Considerations for study design in the DAHANCA 35 trial of protons versus photons for head and neck cancer

Proton radiotherapy offers a dosimetric advantage compared to photon therapy in sparing normal tissue, but the clinical evidence for toxicity reductions in the treatment of head and neck cancer is limited. The Danish Head and Neck Cancer Group (DAHANCA) has initiated the DAHANCA 35 randomised trial to clarify the value of proton therapy (NCT04607694). The DAHANCA 35 trial is performed in an enriched population of patients selected by an anticipated benefit of proton therapy to reduce the risk of late dysphagia or xerostomia based on normal tissue complication probability (NTCP) modelling. We present our considerations on the trial design and a test of the selection procedure conducted before initiating the randomised study.

Analytical solution of phosphate kinetics for hemodialysis

Chronic kidney diseases imply an ongoing need to remove toxins, with hemodialysis as the preferred treatment modality. We derive analytical expressions for phosphate clearance during dialysis, the single pass (SP) model corresponding to a standard clinical hemodialysis and the multi pass (MP) model, where dialysate is recycled and therefore makes a smaller clinical setting possible such as a transportable dialysis suitcase. For both cases we show that the convective contribution to the dialysate is negligible for the phosphate kinetics and derive simpler expressions. The SP and MP models are calibrated to clinical data of ten patients showing consistency between the models and provide estimates of the kinetic parameters. Immediately after dialysis a rebound effect is observed. We derive a simple formula describing this effect which is valid both posterior to SP or MP dialysis. The analytical formulas provide explanations to observations of previous clinical studies.

Antibodies to calnexin and mutated calreticulin are common in human sera

PURPOSE OF THE STUDY

Calreticulin is an endoplasmic reticulum chaperone protein, which is involved in protein folding and in peptide loading of major histocompatibility complex class I molecules together with its homolog calnexin. Mutated calreticulin is associated with a group of hemopoietic disorders, especially myeloproliferative neoplasms. Currently only the cellular immune response to mutated calreticulin has been described, although preliminary findings have indicated that antibodies to mutated calreticulin are not specific for myeloproliferative disorders. These findings have prompted us to characterize the humoral immune response to mutated calreticulin and its chaperone homologue calnexin.

PATIENTS AND METHODS

We analyzed sera from myeloproliferative neoplasm patients, healthy donors and relapsing-remitting multiple sclerosis patients for the occurrence of autoantibodies to wild type and mutated calreticulin forms and to calnexin by enzyme-linked immunosorbent assay.

RESULTS

Antibodies to mutated calreticulin and calnexin were present at similar levels in serum samples of myeloproliferative neoplasm and multiple sclerosis patients as well as healthy donors. Moreover, a high correlation between antibodies to mutated calreticulin and calnexin was seen for all patient and control groups. Epitope binding studies indicated that cross-reactive antibodies bound to a three-dimensional epitope encompassing a short linear sequence in the C-terminal of mutated calreticulin and calnexin.

CONCLUSION

Collectively, these findings indicate that calreticulin mutations may be common and not necessarily lead to onset of myeloproliferative neoplasm, possibly due to elimination of cells with mutations. This, in turn, may suggest that additional molecular changes may be required for development of myeloproliferative neoplasm.

Prenatal and early postnatal exposure to perfluoroalkyl substances and bone mineral content and density in the Odense child cohort

INTRODUCTION

Exposure to perfluoroalkyl substances (PFAS) has been associated with lower bone mineral density (BMD) in animal and human studies, but prospective data from children are limited.

OBJECTIVES

To determine associations between prenatal and early postnatal PFAS exposure and BMD at age 7 years.

METHODS

In the Odense Child Cohort, Denmark, pregnant women were recruited in 2010-2012, and their children were invited for subsequent health examinations. At 12 weeks of gestation the pregnant women delivered a serum sample, and at age 18 months serum was obtained from the child to measure perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA) by LC-MS/MS. At age 7 years DXA scans were performed to measure bone mineral content (BMC) and BMD Z-score. PFAS in pregnancy (n = 924) and/or at age 18 months (n = 511) were regressed against DXA measurements, adjusted for maternal education, child height Z-score, sex (for BMC) and for postnatal exposure, additionally duration of total breastfeeding. We additionally performed structural equation models determining combined effects of pre-and postnatal PFAS exposures.

RESULTS

Higher prenatal and early postnatal serum concentrations of all measured PFAS were associated with lower BMC and BMD Z-scores at age 7 years, all estimates were negative although not all significant. For each doubling of prenatal or 18-month exposure to PFDA, BMD Z-scores were lowered by -0.07 (95 % CI -0.10; -0.03) and -0.14 (-0.25; -0.03), respectively after adjustment. Pre- and postnatal PFAS were correlated, but structural equation models suggested that associations with BMD were stronger for 18-month than prenatal PFAS exposure.

DISCUSSION

Bone density is established in childhood, and a reduction in BMD during early childhood may have long-term implication for peak bone mass and lifelong bone health. Future studies of the impact of PFAS exposure on fracture incidence will help elucidate the clinical relevance.

Epidemiology and impact of frailty in patients with atrial fibrillation in Europe

BACKGROUND

Frailty is a medical syndrome characterised by reduced physiological reserve and increased vulnerability to stressors. Data regarding the relationship between frailty and atrial fibrillation (AF) are still inconsistent.

OBJECTIVES

We aim to perform a comprehensive evaluation of frailty in a large European cohort of AF patients.

METHODS

A 40-item frailty index (FI) was built according to the accumulation of deficits model in the AF patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Association of baseline characteristics, clinical management, quality of life, healthcare resources use and risk of outcomes with frailty was examined.

RESULTS

Among 10,177 patients [mean age (standard deviation) 69.0 (11.4) years, 4,103 (40.3%) females], 6,066 (59.6%) were pre-frail and 2,172 (21.3%) were frail, whereas only 1,939 (19.1%) were considered robust. Baseline thromboembolic and bleeding risks were independently associated with increasing FI. Frail patients with AF were less likely to be treated with oral anticoagulants (OACs) (odds ratio 0.70, 95% confidence interval 0.55-0.89), especially with non-vitamin K antagonist OACs and managed with a rhythm control strategy, compared with robust patients. Increasing frailty was associated with a higher risk for all outcomes examined, with a non-linear exponential relationship. The use of OAC was associated with a lower risk of outcomes, except in patients with very/extremely high frailty.

CONCLUSIONS

In this large cohort of AF patients, there was a high burden of frailty, influencing clinical management and risk of adverse outcomes. The clinical benefit of OAC is maintained in patients with high frailty, but not in very high/extremely frail ones.

