The Brain Tumor Segmentation (BraTS) Challenge 2023: Glioma Segmentation in Sub-Saharan Africa Patient Population (BraTS-Africa)

Gliomas are the most common type of primary brain tumors. Although gliomas are relatively rare, they are among the deadliest types of cancer, with a survival rate of less than 2 years after diagnosis. Gliomas are challenging to diagnose, hard to treat and inherently resistant to conventional therapy. Years of extensive research to improve diagnosis and treatment of gliomas have decreased mortality rates across the Global North, while chances of survival among individuals in low- and middle-income countries (LMICs) remain unchanged and are significantly worse in Sub-Saharan Africa (SSA) populations. Long-term survival with glioma is associated with the identification of appropriate pathological features on brain MRI and confirmation by histopathology. Since 2012, the Brain Tumor Segmentation (BraTS) Challenge have evaluated state-of-the-art machine learning methods to detect, characterize, and classify gliomas. However, it is unclear if the state-of-the-art methods can be widely implemented in SSA given the extensive use of lower-quality MRI technology, which produces poor image contrast and resolution and more importantly, the propensity for late presentation of disease at advanced stages as well as the unique characteristics of gliomas in SSA (i.e., suspected higher rates of gliomatosis cerebri). Thus, the BraTS-Africa Challenge provides a unique opportunity to include brain MRI glioma cases from SSA in global efforts through the BraTS Challenge to develop and evaluate computer-aided-diagnostic (CAD) methods for the detection and characterization of glioma in resource-limited settings, where the potential for CAD tools to transform healthcare are more likely.

Quantitative analysis of redox proteome reveals oxidation-sensitive protein thiols acting in fundamental processes of developmental hematopoiesis

Fetal and adult hematopoietic stem and progenitor cells (HSPCs) are characterized by distinct redox homeostasis that may influence their differential cellular behavior in normal and malignant hematopoiesis. In this work, we have applied a quantitative mass spectrometry-based redox proteomic approach to comprehensively describe reversible cysteine modifications in primary mouse fetal and adult HSPCs. We defined the redox state of 4,438 cysteines in fetal and adult HSPCs and demonstrated a higher susceptibility to oxidation of protein thiols in fetal HSPCs. Our data identified ontogenic changes to oxidation state of thiols in proteins with a pronounced role in metabolism and protein homeostasis. Additional redox proteomic analysis identified oxidation changes to thiols acting in mitochondrial respiration as well as protein homeostasis to be triggered during onset of MLL-ENL leukemogenesis in fetal HSPCs. Our data has demonstrated that redox signaling contributes to the regulation of fundamental processes of developmental hematopoiesis and has pinpointed potential targetable redox-sensitive proteins in in utero-initiated MLL-rearranged leukemia.

OP0298-PARE EXPERIENCES AND IMPACT OF PATIENT AND PUBLIC INVOLVEMENT IN SWEDISH RHEUMATOLOGY RESEARCH: A SURVEY OF RESEARCHERS AND PATIENT RESEARCH PARTNERS

Background

Patient and public involvement (PPI) in research is based on the principle that research should be conducted “with” or “by” members of the public, rather than “to”, “for”, or “about” them.(1) Successful PPI is dependent on active partnerships between researchers and people living with rheumatic diseases throughout the research process. Such partnerships have been shown to improve the quality and relevance of the research. However, as funding bodies increase their demands for PPI, so too may the risk for tokenistic “involvement”.

Since 2008, the Swedish Rheumatism Association (SRA) has trained people living with rheumatic diseases to become patient research partners (PRPs) and encouraged their involvement in research projects. The network has grown substantially in terms of the number of registered PRPs, the number of research projects aiming to include PRPs, as well as the number of active partnerships between researchers and PRPs. However, the quality of partnerships and the impact of PPI on Swedish rheumatology research is unknown.

Objectives

To examine the extent of PPI in Swedish rheumatology research, the nature of partnerships between researchers and PRPs, and the perceived impact of PRPs on the research processes.

Methods

The target population was researchers and PRPs linked to the SRA in 2021, the largest private funder of Swedish rheumatology research. In practice, this included researchers who had applied for research grants from the SRA, researchers that had sought PRPs through the SRA, PRPs trained and registered with the SRA, as well as external PRPs named in grant applications submitted to the SRA.

An online questionnaire was developed to examine the target population’s understanding of the concept of PPI, their current involvement and experience of PPI, the nature of the partnerships between PRPs and researchers, and their future needs.(2,3) The survey was shared via email to the target population and remained open for one month.

PRPs were involved in the development and testing of the survey and will be involved in the interpretation and implementation of results.

Results

A total of 126 researchers that had submitted research grant applications to the SRA were identified. A further 5 researchers who had previously registered interest in collaborating with PRPs were identified from our records. Review of our internal register of trained PRPs identified 36 PRPs, whilst a further 9 external PRPs were identified from grant applications. However, contact details were unavailable for 7 of the external PRPs. As such, the survey was circulated to 131 researchers and 38 PRPs.

Preliminary response rates, one week into the survey period, were 31.3% for the researchers (41 responses) and 39.5% for the PRPs (15 responses).

