This is partly caused by inaccuracy of manufacturers’ stated International Sensitivity Index (ISI) and/or local instrumentation effects. The interlaboratory variation and accuracy of INR determinations may be improved by a local calibration procedure based on lyophilized plasmas with assigned INRs. The purpose of the present study was to determine INR values for different types of lyophilized plasmas to be used for local calibration. A total of 13 lyophilized plasmas (one normal, six from coumarin-treated patients, six artificially depleted) were analyzed by 10 laboratories, each using five calibrated prothrombin time (PT) systems. INRs were calculated for each plasma using each laboratory’s specific ISI and mean normal prothrombin time values. In the same way, five deep-frozen pooled plasmas from coumarin-treated patients were analyzed. There were significant INR differences for the lyophilized plasmas between the prothrombin time systems. The differences were relatively small for the deep-frozen coumarin plasmas (CV 2.6-3.3%) and three lyophilized coumarin plasmas from one manufacturer (CV 3.7-4.8%). Important INR differences were observed for three lyophilized coumarin plasmas from another manufacturer (CV 9.5-14.1%) and several artificially depleted plasmas (CV 5.3-12.8%). The citrate concentrations in the artificially depleted plasmas were lower than those in the normal and coumarin plasmas. These differences should be considered in the selection and certification of plasmas as calibrants for local calibration of PT systems. The lyophilized plasmas’ INR values obtained in the present study will be used for a field study of local PT calibration to assess their efficacy.

Influence of Three Types of Automated Coagulometers on the International Sensitivity Index (ISI) of Rabbit, Human, and Recombinant Human Tissue Factor Preparations

Five tissue factor reagents and three types of automated instruments for prothrombin time (PT) determination were studied in an international multicenter collaborative exercise. The purpose of this work was to determine the international sensitivity index (ISI) for each combination of reagent and instrument against the international reference preparation RBT/90. Each type of instrument was used by 3 or 4 centers to assess the interlaboratory variation of the ISI. The interlaboratory variation of the ISI for each combination of reagent and instrument ranged between 0.4% and 7.8% coefficient of variation. For three reagents, the mean ISI values for ACL (nephelometric) and STA (mechanical) were practically identical, but the mean ISI values for MLA (photo-optical) were at least 10% higher. For two other reagents prepared from rabbit tissue, the mean ISI values increased in the order ACL, STA, MLA. The widest range of mean ISI values was noted with one rabbit tissue factor reagent: 1.68 for ACL and 2.00 for MLA. Exclusion of patient specimens with INR <1.5 and INR >4.5 determined by the international reference preparation resulted in a slight decrease of the mean ISI.

The interlaboratory variation of the International Normalized Ratio (INR) was assessed from the results obtained with common lyophilized and deep-frozen plasmas. The use of instrument-specific ISI values resulted in reduced interlaboratory variation of the INR. It is recommended that thromboplastin manufacturers provide instrument-specific ISI values.

Does motor imagery training improve hand function in chronic stroke patients? A pilot study

Objective: To assess the efficacy of motor imagery training for arm function in chronic stroke patients. The relation between mental processes such as attentional and perceived personal control over recovery, and motor imagery was additionally investigated.

Design and subjects: Twenty patients with long-term motor impairments (mean two years post stroke), were assessed before and after four weeks of training. Ten patients mentally rehearsed movements with their affected arm. Their recovery was compared with patients who performed nonmotor imagery (n =5), or who were not engaged in mental rehearsal (n =5).

Setting: Patients were recruited from the stroke database of Ninewells Hospital, Dundee. Assessment and training were performed at the patients' home.

Interventions: The motor imagery group was asked to practise daily imagining moving tokens with their affected arm. The nonmotor imagery group rehearsed visual imagery of previously seen pictures. All patients practised physically moving the tokens.

Main measures: The following variables were assessed before and after training: motor function (training task, pegboard and dynamometer), perceived locus of control, attention control and ADL independence.

Results: All patient groups improved on all motor tasks except the dynamometer. Improvement was greater for the motor imagery group on the training task only (average of 14% versus 6%). No effect of motor imagery training was found on perceived or attentional control.

Conclusions: Motor imagery training without supervision at home may improve performance on the trained task only. The relation between movement imagery, attention and perceived personal control over recovery remained unclear.

pHAST (pH-Driven Aptamer Switch for Thrombin) Catch-and-Release of Target Protein

A pH-driven DNA nanomachine based on the human α-thrombin binding aptamer was designed for the specific catch-and-release of human α-thrombin at neutral and acidic pH, respectively. In neutral conditions, the thrombin aptamer component of the nanomachine is exposed and exists in the G-quadruplex conformation required to bind to the target protein. At slightly acidic pH, the polyadenine tail of the nanomachine becomes partially protonated and A+(anti)•G(syn) mispairing results in a conformational change, causing the target protein to be released. Förster resonance energy transfer (FRET) was used to monitor conformational switching over multiple pH cycles. Electrophoretic mobility shift assay (EMSA) and fluorescence anisotropy were used to show pH dependent protein binding and release by the nanomachine. This approach could be applied generally to existing G-rich aptamers to develop novel biosensors, theranostics, and nanoswitches.