A risk assessment review of mercury exposure in Arctic marine and terrestrial mammals

There has been a considerable number of reports on Hg concentrations in Arctic mammals since the last Arctic Monitoring and Assessment Programme (AMAP) effort to review biological effects of the exposure to mercury (Hg) in Arctic biota in 2010 and 2018. Here, we provide an update on the state of the knowledge of health risk associated with Hg concentrations in Arctic marine and terrestrial mammal species. Using available population-specific data post-2000, our ultimate goal is to provide an updated evidence-based estimate of the risk for adverse health effects from Hg exposure in Arctic mammal species at the individual and population level. Tissue residues of Hg in 13 species across the Arctic were classified into five risk categories (from No risk to Severe risk) based on critical tissue concentrations derived from experimental studies on harp seals and mink. Exposure to Hg lead to low or no risk for health effects in most populations of marine and terrestrial mammals, however, subpopulations of polar bears, pilot whales, narwhals, beluga and hooded seals are highly exposed in geographic hotspots raising concern for Hg-induced toxicological effects. About 6% of a total of 3500 individuals, across different marine mammal species, age groups and regions, are at high or severe risk of health effects from Hg exposure. The corresponding figure for the 12 terrestrial species, regions and age groups was as low as 0.3% of a total of 731 individuals analyzed for their Hg loads. Temporal analyses indicated that the proportion of polar bears at low or moderate risk has increased in East/West Greenland and Western Hudson Bay, respectively. However, there remain numerous knowledge gaps to improve risk assessments of Hg exposure in Arctic mammalian species, including the establishment of improved concentration thresholds and upscaling to the assessment of population-level effects.

POS0008 THE UTILITY OF TRANS-BRONCHIAL LUNG BIOPSIES TO GUIDE THE TREATMENT IN PATIENTS WITH RHEUMATIC INFLAMMATORY DISEASES: A RETROSPECTIVE CROSS-SECTIONAL STUDY

Background

Rheumatic inflammatory disease associated interstitial lung disease (R-ILD) is associated with significant mortality and morbidity1. On a patient-to-patient level, imaging which is a cornerstone in diagnosing R-ILD may not be sufficent to determine the underlying cause of the imaging pathology or the degree of reversibilty. Furthermore the precense of co-morbidity and diffential diagnoses such as infections or malignacy needs to be taken into account when dertemining the therapeutic strategy. The role of transbronchial lung biopsies (TBB) in the diagnostic workup of R-ILD is unclear and TBB is not generally recommended2-4.

Objectives

The study objective was to examine the utility of TBB to guide treatment in a population of patients with R-ILD reffered for bronchoscopy.

Methods

All patients from the Department of Rheumatology, Rigshospitalet, Copenhagen, Denmark referred for a TBB on the suspicion of R-ILD, from 2002 to 2016 were identified.

Patient demographics as well as smoking status, previous lung disease, pulmonary function test, CTD-diagnosis, imaging results and immunomodulatory therapy pre- and post-bronchoscopy were obtained.

Histology findings were used to dichotomize patients into a high inflammatory group or a low inflammatory group. The high inflammation group primarily consisted of non-specific interstitial pneumonia (NSIP), organizing pneumonia (OP), lymphocytic infiltrating pneumonia (LIP) and granulomatous inflammation whereas the low inflammation group primarily consisted of histological findings of usual interstitial pneumonitis (UIP) and biopsies describing fibrosis and/or sparse unspecific inflammation. Therapeutic consequence was defined as intensification of therapy. Differences in treatment intensification were calculated using a binominal logistic regression model. Differences in treatment intensification were calculated using a binominal logistic regression model adjusted for age, gender, smoking status, previous lung disease, diffusion capacity, rheumatologic diagnose, c-reactive protein level prior to TBB. Covariates with P>0.1 were excluded by a stepwise ‘backwards’ elimination.

Results

96 patients had TBB performed. Biopsies from 55 patients were categorized as high-inflammatory and 41 as low-inflammatory, respectively. In the high inflammatory group thirty-eight (69%) had their therapy intensified compared to 6 (14%) in the low-inflammatory group (P <0.001). TBB inflammation type was the only covariate that was significantly associated with treatment intensification.

No procedure related complications were registered.

Conclusion

TBB findings can guide treatment strategy in R-ILD patients with suspected activity in the pulmonary disease. TBB appears safe and could be considered as part of the diagnostic workup in patients with inflammatory rheumatic diseases where clinical features, bloodsamples, imaging and/or pulmonary function test do not provide suffcient information to guide the therapeutic strategy.

References

[1]Mathai SC, Danoff SK. Management of interstitial lung disease associated with connective tissue disease. BMJ. 2016;352:h6819. doi: 10.1136/bmj.h6819 [doi].

[2]Sebastiani M, Faverio P, Manfredi A, Cassone G, Vacchi C, Stainer A, et al. Interstitial Pneumonia with Autoimmune Features: Why Rheumatologist-Pulmonologist Collaboration Is Essential. Biomedicines. 2020;9(1). Epub 2020/12/31. doi: 10.3390/biomedicines9010017. PubMed PMID: 33375368; PubMed Central PMCID: PMCPMC7824155.

[3]Mochimaru H, Kawamoto M, Enomoto T, Saitoh Y, Abe S, Nei T, et al. Transbronchial biopsy is clinically useful in classifying patients with interstitial pneumonia associated with polymyositis and dermatomyositis. Respirology. 2008;13(6):863-70.

[4]Morell F, Reyes L, Domenech G, De GJ, Majo J, Ferrer J. [Diagnoses and diagnostic procedures in 500 consecutive patients with clinical suspicion of interstitial lung disease]. Arch Bronconeumol. 2008;44(4):185-91.

Disclosure of Interests

Martin Andersen Employee of: Novo Nordisk A/S: 2010-2015, Thomas K. Lund: None declared, Thomas H. L. Jensen: None declared, Martin Iversen: None declared, Michael Perch Speakers bureau: Mallinckrodt, Novartis, GSK, PulmonX, Consultant of: Ambu, PulmonX, Takeda, Grant/research support from: Roche, Bo Baslund: None declared

POS0761 TIME-DEPENDENT ANALYSES OF CLINICAL MANIFESTATIONS OF SYSTEMIC LUPUS ERYTHEMATOSUS IDENTIFY PATIENTS AT HIGH RISK OF INCIDENT PROTEINURIA

Background

Nephritis (LN) in systemic lupus erythematosus (SLE) is still a major determinant of poor prognosis[1].

The vast majority of LN occurs in proximity to the SLE diagnosis[2]. Identification of individuals at high risk, especially early onset SLE, is therefore warranted. Inclusion of risk factors prior to the SLE diagnosis may thus be of importance to enable sufficient risk factor profiling. SLE-patients seem to cluster according to clinical and serological phenotypes suggesting distinct disease trajectories[3-5].

Objectives

To determine if incident proteinuria associated with the debut age of non-renal SLE characteristics.

Methods

Data of SLE patients from six Danish centers were obtained from the Danbio-database from 2017 – 2020. The occurrence and timing of proteinuria was compared with first time onset of any non-renal manifestations as defined by the 1997 American College of Rheumatology Classification Criteria. Cox-regression models were used to identify risk factors for incident proteinuria. Time from first occurring non-renal manifestation to incident proteinuria or censoring defined time at risk. Covariates were eliminated if p >0.01 in a ‘backwards’ manner. After the model reduction process p-values <0.05 were considered statistically significant.

Results

586 SLE patients, mainly white (94%) women (88%), mean age at inclusion of 34.6 years (standard deviation, SD = 0.6 years) and observed for a mean of 14.9 years (SD =0.5 years), were recruited. The cumulative prevalence of proteinuria was 40%. Male gender hazard ratio, HR = 1.35 (range 0.77-2.35), p=0.009, lymphopenia HR = 1.77 (range 1.24-2.52), p=0.005 were associated with incident proteinuria. In contrast, patients with discoid rash had lower risk of incident proteinuria HR 0.42 (range 0.21-0.83), p=0.01. Male patients with lymphopenia had the highest risk of proteinuria with a one-, 5- and 10-year risk of proteinuria ranging from 9-27%, 34-75% and 51-89 %, depending on the age at presentation (debut at 20, 30, 40 or 50 years). The corresponding risk-profiles for women with lymphopenia were 3-9%, 8-34% and 12-58%, respectively, as illustrated in Figure 1.