Conclusion

As funding bodies increase their demands for PPI in grant applications, evaluations of the nature of PPI are required to ensure that funders’ efforts do not mistakenly result in tokenistic efforts to include patients and the public in research. A better understanding of the nature of PPI, the impact of PPI on research, and the needs of the researchers and PRPs will allow appropriate support and training to be developed. This will allow growth not only in the number of partnerships, but also in the quality of partnerships between researchers and PRPs. This, in turn, is likely to improve the quality of rheumatology research.

References

[1]INVOLVE. Briefing notes for researchers - public involvement in NHS, health and social care research. In Eastleigh; 2021.

[2]Wilson P, Mathie E, Keenan J, McNeilly E, Goodman C, Howe A, et al. ReseArch with Patient and Public invOlvement: a RealisT evaluation – the RAPPORT study. NIHR J Libr. 2015.

[3]Warner G, Baghdasaryan Z, Osman F, Lampa E, Sarkadi A. ‘I felt like a human being’—An exploratory, multi-method study of refugee involvement in the development of mental health intervention research. Health Expect Int J Public Particip Health Care Health Policy. 2021 May;24(Suppl 1):30–9.

Disclosure of Interests

None declared

Modeling the migration of chemicals from food contact materials to food: The MERLIN-expo/VERMEER toolbox

Evaluating the migration of chemicals from food contact materials (FCM) into food is a key step in the safety assessment of such materials. In this paper, a simple mechanistic model describing the migration of chemicals from FCM to food was combined with quantitative property-property relationships (QPPRs) for the prediction of diffusion coefficients and FCM-Food partition coefficients. The aim of the present study was to evaluate the performance of these operational models in the prediction of a chemical's concentration in food in contact with a plastic monolayer FCM. A comparison to experimental migration values reported in literature was conducted. Deterministic simulations showed a good match between predicted and experimental values. The tested models can be used to provide insights in the amount and the type of toxicological data that are needed for the safety evaluation of the FCM substance. Uncertainty in QPPRs used for describing the processes of both diffusion in FCM and partition at the FCM-Food interface was included in the analysis. Combining uncertainty in QPPR predictions, it was shown that the third quartile (75th percentile) derived from probabilistic calculations can be used as a conservative value in the prediction of chemical concentration in food, with reasonable safety factors.

Intervention versus surveillance in patients with common bile duct stones detected by intraoperative cholangiography: a population-based registry study

BACKGROUND

Each year 13 000 patients undergo cholecystectomy in Sweden, and routine intraoperative cholangiography (IOC) is recommended to minimize bile duct injuries. The risk of requiring endoscopic retrograde cholangiopancreatography (ERCP) following cholecystectomy for common bile duct (CBD) stones where IOC is omitted and in patients with CBD stones left in situ is not well known.

METHODS

Data were retrieved from the population-based Swedish Registry of Gallstone Surgery and ERCP between 1 January 2009 and 10 December 2019. Primary outcome was risk for postoperative ERCP for retained CBD stones.

RESULTS

A total of 134 419 patients that underwent cholecystectomy were included and 2691 (2.0 per cent) subsequently underwent ERCP for retained CBD stones. When adjusting for emergency or planned cholecystectomy, preoperative symptoms suggestive of CBD stones, sex and age, there was an increased risk for ERCP when IOC was not performed (hazard ratio (HR) 1.4, 95 per cent c.i. 1.3 to 1.6). The adjusted risk for ERCP was also increased if CBD stones identified by IOC were managed with surveillance (HR 5.5, 95 per cent c.i. 4.8 to 6.4). Even for asymptomatic small stones (less than 4 mm), the adjusted risk for ERCP was increased in the surveillance group compared with the intervention group (HR 3.5, 95 per cent c.i. 2.4 to 5.1).

CONCLUSION

IOC plus an intervention to remove CBD stones identified during cholecystectomy was associated with reduced risk for retained stones and unplanned ERCP, even for the smallest asymptomatic CBD stones.

Diagnosing Carotid Near-Occlusion with Phase-Contrast MRI

Carotid near-occlusion is a frequently overlooked diagnosis when CTA examinations are assessed in routine practice. To evaluate the potential value of phase-contrast MR imaging in identifying near-occlusion, we examined 9 carotid near-occlusions and 20 cases of conventional ≥50% carotid stenosis (mean stenosis degree, 65%) with phase-contrast MR imaging. Mean ICA flow was lower in near-occlusions (52 mL/min) than in conventional ≥50% stenosis (198 mL/min, P < .001). ICA flow of ≤110 mL/min was 100% sensitive and specific for near-occlusion. Phase-contrast MR imaging is a promising tool for diagnosing carotid near-occlusion.

PARE0007 PATIENT AND PUBLIC INVOLVEMENT IN CLINICAL TRIAL DESIGN

Background:

Patient and public involvement (PPI) is gaining increasing recognition as important in ensuring research is relevant and acceptable to participants. Rheuma Tolerance for Cure (RTCure) is a 5 year international collaboration between academia and industry; focusing on earlier detection and prevention of rheumatoid arthritis (RA) through the use of immune-tolerising treatments.

Objectives:

To bring lived experience and insight into scientific discussions; and to evolve collaboration between lay representatives and academia/industry.