[Better Reporting of Interventions: Template for Intervention Description and Replication (TIDieR) Checklist and Guide]

Without a complete published description of interventions, clinicians and patients cannot reliably implement interventions that are shown to be useful, and other researchers cannot replicate or build on research findings. The quality of description of interventions in publications, however, is remarkably poor. To improve the completeness of reporting, and ultimately the replicability, of interventions, an international group of experts and stakeholders developed the Template for Intervention Description and Replication (TIDieR) checklist and guide. The process involved a literature review for relevant checklists and research, a Delphi survey of an international panel of experts to guide item selection, and a face-to-face panel meeting. The resultant 12-item TIDieR checklist (brief name, why, what (materials), what (procedure), who intervened, how, where, when and how much, tailoring, modifications, how well (planned), how well (actually carried out)) is an extension of the CONSORT 2010 statement (item 5) and the SPIRIT 2013 statement (item 11). While the emphasis of the checklist is on trials, the guidance is intended to apply across all evaluative study designs. This paper presents the TIDieR checklist and guide, with a detailed explanation of each item, and examples of good reporting. The TIDieR checklist and guide should improve the reporting of interventions and make it easier for authors to structure the accounts of their interventions, reviewers and editors to assess the descriptions, and readers to use the information.

Multiple daily doses of acetyl-salicylic acid (ASA) overcome reduced platelet response to once-daily ASA after coronary artery bypass graft surgery: a pilot randomized controlled trial

BACKGROUND

The efficacy of ASA for prevention of graft failure following CABG surgery may be limited by incomplete platelet inhibition due to increased post-operative platelet turnover.

OBJECTIVES

To determine whether acetyl-salicylic acid (ASA) 325 mg once-daily or 81 mg four-times daily overcomes the impaired response to ASA 81 mg once-daily in post-operative coronary artery bypass graft (CABG) patients.

METHODS

We randomized 110 patients undergoing CABG surgery to either ASA 81 mg once-daily, 81 mg four times daily or 325 mg once-daily and compared their effects on serum thromboxane B2 (TXB2 ) suppression and arachidonate-induced platelet aggregation.

RESULTS

One hundred patients were included in the final analysis. Platelet counts fell after surgery, reached a nadir on day 2, and then gradually increased. Although there was near complete suppression of TXB2 on the second or third post-operative day, TXB2 levels increased in parallel with the rise in platelet count on subsequent days. This increase was most marked in patients receiving ASA 81 mg once-daily and less evident in those receiving ASA four times daily. On post-operative day 4, (i) median TXB2 levels were lower with four times daily ASA than with either ASA 81 mg once-daily (1.1 ng/mL; Quartile(Q) Q1,Q3: 0.5, 2.4 and 13.3 ng/mL; Q1,Q3: 7.8, 30.8 ng/mL, respectively; P < 0.0001) or ASA 325 mg once-daily (3.4 ng/mL; Q1,Q3: 2.0, 8.2 ng/mL; P = 0.002), and (ii) ASA given four times daily was more effective than ASA 81 mg once-daily and 325 mg once-daily at suppressing platelet aggregation.

CONCLUSIONS

Four times daily ASA is more effective than ASA 81 and 325 mg once-daily at suppressing serum TXB2 formation and platelet aggregation immediately following CABG surgery.

Comparison of the effects of apixaban and rivaroxaban on prothrombin and activated partial thromboplastin times using various reagents

BACKGROUND

Clinical situations occur where expedient assessment of the anticoagulant activity of the direct factor Xa (FXa) inhibitors is required. Although quantitative anti-FXa (FXa) assays can be used to measure plasma levels of apixaban or rivaroxaban, turnaround is often slow and many laboratories do not perform these assays.

OBJECTIVE

We compared the in vitro effects of apixaban and rivaroxaban on two readily available laboratory tests, the prothrombin time (PT) and activated partial thromboplastin time (APTT), performed with different reagents. We aimed to identify the most sensitive reagents.

METHODS

Rivaroxaban or apixaban was added to human plasma at a range of concentrations covering expected peak and trough levels, and concentrations were confirmed using calibrated anti-FXa assays. Samples were assayed with six PT and seven APTT reagents using different coagulometers.

RESULTS AND CONCLUSIONS

TriniCLOT PT Excel S was the only reagent to demonstrate sensitivity to apixaban. All of the PT reagents were sensitive to rivaroxaban with TriniCLOT PT Excel S and HemosIL HS PLUS being the most sensitive. Sensitivity to rivaroxaban varied among APTT reagents; four reagents exhibited the greatest responsiveness, and of these, Actin FSL was the most responsive. Commonly used coagulation tests may be useful for assessing the anticoagulant effect of rivaroxaban but not of apixaban. The reason for the different effects of apixaban and rivaroxaban on the PT and APTT is unknown.

Otolaryngological complications of occipitocervical injury

Occipitocervical injuries are rare, accounting for 15% of all fatal spinal trauma. In patients who survive the initial incident, early detection and appropriate management is vital to avoid significant neurological disability and mortality. We present the case of a patient with neck trauma who was initially cleared of spinal injuries in the emergency department but who later developed acute hearing loss. We describe how the investigation of the hearing loss led to the detection of this devastating injury and report its successful management. Patients with persistent neck pain following trauma, particularly in the presence of degenerative spinal disease, should have cervical spine computed tomography to exclude occipitocervical injuries and other occult injuries.