Conclusion

The occurrences of lymphopenia and discoid rash were oppositely associated with risk of incident proteinuria and the risk effects varied according to gender and patient age at onset of these manifestations. Thus, the risk of proteinuria may not be constant but could vary according to presentation of non-renal manifestations that may call for a differentiated clinical follow-up. Based on these findings, we suggest that the debut age of known prognostic factors, even prior to the SLE diagnosis should be considered when designing prognostic statistical models.

References

[1]Faurschou, M., et al., Prognostic factors in lupus nephritis: diagnostic and therapeutic delay increases the risk of terminal renal failure. J Rheumatol, 2006. 33(8): p. 1563-9.

[2]Hanly, J.G., et al., The frequency and outcome of lupus nephritis: results from an international inception cohort study. Rheumatology (Oxford), 2016. 55(2): p. 252-62.

[3]Diaz-Gallo, L.M., et al., Four Systemic Lupus Erythematosus Subgroups, Defined by Autoantibodies Status, Differ Regarding HLA-DRB1 Genotype Associations and Immunological and Clinical Manifestations. ACR Open Rheumatol, 2022. 4(1): p. 27-39.

[4]Jacobsen, S., et al., A multicentre study of 513 Danish patients with systemic lupus erythematosus. II. Disease mortality and clinical factors of prognostic value. Clin Rheumatol, 1998. 17(6): p. 478-84.

[5]Leffers, H.C.B., et al., Smoking associates with distinct clinical phenotypes in patients with systemic lupus erythematosus: a nationwide Danish cross-sectional study. Lupus Sci Med, 2021. 8(1).

Disclosure of Interests

Martin Andersen Employee of: Novo Nordisk A/S: 2010-2014, Anders Stockmarr: None declared, Henrik Leffers: None declared, Anne Troldborg: None declared, Anne Voss: None declared, Salome Kristensen: None declared, Bent Deleuran: None declared, Lene Dreyer Speakers bureau: Speakers bureau: Eli Lilly, Galderma and Janssen, Grant/research support from: Grant from BMS outside the present work, Laura Johnsen: None declared, Ada Colic: None declared, Søren Jacobsen: None declared

AB0103 SITE SPECIFICITY OF RHEUMATOID ARTHRITIS INFLAMMATION: A SECONDARY ANALYSIS OF BIOPSIES FROM RADIAL AND ULNAR ASPECTS OF MCP JOINTS

Background

Ulnar drift is a common complication of Rheumatoid Arthritis (RA) (1,2). There is no clear consensus regarding the etiology of the hand deformity. Observations from corrective hand surgery and other studies have noted more pronounced inflammation in the radial site of the MCP-joints (3,4). This could partly explain the pathophysiology behind the ulnar deviation.

Objectives

To determine if there is more pronounced inflammation, measured by increased CD-68 expression (5) and Krenn-synovitis score (6), at the radial side of the MCP joints when compared to the ulnar side, in patients with verified RA.

Methods

We included RA patients from a previous study who had biopsies taken from the most affected joints based on clinical examination and ultrasound (7). Twenty-nine PIP-, MCP- and wrist-joints were biopsied. Biopsies from the MCP-joints were taken from the dorso-ulnar and dorso-radial concavity. Inflammation was graded by the Krenn-synovitis score (0-9) and the density of CD-68-positive cells (%). The difference between radial and ulnar joint inflammation was calculated by paired t-test. P-value <0.05 was considered statistically significant.

Results

In 8 patients biopsies were taken from both the ulnar and the radial site of the same MCP-joint. The mean difference in inflammation on the radial and ulnar site of MCP-joints was based on differences in CD-68 density: 0,67% (95%-CI -4,77 to 6,10; P = 0,77) (Figure 1) and Krenn-score: 0,83 (95%-CI -1,31 to 2,98; P = 0,36), respectively.

Figure 1.

Paired data on CD-68 percentage in radial and ulnar sites

Conclusion

There was no difference in concentration of inflammatory cells or overall synovial pathology between the radial and ulnar site of MCP-joints in RA patients. The impression of a more pronounced inflamed synovium on the radial site of MCP joints, as observed during surgery, does not seem to arise from an immunological preference, but rather to be linked to a larger synovial volume.

References

[1]Wise KS: The anatomy of the metacarpo-phalangeal joints, with observations of the aetiology of ulnar drift. J. Bone Joint Surg. Br. 1975; 57:485–90

[2]Johnsson PM, Eberhardt K: Hand deformities are important signs of disease severity in patients with early rheumatoid arthritis. Rheumatology 2009; 48:1398–1401

[3]Philpott H.T. Synovial tissue perivascular edema is associated with altered gait patterns in patients with knee osteoarthritis, Osteoarthritis and Cartilage. 2022; 30(1): 42-51

[4]Tan AL, Tanner SF, Conaghan PG, et al.: Role of metacarpophalangeal joint anatomic factors in the distribution of synovitis and bone erosion in early rheumatoid arthritis. Arthritis Rheum. 2003; 48:1214–22

[5]Zhang X.-P: Addition of Fibroblast-Stromal Cell Markers to Immune Synovium Pathotypes Better Predicts Radiographic Progression at 1 Year in Active Rheumatoid Arthritis, Frontiers in Immunology 2021; 12: 778480

[6]Krenn V, Morawietz L, Burmester G-R, et al.: Synovitis score: discrimination between chronic low-grade and high-grade synovitis. Histopathology 2006; 49:358–364

[7]Andersen M, Ellegaard K, Hebsgaard JB, et al.: Ultrasound colour Doppler is associated with synovial pathology in biopsies from hand joints in rheumatoid arthritis patients: a cross-sectional study. Ann. Rheum. Dis. 2014; 73:678–683

Acknowledgements

The authors would like to thank the study participants as well as Inger Wätjen, Eva Littrup Andersen, Mette Okkels, Jette Møller Frøsig and Suzi Høeg Madsen for technical assistance. I have no acknowledgements to declare.

Disclosure of Interests

Katrine Skovsgaard Itenov: None declared, Niels Søe: None declared, Else Marie Bartels: None declared, Henning Bliddal: None declared, Martin Andersen Grant/research support from: The primary study was supported by unrestricted grants from Novo Nordisk, Employee of: Was employed at Novo Nordisk A/S during the conduction of the study.