Methods:

9 Patient Research Partners (PRPs) from 5 European countries were recruited via the EULAR PARE Network and institutions within the RTCure Consortium (8 PRPs with RA and 1 ‘at risk’). They were asked to enter into a legal agreement with the Consortium. PRPs participated in teleconferences (TCs) and were invited to attend face-to-face (F2F) meetings at least annually. Requests for input/feedback were sent from researchers to PRPs via the project’s Patient Engagement Expert [SK].

Results:

PRP involvement has given researchers and industry partners a new perspective on patient priorities, and focused thought on the ethics of recruitment for and participation in clinical trials of people ‘at risk’ of developing RA. PRPs have helped define the target populations, given their thoughts on what types of treatments are acceptable to people ‘at risk’ and have aided the development of a survey (sent to EULAR PARE members) regarding the use of animal models in biomedical research. Positive informal feedback has been received from researchers and industry regarding the contribution of PRPs to the ongoing project (formal evaluation of PPI in RTCure will be carried out in 2020 and at the project end in 2022).

Challenges:

Legal agreements- Many PRPs refused to sign the Consortium’s complex PRP Agreement; feeling it unnecessary, incomprehensible and inequitable. After extensive consultation with various parties (including EULAR and the Innovative Medicines Initiative) no similar contract was found. Views for its requirement even varied between legal experts. After 2 years of intense discussion, a simple non-disclosure agreement was agreed upon. Ideally any contract, if required, should be approved prior to project onset.

Meeting logistics- Other improvements identified were to locate the meeting venue and accommodation on the same site to minimise travel, and to make it easier for PRPs to take breaks when required. This also facilitates informal discussions and patient inclusivity. We now have agreed a policy to fund PRPs extra nights before and after meetings, and to bring a carer if needed.

Enabling understanding– Future annual meetings will start with a F2F meeting between PRPs and Work Package Leads. Researchers will be encouraged to start presentations with a summary slide in lay language. Additionally, an RTCure Glossary is in development.

Enabling participation– SK will provide monthly project updates and PRP TCs will be held in the evening (as some PRPs remain employed). PRPs will be invited to all project TCs and F2F meetings. Recruitment is underway to increase the number of ‘at risk’ PRPs as their viewpoint is vital to this study.

Conclusion:

Currently PPI in RTCure is an ongoing mutual learning process. Universal guidance regarding what types of contracts are needed for PPI would be useful. Communication, trust and fruitful discussions have evolved through F2F meetings (both formal and informal) between PRPs, academia and industry. It is important that all parties can be open with each other in order to make PPI more meaningful.

Acknowledgments:

This work has received support from the EU/EFPIA Innovative Medicines Initiative 2 Joint Undertaking RTCure grant number 777357.

Disclosure of Interests:

Savia de Souza: None declared, Ruth Williams: None declared, Eva Johansson: None declared, Codruta Zabalan: None declared, Tom Esterine: None declared, Margôt Bakkers: None declared, Wolfgang Roth: None declared, Neil Mc Carthy: None declared, Meryll Blake: None declared, Susanne Karlfeldt: None declared, Martina Johannesson: None declared, Karim Raza Grant/research support from: KR has received research funding from AbbVie and Pfizer, Consultant of: KR has received honoraria and/or consultancy fees from AbbVie, Sanofi, Lilly, Bristol-Myers Squibb, UCB, Pfizer, Janssen and Roche Chugai, Speakers bureau: KR has received honoraria and/or consultancy fees from AbbVie, Sanofi, Lilly, Bristol-Myers Squibb, UCB, Pfizer, Janssen and Roche Chugai

Validation of automated whole-body analysis of metabolic and morphological parameters from an integrated FDG-PET/MRI acquisition

Automated quantification of tissue morphology and tracer uptake in PET/MR images could streamline the analysis compared to traditional manual methods. To validate a single atlas image segmentation approach for automated assessment of tissue volume, fat content (FF) and glucose uptake (GU) from whole-body [18F]FDG-PET/MR images. Twelve subjects underwent whole-body [18F]FDG-PET/MRI during hyperinsulinemic-euglycemic clamp. Automated analysis of tissue volumes, FF and GU were achieved using image registration to a single atlas image with reference segmentations of 18 volume of interests (VOIs). Manual segmentations by an experienced radiologist were used as reference. Quantification accuracy was assessed with Dice scores, group comparisons and correlations. VOI Dice scores ranged from 0.93 to 0.32. Muscles, brain, VAT and liver showed the highest scores. Pancreas, large and small intestines demonstrated lower segmentation accuracy and poor correlations. Estimated tissue volumes differed significantly in 8 cases. Tissue FFs were often slightly but significantly overestimated. Satisfactory agreements were observed in most tissue GUs. Automated tissue identification and characterization using a single atlas segmentation performs well compared to manual segmentation in most tissues and will be valuable in future studies. In certain tissues, alternative quantification methods or improvements to the current approach is needed.