Spatial variation in mercury concentrations in polar bear (Ursus maritimus) hair from the Norwegian and Russian Arctic

We examined spatial variation in total mercury (THg) concentrations in 100 hair samples collected between 2008 and 2016 from 87 polar bears (Ursus maritimus) from the Norwegian (Svalbard Archipelago, western Barents Sea) and Russian Arctic (Kara Sea, Laptev Sea, and Chukchi Sea). We used latitude and longitude of home range centroid for the Norwegian bears and capture position for the Russian bears to account for the locality. We additionally examined hair stable isotope values of carbon (δ¹³C) and nitrogen (δ¹⁵N) to investigate feeding habits and their possible effect on THg concentrations. Median THg levels in polar bears from the Norwegian Arctic (1.99 μg g^-1 dry weight) and the three Russian Arctic regions (1.33-1.75 μg g^-1 dry weight) constituted about 25-50% of levels typically reported for the Greenlandic or North American populations. Total Hg concentrations in the Norwegian bears increased with intake of marine and higher trophic prey, while δ¹³C and δ¹⁵N did not explain variation in THg concentrations in the Russian bears. Total Hg levels were higher in northwest compared to southeast Svalbard. δ¹³C and δ¹⁵N values did not show any spatial pattern in the Norwegian Arctic. Total Hg concentrations adjusted for feeding ecology showed similar spatial trends as the measured concentrations. In contrast, within the Russian Arctic, THg levels were rather uniformly distributed, whereas δ¹³C values increased towards the east and south. The results indicate that Hg exposure in Norwegian and Russian polar bears is at the lower end of the pan-Arctic spectrum, and its spatial variation in the Norwegian and Russian Arctic is not driven by the feeding ecology of polar bears.

Adherence to Direct Oral Anticoagulants in Patients With Non-Valvular Atrial Fibrillation: A Cross-National Comparison in Six European Countries (2008-2015)

Aims: To describe and compare the adherence to different direct oral anticoagulants (DOACs) in eight European databases representing six countries. Methods: Longitudinal drug utilization study of new users (≥18 years) of DOACs (dabigatran, rivaroxaban, apixaban) with a diagnosis of non-valvular atrial fibrillation (2008-2015). Adherence was examined by estimating persistence, switching, and discontinuation rates at 12 months. Primary non-adherence was estimated in BIFAP and SIDIAP databases. Results: The highest persistence rate was seen for apixaban in the CPRD database (81%) and the lowest for dabigatran in the Mondriaan database (22%). The switching rate for all DOACs ranged from 2.4 to 13.1% (Mondriaan and EGB databases, respectively). Dabigatran had the highest switching rate from 5.0 to 20.0% (Mondriaan and EGB databases, respectively). The discontinuation rate for all DOACs ranged from 16.0 to 63.9% (CPRD and Bavarian CD databases, respectively). Dabigatran had the highest rate of discontinuers, except in the Bavarian CD and AOK NORDWEST databases, ranging from 23.2 to 64.6% (CPRD and Mondriaan databases, respectively). Combined primary non-adherence for examined DOACs was 11.1% in BIFAP and 14.0% in SIDIAP. There were differences in population coverage and in the type of drug data source among the databases. Conclusion: Despite the differences in the characteristics of the databases and in demographic and baseline characteristics of the included population that could explain some of the observed discrepancies, we can observe a similar pattern throughout the databases. Apixaban was the DOAC with the highest persistence. Dabigatran had the highest proportion of discontinuers and switchers at 12 months in most databases (EMA/2015/27/PH).

Sea ice reduction drives genetic differentiation among Barents Sea polar bears

Loss of Arctic sea ice owing to climate change is predicted to reduce both genetic diversity and gene flow in ice-dependent species, with potentially negative consequences for their long-term viability. Here, we tested for the population-genetic impacts of reduced sea ice cover on the polar bear (Ursus maritimus) sampled across two decades (1995-2016) from the Svalbard Archipelago, Norway, an area that is affected by rapid sea ice loss in the Arctic Barents Sea. We analysed genetic variation at 22 microsatellite loci for 626 polar bears from four sampling areas within the archipelago. Our results revealed a 3-10% loss of genetic diversity across the study period, accompanied by a near 200% increase in genetic differentiation across regions. These effects may best be explained by a decrease in gene flow caused by habitat fragmentation owing to the loss of sea ice coverage, resulting in increased inbreeding of local polar bears within the focal sampling areas in the Svalbard Archipelago. This study illustrates the importance of genetic monitoring for developing adaptive management strategies for polar bears and other ice-dependent species.

Human induced pluripotent stem cells (BIONi010-C) generate tight cell monolayers with blood-brain barrier traits and functional expression of large neutral amino acid transporter 1 (SLC7A5)

The barrier properties of the brain capillary endothelium, the blood-brain barrier (BBB) restricts uptake of most small and all large molecule drug compounds to the CNS. There is a need for predictive human in vitro models of the BBB to enable studies of brain drug delivery. Here, we investigated whether human induced pluripotent stem cell (hiPSC) line (BIONi010-C) could be differentiated to brain capillary endothelial- like cells (BCEC) and evaluated their potential use in drug delivery studies. BIONi010-C hIPSCs were differentiated according to established protocols. BCEC monolayers displayed transendothelial electrical resistance (TEER) values of 5,829±354 Ω∙cm², a P_app,_mannitol of 1.09±0.15 ∙ 10^-6 cm∙s^-1 and a P_app,diazepam of 85.7 ± 5.9 ∙ 10^-6 cm ∙s^-1. The P_diazepam/P_mannitol ratio of ~80, indicated a large dynamic passive permeability range. Monolayers maintained their integrity after medium exchange. Claudin-5, Occludin, Zonulae Occludens 1 and VE-Cadherin were expressed at the cell-cell contact zones. Efflux transporters were present at the mRNA level, but functional efflux of substrates was not detected. Transferrin-receptor (TFR), Low density lipoprotein receptor-related protein 1 (LRP1) and Basigin receptors were expressed at the mRNA-level. The presence and localization of TFR and LRP1 were verified at the protein level. A wide range of BBB-expressed solute carriers (SLC's) were detected at the mRNA level. The presence and localization of SLC transporters GLUT1 and LAT1 was verified at the protein level. Functional studies revealed transport of the LAT1 substrate [³H]-L-Leucine and the LRP1 substrate angiopep-2. In conclusion, we have demonstrated that BIONi010-C-derived BCEC monolayers exhibited, BBB properties including barrier tightness and integrity, a high dynamic range, expression of some of the BBB receptor and transporter expression, as well as functional transport of LAT1 and LRP1 substrates. This suggests that BIONi010-C-derived BCEC monolayers may be useful for studying the roles of LAT-1 and LRP1 in brain drug delivery.

Early Mortality after Radical Radiotherapy in Head and Neck Cancer - A Nationwide Analysis from the Danish Head and Neck Cancer Group (DAHANCA) Database

AIMS

Curative-intent radiotherapy (RT) or chemoradiation (CRT) of squamous cell carcinoma of the head and neck (HNSCC) produces high survival rates, but is associated with substantial toxicity. However, there are no commonly accepted quality metrics for early mortality in radiation oncology. To assess the applicability of early mortality as a clinical quality indicator, this study investigated the temporal distribution, risk factors and trends of 90- and 180-day overall and non-cancer mortality in a nationwide cohort of HNSCC patients treated with RT/CRT.

MATERIALS AND METHODS

Information on all HNSCC patients treated with curative-intent RT/CRT in Denmark between 2000 and 2017 was obtained from the national Danish Head and Neck Cancer Group clinical database. Deaths in patients with residual or recurrent disease after RT/CRT were classified as cancer-related. Possible risk factors were investigated using logistic regression analysis.

RESULTS

Data from 11 419 patients were extracted. In total, 90- and 180-day mortality risks were 3.1% and 7.1%, respectively. There was a uniform temporal distribution of 180-day mortality. In multivariable analysis, increasing age, stage, performance status, earlier treatment year and hypopharyngeal cancer were significantly associated with an increased risk (P < 0.05). Risk factor estimates were comparable for 90- versus 180-day mortality as well as for overall versus non-cancer mortality. Between 2000 and 2017 there was a significant decrease in 180-day mortality, which was driven by a reduction in cancer-related events.

CONCLUSION

The distribution of 180-day overall and non-cancer mortality did not indicate a well-defined early high-risk period. Moreover, risk factor estimates were highly similar across risk periods and groups. Taken together, our findings question the applicability of early mortality as a standard metric for treatment-associated toxicity.

Two Decades of Mercury Concentrations in Barents Sea Polar Bears (Ursus maritimus) in Relation to Dietary Carbon, Sulfur, and Nitrogen

Temporal trends of total mercury (THg) were examined in female polar bear (Ursus maritimus) hair (n = 199) from the Barents Sea in 1995-2016. In addition, hair values of stable isotopes (n = 190-197) of carbon (δ¹³C), sulfur (δ³⁴S), and nitrogen (δ¹⁵N) and information on breeding status, body condition, and age were obtained. Stable isotope values of carbon and sulfur reflect dietary source (e.g., marine vs terrestrial) and the nitrogen trophic level. Values for δ¹³C and δ³⁴S declined by -1.62 and -1.18‰ over the time of the study period, respectively, while values for δ¹⁵N showed no trend. Total Hg concentrations were positively related to both δ¹³C and δ³⁴S. Yearly median THg concentrations ranged from 1.61 to 2.75 μg/g and increased nonlinearly by 0.86 μg/g in total over the study. Correcting THg concentrations for stable isotope values of carbon and sulfur and additionally breeding status and age slightly accelerated the increase in THg concentrations; however, confidence intervals of the raw THg trend and the corrected THg trend had substantial overlap. The rise in THg concentrations in the polar bear food web was possibly related to climate-related re-emissions of previously stored Hg from thawing sea-ice, glaciers, and permafrost.

SAT0130 TREAT-TO-TARGET STRATEGY OF >8.000 PATIENTS WITH EARLY RHEUMATOID ARTHRITIS: DOES SMOKING AFFECT ACHIEVEMENT OF REMISSION ON METHOTREXATE AND TIME TO START OF FIRST BIOLOGIC? RESULTS FROM THE NATIONWIDE DANISH DANBIO REGISTRY

Background:

Smoking is a known risk factor for rheumatoid arthritis (RA). It is largely unknown whether smoking has any impact on disease activity and treatment outcomes (e.g. achieving remission on methotrexate and time to first biological disease modifying anti-rheumatic treatments (bDMARD)) in early RA with a modern treat-to-target strategy.

Objectives:

To explore if smoking was associated with treatment outcomes in newly diagnosed patients with RA starting first conventional synthetic (cs)DMARDs in routine care.

Methods:

Observational cohort study. Adult patients with RA starting first csDMARD during year 2010-2018 were identified in the Danish nationwide quality registry, DANBIO. Smoking status (current/never/previous) upon start of csDMARD (=baseline), disease activity, 1-year treatment outcomes and bDMARD treatment were retrieved from DANBIO. Data were censored Oct 2019.

Impact of smoking status was explored for the following outcomes: 1) median baseline disease activity baseline, 2) remission at 1-year (logistic regression analyses), 3) time to first bDMARD (Cox-regression analyses). Regression analyses were adjusted for gender and age.

Results:

Among 9515 patients, 8647 (91%) had available smoking status (Current 23%/never 50%/previous 27%) and were included. Baseline disease activity was independent of smoking status (Table 1). First line csDMARD was methotrexate in 91% of patients. Compared to never smokers, the current smokers were more often men, younger and sero-positive for IgM-RF and anti-CCP.

Table 1.

Patient characteristics and disease activity at baseline and 1 year stratified by smoking status. Numbers are medians (IQR) unless otherwise stated.

Smoking statusCurrentNeverPreviousBaselinePatient numbers, N200743082332Age, yrs58 (49-66)61 (48-71)62 (52-70)Female, %627163IgM-RF positive, %715465Anti-CCP positive, %715365DAS284.4 (3.4-5.3)4.4 (3.4-5.3)4.3 (3.3-5.3)CDAI18.7 (11.7-27.3)18.4 (10.9-27.4)18.5 (10.4-27.6)VAS patient global, mm60 (35-81)55 (30-77)55 (31-78)1 yearPatient number, N179338372053DAS282.6 (1.9-3.7)2.3 (1.7-3.4)2.5 (1.8-3.4)CDAI6.4 (2.8-12.5)4.9 (1.8-10.3)5.4 (2-10.8)DAS28-remission, %495753CDAI-remission, %273533VAS patient global, mm37 (14-67)29 (10-57)30 (11-58)

DAS28-response: DAS28(CRP)≤2.6; CDAI-remission: CDAI≤2.8

Never and previous smokers had higher odds of remission at 1 year’s follow-up compared to current smokers. In adjusted Cox regression analyses, baseline smoking was associated with shorter time to start of first bDMARD (Table 2).

Table 2.

Impact of baseline smoking status on treatment outcomes

ComparisonOdds Ratio (95% CI)pDAS28-remission 1 yr, yes vs. no*Never vs. current smoker1.43 (1.27;1.62)<0.001Previous vs. current1.14 (0.99;1.30)0.07CDAI remission 1 yr, yes vs. no*Never vs. current1.53 (1.34;1.75)<0.001Previous vs. current1.29 (1.11;1.50)<0.001ComparisonHazard Ratio (95% CI)pStart of bDMARD duringfollow-up**Never vs current smoker0.85 (0.76;0.96)0.006Previous vs. current1.05 (0.93;1.19)0.4

*Logistic regression analyses (adjusted for gender and age)

** Cox regression analyses (adjusted for gender and age)

Conclusion:

In this observational study of >8000 patients with RA starting a first csDMARD, current smoking was associated with lower odds of achieving remission on methotrexate and higher chance of having started bMDARD compared to never smokers. Seropositivity may be an intermediate variable. Further analyses are planned to study impact of comorbidities and other confounding factors.

Acknowledgments :

Thank you to all patients and departments who contribute to the DANBIO registry

Disclosure of Interests: :

Bente Glintborg Grant/research support from: Grants from Pfizer, Biogen and Abbvie, Oliver Hendricks Grant/research support from: Pfizer, MSD, Ada Colic Consultant of: Advisory board Sanofi, Hanne Merete Lindegaard: None declared, Rabiah Ahmed: None declared, Anne Gitte Loft Grant/research support from: Novartis, Consultant of: AbbVie, MSD, Novartis, Pfizer and UCB, Speakers bureau: AbbVie, MSD, Novartis, Pfizer and UCB, Gina Kollerup Speakers bureau: Eli Lilly, Marlene Andersen: None declared, Jolanta Grydehøj: None declared, Johnny Raun: None declared, Toke Thorgrimsen: None declared, Kasper Mortensen: None declared, Line Uhrenholt Speakers bureau: Abbvie, Eli Lilly and Novartis (not related to the submitted work), Dorte Jensen: None declared, Iben Ruge Grant/research support from: Novo Nordisk Foundation, Maren Kalisz: None declared, Kamilla Danebod: None declared, Niels Lomborg: None declared, Niels Steen Krogh: None declared, Merete L. Hetland Grant/research support from: BMS, MSD, AbbVie, Roche, Novartis, Biogen and Pfizer, Consultant of: Eli Lilly, Speakers bureau: Orion Pharma, Biogen, Pfizer, CellTrion, Merck and Samsung Bioepis

0270 Somnolence Profiles in Mice Submitted to Acute and Chronic Sleep Deprivation

Introduction

Sleepiness is a behavioral marker of homeostatic sleep regulation and is related to several negative outcomes with interindividual variation, which may amount to central sleep mechanisms. However, there is a lack of evidence linking progressive sleep need and sleepiness with factors of individual variability, which could be tested by acute and chronic sleep deprivation. Thus, the study objective was to investigate the development of sleepiness in sleep deprived mice.