Anti-Inflammatory Substances in Wheat Malt Inducing Antisecretory Factor

Extensively malted cereals counteract enterotoxic diarrhea and inflammatory bowel diseases. This effect depends on a protein called antisecretory factor (AF), which is secreted into the blood as a larger complex known as the compleasome. In this study, we identified anti-inflammatory substances in malt and assayed their capacity to induce AF. Guaiacol and quercetin inhibited inflammation in a mouse footpad model, while catechin, sinapic acid, ferulic acid, and quercetin inhibited nitric oxide formation in RAW 264.7 cells. The proteasome activity in these cells was inhibited by vanillic acid and quercetin but not by the other tested phenols. As the transient receptor potential vanilloid 1 (TRPV1) might be involved in AF induction, the TRPV1 antagonist capsazepine was tested and shown to inhibit inflammation in mouse paw and nitric oxide formation. Catechin, ferulic acid, and sinapic acid induced AF in rat blood, and these substances were all increased in malt compared to control wheat. These phenols might therefore be of particular importance for the beneficial effect of malted cereals on inflammatory diseases. Our results further suggest that TRPV1 might play a role in the anti-inflammatory activity of phenols via the induction of AF.

SPCG-15: a prospective randomized study comparing primary radical prostatectomy and primary radiotherapy plus androgen deprivation therapy for locally advanced prostate cancer

OBJECTIVE

To describe study design and procedures for a prospective randomized trial investigating whether radical prostatectomy (RP) ± radiation improves cause-specific survival in comparison with primary radiation treatment (RT) and androgen deprivation treatment (ADT) in patients with locally advanced prostate cancer (LAPC).

MATERIALS AND METHODS

SPCG-15 is a prospective, multi-centre, open randomized phase III trial. Patients are randomized to either standard (RT + ADT) or experimental (RP with extended pelvic lymph-node dissection and with addition of adjuvant or salvage RT and/or ADT if deemed necessary) treatment. Each centre follows guidelines regarding the timing and dosing of postoperative RT and adjuvant treatment such as ADT The primary endpoint is cause-specific survival. Secondary endpoints include metastasis-free and overall survival, quality-of-life, functional outcomes and health-services requirements. Each subject will be followed up for a minimum of 10 years.

RESULTS

Twenty-three centres in Denmark, Finland, Norway and Sweden, well established in performing RP and RT for prostate cancer participated. Each country's sites were coordinated by national coordinating investigators and sub-investigators for urology and oncology. Almost 400 men have been randomized of the stipulated 1200, with an increasing rate of accrual.

CONCLUSIONS

The SPCG-15 trial aims to compare the two curatively intended techniques supplying new knowledge to support future decisions in treatment strategies for patients with LAPC The Scandinavian healthcare context is well suited for performing multi-centre long-term prospective randomized clinical trials. Similar care protocols and a history of entirely tax-funded healthcare facilitate joint trials.

Omega-3 fatty acids does not affect physical activity and body weight in primary school children - a double-blind randomized placebo-controlled trial

It was hypothesized that supplementation of omega-3 fatty acids could increase physical activity (PA) levels, where traditional interventions often fail. The aim of this double-blind, randomized, placebo-controlled trail was to evaluate the effects of 15-week administration of omega-3 fatty acids on objectively measured PA and relative body weight in 8–9 year-old children. The children were randomly assigned to supplementation of omega-3 fatty acids or placebo. Primary outcome was change in PA counts per minute (cpm), and secondly change in body mass index standard deviation score (BMI SDS). Covariance models were applied adjusting for age, gender, weight status, PA and intervention season. Compliance was controlled for by analyzing fatty acid composition in plasma. The intention to treat population consisted of 362 children (omega-3 n = 177, placebo n = 185). No significant effects of omega-3 fatty acids on PA or relative body weight were observed. In covariance models no effects were observed by gender, weight status or change in PA (all p > 0.05), but inactive children increased their PA more than children classified as active at baseline (p < 0.05).

Climate change and landscape development in post-closure safety assessment of solid radioactive waste disposal: Results of an initiative of the IAEA

The International Atomic Energy Agency has coordinated an international project addressing climate change and landscape development in post-closure safety assessments of solid radioactive waste disposal. The work has been supported by results of parallel on-going research that has been published in a variety of reports and peer reviewed journal articles. The project is due to be described in detail in a forthcoming IAEA report. Noting the multi-disciplinary nature of post-closure safety assessments, here, an overview of the work is given to provide researchers in the broader fields of radioecology and radiological safety assessment with a review of the work that has been undertaken. It is hoped that such dissemination will support and promote integrated understanding and coherent treatment of climate change and landscape development within an overall assessment process. The key activities undertaken in the project were: identification of the key processes that drive environmental change (mainly those associated with climate and climate change), and description of how a relevant future may develop on a global scale; development of a methodology for characterising environmental change that is valid on a global scale, showing how modelled global changes in climate can be downscaled to provide information that may be needed for characterising environmental change in site-specific assessments, and illustrating different aspects of the methodology in a number of case studies that show the evolution of site characteristics and the implications for the dose assessment models. Overall, the study has shown that quantitative climate and landscape modelling has now developed to the stage that it can be used to define an envelope of climate and landscape change scenarios at specific sites and under specific greenhouse-gas emissions assumptions that is suitable for use in quantitative post-closure performance assessments. These scenarios are not predictions of the future, but are projections based on a well-established understanding of the important processes involved and their impacts on different types of landscape. Such projections support the understanding of, and selection of, plausible ranges of scenarios for use in post-closure safety assessments.