Methods

C57BL/6J male mice (n=340) were distributed in 5 sleep deprivation groups, 5 sleep rebound groups and 10 control groups. Animals underwent acute total sleep deprivation for 3, 6, 9 or 12 hours or chronic sleep deprivation for 6 hours for 5 consecutive days. Sleep rebound groups had the opportunity to sleep for 1, 2, 3, 4 hours after acute sleep deprivation or 24 hours after chronic sleep deprivation. During the protocol, sleep attempts were counted as a sleepiness index. After euthanasia, blood was collected for corticosterone assessment.

Results

Using the average group sleep attempts, it was possible to differentiate between sleepy (mean&gt;group average) and resistant to sleepiness animals (mean&lt;group average). Frequency of resistant mice was 65%, 56%, 56% and 53% for 3, 6, 9 and 12 hours of acute sleep deprivation, respectively, and 74% in chronic sleep deprivation. 52% of the sleepiness variance might be explained by individual variation during chronic sleep deprivation and 68% of sleepiness variance during acute sleep deprivation was attributed to extended wakefulness. A normal corticosterone zenith was observed at the start of the dark phase, independent of sleep deprivation.

Conclusion

Different degrees of sleepiness in sleep deprived mice were verified. Sleep deprivation per se was the main factor explaining sleepiness during acute sleep deprivation whereas in chronic deprivation individual variation was more relevant.

Support

This work was financially supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) (#2017/18455-5), Coordenação de Aperfeiçoamento de Pessoal Nível Superior (CAPES) - grant code 001, ConselhoNacional de Desenvolvimento Científico e Tecnológico (CNPq) (#169040/2017–8)and Associação Fundo de Incentivo à Pesquisa (AFIP).

1126 Relationship Between Headache and Sleep: A Longitudinal Study from the Population of Sao Paulo City (Brazil)

Introduction

The complaint of nocturnal awakening with headache (NAH), was prevalent (8.4%) in the São Paulo population and was associated with sleep disturbances, as demonstrated in a study conducted in 2007 (EPISONO). Indeed, this relationship between sleep and headache is well documented in the literature. Objective: To assess the incidence and evolution of NAH and to associate sleep-related variables in an eight-year prospective study.

Methods

From 1042 volunteers enrolled in the baseline, 712 agreed to participate in the follow-up. Questionnaires and scales were applied and polysomnography and actigraphy performed. The complaint of NAH was analyzed according to a frequency questionnaire and separated into frequent or occasional.

Results

At follow-up, 110 volunteers reported NAH, of which 82 were the same as those from the baseline, but only 38 had frequent complaints. Comparing with volunteers whose headache has become occasional, we have as a difference the insomnia severity index which is significantly higher in the group with frequent NAH (8.40 ± 5.10 vs 11.20±6.40 p:0.03) and worse sleep quality as measured by the Pittsburgh questionnaire (7.25±3.60 vs 10.25±4.60 p:0.002). In addition, these volunteers had higher anxiety (10.40±9.30 vs 12.00± 10:00 p: 0.008) and depression (10.60±9.90 vs 12:00±9.90 p:0.005) from Beck’s questionnaires and greater fatigue (4.85±3.10 vs 9.75±5.55 p:0.001). The associations of NAH with insomnia, nightmares, and bruxism observed in the baseline continued, but no difference was observed between those who had frequent or occasional complaints at follow-up.

Conclusion

Our study showed that NAH was highly prevalent in the Sao Paulo population in both the baseline and follow-up studies, but this frequency had a reduction in follow-up. Volunteers who persisted with the frequent complaint showed greater severity of insomnia, higher anxiety and depression and greater fatigue.

Support

Associação Fundo de Incentivo à Pesquisa (AFIP) and São Paulo Research Foundation (FAPESP)

First abundance estimate for white whales Delphinapterus leucas in Svalbard, Norway

The Svalbard Archipelago (Norway) is experiencing rapid declines in the seasonal duration and extent of sea-ice cover, and local tidewater glaciers are melting. These environmental changes represent a threat to ice-associated species in the region, including white whales Delphinapterus leucas. However, no estimates of stock size or trends are available for this stock. An aerial survey was conducted during the summer of 2018, covering the coastlines of all major islands in Svalbard, as well fjords and open ocean areas. A total count was attempted for the coastlines, while coverage of the fjords and open ocean areas was designed as distance-sampling line transects. In total, 265 white whales were detected in 22 groups along the 4965 km of coastline coverage. No whales were observed on fjord (1481 km) or open ocean transects (535 km). After correcting for surface availability using behavioural data from the same area (in summer) and making adjustments for small areas not flown during the survey, the stock size was estimated to be 549 individuals (95% CI: 436%%CONV_ERR%%723). This estimate is surprisingly low given that this species is one of the most frequently observed cetaceans in the area, but it confirms suspicions based on difficulties in finding animals when operating white whale tagging programmes over the past decade. This first population estimate is important in the context of the rapid environmental change taking place in the Arctic and for providing a baseline for comparison with future estimates.

Pelagic vs Coastal-Key Drivers of Pollutant Levels in Barents Sea Polar Bears with Contrasted Space-Use Strategies

In the Barents Sea, pelagic and coastal polar bears are facing various ecological challenges that may explain the difference in their pollutant levels. We measured polychlorinated biphenyls, organochlorine pesticides, polybrominated diphenyl ethers in fat, and perfluoroalkyl substances in plasma in pelagic and coastal adult female polar bears with similar body condition. We studied polar bear feeding habits with bulk stable isotope ratios of carbon and nitrogen. Nitrogen isotopes of amino acids were used to investigate their trophic position. We studied energy expenditure by estimating field metabolic rate using telemetry data. Annual home range size was determined, and spatial gradients in pollutants were explored using latitude and longitude centroid positions of polar bears. Pollutant levels were measured in harp seals from the Greenland Sea and White Sea-Barents Sea as a proxy for a West-East gradient of pollutants in polar bear prey. We showed that pelagic bears had higher pollutant loads than coastal bears because (1) they feed on a higher proportion of marine and higher trophic level prey, (2) they have higher energy requirements and higher prey consumption, (3) they forage in the marginal ice zones, and (4) they feed on prey located closer to pollutant emission sources/transport pathways.