Venous collapse regulates intracranial pressure in upright body positions

Recent interest in intracranial pressure (ICP) in the upright posture has revealed that the mechanisms regulating postural changes in ICP are not fully understood. We have suggested an explanatory model where the postural changes in ICP depend on well-established hydrostatic effects in the venous system and where these effects are interrupted by collapse of the internal jugular veins (IJVs) in more upright positions. The aim of this study was to investigate this relationship by simultaneous invasive measurements of ICP, venous pressure, and IJV collapse in healthy volunteers. ICP (monitored via the lumbar route), central venous pressure (peripherally inserted central catheter line), and IJV cross-sectional area (ultrasound) were measured in 11 healthy volunteers (47 ± 10 yr, mean ± SD) in 7 positions, from supine to sitting (0–69°). Venous pressure and anatomical distances were used to predict ICP in accordance with the explanatory model, and IJV area was used to assess IJV collapse. The hypothesis was tested by comparing measured ICP with predicted ICP. Our model accurately described the general behavior of the observed postural ICP changes (mean difference, −0.03 ± 2.7 mmHg). No difference was found between predicted and measured ICP for any tilt angle ( P values, 0.65–0.94). The results support the hypothesis that postural ICP changes are governed by hydrostatic effects in the venous system and IJV collapse. This improved understanding of postural ICP regulation may have important implications for the development of better treatments for neurological and neurosurgical conditions affecting ICP.

Antibiotic use during infectious episodes in the first 6 months of anticancer treatment-A Swedish cohort study of children aged 7-16 years

BACKGROUND

Children undergoing cancer therapy are at risk for infectious complications that require hospitalization and antimicrobial therapy. Host factors such as age and underlying disease may predict the risk of severe infections in these children. To describe the increased morbidity due to infections in children with cancer, we characterized the antibiotic use during the infectious complications in a national cohort of children 7-16 years of age with cancer.

PROCEDURE

Data on infectious complications were prospectively collected from the medical records of all newly diagnosed children with cancer, aged 7-16 years, in Sweden between 2004 and 2006. An episode of infection was defined as a period of time when oral or intravenous antimicrobial treatment was prescribed because of symptoms of infection.

RESULTS

A total of 230 infectious episodes occurred in 80 of the 101 patients. Pathogens were isolated in 15% of the blood cultures that showed a predominance of Gram-positive bacteria. Intravenous broad-spectrum antibiotics with cephalosporins and carbapenems were mostly used as single drugs but also in combination with aminoglycosides and glycopeptide. The median treatment length varied between 6 and 11 days depending on cancer diagnosis.

CONCLUSION

Our data demonstrate that infectious complications contribute significantly to morbidity in children with cancer aged 7-16 years. At the time of this survey, antibiotic prescription patterns varied and cephalosporins and carbapenems were mostly used. With increasing antibiotic resistance, a more stringent antibiotic stewardship with less use of cephalosporins and carbapenems should be encouraged for children with cancer. Data on prescription patterns should be incorporated as a quality measurement in pediatric cancer care.

Modelling the exposure to chemicals for risk assessment: a comprehensive library of multimedia and PBPK models for integration, prediction, uncertainty and sensitivity analysis - the MERLIN-Expo tool

MERLIN-Expo is a library of models that was developed in the frame of the FP7 EU project 4FUN in order to provide an integrated assessment tool for state-of-the-art exposure assessment for environment, biota and humans, allowing the detection of scientific uncertainties at each step of the exposure process. This paper describes the main features of the MERLIN-Expo tool. The main challenges in exposure modelling that MERLIN-Expo has tackled are: (i) the integration of multimedia (MM) models simulating the fate of chemicals in environmental media, and of physiologically based pharmacokinetic (PBPK) models simulating the fate of chemicals in human body. MERLIN-Expo thus allows the determination of internal effective chemical concentrations; (ii) the incorporation of a set of functionalities for uncertainty/sensitivity analysis, from screening to variance-based approaches. The availability of such tools for uncertainty and sensitivity analysis aimed to facilitate the incorporation of such issues in future decision making; (iii) the integration of human and wildlife biota targets with common fate modelling in the environment. MERLIN-Expo is composed of a library of fate models dedicated to non biological receptor media (surface waters, soils, outdoor air), biological media of concern for humans (several cultivated crops, mammals, milk, fish), as well as wildlife biota (primary producers in rivers, invertebrates, fish) and humans. These models can be linked together to create flexible scenarios relevant for both human and wildlife biota exposure. Standardized documentation for each model and training material were prepared to support an accurate use of the tool by end-users. One of the objectives of the 4FUN project was also to increase the confidence in the applicability of the MERLIN-Expo tool through targeted realistic case studies. In particular, we aimed at demonstrating the feasibility of building complex realistic exposure scenarios and the accuracy of the modelling predictions through a comparison with actual measurements.

Echo-planar MR imaging of dissolved hyperpolarized 129Xe: Potential for MR angiography

Purpose: The feasibility of hyperpolarized 129Xe for fast MR angiography (MRA) was evaluated using the echo-planar imaging (EPI) technique.

Material and Methods: Hyperpolarized Xe gas was dissolved in ethanol, a carrier agent with high solubility for Xe (Ostwald solubility coefficient 2.5) and long relaxation times. The dissolved Xe was injected as a bolus into a flow phantom where the mean flow velocity was 15 cm/s. Ultrafast EPI images with 44 ms scan time were acquired of the flowing bolus and the signal-to-noise ratios (SNR) were measured.

Results: The relaxation times of hyperpolarized Xe in ethanol were measured to T1=160±11 s and T2≈20 s. The resulting images of the flowing liquid were of reasonable quality and had an SNR of about 70.

Conclusion: Based on the SNR of the obtained Xe EPI images, it was estimated that rapid in vivo MRA with 129Xe may be feasible, provided that an efficient, biologically acceptable carrier for Xe can be found and polarization levels of more than 25% can be achieved in isotopically enriched 129Xe.

Transmission of HIV Drug Resistance and the Predicted Effect on Current First-line Regimens in Europe

Transmitted human immunodeficiency virus drug resistance in Europe is stable at around 8%. The impact of baseline mutation patterns on susceptibility to antiretroviral drugs should be addressed using clinical guidelines. The impact on baseline susceptibility is largest for nonnucleoside reverse transcriptase inhibitors.

Background. Numerous studies have shown that baseline drug resistance patterns may influence the outcome of antiretroviral therapy. Therefore, guidelines recommend drug resistance testing to guide the choice of initial regimen. In addition to optimizing individual patient management, these baseline resistance data enable transmitted drug resistance (TDR) to be surveyed for public health purposes. The SPREAD program systematically collects data to gain insight into TDR occurring in Europe since 2001.

Methods. Demographic, clinical, and virological data from 4140 antiretroviral-naive human immunodeficiency virus (HIV)–infected individuals from 26 countries who were newly diagnosed between 2008 and 2010 were analyzed. Evidence of TDR was defined using the WHO list for surveillance of drug resistance mutations. Prevalence of TDR was assessed over time by comparing the results to SPREAD data from 2002 to 2007. Baseline susceptibility to antiretroviral drugs was predicted using the Stanford HIVdb program version 7.0.

Results. The overall prevalence of TDR did not change significantly over time and was 8.3% (95% confidence interval, 7.2%–9.5%) in 2008–2010. The most frequent indicators of TDR were nucleoside reverse transcriptase inhibitor (NRTI) mutations (4.5%), followed by nonnucleoside reverse transcriptase inhibitor (NNRTI) mutations (2.9%) and protease inhibitor mutations (2.0%). Baseline mutations were most predictive of reduced susceptibility to initial NNRTI-based regimens: 4.5% and 6.5% of patient isolates were predicted to have resistance to regimens containing efavirenz or rilpivirine, respectively, independent of current NRTI backbones.

Conclusions. Although TDR was highest for NRTIs, the impact of baseline drug resistance patterns on susceptibility was largest for NNRTIs. The prevalence of TDR assessed by epidemiological surveys does not clearly indicate to what degree susceptibility to different drug classes is affected.

Single cell analysis of cancer cells using an improved RT-MLPA method has potential for cancer diagnosis and monitoring

Single cell analysis techniques have great potential in the cancer genomics field. The detection and characterization of circulating tumour cells are important for identifying metastatic disease at an early stage and monitoring it. This protocol is based on transcript profiling using Reverse Transcriptase Multiplex Ligation-dependent Probe Amplification (RT-MLPA), which is a specific method for simultaneous detection of multiple mRNA transcripts. Because of the small amount of (circulating) tumour cells, a pre-amplification reaction is performed after reverse transcription to generate a sufficient number of target molecules for the MLPA reaction. We designed a highly sensitive method for detecting and quantifying a panel of seven genes whose expression patterns are associated with breast cancer, and optimized the method for single cell analysis. For detection we used a fluorescence-dependent semi-quantitative method involving hybridization of unique barcodes to an array. We evaluated the method using three human breast cancer cell lines and identified specific gene expression profiles for each line. Furthermore, we applied the method to single cells and confirmed the heterogeneity of a cell population. Successful gene detection from cancer cells in human blood from metastatic breast cancer patients supports the use of RT-MLPA as a diagnostic tool for cancer genomics.

Carotid Near-Occlusion: A Comprehensive Review, Part 2--Prognosis and Treatment, Pathophysiology, Confusions, and Areas for Improvement

In Part 1 of this review, the definition, terminology, and diagnosis of carotid near-occlusion were presented. Carotid near-occlusions (all types) showed a lower risk of stroke than other severe stenoses. However, emerging evidence suggests that the near-occlusion prognosis with full collapse (higher risk) differs from that without full collapse (lower risk). This systematic review presents what is known about carotid near-occlusion. In this second part, the foci are prognosis and treatment, pathophysiology, the current confusion about near-occlusion, and areas in need of future improvement.

Carotid Near-Occlusion: A Comprehensive Review, Part 1--Definition, Terminology, and Diagnosis

Carotid near-occlusion is distal ICA luminal collapse beyond a tight stenosis, where the distal lumen should not be used for calculating percentage stenosis. Near-occlusion with full ICA collapse is well-known, with a threadlike lumen. However, near-occlusion without collapse is often subtle and can be overlooked as a usual severe stenosis. More than 10 different terms have been used to describe near-occlusion, sometimes causing confusion. This systematic review presents what is known about carotid near-occlusion. In this first part, the foci are definition, terminology, and diagnosis.