Derivation of whole blood biomonitoring equivalents for lithium for the interpretation of biomonitoring data

INTRODUCTION

Lithium salts have numerous industrial uses and are also used in the treatment of bipolar disorders. The main source of lithium exposure to the general population is drinking water and foods. Lithium is nephrotoxic at higher doses. Thus, oral exposure guidelines for lithium have been derived, including ICH's permitted daily exposure (PDE = 0.008 mg lithium/kg-bw/day) adopted by Health Canada and the United States Environmental Protection Agency's (U.S. EPA) provisional peer reviewed toxicity value (PPRTV = 0.002 mg lithium/kg-bw/day), both based on human data.

OBJECTIVE

To derive whole blood biomonitoring equivalents (BEs) associated with PDE and PPRTV to interpret population-level biomonitoring data in health risk context.

METHOD

A simple kinetic relationship based on plasma clearance value (0.5 L/kg-bw/day) and the oral absorption fraction (100%) was used to derive blood BEs for PDE and PPRTV.

RESULTS

This analysis resulted in BE values in plasma and whole blood of 16 and 10 μg/L, respectively, based on the PDE values developed by the Health Canada and of 4.2 and 2.7 μg/L, respectively, based on the PPRTV developed by U.S. EPA.

CONCLUSION

The derived BE values can be used to interpret population-level biomonitoring data.

Health assessment of newly arrived refugees to the Municipality of Copenhagen, Denmark

Background

Research data on the health status of newly arrived refugees is sparse. Newly arrived refugees and family reunified in The Municipality of Copenhagen has since 2016 been offered a general health assessment. These assessments are conducted by clinicians with expertise in refugee and migrant health from the Section of Immigrant Health. This study describes the sociodemographic characteristics and the burden of disease in this population.

Methods

In this cross-sectional study the population consists of adult patients examined January 2017 to February 2019. Clinicians performed the health assessment including a questionnaire regarding sociodemographics, medical history, symptoms, traumatic events during/before migration, a clinical examination and blood samples.

Results

The population had an equal presentation of males (N = 81) and females (N = 79) primarily from Syria (33%) and Iran (29%). The median age was 31,5 years (SD = 10,9). 67% had ≥8 years of schooling, while 11% had a maximum of 2 years. More than half had experienced war and 50% persecution. 76% suffered from Vitamin D deficiency, 31% of B12 deficiency and 12% of anemia. Few suffered from infectious and somatic diseases, yet many experiences symptoms such as pain (53%) and headaches (54%). 33% presented with symptoms of PTSD.

Conclusions

A high frequency of micronutrition deficiency was prevalent in the refugee group. Furthermore, many suffered from physical symptoms while very few had serious somatic issues. Numerous traumatic experiences were reported and 33% presented with symptoms of PTSD. The data is presumably a reflection of the healthy migrant bias.

Key messages

Despite refugees presumably being tested pre-entry and at holding level, they still suffer several health issues when granted asylum. Many newly arrived refugees suffer from micronutrition deficiency. These conditions are easily treated and could enhance the overall health of the individual.

NTCP model validation method for DAHANCA patient selection of protons versus photons in head and neck cancer radiotherapy

Introduction: Prediction models using logistic regression may perform poorly in external patient cohorts. However, there is a need to standardize and validate models for clinical use. The purpose of this project was to describe a method for validation of external NTCP models used for patient selection in the randomized trial of protons versus photons in head and neck cancer radiotherapy, DAHANCA 35. Material and methods: Organs at risk of 588 patients treated primarily with IMRT in the randomized controlled DAHANCA19 trial were retrospectively contoured according to recent international recommendations. Dose metrics were extracted using MatLab and all clinical parameters were retrieved from the DAHANCA database. The model proposed by Christianen et al. to predict physician-rated dysphagia was validated through the closed testing, where change of the model intercept, slope and individual beta's were tested for significant prediction improvements. Results: Six months prevalence of dysphagia in the validation cohort was 33%. The closed testing procedure for physician-rated dysphagia showed that the Christianen et al. model needed an intercept refitting for the best match for the Danish patients. The intercept update increased the risk of dysphagia for the validation cohort by 7.9 ± 2.5% point. For the raw model performance, the Brier score (mean squared residual) was 0.467, which improved significantly with a new intercept to 0.415. Conclusions: The previously published Dutch dysphagia model needed an intercept update to match the Danish patient cohort. The implementation of a closed testing procedure on the current validation cohort allows quick and efficient validation of external NTCP models for patient selection in the future.

Life-Cycle Assessment as a decision-support tool for early phases of urban planning: evaluating applicability through a comparative approach

While ambitious environmental objectives are being set for new constructions in Switzerland, the assessment of urban-scale projects and comparison of their performance to national targets are made possible by a growing number of life-cycle assessment (LCA) tools. However, previous research emphasizes the lack of existing tools to support the decision-making process at the early design stage, characterized by a low level of project details. This paper presents a comparison between three LCA tools. The first, stemming from a research and development project (SETUP), is an exploration tool relying on a database of urban-level scenarios and their environmental performance, able to convert district targets (e.g. 2000-Watt society objectives) into specific sub-targets at the building or component levels. The other two are online LCA tools currently available to practitioners (Sméo and Calculation tool for 2000-Watt-society-sites RH II ), that allow assessing the project and verifying its compliance with a given target. Each tool was applied to a low-carbon case study, the blueFactory district in Fribourg (Switzerland), in two hypothetical contexts corresponding to the schematic and detailed project development phases, characterized by different levels of details. When used for the assessment of a project at a more advanced development stage with a high resolution of detail, findings indicate that Smeo and RH II provide similar environmental performance results. However, in early planning stages, SETUP shows better abilities to support decision-making by providing ranges of results and highlighting uncertainties and the influence of design parameters that have not yet been fixed.

Temporal Trends of Persistent Organic Pollutants in Barents Sea Polar Bears ( Ursus maritimus) in Relation to Changes in Feeding Habits and Body Condition

Temporal trends of persistent organic pollutants (POPs: PCBs, OH-PCBs, p, p'-DDE, HCB, β-HCH, oxychlordane, BDE-47, and 153) in relation to changes in feeding habits and body condition in adult female polar bears ( Ursus maritimus) from the Barents Sea subpopulation were examined over 20 years (1997-2017). All 306 samples were collected in the spring (April). Both stable isotope values of nitrogen (δ¹⁵N) and carbon (δ¹³C) from red blood cells declined over time, with a steeper trend for δ¹³C between 2012 and 2017, indicating a decreasing intake of marine and high trophic level prey items. Body condition, based on morphometric measurements, had a nonsignificant decreasing tendency between 1997 and 2005, and increased significantly between 2005 and 2017. Plasma concentrations of BDE-153 and β-HCH did not significantly change over time, whereas concentrations of Σ₄PCB, Σ₅OH-PCB, BDE-47, and oxychlordane declined linearly. Concentrations of p, p'-DDE and HCB, however, declined until 2012 and 2009, respectively, and increased thereafter. Changes in feeding habits and body condition did not significantly affect POP trends. The study indicates that changes in diet and body condition were not the primary driver of POPs in polar bears, but were controlled in large part by primary and/or secondary emissions of POPs.

General practitioners' and nurses' views on medication reviews and potentially inappropriate medicines in elderly patients - a qualitative study of reports by educating pharmacists

OBJECTIVE

The aim with this study was to understand more about how general practitioners (GPs) and nurses in primary care experience their work with medication reviews in elderly patients.

DESIGN

This qualitative study was nested within a cluster randomised trial and analysed narrative and unstructured diaries written by two pharmacists who performed academic detailing, i.e. educational outreach visits in primary care. The educational sessions dealt with potentially inappropriate medicines, and stimulated interprofessional dialogue in relation to medication reviews. The purpose of the diaries was to document and structure the pedagogical process of academic detailing and contained quotes from 194 GP and 113 nurse participants in the sessions, and the pharmacists' reflections. The data was explored using thematic analysis.

SETTING

Thirty-three primary care practices in Stockholm, Sweden.

SUBJECTS

GPs and nurses working in primary care.

MAIN OUTCOME MEASURES

Thematic descriptions of academic detailing by pharmacists.

RESULTS

Five themes were identified: 1) Complexity in 3 'P': patients, pharmacotherapy, and primary care; 2) What, when, who? Clash between GPs' and nurses' experiences and guidelines; 3) Real-world problems and less-than-ideal solutions; 4) Eureka? Experiences with different steps during a medication review; and 5) Threats to GP autonomy.

CONCLUSION

GPs and nurses should participate in the construction and release of guidelines in order to increase their usability in clinical practice. Future research should analyse if alternative strategies such as condensed medical reviews and feedback on prescribing are easier to implement in primary care. Key points Complex medication reviews have been introduced on a large scale in Swedish primary care, but knowledge on GPs' and nurses' views on such reviews is lacking. In the context of primary care alternative strategies such as condensed medication reviews and feedback on prescribing may be more applicable than medication reviews according to guidelines. GPs and nurses should make contributions to the development of guidelines on medication reviews in order to increase their usability in clinical practice.

Aquatic behaviour of polar bears (Ursus maritimus) in an increasingly ice-free Arctic

Polar bears are ice-associated marine mammals that are known to swim and dive, yet their aquatic behaviour is poorly documented. Reductions in Arctic sea ice are clearly a major threat to this species, but understanding polar bears’ potential behavioural plasticity with respect to the ongoing changes requires knowledge of their swimming and diving skills. This study quantified time spent in water by adult female polar bears (n = 57) via deployment of various instruments bearing saltwater switches, and in some case pressure sensors (79 deployments, 64.8 bear-years of data). There were marked seasonal patterns in aquatic behaviour, with more time spent in the water during summer, when 75% of the polar bears swam daily (May-July). Females with cubs-of-the-year spent less time in the water than other females from den emergence (April) until mid-summer, consistent with small cubs being vulnerable to hypothermia and drowning. Some bears undertook notable long-distance-swims. Dive depths up to 13.9 m were recorded, with dives ≥5 m being common. The considerable swimming and diving capacities of polar bears might provide them with tools to exploit aquatic environments previously not utilized. This is likely to be increasingly important to the species’ survival in an Arctic with little or no persistent sea ice.

Mitochondria, glycogen, and lipid droplets in skeletal muscle during testosterone treatment and strength training: a randomized, double-blinded, placebo-controlled trial

Low testosterone levels in aging men are associated with insulin resistance. Mitochondrial dysfunction, changes in glycogen metabolism, and lipid accumulation are linked to insulin resistance in skeletal muscle. In this randomized, double-blinded, placebo-controlled study, we investigated the effects of six-month testosterone replacement therapy (TRT) and strength training (ST) on mitochondrial, glycogen, and lipid droplet (LD) content in skeletal muscle of aging men with subnormal bioavailable testosterone (BioT) levels. Mitochondrial, glycogen, and LD volume fractions in muscle biopsies were estimated by transmission electron microscopy. Insulin sensitivity (insulin-stimulated Rd) and body composition were assessed by euglycemic-hyperinsulinemic clamp and dual X-ray absorptiometry, respectively. TRT significantly increased total testosterone levels, BioT, and lean body mass (LBM) (p < 0.05), whereas percent body fat decreased (p < 0.05), and insulin sensitivity was unchanged. Baseline mitochondrial volume fraction correlated inversely with percent body fat (ρ = -0.43; p = 0.003). Δ-mitochondrial fraction correlated positively with Δ-total testosterone (ρ = 0.70; p = 0.02), and Δ-glycogen fraction correlated inversely with Δ-LBM (ρ = -0.83; p = 0.002) during six-month TRT, but no significant changes were observed in mitochondrial, glycogen, and LD volume fractions during TRT and ST. In conclusion, in this exploratory small-scale study, the beneficial effects of six-month TRT on total testosterone, LBM, and percent body fat were not followed by significant changes in fractions of mitochondria, glycogen, or lipid in skeletal muscle of aging men with lowered testosterone levels. Six-month ST or combined three-month ST+TRT did not change intramyocellular mitochondria, glycogen, and LD fractions compared to placebo. However, further studies with a larger sample size are needed.

Choose Your Poison-Space-Use Strategy Influences Pollutant Exposure in Barents Sea Polar Bears

Variation in space-use is common within mammal populations. In polar bears, Ursus maritimus, some individuals follow the sea ice (offshore bears) whereas others remain nearshore yearlong (coastal bears). We studied pollutant exposure in relation to space-use patterns (offshore vs coastal) in adult female polar bears from the Barents Sea equipped with satellite collars (2000-2014, n = 152). First, we examined the differences in home range (HR) size and position, body condition, and diet proxies (nitrogen and carbon stable isotopes, n = 116) between offshore and coastal space-use. Second, we investigated how HR, space-use, body condition, and diet were related to plasma concentrations of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) ( n = 113), perfluoroalkyl substances (PFASs; n = 92), and hydroxylated-PCBs ( n = 109). Offshore females were in better condition and had a more specialized diet than did coastal females. PCBs, OCPs, and hydroxylated-PCB concentrations were not related to space-use strategy, yet PCB concentrations increased with increasing latitude, and hydroxylated-PCB concentrations were positively related to HR size. PFAS concentrations were 30-35% higher in offshore bears compared to coastal bears and also increased eastward. On the basis of the results we conclude that space-use of Barents Sea female polar bears influences their pollutant exposure, in particular plasma concentrations of PFAS.

Ambient pressure phase transitions over Ir(1 1 1): at the onset of CO oxidation

In this study we report on the adsorbate structures on an Ir(1 1 1) surface during the phase transition from the inactive to the active state during CO oxidation. The CO oxidation over Pt(1 1 1) is used as a reference case. Where Pt(1 1 1) either is inactive and CO covered or active and O covered, Ir(1 1 1) exhibits a transition state with co-existing chemisorbed O and CO. The observed structural differences are explained in terms of DFT-calculated adsorption energies. For Pt(1 1 1) the repulsive CO-O interaction makes co-existing chemisorbed CO and O unfavourable, while for Ir(1 1 1) the stronger O and CO adsorption allows for overcoming the repulsive interaction. At the onset of CO oxidation over Ir(1 1 1), a CO structure containing defects forms, which enables O₂ to dissociatively adsorb on the Ir(1 1 1) surface, thus enabling the CO oxidation reaction. At the mass transfer limit, the Ir(1 1 1) surface is covered by a chemisorbed O structure with defects; hence, the active surface is predominately chemisorbed O covered at a total pressure of 0.5 mbar and no oxide formation is observed.