Current practices used for the prevention of central venous catheter-associated infection in hematopoietic stem cell transplantation recipients: a survey from the Infectious Diseases Working Party and Nurses' Group of EBMT

BACKGROUND

Central line-associated bloodstream infection (CLABSI) is one of the most common infectious complications after hematopoietic stem cell transplantation. To prevent this complication, international guidelines recommend the implementation of the CLABSI 'prevention bundle' consisting of hand hygiene, full barrier precautions, cleaning the insertion site with chlorhexidine, avoiding femoral sites for insertion, and removing unnecessary catheters. The aim of this survey was to analyze to what extent European Group for Blood and Marrow Transplantation (EBMT) centers have included the CLABSI prevention bundle in practice.

METHODS

A questionnaire used for data collection was sent to the 545 EBMT centers worldwide, 103 of which responded.

RESULTS

All 5 components of the CLABSI prevention bundle were recorded in 28% of the centers' standard operating procedures (SOP), and 21% of the centers answered that they used all of the bundle components in clinical practice. The most common recommendation absent from the SOP was specification of all the components of full barrier precautions (43% of the centers did not include at least 1 component). Skin disinfection with chlorhexidine before catheter insertion was reported by 66% centers. CLABSI rates were monitored in 21% of centers.

CONCLUSIONS

Although most of the centers lacked 1 or more of the CLABSI prevention bundle components in their SOP, improvements could easily be made by updating the centers' SOP. The first important step is introduction of CLABSI rate monitoring in this high-risk patient population.

Peripheral venous catheter related complications are common among paediatric and neonatal patients

AIM

The aims of this study were to describe the characteristics of peripheral venous catheters (PVCs), including dwell time and reasons for removal, and explore predictors for PVC-related complications.

METHODS

We included PVCs in 2032 children - 484 neonatal and 1548 paediatric - from 12 inpatient units. Data were retrieved from the patient record system, and predictors for complications were explored using logistic regression analyses.

RESULTS

Just over one-third (35.4%) of the PVCs were removed due to complications, in particular infiltration and occlusion (51.9 and 48.4/1000 PVC days, respectively). PVC survival time was shorter in neonatal than paediatric patients (4 versus 5 days), and infiltration was more frequent in neonatal patients (92.8 versus 38.7/1000 PVC days). Infiltration was associated with younger age (odds ratio 0.97) for neonatal patients and with younger age (OR 0.96), insertion in the bend of the arm (OR 1.48) or ankle (OR 2.81) for paediatric patients. Occlusion was, both for neonatal and paediatric patients, associated with longer dwell time (OR 1.32 and 1.22 respectively), insertion in the ankle (OR 5.00 and 3.51) or foot (OR 3.47 and 1.99).

CONCLUSION

PVC-related complications, particularly infiltration and occlusion, were more common in hospitalised children but decreased with the child's age.

Symptomatic carotid near-occlusion with full collapse might cause a very high risk of stroke

BACKGROUND

The risk of early stroke recurrence amongst patients with symptomatic carotid near-occlusion with and without full collapse is unknown. Therefore, the aim of this study was to analyse the 90-day risk of recurrent ipsilateral ischaemic stroke in patients with symptomatic carotid near-occlusion both with and without full collapse.

METHODS

This study was a secondary analysis of the Additional Neurological SYmptoms before Surgery of the Carotid Arteries: a Prospective study (ANSYSCAP). We prospectively analysed 230 consecutive patients with symptomatic 50-99% carotid stenosis or near-occlusion. Based on the combination of several imaging modalities, 205 (89%) patients were classified as having 50-99% carotid stenosis, and 10 (4%) and 15 (7%) as having near-occlusion with and without full collapse, respectively. The 90-day risk of recurrent ipsilateral ischaemic stroke was compared between these three groups. Only events that occurred before carotid endarterectomy were analysed.

RESULTS

The 90-day risk of recurrent stroke was 18% [95% confidence interval (CI) 12-25%; n = 29] for patients with 50-99% carotid stenosis, 0% for patients with near-occlusion without full collapse and 43% (95% CI 25-89%; n = 4) for patients with near-occlusion with full collapse (P = 0.035, log-rank test). The increased risk of recurrent ipsilateral ischaemic stroke for patients with symptomatic near-occlusion with full collapse remained significant after multivariable adjustment for age, sex and type of presenting event.

CONCLUSIONS

Patients with symptomatic carotid near-occlusion with full collapse might have a very high risk of stroke recurrence. Carotid endarterectomy could be considered for these patients.

Calibration and cross-validation of a wrist-worn Actigraph in young preschoolers

OBJECTIVE

To calibrate the Actigraph GT3X+ accelerometer for wrist-worn placement in young preschoolers by developing intensity thresholds for sedentary, low- and high-intensity physical activity. Furthermore, to cross-validate the developed thresholds in young preschoolers.

METHODS

Actigraph GT3X+ was used to measure physical activity during structured activities and free play in 38 children (15-36 months). Activity was video recorded and scored into sedentary, low- and high-intensity physical activity based on Children's Activity Rating Scale (CARS) and combined with accelerometer data using a 5 s epoch. Receiver operating characteristic analysis was used to develop intensity thresholds in 26 randomly selected children. The remaining 12 children were used for cross-validation.

RESULTS

Intensity thresholds for sedentary were ≤89 vertical counts (Y) and ≤221 vector magnitude (VM) counts per 5 s and ≥440 Y counts and ≥730 VM counts per 5 s for high-intensity physical activity. Sensitivity and specificity were 60-100% for the developed intensity thresholds. Strong correlations (Spearman rank correlation 0.69-0.91) were found in the cross-validation sample between the developed thresholds for the accelerometer and CARS scoring time in all intensity categories.

CONCLUSION

The developed intensity thresholds appear valid to categorize sedentary behaviour and physical activity intensity categories in children 2 years of age.

Genotyping of Pseudomonas aeruginosa reveals high diversity, stability over time and good outcome of eradication

BACKGROUND

Genotyping of Pseudomonas aeruginosa (P.a) is used for surveillance at our CF clinic.

METHODS

P.a from 1999 to 2012 were analysed, using pulsed-field gel electrophoresis (PFGE) and multiple-locus variable number of tandem repeats analysis (MLVA).

RESULTS

Among 232 isolates from 104 patients, we identified 78 unique strains, of which 56 were isolated from individual patients. The B-clone was isolated from 13 patients and the camp transmission clone J-strains from 8 patients at the start of the study. There was no indication of transmission within the clinic. PFGE and MLVA clone identification was in 91% agreement. For patients who provided more than 2 P.a isolates, similar strains were identified over time for 45/49 chronically- and for 6/16 intermittently-colonized patients despite, periods of no detectable P.a after eradication therapy.

CONCLUSIONS

Analyses revealed high genotypic diversity, acceptable outcome of eradication therapy and no indication of cross-infection at the CF centre.

TLX activates MMP-2, promotes self-renewal of tumor spheres in neuroblastoma and correlates with poor patient survival

Nuclear orphan receptor TLX (Drosophilatailless homolog) is essential for the maintenance of neural stem/progenitor cell self-renewal, but its role in neuroblastoma (NB) is not well understood. Here, we show that TLX is essential for the formation of tumor spheres in three different NB cell lines, when grown in neural stem cell media. We demonstrate that the knock down of TLX in IMR-32 cells diminishes its tumor sphere-forming capacity. In tumor spheres, TLX is coexpressed with the neural progenitor markers Nestin, CD133 and Oct-4. In addition, TLX is coexpressed with the migratory neural progenitor markers CD15 and matrix metalloproteinase-2 (MMP-2) in xenografts of primary NB cells from patients. Subsequently, we show the effect of TLX on the proliferative, invasive and migratory properties of IMR-32 cells. We attribute this to the recruitment of TLX to both MMP-2 and Oct-4 gene promoters, which resulted in the respective gene activation. In support of our findings, we found that TLX expression was high in NB patient tissues when compared with normal peripheral nervous system tissues. Further, the Kaplan–Meier estimator indicated a negative correlation between TLX expression and survival in 88 NB patients. Therefore, our results point at TLX being a crucial player in progression of NB, by promoting self-renewal of NB tumor-initiating cells and altering their migratory and invasive properties.

First antimicrobial resistance data and genetic characteristics of Neisseria gonorrhoeae isolates from Estonia, 2009-2013

Gonorrhoea is a sexually transmitted infection with major public health implications and Neisseria gonorrhoeae has developed resistance to all antimicrobials introduced for treatment. Enhanced surveillance of antimicrobial resistance in N. gonorrhoeae is crucial globally. This is the first internationally reported antimicrobial resistance data for N. gonorrhoeae from Estonia (44 isolates cultured in 2009–2013). A high prevalence of resistance was observed for azithromycin, ciprofloxacin and tetracycline. One and two isolates with resistance and decreased susceptibility to the last remaining first-line treatment option ceftriaxone, respectively, were identified. It is crucial to implement surveillance of gonococcal antimicrobial resistance (ideally also treatment failures) in Estonia.

Infant growth is associated with parental education but not with parental adiposity - Early Stockholm Obesity Prevention Project

AIM

To explore the simultaneous impact of parental adiposity and education level on infant growth from birth to 12 months, adjusting for known early-life risk factors for subsequent childhood obesity.

METHODS

Baseline data for 197 one-year-old children and their parents, participating in a longitudinal obesity intervention, were used. Obesity risk groups, high/low, were defined based on parental body mass index (n = 144/53) and parental education (n = 57/139). Observational data on infant growth between 0 and 12 months were collected. The children's relative weight (body mass index standard deviation score) at 3, 6 and 12 months and rapid weight gain 0-6 months were analysed in regression models, with obesity risk as primary exposure variables, adjusting for gestational weight gain, birth weight, short exclusive breastfeeding and maternal smoking.

RESULTS

Relative weight at 3, 6 and 12 months was associated with low parental education but not with parental adiposity. No significant associations were observed with rapid weight gain. None of the early-life factors could explain the association with parental education.

CONCLUSION

Low parental education level is independently associated with infant growth, whereas parental obesity does not contribute to a higher weight or to rapid weight gain during the first year.